Self-cleaning control method for automotive air conditioner

Abstract

The present application relates to the technical field of automobile air conditioning, in particular to a self-cleaning control method of automobile air conditioner. The present application aims to solve the problem that the existing outdoor machine external type automobile air conditioner is easy to be dirty and blocked. For this purpose, the automobile air conditioner of the present application comprises a compressor, an outdoor heat exchanger, an outdoor fan, a throttling element, an indoor heat exchanger and an indoor fan, and the self-cleaning control method comprises: obtaining the outdoor environment temperature, the operating frequency of the compressor, the middle temperature of the outdoor heat exchanger and the outlet temperature of the outdoor heat exchanger when the automobile air conditioner is running; calculating the standard supercooling degree of the outdoor heat exchanger based on the outdoor environment temperature and the operating frequency; calculating the actual supercooling degree of the outdoor heat exchanger based on the middle temperature and the outlet temperature; comparing the size of the standard supercooling degree and the actual supercooling degree; and selectively performing self-cleaning on the outdoor heat exchanger based on the comparison result. The present application can judge the degree of dirt and blockage of the outdoor heat exchanger and effectively perform self-cleaning on the outdoor heat exchanger in time.

Description

Technical Field

[0001] This invention relates to the field of automotive air conditioning technology, and more specifically to a self-cleaning control method for automotive air conditioning. Background Technology

[0002] To improve the comfort of the driver's cab, existing trucks, RVs, buses, and other vehicles are equipped with air conditioning.

[0003] The outdoor unit of an air conditioner in a truck or RV is typically installed on the roof or behind the driver's cab, and is constantly exposed to the outside. During long-term transportation, dust or oil stains accumulate on the surface of the heat exchanger, obstructing airflow. Over time, the heat exchanger surface becomes very dirty, severely affecting heat exchange efficiency. Furthermore, air conditioners are generally powered by batteries. If the heat exchanger is dirty and clogged, it will lead to two problems: firstly, increased battery consumption, reducing battery life; and secondly, a decrease in indoor cooling efficiency, significantly impacting the driver's comfort needs.

[0004] Accordingly, a new technical solution is needed in this field to solve the above problems. Summary of the Invention

[0005] To address at least one of the aforementioned problems in the prior art, namely, to solve the problem of easy dirt and clogging in existing outdoor unit-type automotive air conditioners, this application provides a self-cleaning control method for automotive air conditioners. The automotive air conditioner includes a compressor, an outdoor heat exchanger, an outdoor fan, a throttling element, an indoor heat exchanger, and an indoor fan. The vehicle is equipped with a battery, which is connected to the automotive air conditioner to supply power. The self-cleaning control method includes:

[0006] When the car air conditioner is running, the outdoor ambient temperature, the operating frequency of the compressor, the middle temperature of the outdoor heat exchanger, and the outlet temperature of the outdoor heat exchanger are acquired.

[0007] The standard subcooling of the outdoor heat exchanger is determined based on the outdoor ambient temperature and the operating frequency.

[0008] The actual subcooling of the outdoor heat exchanger is determined based on the central temperature and the outlet temperature.

[0009] Compare the standard subcooling with the actual subcooling.

[0010] Based on the comparison results, the outdoor heat exchanger is selectively self-cleaned.

[0011] In the preferred embodiment of the above-mentioned self-cleaning control method for automotive air conditioning, the step of "determining the standard subcooling of the outdoor heat exchanger based on the outdoor ambient temperature and the operating frequency" further includes:

[0012] The standard subcooling of the outdoor heat exchanger is calculated using the following formula:

[0013] △t=k1×Tao+k2×f+b

[0014] Wherein, △t is the standard subcooling; Tao is the outdoor ambient temperature; f is the operating frequency; k1 is the ambient temperature coefficient; k2 is the frequency coefficient; and b is the correction value for the subcooling.

[0015] In the preferred embodiment of the above-mentioned self-cleaning control method for automotive air conditioning, the step of "determining the actual subcooling of the outdoor heat exchanger based on the central temperature and the outlet temperature" further includes:

[0016] The actual subcooling of the outdoor heat exchanger is calculated using the following formula:

[0017] △T=Tc-Tout

[0018] Wherein, △T is the actual subcooling degree; Tc is the middle temperature of the outdoor heat exchanger; and Tout is the outlet temperature of the outdoor heat exchanger.

[0019] In the preferred embodiment of the above-mentioned self-cleaning control method for automotive air conditioning, the step of "selectively controlling the outdoor heat exchanger to perform self-cleaning based on the comparison results" further includes:

[0020] If the standard subcooling is greater than the actual subcooling, then the difference between the standard subcooling and the actual subcooling is further calculated;

[0021] Based on the range of the difference, the outdoor heat exchanger is selectively controlled to perform self-cleaning.

[0022] In the preferred embodiment of the above-mentioned self-cleaning control method for automotive air conditioning, the step of "selectively controlling the outdoor heat exchanger to perform self-cleaning based on the range of the difference" further includes:

[0023] If the difference is greater than or equal to a first preset threshold, the car air conditioner is controlled to immediately run in self-cleaning mode.

[0024] In the preferred embodiment of the above-mentioned self-cleaning control method for automotive air conditioning, the step of "selectively controlling the outdoor heat exchanger to perform self-cleaning based on the range of the difference" further includes:

[0025] If the difference is less than the first preset threshold and greater than or equal to the second preset threshold, then the compressor is controlled to stop and the external fan is controlled to rotate in the opposite direction.

[0026] After the external fan has rotated in the reverse direction for a first preset time, the compressor is controlled to start running, and the external fan rotates in the forward direction.

[0027] In the preferred embodiment of the above-mentioned self-cleaning control method for automotive air conditioning, the self-cleaning control method further includes:

[0028] The internal fan is controlled to continue running while, before, or after the compressor is stopped.

[0029] In the preferred embodiment of the above-mentioned self-cleaning control method for automotive air conditioning, the step of "selectively controlling the outdoor heat exchanger to perform self-cleaning based on the range of the difference" further includes:

[0030] If the difference is less than the second preset threshold and greater than zero, the car air conditioner will continue to run until a shutdown signal is received or the cabin temperature equals the set temperature, at which point the car air conditioner will be controlled to run in self-cleaning mode.

[0031] In the preferred embodiment of the above-mentioned self-cleaning control method for automotive air conditioning, the self-cleaning control method further includes:

[0032] If the standard subcooling is less than or equal to the actual subcooling, the car air conditioning is controlled to maintain its current operating state.

[0033] In the preferred embodiment of the above-mentioned self-cleaning control method for automotive air conditioning, the automotive air conditioning further includes a reversing valve, and the step of "controlling the operation of the automotive air conditioning in self-cleaning mode" further includes:

[0034] The car air conditioner is controlled to operate in heating mode to cause frost to form on the surface of the outdoor heat exchanger.

[0035] The vehicle's air conditioning is controlled to operate in cooling mode to defrost the surface of the outdoor heat exchanger.

[0036] It should be noted that, in the preferred embodiment of this application, the automotive air conditioner includes a compressor, an outdoor heat exchanger, an outdoor fan, a throttling element, an indoor heat exchanger, and an indoor fan. The vehicle is equipped with a battery, which is connected to the automotive air conditioner to supply power. The self-cleaning control method includes: when the automotive air conditioner is running, acquiring the outdoor ambient temperature, the compressor's operating frequency, the mid-temperature of the outdoor heat exchanger, and the outlet temperature of the outdoor heat exchanger; determining the standard subcooling of the outdoor heat exchanger based on the outdoor ambient temperature and the operating frequency; determining the actual subcooling of the outdoor heat exchanger based on the mid-temperature and the outlet temperature; comparing the standard subcooling with the actual subcooling; and selectively self-cleaning the outdoor heat exchanger based on the comparison results.

[0037] By determining the standard subcooling and actual subcooling of the outdoor heat exchanger and comparing their magnitudes, the degree of dirt and blockage in the outdoor heat exchanger can be judged. This allows for timely and effective self-cleaning of the outdoor heat exchanger when dirt and blockage occur, ensuring the heat exchange effect of the outdoor heat exchanger, improving the comfort of the driver's cabin during air conditioning operation, reducing battery power consumption, and extending battery range.

[0038] Furthermore, by using a formula to calculate the standard subcooling, the accuracy of the standard subcooling calculation can be improved, thereby enhancing the accuracy of judgment under different outdoor environments.

[0039] Furthermore, by determining the self-cleaning timing and specific self-cleaning method of the outdoor heat exchanger based on the range of the difference between the standard subcooling and the actual subcooling, this application can adopt different self-cleaning methods in a targeted manner based on different degrees of dirt and blockage, thereby improving the self-cleaning effect and efficiency. Attached Figure Description

[0040] The self-cleaning control method for automotive air conditioning according to this application will be described below with reference to the accompanying drawings. In the drawings:

[0041] Figure 1 This is a flowchart of the self-cleaning control method for automotive air conditioning according to this application;

[0042] Figure 2 This is a logic diagram of the self-cleaning control method for automotive air conditioning according to this application. Detailed Implementation

[0043] Preferred embodiments of this application are described below with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are merely illustrative of the technical principles of this application and are not intended to limit the scope of protection of this application. For example, although the detailed steps of the method of this application are described in detail below, those skilled in the art can combine, split, and rearrange the following steps without departing from the basic principles of this application. Such modified technical solutions do not change the basic concept of this application and therefore also fall within the scope of protection of this application.

[0044] It should also be noted that in the following description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0045] First refer to Figure 1 This application is described. Among other things, Figure 1 This is a flowchart of the self-cleaning control method for automotive air conditioning according to this application.

[0046] like Figure 1As shown, to address the problem of easy clogging and dirt buildup in existing outdoor-unit automotive air conditioners, this application provides a self-cleaning control method for automotive air conditioners. The automotive air conditioner includes a compressor, an outdoor heat exchanger, an outdoor fan, a throttling element, an indoor heat exchanger, and an indoor fan. The compressor, outdoor heat exchanger, throttling element, and indoor heat exchanger are connected via refrigerant piping to form a refrigerant circulation. The throttling element is a valve body such as an electronic expansion valve that can control its opening degree. The automotive air conditioner is installed in a transport truck, bus, or RV. The vehicle is equipped with a battery, which is connected to the automotive air conditioner to power the parking air conditioner. The self-cleaning control method includes:

[0047] S101. During the operation of the vehicle air conditioning, the outdoor ambient temperature, the compressor operating frequency, the mid-temperature of the outdoor heat exchanger, and the outlet temperature of the outdoor heat exchanger are acquired. For example, during the operation of the vehicle air conditioning, the outdoor ambient temperature is acquired by a temperature sensor installed on the outdoor unit (such as on the outdoor unit casing or air inlet), the compressor operating frequency is acquired by the compressor's computer board or frequency detection electrical component, the mid-temperature of the outdoor heat exchanger is acquired by a temperature sensor installed in the middle of the outdoor heat exchanger pipeline (approximately the middle of the pipeline's length), and the outlet temperature of the outdoor heat exchanger is acquired by a temperature sensor installed on the outdoor heat exchanger outlet pipeline.

[0048] S103. Determine the standard subcooling of the outdoor heat exchanger based on the outdoor ambient temperature and operating frequency. For example, the standard subcooling can be determined based on a fitting formula or reference table between the outdoor ambient temperature, operating frequency, and the standard subcooling of the outdoor heat exchanger. The standard subcooling refers to the theoretical subcooling of the outdoor heat exchanger under the current operating environment, which can be obtained experimentally. For instance, when the outdoor heat exchanger is not clogged, adjust the air conditioner's operating parameters to a state with optimal cooling effect, and calculate the subcooling of the outdoor heat exchanger at this time as the standard subcooling.

[0049] S105. Determine the actual subcooling of the outdoor heat exchanger based on the mid-temperature and outlet temperatures. For example, determine the actual subcooling based on a calculation formula or a reference table relating the mid-temperature, outlet temperature, and the actual subcooling of the outdoor heat exchanger.

[0050] S107. Compare the standard subcooling with the actual subcooling; for example, by calculating the difference or ratio between the two to compare the standard subcooling with the actual subcooling.

[0051] S109. Based on the comparison results, selectively perform self-cleaning on the outdoor heat exchanger. For example, if the standard subcooling is less than or equal to the actual subcooling, it indicates that the blockage is not serious, and there is no need to clean the outdoor heat exchanger. Conversely, if the standard subcooling is greater than the actual subcooling, it indicates that the outdoor heat exchanger is blocked, causing the actual subcooling to decrease. In this case, self-cleaning of the outdoor heat exchanger is necessary to reduce the blockage.

[0052] As can be seen, by determining the standard subcooling and actual subcooling of the outdoor heat exchanger and comparing their magnitudes, this application can judge the degree of dirt and blockage of the outdoor heat exchanger. This enables timely and effective self-cleaning of the outdoor heat exchanger when dirt and blockage occur, ensuring the heat exchange effect of the outdoor heat exchanger, improving the comfort of the driver's cab during air conditioning operation, reducing battery power consumption, and extending battery range.

[0053] The preferred embodiments of this application are described below.

[0054] In a preferred embodiment, the step of "calculating the standard subcooling of the outdoor heat exchanger based on the outdoor ambient temperature and operating frequency" further includes: calculating and determining the standard subcooling of the outdoor heat exchanger using the following formula:

[0055] △t=k1×Tao+k2×f+b (1)

[0056] In formula (1), Δt is the standard subcooling; Tao is the outdoor ambient temperature; f is the compressor operating frequency; k1 is the ambient temperature coefficient; k2 is the frequency coefficient; and b is the correction value for subcooling. Among them, k1, k2, and b can be determined based on experiments or experience, and will not be elaborated here.

[0057] As can be seen from formula (1), a standard subcooling degree is calculated for each type of outdoor ambient temperature and compressor operating frequency.

[0058] By using a formula to calculate the standard subcooling, the accuracy of the standard subcooling calculation can be improved, thereby enhancing the accuracy of judgment under different outdoor environments.

[0059] In a preferred embodiment, the step of "calculating the actual subcooling of the outdoor heat exchanger based on the midpoint temperature and the outlet temperature" further includes: calculating and determining the actual subcooling of the outdoor heat exchanger using the following formula:

[0060] △T=Tc-Tout (2)

[0061] In formula (2), △T is the actual subcooling; Tc is the temperature at the middle of the outdoor heat exchanger; and Tout is the outlet temperature of the outdoor heat exchanger.

[0062] The actual subcooling can be calculated quickly and easily by calculating the mid-temperature and outlet temperatures of the outdoor heat exchanger.

[0063] In a preferred embodiment, the step of "selectively controlling the outdoor heat exchanger to perform self-cleaning based on the comparison results" further includes: if the standard subcooling is less than or equal to the actual subcooling, then controlling the vehicle air conditioning to maintain its current operating state. If the standard subcooling is greater than the actual subcooling, then further calculating the difference between the standard subcooling and the actual subcooling; and selectively controlling the outdoor heat exchanger to perform self-cleaning based on the range of the difference.

[0064] Specifically, if the standard subcooling is less than or equal to the actual subcooling, the outdoor heat exchanger has a good heat exchange effect. The temperature difference between the middle temperature and the outlet temperature of the heat exchanger is large, which proves that the heat exchanger is not clogged or only slightly clogged and does not affect heat exchange. In this case, there is no need to perform self-cleaning, and the car air conditioner can be kept in its current operating state.

[0065] If the standard subcooling is greater than the actual subcooling, it indicates that the outdoor heat exchanger is clogged. In this case, it's necessary to further assess the degree of clog and implement targeted self-cleaning measures. The difference between the standard and actual subcooling is calculated, and based on the range of this difference, the outdoor heat exchanger is selectively controlled to perform self-cleaning. Specifically, this step includes:

[0066] (1) If the difference is greater than or equal to the first preset threshold, the car air conditioner will be controlled to run immediately in self-cleaning mode.

[0067] For example, the first preset threshold can be any value between 3 and 7°C. This application takes 5°C as an example. When the difference is greater than or equal to 5°C, the difference between the standard subcooling and the actual subcooling is large, and the outdoor heat exchanger is seriously clogged, resulting in a decrease in heat exchange effect and a small actual subcooling. It is necessary to perform self-cleaning immediately. At this time, the car air conditioner is controlled to immediately execute the self-cleaning mode to reduce the clog of the outdoor heat exchanger.

[0068] (2) If the difference is less than the first preset threshold and greater than or equal to the second preset threshold, the compressor is stopped and the external fan is rotated in the reverse direction. After the external fan rotates in the reverse direction for a first preset time, the compressor is started and the external fan rotates in the forward direction. At the same time, before or after the compressor is stopped, the internal fan is kept running.

[0069] For example, the second preset threshold is less than the first preset threshold, and the second preset threshold can be any value between 1 and 5℃. Taking 3℃ as an example, when the difference is less than 5℃ but greater than or equal to 3℃, the outdoor heat exchanger experiences moderate dirt blockage, which has a certain impact on its operation. However, considering that the car air conditioner is running, to prevent excessive degradation of comfort in the driver's cabin, the air conditioner is not controlled to enter the self-cleaning mode. At this time, the compressor is stopped, and the outdoor fan is controlled to rotate in the reverse direction for a first preset time to blow off the dirt adhering to the outdoor heat exchanger. At the same time, the interior fan continues to run to ensure comfort in the driver's cabin. The first preset time can be any value between 1 and 10 minutes in this application, preferably 5 minutes. After the outdoor fan rotates in the reverse direction for 5 minutes, the compressor is restarted, and the outdoor fan is controlled to rotate in the forward direction, and the air conditioner continues to operate in the previous mode.

[0070] (3) If the difference is less than the second preset threshold and greater than zero, the car air conditioner will continue to run until a shutdown signal is received or the cabin temperature is equal to the set temperature, at which point the car air conditioner will be controlled to run in self-cleaning mode.

[0071] Specifically, when the temperature difference is less than 3°C but greater than 0°C, the outdoor heat exchanger is only slightly clogged. Although the heat exchange effect is affected, the impact is not significant. To ensure comfort in the driver's cabin, the outdoor heat exchanger is not self-cleaned at this time. Instead, the self-cleaning mode of the car air conditioner is activated only when a shutdown signal is received or the cabin temperature reaches the set temperature.

[0072] By determining the self-cleaning timing and specific self-cleaning method of the outdoor heat exchanger based on the range of the difference between the standard subcooling and the actual subcooling, this application can adopt different self-cleaning methods in a targeted manner based on different degrees of dirt and blockage, thereby improving the self-cleaning effect and efficiency.

[0073] In a preferred embodiment, the vehicle air conditioner further includes a reversing valve, and the step of "controlling the vehicle air conditioner to operate in self-cleaning mode" further includes: controlling the vehicle air conditioner to operate in heating mode to cause frost to form on the surface of the outdoor heat exchanger; and controlling the vehicle air conditioner to operate in cooling mode to cause defrosting on the surface of the outdoor heat exchanger.

[0074] For example, if the reversing valve is a four-way valve, when the car's air conditioning system has a four-way valve, the air conditioner can switch between cooling and heating modes. This allows the air conditioner to first operate in heating mode, causing the outdoor heat exchanger (acting as an evaporator) to frost over, and then switch to cooling mode, causing the outdoor heat exchanger (acting as a condenser) to defrost and turn into condensate. The flow of this condensate carries away the dirt adhering to the outdoor heat exchanger. This method of defrosting by switching between heating and cooling modes is quite common in the field and will not be elaborated further.

[0075] It should be noted that the above preferred embodiments are merely illustrative of the principles of this application and are not intended to limit the scope of protection of this application. Without departing from the principles of this application, those skilled in the art can adjust the above settings to make this application applicable to more specific application scenarios.

[0076] For example, in an alternative embodiment, although the above embodiment describes calculating the difference between the standard subcooling and the actual subcooling and then selectively implementing different self-cleaning methods based on the range of the difference, this embodiment is not unique. Those skilled in the art can adjust it, as long as the self-cleaning purpose of the outdoor heat exchanger can be achieved when the standard subcooling is greater than the actual subcooling. For example, the self-cleaning mode can be entered directly when the standard subcooling is greater than the actual subcooling, or the temperature can be divided into fewer or more intervals for targeted control. However, it is obvious that the control method of directly entering the self-cleaning mode when the standard subcooling is greater than the actual subcooling cannot achieve the control accuracy of the preferred embodiment described above.

[0077] For example, in another alternative implementation, although the self-cleaning mode in the above implementation is described using the alternating operation of cooling and heating modes as an example, the methods for performing self-cleaning on the outdoor heat exchanger are not limited to this. Those skilled in the art can choose different self-cleaning methods based on specific application scenarios. For example, self-cleaning of the outdoor heat exchanger can also be achieved by setting self-cleaning nozzles or other methods.

[0078] For example, in another alternative implementation, the specific values ​​of the above-mentioned first preset threshold, second preset threshold, first preset duration, and other parameters are not fixed. Those skilled in the art can select them based on specific application scenarios. Such changes in values ​​do not deviate from the principles of this application.

[0079] For example, in another alternative implementation, although different self-cleaning methods are used when the above-mentioned difference is in different ranges, it does not mean that only the self-cleaning method described above can be used when the difference is in each range. On the contrary, those skilled in the art can adjust the above-mentioned self-cleaning method as needed, as long as the cleaning intensity of each self-cleaning method is adapted to the dirt and blockage of the outdoor heat exchanger.

[0080] Of course, the alternative implementation methods described above, as well as the alternative implementation methods and preferred implementation methods, can be used in combination to create new implementation methods that are suitable for more specific application scenarios.

[0081] The following is combined Figure 2 This paper briefly describes one possible control process of the automotive air conditioning control method of this application. Figure 2 This is a logic diagram of the self-cleaning control method for automotive air conditioning according to this application.

[0082] like Figure 2 As shown, in one possible control process:

[0083] S201, the car air conditioner is turned on and running, then S202 is executed.

[0084] S202, obtain the outdoor ambient temperature Tao, the compressor operating frequency f, the middle temperature Tc of the outdoor heat exchanger, and the outlet temperature Tout.

[0085] S203, calculate the standard subcooling Δt = k1 × Tao + k2 × f + b, calculate the actual subcooling ΔT = Tc - Tout, and then execute S204.

[0086] S204. Determine if △t-△T>0 is true. If true, execute S205; otherwise, execute S208.

[0087] S205, determine whether △t-△T≥5 is true? If true, execute S209; otherwise, if false, execute S206.

[0088] S206, determine whether △t-△T<3 is true? If true, execute S207; otherwise, if false, execute S210.

[0089] S207: Determine if a shutdown signal has been received or if the temperature in the cab has reached the set temperature. If yes, proceed to S209; otherwise, return to continue executing S207.

[0090] S208 controls the car's air conditioning to maintain the current operating mode.

[0091] S209 controls the car's air conditioning to enter self-cleaning mode.

[0092] S210 controls the compressor to stop, the internal fan to continue running and the external fan to rotate in the opposite direction. After 5 minutes, controls the compressor to start, the internal fan to continue running and the external fan to rotate in the forward direction, and the car air conditioner to return to its previous mode and continue running.

[0093] It should be noted that although the steps in the above embodiments are described in the above order, those skilled in the art will understand that, in order to achieve the effect of this embodiment, different steps do not necessarily need to be executed in this order. They can be executed simultaneously (in parallel) or in a reversed order, and these simple variations are all within the scope of protection of this application. For example, several parameters in S101 can be obtained simultaneously or sequentially. Similarly, S103 and S105 can be executed simultaneously or in reverse order.

[0094] Furthermore, those skilled in the art will understand that although some embodiments described herein include certain features included in other embodiments but not others, combinations of features from different embodiments are intended to be within the scope of this application and form different embodiments. For example, any of the claimed embodiments in the claims of this application can be used in any combination.

[0095] The technical solutions of this application have been described above with reference to the preferred embodiments shown in the accompanying drawings. However, it will be readily understood by those skilled in the art that the scope of protection of this application is obviously not limited to these specific embodiments. Without departing from the principles of this application, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the scope of protection of this application.

Claims

1. A self-cleaning control method of an automobile air conditioner, characterized by, The automobile air conditioner comprises a compressor, an outdoor heat exchanger, an outdoor fan, a throttling element, an indoor heat exchanger and an indoor fan, the automobile is provided with a storage battery, the storage battery is connected with the automobile air conditioner to supply power to the automobile air conditioner, and the self-cleaning control method comprises the following steps: When the automobile air conditioner is running, the outdoor environment temperature, the running frequency of the compressor, the middle temperature of the outdoor heat exchanger and the outlet temperature of the outdoor heat exchanger are obtained; Based on the outdoor environment temperature and the running frequency, the standard supercooling degree of the outdoor heat exchanger is determined; Based on the middle temperature and the outlet temperature, the actual supercooling degree of the outdoor heat exchanger is determined; The standard supercooling degree and the actual supercooling degree are compared; Based on the comparison result, the outdoor heat exchanger is selectively cleaned; The step of "selectively controlling the outdoor heat exchanger to clean based on the comparison result" further comprises the following steps: If the standard supercooling degree is greater than the actual supercooling degree, the difference between the standard supercooling degree and the actual supercooling degree is further calculated; If the difference is greater than or equal to a first preset threshold value, the automobile air conditioner is immediately controlled to run in the self-cleaning mode; If the difference is less than the first preset threshold value and greater than or equal to a second preset threshold value, the compressor is controlled to stop running, and the outdoor fan is controlled to reverse rotation; after the outdoor fan reverses rotation for a first preset time length, the compressor is controlled to start running, and the outdoor fan is controlled to rotate forward; If the difference is less than the second preset threshold value and greater than zero, the automobile air conditioner is controlled to continue running, and when a shutdown signal is received or the temperature of the driver's cabin is equal to a set temperature, the automobile air conditioner is controlled to run in the self-cleaning mode.

2. The self-cleaning control method of an automobile air conditioner according to claim 1, characterized by, The step of "determining the standard supercooling degree of the outdoor heat exchanger based on the outdoor environment temperature and the running frequency" further comprises the following steps: The standard supercooling degree of the outdoor heat exchanger is calculated by the following formula: △t=k1×Tao+k2×f+b Wherein, △t is the standard supercooling degree; Tao is the outdoor environment temperature; f is the running frequency; k1 is the outer ring temperature coefficient, k2 is the frequency coefficient, and b is the correction value of the supercooling degree.

3. The self-cleaning control method of an automobile air conditioner according to claim 1, characterized by, The step of "determining the actual supercooling degree of the outdoor heat exchanger based on the middle temperature and the outlet temperature" further comprises the following steps: The actual supercooling degree of the outdoor heat exchanger is calculated by the following formula: △T=Tc-Tout Wherein, △T is the actual supercooling degree; Tc is the middle temperature of the outdoor heat exchanger; and Tout is the outlet temperature of the outdoor heat exchanger.

4. The self-cleaning control method of an automobile air conditioner according to claim 1, characterized by, The self-cleaning control method further comprises the following steps: The indoor fan is controlled to continue running at the same time, before or after the compressor is controlled to stop running.

5. The self-cleaning control method of an automobile air conditioner according to claim 1, characterized by, The self-cleaning control method further comprises the following steps: If the standard supercooling degree is less than or equal to the actual supercooling degree, the automobile air conditioner is controlled to maintain the current running state.

6. The self-cleaning control method of an automobile air conditioner according to claim 1, characterized by, The automobile air conditioner further comprises a reversing valve, and the step of "controlling the automobile air conditioner to run in the self-cleaning mode" further comprises the following steps: The automobile air conditioner is controlled to run in the heating mode to make the surface of the outdoor heat exchanger frost. controlling the automobile air conditioner to operate in a cooling mode to defrost the surface of the outdoor heat exchanger.

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