Non-azeotropic mixed working medium heat pump system and control method thereof

Abstract

The invention relates to the technical field of heat pumps, and discloses a non-azeotropic mixed working medium heat pump system and a control method thereof.The electric control valve set is used for controlling the heat pump system to operate in a first heat exchange mode or a second heat exchange mode; a refrigerant sequentially flows through the condenser, the first heat exchange channel, the second throttling device, the evaporator, the second heat exchange channel and an air return port of the compressor; when the heat pump system is in a second heat exchange mode, the refrigerant sequentially flows through the condenser, the first heat exchange channel, the first circulation branch and the second circulation branch, and the refrigerant on the first circulation branch sequentially flows through the second throttling device, the evaporator and an air return port of the compressor; a refrigerant on the second circulation branch sequentially flows through the third throttling device, the second heat exchange channel and an air supply opening of the compressor. The heat exchange mode of the heat pump system can be switched according to the change of the environment temperature, so that the overall energy consumption of the heat pump system is effectively reduced under the conditions that the heat pump system operates stably and meets the heating requirement.

Description

Technical Field

[0001] The present invention relates to the technical field of heat pumps, and particularly to azeotropic mixture refrigerant heat pump system and its control method. Background Art

[0002] With the development of technology and the improvement of people's living standards, heat pump technology has been increasingly widely used in the fields of home and industry. Since the temperature change range of the heat source and heat sink in the heat pump system is relatively large, it has become difficult for traditional single refrigerants to meet the usage requirements, such as heating at extremely low ambient temperatures in the building field. Azeotropic mixture refrigerants can flexibly select the refrigerant components and their proportions according to the application scenarios, increasing the temperature difference between the heat source and heat sink, so as to meet the large temperature difference requirements of specific application scenarios.

[0003] However, when applying azeotropic mixture refrigerants to traditional heat pump systems, it is impossible to balance the heating capacity and energy efficiency under low ambient temperature conditions. Therefore, there is room for improvement. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide an azeotropic mixture refrigerant heat pump system, which effectively solves the technical problems of poor heating performance and high energy consumption of the heat pump system.

[0005] The above technical problems are solved by the following technical solutions: An azeotropic mixture refrigerant heat pump system, comprising: A refrigerant circulation loop connected to the exhaust port and the suction port of the compressor to form a loop, and a condenser, a heat exchanger, a second throttling device, and an evaporator are sequentially arranged on the refrigerant circulation loop along the refrigerant flow direction; The heat exchanger has a first heat exchange channel and a second heat exchange channel for heat exchange with each other. The first heat exchange channel is connected between the outlet of the condenser and the inlet of the evaporator, and the second heat exchange channel is connected between the outlet of the evaporator and the suction port of the compressor; The heat pump system further includes a third throttling device, which is connected between the outlet of the first heat exchange channel and the inlet of the second heat exchange channel; The heat pump system includes an electronic control valve group for controlling the operation of the heat pump system in a first heat exchange mode or a second heat exchange mode; In the first heat exchange mode, the refrigerant flows through the condenser, the first heat exchange channel, the second throttling device, the evaporator, the second heat exchange channel, and the suction port of the compressor in sequence; In the second heat exchange mode, the refrigerant flows through the condenser and the first heat exchange channel in sequence. After flowing out from the outlet of the first heat exchange channel, the refrigerant flows along the first circulation branch and the second circulation branch respectively. On the first circulation branch, the refrigerant flows through the second throttling device, the evaporator, and the suction port of the compressor in sequence. On the second circulation branch, the refrigerant flows through the third throttling device, the second heat exchange channel, and the gas injection port of the compressor in sequence.

[0006] Compared with the background technology, the non-azeotropic mixture refrigerant heat pump system of the present invention has the following beneficial effects: In the first heat exchange mode, after the non-azeotropic mixture refrigerant (i.e., the refrigerant) is discharged from the outlet of the compressor, it enters the condenser for cooling. After cooling, the non-azeotropic mixture refrigerant is transmitted along the connecting pipeline into the first heat exchange channel of the heat exchanger for cooling; the cooled refrigerant passes through the second throttling device along the connecting pipeline for throttling, and then enters the evaporator. After heat exchange in the evaporator, the refrigerant mixture flows out from the outlet of the evaporator and then enters the second heat exchange channel of the heat exchanger to cool the refrigerant mixture flowing into the first heat exchange channel from the condenser. Subsequently, the refrigerant mixture is transmitted into the compressor through the suction port of the compressor.

[0007] In the second heat exchange mode, after the non-azeotropic mixture refrigerant is discharged from the outlet of the compressor, it enters the condenser for cooling. After cooling, the non-azeotropic mixture refrigerant is transmitted along the connecting pipeline into the first heat exchange channel of the heat exchanger for cooling; when the refrigerant flows out from the outlet of the first heat exchange channel, the refrigerant flows along the first circulation branch and the second circulation branch respectively; when the refrigerant flows along the first circulation branch, the refrigerant mixture passes through the second throttling device along the connecting pipeline for throttling, and then enters the evaporator. After heat exchange in the evaporator, the refrigerant mixture flows out from the outlet of the evaporator and is transmitted into the compressor through the suction port of the compressor; when the refrigerant flows along the second circulation branch, the refrigerant mixture passes through the third throttling device along the connecting pipeline for throttling, and the throttled refrigerant mixture is then transmitted into the second heat exchange channel of the heat exchanger to cool the refrigerant mixture flowing into the first heat exchange channel from the condenser. Subsequently, the refrigerant mixture is transmitted into the compressor through the gas injection port of the compressor.

[0008] The non-azeotropic mixture refrigerant heat pump system disclosed by the present invention can select different heat exchange modes according to the actual ambient temperature. When the ambient temperature is relatively high, the heat pump system is controlled to operate in the first heat exchange mode; during the refrigerant circulation process, the evaporator absorbs heat from the air, and together with the work done by the compressor, the two parts of energy are finally released as heat in the condenser, enabling the heat pump system to heat and raise the water temperature. Moreover, during the process of the non-azeotropic mixture refrigerant being transmitted from the outlet of the condenser to the inlet of the evaporator, the refrigerant mixture undergoes throttling and one-time regenerative heat exchange successively, resulting in a significant reduction in the throttling temperature difference from the condenser to the evaporator compared with the traditional heat pump system. Eventually, the throttling loss is greatly reduced, thereby improving the heating performance of the non-azeotropic mixture refrigerant heat pump system.

[0009] When the ambient temperature is relatively low, the compression ratio of the compressor increases, resulting in an increase in the exhaust temperature. Therefore, the heat pump system is controlled to operate in the second heat exchange mode. During the refrigerant circulation process, the mixed refrigerant flows through the third throttling device and then into the second heat exchange channel of the heat exchanger, and then flows into the gas injection port of the compressor to inject gas into the compressor, thereby reducing the compression ratio of the compressor to lower the compressor exhaust temperature, enabling the heat pump system to operate more stably and efficiently at low ambient temperatures. Moreover, the refrigerant in the first circulation branch and the refrigerant in the second circulation branch exchange heat in the heat exchanger, thereby effectively reducing the temperature of the mixed refrigerant flowing out of the first heat exchange channel, making the mixed refrigerant further subcooled before entering the evaporator, and thus effectively improving the heating effect of the heat pump system. It can meet the higher heating demand indoors under relatively low ambient temperatures. According to the change of the ambient temperature, the azeotropic mixture refrigerant heat pump system is controlled to switch between the first heat exchange mode and the second heat exchange mode, so that the heat pump system can effectively reduce the overall energy consumption of the heat pump system while operating stably and meeting the heating demand, thereby enhancing the user experience.

[0010] In one embodiment, it further includes: The first throttling device is connected between the outlet of the condenser and the inlet of the first heat exchange channel; the second throttling device is connected between the outlet of the first heat exchange channel and the inlet of the evaporator.

[0011] In one embodiment, the electronic control valve group includes a first electronic control valve, a second electronic control valve, and a fourth electronic control valve. The first electronic control valve is arranged between the outlet of the evaporator and the suction port of the compressor; the second electronic control valve is arranged between the outlet of the second heat exchange channel and the gas injection port of the compressor; the fourth electronic control valve is arranged between the outlet of the second heat exchange channel and the suction port of the compressor.

[0012] In one embodiment, the electronic control valve group further includes a third electronic control valve, and the third electronic control valve is connected between the outlet of the evaporator and the inlet of the second heat exchange channel.

[0013] In one embodiment, it further includes: A liquid receiver, which is provided with a refrigerant inlet, a first refrigerant outlet, and a second refrigerant outlet. The refrigerant inlet is connected to the first throttling device, the first refrigerant outlet is connected to the inlet of the first heat exchange channel, the second refrigerant outlet is connected to the inlet of the evaporator through a bypass pipeline, and a fifth electronic control valve is arranged on the bypass pipeline.

[0014] In one embodiment, the first throttling device, the second throttling device, and the third throttling device are all expansion valves.

[0015] In one embodiment, a gas-liquid separator is further provided on the refrigerant circulation loop. The inlet of the gas-liquid separator is respectively connected to the outlet of the second heat exchange channel and the outlet of the evaporator, and the outlet of the gas-liquid separator is connected to the suction port of the compressor.

[0016] In one embodiment, an evaporator fan is further included, and the evaporator fan is configured to drive air to flow through the evaporator.

[0017] On the other hand, the present invention further provides a control method for an azeotropic mixture refrigerant heat pump system, which is applied to the azeotropic mixture refrigerant heat pump system described above. The control method includes: Obtain the ambient temperature, and compare the ambient temperature with a first target temperature and a second target temperature respectively, where the first target temperature is greater than the second target temperature; When the ambient temperature is greater than or equal to the first target temperature, control the electric control valve group to act so that the heat pump system operates in the first heat exchange mode; When the ambient temperature is less than or equal to the second target temperature, control the electric control valve group to act so that the heat pump system operates in the second heat exchange mode.

[0018] Compared with the background art, the control method of the azeotropic mixture refrigerant heat pump system of the present invention has the beneficial effects as follows: The azeotropic mixture refrigerant heat pump system disclosed in the present invention can select different heat exchange modes according to the actual ambient temperature. When the ambient temperature is greater than or equal to the first target temperature, the heat pump system is controlled to operate in the first heat exchange mode by controlling the electric control valve group; the refrigerant flows through the condenser, the first heat exchange channel, the second throttling device, the evaporator, the second heat exchange channel, and the suction port of the compressor in sequence. During the refrigerant circulation process, the evaporator absorbs heat from the air, and together with the work done by the compressor, the two parts of energy are finally released in the condenser, so that the heat pump system heats up the water temperature. Moreover, when the azeotropic mixture refrigerant transfers from the outlet of the condenser to the inlet of the evaporator, the refrigerant mixture undergoes throttling and one-time heat regeneration successively, so that the throttling temperature difference from the condenser to the evaporator is greatly reduced compared with the traditional heat pump system, and finally the throttling loss is greatly reduced, thereby improving the heating performance of the azeotropic mixture refrigerant heat pump system.

[0019] When the ambient temperature is less than or equal to the second target temperature, the heat pump system is controlled to operate in the second heat exchange mode by controlling the electronic control valve group; the refrigerant flows through the condenser and the first heat exchange channel in sequence, and after the refrigerant flows out of the outlet of the first heat exchange channel, it flows along the first circulation branch and the second circulation branch respectively; wherein, on the first circulation branch, the refrigerant flows through the second throttling device, the evaporator and the suction port of the compressor in sequence, and on the second circulation branch, the refrigerant flows through the third throttling device, the second heat exchange channel and the gas injection port of the compressor in sequence. During the refrigerant circulation process, the mixed refrigerant flows into the second heat exchange channel of the heat exchanger after being throttled by the third throttling device, and then flows into the gas injection port of the compressor to inject gas into the compressor, thereby reducing the compressor pressure ratio to reduce the compressor exhaust temperature, so that the heat pump system operates more stably and efficiently at low ambient temperature, and the refrigerant on the first circulation branch exchanges heat with the refrigerant on the second circulation branch in the heat exchanger, thereby effectively reducing the temperature of the mixed refrigerant flowing out of the first heat exchange channel, making the mixed refrigerant further subcooled before entering the evaporator, so as to effectively improve the heating effect of the heat pump system, and can meet the higher heating demand in the room under the condition of lower ambient temperature. By switching the non-azeotropic mixed refrigerant heat pump system between the first heat exchange mode and the second heat exchange mode, the overall energy consumption of the heat pump system can be effectively reduced when the heat pump system operates stably and meets the heating demand, thereby improving the user experience.

[0020] In one embodiment, the electronic control valve group includes a first electronic control valve, a second electronic control valve, a third electronic control valve and a fourth electronic control valve. The first electronic control valve is arranged between the outlet of the evaporator and the suction port of the compressor; the second electronic control valve is arranged between the outlet of the second heat exchange channel and the gas injection port of the compressor; the third electronic control valve is connected between the outlet of the evaporator and the inlet of the second heat exchange channel; the fourth electronic control valve is arranged between the outlet of the second heat exchange channel and the suction port of the compressor; the heat pump system further includes a first throttling device connected between the outlet of the condenser and the inlet of the first heat exchange channel; The method further includes: When the heat pump system operates in the first heat exchange mode, control the first throttling device, the second throttling device, the third electronic control valve and the fourth electronic control valve to be in the open state, and control the third throttling device, the first electronic control valve and the second electronic control valve to be in the closed state; When the heat pump system operates in the second heat exchange mode, control the first throttling device, the second throttling device, the third throttling device, the first electronic control valve and the second electronic control valve to be in the open state, and control the third electronic control valve and the fourth electronic control valve to be in the closed state.

[0021] In one embodiment, the method further includes: When the ambient temperature is greater than the second target temperature and less than the first target temperature, control the heat pump system to operate in the current mode, where the current mode includes the first heat exchange mode and the second heat exchange mode.

[0022] In one embodiment, the heat pump system further includes a liquid accumulator and an evaporator fan for driving air to flow through the evaporator. The liquid accumulator is provided with a refrigerant inlet, a first refrigerant outlet, and a second refrigerant outlet. The refrigerant inlet is connected to the first throttling device, the first refrigerant outlet is connected to the inlet of the first heat exchange channel, the second refrigerant outlet is connected to the inlet of the evaporator through a bypass pipeline, and a fifth electric control valve is arranged on the bypass pipeline; The method further includes: Compare the ambient temperature with a third target temperature, where the third target temperature is less than the second target temperature; When the ambient temperature is less than the third target temperature, control the first electric control valve, the fifth electric control valve, and the first throttling device to be in an open state, and control the first throttling device to be opened to the maximum opening degree. Control the second throttling device, the third throttling device, the second electric control valve, the third electric control valve, the fourth electric control valve, and the evaporator fan to be in a closed state; When the ambient temperature is greater than or equal to the third target temperature, control the fifth electric control valve, the third electric control valve, and the fourth electric control valve to be in a closed state, and control the first throttling device, the second throttling device, the third throttling device, the first electric control valve, the second electric control valve, and the evaporator fan to be in an open state.

[0023] In one embodiment, the method further includes: In response to the heat pump system being in the defrost mode, detect the evaporator outlet temperature and compare the evaporator outlet temperature with a fourth target temperature; When the evaporator outlet temperature is greater than or equal to the fourth target temperature, control the evaporator fan, the first throttling device, the second throttling device, the third throttling device, the first electric control valve, and the second electric control valve to be opened, and control the fifth electric control valve, the third electric control valve, and the fourth electric control valve to be closed to switch to the second heat exchange mode; When the evaporator outlet temperature is less than the fourth target temperature, control the evaporator fan, the second throttling device, the third throttling device, the second electric control valve, the third electric control valve, and the fourth electric control valve to be in a closed state, and control the first electric control valve, the fifth electric control valve, and the first throttling device to be in an open state to maintain the defrost mode. Description of the Drawings

[0024] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0025] Figure 1 It is a schematic structural diagram of a non-azeotropic mixture refrigerant heat pump system according to an embodiment of the present invention; Figure 2 It is a schematic structural diagram of a non-azeotropic mixture refrigerant heat pump system according to another embodiment of the present invention; Figure 3 It is a schematic structural diagram of a non-azeotropic mixture refrigerant heat pump system according to another embodiment of the present invention; Figure 4 It is a schematic structural diagram of a non-azeotropic mixture refrigerant heat pump system according to another embodiment of the present invention; Figure 5 It is a schematic flow diagram of a control method for a non-azeotropic mixture refrigerant heat pump system according to an embodiment of the present invention; Figure 6 It is a schematic flow diagram of a control method for a non-azeotropic mixture refrigerant heat pump system according to another embodiment of the present invention; Figure 7 It is a schematic flow diagram of a control method for a non-azeotropic mixture refrigerant heat pump system according to another embodiment of the present invention; Figure 8 It is a schematic flow diagram of a control method for a non-azeotropic mixture refrigerant heat pump system according to another embodiment of the present invention; Figure 9 It is a schematic structural diagram of a non-azeotropic mixture refrigerant heat pump system according to another embodiment of the present invention.

[0026] Explanation of reference numerals: 1. Compressor; 2. Condenser; 3. First throttling device; 4. Liquid receiver; 41. Bypass pipeline; 42. Refrigerant inlet; 43. First refrigerant outlet; 44. Second refrigerant outlet; 5. Fifth electronic control valve; 6. Heat exchanger; 61. First heat exchange channel; 62. Second heat exchange channel; 7. Third throttling device; 8. Second throttling device; 9. Evaporator; 10. Fourth electronic control valve; 11. Third electronic control valve; 12. First electronic control valve; 13. Second electronic control valve; 14. Gas-liquid separator; 15. Evaporator fan. Specific embodiments

[0027] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0028] In the description of the present invention, it should be understood that the terms "first" and "second" are only used for descriptive purposes and cannot be construed as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, the features defined with "first" and "second" may explicitly or implicitly include one or more of such features. In the description of the present invention, unless otherwise specified, the meaning of "plurality" is two or more. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0029] According to an embodiment of the present invention, as Figures 1 to 3 shown, on the one hand, a zeotropic mixture refrigerant heat pump system is provided, including: a refrigerant circulation loop connected to the exhaust port and the suction port of the compressor 1 to form a loop, and a condenser 2, a heat exchanger 6, a second throttling device 8, and an evaporator 9 are sequentially arranged on the refrigerant circulation loop along the refrigerant flow direction; the heat exchanger 6 has a first heat exchange channel 61 and a second heat exchange channel 62 for heat exchange with each other, the first heat exchange channel 61 is connected between the outlet of the condenser 2 and the inlet of the evaporator 9, and the second heat exchange channel 62 is connected between the outlet of the evaporator 9 and the suction port of the compressor 1; the heat pump system further includes a third throttling device 7, and the third throttling device 7 is connected between the outlet of the first heat exchange channel 61 and the inlet of the second heat exchange channel 62; the heat pump system includes an electronic control valve group for controlling the operation of the heat pump system in a first heat exchange mode or a second heat exchange mode; in the first heat exchange mode, the refrigerant flows through the condenser 2, the first heat exchange channel 61, the second throttling device 8, the evaporator 9, the second heat exchange channel 62, and the suction port of the compressor 1 in sequence; in the second heat exchange mode, the refrigerant flows through the condenser 2 and the first heat exchange channel 61 in sequence. After flowing out from the outlet of the first heat exchange channel 61, the refrigerant flows along a first circulation branch and a second circulation branch respectively. On the first circulation branch, the refrigerant flows through the second throttling device 8, the evaporator 9, and the suction port of the compressor 1 in sequence, and on the second circulation branch, the refrigerant flows through the third throttling device 7, the second heat exchange channel 62, and the gas supplement port of the compressor 1 in sequence.

[0030] In this embodiment, the arrows in the figure indicate the refrigerant flow direction. The refrigerant can specifically adopt a zeotropic mixture refrigerant. The heat exchange modes of the zeotropic mixture refrigerant heat pump system provided by the embodiments of the present invention include a first heat exchange mode and a second heat exchange mode, and the operation of the heat pump system in different heat exchange modes can be specifically controlled according to the actual ambient temperature.

[0031] In the first heat exchange mode, specifically, the heating working principle is as follows: The compressor 1 compresses the low-pressure and low-temperature refrigerant gas into a high-pressure and high-temperature gas. The high-pressure and high-temperature refrigerant gas enters the condenser 2, where it exchanges heat with the medium to be heated (such as indoor air or water), transfers the heat to the indoor air or water to achieve the heating effect. After heat exchange, the temperature and pressure of the refrigerant itself decrease, and it becomes a high-pressure and low-temperature gas-liquid mixture. The zeotropic mixture is transported along the connecting pipeline to the first heat exchange channel 61 of the heat exchanger 6 for cooling; the cooled working medium is throttled by the second throttling device 8 along the connecting pipeline, further reducing the pressure and temperature of the refrigerant, so that the zeotropic mixture becomes a pure liquid state after throttling by the second throttling device 8, preparing for heat exchange in the evaporator 9. Then, the zeotropic mixture passing through the second throttling device 8 flows into the evaporator 9 along the connecting pipeline; the liquid working medium absorbs heat in the evaporator 9, then flows out from the outlet of the evaporator 9, and flows into the second heat exchange channel 62 along the connecting pipeline to cool the zeotropic mixture flowing into the first heat exchange channel 61 from the condenser 2. Subsequently, the zeotropic mixture is transported into the compressor 1 through the suction port of the compressor 1 and continues to circulate through the compressor 1.

[0032] During the refrigerant circulation process, the evaporator 9 absorbs heat from the air, and together with the work done by the compressor 1, the two parts of energy are finally released as heat in the condenser 2, enabling the heat pump system to heat and raise the water temperature. Moreover, during the process of the zeotropic mixture being transported from the outlet of the condenser 2 to the inlet of the evaporator 9, the zeotropic mixture undergoes throttling and once regenerative heat exchange, resulting in a significant reduction in the throttling temperature difference from the condenser 2 to the evaporator 9 compared to the traditional heat pump system. Eventually, the throttling loss is greatly reduced, thereby improving the heating performance of the zeotropic mixture heat pump system.

[0033] In the second heat exchange mode, specifically, the heating principle is as follows: The compressor 1 compresses the low-pressure and low-temperature refrigerant gas into a high-pressure and high-temperature gas. The high-pressure and high-temperature refrigerant gas enters the condenser 2, where it exchanges heat with the medium to be heated (such as indoor air or water), transferring heat to the indoor air or water to achieve the heating effect. After heat exchange, the temperature and pressure of the refrigerant itself decrease, becoming a high-pressure and low-temperature gas-liquid mixture. The zeotropic mixture is transported along the connecting pipeline into the first heat exchange channel 61 of the heat exchanger 6 for cooling. When the mixture flows out of the outlet of the first heat exchange channel 61, the mixture continues to flow along the first circulation branch and the second circulation branch respectively; when the mixture flows along the first circulation branch, the mixture passes through the second throttling device 8 along the connecting pipeline for throttling, further reducing the pressure and temperature of the refrigerant, so that the zeotropic mixture becomes a pure liquid state after throttling through the second throttling device 8, preparing for heat exchange in the evaporator 9. Then, the zeotropic mixture passing through the second throttling device 8 flows into the evaporator 9 along the connecting pipeline; the liquid refrigerant absorbs heat in the evaporator 9, then flows out of the outlet of the evaporator 9, and is transported into the compressor 1 through the suction port of the compressor 1. When the mixture flows along the second circulation branch, the mixture is transported along the connecting pipeline to the third throttling device 7 for throttling, and the throttled mixture is then transported to the second heat exchange channel 62 of the heat exchanger 6 to cool the mixture flowing into the first heat exchange channel 61 from the condenser 2. Subsequently, the mixture is transported into the compressor 1 through the gas supplement port of the compressor 1.

[0034] During the refrigerant circulation process, the zeotropic mixture flows into the second heat exchange channel 62 of the heat exchanger 6 after throttling through the third throttling device 7, and then flows into the gas supplement port of the compressor 1 to supplement gas to the compressor 1, thereby reducing the compression ratio of the compressor 1 to lower the exhaust temperature of the compressor 1, enabling the heat pump system to operate more stably and efficiently at low ambient temperatures. Moreover, the refrigerant in the first circulation branch exchanges heat with the refrigerant in the second circulation branch in the heat exchanger 6, thereby effectively reducing the temperature of the mixture flowing out of the first heat exchange channel 61, making the mixture further subcooled before entering the evaporator 9, and thus effectively improving the heating effect of the heat pump system, and can meet the higher heating demand indoors under lower ambient temperature conditions. According to the change of the ambient temperature, the zeotropic mixture heat pump system is controlled to switch between the first heat exchange mode and the second heat exchange mode, so that the heat pump system can effectively reduce the overall energy consumption of the heat pump system while operating stably and meeting the heating demand, thereby enhancing the user experience.

[0035] In one embodiment, it further includes: a first throttling device 3, and the first throttling device 3 is connected between the outlet of the condenser 2 and the inlet of the first heat exchange channel 61; a second throttling device 8 is connected between the outlet of the first heat exchange channel 61 and the inlet of the evaporator 9.

[0036] In this embodiment, one end of the first throttling device 3 is connected to the outlet of the condenser 2, and the other end is connected to the inlet of the first heat exchange channel 61. After the mixed refrigerant flows out of the condenser 2, the first throttling device 3 can throttle the mixed refrigerant to reduce the pressure of the mixed refrigerant. One end of the second throttling device 8 is connected to the outlet of the first heat exchange channel 61, and the other end is connected to the inlet of the evaporator 9. After the mixed refrigerant flows out of the first heat exchange channel 61, it can be throttled by the second throttling device 8 to further reduce the pressure and temperature of the mixed refrigerant, so that the mixed refrigerant becomes a pure liquid state after being throttled by the second throttling device 8, preparing for heat exchange in the evaporator 9.

[0037] In one embodiment, the electronic control valve group includes a first electronic control valve 12, a second electronic control valve 13, and a fourth electronic control valve 10. The first electronic control valve 12 is arranged between the outlet of the evaporator 9 and the suction port of the compressor 1; the second electronic control valve 13 is arranged between the outlet of the second heat exchange channel 62 and the gas supplement port of the compressor 1; the fourth electronic control valve 10 is arranged between the outlet of the second heat exchange channel 62 and the suction port of the compressor 1.

[0038] Further, the electronic control valve group includes a third electronic control valve 11, and the third electronic control valve 11 is connected between the outlet of the evaporator 9 and the inlet of the second heat exchange channel 62.

[0039] In this embodiment, through the cooperation of the first electronic control valve 12, the second electronic control valve 13, the third electronic control valve 11, and the fourth electronic control valve 10, the on-off of the refrigerant circulation circuit in the heat pump system can be controlled to change the heating operation mode of the heat pump system. When the third electronic control valve 11 and the fourth electronic control valve 10 are in the open state, the connecting pipelines between the outlet of the evaporator 9 and the inlet of the second heat exchange channel 62 and between the outlet of the second heat exchange channel 62 and the suction port of the compressor 1 are connected; when the first electronic control valve 12, the second electronic control valve 13, and the third throttling device 7 are in the closed state, the connecting pipelines between the outlet of the first heat exchange channel 61 and the inlet of the second heat exchange channel 62, between the outlet of the second heat exchange channel 62 and the gas supplement port of the compressor 1, and another connecting pipeline between the outlet of the evaporator 9 and the suction port of the compressor 1 are all in the disconnected state. At this time, the heat pump system is in the first heat exchange mode, and the refrigerant in the refrigerant circulation circuit is discharged from the exhaust port of the compressor 1 and then flows through the condenser 2, the first throttling device 3, the first heat exchange channel 61, the second throttling device 8, the evaporator 9, the third electronic control valve 11, the second heat exchange channel 62, the fourth electronic control valve 10, and the suction port of the compressor 1 in sequence.

[0040] When the third electronic control valve 11 and the fourth electronic control valve 10 are in the closed state, the connecting pipelines between the outlet of the evaporator 9 and the inlet of the second heat exchange channel 62, and between the outlet of the second heat exchange channel 62 and the suction port of the compressor 1 are disconnected; when the first electronic control valve 12, the second electronic control valve 13, and the third throttling device 7 are in the open state, the connecting pipelines between the outlet of the first heat exchange channel 61 and the inlet of the second heat exchange channel 62, between the outlet of the second heat exchange channel 62 and the gas supplement port of the compressor 1, and another connecting pipeline between the outlet of the evaporator 9 and the suction port of the compressor 1 are all in the connected state. At this time, the heat pump system is in the second heat exchange mode. The refrigerant in the refrigerant circulation loop is discharged from the discharge port of the compressor 1 and then flows through the condenser 2, the first throttling device 3, and the first heat exchange channel 61 in sequence. After the refrigerant flows out from the outlet of the first heat exchange channel 61, it flows along the first circulation branch and the second circulation branch respectively. On the first circulation branch, the refrigerant flows through the second throttling device 8, the evaporator 9, the first electronic control valve 12, and the suction port of the compressor 1 in sequence; at the same time, on the second circulation branch, the refrigerant flows through the third throttling device 7, the second heat exchange channel 62, the second electronic control valve 13, and the gas supplement port of the compressor 1 in sequence.

[0041] As Figure 4 shown, in one of the embodiments, it further includes: a liquid receiver 4. The liquid receiver 4 is provided with a refrigerant inlet 42, a first refrigerant outlet 43, and a second refrigerant outlet 44. The refrigerant inlet 42 is connected to the first throttling device 3, the first refrigerant outlet 43 is connected to the inlet of the first heat exchange channel 61, the second refrigerant outlet 44 is connected to the inlet of the evaporator 9 through a bypass pipeline 41, and a fifth electronic control valve 5 is provided on the bypass pipeline 41.

[0042] In this embodiment, due to the low ambient temperature, the evaporation capacity of the unit is weakened. Therefore, the evaporator 9 may frost in a low-temperature environment. When the non-azeotropic mixture heat pump system is in the defrosting mode, the fifth electronic control valve 5 is opened and the opening degree of the first throttling device 3 is maximized, and the second throttling device 8, the third throttling device 7, the second electronic control valve 13, the third electronic control valve 11, and the fourth electronic control valve 10 are all controlled to be in the closed state; the gaseous refrigerant in the non-azeotropic mixture heat pump system is then discharged through the second refrigerant outlet 44 and enters the bypass pipeline 41. Then, in the refrigerant circulation loop, the flow direction of the refrigerant in the compressor 1 is the condenser 2, the first throttling device 3, the liquid receiver 4, the fifth electronic control valve 5, the evaporator 9, the first electronic control valve 12, and the compressor 1.

[0043] The specific defrosting working principle is as follows: The compressor 1 compresses the low-pressure and low-temperature refrigerant gas into a high-pressure and high-temperature gas. The high-pressure and high-temperature refrigerant gas enters the condenser 2, where it exchanges heat with the medium to be heated, transferring heat to the indoor air or water to achieve the heating effect. After heat exchange, the temperature and pressure of the refrigerant itself decrease, becoming a high-pressure and low-temperature gas-liquid mixture. Most of the low-boiling-point refrigerant is in a gaseous state, and most of the high-boiling-point refrigerant is in a liquid state. The gas-liquid mixed refrigerant passes through the first throttling device 3. Since the opening of the first throttling device 3 is adjusted to the maximum, the throttling effect is poor and the temperature of the mixed refrigerant is little affected. The gas-liquid mixed refrigerant enters the liquid receiver 4 through the refrigerant inlet 42 and is separated; in the liquid receiver 4, most of the gaseous refrigerant is discharged from the second refrigerant outlet 44 of the liquid receiver 4 into the bypass pipeline 41 and is sent to the evaporator 9 for defrosting through the fifth electronic control valve 5, and then is sucked into the compressor 1 and continues to circulate through the compressor 1. Thus, a defrosting cycle is completed.

[0044] During the defrosting cycle, since the opening of the first throttling device 3 is adjusted to the maximum, the temperature and pressure of the azeotropic mixture are still relatively high and the temperature is relatively high after flowing through the first throttling device 3, and most of the low-boiling-point working fluid is in a gaseous state. When the gaseous refrigerant condenses in the evaporator 9, a large amount of heat is released for defrosting; according to the characteristics of the azeotropic mixture, the proportion of the low-boiling-point component in the gaseous working fluid is relatively large, that is, the proportion of the refrigerant component actually participating in the entire defrosting cycle is larger than that of the low-boiling-point component in the heating cycle. And since the density of the low-boiling-point working fluid is greater than that of the high-boiling-point working fluid, the high pressure of the working fluid and the mass flow rate increase during the defrosting cycle, and finally the compressor 1 does more work, that is, the condensation heat dissipation for defrosting of the evaporator 9 is greater, thus effectively improving the defrosting effect of the azeotropic mixture heat pump system.

[0045] Further, in the first heat exchange mode, the specific heat generation working principle is as follows: The compressor 1 compresses the low-pressure and low-temperature refrigerant gas into a high-pressure and high-temperature gas. The high-pressure and high-temperature refrigerant gas enters the condenser 2, where it exchanges heat with the medium to be heated (such as indoor air or water), transfers the heat to the indoor air or water to achieve the heat generation effect. Then, the gas-liquid mixture rapidly expands after throttling through the first throttling device 3, and then enters the liquid receiver 4 through the refrigerant inlet 42; the gas-liquid mixture continues to be discharged from the first refrigerant outlet 43 and flows along the connecting pipeline to the first heat exchange channel 61 of the heat exchanger 6 connected to the liquid receiver 4 to enter the first heat exchange channel 61 of the heat exchanger 6 for cooling; the cooled working medium is throttled through the second throttling device 8 along the connecting pipeline to further reduce the pressure and temperature of the refrigerant, so that the mixed working medium becomes a pure liquid state after throttling through the second throttling device 8, preparing for heat exchange in the evaporator 9. Then, the zeotropic mixture working medium passing through the second throttling device 8 flows into the evaporator 9 along the connecting pipeline; the liquid working medium absorbs heat in the evaporator 9, then flows out from the outlet of the evaporator 9, and flows along the connecting pipeline into the second heat exchange channel 62 to flow into the heat exchanger 6 and cool the mixed working medium coming out of the liquid receiver 4 in the heat exchanger 6; then the mixed working medium flows out from the second heat exchange channel 62 and is transmitted to the compressor 1 through the suction port of the compressor 1 and continues to circulate through the compressor 1.

[0046] In the second heat exchange mode, specifically, the heating working principle is as follows: The compressor 1 compresses the low-pressure and low-temperature refrigerant gas into a high-pressure and high-temperature gas. The high-pressure and high-temperature refrigerant gas enters the condenser 2, where it exchanges heat with the medium to be heated (such as indoor air or water), transfers the heat to the indoor air or water to achieve the heating effect. After heat exchange, the temperature and pressure of the refrigerant itself decrease. Then, the gas-liquid mixture rapidly expands after throttling through the first throttling device 3, and then enters the accumulator 4 through the refrigerant inlet 42; the gas-liquid mixture continues to be discharged from the first refrigerant outlet 43 and flows along the connecting pipeline to the first heat exchange channel 61 of the heat exchanger 6 connected to the accumulator 4 to enter the first heat exchange channel 61 of the heat exchanger 6 for cooling; the cooled working medium is throttled through the second throttling device 8 along the connecting pipeline, further reducing the pressure and temperature of the refrigerant, so that the mixed working medium becomes a pure liquid state after throttling through the second throttling device 8, preparing for heat exchange in the evaporator 9. Then, the zeotropic mixture working medium passing through the second throttling device 8 flows into the evaporator 9 along the connecting pipeline; the liquid working medium absorbs heat in the evaporator 9, then flows out from the outlet of the evaporator 9, and is transmitted to the compressor 1 through the suction port of the compressor 1. At the same time, after flowing out from the outlet of the first heat exchange channel 61, the mixed working medium is also transmitted to the third throttling device 7 through the connecting pipeline for throttling, and the throttled mixed working medium is then transmitted to the second heat exchange channel 62 of the heat exchanger 6 to flow into the heat exchanger 6 and cool the mixed working medium coming out from the accumulator 4 in the heat exchanger 6; then the mixed working medium flows out from the second heat exchange channel 62 and is transmitted to the compressor 1 through the gas injection port of the compressor 1.

[0047] In one embodiment, the first throttling device 3, the second throttling device 8, and the third throttling device 7 are all expansion valves. The first throttling device 3, the second throttling device 8, and the third throttling device 7 are respectively electrically connected to the controller, and the controller controls the start and stop of the first throttling device 3, the second throttling device 8, and the third throttling device 7, and controls the opening degrees of the first throttling device 3, the second throttling device 8, and the third throttling device 7 according to the operating requirements of different working conditions to control the refrigerant flow rate.

[0048] In one embodiment, a gas-liquid separator 14 is further provided on the refrigerant circulation loop. The inlet of the gas-liquid separator 14 is respectively connected to the outlet of the second heat exchange channel 62 and the outlet of the evaporator 9, and the outlet of the gas-liquid separator 14 is connected to the suction port of the compressor 1.

[0049] In this embodiment, the gas-liquid separator 14 can separate the liquid refrigerant in the zeotropic mixture refrigerant returning from the heat exchanger 6 or the evaporator 9, preventing the liquid refrigerant from directly entering the compressor 1. If the liquid refrigerant enters the compressor 1, it may cause liquid hammer. That is, when the liquid is compressed in the compressor 1, due to the incompressibility of the liquid, a huge impact force will be generated on the components of the compressor 1, resulting in damage to components such as the valve plate and piston of the compressor 1. In severe cases, the compressor 1 may even be scrapped. Moreover, by separating the gas and liquid, the flow rate of the gaseous refrigerant entering the compressor 1 becomes more stable and uniform, which helps the compressor 1 work more efficiently, thereby improving the performance and energy efficiency ratio of the entire heat pump system.

[0050] In one embodiment, an evaporator fan 15 is further included, and the evaporator fan 15 is used to drive air to flow through the evaporator 9.

[0051] In this embodiment, the evaporator fan 15 is used to promote air flow, enabling the air to continuously and evenly flow through the surface of the evaporator 9, accelerating the heat transfer between the air and the evaporator 9. Moreover, by evenly supplying air, the evaporator fan 15 helps to keep the temperature on the surface of the evaporator 9 uniform, reducing the possibility of frosting or making the frosting more uniform, thereby extending the effective working time of the evaporator 9, reducing the defrosting frequency, and improving the overall operating efficiency of the zeotropic mixture refrigerant heat pump system.

[0052] On the other hand, as Figure 5 shown, the present invention also provides a control method for a zeotropic mixture refrigerant heat pump system, which is applied to a zeotropic mixture refrigerant heat pump system. The control method includes the following steps: Step S100: Obtain the ambient temperature, and compare the ambient temperature with a first target temperature and a second target temperature respectively, where the first target temperature is greater than the second target temperature; Step S200: When the ambient temperature is greater than or equal to the first target temperature, control the electric control valve group to act so that the heat pump system operates in a first heat exchange mode; Step S300: When the ambient temperature is less than or equal to the second target temperature, control the electric control valve group to act so that the heat pump system operates in a second heat exchange mode.

[0053] In this embodiment, the non-azeotropic mixture refrigerant heat pump system disclosed by the present invention can select different heat exchange modes according to the actual ambient temperature. When the ambient temperature is greater than or equal to the first target temperature, the heat pump system is controlled to operate in the first heat exchange mode by controlling the electronic control valve group; the refrigerant flows through the condenser 2, the first heat exchange channel 61, the second throttling device 8, the evaporator 9, the second heat exchange channel 62 and the suction port of the compressor 1 in sequence. During the refrigerant circulation process, the evaporator 9 absorbs the heat in the air, and together with the work done by the compressor 1, the two parts of energy are finally released in the condenser 2, so that the heat pump system heats up the water temperature. Moreover, during the process of the non-azeotropic mixture refrigerant being transported from the outlet of the condenser 2 to the inlet of the evaporator 9, the mixture refrigerant undergoes throttling and one-time regenerative heat exchange successively, so that the throttling temperature difference from the condenser 2 to the evaporator 9 is greatly reduced compared with the traditional heat pump system, and finally the throttling loss is greatly reduced, thereby improving the heating performance of the non-azeotropic mixture refrigerant heat pump system.

[0054] When the ambient temperature is less than or equal to the second target temperature, the heat pump system is controlled to operate in the second heat exchange mode by controlling the electronic control valve group; the refrigerant flows through the condenser 2, the first heat exchange channel 61, and after the refrigerant flows out of the outlet of the first heat exchange channel 61, it flows along the first circulation branch and the second circulation branch respectively; wherein, on the first circulation branch, the refrigerant flows through the second throttling device 8, the evaporator 9 and the suction port of the compressor 1 in sequence, and on the second circulation branch, the refrigerant flows through the third throttling device 7, the second heat exchange channel 62 and the gas supplement port of the compressor 1 in sequence. During the refrigerant circulation process, the mixture refrigerant is throttled by the third throttling device 7 and then flows into the second heat exchange channel 62 of the heat exchanger 6, and then flows into the gas supplement port of the compressor 1 to supplement gas to the compressor 1, thereby reducing the compression ratio of the compressor 1 to reduce the exhaust temperature of the compressor 1, so that the heat pump system operates more stably and efficiently at low ambient temperature. And the refrigerant on the first circulation branch exchanges heat with the refrigerant on the second circulation branch in the heat exchanger 6, thereby effectively reducing the temperature of the mixture refrigerant flowing out of the first heat exchange channel 61, so that the mixture refrigerant is further subcooled before entering the evaporator 9, thereby effectively improving the heating effect of the heat pump system, and can meet the higher heating demand indoors under the condition of lower ambient temperature. By switching the non-azeotropic mixture refrigerant heat pump system between the first heat exchange mode and the second heat exchange mode, the overall energy consumption of the heat pump system can be effectively reduced while the heat pump system operates stably and meets the heating demand, thereby improving the user experience.

[0055] As Figure 6 shown, in one of the embodiments, the following steps are further included: Step S400, when the heat pump system operates in the first heat exchange mode, control the first throttling device 3, the second throttling device 8, the third electronic control valve 11 and the fourth electronic control valve 10 to be in the open state, and control the third throttling device 7, the first electronic control valve 12 and the second electronic control valve 13 to be in the closed state; Step S500: When the heat pump system operates in the second heat exchange mode, control the first throttling device 3, the second throttling device 8, the third throttling device 7, the first electric control valve 12, and the second electric control valve 13 to be in the open state, and control the third electric control valve 11 and the fourth electric control valve 10 to be in the closed state.

[0056] In this embodiment, when the heat pump system operates in the first heat exchange mode, control the first throttling device 3, the second throttling device 8, the third electric control valve 11, and the fourth electric control valve 10 to be in the open state, and control the third throttling device 7, the first electric control valve 12, and the second electric control valve 13 to be in the closed state; make the refrigerant discharge from the exhaust port of the compressor 1 and flow through the condenser 2, the first throttling device 3, the first heat exchange channel 61, the second throttling device 8, the evaporator 9, the second heat exchange channel 62, and the suction port of the compressor 1 in sequence. During the refrigerant circulation process, the evaporator 9 absorbs the heat in the air, and together with the work done by the compressor 1, the two parts of energy are finally released as heat in the condenser 2, so that the heat pump system heats up the water temperature. Moreover, during the process of the non-azeotropic mixture refrigerant being transmitted from the outlet of the condenser 2 to the inlet of the evaporator 9, the mixture refrigerant undergoes two-stage throttling and one-time heat regeneration, so that the throttling temperature difference from the condenser 2 to the evaporator 9 is greatly reduced compared with the traditional heat pump system, and finally the throttling loss is greatly reduced, thereby improving the heating performance of the non-azeotropic mixture refrigerant heat pump system.

[0057] When the heat pump system operates in the second heat exchange mode, control the first throttling device 3, the second throttling device 8, the third throttling device 7, the first electronic control valve 12, and the second electronic control valve 13 to be in the open state, and control the third electronic control valve 11 and the fourth electronic control valve 10 to be in the closed state to control the heat pump system to be in the second heat exchange mode; during the refrigerant circulation process, when the mixed refrigerant flows out of the first heat exchange channel 61, the mixed refrigerant continues to flow along the first circulation branch and the second circulation branch respectively; when the mixed refrigerant flows along the first circulation branch, the mixed refrigerant returns to the suction port of the compressor 1 after passing through the second throttling device 8, the evaporator 9, and the first electronic control valve 12; when the mixed refrigerant flows along the second circulation branch, the mixed refrigerant is throttled by the third throttling device 7 and then flows into the second heat exchange channel 62 of the heat exchanger 6, and enters the gas supplement port of the compressor 1 through the second electronic control valve 13 to supplement gas to the compressor 1, thereby reducing the compression ratio of the compressor 1 to reduce the exhaust temperature of the compressor 1, so that the heat pump system operates more stably and efficiently at low ambient temperatures. And the refrigerant in the first circulation branch exchanges heat with the refrigerant in the second circulation branch in the heat exchanger 6; thereby effectively reducing the temperature of the mixed refrigerant flowing out of the first heat exchange channel 61, making the mixed refrigerant further subcooled before entering the evaporator 9, so as to effectively improve the heating effect of the heat pump system, and can meet the higher heating demand indoors when the ambient temperature is relatively low. According to the change of the ambient temperature, control the zeotropic mixture refrigerant heat pump system to switch between the first heat exchange mode and the second heat exchange mode, so that the heat pump system can effectively reduce the overall energy consumption of the heat pump system while operating stably and meeting the heating demand, thereby enhancing the user experience. Among them, the first target temperature can specifically be -15°C, -14°C, -13°C, -12°C, -11°C, -10°C, etc., and the second target temperature can specifically be -20°C, -21°C, -22°C, -23°C, -24°C, -25°C, etc., and can all be set according to actual usage requirements.

[0058] In one of the embodiments, it further includes: when the ambient temperature is greater than the second target temperature and less than the first target temperature, control the heat pump system to operate in the current mode, and the current mode includes the first heat exchange mode and the second heat exchange mode.

[0059] In this embodiment, when the ambient temperature is greater than the second target temperature and less than the first target temperature, in order to avoid frequent switching of the heat pump system's heat exchange mode, the heat pump system can be maintained to operate in the current mode at this time. For example, when the ambient temperature is less than or equal to the second target temperature and the heat pump system operates in the second heat exchange mode for heating, as the ambient temperature rises and the ambient temperature is greater than the second target temperature but still less than the first target temperature, the heat pump system can be maintained to operate in the second heat exchange mode at this time. Similarly, when the ambient temperature is greater than or equal to the first target temperature and the heat pump system operates in the first heat exchange mode, as the ambient temperature drops and the ambient temperature is less than the first target temperature but still greater than the second target temperature, the heat pump system is still maintained to operate in the first heat exchange mode. This can avoid frequent switching of the heat pump system's heat exchange mode due to the ambient temperature fluctuating near the target temperature, thereby reducing the overall energy consumption of the system.

[0060] In one of the embodiments, as Figure 7 shown, the following steps are further included: Step S700: Compare the ambient temperature with a third target temperature, where the third target temperature is less than the second target temperature; Step S800: When the ambient temperature is less than the third target temperature, control the first electric control valve 12, the fifth electric control valve 5, and the first throttling device 3 to be in the open state, and control the first throttling device 3 to be opened to the maximum opening degree, and control the second throttling device 8, the third throttling device 7, the second electric control valve 13, the third electric control valve 11, the fourth electric control valve 10, and the evaporator fan 15 to be in the closed state; Step S900: When the ambient temperature is greater than or equal to the third target temperature, control the fifth electric control valve 5, the third electric control valve 11, and the fourth electric control valve 10 to be in the closed state, and control the first throttling device 3, the second throttling device 8, the third throttling device 7, the first electric control valve 12, the second electric control valve 13, and the evaporator fan 15 to be in the open state.

[0061] In this embodiment, after the heat pump system is started, the ambient temperature and the inlet water temperature of the condenser 2 are first obtained, and the initial opening degrees of the first throttling device 3 and the second throttling device 8 are determined according to the ambient temperature and the inlet water temperature. For example, when the ambient temperature and / or the inlet water temperature are relatively high, the initial opening degrees of the first throttling device 3 and the second throttling device 8 are relatively small.

[0062] Further compare the ambient temperature with a third target temperature, where the third target temperature can be set according to actual requirements. When the ambient temperature is less than the third target temperature, it indicates that the ambient temperature is relatively low at this time, and frost forms on the surface of the evaporator 9. At this time, control the fifth electric control valve 5 on the pipeline between the liquid storage device 4 and the evaporator 9 to open, so that the liquid storage device 4 and the evaporator 9 are connected, and control the second throttling device 8, the third throttling device 7, the second electric control valve 13, the third electric control valve 11, the fourth electric control valve 10, and the evaporator fan 15 to be in the closed state, so that the heat pump system switches to the defrosting mode. At this time, most of the gaseous working medium in the liquid storage device 4 enters the bypass pipeline 41 from the second refrigerant outlet 44, is transmitted to the evaporator 9 for defrosting, and then is sucked into the compressor 1 and continues to circulate through the compressor 1. When the gaseous working medium condenses in the evaporator 9, a large amount of heat is released for defrosting. At the same time, control the first throttling device 3 to open to the maximum opening degree, so that more refrigerant evaporates and absorbs heat in the evaporator 9, thereby increasing the temperature of the evaporator 9 and accelerating the melting speed of the frost layer.

[0063] When the ambient temperature is greater than or equal to the third target temperature, it indicates that the ambient temperature is in a normal state at this time; the first throttling device 3, the second throttling device 8, the third throttling device 7, the first electric control valve 12, the second electric control valve 13, and the evaporator fan 15 are in the open state, and the fifth electric control valve 5, the third electric control valve 11, and the fourth electric control valve 10 are in the closed state, to prevent the gaseous working medium from flowing directly from the liquid storage device 4 into the evaporator 9, so that the zeotropic mixture refrigerant heat pump system can operate in the second heat exchange mode.

[0064] In one embodiment, as Figure 8 shown, it further includes: Step S810: In response to the heat pump system being in the defrosting mode, detect the temperature at the outlet of the evaporator 9, and compare the temperature at the outlet of the evaporator 9 with a fourth target temperature; Step S820: When the temperature at the outlet of the evaporator 9 is greater than or equal to the fourth target temperature, control the evaporator fan 15, the first throttling device 3, the second throttling device 8, the third throttling device 7, the first electric control valve 12, and the second electric control valve 13 to open, and control the fifth electric control valve 5, the third electric control valve 11, and the fourth electric control valve 10 to close, to switch to the second heat exchange mode; Step S830: When the temperature at the outlet of the evaporator 9 is less than the fourth target temperature, control the evaporator fan 15, the second throttling device 8, the third throttling device 7, the second electric control valve 13, the third electric control valve 11, and the fourth electric control valve 10 to be in the closed state, and control the first electric control valve 12, the fifth electric control valve 5, and the first throttling device 3 to be in the open state, to maintain the defrosting mode.

[0065] In this embodiment, after the operation mode of the zeotropic mixture refrigerant heat pump system is switched to the defrosting mode, the temperature sensor continuously detects the temperature at the outlet of the evaporator 9, and compares the temperature at the outlet of the evaporator 9 with the fourth target temperature, where the fourth target temperature can be set according to actual requirements. When the temperature at the outlet of the evaporator 9 is greater than or equal to the fourth target temperature, it indicates that the operating condition of the zeotropic mixture refrigerant heat pump system has returned to the normal state at this time; at this time, control the evaporator fan 15, the first throttling device 3, the second throttling device 8, the third throttling device 7, the first electric control valve 12 and the second electric control valve 13 to open, so that the heating circuit of the zeotropic mixture refrigerant heat pump system returns to the normal working state; at the same time, control the fifth electric control valve 5, the third electric control valve 11 and the fourth electric control valve 10 to close, so as to switch the working mode of the zeotropic mixture refrigerant heat pump system to the second heat exchange mode. It can be understood that the opening degrees of the first throttling device 3, the second throttling device 8 and the third throttling device 7 all return to the opening degrees before defrosting.

[0066] When the temperature at the outlet of the evaporator 9 is less than the fourth target temperature, it indicates that the frost layer on the surface of the evaporator 9 has not been completely removed at this time; at this time, the evaporator fan 15, the second throttling device 8, the third throttling device 7, the second electric control valve 13, the third electric control valve 11 and the fourth electric control valve 10 still remain in the closed state, and the first electric control valve 12, the fifth electric control valve 5 and the first throttling device 3 still remain in the open state to maintain the defrosting mode until the frost layer on the surface of the evaporator 9 is completely removed.

[0067] Figure 9 The structural schematic diagram of the embodiment of the zeotropic mixture refrigerant heat pump system provided by the embodiment of the present invention is shown. The specific implementation of the zeotropic mixture refrigerant heat pump system in the specific embodiment of the present invention is not limited.

[0068] As Figure 9 shown, the heat pump may include: a processor 502, a communication interface 504, a memory 506, and a communication bus 508.

[0069] Among them: the processor 502, the communication interface 504, and the memory 506 complete mutual communication through the communication bus 508. The communication interface 504 is used to communicate with network elements of other devices such as clients or other servers. The processor 502 is used to execute the program 510, and specifically can execute the relevant steps in the above-mentioned control method embodiment for the zeotropic mixture refrigerant heat pump system.

[0070] Specifically, the program 510 may include program codes, and the program codes include computer executable instructions.

[0071] The processor 502 may be a central processing unit (CPU), or a specific application-specific integrated circuit (ASIC), or one or more integrated circuits configured to implement the embodiments of the present invention. One or more processors included in the zeotropic mixture refrigerant heat pump system may be of the same type, such as one or more CPUs; or may be of different types, such as one or more CPUs and one or more ASICs.

[0072] A memory 506 is used to store a program 510. The memory 506 may include high-speed RAM memory and may also include non-volatile memory, such as at least one disk memory.

[0073] Specifically, the program 510 can be called by the processor 502 to cause the zeotropic mixture refrigerant heat pump system to execute the relevant steps in the above-described control method embodiments for the zeotropic mixture refrigerant heat pump system.

[0074] Those of ordinary skill in the art can understand that Figure 9 the structure shown is only schematic and does not limit the structure of the above device. For example, the zeotropic mixture refrigerant heat pump system may further include more or fewer components than those shown in Figure 9 or have a different configuration from that shown in Figure 9

[0075] Embodiments of the present invention also provide a computer-readable storage medium. The methods according to the embodiments of the present invention can be implemented in hardware, firmware, or be implemented as computer code that can be recorded on a storage medium, or be implemented by downloading via a network and originally stored in a remote storage medium or a non-transitory machine-readable storage medium and will be stored in a local storage medium, so that the methods described herein can be stored as such software processing on a storage medium using a general-purpose computer, a dedicated processor, or programmable or dedicated hardware. Among them, the storage medium can be a magnetic disk, an optical disk, a read-only memory, a random access memory, a flash memory, a hard disk, or a solid-state drive, etc.; further, the storage medium can also include a combination of the above types of memories. It can be understood that a computer, a processor, a microprocessor controller, or programmable hardware includes a storage component that can store or receive software or computer code, and when the software or computer code is accessed and executed by the computer, the processor, or the hardware, the methods shown in the above embodiments are implemented.

[0076] In the specific content of the above specific embodiments, the technical features can be combined arbitrarily without contradiction. For the sake of concise description, not all possible combinations of the above technical features are described. However, as long as the combinations of these technical features do not exist in contradiction, they should all be considered as within the scope described in this specification.

[0077] The specific content of the above specific embodiments only expresses several embodiments of the present invention, and its description is relatively specific and detailed, but it cannot be understood as a limitation to the scope of the invention patent of the present invention. It should be noted that for those of ordinary skill in the art, without departing from the concept of the present invention, several deformations and improvements can still be made, and these all belong to the protection scope of the present invention. Therefore, the protection scope of the invention patent of the present invention should be subject to the appended claims.

Claims

1. Azeotropic-mixture-free refrigerant heat pump system, characterized in that, Comprising: A refrigerant circulation circuit connected to the exhaust port and the suction port of the compressor (1) and forming a loop, on which a condenser (2), a heat exchanger (6), a second throttling device (8) and an evaporator (9) are sequentially arranged along the refrigerant flow direction; The heat exchanger (6) has a first heat exchange channel (61) and a second heat exchange channel (62) for heat exchange with each other. The first heat exchange channel (61) is connected between the outlet of the condenser (2) and the inlet of the evaporator (9), and the second heat exchange channel (62) is connected between the outlet of the evaporator (9) and the suction port of the compressor (1); The heat pump system further includes a third throttling device (7), and the third throttling device (7) is connected between the outlet of the first heat exchange channel (61) and the inlet of the second heat exchange channel (62); The heat pump system includes an electric control valve group for controlling the operation of the heat pump system in a first heat exchange mode or a second heat exchange mode; In the first heat exchange mode, the refrigerant sequentially flows through the condenser (2), the first heat exchange channel (61), the second throttling device (8), the evaporator (9), the second heat exchange channel (62), and the suction port of the compressor (1); In the second heat exchange mode, the refrigerant sequentially flows through the condenser (2), the first heat exchange channel (61). After flowing out from the outlet of the first heat exchange channel (61), the refrigerant flows along a first circulation branch and a second circulation branch respectively. On the first circulation branch, the refrigerant sequentially flows through the second throttling device (8), the evaporator (9), and the suction port of the compressor (1). On the second circulation branch, the refrigerant sequentially flows through the third throttling device (7), the second heat exchange channel (62), and the gas supplement port of the compressor (1).

2. The non-azeotropic mixture refrigerant heat pump system according to claim 1, wherein Further comprising: A first throttling device (3) connected between the outlet of the condenser (2) and the inlet of the first heat exchange channel (61); the second throttling device (8) is connected between the outlet of the first heat exchange channel (61) and the inlet of the evaporator (9).

3. The non-azeotropic mixture working fluid heat pump system according to claim 1, characterized in that, The electric control valve group includes a first electric control valve (12), a second electric control valve (13) and a fourth electric control valve (10). The first electric control valve (12) is arranged between the outlet of the evaporator (9) and the suction port of the compressor (1); the second electric control valve (13) is arranged between the outlet of the second heat exchange channel (62) and the gas supplement port of the compressor (1); the fourth electric control valve (10) is arranged between the outlet of the second heat exchange channel (62) and the suction port of the compressor (1).

4. The non-azeotropic mixture working fluid heat pump system according to claim 1, characterized in that, The electric control valve group further includes a third electric control valve (11), and the third electric control valve (11) is connected between the outlet of the evaporator (9) and the inlet of the second heat exchange channel (62).

5. The non-azeotropic mixture working fluid heat pump system according to claim 2, wherein, Further comprising: A liquid reservoir (4) is provided with a refrigerant inlet (42), a first refrigerant outlet (43) and a second refrigerant outlet (44). The refrigerant inlet (42) is connected to the first throttling device (3). The first refrigerant outlet (43) is connected to the inlet of the first heat exchange channel (61). The second refrigerant outlet (44) is connected to the inlet of the evaporator (9) through a bypass pipeline (41), and a fifth electric control valve (5) is arranged on the bypass pipeline (41).

6. The non-azeotropic mixture refrigerant heat pump system according to claim 2, characterized in that, The first throttling device (3), the second throttling device (8) and the third throttling device (7) are all expansion valves.

7. The zeotropic mixture refrigerant heat pump system according to any one of claims 1-6, characterized in that, An air-liquid separator (14) is further arranged on the refrigerant circulation loop. The inlet of the air-liquid separator (14) is respectively connected to the outlet of the second heat exchange channel (62) and the outlet of the evaporator (9). The outlet of the air-liquid separator (14) is connected to the suction port of the compressor (1).

8. The non-azeotropic mixture working fluid heat pump system according to any one of claims 1-6, characterized in that, An evaporator fan (15) is further included, and the evaporator fan (15) is used to drive air to flow through the evaporator (9).

9. A control method for azeotropic mixture refrigerant heat pump system, applied to the azeotropic mixture refrigerant heat pump system according to any one of claims 1-8, characterized in that, The control method includes: Obtaining the ambient temperature, and comparing the ambient temperature with a first target temperature and a second target temperature respectively, where the first target temperature is greater than the second target temperature; When the ambient temperature is greater than or equal to the first target temperature, controlling the electric control valve group to act so that the heat pump system operates in the first heat exchange mode; When the ambient temperature is less than or equal to the second target temperature, controlling the electric control valve group to act so that the heat pump system operates in the second heat exchange mode.

10. The control method of the zeotropic mixture refrigerant heat pump system according to claim 9, characterized in that, The electric control valve group includes a first electric control valve (12), a second electric control valve (13), a third electric control valve (11) and a fourth electric control valve (10). The first electric control valve (12) is arranged between the outlet of the evaporator (9) and the suction port of the compressor (1); the second electric control valve (13) is arranged between the outlet of the second heat exchange channel (62) and the gas supplement port of the compressor (1); the third electric control valve (11) is connected between the outlet of the evaporator (9) and the inlet of the second heat exchange channel (62); the fourth electric control valve (10) is arranged between the outlet of the second heat exchange channel (62) and the suction port of the compressor (1); the heat pump system further includes a first throttling device (3) connected between the outlet of the condenser (2) and the inlet of the first heat exchange channel (61); The method further includes: When the heat pump system operates in the first heat exchange mode, controlling the first throttling device (3), the second throttling device (8), the third electric control valve (11) and the fourth electric control valve (10) to be in an open state, and controlling the third throttling device (7), the first electric control valve (12) and the second electric control valve (13) to be in a closed state; When the heat pump system operates in the second heat exchange mode, control the first throttling device (3), the second throttling device (8), the third throttling device (7), the first electric control valve (12) and the second electric control valve (13) to be in the open state, and control the third electric control valve (11) and the fourth electric control valve (10) to be in the closed state.

11. The control method of the zeotropic mixture refrigerant heat pump system according to claim 10, characterized in that, The method further includes: When the ambient temperature is greater than the second target temperature and less than the first target temperature, control the heat pump system to operate in the current mode, where the current mode includes the first heat exchange mode and the second heat exchange mode.

12. The control method of the zeotropic mixture refrigerant heat pump system according to claim 10, characterized in that, The heat pump system further includes a liquid receiver (4) and an evaporator fan (15) for driving air to flow through the evaporator (9). The liquid receiver (4) is provided with a refrigerant inlet (42), a first refrigerant outlet (43) and a second refrigerant outlet (44). The refrigerant inlet (42) is connected to the first throttling device (3), the first refrigerant outlet (43) is connected to the inlet of the first heat exchange channel (61), the second refrigerant outlet (44) is connected to the inlet of the evaporator (9) through a bypass pipeline (41), and a fifth electric control valve (5) is provided on the bypass pipeline (41); The method further includes: Compare the ambient temperature with a third target temperature, where the third target temperature is less than the second target temperature; When the ambient temperature is less than the third target temperature, control the first electric control valve (12), the fifth electric control valve (5) and the first throttling device (3) to be in the open state, and control the first throttling device (3) to be opened to the maximum opening degree, and control the second throttling device (8), the third throttling device (7), the second electric control valve (13), the third electric control valve (11), the fourth electric control valve (10) and the evaporator fan (15) to be in the closed state; When the ambient temperature is greater than or equal to the third target temperature, control the fifth electric control valve (5), the third electric control valve (11) and the fourth electric control valve (10) to be in the closed state, and control the first throttling device (3), the second throttling device (8), the third throttling device (7), the first electric control valve (12), the second electric control valve (13) and the evaporator fan (15) to be in the open state.

13. The control method of the zeotropic mixture refrigerant heat pump system according to claim 12, characterized in that, The method further includes: In response to the heat pump system being in the defrosting mode, detect the temperature at the outlet of the evaporator (9), and compare the temperature at the outlet of the evaporator (9) with a fourth target temperature; When the temperature at the outlet of the evaporator (9) is greater than or equal to the fourth target temperature, control the evaporator fan (15), the first throttling device (3), the second throttling device (8), the third throttling device (7), the first electric control valve (12) and the second electric control valve (13) to be opened, and control the fifth electric control valve (5), the third electric control valve (11) and the fourth electric control valve (10) to be closed to switch to the second heat exchange mode; When the outlet temperature of the evaporator (9) is less than the fourth target temperature, control the evaporator fan (15), the second throttling device (8), the third throttling device (7), the second electronic control valve (13), the third electronic control valve (11) and the fourth electronic control valve (10) to be in the closed state, and control the first electronic control valve (12), the fifth electronic control valve (5) and the first throttling device (3) to be in the open state to maintain the defrosting mode.

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