Pressure exchanger integrated booster rack system

Abstract

The system comprises a pressure exchanger configured to receive a first fluid via a high-pressure in (HPIN) port, receive a second fluid via a low-pressure in (LPIN) port, exchange pressure between the first and second fluids, and supply the first fluid via a low-pressure out (LPOUT) port and supply the second fluid via a high-pressure out (HPOUT) port. The system further comprises a main gas cooler coil configured to provide a main gas cooler coil outlet flow, the main gas cooler coil outlet flow being divided into a first flow and a second flow. The system further comprises a first heat exchanger configured to subcool the first flow, supply the first flow to the HPIN of the pressure exchanger, convert the second flow into a gas-liquid two-phase mixture, and supply the gas-liquid two-phase mixture to the first heat exchanger, thereby absorbing heat from the first flow and subcooling the first flow.

Description

[Technical Field]

[0001] This disclosure relates to a booster rack system, and more particularly to a booster rack system with integrated pressure exchanger. [Background technology]

[0002] The system uses fluids at different pressures. The system uses pumps and / or compressors to increase the fluid pressure. The majority of the energy consumption of a fluid processing system can be consumed by the pumps and / or compressors used to increase the fluid pressure.

[0003] This disclosure is illustrated by the figures in the attached drawings and is not limited thereto. [Brief explanation of the drawing]

[0004] [Figure 1A] Figure 1A is a schematic diagram of a fluid processing system equipped with a hydraulic energy transfer system according to several embodiments. [Figure 1B] Figure 1B is a schematic diagram of a fluid processing system equipped with a hydraulic energy transfer system according to several embodiments. [Figure 2A] Figure 2A is an exploded perspective view of a pressure exchanger (PX) according to several embodiments. [Figure 2B] Figure 2B is an exploded perspective view of a pressure exchanger (PX) according to several embodiments. [Figure 2C] Figure 2C is an exploded perspective view of a pressure exchanger (PX) according to several embodiments. [Figure 2D] Figure 2D is an exploded perspective view of a pressure exchanger (PX) according to several embodiments. [Figure 2E] Figure 2E is an exploded perspective view of a pressure exchanger (PX) according to several embodiments. [Figure 3A] Figure 3A is a schematic diagram of a fluid processing system comprising a PX and a heat exchanger for exchanging heat between two flows of a working fluid, according to several embodiments. [Figure 3B] Figure 3B is a schematic diagram of a fluid processing system equipped with a pressure exchanger and an auxiliary receiver, according to several embodiments. [Figure 3C] Figure 3C is a schematic diagram of a fluid processing system comprising a subcooler and an auxiliary receiver according to several embodiments. [Figure 3D] Figure 3D is a schematic diagram of a fluid processing system equipped with a PX according to several embodiments. [Figure 3E] Figure 3E is a schematic diagram of a fluid processing system equipped with a PX according to several embodiments. [Figure 3F] Figure 3F is a schematic diagram of a fluid processing system equipped with a PX according to several embodiments. [Figure 3G] Figure 3G is a schematic diagram of a fluid processing system equipped with a PX according to several embodiments. [Figure 4A] Figure 4A is a schematic diagram of a fluid processing system comprising a PX, a subcooler, and various controllers and other components for providing control of the fluid processing system, according to several embodiments. [Figure 4B] Figure 4B is a schematic diagram of a fluid processing system equipped with sensors and a controller according to several embodiments. [Figure 5A] Figure 5A is a flowchart of a method for providing control of a fluid processing system according to several embodiments. [Figure 5B] Figure 5B is a flowchart of a method for providing control of a refrigeration system according to several embodiments. [Figure 5C] Figure 5C is a flowchart of a method for providing control of a refrigeration system according to several embodiments. [Figure 5D] Figure 5D is a flowchart of a method for providing control of a refrigeration system according to several embodiments. [Figure 5E] Figure 5E is a flowchart of a method for providing control of a refrigeration system according to several embodiments. [Figure 6A]Figure 6A shows a system equipped with a pressure exchanger according to a specific embodiment. [Figure 6B] Figure 6B shows a system comprising a pressure exchanger according to a specific embodiment. [Figure 7A] Figure 7A relates to a PX integrated booster rack system according to a specific embodiment. [Figure 7B] Figure 7B relates to a PX integrated booster rack system according to a specific embodiment. [Figure 7C] Figure 7C relates to a PX integrated booster rack system according to a specific embodiment. [Figure 8] Figure 8 is a block diagram showing a computer system according to a specific embodiment. [Modes for carrying out the invention]

[0005] The embodiments described herein relate to pressure exchanger (PX) integrated booster rack systems (e.g., PX integrated refrigerant booster racks, PX integrated transcritical carbon dioxide (CO2) booster racks). The embodiments described herein are also directed toward the architecture of refrigeration and / or heat pump systems comprising pressure exchangers, as well as the control of such systems. For example, the architecture may comprise a refrigeration system, a heat pump system, a pressure exchanger system, a fluid handling system comprising a pressure exchanger, a heat transfer system, a control system for a carbon dioxide (CO2) refrigeration system integrated with a rotary pressure exchanger, and control of such systems. In particular, the system architecture is described along with associated control modules for controlling, maintaining, regulating, etc., the operation of a system comprising one or more pressure exchangers.

[0006] The system may use fluids at different pressures. The supply of fluid to the system may be at a lower pressure, and one or more portions of the system may operate at a higher pressure. The system may include a closed loop in which various fluid pressures are maintained at different portions of the loop. These systems may include hydraulic fracturing (e.g., fracking or fraccing) systems, desalination systems, refrigeration systems, heat pump systems, energy generation systems, mud pump systems, slurry pump systems, industrial fluid systems, waste fluid systems, fluid transport systems, green hydrogen systems, and the like. A pump or compressor may be used to increase the pressure of the fluid in such systems.

[0007] Conventionally, heat transfer systems (e.g., refrigeration systems, heat pump systems, reversible heat pump systems, etc.) use pumps or compressors to increase the pressure of fluids (e.g., carbon dioxide (CO2), R-744, R-134a, hydrocarbons, hydrofluorocarbons (HFCs), hydrochlorofluorocarbons (HCFCs), ammonia (NH3), refrigerant mixtures, refrigeration fluids such as R-407A, R-404A, etc.). Conventionally, a separate pump or compressor mechanically coupled to a motor is used to increase the fluid pressure in any portion of the system that involves an increase in fluid pressure. Pumps and compressors, especially those operating across large pressure differentials (e.g., those that cause a large pressure rise in the fluid), require large amounts of energy. Therefore, conventional systems consume large amounts of energy to increase the pressure of the fluid (via a motor-driven pump or compressor). Further, conventional fluid transfer systems reduce the pressure of the fluid through expansion valves and / or heat exchangers (e.g., condensers and / or evaporators, etc.). Conventional systems inefficiently increase the fluid pressure and decrease the fluid pressure (e.g., when operating within a loop). This is wasteful in terms of the energy used to operate the conventional systems (e.g., the energy used to repeatedly increase the pressure of the refrigeration fluid to cause an increase or decrease in the temperature of the surrounding environment).

[0008] The systems, apparatuses, and methods of the present disclosure enable control of systems (e.g., fluid processing systems, heat transfer systems, refrigeration systems, heat pump systems, cooling systems, heating systems, etc.) that include one or more pressure exchangers (PX). In the system, the PX may be configured to exchange pressure between a first fluid (e.g., a high-pressure portion of a refrigerant fluid in a refrigeration cycle) and a second fluid (e.g., a low-pressure portion of the refrigerant fluid in the refrigeration cycle). The PX may receive the first fluid (e.g., a portion of the high-pressure refrigerant fluid) via a first inlet (e.g., a high-pressure inlet), and receive the second fluid (e.g., a portion of the low-pressure refrigerant fluid) via a second inlet (e.g., a low-pressure inlet). When entering the PX, the first fluid may be at a higher pressure than the second fluid. The PX may exchange pressure between the first fluid and the second fluid. The first fluid may exit the PX via a first outlet (e.g., a low-pressure outlet), and the second fluid may exit the PX via a second outlet (e.g., a high-pressure outlet). When exiting the PX, the second fluid may have a higher pressure than the first fluid (e.g., pressure is exchanged between the first fluid and the second fluid).

[0009] In some systems, fluid may be pumped, compressed, pressurized, and the like at various portions of the fluid processing system. For example, a main compressor (or set of compressors) may perform work to raise the pressure of a low-pressure fluid into a high-pressure fluid, and various other compressors or boosters may be utilized to provide auxiliary pressure regulation at other points in the fluid processing system. In some embodiments, one or more adjustments may be introduced to the fluid flow path to reduce the number of required pumps or compressors, for example by utilizing the PX to perform compression that was conventionally performed by a booster pump.

[0010] In some embodiments, a heat transfer system (e.g., a refrigeration system, a heat pump system, etc.) may target controlled operating conditions. For example, a refrigeration system may target a specific temperature in a refrigerated area (e.g., for the safe storage of perishable materials such as food, pharmaceuticals, or scientific or research materials); a heat pump system may target a comfortable indoor temperature in a house; a system may target a heat exchange rate between the system and the environment; and one or more parts of the system may target an operating temperature, pressure, fluid density, etc. The operating parameters for maintaining the target conditions may depend on many factors, such as ambient temperature, the mass, type, and initial temperature of the materials in the temperature-controlled area, and the frequency of material and / or energy exchange between the controlled area and the surrounding environment.

[0011] In some embodiments, the PX may be operable within a range of operating speeds. For example, a rotary PX may be operable at various rotational speeds, and a reciprocating PX may be operable at various cycle frequencies, and so on. The PX may be coupled to a motor. The motor may be configured to control the operating speed of the PX. The operating speed of the PX may affect the fluid flow rate, fluid pressure, etc., in various parts of the fluid processing system. In some embodiments, the motor may drive the PX; for example, if a faster flow rate through the PX is targeted, the motor may accelerate the movement of the PX. In some embodiments, the motor may function to suppress the PX; for example, if a slower flow rate through the PX is targeted, the motor may suppress the movement of the PX to maintain the desired flow rate. A controller may be operablely coupled to the motor of the PX. The controller may receive data collected from one or more parts of the fluid processing system, such as pressure data showing the fluid pressure associated with the condenser of the fluid processing system (e.g., in the condenser, out of the condenser), flow rate data showing the flow rate through a part of the fluid processing system, and so on. The controller may generate a control signal for the motor based on received data that displays one or more operating conditions of the fluid processing system. The motor may be configured to adjust the operating speed of the PX based on the control signal.

[0012] In some embodiments, the operating speed of the PX may be used to maintain one or more conditions of the fluid system. For example, the PX speed may be selected to maintain a target fluid pressure in components upstream of the PX. The PX speed may further affect other conditions of the system, but due to the influence of the PX speed on multiple conditions and components of the system, it may not be available for adjustment, at least partially. Additional control methods may be used to maintain one or more target conditions of the fluid system, which may be further influenced by the operating speed of the PX.

[0013] In some embodiments, the fluid system may include one or more control valves that can be opened or closed to enable a target fluid flow rate, a target upstream fluid pressure, a target downstream fluid pressure, and so on. The control valves may be provided in the fluid system coupled to the high-pressure outlet of the PX. For example, the fluid may exit the high-pressure outlet of the PX, pass through an auxiliary gas cooler, and be supplied to the control valves. The control valves may have an adjustable opening to maintain target conditions of the fluid system, and this opening is adjusted based on one or more inputs. The opening of the control valves may be adjusted to maintain a target travel distance of the PX.

[0014] Distance traveled is a measure of fluid flow into or out of a duct in a PX. For example, a fluid may flow into a duct from a first inlet and exchange pressure with a second fluid that enters the duct from an inlet located on the opposite side of the duct. The fluid can then be removed through an outlet located on the same side of the duct from which it entered, after the pressure exchange. Distance traveled is a measure of how deep the first fluid flows into the duct before returning towards the outlet. Distance traveled represents the volumetric flow rate through the PX, based on, for example, the rotational speed of the PX, the number of ducts in the PX, and the total duct volume of the PX. The two inlets of the PX may each have associated distance traveled. For example, during operation, the PX may operate with a first low-pressure distance traveled, associated with the movement of fluid supplied to the low-pressure inlet of the PX, and a second high-pressure distance traveled, associated with the movement of fluid supplied to the high-pressure inlet of the PX. The target distance traveled may be selected based on, for example, the target volumetric flow rate through the PX, the target energy efficiency, the target pressure exchange efficiency, and the target mixing of the first and second fluids.

[0015] The travel distance of one or more PXs can be adjusted and / or maintained by adjusting the operation of components of the fluid transmission system comprising the PX. For example, the low-pressure inlet travel distance (e.g., the volume of fluid supplied to the PX low-pressure inlet compared to the working volume of the PX) can be maintained by adjusting the opening of a control valve coupled to the high-pressure outlet of the PX. The working volume of the PX depends on the operating speed of the PX. For example, in a rotary PX, the number of PX ducts utilized in a given period increases as the rotational speed increases. The control valve may be configured to be controlled based on the PX speed to maintain a target low-pressure inlet travel distance in the PX. When setting the opening of the control valve, further signals such as the total system load (e.g., the total fluid flow rate through the system) and the temperature in one or more gas coolers may be taken into consideration.

[0016] In some embodiments, the fluid system may include one or more heat exchangers to exchange heat between fluids at different points in the fluid processing system, for example. For example, the fluid processing system may include a heat exchanger for cooling the main flow of fluid from a main gas cooler. The portion of fluid supplied by the gas cooler may be supplied to the cooling fluid channels of the heat exchanger to cool the main portion of the fluid. The portion of fluid supplied to each fluid channel may be determined by a control valve. Target cooling conditions may be monitored, and the portion of fluid supplied to the primary or secondary channels of the heat exchanger may be adjusted to achieve target cooling conditions, such as a target subcooling degree of the main body supplied to the heat exchanger.

[0017] In some embodiments, the fluid processing system may include a control valve associated with a fluid flow path that supplies fluid to an auxiliary gas cooler. The control valve associated with the auxiliary gas cooler may be opened to determine the amount of fluid passing through the auxiliary gas cooler, to determine the distance traveled by the PX, etc. The control valve associated with the auxiliary gas cooler may be opened by an amount based on the opening of other valves in the flow path, for example, a control valve configured to determine the portion of fluid supplied to a secondary channel of a heat exchanger in the fluid processing system. The control valve associated with the auxiliary gas cooler may be opened to allow a flow through that valve that matches the flow through other valves controlled based on other criteria of the fluid processing system.

[0018] In some embodiments, the fluid processing system may include a mechanism for adjusting the heat transfer efficiency of one or more heat exchangers, condensers, gas coolers, etc. For example, an auxiliary gas cooler may include, or be associated with, one or more fans to increase heat transfer from the gas cooler to the environment near the gas cooler (e.g., the ambient environment). The operation and / or function of the device for adjusting the heat transfer efficiency (e.g., adjusting the fan speed of the auxiliary gas cooler) may be based on the temperature of the fluid output by the gas cooler. In some embodiments, measures may be taken to achieve and / or maintain a target temperature of the fluid output by the auxiliary gas cooler. The target temperature may be based on the ambient temperature, for example, the target fluid temperature after the fluid has passed through the gas cooler may be within a target ambient temperature, for example, within 5 degrees of the ambient temperature. The target temperature may be based on the fluid temperature at other locations in the fluid processing system, for example, the fluid output by the main gas cooler. Additional architectures, sensors, and processing units may exist to maintain target or optimal conditions for the fluid output by the main gas cooler, and fewer sensors or other architectures may be used to match the fluid output by the auxiliary gas cooler to the fluid output by the main gas cooler.

[0019] In some embodiments, the control of the portion of fluid supplied to the main and secondary fluid channels of a heat exchanger may be based on the conditions of the receiver, in addition to or instead of other conditions. For example, the subcooling supplied to the main flow of fluid in the heat exchanger may reduce the amount of flash gas accumulating in the receiver, for example, by lowering the temperature of the fluid supplied to the receiver. In some embodiments, a flash gas valve may be used to allow flash gas from the receiver to be directed to other components of the fluid processing system, such as a main compressor. The subcooling of the heat exchanger may be controlled based on reducing flash gas in the receiver (for example, by adjusting the portion of fluid supplied to the main and secondary channels of the heat exchanger). The subcooling of the heat exchanger may be controlled based on sensor readings and / or control signals provided to the flash gas valve, and thus they may be based on flash gas in the receiver.

[0020] In some embodiments, the control of the portion of fluid supplied to the first and second channels of the heat exchanger may, alternatively or additionally, be based on the travel distance of the PX. For example, the low-pressure inlet travel distance may be used when generating a control signal for a valve that determines the portion of fluid supplied to the primary and secondary channels of the heat exchanger. The low-pressure inlet travel distance may be calculated based on measured or estimated low-pressure inlet mass flow rate, low-pressure inlet pressure, and low-pressure inlet temperature. In some embodiments, a control valve that determines the fluid flow through an auxiliary gas cooler (e.g., a control valve coupled to the high-pressure outlet of the PX) may be controlled based on the high-pressure outlet travel distance of the PX. The high-pressure outlet travel distance of the PX may be determined based on measured and / or estimated high-pressure outlet mass flow rate and high-pressure outlet density. In some embodiments, several different control inputs may be used when determining the control signal. For example, a function may be generated that takes into account two or more control conditions, and the control signal may be based on multiple control conditions, for example, to optimize the control based on achieving the optimal combination of conditions. In other examples, different condition regimes may allow control to be performed based on different conditions, for example, the target subcool level may be maintained on the condition that the minimum travel distance of the PX and / or the minimum opening of the flash gas valve are maintained.

[0021] In some embodiments, the fluid handling system may comprise a main receiver and an auxiliary receiver. The auxiliary receiver may be maintained at a higher pressure than the main receiver, for example, to drive movement between the low-pressure inlet and low-pressure outlet of the PX. The auxiliary receiver may supply fluid to the low-pressure inlet of the PX. The auxiliary receiver may be further configured to supply fluid to the main receiver via a control valve, for example, to maintain a target pressure difference between the auxiliary receiver and the main receiver. The auxiliary receiver may be configured to receive a portion of the fluid output by the main gas cooler. The auxiliary receiver may be configured to receive fluid output through the high-pressure outlet of the PX, for example, fluid cooled via the auxiliary gas cooler.

[0022] In some embodiments, a control valve may determine which portion of the fluid output by the main gas cooler is supplied to the auxiliary receiver and which is supplied to the high-pressure inlet of the PX. The control valve may be controlled based on the pressure in the auxiliary receiver, and more fluid may be maintained, for example, when the pressure is below a target pressure range or when the pressure difference between the auxiliary receiver and the main receiver is outside the target range.

[0023] In some embodiments, a control valve may determine the fluid flow supplied from an auxiliary receiver to the low-pressure inlet of the PX. Control of the valve may be based on maintaining a target low-pressure inlet travel distance of the PX. The travel distance may be estimated based on valve characteristics, for example, an estimate of the mass flow rate as a function of the valve opening for a given inlet condition. The travel distance may be estimated by determining the low-pressure inlet volume flow rate associated with the target travel distance, for example, based on the operating speed of the PX. In some embodiments, the travel distance may not be directly considered, for example, the opening of the control valve may be based on the operating speed of the PX and / or one or more measured or estimated inlet fluid conditions.

[0024] In some embodiments, a control valve may determine the fluid flow from the auxiliary receiver to the main receiver. The flow may be enabled based on the measured pressure difference and the target pressure difference between the two receivers. The flow may also be enabled based on the measured liquid level in the auxiliary receiver; for example, if the liquid level in the auxiliary receiver exceeds a target threshold, more liquid may be transferred from the auxiliary receiver to the main receiver.

[0025] In some embodiments, the fluid processing system includes a receiver (e.g., a flash tank). The receiver may be configured to receive a first fluid output from the low-pressure outlet of the PX. The receiver may form a chamber from which the gaseous and liquid components of the low-pressure first fluid can be separated. The fluid processing system may further include a pump (e.g., a low-pressure booster pump) in fluid communication between the gas outlet of the receiver and the low-pressure inlet of the PX. The fluid processing system may further include sensors configured to provide indication of one or more properties of the first fluid output by the low-pressure outlet of the PX. For example, a densimeter may be used to determine the liquid / gas ratio of the first low-pressure fluid. A controller may receive data (e.g., fluid density data) indicating one or more properties of the first low-pressure fluid. Based on this data, the controller may generate a control signal for the pump (e.g., a low-pressure booster pump). The pump may be configured to adjust its operation (e.g., adjust the pumping speed) based on the control signal. For example, more or less gas may be supplied to the low-pressure inlet of the PX to achieve target operation (e.g., target energy efficiency, pressure transfer threshold efficiency, etc.) or optimal operation (e.g., maximum energy efficiency, maximum heat transfer efficiency, etc.). In some embodiments, the operation of the pump may be adjusted to minimize the mixing of the first and second fluids in the PX (e.g., to minimize the amount of gas moving from the low-pressure inlet to the low-pressure outlet of the PX).

[0026] In some embodiments, the fluid processing system may comprise a receiver (e.g., a flash tank) and an evaporator fluid-connected to the liquid outlet of the receiver. The evaporator may be configured to exchange heat between the fluid of the fluid processing system and the environment, for example, as the liquid of the fluid evaporates, the fluid may absorb heat from the environment and cool the area around the evaporator. The system may further comprise a valve fluid-connected between the liquid outlet of the receiver and the evaporator. The system may further comprise one or more sensors configured to provide sensor data associated with the operation of the evaporator. For example, the system may comprise a temperature sensor that measures the temperature of the fluid output by the evaporator, a pressure sensor that measures the pressure of the fluid output by the evaporator, and the like. In some embodiments, one or more operating parameters of the evaporator are targeted. For example, the target output of the evaporator may be gas-containing and liquid-free. A target value (e.g., a target range) of superheat (e.g., a temperature above the liquid / gas transition temperature of the fluid) may be selected for operation (e.g., high enough to protect downstream liquid-sensitive components, and low enough to allow for high efficiency of the evaporator). The system may further include a controller operably coupled to a valve positioned between the liquid outlet of the receiver and the evaporator. The controller may receive data from one or more sensors associated with the operation of the evaporator. Based on this data, the controller may generate a control signal for the valve. The valve may be configured to adjust its opening (e.g., the flow rate through the valve, the pressure difference across the valve, etc.) based on the control signal.

[0027] In some embodiments, the fluid processing system may include one or more compressors. One or more compressors may be configured to increase the pressure of a gas from low to high, for example, to be used as an input to the high-pressure inlet of a PX. In some embodiments, one or more sensors may be configured to measure one or more conditions of the operation of the fluid processing system. For example, a pressure gauge may measure the pressure of the fluid on the input side of the compressor, and a pressure gauge may measure the pressure of the fluid on the output side of the compressor, and so on. The fluid processing system may include controllers operably coupled to the compressors. The fluid processing system may include controllers associated with each compressor, controllers associated with multiple compressors, and so on. The controllers may generate control signals for the compressors based on measurements received from one or more sensors. The compressors may be configured to adjust their operation based on the control signals.

[0028] In some embodiments, the fluid processing system may comprise a receiver (e.g., a flash tank) and a bypass valve that provides fluid communication between the receiver outlet (e.g., a gas outlet of the receiver) and the evaporator outlet (e.g., the flow through the bypass valve may bypass the evaporator). One or more sensors may provide measurements indicating the state of the fluid processing system; for example, a pressure gauge may measure the pressure in the receiver. The fluid processing system may further comprise a controller operably coupled to the bypass valve. The controller may generate a control signal for the bypass valve based on measurements from one or more sensors (e.g., based on the receiver pressure). The bypass valve may be configured to adjust its opening in response to receiving the control signal (the opening may affect, for example, the fluid flow through the valve, the pressure difference across the valve, etc.).

[0029] In some embodiments, the fluid handling system may include a pump (e.g., a high-pressure booster pump positioned before the condenser of the heat transfer system) that is in fluid communication between the high-pressure outlet and the high-pressure inlet of the PX. One or more sensors may acquire measurements that indicate the conditions of the fluid handling system affected by the pump, for example, a pressure gauge may measure the fluid pressure of the fluid output by the pump, the fluid pressure of the fluid associated with the condenser (e.g., near the condenser, out of the condenser, into the condenser), etc. A controller may generate control signals based on the measurement data received from one or more sensors. The pump may be configured to adjust its operation (e.g., adjust the pumping speed) based on the control signals.

[0030] In some embodiments, the system (for example, PX system 300A in Figure 3A, PX system 300B in Figure 3B) includes a PX configured to exchange pressure between a first fluid and a second fluid.

[0031] The method includes determining the outlet temperature of the gas cooler, calculating the pressure setpoint of the gas cooler, and causing the rotational speed of the rotor of the PX to be adjusted to satisfy the pressure setpoint of the gas cooler. The PX is configured to exchange pressure between a first fluid and a second fluid.

[0032] The PX comprises a first inlet (e.g., a high-pressure in (HPIN) port) configured to receive a first fluid from a mechanical subcooler, a second inlet (e.g., a low-pressure in (LPIN) port) configured to receive a second fluid from the mechanical subcooler, a first outlet (e.g., a high-pressure out (HPOUT) port) configured to supply the second fluid to a gas cooler, the second fluid being supplied from the gas cooler to an auxiliary high-pressure valve, and the second fluid being supplied from the auxiliary high-pressure valve to a receiver, and a second outlet (e.g., a low-pressure out (LPOUT) port) configured to supply the first fluid to the receiver.

[0033] In some embodiments, a mechanical subcooler is configured to exchange heat between a first fluid received from a gas cooler and a second fluid received from the gas cooler via a bypass high-pressure valve. Causing adjustment of the rotor's rotational speed to meet the gas cooler's pressure setpoint includes decreasing the opening percentage of the bypass high-pressure valve and increasing the rotor's rotational speed until the gas cooler's pressure setpoint is met.

[0034] In some embodiments, the method may include determining the difference between the outlet temperature of a gas cooler and the corresponding outlet temperature of a mechanical subcooler, and adjusting the opening of a bypass high-pressure valve until a subcooler setpoint is met.

[0035] In some embodiments, the method may further include adjusting the corresponding opening of the auxiliary high-pressure valve to substantially match the opening of each of the bypass high-pressure valves.

[0036] In some embodiments, the receiver is configured to reduce flash gas.

[0037] In some embodiments, the controller is configured to control one or more of the following: the rotational speed of the rotor of the PX, the corresponding operation of the bypass high-pressure valve, and the operation of each of the auxiliary high-pressure valves.

[0038] The systems, apparatus, and methods of this disclosure offer advantages over conventional solutions. The systems of this disclosure reduce energy consumption compared to conventional systems (e.g., systems without a PX). For example, the use of a PX in the heat transfer system of this disclosure allows for the recovery of energy stored as pressure, returning that energy to the system, and reducing the energy cost of operating the heat transfer system. This reduction in energy cost may enable the use of lower compressor speeds or power consumption, or cheaper, smaller, and / or lower-power compressors in the system.

[0039] The various controllers employed by the system can improve the energy efficiency of the system by minimizing the work performed by the compressor to maintain target conditions, such as the target temperature of the refrigerated area associated with the fluid processing system. For example, improved energy efficiency can be achieved by maximizing the transfer of pressure from the first fluid to the second fluid via the PX (for example, by adjusting the fluid flow rate, fluid pressure, PX operating speed, etc.).

[0040] The systems of this disclosure can reduce the complexity of the fluid handling system by reducing the number of pumps (e.g., boosters) provided in the system. For example, the architecture of this disclosure may allow the PX to perform some pumping or compression operations that would otherwise be performed by boosters in other architectures, for example. Reducing the number of pumps or compressors can, for example, reduce the equipment cost of the system, reduce the number of components that need to be serviced, and reduce the number of failure points to reduce system downtime or corrective or preventive maintenance.

[0041] The system of this disclosure can reduce wear on components (e.g., pumps, compressors) compared to conventional systems. The introduction of PX can reduce the pumping load of one or more pumps / compressors, for example, reducing the target pressure difference that the compressor must achieve. One or more controllers (e.g., control systems) can improve the operation of pumps and compressors by enabling operation at a pumping speed (e.g., minimum viable pumping speed) selected to meet a target system output (e.g., maintaining a target temperature in the heat transfer system) while protecting one or more components of the system. The disclosure can reduce the footprint of green hydrogen projects (e.g., energy consumption, heat emissions, etc.) compared to conventional solutions. This can lead to reduced energy consumption, reduced waste heat, increased heat reuse, and reduced environmental impact, etc.

[0042] The systems of this disclosure can protect one or more components from damage. For example, the compressor of the system may be sensitive to the phase of the material supplied to the compressor (e.g., it may be configured to compress a gas and may be damaged if a liquid is supplied). The controller of the system may change one or more operating parameters of the system (e.g., fluid flow rate, pumping rate, PX operating rate, control valve opening, etc.) to maintain the supply of gas to the compressor (e.g., by maintaining a target value for the superheat of the gas). The systems of this disclosure can allow for greater flexibility in the selection of components of a fluid processing system. For example, one or more controllers (e.g., control systems) may be operably coupled and can cooperate to maintain one or more operating conditions. For example, the system may comprise multiple controllers (e.g., control systems) operably coupled to multiple components (e.g., configured to facilitate adjustment of one or more operating parameters of the components). Multiple control signals may be generated to achieve one or more target tasks, for example, the temperature of a region associated with a heat transfer system may be maintained, or the load on a pump may be kept within a target range. Such goals may be achievable by utilizing multiple controllers in the system, and / or the user may be able to use a wider selection of components within the system (for example, in a system that can maintain the pressure in the pump within a certain range for various operating conditions, the pump may have a smaller manufacturer-recommended operating pressure range).

[0043] While some embodiments of this disclosure are described in relation to pressure exchangers, energy recovery devices, and hydraulic energy transfer systems, this disclosure may be applied to other systems and devices (e.g., non-isobaric pressure exchangers, non-rotating components, non-rotating pressure exchangers, systems without pressure exchangers, etc.).

[0044] While some embodiments of this disclosure are described in relation to the exchange of pressure between fluids used in fracing systems, desalination systems, heat pump systems, and / or refrigeration systems, this disclosure may be applicable to other types of systems. Fluids may refer to liquids, gases, transcritical fluids, supercritical fluids, subcritical fluids, and / or combinations thereof.

[0045] Some embodiments of this disclosure are described in relation to gas coolers and gas cooler coils, but in some embodiments, the gas cooler refers to a cooler coil that is part of the same unit (e.g., housing, device), and in some embodiments, the gas cooler refers to a separate unit (e.g., housing, device).

[0046] While some embodiments of this disclosure are described in relation to controllers and / or control modules, in some embodiments, multiple controllers are part of a single rack controller of the system. A rack may refer to the overall control unit of the system.

[0047] In some aspects of this disclosure, the system comprises a pressure exchanger (PX) configured to receive a first fluid, receive a second fluid, and exchange pressure between the first fluid and the second fluid. The system further comprises a first gas cooler configured to supply working fluid to a first inlet and a second inlet of a heat exchanger. The heat exchanger is configured to exchange heat between a fluid supplied through the first inlet and a fluid supplied through the second inlet. A first outlet of the heat exchanger supplies the first fluid to the PX. A second outlet of the heat exchanger supplies the second fluid to the PX. The system further comprises a receiver configured to receive the first and second fluids from the PX. The system further comprises a first compressor configured to supply working fluid to the first gas cooler.

[0048] Figures 1A and 1B show a fluid handling system according to a particular embodiment. In some embodiments, the system in Figure 1A and / or Figure 1B (e.g., the PX system in the other figures) comprises a PX configured to exchange pressure between a first fluid and a second fluid. The PX comprises a first inlet (e.g., a high-pressure in (HPIN) port) configured to receive the first fluid from a mechanical subcooler, a second inlet (e.g., a low-pressure in (LPIN) port) configured to receive the second fluid from the mechanical subcooler, a first outlet (e.g., a high-pressure out (HPOUT) port) configured to supply the second fluid to a gas cooler, the second fluid being supplied from the gas cooler to an auxiliary high-pressure valve, and the second fluid being supplied from the auxiliary high-pressure valve to a receiver, and a second outlet (e.g., a low-pressure out (LPOUT) port) configured to supply the first fluid to the receiver.

[0049] In some embodiments, the method includes determining the outlet temperature of a gas cooler, calculating the pressure setpoint of the gas cooler, and causing the rotational speed of the rotor of PX to be adjusted to satisfy the pressure setpoint of the gas cooler. PX is configured to exchange pressure between a first fluid and a second fluid.

[0050] Figure 1A shows a schematic diagram of a fluid processing system 100A (e.g., a heat transfer system, a refrigeration system) equipped with a hydraulic energy transfer system 110 according to a specific embodiment.

[0051] In some embodiments, the hydraulic energy transfer system 110 includes a pressure exchanger (e.g., PX). The hydraulic energy transfer system 110 (e.g., PX, a set of components comprising PX, etc.) receives low-pressure (LP)in fluid 120 from the LPin system 122 (e.g., via a low-pressure inlet). The hydraulic energy transfer system 110 also receives high-pressure (HP)in fluid 130 from the HPin system 132 (e.g., via a high-pressure inlet). The hydraulic energy transfer system 110 (e.g., PX) exchanges pressure between the HPin fluid 130 and the LPin fluid 120 to provide LPout fluid 140 to the LPout fluid system 142 (e.g., via a low-pressure outlet) and HPout fluid 150 to the HPout fluid system 152 (e.g., via a high-pressure outlet). In some embodiments, the fluid processing system 100A includes a booster elimination component 182, for example, this architecture is designed to include one or more components to allow the elimination of one or more pumps or compressors compared to other PX fluid processing systems, such as other PX heat transfer or refrigeration systems. The booster elimination component 182 may include one or more additional heat exchangers, for example, heat exchangers to provide subcooling to the main / primary flow of the fluid in the fluid processing system 100A. In some embodiments, the controller 185 may cause the flow rates of the HPin fluid 130 and LPout fluid 140 to be regulated by one or more flow valves, pumps, and / or compressors (not shown). The controller 185 may actuate the flow valves.

[0052] The controller may cause the flow rate and / or fluid conditions of the HPin fluid 130 and LPout fluid 140 to be adjusted by one or more flow valves, pumps, motors, fans, and / or compressors (not shown). The controller may be configured to perform various operations (for example, of controllable components provided in the fluid processing system 100A). The controller may be configured to cause the operation of one or more valves. The controller may be configured to cause the operating speed of one or more components to be adjusted. The controller may cause other operations of controllable components of the fluid processing system 100A. The controller may actuate one or more valves. The controller may start, stop, or adjust the operation of one or more pumps. The controller may start, stop, or adjust the operation of components that regulate heat transfer to or from the working fluid of the fluid processing system 100A. For example, the controller may actuate fans that increase heat transfer from the working fluid to the ambient environment via one or more gas coolers of the fluid processing system 100A.

[0053] In some embodiments, the hydraulic energy transfer system 110 includes a PX for exchanging pressure between the HPin fluid 130 and the LPin fluid 120. In some embodiments, the PX is substantially or partially isobaric (e.g., an isobaric pressure exchanger (IPX)). The PX may be a device that transfers fluid pressure between the HPin fluid 130 and the LPin fluid 120 with an efficiency of about 50%, 60%, 70%, 80%, 90%, or higher (e.g., pressure transfer efficiency, substantially isobaric) (e.g., without utilizing centrifugal technology). High pressure (e.g., HPin fluid 130, HPout fluid 150) refers to a pressure higher than low pressure (e.g., LPin fluid 120, LPout fluid 140). The LPin fluid 120 in the PX may be pressurized and exit the PX at a high pressure (e.g., HPout fluid 150, at a pressure higher than the pressure of the LPin fluid 120), and the HPin fluid 130 may be at least partially depressurized and exit the PX at a low pressure (e.g., LPout fluid 140, at a pressure lower than the pressure of the HPin fluid 130). The PX may operate such that the HPin fluid 130 directly applies force to pressurize the LPin fluid 120, with or without a fluid separator between the fluids. Examples of fluid separators that may be used with the PX include, but are not limited to, pistons, bladder, and diaphragm.

[0054] In some embodiments, the PX may be a rotary device. Rotary PXs, such as those manufactured by Energy Recovery Inc. in San Leandro, California, do not require a separate valve, as effective valve action is achieved within the device via the relative motion of the rotor to the end cover. In some embodiments, the rotary PX operates using an internal piston to isolate the fluid and transmit pressure with relatively little mixing of the inlet fluid flow. In some embodiments, the rotary PX operates without an internal piston between the fluids.

[0055] In some embodiments, the PX may be a reciprocating device. A reciprocating PX may include a piston that moves back and forth within a cylinder to transfer pressure between fluid flows. For example, a reciprocating PX may include one or more pressure exchange chambers. Each pressure exchange chamber may include a piston. A high-pressure first fluid can enter one side of the pressure exchange chamber and transfer energy (e.g., via the displacement of the piston) to a low-pressure second fluid on the opposite side of the pressure exchange chamber. The low-pressure first fluid can then be discharged from the pressure exchange chamber, while the high-pressure second fluid is utilized for the operation of a fluid processing system (e.g., desalination, fracing, refrigeration, heat transfer, etc.). The low-pressure second fluid can then fill the second side of the pressure exchange chamber, and subsequently, the high-pressure first fluid can be introduced to the first side of the pressure exchange chamber to transfer energy to the other part of the second fluid. The reciprocating device may include a number of pressure exchange chambers operating in a cycle for a substantially continuous flow of the high-pressure second fluid from the device.

[0056] In some embodiments, PX may be a hydraulic turbocharger. The hydraulic turbocharger PX may introduce a high-pressure first fluid into a chamber containing a first impeller. The high-pressure first fluid may rotate the impeller by transferring energy from the first fluid to the impeller. The first impeller is coupled to a shaft, which may be further coupled to a second impeller in a separate chamber. The rotation of the first impeller may cause the rotation of the second impeller. The second impeller may come into contact with a low-pressure second fluid. The rotation of the impeller may transfer energy to the second fluid (for example, it may increase the pressure of the second fluid).

[0057] This disclosure may include, but is not limited to, rotary PXs, reciprocating PXs, hydraulic turbocharger PXs, or any combination thereof. Furthermore, a PX may be positioned on a skid separate from the other components of the fluid handling system 100A (for example, in a situation where a PX is added to an existing fluid handling system). For example, a PX may be fixed to a structure that is movable from one location to another. A PX may be coupled to a system constructed on-site (for example, the system's piping). The structure to which a PX is fixed may be referred to as a “skid”.

[0058] In some embodiments, the motor 160 is coupled to a hydraulic energy transfer system 110 (e.g., PX). In some embodiments, the motor 160 controls the speed of the rotor of the hydraulic energy transfer system 110 (e.g., to increase the pressure of the HPout fluid 150, to decrease the pressure of the LPout fluid 140, etc.). In some embodiments, the motor 160 generates energy based on pressure exchange in the hydraulic energy transfer system 110 (e.g., acting as a generator). For example, a pressure difference (e.g., the difference between the pressure of the LPin fluid 120 and the pressure of the HPin fluid 130) can drive the rotation of a rotary PX, and the motor 160 can introduce resistance to its rotation to slow it down and generate electricity. In some embodiments, the motor may act to decelerate the PX without generating electricity.

[0059] The hydraulic energy transfer system 110 may include a hydraulic turbocharger or hydraulic exchanger, such as a rotary PX. The PX may include one or more chambers and / or channels (e.g., 1 to 100 channels) to facilitate pressure transfer between a first fluid and a second fluid (e.g., a gas, liquid, multiphase fluid, supercritical fluid, etc.).

[0060] In some embodiments, the hydraulic energy transfer system 110 can transfer energy (e.g., pressure) between two fluids having substantially different compositions, phases, etc. For example, the PX of the hydraulic energy transfer system 110 can transfer pressure between a first fluid (e.g., a pressure exchange fluid, a first-phase fluid such as a liquid or supercritical fluid, a propane-free fluid, a substantially propane-free fluid, a lower viscosity fluid, a fluid having less than a threshold amount of a particular chemical) and a second fluid, the second fluid may be of a different phase, may have a higher viscosity (e.g., it may be high viscosity), may contain more than a threshold amount of a particular chemical (e.g., a corrosive chemical), and / or may contain solid particles (e.g., a fracing fluid containing sand, propane, powder, debris, ceramics, etc.). By transferring energy from one type of fluid to another, expensive components such as pumps can be protected from contact with fluids that may be harmful to them, such as viscous, corrosive, or abrasive fluids, or fluids in phases that the component is not designed to handle.

[0061] In some embodiments, the hydraulic energy transfer system 110 can transfer energy (e.g., pressure) between two fluids having substantially similar compositions. For example, in some conventional systems, the waste flow of the system may contain a high-pressure fluid. The hydraulic energy transfer system 110 can receive the high-pressure waste flow as a high-pressure input (e.g., HPin fluid 130) and transfer energy from that flow to a low-pressure working flow (e.g., LPin fluid 120). In some systems, such as closed refrigeration systems, energy can be recovered from the high-pressure portion of the fluid flow, reducing the requirements for pumps and / or compressors for the fluid flow.

[0062] In some embodiments, the LPin system 122 includes a booster (e.g., a pump and / or compressor) that increases the pressure of the fluid to form the LPin fluid 120. In some embodiments, the LPin system 122 receives gas from the LPout system 142. In many embodiments, the LPin system 122 receives fluid from a receiver (e.g., a flush tank). The receiver may receive the LPout fluid 140 output from the hydraulic energy transfer system 110.

[0063] The fluid processing system 100A further comprises a control module 180. The control module 180 may comprise one or more controllers 185. The control module 180 may be configured to perform any of the methods described herein. The controllers 185 of the control module 180 may receive data (e.g., measurement data) from sensors associated with the fluid processing system 100A. The controllers 185 may be configured to generate control signals based on operating parameters (e.g., thresholds, specified operating ranges, target parameter values, etc.) and / or data received from the sensors. The controllers 185 may comprise a single device that performs one or more control tasks, separate devices for each control task (e.g., each controllable component of the fluid processing system 100A), multiple devices, each performing several functions, and so on. For example, each operation of the controller 185 may be performed by a separate device, or all operations of the controller 185 may be performed by a single device, or a combination of separate devices and combined devices may be employed. The components of the control module 180 may include a general-purpose computing device, a personal computer (PC), a laptop, a mobile phone, a tablet computer, a netbook computer, a microcontroller, a dedicated controller (e.g., hardware, circuitry, etc.), a proportional-integral-derivative (PID) controller (e.g., a ternary controller), a web appliance, or any other device capable of executing (sequentially or otherwise) a set of commands specifying the actions to be performed by the device. The control module 180 may include multiple controllers 185 that operate independently (e.g., without input from one controller to another, without measurement data from one sensor being supplied to multiple controllers, etc.). The control module 180 may include multiple controllers that operate in conjunction with each other, for example, target adjustment of the operating parameters of the fluid processing system 110A (e.g., those reported by one or more sensors in the system) may include adjustment of the operation of one or more components of the system by one or more controllers 185 of the control module 180.

[0064] The fluid processing system 100A may further include one or more sensors for providing sensor data associated with the fluid in the fluid processing system 100A (e.g., flow rate data, pressure data, velocity data, etc.). A controller 185 (e.g., the controller of the fluid processing system 100A) may control, based on the sensor data, one or more flow rates of the fluid processing system 100A, the operation of one or more components of the fluid processing system 100A (e.g., the operation of the motor 160, the operation of one or more pumps, etc.), etc. In some embodiments, the controller triggers the operation of one or more flow valves based on the received sensor data.

[0065] The hydraulic energy transfer system 110 can be used in various types of systems, such as fracing systems, desalination systems, refrigeration systems (e.g., Figure 1B), heat pump systems, slurry pump systems, industrial fluid systems, waste fluid systems, and fluid transport systems.

[0066] The controller of the control module may provide control signals to interdependent components of the fluid processing system 100A. For example, the controller may provide a control signal to the motor 160 to control the operating speed of the hydraulic energy transfer system 110. The operating speed of the hydraulic energy transfer system 110 may further affect conditions at other locations in the fluid processing system 100A. Other components, such as valves and pumps, may be operated to control conditions of the fluid processing system 100A that are affected by the operating speed of the hydraulic energy transfer system 110. The controller may provide signals to various controllable components provided in the fluid processing system 100A. Various components of subsystems of the fluid processing system 100A may be controlled by signals provided by the controller based on the operating speed of the hydraulic energy transfer system 110.

[0067] Figure 1B shows a schematic diagram of a fluid processing system 100B comprising a hydraulic energy transfer system 110 according to a particular embodiment. The fluid processing system 100B may be, for example, a heat transfer system, a refrigeration system, or a heat pump system. The fluid processing system 100B may be configured to cool and / or heat an environment (e.g., an indoor space, a refrigerator, a freezer, etc.). In some embodiments, the fluid processing system 100B has more or fewer components, the same or different paths, etc., than those shown in Figure 1B. Some of the features in Figure 1B that have similar reference numerals to those in Figure 1A may have similar characteristics, functions, and / or structures to those in Figure 1A.

[0068] In some embodiments, the hydraulic energy transfer system 100 (e.g., PX) may receive LP fluid 120 from an LPin system 122 (e.g., a low-pressure lift device 128, a low-pressure fluid pump, a low-pressure booster pump, a low-pressure compressor, a low-pressure ejector, etc.) and HPin fluid 130 from an HPin system 132 (e.g., a condenser 138, a gas cooler, a heat exchanger, etc.). In some embodiments, components of the fluid handling system 100B may be provided to eliminate one or more lift devices for increasing pressure in relation to one or more of the LPin systems 122 or HPout systems 152. The HPin fluid 130 may be supplied to the hydraulic energy transfer system 110 from an HPin system 132 (e.g., a condenser 138, a gas cooler, a heat exchanger, etc.). The hydraulic energy transfer system 110 (e.g., PX) may exchange pressure between the LPin fluid 120 and the HPin fluid 130 to supply the HPout fluid 150 to the HPout system 152 (e.g., a high-pressure lift device 159, a high-pressure fluid pump, a high-pressure booster pump, a high-pressure compressor, a high-pressure ejector, etc.) and the LPout fluid 140 to the LPout system 142 (e.g., an evaporator 144, a heat exchanger, etc.). In some embodiments, components of the fluid handling system 100B may be provided to eliminate the high-pressure lift device, for example, the high-pressure lift device is an optional component in some architectures. The LPout system 142 (e.g., an evaporator 144) may supply fluid to the compressor 178 and / or optionally to the low-pressure lift device (e.g., the LPin system 122 may include a low-pressure lift device). The evaporator 144 may supply fluid to the compressor 178 and / or optionally to the low-pressure lift device. In some embodiments, different components may supply fluid to the low-pressure lift device, evaporator 144, etc. For example, the LPout fluid 140 may be supplied to the receiver of the flash tank. The liquid output from the flash tank may be supplied to the evaporator 144 (for example, the gas output from the flash tank may be supplied to the low-pressure lift device of the LPin system 122). In some embodiments, additional valves, lines, piping, fluid passages, etc., may supply fluid to different devices in different orders and / or combinations.The condenser 138 may receive fluid from the compressor 178 (for example, from the high-pressure lift device of the HPout system 152). The controller may control one or more components of the fluid handling system 100B, for example, a component comprising the motor 160 and various other controllable components. The high-pressure lift device (for example, that of the HPout system 152) may be a high-pressure booster, and the low-pressure lift device (for example, that of the LPin system 122) may be a low-pressure booster.

[0069] The fluid processing system 100B may be a closed system. The LPin fluid 120, HPin fluid 130, LPout fluid 140, and HPout fluid 150 may all be fluids (e.g., refrigerant, the same fluid) circulating within the closed system of the fluid processing system 100B.

[0070] The fluid processing system 100B may further include one or more sensors configured to provide sensor data associated with the system. For example, a sensor may report on the properties of the fluid at various stages of the system (e.g., various components of the system), such as temperature, pressure, flow rate, and density. The sensor may measure properties relevant to the function of the fluid processing system 100B; for example, a refrigeration system may include one or more temperature sensors that report on the temperature of the area to be refrigerated. The sensor may measure properties that affect the operation of the fluid processing system 100B; for example, a heat transfer system intended to heat an area associated with a condenser 138 may measure the temperature near the evaporator 144 to improve operational efficiency, for example, to achieve a target output (e.g., temperature), and may use the temperature measurement near the evaporator 144 to modify one or more operating parameters of the fluid processing system 100B.

[0071] The control module 180 may be configured to perform any of the methods described herein (e.g., Figures 5A to 5E). The controller 185 of the control module 180 may receive sensor data from the sensor (e.g., raw sensor data, pre-processed sensor data, averaged sensor data, data as the difference between a measured value and a target / threshold, etc.). The controller 185 may be configured to generate one or more control signals based on the input sensor data. The control signals may facilitate the operation of the adjustable components of the fluid processing system 100B.

[0072] The fluid processing system 100B may include one or more valves with variable openings. For example, the fluid flow rate can be changed by adjusting the opening of the valves. The valves may be electronically adjustable, for example, an electronic expansion valve (EEV). The valves may be configured to adjust their opening (e.g., an opening percentage value) based on a control signal received from the control module 180. The fluid processing system 100B may include one or more pumps, compressors, etc. The pumps and compressors may be configured to have variable operating speeds (e.g., motor operating speed, pumping speed, etc.). The pumps and compressors may be configured to adjust their operating speeds based on control signals received from the control module 180. The fluid processing system 100B may include a motor 160 coupled to the PX of the hydraulic energy transmission system 110. The motor 160 may be configured to adjust the operating speed of the PX based on a signal received from the control module 180. For example, the motor 160 may act as a generator by converting the rotational energy of the PX into electrical energy.

[0073] Figures 2A to 2E are exploded perspective views of a rotary PX40 (e.g., a rotary pressure exchanger, a rotary liquid piston compressor (LPC)) according to a particular embodiment. Some of the features in one or more of Figures 2A to 2E may have similar characteristics, functions, and / or structures to those in one or more of Figures 1A to 1B.

[0074] In some embodiments, one or more PX40s shown in Figures 2A to 2E are configured to exchange pressure between a first fluid and a second fluid. In some embodiments, the PX40 includes a first inlet (e.g., a high-pressure in (HPIN) port) configured to receive the first fluid from a mechanical subcooler, a second inlet (e.g., a low-pressure in (LPIN) port) configured to receive the second fluid from the mechanical subcooler, a first outlet (e.g., a high-pressure out (HPOUT) port) configured to supply the second fluid to a gas cooler, the second fluid being supplied from the gas cooler to an auxiliary high-pressure valve, and the second fluid being supplied from the auxiliary high-pressure valve to a receiver, and a second outlet (e.g., a low-pressure out (LPOUT) port) configured to supply the first fluid to the receiver.

[0075] In some embodiments, the method includes determining the outlet temperature of a gas cooler, calculating the pressure setpoint of the gas cooler, and causing the rotational speed of the rotor of PX40 to be adjusted to satisfy the pressure setpoint of the gas cooler. PX40 is configured to exchange pressure between a first fluid and a second fluid.

[0076] The PX40 is configured to transmit pressure and / or work between a first fluid (e.g., a refrigerant, a particulate fluid, a propane-free fluid, supercritical carbon dioxide, HPin fluid 130, etc.) and a second fluid (e.g., a refrigerant, a slurry fluid, a fracing fluid, superheated gaseous carbon dioxide, LPin fluid 120, etc.) with minimal fluid mixing. The rotary PX40 may comprise a generally cylindrical body portion 42 comprising a sleeve 44 (e.g., a rotor sleeve) and a rotor 46. The rotary PX40 may also comprise two end caps 48 and 50, each comprising a manifold 52 and 54, respectively. Manifold 52 comprises an inlet port 56 and an outlet port 58, respectively, while manifold 54 comprises an inlet port 60 and an outlet port 62, respectively. During operation, these inlet ports 56, 60 allow the first and second fluids to enter the rotary PX40 for pressure exchange, while the outlet ports 58, 62 allow the first and second fluids to then exit the rotary PX40. During operation, inlet port 56 may receive the high-pressure first fluid (e.g., HPin fluid 130) output from the condenser, and after pressure exchange, outlet port 58 may be used to route the low-pressure first fluid (e.g., LPout fluid 140) from the rotary PX40 to a receiver (e.g., a flash tank) configured to receive the first fluid from the rotary PX40. The receiver may form a chamber configured to separate the fluid into gas and liquid. Similarly, the inlet port 60 may receive a low-pressure second fluid (e.g., low-pressure slurry fluid, LPin fluid 120) from a booster configured to receive a portion of the gas from the receiver and increase the pressure of the gas, and the outlet port 62 may be used to route a high-pressure second fluid (e.g., high-pressure slurry fluid, HPout fluid 150) from the rotary PX40. The end caps 48 and 50 are equipped with corresponding end covers 64 and 66 (e.g., end plates) located within the manifolds 52 and 54, respectively, which enable fluid sealing contact with the rotor 46.

[0077] In some embodiments, the ports of PX40 are in fluid communication with a fluid system. The fluid system comprises a fluid processing architecture 92. The fluid processing architecture 92 comprises numerous components for performing operations, regulating fluid conditions, and providing system control, such as the components described in relation to Figures 1A to 1B. The fluid processing architecture 92 may also comprise a booster elimination component 182, which may comprise one or more components that enable the elimination or bypass of one or more pumps or compressors in the fluid processing architecture 92. For example, components such as heat exchangers and / or receivers may enable the elimination of one or more booster pumps compared to other PX fluid systems. Further descriptions of architectures comprising one or more booster elimination components can be found in relation to Figures 3A to 3G and Figures 4A to 4B.

[0078] One or more components of the PX40, for example, the rotor 46, the end cover 64, and / or the end cover 66, may be made of a wear-resistant material (e.g., carbides, cemented carbides, silicon carbide, tungsten carbide, etc.) having a hardness greater than a predetermined threshold (e.g., at least 1000, 1250, 1500, 1750, 2000, 2250, or greater Vickers hardness). For example, tungsten carbide may be more durable and provide improved wear resistance to abrasive fluids compared to other materials such as alumina ceramics. Furthermore, in some embodiments, one or more components of the PX40, for example, the rotor 46, the end cover 64, the end cover 66, and / or other sealing surfaces of the PX40 may be provided with inserts. In some embodiments, the insert may be composed of one or more wear-resistant materials (e.g., carbides, cemented carbides, silicon carbides, tungsten carbides, etc.) having a hardness greater than a predetermined threshold (e.g., at least 1000, 1250, 1500, 1750, 2000, 2250, or greater Vickers hardness) to provide improved wear resistance.

[0079] The rotor 46 may be cylindrical and housed within the sleeve 44, thereby enabling the rotor 46 to rotate about the axis 68. The rotor 46 may have a plurality of channels 70 (e.g., ducts, rotor ducts) extending substantially longitudinally through the rotor 46, each channel 70 having openings 72 and 74 (e.g., rotor ports) at each end, arranged symmetrically about the longitudinal axis 68. The openings 72 and 74 of the rotor 46 are arranged to communicate fluidly with inlet and outlet openings 76 and 78 (e.g., end cover inlet ports and end cover outlet ports) and 80 and 82 (e.g., end cover inlet ports and end cover outlet ports) in the end covers 64 and 66, such that the channels 70 are exposed to high-pressure and low-pressure fluids during rotation. As shown, the inlet and outlet openings 76 and 78 and 80 and 82 may be designed in the form of arcs or segments of a circle (e.g., C-shapes).

[0080] In some embodiments, PX40 may be coupled to a motor 91. The motor 91 may be configured to regulate the rotational speed of PX40, for example, a rotor 46. Components of PX40 may be connected by a shaft (not shown) passing through a rotating axis. The shaft may be coupled to the motor 91. In some embodiments, the motor 91 may act as a generator, for example, to convert the rotational energy of PX40 into electrical energy. In some embodiments, the motor 91 may drive PX40, for example, to increase the operating speed (e.g., rotational speed) of PX40.

[0081] In some embodiments, a control module 94 (e.g., control module 180, controller 185, etc.) may be operably coupled to the motor 91. The control module 94 may be configured to perform any method described herein. The control module 94 may receive sensor data (e.g., revolutions per minute measured through a tachometer or optical encoder, volumetric flow rate measured through a flow meter, pressure or temperature data of fluids in a fluid processing system, etc.). The control module 94 may generate control signals based on the sensor data. The control module 94 may use the control signals to regulate the operation of the motor 91.

[0082] The operating speed of the PX40 (e.g., controlled via the motor 91) can be used to control the degree of mixing between the first and second fluids within the rotary PX40, which can be used to improve the operability of the fluid processing system (e.g., the fluid processing systems 100A-100B in Figures 1A-1B). For example, by changing the volumetric flow rate of the first and / or second fluids entering the rotary PX40, an operator (e.g., a system operator, a plant operator) can control the amount of fluid mixing within the PX40. Furthermore, by changing the rotational speed of the rotor 46 (e.g., via the motor 91), the operator can also control the mixing. Three characteristics of the rotary PX40 that affect the mixing are (1) the aspect ratio of the rotor channel 70, (2) the exposure time between the first and second fluids, and (3) the formation of a barrier (e.g., a fluid barrier, piston, interface) between the first and second fluids within the rotor channel 70. Firstly, the rotor channel 70 (e.g., a duct) is generally long and narrow, thereby stabilizing the flow within the rotary PX40. Furthermore, the first and second fluids can move through the channel 70 in a plug flow regime with minimal axial mixing. Secondly, in certain embodiments, the speed of the rotor 46 reduces contact between the first and second fluids. For example, the speed of the rotor 46 (e.g., a rotor speed of about 1200 revolutions per minute (RPM)) can reduce the contact time between the first and second fluids to less than about 0.15 seconds, 0.10 seconds, or 0.05 seconds. Thirdly, the rotor channel 70 (e.g., a small portion of the rotor channel 70) is used for pressure exchange between the first and second fluids. In some embodiments, a certain volume of fluid remains in the channel 70 as a barrier between the first and second fluids. All of these mechanisms can limit mixing within the rotary PX40. Furthermore, in some embodiments, the rotary PX40 may be designed to operate using a full or partial internal piston or other barrier that isolates the first and second fluids while allowing pressure transmission.

[0083] In some embodiments, the operating speed of PX can be set (for example, targeting the characteristics listed above or other characteristics of the fluid system). The characteristics of the fluid system may be affected by the rotational speed of PX40. The control module may receive an indication of the operating speed of PX40 (for example, from a sensor, from a control signal for the controller of PX40, etc.) and may generate control signals for the controllable components of the fluid processing architecture 92 based on the operating speed of PX40.

[0084] In some embodiments, the control module 94 may receive sensor data indicating the pressure in the condenser of the fluid processing system. For example, a pressure gauge may measure the pressure of the fluid entering the condenser. The output fluid from the condenser may be coupled to the high-pressure inlet of the PX. The pressure of the fluid entering the condenser may be related to the pressure inside the condenser. The operating speed of the PX may be adjusted (e.g., via the motor 91) to maintain a target pressure inside the condenser. For example, if the pressure inside the condenser falls below the target pressure, the motor 91 may be used to suppress the rotation of the PX 40, thereby slowing down the fluid flow through the PX 40 and increasing the pressure of the fluid inside the condenser.

[0085] Figures 2B to 2E are exploded views of one embodiment of the rotary PX40, showing a series of positions of a single rotor channel 70 within the rotor 46 as the channel 70 rotates through a complete cycle. Note that Figures 2B to 2E are simplified diagrams of the rotary PX40 showing one rotor channel 70, and the channel 70 is shown as having a circular cross-sectional shape. In other embodiments, the rotary PX40 may comprise multiple channels 70 having the same or different cross-sectional shapes (e.g., circular, elliptical, square, rectangular, polygonal, etc.). Therefore, Figures 2B to 2E are simplified diagrams for illustrative purposes, and other embodiments of the rotary PX40 may have configurations different from those shown in Figures 2A to 2E. As will be described in detail below, the rotary PX40 facilitates pressure exchange between the first fluid and the second fluid by allowing the first fluid and the second fluid (e.g., a particulate fluid and a slurry fluid, a higher pressure refrigerant and a lower pressure refrigerant, etc.) to come into contact with each other for a short time within the rotor 46. In some embodiments, PX facilitates pressure exchange between the first and second fluids by allowing the first and second fluids to come into contact with the opposite side of a barrier (e.g., a reciprocating barrier, a piston; not shown). In some embodiments, this exchange occurs at a rate that limits mixing of the first and second fluids. The velocity of the pressure wave traveling through the rotor channel 70 (immediately after the channel is exposed to the opening 76), the fluid diffusion velocity, and / or the rotational speed of the rotor 46 may determine whether and to what extent mixing occurs.

[0086] Figures 2B to 2E may include a booster elimination component 182 as part of a fluid system that is fluid-connected to one or more outlets of PX40. The booster elimination component 182 may enable the removal of one or more pumps or compressors (e.g., low-pressure boosters and / or high-pressure boosters) from the fluid handling system, as described in relation to Figure 1A.

[0087] Figures 2B to 2E show a possible configuration comprising a control module 94 coupled to the PX40. The control module 94 may be configured to perform any of the methods disclosed herein. Figures 2B to 2E illustrate various stages of the operation of the PX40. The operation of the PX40 may be controlled by the control module 94. For example, the control module 94 may be operably coupled to a motor (e.g., motor 91). The control module 94 may transmit one or more control signals to the motor. The motor may adjust the operation of the PX40, for example, the rotational speed of the PX40, etc. The control module 94 may be operably coupled to other components of a fluid handling system that affect the operation of the PX40. For example, one or more compressors supplying fluid to the PX40 may be controlled by the control module 94, and one or more valves supplying fluid to the PX40 may be controlled by the control module 94, and so on.

[0088] Control signals may be provided to the controllable components of the fluid handling system coupled to the PX, as shown in Figures 2B to 2E, according to any of the methods described herein (e.g., Figures 5A to 5E). Figures 2B to 2E show various stages of operation of the PX40. The operation of the PX40 may be controlled by a control module. For example, the control module may be operably coupled to the motor of the PX. The control module may transmit one or more control signals to the motor. The motor may adjust the operation of the PX40, for example, the rotational speed of the PX40, etc. The control module may be operably coupled to other components of the fluid handling system that affect the operation of the PX40. For example, one or more compressors supplying fluid to the PX40 may be controlled by the control module, one or more valves supplying fluid to the PX40 may be controlled by the control module, one or more valves coupled to the outlet of the PX40 may be controlled by the control module, and so on. These components may comprise controllable components described in relation to the architecture of Figures 3A to 3G. These controllable components may be associated with control via methods described herein (e.g., Figures 5A to 5E).

[0089] Figure 2B is an exploded perspective view of one embodiment of a rotary PX40 (e.g., rotary LPC) according to a particular embodiment. In Figure 2B, the channel opening 72 is in a first position. In the first position, the channel opening 72 is in fluid communication with an opening 78 in the end cover 64 and therefore with the manifold 52, while the opposite channel opening 74 is in hydraulic communication with an opening 82 in the end cover 66 and therefore with the manifold 54. The rotor 46 can rotate in a clockwise direction indicated by the arrow 84. During operation, a low-pressure second fluid 86 (e.g., low-pressure slurry fluid) passes through the end cover 66 and enters the channel 70, where it comes into contact with the first fluid 88 at the dynamic fluid interface 90. The second fluid 86 then pushes the first fluid 88 out of the channel 70, through the end cover 64, and out of the rotary PX40. However, due to the short contact time, mixing between the second fluid 86 (e.g., a slurry fluid) and the first fluid 88 (e.g., a particle-free fluid) is minimal. In some embodiments, the low-pressure second fluid 86 contacts a first side of a barrier (e.g., a piston, not shown) located within the channel 70, which is in contact with the first fluid 88 (e.g., on the opposite side of the barrier). The second fluid 86 drives the barrier, thereby pushing the first fluid 88 out of the channel 70. In such embodiments, mixing between the second fluid 86 and the first fluid 88 is negligible.

[0090] Figure 2C is an exploded perspective view of one embodiment of a rotary PX40 (e.g., rotary LPC) according to a particular embodiment. In Figure 2C, the channel 70 is rotated clockwise through an arc of approximately 90 degrees. In this position, the opening 74 (e.g., outlet) is no longer in fluid communication with the openings 80 and 82 of the end cover 66, and the opening 72 is no longer in fluid communication with the openings 76 and 78 of the end cover 64. Thus, the low-pressure second fluid 86 is temporarily contained within the channel 70.

[0091] Figure 2D is an exploded perspective view of one embodiment of a rotary PX40 (e.g., rotary LPC) according to a particular embodiment. In Figure 2D, the channel 70 is rotating through an arc of approximately 60 degrees from the position shown in Figure 2B. The opening 74 is now in fluid communication with the opening 80 in the end cover 66, and the opening 72 of the channel 70 is now in fluid communication with the opening 76 of the end cover 64. At this position, a high-pressure first fluid 88 enters, pressurizing a low-pressure second fluid 86, and pushing the second fluid 86 out of the rotor channel 70 through the opening 80.

[0092] Figure 2E is an exploded perspective view of one embodiment of a rotary PX40 (e.g., rotary LPC) according to a particular embodiment. In Figure 2E, the channel 70 has rotated through an arc of approximately 270 degrees from the position shown in Figure 2B. At this position, the opening 74 is no longer in fluid communication with the openings 80 and 82 of the end cover 66, and the opening 72 is no longer in fluid communication with the openings 76 and 78 of the end cover 64. Therefore, the first fluid 88 is no longer pressurized and is temporarily contained within the channel 70 until the rotor 46 rotates another 90 degrees to restart the cycle.

[0093] Figures 3A to 3G and 4A to 4B are schematic diagrams of fluid processing systems 300A to 300G and 400A to 400B, each comprising a PX, according to a particular embodiment. Some of the features in one or more of Figures 3A to 3G may have similar characteristics, functions, and / or structures to one or more of the features in one or more of Figures 1A to 1B and / or one or more of Figures 2A to 2E (e.g., features having similar names and / or reference numbers). One or more of the systems in Figures 3A to 3G may be used to perform one or more of the methods described herein (e.g., one or more of the methods in Figures 5A to 5E). Some of the features in one or more of Figures 3A to 3G may have similar characteristics, properties, functions, and / or structures to the features in one or more of Figures 4A to 4B. One or more of the systems in Figures 4A to 4B may be used to perform one or more of the methods described herein (e.g., one or more of the methods in Figures 5A to 5E).

[0094] Figures 3A to 3G and 4A to 4B show various fluid processing system architectures (fluid processing systems 300A to 300G and 400A to 400B) and various controllers according to a particular embodiment. The shown architectures are exemplary, and for example, they highlight the operation of the controllers in the fluid processing system. Any of the controllers shown in Figures 4A to 4B may be provided in any combination in any architectural design of a fluid processing system. For example, a controller that performs an operation such as controller 490 in Figure 4A may be provided in another architecture that does not show that controller (e.g., fluid processing system 300C in Figure 3C), and a controller that performs an operation such as controller 394 that controls the bypass valve in Figure 3B may be provided in an architecture similar to that shown in Figure 3A, and so on. A fluid processing system comprising any controller shown herein (e.g., any controller that adjusts the operation of components of a fluid processing system and / or energy transfer system that include a PX based on sensor data from the system), either alone or in any combination, is within the scope of this disclosure. A controller can be an individual component (for example, each controller can be a separate device), or it can be a combined component (for example, the operation of two or more controllers can be performed by the same device or control system), and so on. A controller can provide control signals in response to various inputs, such as sensor data provided to the controller. A controller can provide control signals to adjust the characteristics of a fluid processing system, for example, to adjust the value of one or more conditions of a fluid processing system so that the value of those conditions satisfies one or more threshold conditions.

[0095] In some embodiments, the devices of the fluid processing systems 300A-300G and 400A-400B shown in Figures 3A-3G and 4A-4B may communicate via wired connections. In some embodiments, the devices of these fluid processing systems may communicate wirelessly. In some embodiments, the devices shown in Figures 4A-4B may communicate via a network. For example, the controllers in Figures 4A-4B may receive sensor data via a network and transmit control signals via a network. In some embodiments, the devices of the fluid processing systems 400A-400B shown in Figures 4A-4B may communicate via one or more wired networks. In some embodiments, the devices of the fluid processing systems 400A-400B shown in Figures 4A-4B may communicate via one or more wireless networks (e.g., personal area network, wireless local area network, etc.). In some embodiments, the devices of the fluid processing systems 400A-400B may communicate via some wired networks and some wireless networks.

[0096] In some embodiments, the controller of the fluid processing systems 400A-400B may be a PID controller. The controller of the fluid processing systems 400A-400B may calculate an error value (e.g., the difference between a target setpoint and a measured value). The controller of the fluid processing systems 400A-400B may apply corrections (e.g., generate control signals) based on the proportional, integral, and derivative terms of the error value. For example, the proportional term may be based on the difference between the setpoint value and the measured value, the integral term may be based on past values ​​of the time-integrated error term, and the derivative term may be based on the future trend of the error term predicted based on the current rate of change of the error term. In some embodiments, the controller of the fluid processing systems 400A-400B may be a computing device. The controller of the fluid processing systems 400A-400B may be implemented as software (e.g., executed by a general-purpose computing device), hardware, or a combination of hardware and software. In some embodiments, the operation of the controller of the fluid processing system 400A-400B may include receiving one or more adjustable settings, parameters, etc. For example, the controller's response (e.g., magnitude of the output signal, value of adjustment command included in the control signal, etc.) may be of variable intensity (e.g., for a given difference between a measured value and a target value of a measurement characteristic, the controller may have a range of possible output values, and one implementation of the output within that range may respond to one or more settings and / or parameters of the controller). In some embodiments, the controller may have an associated lookup table, and for a given input (e.g., difference between a setpoint and a measured value), the controller may generate an output according to that table. In some embodiments, the controller may perform calculations involving adjustable parameters (e.g., user-adjustable parameters, adjustable settings, etc.), and in response to an input, the controller may generate an output based on that input. In some embodiments, the controller's parameters and / or settings may be selected / adjusted by the user.In some embodiments, the parameters and / or settings of the controller may be adjusted, for example, by the controller, the associated computing device, or a computer implementation of the same.

[0097] In some embodiments, the performance of the controller can be tracked (e.g., measured and stored for analysis over time). If the controller causes overshoot (e.g., if it exceeds a threshold such as a percentage difference between an initial value and a target value, or a threshold for the frequency and / or degree of overshoot), or if it causes overshoot (e.g., if a component of the fluid processing system overcompensates in response to receiving a control signal from the controller, or if a measured characteristic value passes the target value before settling within the threshold for the target value), the sensitivity of the controller (e.g., the strength of its response to measured values ​​different from the target characteristic value) may be reduced. For example, the controller may generate a control signal in response to receiving a measured value different from the setpoint (e.g., if the difference between the setpoint and the measured value exceeds a threshold). The controller may later receive a measured value different from the setpoint in the opposite direction (e.g., the control signal may be intended to compensate for a measured value lower than the setpoint, and subsequent measured values ​​may be higher than the setpoint). The responsiveness of the controller (e.g., parameters for calculations that determine the strength of the output for input differences between a setpoint and a measured value, table entries that determine the degree of action indicated in the control signal based on input from a sensor) may be adjusted to reduce the possibility of overshoot in future operation. The adjustment of controller settings may be global, for example, parameters or tables may be updated so that all future control signals are generated in accordance with the update. The adjustment of controller settings may not be applied globally, for example, one or more lookup table values ​​may be adjusted while others remain unchanged (e.g., a lookup table value associated with a range of difference between a setpoint and a measured value may be adjusted, or a lookup table value associated with one or more differences in a range of measured values ​​may be adjusted), parameters may be updated for use in certain situations (e.g., a list of parameters may be applied to different measured values, different setpoint values, different values ​​of the difference between the measured value and the setpoint, etc.), or similar may be done.

[0098] Similarly, if the controller's sensitivity is insufficient (for example, if a characteristic value in the system takes longer than desired to reach a value within the threshold of the target value), the controller's response may be increased. For example, the controller may receive a measurement different from the setpoint (for example, the controller may be configured to receive a pressure measurement from a pressure gauge and may receive a measurement that differs from the setpoint pressure value by at least a threshold amount). The controller may generate a control signal in response to receiving that measurement (for example, the controller may generate a control signal to open a valve to adjust the pressure in the pressure gauge). The controller may then receive a measurement indicating that the pressure has not reached the setpoint (for example, the action taken by the valve in response to the control signal was not sufficient to reduce the difference between the setpoint and the measurement to below the threshold). One or more settings / parameters of the controller may be adjusted to increase the controller's response to inputs (for example, increasing the output signal generated based on an input signal of a given intensity, increasing the degree of the command included in the control signal associated with a given difference between the setpoint and the measurement, etc.).

[0099] In some embodiments, the decision to update the controller's sensitivity and / or response (e.g., updating parameters or settings that define the strength or severity of the output) may be performed by a machine learning model. The machine learning model may be trained with inputs including target characteristic values, measured characteristic values, the controller's response (e.g., control signals), and / or the results of system components operating based on commands received by the controller. Once trained, the machine learning model may be configured to receive measured characteristic values ​​and target values ​​as inputs and produce an output representing the appropriate actions (e.g., control signals) to be taken by one or more components of the fluid processing system. For example, the machine learning model may be provided with historical data as training data. The machine learning model may be provided with one or more historical characteristic values ​​(e.g., one or more setpoint values, and one or more measurements generated before and after the system components perform actions instructed by the controller) as training inputs, associated with characteristics to be corrected in the fluid processing system. The machine learning model may be further provided with historical characteristic values ​​after adjustments have been made to correct the measured characteristic values ​​(e.g., one or more measurements measured after control signals have been generated for one or more components of the system). A machine learning model may be provided with one or more historical control signals (or data representing control signals) as its target output. Once trained, the machine learning model may take current characteristic values ​​(e.g., one or more setpoint values, one or more measurements) as input and generate control signals (or data associated with control signals) as output that are predicted to bring one or more measured characteristic values ​​within a threshold difference of one or more setpoint values.

[0100] Fluid processing systems 300A-300G and 400A-400B may be heat transfer systems. Fluid processing systems 300A-300G and 400A-400B may be refrigeration systems. Fluid processing systems 300A-300G and 400A-400B may be heat pump systems. Fluid processing systems 300A-300G and 400A-400B may be reversible heat pump systems. Reversible heat pump systems may include components not shown in Figures 3A-3G, such as reversal valves (e.g., four-way valves for reversing flow). Reversible heat pump systems can reverse the direction of the flow of cooling fluid in one or more parts of the fluid processing system, for example, the flow through condensers and / or evaporators (e.g., outdoor heat exchange units and / or indoor heat exchange units) may be reversed. A reversible heat pump system does not require the direction of flow to be reversed in one or more parts of the fluid processing system; for example, the flow through a compressor or pump does not need to be reversed. A reversible heat pump system may include additional flow channels, additional valves, etc., which are used when the flow needs to be reversed. Additional components and flow channels associated with a reversible heat pump system are not shown in Figures 3A to 3G, but a reversible heat pump system having such components is within the scope of this disclosure.

[0101] Figure 3A is a schematic diagram of a fluid processing system 300A, comprising a PX310 and a subcooler 315, which is a heat exchanger for exchanging heat between two flows of working fluid, according to several embodiments. System 300A may be configured to control various components of the system based on sensor data received from sensors of the system. System 300A may be configured to determine the opening of one or more valves based at least in part on the operating speed of the PX310. System 300A may be configured to determine the opening of one or more valves based on measurement conditions of System 300A. Control units of the architecture relating to this disclosure will be described in more detail with reference to Figures 4A-4B.

[0102] The PX310 may be a rotary pressure exchanger. In some embodiments, the PX310 is an isobaric or substantially isobaric pressure exchanger. The PX310 may be configured to exchange pressure between a first fluid and a second fluid. The PX310 may be configured to exchange pressure between a high-pressure first fluid (e.g., provided to the PX310 at a high-pressure inlet labeled HP-IN) and a low-pressure second fluid (e.g., provided to the PX310 at a low-pressure inlet, LP-IN). The PX310 may reduce the pressure of the first fluid (e.g., to output from the PX310 at a low-pressure outlet, LP-OUT) and increase the pressure of the second fluid (e.g., to output from the PX310 at a high-pressure outlet, HP-OUT). In some embodiments, the PX310 is coupled to a motor (e.g., the rotation of the rotor of the PX310 is controlled and / or regulated by the motor). In some embodiments, the mass flow rate through PX310 (e.g., mass flow rate of the first fluid, mass flow rate of the second fluid, etc.) may be related to the operating speed of PX310 (e.g., rotational speed of the rotor of a rotary PX). In some embodiments, the pressure of the fluids (e.g., first fluid, second fluid, etc.) in various components of the fluid processing system (e.g., fluid processing systems 300A-300G) may be related to the operating speed of PX310.

[0103] In some embodiments, PX310 is configured to receive a high-pressure first fluid (e.g., HPin fluid 130 in Figures 1A-1B) via a high-pressure inlet. In some embodiments, PX310 is configured to receive a low-pressure second fluid (e.g., LPin fluid 120 in Figures 1A-1B) via a low-pressure inlet. Although there is a reference to “high pressure” and “low pressure,” “high pressure” and “low pressure” can be relative to each other and do not necessarily mean specific pressure values ​​(e.g., the pressure of HPin fluid 130 is higher than the pressure of LPin fluid 120). PX310 can exchange pressure between the first and second fluids. PX310 can provide the first fluid (e.g., LPout fluid 140) via a low-pressure outlet and the second fluid (e.g., HPout fluid 150) via a high-pressure outlet. In some embodiments, a first fluid supplied through a low-pressure outlet is low-pressure, and a second fluid supplied through a high-pressure outlet is high-pressure. PX310 can act as a high-pressure expansion valve, so that, for example, the fluid flowing through PX310 (e.g., from the high-pressure inlet to the low-pressure outlet) can expand. PX310 can transfer pressure from one fluid flow to the other, increasing the pressure in one fluid flow. PX310 can act as both an isentropic (or substantially isentropic) expansion device and a compressor, thereby causing heat transfer and facilitating one or more operations of a refrigeration cycle. The compression process of PX310 can be substantially isenthalpic.

[0104] In some embodiments, the first fluid may be a supercritical refrigerant fluid (e.g., supercritical CO2). In some embodiments, the first fluid may be a liquid refrigerant fluid (e.g., liquid CO2). In some embodiments, the second fluid may be a gaseous refrigerant fluid (e.g., gaseous CO2). In some embodiments, the second fluid may be a two-phase mixture refrigerant fluid (e.g., a gas-liquid mixture of CO2). In some embodiments, the second fluid may be a liquid refrigerant fluid (e.g., liquid CO2).

[0105] In some embodiments, the fluid processing system 300A comprises a main gas cooler 329 (e.g., a condenser), an auxiliary gas cooler 327, an evaporator 318, and a main compressor 322. In some embodiments, the main gas cooler 329 and / or the auxiliary gas cooler 327 may or may not act as condensers, and for example, the fluid processing system may operate at pressures and temperatures in which the fluid may or may not condense within the gas cooler. Any embodiment described herein may include gas coolers that may or may not act as condensers in one or more applications. In some embodiments, for example, above the critical point of the fluid, the thermodynamic distinction between gas and liquid in the fluid disappears, and the fluid (e.g., the fluid in the condenser) may exist in a supercritical state (e.g., both the in-fluid and out-fluid of the condenser may be supercritical, or one of the in-fluid or out-fluid of the condenser may be supercritical, or neither fluid may be supercritical, etc.). In some embodiments, the fluid processing system 300A is a refrigeration system. For example, the evaporator 318 can facilitate the absorption of heat by the system 300A from a heat source (e.g., a refrigerated area, a low-temperature reservoir, etc.) into the refrigerated fluid. This heat can be released to a heat sink (e.g., the environment, a high-temperature reservoir, etc.) via the main gas cooler 329 and / or auxiliary gas cooler 327. In some embodiments, the refrigerated fluid facilitates heat transfer from the environment associated with the evaporator 318 to the environment associated with the main gas cooler 329. The main compressor 322 of the fluid handling system 300A can increase the corresponding pressure of the refrigerated fluid along the flow path between the evaporator 318 and the main gas cooler 329. In some embodiments, the refrigerated fluid is CO2 or another refrigerated fluid. The refrigerated fluid can flow substantially in a cycle (e.g., from the gas cooler 329 to PX310, evaporator 318, main compressor 322, gas cooler 329, etc.).

[0106] In some embodiments, the fluid processing system 300A is a heat pump system. For example, in the main gas cooler 329, heat can be released by the fluid to a target area to be heated (e.g., to heat the interior space of a building). The heat can be absorbed from the environment by the fluid of the fluid processing system 300A in the evaporator 318 in order to transfer it to the environment of the main gas cooler 329. In some embodiments, the fluid processing system 300A may be a reversible heat pump.

[0107] In some embodiments, the main compressor 322 increases the fluid pressure beyond a threshold amount (for example, the main compressor 322 may operate over a pressure difference greater than the threshold amount). For example, the main compressor 322 may increase the fluid pressure by about 100–1200 PSI (about 0.689–8.274 MPa), about 500–1100 PSI (about 3.447–7.584 MPa), about 800–1000 PSI (about 5.516–6.895 MPa), about 900 PSI (about 6.205 MPa), at least 100 PSI (about 0.689 MPa), at least 500 PSI (about 3.447 MPa), any included range, or similar. In some embodiments, the operation of the main compressor 322 may be performed by two or more physical devices, such as multiple compressors, multiple pumps, or similar. The multiple compressors that perform the operation of the main compressor 322 may be arranged in parallel, in series, or in a combination thereof. Any description of the main compressor 322 may be generalized to include multiple devices, for example, by considering the arrangement, specifications, and operating speed of each compressor in the compressor system and calculating the total energy consumed or the total fluid flow rate through the compressor system.

[0108] A motor or other speed control device may be configured to regulate the operation of PX310 (for example, by regulating the motor's operating speed). Regulating the operating speed of PX310 may be performed in response to receiving a control signal from the controller. Control of PX310 may be based on the fluid pressure of the main gas cooler 329. Control of PX310 may be further based on additional indicators such as ambient temperature, fluid temperature, target evaporator temperature, and operating efficiency of the fluid handling system 300A. The controller may generate a control signal aimed at achieving and / or maintaining a target pressure of the main gas cooler 329. The target pressure of the main gas cooler 329 may be modified by the ambient temperature (e.g., heat sink temperature for released heat) to achieve, for example, optimal energy efficiency, heat transfer, refrigeration, etc. For example, increasing the operating speed of PX310 may increase the fluid flow rate through PX310. Increasing the operating speed of PX310 may decrease the fluid pressure of the main gas cooler 329.

[0109] In some embodiments, the target pressure of the main gas cooler 329 may be selected to maximize the heat transfer of the system, maximize the heat transfer between the main gas cooler 329 and the environment, maximize the energy efficiency of the system, maximize the coefficient of performance (COP, e.g., the ratio of heat transferred by the system to the power consumed by the system's pumps / compressors), or similar purposes.

[0110] In some embodiments, a device for adjusting the speed of the PX may act to operate, activate, or accelerate the PX310. For example, a motor may drive the PX310. The motor may draw power from a power source to drive the PX310. In some embodiments, the motor may act like a generator. For example, the PX310 may be driven by the fluid of the fluid handling system 300A (e.g., driven by a pressure difference in the fluid, or driven by one or more pumps and / or compressors in the system). The motor may provide additional resistance to the operation of the PX310 (e.g., resistance to the rotation of the rotor of a rotary PX), which may reduce the operating speed of the PX310. The motor may generate power (e.g., convert the rotational energy of the PX310 into electrical energy).

[0111] In some embodiments, the evaporator 318 is a heat exchanger for providing corresponding thermal energy from the environment (e.g., the medium of the environment) to the fluid of the fluid processing system 300A. For example, the evaporator 318 may receive heat (e.g., thermal energy) from the air of the environment and provide that heat to the fluid. In some embodiments, the environment is a refrigerated space such as the inside of a refrigerator or freezer, an indoor space (e.g., the interior of a building or vehicle), or any other space that should be kept in a cooled state. For example, the environment may be the inside of a refrigerated or frozen section in a supermarket or warehouse. In some embodiments, the evaporator 318 may absorb heat from the environment to be provided to the main gas cooler 329, and for example, heating the area surrounding the main gas cooler 329 may be a target result of the fluid processing system 300A.

[0112] In some embodiments, the fluid handling system 300A may include a secondary evaporator. The fluid handling system 300A may further include secondary components corresponding to any component of the evaporator 318, such as input and output lines, valves, gauges, controllers, etc. In some embodiments, the secondary evaporator receives a portion of the fluid flow directed to the evaporator 318. For example, the secondary evaporator may receive a portion of the flow from the low-pressure outlet of PX310, for example, via a receiver 313. In some embodiments, the secondary evaporator may target a different temperature than the evaporator 318 (for example, the evaporator may be associated with a refrigeration system having different target temperatures, such as a refrigerator and a freezer). In some embodiments, the two evaporators (e.g., evaporator 318 and the secondary evaporator) may operate at different fluid pressures. The fluid output by one or more secondary evaporators may be directed to one or more components (e.g., valves, expansion valves, pumps, compressors, etc.) for changing the pressure of the output fluid so that the pressure is substantially similar when the output flows of the two evaporators are combined.

[0113] In some embodiments, the main gas cooler 329 and / or auxiliary gas cooler 329 are heat exchangers for transferring thermal energy from the fluid of the fluid processing system 300A to the surrounding environment. For example, the main gas cooler 329 may release heat (e.g., thermal energy) to the air in the external (e.g., outdoor) environment. In some embodiments, the main gas cooler 329 exchanges thermal energy (e.g., releases heat) to the external space. For example, the main gas cooler 329 may be located outside a supermarket or warehouse building (e.g., on the roof of the building) and release heat to the external environment. In other examples, the main gas cooler 329 may be located underground to facilitate the transfer of thermal energy between the fluid and the ground. In some embodiments, the main gas cooler 329 releases heat to the internal space while the evaporator 318 absorbs heat from the external space (e.g., in a heat pump configuration that provides heating to the internal space). The thermal energy released from the main gas cooler 329 can be used to heat a closed (e.g., substantially closed) space.

[0114] In some embodiments, the fluid handling system 300A may include an auxiliary gas cooler 327. In some embodiments, the auxiliary condenser receives a second fluid from the high-pressure outlet of PX310, and the main gas cooler 329 receives output from the main compressor 322. In some embodiments, the auxiliary gas cooler 327 is a heat exchanger that exchanges thermal energy (e.g., heat) between the second fluid and the environmental medium. In some embodiments, the auxiliary gas cooler 327 exchanges thermal energy between the second fluid and the same environment in which the main gas cooler 329 exchanges thermal energy, such as the exterior space of a building. In other embodiments, the auxiliary condenser exchanges thermal energy between the second fluid and an environment different from the environment in which the main gas cooler 329 exchanges thermal energy. In some embodiments, the auxiliary gas cooler 327 operates at a different temperature than the main gas cooler 329. In some embodiments, the auxiliary gas cooler 327 may operate at a different pressure than the main gas cooler 329. For example, the auxiliary gas cooler 327 may operate at a lower pressure than the main gas cooler 329. The auxiliary gas cooler 327 may operate at a target pressure different from the target pressure of the main gas cooler 329, at a target pressure difference compared to the main gas cooler 329, or in a similar manner. The auxiliary gas cooler 327 may operate at a pressure about 20 PSI (about 0.138 MPa) lower than the main gas cooler 329. The auxiliary gas cooler 327 may operate at a pressure 15 to 30 PSI (about 0.103 to 0.207 MPa) lower than the pressure of the main gas cooler 329. In some embodiments, the main gas cooler and the auxiliary gas cooler may be provided by the same device, for example, by a gas cooler having multiple fluid channels for accommodating multiple fluid flows. In some embodiments, the main gas cooler and / or the auxiliary gas cooler may be associated with a device for regulating the heat exchanged with the fluid in the gas cooler. For example, the main gas cooler 329 and / or auxiliary gas cooler 327 may be equipped with or associated with a fan, for example, to increase the airflow near the gas cooler or to increase heat transfer from the gas cooler.

[0115] The fluid processing system 300A further comprises a flash gas valve 320. The fluid processing system 300A may also comprise a flash gas valve 320 for regulating the flow of gas in a flash gas bypass channel. In some embodiments, the flash gas valve 320 is a bypass valve that regulates the flow of gas from the gas outlet of the receiver 313 (e.g., a flash tank) to be combined with the output of the evaporator 318. In some embodiments, the gas flow from the receiver 313 flows along the flash gas bypass channel to bypass the evaporator 318. In some embodiments, the flash gas channel is located between the receiver 313 and a position downstream of the outlet of the evaporator 318. The gas flowing along the flash gas bypass channel may be combined with the output of the evaporator 318. The flash gas valve 320 may expand the gas collected in the receiver 313 as it flows toward the main compressor 322 (e.g., reduce its pressure). In some embodiments, the flash gas valve 320 may be an adjustable valve. In some embodiments, the flash gas valve 320 is operated by a controller based on sensor data.

[0116] The fluid processing system 300A may include an expansion valve 316. In some embodiments, the expansion valve 316 is positioned along the flow path between the receiver 313 and the evaporator 318, for example, coupled between the receiver 313 and the evaporator 318. The expansion valve 316 may be an adjustable valve (e.g., an electronic expansion valve, a thermostatic expansion valve, a ball valve, a gate valve, a poppet valve, etc.). The expansion valve 316 may be controllable by a user (e.g., a technician, operator, engineer, etc.) or a controller. In some embodiments, the expansion valve 316 is actuated by a controller based on sensor data (e.g., pressure sensor data, flow sensor data, temperature sensor data, etc.). In some embodiments, the expansion valve 316 is a thermal expansion valve. The expansion valve 316 may be actuated (e.g., open and / or close) based on temperature data associated with the evaporator 318 (e.g., the temperature of the liquid in the evaporator, the temperature of the gas in the evaporator, the temperature of the fluid entering the evaporator, the temperature of the fluid leaving the evaporator, etc.). For example, a pressure-sensitive component of the expansion valve 316 (e.g., a sensing bulb) may increase or decrease the pressure on the diaphragm of the expansion valve 316, thereby opening or closing a poppet valve coupled to the diaphragm, and thus increasing or decreasing the fluid flow to the evaporator 318 and increasing or decreasing the fluid expansion. The pressure-sensitive component of the expansion valve may be positioned close to the downstream end of the evaporator 318 (e.g., close to the outlet of the evaporator 318, outside the evaporator 318, inside the evaporator 318, or similar position) and may be in fluid communication with the diaphragm via a fluid line (e.g., a sensing capillary). In some embodiments, the expansion valve 316 is controlled and actuated entirely on the basis of electronic commands (e.g., from a controller).

[0117] The fluid processing system 300A includes a subcooler 315. The subcooler 315 may be a heat exchanger configured to exchange heat between portions of the fluid output by the main gas cooler 329. The subcooler 315 may include a main fluid channel or primary fluid channel coupled to the main cooling flow of the working fluid. The subcooler 315 may include a secondary channel or cooling fluid channel coupled to the fluid flow to absorb heat from the main flow within the subcooler 315. A subcool valve 312 may be a control valve that can be opened to a target opening, for example, to allow a target flow through the secondary channel of the subcooler 315. The subcool valve 312 may act as an expansion valve, for example, the temperature of the fluid supplied to the subcool valve 312 may be higher than the temperature of the fluid supplied by the subcool valve 312 to the secondary channel of the subcooler 315. PX310 can enable this additional cooling step without efficiency losses due to the additional pumping power required to increase the pressure of the secondary cooling fluid by providing fluid compression by exchanging fluid and pressure from the main channel of subcooler 315. The main body can be supplied to the high-pressure inlet of PX310 by subcooler 315. The secondary cooling fluid can be supplied to the low-pressure inlet of PX310 by subcooler 315.

[0118] The fluid processing system 300A further includes an auxiliary valve 369. The auxiliary valve 369 may be a control valve and, for example, can allow a target fluid flow through the auxiliary valve 369. The auxiliary valve 369 may be an auxiliary control valve. The auxiliary valve 369 may be coupled between the high-pressure outlet of PX310 and the inlet of receiver 313, and may be coupled either before or after the auxiliary gas cooler 327 (with respect to the fluid flow path).

[0119] This specification includes references to “first fluid” and “second fluid.” In some embodiments, the first fluid and the second fluid are the same type of fluid (for example, a refrigeration fluid flowing within a fluid processing system). “First fluid” may refer to the fluid flowing through PX310 from the high-pressure inlet to the low-pressure outlet, and / or the fluid flowing to or from the high-pressure inlet and / or low-pressure outlet of PX310. “Second fluid” may refer to the fluid flowing through PX310 from the low-pressure inlet to the high-pressure outlet, and / or the fluid flowing to or from the low-pressure inlet and / or high-pressure outlet of PX310.

[0120] In some embodiments, system 300A is a heat pump system capable of heating and cooling an environment (e.g., an indoor space). In some examples, one of the main gas cooler 329 or the evaporator 318 is an outdoor unit, and the other of the main gas cooler 329 or the evaporator 318 is an indoor unit. In some examples, the main gas cooler 329 is an outdoor unit (e.g., a condensing unit), and the evaporator 318 is an indoor unit (e.g., one located in a refrigerated space for storing food, pharmaceuticals, sensitive chemicals or materials, etc.). The fluid flow through the main gas cooler 329 and the evaporator 318 may be reversible (e.g., via a reversal valve coupled to the main compressor 322). The reversal valve may allow the fluid flow leaving the main compressor 322 to be switched between being directed towards the inlet of the main gas cooler 329 (e.g., an outdoor unit) and being directed towards the inlet of the evaporator 318 (e.g., an indoor unit). In some embodiments, one or more valves and piping may be used to direct the fluid flow through all components (e.g., one or more of the PX310, main compressor 322, and / or similar) in the same direction, while reversing the fluid flow through the main gas cooler 329 and evaporator 318.

[0121] In some embodiments, the systems described herein are heat pump systems capable of heating an environment (e.g., an indoor space). In such a heat pump system, the main gas cooler 329 is located indoors, and the evaporator 318 is located outdoors. In the heat pump system, the evaporator absorbs heat from the surrounding environment and can vaporize the two-phase refrigerant fluid flowing through the evaporator before sending it to the compressor inlet. In some embodiments, a reversing valve may be used to switch from a refrigeration system or an air cooling system to a heat pump system, thereby allowing the fluid flow leaving the main compressor 322 to be switched between being directed to the inlet of an outdoor unit and being directed to the inlet of an indoor unit. In some embodiments, one or more valves and piping may be used to direct the fluid flow through all components (e.g., PX310, main compressor 322, and / or one or more of the same) in the same direction while switching the fluid flow from the indoor unit to the outdoor unit.

[0122] In some embodiments, the systems described herein (e.g., one or more systems in Figures 3A to 3G) may be used to heat an internal space and / or a closed space, to cool an internal space and / or a closed space, and / or to selectively (e.g., reversibly) heat and cool a space.

[0123] In some embodiments, one or more additional components that can bypass or partially bypass PX310 may be provided in the fluid processing system, such as the fluid processing system 300A. For example, one or more valves may enable a connection between the output of the primary channel of the subcooler 315 and the inlet of the receiver 313 that bypasses PX310. In some situations (e.g., in a particular set of fluid and / or ambient conditions), PX310 may not be utilized, or may be utilized only partially. For example, under certain conditions, the improvement in efficiency of the fluid processing system provided by PX310 may not meet a target threshold, and the use of PX310 may be reduced until a change in conditions occurs. One or more high-pressure valves, expansion valves, connections to a parent rack, control valves, or similar may determine the portion of the fluid supplied to PX in any of the systems described herein. For example, a high-pressure control valve may be coupled between the primary outlet of the subcooler 315 and the inlet of the receiver 313. This high-pressure control valve may be used to determine which portion of the fluid is output by the subcooler 315 and supplied to the high-pressure inlet of PX310, and which portion is supplied to the receiver 313 without being supplied to PX310. The fluid may be expanded in such a high-pressure valve, cooled by such a high-pressure valve, and so on.

[0124] Additional components may include an optional mixer 301. Any system described herein may include one or more mixers for incorporating fluid components that may have different temperatures, densities, phases, etc. In the fluid processing system 300A, a portion of the fluid cooled by the bypass valve 312 may be supplied to the mixer 301 along with at least a portion of the fluid output by the secondary or cooling channel of the subcooler 315. This may reduce the temperature or overheating of the fluid supplied to the low-pressure inlet of the PX. This may regulate the phase of the fluid supplied to the low-pressure inlet of the PX 310. The fluid may also be supplied to the mixer 301 by one or more control valves, which determine, for example, the portion of the fluid output by the bypass valve 312 and supplied to the mixer 301, the portion of the fluid output by the cooling channel of the subcooler 315 and supplied to the mixer 301, etc. The control of these valves may be based on fluid temperature measurements (e.g., near the low-pressure inlet of the PX 310), fluid pressure measurements, fluid phase, fluid density, or other conditions.

[0125] Figure 3B is a schematic diagram of a fluid processing system 300B comprising a pressure exchanger (PX310) having an auxiliary receiver 311, according to several embodiments. In some embodiments, features having reference numbers corresponding to reference numbers in other figures have the same characteristics, structure, and / or functions as those described in the other figures. In some embodiments, optional components described in relation to Figure 3A (e.g., a secondary evaporator, a compressor system replacing the main compressor 322, etc.) may be optional components of the fluid processing system 300B. In some examples, the features of the fluid processing system 300B have the same characteristics, structure, and / or functions as the fluid processing system 300A in Figure 3A.

[0126] The fluid processing system 300B may be configured to provide heat transfer (e.g., refrigeration) through the circulation of a working fluid (e.g., CO2). The fluid processing system 300B may be configured to perform operations that adjust one or more components of the fluid processing system 300B based on sensor data generated by sensors of the fluid processing system 300B. In some embodiments, the fluid processing system 300B may perform operations to achieve and / or maintain a target temperature of a target environment, such as the environment near the evaporator 318 and / or the second evaporator 319. The fluid processing system 300B may achieve a target temperature near the evaporator 318 (e.g., food refrigeration temperature, first target refrigeration temperature) and a second target temperature near the second evaporator 319 (e.g., freezer temperature, second target refrigeration temperature).

[0127] In some embodiments, the fluid processing system 300B may receive data indicating conditions for the fluid processing system 300B, which may include working fluid conditions, ambient conditions, conditions near the evaporator and / or gas cooler, etc. Fluid conditions may include temperature, pressure, mass flow rate, density, liquid level in the receiver, etc. The fluid processing system 300B may receive temperature data and / or other condition data from one or more sensors indicating the fluid conditions for the fluid processing system 300B. Based on the temperature data, the fluid processing system 300B may actuate one or more valves (e.g., bypass high-pressure valve 348). The fluid processing system 300B may adjust one or more components to achieve and / or maintain a target fluid temperature, a target fluid subcooling degree, etc.

[0128] The fluid handling system 300B may include a bypass high-pressure valve 348. The bypass high-pressure valve 348 may be an expansion valve or a flow control valve. In some embodiments, the bypass high-pressure valve 348 selectively adjusts the flow of fluid from the outlet of the main gas cooler 329 (e.g., fluid discharged by the main gas cooler 329) to an auxiliary receiver 311, for example, in parallel with PX310. In some embodiments, the bypass high-pressure valve 348 may be operated to selectively adjust the fluid flow. The bypass high-pressure valve 348 may selectively provide a portion of the fluid output by the main gas cooler 329 to the auxiliary receiver 311. For example, the bypass high-pressure valve 348 may be operated to open further to allow more fluid to flow from the main gas cooler 329 to the auxiliary receiver 311, or the bypass high-pressure valve 348 may be operated to close further to allow less fluid to flow from the main gas cooler 329 to the auxiliary receiver 311. The fluid may expand as it flows through the bypass high-pressure valve 348, which causes a decrease in the fluid's pressure and / or temperature.

[0129] In some embodiments, the main gas cooler 329 may function as a condenser. In some embodiments, the fluid handling system may operate at pressures and temperatures in which the fluid may or may not condense within the main gas cooler 329. Any embodiment described herein may include a condenser that can function as a gas cooler in one or more applications.

[0130] The fluid handling system 300B may include a receiver 313 (e.g., a flash tank). In some embodiments, the receiver 313 is a receiver configured to receive a flow of fluid (e.g., a first fluid) output from the low-pressure outlet of the PX310. The receiver 313 may form a chamber for collecting the first fluid from the first outlet of the PX310. The receiver 313 may receive the first fluid in a two-phase state (e.g., liquid and gas), a transcritical fluid, a supercritical fluid, a subcritical fluid, and / or a combination thereof. The receiver 313 may further receive the fluid flow from an auxiliary receiver 311, for example, via a low-pressure control valve. In some embodiments, the receiver 313 (e.g., a flash tank) is a tank constructed of welded sheet metal. The receiver 313 may include one or more flash tank inlets for receiving fluid and one or more flash tank outlets (e.g., a gas outlet and a liquid outlet) for discharging fluid. The first fluid (low pressure) can separate into gas and liquid within the receiver 313 (for example, as shown by the liquid level in Figure 3B). The liquid of the first fluid may settle at the bottom of the receiver 313, while the gas of the first fluid may rise to the top of the receiver 313. The liquid may flow from the receiver 313 toward the evaporator 318 (for example, via the expansion valve 316). The liquid may also flow from the receiver 313 toward the second evaporator 319, for example, via the secondary expansion valve 317. The chamber of the receiver 313 can be maintained at a set pressure. The pressure can be set by the user (e.g., operator, technician, engineer, etc.) and / or a controller. In some embodiments, the pressure in the receiver 313 is controlled by one or more valves (e.g., expansion valve 316, flash gas valve 320, pressure regulating valve, safety valve, etc.). In some embodiments, the receiver 313 includes at least one pressure sensor (e.g., pressure transducer). In some embodiments, the liquid level in the receiver 313 may be monitored (for example, to prevent the liquid from being routed through the flash gas valve 320).In some embodiments, a pressure difference between the receiver 313 and the auxiliary receiver 311 may be maintained, for example, a target pressure difference such as a difference of 50 PSI (approximately 0.345 MPa) may be maintained between the auxiliary receiver 311 and the receiver 313.

[0131] The fluid processing system 300B may include an expansion valve 316. The fluid processing system 300B may also include a secondary expansion valve 317. In some embodiments, the expansion valve 316 is positioned along the flow path between the receiver 313 and the evaporator 318, for example, coupled between the receiver 313 and the evaporator 318. The secondary expansion valve 317 may be coupled between the receiver 313 and a second evaporator 319. The expansion valve 316 may be an adjustable valve (e.g., an electronic expansion valve, a thermostatic expansion valve, a ball valve, a gate valve, a poppet valve, etc.). The expansion valve 316 may be controllable by a user (e.g., a technician, operator, engineer, etc.) or a controller. In some embodiments, the expansion valve 316 is actuated by a controller based on sensor data (e.g., pressure sensor data, flow sensor data, temperature sensor data, etc.). In some embodiments, the expansion valve 316 is a thermal expansion valve. The expansion valve 316 can be operated (e.g., opened and / or closed) based on temperature data associated with the evaporator 318 (e.g., the temperature of the liquid in the evaporator, the temperature of the gas in the evaporator, the temperature of the fluid entering the evaporator, the temperature of the fluid leaving the evaporator, etc.). For example, a pressure-sensitive component of the expansion valve 316 (e.g., a sensing tube) may increase or decrease the pressure on the diaphragm of the expansion valve 316, thereby opening or closing a poppet valve coupled to the diaphragm, and thus increasing or decreasing the fluid flow to the evaporator 318 and increasing or decreasing the expansion of the fluid. The pressure-sensitive component of the expansion valve can be positioned close to the downstream end of the evaporator 318 (e.g., close to the outlet of the evaporator 318, outside the evaporator 318, inside the evaporator 318, or similar position) and can be in fluid communication with the diaphragm via a fluid line (e.g., a sensing capillary). In some embodiments, the expansion valve 316 is controlled and operated entirely on the basis of electronic commands. The operation and control of the secondary expansion valve 317 may be similar, for example, with reference to the fluid conditions of the second evaporator 319.

[0132] The fluid processing system 300B may include a flash gas valve 320 to regulate the flow of gas in a flash gas bypass channel. In some embodiments, the flash gas valve 320 is a bypass valve that regulates the flow of gas from the gas outlet of the receiver 313 to be combined with the output of the evaporator 318. In some embodiments, the gas flow from the receiver 313 flows along the flash gas bypass channel to bypass the evaporator 318. In some embodiments, the flash gas channel is located between the receiver 313 and a position downstream of the outlet of the evaporator 318. The gas flowing along the flash gas bypass channel may be combined with the output of the evaporator 318. The flash gas valve 320 may expand the gas collected in the receiver 313 as it flows toward the main compressor 322 (e.g., reduce its pressure). In some embodiments, the flash gas valve 320 may be an adjustable valve. In some embodiments, the flash gas valve 320 is actuated by a controller based on sensor data.

[0133] In some embodiments, the fluid handling system 300B further comprises an auxiliary receiver 311. The auxiliary receiver 311 may be maintained at a higher pressure than the receiver 313. In some embodiments, the auxiliary receiver 311 may be maintained at a pressure higher than the receiver 313 by a target pressure difference, for example, a difference of 50 PSI (approximately 0.345 MPa), a difference between 40 and 60 PSI (approximately 0.276 and 0.414 MPa), a difference between 20 and 100 PSI (approximately 0.138 and 0.689 MPa), any sub-range, or any other target pressure difference between the auxiliary receiver 311 and the receiver 313. The auxiliary receiver 311 may be maintained at a higher pressure than the receiver 313 in order to drive the fluid flow through a portion of the fluid handling system 300B. For example, the pressure difference may be maintained between the low-pressure outlet and the low-pressure inlet of the PX, for example, in order to drive the fluid flow to the low-pressure inlet of the PX. Maintaining a pressure difference between receiver 313 and auxiliary receiver 311 can enable fluid flow through PX.

[0134] In some embodiments, the pressure in the auxiliary receiver 311 may be maintained to achieve a target flow rate through the PX. For example, the pressure difference between the receiver 313 and the auxiliary receiver 311 may be maintained to maintain a target flow rate to the low-pressure inlet of the PX, a target flow rate from the high-pressure outlet, or a target flow rate from the low-pressure outlet. The target flow rate may be based further on other conditions of the fluid processing system 300B, such as a target efficiency, a target operating speed of the PX, one or more fluid properties of the working fluid of the fluid processing system 300B, or other properties of the fluid processing system 300B. The flow rate may be estimated by various properties of the fluid processing system 300B (e.g., fluid conductance estimates based on temperature and pressure measurements, or similar). The flow rate may be measured using, for example, a mass flow meter, a density measurement (e.g., by a Coriolis flow meter), or similar.

[0135] In some embodiments, the low-pressure outlet of PX310 may be directly connected to a receiver 313 and maintained at the same pressure as the receiver 313, for example. The low-pressure inlet of PX310 may be directly connected to an auxiliary receiver 311 and maintained at the same pressure as the auxiliary receiver 311, for example. The pressure difference between the low-pressure inlet and the low-pressure outlet of PX310 can drive the flow through PX310. The auxiliary receiver 311 may enable the driving of the low-pressure flow in PX310 due to this difference, eliminating the need for low-pressure lift devices such as a low-pressure booster to drive fluid to the low-pressure inlet of PX310.

[0136] The fluid handling system 300B includes a bypass high-pressure valve 348. The bypass high-pressure valve 348 may optionally be provided in a fluid handling system having two receivers. The bypass high-pressure valve 348 may be configured to provide a portion of the fluid output by the main gas cooler 329 to the auxiliary receiver 311. The bypass high-pressure valve 348 may be configured to maintain or achieve a target pressure (or pressure range) in the auxiliary receiver 311. For example, the bypass high-pressure valve 348 may be configured to allow more fluid to flow to the auxiliary receiver 311 when a sensor determines that the pressure in the auxiliary receiver 311 has fallen below a threshold. The bypass high-pressure valve 348 may be controlled to achieve a target pressure condition in the auxiliary receiver 311.

[0137] The fluid handling system 300B includes a first low-pressure control valve 386 and a second low-pressure control valve 387. The first low-pressure control valve 386 may be configured to supply fluid from the auxiliary receiver 311 to the receiver 313. The second low-pressure control valve 387 may be configured to supply fluid from the auxiliary receiver 311 to the low-pressure inlet of PX310. In some embodiments, the first low-pressure control valve 386 may be an on / off valve.

[0138] In some embodiments, the first low-pressure control valve 386 may be used to maintain a target pressure difference between the receiver 313 and the auxiliary receiver 311. The auxiliary receiver 311 may be maintained at a higher pressure than the receiver 313. The first low-pressure control valve 386 may be opened to reduce the pressure difference between the auxiliary receiver 311 and the receiver 313.

[0139] In some embodiments, the first low-pressure control valve 386 may be used to maintain a target level of liquid in the auxiliary receiver 311. If the liquid level detected in the auxiliary receiver 311 exceeds a target threshold (e.g., a target portion of the capacity of the auxiliary receiver 311), the first low-pressure control valve 386 may be opened to allow fluid flow to the receiver 313. If the liquid level detected in the auxiliary receiver 311 falls below the target threshold, the first low-pressure control valve 386 may be closed to reduce flow from the auxiliary receiver 311.

[0140] The fluid handling system 300B includes a second low-pressure control valve 387. The second low-pressure control valve 387 may be configured to supply fluid from the auxiliary receiver 311 to the low-pressure inlet of PX310. The second low-pressure control valve 387 may be used to control the travel distance of the low-pressure inlet of PX310. The second low-pressure control valve 387 may be operated to achieve and / or maintain a target travel distance of the low-pressure inlet of PX310, for example, 110% of the travel distance.

[0141] In some embodiments, a second low-pressure control valve 387 may be located between the low-pressure outlet of PX310 and the receiver 313. In some embodiments, the valve may be located in both positions, for example, between the auxiliary receiver 311 and the low-pressure inlet of PX310, and between the low-pressure outlet of PX310 and the receiver 313. In some embodiments, by placing the control valve between the low-pressure outlet of PX310 and the receiver 313, it may be possible to control the fluid pressure at the low-pressure inlet of PX310. By placing the control valve between the low-pressure outlet of PX310 and the receiver 313, it may be possible to control the pressure at the low-pressure inlet of PX310 independently of the pressure at the receiver 313. An increase in fluid density at the low-pressure inlet of PX310 may increase the mass boost ratio, for example, the maximum mass flow rate that can be compressed through PX310. In some embodiments, some components of the fluid handling system 300B may be an existing system (e.g., a parent rack) to which the PX system is added. Controlling the components of the parent rack may be difficult, inconvenient, or impossible during the installation of the PX system. Such valves may allow control of the fluid density supplied to the PX without adjusting the control unit of the parent rack.

[0142] Figure 3C is a schematic diagram of a fluid processing system 300C comprising a subcooler 315 and an auxiliary receiver 311 according to several embodiments. Features having reference numbers corresponding to reference numbers in other figures may have the same characteristics, structure, and / or functions as those described in other figures. In some embodiments, optional components described in relation to Figures 3A to 3B may be optional components of the fluid processing system 300C. Features of the fluid processing system 300B may have the same characteristics, structure, and / or functions as those of the fluid processing systems 300A to 300B.

[0143] The fluid processing system 300C may be configured to provide heat transfer (e.g., refrigeration) through the circulation of a working fluid (e.g., CO2 in one or more phases, such as a liquid, gas, or supercritical fluid). The fluid processing system 300C may be configured to perform operations that adjust one or more components of the fluid processing system 300C based on sensor data generated by sensors associated with the fluid processing system 300C. The fluid processing system 300C may perform operations to achieve and / or maintain a target temperature in one or more environments, such as the interior of a building or a refrigerated case in a grocery store. The fluid processing system 300C may perform operations to achieve and / or maintain target conditions of the fluid processing system, such as fluid temperature, pressure, density, liquid level, or the like at various locations of the fluid processing system 300C. The fluid processing system 300C may adjust one or more components to achieve target conditions by acting valves, adjusting the motor of PX310, adjusting fan speed, adjusting compressor speed, or the like.

[0144] The fluid handling system 300C is equipped with a bypass high-pressure valve 348. The bypass high-pressure valve 348 can at least partially determine the flow of working fluid to the auxiliary receiver 311. The bypass high-pressure valve 348 can selectively supply a portion of the fluid output by the main gas cooler 329 to the auxiliary receiver 311.

[0145] In some embodiments, the main gas cooler 329 may function as a condenser. In some embodiments, the fluid handling system may operate at pressures and temperatures in which the fluid may or may not condense within the main gas cooler 329. Any embodiment described herein may include a condenser that can function as a gas cooler in one or more applications.

[0146] The fluid handling system 300C further comprises a receiver 313. The receiver 313 can receive fluid from the low-pressure outlet of the PX 310 and from the auxiliary receiver 311. The receiver 313 can supply fluid to the evaporator 318 and / or to the main compressor 322 via the flash gas valve 320 in order to absorb heat from the environment near the evaporator 318. The auxiliary receiver 311 and the receiver 313 can enable phase separation of the working fluid of the fluid handling system 300C.

[0147] Components such as the first low-pressure control valve 386, the second low-pressure control valve 387, the auxiliary valve 369, and the bypass high-pressure valve 348, as well as the operation of these components, may share one or more features with the corresponding components in Figure 3B. For example, the first low-pressure control valve 386 may be controlled based on the pressure of the auxiliary receiver 311, the pressure of the receiver 313, the pressure difference between the receivers, the liquid level of the auxiliary receiver 311, etc. The second low-pressure control valve 387 may be controlled based on the low-pressure inlet travel distance. The control of the auxiliary valve 369 may be based on the high-pressure outlet travel distance. The control of the bypass high-pressure valve 348 may be based on the pressure of the auxiliary receiver. In some embodiments, instead of or in addition to the low-pressure control valve 387, a low-pressure valve may be provided between the low-pressure outlet of PX310 and the receiver 313.

[0148] The fluid processing system 300C further includes a subcooler 315. The subcooler 315 may receive a portion of the fluid into a secondary channel or cooling fluid channel to exchange heat with the fluid output by the main gas cooler 329. The secondary channel or cooling fluid channel of the subcooler 315 may receive fluid from an auxiliary gas cooler 327, which may receive fluid from the high-pressure outlet of PX310. In some embodiments, such as the fluid processing system 300C lacking the subcool valve 312 in Figure 3A, the subcooling may not be controlled, and there may be no control signals associated with monitoring and / or regulating the subcooling performed by the subcooler 315, for example.

[0149] Further components of the fluid processing system 300C, such as the PX310, main compressor 322, and expansion valve 316, may perform functions corresponding to those functions described in relation to the fluid processing systems 300A to 300B shown in Figures 3A to 3B.

[0150] Figure 3D is a schematic diagram of a fluid processing system 300D comprising a PX310 according to several embodiments. In some embodiments, the fluid processing system 300D is a boosterless PX architecture in which a low-pressure (LP) out (LPout) fluid flows into an MT (medium temperature) inlet (e.g., the outlet of the evaporator 318).

[0151] The flow can branch after the main gas cooler 329 to produce two flows. The first flow can proceed to the high-pressure (HP)-in (HPin) fluid in PX310, which expands to a lower pressure to become a low-temperature gas-liquid two-phase mixture in LPout of PX310. The LPout flow proceeds through the heat exchanger 370 (HX1), absorbing heat from the second flow (from the flow branching point from the main gas cooler 329) and converting substantially all of the liquid into gas. The low-pressure gas flow then passes through the LP valve 364, further reducing its pressure to substantially the same as the evaporator pressure, and proceeds to the inlet of the main compressor 322 (e.g., the MT compressor inlet of the main compressor 322).

[0152] The second flow cooled in heat exchanger 370 (HX1) can expand to low pressure through the auxiliary expansion valve 375, becoming a low-temperature gas-liquid two-phase mixture. This can further release heat to the outlet flow of evaporator 318 (e.g., a medium-temperature (MT) evaporator) in heat exchanger 372 (HX2), reducing the gas mass fraction and increasing the liquid mass fraction. The two-phase flow, with reduced flash gas, can then proceed to receiver 313 (e.g., a flash tank).

[0153] Flash gas from receiver 313 (e.g., a flash tank) can be introduced through the LPin fluid (LPin) port of PX310. The LPout pressure can be lower than the pressure of receiver 313 discharged to the main compressor 322 at this time (e.g., down to the MT compressor inlet pressure), so the differential pressure between the LPin and LPout ports of PX drives the flow through the LPin port of PX310.

[0154] The LPin flow can be compressed to a high pressure by PX310 and exit through the HPout fluid (HPout) port. The output of the HPout of PX310 can proceed to the auxiliary gas cooler 327, where it can become cooler by releasing heat. The fluid exiting the auxiliary gas cooler 327 can be depressurized across the auxiliary valve 369 and become a low-temperature gas-liquid two-phase mixture, which in the heat exchanger 374 (HX3) further releases heat to the cooler fluid outlet flow from the second evaporator 319 (e.g., a low-temperature (LT) evaporator). This reduces the gaseous mass fraction and increases the liquid mass fraction. This results in a two-phase flow with reduced flash gas, which then proceeds to the receiver 313 (e.g., a flash tank).

[0155] The heat exchanger 372 (HX2) can provide superheated fluid to the outlet of the evaporator 318 (e.g., the MT evaporator outlet), thereby increasing the pressure in the evaporator 318 (e.g., the MT evaporator pressure) while still meeting the inlet superheating requirements of the main compressor 322 (e.g., the MT compressor inlet superheating requirements). This increased pressure in the evaporator 318 (e.g., increased MT evaporator pressure) can reduce the energy consumption of the main compressor 322 (e.g., the energy consumption of the MT compressor) for the same amount of heat absorption, thereby further improving the energy efficiency of the fluid handling system 300D.

[0156] The heat exchanger 374 (HX3) can provide superheated fluid to the outlet of the second evaporator 319 (e.g., the LT evaporator outlet), thereby increasing the pressure in the evaporator 319 (e.g., the LT evaporator pressure) while still satisfying the inlet superheating requirement of the compressor 323 (e.g., the LT compressor). This increased pressure in the second evaporator 319 (e.g., increased LT evaporator pressure) can reduce the energy consumption of the compressor 323 (e.g., the energy consumption of the LT compressor) for the same amount of heat absorption, thereby further improving the energy efficiency of the fluid handling system 300D.

[0157] The three-way valve may be located after the evaporator 318 (e.g., the MT evaporator) and, if necessary, can be bypassed so that at least a portion of the flow from the evaporator 318 does not pass through the heat exchanger 372, thereby facilitating control of inlet overheating of the main compressor 322 (e.g., MT compressor inlet overheating).

[0158] The three-way valve may be located after the second evaporator 319 (e.g., the LT evaporator) and, if necessary, can bypass at least a portion of the flow from the second evaporator 319 so that it does not pass through the heat exchanger 374, thereby facilitating control of compressor 323 inlet overheating (e.g., LT compressor inlet overheating).

[0159] Figure 3E is a schematic diagram of a fluid processing system 300E comprising a PX310 according to several embodiments. In some embodiments, the fluid processing system 300E is a boosterless subcooled PX architecture having LPin cooling using the outlet flow from the evaporator 318 (e.g., MT evaporator outlet flow).

[0160] The outlet flow from the main gas cooler 329 is split into two flows. The first flow is subcooled in the subcooler 315 (HX1) and then proceeds to the HPin of PX310. The second flow passes through the subcooling valve 312 (subcooling high pressure valve) to reduce pressure and become a low-temperature gas-liquid two-phase mixture, which then proceeds through the subcooler 315 (HX1) and exchanges heat with the first flow. Because the second flow contains a low-temperature liquid (for example, a liquid that is colder than the first flow), the second flow absorbs heat from the first flow, thereby subcooling the first flow. This subcools the HPin of PX310, making it possible to reduce flash gas in the LPout flow after expansion passing through PX310.

[0161] The subcooled HPin flow then expands to a lower pressure through PX310 and is discharged from the LPout port of PX310. This expansion of the subcooled HPin flow generates a larger liquid mass fraction (e.g., less flash gas) in the LPout flow. The LPout flow then proceeds to receiver 313 (e.g., flash tank). The flash gas in the LPout does not contribute to any heat absorption in the fluid handling system 300E (e.g., refrigeration system), but will still be compressed by compressor 322 (e.g., MT compressor). Therefore, the reduction in flash volume caused by subcooling in subcooler 315 (HX1) increases the COP (e.g., system efficiency).

[0162] The second flow exchanges heat with the first flow in the subcooler 315 (HX1), then passes through the heat exchanger 376 (HX2) before proceeding to the LPin port of PX310. PX310 compresses the second flow to high pressure and discharges it from the HPout port. The HPout flow is then cooled in the auxiliary gas cooler 327, releasing heat into the surrounding environment. The second flow then passes through the auxiliary valve 369 (e.g., auxiliary high-pressure valve), where it is reduced in pressure to become a significantly colder gas-liquid two-phase mixture and proceeds to the receiver 313 (e.g., flash tank), where it merges with the LPout flow.

[0163] Heat exchanger 376 (HX2) is used to cool the LPin flow using a portion of the outlet flow from evaporator 318 (the MT evaporator outlet flow, which is significantly cooler than the LPin flow). This lowers the temperature of the LPin flow and increases the density of the LPin flow and the mass boost ratio of PX310 (e.g., PX can compress more LPin mass flow per unit HPin mass flow). This provides flexibility to increase the mass flow through the subcool valve 312 (e.g., subcool high-pressure valve) used to subcool the HPin flow through PX310, thereby achieving flow branching after the main gas cooler 329 (e.g., substantially optimal flow branching) and improving the efficiency of the fluid handling system 300E.

[0164] A three-way valve after the evaporator 318 (e.g., MT evaporator) may be controlled based on how much of the flow from the evaporator 318 (e.g., MT evaporator) is used to cool the LPin flow and heat the outlet flow of the evaporator 318 (e.g., MT evaporator outlet flow) before proceeding to the inlet of the compressor 322 (e.g., MT compressor inlet).

[0165] The heat exchanger 376 (HX2) can supply superheated fluid to the outlet flow of the evaporator 318 (e.g., the MT evaporator outlet flow), thereby increasing the pressure in the evaporator 318 (e.g., the MT evaporator pressure) while still satisfying the inlet superheating requirement of the main compressor 322 (e.g., the MT compressor inlet superheating requirement). This increased pressure in the evaporator 318 (e.g., increased MT evaporator pressure) can reduce the power consumption of the main compressor 322 (e.g., the MT compressor power consumption) for a given amount of heat absorbed in the evaporator 318, thereby further improving the efficiency of the fluid handling system 300E.

[0166] Figure 3F is a schematic diagram of a fluid processing system 300F equipped with a PX310 according to several embodiments. The fluid processing system 300F may be a boosterless subcooled PX architecture having LPin cooling and LPout heat exchange. The architecture of the fluid processing system 300F may be the same as the architecture of the fluid processing system 300E, except for one or more of the following.

[0167] The heat exchanger 379 (HX3) may be used to increase the liquid mass fraction of the LPout flow by using at least a portion of the outlet flow of the second evaporator 319 (e.g., the LT evaporator outlet flow, which may be significantly colder than the LPout flow). This reduces the amount of flash gas in the LPout flow, which is then compressed by the main compressor 322 (e.g., the MT compressor). The reduction in flash gas reduces the energy consumption of the main compressor 322 (e.g., the MT compressor), thereby improving the energy efficiency of the fluid handling system 300F.

[0168] A three-way valve may be positioned after the second evaporator 319 (e.g., the LT evaporator) and may be controlled based on how much of the flow from the second evaporator 319 is used to exchange heat with the LPout flow and heat the outlet fluid flow of the second evaporator 319 (e.g., the LT compressor inlet) before proceeding to the inlet of the compressor 323 (e.g., the LT compressor inlet).

[0169] The heat exchanger 379 (HX3) can provide superheated fluid to the outlet flow of the second evaporator 319 (e.g., the LT evaporator outlet flow), thereby increasing the pressure in the second evaporator 319 (e.g., the LT evaporator pressure) while still satisfying the inlet superheating requirement of the compressor 323 (e.g., the LT compressor inlet superheating requirement). This increased pressure in the second evaporator 319 (e.g., increased LT evaporator pressure) can reduce the power consumption of the second compressor 323 (e.g., the LT compressor power consumption) for a given amount of heat absorbed in the second evaporator 319 (e.g., the LT evaporator), thereby further improving the system efficiency of the fluid handling system 300F.

[0170] Figure 3G is a schematic diagram of a fluid processing system 300G comprising a PX310 according to several embodiments. The fluid processing system 300G may have a boosterless subcool PX architecture with an LPout heat exchanger and a main high-pressure valve bypass (e.g., valve X). The architecture of the fluid processing system 300G may be similar to the architecture of the fluid processing system 300F, except for one or more of the following:

[0171] A flow branching section 380 (e.g., a first flow branching section, a three-way valve) can bypass at least a portion of the flow from the outlet of the main gas cooler 329 and send it through a valve 384 (e.g., a main high-pressure valve). The valve 384 can reduce the pressure of this flow and convert it into a low-temperature gas-liquid two-phase mixture. This low-pressure, low-temperature two-phase flow can then proceed to a receiver 313 (e.g., a flash tank).

[0172] If PX310 is shut down, substantially all of the flow can be bypassed and sent through valve 384. This allows for the continued normal operation of the fluid handling system 300G even when PX310 is taken offline (for example, for maintenance). Any of the architectures described herein may have features such as those shown in Figure 3G for bypassing PX, servicing PX, taking PX offline, or similar purposes.

[0173] If the outlet flow of the main gas cooler 329 exceeds the amount that PX310 can handle, a portion of the flow is bypassed through the flow branch 380. In such a scenario, a certain amount of flow (e.g., a substantially optional amount) is directed through the HPin of PX310, and the remainder of the flow proceeds through the valve 384. For example, flow may be supplied to PX310 until its maximum operating speed is achieved, and any additional flow (e.g., that is required to maintain the target pressure of the main gas cooler 329) may be bypassed by PX310.

[0174] The pressure setting point of valve 384 can be set higher (for example, slightly higher) than the pressure setting point of HPin of PX310, so that valve 384 opens only when the maximum flow capacity of PX310 is reached.

[0175] The flow branching section 382 can be controlled to control the flow through the subcooler 315 and the subcooling valve 312.

[0176] The heat exchanger 378 may be used to cool the fluid flowing from the subcooler 315 before providing it to the low-pressure inlet of the PX 310. The fluid flow output by the evaporator 318 (e.g., a cooler fluid flow) may be utilized in the heat exchanger 378 to cool the fluid flowing between the secondary outlet of the subcooler 315 (e.g., a cooling outlet) and the low-pressure inlet of the PX 310. Cooling the fluid provided to the low-pressure inlet of the PX 310 can increase the fluid density, increase the mass boost ratio, and increase the mass flow rate that can be compressed by the PX, thereby improving the efficiency of the fluid handling system 300G. The heat exchanger 378 may also allow for an increase in the operating pressure of the evaporator 318 and the inlet pressure of the main compressor 322 while maintaining the target inlet superheating for the main compressor 322. Increasing the pressure of the evaporator 318 can reduce the energy consumption of the main compressor 322 and further improve system efficiency.

[0177] Figure 4A is a schematic diagram of a fluid processing system 400A comprising a PX410, a subcooler 415, and various controllers and other components for providing control of the fluid processing system 400A, according to several embodiments.

[0178] The fluid processing system 400A comprises components for performing heat transfer operations. The fluid processing system 400A includes a PX410, a main gas cooler 429, an auxiliary gas cooler 427, and an evaporator 418. The fluid processing system 400A further includes a subcooler 415 and a subcooling valve 412. The fluid processing system 400A further includes a receiver 413, a flash gas valve 420, and an expansion valve 416. The fluid processing system 400A further includes an auxiliary valve 469, a main compressor 422, and an auxiliary cooling component 428. The components of the fluid processing system 400A may share one or more features with the corresponding components of the fluid processing system 300A in Figure 3A.

[0179] The fluid processing system 400A may be equipped with one or more sensors. One or more sensors measure characteristic values ​​associated with the system. For example, one or more temperature sensors may measure the temperature of the flowing fluid, the ambient temperature, the temperature of a hot sink and / or cold sink associated with the system, etc. One or more pressure gauges may measure the pressure of the fluid in the fluid processing system 400A. One or more flow meters may measure the fluid flow (e.g., mass flow rate) through the fluid processing system 400A. One or more densimeters (e.g., two-phase fluid densimeter, two-phase densimeter, Coriolis flow meter, etc.) may measure the density of the fluid in the fluid processing system 400A. Other sensors (e.g., gauges) may measure additional characteristic values, such as the work performed by various components, the heat flow through the system, the power consumed by the components of the system, the total fluid flow rate through various parts of the system, etc. Figure 4A shows gauges 480, 481, 482, and 483. In some embodiments, the illustration of a gauge may indicate the inclusion of multiple instruments; for example, a gauge for determining volumetric flow rate may include a device for measuring mass flow rate and a device for measuring fluid density. In some cases, one or more sensors may be omitted for the sake of visual clarity in Figures 4A and 4B.

[0180] The fluid processing system 400A comprises controllers 490, 491, 492, 493, 494, and 495. The controllers of the fluid processing system 400A may be PID controllers. The controllers of the fluid processing system 400A may perform operations based on known relationships between sensor data and control outputs, for example, via lookup tables, functional forms of those relationships, or similar.

[0181] The control of the fluid processing system 400A may be performed by a computing device, such as a general-purpose computing device (desktop computer, laptop computer, tablet, smartphone, etc.) that executes commands to perform control tasks. The control of the fluid processing system 400A may be performed by a dedicated computing device. The control of the fluid processing system 400A may be performed by a control device such as a PID controller, a microcontroller, or by other known methods for providing control signals. The control unit of the fluid processing system 400A may comprise devices that perform multiple operations, for example, a single device performing the operations of controllers 490 and 491, a single device performing the operations of controllers 491, 492, and 495, a single device performing the operations of all controllers of the fluid processing system 400A, or any arrangement of the functions of various controllers may be performed by a combination of computing devices.

[0182] The controller 490 is operably coupled to the PX410. The controller 490 may receive one or more measurements from the gauge 480. The controller 490 may receive fluid pressure measurements from the gauge 480. The controller 490 may receive measurements as raw measurement data, pre-processed measurement data, averaged (e.g., Boxcar averaged) measurement data, or similar. In some embodiments, the controller 490 may receive additional measurement data, e.g., measurement data from one or more other sensors associated with the fluid handling system 400A. The controller 490 may receive ambient temperature data, e.g., for the environment near the main gas cooler 429 and / or auxiliary gas cooler 427 (e.g., in the case of a refrigeration system), or for the environment near the evaporator 418 (e.g., in the case of a heat pump system). The controller 490 may receive sensor data from the PX410, e.g., data displaying the operating speed of the PX410, etc. The controller 490 may be configured to generate one or more control signals based on the received measurement data. The controller 490 may provide control signals to devices configured to adjust the operating speed of the PX410, such as a motor coupled to the PX410 (for example, coupled to the rotor of the PX410).

[0183] The controller 493 is operably coupled to the auxiliary cooling component 428. The auxiliary cooling component 428 may be a device configured to increase heat transfer between the auxiliary gas cooler 427 and the ambient environment. For example, the auxiliary gas cooler 427 may release heat to the ambient atmosphere, and the cooling component 428 may be a fan that increases heat transfer from the auxiliary gas cooler 427 to the atmosphere. The auxiliary cooling component 428 may be a heat exchanger coupled to the auxiliary gas cooler 427, or other types of components that increase heat transfer away from the auxiliary gas cooler 427.

[0184] In some embodiments, the controller 493 may receive data measurements from the gauge 482. The gauge 482 may provide temperature measurements of the fluid temperature of the auxiliary gas cooler 427. The gauge 482 may provide temperature measurements of the fluid temperature of the fluid output from the auxiliary gas cooler 427. The controller 493 may generate control signals based on the data provided by the gauge 482. The controller 493 may generate control signals to achieve a target temperature of the fluid output from the auxiliary gas cooler 427. The controller 493 may generate control signals to adjust the operation of the auxiliary cooling components 428. For example, the controller 493 may adjust the operating speed of the fan to achieve a target temperature (e.g., within a threshold) of the fluid at the outlet of the auxiliary gas cooler 427.

[0185] In some embodiments, the target fluid temperature of the fluid output by the auxiliary gas cooler 427 may be based on the temperature of the fluid output by the main gas cooler 429. The target fluid temperature of the fluid output by the main gas cooler 429 may be generated based on environmental conditions including ambient temperature, target performance, efficiency, or heat transfer of the fluid processing system 400A. In some embodiments, the main gas cooler 429 and the auxiliary gas cooler 427 may release heat to the same environment (for example, both gas coolers may be placed on the roof of a building to release heat to the environment). The controller 493 may receive a display of the fluid temperature output by the main gas cooler 429 (for example, a display via the gauge 480) and generate a control signal based on maintaining the difference between the fluid temperature output by the main gas cooler 429 and the fluid temperature output by the auxiliary gas cooler 427 within a target threshold.

[0186] The controller 491 is operably coupled to the subcooling valve 412. The controller 491 may receive sensor data from the gauge 481. The gauge 481 may display the temperature of the fluid output by the subcooler 415. The data generated by the gauge 481 may be used to determine the subcooling performed by the subcooler 415 (e.g., further cooling beyond the cooling required to transition the fluid to a liquid phase, which may be performed by the main gas cooler 429). Data displaying the temperature before the subcooler 415 (e.g., data generated by the gauge 480) may be used to determine the subcooling of the fluid performed by the subcooler 415. The controller 491 may provide one or more control signals to the subcooling valve 412. Based on the temperature data, the controller 491 may provide control signals to the subcooling valve 412. The controller 491 may provide one or more control signals to the subcooler valve 412 based on the temperature difference between the fluid supplied to the main inlet of the subcooler 415 (e.g., fluid from the main gas cooler 429) and the fluid supplied by the main outlet of the subcooler 415 (e.g., fluid to the high-pressure inlet of PX 410). The controller 491 may generate and / or provide control signals based on the difference between temperature readings provided by gauges 481 and 480, the difference between the temperature reading provided by gauge 481 and the target fluid temperature of the fluid output by the main gas cooler 429 (e.g., based on ambient temperature), or similar.

[0187] Controller 492 is operably coupled to auxiliary valve 469. Controller 492 may provide control signals to auxiliary valve 469 based on the opening degree of subcooling valve 412, for example, a signal indicating the opening degree of subcooling valve 412 received from controller 491. In some embodiments, a signal indicating the opening degree of subcooling valve 412 (e.g., a percentage of the maximum opening degree) may be provided by subcooling valve 412. In some embodiments, the control signals provided to subcooling valve 412 may be provided to controller 492 and / or directly to auxiliary valve 469. The opening degree of auxiliary valve 469 may be based on the opening degree of subcooling valve 412.

[0188] In some embodiments, the controller 494 may be operably coupled to the subcooling valve 412. The controller 494 may receive data indicating the opening degree of the flash gas valve 420. In some embodiments, the flash gas valve 420 may be operated by the control unit of the parent rack, for example, the control unit of an existing system to which the PX 410 and associated equipment have been added retrofitted. Control of the flash gas valve 420 may be difficult or impossible to adjust by the PX system. However, increased cooling of the main fluid flow by the subcooler 415 may reduce the amount of flash gas in the receiver 413. The flash gas valve 420 may be operated based on the gas content of the receiver 413, the pressure of the receiver 413, or similar. By adjusting the subcooling valve 412 based on the opening degree of the flash gas valve 420, the fluid handling system 400A may maintain a target cooling level for the main body passing through the subcooler 415. In some embodiments, the control of the subcooling valve 412 may include multiple inputs, for example, inputs based on the flash gas valve 420 and the gauge 481. In some embodiments, the minimum opening of the flash gas valve 420 may be maintained, and the control of the subcool valve 412 may revert to control based on the flash gas valve 420 when the opening approaches its minimum (e.g., within a threshold).

[0189] The controller 495 is communicatively coupled to the subcool valve 412. The controller 495 obtains information from the gauge 483 indicating the low-pressure inlet travel distance of the PX410 and generates and / or provides a control signal to the subcool valve 412 based on the low-pressure inlet travel distance. The travel distance may be, or include, a measure of the flow through the PX410 compared to the operating volume of the PX410 (e.g., duct volume, duct volume modified by operating speed, etc.). The travel distance may describe a portion of the operating volume of the PX410 that is filled or displaced by the inflow or outflow fluid. The value or range of the travel distance may be targeted, for example, to optimize the efficiency of system 400A, optimize heat transfer, etc. In some embodiments, the target low-pressure inlet travel distance may be about 100%, 90%–110%, 80%–120%, 70%–130%, or any included range or other range. Gauge 483 may include instrumentation for determining the low-pressure inlet travel distance of PX410. Gauge 483 may include a mass flow meter. Gauge 483 may include a pressure gauge. Gauge 483 may include a temperature gauge. Controller 495 may further obtain an indication of the operating speed of PX410, for example, to determine the travel distance associated with PX410, to determine the duct volume of PX410 available for fluid per unit period. In some embodiments, the auxiliary valve 469 may also be controlled based on a travel distance, for example, the high-pressure outlet travel distance of PX410. The high-pressure outlet travel distance may also be determined by a gauge (not shown), which may include instrumentation for determining the high-pressure outlet fluid mass flow rate, high-pressure outlet fluid density, etc. Controller 495 may be used in combination with controller 494, in combination with controller 491, or in combination with controllers 494 and 491. In some embodiments, the operation of controllers 491, 494, and 495 may be used on a conditional basis, for example, different control operations based on different sensor inputs may be used for controlling the subcooling valve 412 under different conditions. In some embodiments, combinations of the operation of controllers 491, 494, and / or 495 may be used when generating and / or providing control signals to the subcooling valve 412.For example, the lookup table may include a value for the opening degree of the subcool valve 412, based on inputs including measurements of gauge 481, flash gas valve 420, and / or gauge 483.

[0190] A fluid processing system (e.g., a refrigeration system) may include devices for performing the operation of any combination of the controllers described above. The fluid processing system may include devices for performing the operation of controller 490. The fluid processing system may include devices for performing the operation of controller 491. The fluid processing system may include devices for performing the operation of controller 492. The fluid processing system may include devices for performing the operation of controller 493. The fluid processing system may include devices for performing the operation of controller 494. The fluid processing system may include devices for performing the operation of controller 495. The fluid processing system may include sensors, gauges, or other instrumentation in connection with any of the controllers described herein. The fluid processing system may include devices for performing the operation of any two of these controllers (e.g., controllers 490 and 491, controllers 490 and 494, controllers 492 and 495, etc.), any three of these controllers, etc. Any combination of these controllers may be provided in a fluid processing system (e.g., a refrigeration system).

[0191] In some embodiments, a controller (e.g., a central controller, a system controller, which may be combined with one or more of the controllers 490-495) receives sensor data indicating the temperature of the refrigerated space (e.g., a low-temperature reservoir near the evaporator 418) and / or the temperature of the heated space (e.g., a high-temperature reservoir near the main gas cooler 429). Based on sensor data received from one or more sensors of the fluid processing system 400A (e.g., one or more fluid flow sensors, temperature sensors, pressure sensors, etc.), the controller may control the subcool valve 412, auxiliary valve 369, auxiliary cooling components 428, etc. In some embodiments, one or more sensors (e.g., pressure sensors, flow sensors, temperature sensors, etc.) are located near the inlets and / or outlets of the components of the fluid processing system 400A (e.g., located near the fluid discharged from the components). In some embodiments, one or more sensors are located inside the components of the fluid processing system 400A. In some embodiments, a pressure sensor may be located near the inlet of the main compressor 422, and an additional pressure sensor may be located near the outlet of the main compressor 422. In some embodiments, a temperature sensor may be located near the inlet of the evaporator 418, and another temperature sensor may be located near the outlet of the evaporator 418 (for example, to measure the temperature of the fluid discharged from the evaporator 18). In some embodiments, temperature sensors may be located inside the main gas cooler 3429 and / or the auxiliary gas cooler 427. In some embodiments, flow sensors may be located at the inlet and outlet of the PX410, respectively, to measure the flow of the first and second fluids into and out of the PX410.

[0192] In some embodiments, a controller (e.g., a central controller, a system controller, which may be combined with one or more controllers 490-495 and / or additional controllers 496-499 in Figure 4B) receives sensor data indicating the temperature of the refrigerated space (e.g., a low-temperature reservoir near the evaporator 418) and / or the temperature of the heated space (e.g., a high-temperature reservoir near the main gas cooler 429). Based on sensor data received from one or more sensors of the fluid processing system (e.g., one or more fluid flow sensors, temperature sensors, pressure sensors, etc.), the controller may control the auxiliary cooling component 428, auxiliary valve 469, PX410, main compressor 422, subcool valve 412, or any other controllable component of the fluid processing system. In some embodiments, one or more sensors (e.g., pressure sensors, flow sensors, temperature sensors, etc.) are positioned close to the inlets and / or outlets of the various components of the fluid processing system 400A (e.g., close to the fluid discharged from the various components). In some embodiments, one or more sensors are located inside the components of the fluid processing system 400A. In some embodiments, a pressure sensor may be located near the inlet of the main compressor 422, and an additional pressure sensor may be located near the outlet of the main compressor 422. In some embodiments, a temperature sensor may be located near the inlet of the evaporator 418, and another temperature sensor may be located near the outlet of the evaporator 418 (for example, to measure the temperature of the fluid discharged from the evaporator 418). In some embodiments, temperature sensors may be located inside the main gas cooler 429 and / or auxiliary gas cooler 427. In some embodiments, flow sensors may be located at the inlet and outlet of PX410, respectively, to measure the flow of the first and second fluids into and out of PX410.

[0193] Figure 4B is a schematic diagram of a fluid processing system 400B comprising sensors and controllers according to several embodiments. The fluid processing system 400B has components similar to those of the fluid processing system 300B in Figure 3B. The components of the fluid processing system 400B may share one or more features, functions, or characteristics of the corresponding components of the fluid processing system 300B. The fluid processing system 400B comprises several sensors, for example, gauge 480, gauge 483, gauge 484, etc. The sensors may share one or more features, functions, or characteristics with the sensors provided in the fluid processing system 400A in Figure 4A. The fluid processing system 400B comprises several controllers, such as controller 490, controller 496, controller 497, controller 498, and controller 499. The controllers may include or share features and / or characteristics with the controllers provided in the fluid processing system 400B, such as controller architecture, potential grouping of controller functions by fewer computing devices, or similar. Some controllers may be applicable to various types of architectures, and controllers may be used together in any combination relating to the target fluid handling system architecture. For example, an architecture such as fluid handling system 400B may benefit from a controller directed to an auxiliary cooling component, such as controller 492 in Figure 4A. Any number of controllers described herein may be provided in the target architecture and may be implemented by any number of devices.

[0194] The fluid handling system 400B comprises a main gas cooler 429, PX410, associated motor 408, bypass high-pressure valve 448, first low-pressure control valve 450, second low-pressure control valve 452, auxiliary gas cooler 427, auxiliary receiver 411, receiver 413, flash gas valve 420, expansion valve 416, second expansion valve 417, evaporator 418, second evaporator 419, cryogenic compressor 423, and main compressor 422. These components can perform similar functions to the corresponding components of the fluid handling system 300B.

[0195] The fluid processing system 400B includes gauges 480, 483, and 484. These gauges may have similar characteristics to the gauges of the fluid processing system 400A. Each gauge of the fluid processing system may include multiple sensors, meters, or other instruments for determining measurements relevant to the control of the fluid processing system 400B. The gauges may include one or more temperature sensors, pressure sensors, flow meters, densimeters, or similar devices.

[0196] The fluid handling system 400B includes a controller 490. The controller 490 may be used to provide a control signal for adjusting the operating speed of the PX410 (e.g., via the motor 408). The controller 490 may adjust the operating speed of the PX410 to maintain a target fluid pressure in the main gas cooler 429, which may be provided, for example, by a gauge 480, or by a gauge inside the main gas cooler 429, or similar.

[0197] The fluid handling system 400B includes a controller 496. The controller 496 is operably coupled to a bypass high-pressure valve 448. The bypass high-pressure valve 448 may provide a portion of the fluid output by the main gas cooler 429 to the auxiliary receiver 411. The opening of the bypass high-pressure valve 448 (e.g., a percentage of the maximum opening) may be used to determine the portion of the fluid output by the main gas cooler 429 and provided to the auxiliary receiver 411, and the portion provided to the high-pressure inlet of PX410. The controller 496 may generate control signals based on measurements from one or more sensors (not shown) that measure the conditions of the auxiliary receiver 411. The controller 496 may generate control signals based on the pressure of the auxiliary receiver 411, for example, the fluid pressure of the auxiliary receiver 411. The controller 496 may generate control signals to regulate the fluid flow to the auxiliary receiver 411 until a target pressure condition is achieved (e.g., until achieved within a threshold).

[0198] The fluid handling system 400B includes a controller 497, which is operably coupled to an auxiliary valve 469. The controller 497 can generate control signals based on measurement data received from a gauge 484. The gauge 484 may be configured to generate a display of the high-pressure outlet travel distance of the PX410. Determining the high-pressure outlet travel distance may involve performing calculations based on the high-pressure outlet mass flow rate, high-pressure outlet density, and / or the operating speed of the PX410 (e.g., rotational speed, operating volume, or similar). The auxiliary valve 469 may be adjusted until a target high-pressure outlet travel distance is achieved (e.g., until achieved within a threshold).

[0199] The fluid handling system 400B includes a controller 498. The controller 498 is operably coupled to a second low-pressure control valve 452. The second low-pressure control valve 452 determines the fluid flow from the auxiliary receiver 411 to the low-pressure inlet of PX410. The controller 498 may generate a control signal based on one or more signals received from the gauge 483. The gauge 483 may determine the low-pressure inlet travel distance of PX410. The low-pressure inlet travel distance may be determined or estimated based on several different criteria, combinations of criteria, averaging of values ​​determined by various methods, or other statistical indicators, or similar. In some embodiments, the low-pressure inlet travel distance of PX410 may be determined or estimated based on the valve characteristics of the second low-pressure control valve 452. For example, the mass flow rate through the second low-pressure control valve 452 may be estimated based on the valve characteristics (e.g., bend characteristics) and fluid conditions (e.g., pressure and temperature at the valve inlet). In some embodiments, the low-pressure inlet travel distance may be targeted, and the volumetric flow rate through the second low-pressure control valve 452 may be generated to achieve the target travel distance (e.g., as a function of the operating speed of PX410). In some embodiments, the opening degree of the second low-pressure control valve 452 may be determined as a function of the operating speed of PX410 (e.g., via a lookup table, via a mathematical function, or similar). In some embodiments, the gauge 483 may provide an indication of the travel distance, e.g., mass flow rate, fluid pressure, fluid temperature, etc., which may be used by the controller 498 to generate a control signal for the second low-pressure control valve 452.

[0200] The fluid handling system 400B includes a controller 499, which is operably coupled to a first low-pressure control valve 450. The controller 499 may receive data from one or more sensors in an auxiliary receiver 411 to generate a control signal. The controller 499 may obtain an indication of the liquid level of a mixed fluid (e.g., including gaseous and liquid components) in the auxiliary receiver 411. The first low-pressure control valve 450 may be provided with a control signal to maintain the fluid level in the auxiliary receiver 411 within a target range. The first low-pressure control valve 450 may be opened in response to an increase in the liquid level in the auxiliary receiver 411. The first low-pressure control valve 450 may be configured to close when the liquid level in the auxiliary receiver 411 falls below a target level.

[0201] Figures 5A to 5E are flowcharts illustrating methods 500A to 500E for controlling a fluid processing system (for example, one or more of the fluid processing systems 300A to 300B in Figures 3A to 3B) according to several embodiments. In some embodiments, methods 500A to 500E are executed by processing logic including hardware (e.g., circuits, dedicated logic, programmable logic, microcode, processing units, etc.), software (e.g., commands run on processing units, processors such as central processing units or image processing units, general-purpose computer systems, or dedicated machines), firmware, microcode, or a combination thereof. In some embodiments, methods 500A to 500E are executed at least in part by one or more controllers. In some embodiments, a non-temporary storage medium stores commands that cause one or more processing units to execute methods 500A to 500E when executed by one or more processing units.

[0202] For the sake of brevity, methods 500A to 500E are presented and described as a series of operations. However, the operations relating to this disclosure may occur in various orders and / or simultaneously, along with other operations not presented and described herein. Furthermore, in some embodiments, not all illustrated operations are performed to implement methods 500A to 500E in accordance with the subject matter of this disclosure. In addition, those skilled in the art will understand and recognize that methods 500A to 500E may alternatively be represented as a series of interrelated states via a state diagram or events.

[0203] Figure 5A is a flow diagram of method 500A, which provides control of a fluid processing system according to several embodiments. In block 502, processing logic (e.g., processing unit, controller, computer processor, etc.) acquires first temperature data that indicates the subcooling degree of a first fluid in a heat exchanger. The subcooling degree may be the temperature difference between the fluid supplied to the heat exchanger and the fluid supplied by the heat exchanger. The first fluid may flow through a first fluid channel of the heat exchanger. The first fluid channel may be a main channel, primary channel, etc. The fluid in the first fluid channel may be configured to exchange heat with fluids in a second channel, cooling channel, cooling fluid channel, etc. The fluid in the first channel may lose heat to a lower temperature secondary fluid in a secondary channel. The first fluid may be supplied to the heat exchanger from a first gas cooler, such as a main gas cooler. The first fluid may be supplied from the heat exchanger to a PX. The first fluid may be supplied to the high-pressure inlet of the PX.

[0204] In block 504, the processing logic optionally acquires opening data for a second control valve. The second control valve is coupled between the receiver outlet and the compressor inlet. The second control valve may be a flash gas valve, for example, it may allow the removal of gas from a gas / liquid mixture contained in the receiver. The second control valve may be opened based on the receiver conditions. The opening data may be received from the second control valve, from a sensor associated with the second control valve, from a controller associated with the second control valve, etc.

[0205] In block 506, the processing logic optionally obtains a display of a first travel distance associated with the low-pressure inlet of the PX. The first travel distance may be determined based on a sensor adjacent to the low-pressure inlet of the PX. The first travel distance may be determined based on the measurement characteristics of the fluid supplied to the low-pressure inlet of the PX. The first travel distance may be determined based on mass flow rate, fluid temperature, fluid pressure, etc.

[0206] In block 508, the processing logic generates a first control signal. The generation of the first control signal may optionally include the operations of blocks 510 and 512. The first control signal is based on at least first temperature data. The first control signal may further be based on opening data and first travel distance. Generating the first control signal optionally includes determining that the subcooling degree of a first fluid, for example, the subcooling degree of a target temperature drop through a heat exchanger, does not satisfy a target threshold condition. Generating the first control signal optionally includes obtaining second temperature data that shows the temperature of the fluid output by the first gas cooler. Generating the first control signal optionally includes determining a target subcooling degree threshold, for example, that the target subcooling temperature change may be based on the temperature of the fluid output by the first gas cooler, or on the ambient temperature, etc.

[0207] In block 510, generating a first control signal optionally includes determining whether the opening data is within a threshold of the minimum target opening of the second control valve. For example, the first control signal may ensure that the second control valve does not close beyond the minimum target opening.

[0208] In block 512, generating a first control signal optionally includes determining a target opening of a first control valve. The target opening of the first control valve may be selected to maintain at least a minimum target opening of the second control valve. In some embodiments, flash gas in the receiver may be reduced by increasing the subcooling performed by the heat exchanger. Subcooling may be maintained so that there is enough flash gas in the receiver to maintain at least a minimum opening of the second control valve.

[0209] In block 514, the processing logic provides a first control signal to a first control valve. The first control valve is coupled between the outlet of a first gas cooler (e.g., a main gas cooler) and the inlet of a second fluid channel (e.g., a cooling channel) of a heat exchanger. The first control valve may be configured to adjust its opening degree based on the first control signal. The opening degree of the first control valve may determine the portion of fluid output from the first gas cooler that is supplied to the first fluid channel of the heat exchanger.

[0210] In block 516, the processing logic optionally obtains an indication of a second travel distance associated with the high-pressure outlet of the PX. The processing logic further optionally generates a second control signal based on the second travel distance. The processing logic further provides the second control signal to a third control valve, which is coupled to receive the second fluid from the PX and provide the second fluid to the receiver. The third control valve is configured to adjust its opening degree based on the second control signal.

[0211] Figure 5B is a flow diagram of method 500B for providing control of a refrigeration system according to several embodiments. In block 518, the processing logic obtains an indication of the fluid level in an auxiliary receiver of the refrigeration system. The refrigeration system includes a pressure exchanger. The pressure exchanger is configured to receive a first fluid from a first gas cooler and a second fluid from an auxiliary receiver, and to exchange pressure between the first and second fluids. The refrigeration system may further include a main receiver, which may be in fluid communication with the auxiliary receiver.

[0212] In block 520, the processing logic generates a first control signal based on the fluid level of the auxiliary receiver. In some embodiments, the fluid level may exceed a threshold level. In some embodiments, the fluid level may be below a threshold level. In some embodiments, there may be multiple thresholds, for example, a range of fluid levels in which no control signal for adjusting the fluid level is generated.

[0213] In block 522, the processing logic provides a first control signal to a first control valve. The first control valve is configured to determine the fluid flow from the auxiliary receiver to the main receiver based on the first control signal. For example, the mass flow rate, volumetric flow rate, flow velocity, etc., may be determined by the opening of the first control valve (e.g., a percentage of the maximum opening).

[0214] In block 524, the processing logic optionally obtains an indication of the fluid pressure of the first gas cooler. The processing logic further optionally generates a second control signal based on the fluid pressure of the first gas cooler. The processing logic further provides the second control signal to the motor of PX. The motor of PX may be configured to adjust the operating speed of PX based on the second control signal.

[0215] In block 526, the processing logic optionally obtains an indication of the pressure difference between the auxiliary receiver and the main receiver. The processing logic further optionally generates a third control signal based on the pressure difference between the auxiliary receiver and the main receiver. The processing logic further optionally provides the third control signal to a second control valve. The second control valve is coupled to supply a first fluid from the first gas cooler to the auxiliary receiver, and is configured to maintain a target pressure difference between the auxiliary receiver and the main receiver.

[0216] In block 528, the processing logic optionally obtains an indication of the distance traveled by a second fluid associated with the high-pressure outlet of the PX. The indication of the distance traveled can be based on the measured mass flow rate and the measured density of the second fluid. The processing logic further optionally generates a fourth control signal based on the distance traveled by the second fluid associated with the high-pressure outlet. The processing logic further optionally provides the fourth control signal to a third control valve. The third control valve is coupled to determine the fluid flow of the second fluid from the high-pressure outlet of the PX through the second gas cooler to the auxiliary receiver based on the opening of the third control valve. The third control valve may be configured to adjust the opening of the third control valve based on the fourth control signal.

[0217] In block 530, the processing logic optionally obtains an indication of the fluid temperature at the outlet of the second gas cooler. The processing logic may further optionally generate a fifth control signal based on the fluid temperature. The processing logic may further optionally provide the fifth control signal to a device for regulating heat transfer from the second gas cooler, for example, to a fan for increasing heat transfer from the second gas cooler to the environment near the second gas cooler.

[0218] Figure 5C is a flowchart of method 500C for providing control of a refrigeration system according to several embodiments. The operations associated with blocks 532, 534, and 536 may share one or more features with the operations of blocks 518, 520, and 522 in Figure 5B.

[0219] In block 532, the processing logic obtains an indication of the fluid level in the auxiliary receiver of the refrigeration system. The refrigeration system includes a pressure exchanger. The pressure exchanger is configured to receive a first fluid from a first gas cooler and a second fluid from the auxiliary receiver, and to exchange pressure between the first fluid and the second fluid.

[0220] In block 534, the processing logic generates a first control signal based on the fluid level of the auxiliary receiver. In some embodiments, the fluid level may exceed a threshold level. In some embodiments, the fluid level may be below a threshold level. In some embodiments, there may be multiple thresholds, for example, a range of fluid levels in which no control signal for adjusting the fluid level is generated.

[0221] In block 536, the processing logic provides a first control signal to a first control valve. The first control valve is configured to determine the fluid flow from the auxiliary receiver to the main receiver based on the first control signal. For example, the mass flow rate, volumetric flow rate, flow velocity, etc., may be determined by the opening of the first control valve (e.g., a percentage of the maximum opening).

[0222] In block 538, the processing logic optionally obtains a representation of the distance traveled by a second fluid associated with the low-pressure inlet of the PX. The representation of the distance traveled by a second fluid associated with the low-pressure inlet of the PX may be based on the characteristics of the fluid supplied to the low-pressure inlet of the PX (e.g., temperature, pressure, mass flow rate, etc.). The representation of the distance traveled by a second fluid associated with (e.g., supplied to) the low-pressure inlet of the PX may include considering the valve characteristics of one or more valves in the refrigeration system. The representation of the distance traveled by a second fluid associated with the low-pressure inlet of the PX may include considering the operating speed of the PX (e.g., rotational speed).

[0223] In block 540, the processing logic optionally generates a sixth control signal based on the distance traveled by a second fluid associated with the low-pressure inlet. The sixth control signal may be used to achieve and / or maintain a target distance traveled by the low-pressure inlet of PX.

[0224] In block 542, the processing logic optionally provides a sixth control signal to the fourth control valve. The fourth control valve may be coupled to determine the fluid flow of the second fluid from the auxiliary receiver to the low-pressure inlet of PX. Based on the sixth control signal, the fourth control valve may adjust its opening.

[0225] Figure 5D is a flow diagram of method 500D for providing control of a refrigeration system according to several embodiments. In block 544, the processing logic obtains an indication of the pressure difference between the main receiver and the auxiliary receiver of the refrigeration system. The refrigeration system may comprise a PX, two receivers, one or more gas coolers, one or more evaporators, and one or more compressors. The auxiliary receiver and PX are configured to receive a first fluid from the first gas cooler. The auxiliary receiver is configured to supply a second fluid to PX. PX is configured to exchange pressure between the first fluid and the second fluid. The main receiver is configured to receive the first fluid from PX.

[0226] In block 546, the processing logic generates a first control signal based on the pressure difference. The first sensor may generate pressure data for the main receiver, and the second sensor may generate pressure data for the auxiliary receiver. The pressure difference may be based on the data from the first sensor and the data from the second sensor.

[0227] In block 548, the processing logic provides a first control signal to a first control valve coupled between the first gas cooler and the auxiliary receiver. The first control valve is configured to adjust its opening degree based on the first control signal. The opening degree of the first control valve may determine the portion of fluid supplied to the auxiliary receiver and the portion of fluid supplied to the PX.

[0228] In block 550, the processing logic optionally obtains an indication of the fluid level in the auxiliary receiver. The processing logic further optionally generates a second control signal based on the fluid level in the auxiliary receiver. The processing logic further optionally provides the second control signal to a second control valve. The second control valve is coupled between the auxiliary receiver and the main receiver, and for example, fluid may be supplied through the second control valve from the auxiliary receiver (maintained at a higher pressure) to the main receiver (maintained at a lower pressure). The second control valve is configured to adjust the opening of the second control valve based on the second control signal.

[0229] In block 552, the processing logic optionally obtains an indication of the fluid pressure of the first gas cooler. The processing logic further optionally generates a third control signal based on the fluid pressure of the first gas cooler. The processing logic further optionally provides the third control signal to the motor of PX. The motor of PX is configured to adjust the operating speed of PX based on the third control signal. In some embodiments, the motor may accelerate the operation of PX. In some embodiments, the motor may decelerate the operation of PX against the motion of PX. In some embodiments, decelerating PX may be used to generate electricity through the motor.

[0230] In block 554, the processing logic optionally obtains an indication of the distance traveled by the second fluid associated with the low-pressure inlet of PX. The processing logic further optionally generates a fourth control signal based on the distance traveled by the second fluid associated with the low-pressure inlet. The processing logic further optionally provides the fourth control signal to a third control valve. The third control valve is coupled to determine the fluid flow of the second fluid from the auxiliary receiver to the low-pressure inlet. The third control valve adjusts its opening degree based on the fourth control signal.

[0231] Figure 5E is a flow diagram of method 500E for providing control of a refrigeration system according to several embodiments. The operation of blocks 556, 558, and 560 may share one or more features with the operation of blocks 544, 546, and 548 in Figure 5D. In block 556, the processing logic obtains an indication of the pressure difference between the main receiver and the auxiliary receiver of the refrigeration system. The refrigeration system may comprise a PX, two receivers, one or more gas coolers, one or more evaporators, and one or more compressors. The auxiliary receiver and PX are configured to receive a first fluid from the first gas cooler. The auxiliary receiver is configured to supply a second fluid to PX. PX is configured to exchange pressure between the first fluid and the second fluid. The main receiver is configured to receive the first fluid from PX.

[0232] In block 558, the processing logic generates a first control signal based on the pressure difference. The first sensor may generate pressure data for the main receiver, and the second sensor may generate pressure data for the auxiliary receiver. The pressure difference may be based on the data from the first sensor and the data from the second sensor.

[0233] In block 560, the processing logic provides a first control signal to a first control valve coupled between the first gas cooler and the auxiliary receiver. The first control valve is configured to adjust its opening degree based on the first control signal. The opening degree of the first control valve may determine the portion of fluid supplied to the auxiliary receiver and the portion of fluid supplied to the PX.

[0234] In block 562, the processing logic optionally obtains an indication of the distance traveled by a second fluid associated with the high-pressure outlet of the PX. The indication of the distance traveled may include, or be based on, a measured mass flow rate and / or measured density of the second fluid. The processing logic further optionally generates a fifth control signal based on the distance traveled by the second fluid associated with the high-pressure outlet. The processing logic further optionally provides the fifth control signal to a fourth control valve. The fourth control valve is coupled to determine the fluid flow of the second fluid from the high-pressure outlet of the PX through the second gas cooler to the auxiliary receiver based on the opening of the fourth control valve. The fourth control valve is configured to adjust the opening of the fourth control valve based on the fifth control signal.

[0235] In block 564, the processing logic optionally obtains an indication of the fluid temperature at the outlet of a second gas cooler, such as an auxiliary gas cooler. The processing logic further optionally generates a sixth control signal based on the fluid temperature. The processing logic further optionally provides the sixth control signal to a device for regulating heat transfer from the second gas cooler. The device for regulating heat transfer may be one or more fans to increase the heat transfer from the second gas cooler to the surrounding environment.

[0236] Figures 6A to 6B show systems 600A to 600B comprising a pressure exchanger according to a particular embodiment. Some of the features in one or more of Figures 6A to 6B may have similar characteristics, functions, and / or structures to features in one or more of Figures 1A to 1B, Figures 2A to 2E, Figure 3AG, and / or Figures 4A to 4B (for example, features having similar names and / or reference numbers). One or more systems in Figures 6A to 6B may be used to perform one or more of the methods described herein.

[0237] Systems 600A to 600B may be referred to as PX integrated booster rack systems (e.g., PX integrated refrigerant booster rack, PX integrated transcritical carbon dioxide (CO2) booster rack, etc.) depending on the particular embodiment. In some embodiments, systems 600A and / or systems 600B are energy-optimized (e.g., mechanical "subcool") PX systems.

[0238] In some embodiments, the PX integrated booster rack system comprises one evaporator and one compressor (e.g., a medium-temperature (MT) evaporator and an MT compressor in Figure 6B). In some embodiments, the PX integrated booster rack system comprises multiple evaporators (e.g., an MT evaporator and a low-temperature (LT) evaporator in Figure 6A) and multiple compressors (e.g., an MT compressor and an LT compressor in Figure 6A). Figure 6A shows two evaporators and two compressors, and Figure 6B shows one evaporator and one compressor, but systems 600A and / or systems 600B may have more or fewer evaporators and / or compressors than those shown in the figures.

[0239] System 600A may include a pressure exchanger 410 having an HPIN port, an LPIN port, an HPOUT port, and an LPOUT port. A motor 408 may be coupled to the pressure exchanger 410 (for example, to control the rotation of the rotor of the pressure exchanger 410).

[0240] System 600A may include a main gas cooler coil 429 and an auxiliary gas cooler coil 427. In some embodiments, the main gas cooler coil 429 and the auxiliary gas cooler coil 427 are part of a single unit (e.g., located in a single housing, located in a single gas cooler device). In some embodiments, the main gas cooler coil 429 is part of a first unit (e.g., located in a first housing, located in a first gas cooler device), and the auxiliary gas cooler coil 427 is part of a second unit (e.g., located in a second housing, located in a second gas cooler device).

[0241] System 600A may comprise one or more of the following: receiver 411 (e.g., flash tank), evaporator 418 (e.g., MT evaporator), second evaporator 419 (e.g., LT evaporator), compressor 422 (e.g., MT compressor), compressor 423 (e.g., LT compressor), etc.

[0242] System 600A may comprise at least one HPV 602 (e.g., bypass HPV 602A and / or auxiliary HPV 602B), a subcooler 604, a flash gas valve 420, an expansion valve 416 (e.g., an electronic expansion valve (EEV)), an expansion valve 417 (e.g., an electronic expansion valve (EEV)), and one or more of the above.

[0243] System 600A could be a boosterless PX system.

[0244] The receiver 411 may be configured to reduce flash gas.

[0245] PX410 can enable mechanical "subcooling" (e.g., "free" compression of subcooled flow), which can reduce the amount of flash gas in the receiver 411 (e.g., flash tank), thereby reducing the work and size of the compressor 422 (e.g., the work and size of the MT compressor).

[0246] System 600A and / or 600B may have one or more of the components listed in Table 1. [Table 1]

[0247] In rack-integrated systems, the auxiliary (AUX) gas cooler coil 427 may be combined with the main gas cooler coil 429 (for example, as shown in Figures 6A and 6B). Fan speed control of the auxiliary gas cooler coil 427 may not be necessary (for example, with appropriate sizing). The fan of the auxiliary gas cooler coil 427 may be controlled in the same way as the fan of the main gas cooler coil 429, or the fan of the auxiliary gas cooler coil 427 may be operated at maximum speed.

[0248] Figure 6B may illustrate the control of system 600B (e.g., a PX integrated booster rack system, a rack integrated energy optimization system). System 600B may have one or more of the same components as system 600A.

[0249] System 600B may be equipped with one or more sensors 606.

[0250] Sensor 606A associates the subcooler outlet temperature data (T) with the fluid leaving the subcooler 604. SCout It could be a temperature sensor that provides )

[0251] Sensor 606B associates the main gas cooler coil temperature data (T) with the fluid exiting the main gas cooler coil 429. GCout It could be a temperature sensor that provides )

[0252] Sensor 606C may be a pressure sensor that provides main gas cooler coil pressure data associated with the fluid exiting the main gas cooler coil 429.

[0253] System 600B may have one or more control parameters and setpoints as shown in Table 2. [Table 2]

[0254] Regarding the HPIN subcooling ΔT, ΔT is T GCout -T SCoutIt may be equal to.

[0255] T GCout This could be the gas cooler outlet temperature (for example, provided by sensor 606B).

[0256] T SCout This could be the subcooler outlet temperature (for example, provided by sensor 606A).

[0257] Regarding control, the measurements used are: Main gas cooler pressure (provided, for example, by sensor 606C), Main gas cooler outlet temperature (e.g., provided by sensor 606B), and / or Subcooler outlet temperature (e.g., provided by sensor 606A, main flow), It may include one or more of the following.

[0258] Three components (e.g., main gas cooler pressure, main gas cooler outlet temperature, and sub-cooler outlet temperature) can be controlled. One additional temperature sensor may be used to control the PX integrated booster rack system 606B (e.g., rack-integrated energy optimization system).

[0259] Regarding the PX rotation speed, the rack controller (e.g., control module 94) can sense the main gas cooler outlet temperature, calculate the gas cooler pressure setpoint (e.g., the optimal gas cooler pressure setpoint according to an algorithm), and adjust the PX rotation speed (e.g., RPM) until the setpoint is reached.

[0260] Regarding startup, when PX is turned on, the main HPV may be gradually shut down, and the PX rotation speed (e.g., RPM) may be gradually increased until the setpoint is met.

[0261] With respect to the minimum PX rotational speed (e.g., RPM), if the setpoint (e.g., gas cooler pressure setpoint) is met at a PX rotational speed below the minimum threshold (e.g., 137 RPM), the PX may be stopped, and the controller may operate the main HPV to control the gas cooler pressure (e.g., failsafe mode).

[0262] Regarding the maximum PX rotational speed (e.g., RPM), if the PX rotational speed is at the maximum threshold and the setpoint cannot be achieved even when the main HPV is completely closed, the gas cooler pressure control returns to PX and the PX rotational speed is reduced to achieve the setpoint.

[0263] In some embodiments, the gas cooler pressure setpoint (e.g., the optimal gas cooler pressure setpoint) can be calculated using a gas cooler pressure versus outlet temperature algorithm (e.g., an algorithm that may be associated with the rack controller). This can be designed to change automatically when the rack operating mode changes (e.g., heat recovery). The curve to follow is the curve when the PX is on, the main HPV is closed, and the rack is operating in transitional criticality mode. This curve can be programmed by the controller to be triggered when the above conditions are met.

[0264] Regarding the bypass HPV opening, the rack controller can sense the "subcooling level" (e.g., the difference between the main gas controller outlet temperature and the subcooler outlet temperature) and adjust the bypass HPV opening until the subcooling setpoint is achieved.

[0265] The subcool setting point may be a fixed value (e.g., 10 degrees Fahrenheit), or it may be set to change according to the main gas cooler outlet temperature, PX rotation speed (e.g., RPM), etc.

[0266] If the subcool setting point is not reached even when the bypass HPV is fully open (e.g., 100%), the controller may maintain this setting.

[0267] Regarding the auxiliary HPV opening, the auxiliary HPV and bypass HPV may have the same control value. The PX controller may send the same signal to the auxiliary HPV as the one sent to the bypass HPV (e.g., a signal to control the bypass HPV opening). This may make it possible to match the auxiliary HPV opening with the bypass HPV opening. The auxiliary HPV opening may have a small offset (e.g., about 3% higher) from the bypass HPV opening to account for pressure loss in the HP line of the PX.

[0268] The offset can be a function of the PX rotational speed (e.g., RPM) because the pressure loss changes depending on the PX rotational speed (e.g., RPM).

[0269] System 600 may further include a rack controller. The processing logic of the rack controller (e.g., processing unit, control module, PID controller, etc.) Determining the outlet temperature of the gas cooler coil, Calculating the pressure setting point for the gas cooler coil, This causes the rotational speed of the pressure exchanger (PX) rotor to be adjusted to meet the pressure setpoint of the gas cooler coil, It may be configured to perform an operation that includes one or more of the following. The PX is configured to exchange pressure between a first fluid and a second fluid. The PX includes a first inlet configured to receive the first fluid from a mechanical subcooler, a second inlet configured to receive the second fluid from the mechanical subcooler, a first outlet configured to supply the second fluid to a gas cooler coil, the second fluid being supplied from the gas cooler coil to an auxiliary high-pressure valve, and the second fluid being supplied from the auxiliary high-pressure valve to a receiver, and a second outlet configured to supply the first fluid to the receiver.

[0270] In some embodiments, the mechanical subcooler is configured to exchange heat between a first fluid received from the gas cooler coil and a second fluid received from the gas cooler coil via the bypass high-pressure valve. In some embodiments, causing adjustment of the rotational speed of the rotor to meet the pressure setpoint of the gas cooler coil includes decreasing the opening percentage value of the bypass high-pressure valve and increasing the rotational speed of the rotor until the pressure setpoint of the gas cooler coil is met.

[0271] The processing logic of the rack controller (e.g., processing device, control module, PID controller, etc.) is determining the difference between the outlet temperature of the gas cooler coil and the corresponding outlet temperature of the mechanical subcooler, and adjusting the opening of the bypass high-pressure valve until the subcool setpoint is met, may be configured to perform operations including one or more of the above.

[0272] The processing logic of the rack controller (e.g., processing device, control module, PID controller, etc.) may be configured to perform operations including adjusting the corresponding opening of the auxiliary high-pressure valve to substantially match the respective opening of the bypass high-pressure valve.

[0273] In some embodiments, the receiver 411 is configured to reduce flash gas.

[0274] In some embodiments, the first inlet of PX 410 is a high-pressure in port, the second inlet of PX 410 is a low-pressure in port, the first outlet of PX 410 is a high-pressure out port, and the second outlet of PX 410 is a low-pressure out port.

[0275] In some embodiments, the processing logic of the rack controller of system 600 (e.g., a processing unit, control module, PID controller, etc.) may be configured to control one or more of the following: the rotational speed of the rotor of PX410, the corresponding operation of the bypass high-pressure valve 602A, or the operation of each of the auxiliary high-pressure valves 602B.

[0276] The processing logic of a rack controller (e.g., processing unit, control module, PID controller, etc.) Identifying sensor data including at least one of the following: main gas cooler coil outlet temperature associated with the main gas cooler coil, main gas cooler coil pressure associated with the main gas cooler coil, or subcooler outlet pressure associated with the subcooler, Based on sensor data, determine the high-pressure in(HPIN) subcool delta temperature setpoint associated with a pressure exchanger equipped with an HPIN port, Based on the HPN subcool delta temperature setpoint, this triggers the activation of the bypass high-pressure valve (HPV) located between the main gas cooler coil and the subcooler, It may be configured to perform an action that includes one or more of the following.

[0277] In some embodiments, the HPN subcool delta temperature is associated with the difference between the main gas cooler coil outlet temperature and the subcooler outlet temperature.

[0278] The processing logic of a rack controller (e.g., processing unit, control module, PID controller, etc.) Based on sensor data, the setpoint for the main gas cooler coil outlet pressure is determined, To cause the pressure exchanger to operate at revolutions per minute (RPM) such that the outlet pressure associated with the main gas cooler coil approaches the main gas cooler coil outlet pressure setpoint, It may be configured to perform an action that includes one or more of the following.

[0279] The processing logic of a rack controller (e.g., processing unit, control module, PID controller, etc.) Based on sensor data, the bypass HPV opening setpoint is determined, To trigger the operation of the auxiliary HPV opening so that it approaches the bypass HPV opening setting point, It may be configured to perform an action that includes one or more of the following.

[0280] Figures 7A to 7C show systems 700A to 700C comprising a pressure exchanger according to a particular embodiment. Some of the features in one or more of Figures 7A to 7C may have similar characteristics, functions, and / or structures to features in one or more of Figures 1A to 1B, Figures 2A to 2E, Figure 3AG, Figures 4A to 4B, and / or Figures 6A to 6B (for example, features having similar names and / or reference numbers). One or more systems in Figures 7A to 7C may be used to perform one or more of the methods described herein.

[0281] Systems 700A-700C may demonstrate control of a rack-integrated, boosterless PX refrigeration architecture.

[0282] Figures 7A and 7B may illustrate a first type of boosterless architecture (e.g., a subcool architecture) and control.

[0283] In some embodiments, Figure 7A shows a rack-integrated boosterless subcool PX architecture with LPIN cooling using MT evaporator outlet flow.

[0284] In some embodiments, the main gas cooler coil 429 and the auxiliary gas cooler coil 427 are part of the same unit (e.g., in the same housing, in the same gas cooler device, etc.). In a rack-integrated PX system, the main gas cooler coil 429 and the auxiliary gas cooler coil 427 may be part of the same unit, but may have two separate coils maintained at different pressures.

[0285] In some embodiments, the main gas cooler outlet flow from the main cooler coil 429 is split into two flows (e.g., a first flow and a second flow) (e.g., via a flow branch 708). The first flow may proceed to the HPIN of PX410 after being subcooled in heat exchanger 370 (HX1). The second flow may proceed through the subcooled HPV610 to reduce pressure, become a low-temperature gas-liquid two-phase mixture, and then proceed through heat exchanger 370 (HX1) to exchange heat with the first flow. Since the second flow may contain a low-temperature liquid (e.g., a liquid that is colder than the first flow), the second flow may absorb heat from the first flow (e.g., it may subcool the first flow). This allows the HPIN of PX410 to be subcooled, reducing flash gas in the LPOUT flow after expansion through PX410.

[0286] The subcooled HPIN flow can expand to a lower pressure through PX410 and be discharged from the LPOUT port of PX410. This expansion of the subcooled HPIN flow can generate a higher liquid mass fraction (e.g., less flash gas) in the LPOUT flow. The LPOUT flow can then proceed to receiver 411 (e.g., flash tank). Since the flash gas in the LPOUT cannot contribute to heat absorption in system 700A and may still need to be compressed by compressor 422 (e.g., MT compressor), the reduction in flash volume resulting from subcooling in heat exchanger 370 (HX1) can improve the COP (e.g., system efficiency) of system 700A.

[0287] The second stream may proceed to the LPIN port of PX410 after passing through heat exchanger 372 (HX2) (e.g., after exchanging heat with the first stream in heat exchanger 370 (HX1)). PX410 is capable of compressing the second stream to a high pressure, and discharges the second stream from the HPOUT port. Thereafter, the HPOUT stream may release heat to the surrounding environment in auxiliary gas cooler coil 427, and the temperature thereof may decrease (e.g., may be cooled). Subsequently, the second stream may experience a pressure drop across auxiliary HPV 602B, and may become a lower-temperature gas-liquid two-phase mixture (e.g., a significantly lower-temperature gas-liquid two-phase mixture), which may proceed to receiver 411 (e.g., a flash tank) to merge with the LPOUT stream.

[0288] Heat exchanger 372 (HX2) may be used to cool the LPIN stream using a portion of the MT evaporator outlet stream (e.g., one that is at a significantly low temperature). As a result, the temperature of the LPIN stream may decrease, which may increase the density of the LPIN stream and the mass boost ratio of PX410 (e.g., PX410 may compress a greater LPIN mass flow rate per unit HPIN mass flow rate). This may provide the flexibility to increase the mass flow rate flowing through subcool HPV 602C, which is used to subcool the HPIN stream passing through PX410, and a more optimal flow split after main gas cooler coil 429 may be achieved to improve the system efficiency of system 700A.

[0289] In some embodiments, system 700A includes a three-way valve 710 after evaporator 418 (e.g., an MT evaporator). A processing device (e.g., the processing device of control module 94, the processing device of three-way valve 710, the processing device of a rack controller, etc.) may determine how much of the stream from evaporator 418 is to be used to cool the LPIN stream and heat the outlet stream from evaporator 418 (e.g., the MT evaporator outlet stream) before it proceeds to the compressor suction port (e.g., the MT compressor suction port) of compressor 422. The processing device may control the adjustment of three-way valve 710 accordingly.

[0290] The heat exchanger 372 (HX2) can provide superheat to the outlet flow from the evaporator 418 (e.g., the MT evaporator outlet flow), which can increase the pressure in the evaporator 418 (e.g., the MT evaporator pressure) while still satisfying the compressor inlet superheating requirement of the compressor 422 (e.g., the MT compressor inlet superheating requirement). The increased pressure in the evaporator 418 (e.g., the increased MT evaporator pressure) can reduce the power consumption of the compressor 422 (e.g., the MT compressor power consumption) for a given amount of heat absorbed in the evaporator 418, which can help further improve the efficiency of system 700A.

[0291] In some embodiments, system 700A includes control of a rack-integrated boosterless subcool PX architecture with LPin subcooling via main gas cooler coil pressure control of the main gas cooler coil 429. The main gas cooler coil 429 and the auxiliary gas cooler coil 427 may be integrated into a single unit. In some embodiments, the auxiliary gas cooler coil 427 has a lower pressure than the main gas cooler coil 429 (e.g., about 1 to about 3 bar (about 0.1 to about 0.3 MPa)).

[0292] In some embodiments, control is performed via a main rack controller.

[0293] In some embodiments, the fan of the gas cooler unit (e.g., comprising a main gas cooler coil 429 and / or an auxiliary gas cooler coil 427) brings the gas cooler outlet temperature of the refrigerant fluid closer to the ambient temperature (e.g., as close to the ambient temperature as possible). The fan speeds of both the main gas cooler coil 429 and the auxiliary gas cooler coil 427 can be controlled by a main rack controller.

[0294] Sensor 606B associates the main gas cooler coil temperature data (T) with the fluid exiting the main gas cooler coil 429. GCoutThe sensor 606B may be a temperature sensor (for example, located between the flow branch 708 and the main gas cooler coil 429) that provides the temperature. The sensor 606B may measure the gas cooler outlet temperature.

[0295] Sensor 606C associates the main gas cooler coil pressure data (P) with the fluid exiting the main gas cooler coil 429. GCout A pressure sensor (for example, located between the flow branch 708 and the main gas cooler coil 429) may provide the following. Sensor 606C may measure the gas cooler outlet pressure.

[0296] The main gas cooler coil temperature data from sensor 606B and the main gas cooler coil pressure data from sensor 606C can be provided as input signals to the PID controller of the main rack.

[0297] The PID controller may have a main gas cooler pressure setpoint (e.g., main gas cooler coil pressure setpoint) based on a function (e.g., a substantially optimal curve as a function) of the gas cooler coil outlet temperature of the main gas cooler coil 429 in order to reduce (e.g., minimize) the energy consumption of the system 700A. The function (e.g., curve) may include the fact that as the temperature of the main gas cooler coil 429 increases, the pressure of the main gas cooler coil 429 increases (e.g., P_GC=f1(T_GC)).

[0298] The PID controller can measure the error (e.g., difference) between the setpoint and the actual P_GC and calculate a command signal as an output to be sent to the PX410's motor (e.g., a variable frequency drive (VFD)). Using the command signal, the PX410's motor can adjust its speed until the gas cooler coil pressure substantially matches the gas cooler coil pressure setpoint (e.g., until the desired gas cooler pressure = setpoint is reached).

[0299] In some embodiments, the system 700A includes control of a rack-integrated boosterless subcool PX architecture with LPIN subcooling via auxiliary gas cooler coil pressure control of auxiliary gas cooler coil 427.

[0300] Sensor 606D may be a pressure sensor located at the fluid outlet of the auxiliary gas cooler coil 427 (for example, sensor 606D measures the auxiliary gas cooler coil pressure). The signal from sensor 606D (e.g., sensor data, auxiliary gas cooler coil pressure) may be provided as input signals to the PID controller in the main rack, along with the main gas cooler coil temperature (e.g., the T_GC signal from sensor 606B).

[0301] In some embodiments, the PID controller has a setpoint for the auxiliary gas cooler coil pressure of the auxiliary gas cooler coil 427, based on a function (e.g., a substantially optimal curve as a function) of the gas cooler outlet temperature (e.g., T_GC) to minimize the energy consumption of the system 700A. The function (e.g., curve) may be similar to a function (e.g., a substantially optimal curve as a function) of the gas cooler coil outlet temperature of the main gas cooler coil 429, which is used to reduce (e.g., minimize) the energy consumption of the system 700A. The function (e.g., curve) may include an increase in the auxiliary gas cooler coil pressure of the auxiliary gas cooler coil 427 as the temperature increases (e.g., P_Aux_GC=f2(T_GC)).

[0302] The function of the auxiliary gas cooler coil 427 (e.g., the curve) can be at a lower pressure (e.g., about 1 to about 3 bar (about 0.1 to about 0.3 MPa)) than the function of the main gas cooler coil 429 (e.g., the curve) in order to maintain a pressure offset between the main gas cooler coil 429 and the auxiliary gas cooler coil 427.

[0303] The PID controller can measure the error between the auxiliary gas cooler coil pressure setpoint and the actual auxiliary gas cooler coil pressure (P_Aux_GC) and calculate a command signal as an output, which is then sent to adjust the auxiliary HPV602B (for example, to the auxiliary HPV1 motor).

[0304] Using a command signal, the motor of the auxiliary HPV602B can adjust the opening of the auxiliary HPV602B so that the auxiliary gas cooler coil pressure approaches the auxiliary gas cooler coil pressure setpoint (for example, to achieve the desired P_Aux_GC=P_AUX_GC_setpoint). This allows a threshold amount (e.g., an optimal amount) of HPOUT flow to be obtained through PX410 for the threshold efficiency (e.g., good system efficiency) of the system 700A.

[0305] In some embodiments, the system 700A includes control of a rack-integrated boosterless subcool PX architecture with LPIN subcool via control for LPIN cooling with increased evaporator pressure of evaporator 418.

[0306] Sensor 606E may be a temperature sensor (for example, located between evaporator 418 and compressor 422, and between compressor 423 and compressor 422) that provides the compressor inlet temperature of compressor 422 (for example, MT compressor inlet temperature) to the PID controller of the main rack.

[0307] Sensor 606F may be a pressure sensor (for example, located between evaporator 418 and compressor 422, and between compressor 423 and compressor 422) that provides the compressor inlet pressure of compressor 422 (for example, MT compressor inlet pressure) to the PID controller of the main rack.

[0308] The PID controller can calculate the overheat temperature (e.g., overheat = T_MT_inlet - saturation temperature (at P_MT_inlet)). The PID controller may have a programmed setpoint for the overheat value (e.g., 20 degrees Fahrenheit).

[0309] The PID controller can measure the error between the actual overheat value and the overheat setpoint and calculate a command signal as an output to be sent to the three-way valve 710. Using this command signal, the three-way valve motor can open the valve to allow a portion of the flow from the evaporator 418 (e.g., the MT evaporator) to pass through the heat exchanger 372 (HX2). The remaining flow can bypass the heat exchanger 372 (HX2) and proceed to the inlet of the compressor 422 (e.g., the MT compressor inlet).

[0310] The amount of flow passing through heat exchanger 372 (HX2) can cool the LPIN flow, thereby increasing the density of the LPIN flow. This increase in LPIN flow density can improve the performance of PX410 and improve the efficiency of system 700A.

[0311] This control makes it easier to raise the pressure in the evaporator 418 (e.g., the MT evaporator pressure) to a higher value (e.g., an increase of about 30 to 80 PSI (about 0.207 to 0.552 MPa)) compared to conventional systems, while still being able to provide a threshold amount of superheating to the inlet of the compressor 422 (e.g., the MT compressor inlet). This may be because a portion of the flow from the evaporator 318 through the heat exchanger 372 (HX2) (e.g., the MT evaporator flow) heats the LPIN flow and provides additional superheating to the inlets of the evaporator 418 and / or the compressor 422 (e.g., the MT inlet). The increased evaporator pressure in the evaporator 418 (e.g., the increased MT evaporator pressure) can improve system efficiency by reducing the work done by the compressor 422 (e.g., reducing the work done by the MT compressor).

[0312] In some embodiments, the system 700 includes a PX410. The PX may be configured to receive a first fluid via a high-pressure in (HPIN) port, receive a second fluid via a low-pressure in (LPIN) port, exchange pressure between the first and second fluids, and provide the first fluid via a low-pressure out (LPOUT) port and the second fluid via a high-pressure out (HPOUT) port.

[0313] The system 700 may further comprise a main gas cooler coil 429 configured to provide a main gas cooler coil outlet flow, the main gas cooler coil outlet flow being divided into a first flow and a second flow. The system 700 may further comprise a first heat exchanger 370 configured to subcool the first flow, provide the first flow to the HPIN of PX410, and convert the second flow into a gas-liquid two-phase mixture, and provide the gas-liquid two-phase mixture to the first heat exchanger 370 to absorb heat from the first flow and subcool the first flow.

[0314] The system 700 may further include a second heat exchanger 372 configured to receive a second flow from the first heat exchanger 370 and to provide the second flow as a second fluid to the LPIN port. The second heat exchanger 372 is configured to cool the second flow using at least a portion of the outlet flow from the first evaporator 418. The second heat exchanger 372 is configured to heat the outlet flow from the first evaporator 418.

[0315] The system 700 may further include an auxiliary gas cooler coil 427 configured to receive a second fluid from the HPOUT port, dissipate heat from the second fluid, and supply the second fluid to the receiver 411.

[0316] The system 700 may further include a receiver 411 configured to receive a first fluid from the LPOUT port and a second fluid from the auxiliary gas cooler coil 427.

[0317] The system 700 may further include a three-way valve 710 downstream of the first evaporator 418, which is configured to control at least a portion of the outlet flow from the first evaporator 418 to the second heat exchanger 372.

[0318] System 700 may further include a rack controller. The processing logic of the rack controller (e.g., processing unit, control module, PID controller, etc.) The fan for the main gas cooler coil is operated in such a way that the temperature at the outlet of the main gas cooler coil approaches the ambient temperature. Identifying sensor data associated with the main gas cooler coil outlet flow, wherein the sensor data includes the main gas cooler coil outlet temperature and the main gas cooler coil outlet pressure. Based on the outlet temperature of the main gas cooler coil, the pressure setpoint for the main gas cooler coil is determined, Based on the difference between the main gas cooler coil pressure setpoint and the main gas cooler coil outlet pressure, the motor speed associated with the pressure exchanger is adjusted to bring the main gas cooler coil outlet pressure closer to the main gas cooler coil pressure setpoint. It can be configured to perform one or more of the following actions.

[0319] In some embodiments, the processing logic of the rack controller (e.g., processing unit, control module, PID controller, etc.) Identifying the auxiliary gas cooler coil pressure, Based on the outlet temperature of the main gas cooler coil, the set point of the auxiliary gas cooler coil pressure is determined, Based on the difference between the auxiliary gas cooler coil pressure setpoint and the auxiliary gas cooler coil pressure, the auxiliary high-pressure valve is adjusted to bring the auxiliary gas cooler coil pressure closer to the auxiliary gas cooler coil pressure setpoint. It can be configured to perform one or more of the following actions.

[0320] In some embodiments, the processing logic of the rack controller (e.g., processing unit, control module, PID controller, etc.) To determine the temperature of the first compressor inlet and the pressure of the first compressor inlet, Based on the pressure at the first compressor inlet, the temperature setpoint at the first compressor inlet is determined, Based on the difference between the first compressor inlet temperature setpoint and the first compressor inlet temperature, adjustment is triggered to the first three-way valve located between the first evaporator, the second heat exchanger, and the first compressor. It can be configured to perform one or more of the following actions.

[0321] In some embodiments, the processing logic of the rack controller (e.g., processing unit, control module, PID controller, etc.) To determine the temperature of the second compressor inlet and the pressure of the second compressor inlet, Based on the pressure at the second compressor inlet, the temperature setpoint at the second compressor inlet is determined, Based on the difference between the second compressor inlet temperature setpoint and the second compressor inlet temperature, adjustment is triggered to the second three-way valve located between the second evaporator, the third heat exchanger, and the second compressor. It can be configured to perform one or more of the following actions.

[0322] In some embodiments, the main gas cooler coil 429 and the auxiliary gas cooler coil 427 are part of the same unit and are configured to be at different pressures from each other.

[0323] Figure 7B shows System 700B, which includes control of a rack-integrated boosterless subcool PX architecture with LPIN subcool via control for increasing LPOUT liquid content with increased pressure in evaporator 419 (e.g., increased LT evaporator pressure).

[0324] System 700B may have control of the three-way valve 710 (e.g., three-way valve 710A and / or three-way valve 701B) to maintain inlet superheating of the evaporator 418 and / or compressor 422 (e.g., to maintain MT inlet superheating) at the increased pressure of the evaporator 418 (e.g., the increased evaporator pressure described with respect to System 700A).

[0325] Compared to system 700A, system 700B may have an additional heat exchanger 374 (HX3) and an additional three-way valve 701B, which are added after the evaporator 419 (e.g., LT evaporator).

[0326] Sensor 606G may be a temperature sensor located between the evaporator 419 and the compressor 423 (for example, located at the LT compressor inlet). The signal from sensor 606G may be provided as an input signal to the PID controller in the main rack.

[0327] Sensor 606H may be a pressure sensor located between the evaporator 419 and the compressor 423 (for example, located at the LT compressor inlet). The signal from sensor 606H may be provided as an input signal to the PID controller in the main rack.

[0328] The PID controller can calculate the overheat temperature (e.g., overheat = T_LT_inlet - saturation temperature (at P_LT_inlet)). The PID controller may have programmed setpoints for the overheat value (e.g., 20 degrees Fahrenheit).

[0329] The PID controller can measure the error between the actual overheat value and the overheat setpoint and calculate a command signal as an output to be sent to the three-way valve 710B. Using this command signal, the motor of the three-way valve 710B opens the valve so that a portion of the flow from the evaporator 419 (e.g., LT evaporator) is sent through the heat exchanger 374 (HX3), while the remaining flow bypasses the heat exchanger 374 (HX3) and is supplied to the inlet of the compressor 423 (e.g., LT compressor inlet).

[0330] The amount of flow through the heat exchanger 374 (HX3) increases the liquid content of the LPOUT flow, thereby increasing the total liquid mass fraction of the flow entering the receiver 411. This increased liquid mass fraction improves the efficiency of system 700B by increasing the heat absorption capacity per unit compressor work consumed, or by reducing the compressor work per unit heat absorbed in the evaporator.

[0331] This control can facilitate raising the pressure in the evaporator 419 to a higher value (e.g., by about 30 to about 80 PSI (about 0.207 to about 0.552 MPa)) while providing a threshold amount of superheating to the compressor 423 (e.g., the LT compressor inlet). This is because a portion of the outlet flow from the evaporator 419 through the heat exchanger 374 (HX3) heats the flow, providing additional superheating to the inlet of the compressor 423 (e.g., the LT inlet). The increased pressure in the evaporator 419 (e.g., the increased LT evaporator pressure) can improve the efficiency of the system 700B by reducing the work done by the compressor 423 (e.g., reducing the work done by the LT compressor).

[0332] Figure 7C may show a system 700C comprising a second type of boosterless architecture (e.g., parallel compression without LP boosters) and a control unit.

[0333] In some embodiments, the system 700C exhibits a boosterless PX architecture in which the LPOUT flow from PX410 is supplied (e.g., drops into) the inlet (e.g., MT inlet) of the compressor 422.

[0334] The flow from the main gas cooler coil 429 may pass through the flow branch 708 to generate two flows (e.g., a first flow and a second flow). The first flow may proceed to the HPN of PX410, where it may expand to a lower pressure and become a low-temperature gas-liquid two-phase mixture at LPOUT.

[0335] The LPOUT flow can proceed through the heat exchanger 370 (HX1), absorbing heat from the second flow at the flow branch and converting substantially all (e.g., all) of the liquid into gas. This low-pressure gas flow can then pass through the low-pressure valve (LPV) 603 and be further reduced in pressure to substantially the same as the pressure in the evaporator 418 (e.g., the MT evaporator pressure), and proceed to the inlet of the compressor 422 (e.g., the MT compressor inlet).

[0336] The second flow, cooled in heat exchanger 370 (HX1), can then expand to a low pressure through auxiliary HPV 602D, becoming a low-temperature gas-liquid two-phase mixture. This low-temperature gas-liquid two-phase mixture can further release heat in heat exchanger 372 (HX2) to the lower-temperature outlet flow of evaporator 418 (lower-temperature MT evaporator outlet flow), reducing the gas mass fraction and increasing the liquid mass fraction. This two-phase flow with reduced flash gas can then proceed to receiver 411.

[0337] Flash gas from receiver 411 can be guided through the LPIN port of PX410. Since the LPOUT pressure may be lower than the pressure in receiver 411 at this time (for example, as it is discharged to the MT compressor inlet pressure), the differential pressure between the LPIN port and the LPOUT port of PX410 can drive the flow through the LPIN port of PX410.

[0338] In some embodiments, the LPIN flow is compressed to a high pressure by PX410 and exits through the HPOUT port. The flow then releases heat in the auxiliary gas cooler coil 427 and becomes cooler. The flow then decreases in pressure across the auxiliary HPV602B and becomes a cool gas-liquid two-phase mixture. The flow then releases further heat in the heat exchanger 374 (HX3) to a cooler outlet flow from the evaporator 419 (e.g., a cooler LT evaporator outlet flow), which can reduce the gaseous mass fraction and increase the liquid mass fraction. This reduces the flash gas of the two-phase flow before the flow proceeds to the receiver.

[0339] The heat exchanger 372 (HX2) can provide superheat to the outlet of the evaporator 418 (e.g., the MT evaporator outlet), which may allow the pressure in the evaporator 418 (e.g., the MT evaporator pressure) to be increased while satisfying the superheat threshold at the compressor 422 inlet (e.g., the MT compressor inlet superheat threshold). This increased pressure in the evaporator 418 (e.g., increased MT evaporator pressure) may reduce the energy consumption of the compressor 422 (e.g., the MT compressor energy consumption) for substantially the same amount of heat absorption, thereby further improving the energy efficiency of system 700C.

[0340] The heat exchanger 374 (HX3) can provide superheat to the outlet of the evaporator 419 (e.g., the LT evaporator outlet), which may allow the pressure in the evaporator 419 (e.g., the LT evaporator pressure) to be increased while still satisfying the compressor 423 inlet superheat threshold (e.g., the LT compressor inlet superheat requirement). This increased pressure in the evaporator 419 (e.g., increased LT evaporator pressure) may reduce the energy consumption of the compressor 423 (e.g., the LT compressor energy consumption) for substantially the same amount of heat absorption, thereby further improving the energy efficiency of system 700C.

[0341] System 700C may be equipped with a three-way valve 710A after the evaporator 418 (e.g., MT evaporator), which may bypass a portion of the evaporator flow (e.g., MT evaporator flow) so as not to pass through the heat exchanger 372 (HX2) in order to provide control over the overheating of the compressor 422 (e.g., to facilitate control over the overheating of the MT compressor intake).

[0342] System 700C may be equipped with a three-way valve 710B after the evaporator 419 (e.g., LT evaporator), which may bypass a portion of the evaporator flow (e.g., LT evaporator flow) so as not to pass through the heat exchanger 374 (HX3) in order to provide control over the overheating of the compressor 423 (e.g., to facilitate control over the overheating of the LT compressor intake).

[0343] In some embodiments, the system 700C provides control for a rack-integrated booster-less PX system via main gas cooler coil pressure control of the main gas cooler coil 429. In some embodiments, the main gas cooler coil 429 and the auxiliary gas cooler coil 427 are integrated into a single unit (e.g., the auxiliary gas cooler coil 427 has a pressure that is about 1 to about 3 bar (about 0.1 to about 0.3 MPa) lower than the pressure of the main gas cooler coil 429).

[0344] In some embodiments, the control is performed via a main rack controller.

[0345] In some embodiments, the fan of the gas cooler unit (e.g., the unit comprising the main gas cooler coil 429 and / or the auxiliary gas cooler coil 427) causes the gas cooler outlet temperature of the refrigerant fluid to approach the ambient temperature (e.g., to approach the ambient temperature as close as possible). The fan speeds of both the main gas cooler coil 429 and the auxiliary gas cooler coil 427 may be controlled by the main rack controller.

[0346] The sensor 606B is main gas cooler coil temperature data (T associated with the fluid exiting the main gas cooler coil 429 GCout ) (e.g., located between the flow branch 708 and the main gas cooler coil 427) that provides a temperature sensor. The sensor 606B may measure the gas cooler outlet temperature.

[0347] The sensor 606C is main gas cooler coil pressure data (P associated with the fluid exiting the main gas cooler coil 429 GCout ) (e.g., located between the flow branch 708 and the main gas cooler coil 429) that provides a pressure sensor. The sensor 606C may measure the gas cooler outlet pressure.

[0348] The main gas cooler coil temperature data from the sensor 606B and the main gas cooler coil pressure data from the sensor 606C may be provided as input signals to the PID controller of the main rack.

[0349] The PID controller may have a main gas cooler pressure setpoint (e.g., main gas cooler coil pressure setpoint) based on a function (e.g., a substantially optimal curve as a function) of the gas cooler coil outlet temperature of the main gas cooler coil 429 in order to reduce (e.g., minimize) the energy consumption of the system 700C. The function (e.g., curve) may include the fact that as the temperature of the main gas cooler coil 429 increases, the pressure of the main gas cooler coil 429 increases (e.g., P_GC=f1(T_GC)).

[0350] The PID controller can measure the error (e.g., difference) between the setpoint and the actual P_GC and calculate a command signal as an output to be sent to the PX410's motor (e.g., a variable frequency drive (VFD)). Using the command signal, the PX410's motor can adjust its speed until the gas cooler coil pressure substantially matches the gas cooler coil pressure setpoint (e.g., until the desired gas cooler pressure = setpoint is reached).

[0351] In some embodiments, system 700C provides control of the rack-integrated boosterless PX system via auxiliary gas cooler coil pressure control of auxiliary gas cooler coil 427.

[0352] Sensor 606D may be a pressure sensor located at the fluid outlet of the auxiliary gas cooler coil 427 (for example, sensor 606D measures the auxiliary gas cooler coil pressure). The signal from sensor 606D (e.g., sensor data, auxiliary gas cooler coil pressure) may be provided as input signals to the PID controller in the main rack, along with the main gas cooler coil temperature (e.g., the T_GC signal from sensor 606B).

[0353] In some embodiments, the PID controller has a setpoint for the auxiliary gas cooler coil pressure of the auxiliary gas cooler coil 427, based on a function (e.g., a substantially optimal curve as a function) of the gas cooler outlet temperature (e.g., T_GC) to minimize the energy consumption of the system 700C. The function (e.g., curve) may be similar to a function (e.g., a substantially optimal curve as a function) of the gas cooler coil outlet temperature of the main gas cooler coil 429, which is used to reduce (e.g., minimize) the energy consumption of the system 700C. The function (e.g., curve) may include an increase in the auxiliary gas cooler coil pressure of the auxiliary gas cooler coil 427 as the temperature increases (e.g., P_Aux_GC=f2(T_GC)).

[0354] The function of the auxiliary gas cooler coil 427 (e.g., the curve) can be at a lower pressure (e.g., about 1 to about 3 bar (about 0.1 to about 0.3 MPa)) than the function of the main gas cooler coil 429 (e.g., the curve) so as to maintain a pressure offset between the main gas cooler coil 429 and the auxiliary gas cooler coil 427.

[0355] The PID controller can measure the error between the auxiliary gas cooler coil pressure setpoint and the actual auxiliary gas cooler coil pressure (P_Aux_GC) and calculate a command signal as an output, which is then sent to adjust the auxiliary HPV602B (for example, to the auxiliary HPV1 motor).

[0356] Using a command signal, the motor of the auxiliary HPV602B can adjust the opening of the auxiliary HPV602B so that the auxiliary gas cooler coil pressure approaches the auxiliary gas cooler coil pressure setpoint (for example, to achieve the desired P_Aux_GC=P_AUX_GC_setpoint). This allows a threshold amount (e.g., an optimal amount) of HPOUT flow to be obtained through PX410 for the threshold efficiency (e.g., good system efficiency) of the system 700C.

[0357] In some embodiments, the system 700C provides control of the rack-integrated boosterless PX system via controls for increasing the liquid mass fraction of the flow toward the receiver 411 and controls for increasing the pressure in the evaporator 418 (e.g., MT evaporator) and / or evaporator 419 (e.g., LT evaporator).

[0358] Sensor 606E may be a temperature sensor (for example, located between evaporator 418 and compressor 422, and between compressor 423 and compressor 422) that provides the compressor inlet temperature of compressor 422 (for example, MT compressor inlet temperature) to the PID controller of the main rack.

[0359] Sensor 606F may be a pressure sensor (for example, located between evaporator 418 and compressor 422, and between compressor 423 and compressor 422) that provides the compressor inlet pressure of compressor 422 (for example, MT compressor inlet pressure) to the PID controller of the main rack.

[0360] The PID controller can calculate the overheat temperature (e.g., overheat = T_MT_inlet - saturation temperature (at P_MT_inlet)). The PID controller may have programmed setpoints for the overheat value (e.g., 20 degrees Fahrenheit).

[0361] The PID controller can measure the error between the actual overheat value and the overheat setpoint and calculate a command signal as an output to be sent to the three-way valve 710A. Using this command signal, the three-way valve motor can open the three-way valve 710A to allow a portion of the flow from the evaporator 418 (e.g., the MT evaporator) to pass through the heat exchanger 372 (HX2). The remaining flow can bypass the heat exchanger 372 (HX2) and proceed to the inlet of the compressor 422 (e.g., the MT compressor inlet).

[0362] The amount of flow passing through heat exchanger 372 (HX2) can increase the liquid content of the flow exiting auxiliary HPV 602D, thereby increasing the total liquid mass fraction of the flow entering receiver 411. This increased liquid mass fraction can improve the efficiency of system 700C by increasing the heat absorption capacity per unit compressor work consumed, or by reducing the compressor work per unit heat absorbed in evaporators 418 and / or 419.

[0363] This control makes it easier to raise the pressure in the evaporator 418 (e.g., the MT evaporator pressure) to a higher value (e.g., an increase of about 30 to 80 PSI (about 0.207 to 0.552 MPa)) compared to conventional systems, while still being able to provide a threshold amount of superheating to the inlet of the compressor 422 (e.g., the MT compressor inlet). This may be because a portion of the flow from the evaporator 318 through the heat exchanger 372 (HX2) (e.g., the MT evaporator flow) heats the LPIN flow, providing additional superheating to the inlets of the evaporator 418 and / or the compressor 422 (e.g., the MT inlet). The increased evaporator pressure in the evaporator 418 (e.g., the increased MT evaporator pressure) can improve system efficiency by reducing the work done by the compressor 422 (e.g., reducing the work done by the MT compressor).

[0364] Sensor 606G may be a temperature sensor located between the evaporator 419 and the compressor 423 (for example, located at the LT compressor inlet). The signal from sensor 606G may be provided as an input signal to the PID controller in the main rack.

[0365] Sensor 606H may be a pressure sensor located between the evaporator 419 and the compressor 423 (for example, located at the LT compressor inlet). The signal from sensor 606H may be provided as an input signal to the PID controller in the main rack.

[0366] The PID controller can calculate the overheat temperature (e.g., overheat = T_LT_inlet - saturation temperature (at P_LT_inlet)). The PID controller may have programmed setpoints for the overheat value (e.g., 20 degrees Fahrenheit).

[0367] The PID controller can measure the error between the actual overheat value and the overheat setpoint and calculate a command signal as an output to be sent to the three-way valve 710B. Using this command signal, the motor of the three-way valve 710B opens the valve so that a portion of the flow from the evaporator 419 (e.g., LT evaporator) is sent through the heat exchanger 374 (HX3), while the remaining flow bypasses the heat exchanger 374 (HX3) and is supplied to the inlet of the compressor 423 (e.g., LT compressor inlet).

[0368] The amount of flow passing through the heat exchanger 374 (HX3) increases the liquid content of the LPOUT flow, thereby increasing the total liquid mass fraction of the flow entering the receiver 411. This increased liquid mass fraction improves the efficiency of system 700C by increasing the heat absorption capacity per unit compressor work consumed, or by reducing the compressor work per unit heat absorbed in the evaporator.

[0369] This control can facilitate raising the pressure in the evaporator 419 to a higher value (e.g., by about 30 to about 80 PSI (about 0.207 to about 0.552 MPa)) (e.g., raising the LT evaporator pressure) while providing a threshold amount of superheating to the compressor 423 (e.g., the LT compressor inlet). This is because a portion of the outlet flow from the evaporator 419 through the heat exchanger 374 (HX3) heats the flow, providing additional superheating to the inlet of the compressor 423 (e.g., the LT inlet). The increased pressure in the evaporator 419 (e.g., the increased LT evaporator pressure) can improve the efficiency of the system 700C by reducing the work done by the compressor 423 (e.g., reducing the work done by the LT compressor).

[0370] In some embodiments, the system 700C includes a PX410 configured to receive a first fluid via an HPIN port, receive a second fluid via an LPIN port, exchange pressure between the first and second fluids, and provide the first fluid via an LPOUT port and the second fluid via an HPOUT port.

[0371] System 700C may further comprise a main gas cooler coil 429 configured to provide a main gas cooler coil outlet flow, which is divided into a first flow and a second flow. The first flow is provided to the HPIN port and expands to a lower pressure to become a low-temperature gas-liquid two-phase mixture at the LPOUT port.

[0372] System 700C may further comprise a first heat exchanger 370 configured to receive a low-temperature gas-liquid two-phase mixture from an LPOUT port, receive a second flow, and transfer heat from the second flow to the low-temperature gas-liquid two-phase mixture to convert the low-temperature gas-liquid two-phase mixture into a gas.

[0373] System 700C may further include a low-pressure valve (LPV) 603 configured to receive gas from a first heat exchanger 370 and supply the gas to a first compressor 422, and a second auxiliary high-pressure valve (HPV) 602D configured to receive a second flow from the first heat exchanger 370.

[0374] System 700C may further comprise a second heat exchanger 372 configured to receive a second flow from the auxiliary HPV602D, receive an outlet flow from the first evaporator 418, and cause heat transfer from the second flow to the outlet flow. System 700C may further comprise a receiver 411 configured to receive a second flow from the second heat exchanger 372 and supply gas to the LPIN port.

[0375] System 700C may further comprise an auxiliary gas cooler coil 427 configured to receive a second flow from the HPOUT port. System 700C may further comprise an auxiliary HPV 602B configured to receive a second flow from the auxiliary gas cooler coil 427. System 700C may further comprise a third heat exchanger 374 configured to receive a second flow from the first auxiliary HPV 602B, receive an outlet flow from a second evaporator 419, provide heat from the second flow to the outlet flow, and provide the second flow to a receiver 411.

[0376] System 700C may further include a first three-way valve 710A located between a first evaporator 418, a second heat exchanger 372, and a first compressor 422. System 700C may further include a second three-way valve 710B located between a second evaporator 419, a third heat exchanger 374, and a second compressor 423.

[0377] The System 700C may also include a rack controller. The processing logic of the rack controller (e.g., processing unit, control module, PID controller, etc.) The fan associated with the main gas cooler coil is operated to bring the temperature at the outlet of the main gas cooler coil closer to the ambient temperature, Identifying sensor data associated with the main gas cooler coil outlet flow, wherein the sensor data includes the main gas cooler coil outlet temperature and the main gas cooler coil outlet pressure. Based on the outlet temperature of the main gas cooler coil, the pressure setpoint for the main gas cooler coil is determined, Based on the difference between the main gas cooler coil pressure setpoint and the main gas cooler coil outlet pressure, the motor speed associated with the pressure exchanger is adjusted to bring the main gas cooler coil outlet pressure closer to the main gas cooler coil pressure setpoint. It can be configured to perform one or more of the following actions.

[0378] In some embodiments, the processing logic of the rack controller (e.g., processing unit, control module, PID controller, etc.) Identifying the auxiliary gas cooler coil pressure, Based on the outlet temperature of the main gas cooler coil, the set point of the auxiliary gas cooler coil pressure is determined, Based on the difference between the auxiliary gas cooler coil pressure setpoint and the auxiliary gas cooler coil pressure, the auxiliary high-pressure valve is adjusted to bring the auxiliary gas cooler coil pressure closer to the auxiliary gas cooler coil pressure setpoint. It can be configured to perform one or more of the following actions.

[0379] In some embodiments, the processing logic of the rack controller (e.g., processing unit, control module, PID controller, etc.) To determine the temperature of the first compressor inlet and the pressure of the first compressor inlet, Based on the pressure at the first compressor inlet, the temperature setpoint at the first compressor inlet is determined, Based on the difference between the first compressor inlet temperature setpoint and the first compressor inlet temperature, adjustment is triggered to a three-way valve located between the first evaporator, the second heat exchanger, and the first compressor. It can be configured to perform one or more of the following actions.

[0380] In some embodiments, the processing logic of the rack controller (e.g., processing unit, control module, PID controller, etc.) To determine the temperature of the second compressor inlet and the pressure of the second compressor inlet, Based on the pressure at the second compressor inlet, the temperature setpoint at the second compressor inlet is determined, Based on the difference between the second compressor inlet temperature setpoint and the second compressor inlet temperature, adjustment is triggered to the three-way valve located between the second evaporator, the third heat exchanger, and the second compressor. It can be configured to perform one or more of the following actions.

[0381] In some embodiments, the main gas cooler coil 429 and the auxiliary gas cooler coil 427 are part of the same unit and are configured to be at different pressures from each other.

[0382] Figure 8 is a block diagram showing a computer system 800 according to several embodiments. In some embodiments, the computer system 800 is a client device. In some embodiments, the computer system 800 is a controller device (e.g., a server, a control module, a central control system, a controller of this disclosure, etc.).

[0383] In some embodiments, the computer system 800 is connected to other computer systems (for example, via a network such as a local area network (LAN), intranet, extranet, or the Internet). The computer system 800 operates as a server or client computer in a client-server environment, or as a peer computer in a peer-to-peer or distributed network environment. In some embodiments, the computer system 800 is provided by a personal computer (PC), tablet PC, set-top box (STB), personal digital assistant (PDA), mobile phone, web appliance, server, network router, switch or bridge, or any device capable of executing (sequentially or otherwise) a set of instructions specifying the actions to be performed by such device. Furthermore, the term “computer” includes any set of computers that individually or jointly execute a set (or more sets) of instructions to perform one or more of the methods described herein.

[0384] In some embodiments, the computer system 800 comprises a processing unit 802, a volatile memory 804 (e.g., random access memory (RAM)), a non-volatile memory 806 (e.g., read-only memory (ROM) or EEPROM (Electrically-Erasable Programmable ROM)), and / or a data storage device 816, which communicate with each other via a bus 808.

[0385] In some embodiments, the processing unit 802 is provided by one or more processors, for example, a general-purpose processor (e.g., a CISC (Complex Instruction Set Computing) microprocessor, a RISC (Reduced Instruction Set Computing) microprocessor, a VLIW (Very Long Instruction Word) microprocessor, a microprocessor implementing other types of instruction sets, or a microprocessor implementing a combination of multiple types of instruction sets) or a dedicated processor (e.g., an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), a digital signal processor (DSP), a PID controller, or a network processor). In some embodiments, the processing unit 802 is provided by one or more of the following: a single processor, multiple processors, a single processor having multiple processing cores, and / or the like.

[0386] In some embodiments, the computer system 800 further comprises a network interface device 822 (e.g., coupled to network 874). In some embodiments, the computer system 800 comprises one or more input / output (I / O) devices. In some embodiments, the computer system 800 also comprises a video display unit 810 (e.g., a liquid crystal display (LCD)), an alphanumeric input device 812 (e.g., a keyboard), a cursor control device 814 (e.g., a mouse), and / or a signal generator 820. The computer system 800 may also comprise a signal input device 815 for receiving signals from other devices, for example. For example, the signal input device 815 may facilitate the computer system 800 receiving measurement data from sensors associated with the fluid processing system. The signal generator 820 may be used to generate and / or transmit control signals for sending commands to one or more components of the fluid processing system. The signal generator 820 may transmit control signals to various high-pressure valves, booster pumps, cooling components, PX components, etc.

[0387] In some implementations, a data storage device 816 (e.g., disk drive storage, fixed and / or removable storage, fixed disk drive, removable memory card, optical storage, network-attached storage (NAS), and / or storage area network (SAN)) includes a non-temporary computer-readable storage medium 824 that stores a directive 826 for encoding one or more of the methods or functions described herein and for implementing the methods described herein. A control module 180 (e.g., comprising either the controller and / or control module of this disclosure) may be included in the directive 826.

[0388] In some embodiments, the instruction 826 also resides entirely or partially in the volatile memory 804 and / or the processing unit 802 during execution by the computer system 800, and therefore, in some embodiments, the volatile memory 804 and the processing unit 802 also constitute a machine-readable storage medium.

[0389] In illustrative examples, the computer-readable storage medium 824 is shown as a single medium, but the term “computer-readable storage medium” includes a single or multiple mediums (e.g., a centralized or distributed database, and / or associated caches and servers) that store one or more sets of executable instructions. The term “computer-readable storage medium” also includes any tangible medium capable of storing or encoding a set of instructions for execution by a computer, such instructions causing the computer to execute one or more of the methods described herein. The term “computer-readable storage medium” includes, but is not limited to, solid-state memory, optical media, and magnetic media.

[0390] The methods, components, and features described herein may be implemented by individual hardware components or integrated into the functionality of other hardware components such as ASICs, FPGAs, DSPs, or similar devices. Furthermore, the methods, components, and features may be implemented by firmware modules or functional circuits within a hardware device. Furthermore, the methods, components, and features may be implemented in any combination of hardware devices and computer program components, or within a computer program.

[0391] Unless otherwise specified or evident from the context, terms such as “operate,” “regulate,” “cause,” “control,” “determine,” “specify,” “provide,” “receive,” “generate,” “obtain,” “calculate,” “operate,” and “obtain” refer to actions and processes performed or implemented by a computer system, which manipulates data represented as physical (electronic) quantities in the computer system’s registers and memory, and converts it to other data similarly represented as physical quantities in the computer system’s memory or registers, or in other such information storage devices, transmitters, or display devices. Furthermore, terms such as “first,” “second,” “third,” and “fourth” as used herein are intended as labels to distinguish between different elements and do not necessarily have an ordinal meaning according to their numerical designation.

[0392] The examples described herein also relate to apparatus for carrying out the methods described herein. This apparatus may be specifically configured for carrying out the methods described herein, or it may comprise a general-purpose computer system selectively programmed by computer programs stored in the computer system. Such computer programs may be stored in computer-readable tangible storage media.

[0393] The methods and illustrative examples described herein are not inherently related to any particular computer or other device. Various general-purpose systems may be used in accordance with the teachings described herein, or it may be preferable to configure more dedicated devices to perform each of the methods and / or their individual functions, routines, subroutines, or operations described herein. Examples of the structures of these various systems are described above.

[0394] The foregoing description includes numerous specific details, such as examples of particular systems, components, and methods, in order to provide a full understanding of some embodiments of the Disclosure. However, it will be apparent to those skilled in the art that at least some embodiments of the Disclosure can be implemented without these specific details. In other examples, well-known components or methods are not described in detail or are presented in simple block diagram form, in order to avoid unnecessarily obscuring the Disclosure. Thus, the specific details described are merely illustrative. Specific implementations may differ from these exemplary details and are still intended to be within the scope of the Disclosure. Descriptions of systems in this Specified Specification may include descriptions of one or more optional components. Components may be provided in combinations not specifically described in the Disclosure and are still within the scope of the Disclosure. For example, any of the controllers and / or control modules of the Disclosure may be provided alone or in any combination in a fluid processing system within the scope of the Disclosure.

[0395] Throughout this specification, any reference to “one embodiment” or “embodiment” means that a particular feature, structure, or characteristic described in relation to that embodiment is present in at least one embodiment. Therefore, the occurrence of the phrase “in one embodiment” or “in one embodiment” in various parts of this specification does not necessarily refer to the same embodiment. Furthermore, the term “or” is intended to mean inclusive, not exclusive. Where the terms “about,” “substantially,” or “approximately” are used in this specification, this is intended to mean that the presented nominal value is accurate to within 10 percent. Also, terms such as “first,” “second,” “third,” and “fourth” used in this specification are intended as labels to distinguish between different elements and do not necessarily have an ordinal meaning according to their numerical designation.

[0396] As used herein, the terms “above,” “below,” “between,” “placed above,” “before,” “behind,” and “on top” refer to the relative position of one material layer or component with respect to other layers or components. For example, one layer placed above, above, or below another layer may be in direct contact with the other layer or may have one or more intervening layers. Furthermore, one layer placed between two layers may be in direct contact with both layers or may have one or more intervening layers. Similarly, unless expressly stated otherwise, one feature placed between two features may be in direct contact with an adjacent feature or may have one or more intervening layers or components.

[0397] Although the operations of the methods described herein are shown and described in a specific order, the order of operations of each method may be modified so that certain operations may be performed in reverse order, or so that certain operations may be performed at least partially concurrently with other operations. In other embodiments, separate operation commands or sub-operations may be performed intermittently and / or alternately.

[0398] It should be understood that the above description is intended to be illustrative and not limiting. Many other embodiments will become apparent to those skilled in the art upon reading and understanding the above description. Therefore, the scope of this disclosure should be determined by reference to the appended claims, along with the full scope of equivalents to which each claim is entitled.

Claims

1. A system, wherein the system is A pressure exchanger configured to receive a first fluid via a high-pressure in (HPIN) port, receive a second fluid via a low-pressure in (LPIN) port, exchange pressure between the first fluid and the second fluid, provide the first fluid via a low-pressure out (LPOUT) port, and provide the second fluid via a high-pressure out (HPOUT) port, A main gas cooler coil configured to provide a main gas cooler coil outlet flow, wherein the main gas cooler coil outlet flow is divided into a first flow and a second flow, and A system comprising: a first heat exchanger configured to subcool the first flow, provide the first flow to the HPIN of the pressure exchanger, convert the second flow into a gas-liquid two-phase mixture, and provide the gas-liquid two-phase mixture to the first heat exchanger, thereby absorbing heat from the first flow and subcooling the first flow.

2. The system according to claim 1, further comprising a second heat exchanger configured to receive the second flow from the first heat exchanger and to provide the second flow as the second fluid to the LPIN port, wherein the second heat exchanger is configured to cool the second flow using at least a portion of the outlet flow from the first evaporator, and the second heat exchanger is configured to heat the outlet flow from the first evaporator.

3. The system according to claim 2, further comprising an auxiliary gas cooler coil configured to receive the second fluid from the HPOUT port, release heat from the second fluid, and supply the second fluid to a receiver.

4. The system according to claim 3, further comprising the receiver configured to receive the first fluid from the LPOUT port and the second fluid from the auxiliary gas cooler coil.

5. The system according to claim 4, wherein a three-way valve downstream of the first evaporator is configured to control at least a portion of the outlet flow from the first evaporator to the second heat exchanger.

6. The system further comprises a rack controller, the rack controller is The fan of the main gas cooler coil is operated to bring the temperature at the outlet of the main gas cooler coil closer to the ambient temperature. Identifying sensor data associated with the main gas cooler coil outlet flow, wherein the sensor data includes the main gas cooler coil outlet temperature and the main gas cooler coil outlet pressure. Based on the outlet temperature of the main gas cooler coil, the pressure setpoint for the main gas cooler coil is determined, Based on the difference between the main gas cooler coil pressure setpoint and the main gas cooler coil outlet pressure, the motor speed associated with the pressure exchanger is adjusted so that the main gas cooler coil outlet pressure approaches the main gas cooler coil pressure setpoint. The system according to claim 1, configured to perform the following:

7. The system further comprises a rack controller, the rack controller is Identifying the auxiliary gas cooler coil pressure, Based on the outlet temperature of the main gas cooler coil, the set point of the auxiliary gas cooler coil pressure is determined, Based on the difference between the auxiliary gas cooler coil pressure setting point and the auxiliary gas cooler coil pressure, the auxiliary high-pressure valve is adjusted to bring the auxiliary gas cooler coil pressure closer to the auxiliary gas cooler coil pressure setting point. The system according to claim 1, configured to perform the following:

8. The system further comprises a rack controller, the rack controller is To determine the temperature of the first compressor inlet and the pressure of the first compressor inlet, Based on the pressure at the first compressor inlet, the temperature setpoint for the first compressor inlet is determined, Based on the difference between the first compressor inlet temperature setpoint and the first compressor inlet temperature, adjustment is triggered to the first three-way valve located between the first evaporator, the second heat exchanger, and the first compressor. The system according to claim 1, configured to perform the following:

9. The aforementioned rack controller is To determine the temperature of the second compressor inlet and the pressure of the second compressor inlet, Based on the pressure at the second compressor inlet, the temperature setpoint at the second compressor inlet is determined, Based on the difference between the second compressor inlet temperature setpoint and the second compressor inlet temperature, adjustment is triggered to the second three-way valve located between the second evaporator, the third heat exchanger, and the second compressor. The system according to claim 8, further configured to perform the following.

10. The system according to claim 3, wherein the main gas cooler coil and the auxiliary gas cooler coil are part of the same unit and are configured to be at different pressures from each other.

11. It is a system, A pressure exchanger configured to receive a first fluid via a high-pressure in (HPIN) port, receive a second fluid via a low-pressure in (LPIN) port, exchange pressure between the first fluid and the second fluid, provide the first fluid via a low-pressure out (LPOUT) port, and provide the second fluid via a high-pressure out (HPOUT) port, A main gas cooler coil configured to provide a main gas cooler coil outlet flow, wherein the main gas cooler coil outlet flow is divided into a first flow and a second flow, the first flow being supplied to the HPIN port and expanding to a lower pressure to become a low-temperature gas-liquid two-phase mixture at the LPOUT port, A system comprising: a first heat exchanger configured to receive the low-temperature gas-liquid two-phase mixture from the LPOUT port, receive the second flow, and transfer heat from the second flow to the low-temperature gas-liquid two-phase mixture to convert the low-temperature gas-liquid two-phase mixture into a gas.

12. The aforementioned system, A low-pressure valve (LPV) configured to receive the gas from the first heat exchanger and supply the gas to the first compressor, The system according to claim 11, further comprising a second auxiliary high-pressure valve (HPV) configured to receive the second flow from the first heat exchanger.

13. The aforementioned system, A second heat exchanger is configured to receive the second flow from the auxiliary HPV, receive the outlet flow from the first evaporator, and cause heat transfer from the second flow to the outlet flow. The system according to claim 12, further comprising a receiver configured to receive the second flow from the second heat exchanger and to supply the gas to the LPIN port.

14. The aforementioned system, An auxiliary gas cooler coil configured to receive the second flow from the HPOUT port, A first auxiliary HPV configured to receive the second flow from the auxiliary gas cooler coil, The system according to claim 13, further comprising: a third heat exchanger configured to receive the second flow from the first auxiliary HPV, receive the outlet flow from the second evaporator, provide heat from the second flow to the outlet flow, and provide the second flow to the receiver.

15. The aforementioned system, A first three-way valve is positioned between the first evaporator, the second heat exchanger, and the first compressor, The system according to claim 14, further comprising a second three-way valve positioned between the second evaporator, the third heat exchanger, and the second compressor.

16. The system further comprises a rack controller, the rack controller is The fan associated with the main gas cooler coil is operated to bring the outlet temperature of the main gas cooler coil closer to the ambient temperature. Identifying sensor data associated with the main gas cooler coil outlet flow, wherein the sensor data includes the main gas cooler coil outlet temperature and the main gas cooler coil outlet pressure. Based on the outlet temperature of the main gas cooler coil, the pressure setpoint for the main gas cooler coil is determined, Based on the difference between the main gas cooler coil pressure setpoint and the main gas cooler coil outlet pressure, the motor speed associated with the pressure exchanger is adjusted so that the main gas cooler coil outlet pressure approaches the main gas cooler coil pressure setpoint. The system according to claim 11, configured to perform the following:

17. The system further comprises a rack controller, the rack controller is Identifying the auxiliary gas cooler coil pressure, Based on the outlet temperature of the main gas cooler coil, the set point of the auxiliary gas cooler coil pressure is determined, Based on the difference between the auxiliary gas cooler coil pressure setting point and the auxiliary gas cooler coil pressure, the auxiliary high-pressure valve is adjusted to bring the auxiliary gas cooler coil pressure closer to the auxiliary gas cooler coil pressure setting point. The system according to claim 11, configured to perform the following:

18. The system further comprises a rack controller, the rack controller is To determine the temperature of the first compressor inlet and the pressure of the first compressor inlet, Based on the pressure at the first compressor inlet, the temperature setpoint for the first compressor inlet is determined, Based on the difference between the first compressor inlet temperature setpoint and the first compressor inlet temperature, adjustment is triggered to the three-way valve located between the first evaporator, the second heat exchanger, and the first compressor. The system according to claim 11, configured to perform the following:

19. The system further comprises a rack controller, the rack controller is To determine the temperature of the second compressor inlet and the pressure of the second compressor inlet, Based on the pressure at the second compressor inlet, the temperature setpoint at the second compressor inlet is determined, Based on the difference between the second compressor inlet temperature setpoint and the second compressor inlet temperature, adjustment is triggered to the three-way valve located between the second evaporator, the third heat exchanger, and the second compressor. The system according to claim 11, configured to perform the following:

20. The system according to claim 14, wherein the main gas cooler coil and the auxiliary gas cooler coil are part of the same unit and are configured to be at different pressures from each other.

21. A method, wherein the said method is Determining the outlet temperature of the gas cooler coil, Calculating the pressure setting point of the aforementioned gas cooler coil, This includes causing the rotational speed of the rotor of a pressure exchanger (PX) to be adjusted to satisfy the pressure setpoint of the gas cooler coil, wherein the PX is configured to exchange pressure between a first fluid and a second fluid, A first inlet configured to receive the first fluid from a mechanical subcooler, A second inlet configured to receive the second fluid from the mechanical subcooler, A first outlet configured to supply the second fluid to the gas cooler coil, wherein the second fluid is supplied from the gas cooler coil to an auxiliary high-pressure valve, and the second fluid is supplied from the auxiliary high-pressure valve to a receiver, A method comprising a second outlet configured to supply the first fluid to the receiver.

22. The mechanical subcooler is configured to exchange heat between the first fluid received from the gas cooler coil and the second fluid received from the gas cooler coil via a bypass high-pressure valve, and The method according to claim 21, wherein causing the adjustment of the rotational speed of the rotor to satisfy the pressure setpoint of the gas cooler coil includes reducing the opening ratio value of the bypass high pressure valve and increasing the rotational speed of the rotor until the pressure setpoint of the gas cooler coil is satisfied.

23. The aforementioned method, The difference between the outlet temperature of the gas cooler coil and the corresponding outlet temperature of the mechanical subcooler is determined. The method according to claim 22, comprising adjusting the opening degree of the bypass high-pressure valve until the subcooling setting point is met.

24. The method according to claim 22, further comprising adjusting the corresponding opening of the auxiliary high-pressure valve to substantially match the opening of each of the bypass high-pressure valves.

25. The method according to claim 21, wherein the receiver is configured to reduce flash gas.

26. The first inlet is a high-voltage in port. The second inlet is a low-voltage in port. The first outlet is a high-voltage out port, and, The method according to claim 21, wherein the second outlet is a low-pressure out port.

27. The controller is The rotational speed of the rotor of the PX, The corresponding operation of the bypass high-pressure valve, or The operation of each of the auxiliary high-pressure valves, The method according to claim 21, configured to control one or more of the following.

28. A method, wherein the said method is Main gas cooler coil outlet temperature associated with the main gas cooler coil, The main gas cooler coil pressure associated with the main gas cooler coil, or Subcooler outlet pressure associated with the subcooler, Identifying sensor data that includes at least one of the following, Based on the aforementioned sensor data, the high-pressure in (HPIN) subcool delta temperature setpoint associated with a pressure exchanger equipped with an HPIN port is determined, A method comprising causing the operation of a bypass high-pressure valve (HPV) located between the main gas cooler coil and the subcooler based on the HPN subcooler delta temperature setpoint.

29. The method according to claim 28, wherein the HPN subcool delta temperature is associated with the difference between the main gas cooler coil outlet temperature and the subcooler outlet temperature.

30. The aforementioned method, Based on the aforementioned sensor data, the setpoint for the main gas cooler coil outlet pressure is determined, The method according to claim 28, further comprising causing the rotations per minute (RPM) of the pressure exchanger to operate such that the outlet pressure associated with the main gas cooler coil approaches the main gas cooler coil outlet pressure setpoint.

31. The aforementioned method, Based on the aforementioned sensor data, the bypass HPV opening setpoint is determined, The method according to claim 28, further comprising causing the operation of an auxiliary HPV opening to approach the bypass HPV opening setting point.

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