Anti-freezing control method of air conditioner and air conditioner

Abstract

The invention discloses an anti-freezing control method of an air conditioner and the air conditioner. The anti-freezing control method of the air conditioner comprises the steps that when the air conditioner runs in a refrigeration mode, after a compressor is started for a certain time, the air suction temperature of the compressor and the temperature of a refrigerant flowing into an outdoor unit from an indoor unit are detected in each detection period, and the temperature difference obtained by subtracting the temperature of the refrigerant flowing into the outdoor unit from the air suction temperature is calculated; continuously counting and recording the minimum value and the maximum value of the temperature difference from the end of the last anti-freezing treatment; and when the judgment duration is reached, the difference value obtained by subtracting the minimum value from the maximum value of the temperature difference is larger than or equal to the preset difference value, and the air suction temperature and the refrigerant temperature entering the outdoor unit are smaller than or equal to the corresponding preset first temperature, the air conditioner is controlled to conduct anti-freezing treatment. The anti-freezing treatment does not need to depend on pipe temperature detection of the evaporator of the indoor unit, and the cost is low.

Description

Technical Field

[0001] The present invention relates to the technical field of air conditioners, and in particular to an anti-freezing control method of an air conditioner and an air conditioner. Background Art

[0002] In the air conditioning system, when the evaporator is running at a low temperature, frost or freezing will inevitably occur, thus affecting the operating efficiency and reliability of the entire system. When the air conditioning system is running in cooling mode, if the temperature on the low-pressure side is low, frost will gradually accumulate on the surface of the evaporator or form ice, resulting in increased resistance of the heat exchanger, decreased air volume, and further deterioration of indoor heat exchange efficiency. At this time, the refrigerant cannot be completely and effectively evaporated in the evaporator, resulting in a decrease in the cooling capacity of the system and an increased risk of unevaporated refrigerant flowing back to the compressor. This liquid return condition will have a serious impact on the operating stability of the compressor, reduce the service life of the compressor, and may even cause mechanical failure of the compressor.

[0003] Usually, when the indoor and outdoor units can communicate normally, the air conditioning system can monitor the temperature of the evaporator surface in real time through the temperature sensor arranged on the evaporator pipeline, and judge whether the evaporator has frosting or freezing problems based on the detection data. At this time, the air conditioning control module can control the operating parameters, opening or closing of components such as the compressor in real time through the data feedback from the sensor to adjust the evaporator temperature, thereby effectively avoiding freezing problems and ensuring the reliability of the system.

[0004] However, for air-conditioning systems without indoor and outdoor communication, when the indoor and outdoor units of different manufacturers and models are matched, the outdoor unit cannot obtain the indoor pipe temperature status. Moreover, even for air-conditioning systems with indoor and outdoor communication, when the communication between the indoor and outdoor units is interrupted due to signal loss or line failure, the evaporator pipe temperature cannot be obtained.

[0005] The existing control method is generally to detect outdoor low pressure. When the system low pressure gradually drops to the low pressure protection threshold, low pressure protection is performed and the compressor is stopped. This method will cause the unit to frequently perform low pressure protection under long-term low temperature conditions, which is not conducive to system reliability.

[0006] Using a low-pressure sensor to detect low pressure can make anti-freeze judgments based on the specific value of the low pressure. Compared with direct low-pressure protection, different anti-freeze strategies can be adopted according to different low-pressure values, which is better for system reliability. However, the pressure sensor will increase the cost and is not suitable for large-scale promotion and application.

[0007] Therefore, how to provide an anti-freezing control method that is independent of the evaporator tube temperature and has low cost is a technical problem to be solved. Summary of the invention

[0008] In order to solve the technical problem that the anti-freezing control of the indoor evaporator in the prior art depends on the evaporator pipe temperature or is relatively costly, the present invention proposes an anti-freezing control method for an air conditioner and an air conditioner.

[0009] The anti-freezing control method of the air conditioner proposed by the present invention comprises:

[0010] When the air conditioner is running in cooling mode, after the compressor is started for a certain period of time, the suction temperature of the compressor and the temperature of the refrigerant flowing from the indoor unit to the outdoor unit are detected in each detection cycle, and the temperature difference between the suction temperature and the temperature of the refrigerant flowing into the outdoor unit is calculated;

[0011] Continuously counting and recording the minimum and maximum values ​​of the temperature difference since the end of the last antifreeze treatment;

[0012] When the judgment time is reached, and the difference between the maximum value and the minimum value of the temperature difference is greater than or equal to the preset difference, and the intake temperature and the refrigerant temperature entering the outdoor unit are less than or equal to their respective corresponding preset first temperatures, the air conditioner is controlled to perform anti-freeze processing.

[0013] Furthermore, when the air conditioner performs anti-freezing processing, the compressor is controlled to reduce the frequency by a certain amplitude each time according to a certain time frequency until the frequency of the compressor is reduced to a preset minimum frequency.

[0014] Furthermore, when the air conditioner performs anti-freezing processing, if the temperature difference is greater than or equal to a preset minimum value, and / or the suction temperature is greater than its corresponding preset second temperature, and / or the temperature of the refrigerant entering the outdoor unit is greater than its corresponding preset second temperature, the compressor stops reducing the frequency and maintains the current frequency;

[0015] The preset second temperature is greater than the preset first temperature.

[0016] Furthermore, when the air conditioner is performing anti-freeze processing, if the compressor runs at the preset minimum frequency for a preset minimum time, the temperature difference is less than the preset minimum value, the intake temperature is less than or equal to its corresponding preset second temperature, and the refrigerant temperature entering the outdoor unit is less than or equal to its corresponding preset second temperature, the compressor is shut down for a preset time and then restarted to end the anti-freeze processing.

[0017] Furthermore, when the air conditioner is performing anti-freeze processing, if it is detected multiple times that the temperature difference is greater than or equal to the preset minimum value, the intake temperature is greater than its corresponding preset third temperature, and the refrigerant temperature entering the outdoor unit is greater than its corresponding preset third temperature, the anti-freeze processing is exited.

[0018] Furthermore, the communication connection between the outdoor unit and the indoor unit of the air conditioner is disconnected or there is no communication connection.

[0019] The air conditioner provided by the present invention comprises a control module, and the control module adopts the anti-freezing control method of the air conditioner of the above technical solution to perform anti-freezing control.

[0020] In one embodiment, the air conditioner is a heat pump air conditioner.

[0021] Furthermore, the air conditioner detects the temperature of the refrigerant flowing from the indoor unit to the outdoor unit by means of a temperature sensing package arranged at the port E of the four-way valve.

[0022] Furthermore, the control module is a control module of an outdoor unit.

[0023] The present invention can judge and process the anti-freezing condition of the indoor unit without relying on the indoor unit to detect the pipe temperature of the evaporator of the indoor unit in real time. The present invention can directly detect the temperature of the refrigerant entering the outdoor unit on the outdoor unit side, and then monitor its change, and judge whether the indoor unit needs to be anti-freezing based on the change. The technical solution of the present invention does not require the outdoor unit to communicate with the indoor unit, and is therefore particularly suitable for when the indoor unit lacks a communication connection with the outdoor unit or a communication failure occurs. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The present invention is described in detail below with reference to the embodiments and accompanying drawings, wherein:

[0025] Figure 1 It is a main flow chart of an embodiment of the present invention.

[0026] Figure 2 The present invention is a flow chart of compressor frequency control for anti-freezing processing according to an embodiment of the present invention.

[0027] Figure 3 The present invention is a flow chart of the control of stopping the compressor according to an embodiment of the present invention.

[0028] Figure 4 4 is a control flow chart for maintaining the compressor frequency according to an embodiment of the present invention.

[0029] Figure 5 It is a control flow chart for restoring the normal operation of the compressor according to an embodiment of the present invention.

[0030] Figure 6 It is a schematic diagram of the pipe connection of an air conditioner according to an embodiment of the present invention.

[0031] Description of reference numerals:

[0032] 1. Compressor; 2. Four-way valve; 3. Condenser; 4. Outdoor fan; 5. Gas-liquid separator; 6. Intake temperature sensor; 7. Outdoor ambient temperature sensor; 8. Electronic expansion valve; 9. Liquid pipe valve; 10. Gas pipe valve sensor; 11. Gas pipe valve; 12. Evaporator; 13. Indoor ambient temperature sensor; 14. Indoor fan; 100. Outdoor unit; 200. Indoor unit. DETAILED DESCRIPTION

[0033] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0034] Thus, a feature indicated in this specification will be used to illustrate one of the features of an embodiment of the present invention, rather than implying that each embodiment of the present invention must have the described feature. In addition, it should be noted that this specification describes many features. Although some features can be combined together to illustrate possible system designs, these features can also be used in other combinations that are not explicitly described. Thus, unless otherwise stated, the described combinations are not intended to be limiting.

[0035] When the indoor unit cannot communicate with the outdoor unit, it loses real-time monitoring of important information such as the evaporator tube temperature of the indoor unit. Especially in low temperature mode, the surface temperature of the evaporator is low. If the load of the compressor cannot be adjusted in time, the frost layer on the surface of the evaporator will gradually thicken, the resistance of the heat exchanger will also increase, and the air volume will decrease, which will further reduce the cooling effect of the air conditioning system. Normally, starting or stopping the compressor is one of the main means to prevent the evaporator from freezing. In the absence of communication support, the compressor may continue to run, increasing the risk of evaporator freezing.

[0036] In order to solve these problems, the present invention proposes a new anti-freezing control method for an air conditioner, which is independent of the tube temperature of the evaporator and has a low cost, and mainly includes the following steps.

[0037] like Figure 1 As shown, when the air conditioner is running in cooling mode, if the compressor has been started for a certain period of time, the suction temperature of the compressor and the temperature of the refrigerant flowing from the indoor unit to the outdoor unit are detected in each detection cycle, and the temperature difference of the suction temperature minus the temperature of the refrigerant flowing into the outdoor unit is calculated.

[0038] The specific duration in the above steps depends on the specific model of the compressor or the specific situation of the air conditioner. It is necessary to achieve a stable operation state of the air conditioner cooling mode before starting the anti-freeze detection to avoid misjudgment due to failure to reach a stable state.

[0039] The minimum and maximum values ​​of the temperature difference are continuously counted and recorded since the end of the last anti-freeze treatment. That is to say, after each anti-freeze treatment, a new round of temperature difference and maximum and minimum temperature difference statistics and records begins. The relevant data of the temperature difference of the last anti-freeze treatment is not used for the relevant judgment of the current round of temperature difference.

[0040] When the judgment time is reached, and the difference between the maximum value and the minimum value of the temperature difference is greater than or equal to the preset difference, and the intake temperature and the refrigerant temperature entering the outdoor unit are less than or equal to their respective corresponding preset first temperatures, the air conditioner is controlled to perform anti-freeze processing.

[0041] Although the intake temperature and the temperature of the refrigerant entering the outdoor unit have their own corresponding preset first temperatures, their preset first temperatures may be the same or different, and the technicians in this field can determine it according to the specific situation.

[0042] In the above technical scheme, the present invention detects two refrigerant temperatures, one is the temperature of the refrigerant entering the outdoor unit from the indoor unit, and the other is the intake temperature. In fact, after the refrigerant enters the outdoor unit from the indoor unit, there is no heating or cooling equipment, basically just some pipes. Therefore, the change in the refrigerant temperature is usually small. Only when the evaporator is likely to freeze, the temperature of the refrigerant will change significantly, that is, the maximum value of the temperature difference will change significantly, which will cause the temperature of the refrigerant to satisfy the difference between the maximum value of the temperature difference and the minimum value of the temperature difference to be greater than or equal to the preset difference. If the intake temperature and the temperature of the refrigerant entering the outdoor unit are also less than or equal to their respective preset first temperatures, it means that the evaporator may be frozen and anti-freeze treatment needs to be started. Through the above method of the present invention, anti-freeze control can be performed without relying on the pipe temperature of the evaporator, and the required hardware is only the temperature sensing package, so the cost is relatively low and suitable for promotion.

[0043] like Figure 2 As shown, in a specific embodiment, when the air conditioner performs anti-freezing processing, the compressor is controlled to reduce the frequency by a certain amplitude each time according to a certain time frequency until the frequency of the compressor is reduced to a preset minimum frequency.

[0044] This embodiment is a specific operation of the air conditioner to perform anti-freezing treatment. The present invention first reduces the frequency of the air conditioner, and the air conditioner reduces the frequency at a certain time frequency to avoid excessive temperature fluctuations in the indoor unit.

[0045] like Figure 4 As shown, in one embodiment, when the air conditioner performs anti-freeze processing, if the temperature difference is greater than or equal to the preset minimum value, and / or the intake temperature is greater than its corresponding preset second temperature, and / or the temperature of the refrigerant entering the outdoor unit is greater than its corresponding preset second temperature, the compressor stops reducing the frequency and maintains the current frequency; the preset second temperature is greater than the preset first temperature.

[0046] In this embodiment, the preset minimum value is less than the preset difference value, that is, when the difference between the maximum value and the minimum value of the temperature difference is reduced, it indicates that the anti-freezing treatment has a certain effect, and the compressor frequency can be maintained at this time. Similarly, the rise in the suction temperature and the temperature of the refrigerant entering the outdoor unit also indicates that the anti-freezing treatment has a certain effect, and the compressor frequency can be maintained without reducing the frequency.

[0047] like Figure 3 As shown, in one embodiment, when the air conditioner performs anti-freeze processing, if the compressor runs at the preset minimum frequency for the preset minimum time, the temperature difference is less than the preset minimum value, the suction temperature is less than or equal to the corresponding preset second temperature, and the refrigerant temperature entering the outdoor unit is less than or equal to the corresponding preset second temperature, the compressor is shut down and restarted after the preset shutdown time to end the anti-freeze processing.

[0048] In this embodiment, if the compressor has dropped to a preset minimum frequency and has been running at the preset minimum frequency for a sufficiently long time, and none of the temperature difference, intake temperature, and refrigerant temperature entering the outdoor unit meet the standards, the compressor needs to be shut down to achieve a better anti-freeze treatment effect, and then shut down for a preset time and then restarted, and a round of anti-freeze treatment is completed.

[0049] like Figure 5 As shown, in one embodiment, when the air conditioner is performing anti-freeze processing, if it is detected multiple times that the temperature difference is greater than or equal to the preset minimum value, the intake temperature is greater than its corresponding preset third temperature, and the refrigerant temperature entering the outdoor unit is greater than its corresponding preset third temperature, the anti-freeze processing is exited.

[0050] In this embodiment, when the gap between the maximum and minimum values ​​of the temperature difference is significantly reduced compared to when the anti-freeze treatment is entered, and the intake temperature and the temperature of the refrigerant entering the outdoor unit are significantly increased, it means that the anti-freeze treatment is effective and the anti-freeze treatment can be exited without shutting down the machine, thus avoiding the frequent start and stop caused by the anti-freeze method in the prior art that only uses the compressor start and stop method.

[0051] When the above-mentioned situations may occur in an embodiment, after judging a condition, no matter whether it is satisfied or not, it is necessary to wait for a certain period of time before making the next judgment to avoid misjudgment due to temperature fluctuation during adjustment.

[0052] In one embodiment, the communication connection between the outdoor unit and the indoor unit of the air conditioner is disconnected or there is no communication connection. The above technical solution of the present invention can accurately prevent freezing when the outdoor unit and the indoor unit cannot communicate. In addition, even if there is communication between the outdoor unit and the indoor unit, when the evaporator pipe temperature sensing package of the indoor unit fails, or when multiple verifications are required to prevent freezing, the anti-freezing control method of the present invention can be applied.

[0053] The present invention also protects a corresponding air conditioner, which includes a control module, and the control module adopts the anti-freezing control method of the air conditioner of the above technical solution to perform anti-freezing control.

[0054] In one embodiment, the air conditioner is a heat pump air conditioner. If the air conditioner is a heat pump air conditioner, a temperature sensing package can be set at the port E of the four-way valve to detect the temperature of the refrigerant flowing from the indoor unit to the outdoor unit. This temperature can also be called the air pipe valve temperature. By monitoring and judging the suction temperature and the air pipe valve temperature, anti-freezing processing can be carried out in time.

[0055] In one embodiment, the control module is a control module of an outdoor unit, and the control module of the outdoor unit can monitor the suction temperature and the air pipe valve temperature. Even if the indoor unit is of different brands, it does not affect the judgment of the anti-freezing treatment of the outdoor unit, thereby improving market applicability. The present invention is not limited to detecting the air pipe valve temperature, and can also detect the refrigerant temperature of other pipe sections entering the indoor unit, such as the refrigerant temperature before the air pipe valve.

[0056] Figure 6 A schematic diagram of a pipe connection of an air conditioner of the present invention is shown. The air conditioner is a heat pump air conditioner, comprising an indoor unit 100 and an outdoor unit 200.

[0057] The indoor unit 100 includes a compressor 1, a four-way valve 2, a condenser 3 (in cooling mode), an outdoor fan 4, a gas-liquid separator 5, an intake temperature sensor 6, an outdoor ambient temperature sensor 7, an electronic expansion valve 8, a liquid pipe valve 9, a gas pipe valve sensor 10, and a gas pipe valve 11.

[0058] The indoor unit 200 includes an evaporator 12 (in cooling mode), an indoor ambient temperature sensing package 13 , and an indoor fan 14 .

[0059] The concept of the present invention is described in detail below by taking the air conditioner as an example.

[0060] When the air conditioner is turned on and in cooling mode, if the compressor runs continuously for more than 10 minutes, the suction temperature T 吸气 And the air pipe valve temperature T 气管阀门 , and calculate the temperature difference △T=T 吸气 -T 气管阀门 .

[0061] At the same time, find the minimum value △Tmin of the temperature difference △T and the maximum value △Tmax of the temperature difference △T.

[0062] After recording the minimum value △Tmin, record the value of the temperature difference △T at any subsequent time in this round. As long as the new temperature difference △T in this round is less than △Tmin, the minimum value of the temperature difference △T becomes the new minimum value △Tmin. After completing an anti-freeze control, re-record the minimum value △Tmin.

[0063] Similarly, after recording the maximum value △Tmax, record the value of the temperature difference △T at any subsequent time in this round. As long as the temperature difference △T>△Tmax, the maximum value of the temperature difference △T becomes the new maximum value △Tmax. After completing an anti-freeze control, re-record the maximum value △Tmax.

[0064] After the compressor has been running for 18 minutes, if the following conditions are met at the same time, the anti-freeze process will be started immediately:

[0065] A1.△Tmax-△Tmin≥2℃;

[0066] A2.T 气管阀门 ≤-3℃;

[0067] A3.T 吸气 ≤-3℃;

[0068] The specific running time of the compressor can be adjusted according to the actual situation. Setting a cumulative running time is to avoid misjudgment caused by temperature fluctuations. It can also be monitored and judged after the compressor is running stably to avoid misjudgment. Similarly, the specific temperature value can also be adjusted according to the actual situation. In the case of freezing indoors, the heat exchange efficiency of the indoor heat exchanger deteriorates, the refrigerant is in an incompletely evaporated state, and the refrigerant coming out of the evaporator is in a gas-liquid mixed state. As the freezing intensifies, the liquid ratio will gradually increase. Due to the extended resistance loss from the connecting pipeline and the air pipe valve to the compressor suction port, the system low pressure will be further reduced, and the refrigerant temperature will also be reduced. Through T 气管阀门 With T 吸气 The absolute value is lower than -3℃ (this value is an empirical value. Generally, below -3℃, the heat exchanger fins will show obvious frost and ice). This can prove that the saturation temperature corresponding to the system low pressure is below zero, and there are freezing phenomena such as frost and ice on the indoor heat exchanger. By comparing the difference between the maximum value △Tmax and the minimum value △Tmin, it can reflect the degree of system low pressure reduction after the refrigerant freezes, and enter the anti-freeze protection in time before the freezing deteriorates sharply.

[0069] After entering the anti-freeze state, the compressor is controlled to reduce the frequency by 10Hz every 2 minutes until the frequency drops to the lowest frequency allowed by the program.

[0070] If any of the following conditions B1 to B3 are met during the frequency reduction process, the compressor stops reducing the frequency and does not allow the frequency to increase. In other words, the compressor will maintain the current frequency.

[0071] B1.△T≥1℃;

[0072] B2.T 气管阀门 >-2℃;

[0073] B3.T 吸气 >-2℃;

[0074] The above temperature value is also an example, and technicians in this field can adjust it as needed, and it is not used to limit the scope of protection of the present invention. A positive value of △T indicates that the compressor has no risk of liquid return and can operate reliably. The absolute value of the air pipe valve temperature or the suction temperature is higher than 0°C, which also means that the pressure of the refrigerant at this time (the saturation temperature corresponding to the low pressure) is also higher than 0°C. In the refrigeration cycle system, considering the pipeline pressure loss, the pressure on the suction side is lower than the pressure of the indoor evaporator. If it is detected to be higher than 0°C at this time, it can be considered that the indoor evaporator pipe temperature is also higher than 0°C, and there is no frost or freezing problem. Normal operation can be restored.

[0075] After 6 minutes, if the conditions C1 to C3 are met at the same time, the compressor will resume normal control. Otherwise, the control without frequency increase will continue.

[0076] C1.△T≥1℃;

[0077] C2.T 气管阀门 >0℃;

[0078] C3.T 吸气 >0℃;

[0079] The above 6 minutes is an example of a specific numerical value of the interval time between two judgments in this embodiment, and is not used to limit the protection scope of the present invention. In fact, in the process of reducing the frequency or maintaining the current frequency, if multiple judgments are made and the C1 to C3 conditions are met at the same time, it means that the anti-freezing measures of the evaporator of the indoor unit have achieved obvious results, the anti-freezing process can be terminated, and the compressor can also be restored to normal control.

[0080] If the compressor is reduced to the lowest frequency and it is still judged that any of the conditions B1 to B3 cannot be met, the compressor will stop running after running at the lowest frequency for 3 minutes.

[0081] After the compressor stops for 3 minutes, the outdoor unit restarts and re-tests the anti-freezing condition according to the normal cooling operation control. The specific time value mainly refers to the compressor's requirement of 6-on and 3-off, that is, it runs for at least 6 minutes after starting and stops for at least 3 minutes after stopping. Those skilled in the art can make specific settings based on the requirements of the compressor.

[0082] In addition, although the above examples are based on heat pump air conditioners, the present invention is not limited to heat pump air conditioners, but can also be applied to refrigeration-only air conditioners.

[0083] The present invention can be used for air-conditioning systems without indoor and outdoor communication. When indoor and outdoor units of different manufacturers and models are matched, when the outdoor unit cannot obtain the indoor pipe temperature status, anti-freezing processing can be performed in time to ensure the reliability of the system, and the implementation cost is also low.

[0084] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. An anti-freezing control method for an air conditioner, characterized in that: include: When the air conditioner is running in cooling mode, after the compressor is started for a certain period of time, the suction temperature of the compressor and the temperature of the refrigerant flowing from the indoor unit to the outdoor unit are detected in each detection cycle, and the temperature difference between the suction temperature and the temperature of the refrigerant flowing into the outdoor unit is calculated; Continuously counting and recording the minimum and maximum values ​​of the temperature difference since the end of the last antifreeze treatment; When the judgment time is reached, and the difference between the maximum value and the minimum value of the temperature difference is greater than or equal to the preset difference, and the intake temperature and the refrigerant temperature entering the outdoor unit are less than or equal to their respective corresponding preset first temperatures, the air conditioner is controlled to perform anti-freeze processing.

2. The air conditioner anti-freezing control method according to claim 1, characterized in that: When the air conditioner performs anti-freezing processing, the compressor is controlled to reduce the frequency by a certain amplitude each time according to a certain time frequency until the frequency of the compressor is reduced to a preset minimum frequency.

3. The air conditioner anti-freezing control method according to claim 2, characterized in that: When the air conditioner performs anti-freezing processing, if the temperature difference is greater than or equal to the preset minimum value, and / or the suction temperature is greater than the corresponding preset second temperature, and / or the temperature of the refrigerant entering the outdoor unit is greater than the corresponding preset second temperature, the compressor stops reducing the frequency and maintains the current frequency; The preset second temperature is greater than the preset first temperature.

4. The air conditioner anti-freezing control method according to claim 2, characterized in that: When the air conditioner is performing anti-freeze processing, if the compressor runs at the preset minimum frequency for the preset minimum time, the temperature difference is less than the preset minimum value, the suction temperature is less than or equal to its corresponding preset second temperature, and the refrigerant temperature entering the outdoor unit is less than or equal to its corresponding preset second temperature, the compressor is shut down for a preset time and then restarted to end the anti-freeze processing.

5. The air conditioner anti-freezing control method according to claim 2, characterized in that: When the air conditioner is performing anti-freeze processing, if it is detected multiple times that the temperature difference is greater than or equal to the preset minimum value, the intake temperature is greater than its corresponding preset third temperature, and the refrigerant temperature entering the outdoor unit is greater than its corresponding preset third temperature, the anti-freeze processing is exited.

6. The anti-freezing control method of the air conditioner according to any one of claims 1 to 5, characterized in that: The communication connection between the outdoor unit and the indoor unit of the air conditioner is disconnected or there is no communication connection.

7. An air conditioner, comprising a control module, characterized in that: The control module performs anti-freezing control using the anti-freezing control method of the air conditioner according to any one of claims 1 to 6.

8. The air conditioner according to claim 7, characterized in that: The air conditioner is a heat pump air conditioner.

9. The air conditioner according to claim 8, characterized in that: The air conditioner detects the temperature of the refrigerant flowing from the indoor unit to the outdoor unit by means of a temperature sensing package arranged at the port E of the four-way valve.

10. The air conditioner according to claim 9, characterized in that The control module is a control module of the outdoor unit.

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