Carbon dioxide air conditioner heat pump system integrated with multi-way valve

Abstract

The invention belongs to the related technical field of refrigerating and heating equipment, and discloses a carbon dioxide air conditioner heat pump system integrated with a multi-way valve, which comprises the multi-way valve, an ejector, a first indoor heat exchanger, a second indoor heat exchanger, a gas-liquid separator, an outdoor heat exchanger, a compressor, a throttle valve and a four-way reversing valve, four valve ports of the four-way reversing valve are respectively connected to an inlet of the outdoor heat exchanger, an exhaust port of the compressor, an outlet of the throttle valve and an inlet of the second indoor heat exchanger; a gas outlet of the gas-liquid separator is connected to a gas suction port of the compressor; the multi-way valve is an eight-way valve and is provided with eight connectors which are connected with the ejector, the gas-liquid separator, the first indoor heat exchanger, the outdoor heat exchanger and the second indoor heat exchanger correspondingly, the communication state between the connectors of the multi-way valve is changed by adjusting a valve element of the multi-way valve, and the flow direction of refrigerants is changed. Therefore, the system can be switched between a refrigerating mode and a heating mode. According to the invention, the complexity and cost of the system are reduced.

Description

Technical Field

[0001] The present invention belongs to the technical field related to refrigeration and heating equipment, and more specifically, relates to a carbon dioxide air-conditioning heat pump system integrated with a multi-way valve. Background Art

[0002] In response to increasingly stringent environmental policies and low-carbon emission targets, the refrigeration industry is accelerating its exploration of new refrigerant solutions that meet sustainable development requirements. As a natural refrigerant with great application prospects, carbon dioxide (R744) has become a key candidate to replace traditional CFC-based refrigerants due to its unique environmental advantages and excellent safety characteristics. However, carbon dioxide-based refrigeration heat pump systems still face several technical bottlenecks in practical applications. On the one hand, its unique transcritical operating cycle is accompanied by high operating pressures, resulting in significant energy losses in the throttling process. On the other hand, when the system is operating for heating at low temperatures, the excessively large compression ratio leads to reduced compressor efficiency, limiting the system's energy efficiency.

[0003] Relevant scholars in this field have done some research. For example, patent CN202110481981.6 discloses a carbon dioxide heat pump air-conditioning system. The system realizes switching operation between cooling and heating conditions through innovative pipeline layout and valve configuration. In cooling mode, the system adopts a dual-temperature ejector expansion cycle architecture, recovers expansion work through the ejector, and uses dual indoor heat exchangers to control different evaporation temperatures respectively, thereby achieving independent cooling and dehumidification of the air, significantly improving the system's refrigeration performance coefficient. However, in this patent, the ejector is only used in cooling mode, and the system's heating mode still uses a conventional heat pump cycle design. Under low-temperature conditions, there are still shortcomings such as excessively high compressor pressure ratio and significant system efficiency attenuation. The existing technology still has room for improvement in system configuration and performance improvement. Summary of the Invention

[0004] In response to the above defects or improvement needs of the prior art, the present invention provides a carbon dioxide air-conditioning heat pump system with an integrated multi-way valve, which aims to solve the problems of complexity and high cost of the existing air-conditioning heat pump system.

[0005] To achieve the above-mentioned object, according to one aspect of the present invention, a carbon dioxide air-conditioning heat pump system with an integrated multi-way valve is provided, wherein the system comprises a multi-way valve, an ejector, a first indoor heat exchanger, a second indoor heat exchanger, a gas-liquid separator, an outdoor heat exchanger, a compressor, a throttle valve and a four-way reversing valve, wherein the four valve ports of the four-way reversing valve are respectively connected to the inlet of the outdoor heat exchanger, the exhaust port of the compressor, the outlet of the throttle valve and the inlet of the second indoor heat exchanger; the gas outlet of the gas-liquid separator is connected to the air intake port of the compressor; the multi-way valve is an eight-way valve, which is provided with eight interfaces, which are A first interface, a second interface, a third interface, a fourth interface, a fifth interface, a sixth interface, a seventh interface, and an eighth interface; the first interface is connected to the outlet of the ejector; the second interface is connected to the inlet of the gas-liquid separator; the third interface is connected to the outlet of the first indoor heat exchanger; the fourth interface is connected to the first inlet of the ejector; the fifth interface is connected to the outlet of the outdoor heat exchanger; the sixth interface is connected to the second inlet of the ejector; the seventh interface is connected to the outlet of the second indoor heat exchanger; and the eighth interface is connected to the inlet of the first indoor heat exchanger;

[0006] By adjusting the valve core of the multi-way valve to change the communication state between the interfaces of the multi-way valve, the refrigerant flow direction is changed, thereby achieving the switching of the system between the cooling mode and the heating mode.

[0007] Furthermore, the system further includes a fan, and the fan is provided on one side of the outdoor heat exchanger and one side of the second indoor heat exchanger.

[0008] Furthermore, the system also includes a regenerator, the first outlet of the regenerator is connected to the first inlet of the ejector, and the first inlet of the regenerator is connected to the fourth interface of the multi-way valve; the second inlet of the regenerator is connected to the gas outlet of the gas-liquid separator, and its second outlet is connected to the suction port of the compressor; the first inlet of the regenerator is connected to its first outlet; the second inlet of the regenerator is connected to its second outlet.

[0009] Furthermore, the system is equipped with ejectors for cooling and heating modes. The ejector can be a single ejector or a plurality of ejectors arranged in parallel, i.e., an ejector group. The specific configuration should be designed according to actual application requirements and space cost.

[0010] Furthermore, the refrigerant circulating in the system is carbon dioxide.

[0011] Furthermore, the multi-way valve is a single eight-way valve or a combination of several valves.

[0012] Furthermore, when the multi-way valve is an eight-way valve, the structure of the eight-way valve may be a disc-shaped structure or other structures.

[0013] Furthermore, when the multi-way valve is an eight-way valve, the control mode of the eight-way valve can be electric control or pressure difference control.

[0014] In general, the above technical solutions conceived by the present invention, compared with the prior art, provide a carbon dioxide air conditioning heat pump system with an integrated multi-way valve, which has the following beneficial effects:

[0015] 1. The present invention realizes efficient switching of the carbon dioxide refrigerant system between cooling and heating conditions by integrating a multi-way valve, eliminating the need for multiple reversing valves and one-way valves, and reducing the complexity and cost of the system.

[0016] 2. By adjusting the multi-way valve to change the flow direction of the refrigerant, the system can switch between cooling mode and heating mode. In both working modes, the ejector is effectively utilized to improve system performance. In cooling conditions, the ejector throttling method is used to achieve independent control of temperature and humidity. In heating conditions, the ejector boosting method is used to further improve system efficiency and achieve dual high efficiency in cooling and heating.

[0017] 3. By arranging the first and second indoor heat exchangers in series, in heating mode, high-temperature, high-pressure refrigerant sequentially enters the second and first indoor heat exchangers, cooling and releasing heat. In contrast, indoor air is heated by the first and second indoor heat exchangers, achieving countercurrent heat exchange between the refrigerant and air, effectively improving heating capacity. Furthermore, the introduction of the ejector increases the compressor's suction pressure, reducing compressor power consumption and further enhancing the system's heating efficiency.

[0018] 4. The regenerator is an optional module, flexibly selected based on application requirements, cost budget, and space constraints. When configured with a regenerator, only the inlet and outlet piping connections need to be adjusted appropriately, while the other system components and their layout remain unchanged. This design gives the system a high degree of inclusiveness and flexibility. When configured with a regenerator, the system's key component connections enable heat exchange between the high-pressure refrigerant at the heat exchanger outlet and the low-temperature refrigerant returning from the gas-liquid separator in both cooling and heating modes, improving circulation efficiency.

[0019] 5. By placing the four-way reversing valve on the compressor exhaust line behind the throttle valve and connecting key components with a multi-way valve, this invention achieves a system-integrated design for both cooling and heating modes. In both cooling and heating modes, the system shares components such as the gas-liquid separator, throttle valve, multi-way valve, and piping. Simply adjusting the multi-way valve switches the system operating mode, eliminating the need for additional piping, valves, or other components. This achieves high-efficiency dual cooling and heating while maintaining a simple, compact, and low-cost structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 Schematic diagram of a carbon dioxide air conditioning heat pump system with an integrated multi-way valve provided in an embodiment of the present invention;

[0021] Figure 2 yes Figure 1 The communication state between the disc-shaped multi-way valve and its interface of the air conditioning heat pump system in the cooling mode, at which time the valve core of the multi-way valve is in the first working position;

[0022] Figure 3 yes Figure 1 The communication state between the disc-shaped multi-way valve and its interface of the air conditioning heat pump system in the heating mode, at which time the valve core of the multi-way valve is in the second working position;

[0023] Figure 4 Schematic diagram of a carbon dioxide air-conditioning heat pump system with an integrated multi-way valve provided in another embodiment of the present invention.

[0024] In all the drawings, the same figure numbers are used to represent the same elements or structures, including: 1-compressor, 2-gas-liquid separator, 3-throttle valve, 4-four-way reversing valve, 5-outdoor heat exchanger, 6-regenerator, 7-ejector, 8-multi-way valve, A-first interface, B-second interface, C-third interface, D-fourth interface, E-fifth interface, F-sixth interface, G-seventh interface, H-eighth interface, 9-first indoor heat exchanger, 10-second indoor heat exchanger, 11-fan. DETAILED DESCRIPTION

[0025] In order to make the objectives, technical solutions, and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

[0026] Among technical solutions for improving system energy efficiency, ejectors have garnered widespread attention in the refrigeration and air-conditioning sector due to their simple structure, reliable operation, and good economic efficiency. Research has shown that integrating ejectors into CO2 transcritical cycles can significantly improve performance. Under cooling conditions, the use of ejectors effectively recovers expansion work, reducing the compressor's pressure ratio and thereby improving the system's coefficient of performance. Under heating conditions, the use of high-pressure-side energy to eject low-temperature refrigerant from the evaporator can increase the compressor's suction pressure, which has a positive effect on improving the system's high-pressure ratio operation in low-temperature environments.

[0027] See also Figure 1 The present invention provides a carbon dioxide air-conditioning heat pump system with an integrated multi-way valve. The system realizes the conversion between cooling mode and heating mode by adjusting the multi-way valve. In cooling mode, it operates as a dual-temperature injection expansion refrigeration cycle, and in heating mode, it operates as a dual-air cooler injection boost heat pump, thereby realizing synergistic energy efficiency improvement in both cooling and heating modes.

[0028] The system uses environmentally friendly carbon dioxide as a refrigerant and utilizes a multi-way valve 8 to switch the refrigerant flow direction, achieving dual operating modes of jet expansion refrigeration and jet boost heat pump. The system includes a compressor 1, a gas-liquid separator 2, a throttle valve 3, a four-way reversing valve 4, an outdoor heat exchanger 5, a regenerator 6, an ejector 7, a multi-way valve 8, a first indoor heat exchanger 9, a second indoor heat exchanger 10, and a fan 11. The multi-way valve 8 is an eight-way valve with eight ports evenly arranged around its central axis: a first port A, a second port B, a third port C, a fourth port D, a fifth port E, a sixth port F, a seventh port G, and an eighth port H.

[0029] The first interface A is connected to the outlet of the ejector 7. The second interface B is connected to the inlet of the gas-liquid separator 2. The third interface C is connected to the outlet of the first indoor heat exchanger 9. The fourth interface D is connected to the first inlet of the regenerator 6. The fifth interface E is connected to the outlet of the outdoor heat exchanger 5. The sixth interface F is connected to the second inlet of the ejector 7. The seventh interface G is connected to the outlet of the second indoor heat exchanger. The eighth interface H is connected to the inlet of the first indoor heat exchanger. By adjusting the valve core of the multi-way valve 8 to change the connection state between the interfaces of the multi-way valve 8, the refrigerant flow direction is changed, thereby realizing the switching of the system between the cooling mode and the heating mode.

[0030] The four valve ports of the four-way valve are respectively connected to the inlet of the second indoor heat exchanger 10, the outlet of the throttle valve 3, the exhaust port of the compressor 1, and the inlet of the outdoor heat exchanger 5. The inlet of the throttle valve 3 is connected to the liquid outlet of the gas-liquid separator 2. The gas outlet of the gas-liquid separator 2 is connected to the second inlet of the regenerator 6; the second outlet of the regenerator 6 is connected to the intake port of the compressor 1. The first inlet of the regenerator 6 is connected to its first outlet, and the corresponding second inlet is connected to the second outlet.

[0031] The fan 11 is provided on one side of the outdoor heat exchanger 5 and one side of the second indoor heat exchanger 10. In one embodiment, the multi-way valve 8 can be implemented as a single eight-way valve, or a combination of multiple control valves can be used to achieve the same function, including but not limited to a combination of eight solenoid valves, a combination of four four-way reversing valves, etc. When the multi-way valve is an eight-way valve, the structure of the eight-way valve can be a disc structure or other structures. When the multi-way valve is an eight-way valve, the control method of the eight-way valve can be electric control or pressure differential control.

[0032] See also Figure 2 In the cooling mode, the valve core of the eight-way valve is in the first working position. In this cooling mode, the first port A is connected to the eighth port H, the second port B is connected to the third port C, the fourth port D is connected to the fifth port E, and the sixth port F is connected to the seventh port G. The flow direction of the refrigerant is as follows: Figure 2 As shown by the arrow in .

[0033] See also Figure 3 In heating mode, the valve core of the eight-way valve is in the second working position. In this heating mode, the first port A is connected to the second port B, the third port C is connected to the fourth port D, the fifth port E is connected to the sixth port F, and the seventh port G is connected to the eighth port H. The flow direction of the refrigerant is as follows: Figure 3 As shown by the arrow in .

[0034] The system is equipped with the multi-way valve 8 as a refrigerant flow direction switching mechanism, which realizes the conversion between the cooling mode and the heating mode by switching the refrigerant flow direction. In the cooling mode, the valve core is in the first working position, establishing the flow path connection relationship of A→H, C→B, E→D and G→F, so that the system operates according to the refrigeration cycle; when the valve core is in the second working position, the flow path connection relationship becomes A→B, C→D, E→F and G→H accordingly, and the system switches to the heating cycle operation.

[0035] In cooling mode, the four-way reversing valve 4 connects the exhaust port of the compressor 1 with the inlet of the outdoor heat exchanger 5, and the four-way reversing valve 4 connects the outlet of the throttle valve 3 with the inlet of the second indoor heat exchanger 10. The first interface A is connected to the eighth interface H, the second interface B is connected to the third interface C, the fourth interface D is connected to the fifth interface E, and the sixth interface F is connected to the seventh interface G. The compressor 1 compresses the refrigerant to high temperature and high pressure and then enters the outdoor heat exchanger 5 after passing through the four-way reversing valve 4. The refrigerant in the indoor After cooling, the external heat exchanger 5 flows from the fifth port E to the fourth port D, and then enters the regenerator 6. After heat exchange with the returning low-temperature refrigerant gas in the regenerator 6, the refrigerant enters the first inlet of the ejector 7. The high-pressure refrigerant, acting as the motive fluid, enters the ejector 7 from the first inlet and is ejected, forming a first pressure and a second pressure at the outlet and second inlet of the ejector 7, respectively. The first pressure is higher than the second pressure, and both the first pressure and the second pressure are lower than the pressure of the high-pressure gas at the first inlet of the ejector 7. The refrigerant vapor at the outlet of the second indoor heat exchanger 10, at the second pressure, flows from the seventh port G to the sixth port F, and then enters the ejector 7 through the second inlet to mix with the motive fluid refrigerant. The resulting mixed refrigerant is raised to the first pressure and then flows out of the outlet of the ejector 7. The refrigerant at the first pressure at the outlet of the ejector 7 flows through the first port A of the multi-way valve 8 to the eighth port H, and then enters the first indoor heat exchanger 9 for evaporation and heat absorption. The refrigerant at the outlet of the first indoor heat exchanger 9 passes through the first inlet. The three interfaces C flow to the second interface B, and then enter the gas-liquid separator 2. The refrigerant liquid in the gas-liquid separator 2 that cannot be completely evaporated in the first indoor heat exchanger 9 is separated from the gas and liquid and flows out from the liquid outlet of the gas-liquid separator 2. After throttling, reducing pressure and cooling by the throttle valve 3, it enters the second indoor heat exchanger 10 through the four-way reversing valve 4 to evaporate and absorb heat, and then is sucked into the second inlet of the ejector 7 through the multi-way valve 8. The refrigerant vapor at the gas outlet of the gas-liquid separator 2 further absorbs heat through the regenerator 6 and enters the intake port of the compressor 1, completing the refrigeration cycle.

[0036] In the heating mode, the four-way reversing valve 4 connects the exhaust port of the compressor 1 with the inlet of the second indoor heat exchanger 10, and the four-way reversing valve 4 connects the outlet of the throttle valve 3 with the inlet of the outdoor heat exchanger 5. The first interface A of the multi-way valve 8 is connected to the second interface B, the third interface C is connected to the fourth interface D, the fifth interface E is connected to the sixth interface F, and the seventh interface G is connected to the eighth interface H. The compressor 1 compresses the refrigerant to high temperature and high pressure and then enters the second indoor heat exchanger 10 through the four-way reversing valve 4 for heating. Heat release, after the fluid flows out of the second indoor heat exchanger 10, it flows to the eighth port H through the seventh port G of the multi-way valve 8, and then enters the first indoor heat exchanger 9 for further heat release. The fluid flowing out of the first indoor heat exchanger 9 flows to the fourth port D through the third port C of the multi-way valve 8, and then flows into the regenerator 6, exchanges heat with the returning low-temperature refrigerant gas, and then enters the first inlet of the ejector 7. The high-pressure refrigerant is used as the motive fluid and enters the ejector 7 from the first inlet. After being ejected, the first pressure and the second pressure are formed at the outlet and the second inlet of the ejector 7 respectively, wherein the first pressure is higher than the second pressure, and the first pressure and the second pressure are both lower than the pressure of the high-pressure gas at the first inlet of the ejector 7. The refrigerant at the outlet of the outdoor heat exchanger 5 with a pressure of the second pressure flows from the fifth port E to the sixth port F, and then enters the ejector 7 through the second inlet of the ejector 7 to mix with the motive fluid refrigerant. The pressure of the mixed refrigerant is increased to the first pressure and then flows out from the outlet of the ejector 7. The refrigerant at the outlet of the ejector 7 with a pressure of the first pressure passes through the multi-way valve 8. The first interface A flows to the second interface B, and then enters the gas-liquid separator 2. After gas-liquid separation, the refrigerant liquid flows out from the liquid outlet of the gas-liquid separator 2, enters the four-way reversing valve 4 after throttling, reducing pressure and cooling by the throttle valve 3, and then enters the outdoor heat exchanger 5. The low-temperature and low-pressure refrigerant absorbs heat and evaporates in the outdoor heat exchanger 5, and is sucked into the second inlet of the ejector 7 through the multi-way valve 8. The refrigerant vapor at the gas outlet of the gas-liquid separator 2 further absorbs heat through the regenerator 6 and enters the intake port of the compressor 1, completing the heating cycle.

[0037] In cooling mode, the two indoor heat exchangers realize independent air dry cooling and dehumidification, and the ejector 7 recovers expansion work at the same time; in heating mode, the high-temperature and high-pressure refrigerant enters the second indoor heat exchanger 10 and the first indoor heat exchanger 9 in sequence to cool down and release heat, while the indoor air is heated and heated in sequence through the first indoor heat exchanger 9 and the second indoor heat exchanger 10, realizing countercurrent heat exchange between the refrigerant and the air, effectively improving the heating capacity. At the same time, the ejector 7 recovers the pressure energy of the high-pressure refrigerant flowing out of the first indoor heat exchanger 9, and inhales the refrigerant with a pressure of the second pressure flowing out of the outdoor heat exchanger 5, and flows out from the outlet of the ejector 7 after mixing and pressurizing, thereby increasing the suction pressure of the compressor 1, reducing the power consumption of the compressor 1, and achieving efficient heating.

[0038] The system is equipped with a regenerator 6. Under cooling conditions, the regenerator 6 exchanges heat between the high-pressure refrigerant at the outlet of the outdoor heat exchanger 5 and the low-temperature refrigerant refluxed from the gas-liquid separator 2, thereby further cooling the power fluid at the inlet of the ejector 7. Under heating conditions, the regenerator 6 exchanges heat between the high-pressure refrigerant at the outlet of the first indoor heat exchanger 9 and the low-temperature refrigerant refluxed from the gas-liquid separator 2, thereby improving the circulation efficiency.

[0039] The system is equipped with ejectors 7 for both cooling and heating modes. These ejectors 7 can be a single ejector 7 or multiple ejectors 7 arranged in parallel, i.e., an ejector group. The specific configuration should be designed based on actual application requirements and space costs. In cooling mode, ejectors 7 recover the expansion work of the high-pressure refrigerant at the outlet of outdoor heat exchanger 5, improving the system's cooling efficiency. In heating mode, ejectors 7 increase the suction pressure of compressor 1 by ejecting refrigerant from the outlet of outdoor heat exchanger 5, reducing compression power consumption and improving the system's heating performance.

[0040] See also Figure 4 Another embodiment of the present invention provides a carbon dioxide air conditioning heat pump system with an integrated multi-way valve, relative to Figure 1 The carbon dioxide air conditioning heat pump system shown is basically the same, except that the regenerator 6 is not configured, so the fourth interface D of the multi-way valve 8 is connected to the first inlet of the ejector 7, and the gas outlet of the gas-liquid separator 2 is directly connected to the air intake of the compressor 1.

[0041] Specifically, the system includes a compressor 1, a gas-liquid separator 2, a throttle valve 3, a four-way reversing valve 4, an outdoor heat exchanger 5, an ejector 7, a multi-way valve 8, a first indoor heat exchanger 9, a second indoor heat exchanger 10 and a fan 11. The multi-way valve 8 has eight interfaces, and the first interface A to the eighth interface H are numbered A to H respectively. The first interface A of the multi-way valve 8 is connected to the outlet of the ejector 7, the second interface B of the multi-way valve 8 is connected to the inlet of the gas-liquid separator 2, the third interface C of the multi-way valve 8 is connected to the outlet of the first indoor heat exchanger 9, and the multi-way valve 8 has eight interfaces. The fourth interface D of the valve 8 is connected to the first inlet of the ejector 7, the fifth interface E of the multi-way valve 8 is connected to the outlet of the outdoor heat exchanger 5, the sixth interface F of the multi-way valve 8 is connected to the second inlet of the ejector 7, the seventh interface G of the multi-way valve 8 is connected to the outlet of the second indoor heat exchanger 10, and the eighth interface H of the multi-way valve 8 is connected to the inlet of the first indoor heat exchanger 9. By adjusting the multi-way valve 8 to change the flow direction of the refrigerant, the system can be switched between cooling mode and heating mode. The system uses carbon dioxide (R744) as the refrigerant.

[0042] In the cooling mode, the four-way reversing valve 4 connects the exhaust port of the compressor 1 with the inlet of the outdoor heat exchanger 5, and the four-way reversing valve 4 connects the outlet of the throttle valve 3 with the inlet of the second indoor heat exchanger 10. The first port A of the multi-way valve 8 is connected to the eighth port H, the second port B is connected to the third port C, the fourth port D is connected to the fifth port E, and the sixth port F is connected to the seventh port G. The compressor 1 compresses the refrigerant to high temperature and high pressure and then enters the outdoor heat exchanger 5 after passing through the four-way reversing valve 4. After cooling the outdoor heat exchanger 5, the refrigerant flows from the fifth port E of the multi-way valve 8 to the fourth port D, and then enters the first inlet of the ejector 7. After the high-pressure refrigerant enters the ejector 7 from the first inlet as a motive fluid and is ejected, a first pressure and a second pressure are formed at the outlet and the second inlet of the ejector 7, respectively, wherein the first pressure is higher than the second pressure, and both the first pressure and the second pressure are lower than the high-pressure gas pressure at the inlet of the ejector 7. The refrigerant vapor at the outlet of the second indoor heat exchanger 10 with a pressure of the second pressure is discharged by the The seventh port G of the multi-way valve 8 flows to the sixth port F, and then enters the ejector 7 through the second inlet of the ejector 7 to mix with the power fluid refrigerant. The pressure of the mixed refrigerant is increased to the first pressure and then flows out from the outlet of the ejector 7. The refrigerant at the outlet of the ejector 7 with a pressure of the first pressure flows to the eighth port H through the first port A of the multi-way valve 8, and then enters the first indoor heat exchanger 9 for evaporation and heat absorption and refrigeration. The refrigerant coming out of the outlet of the first indoor heat exchanger 9 flows to the second port C of the multi-way valve 8. Port B, and then enters the gas-liquid separator 2. In the gas-liquid separator 2, the refrigerant liquid that has not been completely evaporated in the first indoor heat exchanger 9 is separated from the gas and liquid and flows out from the liquid outlet of the gas-liquid separator 2. After throttling, reducing pressure and cooling by the throttle valve 3, it enters the second indoor heat exchanger 10 through the four-way reversing valve 4 to evaporate and absorb heat, and then passes through the multi-way valve 8 to be sucked into the second inlet of the ejector 7. The refrigerant vapor coming out of the gas outlet of the gas-liquid separator 2 directly enters the compressor suction port, completing the refrigeration cycle.

[0043] In the heating mode, the four-way reversing valve 4 connects the exhaust port of the compressor with the inlet of the second indoor heat exchanger 10, and the four-way reversing valve 4 connects the outlet of the throttle valve 3 with the inlet of the outdoor heat exchanger 5. The first port A of the multi-way valve 8 is connected to the second port B, the third port C is connected to the fourth port D, the fifth port E is connected to the sixth port F, and the seventh port G is connected to the eighth port H. The compressor compresses the refrigerant to a high temperature and high pressure, and then enters the second indoor heat exchanger 10 through the four-way reversing valve 4 to release heat. After flowing out of the second indoor heat exchanger 10, the fluid flows through the seventh port G of the multi-way valve 8 to the eighth port H, and then enters the first indoor heat exchanger 9 for further heat release. The fluid flowing out of the first indoor heat exchanger 9 flows through the third port C of the multi-way valve 8 to the fourth port D, and then flows into the first inlet of the ejector 7. After the high-pressure refrigerant is ejected from the first inlet into the ejector 7 as the motive fluid, a first pressure and a second pressure are formed at the outlet and the second inlet of the ejector 7, respectively. The first pressure is higher than the second pressure, and both the first pressure and the second pressure are lower than the pressure of the high-pressure gas at the inlet of the ejector 7. The refrigerant at the outlet of the outdoor heat exchanger 5 with a pressure of the second pressure flows from the fifth port E of the multi-way valve 8 to the sixth port F, and then enters the ejector 7 through the second inlet of the ejector 7 to mix with the power fluid refrigerant. The pressure of the mixed refrigerant is increased to the first pressure and then flows out from the outlet of the ejector 7. The refrigerant at the outlet of the ejector 7 with a pressure of the first pressure flows through the first port A of the multi-way valve 8 to the second port B, and then enters the gas-liquid separator 2. After gas-liquid separation, the refrigerant liquid flows out from the liquid outlet of the gas-liquid separator 2, is throttled, reduced in pressure and temperature by the throttle valve 3, enters the four-way reversing valve 4, and then enters the outdoor heat exchanger 5. The low-temperature and low-pressure refrigerant absorbs heat and evaporates in the outdoor heat exchanger 5, and is then sucked into the second inlet of the ejector 7 through the multi-way valve 8. The refrigerant vapor coming out of the gas outlet of the gas-liquid separator 2 directly enters the intake port of the compressor, completing the heating cycle.

[0044] The present invention is further described in detail below with reference to specific application examples.

[0045] (1) Environmental parameters of the air conditioner under cooling conditions: indoor dry-bulb temperature is 27°C, wet-bulb temperature is 19°C, and outdoor dry-bulb temperature is 35°C. Basic performance parameters of the air conditioner: refrigerant is R744 (carbon dioxide), the outlet temperature of the outdoor heat exchanger 5 is 40°C, the outlet temperature of the hot fluid of the regenerator 6 is 38°C (the system is equipped with a regenerator 6, if not equipped with a regenerator 6, this condition will not apply), the evaporation temperature of the first indoor heat exchanger 9 (medium temperature / cooling evaporator) is 18°C, the evaporation temperature of the second indoor heat exchanger 10 (low temperature / dehumidification evaporator) is 10°C, the outlet of the dehumidification evaporator is saturated steam, and the compressor displacement is 0.0003m3 / s, the compressor isentropic efficiency is 0.85, the compressor exhaust pressure is 10MPa, the compressor electrical efficiency is 0.92, and the compressor friction efficiency is 0.92.

[0046] a. Specific operating parameters of the high-efficiency carbon dioxide air-conditioning heat pump system with an integrated multi-way valve and a heat regenerator according to the present invention under the above-mentioned refrigeration conditions: the evaporation pressure of the first indoor heat exchanger 9 is 5.46 MPa, the suction temperature of the compressor is 21.1°C, the refrigerant is sucked into the compressor and compressed to 10 MPa, and the exhaust temperature is 68.6°C. The exhaust enters the outdoor heat exchanger 5 and is cooled to 40°C. It is further cooled to 38°C by the heat regenerator 6 and then enters the ejector 7. The pressure at the second inlet of the ejector 7 connected to the second indoor evaporator is 4.5 MPa, and the outlet pressure of the ejector 7 is The pressure is 5.46 MPa, the evaporating temperature of the first indoor heat exchanger 9 (cooling evaporator) is 18°C, the cooling capacity is 2.68 kW, the evaporating temperature of the second indoor heat exchanger 10 (dehumidification evaporator) is 10°C, the dehumidification capacity is 2.75 kW, the refrigerant flow rate at the first inlet of the ejector 7 is 0.0497 kg / s, the ejection coefficient of the ejector 7 is 0.318, the power consumption of the compressor is 1.488 kW, the heat load of the outdoor heat exchanger 5 is 6.69 kW, the heat load of the regenerator 6 is 0.52 kW, and the refrigeration coefficient of the cycle is 3.65.

[0047] b. The specific operating parameters of the high-efficiency carbon dioxide air-conditioning heat pump system with an integrated multi-way valve without a heat regenerator under the above-mentioned refrigeration conditions of the present invention are as follows: the evaporation pressure of the first indoor heat exchanger 9 is 5.46 MPa, the suction temperature of the compressor is 18°C, the refrigerant is sucked into the compressor and compressed to 10 MPa, the exhaust temperature is 63.6°C, the exhaust enters the outdoor heat exchanger 5 and is cooled to 40°C, the pressure at the second inlet of the ejector 7 connected to the second indoor evaporator is 4.5 MPa, and the outlet pressure of the ejector 7 is 5.4 6MPa, the evaporating temperature of the first indoor heat exchanger 9 (cooling evaporator) is 18°C, the cooling capacity is 2.61kW, the evaporating temperature of the second indoor heat exchanger 10 (dehumidification evaporator) is 10°C, the dehumidification capacity is 2.7kW, the refrigerant flow rate at the first inlet of the ejector 7 is 0.0539kg / s, the ejection coefficient of the ejector 7 is 0.289, the power consumption of the compressor is 1.49kW, the heat load of the outdoor heat exchanger 5 is 6.58kW, and the cooling coefficient of the cycle is 3.57.

[0048] (2) Environmental parameters of the air conditioner under heating conditions: indoor dry bulb temperature is 20℃, outdoor dry bulb temperature is 7℃. Basic performance parameters of the air conditioner: refrigerant is R744 (carbon dioxide), evaporation temperature of outdoor heat exchanger 5 is -1℃, outlet of outdoor heat exchanger 5 is saturated steam, subcooling degree of regenerator 6 is 2℃ (the system is equipped with regenerator 6, if not equipped with regenerator 6, this condition will not be met), compressor displacement is 0.0003m 3 / s, the compressor isentropic efficiency is 0.85, the compressor exhaust pressure is 7.5MPa, the compressor electrical efficiency is 0.92, and the compressor mechanical efficiency is 0.92.

[0049] a. The specific operating parameters of the high-efficiency carbon dioxide air-conditioning heat pump system with an integrated multi-way valve and a heat regenerator of the present invention under the above-mentioned heating conditions are as follows: the evaporation pressure of the outdoor heat exchanger 5 is 3.39 MPa, the compressor suction temperature is 8.81°C, the refrigerant is sucked into the compressor and compressed to 7.5 MPa, and the exhaust temperature is 64.91°C. The exhaust gas enters the first indoor heat exchanger 9 and the second indoor heat exchanger 10 and is cooled to 29.2°C. The refrigerant circulation rate is 0.0298 kg / s, the ejection coefficient of the ejector 7 is 0.687, the total heating capacity of the air-conditioning system is 5.586 kW, the heat absorption of the outdoor heat exchanger 5 is 4.589 kW, the compressor power consumption is 1.178 kW, and the cycle heating coefficient is 4.742.

[0050] b. The specific operating parameters of the high-efficiency carbon dioxide air-conditioning heat pump system with an integrated multi-way valve without a heat regenerator of the present invention under the above-mentioned heating conditions are as follows: the evaporation pressure of the outdoor heat exchanger 5 is 3.39 MPa, the compressor suction temperature is 3.8°C, the refrigerant is sucked into the compressor and compressed to 7.5 MPa, and the exhaust temperature is 56.2°C. The exhaust enters the first indoor heat exchanger 9 and the second indoor heat exchanger 10 and is cooled to 30.11°C. The refrigerant circulation volume is 0.033 kg / s, the ejection coefficient of the ejector 7 is 0.61, the total heating capacity of the air-conditioning system is 5.476 kW, the heat absorption of the outdoor heat exchanger 5 is 4.49 kW, the compressor power consumption is 1.163 kW, and the cycle heating coefficient is 4.709.

[0051] The cooling coefficient of the air conditioning system using carbon dioxide as a refrigerant is comparable to the performance coefficient of a Freon system. Furthermore, the heating coefficient of the air conditioning system can reach 4.709, demonstrating high heating efficiency.

[0052] It will be easily understood by those skilled in the art that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A carbon dioxide air conditioning heat pump system with an integrated multi-way valve, characterized by: The system includes a multi-way valve, an ejector, a first indoor heat exchanger, a second indoor heat exchanger, a gas-liquid separator, an outdoor heat exchanger, a compressor, a throttle valve and a four-way reversing valve, wherein the four valve ports of the four-way reversing valve are respectively connected to the inlet of the outdoor heat exchanger, the exhaust port of the compressor, the outlet of the throttle valve and the inlet of the second indoor heat exchanger; the gas outlet of the gas-liquid separator is connected to the suction port of the compressor; the multi-way valve is an eight-way valve, which is provided with eight interfaces, namely, a first interface, a second interface, a third interface, a fourth interface, a fifth interface, a sixth interface, a seventh interface and an eighth interface; the first interface is connected to the outlet of the ejector; the second interface is connected to the inlet of the gas-liquid separator; the third interface is connected to the outlet of the first indoor heat exchanger; The fourth interface is connected to the first inlet of the ejector; the fifth interface is connected to the outlet of the outdoor heat exchanger; The sixth interface is connected to the second inlet of the ejector; the seventh interface is connected to the outlet of the second indoor heat exchanger; and the eighth interface is connected to the inlet of the first indoor heat exchanger; By adjusting the valve core of the multi-way valve to change the communication state between the interfaces of the multi-way valve, the refrigerant flow direction is changed, thereby achieving the switching of the system between the cooling mode and the heating mode.

2. The carbon dioxide air conditioning heat pump system with integrated multi-way valve according to claim 1, characterized in that: The system further includes a fan, and the fan is provided on one side of the outdoor heat exchanger and one side of the second indoor heat exchanger.

3. The carbon dioxide air conditioning heat pump system with integrated multi-way valve according to claim 1, characterized in that: The system also includes a regenerator, wherein the first outlet of the regenerator is connected to the first inlet of the ejector, and the first inlet of the regenerator is connected to the fourth interface of the multi-way valve; the second inlet of the regenerator is connected to the gas outlet of the gas-liquid separator, and the second outlet is connected to the suction port of the compressor; the first inlet of the regenerator is connected to the first outlet; the second inlet of the regenerator is connected to the second outlet.

4. The carbon dioxide air conditioning heat pump system with integrated multi-way valve according to claim 1, characterized in that: The system is equipped with ejectors for cooling and heating modes, and the ejectors are single ejectors or multiple ejectors arranged in parallel, i.e., ejector groups.

5. The carbon dioxide air conditioning heat pump system with integrated multi-way valve according to any one of claims 1 to 4, characterized in that: The refrigerant circulating in the system is carbon dioxide.

6. The carbon dioxide air conditioning heat pump system with integrated multi-way valve according to any one of claims 1 to 4, characterized in that: The multi-way valve is a single eight-way valve or a combination of several valves.

7. The carbon dioxide air conditioning heat pump system with integrated multi-way valve according to any one of claims 1 to 4, characterized in that: When the multi-way valve is an eight-way valve, the structure of the eight-way valve is a disc-shaped structure.

8. The carbon dioxide air conditioning heat pump system with integrated multi-way valve according to any one of claims 1 to 4, characterized in that: When the multi-way valve is an eight-way valve, the control mode of the eight-way valve is electric control or pressure difference control.

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