A CO2 heat pump circulation system using a pressure exchanger to increase efficiency

Abstract

The present invention discloses a CO2 heat pump circulation system that uses a pressure exchanger to increase efficiency. The system includes a pressure exchanger, a compressor with an intermediate air supply function or two compressors in series or two compressors in parallel, two gas coolers, a gas-liquid separator, two throttle valves, a regenerator, and an evaporator. The pressure exchanger in the circulation system receives a high-pressure driving fluid and a low-pressure driven fluid, recovers the expansion work of the high-pressure driving fluid to increase the pressure of the low-pressure driven fluid, and realizes the exchange of pressure between the two fluids; after the driven fluid is pressurized, it enters the second gas cooler to release heat, which can reduce the power consumption of the compressor and improve the system's heating performance coefficient; the excess saturated gas phase in the gas-liquid separator enters the compressor through the air supply port, realizing incomplete intermediate cooling and improving the efficiency of the compressor; the saturated liquid phase at the outlet of the gas-liquid separator is throttled to the evaporation temperature after being supercooled, the specific enthalpy at the evaporator inlet is reduced, the unit mass cooling capacity is increased, and the overall performance of the circulation system can be further improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of vapor compression heat pump heating, and in particular relates to a CO2 heat pump circulation system using a pressure exchanger for efficiency enhancement. Background Art

[0002] Modern society is increasingly demanding efficient and environmentally friendly energy utilization solutions. Energy conservation, emission reduction, and improved energy efficiency are the future trends of energy utilization. Heat pumps are characterized by waste heat recovery, high heating efficiency, and strong sustainability. Carbon dioxide (CO2) has become a highly valued working fluid due to its high-temperature heating properties, good low-temperature adaptability, and environmental friendliness. However, CO2 has a critical pressure of 7.37 MPa, and the high pressure during system operation is typically above 10 MPa. Under heating conditions, the air cooler outlet temperature is high, the pressure differential between high and low pressure is large, and throttling losses are significant. Simultaneously, the compressor power consumption is also high, resulting in a serious decline in circulation system performance.

[0003] Adding a regenerator or recovering expansion work is an effective measure to reduce system throttling losses and improve heat pump cycle performance. A wave rotor pressure exchanger is a power device that uses unsteady pressure waves to exchange energy between a high-pressure driving fluid and a low-pressure driven fluid. This device simultaneously achieves expansion cooling and shock wave pressurization, and offers advantages such as a compact structure and ease of maintenance. Therefore, combining a regenerator and pressure exchanger can create a more efficient CO2 heat pump cycle. Summary of the Invention

[0004] In order to improve the overall performance of the heat pump system and reduce energy consumption, the present invention proposes a CO2 heat pump circulation system that uses a pressure exchanger for efficiency enhancement. The system can use a compressor with an intermediate air supply function or two compressors in series or two compressors in parallel to recover the remaining saturated gas phase in the gas-liquid separator, thereby achieving incomplete intermediate cooling, reducing the exhaust temperature and the irreversible loss of the compressor; the pressure exchanger can be used to recover the expansion work of the high-pressure driving fluid to increase the pressure of the saturated gas phase separated from the two-phase flow after its own flash evaporation, and then this part of the fluid enters the second gas cooler to release heat, thereby improving the heating performance of the system; the gas-liquid separator can separate the two-phase flow from the pressure exchanger and the first throttle valve, reduce the evaporator inlet dryness, improve the evaporator heat exchange efficiency, and at the same time reduce the evaporator inlet specific enthalpy and increase the unit mass cooling capacity.

[0005] To achieve the above objectives, the technical solution adopted by the present invention is:

[0006] The present invention provides a first CO2 heat pump circulation system using a pressure exchanger for efficiency enhancement, which uses a compressor with an intermediate air supply function and a pressure exchanger to achieve efficient heating. The compressor with the intermediate air supply function recovers excess saturated gas in the gas-liquid separator to achieve incomplete intermediate cooling, thereby reducing exhaust temperature and irreversible losses of the compressor. The heat pump circulation system includes a compressor with intermediate air supply 101, a first gas cooler 102, a pressure exchanger 103, a gas-liquid separator 104, a second gas cooler 105, a first throttle valve 106, a regenerator 107, a second throttle valve 108, and an evaporator 109.

[0007] The outlet of the compressor with intermediate air supply 101 is connected to the inlet of the first gas cooler 102; the outlet of the first gas cooler 102 is connected to the high-pressure inlet 103a of the pressure exchanger; the two inlets of the gas-liquid separator 104 are respectively connected to the low-pressure outlet 103b of the pressure exchanger and the outlet of the first throttle valve 106; the two saturated gas phase outlets of the gas-liquid separator 104 are respectively connected to the low-pressure inlet 103c of the pressure exchanger and the air supply port of the compressor with intermediate air supply 101; the high-pressure outlet 103d of the pressure exchanger is connected to the second gas The inlet of the gas cooler 105 is connected; the outlet of the second gas cooler 105 is connected to the inlet of the first throttle valve 106; the saturated liquid phase outlet of the gas-liquid separator 104 is connected to the hot end inlet of the regenerator 107; the hot end outlet of the regenerator 107 is connected to the inlet of the second throttle valve 108; the outlet of the second throttle valve 108 is connected to the inlet of the evaporator 109; the outlet of the evaporator 109 is connected to the cold end inlet of the regenerator 107; the cold end outlet of the regenerator 107 is connected to the inlet of the compressor 101 with intermediate air supply, forming a complete heat pump circulation system.

[0008] The second CO2 heat pump circulation system using a pressure exchanger for efficiency enhancement provided by the present invention achieves efficient heating by connecting two compressors in series and using a pressure exchanger. The use of two compressors in series effectively reduces the pressure ratio of a single compressor, thereby reducing compressor power consumption. The heat pump circulation system includes a first compressor 201, a second compressor 202, a first gas cooler 102, a pressure exchanger 103, a gas-liquid separator 104, a second gas cooler 105, a first throttle valve 106, a regenerator 107, a second throttle valve 108, and an evaporator 109.

[0009] The outlet of the first compressor 201 and one of the saturated gas phase outlets of the gas-liquid separator 104 are both connected to the inlet of the second compressor 202; the outlet of the second compressor 202 is connected to the inlet of the first gas cooler 102; the outlet of the first gas cooler 102 is connected to the high-pressure inlet 103a of the pressure exchanger; the two inlets of the gas-liquid separator 104 are respectively connected to the low-pressure outlet 103b of the pressure exchanger and the outlet of the first throttle valve 106; the other saturated gas phase outlet of the gas-liquid separator 104 is connected to the low-pressure inlet 103c of the pressure exchanger; the pressure exchanger The high-pressure outlet 103d is connected to the inlet of the second gas cooler 105; the outlet of the second gas cooler 105 is connected to the inlet of the first throttle valve 106; the saturated liquid phase outlet of the gas-liquid separator 104 is connected to the hot end inlet of the regenerator 107; the hot end outlet of the regenerator 107 is connected to the inlet of the second throttle valve 108; the outlet of the second throttle valve 108 is connected to the inlet of the evaporator 109; the outlet of the evaporator 109 is connected to the cold end inlet of the regenerator 107; the cold end outlet of the regenerator 107 is connected to the inlet of the first compressor 201, forming a complete heat pump circulation system.

[0010] The third CO2 heat pump circulation system using a pressure exchanger for efficiency enhancement provided by the present invention achieves efficient heating by connecting two compressors in parallel and using a pressure exchanger. By connecting two compressors in parallel, an auxiliary compressor is used to recover excess saturated gas in the gas-liquid separator 104 at an intermediate pressure, thereby reducing the compression ratio and compressor power consumption. The heat pump circulation system includes a main compressor 301, an auxiliary compressor 302, a first gas cooler 102, a pressure exchanger 103, a gas-liquid separator 104, a second gas cooler 105, a first throttle valve 106, a regenerator 107, a second throttle valve 108, and an evaporator 109.

[0011] The outlet of the main compressor 301 is connected to the inlet of the first gas cooler 102; the outlet of the first gas cooler 102 is connected to the high-pressure inlet 103a of the pressure exchanger; the two inlets of the gas-liquid separator 104 are respectively connected to the low-pressure outlet 103b of the pressure exchanger and the outlet of the first throttle valve 106; the two saturated gas phase outlets of the gas-liquid separator 104 are respectively connected to the low-pressure inlet 103c of the pressure exchanger and the inlet of the auxiliary compressor 302; the outlet of the auxiliary compressor 302 is connected to the inlet of the first gas cooler 102; the high-pressure outlet 103b of the pressure exchanger is connected to the outlet of the first throttle valve 106; the two saturated gas phase outlets of the gas-liquid separator 104 are respectively connected to the low-pressure inlet 103c of the pressure exchanger and the inlet of the auxiliary compressor 302; the outlet of the auxiliary compressor 302 is connected to the inlet of the first gas cooler 102; the high-pressure outlet 103c of the pressure exchanger is connected to the outlet of the first gas cooler 102; the high-pressure outlet 103b of the pressure exchanger is connected to the outlet of the first throttle valve 106; the two saturated gas phase outlets of the gas-liquid separator 104 are respectively connected to the low-pressure inlet 103c of the pressure exchanger and the inlet of the auxiliary compressor 302. Port 103d is connected to the inlet of the second gas cooler 105; the outlet of the second gas cooler 105 is connected to the inlet of the first throttle valve 106; the saturated liquid phase outlet of the gas-liquid separator 104 is connected to the hot end inlet of the regenerator 107; the hot end outlet of the regenerator 107 is connected to the inlet of the second throttle valve 108; the outlet of the second throttle valve 108 is connected to the inlet of the evaporator 109; the outlet of the evaporator 109 is connected to the cold end inlet of the regenerator 107; the cold end outlet of the regenerator 107 is connected to the inlet of the main compressor 201, forming a complete heat pump circulation system.

[0012] The pressure exchanger 103 consists of a rotor, two end covers and four ports, namely a high-pressure inlet 103a, a low-pressure outlet 103b, a low-pressure inlet 103c and a high-pressure outlet 103d. As the rotor rotates, it gradually connects the various pipes first with the low-pressure inlet 103c to receive the low-pressure driven fluid from the saturated gas phase outlet of the gas-liquid separator 104, and then seals the low-pressure inlet 103c. As the pipes continue to rotate and are exposed to the high-pressure inlet 103a, the high-pressure driving fluid from the first gas cooler 102 pressurizes the low-pressure driven fluid to the discharge pressure and ejects it through the high-pressure outlet 103d. At the other end of the rotor, the low-pressure driven fluid entering from the low-pressure inlet 103c is expanded and discharged through the high-pressure outlet 103d, and the process is repeated.

[0013] The gas-liquid separator 104 has two inlets, one saturated liquid phase outlet and two saturated gas phase outlets. The saturated gas phase separated from the two-phase flow from the pressure exchanger 103 and the first throttle valve 106 is pressurized to a high-temperature and high-pressure supercritical fluid state through the pressure exchanger 103 and then enters the second gas cooler 105. The excess saturated gas phase returns to the compressor through another outlet of the gas-liquid separator 104, realizing incomplete intermediate cooling, reducing the exhaust temperature and the irreversible loss of the compressor.

[0014] The system has two gas coolers. Due to the pressure loss during the pressure exchange process, the pressure in the second gas cooler 105 is lower than that in the first gas cooler 102. The two gas coolers can be integrated into a single heat exchanger through piping, resulting in a more compact structure. The fluid entering the second gas cooler 105 does not need to be directly compressed by the compressor, but instead reaches a higher pressure through the pressure exchanger 103, effectively reducing compressor power consumption.

[0015] Compared with the prior art, the present invention has the following advantages:

[0016] The present invention uses a pressure exchanger to recover the expansion work of the fluid at the outlet of the first gas cooler 102, so that the saturated gas phase separated by the gas-liquid separator 104 returns to a high-temperature and high-pressure state and enters the second gas cooler 105 to release heat, effectively increasing the heating capacity, reducing the power consumption of the compressor, and improving the overall performance of the system.

[0017] The compressor 101 with intermediate air replenishment can achieve incomplete intermediate cooling of the fluid compressed to the intermediate pressure by recovering the excess saturated gas phase in the gas-liquid separator 104, thereby reducing the exhaust temperature and irreversible losses of the compressor; the use of compressors in series can effectively reduce the pressure ratio of a single compressor and improve the efficiency of the compressor; the use of compressors in parallel can reasonably match the exhaust volume of the auxiliary compressor and the main compressor according to the saturated gas phase to be recovered, thereby improving the overall efficiency of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 Schematic diagram of a heat pump circulation system according to a first embodiment of the present invention.

[0019] Figure 2 The pressure-enthalpy diagram of the working process of the heat pump circulation system of the first embodiment of the present invention ph picture.

[0020] Figure 3 This is a schematic diagram of a heat pump circulation system according to a second embodiment of the present invention.

[0021] Figure 4 The pressure-enthalpy diagram of the working process of the heat pump circulation system of the second embodiment of the present invention ph picture.

[0022] Figure 5 This is a schematic diagram of a heat pump circulation system according to embodiment 3 of the present invention.

[0023] Figure 6 The pressure-enthalpy diagram of the working process of the heat pump circulation system of the third embodiment of the present invention ph picture. DETAILED DESCRIPTION

[0024] In order to make the purpose, technical solutions and advantages of the present invention more clear and concise, the present invention is further described in detail below with reference to the accompanying drawings and three embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0025] Example 1

[0026] Figure 1This is the first implementation of a CO2 heat pump circulation system that uses a pressure exchanger for efficiency enhancement. A compressor with an intermediate air supply function and a pressure exchanger are used to achieve efficient heating. The heat pump circulation system includes a compressor with intermediate air supply 101, a first gas cooler 102, a pressure exchanger 103, a gas-liquid separator 104, a second gas cooler 105, a first throttle valve 106, a regenerator 107, a second throttle valve 108 and an evaporator 109. The outlet of the compressor with intermediate air supply 101 is connected to the inlet of the first gas cooler 102. The outlet of the first gas cooler 102 is connected to the high-pressure inlet 103a of the pressure exchanger. The two inlets of the gas-liquid separator 104 are respectively connected to the low-pressure outlet 103b of the pressure exchanger and the outlet of the first throttle valve 106. The two inlets of the gas-liquid separator 104 are respectively connected to the low-pressure outlet 103b of the pressure exchanger and the outlet of the first throttle valve 106. The saturated gas phase outlets are respectively connected to the low-pressure inlet 103c of the pressure exchanger and the gas supply port of the compressor 101 with intermediate gas supply; the high-pressure outlet 103d of the pressure exchanger is connected to the inlet of the second gas cooler 105; the outlet of the second gas cooler 105 is connected to the inlet of the first throttle valve 106; the saturated liquid phase outlet of the gas-liquid separator 104 is connected to the hot end inlet of the regenerator 107; the hot end outlet of the regenerator 107 is connected to the inlet of the second throttle valve 108; the outlet of the second throttle valve 108 is connected to the inlet of the evaporator 109; the outlet of the evaporator 109 is connected to the cold end inlet of the regenerator 107; the cold end outlet of the regenerator 107 is connected to the inlet of the compressor 101 with intermediate gas supply, forming a complete heat pump circulation system.

[0027] Figure 2 The pressure-enthalpy diagram of the working process of the circulation system of Example 1 ( ph Figure). The specific working process is: superheated vapor refrigerant ( Figure 2 1 point) is compressed to the intermediate pressure ( Figure 2 1' point), and the excess saturated gas phase from the gas-liquid separator 104 ( Figure 2 After mixing (9 o'clock) Figure 2 1" point), compressed to exhaust pressure ( Figure 2 2 points), then enters the first gas cooler 102, and releases heat at isobaric pressure under supercritical state ( Figure 2 3) enters the high-pressure inlet of the pressure exchanger 103, and after expansion, flash evaporates into a two-phase state ( Figure 2 4 points) and then enters the gas-liquid separator 104; the saturated gas phase ( Figure 2 5 points) enters the low-pressure inlet of the pressure exchanger 103 and is pressurized to a high-temperature and high-pressure supercritical fluid ( Figure 2 6 o'clock) and then enter the second gas cooler 105, and release heat at the same pressure under supercritical state ( Figure 2 7 o'clock) enters the first throttle valve 106 and becomes a two-phase state after expansion ( Figure 2 8 o'clock) and then enters the gas-liquid separator 104; the saturated liquid phase in the gas-liquid separator 104 ( Figure 2 10 o'clock) enters the regenerator 107 and releases heat to become a supercooled liquid ( Figure 2 11 o'clock), and then expands to a two-phase fluid ( Figure 2 12 o'clock); the two-phase fluid enters the evaporator 109 and absorbs heat to become a saturated gas phase ( Figure 2 13 o'clock), then enters the regenerator 107 to absorb heat and become superheated steam ( Figure 2 1 point), complete the whole cycle.

[0028] Example 2

[0029] Figure 3 This is a second implementation of a CO2 heat pump circulation system that uses a pressure exchanger for efficiency enhancement. Efficient heating is achieved by connecting two compressors in series and a pressure exchanger; the use of two compressors in series effectively reduces the pressure ratio of a single compressor, thereby reducing the power consumption of the compressor. The heat pump circulation system includes a first compressor 201, a second compressor 202, a first gas cooler 102, a pressure exchanger 103, a gas-liquid separator 104, a second gas cooler 105, a first throttle valve 106, a regenerator 107, a second throttle valve 108 and an evaporator 109; the outlet of the first compressor 201 and one of the saturated gas phase outlets of the gas-liquid separator 104 are both connected to the inlet of the second compressor 202; the outlet of the second compressor 202 is connected to the inlet of the first gas cooler 102; the outlet of the first gas cooler 102 is connected to the high-pressure inlet 103a of the pressure exchanger; the two inlets of the gas-liquid separator 104 are respectively connected to the low-pressure outlet 103b of the pressure exchanger and the first The outlet of the throttle valve 106 is connected; another saturated gas phase outlet of the gas-liquid separator 104 is connected to the low-pressure inlet 103c of the pressure exchanger; the high-pressure outlet 103d of the pressure exchanger is connected to the inlet of the second gas cooler 105; the outlet of the second gas cooler 105 is connected to the inlet of the first throttle valve 106; the saturated liquid phase outlet of the gas-liquid separator 104 is connected to the hot end inlet of the regenerator 107; the hot end outlet of the regenerator 107 is connected to the inlet of the second throttle valve 108; the outlet of the second throttle valve 108 is connected to the inlet of the evaporator 109; the outlet of the evaporator 109 is connected to the cold end inlet of the regenerator 107; the cold end outlet of the regenerator 107 is connected to the inlet of the first compressor 201, forming a complete heat pump circulation system.

[0030] Figure 4 The pressure-enthalpy diagram of the working process of the circulation system of Example 2 ( ph Figure). The specific working process is: superheated vapor refrigerant ( Figure 4 1 point) is compressed to the intermediate pressure ( Figure 41' point), and the excess saturated gas phase from the gas-liquid separator 104 ( Figure 4 After mixing (5 o'clock) Figure 4 9 o'clock), enters the second compressor 202 and is compressed to the exhaust pressure ( Figure 4 2 points), then enters the first gas cooler 102) and releases heat at isobaric pressure under supercritical state ( Figure 4 3) enters the high-pressure inlet of the pressure exchanger 103, and after expansion, flash evaporates into a two-phase state ( Figure 4 4 points) and then enters the gas-liquid separator 104; the saturated gas phase ( Figure 4 5 points) enters the low-pressure inlet of the pressure exchanger 103 and is pressurized to a high-temperature and high-pressure supercritical fluid ( Figure 4 6 o'clock) and then enter the second gas cooler 105, and release heat at the same pressure under supercritical state ( Figure 4 7 o'clock) enters the first throttle valve 106 and becomes a two-phase state after expansion ( Figure 2 8 o'clock) and then enters the gas-liquid separator 104; the saturated liquid phase in the gas-liquid separator 104 ( Figure 4 10 o'clock) enters the regenerator 107 and releases heat to become a supercooled liquid ( Figure 4 11 o'clock), and then expands to a two-phase fluid ( Figure 4 12 o'clock); the two-phase fluid enters the evaporator 109 and absorbs heat to become a saturated gas phase ( Figure 4 13 o'clock), then enters the regenerator 107 to absorb heat and become superheated steam ( Figure 4 1 point), complete the whole cycle.

[0031] Example 3

[0032] Figure 5This is a third implementation of a CO2 heat pump circulation system that uses a pressure exchanger for efficiency enhancement. Efficient heating is achieved by connecting two compressors in parallel and using a pressure exchanger. By connecting two compressors in parallel, an auxiliary compressor is used to recover excess saturated gas in the gas-liquid separator 104 at an intermediate pressure, thereby reducing the compression ratio and the power consumption of the compressor. The heat pump circulation system includes a main compressor 301, an auxiliary compressor 302, a first gas cooler 102, a pressure exchanger 103, a gas-liquid separator 104, a second gas cooler 105, a first throttle valve 106, a regenerator 107, a second throttle valve 108 and an evaporator 109. The outlet of the main compressor 301 is connected to the inlet of the first gas cooler 102. The outlet of the first gas cooler 102 is connected to the high-pressure inlet 103a of the pressure exchanger. The two inlets of the gas-liquid separator 104 are respectively connected to the low-pressure outlet 103b of the pressure exchanger and the first The outlet of the throttle valve 106 is connected; the two saturated gas phase outlets of the gas-liquid separator 104 are respectively connected to the low-pressure inlet 103c of the pressure exchanger and the inlet of the auxiliary compressor 302; the outlet of the auxiliary compressor 302 is connected to the inlet of the first gas cooler 102; the high-pressure outlet 103d of the pressure exchanger is connected to the inlet of the second gas cooler 105; the outlet of the second gas cooler 105 is connected to the inlet of the first throttle valve 106; the saturated liquid phase outlet of the gas-liquid separator 104 is connected to the hot end inlet of the regenerator 107; the hot end outlet of the regenerator 107 is connected to the inlet of the second throttle valve 108; the outlet of the second throttle valve 108 is connected to the inlet of the evaporator 109; the outlet of the evaporator 109 is connected to the cold end inlet of the regenerator 107; the cold end outlet of the regenerator 107 is connected to the inlet of the main compressor 201, forming a complete heat pump circulation system.

[0033] Figure 6 The pressure-enthalpy diagram of the working process of the circulation system of Example 3 ( ph Figure). The specific working process is: superheated vapor refrigerant ( Figure 6 1 point) is compressed to the exhaust pressure ( Figure 6 1' point), from the excess saturated gas phase in the gas-liquid separator 104 ( Figure 6 9 o'clock) enters the auxiliary compressor 302 and is compressed to the exhaust pressure ( Figure 6 1'' point), mixed with the exhaust gas of the main compressor 301 ( Figure 6 2 points), then enters the first gas cooler 102, and releases heat at isobaric pressure under supercritical state ( Figure 6 3) enters the high-pressure inlet of the pressure exchanger 103, and after expansion, flash evaporates into a two-phase state ( Figure 6 4 points) and then enters the gas-liquid separator 104; the saturated gas phase ( Figure 6 5 points) enters the low-pressure inlet of the pressure exchanger 103 and is pressurized to a high-temperature and high-pressure supercritical fluid ( Figure 6 6 o'clock) and then enters the second gas cooler 105, and releases heat at isobaric pressure under supercritical state ( Figure 6 7 o'clock) enters the first throttle valve 106 and becomes a two-phase state after expansion ( Figure 6 8 o'clock) and then enters the gas-liquid separator 104; the saturated liquid phase in the gas-liquid separator 104 ( Figure 6 10 o'clock) enters the regenerator 107 and releases heat to become a supercooled liquid ( Figure 6 11 o'clock), and then expands to a two-phase fluid ( Figure 6 12 o'clock); the two-phase fluid enters the evaporator 109 and absorbs heat to become a saturated gas phase ( Figure 6 13 o'clock), then enters the regenerator 107 to absorb heat and become superheated steam ( Figure 6 1 point), complete the whole cycle.

Claims

1. A CO2 heat pump circulation system using a pressure exchanger for efficiency enhancement, characterized in that: A compressor with an intermediate air supply function and a pressure exchanger are used to achieve efficient heating. The compressor with the intermediate air supply function recovers excess saturated gas in a gas-liquid separator to achieve incomplete intermediate cooling, thereby improving compressor efficiency. The heat pump circulation system comprises a compressor with an intermediate air supply (101), a first gas cooler (102), a pressure exchanger (103), a gas-liquid separator (104), a second gas cooler (105), a first throttle valve (106), a regenerator (107), a second throttle valve (108), and an evaporator (109). The outlet of the compressor (101) with intermediate air supply is connected to the inlet of the first gas cooler (102); the outlet of the first gas cooler (102) is connected to the high-pressure inlet (103a) of the pressure exchanger; the two inlets of the gas-liquid separator (104) are respectively connected to the low-pressure outlet (103b) of the pressure exchanger and the outlet of the first throttle valve (106); the two saturated gas phase outlets of the gas-liquid separator (104) are respectively connected to the low-pressure inlet (103c) of the pressure exchanger and the air supply port of the compressor (101) with intermediate air supply; the high-pressure outlet (103d) of the pressure exchanger is connected to the second gas cooler (102). The inlet of the heat exchanger (105) is connected; the outlet of the second gas cooler (105) is connected to the inlet of the first throttle valve (106); the saturated liquid phase outlet of the gas-liquid separator (104) is connected to the hot end inlet of the regenerator (107); the hot end outlet of the regenerator (107) is connected to the inlet of the second throttle valve (108); the outlet of the second throttle valve (108) is connected to the inlet of the evaporator (109); the outlet of the evaporator (109) is connected to the cold end inlet of the regenerator (107); the cold end outlet of the regenerator (107) is connected to the inlet of the compressor (101) with intermediate air supply, thereby forming a complete heat pump circulation system; The pressure exchanger (103) comprises a rotor, two end covers and four ports, namely a high-pressure inlet (103a), a low-pressure outlet (103b), a low-pressure inlet (103c) and a high-pressure outlet (103d); when the rotor rotates, each pipe is gradually connected to the low-pressure inlet (103c) first to receive the low-pressure driven fluid from the saturated gas phase outlet of the gas-liquid separator (104), and then the low-pressure inlet (103c) is sealed; when the pipe continues to rotate and is exposed to the high-pressure inlet (103a), the high-pressure driving fluid from the first gas cooler (102) pressurizes the low-pressure driven fluid to the discharge pressure and ejects it through the high-pressure outlet (103d); at the other end of the rotor, the low-pressure driven fluid entering from the low-pressure inlet (103c) is expanded and discharged through the high-pressure outlet (103d), and the process is repeated.

2. A CO2 heat pump circulation system using a pressure exchanger for efficiency enhancement, characterized in that: Efficient heating is achieved by connecting two compressors in series and a pressure exchanger; the two compressors are connected in series to effectively reduce the pressure ratio of a single compressor, thereby reducing the power consumption of the compressor; the heat pump circulation system includes a first compressor (201), a second compressor (202), a first gas cooler (102), a pressure exchanger (103), a gas-liquid separator (104), a second gas cooler (105), a first throttle valve (106), a regenerator (107), a second throttle valve (108) and an evaporator (109); The outlet of the first compressor (201) and one of the saturated gas phase outlets of the gas-liquid separator (104) are both connected to the inlet of the second compressor (202); the outlet of the second compressor (202) is connected to the inlet of the first gas cooler (102); the outlet of the first gas cooler (102) is connected to the high-pressure inlet (103a) of the pressure exchanger; the two inlets of the gas-liquid separator (104) are respectively connected to the low-pressure outlet (103b) of the pressure exchanger and the outlet of the first throttle valve (106); the other saturated gas phase outlet of the gas-liquid separator (104) is connected to the low-pressure inlet (103c) of the pressure exchanger; the high-pressure inlet (103d) of the pressure exchanger The outlet (103d) is connected to the inlet of the second gas cooler (105); the outlet of the second gas cooler (105) is connected to the inlet of the first throttle valve (106); the saturated liquid phase outlet of the gas-liquid separator (104) is connected to the hot end inlet of the regenerator (107); the hot end outlet of the regenerator (107) is connected to the inlet of the second throttle valve (108); the outlet of the second throttle valve (108) is connected to the inlet of the evaporator (109); the outlet of the evaporator (109) is connected to the cold end inlet of the regenerator (107); the cold end outlet of the regenerator (107) is connected to the inlet of the first compressor (201), thereby forming a complete heat pump circulation system; The pressure exchanger (103) comprises a rotor, two end covers and four ports, namely a high-pressure inlet (103a), a low-pressure outlet (103b), a low-pressure inlet (103c) and a high-pressure outlet (103d); when the rotor rotates, each pipe is gradually connected to the low-pressure inlet (103c) first to receive the low-pressure driven fluid from the saturated gas phase outlet of the gas-liquid separator (104), and then the low-pressure inlet (103c) is sealed; when the pipe continues to rotate and is exposed to the high-pressure inlet (103a), the high-pressure driving fluid from the first gas cooler (102) pressurizes the low-pressure driven fluid to the discharge pressure and ejects it through the high-pressure outlet (103d); at the other end of the rotor, the low-pressure driven fluid entering from the low-pressure inlet (103c) is expanded and discharged through the high-pressure outlet (103d), and the process is repeated.

3. A CO2 heat pump circulation system using a pressure exchanger for efficiency enhancement, characterized in that: High-efficiency heating is achieved by connecting two compressors in parallel and a pressure exchanger. By connecting two compressors in parallel, an auxiliary compressor is used to recover excess saturated gas in a gas-liquid separator (104) at an intermediate pressure, thereby reducing the compression ratio and the power consumption of the compressor. The heat pump circulation system comprises a main compressor (301), an auxiliary compressor (302), a first gas cooler (102), a pressure exchanger (103), a gas-liquid separator (104), a second gas cooler (105), a first throttle valve (106), a regenerator (107), a second throttle valve (108), and an evaporator (109). The outlet of the main compressor (301) is connected to the inlet of the first gas cooler (102); the outlet of the first gas cooler (102) is connected to the high-pressure inlet (103a) of the pressure exchanger; the two inlets of the gas-liquid separator (104) are respectively connected to the low-pressure outlet (103b) of the pressure exchanger and the outlet of the first throttle valve (106); the two saturated gas phase outlets of the gas-liquid separator (104) are respectively connected to the low-pressure inlet (103c) of the pressure exchanger and the inlet of the auxiliary compressor (302); the outlet of the auxiliary compressor (302) is connected to the inlet of the first gas cooler (102); the high-pressure outlet ( 103d) is connected to the inlet of the second gas cooler (105); the outlet of the second gas cooler (105) is connected to the inlet of the first throttle valve (106); the saturated liquid phase outlet of the gas-liquid separator (104) is connected to the hot end inlet of the regenerator (107); the hot end outlet of the regenerator (107) is connected to the inlet of the second throttle valve (108); the outlet of the second throttle valve (108) is connected to the inlet of the evaporator (109); the outlet of the evaporator (109) is connected to the cold end inlet of the regenerator (107); the cold end outlet of the regenerator (107) is connected to the inlet of the main compressor (301), forming a complete heat pump circulation system; The pressure exchanger (103) comprises a rotor, two end covers and four ports, namely a high-pressure inlet (103a), a low-pressure outlet (103b), a low-pressure inlet (103c) and a high-pressure outlet (103d); when the rotor rotates, each pipe is gradually connected to the low-pressure inlet (103c) first to receive the low-pressure driven fluid from the saturated gas phase outlet of the gas-liquid separator (104), and then the low-pressure inlet (103c) is sealed; when the pipe continues to rotate and is exposed to the high-pressure inlet (103a), the high-pressure driving fluid from the first gas cooler (102) pressurizes the low-pressure driven fluid to the discharge pressure and ejects it through the high-pressure outlet (103d); at the other end of the rotor, the low-pressure driven fluid entering from the low-pressure inlet (103c) is expanded and discharged through the high-pressure outlet (103d), and the process is repeated.

4. A CO2 heat pump circulation system using a pressure exchanger for efficiency enhancement according to claim 1, 2 or 3, characterized in that: The gas-liquid separator (104) has two inlets, one saturated liquid phase outlet and two saturated gas phase outlets. The saturated gas phase separated from the two-phase flow from the pressure exchanger (103) and the first throttle valve (106) is pressurized to a high-temperature and high-pressure supercritical fluid state through the pressure exchanger (103) and then enters the second gas cooler (105). The excess saturated gas phase returns to the compressor through another outlet of the gas-liquid separator (104), thereby achieving incomplete intermediate cooling and reducing the exhaust temperature and irreversible loss of the compressor.

5. A CO2 heat pump circulation system using a pressure exchanger for efficiency enhancement according to claim 1, 2 or 3, characterized in that: The system has two gas coolers, and due to a certain pressure loss in the pressure exchange process, the pressure of the second gas cooler (105) is lower than that of the first gas cooler (102); the two gas coolers are integrated on a heat exchanger through a pipeline arrangement, and the structure is more compact; the fluid entering the second gas cooler (105) does not need to be directly compressed by the compressor but obtains a higher pressure through the pressure exchanger (103), thereby effectively reducing the power consumption of the compressor.

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