Equipment and methods for diversion expansion in heat pump cycles

Abstract

This disclosure provides a heat pump cycle that allows for improved matching of the T(Q) slope of the heat pump cycle. More specifically, the high-temperature heat exchange is divided into two stages. Furthermore, a portion of the working fluid cooled in the first stage is further cooled by expansion before being mixed with the heated working fluid used to feed into the regenerative heat exchanger.

Description

[0001] Cross-references to related applications

[0002] This application claims priority to and is a continuation of U.S. Patent Application No. 16,867,447, filed May 5, 2020, the contents of which are incorporated herein by reference.

[0003] Statement regarding federally funded research or development

[0004] not applicable. Background Technology

[0005] This section introduces information from the prior art that may relate to or provide background to some aspect of the art described herein and / or claimed below. This information is background information to facilitate a better understanding of the information disclosed herein. This is a discussion of "related" art. Such art is by no means intended to be "prior art." Related art may or may not be prior art. The discussion should be confined to this topic and not as an endorsement of prior art.

[0006] See Figure 1 In a conventional heat pump cycle, the working fluid is compressed from a relatively low temperature and low pressure state (state 2) to one of higher temperatures and pressures (state 3). This heat can then be transferred to a heat transfer target (HTR), which receives, uses, or stores the heat. Figure 1 In this process, the heat transfer target HTR begins under the conditions of HTRc and is stored at HTRh. During the process of heating the material containing HTR from HTRc to HTRh, the working fluid is cooled to state 4.

[0007] The process of transferring heat from the working fluid to the HTR takes place in a counter-current heat exchanger. This heat transfer process can be depicted on a "TQ" (temperature-heat flux) curve or graph, such as... Figure 2 The graph shown illustrates this. The example illustrated uses supercritical carbon dioxide (“sCO2”) at 30 MPa as the working fluid and silica sand as the HTR medium. Summary of the Invention

[0008] In some embodiments, a heat pump includes a heat transfer source, a heat transfer target, and a closed fluid loop for circulating a working fluid. The closed fluid loop also includes a compression device, a counter-current heat exchanger, a cryogenic expansion device, a cryogenic heat exchanger, a high-temperature expansion device, and a regenerative heat exchanger. Each of these elements of the closed fluid loop operates the working fluid within the closed fluid loop.

[0009] More specifically, in operation, the compression unit receives the working fluid in a first state and raises its temperature and pressure through mechanical work to bring it to a second state. The countercurrent heat exchanger includes a first stage and a second stage. The first stage is in thermal communication with the heat transfer target and receives the working fluid in the second state from the compression unit, transferring heat from the received working fluid to the heat transfer target to cool the working fluid to a third state. The second stage is in thermal communication with the heat transfer target and receives a first portion of the working fluid in the third state from the first stage, transferring heat from the received first portion of the working fluid in the third state to the heat transfer target to cool the working fluid to a fourth state.

[0010] In operation, the cryogenic expansion device receives the working fluid in the fifth state, causing it to expand to the sixth state. The cryogenic heat exchanger is thermally connected to a heat transfer source and receives the working fluid in the sixth state, transferring heat from the heat transfer source to the working fluid in the sixth state to heat it to the seventh state. The high-temperature expansion device receives a second portion of the working fluid in the third state from the first stage of the counter-current heat exchanger and expands this second portion to the eighth state. The regenerative heat exchanger transfers heat from the working fluid in the fourth state received from the second stage of the counter-current heat exchanger to a combination of the working fluid in the eighth state received from the high-temperature expansion device and the working fluid in the seventh state received from the cryogenic heat exchanger, thereby heating the mixed working fluid to the first state and cooling the working fluid in the fourth state to the fifth state.

[0011] In other examples, the heat pump includes: a heat transfer target; a heat transfer source; and a closed fluid loop for circulating the working fluid. The closed fluid loop includes: a compression device, a device for performing diversion expansion of the working fluid, a cryogenic heat exchanger, and a regenerative heat exchanger. The compression device receives the working fluid in a first state and heats and pressurizes the received working fluid to a second state. The device for performing diversion expansion of the working fluid in the second state, after a second portion of the working fluid in the third state is further cooled to a fourth state (after two coolings) and further cooled to a fifth state, expands a first portion of the working fluid in the partially cooled third state to an eighth state, and expands a second portion of the working fluid in the partially cooled third state to a sixth state. The cryogenic heat exchanger is in thermal communication with the heat transfer source and receives the working fluid in the sixth state and transfers heat from the heat transfer source to the working fluid in the sixth state to heat the working fluid to a seventh state. The regenerative heat exchanger transfers heat from the working fluid in the fourth state, which is received in the second stage of the countercurrent heat exchanger, to a combination of the working fluid in the eighth state, which is received from the high-temperature expansion device, and the working fluid in the seventh state, which is received from the low-temperature heat exchanger. This heats the mixed working fluid to the first state and cools the working fluid in the fourth state to the fifth state.

[0012] In yet another embodiment, this disclosure describes a method for operating a heat pump in a closed fluid loop, the method comprising: compressing a working fluid in a first state to raise its temperature and pressure to a second state; and cooling the working fluid in the second state in a counter-current heat exchanger. Cooling in the counter-current heat exchanger comprises: cooling the working fluid in the second state in a first stage to a third state; and cooling a first portion of the working fluid in the third state in a second stage to a fourth state. The method further comprises expanding the working fluid in the fifth state to a sixth state; heating the working fluid in the sixth state to a seventh state; expanding a second portion of the working fluid in the third state to an eighth state; mixing the working fluid in the seventh state with the working fluid in the eighth state; and heating the mixture of the working fluids in the seventh and eighth states to a first state in a regenerative heat exchanger while cooling the working fluid in the fourth state to the fifth state.

[0013] The foregoing provides a simplified overview to offer a basic understanding of some aspects of the invention. This overview is not an exhaustive summary of the invention. It is not intended to identify key or essential elements of the invention or to define its scope. Its sole purpose is to present some concepts in a simplified form as a prelude to the more detailed descriptions discussed later. Attached Figure Description

[0014] The disclosed subject matter can be understood from the following description taken in conjunction with the accompanying drawings, in which the same reference numerals identify the same elements, and wherein:

[0015] Figure 1 This is a schematic diagram of a conventional heat pump that uses a conventional heat pump cycle.

[0016] Figure 2 yes Figure 1 T(Q) curve of a countercurrent heat exchanger in a heat pump cycle.

[0017] Figure 3 yes Figure 1 The graph of the heat capacity of the heat pump cycle versus temperature illustrates how the heat capacity of the working fluid and the heat transfer medium changes with their temperature.

[0018] Figure 4 yes Figure 1 The second T(Q) curve of the countercurrent heat exchanger of the heat pump cycle illustrates how the rate of change of the working fluid temperature will increase as the working fluid flow rate increases relative to the heat transfer medium flow rate, until it reaches a point where further increases in the working fluid flow rate cannot reduce the working fluid outlet temperature.

[0019] Figure 5 This is a schematic diagram of a split-expansion heat pump employing a split-expansion heat pump cycle, according to one or more embodiments of the subject matter claimed below.

[0020] Figure 6 In a particular embodiment Figure 5 Pressure-enthalpy diagram of the working fluid at certain points in a heat pump cycle.

[0021] Figure 7 yes Figure 5 T(Q) curve of a countercurrent heat exchanger in a heat pump cycle.

[0022] Figure 8 The coefficient of performance ("COP") of a heat pump cycle increases with the performance of the heat pump cycle. Figure 5 A graph showing the change in the flow portion extracted between the first and second stages of a countercurrent heat exchanger in a heat pump cycle.

[0023] Figure 9 yes Figure 5 A schematic diagram of a second specific embodiment of a split-flow expansion heat pump cycle.

[0024] While the disclosed technology is susceptible to various modifications and alternatives, the accompanying drawings illustrate specific embodiments described in detail herein by way of example. However, it should be understood that the description of particular embodiments herein is not intended to limit the claims to the specific forms disclosed, but rather, is intended to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the appended claims. Detailed Implementation

[0025] Several illustrative embodiments of the claimed subject matter will now be disclosed. For clarity, not all features of an actual implementation are described in this specification. It will be understood that in any improvement to such an actual embodiment, many decisions must be made, varying from implementation to achieve the improver's specific goals, such as compliance with system-related and business-related constraints, which will vary from implementation to implementation. Furthermore, it should be understood that such improvement efforts, even if complex and time-consuming, will be routine tasks for those skilled in the art who benefit from this disclosure.

[0026] See again the above relative to Figure 1 and Figure 2 In the conventional heat pump cycle discussed, the slopes of the Twf and Thtr curves in the TQ plot are determined by the fluid velocity and heat capacity (“cp”). Figure 3 As shown, the two fluids exhibit significant changes in heat capacity as their respective temperatures change through the heat exchanger. This change occurs in... Figure 3 The curve can be viewed as the curvature in the T(Q) curve. Because the heat capacity curves are mismatched, the amount of heat that can be transferred from the working fluid to the HTR medium is limited.

[0027] As the working fluid velocity decreases relative to the HTR medium velocity, the slope of the Twf curve will decrease until the T(Q) curve reaches a point where... Figure 4 The curves intersect at point 400. At this intersection, further reduction of the working fluid velocity cannot lower the working fluid outlet temperature because the heat transfer process cannot proceed more rapidly due to the near-zero temperature difference between the fluids at the intersection point. This phenomenon is often referred to as "squeezing," and in this case, it occurs in the middle of the heat exchanger.

[0028] Since heat pump performance is affected by this pinch-in phenomenon, matching the slopes of the T(Q) curves of the working fluid and the HTR medium is beneficial. Because heat capacity is a thermodynamic property of both materials and therefore cannot be changed, the T(Q) slope can only be altered by changing the flow rates of one or both materials. Furthermore, the HTR medium flow rate may be difficult to control and may store more than [a certain amount of heat]. Figure 1 The two heat transfer targets shown would be complex and prohibitively expensive.

[0029] The technology disclosed herein provides a heat pump cycle that allows for improved matching of the T(Q) slope and improves the performance of the heat pump cycle. More specifically, high-temperature heat exchange (e.g., as in...) Figure 1 The process (which occurs in the countercurrent heat exchanger HTX) is instead divided into two stages. Furthermore, a portion of the working fluid cooled in the first stage is further cooled by expansion before being mixed with the heated working fluid used to feed into the regenerating heat exchanger. Other variations can be seen in other embodiments.

[0030] Figure 5 This is a schematic diagram of a heat pump 500 employing a split-expansion heat pump cycle according to one or more embodiments. The heat pump 500 includes a heat transfer source 502, a heat transfer target 504, and a closed fluid loop 506. In operation, the closed fluid loop 506 circulates a working fluid used for heat transfer in a manner further described below. The working fluid can be, for example, carbon dioxide. Depending on the points discussed regarding the closed fluid loop 506, the working fluid may be referred to as a "heated working fluid," a "compressed working fluid," a "cooled working fluid," etc., during the operation of the closed fluid loop 506.

[0031] Heat transfer source 502 includes a heat transfer medium not shown separately. The heat transfer medium can have a variable heat capacity, although not in all embodiments this is so limited, and can be a fluid or a solid. If it is a fluid, the heat transfer medium can be, for example, a synthetic oil heat transfer fluid, water, or sand. Heat transfer source 502 can be, for example, a fluid circulating in a pipe, depending on the embodiment. If the heat transfer medium is a solid, the solid can be, for example, a solid material contained in a reservoir or flowing sand.

[0032] Heat transfer target 504 includes a heat transfer medium (not shown separately), which can be one or more materials with variable heat capacity, although not all embodiments are so limited. The heat transfer medium can be a fluid or a solid. If it is a fluid, the heat transfer medium can be, for example, a synthetic oil heat transfer fluid, water, or sand. For example, the fluid can circulate in a pipe. Thus, heat transfer target 504 can be a fluid circulating in a pipe. If the heat transfer medium is a solid, the solid can be, for example, a solid substance or sand.

[0033] Figure 5The closed fluid loop 506 is used to circulate the working fluid and includes a regenerating heat exchanger 508, a compression device 510, a counter-current heat exchanger 512, a cryogenic expansion device 514, a cryogenic heat exchanger 516, and a high-temperature expansion device 518. In operation, the compression device 510 receives the working fluid in a first state ① from the regenerating heat exchanger 508. The compression device 510 increases the temperature and pressure of the working fluid in the first state to a second state ② through mechanical work. In operation, the compression device 510 provides the power for circulating the working fluid through the closed fluid loop 506.

[0034] The counter-current heat exchanger 512 includes a first stage 538 and a second stage 540, both of which are in thermal communication with the heat transfer target 504. The counter-current heat exchanger 512 can be implemented in various ways according to embodiments. For example, in some embodiments, the counter-current heat exchanger 512 can be implemented in two single-stage heat exchangers, each implementing a corresponding one of the first stage 538 or the second stage 540. In other embodiments, the counter-current heat exchanger 512 can be a single heat exchanger with an intermediate manifold. Other variations in the implementation of the counter-current heat exchanger 512 will be understood by those skilled in the art who benefit from this disclosure.

[0035] In operation, the first stage 538 of the countercurrent heat exchanger 512 receives the working fluid in the second state and transfers the heat from the working fluid to the heat transfer target 504 to cool the working fluid to the third state ③. The second stage 540 receives a first portion 544 of the working fluid in the third state and transfers the heat from the first portion 544 to the heat transfer target 504 to cool the working fluid from the third state to the fourth state ④.

[0036] Note that in the third state, there exists an optimal split between the first portion 544 and the second portion 550 of the working fluid that maximizes the coefficient of performance (“COP”) of the heat pump 500. This can be relative to... Figure 5 heat pump cycle from Figure 8 This is inferred from the above. In this context, "optimal" refers to the maximum achievable heat pump performance, as defined by the amount of net work required to transfer a given amount of heat to the heat transfer target 504. The optimal flow split is a function of the thermodynamic properties (specifically, heat capacity) of the working fluid and the heat transfer medium of the heat transfer target 504.

[0037] In operation, the cryogenic expansion device 514 receives the working fluid in the fifth state ⑤ from the regenerating heat exchanger 508. The cryogenic expansion device 514 reduces the pressure and temperature of the working fluid in the first state to cool the working fluid to the sixth state ⑥. The cryogenic expansion device 514 can be implemented, for example, in an expansion valve or a turbine.

[0038] The cryogenic heat exchanger 516 is thermally connected to the heat transfer source 502. In operation, the cryogenic heat exchanger 516 receives the working fluid in the sixth state from the cryogenic expansion device 514 and heats the working fluid to the seventh state.

[0039] The countercurrent heat exchanger 512, the low-temperature expansion device 514, and the high-temperature expansion device 518 (by way of example and illustration) in some embodiments form a means for performing a diversion expansion of the working fluid in the second state, the diversion expansion including, after the second portion of the working fluid in the third state is further cooled to the fourth state and further cooled to the fifth state, expanding the first portion of the working fluid in the partially cooled third state to the eighth state, and expanding the second portion of the working fluid in the partially cooled third state to the sixth state. Other embodiments may include... Figure 5 The disclosed structure is subject to change. It should be understood that such a device can be implemented by a structural equivalent that performs the aforementioned function.

[0040] The high-temperature expander 518 receives a second portion 550 of the working fluid in the third state. The high-temperature expander 518 expands the second portion 550 of the working fluid in the third state to reduce its pressure and temperature to the eighth state. The high-temperature expander 518 can be implemented, for example, in an expansion valve or a turbine.

[0041] See also Figure 5 The heat pump 500 transfers heat from the working fluid in the fourth state to a combination or mixture 526 of the working fluids in the seventh and eighth states. This returns the working fluid in the fourth state to the fifth state and the mixture 526 to the first state. The working fluid in the first state is then compressed as described above to increase its temperature and pressure.

[0042] More specifically, in operation, the regenerating heat exchanger 508 receives the twice-cooled working fluid in the fourth state from the counter-current heat exchanger 512, and receives a combination 526 of the working fluid in the seventh state from the cryogenic heat exchanger 516 and the working fluid in the eighth state from the high-temperature expansion device 518. Heat transfer in the regenerating heat exchanger 508 returns the working fluid in the fourth state to the fifth state and keeps the mixture 526 in the first state.

[0043] The heat pump 500 achieves split expansion of the working fluid. As used herein, "split expansion" refers to the characteristic where a portion of the working fluid expands after being partially cooled in the first stage heat exchange, and the remaining portion of the working fluid expands after being cooled in both the first and second stage heat exchanges. Therefore, in Figure 5In this heat pump 500, both the first part 544 and the second part 550 expand in this split-flow expansion manner. The first part 544 is cooled in the heat exchange between the first stage 538 and the second stage 540, and then expands through the low-temperature expansion device 514. The second part 550 is cooled only in the first stage 538 for heat transfer before being expanded by the high-temperature expansion device 518. Therefore, the working fluid in the heat pump 500 undergoes "split-flow expansion".

[0044] To further understand the subject matter claimed below, a specific embodiment will now be disclosed. Figure 6 In a particular embodiment Figure 5 The pressure-enthalpy diagram of the working fluid at certain points in the heat pump cycle of heat pump 500. In this specific embodiment, the working fluid is carbon dioxide (CO2). The heat transfer medium for heat transfer target 512 is sand.

[0045] Heat pump cycle 500 (similar) Figure 5 The heat pump 500 divides the high-temperature heat exchange into two stages 538 and 540. In this particular embodiment, the two stages 538 and 540 are implemented in two stages of similar size. "Similar size" refers to the thermal conductivity of the stages. Thermal conductivity, commonly referred to as "UA," is the product of the average heat transfer coefficient ("U") and the heat transfer area ("A"). In other embodiments, the relative sizes of the two stages 538 and 540 may vary, with one being larger than the other. The specific sizes of the stages 538 and 540 can be selected during the design process based on the relative thermodynamic properties (e.g., heat capacity) of the working fluid and the heat transfer medium of the heat transfer target 504.

[0046] In the second state, the working fluid flows out of the compression unit 510 and enters the first stage 538. In the first stage 538, the temperature of the working fluid in the second state decreases as the first stage 538 completes the heating of the heat transfer medium in the heat transfer target 504. The first portion 544 of the cooled working fluid 542 then proceeds to the second stage 540 in the third state.

[0047] In the third state, the first portion 544 of the first-cooled working fluid is further cooled by the heat transfer medium of the heat transfer target 504 in the second stage 540 while the heat transfer medium is being heated. Then, the first portion 544 of the working fluid in the third state is cooled to the fourth state, the second-cooled working fluid 524. The second-cooled working fluid in the fourth state can still contain heat at a useful temperature that can be transferred back into the working fluid before the inlet 511 of the compressor 510 in another heater. The other heater is a regenerative heat exchanger 508.

[0048] The regenerating working fluid 532 is still under high pressure (i.e., Figure 6(State 5 in the process). The working fluid in the fifth state is then expanded by a cryogenic expansion device 514, which can be a valve or a cryogenic turbine (“LT turbine”). As a result, the process significantly reduces the temperature of the working fluid in the fifth state, forming the working fluid in the sixth state.

[0049] The temperature reduction in the cryogenic expansion device 514 allows the working fluid in the second state to receive heat from the heat transfer source 502. The heat transfer medium of the heat transfer source 502 is a synthetic oil heat transfer fluid, water, or sand. At this time, the working fluid in the sixth state (i.e., CO2) is a liquid or a liquid / vapor mixture. Heat is transferred to the working fluid in the cryogenic heat exchanger 516. This heat transfer causes the working fluid to evaporate, thereby producing the working fluid in the seventh state. The working fluid in the seventh state is then mixed with the working fluid in the eighth state. The combination 526 of the working fluid in the seventh state and the working fluid in the eighth state is then further heated to the first state in the regenerative heat exchanger 508 before being compressed again.

[0050] In the third state, a second portion 550 of the primary cooled working fluid is extracted between the first stage 538 and the second stage 540 and expanded by a high-temperature expander 518, which in this embodiment is a high-temperature turbine. In the high-temperature expander 518, the working fluid generates shaft work, which can offset the work required to operate the charging compressor 510. The working fluid generated in the eighth state is then mixed downstream of the cryogenic heat exchanger 516 and upstream of the regenerating heat exchanger 508 and returned to the main fluid flow, as... Figure 5 As shown in the image.

[0051] The T(Q) curve of the counter-current heat exchanger 512 in the heat pump cycle 500 is shown in Figure 7 As shown in the figure. At approximately 70% Q / Q 总 The slope change is at point 700, where approximately 34% of the working fluid has been extracted between the first stage 538 and the second stage 540. Figure 8 The figure shows the coefficient of performance (“COP”) of the heat pump cycle of heat pump 500 as a function of the portion of the flow extracted between the first stage 538 and the second stage 540. For this set of conditions and assumptions, the improvement in COP is almost 10%.

[0052] As mentioned above Figure 5 As indicated in the embodiments, there is an "optimal" split in the proportion of expanding working fluid. These proportions are set in such a way that the slope of the working fluid temperature profile approximately matches the temperature profile of the heat transfer medium, such as... Figure 7As shown. Recalling that the slope of these curves is inversely proportional to the product of the fluid mass flow rate and the fluid heat capacity (i.e., the slope ~ 1 / (m·cp)), one can calculate the approximate flow rate of the working fluid in each stage of the countercurrent heat exchanger, which would result in this slope matching.

[0053] Figure 9 This is a schematic diagram of a heat pump 900, illustrating some variations that can be found in some embodiments. Some components of the heat pump 900 are similar to... Figure 5 The heat pump 500 is common, and the same components have the same numbers. In one example variant, the countercurrent heat exchanger 912 is implemented in a single heat exchanger, wherein an intermediate manifold 939 defines a first stage 938 and a second stage 940. A second portion 550 of the primary cooled working fluid 542 is extracted from the intermediate manifold 939. In a second example variant, the heating side 922 includes an auxiliary heat exchanger 950 disposed between the regenerating heat exchanger 508 and the low-pressure expansion device 514. The auxiliary heat exchanger 950 dissipates heat from the second portion 546 of the regenerating working fluid 532 to the surrounding environment before the second portion 546 is received by the low-temperature expansion device 514. Further variations will be appreciated by those skilled in the art who benefit from this disclosure.

[0054] The disclosed heat pump cycle device claimed below is applicable to any heat pump application, wherein the heated fluid (e.g., heat transfer medium) has a heat capacity versus temperature profile that is substantially different from the heat capacity versus temperature profile of the working fluid (e.g., CO2), which covers most practical fluids. For example, commercially available heat transfer fluids (like DURATHERMHF) TM (High-temperature resistant membrane element) TM ) or DOWTHERM TM (thermal conductive heat exchanger) TM The heat capacity of sand follows the relationship with the temperature (c) as the temperature increases. p Similar to temperature dependence.

[0055] This summarizes the detailed description. The specific embodiments disclosed above are merely illustrative, as the claimed subject matter can be modified and practiced in different but equivalent ways, as will be apparent to those skilled in the art who benefit from the teachings herein. Furthermore, nothing is intended to limit the details of the constructions or designs shown herein, except as described in the following claims. It is therefore clear that the specific embodiments disclosed above can be altered or modified, and all such variations are considered to be within the scope and spirit of the claims. Therefore, the protection sought herein is as set forth in the following claims.

Claims

1. A heat pump, comprising: Heat transfer source; Heat transfer target; as well as A closed fluid loop for circulating the working fluid, the closed fluid loop comprising: A compression device, the compression device being used to receive a working fluid in a first state and to raise the temperature and pressure of the working fluid by mechanical work, so as to bring the working fluid to a second state; Countercurrent heat exchangers include: A first stage, thermally connected to the heat transfer target, is used to receive the working fluid in the second state and transfer heat from the received working fluid to the heat transfer target to cool the working fluid to the third state; and The second stage is in thermal communication with the heat transfer target. The second stage receives a first portion of the working fluid in the third state and transfers heat from the first portion of the working fluid in the third state to the heat transfer target to cool the working fluid to the fourth state. A cryogenic expansion device, the cryogenic expansion device being used to receive a working fluid in a fifth state and expand the working fluid to a sixth state; A low-temperature heat exchanger is thermally connected to the heat transfer source. The low-temperature heat exchanger receives the working fluid in a sixth state and transfers heat from the heat transfer source to the working fluid in the sixth state to heat the working fluid to a seventh state. A high-temperature expansion device, the high-temperature expansion device being used to receive a second portion of the working fluid in the third state and to expand the received second portion of the working fluid in the third state to an eighth state; and A regenerative heat exchanger is used to transfer heat from the working fluid in the fourth state, received from the second stage of the countercurrent heat exchanger, to a combination of the working fluid in the eighth state, received from the high-temperature expansion device, and the working fluid in the seventh state, received from the low-temperature heat exchanger, thereby heating the combined working fluid to the first state and cooling the working fluid in the fourth state to the fifth state.

2. The heat pump according to claim 1, wherein, At least one of the high-temperature expansion device and the low-temperature expansion device includes a turbine or a valve.

3. The heat pump according to claim 1, wherein, At least one of the heat transfer source and the heat transfer target includes a heat transfer medium, which includes at least one of a fluid and a solid.

4. The heat pump according to claim 3, wherein, The fluid flows in the pipe.

5. The heat pump according to claim 3, wherein, The solid is a clump of solid or flowing sand.

6. The heat pump according to claim 3, wherein, The fluid is water, a water / propylene glycol mixture, or air.

7. The heat pump according to claim 1, wherein, At least one of the heat transfer source and the heat transfer target includes a heat transfer medium, and the heat transfer medium is a synthetic oil heat transfer fluid, water, or sand.

8. The heat pump according to claim 1, wherein, The countercurrent heat exchanger comprises two single-stage heat exchangers or a single heat exchanger with an intermediate manifold.

9. The heat pump according to claim 8, wherein, The two single-stage heat exchangers are of different sizes, with one being larger than the other.

10. The heat pump of claim 1, further comprising an auxiliary heat exchanger disposed between the regenerating heat exchanger and the cryogenic expansion device, the auxiliary heat exchanger being used to discharge heat from the first portion of the regenerating working fluid to the surrounding environment before the first portion of the regenerating working fluid is received by the cryogenic expansion device.

11. The heat pump of claim 1, wherein the working fluid is carbon dioxide.

12. A heat pump, comprising: Heat transfer target; Heat transfer source; as well as A closed fluid loop for circulating the working fluid, the closed fluid loop comprising: A compression device for receiving the working fluid in a first state and heating and pressurizing the received working fluid to a second state; A device for performing a diversion expansion of the working fluid in the second state, the diversion expansion comprising partially cooling the working fluid from the second state to a third state, further cooling a first portion of the working fluid in the third state to a fourth state and further cooling it to a fifth state, expanding a second portion of the working fluid in the partially cooled third state to an eighth state, and expanding a first portion of the working fluid in the fifth state to a sixth state. A low-temperature heat exchanger is thermally connected to the heat transfer source to receive the working fluid in the sixth state and transfer heat from the heat transfer source to the working fluid in the sixth state to heat the working fluid in the sixth state to the seventh state. A regenerative heat exchanger is used to transfer heat from the working fluid received by the device performing the diversion expansion in the fourth state to a combination of the working fluid received by the device performing the diversion expansion in the eighth state and the working fluid received by the cryogenic heat exchanger in the seventh state, thereby heating the combined working fluid to the first state and cooling the working fluid in the fourth state to the fifth state.

13. The heat pump according to claim 12, wherein, The device used to perform the shunt expansion includes: Countercurrent heat exchangers include: A first stage, thermally connected to a heat transfer target, receives the working fluid in the second state from the compression device and transfers heat from the received working fluid in the second state to the heat transfer target to cool the received working fluid in the second state to a third state; and The second stage is in thermal communication with the heat transfer target to receive the first portion of the working fluid in the third state from the first stage and to transfer heat from the working fluid in the third state to the heat transfer target to cool the working fluid to a fourth state of secondary cooling. A cryogenic expansion device that expands the working fluid received from the regenerating heat exchanger in the fifth state to the sixth state; and A high-temperature expansion device receives a second portion of the working fluid in the third state from the first stage of the countercurrent heat exchanger and expands the received second portion of the working fluid to the eighth state.

14. The heat pump according to claim 13, wherein the closed fluid loop further comprises an auxiliary heat exchanger that discharges the heat of the working fluid in the fifth state to the surrounding environment.

15. The heat pump according to claim 13, wherein, The countercurrent heat exchanger comprises two single-stage heat exchangers or a single heat exchanger with an intermediate manifold.

16. A heat pump cycle method in a closed fluid loop, the heat pump cycle method comprising: The working fluid in the first state is compressed to raise the temperature and pressure to the second state; Cooling the working fluid in the second state in a countercurrent heat exchanger includes: In the first stage, the working fluid in the second state is cooled to the third state; and In the second stage, a first portion of the working fluid in the third state is cooled to the fourth state; The working fluid in the fifth state will expand to the sixth state; The working fluid in the sixth state is heated to the seventh state; The second portion of the working fluid in the third state is expanded to the eighth state; Mixing the working fluid in the seventh state with the working fluid in the eighth state; and In a regenerative heat exchanger, the mixture of the working fluid in the seventh and eighth states is heated to the first state, while the working fluid in the fourth state is cooled to the fifth state.

17. The heat pump cycle method according to claim 16, wherein, The first stage is the first heat exchanger, and the second stage is the second heat exchanger.

18. The heat pump cycle method according to claim 16, wherein, The first and second stages each include portions of a single heat exchanger with an intermediate manifold.

19. The heat pump cycle method of claim 16, further comprising, before expanding the working fluid in the fifth state to the sixth state, further cooling the working fluid in the fifth state by discharging heat into the ambient atmosphere.

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