WO2023284197A1

WO2023284197A1 - In-pipe self-cleaning control method for outdoor heat exchanger

Info

Publication number: WO2023284197A1
Application number: PCT/CN2021/129807
Authority: WO
Inventors: 罗荣邦; 崔俊
Original assignee: 青岛海尔空调器有限总公司; 青岛海尔空调电子有限公司; 海尔智家股份有限公司
Priority date: 2021-07-15
Filing date: 2021-11-10
Publication date: 2023-01-19
Also published as: CN113654192A; CN113654192B

Abstract

The present invention relates to the technical field of air conditioner self-cleaning, and in particular, to an in-pipe self-cleaning control method for an outdoor heat exchanger. The present application aims to solve the problem of how to achieve different degrees of in-pipe self-cleaning of the outdoor heat exchanger. For this purpose, the air conditioner of the present application comprises a recovery pipeline, a first on/off valve, and a second on/off valve. The control method comprises: acquiring running data of the air conditioner; on the basis of the running data, determining the degree of dirt blockage of the outdoor heat exchanger; and on the basis of the degree of dirt blockage, executing a corresponding in-pipe self-cleaning mode, the degree of dirt blockage comprising mild dirt blockage, moderate dirt blockage, and severe dirt blockage, and the in-pipe self-cleaning mode comprising a mild self-cleaning mode, a moderate self-cleaning mode, and a deep self-cleaning mode. According to the present application, on the basis of the degree of dirt blockage of an outdoor heat exchanger, a corresponding degree of in-pipe self-cleaning mode can be executed, thereby achieving more intelligent in-pipe self-cleaning.

Description

In-pipe self-cleaning control method of outdoor 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 outdoor heat exchangers.

Background technique

Some of the current air conditioners have the self-cleaning function of the inner and outer units. Taking the self-cleaning process of the outdoor heat exchanger as an example, when the self-cleaning function is executed, the frosting and defrosting operations on the outer surface of the coil of the outdoor heat exchanger are realized through the switching of cooling and heating modes combined with the opening and closing of the outdoor fan , so that when the frost layer melts, the dirt on the surface of the coil is washed away.

However, the current self-cleaning function is limited to cleaning the outer surface of the outdoor coil, but cannot clean the inside of the coil. Usually, the inside of the outdoor coil will accumulate impurities and refrigerating machine oil generated during the operation of the air conditioner, resulting in heat exchange. The effect becomes worse, so it is especially necessary to self-clean the interior of the outdoor coil. 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 outdoor coil. The self-cleaning time is long, which affects the normal user experience, and the self-cleaning is not thorough when the outer surface of the outdoor coil is seriously dirty.

Correspondingly, there is a need in the art for a new control method for self-cleaning in tubes of outdoor 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 realize different degrees of self-cleaning in the tube of the outdoor heat exchanger, the application provides a self-cleaning control method in the tube of the outdoor heat exchanger, which is applied to An air conditioner, the air conditioner includes a compressor, a four-way valve, an indoor heat exchanger, a throttling device, and an outdoor 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 indoor heat exchanger and the throttling device, one end of the recovery pipeline is set on the first On the refrigerant pipeline between the off valve and the throttling device, 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 dirt and blockage of the outdoor 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 run in the heating mode; adjusting the operating parameters of the air conditioner so that the coil temperature of the outdoor heat exchanger is less than or equal to the first preset temperature; 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 cooling 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 a heating mode; adjusting the operating parameters of the air conditioner so that the coil temperature of the outdoor heat exchanger is less than or equal to the second preset temperature; 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 cooling mode; control the first on-off valve and the second on-off valve to close; When the first preset condition is met, control the second on-off valve to open for a fourth preset duration;

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

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-pipe self-cleaning control method for outdoor heat exchangers, in the mild self-cleaning mode,

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

After controlling the air conditioner to switch to cooling mode, controlling the indoor fan to stop running; and/or

The step of adjusting the operating parameters of the air conditioner includes: controlling the compressor to adjust to a first self-cleaning frequency, controlling the outdoor fan to run at a minimum wind speed, and controlling the indoor fan to run at a first preset speed; and/or 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 cooling mode, the throttling device is controlled to open to a maximum opening degree.

In the preferred technical solution of the control method for in-pipe self-cleaning of the above-mentioned outdoor 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-pipe self-cleaning control method for outdoor heat exchangers, in the moderate self-cleaning mode,

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

After the second 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 in-pipe self-cleaning control method for outdoor heat exchangers, in the deep self-cleaning mode,

The step of adjusting the operating parameters of the air conditioner includes: controlling the compressor to adjust to a third self-cleaning frequency, controlling the outdoor fan to operate at the lowest rotational speed, and controlling the indoor fan to operate at the third preset rotational speed; and/or or

After the second on-off valve is opened again for a seventh preset period of time, 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 control method for in-pipe self-cleaning of the outdoor heat exchanger, the operating data includes the cumulative operating time of the air conditioner and the coil temperature of the outdoor 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 fouling and clogging of the outdoor heat exchanger based on the operating 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 outdoor 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 outdoor 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 outdoor heat exchanger is severely dirty.

In the preferred technical solution of the control method for in-pipe self-cleaning of the outdoor 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;

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 determined that the outdoor 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 outdoor heat exchanger is moderately dirty;

When the ratio is greater than the fifth threshold, it is judged that the outdoor 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 outdoor 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;

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 outdoor 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 outdoor heat exchanger is moderately dirty;

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

By judging the degree of dirty clogging of the outdoor 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 outdoor heat exchanger in the tube, but also Based on the degree of fouling and blockage of the outdoor heat exchanger, a suitable in-pipe self-cleaning mode can be implemented to achieve a more intelligent in-pipe self-cleaning.

Description of drawings

The method for controlling self-cleaning in tubes of an outdoor heat exchanger according to 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 heating mode;

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

Fig. 3 is the flowchart of the self-cleaning control method in the tube of the outdoor 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 an outdoor heat exchanger 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 principles of the present application, and are not intended to limit the protection scope of the present 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" and "Ninth" are used for descriptive purposes only, and should not be understood 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 indoor heat exchanger 5 , a throttling device 4 , an outdoor heat exchanger 3 and a liquid accumulator 11 . The exhaust port of the compressor 1 is connected with the P port of the four-way valve 2 through the refrigerant pipeline 6, and the E port of the four-way valve 2 is connected with the inlet of the indoor heat exchanger 5 through the 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 outdoor heat exchanger 3 through the refrigerant pipeline 6, and the outlet of the outdoor heat exchanger 3 passes through the refrigerant pipeline 6 is connected with the C port of the four-way valve 2, the S port of the four-way valve 2 is connected with the inlet of the accumulator 11 through the refrigerant pipeline 6, and the outlet of the accumulator 11 is connected 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 control method for self-cleaning in the pipe of the outdoor 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 method for controlling the self-cleaning in the tube of the outdoor 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 cooling mode; FIG. 3 is a flow chart of the control method for self-cleaning in pipes of the outdoor heat exchanger 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 outdoor heat exchanger, the self-cleaning control method in the tube of the outdoor 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 outdoor heat exchanger, the actual opening of the throttling device (when the throttling device is an electronic expansion valve), 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 dirt and blockage of the outdoor 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 outdoor 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 blockage of the outdoor heat exchanger is mild, the air conditioner is controlled to execute a mild self-cleaning mode; when it is judged that the degree of dirty blockage of the outdoor heat exchanger is moderately dirty, The air conditioner is controlled to execute the moderate self-cleaning mode; when it is judged that the degree of dirty clogging of the outdoor 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 dirt blockage of the outdoor 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 dirt blockage, the control method of the present application can not only realize the self-cleaning of the outdoor heat exchanger in the pipe. It is also able to perform a corresponding degree of in-pipe self-cleaning mode based on the degree of dirt and blockage of the outdoor heat exchanger, so that the self-cleaning effect can be adapted to the degree of dirt and clogging, realizing more intelligent self-cleaning in the pipe.

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

Example 1

In this embodiment, the throttling device may 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 outdoor 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 accumulative running time of the air conditioner reaches 20 hours, it indicates that the outdoor 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 outdoor heat exchanger in 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 running time reaches 20 hours, the average value of the coil temperature within two consecutive 15 minutes may be acquired 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 fouling and clogging of the outdoor 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 outdoor heat exchanger is mildly 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 outdoor 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 outdoor heat exchanger is severely dirty.

In a possible implementation manner, taking the heating mode of the air conditioner as an example, the more dirty the outdoor heat exchanger is, the worse the heat exchange effect is, so the coil temperature of the outdoor 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 outdoor heat exchanger is considered to be mildly dirty; if 2≤|Tp1-Tp2|<4, the outdoor heat exchanger is considered to be moderately dirty; if |Tp1-Tp2| ≥4, the outdoor heat exchanger is considered to be severely dirty and blocked.

When the air conditioner is running in cooling mode, the more dirty the outdoor heat exchanger is, the worse the heat transfer effect will be, so the coil temperature of the outdoor heat exchanger will be higher. Wherein, based on the operation data, the process of judging the degree of dirty blockage of the outdoor heat exchanger is similar to that in the heating 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 ways to determine 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 degree of the electronic expansion valve, the step of "judging the degree of dirtyness and blockage of the outdoor 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 outdoor 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 outdoor heat exchanger is moderately dirty; when the ratio is greater than the fifth threshold, it is judged that the outdoor 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 outdoor 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 outdoor heat exchanger, the worse the heat exchange effect, the higher the suction temperature and discharge temperature of the compressor, and the opening degree of the electronic expansion valve at this time must be greater than its target opening degree . Therefore, it is possible to determine whether the outdoor heat exchanger is dirty and to what extent by comparing the actual opening of the electronic expansion valve with its target opening.

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 degree of dirty blockage of the outdoor heat exchanger is not large, and self-cleaning is not required; if 1<△B/Bset≤1.1, it is considered that the outdoor heat exchanger is slightly dirty; if 1.1< If △B/Bset≤1.2, the outdoor heat exchanger is considered to be moderately dirty; if △B/Bset>1.2, the outdoor 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 outdoor 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 outdoor 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 outdoor heat exchanger is moderately dirty; when the ratio is greater than the eighth threshold, it is judged that the outdoor 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 dirty the outdoor heat exchanger is, the worse the heat exchange effect will be, and the higher the suction temperature and discharge temperature of the compressor will be. Therefore, it can be determined whether the outdoor heat exchanger is dirty and the degree of dirty blocking can be determined 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 outdoor heat exchanger is not large, and self-cleaning is not required; if 1<△T/Td≤1.1, it is considered that the outdoor heat exchanger is slightly dirty; if 1.1< If △T/Td≤1.2, the outdoor heat exchanger is considered to be moderately dirty; if △T/Td>1.2, the outdoor 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 manner, the mild self-cleaning mode includes: controlling the air conditioner to operate in a heating mode; adjusting the operating parameters of the air conditioner so that the coil temperature of the outdoor heat exchanger is less than or equal to the first preset temperature; when 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 cooling mode; control the second on-off valve to open and last for the first preset time 2. 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 a heating 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 on, the air conditioner operates in heating mode, and when the four-way valve is powered off, the air conditioner operates in cooling mode. model. In this embodiment, after entering the mild self-cleaning mode, if the air conditioner is running in the heating mode, no adjustment is required, and the air conditioner is controlled to continue running; if the air conditioner is running in the non-heating mode, the air conditioner is controlled to switch to heating Hot mode operation.

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

室外环境温度(℃)Outdoor ambient temperature (℃)	第一自清洁频率(Hz)First self-cleaning frequency (Hz)
Tao≤-20Tao≤-20	外环温限频最高频-5Maximum frequency of outer ring temperature limit frequency -5
-20<Tao≤-10-20<Tao≤-10	外环温限频最高频-5Maximum frequency of outer ring temperature limit frequency -5
-10<Tao≤-5-10<Tao≤-5	外环温限频最高频-5Maximum frequency of outer ring temperature limit frequency -5
-5<Tao≤0-5<Tao≤0	外环温限频最高频Maximum frequency of outer ring temperature limit frequency
0<Tao≤50<Tao≤5	外环温限频最高频Maximum frequency of outer ring temperature limit frequency
5<Tao≤105<Tao≤10	外环温限频最高频+5The highest frequency of the outer ring temperature limit frequency +5
10<Tao≤1610<Tao≤16	外环温限频最高频+5The highest frequency of the outer ring temperature limit frequency +5
Tao>16Tao>16	外环温限频最高频+5The highest frequency of the outer ring temperature limit frequency +5

Next, control the outdoor fan to run at the lowest speed, and control the indoor fan to run at the first preset speed. Specifically, in the mild self-cleaning mode, before adjusting the opening of the throttling device, the outdoor fan is first controlled to run at the lowest speed to reduce the heat exchange effect between the outdoor heat exchanger and the air, thereby speeding up the cooling of the outdoor disk. The temperature reduction speed of the tube improves the self-cleaning efficiency in the tube. In this application, the first preset speed can be a low speed in the speed of the indoor fan, such as 400r/min-700r/min, and this application can be 500r/min, because the dirty blockage of the outdoor heat exchanger is not serious , and the air conditioner is adjusting the indoor ambient temperature before entering the mild self-cleaning mode, so on the basis of ensuring the self-cleaning effect, by controlling the outdoor fan to run at the lowest speed, and the indoor fan to run at the first preset speed , to ensure a certain degree of indoor comfort.

Next, adjust the opening degree of the throttling device so that the coil temperature of the outdoor 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 outdoor heat exchanger, and dynamically adjust the opening degree of the electronic expansion valve, so that the coil temperature of the outdoor heat exchanger is less than or equal to the first preset temperature. Since the freezing point of the refrigerating machine oil is much lower than the freezing point of the oil stain, the oil stain can be first solidified and precipitated when the temperature of the coil tube is less than or equal to the first 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 outdoor 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 outdoor 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 the heating mode, keep the coil temperature of the outdoor heat exchanger at a temperature less than or equal to -5°C. At this time, the oil in the outdoor heat exchanger will be stripped from the refrigerant circulation and adhered On the inner wall of the coil of the outdoor heat exchanger.

Certainly, in other implementation manners, the coil temperature of the outdoor heat exchanger can also be made to be less 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 cooling 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 outdoor 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 power on and off of the four-way valve, for example, the power off of the four-way valve is controlled, and the air conditioner operates in the cooling mode.

Next, after the control air conditioner is switched to the cooling mode, the operation of the control room fan is stopped. Specifically, when the cooling mode is running, the outlet air temperature of the indoor unit gradually decreases, which will bring bad user experience to the user. At this time, the fan in the control room stops running after running for 30 seconds, which can prevent the temperature of the outlet air from being too low and affect the user experience. Of course, those skilled in the art can adjust the above 30s, such as adjusting to any value in 10s-1min.

Finally, the second on-off valve is controlled to be opened, and the throttling device is opened to a maximum opening degree for a second preset time period. The second preset duration can be any value in 3min-10min, preferably 5min in this application. When the operation mode is switched to refrigeration mode, control the opening of the second on-off valve and the throttling device to the maximum 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 outdoor heat exchanger, and the high-temperature and high-pressure refrigerant quickly impacts the coil of the outdoor heat exchanger, and the oil that is temporarily stored inside 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 outdoor heat exchanger. Controlling the throttling device to open to the maximum opening can allow the high-temperature and high-pressure refrigerant to pass quickly, reduce the pressure drop during the refrigerant flow process, and improve the self-cleaning effect in the pipe.

In a possible implementation manner, the mild self-cleaning mode further includes: after the step of controlling the air conditioner to switch to cooling 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 cooling mode, the rating of the compressor is adjusted to the current outdoor ambient 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 outdoor antifreeze protection function and the outdoor ambient temperature frequency limiting function. Since the coil temperature of the outdoor 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. function to ensure the smooth execution of this method. But other protection functions are turned on as usual, such as compressor exhaust protection and current overload protection, and other functions remain turned on 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 outdoor 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 cooling mode, no adjustments may be made to the throttling device.

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 second on-off valve is opened and the throttling device is closed 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 second on-off valve is opened and the throttling device is opened to When the maximum opening lasts 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 maintain 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 heating mode of the air conditioner 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 heating mode. At this time, control the four-way valve to restore the heating mode, control the frequency of the compressor to return from the maximum 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 maintains a maximum opening degree and controls the closing of the second on-off valve, so that the refrigerant flows in the normal heating mode flow direction. Among them, the indoor fan is turned on and the air deflector of the indoor unit blows air upwards, so as to prevent the user from having a bad user experience due to the low temperature of the indoor heat exchanger coil when the air conditioner just switches to the heating mode. Among them, the throttling device maintains the maximum opening degree, because the refrigerant circulates between the compressor and the outdoor heat exchanger when the mild self-cleaning mode is running, resulting in the lack of refrigerant in the indoor heat exchanger, so the throttling device maintains the maximum opening degree, making The refrigerant quickly fills the indoor heat exchanger to realize the normal circulation of the refrigerant as soon as possible.

Correspondingly, after the fan in the control room is turned on and the wind deflector is blowing air upwards for the first duration, the fan in the control room and the wind 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 wind deflector is blowing air upwards for 30s, the temperature of the coil of the indoor heat exchanger has risen to the same level as that of heating. At this time, control the indoor fan and the wind deflector to return to the operating mode before entering the mild self-cleaning mode to meet the heating demand of the user.

Correspondingly, after the throttling device is controlled to maintain the maximum opening for the 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, and it is preferably 3min in this application. When the electronic expansion valve maintains the maximum opening and runs for 3min, the refrigerant circulation has tended to be stable. The opening degree before the mild self-cleaning mode, so that the air conditioner can fully restore the heating parameters before entering the mild self-cleaning mode and continue to run.

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 it entered the mild self-cleaning mode; another example, the indoor fan can be controlled to be turned off first, and then the coil temperature of the indoor heat exchanger can be obtained to rise to a temperature suitable for the heating mode. After the temperature is reached, the indoor fan is controlled to 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 run in the heating mode; adjusting the operating parameters of the air conditioner so that the coil temperature of the outdoor heat exchanger is less than or equal to the second preset temperature; After the pipe 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 cooling mode; control the first on-off valve and the second on-off valve to close; when the first preset condition is met, control The second on-off valve is opened 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 a heating 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 heating mode, no adjustment is required, and the air conditioner is controlled to continue running; if the air conditioner is in the non-heating mode, the air conditioner is controlled to switch to the heating mode Hot mode operation.

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 lowest speed, and control the indoor fan to run at the second preset speed. Specifically, in the moderate self-cleaning mode, before adjusting the opening degree of the throttling device, the outdoor fan is first controlled to run at the lowest speed to reduce the heat exchange effect between the outdoor heat exchanger and the air, thereby speeding up the cooling of the outdoor disk. The temperature reduction speed of the tube improves the self-cleaning efficiency in the tube. In this application, the second preset speed can be the highest speed of the indoor fan. Since the outdoor heat exchanger is more dirty and clogged, before adjusting the opening of the throttling device, the indoor fan can be controlled to run at the highest speed, which can improve The heat exchange effect between the refrigerant in the indoor heat exchanger and the environment, thereby reducing the temperature and pressure of the refrigerant, improving the evaporation effect of the refrigerant in the outdoor heat exchanger, and reducing the outdoor coil to the second preset temperature at a faster speed .

Next, the opening degree of the throttling device is adjusted so that the coil temperature of the outdoor 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. In this application, the second preset temperature may be -10°C. That is to say, the coil temperature of the outdoor heat exchanger is less than or equal to the second 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 outdoor 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 the heating mode, keep the coil temperature of the outdoor heat exchanger at or below -10°C. At this time, the oil in the outdoor heat exchanger will be stripped from the refrigerant circulation and adhered to On the inner wall of the coil of the outdoor heat exchanger.

Certainly, in other implementation manners, the coil temperature of the outdoor 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 cooling 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 outdoor 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 power on and off of the four-way valve, for example, the power off of the four-way valve is controlled, and the air conditioner operates in the cooling mode.

Next, after the control air conditioner is switched to the cooling mode, the operation of the control room fan is stopped. Specifically, when the cooling mode is running, the outlet air temperature of the indoor unit gradually decreases, which will bring bad user experience to the user. At this time, the fan in the control room stops running after running for 30 seconds, which can prevent the temperature of the outlet air from being too low and affect the user experience. Of course, those skilled in the art can adjust 30s, such as adjusting to any value in 10s-1min.

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

Finally, it is judged whether the first preset condition is met, and when the first preset condition is met, the second on-off valve is controlled to be opened, and the throttling device is opened to a maximum 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 open to the maximum opening, so that the high-temperature and high-pressure refrigerant can pass quickly. 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 outdoor 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 second on-off valve, open the throttling device to the maximum 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 outdoor heat exchanger, and the high-temperature and high-pressure refrigerant quickly impacts the coil of the outdoor heat exchanger, and the oil that is temporarily stored inside 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 outdoor heat exchanger.

In a possible implementation manner, the moderate self-cleaning mode further includes: after the step of controlling the air conditioner to switch to cooling 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 cooling mode, the rating of the compressor is adjusted to the current outdoor ambient 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 outdoor 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 coil temperature of the outdoor 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 cooling mode, no adjustments may be made to the throttling device.

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 and the second on-off valve are opened 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 second on-off valve is opened and the throttling device is opened to the maximum When the opening degree lasts 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 to be turned off first, and then the temperature of the coil of the indoor heat exchanger rises to a temperature suitable for the heating mode. After the temperature is reached, the indoor fan is controlled to 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 run in the heating mode; adjusting the operating parameters of the air conditioner so that the coil temperature of the outdoor heat exchanger is less than or equal to the third preset temperature; when the coil After the temperature is less than or equal to the third preset temperature and lasts for the fifth preset time, the air conditioner is controlled to switch to cooling mode; the first on-off valve and the second on-off valve are controlled to close; when the second preset condition is met, the second on-off valve is controlled to The two on-off valve is opened; after the sixth preset time period, the second on-off valve is controlled to close; when the second preset condition is met again, the second 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 a heating mode. Then, control the compressor to adjust to the third self-cleaning frequency. Next, control the outdoor fan to run at the lowest speed, and control the indoor fan to run at the third preset speed. Next, adjust the opening degree of the throttling device, so that the coil temperature of the outdoor 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 cooling mode. Then, the first on-off valve and the second on-off valve are controlled to be closed, and when the second preset condition is met, the second on-off valve is controlled to be opened, and the throttling device is opened to a maximum opening degree for a sixth preset time period. Then, after the sixth preset duration, the second on-off valve is controlled to close; when the second preset condition is met again, the second on-off valve is controlled to open again, and lasts for the seventh preset duration.

More preferably, the above operating parameters of 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 speed, the third preset temperature, the third Parameters such as the fifth preset duration, 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 second on-off valve is controlled to open for the sixth preset period of time, the deep self-cleaning mode is not exited immediately, but the second on-off valve is controlled to close again, and then continue to judge whether the second on-off valve is satisfied. The second preset condition is to open the second on-off valve again when the condition is satisfied, to perform self-cleaning on the indoor heat exchanger, and last for the seventh preset duration. 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 second on-off valve to close and open again, the self-cleaning of the outdoor heat exchanger is more thorough, and the self-cleaning effect is more in line with the degree of dirt and blockage of the current outdoor 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 manner, the deep self-cleaning mode further includes: after the step of controlling the air conditioner to switch to cooling 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 outdoor 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 coil temperature of the outdoor heat exchanger can be kept at or below 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 cooling mode, no adjustments may be made to the throttling device.

In a possible implementation, the method further includes: exiting the deep self-cleaning mode after the second on-off valve is opened again for a seventh preset period of time, and controlling the air conditioner to return to the operating state before entering the deep self-cleaning mode. When the second on-off valve is opened for the second time and lasts for the seventh preset period of time, it is sufficient to produce a better self-cleaning effect, so when the second on-off valve is opened for the second time and lasts for the seventh preset period of time, it can Exit deep 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 be turned off first, and then the coil temperature of the indoor heat exchanger can be obtained to rise to a temperature suitable for the heating mode After that, control the indoor fan to start running. 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 heating mode first, and adjust the operating parameters of the air conditioner so that the oil in the coil of the outdoor heat exchanger is solidified and stripped from the refrigerant cycle. Attached to the inner wall of the coil of the outdoor heat exchanger, then control the air conditioner to switch to cooling mode, and open the second on-off valve or first close the first on-off valve and the second on-off valve and open when the preset conditions are met The second on-off valve uses the rapid flow of high-temperature and high-pressure refrigerant to impact the inside of the coil of the outdoor heat exchanger, and the oil temporarily stored inside the coil is melted by high temperature and returns directly to the interior of the liquid receiver through the recovery pipeline along with the refrigerant , to achieve self-cleaning of the outdoor heat exchanger tube. In addition, 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 the outdoor heat exchanger.

In addition, by setting the recovery pipeline in the air conditioner, the application can use the recovery pipeline to realize the recovery of oil pollution during the self-cleaning process of the outdoor heat exchanger, and realize the high-temperature and high-pressure refrigerant to flush the outdoor heat exchanger. 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 method for controlling self-cleaning in tubes of an outdoor heat exchanger of the present application.

As shown in Figure 4, the air conditioner is turned on for heating and running, 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 outdoor heat exchanger within 0-15 minutes and the second average value of the coil temperature of the outdoor 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 not, then step S209 is executed; otherwise, if true, step S211 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

An in-pipe self-cleaning control method for an outdoor heat exchanger, applied to an air conditioner, characterized in that the air conditioner includes a compressor, a four-way valve, an indoor heat exchanger, a throttling device, An outdoor 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 indoor heat exchanger and the throttling device On the refrigerant pipeline, one end of the recovery pipeline is set on the refrigerant pipeline between the first on-off valve and the throttling device, 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 dirt and blockage of the outdoor 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 run in the heating mode; adjusting the operating parameters of the air conditioner so that the coil temperature of the outdoor heat exchanger is less than or equal to the first preset temperature; 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 cooling 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 a heating mode; adjusting the operating parameters of the air conditioner so that the coil temperature of the outdoor heat exchanger is less than or equal to the second preset temperature; 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 cooling mode; control the first on-off valve and the second on-off valve to close; When the first preset condition is met, control the second on-off valve to open for a fourth preset duration;

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

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.
The method for controlling self-cleaning in tubes of outdoor heat exchangers according to claim 1, characterized in that, in the mild self-cleaning mode,

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

After controlling the air conditioner to switch to cooling mode, controlling the indoor fan to stop running; and/or

The step of adjusting the operating parameters of the air conditioner includes: controlling the compressor to adjust to a first self-cleaning frequency, controlling the outdoor fan to run at a minimum wind speed, and controlling the indoor fan to run at a first preset speed; and/or 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 cooling mode, the throttling device is controlled to open to a maximum opening degree.
The control method for in-pipe self-cleaning of an outdoor heat exchanger according to claim 2, 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.
The method for controlling self-cleaning in tubes of outdoor heat exchangers according to claim 1, characterized in that, in the moderate self-cleaning mode,

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

After controlling the air conditioner to switch to cooling mode, controlling the indoor fan to stop running; and/or

The step of adjusting the operating parameters of the air conditioner includes: controlling the compressor to adjust to a second self-cleaning frequency, controlling the outdoor fan to run at the lowest speed, and controlling the indoor fan to run at the second preset speed; and/or 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 cooling mode, the throttling device is controlled to open to a maximum opening degree.
The control method for in-pipe self-cleaning of an outdoor heat exchanger according to claim 4, wherein the control method further comprises:

After the second 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.
The tube self-cleaning control method of an outdoor heat exchanger according to claim 1, characterized in that, in the deep self-cleaning mode,

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

After controlling the air conditioner to switch to cooling mode, controlling the indoor fan to stop running; and/or

The step of adjusting the operating parameters of the air conditioner includes: controlling the compressor to adjust to a third self-cleaning frequency, controlling the outdoor fan to operate at the lowest rotational speed, and controlling the indoor fan to operate at the third preset rotational speed; and/or 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 cooling mode, the throttling device is controlled to open to a maximum opening degree.
The control method for self-cleaning in tubes of outdoor heat exchangers according to claim 6, characterized in that the control method further comprises:

After the second on-off valve is opened again for a seventh preset period of time, 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.
The method for controlling self-cleaning in pipes of an outdoor heat exchanger according to claim 1, wherein the operating data includes the cumulative operating time of the air conditioner and the coil temperature of the outdoor 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 fouling and clogging of the outdoor heat exchanger based on the operating 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 outdoor 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 outdoor 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 outdoor heat exchanger is severely dirty.
The control method for in-pipe self-cleaning of an outdoor 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 fouling and clogging of the outdoor 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 determined that the outdoor 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 outdoor heat exchanger is moderately dirty;

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

Wherein, the target opening degree is determined based on the target exhaust temperature and the outdoor environment temperature.
The self-cleaning control method in the tube of an outdoor 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 fouling and clogging of the outdoor 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 outdoor 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 outdoor heat exchanger is moderately dirty;

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