Heat exchange structure, air conditioner and control method

Abstract

The application provides a heat exchange structure, an air conditioner and a control method. The heat exchange structure comprises: an outdoor unit arranged outdoors, the outdoor unit comprising a compressor, a defrosting pipeline arranged on the compressor; an outdoor heat exchanger arranged in the outdoor unit, the outdoor heat exchanger being connected with the defrosting pipeline, the defrosting pipeline being connected with the compressor, so that fluid in the compressor flows into the outdoor heat exchanger; a heating pipeline, one end of the heating pipeline being connected with the outdoor heat exchanger, the other end of the heating pipeline being connected with the compressor, so that fluid in the outdoor heat exchanger flows into the compressor, the heating pipeline being provided with a heating component for heating fluid; the heating pipeline is provided with a gas-liquid separator for separating gas and liquid; a heat exchange device, the heat exchange device being connected with the heating pipeline and the defrosting pipeline, so as to exchange heat between fluid in the heating pipeline and fluid in the defrosting pipeline. The heat exchange structure solves the problem of liquid accumulation in the gas-liquid separator, improves the amount of refrigerant circulation during heating, reduces the defrosting frequency of the unit, and improves the heating use comfort.

Description

Technical Field

[0001] This invention relates to the field of air conditioner technology, specifically to a heat exchange structure, an air conditioner, and a control method. Background Technology

[0002] When an air source heat pump is in heating mode, the outdoor heat exchanger acts as an evaporator, and its temperature is relatively low. When the temperature is below zero degrees Celsius and the outdoor environment has a certain level of humidity, the outdoor heat exchanger may frost up. Frosting of the outdoor heat exchanger will lead to poor heat exchange performance, obstructed air circulation, and reduced heating capacity of the unit. In severe cases, there may be no heating effect or even cold air blowing out, resulting in a poor user experience and even customer complaints.

[0003] Current technology typically adds electric auxiliary heating to the indoor unit to ensure heating performance. However, this method has high power consumption, is not energy-efficient, and is facing gradual phase-out. Furthermore, outdoor heat exchangers usually defrost in reverse, typically by switching to cooling mode via a four-way valve. During defrosting, this can cause fluctuations in indoor temperature, leading to discomfort for users.

[0004] Therefore, existing technologies need further development. Summary of the Invention

[0005] The purpose of this invention is to overcome the above-mentioned technical deficiencies and provide a heat exchange structure, air conditioner and control method to increase the refrigerant circulation during heating, reduce the number of defrosting cycles, improve the comfort of heating use, and solve the problem of liquid accumulation in the gas-liquid separator.

[0006] To achieve the above technical objectives, the present invention adopts the following technical solution: A heat exchange structure is provided, comprising: an outdoor unit installed outdoors, the outdoor unit including a compressor, the compressor being provided with a defrost pipe; an outdoor heat exchanger installed inside the outdoor unit, the outdoor heat exchanger being connected to the defrost pipe, the defrost pipe being connected to the compressor, so that fluid in the compressor flows into the outdoor heat exchanger; a heating pipe, one end of the heating pipe being connected to the outdoor heat exchanger, the other end of the heating pipe being connected to the compressor, so that fluid in the outdoor heat exchanger flows into the compressor, the heating pipe being provided with a heating component for heating the fluid; a gas-liquid separator for separating gas and liquid being provided on the heating pipe; and a heat exchange device connected to both the heating pipe and the defrost pipe to exchange heat between the fluid in the heating pipe and the fluid in the defrost pipe.

[0007] Furthermore, the heat exchange structure also includes: an indoor unit installed indoors, an indoor heat exchanger installed inside the indoor unit, indoor pipes installed on the indoor heat exchanger, and indoor pipes connected to the compressor so that fluid in the compressor can flow into the indoor heat exchanger; and heating pipes connected to the indoor pipes.

[0008] Furthermore, the heat exchange structure also includes a return pipe, one end of which is connected to the indoor heat exchanger and the other end of which is connected to the outdoor heat exchanger, so that the fluid in the indoor heat exchanger can flow into the outdoor heat exchanger; the end of the return pipe away from the indoor heat exchanger is connected to the defrost pipe.

[0009] Furthermore, the heat exchange structure also includes a heat exchange pipeline, one end of which is connected to the return pipeline and the other end of which is connected to the compressor. A return heat exchanger is installed on the heat exchange pipeline and is connected to the return pipeline to exchange heat between the return pipeline and the heat exchange pipeline.

[0010] Furthermore, a heat exchange solenoid valve for controlling the flow rate of the heat exchange pipeline is installed on the heat exchange pipeline, and the heat exchange solenoid valve is located between the reflux heat exchanger and the indoor heat exchanger; and / or, a reflux solenoid valve for controlling the flow rate of the reflux pipeline is installed on the reflux pipeline, and the reflux solenoid valve is located between the reflux heat exchanger and the outdoor heat exchanger.

[0011] Furthermore, a heating solenoid valve for controlling the flow rate of the heating pipeline is installed on the heating pipeline, and the heating solenoid valve is located between the heat exchange device and the outdoor heat exchanger.

[0012] Furthermore, a liquid-distributing solenoid valve is installed on the heating pipeline to control the flow rate of the heating pipeline. The liquid-distributing solenoid valve is located between the gas-liquid separator and the heat exchange device.

[0013] An air conditioner includes a heat exchange structure, which is the heat exchange structure described above.

[0014] A control method applicable to the above-mentioned heat exchange structure includes: acquiring the evaporation temperature t inside the outdoor heat exchanger and acquiring the ambient temperature T outside the outdoor heat exchanger; setting a temperature threshold W; calculating the difference between the evaporation temperature t and the ambient temperature T; if tT > W, then opening the heating pipe; if tT ≤ W, then closing the heating pipe.

[0015] Furthermore, the method for setting the temperature threshold W includes: setting multiple values ​​of W based on the outdoor ambient temperature and outdoor humidity; and / or, setting multiple values ​​of W based on the low pressure of the compressor.

[0016] Beneficial effects:

[0017] 1. When the heat exchange structure of the present invention is in heating operation, the refrigerant enters the outdoor unit heat exchanger through the exhaust bypass branch, which increases the heat exchanger tube temperature, delays the frost formation of the outdoor unit heat exchanger, reduces the number of defrosting cycles of the air conditioner, and improves user comfort.

[0018] 2. The heat exchange structure of the present invention reduces the amount of liquid in the vapor separator by drawing out the accumulated liquid and exchanging heat with the refrigerant in the exhaust bypass branch before entering the compressor suction port, thereby increasing the amount of refrigerant circulating in the system and improving the heating capacity. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the heat exchange structure used in an embodiment of the present invention;

[0020] Figure 2 This is a schematic diagram of the refrigerant flow state in the heat exchange structure used in an embodiment of the present invention.

[0021] The above figures include the following reference numerals:

[0022] 100. Outdoor unit; 1. Compressor; 2. Four-way valve; 3. Outdoor heat exchanger; 4. Return solenoid valve; 5. Heating solenoid valve; 6. Return heat exchanger; 7. Heat exchange solenoid valve; 8. Heat exchange device; 9. Liquid distribution solenoid valve; 10. Defrosting pipeline; 11. Heating component; 12. Gas injection solenoid valve; 13. Enthalpy increasing solenoid valve; 20. Heating pipeline; 30. Indoor pipeline; 40. Return pipeline; 50. Heat exchange pipeline; 200. Indoor unit; 201. Indoor heat exchanger; 202. Gas-liquid separator. Detailed Implementation

[0023] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present application, and not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without creative effort should fall within the scope of protection of the present application.

[0024] According to an embodiment of the present invention, a heat exchange structure is provided; please refer to [link / reference]. Figures 1 to 2 The system includes: an outdoor unit 100 installed outdoors, the outdoor unit 100 including a compressor 1, the compressor 1 being provided with a defrost pipe 10; an outdoor heat exchanger 3, the outdoor heat exchanger 3 being installed inside the outdoor unit 100, the outdoor heat exchanger 3 being connected to the defrost pipe 10, the defrost pipe 10 being connected to the compressor 1, so that fluid in the compressor 1 flows into the outdoor heat exchanger 3; a heating pipe 20, one end of the heating pipe 20 being connected to the outdoor heat exchanger 3, the other end of the heating pipe 20 being connected to the compressor 1, so that fluid in the outdoor heat exchanger 3 flows into the compressor 1, the heating pipe 20 being provided with a heating component 11 for heating the fluid; a gas-liquid separator 202 for separating gas and liquid being provided on the heating pipe 20; and a heat exchange device 8, the heat exchange device 8 being connected to both the heating pipe 20 and the defrost pipe 10, so as to exchange the heat of the fluid in the heating pipe 20 and the fluid in the defrost pipe 10.

[0025] With the above configuration, the heat exchange structure includes a heat exchange device 8 and a heating element 11. The heat exchange device 8 is connected to the exhaust side of the compressor 1 and to the outlet pipe of the gas-liquid separator 202. The heating element 11 is installed on the heating pipe 20 between the outlet pipe of the heat exchange device 8 and the compressor 1, allowing the high-temperature, high-pressure refrigerant discharged from the compressor 1 to enter the heat exchange device 8 for heat exchange. After heat exchange in the heat exchange device 8, the refrigerant enters the outdoor heat exchanger 3 for mixing. Its high-temperature, medium-pressure characteristics increase the coil temperature of the outdoor heat exchanger 3, slowing down the frosting rate. Simultaneously, the refrigerant accumulated at the bottom of the gas-liquid separator 202 is heated and evaporated by the heat exchange device 8 and then heated by the heating element 11, causing the refrigerant to become a superheated gaseous state. Finally, it enters the suction port of the compressor 1 through the gas replenishment solenoid valve 12, increasing the refrigerant circulation flow rate, thereby improving heating capacity, preventing liquid compression, and improving reliability. In this way, by setting a heating element 11, defrosting and heating capacity can be achieved, and liquid accumulation in the gas-liquid separator can be avoided, thus solving the problem of liquid accumulation in the gas-liquid separator.

[0026] Specifically, the heat exchange device 8 exchanges heat between the low-temperature, low-pressure gas-liquid separator 202 discharged from the gas-liquid separator 202 and the high-temperature, high-pressure gaseous refrigerant from the exhaust side of the compressor 1.

[0027] Specifically, when the gas-liquid separator 202 heated in the heat exchange device 8 does not evaporate sufficiently, the heating device operates to ensure that the refrigerant entering the suction port of the compressor 1 is gaseous refrigerant. This serves two purposes: first, to increase the amount of refrigerant circulating in the system, and second, to prevent the compressor 1 from being liquid compressed, thereby improving reliability.

[0028] See Figure 1 , Figure 2 In this embodiment, the heat exchange structure further includes: an indoor unit 200 installed indoors, an indoor heat exchanger 201 installed inside the indoor unit 200, an indoor pipe 30 installed on the indoor heat exchanger 201, and the indoor pipe 30 connected to the compressor 1 so that the fluid in the compressor 1 can flow into the indoor heat exchanger 201; a heating pipe 20 is connected to the indoor pipe 30. In this way, a portion of the high-temperature, high-pressure refrigerant discharged from the compressor 1 enters the indoor heat exchanger 201 to achieve indoor heating through condensation and heat release, while a portion enters the heat exchange device 8 through a bypass branch for heat exchange, thus improving the compressor's operating efficiency.

[0029] In the heat exchange structure of this embodiment, see Figure 1 , Figure 2The heat exchange structure also includes a return pipe 40, one end of which is connected to the indoor heat exchanger 201, and the other end of which is connected to the outdoor heat exchanger 3, so that the fluid in the indoor heat exchanger 201 can flow into the outdoor heat exchanger 3; the end of the return pipe 40 away from the indoor heat exchanger 201 is connected to the defrost pipe 10. In this way, the refrigerant flows from the indoor heat exchanger 201 to the outdoor heat exchanger 3, achieving the effect of refrigerant circulation.

[0030] In the heat exchange structure of this embodiment, the heat exchange structure also includes a heat exchange pipeline 50. One end of the heat exchange pipeline 50 is connected to the return pipeline 40, and the other end of the heat exchange pipeline 50 is connected to the compressor 1. A return heat exchanger 6 is provided on the heat exchange pipeline 50. The return heat exchanger 6 is connected to the return pipeline 40 so as to exchange the heat between the return pipeline 40 and the heat exchange pipeline 50 through the return heat exchanger 6.

[0031] In the heat exchange structure of this embodiment, see Figure 1 , Figure 2 A heat exchange solenoid valve 7 for controlling the flow rate of the heat exchange pipeline 50 is installed on the heat exchange pipeline 50. The heat exchange solenoid valve 7 is located between the return heat exchanger 6 and the indoor heat exchanger 201. A return solenoid valve 4 for controlling the flow rate of the return pipeline 40 is installed on the return pipeline 40. The return solenoid valve 4 is located between the return heat exchanger 6 and the outdoor heat exchanger 3.

[0032] Specifically, an enthalpy-increasing solenoid valve 13 is installed on the heat exchange pipeline 50 to control the refrigerant flow rate in the heat exchange pipeline 50.

[0033] To achieve precise control of the refrigerant quantity in heating pipe 20, see [link / reference]. Figure 1 , Figure 2 In the heat exchange structure of this embodiment, a heating solenoid valve 5 for controlling the flow rate of the heating pipe 20 is provided on the heating pipe 20. The heating solenoid valve 5 is located between the heat exchange device 8 and the outdoor heat exchanger 3.

[0034] Specifically, the system is divided into X intervals based on outdoor ambient temperature and humidity. Within each interval, Y low-pressure intervals are further subdivided based on the system's low-pressure level. Each low-pressure interval is configured with execution conditions, exit conditions, and the adjustment range of the electronic expansion valve. When the difference between the evaporation temperature and the ambient temperature (ambient temperature - evaporation temperature) exceeds the set temperature for each interval, it is determined that the system is in a state of reduced heating capacity, and the heating solenoid valve 5 opens. With a suitable opening degree, high-temperature, high-pressure refrigerant is introduced into the outdoor heat exchanger 3 through the refrigerant branch, mixing with the refrigerant inside the outdoor heat exchanger 3 to increase its evaporation pressure and coil temperature, thereby slowing down the frosting rate of the outdoor heat exchanger 3 and ensuring the heating capacity of the indoor heat exchanger 201.

[0035] Specifically, the evaporation temperature is the temperature at which the refrigerant boils in the evaporator, and the pressure within the system corresponding to the evaporation temperature is the system low-pressure pressure.

[0036] In the heat exchange structure of this embodiment, see Figure 1 , Figure 2 A liquid-distributing solenoid valve 9 is installed on the heating pipe 20 to control the flow rate of the heating pipe 20. The liquid-distributing solenoid valve 9 is located between the gas-liquid separator 202 and the heat exchange device 8.

[0037] Specifically, using the above settings, when the difference between the outlet temperature of the gas-liquid separator 202 and the saturation temperature corresponding to the suction pressure is less than the set value for a continuous period of time, it is determined that the gas-liquid separator 202 already contains gas-liquid separator 202, and the liquid separation solenoid valve 9 is opened.

[0038] The air conditioner of this embodiment includes a heat exchange structure, which is the heat exchange structure described above.

[0039] The control method of this embodiment is applicable to the heat exchange structure described above. The control method includes: obtaining the evaporation temperature t inside the outdoor heat exchanger 3 and obtaining the ambient temperature T outside the outdoor heat exchanger 3; setting a temperature threshold W; calculating the difference between the evaporation temperature t and the ambient temperature T; if tT > W, then opening the heating pipe 20; if tT ≤ W, then closing the heating pipe 20.

[0040] In the control method of this embodiment, the method of setting the temperature threshold W includes: setting multiple values ​​of W based on the outdoor ambient temperature and outdoor humidity; and / or setting multiple values ​​of W based on the low pressure of compressor 1.

[0041] Specifically, the system is divided into X intervals based on outdoor ambient temperature and humidity. Within each interval, Y low-pressure intervals are further subdivided based on the system's low-pressure level. Each low-pressure interval is configured with execution conditions, exit conditions, and the adjustment range of the electronic expansion valve. When the difference between the evaporation temperature and the ambient temperature (ambient temperature - evaporation temperature) exceeds the set temperature for each interval, it is determined that the system is in a state of reduced heating capacity, and the heating solenoid valve 5 opens. With a suitable opening degree, high-temperature, high-pressure refrigerant is introduced into the outdoor heat exchanger 3 through the refrigerant branch, mixing with the refrigerant inside the outdoor heat exchanger 3 to increase its evaporation pressure and coil temperature, thereby slowing down the frosting rate of the outdoor heat exchanger 3 and ensuring the heating capacity of the indoor heat exchanger 201.

[0042] See attached system operation diagram. Figure 2 The operating principle is as follows:

[0043] During normal heating operation, the four-way valve 2 is energized. A portion of the high-temperature, high-pressure gaseous refrigerant discharged from the compressor 1 flows through the four-way valve 2 to the indoor side. After condensation and heat release in the indoor heat exchanger 201, it becomes a high-temperature, medium-pressure gas-liquid separator 202. Then, after being throttled by the return solenoid valve 4, it becomes a low-pressure gas-liquid mixture and enters the outdoor heat exchanger 3 for further evaporation and heat exchange, becoming a low-pressure gaseous refrigerant. It then returns to the gas-liquid separator through the four-way valve 2 and finally returns to the suction side of the compressor 1. The remaining refrigerant enters the heat exchanger 8 through a bypass branch for heat exchange. After heat exchange in the heat exchanger, the refrigerant is throttled by the heating solenoid valve 5 and enters the outdoor heat exchanger for mixing. Finally, it returns to the suction side of the compressor through the vapor separator.

[0044] A heat exchanger 8 and a heating element 11 are added to the system. The heat exchanger 8 has two branches, one of which connects to the exhaust side of the compressor 1, and the other branch connects to the outlet pipe of the gas-liquid separator 202. The heating element 11 is located between the outlet pipe of the heat exchanger 8 and the enthalpy-increasing branch of the compressor 1.

[0045] The refrigerant branch added between the discharge side of compressor 1 and outdoor heat exchanger 3 controls the flow of the heating pipe 20 through an electronic expansion valve. This allows part of the high-temperature and high-pressure refrigerant discharged from compressor 1 to enter indoor heat exchanger 201 for condensation and heat release to achieve indoor heating, while the other part enters heat exchange device 8 through a bypass branch for heat exchange. The refrigerant after heat exchange in heat exchange device 8 enters outdoor heat exchanger 3 for mixing. The high-temperature and medium-pressure refrigerant is used to increase the coil temperature of outdoor heat exchanger 3 and slow down the frosting rate of outdoor heat exchanger 3.

[0046] The gas-liquid separator 202 accumulates at the bottom of the gas-liquid separator 202. After being heated and evaporated by the heat exchange device 8, it is then heated by the heating component 11, causing the refrigerant to become a superheated gaseous state. Finally, it enters the suction port of the compressor 1 through the gas replenishment solenoid valve 12, increasing the refrigerant circulation flow rate, thereby improving the heating capacity, preventing liquid compression, and improving reliability.

[0047] The working principle of the gas replenishment solenoid valve 12 is as follows: During normal heating operation, when the liquid distribution solenoid valve 9 is detected to be open, the electric gas replenishment solenoid valve performs the opening action.

[0048] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0049] Optionally, specific examples in this embodiment can refer to the examples described in the above embodiments, and will not be repeated here.

[0050] The sequence numbers of the embodiments in this application are for descriptive purposes only and do not represent the superiority or inferiority of the embodiments.

[0051] In the above embodiments of this application, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions of other embodiments.

[0052] The above description is only a preferred embodiment of this application. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this application, and these improvements and modifications should also be considered within the scope of protection of this application.

Claims

1. A heat exchange structure, characterized in that, include: An outdoor unit (100) is installed outdoors, the outdoor unit (100) includes a compressor (1), and the compressor (1) is provided with a defrosting pipe (10). An outdoor heat exchanger (3) is installed inside the outdoor unit (100). The outdoor heat exchanger (3) is connected to the defrost pipe (10), and the defrost pipe (10) is connected to the compressor (1) so that the fluid in the compressor (1) can be introduced into the outdoor heat exchanger (3). A heating pipe (20) is provided, one end of which is connected to the outdoor heat exchanger (3) and the other end of which is connected to the compressor (1) so that the fluid in the outdoor heat exchanger (3) flows into the compressor (1). The heating pipeline (20) is equipped with a gas-liquid separator (202) for separating gas and liquid; A heat exchange device (8) is connected to the defrosting pipeline (10) and connected to the heating pipeline (20) downstream of the gas-liquid separator (202) to exchange heat between the fluid flowing out of the gas-liquid separator (202) and the fluid in the defrosting pipeline (10). The heating pipeline (20) is also provided with a heating component (11) for heating fluid, and the heating component (11) is located between the heat exchange device (8) and the compressor (1).

2. The heat exchange structure according to claim 1, characterized in that, The heat exchange structure also includes: An indoor unit (200) is installed indoors, and an indoor heat exchanger (201) is installed inside the indoor unit (200). An indoor pipe (30) is installed on the indoor heat exchanger (201). The indoor pipe (30) is connected to the compressor (1) so that the fluid in the compressor (1) can be introduced into the indoor heat exchanger (201). The heating pipe (20) is connected to the indoor pipe (30).

3. The heat exchange structure according to claim 2, characterized in that, The heat exchange structure also includes a return pipe (40), one end of which is connected to the indoor heat exchanger (201), and the other end of which is connected to the outdoor heat exchanger (3) so that the fluid in the indoor heat exchanger (201) can be introduced into the outdoor heat exchanger (3); the end of the return pipe (40) away from the indoor heat exchanger (201) is connected to the defrost pipe (10).

4. The heat exchange structure according to claim 3, characterized in that, The heat exchange structure also includes a heat exchange pipeline (50), one end of which is connected to the return pipeline (40), and the other end of which is connected to the compressor (1). A return heat exchanger (6) is provided on the heat exchange pipeline (50), and the return heat exchanger (6) is connected to the return pipeline (40) to exchange heat between the return pipeline (40) and the heat exchange pipeline (50) through the return heat exchanger (6).

5. The heat exchange structure according to claim 4, characterized in that, A heat exchange solenoid valve (7) for controlling the flow rate of the heat exchange pipeline (50) is provided on the heat exchange pipeline (50), and the heat exchange solenoid valve (7) is located between the return heat exchanger (6) and the indoor heat exchanger (201); and / or, The return pipeline (40) is provided with a return solenoid valve (4) for controlling the flow rate of the return pipeline (40), and the return solenoid valve (4) is located between the return heat exchanger (6) and the outdoor heat exchanger (3).

6. The heat exchange structure according to claim 2, characterized in that, The defrosting pipeline (10) is equipped with a heating solenoid valve (5) for controlling the flow rate of the defrosting pipeline (10), and the heating solenoid valve (5) is located between the heat exchange device (8) and the outdoor heat exchanger (3).

7. The heat exchange structure according to claim 1, characterized in that, The heating pipeline (20) is provided with a liquid-distributing solenoid valve (9) for controlling the flow rate of the heating pipeline (20), and the liquid-distributing solenoid valve (9) is located between the gas-liquid separator (202) and the heat exchange device (8).

8. An air conditioner, comprising a heat exchange structure, characterized in that, The heat exchange structure is the heat exchange structure according to any one of claims 1 to 7.

9. A control method applicable to the heat exchange structure according to any one of claims 1 to 7, characterized in that, The control method includes: Obtain the evaporation temperature t inside the outdoor heat exchanger (3), obtain the ambient temperature T outside the outdoor heat exchanger (3); set the temperature threshold W; Calculate the difference between the evaporation temperature t and the ambient temperature T; If tT > W, then the heating pipe (20) is opened; if tT ≤ W, then the heating pipe (20) is closed.

10. The control method according to claim 9, characterized in that, The method for setting the temperature threshold W includes: Multiple W values ​​can be set based on the outdoor ambient temperature and humidity; and / or, Multiple W values ​​are set according to the low pressure of the compressor (1).

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