Refrigeration system including pressure exchanger and its control

Abstract

The system includes a pressure exchanger (PX) configured to receive a first fluid, receive a second fluid, and exchange pressure between the first and second fluids. The system further includes 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 the fluid supplied through the first inlet and the fluid supplied through the second inlet. The first outlet of the heat exchanger supplies the first fluid to the PX. The second outlet of the heat exchanger supplies the second fluid to the PX. The system further includes a receiver configured to receive the first and second fluids from the PX. The system further includes a first compressor configured to supply working fluid to the first gas cooler.

Description

Technical Field

[0001] The present disclosure relates to the control of a system, and more particularly to the control of refrigeration and heat pump systems including a pressure exchanger.

Background Art

[0002] Systems use fluids at different pressures. Systems use pumps and / or compressors to raise the pressure of the fluid. A significant portion of the energy use in a fluid processing system can be consumed by pumps and / or compressors that raise the fluid pressure.

[0003] The present disclosure is illustrated by way of example and not limitation in the figures of the accompanying drawings.

Brief Description of the Drawings

[0004] [Figure 1A] FIG. 1A is a schematic diagram of a fluid processing system including a hydraulic energy transfer system according to some embodiments. [Figure 1B] FIG. 1B is a schematic diagram of a fluid processing system including a hydraulic energy transfer system according to some embodiments. [Figure 2A] FIG. 2A is an exploded perspective view of a pressure exchanger (PX) according to some embodiments. [Figure 2B] FIG. 2B is an exploded perspective view of a pressure exchanger (PX) according to some embodiments. [Figure 2C] FIG. 2C is an exploded perspective view of a pressure exchanger (PX) according to some embodiments. [Figure 2D] FIG. 2D is an exploded perspective view of a pressure exchanger (PX) according to some embodiments. [Figure 2E] FIG. 2E is an exploded perspective view of a pressure exchanger (PX) according to some embodiments. [Figure 3A] FIG. 3A is a schematic diagram of a fluid processing system including a PX and a heat exchanger for exchanging heat between the flows of two working fluids according to some embodiments. [Figure 3B] Figure 3B is a schematic diagram of a fluid processing system including a pressure exchanger with an auxiliary receiver, according to several embodiments. [Figure 3C] Figure 3C is a schematic diagram of a fluid handling system including a subcooler and an auxiliary receiver, according to several embodiments. [Figure 3D] Figure 3D is a schematic diagram of a fluid processing system including a PX according to several embodiments. [Figure 3E] Figure 3E is a schematic diagram of a fluid processing system including PX according to several embodiments. [Figure 3F] Figure 3F is a schematic diagram of a fluid processing system including a PX according to several embodiments. [Figure 3G] Figure 3G is a schematic diagram of a fluid processing system including a PX according to several embodiments. [Figure 4A] Figure 4A is a schematic diagram of a fluid processing system, according to several embodiments, including a PX, a subcooler, and various controllers and other components for providing control of the fluid processing system. [Figure 4B] Figure 4B is a schematic diagram of a fluid processing system including 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 6] Figure 6 is a block diagram illustrating a computer system according to a specific embodiment. [Modes for carrying out the invention]

[0005] Embodiments described herein relate to architectures of refrigeration and / or heat pump systems including pressure exchangers, and control of such systems. For example, architectures may include refrigeration systems, heat pump systems, pressure exchanger systems, fluid handling systems including pressure exchangers, heat transfer systems, control systems for carbon dioxide (CO2) refrigeration systems integrated with rotary pressure exchangers, and control of such systems. In particular, system architectures and associated control modules for controlling, maintaining, regulating, etc., the operation of a system including one or more pressure exchangers will be described.

[0006] A system may use fluids at different pressures. One fluid supply to the system may be at a lower pressure, while one or more parts of the system operate at higher pressures. A system may include a closed loop where different fluid pressures are maintained in different parts of the loop. These systems may include refrigeration systems, heat pump systems, energy generation systems, fluid transport systems, and so on. Pumps or compressors may be used to increase the fluid pressure in such systems.

[0007] Conventionally, heat transfer systems (e.g., refrigeration systems, heat pump systems, reversible heat pump systems, or similar) use pumps or compressors to increase the pressure of a fluid (e.g., refrigeration fluids such as carbon dioxide (CO2), R-744, R-134a, hydrocarbons, hydrofluorocarbons (HFCs), hydrochlorofluorocarbons (HCFCs), ammonia (NH3), refrigerant mixtures, 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 part of the system, including increasing the fluid pressure. Pumps and compressors, especially those operating with large pressure differences (e.g., those causing a large pressure increase in the fluid), require a great deal of energy. Therefore, conventional systems expend a great deal of energy increasing the fluid pressure (via pumps or compressors driven by motors). In addition, conventional heat transfer systems reduce the fluid pressure through expansion valves and / or heat exchangers (e.g., condensers and / or evaporators, etc.). Conventional systems inefficiently increase and decrease fluid pressure. This is wasteful in terms of the energy used to operate conventional systems (for example, the energy used to repeatedly increase the pressure of a refrigerating fluid to cause an increase or decrease in ambient temperature).

[0008] The systems, apparatus, and methods of this disclosure enable the operation and control of a system (e.g., a fluid processing system, a heat transfer system, a refrigeration system, a heat pump system, a cooling system, a heating system, etc.) that includes one or more pressure exchangers (PXs). In the system, the PX may be configured to exchange pressure between a first fluid (e.g., a high-pressure portion of a refrigeration fluid in a refrigeration cycle) and a second fluid (e.g., a low-pressure portion of a refrigeration fluid in a refrigeration cycle). The PX may receive the first fluid (e.g., a high-pressure portion of the refrigeration fluid) through a first inlet (e.g., a high-pressure inlet) and receive the second fluid (e.g., a low-pressure portion of the refrigeration fluid) through 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 through a first outlet (e.g., a low-pressure outlet), and the second fluid may exit the PX through a second outlet (e.g., a high-pressure outlet). When the second fluid exits the PX, it may be at a higher pressure than the first fluid (for example, pressure may have been exchanged between the first and second fluids).

[0009] In some systems, fluids may be pumped, compressed, have their pressure increased, or similarly, in various parts of the fluid handling system. For example, a main compressor (or set of compressors) may work to increase the pressure of a low-pressure fluid to a high-pressure fluid, and other compressors or boosters may be used to provide auxiliary pressure regulation in other parts of the fluid handling system. In some embodiments, one or more adjustments to the fluid flow path may be introduced to reduce the number of pumps or compressors required, for example, by using a 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 zone (e.g., for the safe storage of perishable goods such as food, pharmaceuticals, or materials for scientific or research purposes), a heat pump system may target a comfortable indoor temperature in a home, a system may target the rate of heat exchange between the system and the environment, and one or more parts of the system may target operating temperature, pressure, fluid density, or similar parameters. 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 material in the temperature-controlled area, and the frequency of material and / or energy exchange between the control 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, etc. 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 the goal is to increase the flow rate through the PX, the motor may increase the operating speed of the PX. In some embodiments, the motor may play a role in suppressing the PX. For example, if the goal is to decrease the flow rate through the PX, the motor may suppress the motion of the PX to maintain the desired flow rate. A controller may be operationally 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 suggesting the fluid pressure associated with (e.g., inside and outside) a condenser of the fluid processing system, flow rate data suggesting the flow rate through a part of the fluid processing system, or similar data. The controller may generate a control signal for the motor based on received data that indicates 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 that control signal.

[0012] In some embodiments, the operating speed of the PX can be utilized to maintain one or more conditions of the fluid system. For example, the PX speed can be selected to maintain a target fluid pressure in a component upstream of the PX. The PX speed can further affect other conditions of the system, but may be at least partially unregulated due to the influence of the PX speed on multiple conditions of the system and components. Additional control methods can be utilized in maintaining one or more target conditions of the fluid system that can be further affected by the operating speed of the PX.

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

[0014] The movement distance is a measure of the inflow or outflow of fluid into the PX duct. For example, fluid can flow into the duct from a first inlet and exchange pressure with a second fluid entering the duct from an inlet located on the opposite side of the duct. Thereafter, the fluid can be removed via an outlet located on the same side as the fluid entered after the pressure exchange. The movement distance is a measure of how far into the duct the first fluid flows before retreating back to the outlet. The movement distance implies the volumetric flow rate through the PX and is based, for example, on the rotational speed of the PX, the number of ducts in the PX, and the total volume of the ducts in the PX. The two inlets of the PX can have associated movement distances for each. For example, during operation, the PX can operate with a first low-pressure movement distance associated with the movement of fluid provided to the low-pressure inlet of the PX and a second high-pressure movement distance associated with the movement of fluid provided to the high-pressure inlet of the PX. The target movement distance can be selected based on the target volumetric flow rate through the PX, the target energy efficiency, the target pressure exchange efficiency, the target degree of mixing of the first fluid and the second fluid, or the like.

[0015] One or more movement distances of the PX can be adjusted and / or maintained by adjusting the operation of components of the fluid transfer system including the PX. For example, the low-pressure inlet movement distance (e.g., the volume of fluid provided to the low-pressure inlet of the PX compared to the operating volume of the PX) can be maintained by adjusting the opening degree of a control valve coupled to the high-pressure outlet of the PX. The operating volume of the PX depends on the operating speed of the PX. For example, in a rotary PX, as the rotational speed increases, the number of ducts of the PX utilized within a given time period increases. The control valve can be configured to be controlled based on the PX speed to maintain a target low-pressure inlet movement distance within the PX. Further, when setting the opening degree of the control valve, additional signals such as, for example, the overall system load (e.g., the total fluid flow rate through the system), the temperature in one or more gas coolers, etc. can be considered.

[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, the fluid processing system may include a heat exchanger for cooling a main fluid flow from a main gas cooler. A portion of the 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 proportion of fluid supplied to each fluid channel may be determined by a control valve. Target cooling conditions are monitored, and the proportion of fluid supplied to the primary or secondary channels of the heat exchanger may be adjusted to achieve the target cooling conditions, for example, to achieve 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, for example, to determine the distance traveled by the PX. The control valve associated with the auxiliary gas cooler may be opened by an amount based on the degree of opening of other valves in the flow path, and may be a control valve configured to determine, for example, the proportion of fluid supplied to the secondary channels of the heat exchanger of the fluid processing system. The control valve associated with the auxiliary gas cooler may be opened to allow a flow rate through the control valve that matches the flow rate 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 its vicinity (e.g., the ambient environment). The activation and / or operation 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 discharged by the gas cooler. In some embodiments, an operation may be performed to achieve and / or maintain a target temperature of the fluid discharged by the auxiliary gas cooler. The target temperature may be based on the ambient temperature, for example, the target temperature after the fluid has passed through the gas cooler may be within a target temperature range of the ambient temperature, e.g., within ±5 degrees Celsius of the ambient temperature. The target temperature may be based on the temperature of the fluid at other parts of the fluid processing system, for example, the temperature of the fluid discharged by the main gas cooler. Additional architectures, sensors, processing devices, etc., may be used to maintain target or optimal conditions for the fluid discharged by the main gas cooler, and fewer sensors or other architectures may be used to match the fluid discharged by the auxiliary gas cooler to the fluid discharged by the main gas cooler.

[0019] In some embodiments, the control of the proportion of fluid supplied to the primary and secondary channels of the heat exchanger may be based on the conditions of the receiver, either alternatively or additionally to other conditions. For example, the subcooling supplied to the main fluid flow 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 handling system, such as a main compressor. The degree of subcooling of the heat exchanger may be controlled based on reducing flash gas in the receiver (for example, by adjusting the proportion of fluid supplied to the primary and secondary channels of the heat exchanger). The degree of subcooling of the heat exchanger may also be controlled based on sensor readings and / or control signals supplied to a flash gas valve, which may further be based on flash gas in the receiver.

[0020] In some embodiments, the control of the proportion of fluid supplied to the first and second channels of a 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 to generate a control signal for a valve that determines the proportion 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 values ​​of the low-pressure inlet mass flow rate, low-pressure inlet pressure, and low-pressure inlet temperature. In some embodiments, a control valve that determines the flow rate of fluid flowing through an auxiliary gas cooler (e.g., 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 values ​​of the high-pressure outlet mass flow rate and high-pressure outlet density. In some embodiments, multiple different control inputs may be used to determine the control signal. For example, a function that considers multiple control conditions may be generated, and a control signal may be generated based on multiple conditions for the purpose of achieving an optimal combination of conditions. In other examples, control may be based on different conditions if the condition domains are different. For example, the amount of subcooling can be controlled to maintain a target level, provided that the minimum travel distance of the PX and / or the minimum opening degree of the flash gas valve are maintained.

[0021] In some embodiments, the fluid handling system may include a main receiver and an auxiliary receiver. The auxiliary receiver may be maintained at a higher pressure than the main receiver and may be used, 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 further be 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 discharged by the main gas cooler. The auxiliary receiver may also be configured to receive fluid that has been cooled, for example, via the auxiliary gas cooler, after being discharged through the high-pressure outlet of the PX.

[0022] In some embodiments, a control valve can determine the proportion of fluid discharged by the main gas cooler that is supplied to the auxiliary receiver and the proportion supplied to the high-pressure inlet of the PX. The control valve can be controlled based on the pressure inside the auxiliary receiver, and can be controlled to maintain more fluid, 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 flow rate of fluid 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 by valve characteristics, such as an estimate of the mass flow rate as a function of valve opening and mass flow rate for a given inlet condition. The travel distance may also 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 degree of the control valve may be based on the operating speed of the PX and / or measured or estimated values ​​of one or more inlet fluid conditions.

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

[0025] The systems, apparatus, and methods of this disclosure offer advantages over conventional solutions. The systems of this disclosure can reduce energy consumption compared to, for example, conventional systems that do not include PX. For example, by using PX in the heat transfer system of this disclosure, the energy stored as pressure can be recovered and reintroduced into the system, thereby reducing the operating cost of the heat transfer system. This reduction in energy cost may allow for lower compressor rotation speeds and power consumption, or it may be possible to use a less expensive, smaller, and / or lower-power compressor in the system.

[0026] The various controllers used in the system are for maintaining target conditions and can increase the energy efficiency of the system, for example, by minimizing the work performed by the compressor to maintain the target temperature of the refrigeration zone associated with the fluid processing system. Energy efficiency can be improved, for example, by maximizing the pressure transfer 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.).

[0027] The systems of this disclosure can reduce the complexity of the fluid handling system by reducing the number of pumps (e.g., boosters) included in the system. For example, in the architecture of this disclosure, it may be possible to reduce one or more pumps or compressors by enabling the PX to perform some pressurizing and compression operations that may be performed by boosters in other architectures. Reducing the number of pumps or compressors can reduce the equipment cost of the system, reduce the number of parts that need to be serviced, and reduce the number of failure points to decrease system downtime or corrective or preventive maintenance.

[0028] 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 on one or more pumps / compressors, for example, by reducing the target pressure difference that the compressor must achieve. One or more controllers (e.g., control systems) can improve the operation of the pumps and compressors by enabling operation at a target pumping speed, such as a pumping speed (e.g., minimum allowable pumping speed) selected to protect one or more components of the system while meeting the target system output (e.g., maintaining the target temperature of the heat transfer system).

[0029] The systems of this disclosure can protect one or more components from damage. For example, the compressor of the system is sensitive to the phase of the substance 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 can adjust one or more operating parameters of the system (e.g., fluid flow rate, pumping rate, operating speed of the PX, control valve opening degree, etc.) to maintain the supply of gas to the compressor (e.g., by maintaining a target superheat value of the gas). The systems of this disclosure can increase flexibility in the selection of components for a fluid handling system. For example, one or more controllers (e.g., control systems) can be operationally coupled and work together to maintain one or more operating conditions. For example, the system may include multiple controllers (e.g., control systems) operationally coupled to multiple components (e.g., configured to facilitate the adjustment of one or more operating parameters of those components). Multiple control signals can be generated to achieve one or more target tasks. For example, the temperature of a region associated with a heat transfer system can be maintained, and the load of a pump can be kept within a target range. By utilizing multiple controllers in the system, these goals can be achieved, and / or users may be able to use a wider selection of components in the system (for example, pumps with a smaller manufacturer-recommended operating pressure range in a system where the pump pressure can be maintained within that range under a variety of operating conditions).

[0030] While some embodiments of this disclosure are described in relation to pressure exchangers, energy recovery devices, and hydraulic energy transfer systems, this disclosure is also applicable to other systems and devices (e.g., non-isobaric pressure exchangers, non-rotating components, non-rotating pressure exchangers, systems without pressure exchangers, etc.).

[0031] While some embodiments of this disclosure are described in relation to pressure exchange between fluids used in fracing systems, desalination systems, heat pump systems, and / or refrigeration systems, this disclosure is also applicable to other types of systems. Fluids may refer to liquids, gases, transcritical fluids, supercritical fluids, subcritical fluids, and / or combinations thereof.

[0032] In some aspects of the present 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 first and second inlets 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.

[0033] Figure 1A illustrates a schematic diagram of a fluid processing system 100A (e.g., a heat transfer system, a refrigeration system) including a hydraulic energy transfer system 110 according to a specific embodiment.

[0034] In some embodiments, the hydraulic energy transfer system 110 may include a pressure exchanger (e.g., PX). The hydraulic energy transfer system 110 (e.g., PX, a collection of components including 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, providing LPout fluid 140 to the LPout system 142 (e.g., via a low-pressure outlet) and also providing HPout fluid 150 to the HPout system 152 (e.g., via a high-pressure outlet). The fluid handling system 100A includes a booster elimination component 182. For example, the architecture is designed to include one or more components to allow for the elimination of one or more pumps or compressors compared to other PX fluid handling systems such as other PX heat transfer systems or refrigeration systems. The booster elimination component 182 may include one or more additional heat exchangers, for example, to provide subcooling to the main / primary fluid flow of the fluid handling system 100A.

[0035] The controller may regulate the flow rate and / or conditions of the HPin fluid 130 and the LPout fluid 140 by one or more flow valves, pumps, motors, fans, and / or compressors (not shown). The controller may be configured to perform various operations (e.g., of controllable components included in the fluid processing system 100A). The controller may be configured to trigger the operation of one or more valves. The controller may be configured to trigger adjustments to the operating speed of one or more components. The controller may trigger 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 regulate the operation of one or more pumps. The controller may start, stop, or regulate the operation of components that regulate heat transfer between the working fluid and the working fluid of the fluid processing system 100A. For example, the controller may start a fan that increases heat transfer from the working fluid to the ambient environment via one or more gas coolers.

[0036] In some embodiments, the hydraulic energy transfer system 110 includes a PX that exchanges pressure between the HPin fluid 130 and the LPin fluid 120. In some embodiments, the PX may be 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, and its efficiency (e.g., substantially isobaric pressure transfer efficiency) may be greater than or equal to about 50%, 60%, 70%, 80%, or 90% (e.g., without using centrifugal technology). High pressure (e.g., HPin fluid 130, HPout fluid 150) refers to a pressure greater than low pressure (e.g., LPin fluid 120, LPout fluid 140). In some cases, the LPin fluid 120 in the PX is pressurized and exits the PX at high pressure (e.g., HPout fluid 150 at a higher pressure than the LPin fluid 120), while the HPin fluid 130 is at least partially depressurized and exits the PX at low pressure (e.g., LPout fluid 140 at a lower pressure than the HPin fluid 130). The PX can operate in such a way that the HPin fluid 130 directly applies a pressurizing force to 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, bladders, and diaphragms.

[0037] In some embodiments, the PX may be a rotary device. For example, a rotary PX like the one manufactured by Energy Recovery Inc. in San Leandro, California, may not have any separate valves at all. This is because substantial valve action is achieved within the device through the relative motion of the rotor with respect to the end cover. In some embodiments, the rotary PX may operate using an internal piston to separate fluids and transmit pressure while minimizing mixing of the inlet fluid flow. In some embodiments, the rotary PX operates without an internal piston between the fluids.

[0038] 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 may flow into 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 can be used for the operation of the fluid processing system (e.g., for desalination, fracing, refrigeration, heat transfer, or similar applications). The low-pressure second fluid can then fill the second side of the pressure exchange chamber, after which the high-pressure first fluid can be introduced into the first side of the pressure exchange chamber and transfer energy to the other part of the second fluid. A reciprocating device may comprise multiple pressure exchange chambers and operate in a cycle to achieve a substantially continuous flow of a high-pressure second fluid from the device.

[0039] In some embodiments, PX may be a hydraulic turbocharger. A hydraulic turbocharger PX may introduce a high-pressure first fluid into a chamber containing a first impeller. The high-pressure first fluid can rotate the impeller by energy transfer from the first fluid to the impeller. The first impeller is coupled to a shaft, which may also be 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, by increasing the pressure of the second fluid).

[0040] In this disclosure, any or more PXs may be used, for example, rotary PXs, reciprocating PXs, hydraulic turbocharger PXs, or any combination thereof. Furthermore, PXs may be placed on skids separate from other components of the fluid handling system 100A (for example, in situations where PXs are added to an existing fluid handling system). For example, PXs may be fixed to structures that are movable from one location to another. PXs may be coupled to systems constructed on-site (for example, system piping). The structures to which PXs are fixed may be referred to as “skids.”

[0041] In some embodiments, the motor 160 may be coupled to a hydraulic energy transfer system 110 (e.g., to a 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, or to decrease the pressure of the HPout fluid 150). In some embodiments, the motor 160 generates energy based on pressure exchange in the hydraulic energy transfer system 110 (e.g., to act 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 decelerate the rotation and generate electricity. Alternatively, the motor may operate to decelerate the PX without generating electricity.

[0042] The hydraulic energy transfer system 110 may include a hydraulic turbocharger or hydraulic pressure 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.).

[0043] In some embodiments, the hydraulic energy transfer system 110 can transfer energy (e.g., pressure) between two fluids that are substantially different in composition, phase, or similar respects. For example, the PX of the hydraulic energy transfer system 110 can transfer pressure between a first fluid (e.g., a pressure exchange fluid, such as a first-phase fluid like a liquid or supercritical fluid, a propane-free fluid, a substantially propane-free fluid, a low-viscosity fluid, a fluid in which a specific chemical is below a predetermined threshold amount, etc.) and a second fluid, which may be in a different phase, have a higher viscosity (e.g., be high viscosity), contain a specific chemical (e.g., a corrosive chemical) above a predetermined threshold amount, and / or contain solid particles (e.g., a fracking fluid including sand, propane, powder, fragments, ceramics, etc.). By transferring energy from one type of fluid to another, expensive components such as pumps can sometimes be protected from contact with fluids that could be harmful to them (e.g., highly viscous, corrosive, or abrasive fluids, or fluids in phases not designed to be handled by the component).

[0044] 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 accept this 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, for example in a closed-loop refrigeration system, energy can be recovered from the high-pressure portion of the fluid flow, reducing the requirements for pumps and / or compressors for that flow.

[0045] 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). This receiver may receive the LPout fluid 140 discharged from the hydraulic energy transfer system 110.

[0046] The fluid processing system 100A further includes a control module. The control module may include one or more controllers. The control module may be configured to perform any of the methods shown in Figures 5A to 5E. The controllers of the control module may receive data (e.g., measurement data) from sensors associated with the fluid processing system 100A. The controllers 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 sensors. The controllers may include a single device that performs one or more control tasks, a separate device for each control task (e.g., each controllable component of the fluid processing system 100A), a plurality of devices, each performing multiple functions, etc. For example, the operation of each controller may be performed by a separate device, or the operation of all controllers may be performed by a single device, or a combination of individual and integrated devices may be employed. The components of a control module may include general-purpose computing devices, personal computers (PCs), laptops, mobile phones, tablet computers, netbooks, microcontrollers, custom-designed controllers (e.g., hardware, circuitry, etc.), proportional-integral-derivative (PID) controllers (e.g., ternary controllers), web appliances, or any other device capable of executing a set of commands (whether periodic or not) that specify the actions the device should perform. A control module may include multiple controllers that operate independently (e.g., no input between one controller and another, measurement data from one sensor is not provided to multiple controllers, etc.). A control module 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 of the control module.

[0047] The fluid processing system 100A may further include one or more sensors that provide sensor data associated with the fluid in the fluid processing system 100A (e.g., flow rate data, pressure data, velocity data, etc.). Based on the sensor data, the controller of the fluid processing system 100A may control 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.), or similar. In some embodiments, the controller may actuate one or more flow valves based on the received sensor data.

[0048] 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.

[0049] 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 included 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.

[0050] Figure 1B illustrates a schematic diagram of a fluid processing system 100B including 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 refrigeration device, a freezer, etc.). In some embodiments, the fluid processing system 100B may include more or fewer components, the same routing configurations, different routing configurations, and / or similar configurations than those shown in Figure 1B. Features in Figure 1B that have the same reference numerals as those in Figure 1A may have similar characteristics, functions, and / or structures as those in Figure 1A.

[0051] In some embodiments, the components of the fluid handling system 100B may be configured to eliminate one or more lift devices for increasing pressure in relation to one or more of the LPin system 122 or HPout system 152. HPin fluid 130 may be supplied from the HPin system 132 (including, for example, a condenser 138, a gas cooler, a heat exchanger, etc.) to the hydraulic energy transfer system 110. The hydraulic energy transfer system 110 (e.g., PX) may exchange pressure between the LPin fluid 120 and the HPin fluid 130, supply HPout fluid 150 to the HPout system 152 (e.g., any high-pressure lift device, a high-pressure fluid pump, a high-pressure compressor, etc.), and supply LPout fluid 140 to the LPout system 142 (e.g., an evaporator 144, a heat exchanger, etc.). In some embodiments, the components of the fluid handling system 100B may be configured to eliminate high-pressure lift devices, for example, in some architectures, high-pressure lift devices are optional components. The LPout system 142 (e.g., evaporator 144) may supply fluid to the compressor 178 and / or optionally to the 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, other 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 discharged from the flash tank may be supplied to the evaporator 144. 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. The controller may control one or more components of the fluid handling system 100B, including the motor 160 and various other controllable components.

[0052] 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) that circulate within the fluid processing system 100B.

[0053] 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 the properties of the fluid at various stages of the system (e.g., various components of the system), namely temperature, pressure, flow rate, density, etc. A sensor may also measure properties related to the function of the fluid processing system 100B. For example, a refrigeration system may include one or more temperature sensors that report the temperature of the area to be refrigerated. A sensor may also 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, and may use the temperature measurement near the evaporator 144 to adjust one or more operating parameters of the fluid processing system 100B, for example, to achieve a target output (e.g., temperature), to improve operating efficiency, or for similar purposes.

[0054] The control module 133 may be configured to perform any of the methods described in relation to Figures 5A to 5E. The controller of the fluid processing system 100B may receive sensor data from the sensor (e.g., raw sensor data, pre-processed sensor data, averaged sensor data, data as the difference of measured values ​​from a target value / threshold, etc.). The controller of the fluid processing system 100B 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 tunable components of the fluid processing system 100B.

[0055] The fluid handling system 100B may include one or more valves with variable opening degrees. For example, the fluid flow rate may be changed by adjusting the opening degree 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 degree (e.g., a percentage value of the opening degree) based on a control signal received from the control module 133. The fluid handling system 100B may include one or more pumps, compressors, or similar devices. 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 133. The fluid handling system 100B may include a motor 160 coupled to the PX of the hydraulic energy transfer 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 133. For example, motor 160 can function as a generator by converting the rotational energy of PX into electrical energy.

[0056] Figures 2A-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 of one or more of Figures 2A-2E may have similar characteristics, functions, and / or structures to one or more of the features of Figures 1A-1B.

[0057] The PX40 may be configured to transmit pressure and / or work between a first fluid (e.g., refrigerant, supercritical carbon dioxide, HPin fluid 130) and a second fluid (e.g., refrigerant, superheated vaporized carbon dioxide, LPin fluid 120) with minimal fluid mixing. The rotary PX40 may include a generally cylindrical body 42, which includes a sleeve 44 (e.g., rotor sleeve) and a rotor 46. The rotary PX40 may also include two end caps 48 and 50, which include manifolds 52 and 54, respectively. Manifold 52 includes its respective inlet port 56 and outlet port 58, while manifold 54 includes its respective inlet port 60 and outlet port 62. During operation, these inlet ports 56, 60 allow the first and second fluids to enter the rotary PX40 and exchange pressure, while the outlet ports 58, 62 allow the first and second fluids to exit the rotary PX40 thereafter. During operation, the inlet port 56 receives a high-pressure first fluid (e.g., HPin fluid 130) discharged from the condenser, and after pressure exchange, the outlet port 58 may be used to route the low-pressure first fluid (e.g., LPout fluid 140) coming out of the rotary PX40 to a receiver (e.g., a flash tank) configured to receive the first fluid from the PX40. The receiver may form a chamber configured to separate the fluid into gas and liquid. Similarly, the inlet port 60 may be used to receive a low-pressure second fluid (e.g., low-pressure slurry fluid, LPin fluid 120) from a booster configured to receive the gaseous portion 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 each include end covers 64 and 66 (e.g., end plates) located within the respective manifolds 52 and 54, which enable fluid sealing contact with the rotor 46.

[0058] The ports of the PX are in fluid communication with a fluid system, which includes a fluid processing architecture 92. The fluid processing architecture 92 includes several components for performing operations, regulating fluid conditions, providing system control, etc., such as the components described in relation to Figures 1A-1B. The fluid processing architecture 92 may include a booster elimination component 182, which may include one or more components that enable the removal or bypass of one or more pumps or compressors in the fluid processing architecture 92. For example, a component such as a heat exchanger and / or receiver may enable the elimination of one or more booster pumps compared to other PX fluid systems. Further discussion of architectures including one or more booster elimination components can be found in relation to Figures 3A-3G and 4A-4B.

[0059] One or more components of the PX40, such as the rotor 46, end cover 64 and / or end cover 66, may be made of a wear-resistant material (e.g., carbides, cemented carbide, silicon carbide, tungsten carbide, etc.) having a hardness higher than a predetermined threshold (e.g., Vickers hardness of at least 1000, 1250, 1500, 1750, 2000, or 2250). For example, tungsten carbide may have higher durability and improved wear resistance to abrasive fluids compared to other materials such as alumina ceramics. One or more components of the PX40, such as the rotor 46, end cover 64 and / or end cover 66, and / or other sealing surfaces of the PX40 may be provided with inserts. In some embodiments, the insert may be made of a wear-resistant material (e.g., carbides, cemented carbides, silicon carbides, tungsten carbides, etc.) having a hardness higher than a predetermined threshold (e.g., Vickers hardness of at least 1000, 1250, 1500, 1750, 2000, 2250 or higher) in order to improve wear resistance.

[0060] The rotor 46 is cylindrical and may be housed within a sleeve 44, thereby allowing the rotor 46 to rotate around an axis 68. The rotor 46 has a plurality of channels 70 (e.g., ducts, rotor ducts) that penetrate substantially longitudinally through the rotor 46, and openings 72 and 74 (e.g., rotor ports) may be symmetrically arranged at each end around the longitudinal axis 68. The openings 72 and 74 of the rotor 46 are arranged to communicate fluidly with inlet apertures 76 and outlet apertures 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) of the end covers 64 and 66, in such a manner that the channels 70 are exposed to high-pressure and low-pressure fluids during rotation. As shown in the figure, the inlet apertures 76 and outlet apertures 78, 80 and 82 may be designed in the shape of an arc or a part of a circle (e.g., C-shape).

[0061] The operating speed of the PX40 may be used to control the degree of mixing between the first fluid and the second fluid within the rotary PX40, which can be used to improve the operability of the fluid processing system (e.g., fluid processing system 100A-B in Figure 1A-1B). For example, by changing the volumetric flow rate of the first and / or second fluids flowing into the rotary PX40, the operator (e.g., system operator, 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 a motor), the operator can also control the mixing. Three features 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 creation of a barrier (e.g., fluid barrier, piston, interface) between the first and second fluids within the rotor channel 70. Firstly, because the rotor channel 70 (e.g., a duct) is generally long and narrow, the flow within the rotating PX40 is stabilized. Furthermore, the first and second fluids may move through the channel 70 in a plug flow manner, minimizing 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)) may 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 to exchange pressure between the first and second fluids. In some embodiments, a certain amount of fluid remains in the channel 70 as a barrier between the first and second fluids. Any such mechanism may limit mixing within the rotating PX40. Furthermore, in some embodiments, the rotary PX40 may be designed to operate using all or part of an internal piston, or other barriers, to isolate the first fluid from the second fluid while allowing pressure transmission.

[0062] In some embodiments, the operating speed of PX can be set (for example, targeting the characteristics listed above, or other characteristics of interest in the fluid system). The characteristics of the fluid system may be affected by the rotational speed of PX40. The control module receives an indicative value 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.

[0063] Figures 2B to 2E are exploded views of one embodiment of the rotary PX40, showing the sequence of positions of a single rotor channel 70 within the rotor 46 when the channel 70 rotates in 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.). For this reason, Figures 2B to 2E are simplified 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 a first fluid and a second fluid (e.g., a particulate-free fluid and a slurry fluid, a high-pressure refrigerant and a low-pressure refrigerant, etc.) by allowing the first fluid and the second fluid 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 on opposite sides of a barrier (e.g., a reciprocating barrier, a piston; not shown). In some embodiments, this exchange occurs at a rate that limits the mixing of the first and second fluids. The velocity of the pressure wave passing through the rotor channel 70 (as soon as the channel is exposed to the aperture 76), the fluid diffusion velocity, and the rotational speed of the rotor 46 determine whether, and to what extent, mixing occurs.

[0064] Figures 2B-2E 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 be capable of removing 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.

[0065] The controllable components of the fluid processing system coupled to the PX shown in Figures 2B-2E may provide control signals according to any of the methods shown in Figures 5A-5E. Figures 2B-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 operationally 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, by adjusting the rotational speed of the PX40. The control module may be operationally coupled to other components of the fluid processing 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, and one or more valves coupled to the outlet of the PX40 may be controlled by the control module. These components may include the controllable components described in relation to the architecture in Figures 3A-3G. These controllable components may be associated with control via the methods described in conjunction with Figures 5A to 5E.

[0066] 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 the aperture 78 of the end cover 64 and, consequently, with the manifold 52, while the opposite channel opening 74 is in fluid communication with the aperture 82 of the end cover 66, and from there extends to the manifold 54. The rotor 46 may rotate in the clockwise direction indicated by the arrow 84. During operation, a low-pressure second fluid 86 (e.g., a low-pressure slurry fluid) flows through the end cover 66 into 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, and the barrier contacts the first fluid 88 (e.g., on the opposite side of the barrier). The second fluid 86 drives the barrier, 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.

[0067] 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 in an arc of approximately 90 degrees. In this position, the opening 74 (e.g., the outlet) is not in fluid communication with the apertures 80 and 82 of the end cover 66, and the opening 72 is not in fluid communication with the apertures 76 and 78 of the end cover 64. Therefore, the low-pressure second fluid 86 is temporarily contained within the channel 70.

[0068] Figure 2D is an exploded perspective view of one embodiment of a rotary PX40 (e.g., rotary LPC) according to a specific embodiment. In Figure 2D, the channel 70 is rotated in an arc of approximately 60 degrees from the position shown in Figure 2B. The opening 74 here is in fluid communication with the aperture 80 of the end cover 66, and the opening 72 of the channel 70 here is in fluid communication with the aperture 76 of the end cover 64. At this position, a high-pressure first fluid 88 flows in, pressurizing a low-pressure second fluid 86, and pushing the second fluid 86 out of the rotor channel 70 through the aperture 80.

[0069] 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 in 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 apertures 80 and 82 of the end cover 66, and the opening 72 is no longer in fluid communication with the apertures 76 and 78 of the end cover 64. As a result, the first fluid 88 is no longer pressurized and is temporarily held in the channel 70 until the rotor 46 rotates another 90 degrees and the cycle is restarted.

[0070] Figures 3A-3G and 4A-4B are schematic diagrams of fluid processing systems 300A-3G and 400A-400B, including a PX, according to a particular embodiment. Some features in one or more of Figures 3A-3G may have similar characteristics, functions, and / or structures to features in one or more of Figures 1A-1B and / or Figures 2A-2E (e.g., features with similar names and / or reference numerals). A system in one or more of Figures 3A-3G may be used to perform one or more of the methods in Figures 5A-5E. Some features in one or more of Figures 3A-3G may have similar characteristics, properties, functions, and / or structures to features in one or more of Figures 4A-4B. A system in one or more of Figures 4A-4B may be used to perform one or more of the methods in Figures 5A-5E.

[0071] Figures 3A-G and 4A-B show various fluid processing system architectures (fluid processing systems 300A-300G and 400A-400B) and various controllers according to specific embodiments. The shown architectures are exemplary and, for example, highlight the operation of the controllers in the fluid processing system. Any controllers shown in Figures 4A-4B may be included in any combination in any architectural design of a fluid processing system. For example, a controller performing an operation like controller 490 in Figure 4A may be included in another architecture not shown (e.g., fluid processing system 300C in Figure 3C), and a controller performing an operation like controller 394 controlling a bypass valve in Figure 3B may be included in an architecture similar to that shown in Figure 3A. Fluid processing systems including any controllers shown herein (e.g., any controllers that adjust the operation of components of a fluid processing and / or energy transfer system, including PX, based on sensor data from the system), either individually or in any combination, are within the scope of this disclosure. Controllers can be separate components (for example, each controller can be a separate device), or they can be combined components (for example, the operation of two or more controllers is performed by the same device or control system), and so on. Controllers can provide control signals in response to various inputs, for example, in response to sensor data provided to the controller. Controllers may also provide control signals to adjust the characteristics of a fluid processing system, for example, to adjust the value of one or more conditions of the fluid processing system so that the condition value satisfies one or more threshold conditions.

[0072] 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 the same 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 partially via wired networks and partially via wireless networks.

[0073] In some embodiments, the controller of the fluid processing system 400A-B may be a PID controller. The controller of the fluid processing system 400A-B may calculate an error value (e.g., the difference between a target setpoint and a measured value). The controller of the fluid processing system 400A-B may apply corrections based on the proportional, integral, and derivative terms of the error value (e.g., generate a control signal). For example, the proportional term may be based on the difference between the setpoint and the measured value, the integral term may be based on the value of the error term in the past integrated over time, and the derivative term may be based on a prediction of the future trend of the error term based on the rate of change of the current error term. In some embodiments, the controller of the fluid processing system 400A-B may be a computing device. The controller of the fluid processing system 400A-B 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-B may include receiving one or more adjustable setpoints, parameters, etc. For example, the controller's response (e.g., the magnitude of the output signal, the value of the adjustment command included in the control signal, etc.) may be variable in strength (e.g., for a given difference between a measured value and a target value for a particular measurement characteristic, the controller may have a range of possible output values, one of which may correspond to one or more setpoints and / or parameters of the controller). In some embodiments, the controller may have a corresponding lookup table, and for a given input (e.g., the difference between a setpoint and a measured value), the controller may generate an output according to the table. In some embodiments, the controller may perform calculations involving adjustable parameters (e.g., user-adjustable parameters, adjustable setpoints, etc.), and in response to the input, the controller may generate an output based on the input. In some embodiments, the controller's parameters and / or setpoints may be selected / adjusted by the user. In some embodiments, the controller's parameters and / or setpoints may be adjusted, for example, by the controller itself, the associated computing device, or the computer implementation method.

[0074] In some embodiments, the performance of the controller can be tracked (e.g., measured and stored over time). If the controller causes overshoot beyond a threshold (e.g., a percentage of the difference between an initial value and a target value that exceeds a threshold for the frequency and / or intensity of overshoot) (e.g., if a component of the fluid processing system overcompensates in response to receiving a control signal from the controller, causing the measured characteristic value to pass the target value before settling within the threshold range of the target value), the sensitivity of the controller (e.g., the strength of the response to measured values ​​that differ from the target characteristic value) can be reduced. For example, the controller may generate a control signal in response to receiving a measured value that differs from the setpoint (e.g., the difference between the setpoint and the measured value exceeds a threshold). Subsequently, the controller may receive a different measured value in the opposite direction to the setpoint (e.g., if the control signal was intended to compensate for a measured value lower than the setpoint, but a subsequent measured value is higher than the setpoint). The responsiveness of the controller (e.g., parameters in calculations that determine the strength of the output in response to an input such as the difference between the setpoint and the measured value, or table entries that determine the severity of the action commanded in the control signal based on the input from the sensor) can be adjusted to reduce the possibility of overshoot in future operation. Adjustments to the controller setpoint can be global, for example, by updating parameters or tables so that all future control signals are generated in accordance with that update. Adjustments to the controller setpoint may not be applied globally, for example, one or more lookup table values ​​may be adjusted while others are not (e.g., lookup table values ​​associated with a range of differences between the setpoint and the measured value may be adjusted, or lookup table values ​​associated with one or more differences in a range of measured values ​​may be adjusted), or parameters used in certain situations may be updated (e.g., a list of parameters may apply for different measured values, different setpoints, or different values ​​of the difference between the measured value and the setpoint), and so on.

[0075] 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 that differs from the setpoint (for example, the controller is configured to receive a pressure measurement from a pressure gauge and may receive a measurement that differs from the set pressure value by at least a threshold amount). The controller may generate a control signal in response to receiving such a measurement (for example, the controller may generate a control signal to open a valve to regulate the pressure in the pressure gauge). The controller may then receive a measurement indicating that the pressure has not reached the setpoint (for example, if the action taken by the valve in response to the control signal was insufficient to reduce the difference between the setpoint and the measurement to below a threshold). One or more setpoints / parameters of the controller may be adjusted to increase the controller's response to input (for example, increasing the output signal generated based on an input signal of a given strength, or increasing the strength of a command included in the control signal associated with a given difference between the setpoint and the measurement).

[0076] In some embodiments, determining the controller's sensitivity and / or response (e.g., output strength or updates to parameters or setpoints defining the strength) can 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 actions taken by system components based on commands received by the controller. Once trained, the machine learning model may be configured to take measured characteristic values ​​and target values ​​as inputs and generate outputs indicating appropriate actions (e.g., control signals) that one or more components of the fluid processing system should take. 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 setpoints and one or more measurements generated before and after system components act according to controller commands) associated with characteristics to be corrected in the fluid processing system as training inputs. The machine learning model may also be provided with historical characteristic values ​​after adjustments have been made to correct the measured characteristic values ​​(e.g., one or more measurements taken 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 suggesting such control signals) as its target output. Once trained, the machine learning model may take current characteristic values ​​(e.g., one or more setpoints, one or more measured values, etc.) as input and generate as output control signals (or data associated with control signals) that are predicted to bring one or more measured characteristic values ​​within a threshold difference of one or more setpoints.

[0077] 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 reversing valves (e.g., four-way valves for reversing flow). Reversible heat pump systems may reverse the direction of refrigerant fluid flow 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 may not reverse the direction of flow in one or more parts of the fluid processing system; for example, the flow through a compressor or pump may not be reversed. A reversible heat pump system may include, for example, additional flow channels, additional valves, etc., that are used when the flow is 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 including such components is within the scope of this disclosure.

[0078] Figure 3A is a schematic diagram of a fluid processing system 300A, comprising a PX310 and a subcooler 315, which is a heat exchanger that exchanges heat between two working fluid flows, 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 degree of opening of one or more valves, at least in part, based on the operating speed of the PX310. System 300A may be configured to determine the degree of opening of one or more valves, based on measurement conditions of System 300A. Control of the architecture related to this disclosure will be discussed in more detail with reference to Figures 4A-4B.

[0079] PX310 can be a rotary pressure exchanger. In some embodiments, PX310 is an isobaric or substantially isobaric pressure exchanger. PX310 may be configured to exchange pressure between a first fluid and a second fluid. PX310 may be configured to exchange pressure between a high-pressure first fluid (e.g., supplied to the high-pressure inlet of PX310 and labeled HPIN) and a low-pressure second fluid (e.g., supplied to the low-pressure inlet of PX310 and labeled LPIN). PX310 can reduce the pressure of the first fluid (e.g., discharged from PX310 at the low-pressure outlet and labeled LPOUT) and increase the pressure of the second fluid (e.g., discharged from PX310 at the high-pressure outlet and labeled HPOUT). In some embodiments, PX310 is coupled to a motor (e.g., the rotation of the rotor of PX310 is controlled and / or regulated by the motor). In some embodiments, the mass flow rate (e.g., of the first fluid, the second fluid, etc.) passing through the PX310 may be related to the operating speed of the PX310 (e.g., the rotational speed of the rotor of a rotary PX). In some embodiments, the pressure of the fluids (e.g., the first fluid, the second fluid, etc.) in the various components of the fluid processing system (e.g., fluid processing systems 300A-300G) may be related to the operating speed of the PX310.

[0080] In some embodiments, the 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, the 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 "high pressure" and "low pressure" are mentioned, they may be relative to each other and may not mean specific pressure values ​​(e.g., the pressure of HPin fluid 130 is higher than the pressure of LPin fluid 120). The PX310 may exchange pressure between the first and second fluids. The PX310 may provide a first fluid (e.g., LPout fluid 140) via a low-pressure outlet and a second fluid (e.g., HPout fluid 150) via a high-pressure outlet. In some embodiments, the first fluid provided via the low-pressure outlet is low-pressure, and the second fluid provided via the high-pressure outlet is high-pressure. The PX310 can operate as a high-pressure expansion valve, for example, the fluid flowing through it (e.g., from a high-pressure inlet to a low-pressure outlet) can expand. The PX310 can transfer pressure from one fluid flow to another, increasing the pressure in one fluid flow. The PX310 can operate as both an isentropic (or substantially isentropic) expansion device and compressor, thereby causing heat transfer and accelerating one or more operations of the refrigeration cycle, or similar actions. The compression process of the PX310 can be substantially isenthalpic.

[0081] 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 liquid-gas mixture of CO2). In some embodiments, the second fluid may be a liquid refrigerant fluid (e.g., liquid CO2).

[0082] In some embodiments, the fluid processing system 300A includes 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 operate as condensers, and for example, the fluid processing system may operate at pressures and temperatures at which the fluid condenses or does not condense within the gas cooler. Any embodiment discussed herein may include a gas cooler that may or may not operate as a condenser in one or more applications. In some embodiments, for example, beyond 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 input and output fluids of the condenser may be supercritical, only one of the input or output fluids of the condenser may be supercritical, or neither fluid may be supercritical). In some embodiments, the fluid handling system 300A is a refrigeration system. For example, the evaporator 318 may facilitate the absorption of heat from a heat source (e.g., a cooling area, a low-temperature reservoir, etc.) into the refrigerating fluid by the system 300A. This heat may be released to a heat sink (e.g., the environment, a high-temperature reservoir) via the main gas cooler 329 and / or the auxiliary gas cooler 327. In some embodiments, the refrigerating 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 may increase the pressure of the corresponding refrigerating fluid along the flow path between the evaporator 318 and the main gas cooler 329. In some embodiments, the refrigerating fluid is CO2 or another refrigerating fluid. The refrigerating fluid may flow in a substantially cyclic manner (e.g., from the gas cooler 329 to PX310, and then to the evaporator 318, and then to the main compressor 322, and then to the gas cooler 329).

[0083] In some embodiments, the fluid processing system 300A is a heat pump system. For example, in the main gas cooler 329, heat may be released by the fluid and provided to a target area to be heated (for example, for heating the interior space of a building). In the evaporator 318, the fluid of the fluid processing system 300A may absorb heat from the environment and 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.

[0084] In some embodiments, the main compressor 322 increases the fluid pressure by a threshold amount (for example, the main compressor 322 may operate at a pressure difference greater than the threshold amount). For example, the main compressor 322 may increase the fluid pressure by approximately 100–1200 psi (approximately 0.689–8.27 MPa), approximately 500–1100 psi (approximately 3.45–7.58 MPa), approximately 800–1000 psi (approximately 5.52–6.89 MPa), approximately 900 psi (approximately 6.21 MPa), at least 100 psi (approximately 0.689 MPa), at least 500 psi (approximately 3.45 MPa), any range within these limits, or a similar amount. In some embodiments, the operation of the main compressor 322 may be performed by multiple 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 discussion relating to the main compressor 322 may be generalized to include multiple devices, for example, by summing the energy consumption, or by summing the energy consumption considering the arrangement, specifications, and operating speed of each compressor in the compressor system, or by calculating the total fluid flow rate through the entire compressor system.

[0085] A motor or other speed control device may be configured to regulate the operation of PX310 (for example, by regulating the operating speed of the motor). 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 also be based on additional indicators, such as ambient temperature, fluid temperature, target evaporator temperature, operating efficiency of the fluid handling system 300A, etc. 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 (for example, the temperature of the heat sink for released heat), for example, to achieve optimal energy efficiency, heat transfer, refrigeration, or similar. For example, increasing the operating speed of PX310 may increase the flow rate of fluid through PX310. Increasing the operating speed of PX310 may decrease the fluid pressure of the main gas cooler 329.

[0086] In some embodiments, the target pressure of the main gas cooler 329 may be selected to maximize the heat transfer of the system, to maximize the heat transfer between the main gas cooler 329 and the environment, to maximize the energy efficiency of the system, to maximize the coefficient of performance (COP, e.g., the ratio of the amount of heat transferred by the system to the power expended by the system's pumps / compressors), or for similar purposes.

[0087] In some embodiments, a device for adjusting the speed of the PX may operate 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 as a generator. For example, the PX310 may be driven by the fluid of the fluid processing system 300A (e.g., driven by the pressure difference of the fluid, driven by one or more pumps and / or compressors of the system, etc.). 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), thereby reducing the operating speed of the PX310. The motor may generate power (e.g., convert the rotational energy of the PX310 into electrical energy).

[0088] 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 may be a refrigerated space such as the inside of a refrigeration unit or freezer, an indoor space (e.g., one in a building or vehicle), or any other space that should be kept cool. For example, the environment may be the inside of a freezer or refrigerated compartment in a supermarket or warehouse. In some embodiments, the evaporator 318 may also provide the heat absorbed from the environment to the main gas cooler 329, for example, the target result of the fluid processing system 300A may be heating the area surrounding the main gas cooler 329.

[0089] 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 discharge lines, valves, instruments, 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, if those evaporators are associated with refrigeration systems with different target temperatures, i.e., a refrigeration unit 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 discharged from one or more secondary evaporators may be directed to one or more components (e.g., valves, expansion valves, pumps, compressors, or similar) to change its pressure so that the pressures are substantially similar when the discharge flows from the two evaporators are merged.

[0090] 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 other environments. For example, the main gas cooler 329 may release heat (e.g., thermal energy) to the air of 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 installed outside a supermarket or warehouse building (e.g., on the roof of the building) and release heat to the external environment. As another example, the main gas cooler 329 may be installed underground to facilitate the transfer of thermal energy between the fluid and the ground. In some embodiments, the main gas cooler 329 releases heat into the indoor space, while the evaporator 318 absorbs heat from the outdoor space (e.g., in a heat pump configuration that provides heating to the indoor space). The thermal energy released from the main gas cooler 329 can be used to heat a closed (e.g., substantially closed) space.

[0091] In some embodiments, the fluid handling system 300A may include an auxiliary gas cooler 327. In some embodiments, the auxiliary gas cooler receives a second fluid from the high-pressure outlet of PX310, and the main gas cooler 329 receives waste 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 with the second fluid and the same environment in which the main gas cooler 329 exchanges thermal energy, such as the outdoor space of a building. In other embodiments, the auxiliary gas cooler exchanges thermal energy with 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 relative to the main gas cooler 329, or under similar conditions. 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, they may be provided by a gas cooler having multiple fluid channels corresponding to 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 include or be associated with a fan for increasing airflow near the gas cooler, thereby increasing heat transfer from the gas cooler.

[0092] The fluid handling system 300A further includes a flash gas valve 320. The fluid handling system 300A may include 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 merge with the discharge of the evaporator 318. In some embodiments, the flow of gas 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 merge with the discharge of the evaporator 318. The flash gas valve 320 may expand (e.g., reduce the pressure) the gas collected in the receiver 313 as the gas flows toward the main compressor 322. In some embodiments, the flash gas valve 320 may be an adjustable valve. In some embodiments, the flash gas valve 320 is activated by a controller based on sensor data.

[0093] The fluid processing system 300A may include an expansion valve 316. In some embodiments, the expansion valve 316 may be positioned along a flow path between the receiver 313 and the evaporator 318, and may be coupled, for example, 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., opened 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 flowing into the evaporator, the temperature of the fluid flowing out of the evaporator, etc.). For example, a pressure-sensitive component of the expansion valve 316 (e.g., a sensing valve (bulb)) can increase or decrease the pressure on the diaphragm of the expansion valve 316, opening or closing a poppet valve coupled to the diaphragm, thereby increasing or decreasing the flow rate of fluid to the evaporator 318 and increasing or decreasing the amount of fluid expansion. The pressure-sensitive component of the expansion valve may be located near the downstream end of the evaporator 318 (e.g., near the outlet of the evaporator 318, outside the evaporator 318, inside the evaporator 318, or a similar location) 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).

[0094] 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 discharged by the main gas cooler 329. The subcooler 315 may include a main or primary fluid channel coupled to the main cooling flow of the working fluid. The subcooler 315 may include a secondary or cooling fluid channel coupled to a fluid flow that absorbs heat from the main flow within the subcooler 315. A subcool valve 312 may be a control valve and may be opened to a target degree to allow a target flow rate 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 the efficiency loss associated with additional pumping power to increase the pressure of the secondary cooling fluid by compressing the fluid through pressure exchange with the fluid from the main channel of the subcooler 315. The main body can be supplied to the high-pressure inlet of PX310 by the subcooler 315. The secondary cooling fluid can be supplied to the low-pressure inlet of PX310 by the subcooler 315.

[0095] The fluid handling system 300A further includes an auxiliary valve 369. The auxiliary valve 369 may be a control valve and may have the capability to allow a target fluid flow rate through it, for example. 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 located, for example, before or after the auxiliary gas cooler 327 (with respect to the fluid flow path).

[0096] This specification includes references to “first fluid” and “second fluid.” In some embodiments, the first fluid and the second fluid may be the same type of fluid (for example, a refrigerating 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 and 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 and from the low-pressure inlet and / or high-pressure outlet of PX310.

[0097] 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, either the main gas cooler 329 or the evaporator 318 is an outdoor unit, and the other 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., 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 reversing valve coupled to the main compressor 322). The reversing valve may be switchable between directing the fluid flow leaving the main compressor 322 towards the inlet of the main gas cooler 329 (e.g., an outdoor unit) or 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 reverse only the fluid flow through the main gas cooler 329 and evaporator 318, while guiding the fluid flow to pass through all components (e.g., one or more PX310s, main compressor 322, etc.) in the same direction.

[0098] In some embodiments, the system described herein is a heat pump system capable of heating an environment (e.g., an indoor space). In such a heat pump system, a main gas cooler 329 is located indoors, and an evaporator 318 is located outdoors. In the heat pump system, the evaporator can absorb heat from the environment and vaporize a two-phase refrigerant fluid flowing through it before sending it to the compressor inlet. In some embodiments, a reversing valve may be used to switch the fluid flow leaving the main compressor 322 between being directed towards the inlet of an outdoor unit or towards the inlet of an indoor unit in order to switch from a refrigeration or air conditioning system to a heat pump system. In some embodiments, one or more valves and piping may be used to reverse the fluid flow from the indoor unit to the outdoor unit, while ensuring that the fluid flow passes through all components (e.g., one or more PX310s, the main compressor 322, etc.) in the same direction of flow.

[0099] In some embodiments, the systems described herein (e.g., one or more systems in Figures 3A-3G) may be used to heat a room and / or a closed space, to cool a room and / or a closed space, and / or to selectively (e.g., reversibly) heat and / or cool a space.

[0100] In some embodiments, one or more additional components that can bypass or partially bypass PX310 may be included in the fluid handling system, such as the fluid handling system 300A. For example, one or more valves may enable a connection that bypasses PX310 between the discharge of the primary channel of the subcooler 315 and the inlet of the receiver 313. In some situations (e.g., under certain fluid and / or ambient environmental conditions), PX310 may not be used or may only be used partially. For example, under certain conditions, the efficiency improvement of the fluid handling system provided by PX310 may not meet a predetermined target threshold, and the use of PX310 may be reduced until a change in conditions occurs. In any system discussed herein, one or more high-pressure valves, expansion valves, connections to a parent rack, control valves, or similar may determine the proportion of fluid supplied to PX. 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 the proportion of the fluid discharged by the subcooler 315 that is supplied to the high-pressure inlet of PX310 and the proportion that is supplied to the receiver 313 without being supplied to PX310. The fluid may be expanded in such a high-pressure valve, for example, or it may be cooled by such a high-pressure valve.

[0101] Additional components may include an optional mixer 301. Any system described herein may include one or more mixers for taking in fluid components that may differ in temperature, density, phase, and other properties. 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 discharged by the secondary or cooling channel of the subcooler 315. This may reduce the temperature or superheating of the fluid supplied to the low-pressure inlet of the PX. This may also adjust the phase of the fluid supplied to the low-pressure inlet of the PX 310. Fluid may be supplied to the mixer 301 by one or more control valves, which determine, for example, the proportion of fluid discharged by the bypass valve 312 supplied to the mixer 301, the proportion of fluid discharged by the cooling channel of the subcooler 315 supplied to the mixer 301, and so on. The control of these valves can be based on fluid temperature measurements (e.g., near the low-pressure inlet of the PX310), fluid pressure measurements, fluid phase, fluid density, and other conditions.

[0102] Figure 3B is a schematic diagram of a fluid handling system 300B including a pressure exchanger (PX310) with an auxiliary receiver 311, according to several embodiments. In some embodiments, features having reference numerals corresponding to reference numerals in other figures include 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 in place of the main compressor 322, etc.) may also be optional components for the fluid handling system 300B. In some examples, the features of the fluid handling system 300B have the same characteristics, structure, and / or functions as the fluid handling system 300A in Figure 3A.

[0103] 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 actions to 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 actions to achieve and / or maintain a target temperature in a target environment, such as 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 freezing temperature, first target freezing temperature) and a second target temperature near the second evaporator 319 (e.g., freezer temperature, second target freezing temperature).

[0104] In some embodiments, the fluid processing system 300B may receive data indicating the state of the fluid processing system 300B, which may include the state of the working fluid, ambient environmental conditions, conditions near the evaporator and / or gas cooler, etc. The fluid state 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 state data from one or more sensors indicating the state of the fluid in 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, or similar.

[0105] 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 rate of fluid from the outlet of the main gas cooler 329 (e.g., the fluid discharged by the main gas cooler 329) to the auxiliary receiver 311, for example, in parallel with PX310. In some embodiments, the bypass high-pressure valve 348 may be actuated to selectively adjust the flow rate of fluid. The bypass high-pressure valve 348 may selectively provide a portion of the fluid discharged by the main gas cooler 329 to the auxiliary receiver 311. For example, by acting the bypass high-pressure valve 348 to open further, more fluid can flow from the main gas cooler 329 to the auxiliary receiver 311, or by acting the bypass high-pressure valve 348 to close further, less fluid can flow from the main gas cooler 329 to the auxiliary receiver 311. The fluid expands as it flows through the bypass high-pressure valve 348, which can cause a decrease in the fluid's pressure and / or temperature.

[0106] 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 such that the fluid may or may not condense within the main gas cooler 329. Any embodiment discussed herein may include a condenser that can function as a gas cooler in one or more applications.

[0107] 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) discharged from the low-pressure outlet of the PX 310. The receiver 313 may form a chamber for collecting the first fluid from the first outlet of the PX 310. The receiver 313 may receive the first fluid, which is 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 a 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 made 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 (as indicated, for example, by the liquid level depicted in Figure 3B). The liquid of the first fluid settles at the bottom of the receiver 313, while the gas of the first fluid rises to the top of the receiver 313. The liquid can flow from the receiver 313 toward the evaporator 318 (for example, via the expansion valve 316). The liquid can 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 predetermined pressure. This 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 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 may be maintained between receiver 313 and auxiliary receiver 311, such that a target pressure difference of 50 psi (0.345 MPa) may be maintained between the auxiliary receiver 311 and receiver 313.

[0108] The fluid processing system 300B may include an expansion valve 316. The fluid processing system 300B may include a secondary expansion valve 317. In some embodiments, the expansion valve 316 may be positioned along the flow path between the receiver 313 and the evaporator 318, and may be coupled, for example, between the receiver 313 and the evaporator 318. The secondary expansion valve 317 may be coupled between the receiver 313 and the 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 may be operated (e.g., opened or closed) based on temperature data associated with the evaporator 318 (e.g., liquid temperature in the evaporator, gas temperature in the evaporator, temperature of fluid flowing into the evaporator, temperature of fluid flowing out of the evaporator, etc.). For example, a pressure-sensitive component of the expansion valve 316 (e.g., a sensing valve (bulb)) may increase or decrease the pressure on the diaphragm of the expansion valve 316, opening or closing a poppet valve coupled to the diaphragm, thereby increasing or decreasing the flow rate of fluid to the evaporator 318 and increasing or decreasing the amount of fluid expansion. The pressure-sensitive component of the expansion valve may be located near the downstream end of the evaporator 318 (e.g., near the outlet of the evaporator 318, outside the evaporator 318, inside the evaporator 318, or a similar location) 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 operated entirely on electronic commands. The operation and control of a secondary expansion valve 317 may be similar. For example, the same applies to the fluid conditions in the second evaporator 319.

[0109] The fluid handling system 300B may include 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 to merge with the exhaust of the evaporator 318. In some embodiments, the flow of gas 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 merge with the exhaust of the evaporator 318. The flash gas valve 320 may expand (e.g., reduce the pressure) the gas collected in the receiver 313 as the gas flows toward the main compressor 322. In some embodiments, the flash gas valve 320 is an adjustable valve. In some embodiments, the flash gas valve 320 is actuated by a controller based on sensor data.

[0110] In some embodiments, the fluid handling system 300B further includes 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 target pressure difference above the receiver 313, such that the target pressure difference is, for example, 50 psi (approximately 0.345 MPa), 40–60 psi (approximately 0.276–0.414 MPa), 20–100 psi (approximately 0.138–0.689 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, a pressure difference may be maintained between the low-pressure outlet and the low-pressure inlet of the PX to drive the fluid flow to the low-pressure inlet of the PX, for example. Maintaining a pressure difference between receiver 313 and auxiliary receiver 311 can enable fluid flow through PX.

[0111] 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 entering the low-pressure inlet of the PX, a target flow rate exiting the high-pressure outlet of the PX, or a target flow rate exiting the low-pressure outlet of the PX. The target flow rate may further be based 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). The flow rate may be measured using, for example, a mass flow meter, a density measurement (e.g., by a Coriolis flow meter, etc.).

[0112] In some embodiments, the low-pressure outlet of PX310 may be directly connected to a receiver 313 and may be 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 may be 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 enables the driving of the low-pressure flow in PX310 by this difference, eliminating the need for a low-pressure lift device to drive fluid to the low-pressure inlet of PX310, for example, the need for a low-pressure booster.

[0113] The fluid handling system 300B includes a bypass high-pressure valve 348. The bypass high-pressure valve 348 may optionally be part of a fluid handling system that includes two receivers. The bypass high-pressure valve 348 may be configured to provide a portion of the fluid discharged 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.

[0114] 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.

[0115] 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.

[0116] In some embodiments, the first low-pressure control valve 386 may be used to maintain a target liquid level in the auxiliary receiver 311. When the liquid level detected in the auxiliary receiver 311 exceeds a target threshold (e.g., a target percentage 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. When 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.

[0117] 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 actuated to achieve and / or maintain a target travel distance of the low-pressure inlet of PX310, for example, 110% of the travel distance.

[0118] 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 at both positions, for example, the control valve may be located between the auxiliary receiver 311 and the low-pressure inlet of PX310, and the control valve may be located between the low-pressure outlet of PX310 and the receiver 313. In some embodiments, placing the control valve between the low-pressure outlet of PX310 and the receiver 313 allows control of the fluid pressure at the low-pressure inlet of PX310. Placing the control valve between the low-pressure outlet of PX310 and the receiver 313 allows control of 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 can increase the mass boost ratio, for example, the maximum mass flow rate compressible through PX310. In some embodiments, some components of the fluid handling system 300B are existing systems (e.g., a parent rack), to which the PX system is added. Controlling the components of the parent rack during the implementation of a PX system can be difficult, inconvenient, or impossible. Such valves may allow for control of the fluid density supplied to the PX without adjusting any control unit on the parent rack.

[0119] Figure 3C is a schematic diagram of a fluid handling system 300C, including a subcooler 315 and an auxiliary receiver 311, according to several embodiments. Features having reference numerals corresponding to reference numerals in other figures may include the same characteristics, structure, and / or functions as those described in the other figures. In some embodiments, optional components described in relation to Figures 3A-3B may also be optional components for the fluid handling system 300C. Features of the fluid handling system 300B may have the same characteristics, structure, and / or functions as those of the fluid handling systems 300A-300B.

[0120] 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, i.e., liquid, gas, or supercritical fluid). The fluid processing system 300C may be configured to perform actions to 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 actions to achieve and / or maintain a target temperature in one or more environments, for example, inside a building or in a refrigerated case in a grocery store. The fluid processing system 300C may perform actions to achieve and / or maintain target conditions of the fluid processing system, such as fluid temperature, pressure, density, liquid level, or similar, at various locations within the fluid processing system 300C. The fluid processing system 300C may adjust one or more components to achieve target conditions, for example, by acting on a valve, adjusting the motor of PX310, adjusting the fan speed, adjusting the compressor speed, etc.

[0121] The fluid handling system 300C includes a bypass high-pressure valve 348. The bypass high-pressure valve 348 can, at least in part, determine the flow rate of the working fluid flowing into the auxiliary receiver 311. The bypass high-pressure valve 348 can selectively supply a portion of the fluid discharged by the main gas cooler 329 to the auxiliary receiver 311.

[0122] 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 such that the fluid may or may not condense within the main gas cooler 329. Any embodiment discussed herein may include a condenser that can function as a gas cooler in one or more applications.

[0123] The fluid handling system 300C further includes a receiver 313. The receiver 313 can receive fluid from the low-pressure outlet of PX310 and from the auxiliary receiver 311. The receiver 313 can supply fluid to the evaporator 318 to absorb heat from the environment near the evaporator 318 and / or to the main compressor 322 via the flash gas valve 320. The auxiliary receiver 311 and the receiver 313 can enable phase separation of the working fluid of the fluid handling system 300C.

[0124] 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, and 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 in the auxiliary receiver 311, the pressure in the receiver 313, the pressure difference between the receivers, the liquid level in 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 auxiliary receiver pressure. In some embodiments, a low-pressure valve may be included between the low-pressure outlet of PX310 and the receiver 313, as an alternative to or in addition to the second low-pressure control valve 387.

[0125] The fluid handling system 300C further includes a subcooler 315. The subcooler 315 may receive a portion of the fluid into a secondary or cooling fluid channel to exchange heat with the fluid discharged by the main gas cooler 329. The secondary or cooling fluid channel of the subcooler 315 may receive fluid from an auxiliary gas cooler 327, which in turn may receive fluid from the high-pressure outlet of PX310. In some embodiments, such as the fluid handling system 300C lacking the subcool valve 312 in Figure 3A, the degree of subcooling may be uncontrolled, and there may be no control signals associated with monitoring and / or regulating the subcooling performed by the subcooler 315.

[0126] Further components of the fluid processing system 300C, such as PX310, main compressor 322, expansion valve 316, etc., may perform functions corresponding to those described in relation to the fluid processing systems 300A to 300B in Figures 3A to 3B.

[0127] Figure 3D is a schematic diagram of a fluid handling system 300D including a PX310 according to several embodiments. In some embodiments, the fluid handling system 300D is a boosterless PX architecture in which a low-pressure (LP) out (LPout) fluid falls into an MT (medium temperature) suction section (e.g., the outlet of the evaporator 318).

[0128] The flow may split after the main gas cooler 329 to produce two flows. The first flow proceeds to the high-pressure (HP) in (HPin) fluid in PX310, where it expands to low pressure and may become a low-temperature two-phase liquid-gas mixture at the LPout in PX310. The LPout flow proceeds through the heat exchanger 370 (HX1), absorbing heat from the second flow (of which the flow split from the main gas cooler 329) and converting substantially all of the liquid into gas. The low-pressure gas flow then further reduces its pressure through the LP valve 364 to substantially the same pressure as the evaporator pressure and proceeds to the inlet of the main compressor 322 (e.g., the MT compressor suction section of the main compressor 322).

[0129] The second flow, cooled in heat exchanger 370 (HX1), expands through the auxiliary expansion valve 375 to a low pressure, potentially becoming a low-temperature two-phase liquid-gas mixture. This releases further heat to the discharge flow of evaporator 318 (e.g., a medium-temperature (MT) evaporator) in heat exchanger 372 (HX2), decreasing the gaseous mass fraction and increasing the liquid mass fraction. The two-phase flow, with reduced flash gas, then proceeds to receiver 313 (e.g., a flash tank).

[0130] Flash gas from receiver 313 (e.g., flash tank) can be guided through the LPin fluid (LPin) port of PX310. The LPout pressure can be lower than the pressure of receiver 313 now discharged to main compressor 322 (e.g., MT compressor suction pressure), so the differential pressure between the LPin and LPout ports of PX drives the flow through the LPin port of PX310.

[0131] The LPin flow is compressed to high pressure by PX310 and exits through the HPout fluid (HPout) port. The HPout discharge from PX310 proceeds to the auxiliary gas cooler 327, where it releases heat and becomes cooler. The fluid exiting the auxiliary gas cooler 327 passes through the auxiliary valve 369, where its pressure is reduced, becoming a cool two-phase liquid-gas mixture that further releases heat to the cooler fluid discharge flow from the second evaporator 319 (e.g., the low-temperature (LT) evaporator) in the heat exchanger 374 (HX3). This reduces the gaseous mass fraction and increases the liquid mass fraction. This two-phase flow with reduced flash gas then proceeds to the receiver 313 (e.g., the flash tank).

[0132] The heat exchanger 372 (HX2) can provide superheated fluid to the outlet of the evaporator 318 (e.g., the outlet of the MT evaporator), which can increase the pressure in the evaporator 318 (e.g., the pressure in the MT evaporator) while satisfying the intake superheat requirement of the main compressor 322 (e.g., the intake superheat requirement of the MT compressor). Such an increase in the pressure of the evaporator 318 (e.g., the pressure increase in the MT evaporator) 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 absorbed, which can further increase the energy efficiency of the fluid handling system 300D.

[0133] The heat exchanger 374 (HX3) can supply superheated fluid to the outlet of the second evaporator 319 (e.g., the outlet of the LT evaporator), which can increase the pressure of the second evaporator 319 (e.g., the LT evaporator pressure) while satisfying the intake superheat requirement of the compressor 323 (e.g., the LT compressor). Such an increase in the pressure of the second evaporator 319 (e.g., the pressure increase of the LT evaporator) can reduce the energy consumption of the compressor 323 (e.g., the energy consumption of the LT compressor) for the same amount of heat absorbed, which can further increase the energy efficiency of the fluid handling system 300D.

[0134] A three-way valve may be positioned downstream of the evaporator 318 (e.g., an MT evaporator) to bypass at least a portion of the flow from the evaporator 318 as needed, so as not to pass through the heat exchanger 372, thereby facilitating control of the suction superheat of the main compressor 322 (e.g., the suction superheat of the MT compressor).

[0135] A three-way valve may be positioned downstream of the second evaporator 319 (e.g., the LT evaporator) to bypass at least a portion of the flow from the second evaporator 319 from passing through the heat exchanger 374 as needed, thereby facilitating control of the suction superheat of the compressor 323 (e.g., the suction superheat of the LT compressor).

[0136] Figure 3E is a schematic diagram of a fluid processing system 300E including a PX310 according to several embodiments. In some embodiments, the fluid processing system 300E is a boosterless subcooled PX architecture having an LPin cooling section using the discharge flow from the evaporator 318 (e.g., the discharge flow from the MT evaporator).

[0137] The flow leaving the main gas cooler 329 is split into two flows. The first flow is subcooled in the subcooler 315 (HX1) before proceeding to the HPin of PX310. The second flow passes through the subcooling valve 312 (subcooling high-pressure valve) to reduce its pressure, becoming a low-temperature two-phase liquid-gas 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, lower temperature than the first flow), it absorbs heat from the first flow, subcooling the first flow in the process. This subcools the HPin of PX310 and reduces the amount of flash gas in the LPout flow after expansion through PX310.

[0138] The subcooled HPin flow then expands through PX310 to a lower pressure and is discharged from the LPout port of PX310. This expansion of the subcooled HPin flow increases the liquid mass fraction in the LPout flow (e.g., less flash gas). The LPout flow then proceeds to receiver 313 (e.g., flash tank). The flash gas in the LPout does not contribute to heat absorption in the fluid handling system 300E (e.g., refrigeration system) but needs to be compressed by compressor 322 (e.g., MT compressor). Therefore, the reduction in the amount of flash caused by subcooling in subcooler 315 (HX1) increases the COP (e.g., system efficiency).

[0139] The second flow exchanges heat with the first flow in the subcooler 315 (HX1), then passes through the heat exchanger 376 (HX2) 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 by releasing heat to the surrounding environment in the auxiliary gas cooler 327. The second flow then has its pressure reduced through the auxiliary valve 369 (e.g., auxiliary high-pressure valve) to become a much colder two-phase liquid-gas mixture, which proceeds to the receiver 313 (e.g., flash tank), where the second flow merges with the LPout flow.

[0140] Heat exchanger 376 (HX2) is used to cool the LPin flow using a portion of the effluent from evaporator 318 (the effluent from the MT evaporator, which is much colder 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 rate through the subcooling valve 312 (e.g., subcooling high-pressure valve) used to subcool the HPin flow through PX310, thereby achieving flow splitting after the main gas cooler 329 (e.g., substantially optimal flow splitting) and increasing the efficiency of the fluid handling system 300E.

[0141] A three-way valve downstream of the evaporator 318 (e.g., the MT evaporator) is controlled based on how much of the flow from the evaporator 318 (e.g., the MT evaporator) is used for cooling the LPin flow and heating the exhaust flow from the evaporator 318 (e.g., the exhaust flow from the MT evaporator), and this is done before the flow proceeds to the inlet of the compressor 322 (e.g., the suction section of the MT compressor).

[0142] The heat exchanger 376 (HX2) can provide superheated fluid to the discharge flow of the evaporator 318 (e.g., the discharge flow of the MT evaporator), thereby enabling an increase in the pressure of the evaporator 318 (e.g., the pressure of the MT evaporator) while satisfying the intake superheat requirement of the main compressor 322 (e.g., the intake superheat requirement of the MT compressor). Such an increase in the pressure of the evaporator 318 (e.g., the pressure increase of the MT evaporator) can reduce the power consumption of the main compressor 322 (e.g., the power consumption of the MT compressor) for a predetermined amount of heat absorbed in the evaporator 318, thereby further increasing the efficiency of the fluid handling system 300E.

[0143] Figure 3F is a schematic diagram of a fluid processing system 300F including PX310 in several embodiments. The fluid processing system 300F may be a boosterless subcool PX architecture having an LPin cooling section and an LPout heat exchange section. The architecture of the fluid processing system 300F may be similar to the architecture of the fluid processing system 300E, except for one or more of the following points.

[0144] The heat exchanger 379 (HX3) may be used to increase the liquid mass fraction of the LPout flow using at least a portion of the exhaust flow from the second evaporator 319 (e.g., the exhaust flow from the LT evaporator, which is at a much lower temperature than the LPout flow). This reduces the amount of flash gas in the LPout flow, and since the flash gas needs to be compressed by the main compressor 322 (e.g., the MT compressor), this reduction in flash gas reduces the energy consumption of the main compressor 322 (e.g., the MT compressor), thereby increasing the energy efficiency of the fluid handling system 300F.

[0145] A three-way valve may be positioned downstream of the second evaporator 319 (e.g., the LT evaporator) and controlled based on how much of the flow from the second evaporator 319 is used for heat exchange with the LPout flow and for heating the exhaust fluid flow from the second evaporator 319 (e.g., the exhaust flow from the LT evaporator), which is done before it proceeds to the inlet to the compressor 323 (e.g., the suction section of the LT compressor).

[0146] The heat exchanger 379 (HX3) can provide superheated fluid to the discharge flow of the second evaporator 319 (e.g., the discharge flow of the LT evaporator), thereby enabling an increase in the pressure of the second evaporator 319 (e.g., the pressure of the LT evaporator) while satisfying the suction superheat requirement of the compressor 323 (e.g., the suction superheat requirement of the LT compressor). Such an increase in the pressure of the second evaporator 319 (e.g., the pressure increase of the LT evaporator) reduces the power consumption of the second compressor 323 (e.g., the power consumption of the LT compressor) for a given amount of heat absorbed in the second evaporator 319 (e.g., the LT evaporator), thereby further increasing the system efficiency of the fluid handling system 300F.

[0147] Figure 3G is a schematic diagram of a fluid processing system 300G including a PX310 in several embodiments. The fluid processing system 300G may be a booster-less subcool PX architecture having 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 points.

[0148] A flow splitter 380 (e.g., a first flow splitter, a three-way valve) can bypass at least a portion of the flow from the outlet of the main gas cooler 329 and direct 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-pressure, two-phase gas-liquid mixture. This low-pressure, low-temperature, two-phase flow can then proceed to a receiver 313 (e.g., a flash tank).

[0149] If PX310 needs to be shut down, substantially all flow can be bypassed and directed 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 architecture described herein may include functions such as PX bypass, PX maintenance, PX offline, or similar functions, as shown in Figure 3G.

[0150] If the discharge flow from the main gas cooler 329 exceeds the amount that the PX310 can handle, a portion of the flow is bypassed through the flow splitter 380. In such a scenario, a certain amount (substantially arbitrary) of flow is directed to the HPin of the PX310, while the remaining flow proceeds through the valve 384. For example, flow is supplied to the PX310 until it reaches its maximum operating speed, and any additional flow (e.g., the flow required to maintain the target pressure of the main gas cooler 329) may be bypassed.

[0151] The pressure setting of valve 384 may be set higher (for example, slightly higher) than the pressure setting of HPin of PX310, so that valve 384 is opened only when the maximum flow capacity of PX310 is reached.

[0152] The flow splitter 382 can be controlled to control the flow through the subcooler 315 and the subcooling valve 312.

[0153] The heat exchanger 378 may be used to cool the fluid leaving the subcooler 315 before providing it to the low-pressure inlet of the PX 310. The fluid flow discharged by the evaporator 318 (e.g., a cooler fluid flow) may be used 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 may increase the fluid density, increase the mass boost ratio, increase the mass flow rate compressible by the PX, etc., thereby increasing 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 suction pressure of the main compressor 322 while maintaining the target suction superheat for the main compressor 322. Increasing the pressure of the evaporator 318 may reduce the energy consumption of the main compressor 322 and further increase system efficiency.

[0154] Figure 4A is a schematic diagram of a fluid processing system 400A, including a PX410, a subcooler 415, and various controllers and other components for providing control of the fluid processing system 400A, according to several embodiments.

[0155] The fluid processing system 400A includes components for performing heat transfer operations. The fluid processing system 400A includes 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.

[0156] The fluid processing system 400A may include one or more sensors. These one or more sensors measure characteristic values ​​associated with the system. For example, one or more temperature sensors may measure the temperature of the fluid flowing, the ambient temperature, the temperatures of high and / or low temperature sinks 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 flow rate (e.g., mass flow rate) of the fluid 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., meters) may measure additional characteristic values, such as the work done by various components, the heat flow rate through the system, the power consumed by the components of the system, the total fluid flow rate through various parts of the system, etc. Instruments 480, 481, 482, and 483 are shown in Figure 4A. In some embodiments, the illustration of an instrument may suggest the inclusion of multiple devices; for example, an instrument for measuring volumetric flow rate may include a device for measuring mass flow rate and a device for measuring fluid density. In some examples, one or more sensors may be omitted for the sake of visual clarity in Figures 4A-4B.

[0157] The fluid processing system 400A includes 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 relationships, or similar.

[0158] The control of the fluid processing system 400A may be performed by computing devices such as general-purpose computing devices (desktop computers, laptop computers, tablets, smartphones, etc.) that execute commands to perform control tasks. The control of the fluid processing system 400A may be performed by computing devices built for specific purposes. The control of the fluid processing system 400A may be performed by control devices such as PID controllers, microcontrollers, or by other known methods of providing control signals. The control of the fluid processing system 400A may include devices that perform multiple operations. For example, a single device may perform the operations of controllers 490 and 491, a single device may perform the operations of controllers 491, 492, and 495, a single device may perform the operations of all controllers in the fluid processing system 400A, or any combination of the functions of various controllers may be performed by a combination of computing devices.

[0159] Controller 490 is operationally coupled to PX410. Controller 490 may receive one or more measurements from instrument 480. Controller 490 may receive fluid pressure measurements from instrument 480. Controller 490 may receive measurements as raw measurement data, pre-processed measurement data, averaged (e.g., Boxcar average) measurement data, or similar forms. In some embodiments, Controller 490 may receive additional measurement data from one or more other sensors associated with the fluid processing system 400A. Controller 490 may receive ambient temperature data, such as ambient temperature of the environment near the main gas cooler 429 and / or auxiliary gas cooler 427 (e.g., in the case of a refrigeration system), or ambient temperature of the environment near the evaporator 418 (e.g., in the case of a heat pump system). Controller 490 may receive sensor data from PX410, such as data indicating the operating speed of 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 a device configured to adjust the operating speed of the PX410, for example, to a motor coupled to the PX410 (e.g., coupled to the rotor of the PX410).

[0160] The controller 493 is operationally 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 it may be another type of component that increases heat transfer away from the auxiliary gas cooler 427.

[0161] In some embodiments, the controller 493 may receive data measurements from the instrument 482. The instrument 482 may provide temperature measurements of the fluid temperature of the auxiliary gas cooler 427. The instrument 482 may provide temperature measurements of the fluid temperature of the fluid discharged from the auxiliary gas cooler 427. The controller 493 may generate control signals based on the data provided by the instrument 482. The controller 493 may generate control signals to achieve a target temperature for the fluid discharged by the auxiliary gas cooler 427. The controller 493 may generate control signals to adjust the operation of the auxiliary cooling component 428. For example, the controller 493 may adjust the operating speed of the fan to achieve a target temperature (e.g., within a threshold) for the fluid at the outlet of the auxiliary gas cooler 427.

[0162] In some embodiments, the target fluid temperature of the fluid discharged by the auxiliary gas cooler 427 can be based on the temperature of the fluid discharged by the main gas cooler 429. The target temperature of the fluid discharged by the main gas cooler 429 can be generated based on environmental conditions such as 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 can release heat into the same environment (for example, both gas coolers may be installed on the roof of a building and release heat into the environment). The controller 493 may receive an indicated value of the temperature of the fluid discharged by the main gas cooler 429 (for example, via instrument 480) and generate a control signal based on maintaining the temperature difference between the fluids discharged by the main gas cooler 429 and the auxiliary gas cooler 427 within a target threshold.

[0163] Controller 491 is operationally coupled to the subcooling valve 412. Controller 491 may receive sensor data from instrument 481. Instrument 481 may indicate the temperature of the fluid discharged by the subcooler 415. Data generated by instrument 481 may be used to determine the subcooling performed by the subcooler 415 (e.g., further cooling beyond the cooling that causes the fluid to undergo a phase transition to liquid, which may be performed by the main gas cooler 429). Data indicating the temperature before the subcooler 415 (e.g., generated by instrument 480) may also be used to determine the degree of subcooling of the fluid performed by the subcooler 415. Controller 491 may provide one or more control signals to the subcooling valve 412. Controller 491 may provide control signals to the subcooling valve 412 based on temperature data. The controller 491 may provide one or more control signals to the subcool valve 412 based on the temperature difference between the fluid supplied to the main inlet of the subcooler 415 (e.g., from the main gas cooler 429) and the fluid supplied to the main outlet of the subcooler 415 (e.g., to the high-pressure inlet of PX410). The controller 491 may generate and / or provide control signals based on the difference between temperature readings provided by instruments 481 and 480, the difference between the temperature reading provided by instrument 481 and the target fluid temperature of the fluid discharged by the main gas cooler 429 (e.g., based on ambient temperature), or similar.

[0164] Controller 492 is operationally coupled to auxiliary valve 469. Controller 492 may provide control signals to auxiliary valve 469 based on the degree of opening of subcooling valve 412, for example, by providing a signal indicating the degree of opening of subcooling valve 412, which is received from controller 491. In some embodiments, subcooling valve 412 may provide a signal indicating the degree of opening of subcooling valve 412 (e.g., a percentage of maximum opening). 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 degree of opening of auxiliary valve 469 may be based on the degree of opening of subcooling valve 412.

[0165] In some embodiments, the controller 494 may be operationally coupled to the subcooling valve 412. The controller 494 may receive data indicating the degree of opening of the flash gas valve 420. In some embodiments, the flash gas valve 420 may be operated by control of a parent rack (e.g., an existing system to which the PX 410 and associated equipment have been retrofitted). Control of the flash gas valve 420 may be difficult or impossible to adjust by the PX system. However, the amount of flash gas in the receiver 413 may be reduced by increasing the cooling of the main fluid flow by the subcooler 415. 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 degree of opening 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 subcool valve 412 may include multiple inputs, for example, inputs based on the flash gas valve 420 and instrument 481. In some embodiments, the minimum opening degree 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 approaching the minimum opening degree (e.g., within a threshold).

[0166] Controller 495 is communicatively coupled to subcool valve 412. Controller 495 obtains information from instrument 483 indicating the low-pressure inlet travel distance of PX410 and generates and / or provides a control signal to subcool valve 412 based on the low-pressure inlet travel distance. The travel distance may be a measure of the flow through PX410 compared to the operating volume of PX410 (e.g., duct volume, duct volume corrected by operating speed, etc.). The travel distance may describe the percentage of the operating volume of PX410 that is filled or replaced 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 other range that includes it. Instrument 483 may include instrumentation for determining the low-pressure inlet travel distance of PX410. Instrument 483 may include a mass flow meter. Instrument 483 may include a pressure gauge. Instrument 483 may include a thermometer. Controller 495 may further obtain an indication of the operating speed of PX410, for example, to determine the duct volume of PX410 available to the fluid per unit time and to determine the travel distance associated with PX410. In some embodiments, auxiliary valve 469 may also be controlled based on travel distance, for example, based on the high-pressure outlet travel distance of PX410. The high-pressure outlet travel distance may also be determined by an instrument (not shown), which may include instrumentation for determining the mass flow rate of the high-pressure discharge fluid, the density of the high-pressure discharge fluid, 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 can be used on a conditional basis, for example, different control operations based on different sensor inputs can be used to control the subcooling valve 412 under different conditions. In some embodiments, combinations of the operation of controllers 491 and / or 494 and / or 495 can be used to generate and / or provide control signals to the subcooling valve 412.For example, the lookup table may include values ​​for the degree of opening of the subcool valve 412, based on inputs derived from measurements of instrument 481, flash gas valve 420 and / or instrument 483.

[0167] 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, instruments, or other instrumentation in relation to any controller 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 included in a fluid processing system (e.g., a refrigeration system).

[0168] 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), the controller may control the subcool valve 412, auxiliary valve 369, auxiliary cooling component 428, etc. In some embodiments, one or more sensors (e.g., pressure sensors, flow sensors, temperature sensors) are located near the inlets and / or outlets of the various components of the fluid processing system 400A (e.g., fluids 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 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 are located at the inlet and outlet of PX410, respectively, to measure the flow rates of the first and second fluids entering and leaving PX410.

[0169] In some embodiments, a controller (e.g., a central controller, a system controller, which may be combined with one or more of 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), 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) are located near the inlets and / or outlets of the various components of the fluid processing system 400A (e.g., 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 are located at the inlet and outlet of PX410, respectively, to measure the flow of a first fluid and a second fluid into and out of PX410.

[0170] Figure 4B is a schematic diagram of a fluid processing system 400B including sensors and controllers according to several embodiments. The fluid processing system 400B includes 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 includes a plurality of sensors, for example, instrument 480, instrument 483, instrument 484, etc. The sensors may share one or more features, functions, or characteristics with the sensors included in the fluid processing system 400A in Figure 4A. The fluid processing system 400B includes a plurality of controllers, for example, controller 490, controller 496, controller 497, controller 498, and controller 499. The controller may include or share features and / or characteristics of the controller included in the fluid processing system 400B, for example, the controller architecture, possible grouping of controller functions by fewer computing devices, or similar. Several controllers are applicable to various types of architectures, and the controllers may be used together in any combination relating to the target fluid processing system architecture. For example, an architecture like the fluid processing system 400B can benefit from a controller directed toward an auxiliary cooling component, such as controller 492 in Figure 4A. Any number of controllers described herein may be included in the target architecture and may be implemented by any number of devices.

[0171] The fluid handling system 400B includes 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 may perform functions similar to those of the corresponding components of the fluid handling system 300B.

[0172] The fluid processing system 400B includes instruments 480, 483, and 484. These instruments may have characteristics similar to those of the instruments in the fluid processing system 400A. Each instrument in the fluid processing system may include multiple sensors, meters, or other devices for determining measurements related to the control of the fluid processing system 400B. The instruments may include one or more temperature sensors, pressure sensors, flow meters, densimeters, or similar devices.

[0173] 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 (for example, via a 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. This is provided, for example, by an instrument 480, an instrument inside the main gas cooler 429, or similar.

[0174] The fluid handling system 400B includes a controller 496, which is operationally coupled to a bypass high-pressure valve 448. The bypass high-pressure valve 448 may supply a portion of the fluid discharged by the main gas cooler 429 to the auxiliary receiver 411. The degree of opening of the bypass high-pressure valve 448 (e.g., a percentage of the maximum opening) may be used to determine the proportion of the fluid discharged by the main gas cooler 429 supplied to the auxiliary receiver 411 and the proportion supplied 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 state of the auxiliary receiver 411. The controller 496 may generate control signals based on the pressure in the auxiliary receiver 411, for example, based on the fluid pressure in 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 (e.g., within a threshold) is achieved.

[0175] The fluid handling system 400B includes a controller 497, which is operationally coupled to an auxiliary valve 469. The controller 497 can generate control signals based on measurement data received from an instrument 484. The instrument 484 may be configured to generate an indication of the high-pressure outlet travel distance of 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 PX410 (e.g., rotational speed, operating volume, or similar). The auxiliary valve 469 may be adjusted until a target high-pressure outlet travel distance (e.g., within a threshold) is achieved.

[0176] The fluid handling system 400B includes a controller 498, which is operationally coupled to a second low-pressure control valve 452. The second low-pressure control valve 452 determines the fluid flow rate 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 instrument 483. The instrument 483 may determine the low-pressure inlet travel distance of PX410. The low-pressure inlet travel distance may be determined based on several different criteria, combinations of criteria, averaging of values ​​determined from various methods, other statistical measurement methods, 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, a low-pressure inlet travel distance is targeted, and a volumetric flow rate through the second low-pressure valve 452 can be generated such that the target travel distance is achieved (e.g., as a function of the operating speed of PX410). In some embodiments, the degree of opening of the second low-pressure valve 452 can be determined as a function of the operating speed of PX410 (e.g., via a lookup table, a formula function, etc.). In some embodiments, the instrument 483 provides suggestive values ​​for the travel distance, such as mass flow rate, fluid pressure, and fluid temperature, and the controller 498 can use these to generate a control signal for the second low-pressure control valve 452.

[0177] The fluid handling system 400B includes a controller 499, which is operationally 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 indicated value for 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 provide 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 closed when the liquid level in the auxiliary receiver 411 falls below a target level.

[0178] Figures 5A-5E are flowcharts illustrating methods 500A-5E for controlling a fluid processing system (e.g., one or more of the fluid processing systems 300A-5B in Figures 3A-5B) according to several embodiments. In some embodiments, methods 500A-5E are executed by processing logic, which includes hardware (e.g., circuits, dedicated logic, programmable logic, microcode, processing units, etc.), software (e.g., commands run on processing units, commands executed on 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-5E 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-5E when executed by one or more processing units.

[0179] For the sake of simplicity, methods 500A–E are illustrated and described as a series of operations. However, the operations relating to this disclosure may occur in various orders and / or simultaneously with other operations not presented and described herein. Furthermore, in some embodiments, not all illustrated operations are performed to implement methods 500A–E according to the subject matter of this disclosure. In addition, those skilled in the art will understand and appreciate that methods 500A–E may be alternatively represented as a series of interrelated states via state diagrams or events.

[0180] Figure 5A is a flow diagram of Method 500A for providing 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 indicating 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, or similar. The fluid in the first channel may be configured to exchange heat with the fluid in a second channel, cooling channel, cooling fluid channel, or similar. The fluid in the first channel may lose heat to a cooler 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.

[0181] In block 504, the processing logic optionally obtains openness data for a second control valve. The second control valve is coupled between the outlet of the receiver and the inlet of the compressor. The second control valve may be a flash gas valve, and for example, it may be capable of removing gas from a gas-liquid mixture contained in the receiver. The second control valve may be opened based on the conditions of the receiver. The openness 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, or similar.

[0182] In block 506, the processing logic optionally obtains an indication of a first travel distance associated with the low-pressure inlet of the PX. The first travel distance may be determined based on sensors near the low-pressure inlet of the PX. The first travel distance may be determined based on the measured 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, or similar.

[0183] In block 508, the processing logic generates a first control signal. The generation of the control signal optionally includes 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 openness data and first travel distance. Generating the first control signal optionally includes determining that the subcooling degree of the first fluid does not satisfy a target threshold condition, for example, the subcooling degree of a target temperature drop across the heat exchanger. Generating the first control signal optionally includes obtaining second temperature data indicating the temperature of the fluid discharged 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 discharged by the first gas cooler or on the ambient temperature.

[0184] In block 510, generating a first control signal optionally includes determining whether the opening degree data is within a threshold value for the minimum target opening degree of the second control valve. For example, the first control signal may ensure that the second control valve is not closed beyond the minimum target opening degree.

[0185] In block 512, generating a first control signal optionally includes determining a target opening degree of a first control valve. The target opening degree of the first control valve may be selected to maintain at least a minimum target opening degree of a second control valve. In some embodiments, increasing the subcooling performed by the heat exchanger may reduce the flash gas in the receiver. The degree of subcooling may be maintained such that there is enough flash gas in the receiver to maintain at least a minimum opening degree of the second control valve.

[0186] 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 the degree of opening of the first control valve based on the first control signal. The degree of opening of the first control valve may determine the proportion of fluid discharged from the first gas cooler and supplied to the first fluid channel of the heat exchanger.

[0187] In block 516, the processing logic optionally obtains an implied value of a second travel distance associated with the high-pressure outlet of 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. The third control valve is coupled to receive a second fluid from PX and to provide the second fluid to a receiver. The third control valve is configured to adjust the degree of opening of the third control valve based on the second control signal.

[0188] Figure 5B is a flow diagram of method 500B, which provides control of a refrigeration system according to several embodiments. In block 518, the processing logic obtains an indicated value 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 fluid and the second fluid. The refrigeration system may further include a main receiver, which may be in fluid communication with the auxiliary receiver.

[0189] 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.

[0190] 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 flow rate of fluid from an auxiliary receiver to a 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 degree of opening of the first control valve (e.g., a percentage of the maximum opening).

[0191] In block 524, the processing logic optionally obtains an indicative value 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.

[0192] 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.

[0193] In block 528, the processing logic optionally obtains an indicative value of the travel distance of the second fluid associated with the high-pressure outlet of the PX. The indicative value of the travel distance can be obtained 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 travel distance of 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 rate of the second fluid from the high-pressure outlet of the PX through the second gas cooler to the auxiliary receiver based on the degree of opening of the third control valve. The third control valve may be configured to adjust the degree of opening of the third control valve based on the fourth control signal.

[0194] 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. This device may be a fan or the like that increases heat transfer from the second gas cooler to the environment near the second gas cooler.

[0195] Figure 5C is a flow diagram of method 500C, which provides 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.

[0196] In block 532, the processing logic obtains an indicated value for the fluid level of 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.

[0197] 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.

[0198] 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 flow rate of fluid from an auxiliary receiver to a 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 degree of opening of the first control valve (e.g., a percentage of the maximum opening).

[0199] In block 538, the processing logic optionally obtains an indicative value for the travel distance of a second fluid associated with the low-pressure inlet of PX. The indicative value for the travel distance of a second fluid associated with the low-pressure inlet of PX may be based on the characteristics of the fluid supplied to the low-pressure inlet of PX (e.g., temperature, pressure, mass flow rate, etc.). The indicative value for the travel distance of a second fluid associated with (e.g., supplied) the low-pressure inlet of PX may include taking into account the valve characteristics of one or more valves in the refrigeration system. The indicative value for the travel distance of a second fluid associated with the low-pressure inlet of PX may include taking into account the operating speed of PX (e.g., rotational speed).

[0200] 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.

[0201] In block 542, the processing logic optionally provides a sixth control signal to the fourth control valve. The fourth control valve is coupled to determine the fluid flow rate 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 the degree of opening of the fourth control valve.

[0202] 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 implied value of the pressure difference between the main receiver and the auxiliary receiver of the refrigeration system. The refrigeration system may include 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.

[0203] 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.

[0204] 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 the degree of opening of the first control valve based on the first control signal. The degree of opening of the first control valve can determine the proportion of fluid supplied to the auxiliary receiver and the proportion of fluid supplied to the PX.

[0205] In block 550, the processing logic optionally obtains an indication of the fluid level of the auxiliary receiver. The processing logic further optionally generates a second control signal based on the fluid level of 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 can, for example, supply fluid from the auxiliary receiver (maintained at high pressure) to the main receiver (maintained at low pressure) via the second control valve. The second control valve is configured to adjust the degree of opening of the second control valve based on the second control signal.

[0206] In block 552, the processing logic optionally obtains an implied value 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 power through the motor.

[0207] 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 rate 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.

[0208] 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 implied value of the pressure difference between the main receiver and the auxiliary receiver of the refrigeration system. The refrigeration system may include 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.

[0209] 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.

[0210] 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 the degree of opening of the first control valve based on the first control signal. The degree of opening of the first control valve can determine the proportion of fluid supplied to the auxiliary receiver and the proportion of fluid supplied to the PX.

[0211] In block 562, the processing logic optionally obtains an indicative value of the travel distance of a second fluid associated with the high-pressure outlet of the PX. The indicative value of the travel distance can be obtained based on the 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 travel distance of 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 rate of the second fluid from the high-pressure outlet of the PX through the second gas cooler to the auxiliary receiver based on the degree of opening of the fourth control valve. The fourth control valve is configured to adjust the degree of opening of the fourth control valve based on the fifth control signal.

[0212] 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 for increasing the thermal transfer of heat from the second gas cooler to the surrounding environment.

[0213] Figure 6 is a block diagram showing a computer system 600 according to several embodiments. In some embodiments, the computer system 600 is a client device. In some embodiments, the computer system 600 is a controller device (e.g., a server, a control module, a centralized control system, controllers 490-499 in Figures 4A-4B, etc.).

[0214] In some embodiments, the computer system 600 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 600 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 600 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 a set of instructions (whether periodic or not) that specify the actions to be performed by the device. Furthermore, the term “computer” also includes a collection of computers that individually or collectively execute one (or more) sets of instructions for performing one or more of the methods described herein.

[0215] In some embodiments, the computer system 600 includes a processing unit 602, volatile memory 604 (e.g., RAM (Random Access Memory)), non-volatile memory 606 (e.g., ROM (Read Only Memory) or EEPROM (Electrically-Erasable Programmable ROM)), and / or data storage device 616, which communicate with each other via a bus 608.

[0216] In some embodiments, the processing unit 602 is provided by one or more processors, such as a general-purpose processor (e.g., a CISC microprocessor, a RISC microprocessor, a VLIW microprocessor, a microprocessor implementing various command sets, or a microprocessor implementing a combination of command sets) or a specialized processor (e.g., an ASIC, FPGA, DSP, PID controller, or network processor). In some embodiments, the processing unit 602 is provided by one or more of the following: a single processor, multiple processors, a single processor having multiple processing cores, etc.

[0217] In some embodiments, the computer system 600 further includes a network interface device 622 (e.g., connected to network 674). In some embodiments, the computer system 600 includes one or more input / output (I / O) devices. In some embodiments, the computer system 600 further includes a video display device 610 (e.g., a liquid crystal display (LCD)), an alphanumeric input device 612 (e.g., a keyboard), a cursor control device 614 (e.g., a mouse), and / or a signal generator 620. The computer system 600 may include a signal input device 615, which is used, for example, to receive signals from other devices. For example, the signal input device 615 facilitates the computer system 600's reception of measurement data from sensors associated with the fluid processing system. The signal generator 620 may be used to generate and / or transmit control signals to send commands to one or more components of the fluid processing system. The signal generator 620 may transmit control signals to various high-pressure valves, booster pumps, cooling components, PX components, etc.

[0218] In one implementation, a data storage device 616 (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 624 which stores a directive 626 that encodes and implements one or more of the methods or functions described herein. A control module 133 (e.g., including any of the controllers 490 to 499 in Figures 4A to 4B) may be included in the directive 626.

[0219] In some embodiments, the instruction 626 is also present, fully or partially, in the volatile memory 604 and / or the processing unit 602 at the time of its execution. Thus, in some embodiments, the volatile memory 604 and the processing unit 602 also constitute a machine-readable storage medium.

[0220] Although the computer-readable storage medium 624 is shown as a single medium in the illustrated example, the term “computer-readable storage medium” includes single or multiple mediums (e.g., centralized or distributed databases and / or associated caches and servers) that store or encode one or more sets of executable instructions and cause a computer to execute one or more of the methods described herein. The term “computer-readable storage medium” also includes any tangible medium capable of storing or encoding a set of instructions executed by a computer. The term “computer-readable storage medium” is not limited to solid-state memory, optical media, and magnetic media.

[0221] The methods, components, and features described herein may be implemented by discrete 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 hardware devices. Moreover, the methods, components, and features may be implemented in any combination of hardware devices and computer program components, or in computer programs.

[0222] Unless otherwise specified or as is clear from the context, terms such as “operate,” “adjust,” “cause,” “control,” “determine,” “identify,” “provide,” “receive,” “generate,” and “obtain” refer to actions and processes performed or implemented by a computer system, which manipulate and convert data expressed as physical (electronic) quantities in the computer system’s registers and memory devices into other data similarly expressed as physical quantities in the computer system’s memory devices or registers, or other information memory devices, transmission units, or display devices. Furthermore, terms such as “first,” “second,” “third,” and “fourth” used herein are labels to distinguish different elements and do not necessarily have an ordinal meaning according to their numerical representation.

[0223] The examples described herein also relate to apparatus for performing the methods described herein. Such apparatus may be specifically configured for performing the methods described herein, or may include a general-purpose computer system selectively programmed by a computer program stored in the computer system. Such a computer program may be stored in a computer-readable tangible storage medium.

[0224] The methods and 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 herein, or it may be advantageous to configure more specialized devices to perform the methods and / or each of their functions, routines, subroutines, or operations described herein. Examples of these diverse system structures are given above.

[0225] The preceding description sets out numerous specific details, such as examples of particular systems, components, and methods, to provide a good understanding of the various embodiments of this disclosure. However, it will be apparent to those skilled in the art that at least some embodiments of this 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 simplified block diagram form to avoid unnecessarily obscuring this disclosure. Thus, the specific details set out are merely illustrative. A particular implementation may be expected to be within the scope of this disclosure, even if it differs from these exemplary details. A description of a system in this specification may include a description of one or more optional components. Components may be included in combinations not specifically discussed in this disclosure, but may still be within the scope of this disclosure. For example, the controllers 390-395 in Figures 3A-3D may be included in a fluid processing system within the scope of this disclosure, either alone or in any combination.

[0226] Throughout this specification, any reference to “one embodiment” or “one embodiment” means that a particular feature, structure, or characteristic described in relation to that embodiment is included in at least one embodiment. Therefore, the appearance of the phrase “one embodiment” or “one embodiment” in different parts of this specification does not necessarily refer to the same embodiment. Furthermore, the term “or” is inclusive, not exclusive. The terms “about,” “substantially,” or “approximately” in this specification mean that the nominal values ​​shown are accurate within a range of ±10%. Also, terms such as “first,” “second,” “third,” and “fourth” used herein are labels to distinguish different elements and do not necessarily have an ordinal meaning according to their numerical representation.

[0227] As used herein, the terms “above,” “below,” “between,” “placed above,” “before,” “after,” and “above” refer to the relative position of one material layer or component to another layer or component. For example, when a layer is placed above, above, or below another layer, it may be in direct contact with the other layer or it may have one or more intervening layers. Similarly, a layer placed “between” two layers may be in direct contact with both adjacent layers or it may have one or more intervening layers. Likewise, unless otherwise specified, a feature placed “between” two features may be in direct contact with an adjacent feature or it may have one or more intervening layers or components.

[0228] Although the operations of the methods described herein are shown or described in a specific order, the order of operations of each method is modifiable, and certain operations can be performed in reverse order, or certain operations can be performed at least partially simultaneously with other operations. In other embodiments, instructions or suboperations of different operations may be performed intermittently and / or alternately.

[0229] It should be understood that the above description is intended to be illustrative and not limiting. Many other embodiments will be 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, and each claim should be given to the entire extent of its equivalents.

Claims

1. A system, wherein the system is 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, A first gas cooler configured to supply working fluid to a first inlet and a second inlet of a heat exchanger, wherein the heat exchanger is configured to exchange heat between a fluid supplied through the first inlet and a fluid supplied through the second inlet, and a first outlet of the heat exchanger corresponding to the first inlet supplies the first fluid to the PX, and a second outlet of the heat exchanger corresponding to the second inlet supplies the second fluid to the PX, A receiver configured to receive the first fluid and the second fluid from the PX, A system comprising: a first compressor configured to supply the working fluid to the first gas cooler.

2. The system according to claim 1, further comprising a first evaporator configured to receive the working fluid from the receiver and to supply the working fluid to the first compressor.

3. The system according to claim 2, further comprising a second evaporator configured to receive the working fluid from the receiver and to supply the working fluid to the first compressor, wherein the first evaporator is configured to maintain a first temperature of the environment near the first evaporator, and the second evaporator is configured to maintain a second temperature of the environment near the second evaporator that is different from the first temperature.

4. The system according to claim 3, further comprising a second compressor, wherein the working fluid is supplied to the second compressor by the second evaporator, and the outlet of the second compressor is coupled with the working fluid discharged by the first evaporator.

5. The system according to claim 2, further comprising an auxiliary gas cooler, the auxiliary gas cooler being coupled to receive the second fluid from the PX and to supply the second fluid to the receiver.

6. The system according to claim 5, wherein the auxiliary gas cooler is provided with a secondary inlet and a secondary outlet for the first gas cooler.

7. The system according to claim 5, further comprising an auxiliary control valve, the auxiliary control valve coupled between the PX and the receiver to determine the flow rate of the second fluid.

8. The system according to claim 1, further comprising a control valve coupled between the outlet of the first gas cooler and the second inlet of the heat exchanger, wherein the degree of opening of the control valve determines the proportion of working fluid supplied to the first inlet of the heat exchanger.

9. A system, wherein the system is 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, A first receiver, wherein the first receiver is configured to receive the first fluid from the PX, The first gas cooler, A system comprising an auxiliary receiver, wherein the first gas cooler is configured to provide the first fluid to the PX and the working fluid to the auxiliary receiver, and the auxiliary receiver is for providing the second fluid to the PX.

10. The system according to claim 9, further comprising an auxiliary gas cooler, the auxiliary gas cooler configured to receive the second fluid from the PX and to supply the second fluid to the auxiliary receiver.

11. The system according to claim 10, further comprising an auxiliary control valve coupled between the outlet of the PX associated with the second fluid and the auxiliary receiver.

12. The aforementioned system, An evaporator configured to receive working fluid from the first receiver, The system according to claim 9, further comprising a compressor configured to receive the working fluid from the evaporator and to supply the working fluid to a first gas cooler.

13. The system according to claim 9, further comprising a first low-pressure control valve coupled to supply the second fluid from the auxiliary receiver to the PX.

14. The system according to claim 9, further comprising a second low-pressure control valve coupled to provide working fluid from the auxiliary receiver to the first receiver.

15. The system according to claim 9, further comprising a heat exchanger having a first fluid channel having a first inlet coupled to a first outlet and a second fluid channel having a second inlet coupled to a second outlet, wherein the first fluid channel is coupled between the first gas cooler and the PX, and the second fluid channel is coupled to supply the second fluid to the auxiliary receiver.

16. The system according to claim 15, wherein the second fluid channel is coupled to receive working fluid from an auxiliary gas cooler, and the heat exchanger is configured to exchange heat between the fluid in the second fluid channel and the fluid in the first fluid channel.

17. A method, wherein the said method is The method involves acquiring first temperature data, indicated by a processing device, that suggests the degree of subcooling of a first fluid in a heat exchanger, wherein the first fluid flows through a first fluid channel of the heat exchanger, and the first fluid is received by the heat exchanger from a first gas cooler and supplied from the heat exchanger to a pressure exchanger (PX). To generate a first control signal based at least on the first temperature data, A method comprising providing the first control signal to a first control valve, wherein the first control valve is coupled between the outlet of a first gas cooler and the inlet of a second fluid channel of a heat exchanger, and the first control valve is configured to adjust the degree of opening of the first control valve based on the first control signal.

18. The method according to claim 17, wherein the degree of opening of the first control valve determines the proportion of fluid discharged from the first gas cooler and supplied to the first fluid channel of the heat exchanger.

19. The method according to claim 17, wherein generating the first control signal includes determining that the subcooling degree of the first fluid does not satisfy a target threshold condition.

20. Determining that the subcooling degree of the first fluid does not satisfy the target threshold condition means that To obtain second temperature data that indicates the temperature of the fluid discharged by the first gas cooler, The method according to claim 19, comprising determining a target subcooling threshold based on the temperature of the fluid discharged by the first gas cooler.

21. The method according to claim 17, further comprising obtaining opening degree data of a second control valve, the second control valve being coupled between the outlet of a receiver and the inlet of a compressor, and the generation of the first control signal being further based on the opening degree data.

22. Generating the first control signal is The determination of whether the opening degree data is within the threshold of the minimum target opening degree of the second control valve, The method according to claim 21, comprising determining a target opening degree of the first control valve such that at least the minimum target opening degree of the second control valve is maintained.

23. The method according to claim 17, further comprising obtaining an indication value of a first travel distance associated with the low-pressure inlet of the PX, wherein the first control signal is further based on the first travel distance.

24. The aforementioned method, To obtain an indication value of a second travel distance associated with the high-voltage outlet of the PX, Based on the second travel distance, a second control signal is generated, The method according to claim 23, further comprising providing the second control signal to a third control valve, wherein the third control valve is coupled to receive a second fluid from the PX and to provide the second fluid to a receiver, and the third control valve is configured to adjust the degree of opening of the third control valve based on the second control signal.

25. A method, wherein the said method is The method involves obtaining an indication of the fluid level in an auxiliary receiver of a refrigeration system using a processing device, wherein the refrigeration system includes a pressure exchanger (PX) configured to receive a first fluid from a first gas cooler, receive a second fluid from the auxiliary receiver, and exchange pressure between the first fluid and the second fluid. Based on the fluid level of the auxiliary receiver, a first control signal is generated. A method comprising providing the first control signal to a first control valve, the first control valve being configured to enable fluid flow from the auxiliary receiver to the main receiver based on the first control signal.

26. The aforementioned method, To obtain an indicative value of the fluid pressure of the first gas cooler, Based on the fluid pressure of the first gas cooler, a second control signal is generated. The method according to claim 25, further comprising providing the second control signal to the motor of the PX, wherein the motor of the PX is configured to adjust the operating speed of the PX based on the second control signal.

27. The aforementioned method, To obtain an indicative value of the pressure difference between the auxiliary receiver and the main receiver, A third control signal is generated based on the pressure difference between the auxiliary receiver and the main receiver. The method according to claim 25, further comprising providing the third control signal to a second control valve, wherein the second control valve is coupled to provide a first fluid from the first gas cooler to the auxiliary receiver, and the second control valve is configured to maintain a target pressure difference between the auxiliary receiver and the main receiver based on the third control signal.

28. The aforementioned method, To obtain an indicative value of the travel distance of the second fluid associated with the high-pressure outlet of the PX, A fourth control signal is generated based on the distance traveled by the second fluid associated with the high-pressure outlet. The method according to claim 25, further comprising providing the fourth control signal to a third control valve, wherein the third control valve is coupled to determine the fluid flow rate of the second fluid from the high-pressure outlet of the PX through the second gas cooler to the auxiliary receiver based on the degree of opening of the third control valve, and the third control valve is configured to adjust the degree of opening of the third control valve based on the fourth control signal.

29. The method according to claim 28, wherein the suggested value of the displacement distance is based on the measured mass flow rate of the second fluid and the measured density of the second fluid.

30. The aforementioned method, Obtain an indicative value of the fluid temperature at the outlet of the second gas cooler, Based on the fluid temperature, a fifth control signal is generated, The method according to claim 28, further comprising providing the fifth control signal to a device for regulating heat transfer from the second gas cooler.

31. The aforementioned method, To obtain an indicative value of the travel distance of the second fluid associated with the low-pressure inlet of the PX, A sixth control signal is generated based on the distance traveled by the second fluid associated with the low-pressure inlet. The method according to claim 25, further comprising providing the sixth control signal to a fourth control valve, the fourth control valve being coupled to determine the fluid flow rate of the second fluid from the auxiliary receiver to the low-pressure inlet, and the fourth control valve adjusting the degree of opening of the fourth control valve based on the sixth control signal.

32. A method, wherein the said method is The method involves obtaining an indication of the pressure difference between the main receiver and the auxiliary receiver of a refrigeration system using a processing device, wherein the auxiliary receiver and the pressure exchanger (PX) are configured to receive a first fluid from a first gas cooler, the auxiliary receiver is configured to supply a second fluid to the PX, the PX is configured to exchange pressure between the first fluid and the second fluid, and the main receiver is configured to receive the first fluid from the PX. Based on the aforementioned pressure difference, a first control signal is generated, A method comprising providing the first control signal to a first control valve coupled between the first gas cooler and the auxiliary receiver, wherein the first control valve is configured to adjust the degree of opening of the first control valve based on the first control signal.

33. The aforementioned method, To obtain an indicative value of the fluid level in the auxiliary receiver, A second control signal is generated based on the fluid level of the auxiliary receiver. The method according to claim 32, further comprising providing the second control signal to a second control valve, wherein the second control valve is coupled between the auxiliary receiver and the main receiver, and the second control valve is configured to adjust the degree of opening of the second control valve based on the second control signal.

34. The aforementioned method, To obtain an indicative value of the fluid pressure of the first gas cooler, Based on the fluid pressure of the first gas cooler, a third control signal is generated, The method according to claim 32, further comprising providing the third control signal to the motor of the PX, wherein the motor of the PX is configured to adjust the operating speed of the PX based on the third control signal.

35. The aforementioned method, To obtain an indicative value of the travel distance of the second fluid associated with the high-pressure outlet of the PX, A fourth control signal is generated based on the distance traveled by the second fluid associated with the high-pressure outlet. The method according to claim 32, further comprising providing a fourth control signal to a third control valve, wherein the third control valve is coupled to determine the fluid flow rate of the second fluid from the high-pressure outlet of the PX through a second gas cooler to the auxiliary receiver based on the degree of opening of the third control valve, and the third control valve is configured to adjust the degree of opening of the third control valve based on the fourth control signal.

36. The method according to claim 35, wherein the suggested value of the travel distance is based on the measured mass flow rate of the second fluid and the measured density of the second fluid.

37. The aforementioned method, Obtain an indicative value of the fluid temperature at the outlet of the second gas cooler, Based on the fluid temperature, a fifth control signal is generated, The method according to claim 35, further comprising providing the fifth control signal to a device for regulating heat transfer from the second gas cooler.

38. The aforementioned method, To obtain an indicative value of the travel distance of the second fluid associated with the low-pressure inlet of the PX, A sixth control signal is generated based on the distance traveled by the second fluid associated with the low-pressure inlet. The method according to claim 32, further comprising providing the sixth control signal to a fourth control valve, wherein the fourth control valve is coupled to determine the fluid flow rate of the second fluid from the auxiliary receiver to the low-pressure inlet, and the fourth control valve adjusts the degree of opening of the fourth control valve based on the sixth control signal.

39. A non-temporary machine-readable storage medium that stores, when executed, a command causing a processing device to perform the method according to any one of claims 17 to 38.

40. A system comprising a storage device and a processing device coupled to the storage device, wherein the processing device is configured to perform the method described in any one of claims 17 to 38.

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