WO2023284198A1 - Control method for in-pipe self-cleaning of indoor heat exchanger - Google Patents

Abstract

The present invention relates to the technical field of air conditioner self-cleaning, and in particular to a control method for in-pipe self-cleaning of an indoor heat exchanger. The present application aims to solve the problem of how to implement different degrees of in-pipe self-cleaning of the indoor heat exchanger. For this purpose, the air conditioner of the present application comprises a recovery pipe, a first on-off valve, and a second on-off valve. The control method comprises: obtaining operation data of an air conditioner; determining the degree of dirty blockage of an indoor heat exchanger on the basis of the operation data; and performing a corresponding in-pipe self-cleaning mode on the basis of the degree of dirty blockage, the degree of dirty blockage comprising light dirty blockage, moderate dirty blockage, and heavy dirty blockage, and the in-pipe self-cleaning mode comprising a light self-cleaning mode, a moderate self-cleaning mode, and a deep self-cleaning mode. According to the present application, a corresponding degree of in-pipe self-cleaning mode can be performed on the basis of the degree of dirty blockage of the indoor heat exchanger, and thus intelligent in-pipe self-cleaning is implemented.

Description

In-tube self-cleaning control method of indoor heat exchanger technical field

The invention relates to the technical field of self-cleaning of air conditioners, in particular to a method for controlling self-cleaning in tubes of indoor heat exchangers.

Background technique

Some of the current air conditioners have the self-cleaning function of the inner and outer units. Take the self-cleaning process of the indoor heat exchanger as an example. When the self-cleaning function is executed, the frosting and defrosting operations of the indoor heat exchanger are realized by switching between cooling and heating modes, so that the indoor heat exchanger will be turned off when the frost layer melts. Surface dirt is rinsed away.

However, the current self-cleaning function is limited to cleaning the outer surface of the indoor heat exchanger, and cannot clean the inside of the coil. Usually, the inside of the coil of the indoor heat exchanger will accumulate impurities, freezing Therefore, it is especially necessary to self-clean the inside of the coil of the indoor heat exchanger. In addition, after the current air conditioner enters the self-cleaning mode, the cleaning method is fixed, and the degree of self-cleaning cannot be intelligently controlled according to the dirtiness of the indoor heat exchanger. The self-cleaning time is long when it is light, which affects the user's normal experience, and the self-cleaning is not thorough when the outer surface of the indoor heat exchanger is seriously dirty.

Correspondingly, there is a need in the art for a new tube self-cleaning control method for indoor heat exchangers to solve the above problems.

Contents of the invention

In order to solve at least one of the above-mentioned problems in the prior art, that is, to solve the problem of how to achieve different degrees of self-cleaning in the tube of the indoor heat exchanger, the application provides a self-cleaning control method in the tube of the indoor heat exchanger, which is applied to An air conditioner, the air conditioner includes a compressor, a four-way valve, an outdoor heat exchanger, a throttling device, and an indoor heat exchanger connected in sequence through a refrigerant pipeline, and the air conditioner also includes a recovery pipeline, a first on-off valve and a second on-off valve, the first on-off valve is set on the refrigerant pipeline between the throttling device and the indoor heat exchanger, and one end of the recovery pipeline is set on the throttling device On the refrigerant pipeline between the first on-off valve, the other end of the recovery pipeline communicates with the suction port of the compressor, the second on-off valve is arranged on the recovery pipeline,

The control methods include:

Obtain the operating data of the air conditioner;

Based on the operating data, judging the degree of dirty blockage of the indoor heat exchanger;

Based on the degree of dirty blockage, execute a corresponding in-pipe self-cleaning mode;

The degree of dirty clogging includes mild dirty clogging, moderate dirty clogging and severe dirty clogging, and the self-cleaning mode in the pipe includes mild self-cleaning mode, moderate self-cleaning mode and deep self-cleaning mode;

The mild self-cleaning mode includes: controlling the air conditioner to operate in cooling mode; adjusting the operating parameters of the air conditioner so that the coil temperature of the indoor heat exchanger is less than or equal to the first preset temperature; when the After the coil temperature is less than or equal to the first preset temperature and lasts for a first preset time, control the air conditioner to switch to heating mode; control the second on-off valve to open and last for a second preset time;

The moderate self-cleaning mode includes: controlling the air conditioner to operate in cooling mode; adjusting the operating parameters of the air conditioner so that the coil temperature of the indoor heat exchanger is less than or equal to the second preset temperature; when the After the coil temperature is less than or equal to the second preset temperature and lasts for a third preset time, control the air conditioner to switch to heating mode; control the first on-off valve to close and the second on-off valve to open ; When the first preset condition is met, control the first on-off valve to open for a fourth preset duration;

The deep self-cleaning mode includes: controlling the air conditioner to operate in cooling mode; adjusting the operating parameters of the air conditioner so that the coil temperature of the indoor heat exchanger is less than or equal to the third preset temperature; After the pipe temperature is less than or equal to the third preset temperature and lasts for a fifth preset duration, control the air conditioner to switch to heating mode; control the first on-off valve to close and the second on-off valve to open; When the second preset condition is met, the first on-off valve is controlled to open; after a sixth preset duration, the first on-off valve is controlled to close; when the second preset condition is met again, the control The first on-off valve is opened again for a seventh preset period of time;

Wherein, the operating parameters include one or more of the operating frequency of the compressor, the opening of the throttling device, the rotational speed of the indoor fan, and the rotational speed of the outdoor fan.

In the preferred technical solution of the above-mentioned in-tube self-cleaning control method of the indoor heat exchanger, in the mild self-cleaning mode,

After controlling the air conditioner to switch to the heating mode, control the compressor to adjust to the highest limit frequency corresponding to the outdoor ambient temperature; and/or

The step of adjusting the operating parameters of the air conditioner includes: controlling the compressor to adjust to the first self-cleaning frequency, controlling the outdoor fan to maintain the current running state, and controlling the indoor fan to run at a preset speed; and/or

When the throttling device is an electronic expansion valve, the step of adjusting the operating parameters of the air conditioner further includes: adjusting the opening degree of the throttling device; and/or

When the throttling device is an electronic expansion valve, after the air conditioner is controlled to switch to the heating mode, the throttling device is controlled to close to a minimum opening.

In the preferred technical solution of the above-mentioned in-tube self-cleaning control method of the indoor heat exchanger, the control method further includes:

After the second on-off valve is opened for the second preset time period, the mild self-cleaning mode is exited, and the air conditioner is controlled to return to the operating state before entering the mild self-cleaning mode.

In the preferred technical solution of the above-mentioned in-tube self-cleaning control method of the indoor heat exchanger, in the moderate self-cleaning mode,

After controlling the air conditioner to switch to the heating mode, control the compressor to adjust to the highest limit frequency corresponding to the outdoor ambient temperature; and/or

The step of adjusting the operating parameters of the air conditioner includes: controlling the compressor to adjust to the second self-cleaning frequency, controlling the outdoor fan to run at the highest speed, controlling the indoor fan to stop running; and/or

When the throttling device is an electronic expansion valve, the step of adjusting the operating parameters of the air conditioner further includes: adjusting the opening degree of the throttling device; and/or

When the throttling device is an electronic expansion valve, after the air conditioner is controlled to switch to the heating mode, the throttling device is controlled to close to a minimum opening.

In the preferred technical solution of the above-mentioned in-tube self-cleaning control method of the indoor heat exchanger, the control method further includes:

After the first on-off valve is opened for the fourth preset time period, exit the moderate self-cleaning mode, and control the air conditioner to return to the operating state before entering the moderate self-cleaning mode.

In the preferred technical solution of the above-mentioned tube self-cleaning control method of the indoor heat exchanger, in the deep self-cleaning mode,

After controlling the air conditioner to switch to the heating mode, control the compressor to adjust to the highest limit frequency corresponding to the outdoor ambient temperature; and/or

The step of adjusting the operating parameters of the air conditioner includes: controlling the compressor to adjust to the third self-cleaning frequency, controlling the outdoor fan to run at the highest speed, controlling the indoor fan to stop running; and/or

When the throttling device is an electronic expansion valve, the step of adjusting the operating parameters of the air conditioner further includes: adjusting the opening degree of the throttling device; and/or

When the throttling device is an electronic expansion valve, after the air conditioner is controlled to switch to the heating mode, the throttling device is controlled to close to a minimum opening.

In the preferred technical solution of the above-mentioned in-tube self-cleaning control method of the indoor heat exchanger, the control method further includes:

After the first on-off valve is opened again for the seventh preset time period, the deep self-cleaning mode is exited, and the air conditioner is controlled to return to the operating state before entering the deep self-cleaning mode.

In the preferred technical solution of the above-mentioned in-pipe self-cleaning control method of the indoor heat exchanger, the operation data includes the cumulative running time of the air conditioner and the coil temperature of the indoor heat exchanger, "acquire the temperature of the air conditioner The step of running data" further includes:

Obtain the cumulative running time of the air conditioner;

When the accumulated running time reaches the preset time threshold, the first average value of the coil temperature in the first period and the first average value of the coil temperature in the second period of the air conditioner in the next running process are acquired. Two mean values;

The step of "judging the degree of dirty blockage of the indoor heat exchanger based on the operation data" further includes:

calculating the absolute value of the difference between the first average value and the second average value;

When the absolute value of the difference is less than a first threshold, it is judged that the indoor heat exchanger is the mildly dirty blockage;

When the absolute value of the difference is greater than or equal to a first threshold and less than a second threshold, it is determined that the indoor heat exchanger is moderately dirty;

When the absolute value of the difference is greater than or equal to the second threshold, it is determined that the indoor heat exchanger is severely dirty.

In the preferred technical solution of the control method for in-pipe self-cleaning of the indoor heat exchanger, the throttling device is an electronic expansion valve, and the operating data includes the actual opening of the electronic expansion valve and the actual discharge of the compressor. air temperature, the step of "obtaining the operating data of the air conditioner" further includes:

obtaining the actual discharge temperature of the compressor;

Acquire the actual opening of the electronic expansion valve when the actual exhaust temperature reaches the target exhaust temperature;

The step of "judging the degree of dirty blockage of the indoor heat exchanger based on the operating data" further includes:

calculating a difference between the actual opening and a target opening, and calculating a ratio between the difference and the target opening;

When the ratio is greater than the third threshold and less than or equal to the fourth threshold, it is judged that the indoor heat exchanger is the mildly dirty blockage;

When the ratio is greater than the fourth threshold and less than or equal to the fifth threshold, it is determined that the indoor heat exchanger is moderately dirty;

When the ratio is greater than the fifth threshold, it is judged that the indoor heat exchanger is severely dirty;

Wherein, the target opening degree is determined based on the target exhaust temperature and the outdoor ambient temperature.

In the preferred technical solution of the control method for in-pipe self-cleaning of the indoor heat exchanger, the throttling device is a capillary tube, the operating data includes the actual exhaust temperature, and the step of "obtaining the operating data of the air conditioner" further includes :

obtaining the actual discharge temperature of the compressor;

The step of "judging the degree of dirty blockage of the indoor heat exchanger based on the operating data" further includes:

calculating a difference between the actual exhaust temperature and a target exhaust temperature, and calculating a ratio between the difference and the target exhaust temperature;

When the ratio is greater than the sixth threshold and less than or equal to the seventh threshold, it is judged that the indoor heat exchanger is the mildly dirty blockage;

When the ratio is greater than the seventh threshold and less than or equal to the eighth threshold, it is determined that the indoor heat exchanger is moderately dirty;

When the ratio is greater than the eighth threshold, it is determined that the indoor heat exchanger is severely dirty.

By judging the degree of dirty clogging of the indoor heat exchanger according to the operating data of the air conditioner, and then operating different in-pipe self-cleaning modes based on the degree of dirty clogging, the control method of the application can not only realize the self-cleaning of the indoor heat exchanger in the tube, but also It can implement a matching in-tube self-cleaning mode based on the degree of dirty blockage of the indoor heat exchanger to achieve a more intelligent in-tube self-cleaning.

Description of drawings

The method for controlling self-cleaning in tubes of indoor heat exchangers of the present application will be described below with reference to the accompanying drawings. In the attached picture:

Fig. 1 is the system diagram of the air conditioner of the present application in cooling mode;

Fig. 2 is the system diagram of the air conditioner of the present application in heating mode;

Fig. 3 is the flowchart of the self-cleaning control method in the tube of the indoor heat exchanger of the present application;

Fig. 4 is a logic diagram of a possible implementation process of the method for controlling self-cleaning in tubes of indoor heat exchangers of the present application.

List of reference signs

1. Compressor; 2. Four-way valve; 3. Outdoor heat exchanger; 4. Throttle device; 5. Indoor heat exchanger; 6. Refrigerant pipeline; 7. Recovery pipeline; 8. First on-off valve ; 9, the second on-off valve; 11, the reservoir.

detailed description

Preferred embodiments of the present application are described below with reference to the accompanying drawings. Those skilled in the art should understand that these embodiments are only used to explain the technical principle of the application, and are not intended to limit the protection scope of the application. For example, although the detailed steps of the method of the present application are described in detail below, those skilled in the art can combine, split and change the order of the above steps without departing from the basic principles of the present application. The scheme does not change the basic idea of the application, and therefore also falls within the scope of protection of the application.

It should be noted that, in the description of this application, the terms "first", "second", "third", "fourth", "fifth", "sixth", "seventh", "seventh" Eight" is used for descriptive purposes only and is not to be construed as indicating or implying relative importance.

It should also be noted that, in the description of this application, unless otherwise clearly specified and limited, the term "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; It can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediary, and it can be the internal communication of two components. Those skilled in the art can understand the specific meanings of the above terms in this application according to specific situations.

Referring first to FIG. 1 , the structure of the air conditioner of the present application will be described. Wherein, FIG. 1 is a system diagram of the air conditioner of the present application in cooling mode.

As shown in FIG. 1 , in a possible implementation, the air conditioner includes a compressor 1 , a four-way valve 2 , an outdoor heat exchanger 3 , a throttling device 4 , an indoor heat exchanger 5 and a liquid accumulator 11 . The exhaust port of compressor 1 communicates with the P interface of four-way valve 2 through refrigerant pipeline 6, and the C interface of four-way valve 2 communicates with the inlet of outdoor heat exchanger 3 through refrigerant pipeline 6. The outlet communicates with one port of the throttling device 4 through the refrigerant pipeline 6, and the other port of the throttling device 4 communicates with the inlet of the indoor heat exchanger 5 through the refrigerant pipeline 6, and the outlet of the indoor heat exchanger 5 passes through the refrigerant pipeline 6 is in communication with the E port of the four-way valve 2, the S port of the four-way valve 2 is in communication with the inlet of the accumulator 11 through the refrigerant pipeline 6, and the outlet of the accumulator 11 is in communication with the suction port of the compressor 1 through the pipeline . The throttling device 4 can be a capillary tube or an electronic expansion valve. A filter is arranged in the liquid storage 11. The liquid storage 11 can store refrigerant, separate gas and liquid of refrigerant, filter oil, eliminate noise, and buffer refrigerant.

The air conditioner also includes a first on-off valve 8, a second on-off valve 9 and a recovery pipeline 7, the first on-off valve 8 and the second on-off valve 9 are preferably electromagnetic valves, and the first on-off valve 8 is Normally open valve, which is arranged on the refrigerant pipeline 6 between the throttling device 4 and the indoor heat exchanger 5, the second on-off valve 9 is a normally closed valve, which is arranged on the recovery pipeline 7, and the recovery pipeline 7 A copper tube with a smooth inner wall is used. The first end of the copper tube is set on the refrigerant pipeline 6 between the throttling device 4 and the first on-off valve 8, and the second end of the copper tube is set on the S of the four-way valve 2. On the refrigerant pipeline 6 between the interface and the inlet of the accumulator 11. Both the first on-off valve 8 and the second on-off valve 9 are communicatively connected with the controller of the air conditioner, so as to receive opening and closing signals issued by the controller. Of course, one or more of the above-mentioned on-off valves can also be replaced by electronically controlled valves such as electronic expansion valves.

The method for controlling the self-cleaning in the tube of the indoor heat exchanger in this embodiment will be described below in conjunction with the structure of the above-mentioned air conditioner, but those skilled in the art can understand that the specific structural composition of the air conditioner is not static, and those skilled in the art can understand It can be adjusted, for example, components can be added or deleted on the basis of the structure of the above-mentioned air conditioner.

In the following, with reference to FIG. 1 , FIG. 2 and FIG. 3 , the self-cleaning control method in the tube of the indoor heat exchanger of the present application will be introduced. Wherein, FIG. 2 is a system diagram of the air conditioner of the present application in heating mode; FIG. 3 is a flow chart of the control method of the indoor heat exchanger for self-cleaning in the tube of the present application.

As shown in Figure 3, in order to solve the problem of how to achieve different degrees of self-cleaning in the tube of the indoor heat exchanger, the self-cleaning control method in the tube of the indoor heat exchanger of the present application includes:

S101. Obtain operating data of the air conditioner.

In a possible implementation, the operating data of the air conditioner includes the accumulated operating time, the coil temperature of the indoor heat exchanger, the actual opening degree of the throttling device (when the throttling device is an electronic expansion valve), and the actual discharge of the compressor. Air temperature, etc., during the operation of the air conditioner, obtain one or more of the above operation data. Wherein, the above-mentioned acquisition methods of the operation data belong to conventional means in the art, and will not be repeated here.

S103. Based on the operation data, determine the degree of dirty blockage of the indoor heat exchanger.

In a possible implementation, the range of the operating data or the size of the operating data is determined through reasonable calculation of the above operating data and comparison with the preset threshold, and then the degree of dirty blockage of the indoor heat exchanger is determined. .

S105. Based on the degree of fouling and blockage, execute a corresponding self-cleaning mode in the pipe.

In a possible implementation, the degree of dirty clogging in this application can be divided into mild dirty clogging, moderate dirty clogging and severe dirty clogging. Correspondingly, the self-cleaning mode in the pipe includes the mild self-cleaning mode corresponding to each degree of dirty clogging , moderate self-cleaning mode and deep self-cleaning mode. That is to say, when it is judged that the degree of dirty clogging of the indoor heat exchanger is mild dirty clogging, the air conditioner is controlled to perform a mild self-cleaning mode; when it is judged that the dirty clogging degree of the indoor heat exchanger is moderate dirty clogging, The air conditioner is controlled to execute the moderate self-cleaning mode; when it is judged that the degree of dirty clogging of the indoor heat exchanger is severe, the air conditioner is controlled to execute the deep self-cleaning mode.

It can be seen that by judging the degree of dirty clogging of the indoor heat exchanger according to the operating data of the air conditioner, and then operating different in-pipe self-cleaning modes based on the degree of dirty clogging, the control method of the present application can not only realize the self-cleaning of the indoor heat exchanger in the tube Cleaning, and can also implement a corresponding degree of in-tube self-cleaning mode based on the degree of dirt and blockage of the indoor heat exchanger, so that the self-cleaning effect can adapt to the degree of dirt and blockage, and realize more intelligent self-cleaning in the tube.

Several possible embodiments of the present application for judging the degree of fouling and clogging of the indoor heat exchanger according to the operating data of the air conditioner are introduced below.

Example 1

In this embodiment, the throttling device can be a capillary tube or an electronic expansion valve, and the operating data of the air conditioner includes the cumulative operating time of the air conditioner and the coil temperature of the indoor heat exchanger. The step of "obtaining the operating data of the air conditioner" further includes :

Obtain the cumulative running time of the air conditioner; when the cumulative running time reaches the preset time threshold, obtain the first average value of the coil temperature of the air conditioner in the first period of time and the temperature of the coil in the second period of time during the next running process. Second average of tube temperature.

In a possible implementation manner, the cumulative running time can be any value in 15h-40h, and in this application it is 20h. When the cumulative running time of the air conditioner reaches 20 hours, it indicates that the indoor heat exchanger may be dirty and clogged, and the degree of dirty clogging needs to be judged. At this time, the coil temperature of the indoor heat exchanger during the next running process of the air conditioner is obtained for judgment. Specifically, the first period of time and the second period of time can take any value in 10-30min, for example, the first period of time and the second period of time are both 15min, that is to say, when the cumulative running time reaches 20h, the two 15min periods Take the average value of the coil temperature as the first average value and the second average value. More preferably, after the accumulated operating time reaches 20 hours, within 1 hour from the 20th hour until the operating time reaches 21 hours, take the average value of the coil temperature in the first 15 minutes of the 1 hour and the coil temperature in the last 15 minutes. The average value of the temperature was used as the first average value and the second average value.

Of course, the specific way of obtaining the first average value and the second average value is not the only one. Just average. For example, after the accumulative operating time reaches 20 hours, the average value of the coil temperature within two consecutive 15 minutes can be obtained as the first average value and the second average value.

After obtaining the first average value and the second average value above, the step of "judging the degree of dirty blockage of the indoor heat exchanger based on the operating data" further includes:

Calculate the absolute value of the difference between the first average value and the second average value; when the absolute value of the difference is less than the first threshold, it is judged that the indoor heat exchanger is slightly dirty; when the absolute value of the difference is greater than or equal to When the first threshold is less than the second threshold, it is judged that the indoor heat exchanger is moderately dirty; when the absolute value of the difference is greater than or equal to the second threshold, it is judged that the indoor heat exchanger is severely dirty.

In a possible implementation manner, taking the cooling mode of the air conditioner as an example, the more dirty the indoor heat exchanger is, the worse the heat exchange effect is, so the coil temperature of the indoor heat exchanger is lower. In the present application, the first threshold is smaller than the second threshold, the first threshold may be any value in the range of 1-3°C, and the second threshold may be any value in the range of 3-5°C. Assuming that the first average value is Tp1, the second average value is Tp2, the first threshold value is 2°C, and the second threshold value is 4°C, first calculate the absolute value of the difference between the first average value and the second average value, namely |Tp1 -Tp2|, and then judge the size between the absolute value and the first threshold and the second threshold. If |Tp1-Tp2|<2, the indoor heat exchanger is considered to be mildly dirty; if 2≤|Tp1-Tp2|<4, the indoor heat exchanger is considered to be moderately dirty; if |Tp1-Tp2| ≥4, the indoor heat exchanger is considered to be severely dirty and blocked.

When the air conditioner is running in heating mode, the more dirty the indoor heat exchanger is, the worse the heat exchange effect will be, so the coil temperature of the indoor heat exchanger will be higher. Wherein, based on the operation data, the process of judging the degree of dirty blockage of the indoor heat exchanger is similar to that in the cooling mode, and will not be repeated here.

Example 2

In this embodiment, the throttling device is an electronic expansion valve, and the operating data includes the actual opening of the electronic expansion valve and the actual exhaust temperature of the compressor. The step of "obtaining the operating data of the air conditioner" further includes:

Obtain the actual discharge temperature of the compressor; when the actual discharge temperature reaches the target discharge temperature, obtain the actual opening of the electronic expansion valve.

In a possible implementation manner, the actual discharge temperature of the compressor is acquired through a temperature sensor provided at the discharge port of the compressor, and the acquisition method is a conventional means in the art, and will not be repeated here. The target exhaust temperature is a commonly used control parameter in air conditioner control. During the operation of the air conditioner, the target exhaust temperature is determined first, and then the actual exhaust temperature is adjusted by controlling the opening of the electronic expansion valve to make the actual exhaust temperature reach Or as close as possible to the target exhaust temperature. Among them, there are many methods for determining the target exhaust temperature in the prior art, such as determining based on a comparison table or a fitting formula between the target exhaust temperature and the outdoor ambient temperature. During the operation of the air conditioner, the actual exhaust temperature is controlled by adjusting the opening of the expansion valve. When the actual exhaust temperature reaches the target exhaust temperature, the actual opening of the electronic expansion valve at this time is obtained.

After obtaining the actual opening of the electronic expansion valve, the step of "judging the degree of dirtyness and blockage of the indoor heat exchanger based on the operating data" further includes:

Calculate the difference between the actual opening and the target opening, and calculate the ratio between the difference and the target opening; when the ratio is greater than the third threshold and less than or equal to the fourth threshold, it is judged that the indoor heat exchanger is slightly dirty blockage; when the ratio is greater than the fourth threshold and less than or equal to the fifth threshold, it is judged that the indoor heat exchanger is moderately dirty; when the ratio is greater than the fifth threshold, it is judged that the indoor heat exchanger is severely dirty;

In a possible implementation manner, the target opening degree is determined based on the target exhaust gas temperature and the outdoor ambient temperature. Specifically, it is determined based on the fitting formula Bset=K×Td+Tao among the three. In the formula, Bset is the target opening, that is, the ideal opening when there is no dirty blockage, Td is the target exhaust temperature, Tao is the outdoor ambient temperature, K is a coefficient, and the coefficient K can be determined based on experiments. It can be seen from the above that when the indoor heat exchanger is not dirty, each outdoor ambient temperature corresponds to a target exhaust temperature, and the target exhaust temperature together with the outdoor ambient temperature determines the target opening of the electronic expansion valve.

However, the current method of controlling the opening of the electronic expansion valve based on the target exhaust temperature is usually: when the exhaust temperature is higher than the target exhaust temperature → open the electronic expansion valve → increase the amount of refrigerant, reduce the temperature of the refrigerant in the evaporator after heat exchange → reduce the compression The machine suction temperature and exhaust temperature. When the discharge temperature is lower than the target discharge temperature → close the electronic expansion valve → reduce the amount of refrigerant, increase the temperature of the refrigerant in the evaporator after heat exchange → increase the compressor suction temperature and discharge temperature.

Under the above corresponding relationship, the more serious the dirty blockage of the indoor heat exchanger, the worse the heat exchange effect, and the higher the suction temperature and discharge temperature of the compressor, at this time the opening of the electronic expansion valve must be greater than its target opening . Therefore, the comparison between the actual opening degree of the electronic expansion valve and its target opening degree can be used to determine whether the indoor heat exchanger is dirty and to what extent.

For example, assuming that when the actual exhaust temperature reaches the target exhaust temperature, the opening degree of the electronic expansion valve is B, and the target opening degree of the electronic expansion valve at the current outdoor ambient temperature is Bset. The difference ΔB=B-Bset, and then calculate the ratio of the difference ΔB to the target opening Bset, and judge the range of the ratio. In this application, the third threshold, the fourth threshold and the fifth threshold increase sequentially, wherein the third threshold is any value in 0.9-1.05, the fourth threshold is any value in 1.05-1.15, and the fifth threshold is 1.15 Any value from -1.35. In this application, the third threshold is 1, the fourth threshold is 1.1, and the fifth threshold is 1.2 as an example. If △B/Bset≤1, it is considered that the indoor heat exchanger is not very dirty and does not need self-cleaning; if 1<△B/Bset≤1.1, it is considered that the indoor heat exchanger is slightly dirty; if 1.1< If △B/Bset≤1.2, the indoor heat exchanger is considered to be moderately dirty; if △B/Bset>1.2, the indoor heat exchanger is considered to be severely dirty.

Example 3

In this embodiment, the throttling device is a capillary tube, and the operating data includes the actual exhaust temperature. The step of "obtaining the operating data of the air conditioner" further includes:

Get the actual discharge temperature of the compressor. The actual discharge temperature can be obtained based on the temperature sensor installed at the discharge port of the compressor.

After obtaining the actual exhaust gas temperature, the step of "judging the degree of dirtyness and blockage of the indoor heat exchanger based on the operating data" further includes:

Calculate the difference between the actual exhaust temperature and the target exhaust temperature, and calculate the ratio between the difference and the target exhaust temperature; when the ratio is greater than the sixth threshold and less than or equal to the seventh threshold, it is judged that the indoor heat exchanger is Mild dirty blockage; when the ratio is greater than the seventh threshold and less than or equal to the eighth threshold, it is judged that the indoor heat exchanger is moderately dirty; when the ratio is greater than the eighth threshold, it is judged that the indoor heat exchanger is severely dirty.

In a possible implementation manner, the method of determining the target exhaust gas temperature is the same as that in Embodiment 2, which will not be repeated here. Since the opening of the capillary cannot be adjusted, the more serious the indoor heat exchanger is blocked, the worse the heat exchange effect will be, and the higher the suction temperature and discharge temperature of the compressor will be. Therefore, it is possible to determine whether the indoor heat exchanger is dirty and to what extent by comparing the actual exhaust temperature with the target exhaust temperature.

For example, after the air conditioner starts and runs stably, first obtain the actual exhaust temperature T, then calculate the difference ΔT between the actual exhaust temperature T and the target exhaust temperature Td, and calculate the difference between the difference ΔT and the target exhaust temperature The ratio of Td; finally judge the range of the ratio, so as to determine the degree of dirty blockage. In this application, the sixth threshold, the seventh threshold and the eighth threshold increase sequentially, wherein the sixth threshold is any value in 0.9-1.05, the seventh threshold is any value in 1.05-1.15, and the eighth threshold is 1.15 Any value from -1.35. In this application, the sixth threshold is 1, the seventh threshold is 1.1, and the eighth threshold is 1.2 as an example. If △T/Td≤1, it is considered that the degree of dirty blockage of the indoor heat exchanger is not large, and self-cleaning is not required; if 1<△T/Td≤1.1, it is considered that the indoor heat exchanger is slightly dirty; if 1.1< If △T/Td≤1.2, the indoor heat exchanger is considered to be moderately dirty; if △T/Td>1.2, the indoor heat exchanger is considered to be severely dirty.

Taking the throttling device as an example of an electronic expansion valve, the specific control process of each in-pipe self-cleaning mode of the present application will be introduced below. Those skilled in the art can understand that, when the throttling device is a capillary tube, the control methods corresponding to the self-cleaning modes in each tube when the throttling device is a capillary tube can be obtained by adjusting the following self-cleaning modes in each tube. For example, all the following control methods related to the throttling device can be omitted, so as to obtain the control method of the self-cleaning mode in the tube corresponding to the capillary tube.

In a possible implementation, the mild self-cleaning mode includes: controlling the air conditioner to operate in cooling mode; adjusting the operating parameters of the air conditioner so that the coil temperature of the indoor heat exchanger is less than or equal to the first preset temperature; when the coil After the temperature is less than or equal to the first preset temperature and lasts for the first preset time period, the air conditioner is controlled to switch to the heating mode; the second on-off valve is controlled to open and lasts for the second preset time period. Wherein, the operating parameters include the operating frequency of the compressor, the opening degree of the throttling device, the rotating speed of the indoor fan and the rotating speed of the outdoor fan. specifically,

First, the air conditioner is controlled to operate in cooling mode. The switch between the operating modes of the air conditioner can be controlled by controlling the power on and off of the four-way valve. For example, when the four-way valve is powered off, the air conditioner operates in cooling mode; heat mode. In this embodiment, after entering the mild self-cleaning mode, if the air conditioner is running in the cooling mode, no adjustment is required, and the air conditioner is controlled to continue running; if the air conditioner is running in a non-cooling mode, the air conditioner is controlled to switch to the cooling mode. .

Then, control the compressor to adjust to the first self-cleaning frequency. The first self-cleaning frequency is a frequency determined in advance through experiments, for example, it may be determined based on the correspondence between the outdoor ambient temperature and the first self-cleaning frequency in Table 1 below. When the compressor operates at the first self-cleaning frequency, it facilitates the implementation of the subsequent control process.

Table 1 Comparison table between outdoor ambient temperature and first self-cleaning frequency

Outdoor ambient temperature (℃)	First self-cleaning frequency (Hz)
Tao≤16	50
16<Tao≤22	60
22<Tao≤29	70
29<Tao≤35	80
35<Tao≤43	85
43<Tao≤52	78
Tao>52	72

Next, control the outdoor fan to maintain the current running state, and control the indoor fan to run at a preset speed. Specifically, in the mild self-cleaning mode, since the dirty blockage of the indoor heat exchanger is not serious, before adjusting the opening of the throttling device, it is only necessary to control the outdoor fan to maintain the current operating state and keep the refrigerant in the indoor heat exchanger. The evaporative effect in the system can reduce the temperature of the indoor coil to the first preset temperature. In this application, the preset speed can be a medium speed in the speed of the indoor fan, such as 500r/min-800r/min, and this application can be 700r/min, because the air conditioner is running before entering the mild self-cleaning mode. The indoor ambient temperature is adjusted. Therefore, on the basis of ensuring the self-cleaning effect, by controlling the outdoor fan to maintain the current operating state, and the indoor fan runs at a certain preset speed, a certain degree of indoor comfort can be guaranteed.

Next, the opening degree of the throttling device is adjusted so that the coil temperature of the indoor heat exchanger is less than or equal to the first preset temperature. In a possible implementation, the temperature sensor can detect the coil temperature of the indoor heat exchanger, and dynamically adjust the opening of the electronic expansion valve, so that the coil temperature of the indoor heat exchanger is less than or equal to the first preset temperature. Since the freezing point of the refrigerant is much lower than the freezing point of the oil, the oil can be solidified and precipitated first when the coil temperature is less than or equal to the preset temperature. The first preset temperature in this application may be set at -1°C to -10°C, and in this application, the first preset temperature may be -5°C. That is to say, the coil temperature of the indoor heat exchanger is less than or equal to the first preset temperature as the control purpose, and by adjusting the opening degree of the electronic expansion valve (such as PID adjustment, etc.), the coil temperature of the indoor heat exchanger is always at The state of being less than or equal to the first preset temperature.

Referring to Figure 1, when the air conditioner is running in cooling mode, keep the coil temperature of the indoor heat exchanger at a temperature less than or equal to -5°C. At this time, the oil in the indoor heat exchanger will be stripped from the refrigerant circulation and attached to the On the inner wall of the coil of the indoor heat exchanger.

Certainly, in other implementation manners, the coil temperature of the indoor heat exchanger may also be lower than or equal to the first preset temperature by adjusting the opening degree of the electronic expansion valve to a fixed opening degree.

Immediately afterwards, when the coil temperature is less than or equal to the first preset temperature for a first preset time period, the air conditioner is controlled to switch to the heating mode. The first preset duration may be any value in 5-15 minutes. Preferably, the first preset time length in this embodiment is 10 minutes. When the coil temperature is less than or equal to -5°C and lasts for 10 minutes, the oil in the indoor heat exchanger has been stripped, and the stripped oil can be cleaned at this time operate. At this time, the switch between the operation modes of the air conditioner is controlled by controlling the four-way valve to be powered on and off, for example, the four-way valve is controlled to be powered on, and the air conditioner operates in the heating mode.

Finally, the second on-off valve is controlled to be opened, and the throttling device is closed to a minimum opening degree for a second preset time period. Control the throttling device to close to the minimum opening degree, that is, the state where the opening degree is 0, the throttling device realizes complete throttling, and the refrigerant cannot flow through. The second preset duration can be any value in 3min-10min, preferably 5min in this application. When the operating mode is switched to the heating mode, control the opening of the second on-off valve, close the throttling device to the minimum opening degree, and keep running for 5 minutes in this state. At this time, as shown by the arrow in Figure 2, the high-temperature and high-pressure refrigerant discharged from the compressor flows through the indoor heat exchanger, and the high-temperature and high-pressure refrigerant quickly impacts the coil of the indoor heat exchanger, and the oil that is temporarily stored in the coil is melted. The high-temperature refrigerant directly flows back to the liquid receiver through the recovery pipeline to realize recovery and filtration, so as to achieve the purpose of self-cleaning in the tube of the indoor heat exchanger.

In a possible implementation manner, the mild self-cleaning mode further includes: after the step of controlling the air conditioner to switch to the heating mode, controlling the compressor to adjust to the highest limit frequency corresponding to the outdoor ambient temperature. Usually, the operating frequency of the compressor is affected by the outdoor ambient temperature and cannot be increased indefinitely, otherwise the phenomenon of high temperature protection shutdown of the compressor will easily occur, which will have a negative impact on the life of the compressor. Therefore, the compressors are all equipped with a protection mechanism. Under different outdoor ambient temperatures, the corresponding maximum frequency limit is set. In this application, after the air conditioner is switched to heating mode, the rating of the compressor is adjusted to the current outdoor environment. The highest limit frequency under the temperature, under this frequency limit, the compressor can increase the temperature and pressure of the refrigerant in the shortest time, thereby improving the self-cleaning effect. Wherein, the manner of obtaining the outdoor ambient temperature is a conventional means in the field, and will not be repeated here.

In a possible implementation manner, the method further includes: when entering the mild self-cleaning mode, turning off the indoor antifreeze protection function and the outdoor ambient temperature frequency limiting function. Since the coil temperature of the indoor heat exchanger needs to be lowered to a lower value, in order to reach this condition as soon as possible, the compressor needs to run at high frequency, so during the cooling operation, turn off the indoor anti-freeze protection function and the outdoor ambient temperature frequency limit function to ensure the smooth execution of this method. However, other protection functions of the air conditioner are turned on as usual, such as compressor exhaust protection and current overload protection, etc., to prevent adverse effects on the life of the air conditioner.

Of course, the specific control process of the mild self-cleaning mode is not unique, and those skilled in the art can adjust the control method. For example, on the premise that the coil temperature of the indoor heat exchanger can be kept at or below the first preset temperature, the operation frequency of the compressor, the opening degree of the electronic expansion valve, the speed of the indoor fan and the One or more of the rotational speeds of the outdoor fans are omitted. For another example, after the air conditioner is controlled to switch to the heating mode, no adjustments may be made to the throttling device. For another example, when the mild self-cleaning mode is executed, the rotation speed of the outdoor fan may be determined according to the outdoor ambient temperature, and then the operation of the outdoor fan may be controlled.

In a possible implementation, the method further includes: exiting the mild self-cleaning mode and controlling the air conditioner to return to The operating state before entering the light self-cleaning mode. When the throttling device is closed to the minimum opening and the second on-off valve is open for 5 minutes, the high-temperature and high-pressure refrigerant has circulated many times, which is enough to produce a better self-cleaning effect, so the throttle is closed to the minimum opening. , When the second on-off valve is opened for 5 minutes, the mild self-cleaning mode can be exited.

Specifically, the step of exiting the mild self-cleaning mode further includes: controlling the air conditioner to return to the operating mode before entering the mild self-cleaning mode, controlling the compressor to return to the frequency before entering the mild self-cleaning mode, controlling the indoor fan to turn on and The air deflector of the indoor unit supplies air upwards, controls the throttling device to open to the maximum opening, and controls the second on-off valve to close. After the light self-cleaning mode is completed, the air conditioner needs to return to the operating mode before entering the light self-cleaning mode, so as to continue to adjust the indoor temperature. The following takes the air conditioner running in the cooling mode before entering the mild self-cleaning mode as an example. After the light self-cleaning mode is executed, it needs to switch back to the cooling mode. At this time, control the four-way valve to power off to restore the cooling mode, control the frequency of the compressor to return from the highest limit value to the frequency before entering the mild self-cleaning mode, control the indoor fan to turn on and the air deflector of the indoor unit to send air upward, and control the electronic The expansion valve is opened to the maximum opening degree, and the second on-off valve is controlled to be closed, so that the refrigerant flows in the normal cooling mode flow direction. Wherein, when the indoor fan is turned on, the air deflector of the indoor unit blows air upwards, so as to prevent the bad user experience caused by the high temperature of the indoor heat exchanger coil due to the high temperature of the indoor heat exchanger coil when the air conditioner just switches to cooling mode. Among them, the throttling device is opened to the maximum opening, because the refrigerant circulates between the compressor and the indoor heat exchanger when the mild self-cleaning mode is running, resulting in the lack of refrigerant in the outdoor heat exchanger, so the throttling device is opened to the maximum opening , so that the refrigerant quickly fills the outdoor heat exchanger, so as to realize the normal circulation of the refrigerant as soon as possible.

Correspondingly, after controlling the air deflector to send air upward for the first duration, the control indoor fan and the air deflector return to the operating state before entering the mild self-cleaning mode. Wherein, the first duration can be any value from 20s to 1min. In this application, it is preferably 30s. When the indoor fan is turned on and the air deflector is blowing air upwards for 30s, the temperature of the coil of the indoor heat exchanger has dropped to the same level as the cooling mode. At this time, the indoor fan and the air deflector are controlled to return to the operating mode before entering the mild self-cleaning mode to meet the cooling needs of the user.

Correspondingly, after the throttling device is controlled to open to the maximum opening for a second duration, the throttling device is controlled to return to the opening before entering the mild self-cleaning mode. Among them, the second duration can be any value within 1min-5min, preferably 3min in this application. When the electronic expansion valve is opened to the maximum opening and runs for 3min, the refrigerant circulation has tended to be stable. At this time, the electronic expansion valve is controlled to return to The opening degree before entering the mild self-cleaning mode, so that the air conditioner can fully restore the cooling parameters before entering the mild self-cleaning mode and continue to operate.

Of course, the way to exit the mild self-cleaning mode is not limited to the above one, and those skilled in the art can freely choose a specific control mode on the premise that the air conditioner can be restored to the operating state before entering the mild self-cleaning mode. This choice does not depart from the principles of the present application. For example, the outdoor fan can be controlled to return to the operating state before entering the mild self-cleaning mode; another example, the indoor fan can be controlled after the coil temperature of the indoor heat exchanger has dropped to a temperature suitable for the cooling mode Start running. For another example, it is also possible to control the various components of the air conditioner to directly return to the operating parameters before entering the mild self-cleaning mode.

In a possible implementation, the moderate self-cleaning mode includes: controlling the air conditioner to operate in cooling mode; adjusting the operating parameters of the air conditioner so that the coil temperature of the indoor heat exchanger is less than or equal to the second preset temperature; when the coil After the temperature is less than or equal to the second preset temperature and lasts for the third preset time, the air conditioner is controlled to switch to the heating mode; the first on-off valve is controlled to be closed, and the second on-off valve is opened; when the first preset condition is met, Control the opening of the first on-off valve for a fourth preset duration. Wherein, the operating parameters include the operating frequency of the compressor, the opening degree of the throttling device, the rotating speed of the indoor fan and the rotating speed of the outdoor fan. specifically,

First, the air conditioner is controlled to operate in cooling mode. Similar to the above mild self-cleaning mode, switching between operating modes of the air conditioner can be controlled by controlling the four-way valve on and off. In this embodiment, after entering the moderate self-cleaning mode, if the air conditioner is running in the cooling mode, no adjustment is required, and the air conditioner is controlled to continue running; if the air conditioner is running in a non-cooling mode, the air conditioner is controlled to switch to the cooling mode. .

Then, control the compressor to adjust to the second self-cleaning frequency. The second self-cleaning frequency is a frequency determined through experiments in advance, and its determination method can refer to the above-mentioned Table 1, which will not be repeated here. When the compressor operates at the second self-cleaning frequency, it facilitates the implementation of the subsequent control process.

Next, control the outdoor fan to run at the highest speed, and control the indoor fan to stop running. Specifically, in the moderate self-cleaning mode, since the indoor heat exchanger is more dirty and clogged, before adjusting the opening of the throttling device, by controlling the outdoor fan to run at the highest speed, it is possible to improve the flow rate between the refrigerant and the outdoor heat exchanger. The heat exchange effect between environments reduces the temperature and pressure of the refrigerant, improves the evaporation effect of the refrigerant in the indoor heat exchanger, and makes the indoor coil reduce to the second preset temperature at a faster speed. Controlling the stop of the indoor fan can reduce the heat exchange effect between the indoor heat exchanger and the air, thereby speeding up the temperature reduction of the indoor coil and improving the self-cleaning efficiency and effect in the tube.

Next, the opening degree of the throttling device is adjusted so that the coil temperature of the indoor heat exchanger is less than or equal to the second preset temperature. Preferably, the second preset temperature is lower than the first preset temperature, so that the speed of solidification and precipitation of oil stains can be faster than that in the mild self-cleaning mode. The second preset temperature in this application may be -5°C to -15°C, and in this application, the second preset temperature may be -10°C. That is to say, the coil temperature of the indoor heat exchanger is set to be less than or equal to the second preset temperature as the control purpose, and the coil temperature of the indoor heat exchanger is always at The state of being less than or equal to the second preset temperature.

Referring to Figure 1, when the air conditioner is running in cooling mode, keep the coil temperature of the indoor heat exchanger at a temperature less than or equal to -10°C. At this time, the oil in the indoor heat exchanger will be stripped from the refrigerant circulation and attached to On the inner wall of the coil of the indoor heat exchanger.

Certainly, in other implementation manners, the coil temperature of the indoor heat exchanger can also be made to be less than or equal to the second preset temperature by adjusting the opening degree of the electronic expansion valve to a fixed opening degree.

Immediately afterwards, when the coil temperature is less than or equal to the second preset temperature for a third preset time period, the air conditioner is controlled to switch to the heating mode. The third preset duration may be any value in 5-15 minutes. Preferably, the third preset time length in this embodiment is 10 minutes. When the coil temperature is less than or equal to -10°C and lasts for 10 minutes, the oil in the indoor heat exchanger has been stripped, and the stripped oil can be cleaned at this time operate. At this time, the switch between the operation modes of the air conditioner is controlled by controlling the four-way valve to be powered on and off, for example, the four-way valve is controlled to be powered on, and the air conditioner operates in the heating mode.

Next, after the air conditioner switches to the heating mode, the first on-off valve is controlled to be closed and the second on-off valve is opened. After the first on-off valve is closed, the refrigerant pipeline between the throttling device and the indoor heat exchanger is throttled, and after the second on-off valve is opened, the refrigerant returns to the liquid receiver through the recovery pipeline. At this time, as shown in Figure 2, the refrigerant in the outdoor heat exchanger and the refrigerant pipeline is discharged by the compressor and accumulated in the indoor heat exchanger.

Finally, it is judged whether the first preset condition is met, and when the first preset condition is met, the first on-off valve is controlled to be opened, and the throttling device is closed to a minimum opening degree for a fourth preset duration. In the present application, the first preset condition is that the discharge temperature of the compressor is greater than or equal to the discharge temperature threshold and lasts for an eighth preset duration. Wherein, the eighth preset duration is preferably any value in 3s-10s, and 5s is used in this application. The exhaust gas temperature can be acquired continuously or at intervals, such as every 1s-5s. Control the throttling device to close to the minimum opening degree, that is, the state where the opening degree is 0, the throttling device realizes complete throttling, and the refrigerant cannot flow through. The fourth preset time length can be any value in 3min-10min, preferably 5min in this application. When the discharge temperature is greater than or equal to the discharge temperature threshold and lasts for the eighth preset time, the refrigerant has accumulated in the indoor heat exchanger and the pressure of the discharge port of the compressor rises to a higher value at this time, which meets the conditions and can be carried out Oil cleaning operation. Therefore, when the above conditions are met, open the first on-off valve, close the throttling device to the minimum opening, and keep this state for 5 minutes. At this time, as shown by the arrow in Figure 2, the high-temperature and high-pressure refrigerant discharged from the compressor flows through the indoor heat exchanger, and the high-temperature and high-pressure refrigerant quickly impacts the coil of the indoor heat exchanger, and the oil that is temporarily stored in the coil is melted. The high-temperature refrigerant directly flows back to the liquid receiver through the recovery pipeline to realize recovery and filtration, so as to achieve the purpose of self-cleaning in the tube of the indoor heat exchanger.

Although the exhaust gas temperature threshold is not illustrated in the above embodiments, this does not mean that the technical solution of the present application cannot be implemented. On the contrary, those skilled in the art can test and determine the exhaust gas temperature threshold based on the principles disclosed in this application, as long as the threshold is set so that the indoor heat exchanger has better self-cleaning when the first on-off valve is opened The effect is enough. In addition, the first preset condition is not limited to the above-mentioned discharge temperature being greater than or equal to the preset discharge temperature threshold. On the premise that the pressure/temperature state at the compressor discharge port can be judged, those skilled in the art can use other parameters Replace it. For example, the comparison between the discharge pressure of the compressor and the preset discharge pressure may be selected as the first preset condition, or the comparison between the suction pressure of the compressor and the preset suction pressure threshold may be used as the first preset condition.

In a possible implementation manner, the moderate self-cleaning mode further includes: after the step of controlling the air conditioner to switch to the heating mode, controlling the compressor to adjust to the highest limit frequency corresponding to the outdoor ambient temperature. Usually, the operating frequency of the compressor is affected by the outdoor ambient temperature and cannot be increased indefinitely, otherwise the phenomenon of high temperature protection shutdown of the compressor will easily occur, which will have a negative impact on the life of the compressor. Therefore, the compressors are all equipped with a protection mechanism. Under different outdoor ambient temperatures, the corresponding maximum frequency limit is set. In this application, after the air conditioner is switched to heating mode, the rating of the compressor is adjusted to the current outdoor environment. The highest limit frequency under the temperature, under this frequency limit, the compressor can increase the temperature and pressure of the refrigerant in the shortest time, thereby improving the self-cleaning effect. Wherein, the manner of obtaining the outdoor ambient temperature is a conventional means in the field, and will not be repeated here.

In a possible implementation, the method further includes: when entering the moderate self-cleaning mode, turning off the indoor antifreeze protection function and the outdoor ambient temperature frequency limiting function, but turning on other protection functions of the air conditioner as usual. The purpose and implementation of this step are the same as those in the light cleaning mode, so details will not be repeated here.

Of course, the specific control process of the moderate self-cleaning mode is not unique, and those skilled in the art can adjust the control method. For example, on the premise that the temperature of the coil tube of the indoor heat exchanger can be kept less than or equal to the second preset temperature, the operation frequency of the compressor, the opening degree of the electronic expansion valve, the speed of the indoor fan and the One or more of the rotational speeds of the outdoor fans are omitted. For another example, after the air conditioner is controlled to switch to the heating mode, no adjustments may be made to the throttling device. For another example, when the moderate self-cleaning mode is executed, the rotation speed of the outdoor fan may be determined according to the outdoor ambient temperature, and then the operation of the outdoor fan may be controlled.

In a possible implementation, the method further includes: exiting the moderate self-cleaning mode and controlling the air conditioner to return to Operating state prior to entering moderate self-cleaning mode. When the throttling device is closed to the minimum opening and the first on-off valve is open for 5 minutes, the high-temperature and high-pressure refrigerant has circulated many times, which is enough to produce a better self-cleaning effect. Therefore, when the throttling device is closed to the minimum opening , When the first on-off valve is opened for 5 minutes, the moderate self-cleaning mode can be exited.

In the present application, the purpose of exiting the moderate self-cleaning mode can be achieved by using the same control method as that for exiting the mild self-cleaning mode described above, which will not be repeated here.

Of course, the way of exiting the moderate self-cleaning mode is not limited to the same method as exiting the mild self-cleaning mode. On the premise that the air conditioner can be restored to the operating state before entering the moderate self-cleaning mode, the technology in the art Personnel can freely choose a specific control mode, and this choice does not deviate from the principle of the present application. For example, the outdoor fan can be controlled to return to the operating state before entering the moderate self-cleaning mode; another example, the indoor fan can be controlled after the coil temperature of the indoor heat exchanger has dropped to a temperature suitable for the cooling mode Start running. For another example, various components of the air conditioner can be controlled to directly restore to the operating parameters before entering the moderate self-cleaning mode.

In a possible implementation, the deep self-cleaning mode includes: controlling the air conditioner to operate in cooling mode; adjusting the operating parameters of the air conditioner so that the coil temperature of the indoor heat exchanger is less than or equal to the third preset temperature; when the coil temperature After the temperature is less than or equal to the third preset temperature and lasts for the fifth preset time, control the air conditioner to switch to the heating mode; control the first on-off valve to close and the second on-off valve to open; when the second preset condition is met, control The first on-off valve is opened; after the sixth preset time period, the first on-off valve is controlled to close; when the second preset condition is met again, the first on-off valve is controlled to open again, and lasts for the seventh preset time period. Wherein, the operating parameters include the operating frequency of the compressor, the opening degree of the throttling device, the rotating speed of the indoor fan and the rotating speed of the outdoor fan. specifically,

First, the air conditioner is controlled to operate in cooling mode. Then, control the compressor to adjust to the third self-cleaning frequency. Next, control the outdoor fan to run at the highest speed, and control the indoor fan to stop running. Next, the opening degree of the throttling device is adjusted so that the coil temperature of the indoor heat exchanger is less than or equal to the third preset temperature. Immediately afterwards, when the coil temperature is less than or equal to the third preset temperature for a fifth preset time period, the air conditioner is controlled to switch to the heating mode. Then, control the first on-off valve to close and the second on-off valve to open, and when the second preset condition is met, control the first on-off valve to open and the throttling device to close to the minimum opening, and last for the sixth preset time . Then, after the sixth preset duration, the first on-off valve is controlled to close; when the second preset condition is met again, the first on-off valve is controlled to open again, and lasts for the seventh preset duration.

More preferably, the above operating parameters of the deep self-cleaning in the present application can be set the same as the corresponding parameters in the moderate self-cleaning mode, that is, the third self-cleaning frequency, the third preset temperature, the fifth preset duration, the first Parameters such as the second preset condition and the sixth preset duration are the same as the moderate self-cleaning. The difference between the control process of the deep self-cleaning mode and the moderate self-cleaning mode is:

After the second preset condition is met, the first on-off valve is controlled to open for the sixth preset time period, the deep self-cleaning mode is not exited immediately, but the first on-off valve is controlled to close again, and then continue to judge whether the first on-off valve is satisfied. The second preset condition is to open the first on-off valve again when the condition is satisfied, to perform self-cleaning on the indoor heat exchanger, and last for the seventh preset time. Wherein, the seventh preset duration can be any value in 1-5 minutes in this application, and 3 minutes is selected in this application. By controlling the re-closing and re-opening of the first on-off valve, the self-cleaning of the indoor heat exchanger is more thorough, and the self-cleaning effect is more in line with the current degree of dirty blockage of the indoor heat exchanger.

Of course, it is only a preferred embodiment that the control parameters of deep self-cleaning are the same as those of moderate self-cleaning. In other embodiments, those skilled in the art can also adjust the control parameters of deep self-cleaning to achieve better Good deep self-cleaning effect. For example, the deep self-cleaning mode can only run for one cycle, and the third preset temperature can be further reduced compared with the second preset temperature, and the fifth and sixth preset durations can be compared with the third or fourth preset temperature. Set the duration to increase, etc.

In a possible implementation, the deep self-cleaning mode further includes: after the step of controlling the air conditioner to switch to the heating mode, controlling the compressor to adjust to the highest limit frequency corresponding to the outdoor ambient temperature.

In a possible implementation, the method further includes: when entering the deep self-cleaning mode, turning off the indoor antifreeze protection function and the outdoor ambient temperature frequency limiting function, but turning on other protection functions of the air conditioner as usual. The purpose and implementation of this step are the same as those in the light cleaning mode, so details will not be repeated here.

Of course, the specific control process of the deep self-cleaning mode is not unique, and those skilled in the art can adjust the control method. For example, on the premise that the temperature of the coil tube of the indoor heat exchanger can be kept less than or equal to the third preset temperature, the operation frequency of the compressor, the opening degree of the electronic expansion valve, the speed of the indoor fan and the One or more of the rotational speeds of the outdoor fans are omitted. For another example, after the air conditioner is controlled to switch to the heating mode, no adjustments may be made to the throttling device. For another example, when executing the deep self-cleaning mode, the rotation speed of the outdoor fan may be determined according to the outdoor ambient temperature, and then the operation of the outdoor fan may be controlled.

In a possible implementation, the method further includes: after the first on-off valve is opened again for a seventh preset period of time, exiting the deep self-cleaning mode, and controlling the air conditioner to return to the operating state before entering the deep self-cleaning mode . When the first on-off valve is opened for the second time and lasts for the seventh preset time, it is sufficient to produce a better self-cleaning effect, so when the first on-off valve is opened again and lasts for the seventh preset time, the depth can be withdrawn Self-cleaning mode.

In the present application, the purpose of exiting the deep self-cleaning mode can be realized by using the same control method as exiting the light self-cleaning mode described above, which will not be repeated here.

Of course, the method of exiting the deep self-cleaning mode is not limited to the same method as exiting the mild self-cleaning mode. On the premise that the air conditioner can be restored to the operating state before entering the deep self-cleaning mode, those skilled in the art can The specific control mode is free to choose, and this choice does not deviate from the principle of the present application. For example, the outdoor fan can be controlled to return to the operating state before entering the deep self-cleaning mode; another example, the indoor fan can be controlled to start after the coil temperature of the indoor heat exchanger has dropped to a temperature suitable for the cooling mode. run. For another example, it is possible to control the various components of the air conditioner to directly return to the operating parameters before entering the deep self-cleaning mode.

In general, the three in-pipe self-cleaning modes of this application control the air conditioner to run in the cooling mode first, and adjust the opening of the throttling device so that the oil in the coil of the indoor heat exchanger is solidified and stripped from the refrigerant circulation, Attached to the inner wall of the coil of the indoor heat exchanger, then control the air conditioner to switch to heating mode, and open the second on-off valve or first close the first on-off valve and open the first on-off valve when the preset conditions are met , using the rapid flow of high-temperature and high-pressure refrigerant to impact the interior of the coil of the indoor heat exchanger, the oil temporarily stored in the coil is melted by high temperature and returns directly to the interior of the liquid receiver through the recovery pipeline together with the refrigerant, realizing the indoor exchange. The tubes of the heater are self-cleaning. Moreover, the cleaning effects of the three in-tube self-cleaning modes are sequentially enhanced from mild, moderate to deep self-cleaning modes, which can match the cleaning effect with the effect of dirty clogging, and realize intelligent self-cleaning of indoor heat exchangers.

In addition, by setting the recovery pipeline in the air conditioner, the application can use the recovery pipeline to realize the recovery of oil stains during the self-cleaning process of the indoor heat exchanger, and realize the flushing of the indoor heat exchanger by the high-temperature and high-pressure refrigerant. Afterwards, without going through the outdoor heat exchanger again, the oil is directly brought back to the liquid receiver for recovery and filtration, which reduces the flow stroke of high-temperature refrigerant, reduces the pressure drop along the way, and improves the self-cleaning effect in the pipe.

A possible implementation process of the present application will be described below with reference to FIG. 4 . Wherein, FIG. 4 is a logic diagram of a possible implementation process of the control method for self-cleaning in tubes of indoor heat exchangers of the present application.

As shown in Figure 4, the air conditioner starts to cool and run, and then performs the following operations:

Firstly, step S201 is executed to obtain the accumulated running time t of the air conditioner.

Next, step S203 is executed to determine whether the accumulated time t≥20h is established, and if established, step S205 is executed; otherwise, when not established, the operation ends.

S205. Obtain the first average value Tp1 of the coil temperature of the indoor heat exchanger within 0-15 minutes and the second average value of the coil temperature of the indoor heat exchanger within 45 minutes-60 minutes within the next 1 hour of operation Tp2.

Next, step S207 is executed to determine whether |Tp1-Tp2|<2 holds true; if true, step S211 is executed; otherwise, if not established, step S209 is executed.

S209, judging whether |Tp1-Tp2|≥4 holds true; if not, execute step S213; otherwise, if true, execute step S215.

S211, execute a mild self-cleaning mode.

S213, executing a moderate self-cleaning mode.

S215, executing a deep self-cleaning mode.

Those skilled in the art can understand that the above air conditioner also includes some other known structures, such as a processor, a controller, a memory, etc., wherein the memory includes but not limited to random access memory, flash memory, read-only memory, programmable read-only memory, Volatile memory, non-volatile memory, serial memory, parallel memory or registers, etc., processors include but not limited to CPLD/FPGA, DSP, ARM processors, MIPS processors, etc. These well-known structures are not shown in the figures in order to unnecessarily obscure the embodiments of the present disclosure.

In the above embodiment, although the various steps are described according to the above sequence, those skilled in the art can understand that in order to achieve the effect of this embodiment, different steps do not have to be executed in this order, and they can be performed at the same time ( Parallel) execution or execution in reversed order, these simple changes are all within the protection scope of the present application.

So far, the technical solutions of the present application have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, those skilled in the art can easily understand that the protection scope of the present application is obviously not limited to these specific embodiments. Without departing from the principle of the present application, those skilled in the art can make equivalent changes or substitutions to relevant technical features, and the technical solutions after these changes or substitutions will all fall within the protection scope of the present application.

Claims (10)

1. An in-pipe self-cleaning control method for an indoor heat exchanger, applied to an air conditioner, characterized in that the air conditioner includes a compressor, a four-way valve, an outdoor heat exchanger, a throttling device, Indoor heat exchanger, the air conditioner also includes a recovery pipeline, a first on-off valve and a second on-off valve, the first on-off valve is arranged between the throttling device and the indoor heat exchanger On the refrigerant pipeline, one end of the recovery pipeline is set on the refrigerant pipeline between the throttling device and the first on-off valve, and the other end of the recovery pipeline is connected to the suction of the compressor. The port is connected, and the second on-off valve is set on the recovery pipeline,

   The control methods include:

   Obtain the operating data of the air conditioner;

   Based on the operating data, judging the degree of dirty blockage of the indoor heat exchanger;

   Based on the degree of dirty blockage, execute a corresponding in-pipe self-cleaning mode;

   The degree of dirty clogging includes mild dirty clogging, moderate dirty clogging and severe dirty clogging, and the self-cleaning mode in the pipe includes mild self-cleaning mode, moderate self-cleaning mode and deep self-cleaning mode;

   The mild self-cleaning mode includes: controlling the air conditioner to operate in cooling mode; adjusting the operating parameters of the air conditioner so that the coil temperature of the indoor heat exchanger is less than or equal to the first preset temperature; when the After the coil temperature is less than or equal to the first preset temperature and lasts for a first preset time, control the air conditioner to switch to heating mode; control the second on-off valve to open and last for a second preset time;

   The moderate self-cleaning mode includes: controlling the air conditioner to operate in cooling mode; adjusting the operating parameters of the air conditioner so that the coil temperature of the indoor heat exchanger is less than or equal to the second preset temperature; when the After the coil temperature is less than or equal to the second preset temperature and lasts for a third preset time, control the air conditioner to switch to heating mode; control the first on-off valve to close and the second on-off valve to open ; When the first preset condition is met, control the first on-off valve to open for a fourth preset duration;

   The deep self-cleaning mode includes: controlling the air conditioner to operate in cooling mode; adjusting the operating parameters of the air conditioner so that the coil temperature of the indoor heat exchanger is less than or equal to the third preset temperature; After the pipe temperature is less than or equal to the third preset temperature and lasts for a fifth preset duration, control the air conditioner to switch to heating mode; control the first on-off valve to close and the second on-off valve to open; When the second preset condition is met, the first on-off valve is controlled to open; after a sixth preset duration, the first on-off valve is controlled to close; when the second preset condition is met again, the control The first on-off valve is opened again for a seventh preset period of time;

   Wherein, the operating parameters include one or more of the operating frequency of the compressor, the opening of the throttling device, the rotational speed of the indoor fan, and the rotational speed of the outdoor fan.
2. The method for controlling self-cleaning in tubes of indoor heat exchangers according to claim 1, characterized in that, in the mild self-cleaning mode,

   After controlling the air conditioner to switch to heating mode, control the compressor to adjust to the highest limit frequency corresponding to the outdoor ambient temperature; and/or

   The step of adjusting the operating parameters of the air conditioner includes: controlling the compressor to adjust to the first self-cleaning frequency, controlling the outdoor fan to maintain the current running state, and controlling the indoor fan to run at a preset speed; and/or

   When the throttling device is an electronic expansion valve, the step of adjusting the operating parameters of the air conditioner further includes: adjusting the opening degree of the throttling device; and/or

   When the throttling device is an electronic expansion valve, after the air conditioner is controlled to switch to the heating mode, the throttling device is controlled to close to a minimum opening.
3. The control method for in-tube self-cleaning of an indoor heat exchanger according to claim 1, wherein the control method further comprises:

   After the second on-off valve is opened for the second preset time period, the mild self-cleaning mode is exited, and the air conditioner is controlled to return to the operating state before entering the mild self-cleaning mode.
4. The method for controlling self-cleaning in tubes of indoor heat exchangers according to claim 1, characterized in that, in the moderate self-cleaning mode,

   After controlling the air conditioner to switch to the heating mode, control the compressor to adjust to the highest limit frequency corresponding to the outdoor ambient temperature; and/or

   The step of adjusting the operating parameters of the air conditioner includes: controlling the compressor to adjust to the second self-cleaning frequency, controlling the outdoor fan to run at the highest speed, controlling the indoor fan to stop running; and/or

   When the throttling device is an electronic expansion valve, the step of adjusting the operating parameters of the air conditioner further includes: adjusting the opening degree of the throttling device; and/or

   When the throttling device is an electronic expansion valve, after the air conditioner is controlled to switch to the heating mode, the throttling device is controlled to close to a minimum opening.
5. The control method for in-tube self-cleaning of an indoor heat exchanger according to claim 1, wherein the control method further comprises:

   After the first on-off valve is opened for the fourth preset time period, exit the moderate self-cleaning mode, and control the air conditioner to return to the operating state before entering the moderate self-cleaning mode.
6. The method for controlling self-cleaning in tubes of indoor heat exchangers according to claim 1, wherein in the deep self-cleaning mode,

   After controlling the air conditioner to switch to the heating mode, control the compressor to adjust to the highest limit frequency corresponding to the outdoor ambient temperature; and/or

   The step of adjusting the operating parameters of the air conditioner includes: controlling the compressor to adjust to the third self-cleaning frequency, controlling the outdoor fan to run at the highest speed, controlling the indoor fan to stop running; and/or

   When the throttling device is an electronic expansion valve, the step of adjusting the operating parameters of the air conditioner further includes: adjusting the opening degree of the throttling device; and/or

   When the throttling device is an electronic expansion valve, after the air conditioner is controlled to switch to the heating mode, the throttling device is controlled to close to a minimum opening.
7. The control method for in-tube self-cleaning of an indoor heat exchanger according to claim 1, wherein the control method further comprises:

   After the first on-off valve is opened again for the seventh preset time period, the deep self-cleaning mode is exited, and the air conditioner is controlled to return to the operating state before entering the deep self-cleaning mode.
8. The method for controlling self-cleaning in tubes of indoor heat exchangers according to claim 1, wherein the operating data includes the cumulative operating time of the air conditioner and the coil temperature of the indoor heat exchanger, and "acquire the The step of "operating data of the air conditioner" further includes:

   Obtain the cumulative running time of the air conditioner;

   When the accumulated running time reaches the preset time threshold, the first average value of the coil temperature in the first period and the first average value of the coil temperature in the second period of the air conditioner in the next running process are acquired. Two mean values;

   The step of "judging the degree of dirty blockage of the indoor heat exchanger based on the operation data" further includes:

   calculating the absolute value of the difference between the first average value and the second average value;

   When the absolute value of the difference is less than a first threshold, it is judged that the indoor heat exchanger is the mildly dirty blockage;

   When the absolute value of the difference is greater than or equal to a first threshold and less than a second threshold, it is determined that the indoor heat exchanger is moderately dirty;

   When the absolute value of the difference is greater than or equal to the second threshold, it is determined that the indoor heat exchanger is severely dirty.
9. The control method for in-pipe self-cleaning of an indoor heat exchanger according to claim 1, wherein the throttling device is an electronic expansion valve, and the operating data includes the actual opening of the electronic expansion valve and the compression The actual exhaust temperature of the air conditioner, the step of "obtaining the operating data of the air conditioner" further includes:

   obtaining the actual discharge temperature of the compressor;

   Acquire the actual opening of the electronic expansion valve when the actual exhaust temperature reaches the target exhaust temperature;

   The step of "judging the degree of dirty blockage of the indoor heat exchanger based on the operating data" further includes:

   calculating the difference between the actual opening and the target opening, and calculating the ratio between the difference and the target opening;

   When the ratio is greater than the third threshold and less than or equal to the fourth threshold, it is judged that the indoor heat exchanger is the mildly dirty blockage;

   When the ratio is greater than the fourth threshold and less than or equal to the fifth threshold, it is determined that the indoor heat exchanger is moderately dirty;

   When the ratio is greater than the fifth threshold, it is judged that the indoor heat exchanger is severely dirty;

   Wherein, the target opening degree is determined based on the target exhaust temperature and the outdoor environment temperature.
10. The control method for in-pipe self-cleaning of an indoor heat exchanger according to claim 1, wherein the throttling device is a capillary tube, and the operating data includes the actual exhaust temperature, "obtaining the operating data of the air conditioner" The steps further include:

    obtaining the actual discharge temperature of the compressor;

    The step of "judging the degree of dirty blockage of the indoor heat exchanger based on the operation data" further includes:

    calculating a difference between the actual exhaust temperature and a target exhaust temperature, and calculating a ratio between the difference and the target exhaust temperature;

    When the ratio is greater than the sixth threshold and less than or equal to the seventh threshold, it is judged that the indoor heat exchanger is the mildly dirty blockage;

    When the ratio is greater than the seventh threshold and less than or equal to the eighth threshold, it is determined that the indoor heat exchanger is moderately dirty;

    When the ratio is greater than the eighth threshold, it is determined that the indoor heat exchanger is severely dirty.

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