Dual fluid compression cycle

Abstract

A dual-fluid compression cycle method for a heat transfer application, the method constituted of: circulating a refrigerant through a refrigerant circuit to undergo phase changes and produce heating or cooling, the refrigerant circuit comprising a dual fluid compressor pump; and circulating a compression fluid through a compression fluid circuit to compress the refrigerant within the dual fluid compressor pump and transfer heat between the refrigerant and the compression fluid.

Description

DUAL FLUID COMPRESSION CYCLETECHNICAL FIELD

[0001] The present disclosure relates substantially to the field of heating, ventilation, air conditioning, and refrigeration (HVAC&R) systems.BACKGROUND

[0002] HVAC&R systems consume nearly 50% of global electrical energy, with efficiency gains over the past decades driven largely by advances in controls, data, and logic. However, conventional systems using vapor compression cycles with compressors (e.g., reciprocating, rotary, scroll) operate inefficiently under varying loads and require large condensers to dissipate heat. These systems also perform compression far from isothermally, resulting in high energy consumption. Multi-stage and intercooling methods have been explored to improve efficiency but often add complexity and cost without substantial gains. Liquid piston compressors (LPCs) have shown potential for near-isothermal compression but face practical challenges like fluid separation and limited compression ratios. These limitations highlight the need for a novel approach to substantially reduce energy consumption, enhance system efficiency, and support sustainable HVAC&R technology.SUMMARY

[0003] Accordingly, it is a principal object of the present invention to overcome at least some of the disadvantages of prior art systems and methods. This is provided in one example by a dual-fluid compression cycle method for a heat transfer application, the method comprising circulating a refrigerant through a refrigerant circuit to undergo phase changes and produce heating or cooling, the refrigerant circuit comprising a dual fluid compressor. In some examples, the method comprises circulating a compression fluid through a compression fluid circuit to compress the refrigerant within the dual fluid compressor. In some examples, the method comprises transferring heat between the refrigerant and the compression fluid.

[0004] In some examples, unlike traditional single-fluid refrigeration cycles, the present system employs two distinct fluids operating in tandem to achieve higher coefficients of performance (COP). This can be used in various fields, including HVAC&R systems, thermodynamic cycles, energy-efficient cooling and heating technologies, compressor and heat exchanger design, and fluid separation systems. In some examples, by introducing a secondary compression fluid cycle alongside a primary refrigerant cycle, the present disclosure offers substantial energy savings for residential, commercial, and industrial applications.

[0005] In some examples, the present disclosure presents a dual-fluid compression cycle for heating, ventilation, air conditioning, and refrigeration (HVAC&R) systems, designed to enhance energy efficiency, operational flexibility, and environmental sustainability. In some examples, the system combines a primary refrigerant cycle with a secondary compression fluid cycle, employing two separate fluids that interact in a mixed or unmixed configuration. In some examples, this dual-fluid approach enables more efficient compression, significantly reduces energy requirements and allows for higher coefficients of performance (COP) compared to traditional single-fluid refrigeration cycles.

[0006] In some examples, the system includes specialized components for fluid separation, fluid control, and integrated heat exchange. In some examples, a mixed configuration combines immiscible fluids (e.g., R290 and water) for efficient thermal interaction, while the unmixed configuration maintains separate fluid pathways, which can enable precise control and adaptability to various operating conditions. In some examples, a unique pressure storage feature further enhances energy savings by storing high-pressure compression fluid during off- peak times and releasing it during peak demand, which can reduce reliance on electrical power.

[0007] In some examples, the dual-fluid cycle can operate in both cooling and heating modes, functioning as a heat pump. In some examples, the dual-fluid cycle also supports cascading configurations for applications requiring deep freeze or high-temperature heating, which can make it adaptable across a range of residential, commercial, and industrial environments. In some examples, the present systems and methods offer substantial improvements over conventional systems by optimizing compression work, reducing heat exchanger load, and improving overall system efficiency, positioning it as a highly effective and versatile solution for modern HVAC&R demands

[0008] Additional features and advantages of the invention will become apparent from the following drawings and description.

[0009] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention pertains. In case of conflict, the patent specification, including definitions, governs. As used herein, the articles "a" and "an" mean "at least one" or "one or more" unless the context clearly dictates otherwise. As utilized herein, “and / or” means any one or more of the items in the list joined by “and / or”. As an example, “x and / or y” means any element of the three-element set {(x), (y), (x, y) }. In other words, “x and / or y” means “x, y or both of x and y”. As some examples, “x, y, and / or z” means any element of the seven-element set {(x), (y), (z), (x, y), (x, z), (y, z), (x, y, z)}.

[0010] Further, unless expressly stated to the contrary, “or” refers to an inclusive or and not to an exclusive or. For example, a condition A or B is satisfied by anyone of the following: A is true (or present) and B is false (or not present), A is false (or not present) and B is true (or present), and both A and B are true (or present).

[0011] In addition, use of the “a” or “an” are employed to describe elements and components of examples of the instant inventive concepts. This is done merely for convenience and to give a general sense of the inventive concepts, and “a” and “an” are intended to include one or at least one and the singular also includes the plural unless it is obvious that it is meant otherwise.

[0012] As used herein, the term "about", when referring to a measurable value such as an amount, a temporal duration, and the like, is meant to encompass variations of + / -10%, more preferably + / -5%, even more preferably + / -1%, and still more preferably + / -0.1% from the specified value, as such variations are appropriate to perform the disclosed devices and / or methods.

[0013] The following examples and aspects thereof are described and illustrated in conjunction with systems, tools and methods which are meant to be exemplary and illustrative, but not limiting in scope. In various examples, one or more of the above-described problems have been reduced or eliminated, while other examples are directed to other advantages or improvements.BRIEF DESCRIPTION OF DRAWINGS

[0014] For a better understanding of the invention and to show how the same may be carried into effect, reference will now be made, purely by way of example, to the accompanying drawings in which like numerals designate corresponding sections or elements throughout.

[0015] With specific reference now to the drawings in detail, it is stressed that the particulars shown are by way of example and for purposes of illustrative discussion of the preferred examples of the present invention only and are presented in the cause of providing what is believed to be the most useful and readily understood description of the principles and conceptual aspects of the invention. In this regard, no attempt is made to show structural details of the invention in more detail than is necessary for a fundamental understanding of the invention, the description taken with the drawings making apparent to those skilled in the art how several forms of the invention may be embodied in practice. In the accompanying drawings:

[0016] FIG. 1 illustrates a high-level schematic diagram of a refrigeration system in accordance with the prior art;

[0017] FIG. 2 illustrates a high-level schematic diagram of a refrigeration system in accordance with the prior art, further comprising an enhanced vapor injection (EVI) configuration;

[0018] FIG. 3 illustrates a high-level schematic diagram of a refrigeration system comprising an unmixed dual fluid compressor, in accordance with examples of the disclosure;

[0019] FIG. 4 illustrates a high-level schematic diagram of a refrigeration system comprising an unmixed dual fluid compressor and a joined reservoir, in accordance with examples of the disclosure;

[0020] FIG. 5 illustrates a high-level schematic diagram of a refrigeration system comprising a mixed dual fluid compressor, in accordance with examples of the disclosure;

[0021] FIG. 6 illustrates a Pressure-Enthalpy (PH) diagram for HVAC&R and dual fluid compression cycles, in accordance with examples of the disclosure;

[0022] FIG. 7 illustrates a Pressure-Temperature (PT) diagram for HVAC&R and dual fluid compression cycles, in accordance with examples of the disclosure;

[0023] FIG. 8 illustrates a high-level block diagram of a dual fluid compressor pump, in accordance with examples of the disclosure;

[0024] FIGs. 9A - 9D show high-level block diagrams illustrating various steps of operation of a piston-based, unmixed, dual fluid compressor pump, in accordance with examples of the disclosure;

[0025] FIGs. 10A - 10D show high-level block diagrams illustrating various steps of operation of a piston-based, mixed, dual fluid compressor pump, in accordance with examples of the disclosure;

[0026] FIGs. 11 A - 11C illustrate a high-level Pressure-Volume (PV) diagrams of the stage of operation of various positive displacement devices, in accordance with examples of the disclosure;

[0027] FIG. 12 illustrates a high-level diagram illustrating various steps of operation of a vane-based, mixed, dual fluid compressor pump, in accordance with examples of the disclosure;

[0028] FIGs. 13 A - 13B illustrate high-level diagrams illustrating various steps of operation of a scroll-based, mixed, dual fluid compressor pump, in accordance with examples of the disclosure;

[0029] FIGs. 14A - 14B illustrate high-level schematic diagrams of a dual fluid cycle based heat pump, in accordance with examples of the disclosure;

[0030] FIG. 15 illustrates a high-level schematic diagram of the heat pump of FIGs. 14A - 14B, further comprising a heat exchanger for a hot water supply, in accordance with examples of the disclosure;

[0031] FIGs. 16A - 16B illustrate high-level schematic diagrams of the heat pump of FIG. 15, further comprising a pressure storage tank with a charge cycle and a discharge cycle, in accordance with examples of the disclosure; and

[0032] FIG. 17 illustrates a high-level schematic diagram of the refrigeration system of FIG. 5 in a cascaded configuration, in accordance with examples of the disclosure.DETAILED DESCRIPTION OF CERTAIN EXAMPLES

[0033] In the following description, various aspects of the disclosure will be described. For the purpose of explanation, specific configurations and details are set forth in order to provide a thorough understanding of the different aspects of the disclosure. However, it will also be apparent to one skilled in the art that the disclosure may be practiced without specific details being presented herein. Furthermore, well-known features may be omitted or simplified in order not to obscure the disclosure. In the figures, like reference numerals refer to like parts throughout. In order to avoid undue clutter from having too many reference numbers and lead lines on a particular drawing, some components will be introduced via one or more drawings and not explicitly identified in every subsequent drawing that contains that component.

[0034] FIG. 1 illustrates a high-level schematic diagram of a refrigeration system in accordance with the prior art. The refrigeration cycle system includes a refrigerant circuit defined by refrigerant lines 100 fluidly connecting the principal components in a closed loop configuration.

[0035] The principal components comprise an evaporator 40, a condenser 20, a compressor 30, and an expansion device 60. Particularly, condenser 20 is coupled between compressor 30 and expansion device 60. Evaporator 40 is coupled between expansion device 60 and compressor 30. The evaporator 40 and condenser 20 are each operatively coupled to respective fans 80, 90 for facilitating heat transfer with room & ambient air. It should be appreciated that while the illustrated example depicts air-to-refrigerant heat exchangers, the evaporator 40 and condenser 20 may alternatively be configured for heat exchange between the refrigerant and other heat transfer fluids, as known in the art.

[0036] A controller 70, powered by a power supply 120, is operatively coupled to at least the expansion device 60 and the compressor 30, and fans 80, 90 through power and communications lines 110 for controlling operation thereof. In the illustrated example, the expansion device 60 comprises an electronically controlled expansion valve, though it will beunderstood that other types of expansion devices may be employed without departing from the scope of the present disclosure. The controller 70 may operate autonomously according to predetermined parameters or may be configured to receive operational instructions via wired or wireless communication with a user interface (not shown).

[0037] In operation, as known to those skilled in the art, the compressor 30 receives refrigerant in a gaseous state and compresses it to a high-pressure gaseous state. The compressed refrigerant flows to the condenser 20 where it is liquefied. The liquid refrigerant then passes through to a receiver 50 that stores liquid-phase refrigerant at high pressure, ensuring a consistent supply to the expansion device 60 before entering the evaporator 40 where it absorbs heat and returns to a gaseous state before returning to the compressor 30, and via accumulator 10 stores gaseous-phase refrigerant at low pressure to supply the compressor.

[0038] While not explicitly illustrated, it should be understood that the system shown as example of current vapor compression system operation may be configured for reversible operation (i.e., heat pump operation) through the incorporation of a reversing valve or combination of valves to selectively reverse refrigerant flow through the evaporator 40 and condenser 20, as is well known in the art

[0039] FIG. 2 illustrates a high-level schematic diagram of a refrigeration system in accordance with the prior art, further comprising an enhanced vapor injection (EVI) configuration.

[0040] In this configuration, the receiver 50 includes a flow division arrangement wherein the liquid refrigerant outlet flow is selectively split into two parallel paths. A first path comprises the primary refrigerant circuit as described above in relation to FIG. 1. A second path, facilitated by a selection valve 140, directs a portion of the liquid refrigerant through an auxiliary circuit for vapor injection purposes.

[0041] The auxiliary circuit includes: a selection valve 140 for controlling the diverted refrigerant flow; a secondary expansion valve 65 for initial pressure reduction of the diverted flow; and a heat exchanger 130 having a cold side and a hot side arranged in a counterflow configuration.

[0042] The diverted refrigerant flow passes through the secondary expansion valve and subsequently through the cold side of heat exchanger 130. Concurrently, the primaryrefrigerant flow from the receiver 50 passes through the hot side of the same heat exchanger 130, remaining in liquid form. This heat exchange process serves to increase the subcooling of the primary flow prior to its entry into the main expansion valve 60 and subsequent passage through the evaporator.

[0043] The diverted refrigerant flow, after exiting the cold side of heat exchanger 130, is directed to the compressor 30 in what is conventionally termed "liquid injection". This injection serves two purposes known in the art: completing the phase transition of the injected refrigerant to gas; and providing cooling to the compressor.

[0044] As known to those skilled in the art, this EVI configuration, sometimes referred to as liquid injection, provides additional cooling to the compressor by injecting partially expanded refrigerant vapor, which improves performance under high load conditions. The secondary expansion valve is denoted 65, as opposed to the primary valve 60 to avoid confusion in component numbering.

[0045] FIG. 3 illustrates a high-level schematic diagram of a refrigeration system 145 comprising an unmixed dual fluid compressor, with closed pump pressure and a charging control circuit. As opposed to prior art configurations, this example implements a dual fluid arrangement wherein the refrigerant and a compression fluid operate in separate circuits with limited interaction occurring only within a dual fluid compressor pump 230, although other examples are contemplated where there is interaction in other parts of the system.

[0046] In some examples, the system 145 comprises two distinct fluid circuits: a refrigerant circuit; and a compression fluid circuit. The refrigerant circuit comprises primary components, which may also appear in a conventional cycle, including: receiver 50; expansion valve 60; and evaporator 40, which in some examples further has an associated fan 80. In operation, the refrigerant exits the receiver 50, flows through the expansion valve 60 to the evaporator 40, and returns to the dual fluid compressor pump 230. In some examples, system 145 further comprises a dual fluid separated heat exchanger 180, which comprises: a compression fluid section 180A; and a condenser portion 180B. After compression, the refrigerant enters condenser portion 180B of dual fluid separated heat exchanger 180.

[0047] In some examples, the compression fluid circuit comprises a compression fluid reservoir 160. In some examples, the compression fluid circuit further comprises: a liquid compression fluid pump 150; an external reservoir / accumulator 310; and control valves 170for reservoir pressure control of a reservoir 310. In some examples, the compression fluid circuit further comprises: one or more flow control valves 280; and one or more pressure relief valves 210. In some examples, a flow control valve 280 is positioned in a compression fluid line 260, between dual fluid compressor pump 230 and compression fluid reservoir 160. In some examples, as described above, the dual fluid separated heat exchanger 180 represents a configuration comprising: compression fluid section 180A for removing heat from the compression fluid; and a condenser section 180B for the refrigerant circuit. In some examples, the dual fluid separated heat exchanger 180 further comprises a common fan or fans 190 serving both sections 180A and 180B. The heat exchanger 180 may be configured in various arrangements (e.g., side-by-side, top / bottom, or front / back) while maintaining fluid separation. In some examples, compression fluid reservoir 160 is in fluid communication with external reservoir / accumulator 310, via liquid compression fluid pump 150 and control valves 170.

[0048] It is noted that although fans 80 and 190 are illustrated herein, this is not meant to be limiting in any way, and in some examples fans 80 and / or 190 are not provided.

[0049] In operation, the compression of the refrigerant is achieved through the interaction with the pressurized compression fluid within the dual fluid compressor pump 230. The compression fluid's pressure, controlled through the combination of pump 150, reservoirs 160 and 310, and control valves 170, 280, and 210, provides the primary compression force. In some examples, a motor of the dual fluid compressor pump 230 primarily serves to evacuate an internal compression chamber and maintain compression fluid circulation.

[0050] The compression fluid, after leaving the dual fluid compressor pump 230 through a compression fluid line 260, passes through valve 210 to heat exchanger section 180A where it releases both the heat of compression and the heat absorbed from the refrigerant compression process. The cooled compression fluid then returns to the compression fluid reservoir 160.

[0051] In some examples, system 145 further comprises a controller 270. In some examples, controller 270 is implemented as, or as a portion of, a microprocessor, a computer comprising one or more processors, or any suitable computing device. In some examples, a plurality of instructions are stored on a memory (not shown) of controller 270, that when read by one or more processors of controller 270 cause the one or more processors to implement control steps. In some examples, controller 270 manages the overall system operation of system 145, including control of valves and pumps for both fluid circuits.

[0052] In some examples, the above system provides one or more advantages, including: separation of refrigerant and compression fluid circuits; flexibility in fluid selection for both circuits; reduced direct power consumption for refrigerant compression; and the ability to optimize pressure control through the compression fluid circuit.

[0053] FIG. 4 illustrates a high-level schematic diagram of a refrigeration system 146 comprising a dual fluid compressor 230 and an unmixed joined reservoir 200, in accordance with examples of the disclosure. In some examples, refrigeration system 146 is similar to refrigeration system 145 described above, with the exception that compression fluid reservoir 160 is replaced with unmixed joined reservoir 200.

[0054] In some examples, reservoir 200 comprises a physical barrier 200C that enables direct pressure relationship between the compression fluid and refrigerant chambers while maintaining fluid separation. In some examples, the unmixed joined receiver 200 comprises: a refrigerant volume 200A containing liquid refrigerant; a compression fluid volume 200B; and separation barrier 200C. In some examples, refrigerant volume 200A contains liquid refrigerant at near-ambient conditions. In some examples, separation barrier 200C is implemented as a sealed moving weight, a bladder system or other suitable pressure-maintaining barriers, as known to those skilled in the art.

[0055] In some examples (not shown), system 146 can incorporate the pressure control system described in Figure 3, including: external reservoir 310; liquid compression fluid pump 150; and control valves 170. These can be responsive to controller 270, or as a separate circuit used for charging the compression fluid circuit.

[0056] In some examples, operation of this implementation maintains consistency with previously described fluid paths, as follows: refrigerant exits section 200A following traditional refrigeration pathways; compression fluid exits section 200B toward the dual fluid compressor pump 230 as previously detailed; and the barrier 200C enables a predetermined fixed relationship of the pressure between the two fluid circuits.

[0057] FIG. 5 illustrates a high-level schematic diagram of a refrigeration system 147 comprising a mixed dual fluid compressor 300, in accordance with examples of the disclosure.

[0058] In some examples, the system 147 comprises a refrigerant circuit and a compression fluid circuit. In some examples, the refrigerant circuit begins at a separator 220 with liquidrefrigerant exit 220A. The refrigerant then flows through expansion valve 60 and passes through evaporator 40 with optional fan 80, and exits as low-pressure gas to dual fluid compressor pump 300.

[0059] The compression fluid circuit presents a heavier, denser compression fluid that is in liquid state, which collects in separator volume 220B, flows through compression fluid lines 260 and enters dual fluid compressor pump 300 (optionally via a control valve 280), as a liquid injection. In some examples, the compression fluid is a non-compressible fluid throughout its full use within the circuit. In some examples, the refrigerant and the compression fluid are passively separated at separation line 220C of separator 220 due to the different properties thereof.

[0060] In some examples, the system further comprises: combined fluid lines 290 carrying mixed fluids; a dual fluid heat exchanger 240 with an optional fan 250; and a pressure relief valve 210, which maintains a pressure differential of the system.

[0061] In some examples, the refrigerant and the compression fluid are immiscible fluids (e.g., R290 refrigerant and water as compression fluid). In some examples, more efficient compression due to direct heat transfer between the fluids is achieved due to the liquid injection. In some examples, the operation of the dual fluid compressor pump forces the refrigerant to liquify at the dual fluid compressor pump. In some examples, the work requirement is reduced by approximately 50% compared to traditional compression. In some examples, dual fluid heat exchanger 240 operates as fluid-to-air heat exchanger rather than as a condenser, which may require a smaller heat exchanger and reduced work of the heat exchanger fan. In some examples, the present system can also provide enhanced subcooling capabilities and flexible separator design options.

[0062] In some examples (not shown), separator 220 may be of an active separator design, for example utilizing a stirrer to provide centrifugal forces, thereby enhancing the rate of fluid separation, however this can reduce the overall system efficiency due to its power use.

[0063] It is noted that the above described systems can be adjusted to act as a power production system by replacing expansion device 60 with a turbine, which generates power due to the flow within the refrigerant cycle based on the differential at the heat exchanger.

[0064] In some examples, system 147 further comprises various control components, including: temperature sensors 41, 42, 44, 212, 242 and 244; humidity sensors 46 and 246; pressure sensors 43, 45, 211, 243, 245 and 302; and RPM sensors 81, 251 and 301. In some examples, the outputs of these sensors are fed to controller 270.

[0065] The refrigerant circuit begins at separator 220 with liquid refrigerant exit 220A. The refrigerant flows through expansion valve 60, passes through evaporator 40, with optional fan 80, and exits as low-pressure gas to dual fluid compressor pump 300.

[0066] The compression fluid circuit comprises the compression fluid that collects in volume 220B of the separator 200. The compression fluid flows through compression fluid lines 260 and optional flow control valve 280. The compression fluid then enters dual fluid compressor pump 300 as a liquid injection.

[0067] In some examples, the system 147 further comprises combined flow elements, including: combined fluid lines 290 carrying mixed fluids; a dual fluid heat exchanger 240 with a fan 250; a pressure relief valve 210 that maintains system pressure differential; and separator 220 with separation line 220C, as described above.

[0068] The following is an explanation of an example of the decisions of controller 270 to control system 147 according to its internal software guidelines or following external commands from the user of the system, in form of wireless data sent by remote or through a communications network or by connection to a computer.

[0069] In some examples, controller 270 sets the evaporator fan rotational speed in accordance with known fan characteristics and settings, such as specific speed, or by selection of high / mid / low controller fan commands, together with one or more of inlet air side temperature sensor 44, inlet air pressure sensor 45 and inlet air humidity sensor 46, air outlet temperature sensor 47, and the user setting of a desired fan speed and temperature, which allows the controller to decide the overall heat transfer and adjust the fan speed.

[0070] Additionally, controller 270 is responsive to pressure & temperature sensors 42 and 43 to set the pressure of expansion valve 60 and maintain predetermined superheating requirements. All of these are used as known in the art by controller 270 to either increase, decrease or maintain the heat transfer of the evaporator 40 per the user or preset settings.

[0071] In a traditional system, the controller would be set in a similar way to using the sensor and air flow fan rotational speed in conjunction with the calculated exit state and the condenser supercooling in a similar way. In the dual fluid system 147, the condenser is replaced with the dual fluid heat exchanger 240 and controller 270 sets the fan rotational speed measured by sensor 251 according to the known characteristics of fan 250, and a desired temperature difference between: the ambient inlet temperature, measured by sensor 244, and optionally considering the ambient pressure measured by sensor 245 and / or optionally considering ambient humidity measured by sensor 246; and the outlet of the dual fluid heat exchanger 240, which contains the mixed fluids, whose state is indicated by temperature and pressure sensors 242 & 243. Setting the subcooling of the refrigerant in temperature terms can be much like in a traditional system.

[0072] Lastly, similar to the compressor in a traditional system, the rotational speed will set the refrigerant volumetric and mass flow, which is responsive to the controller command of the motor, and measured in the system by RPM sensor 301. This volume is replaced by the volume of the compression fluid partially, or nearly in full, considering the volume of the refrigerant past its move to a liquid state.

[0073] The build of the system 147 will determine a certain compression fluid pressure drop relationship between the mass flow, that will be dependent on the designs causing pressure drops in the dual fluid heat exchanger 240, the fluid lines 290, the separator 220, the compression fluid line 260, the control valve 280, and all the way through the dual fluid compressor pump 300, including the internal nozzle design thereof, and the entire flow path from the exit of pressure control valve 210 of the dual fluids flow, to the entry of the compression fluid to the working chamber or dual fluid compressor pump 300.

[0074] In some examples, in order to keep the motor work to a minimum, utilizing the compression fluid ability to compress the refrigerant in the most efficient way, the outlet set point pressure of the dual fluid compressor pump 300 is responsive to the setting of pressure valve 210, which is set by controller 270 according to the readings of temperature & pressure sensor 211 and 212, setting the dual fluid exit of the dual fluid compressor pump 300 in a pressure that maintains the refrigerant as fully liquid.

[0075] In some examples, controller 270 determines the desired rotational speed of the dual fluid compressor 300 by factoring the input of inlet pressure of the refrigerant to the dual fluidcompressor pump measured by sensor 43, the pressure of the compression fluid at the inlet of the dual fluid compressor pump 300 measured by sensor 302, and verified by RPM sensor 301. This can further be fine-tuned by the controlling the pressure drop of pressure valve 280 as needed to accommodate the user or predetermined values of the controller for increasing, decreasing or maintaining the heat transfer of the evaporator 40.

[0076] FIG. 6 illustrates a pressure-enthalpy (PH) diagram for HVAC and dual fluid compression cycles, in accordance with examples of the disclosure. Particularly, FIG. 6 shows a PH diagram comparing traditional refrigeration and an example mixed dual fluid cycle using R290 and water at a typical point for use by an air conditioner as an example of a refrigeration device. It highlights the cooling capacities for both cycles and illustrates the reduction in compressor work achieved in the dual fluid cycle. Callouts 3001 & 3002 show the saturated liquid line and the saturated vapor line, where within the area they constrain the refrigerant exists in a partial composition of both gas and liquid states. Callout 3003 shows the isothermal lines for easy chart understanding.

[0077] For reference and understanding of the benefits of the present example, both cycles are equal in their “cooling capacity”. For the traditional cycle, this would mean that mass flow multiplied by the enthalpy difference between point 1005 & 1003, where point 1004 is the evaporator point end point of the dual phase refrigerant evaporation and is assumed to be identical for both cycles:Q_ cooling=m_dot_ traditional * (H_ 1005 -H_ 1003)

[0078] In the present example, the same load would be mass flow multiplied by the enthalpy difference between point 1005 & 1002:Q_ cooling=m_dot_ new *(H_1005-H_1002)

[0079] Point 1005 is controlled as known in the art for specific superheat and is assumed the same for both the traditional and preferred example cycle.

[0080] The work of the traditional compressor is shown between points 1005 & 1007, and is equal to:W_ traditional = m_dot_ traditional * (H_ 1007 -H_ 1005)where Point 1007 is calculated as known in the art be the efficiency of the compressor, and in conjunction with the traditional condenser & fan required approach (the temperature difference between the inlet of the two fluid entering a heat exchanger, in this case the condenser), shown in this example calculations as an air to refrigerant condenser, where air ambient temperature is shown by point 1001 and dotted line at 35° for the shown example, for both cycles.

[0081] The traditional condenser is required to transfer the total heat load to the hot side of a heat exchanger usually a condenser or a cooling tower supplied with cold fluid and to the ambient air where:Q_ condenser = Q_ cooling + W_ traditional- compressor,Q_ cooling = the quantity of heat from the room or space where the evaporator refrigerant has absorbed this heat by evaporation, where in both systems the inlet pressure to the evaporator is set by the expansion valve 60. When utilizing a system with a condenser outlet, the supercooled state is achieved from point 1010 to point 1003. When utilizing a system with a dual fluid heat exchanger, the supercooled state is achieved from point 2010 to point 2003. The cooling cycle electrical efficiency or coefficient of performance (COP) is defined as the ratio between cooling and the work of the whole device, or the electrical power used by the refrigeration unit.

[0082] For brevity of the explanation, and as will be clear to those skilled in the art, the traditional cycle and the preferred example will be compared neglecting all power use other than the compressor, which traditionally accounts for 60 % to 80 % of the power requirement of a refrigeration cycle. The condenser fan power load, which traditionally is the second largest power requirement of the cycle, accounting for an additional 10% to 25% of the electrical power consumed by the cooling unit, will be demonstrated numerically. As in larger units, and in refrigeration in particular, the hot side ambient cooling can be done with both air cooling and cooling towers, and the internal units vary, and the additional load of fans is not a part of the COP calculation in most cases. The discussion will be for COP in its simple terms, regarding the load of the compressor only in a traditional unit, and the load of the dual fluid compressor pump described above.

[0083] Thus, the real COP for the traditional unit is:True COP_ traditional = Ikw of cooling / (W traditional compressor + Work traditional condenser fan + Additional power load)Used COP_ traditional (Compressor only normalized) = 1 kw of cooling / W traditional compressor (for that 1 kW cooling)

[0084] Further points of the traditional cycle depicted in FIG 6. are 1008 - the refrigerant entry point to the dual phase state within a condenser, 1009 the exit point of the refrigerant from the condenser that together with point 1010 define the subcooling of the condenser, in a way that sets the enthalpy to point 1003 - the exit of the expansion valve.Thus, the work of the compressor at 90% efficiency as shown in the figure is normalized for 1 Kw cooling at 0.2667 Kw; the traditional refrigeration at the conditions shown is expected to have a COP of ~ 3.75.

[0085] To calculate the efficiency of the suggested cycle, in an example of the present disclosure, one can look at the operation of the dual fluid compressor pump and the whole cycle.

[0086] FIG. 7 shows a complementary pressure temperature diagram to FIG 6, showing in qualitive way the conditions of both refrigerant (R290) and compression fluid (water) in the combined cycle, as well as the points of the traditional cycle using the same numbering as in FIG. 6. This way it is clearer to show the compression fluid thermodynamic properties at the points described in FIG. 6 and so for example, point 1005 describes the condition of the end of the suction phase and lowest pressure in the systems operation, and point 2005 shows also the compression liquid pressure constant to the refrigerant at point 1005 as its pressure drops when entering the working volume, but at a temperature corresponding to its state past the dual heat exchanger.

[0087] Point 2006 in both graphs show the time when both fluids are both pressure and temperature constant during the compression operation of the dual fluid compressor pump, which is also true to point 2010 which is the joint exit of both fluids from the dual fluid heat exchanger. At points 2007, which is the point where the heat transfer between the fluids and the start of the movement of the piston, 2008 & 2009 the liquids are pressure consonants. However, there is a slight temperature gap between the fluids.

[0088] The dual fluid heat exchanger in its turn deals with a mixture of R290 & water entering in liquid state. To those skilled in the art it will be clear that while the mass / volumetric flow of the dual mixture is much higher than the mass / volume flow of the traditional condenser, and the combined liquids thermal Capacity Cp, the actual resulting heat exchanger of nearly the same physical size is more efficient, allowing for a lower outlet temperature anda lower subsequent super cooling point that reduce the overall refrigerant mass flow, and allow reaching the required heat transfer to the air with less fan power.

[0089] For a simple demonstration of the saving effect of fan power, using a standard condenser, normalized for 1 Kw of cooling, is approximately 1.2667KW. In the present system, the normalized Q_ new for 1 Kw of cooling is ~ 1.1368Kw.

[0090] Using basic fan laws, it is known that for the Power 1 / Power 2=( Volumetric flow 2 / Volumetric flow 1)A3 (at the same diameter fan, of the same design), and where Q_cond = Volumetric flow_air*Density_air*CP_air*(delta T air inlet to outlet); assuming for the demonstration that since the air is the same in both applications, then:Assuming a normalized fan load of 0.05Kw, for the shown example.Density _air*CP_air* (delta T air inlet to outlet) = ConstTherefore, W_ dual heat exchanger fan / Work traditional fan = (Q_ traditional / Q_ new)A3, orW_ dual heat exchanger fan=0.050*(l.1368 / 1.2667)A3, or approximately 0.036 Kw and about 30% power saved.

[0091] FIG. 8 illustrates a high-level block diagram of a dual fluid compressor pump, in accordance with examples of the disclosure. FIG. 8 overall describes the general buildup of the dual fluid compressor pump in a general non-limiting way, for the preferred example of mixed fluids, to explain the innovation in certain examples, and following examples utilizing its different designs.

[0092] Like a compressor in a traditional refrigeration system, the dual fluid compressor pump comprises a motor 420 responsive to the unit dedicated controller 270, shown in the illustrated example, in a non-limiting way, in a single package 410 that can be hermetically sealed or semi hermetically sealed, however it can be utilized separately connecting the motor to the compressing unit through a shaft, a magnetic coupling, a gear, or other known in the art ways to drive a compressor or pump.

[0093] Similarly, the shaft and mechanical movement 350 is shown is a general way and may follow according to the final construction of the dual fluid compressor pump that can be of any known compressor and pump rotating technologies.

[0094] The figure further depicts the refrigerant inlet 360, and the compressing fluid inlet 370, where the design of the unit creates a volume about any compression chamber 340 that flows the compression fluid around the compression chamber in a way that any heat generated by the compression of the refrigerant can be directly transferred to the compression fluid. The compression fluid flow volume 430 is open to each of the compression chambers (3 shown as an example in the diagram) through a respective inlet 380, that can compromise a flow mechanism such as a shutter, plunger, or one way valve, as known to those skilled in the art, that works in conjunction with the timing of a shaft 350 and the opening and closing of the inlet 380 to each individual chamber 340. The inlets 440 of the refrigerant into the dual fluid compressor pump can also be controlled in a similar manner, and controller 270 can time the opening of the respective compression chamber 340 in conjunction to the rotation of shaft 350, thereby allowing the flow of refrigerant into the chamber 340.

[0095] Each compression chamber outlet 450, is shown in a non-limiting way to use an additional valve opening / exit to allow the mixed fluids to exit at high pressure fluid volume 390. These can be utilized as reed valves or in any other way known in the art, however the flow of all chambers is directed to the unified unit exit 400, which may also incorporate pressure regulating valve 210 of figure 2 (not shown) as an integral part of the unit.

[0096] As described above, FIG. 8 outlines the dual fluid compressor pump (DFCP) setup in a general, non-limiting format. The unit includes a motor 420 linked to the controller 270, a compression chamber 340, a refrigerant inlet 360, and a compression fluid inlet 370. Additional components (not shown), such as a clutch or free-rotation device could be added to enhance operational flexibility.

[0097] FIGs. 9A - 9D show high-level block diagrams illustrating various steps of operation of an example of a piston-based, unmixed, dual fluid compressor pump, in accordance with examples of the disclosure. The present compressor pump can be used in the systems 145 & 146 of FIGs. 3 and 4, described above. The application is shown in four operational positions. Each position (P1-P4) describes stages from refrigerant fill to high- pressure expulsion, managed by valves: 380, the inlet valve of compression fluid; 440, the inletvalve of refrigerant; 460, the outlet valve of the compression fluid; and 490, the outlet valve of the refrigerant. In this configuration, shaft 350 is split to shaft 350A and 350B, which creates volume 340 for the refrigerant work on it’s bottom side, and together with shaft 350A creates a secondary volume for the compression fluid. FIG. 9A shows position 1 (Pl), FIG. 9B shows position 2 (P2), FIG. 9C shows position 3 (P3) and FIG. 9D shows position 4 (P4). In each position, the inner volume of chamber 340 is shown as split between volume 340A and 340B.

[0098] Pl is the end of the refrigeration fill, P2 is the end of compression fluid entering, P3 is the pumping and final compression, to P4 high pressure - which is the end of the fluids expulsion, as detailed in the following table:Table 1A

[0099] FIGs. 10A - 10D show high-level block diagrams illustrating various steps of operation of an example of a piston-based, mixed, dual fluid compressor pump, in accordance with examples of the disclosure. The present compressor pump can be used in the system of FIG. 5, described above. Shown in four positions, the process includes a nozzle 380 that sprays compression fluid into the chamber to optimize thermal interaction with the refrigerant, compressing and forcing the refrigerant into a liquid phase and achieving efficient compression. The pairing selection of refrigeration and compression fluids optimize operational range and compatibility based on system requirements. As described above in relation to FIGs. 9A - 9D, FIG. 10A shows position 1 (Pl), FIG. 10B shows position 2 (P2), FIG. 10C shows position 3 (P3) and FIG. 10D shows position 4 (P4).

[0100] Pl - P4 are described in the following table:Table IB

[0101] FIGs. 11A - 11C, together with FIGs.lOA - 10D, are shown to further accentuate the difference in the operation of the dual fluid compressor pump (DFCP) and the operations of a positive displacement pump or compressor enabled by valve 380, allowing the compression fluid to enter to the same working volume of the refrigerant.

[0102] FIG 11A shows on a pressure volume (PV) graph the four stages of operation that happen in a traditional positive displacement pump. FIG 1 IB shows on a pressure volume (PV) graph the four stages of operation that happen in a traditional positive displacement compressor. FIG 11C shows on a pressure volume (PV) graph the five stages of operation that happen in the dual fluid compressor pump on both the refrigerant and compression fluid and their interaction.

[0103] In the traditional compressor and pump, point 4111 of FIG. 11A and FIG. 1 IB, and point 4001 of FIG. 11C is the start and end of a work cycle at P4, as shown in FIG. 10D - where the volume 340D shows the work volume at a minimum, also known as dead volume which corresponds to points 1007 of FIG. 6 for the traditional cycle & in the new cycle to point 2009.

[0104] Pl of Figure 10A shows the end of the fill stage. For a standard compressor, the work volume is being filled with gas at point 4333 of FIG. 1 IB, and at point 4333 of FIG. 11 A for pumping a fluid in liquid state. For a dual fluid compressor pump, the work volume is filled with gas at point 4002 of FIG. 11C. In all three graphs (FIGs. 11A - 11C), this includes the expansion and suction stages where the main differences between a compressor and a pump is that the dead volume 340D of the compressor is full of gas, expanding back into a significant volume, while the pump liquid is an incompressible fluid, and expands very little before entering the suction phase. The dead volume of the dual fluid compressor pump is full with at least 95% compression fluid and up to 5% of the refrigerant, causing this stage to behave more like a pump - with the additional probable cavitation that can be addressed. For both thetraditional cycle and the cycle of the dual fluid compressor pump, point 4002 & point 4333 are equivalent to point 1005 of FIG. 6 after taking into account the thermodynamics of the heat transfer models for the expansion and suction that are calculated, accounting for the dead volume difference above, for the dual fluid compressor pump cycle in the same manner as they are for any compressor.

[0105] P2 of FiglOB shows the compression fluid entering through Nozzle 380 - in this example it is shown that the nozzle can be set to introduce the compression fluid into the chamber in a spray form - shown as bubbles 490 for better thermal interaction between the two fluids.

[0106] In FIG. 11C, the entry of the compression fluid, which corresponds in this example to the end of the refrigerant suction, is shown by the broken line between points 4004 & 4005, and as the compression fluid replaces the volume of the refrigerant, by the line between points 4002 to 4006. Point 4006 is equivalent to point 2007 in FIG. 6.

[0107] It will be understood to those skilled in the art that dependent on the compression fluid inlet pressure to inlet valve / nozzle 380, and the nozzle / valve flow characteristics, shown for simplicity as a linear line, and neglecting the heat transfer from the walls for both fluids - as the compression fluid is at the same temperature as the walls, and the heat transfer from the refrigerant in a gaseous state to the walls is an order of magnitude smaller than the heat transfer between the refrigerant and the compressions fluid, one can describe this stage thermodynamically, as the interaction of both fluids by the first law of thermodynamics, where in this example the refrigerant is to be considered a closed system and follows:And the compression fluid is described by the first law as an open thermodynamic system following:Where:Qcf = Qref is the heat transfer between the fluids; andP depicts the work the compression fluid applies to refrigerant.

[0108] Describing the move of the refrigerant from point 4002 through point 4006, where at first the refrigerant is being heated by the incoming compression fluid and the compression process, until reaching both thermal and pressure equilibrium, then the continued incoming compression fluid will now be cooler than the refrigerant until reaching point 2007 of FIGs. 6 & 7, or near it.

[0109] P3 of FIG. 10C shows the reduction of the volume due to the piston movement and the reduction of the refrigerant volume as it moves from a gaseous state to a liquid state. This is shown in FIGs. 6 & 7 as the movement from points 2007 to 2008, and in FIG. 11C on the refrigerant line from points 4006 to 4007.

[0110] This operation continues until reaching the settings of exit valves 450 & 210, that are both responsive to the pressure downstream and may be responsive by controller 270 in a way that may allow the two fluids the dual fluid compressor pump, where the refrigerant is in a mixed gaseous and liquid states, such that the dual fluid heat exchanger 240 acts also as a partial condenser, or continue and liquefy the refrigerant fully and apply work to further raise the pressure of both fluids that are now in a fully liquid state in the manner of a positive displacement pump.

[0111] In the present example, the work added, shown in FIGs. 6 & 7, between points 2008 to 2009, and in FIG. 11C between points 4005 to 4008 for the compression fluid, and between points 4007 to 4009 for the refrigerant in liquid state, and is calculated simply as the pressure rise * constant volume of the now incompressible fluids: w = dP * v which is equal to the total pressure drop of the discharge shown in FIG. 11C as the move from points 4008 & 4009 to point 4001, and the total pressure drop of the compression fluid from the exit of the dual fluid compressor pump and incumbent valve 210, all the way through the dual fluid heat exchanger 240, separator 220, additional control valve 280 (if implemented) and piping 290, including the dual fluid compressor pump internal pressure drop of the compression fluid all the way to the entry pressure of valve / nozzle 380.

[0112] The normalized calculated work for the present example shown in FIGs. 6 and 7 is 136.8w and the COP for the present example, COP_ new = Q_ cooling / (W_ DFCP), which is approximately - 7.309 and nearly 50% better than the traditional unit COP at the same conditions (-3.75).

[0113] FIG. 12 illustrates a high-level diagram illustrating various steps of operation of a vane-based dual fluid compressor pump, in accordance with examples of the disclosure. This setup introduces a nozzle that injects compression fluid, using centrifugal forces for improved dispersion and enhanced compression.

[0114] The application is shown as a rotating vane application, where lines 510 show in a none limiting way the design with three operating volumes, where between each two vanes is a compression chamber shown in the same positions of FIGs. 9A - 9D (shown as positions 1 - 4). However, in this example, the compression fluid inlet 380 can be built following the design of a nozzle that will send a concentrated stream, and where the vane may include a cut, that with solutions known in the art (such as Pelton or other impact turbines), will both help the compression fluid disperse in the chamber, while gaining a reduction of power as thrust. Further shown is the inlet of the compression fluid to flow ring 430, which supplies the flow to the nozzles 380, the refrigerant inlet 360 at Pl, and outlet 450. The main circular body 410 and vanes 500, which slide on rotating member 350, operate as known in the art for both vane compressors and pumps.

[0115] FIG. 13 A illustrates a high-level diagrams illustrating various steps of operation of a scroll-based dual fluid compressor pump, that is disclosed as an example of a positive displacement machine with a reduced volume, in accordance with examples of the disclosure. The illustration shows six positions / angles of the shaft. For clarity, a central marker 520 is shown to illustrate the change in angle.

[0116] At angle 0, the initial refrigerant volume is created, as the entry area to the scroll, shown by broken arrows 360A and 360B at angle 180 where the scroll is at the highest separation, is closed. The positive displacement area marked in strips. In this angle, and all following angles, except at 90°, as the shaft rotates through the following positions the volume of the refrigerant chamber is reduced, thereby compressing the refrigerant.

[0117] The example shown in high level has been adjusted for a lower pressure ratio than accustomed in traditional scroll compressors. The lower center image at 90°, shows as anexample the area that is shared throughout the motion of the refrigerant pocket between position 45° to 135°. This area, in whole or partially, can serve inlets 370A and 370B for the compression fluid.

[0118] To clearly show the 90° better, FIG. 13B shows an enlarged version of the top half of this view, where the striped area marks the possible valve area at inlet 370A.

[0119] The above described examples show 3 types of positive displacement dual fluid compressor pumps that cover in essence reciprocating positive displacement (that include the common piston, plunger and diaphragm machines), rotating displacement machines (that include common vane, gear, lobe and other machines) and progressive cavity positive displacement (that include scroll, screw, and other machines). From these, it should be clear to those skilled in the art how to apply and build any positive displacement dual fluid compressor pump.

[0120] FIGs. 14A - 14B illustrate high-level schematic diagrams of a dual fluid cycle based heat pump 148, in accordance with examples of the disclosure. Particularly, FIG. 14A shows the heat pump 148 in a cooling mode and FIG. 14B shows the heat pump 148 in a heating mode. The configuration of the heat pump 148 of FIGs. 14A and 14B is based on the configuration described above in relation to system 147 shown in FIG. 5. In some examples, the configurations employ a reversing valve 550 and additional valves 60C and 60H to direct refrigerant flow in each mode. In the heating mode, an external reservoir 220 maybe pre-heated for operational efficiency, illustrating adaptability for seasonal operation.

[0121] The depiction of FIGs. 14A - 14B is an example and may include further use of valves, such as one way valve 560, or others not shown. Broken lines 570 show lines that are not functioning in the specific mode.

[0122] Also, it should be clear to those skilled in the art that the reservoir 220 is located in most applications in the external unit, and as such when operating in a heating mode, would be, when the unit is turned on, in low pressure corresponding to the ambient temperature. To reduce this effect, it should be clear that the reservoir depicted can include such devices as an enclosure that can be selectively open or closed to the ambient air, thereby creating thermal insulation per command between the reservoir and the ambient air, or include a thermal connection that can be turned on and off to the now “hot side” in the room in form of a heat pipe, or incorporate heat coils, internally or externally, to heat the reservoir on demand. Thesystem 148 can further include additional charging solutions that utilizes a reservoir, like the charging system shown in FIG. 3 to increase the reservoir pressure on demand.

[0123] FIG. 15 illustrates a high-level schematic diagram of the heat pump 148 of FIGs. 14A - 14B, further comprising a heat exchanger for a hot water supply, in accordance with examples of the disclosure. Particularly, FIG. 15 depicts an additional heat exchanger 600, and controlled valves 280A, 280B, 280C, 280D and 280E, as well as additional fluid flow lines. A controller 270 can adjust flow based on ambient vs. domestic hot water temperatures, optimizing energy use through selection of the “heat” receiving heat exchanger.

[0124] In some examples, a liquid-to-liquid heat exchanger 600 is integrated into the system to provide from the “hot side” the available heat to the system user. One example is the use of the heat for domestic hot water supply. The valves and schematic are shown in a cooling mode, however, the same, or adapted construction, can be applied to drive the heat when in a heating mode from the “cold side” evaporator.

[0125] Also, it should be noted that the heat exchanger 600 as shown can, in some applications of this system, be integrated into the volume of the separator 220.

[0126] The valve arrangement allows as a non-limiting example to control the flow returning from the dual fluid compressor pump 300 to either first heat exchanger 240 then heat exchanger 600, or, according to the following state table, move first through heat exchanger 600 then through heat exchanger 240, or to flow through either one alone. This can be utilized to maximize the system’s efficiency, or maximize the heat transfer to the client, by use of the controller in ways known to those skilled in the art.Table 2

[0127] In some examples, a pump 610 is provided, pump 610 utilized to control the flow of the customer fluid. It is noted that pump 610 is shown in a none limiting way, and the customer fluid flow can be passive / auto syphon as customary in many domestic hot water systems. However, to improve best efficiency it is assumed that pump 610 can be connected to the controller 270, shown in a none limiting way as a wire connection 110, but can also be a wireless connection. Broken lines are utilized to show fluid lines that are not in operation.

[0128] FIGs. 16A - 16B illustrate high-level schematic diagrams of the heat pump 148 of FIG. 15, further comprising a pressure storage tank 620 with a charge cycle and a discharge cycle, in accordance with examples of the disclosure.

[0129] Particularly, FIGs. 16A and 16B introduce a pressure storage system for the dual fluid mixed heat pump. High-pressure compression fluid stored during low-cost electricity periods is discharged during peak times to reduce power consumption by up to 25%, beyond the previous saving of the system. Optional clutch mechanisms could be added to the system for seamless integration of stored pressure and motorized operation.

[0130] In some examples, the pressure storage system is integrated to the example shown, (a dual fluid mixed heat pump, in cooling mode, with domestic heat exchanger disengaged), and in response to controller 270 the system can effectively charge pressure vessels with the compression fluid at high pressure at the correct time daily that corresponds with low costs of electricity for the user.

[0131] In the example described, there is provided a pressure tank system, shown in a none limiting way to include a high pressure tank 620, and a safety discharge connection with pressure control valve 640, shown as a pressure differential device in a non-limiting way, to low pressure tank 630, as well as a pressure expansion tank / reservoir 310.

[0132] Control valves 280K, 280L, 280M, 280N & 280P are shown to explain operation of the storage system. Valves 280K and 280L are shown connected to controller 270 by lines 110, however this is not meant to be limiting in any way, and other methods of communication can be implemented without exceeding the scope of the disclosure. Valves 640, 280M, 280N and 280P are responsive to controller 270, but may be connected wirelessly.

[0133] In state A, the flow from the compression fluid high pressure fluid tank 620, that is previously charged, is in high pressure. In some examples, the high pressure is at a minimumequal to, or greater than, the system's pressure at the current conditions + the system pressure losses at the current conditions, including the compression fluid cycle pressure drop + a set minimum pressure difference, all related to operating conditions and design parameters that are clear to those skilled in the art.

[0134] The high-pressure compression fluid now enters the dual fluid compressor pump 300 in any of it's possible combinations, mixed or unmixed, at a higher pressure than in normal, electrical power assisted operation, and fills and compresses the refrigeration fluid introduced to the dual fluid compressor pump 300 with reduced, or without, additional electrical power. To that effect, dual fluid compressor pump 300 may include in its design a “free rotation” release device such as clutch or a one-way bearing (not shown), to minimize electromagnetic coupling losses from the inoperative electrical motor at the time.

[0135] In state B, shown in FIG. 16B, the use of the dual fluid compressor pump as a charging device is exemplified. In hours of low-priced electricity, usually nighttime, controller 270 sets the refrigeration cycle inoperative, holding expansion valves 60C / 60H closed. When in cooling mode, per setting of reversing valve 550, valve 280A will be closed.

[0136] As such, dual fluid compressor pump 300's only entry is from reservoir 220's inlet line through valve 280 in an open position. Thus, reservoir 220 in turn is connected through compression fluid lines and valve 280N to low pressure tank 630, and is in turn connected to expansion vessel 310, allowing the charging of high-pressure tank 620 to higher a pressure.

[0137] Not shown are the intermediate steps used by controller 270 to command operating valves 280N, 280P and 280M to allow the pressure charging of secondary tank 630 further, and in conjunction to each specific system design of volumes of expansion device 310 and separator 220.

[0138] As described above, table 3 shows settings for the valves of the above system:Table 3

[0139] Additionally, it also should be clear to any one skilled in the art that the application of a unified pressure vessel for the compression fluid can also be utilized with several refrigeration units connected to a single compression fluid pressure storage device system, as well as the design of multiple pressure vessels tied to a single, or as many refrigeration devices as a complete site installation of multiple devices require.

[0140] FIG. 17 illustrates a high-level schematic diagram of the refrigeration system 147 of FIG. 5 in a cascaded configuration, thereby achieving low refrigeration temperatures or high- temperature heat pump applications. Two cycles are coupled through an interface heat exchanger 1240, with the primary cycle “right hand / hot side” operating as a condenser and the secondary “left side / cold side” as an evaporator. In some examples, this configuration supports broader applications across refrigeration and heating.

[0141] The cold side, maintaining the numeration of FIG. 5, would serve for example in refrigeration, as a deep refrigeration cycle reaching -40°C, or in a high temperature heat supply cascade application will be the heat “injection side” operating at ambient conditions.

[0142] The primary cycle, “high temperature side” is shown on the right-hand side of the figure, with the numeration keeping a reference to the original numbering shown in FIG. 5, but with 2XXX prefix, and so for example the separator in FIG. 5 is numbered 220 and the high temperature side separator of FIG. 17 is numbered 2220. Similarly, the low side dual fluid compressor pump is numbered in FIG. 5 as 300, and the high temperature cycle dual fluid compressor pump is numbered in FIG. 17 as 2300.

[0143] The two cycles respond to the same controller 2270 and are joined through heat exchanger 2240, that for the low side acts as the condenser, and for the high side as the evaporator. High side heat exchanger 2240 is shown with fan 2250 in a non-limiting way and can be utilized as a fluid-to-fluid heat exchanger.

[0144] Table 4 lists possible immiscible fluid combinations for various applications. For example, R290 and water are suitable for HVAC systems, while R1270 with water & ethylene glycol mixture could serve in deep freeze applications.Table 4

[0145] It is appreciated that certain features of the invention, which are, for clarity, described in the context of separate examples, may also be provided in combination in a single example. Conversely, various features of the invention which are, for brevity, described in the context of a single example, may also be provided separately or in any suitable subcombination.

[0146] Unless otherwise defined, all technical and scientific terms used herein have the same meanings as are commonly understood by one of ordinary skill in the art to which this invention belongs. Although methods similar or equivalent to those described herein can be used in the practice or testing of the present invention, suitable methods are described herein.

[0147] All publications, patent applications, patents, and other references mentioned herein are incorporated by reference in their entirety. In case of conflict, the patent specification, including definitions, will prevail. In addition, the materials, methods, and examples are illustrative only and not intended to be limiting.

[0148] It will be appreciated by persons skilled in the art that the present invention is not limited to what has been particularly shown and described hereinabove. Rather the scope of the present invention is defined by the appended claims and includes both combinations and subcombinations of the various features described hereinabove as well as variations andmodifications thereof which would occur to persons skilled in the art upon reading the foregoing description.

Claims

CLAIMS1.A dual-fluid compression cycle method for a heat transfer application, the method comprising: circulating a refrigerant through a refrigerant circuit to undergo phase changes and produce heating or cooling, the refrigerant circuit comprising a dual fluid compressor pump; and circulating a compression fluid through a compression fluid circuit to compress the refrigerant within the dual fluid compressor pump and transfer heat between the refrigerant and the compression fluid, wherein the compression fluid is in a liquid state throughout the compression fluid circuit.

2. The method of claim 1, wherein the compression of the refrigerant comprises mixing the compression fluid with the refrigerant, the method further comprising separating the fluids after compression.

3. The method of claim 1 or 2, wherein the refrigerant and the compression fluid are immiscible fluids.

4. The method of claim 2 or 3, wherein the fluid separation is performed passively.

5. The method of any one of claims 1 - 4, wherein the compression fluid enters the dual fluid compressor pump in a liquid state.

6. The method of claims 1 - 3, wherein the refrigerant exits the dual fluid compressor pump in a liquid state.

7. The method of any one of claims 1 - 6, further comprising maintaining a predetermined pressure relationship between the refrigerant and the compression fluid outside the dual fluid compressor pump.

8. The method of claim 7, wherein the predetermined relationship is maintained passively.

9. The method of claim 8, wherein the predetermined relationship is maintained by a pressure maintaining barrier separating the refrigerant and the compression fluid.

10. The method of any one of claims 1 - 9, wherein the dual fluid compressor pump comprises: a first inlet coupled to the refrigerant circuit; and a second inlet coupled to the compression fluid circuit.

11. The method of claim 1, wherein the compression fluid compresses the refrigerant by applying force to a movable member that compresses the refrigerant.

12. The method of any one of claims 1 - 11, further comprising circulating the refrigerant and the compression fluid through a dual fluid heat exchanger.

13. The method of any one of claims 1 - 12, wherein the heat transfer application is a heating, ventilation, air conditioning and refrigeration (HVAC&R) application.

14. The method of any one of claims 1 - 12, further comprising using the heat transfer application for generating power.

15. A dual-fluid compression cycle system for a heat transfer application, the system comprising: a refrigerant circuit configured to circulate a refrigerant therethrough to undergo phase changes and produce heating or cooling, the refrigerant circuit comprising a dual fluid compressor pump; a compression fluid circuit configured to circulate a compression fluid therethrough to compress the refrigerant within the dual fluid compressor pump and transfer heat between the refrigerant and the compression fluid; and a controller configured to regulate flow and pressure in the refrigerant circuit and compression fluid circuit, wherein the compression fluid is in a liquid state throughout the compression fluid circuit.

16. The system of claim 15, wherein the compression of the refrigerant comprises mixing the compression fluid with the refrigerant, the system further comprising a separator configured to separate the fluids after compression.

17. The system of claim 15 or 16, wherein the refrigerant and the compression fluid are immiscible fluids.

18. The system of claim 16 or 17, wherein the fluid separation is performed passively.

19. The system of any one of claims 15 - 18, wherein the compression fluid enters the dual fluid compressor pump in a liquid state.

20. The system of claims 15 - 17, wherein the refrigerant exits the dual fluid compressor pump in a liquid state.

21. The system of any one of claims 15 - 20, further comprising, outside of the dual fluid compressor pump, a pressure maintaining barrier separating the refrigerant and the compression fluid and maintaining a predetermined pressure relationship between the refrigerant and the compression fluid.

22. The system of any one of claims 15 - 21, wherein the dual fluid compressor pump comprises: a first inlet coupled to the refrigerant circuit; and a second inlet coupled to the compression fluid circuit.

23. The system of claim 15, wherein the compression fluid compresses the refrigerant by applying force to a movable member that compresses the refrigerant.

24. The system of any one of claims 15 - 23, further comprising a dual fluid heat exchanger configured to circulating the refrigerant and the compression fluid therethrough.

25. The system of any one of claims 15 - 23, wherein the heat transfer application is a heating, ventilation, air conditioning and refrigeration (HVAC&R) application.

26. The system of any one of claims 15 - 25, wherein the heat transfer application is used for generating power.

27. An apparatus for performing a dual-fluid compression cycle in a heat transfer application, the apparatus comprising: a dual fluid compressor pump; and a controller, wherein the dual fluid compressor pump is configured to: receive a refrigerant from a refrigerant circuit; and receive a compression fluid from a compression fluid circuit to compress the refrigerant within the dual fluid compressor pump and transfer heat between the refrigerant and the compression fluid, wherein the controller is configured to regulate flow and pressure of the refrigerant and the compression fluid, wherein the compression fluid is in a liquid state throughout the compression fluid circuit.

28. The apparatus of claim 27, wherein the compression of the refrigerant comprises mixing the compression fluid with the refrigerant, the apparatus further comprising a separator configured to separate the fluids after compression.

29. The apparatus of claim 27 or 28, wherein the refrigerant and the compression fluid are immiscible fluids.

30. The apparatus of claim 28 or 29, wherein the fluid separation is performed passively.

31. The apparatus of any one of claims 27 - 30, wherein the compression fluid enters the dual fluid compressor pump in a liquid state.

32. The apparatus of claims 27 - 29, wherein the refrigerant exits the dual fluid compressor pump in a liquid state.

33. The apparatus of any one of claims 27 - 32, further comprising, outside of the dual fluid compressor pump, a pressure maintaining barrier separating the refrigerant and thecompression fluid and maintaining a predetermined pressure relationship between the refrigerant and the compression fluid.

34. The apparatus of any one of claims 27 - 33, wherein the dual fluid compressor pump comprises: a first inlet coupled to the refrigerant circuit; and a second inlet coupled to the compression fluid circuit.

35. The apparatus of claim 34, wherein the compression fluid compresses the refrigerant by applying force to a movable member that compresses the refrigerant.

36. The apparatus of any one of claims 27 - 35, further comprising a dual fluid heat exchanger configured to circulating the refrigerant and the compression fluid therethrough.

37. The apparatus of any one of claims 27 - 36, wherein the heat transfer application is a heating, ventilation, air conditioning and refrigeration (HVAC&R) application.

38. The system of any one of claims 27 - 36, wherein the heat transfer application is used for generating power.

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