Heat pump system and device based on reverse brayton cycle

Abstract

The present application relates to the technical field of heat pump, provide a kind of based on reverse brayton cycle heat pump system and equipment, system includes: through working medium pipeline connection for loop compressor mechanism, regenerator and expander mechanism;Compressor mechanism includes n compressor and n-1 intermediate cooler in series and alternately arranged;In the working medium flow direction, first-stage compressor is connected with the low-temperature outlet end of regenerator, last-stage compressor is connected with the high-temperature inlet end of regenerator;Expander mechanism includes m expander and m-1 reheater in series and alternately arranged;In the working medium flow direction, first-stage expander is connected with the high-temperature outlet end of regenerator, last-stage expander is connected with the low-temperature inlet end of regenerator;M and n are both integers greater than 0 and at least one is greater than 1.Such setting makes heat pump can utilize constant-temperature heat source, and output power is more stable, and reach higher efficient purpose.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of heat pumps, in particular to a heat pump system and device based on reverse Brayton cycle. BACKGROUND

[0002] With the growth of global energy demand and the improvement of environmental protection awareness, efficient and environmentally friendly energy conversion and utilization technology has become a research hotspot. Heat pump technology, as a technology that can convert low-grade heat energy into high-grade heat energy, has shown great potential in energy saving and consumption reduction. Reverse Brayton cycle heat pump is a new type of heat pump based on Brayton cycle. Compared with traditional heat pump technologies such as air source heat pump, water source heat pump and ground source heat pump, it has the characteristics of wide application range, low construction difficulty, no pollution to the environment, high efficiency, high energy saving and environmental protection, and has attracted attention from academia and industry.

[0003] In related technologies, referring to Figure 1 , the Brayton cycle heat pump usually includes a compressor 10, a condenser 11, a regenerator 12, an expander 13 and a cold box 14 connected by a working medium pipeline into a loop. When working, the gas working medium first enters the compressor 10, and the working medium is adiabatically compressed in the compressor 10. After that, the compressed gas enters the condenser 11 to cool down, and then enters the regenerator 12, where the gas temperature is greatly reduced. After that, it enters the expander 13, where the working medium is adiabatically expanded to do work outside. Then it enters the cold box 14 to cool down. The low-temperature gas absorbs heat in the cold box 14 and then enters the regenerator 12 to absorb heat, i.e. completes a single cycle, and then enters the compressor 10 to continue the cycle (as shown in Figure 2 ).

[0004] However, in the above related technology, the heat release process of the working medium in the condenser 11 and the heat absorption process of the working medium in the cold box 14 are processes with large temperature changes. The heat absorption and release rate of the working medium is related to its temperature. When the temperature of the working medium changes, the instantaneous refrigeration or heating power of the system will change, and the power output will be unstable. SUMMARY

[0005] The present application provides a heat pump system and device based on reverse Brayton cycle, which solves the defect of unstable output power of heat pump in the prior art and can improve the stability of power output.

[0006] The present application provides a heat pump system based on reverse Brayton cycle, comprising: a compressor mechanism, a regenerator and an expander mechanism connected by a working medium pipeline into a loop;

[0007] The compressor mechanism includes n compressors and n-1 intermediate coolers arranged in series and alternately. In the working medium flow direction, the first-stage compressor is connected with the low-temperature outlet end of the regenerator, and the last-stage compressor is connected with the high-temperature inlet end of the regenerator.

[0008] The expander mechanism comprises m expander machines and m-1 reheaters arranged in series and alternately; in the flow direction of the working medium, the first-stage expander is connected with the high-temperature outlet end of the regenerator, and the last-stage expander is connected with the low-temperature inlet end of the regenerator.

[0009] Both m and n are integers greater than 0, and at least one of them is greater than 1.

[0010] According to the present application, a heat pump system based on reverse Brayton cycle is provided, the number n of the compressors is greater than 1; the compressor mechanism further comprises at least one first valve connected between the compressors; the compressor upstream of each first valve and the intercooler constitute a compressor module; the compressor module comprises at least two compressors arranged alternately and at least one intercooler arranged between adjacent compressors.

[0011] Further comprising at least one first branch, the first end of the first branch is connected to the upstream second end of the first valve and the high-temperature inlet end of the regenerator is conducted, and the first control valve is connected on the first branch.

[0012] According to the present application, a heat pump system based on reverse Brayton cycle is provided, the working medium pipeline comprises a high-pressure section between the last-stage compressor and the regenerator; the second end of the first branch is connected with the high-pressure section.

[0013] According to the present application, a heat pump system based on reverse Brayton cycle is provided, the number m of the expanders is greater than 1; the expander mechanism further comprises at least one second valve connected between the expanders; the expander upstream of each second valve and the reheater constitute an expander module; the expander module comprises at least two expanders arranged alternately and at least one reheater arranged between adjacent expanders.

[0014] Further comprising at least one second branch, the first end of the second branch is connected to the upstream of the second valve, and the second end is conducted to the low-temperature inlet end of the regenerator; the first control valve is connected on the first branch.

[0015] According to the present application, a heat pump system based on reverse Brayton cycle is provided, the working medium pipeline comprises a low-pressure section between the last-stage expander and the regenerator; the second end of the second branch is connected with the low-pressure section.

[0016] According to the present application, a heat pump system based on reverse Brayton cycle is provided, the first-stage compressor is provided with a working medium inlet.

[0017] The application provides a heat pump system based on reverse Brayton cycle, wherein the number n of the compressors is greater than 1, and the number m of the expanders is greater than 1.

[0018] Or, the number n of the compressors is greater than 1, and the number m of the expanders is equal to 1.

[0019] Or, the number n of the compressors is equal to 1, and the number m of the expanders is greater than 1.

[0020] The application provides a heat pump system based on reverse Brayton cycle, wherein the expander comprises an expander or a throttling device.

[0021] The application provides a heat pump system based on reverse Brayton cycle, wherein the compressor comprises a positive displacement compressor, a dynamic compressor or a thermal compressor.

[0022] The application further provides a device comprising the heat pump system based on reverse Brayton cycle.

[0023] Beneficial effects:

[0024] I. When the number n of the compressors is greater than 1, the gas working medium firstly enters a primary compressor and is adiabatically compressed in the primary compressor, then enters an intermediate cooler to release a small amount of compression heat, the temperature of the working medium slightly drops, and then the working medium enters a secondary compressor and is adiabatically compressed, and the process is repeated until the working medium enters a final compressor and enters a regenerator to exchange heat with low-temperature working medium, the temperature of the gas working medium greatly drops, and the working medium after temperature drop enters an expander mechanism. In the above process, the heat pump can output heat through the intermediate cooler, and the heat release process is approximately a constant temperature process, so that the heat pump can stably output heating power.

[0025] II. When the number m of the expanders is greater than 1, the working medium after temperature drop firstly enters a primary expander, the gas is adiabatically expanded in the primary expander, the low-temperature gas after expansion enters a reheater to absorb heat, the temperature slightly rises and cold energy is output, then the working medium enters a secondary expander and is adiabatically expanded, and the process is repeated until the working medium enters a final expander and enters a regenerator to exchange heat with high-temperature working medium, the temperature of the gas working medium greatly rises, and the working medium after temperature rise enters a compressor mechanism. In the above process, the heat pump can absorb heat through the reheater and output cold energy, and the heat absorption process is approximately a constant temperature process, so that the heat pump can utilize a constant temperature heat source, and can stably output refrigeration power.

[0026] III. When the number n of the compressors is greater than 1 and the number m of the expanders is greater than 1, the heat absorption and release processes of the working medium can be approximately constant temperature processes, so that the heat pump can utilize a constant temperature heat source, and the power output of refrigeration or heating is more stable, and a higher efficiency is achieved.

[0027] Four, the utilization of heat pump for constant temperature heat source can greatly broaden the selection range of gas working medium, the heat pump in the related art needs to exist temperature change in the heat absorption stage, if want to utilize constant temperature heat source, need to adopt ammonia, alkane and the like working medium with phase change characteristics, so that the heat absorption stage of the heat pump is constant temperature process; and in the embodiment of the application, by the utilization of multistage expansion and reheater, the temperature of the heat pump in the heat absorption stage is approximately constant temperature, thereby breaking the above limitation, the selection of working medium is no longer limited to working medium with phase change characteristics, and air, nitrogen and other non-polluting gas working medium can be used, the raw material is simple to obtain and low in cost.

[0028] Five, by the arrangement of the first branch and the second branch, the maintenance of the heat pump and the adjustment of the number of compressors or expanders can be facilitated. BRIEF DESCRIPTION OF DRAWINGS

[0029] In order to more clearly illustrate the technical solutions of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0030] Figure 1 is a structure diagram of a Brayton heat pump in the related art

[0031] Figure 2 is a working medium cycle diagram of the Brayton heat pump in the related art.

[0032] Figure 3 is a structure diagram of a heat pump system based on reverse Brayton cycle provided by the embodiment 1 of the present application.

[0033] Figure 4 is a working medium cycle diagram of the heat pump system based on reverse Brayton cycle provided by the embodiment 1 of the present application.

[0034] Figure 5 is a structure diagram of a heat pump system based on reverse Brayton cycle provided by the embodiment 2 of the present application.

[0035] Figure 6 is a working medium cycle diagram of the heat pump system based on reverse Brayton cycle provided by the embodiment 2 of the present application.

[0036] Figure 7 is a structure diagram of a heat pump system based on reverse Brayton cycle provided by the embodiment 3 of the present application.

[0037] Figure 8 is a working medium cycle diagram of the heat pump system based on reverse Brayton cycle provided by the embodiment 3 of the present application.

[0038] Reference signs:

[0039] 10, compressor; 11, condenser; 12, regenerator; 13, expander; 14, cold box; 20, working fluid line; 200, high pressure section; 201, low pressure section; 21, compressor; 210, working fluid inlet; 22, intercooler; 23, regenerator; 24, expander; 25, reheater; 26, first valve; 27, first branch; 270, first control valve; 28, second valve; 29, second branch; 290, second control valve. DETAILED DESCRIPTION

[0040] To make the objects, technical solutions and advantages of the present application clearer, the technical solutions in the present application will be described below in connection with the drawings in the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0041] To facilitate the understanding of the heat pump system and device based on reverse Brayton cycle provided by the present application, the application background thereof is introduced first. The reverse Brayton cycle heat pump is a new type of heat pump based on the Brayton cycle. Compared with the traditional heat pump technologies such as air source heat pump, water source heat pump and ground source heat pump, the reverse Brayton cycle heat pump has the advantages of wide application range, low construction difficulty, no pollution to the environment, high efficiency, high energy saving and environmental protection, etc.

[0042] In the related art, referring to Figure 1 , the Brayton cycle heat pump usually includes a compressor 10, a condenser 11, a regenerator 12, an expander 13 and a cold box 14 connected by working fluid lines to form a loop. When working, referring to Figure 2 , the gaseous working fluid first enters the compressor 10, and the working fluid is adiabatically compressed in the compressor 10. Then the compressed gas enters the condenser 11 to be cooled, and then enters the regenerator 12, in which the temperature of the gas is greatly reduced. Then the working fluid enters the expander 13, in which the working fluid is adiabatically expanded to do work on the outside. Then the working fluid enters the cold box 14 to be cooled, and the low-temperature gas absorbs heat in the cold box 14 and then enters the regenerator 12 to absorb heat, i.e. to complete a single cycle, and then enters the compressor 10 to continue the cycle.

[0043] However, in the above related art, the heat release process of the working fluid in the condenser 11 and the heat absorption process of the working fluid in the cold box 14 are processes in which the temperature changes greatly. The heat absorption and release rate of the working fluid is related to its temperature. When the temperature of the working fluid changes, the instantaneous refrigeration or heating power of the system will change, and the power output is unstable.

[0044] To solve the above problems, the present application provides a heat pump system and device based on reverse Brayton cycle, which can provide stability of the heat pump output power.

[0045] The application is described below in conjunction with Figures 3-8 A heat pump system and device based on reverse Brayton cycle are described.

[0046] With reference to Figures 3 to 8 A heat pump system based on reverse Brayton cycle, comprising a compressor mechanism, a regenerator 23 and an expander mechanism connected as a loop through working fluid pipelines 20; wherein the compressor mechanism comprises n compressors 21 and n-1 intermediate coolers 22 arranged in series and alternately, in the flow direction of the working fluid, the first-stage compressor 21 is connected with the low-temperature outlet end of the regenerator 23, and the last-stage compressor 21 is connected with the high-temperature inlet end of the regenerator 23; the expander 24 comprises m expanders 24 and m-1 reheaters 25 arranged in series and alternately, in the flow direction of the working fluid, the first-stage expander 24 is connected with the high-temperature outlet end of the regenerator 23, and the last-stage expander 24 is connected with the low-temperature inlet end of the regenerator 23; n and m are both integers greater than 0 and at least one of them is greater than 1.

[0047] In actual work, when the number of compressors 21 n is greater than 1, the gas working fluid first enters the first-stage compressor 21 and is adiabatically compressed in the first-stage compressor 21, then enters the intermediate cooler 22 to release a small amount of compression heat, the temperature of the working fluid slightly drops, and then enters the next-stage compressor 21 to be adiabatically compressed, and so on, and finally enters the regenerator 23 through the last-stage compressor 21 to exchange heat with the low-temperature working fluid, the temperature of the gas working fluid greatly drops, and the cooled working fluid enters the expander mechanism. In the above process, the heat pump can output heat through the intermediate cooler 22, and the heat release process is approximately an isothermal process, so that the heat pump can stably output heating power.

[0048] When the number of expanders 24 m is greater than 1, the cooled gas working fluid first enters the first-stage expander 24, the gas is adiabatically expanded in the first-stage expander 24, the expanded low-temperature gas enters the reheater 25 to absorb heat, so that the temperature slightly rises and cold energy is output, then enters the next-stage expander 24 to be adiabatically expanded and cooled, and so on, and finally enters the regenerator 23 through the last-stage expander 24 to exchange heat with the high-temperature working fluid, the temperature of the gas working fluid greatly rises, and the heated working fluid enters the compressor mechanism. In the above process, the heat pump can absorb heat through the reheater 25 and output cold energy, and the heat absorption process is approximately an isothermal process, so that the heat pump can utilize the isothermal heat source, and can stably output refrigeration power.

[0049] When the number of compressors 21 n is greater than 1 and the number of expanders 24 m is greater than 1, the heat absorption and release processes of the working fluid can both be approximately isothermal processes, so that the heat pump can utilize the isothermal heat source, and the power output of refrigeration and heating is more stable, achieving a higher efficiency.

[0050] In addition, the heat pump can greatly expand the selection range of the gas working medium by using the constant temperature heat source. In the related art, the temperature of the heat pump changes in the heat absorption stage. If the constant temperature heat source is used, ammonia, alkane and other working media with phase change characteristics need to be used, so that the heat absorption stage of the heat pump is a constant temperature process. In the embodiment of the present application, the use of the multi-stage expander 24 and the reheater 25 makes the temperature of the heat pump in the heat absorption stage approximately constant, thereby breaking the above limitation, and the selection of the working medium is no longer limited to the working medium with phase change characteristics. Air, nitrogen and other non-polluting gas working media can be used, and the raw materials are easy to obtain and the cost is low.

[0051] It can be understood that the number n of the compressors 21 and the number m of the expanders 24 can be set according to actual working conditions, so as to meet different actual needs.

[0052] Embodiment 1

[0053] Referring to Figure 3 and Figure 4 In the embodiment, the number n of the compressors 21 is greater than 1, and the number m of the expanders 24 is equal to 1. The inlet of the first-stage compressor 21 is connected with the low-temperature outlet end of the regenerator 23, the outlet of the last-stage compressor 21 is connected with the high-temperature inlet end of the regenerator 23, the inlet of the expander 24 is connected with the high-temperature outlet end of the regenerator 23, and the outlet is connected with the low-temperature inlet end of the regenerator 23. The high-temperature working medium flowing out of the last-stage compressor 21 exchanges heat with the low-temperature working medium flowing out of the expander 24 in the regenerator 23.

[0054] In this way, when the working medium passes through the intercooler 22, a small amount of compression heat is released, the temperature of the working medium is slightly reduced and heat is output to the outside, and then the temperature of the working medium is increased after being compressed by the lower-stage compressor 21. In this way, the temperature curve of the working medium in the heat release process is zigzag, and the temperature is approximately constant, so that the constant temperature output of heat is realized by the intercooler 22, so as to stabilize the heating power.

[0055] It should be noted that the specific number of the compressors 21 and the corresponding intercoolers 22 can be arranged according to actual needs, and the embodiment of the present application does not make specific limitation.

[0056] Embodiment 2

[0057] Referring to Figure 5 and Figure 6In the embodiment, the number n of compressors 21 is equal to 1, and the number m of expanders 24 is greater than 1. The inlet of the compressor 21 is connected to the low-temperature outlet end of the regenerator 23, the outlet is connected to the high-temperature inlet end of the regenerator 23, the inlet of the first-stage expander 24 is connected to the high-temperature outlet end of the regenerator 23, and the outlet of the last-stage compressor 21 is connected to the low-temperature inlet end of the regenerator 23. The high-temperature working medium flowing out of the compressor 21 exchanges heat with the low-temperature working medium flowing out of the last-stage expander 24 in the regenerator 23.

[0058] In this way, when the working medium absorbs heat in the reheater 25, a small amount of cold energy is released to the outside, the temperature of the working medium slightly rises, and then the temperature of the working medium decreases after passing through the lower-stage expander 24. In this way, the temperature curve of the working medium in the heat absorption process is zigzag, and the temperature is approximately constant. Therefore, the constant-temperature output of cold energy is realized through the reheater 25, so as to stabilize the refrigeration power and enable the heat pump to utilize the constant-temperature heat source.

[0059] It should be noted that the specific number of expanders 24 and corresponding reheaters 25 can be arranged according to actual needs, and the embodiment of the present application does not make specific limitations.

[0060] Embodiment 3

[0061] In the embodiment, referring to Figure 7 and Figure 8 , the number n of compressors 21 is greater than 1, and the number m of expanders 24 is greater than 1. Through the above technical solution, the temperature of the gas working medium is approximately constant during the compression between the multiple-stage compressors 21 and the temperature reduction in the multiple-stage intercoolers 22. Therefore, the constant-temperature output of heat is realized through the intercoolers 22, so as to stabilize the heating power. The working medium after being cooled by the regenerator 23 enters the expander mechanism. The temperature of the gas working medium is approximately constant during the expansion between the multiple-stage expanders 24 and the heating in the multiple-stage reheaters 25. Therefore, the constant-temperature output of cold energy is realized through the reheaters 25, so as to stabilize the refrigeration power and enable the heat pump to utilize the constant-temperature heat source.

[0062] It should be noted that the specific number n of compressors 21 and the specific number m of expanders 24 can be the same or different, and the embodiment of the present application does not make specific limitations.

[0063] In some optional embodiments, according to different working principles, the above-mentioned compressor 21 includes but is not limited to any device capable of compressing the gas working medium, such as a positive displacement compressor, a dynamic compressor, or a heat-type compressor.

[0064] In some optional embodiments, the expander 24 can adopt an expander so that the working medium can do work while being adiabatic expansion, or can adopt a throttling device to control the temperature and pressure of the gas working medium by adjusting the flow.

[0065] Specifically, the throttling device includes, but is not limited to, an expansion valve, a capillary tube, etc.

[0066] In an embodiment of the present application, the regenerator 23 can adopt a counterflow regenerator, which has a cold working medium flow channel and a hot working medium flow channel. The cold working medium flow channel is used for the cold working medium flowing out of the last-stage expander 24 to pass through, and the hot working medium flow channel is used for the hot working medium flowing out of the last-stage compressor 21 to pass through. The cold working medium and the hot working medium flow in opposite directions to exchange heat.

[0067] It should be noted here that the above is only a brief description of the structure or principle of the counterflow regenerator. In the embodiment of the present application, only the heat exchange function of the counterflow regenerator is utilized without making any changes to its structure or principle. Moreover, the specific structure of the counterflow regenerator is not the main point of the present application. Therefore, the specific structure of the counterflow regenerator can refer to the prior art, and will not be described here in detail.

[0068] It can be understood that the regenerator 23 includes, but is not limited to, the above-mentioned counterflow regenerator. Other forms of regenerators 23 that can achieve heat exchange between the cold working medium and the hot working medium are also applicable, and will not be listed here in detail.

[0069] In an embodiment of the present application, with reference to Figures 3 to 8 When the number n of the compressors 21 is greater than 1, the compressor mechanism further includes at least one first valve 26 connected between the plurality of compressors 21. The compressor 21 upstream of each first valve 26 and the intercooler 22 constitute a compressor module. The compressor module includes at least two compressors 21 arranged alternately and at least one intercooler 22 located between adjacent compressors 21. The compressor mechanism further includes at least one first branch 27. The first end of the first branch 27 is connected to the upstream of the first valve 26, and the second end is in communication with the high-temperature inlet end of the regenerator 23. The first branch 27 is connected with a first control valve 270.

[0070] In this arrangement, when the first valve 26 is closed and the first control valve 270 is opened, the flow path of the working medium changes. At this time, the compressor module located upstream of the first valve 26 maintains normal operation, while the compressor 21 located downstream of the first valve 26 can be shut down for maintenance. Thus, the heat pump can maintain normal operation during maintenance, which is beneficial to improve the convenience of maintenance and replacement of the compressor 21. In addition, by controlling the opening and closing states of the first valve 26 and the first control valve 270, the number of stages of the compressor 21 can be adjusted, and thus the heating power can be regulated.

[0071] It can be understood that the specific number of the first valve 26 and the first branch 27 can be set according to the actual working condition and the demand for heating power regulation, and will not be specifically limited in the embodiment of the present application.

[0072] In one embodiment of the present application, the working medium pipeline 20 comprises a high-pressure section 200 between the last-stage compressor 21 and the regenerator 23; the second end of the first branch 27 is connected to the high-pressure section 200. In this way, the connection of the first branch 27 to the regenerator 23 can be facilitated.

[0073] In one embodiment of the present application, when the number m of the expanders 24 is greater than 1, the expander mechanism further comprises at least one second valve 28 connected between the plurality of expanders 24, the expander 24 upstream of each second valve 28 and the reheater 25 constitute an expander module; the expander module comprises at least two expanders 24 arranged alternately and at least one reheater 25 between adjacent compressors 21; and further comprises at least one second branch 29, the first end of the second branch 29 is connected to the upstream of the second valve 28, and the second end is in communication with the low-temperature inlet end of the regenerator 23, and the second branch 29 is connected with a second control valve 290.

[0074] In this arrangement, when the second valve 28 is closed and the second control valve 290 is opened, the flow path of the working medium changes, at this time, the expander module upstream of the second valve 28 maintains normal operation, while the expander 24 downstream of the second valve 28 can be shut down for maintenance, so that the heat pump can maintain normal operation during maintenance, which is conducive to improving the convenience of maintenance and replacement of the expander 24. In addition, by controlling the opening and closing states of the second valve 28 and the second control valve 290, the number of stages of the expander 24 can be adjusted, and thus the refrigeration power can be regulated.

[0075] In one embodiment of the present application, the working medium pipeline 20 comprises a low-pressure section 201 between the last-stage expander 24 and the regenerator 23; the second end of the second branch 29 is connected to the low-pressure section 201. In this way, the connection of the second branch 29 to the regenerator 23 can be facilitated.

[0076] It can be understood that the specific number of the second valve 28 and the second branch 29 can be set according to the actual working condition and the refrigeration power adjustment requirement, which is not specifically limited in the embodiment of the present application.

[0077] In one embodiment of the present application, the first-stage compressor 21 is provided with a working medium inlet 210, through which new working medium can be supplemented into the heat pump system, solving the problem of working medium loss in the system.

[0078] It can be understood that, without contradiction, a person skilled in the art can combine and combine different embodiments or examples described in the specification and the features of different embodiments or examples.

[0079] The device provided by the present application is described below, and the device described below can be referred to the above-described heat pump system based on reverse Brayton cycle.

[0080] A device comprises the heat pump system based on reverse Brayton cycle provided by any of the above-described embodiments.

[0081] Specifically, the device described above includes but is not limited to various forms of heating and refrigeration devices.

[0082] The heat pump system based on reverse Brayton cycle and the device provided by the embodiments of the present application, the gas working substance enters the intermediate cooler 22 to release a small amount of compression heat and then enters the next-stage compressor 21 to be adiabatically compressed, and so on, so that the heat release process of the intermediate cooler 22 is approximately a constant-temperature process, so that the heat pump can stably output heating power; the gas working substance enters the reheater 25 to absorb a small amount of heat and then enters the next-stage expander 24 to be expanded and cooled, and so on, so that the heat absorption process of the reheater 25 is approximately a constant-temperature process, so that the heat pump can utilize a constant-temperature heat source and can stably output refrigeration power.

[0083] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present application, but not to limit them; although the present application has been described in detail with reference to the above-described embodiments, those skilled in the art should understand that: it can still modify the technical solutions recorded in the above-described embodiments, or make equivalent replacement for part of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A heat pump system based on reverse-Brayton cycle, characterized by, Comprise: A compressor mechanism, a regenerator (23) and an expander mechanism connected as a loop through a working medium pipeline (20); The compressor mechanism comprises n compressors (21) and n-1 intermediate coolers (22) arranged in series and alternately; in the working medium flow direction, the first stage compressor (21) is connected with the low temperature outlet end of the regenerator (23), and the last stage compressor (21) is connected with the high temperature inlet end of the regenerator (23); The expander mechanism comprises m expanders (24) and m-1 reheaters (25) arranged in series and alternately; in the working medium flow direction, the first stage expander (24) is connected with the high temperature outlet end of the regenerator (23), and the last stage expander (24) is connected with the low temperature inlet end of the regenerator (23); m and n are both integers greater than 0 and at least one is greater than 1; The number of compressors (21) n is greater than 1; the compressor mechanism further comprises at least one first valve (26) connected between multiple compressors (21), and the compressor (21) and the intermediate cooler (22) located upstream of each first valve (26) constitute a compressor module; The compressor module comprises at least two compressors (21) arranged alternately and at least one intermediate cooler (22) located between adjacent compressors (21); Further comprising at least one first branch (27), the first end of the first branch (27) is connected to the upstream second end of the first valve (26) and the high temperature inlet end of the regenerator (23) is conducted, and the first control valve (270) is connected on the first branch (27).

2. The reverse-Brayton-cycle-based heat pump system according to claim 1, characterized by, The working medium pipeline (20) comprises a high pressure section (200) between the last stage compressor (21) and the regenerator (23); the second end of the first branch (27) is connected with the high pressure section (200).

3. The inverse Brayton cycle-based heat pump system of any one of claims 1-2, wherein, The number of expanders (24) m is greater than 1; the expander mechanism further comprises at least one second valve (28) connected between multiple expanders (24), and the expander (24) and the reheater (25) located upstream of each second valve (28) constitute an expander module; The expander module comprises at least two expanders (24) arranged alternately and at least one reheater (25) located between adjacent expanders (24); Further comprising at least one second branch (29), the first end of the second branch (29) is connected to the upstream of the second valve (28), and the second end is conducted with the low temperature inlet end of the regenerator (23), and the second control valve (290) is connected on the first branch (27).

4. The reverse-Brayton cycle-based heat pump system of claim 3, wherein, The working medium pipeline (20) comprises a low pressure section (201) between the last stage expander (24) and the regenerator (23); the second end of the second branch (29) is connected with the low pressure section (201).

5. The reverse-Brayton-cycle-based heat pump system according to claim 1, characterized by, The first stage compressor (21) is provided with a working medium inlet (210).

6. The reverse-Brayton-cycle-based heat pump system according to claim 1, characterized by, The number of compressors (21) n is greater than 1, and the number of expanders (24) m is greater than 1; or, the number n of compressors (21) is greater than 1 and the number m of expanders (24) is equal to 1; or, the number n of compressors (21) is equal to 1 and the number m of expanders (24) is greater than 1.

7. The reverse-Brayton-cycle-based heat pump system according to claim 1, characterized by, The expander (24) comprises an expander or a throttling device.

8. The reverse-Brayton-cycle-based heat pump system according to claim 1, characterized by, The compressor (21) comprises a positive displacement compressor (21), a dynamic compressor (21) or a thermal compressor (21).

9. An apparatus, comprising: A heat pump system based on the reverse Brayton cycle comprising a heat pump system according to any one of claims 1 to 8.

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