Integrated heat dissipation compressor vehicle-mounted refrigerator and control method

Abstract

The invention relates to an integrated heat dissipation compressor vehicle-mounted refrigerator and a control method. The technical problem that an existing vehicle-mounted refrigerator is poor in heat exchange effect is solved. Comprising a refrigerator compressor assembly and an air conditioner compressor assembly, the refrigerator compressor assembly and the air conditioner compressor assembly are connected through a heat exchange pipe, and the heat exchange pipe is provided with a low-temperature refrigerant conveying assembly and a high-temperature refrigerant conveying assembly which can exchange heat with each other and are connected with the air conditioner compressor assembly. And a switch valve assembly capable of enabling the air conditioner compressor assembly and the low-temperature refrigerant conveying assembly to be mutually communicated or disconnected is arranged between the refrigerator compressor assembly and the air conditioner compressor assembly. The refrigerator has the advantages that the low-temperature refrigerant of the air conditioner is used for cooling the high-temperature refrigerant in the condenser of the refrigerator, traditional air cooling heat dissipation can be replaced, and vibration and noise of the refrigerator can be reduced under the condition that the heat dissipation effect is improved.

Description

Technical Field

[0001] This invention belongs to the field of vehicle refrigerator technology, specifically relating to an integrated heat dissipation compressor vehicle refrigerator and its control method. Background Technology

[0002] With the popularization of new energy vehicles, car refrigerators have gradually become a standard feature in automobiles, and consumers are paying increasing attention to their user experience. Currently, compressor refrigerators are widely used in car refrigerators due to their fast cooling speed and low cooling temperature. However, compressor refrigerators also have certain limitations: since refrigerators generally dissipate heat through air cooling, their operating ambient temperature generally cannot exceed 55℃, and as the ambient temperature rises, the cooling capacity and energy efficiency of the compressor will decrease accordingly. Traditional car refrigerators mostly use condenser fans to dissipate heat from the high-temperature refrigerant, which not only has poor heat exchange efficiency but also easily generates noise, affecting the user experience. Summary of the Invention

[0003] The purpose of this invention is to address the above-mentioned problems by providing an integrated heat dissipation compressor vehicle refrigerator.

[0004] Another objective of this invention is to provide a control method for an integrated heat dissipation compressor vehicle refrigerator, addressing the aforementioned problems.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: an integrated heat dissipation compressor vehicle refrigerator, comprising a refrigerator compressor assembly and an air conditioning compressor assembly, wherein the refrigerator compressor assembly and the air conditioning compressor assembly are connected by a heat exchange pipe, and the heat exchange pipe has a low-temperature refrigerant delivery assembly that can exchange heat with each other and is connected to the air conditioning compressor assembly, and a high-temperature refrigerant delivery assembly that is connected to the refrigerator compressor assembly; and a switching valve assembly is provided between the refrigerator compressor assembly and the air conditioning compressor assembly to allow the air conditioning compressor assembly and the low-temperature refrigerant delivery assembly to be connected or disconnected. The heat exchange pipe and the switching valve assembly enable switching between two heat dissipation modes. The condenser of the vehicle refrigerator achieves condensation and cooling by introducing low-temperature refrigerant from the automotive air conditioning system, replacing the traditional air-cooling method, improving the refrigerator's cooling performance, and optimizing the customer experience.

[0006] In the aforementioned integrated cooling compressor vehicle refrigerator, the heat exchange tube is a coaxial tube, comprising an inner tube body and an outer tube body coaxially arranged on the outer side of the inner tube body. Several circumferentially evenly distributed support portions are provided between the outer side of the inner tube body and the inner side of the outer tube body. This structure is very compact and has high heat exchange efficiency, embodying a highly efficient and compact counter-current heat exchange design, laying a solid physical foundation for subsequent efficient heat dissipation.

[0007] In the aforementioned integrated cooling compressor vehicle refrigerator, the low-temperature refrigerant delivery assembly includes a cold fluid channel disposed inside the inner tube, and the high-temperature refrigerant delivery assembly includes a hot fluid channel disposed between two adjacent support sections. The cold fluid channel carries the low-temperature refrigerant input from the air conditioner, and the hot fluid channel carries the high-temperature refrigerant input from the refrigerator compressor outlet. Through heat exchange between the two refrigerants at different temperatures, the high-temperature refrigerant in the refrigerator is condensed and cooled.

[0008] In the aforementioned integrated heat dissipation compressor vehicle refrigerator, the air conditioning compressor assembly includes an air conditioning compressor, which is connected to an air conditioning condenser. The air conditioning condenser is connected to an air conditioning dryer filter, which is connected to an electronic expansion valve. The electronic expansion valve is connected to the air conditioning compressor via an air conditioning evaporator assembly.

[0009] In the aforementioned integrated cooling compressor vehicle refrigerator, the air conditioning evaporator assembly includes a front evaporator and a rear evaporator, and a three-way valve is provided between the electronic expansion valve and the rear evaporator. This division of the air conditioning system into a front and rear evaporator provides structural feasibility for diverting a portion of the refrigerant to assist in refrigerator cooling without significantly affecting the air conditioning operation.

[0010] In the aforementioned integrated heat dissipation compressor vehicle refrigerator, the refrigerator compressor assembly includes a refrigerator compressor, which is connected to a refrigerator condenser. The refrigerator condenser is connected to a refrigerator dryer filter, which is connected to a refrigerator capillary tube. The refrigerator capillary tube is connected to the refrigerator condenser via a refrigerator evaporator.

[0011] In the aforementioned integrated heat dissipation compressor vehicle refrigerator, the heat exchange tubes are connected in series on the refrigerator condenser. One end of the heat exchange tube is connected to a three-way valve, and the other end is connected between the air conditioner's rear evaporator and the air conditioner compressor.

[0012] A control method for an integrated heat dissipation compressor vehicle refrigerator, the method comprising the following steps: S1. When the refrigerator compressor unit's cooling function is turned on, check the on / off status of the air conditioner compressor unit. S2. When the air conditioner compressor assembly is in the on state, the refrigerator condenser of the refrigerator compressor assembly can use the low-temperature refrigerant of the air conditioner compressor assembly for heat dissipation. S3. When the air conditioner compressor unit is not turned on, the three-way valve of the air conditioner compressor unit is closed, and the condenser fan of the refrigerator compressor unit is turned on to dissipate heat from the refrigerator condenser, thus adopting conventional air-cooling heat dissipation.

[0013] In the above-mentioned control method of an integrated heat dissipation compressor vehicle refrigerator, when using low-temperature refrigerant for heat dissipation in step S2, the three-way valve of the air conditioning compressor assembly is first opened, and a portion of low-temperature refrigerant flows out from the electronic expansion valve of the air conditioning compressor assembly and enters the refrigerator condenser of the refrigerator compressor assembly through the low-temperature refrigerant delivery assembly, where it exchanges heat with the high-temperature refrigerant discharged from the refrigerator compressor assembly, thereby achieving the cooling and condensation of the high-temperature refrigerant.

[0014] In the above-mentioned control method for an integrated heat dissipation compressor vehicle refrigerator, step S2 includes the following steps: S21. In order to achieve sufficient heat exchange between the hot and cold refrigerants, the opening and closing of the three-way valve needs to be controlled properly. The degree of heat exchange can be judged based on the refrigerant temperature T at the refrigerator condenser outlet. The condensing temperature range is T2-T1. S22. When the three-way valve is opened, if the condensing temperature of the refrigerator compressor assembly cannot be reduced to the target temperature for a long time, i.e., T is greater than T1, the condenser fan can be turned on to assist in enhancing the heat exchange effect. The condenser fan is turned on according to the opening time t of the three-way valve and the preset opening time t1 of the three-way valve. When t is greater than t1, the condenser fan is turned on. S23. When the condensing temperature is too low, i.e., T is less than T2, there is too much low-temperature refrigerant, which cannot absorb heat sufficiently. In this case, the three-way valve needs to be closed.

[0015] Compared with existing technologies, the advantages of this invention are: 1. This device uses the low-temperature refrigerant of an air conditioner to cool the high-temperature refrigerant in the refrigerator condenser, which can replace the traditional air-cooling heat dissipation. While improving the heat dissipation effect, it can reduce the vibration and noise of the refrigerator.

[0016] 2. This device can switch between fan cooling and refrigerant cooling modes through a three-way valve according to the refrigerator's operating environment, ensuring efficient operation under different conditions. It can effectively expand the application range of compressor refrigerators, especially improve the refrigerator's cooling performance under high-temperature conditions.

[0017] 3. The device adopts coaxial tube heat exchange with countercurrent flow between the inner and outer tubes, forming a highly efficient countercurrent heat exchange structure. This design provides a huge heat exchange area per unit volume and has a very compact structure, making it very suitable for space-constrained vehicle environments. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of the present invention.

[0019] Figure 2 This is a cross-sectional view of the heat exchange tube in this invention.

[0020] Figure 3 This is the control principle diagram of the present invention.

[0021] In the diagram: Refrigerator compressor assembly 1, Refrigerator compressor 11, Refrigerator condenser 12, Refrigerator dryer filter 13, Refrigerator capillary tube 14, Refrigerator evaporator 15, Air conditioner compressor assembly 2, Air conditioner compressor 21, Air conditioner condenser 22, Air conditioner dryer filter 23, Electronic expansion valve 24, Air conditioner evaporator assembly 25, Air conditioner front evaporator 26, Air conditioner rear evaporator 27, Three-way valve 28, Heat exchange tube 3, Inner tube body 31, Outer tube body 32, Support part 33, Low temperature refrigerant transport assembly 4, Cold fluid channel 41, High temperature refrigerant transport assembly 5, Hot fluid channel 51. Detailed Implementation

[0022] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments.

[0023] like Figure 1-2 As shown, an integrated cooling compressor vehicle refrigerator includes a refrigerator compressor assembly 1 and an air conditioning compressor assembly 2. The refrigerator compressor assembly 1 and the air conditioning compressor assembly 2 are connected by a heat exchange pipe 3. The heat exchange pipe 3 has a low-temperature refrigerant delivery assembly 4 connected to the air conditioning compressor assembly 2 and a high-temperature refrigerant delivery assembly 5 connected to the refrigerator compressor assembly 1, which can exchange heat with each other. A switching valve assembly is provided between the refrigerator compressor assembly 1 and the air conditioning compressor assembly 2 to allow the air conditioning compressor assembly 2 and the low-temperature refrigerant delivery assembly 4 to be connected or disconnected. The two cooling modes can be switched through the heat exchange pipe 3 and the switching valve assembly. The condenser of the vehicle refrigerator achieves condensation and cooling by introducing low-temperature refrigerant from the car's air conditioning system, replacing the traditional air-cooling method, improving the refrigerator's cooling performance and optimizing the customer experience.

[0024] like Figure 2 As shown, the heat exchange tube 3 is a coaxial tube, and it has an inner tube body 31 and an outer tube body 32 coaxially arranged on the outer side of the inner tube body 31. Several circumferentially evenly distributed support parts 33 are provided between the outer side of the inner tube body 31 and the inner side of the outer tube body 32. This structure is very compact and has high heat exchange efficiency, reflecting a highly efficient and compact countercurrent heat exchange design, laying a solid physical foundation for subsequent efficient heat dissipation.

[0025] The low-temperature refrigerant delivery assembly 4 includes a cold fluid channel 41 disposed inside the inner tube 31, and the high-temperature refrigerant delivery assembly 5 includes a hot fluid channel 51 disposed between two adjacent support parts 33. The cold fluid channel 41 carries the low-temperature refrigerant input from the air conditioner, and the hot fluid channel 51 carries the high-temperature refrigerant input from the outlet of the refrigerator compressor 11. Through heat exchange between the two refrigerants at different temperatures, the high-temperature refrigerant in the refrigerator is condensed and cooled.

[0026] like Figure 1As shown, the air conditioning compressor assembly 2 has an air conditioning compressor 21, which is connected to an air conditioning condenser 22. The air conditioning condenser 22 is connected to an air conditioning dryer filter 23, which is connected to an electronic expansion valve 24. The electronic expansion valve 24 is connected to the air conditioning compressor 21 through an air conditioning evaporator assembly 25.

[0027] The air conditioner evaporator assembly 25 includes a front evaporator 26 and a rear evaporator 27, with a three-way valve 28 located between the electronic expansion valve 24 and the rear evaporator 27. The division between the front evaporator 26 and the rear evaporator 27 provides structural feasibility for diverting a portion of the refrigerant to assist in refrigerator heat dissipation without significantly affecting the operation of the air conditioner.

[0028] Specifically, the refrigerator compressor assembly 1 includes a refrigerator compressor 11, which is connected to a refrigerator condenser 12. The refrigerator condenser 12 is connected to a refrigerator dryer filter 13, which is connected to a refrigerator capillary tube 14. The refrigerator capillary tube 14 is connected to the refrigerator condenser 12 via a refrigerator evaporator 15.

[0029] Meanwhile, heat exchange tube 3 is connected in series on the refrigerator condenser 12. One end of heat exchange tube 3 is connected to the three-way valve 28, and the other end is connected between the air conditioner rear evaporator 27 and the air conditioner compressor 21.

[0030] Combination Figure 1 and Figure 3 As shown, a control method for an integrated heat dissipation compressor vehicle refrigerator is disclosed. This method includes the following steps: S1. After the refrigerator compressor assembly 1 is turned on for cooling, check the on / off status of the air conditioner compressor assembly 2. S2. When the air conditioner compressor assembly 2 is in the on state, the refrigerator condenser 12 of the refrigerator compressor assembly 1 can use the low-temperature refrigerant of the air conditioner compressor assembly 2 for heat dissipation. S3. When the air conditioner compressor assembly 2 is not turned on, the three-way valve 28 of the air conditioner compressor assembly 2 is closed, and the condenser fan of the refrigerator compressor assembly 1 is turned on to dissipate heat from the refrigerator condenser 12, thereby adopting conventional air-cooled heat dissipation.

[0031] In step S2, when using low-temperature refrigerant for heat dissipation, the three-way valve 28 of the air conditioner compressor assembly 2 is first opened. A portion of the low-temperature refrigerant flows out from the electronic expansion valve 24 of the air conditioner compressor assembly 2 and enters the refrigerator condenser 12 of the refrigerator compressor assembly 1 through the low-temperature refrigerant delivery assembly 4. It exchanges heat with the high-temperature refrigerant discharged from the refrigerator compressor 11 of the refrigerator compressor assembly 1, thereby achieving the cooling and condensation of the high-temperature refrigerant.

[0032] Specifically, step S2 includes the following steps: S21. In order to achieve sufficient heat exchange between the hot and cold refrigerants, the opening and closing of the three-way valve 28 needs to be controlled properly. The degree of heat exchange can be judged based on the refrigerant temperature T at the outlet of the refrigerator condenser 12. The condensing temperature range is T2-T1. S22. When the three-way valve 28 is opened, if the condensing temperature of the refrigerator compressor assembly 1 cannot be reduced to the target temperature for a long time, i.e., T is greater than T1, the condenser fan can be turned on to assist in enhancing the heat exchange effect. The opening of the condenser fan is controlled according to the opening time t of the three-way valve 28 and the preset opening time t1 of the three-way valve 28. When t is greater than t1, the condenser fan is turned on. S23. When the condensing temperature is too low, i.e., T is less than T2, there is too much low-temperature refrigerant, which cannot absorb heat sufficiently. In this case, the three-way valve 28 needs to be closed.

[0033] Through the above control methods, the refrigerator can operate reliably even in high-temperature environments, effectively expanding the high-temperature operating range of the compressor refrigerator. At the same time, by using refrigerant heat dissipation, the condensing temperature of the refrigerator can be significantly reduced, improving the refrigerator's energy efficiency and cooling capacity.

[0034] The principle of this embodiment is as follows: The refrigerator compressor assembly 1 and the air conditioner compressor assembly 2 are connected by a heat exchange tube 3. The cold fluid channel 41 of the heat exchange tube 3 is for the low-temperature refrigerant of the air conditioning system to flow through, and the hot fluid channel 51 of the heat exchange tube 3 is for the high-temperature refrigerant of the refrigerator system to flow through. The low-temperature refrigerant and the high-temperature refrigerant flow in opposite directions within the heat exchange tube 3 and exchange heat directly through the inner tube body 31. The heat of the high-temperature refrigerant is absorbed by the low-temperature refrigerant, causing the high-temperature refrigerant to cool down and condense rapidly, meeting the heat dissipation requirements of the refrigerator condenser 22. The low-temperature refrigerant, on the other hand, experiences a slight temperature rise, which does not affect the air conditioning cooling effect. Instead, it absorbs heat in advance, improving the efficiency of the air conditioning evaporator assembly 25. When the air conditioner is turned on, the low-temperature refrigerant assists in heat dissipation. After the refrigerator compressor assembly 1 starts cooling, the system detects that the air conditioner compressor assembly 2 is in the on state and opens the three-way valve 28, allowing a portion of the low-temperature refrigerant flowing out of the electronic expansion valve 24 to flow out and enter the refrigerator compressor assembly 1 through the cold fluid channel 41 of the heat exchange tube 3. The high-temperature and high-pressure refrigerant discharged from the refrigerator compressor 11 flows into the hot fluid channel 51 of the heat exchange tube 3. The diverted low-temperature refrigerant and high-temperature refrigerant... In the heat exchange tube 3, the high-temperature refrigerant is rapidly cooled to the target condensing temperature range of T2-T1 and then enters the refrigerator dryer filter 13 to complete the subsequent refrigeration cycle. If the heat exchange is insufficient, the refrigerant temperature T at the outlet of the refrigerator condenser 12 will be greater than T1, and the opening time t of the three-way valve 28 will be greater than the preset time t1. This indicates that the low-temperature refrigerant alone cannot meet the heat dissipation requirements. The system will automatically turn on the refrigerator condenser fan to assist in heat dissipation and enhance the heat exchange efficiency. If the heat exchange is excessive, T will be less than T2, indicating that the low-temperature refrigerant has been diverted too much and cannot absorb heat sufficiently. The system will automatically close the three-way valve 28 and suspend the low-temperature refrigerant assistance. When the air conditioner is turned off, the traditional air-cooled cooling system will operate. After the refrigerator compressor assembly 1 starts cooling, the system will detect that the air conditioner compressor assembly 2 is in the off state. The three-way valve 28 will automatically close, cutting off the low-temperature refrigerant delivery channel and preventing the refrigerant from flowing idly. The system will directly turn on the refrigerator condenser fan and force airflow to remove the heat from the refrigerator condenser 12. When the high-temperature refrigerant flows through the condenser, the heat will be carried away by the airflow, causing it to cool down and condense into a liquid state. The subsequent refrigeration will be completed according to the conventional refrigerator cycle.

[0035] The specific embodiments described herein are merely illustrative of the spirit of the invention. Those skilled in the art to which this invention pertains may make various modifications or additions to the described specific embodiments or use similar methods to substitute them, without departing from the spirit of the invention or exceeding the scope defined by the appended claims.

[0036] Although this document frequently uses terms such as refrigerator compressor assembly 1, refrigerator compressor 11, refrigerator condenser 12, refrigerator dryer filter 13, refrigerator capillary tube 14, refrigerator evaporator 15, air conditioner compressor assembly 2, air conditioner compressor 21, air conditioner condenser 22, air conditioner dryer filter 23, electronic expansion valve 24, air conditioner evaporator assembly 25, air conditioner front evaporator 26, air conditioner rear evaporator 27, three-way valve 28, heat exchange tube 3, inner tube body 31, outer tube body 32, support part 33, low-temperature refrigerant transport assembly 4, cold fluid channel 41, high-temperature refrigerant transport assembly 5, and hot fluid channel 51, the possibility of using other terms is not excluded. The use of these terms is merely for the convenience of describing and explaining the essence of the invention; interpreting them as any additional limitation would contradict the spirit of the invention.

Claims

1. An integrated heat dissipation compressor vehicle refrigerator, comprising a refrigerator compressor assembly (1) and an air conditioning compressor assembly (2), characterized in that, The refrigerator compressor assembly (1) and the air conditioner compressor assembly (2) are connected by a heat exchange tube (3). The heat exchange tube (3) has a low-temperature refrigerant delivery assembly (4) that can exchange heat with each other and is connected to the air conditioner compressor assembly (2) and a high-temperature refrigerant delivery assembly (5) that is connected to the refrigerator compressor assembly (1). A switching valve assembly is provided between the refrigerator compressor assembly (1) and the air conditioner compressor assembly (2) to enable the air conditioner compressor assembly (2) and the low-temperature refrigerant delivery assembly (4) to be connected or disconnected.

2. The integrated heat dissipation compressor vehicle refrigerator according to claim 1, characterized in that, The heat exchange tube (3) is a coaxial tube, and the heat exchange tube (3) has an inner tube body (31) and an outer tube body (32) coaxially arranged on the outer side of the inner tube body (31). A number of circumferentially evenly distributed support parts (33) are provided between the outer side of the inner tube body (31) and the inner side of the outer tube body (32).

3. The integrated heat dissipation compressor vehicle refrigerator according to claim 2, characterized in that, The low-temperature refrigerant delivery assembly (4) includes a cold fluid channel (41) disposed inside the inner tube (31), and the high-temperature refrigerant delivery assembly (5) includes a hot fluid channel (51) disposed between two adjacent support parts (33).

4. A vehicle-mounted refrigerator with an integrated heat dissipation compressor according to claim 1, 2, or 3, characterized in that, The air conditioning compressor assembly (2) has an air conditioning compressor (21), which is connected to an air conditioning condenser (22), which is connected to an air conditioning dryer filter (23), which is connected to an electronic expansion valve (24), and the electronic expansion valve (24) is connected to the air conditioning compressor (21) through an air conditioning evaporator assembly (25).

5. The integrated heat dissipation compressor vehicle refrigerator according to claim 4, characterized in that, The air conditioner evaporator assembly (25) has a front air conditioner evaporator (26) and a rear air conditioner evaporator (27), and a three-way valve (28) is provided between the electronic expansion valve (24) and the rear air conditioner evaporator (27).

6. The integrated heat dissipation compressor vehicle refrigerator according to claim 5, characterized in that, The refrigerator compressor assembly (1) has a refrigerator compressor (11), which is connected to a refrigerator condenser (12). The refrigerator condenser (12) is connected to a refrigerator dryer filter (13), which is connected to a refrigerator capillary tube (14). The refrigerator capillary tube (14) is connected to the refrigerator condenser (12) through a refrigerator evaporator (15).

7. The integrated heat dissipation compressor vehicle refrigerator according to claim 6, characterized in that, The heat exchange tube (3) is connected in series on the refrigerator condenser (12). One end of the heat exchange tube (3) is connected to the three-way valve (28), and the other end is connected between the air conditioner evaporator (27) and the air conditioner compressor (21).

8. A control method for an integrated heat dissipation compressor vehicle refrigerator according to claims 1-7, characterized in that, This method includes the following steps: S1. When the refrigerator compressor assembly (1) is turned on, the on-state of the air conditioner compressor assembly (2) is detected. S2. When the air conditioner compressor assembly (2) is in the open state, the refrigerator condenser (12) of the refrigerator compressor assembly (1) can use the low-temperature refrigerant of the air conditioner compressor assembly (2) for heat dissipation. S3. When the air conditioner compressor assembly (2) is not turned on, the three-way valve (28) of the air conditioner compressor assembly (2) is closed, and the condenser fan of the refrigerator compressor assembly (1) is turned on to dissipate heat from the refrigerator condenser (12), thereby adopting conventional air cooling.

9. The control method for an integrated heat dissipation compressor vehicle refrigerator according to claim 8, characterized in that, When using low-temperature refrigerant for heat dissipation in step S2, the three-way valve (28) of the air conditioning compressor assembly (2) is first opened. A portion of the low-temperature refrigerant flows out from the electronic expansion valve (24) of the air conditioning compressor assembly (2) and enters the refrigerator condenser (12) of the refrigerator compressor assembly (1) through the low-temperature refrigerant delivery assembly (4). It exchanges heat with the high-temperature refrigerant discharged by the refrigerator compressor (11) of the refrigerator compressor assembly (1), thereby achieving the cooling and condensation of the high-temperature refrigerant.

10. The control method for an integrated heat dissipation compressor vehicle refrigerator according to claim 8, characterized in that, Step S2 includes the following steps: S21. In order to achieve sufficient heat exchange between the hot and cold refrigerants, it is necessary to control the opening and closing of the three-way valve (28) in a reasonable manner. The degree of heat exchange can be judged according to the refrigerant temperature T at the outlet of the refrigerator condenser (12). The condensing temperature range is T2-T1. S22. When the three-way valve (28) is opened, if the condensing temperature of the refrigerator compressor assembly (1) cannot be reduced to the target temperature for a long time, that is, T is greater than T1, the condenser fan can be turned on to help enhance the heat exchange effect. The condenser fan is turned on according to the opening time t of the three-way valve (28) and the preset opening time t1 of the three-way valve (28). When t is greater than t1, the condenser fan is turned on. S23. When the condensing temperature is too low, i.e., T is less than T2, there is too much low-temperature refrigerant and it cannot absorb heat sufficiently. At this time, the three-way valve (28) needs to be closed.

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