CN113654192B

CN113654192B - Method for controlling self-cleaning in pipe of outdoor heat exchanger

Info

Publication number: CN113654192B
Application number: CN202110802942.1A
Authority: CN
Inventors: 罗荣邦; 崔俊
Original assignee: Qingdao Haier Air Conditioner Gen Corp Ltd; Qingdao Haier Air Conditioning Electric Co Ltd; Haier Smart Home Co Ltd
Current assignee: Qingdao Haier Air Conditioner Gen Corp Ltd; Qingdao Haier Air Conditioning Electric Co Ltd; Haier Smart Home Co Ltd
Priority date: 2021-07-15
Filing date: 2021-07-15
Publication date: 2023-04-18
Anticipated expiration: 2041-07-15
Also published as: WO2023284197A1; CN113654192A

Abstract

The invention relates to the technical field of air conditioner self-cleaning, in particular to a method for controlling self-cleaning in a pipe of an outdoor heat exchanger. The application aims to solve the problem of how to realize different degrees of in-pipe self-cleaning of the outdoor heat exchanger. To this end, the air conditioner of the present application includes a recovery line, a first on-off valve, and a second on-off valve. The control method comprises the following steps: acquiring operation data of an air conditioner; judging the filth blockage degree of the outdoor heat exchanger based on the operation data; executing a corresponding in-pipe self-cleaning mode based on the filth blockage degree; the degree of the filth blockage comprises mild filth blockage, moderate filth blockage and severe filth blockage, and the self-cleaning mode in the pipe comprises a mild self-cleaning mode, a moderate self-cleaning mode and a deep self-cleaning mode. This application can carry out the intraductal automatically cleaning mode of corresponding degree based on indoor heat exchanger's dirty stifled degree, realizes more intelligent intraductal automatically cleaning.

Description

Method for controlling self-cleaning in pipe of outdoor heat exchanger

Technical Field

The invention relates to the technical field of air conditioner self-cleaning, in particular to a method for controlling self-cleaning in a pipe of an outdoor heat exchanger.

Background

The existing air conditioner has the self-cleaning function of the internal and external machines. 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 of the outer surface of the coil pipe of the outdoor heat exchanger are realized by combining the mode switching of refrigeration and heating with the switching of the outdoor fan, so that the dirt on the surface of the coil pipe is flushed when a frost layer is melted.

However, the current self-cleaning function is only limited to cleaning the outer surface of the outdoor coil, but cannot clean the interior of the coil, and impurities, refrigerating oil and the like generated in the operation process of the air conditioner are accumulated in the outdoor coil to cause the heat exchange effect to be poor, so that the self-cleaning function of the interior of the outdoor coil is particularly necessary. In addition, the cleaning mode of the current air conditioner is fixed after entering the self-cleaning mode, and the self-cleaning degree cannot be intelligently controlled according to the dirt condition of the outdoor coil pipe, so that the self-cleaning time is long when the dirt degree of the outer surface of the outdoor coil pipe is light, the normal experience of a user is influenced, and the self-cleaning is not thorough when the dirt degree of the outer surface of the outdoor coil pipe is serious.

Accordingly, there is a need in the art for a new method of controlling self-cleaning in a tube of an outdoor heat exchanger to solve the above problems.

Disclosure of Invention

In order to solve at least one of the above problems in the prior art, that is, to solve the problem of how to realize different degrees of in-tube self-cleaning of an outdoor heat exchanger, the present application provides a method for controlling in-tube self-cleaning of an outdoor heat exchanger, which is applied to an air conditioner, the air conditioner comprises a compressor, a four-way valve, an indoor heat exchanger, a throttling device, an outdoor heat exchanger, which are sequentially connected by a refrigerant pipeline, and further comprises a recovery pipeline, a first on-off valve and a second on-off valve, wherein the first on-off valve is arranged on the refrigerant pipeline between the indoor heat exchanger and the throttling device, one end of the recovery pipeline is arranged on the refrigerant pipeline between the first on-off valve and the throttling device, the other end of the recovery pipeline is communicated with an air suction port of the compressor, and the second on-off valve is arranged on the recovery pipeline,

the control method comprises the following steps:

acquiring operation data of the air conditioner;

judging the filth blockage degree of the outdoor heat exchanger based on the operation data;

executing a corresponding in-tube self-cleaning mode based on the filth blockage degree;

the degree of the filth blockage comprises mild filth blockage, moderate filth blockage and severe filth blockage, and the self-cleaning mode in the pipe comprises a mild self-cleaning mode, a moderate self-cleaning mode and a deep self-cleaning mode;

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 temperature of a coil of the outdoor heat exchanger is less than or equal to a first preset temperature; when the temperature of the coil pipe is less than or equal to the first preset temperature and lasts for a first preset time, controlling the air conditioner to be switched into a refrigeration mode; controlling the second on-off valve to be opened 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 to enable the temperature of a coil of the outdoor heat exchanger to be less than or equal to a second preset temperature; when the temperature of the coil pipe is less than or equal to the second preset temperature and lasts for a third preset time, controlling the air conditioner to be switched into a refrigeration mode; controlling the first on-off valve and the second on-off valve to close; when a first preset condition is met, controlling the second on-off valve to be opened and lasting for a fourth preset time;

the deep self-cleaning mode includes: controlling the air conditioner to operate in a heating mode; adjusting the operating parameters of the air conditioner to enable the temperature of a coil of the outdoor heat exchanger to be less than or equal to a third preset temperature; when the temperature of the coil pipe is less than or equal to the third preset temperature and lasts for a fifth preset time, controlling the air conditioner to be switched to a refrigeration mode; controlling the on-off valve to be opened, and controlling the first on-off valve and the second on-off valve to be closed; when a second preset condition is met, controlling the second cut-off valve to be opened; after lasting for a sixth preset time, controlling the second cut-off valve to be closed; when the second preset condition is met again, controlling the second cut-off valve to be opened again for a seventh preset time;

the operation parameters comprise one or more of the operation 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.

In a preferred embodiment of the above method for controlling self-cleaning in the tube of the outdoor heat exchanger, in the mild self-cleaning mode,

after the air conditioner is controlled to be switched into a refrigeration mode, controlling the compressor to adjust to the maximum limit frequency corresponding to the outdoor environment temperature; and/or

After controlling the air conditioner to be switched into a 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 operate at the lowest wind speed, and controlling the indoor fan to operate at a first preset rotating speed; and/or

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

And when the throttling device is an electronic expansion valve, after the air conditioner is controlled to be switched into a refrigeration mode, the throttling device is controlled to be opened to the maximum opening degree.

In a preferred technical solution of the method for controlling self-cleaning in a tube of an outdoor heat exchanger, the method further includes:

and after the second on-off valve is opened and lasts for the second preset time, the mild self-cleaning mode is exited, and the air conditioner is controlled to be restored to the running state before the mild self-cleaning mode is entered.

In a preferred embodiment of the method for controlling self-cleaning in a tube of an outdoor heat exchanger, in the intermediate 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 operate at the lowest rotating speed, and controlling the indoor fan to operate at a second preset rotating speed; and/or

and after the second on-off valve is opened and lasts for the fourth preset time, the air conditioner exits from the moderate self-cleaning mode, and the air conditioner is controlled to be restored to the running state before entering the moderate self-cleaning mode.

In a preferred embodiment of the above method for controlling self-cleaning in a tube of an outdoor heat exchanger, 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 rotating speed, and controlling the indoor fan to operate at a third preset rotating speed; and/or

and after the second on-off valve is opened again and lasts for a seventh preset time, the deep self-cleaning mode is exited, and the air conditioner is controlled to be restored to the running state before the deep self-cleaning mode is entered.

In a preferred technical solution of the method for controlling self-cleaning in a tube of an outdoor heat exchanger, the operation data includes an accumulated operation time of the air conditioner and a coil temperature of the outdoor heat exchanger, and the step of obtaining the operation data of the air conditioner further includes:

acquiring the accumulated running time of the air conditioner;

when the accumulated running time reaches a preset time threshold, acquiring a first average value of the coil temperature in a first time period and a second average value of the coil temperature in a second time period in the next running process of the air conditioner;

the step of "judging the degree of filth blockage of the outdoor heat exchanger based on the operation data" further includes:

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

when the absolute value of the difference value is smaller than a first threshold value, judging that the outdoor heat exchanger is the light filth blockage;

when the absolute value of the difference value is greater than or equal to a first threshold value and smaller than a second threshold value, judging that the outdoor heat exchanger is the moderate dirty blockage;

and when the absolute value of the difference value is larger than or equal to a second threshold value, judging that the outdoor heat exchanger is severely filthy blocked.

In a preferred technical solution of the above method for controlling self-cleaning in a tube of an outdoor heat exchanger, the throttling device is an electronic expansion valve, the operation data includes an actual opening degree of the electronic expansion valve and an actual exhaust temperature of the compressor, and the step of obtaining the operation data of the air conditioner further includes:

acquiring an actual exhaust temperature of the compressor;

when the actual exhaust temperature reaches the target exhaust temperature, acquiring the actual opening degree of the electronic expansion valve;

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

when the ratio is greater than a third threshold and less than or equal to a fourth threshold, judging that the outdoor heat exchanger is the mild filth blockage;

when the ratio is greater than the fourth threshold and less than or equal to a fifth threshold, judging that the outdoor heat exchanger is the medium filth blockage;

when the ratio is larger than a fifth threshold value, judging that the outdoor heat exchanger is severely filtrately blocked;

wherein the target opening degree is determined based on the target exhaust temperature and an outdoor ambient temperature.

In a preferred technical solution of the above method for controlling self-cleaning in a tube of an outdoor heat exchanger, the throttling device is a capillary tube, the operation data includes an actual exhaust temperature, and the step of "acquiring the operation data of the air conditioner" further includes:

acquiring an actual exhaust 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 a sixth threshold and less than or equal to a seventh threshold, judging that the outdoor heat exchanger is the mild filth blockage;

when the ratio is greater than the seventh threshold and less than or equal to an eighth threshold, judging that the outdoor heat exchanger is the moderate filth blockage;

and when the ratio is larger than an eighth threshold value, judging that the outdoor heat exchanger is severely filthy plugged.

Through judging the filthy blockage degree of the outdoor heat exchanger according to the operation data of the air conditioner, and then operating different in-pipe self-cleaning modes based on the filthy blockage degree, the control method not only can realize in-pipe self-cleaning of the outdoor heat exchanger, but also can execute the in-pipe self-cleaning mode matched with the filthy blockage degree of the outdoor heat exchanger, and realize more intelligent in-pipe self-cleaning.

Drawings

The in-tube self-cleaning control method of the outdoor heat exchanger of the present application is described below with reference to the accompanying drawings.

In the drawings:

FIG. 1 is a system diagram of the air conditioner of the present application in a heating mode;

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

fig. 3 is a flowchart of an in-tube self-cleaning control method of an outdoor heat exchanger according to the present application;

fig. 4 is a logic diagram of a possible implementation process of the in-tube self-cleaning control method of the outdoor heat exchanger according to the present application.

List of reference numerals

1. A compressor; 2. a four-way valve; 3. an outdoor heat exchanger; 4. a throttling device; 5. an indoor heat exchanger; 6. a refrigerant pipeline; 7. a recovery pipeline; 8. a first on-off valve; 9. a second on-off valve; 11. a reservoir.

Detailed Description

Preferred embodiments of the present application are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only for explaining the technical principles of the present application, and are not intended to limit the scope of protection of the present application. For example, although the following detailed description describes the detailed steps of the method of the present application, those skilled in the art can combine, split and exchange the order of the above steps without departing from the basic principle of the present application, and the modified technical solution does not change the basic concept of the present application and therefore falls into the protection scope of the present application.

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

It should also be noted that, unless expressly stated or limited otherwise, the term "coupled" is used in the description of the invention in its broadest sense, and thus, for example, may be fixedly coupled, releasably coupled, or integrally coupled; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meaning of the above terms in the present application can be understood by those skilled in the art as the case may be.

First, referring to fig. 1, the structure of the air conditioner of the present application will be described. Fig. 1 is a system diagram of an air conditioner according to the present invention in a cooling mode.

As shown in fig. 1, in one possible embodiment, the air conditioner includes a compressor 1, a four-way valve 2, an indoor heat exchanger 5, a throttle device 4, an outdoor heat exchanger 3, and an accumulator 11. The air vent of compressor 1 passes through refrigerant pipeline 6 and the P interface intercommunication of cross valve 2, the E interface of cross valve 2 passes through refrigerant pipeline 6 and the import intercommunication of indoor heat exchanger 5, the export of indoor heat exchanger 5 passes through refrigerant pipeline 6 and a port intercommunication of throttling arrangement 4, another port of throttling arrangement 4 passes through refrigerant pipeline 6 and the import intercommunication of outdoor heat exchanger 3, the export of outdoor heat exchanger 3 passes through refrigerant pipeline 6 and the C interface intercommunication of cross valve 2, the S interface of cross valve 2 passes through refrigerant pipeline 6 and the import intercommunication of reservoir 11, the export of reservoir 11 passes through pipeline and compressor 1' S induction port intercommunication. The throttling device 4 can be a capillary tube or an electronic expansion valve, a filter screen is arranged in the liquid storage device 11, and the liquid storage device 11 can play roles in storing refrigerants, separating refrigerant gas and liquid, filtering oil stains, silencing, buffering the refrigerants and the like.

The air conditioner further comprises 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, the first on-off valve 8 is a normally open valve and is arranged on a 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 and is arranged on the recovery pipeline 7, the recovery pipeline 7 is made of a copper pipe with a smooth inner wall, the first end of the copper pipe is arranged on the refrigerant pipeline 6 between the throttling device 4 and the first on-off valve 8, and the second end of the copper pipe is arranged on the refrigerant pipeline 6 between an S interface of the four-way valve 2 and an inlet of the liquid storage device 11. The first on-off valve 8 and the second on-off valve 9 are in communication connection with a controller of the air conditioner to receive opening and closing signals sent by the controller. Of course, one or more of the on-off valves may be replaced by an electronic control valve such as an electronic expansion valve.

The method for controlling self-cleaning in the tube of the outdoor heat exchanger in the following embodiment will be described in conjunction with the structure of the air conditioner, but it will be understood by those skilled in the art that the specific structural composition of the air conditioner is not constant, and those skilled in the art may adjust the method, for example, components may be added or deleted on the basis of the structure of the air conditioner.

The method for controlling self-cleaning in the tube of the outdoor heat exchanger according to the present application is described with reference to fig. 1, 2 and 3. Fig. 2 is a system diagram of the air conditioner of the present application in a cooling mode; fig. 3 is a flowchart of an in-tube self-cleaning control method of an outdoor heat exchanger according to the present application.

As shown in fig. 3, in order to solve the problem of how to implement different degrees of in-tube self-cleaning of the outdoor heat exchanger, the in-tube self-cleaning control method of the outdoor heat exchanger of the present application includes:

and S101, acquiring operation data of the air conditioner.

In a possible embodiment, the operation data of the air conditioner includes an accumulated operation time, a coil temperature of the outdoor heat exchanger, an actual opening degree of the throttling device (when the throttling device is an electronic expansion valve), an actual exhaust temperature of the compressor, and the like, and one or more of the operation data are acquired during the operation of the air conditioner. The above-mentioned operation data acquisition methods all belong to conventional means in the field, and are not described herein again.

And S103, judging the filth blockage degree of the outdoor heat exchanger based on the operation data.

In a possible implementation manner, the range of the operation data or the size of the operation data is determined by reasonably calculating the operation data, comparing the operation data with a preset threshold value and the like, and then determining the filth blockage degree of the outdoor heat exchanger.

And S105, executing a corresponding in-pipe self-cleaning mode based on the filth blockage degree.

In a possible embodiment, the filth degree of the present application may be divided into a mild filth, a moderate filth, and a severe filth, and accordingly, the self-cleaning mode in the pipe corresponding to each filth degree includes a mild self-cleaning mode, a moderate self-cleaning mode, and a deep self-cleaning mode. That is, when the filth blockage degree of the outdoor heat exchanger is judged to be light filth blockage, the air conditioner is controlled to execute a light self-cleaning mode; when the filth blockage degree of the outdoor heat exchanger is judged to be medium filth blockage, controlling the air conditioner to execute a medium self-cleaning mode; and when judging that the filth blockage degree of the outdoor heat exchanger is severe filth blockage, controlling the air conditioner to execute a deep self-cleaning mode.

It can be seen that the control method not only can realize the in-pipe self-cleaning of the outdoor heat exchanger, but also can execute the in-pipe self-cleaning mode with the corresponding degree based on the filth blockage degree of the outdoor heat exchanger, so that the self-cleaning effect is adaptive to the filth blockage degree, and more intelligent in-pipe self-cleaning is realized.

Several possible embodiments of the present application for determining the degree of contamination of the outdoor heat exchanger based on the operation data of the air conditioner are described below.

Example 1

In this embodiment, the throttling device may be a capillary tube or an electronic expansion valve, the operation data of the air conditioner includes the accumulated operation time of the air conditioner and the coil temperature of the outdoor heat exchanger, and the step of acquiring the operation data of the air conditioner further includes:

acquiring the accumulated running time of the air conditioner; and when the accumulated running time reaches a preset time threshold, acquiring a first average value of the coil temperature in a first time period and a second average value of the coil temperature in a second time period in the next running process of the air conditioner.

In a possible embodiment, the accumulated running time can be any value from 15h to 40h, in this case 20h. And when the accumulated running time of the air conditioner reaches 20 hours, the outdoor heat exchanger is possibly dirty and blocked, and the dirty and blocked degree needs to be judged. And at the moment, the temperature of the coil pipe of the outdoor heat exchanger in the next operation process of the air conditioner is obtained for judgment. Specifically, the first time interval and the second time interval may take any value from 10 to 30min, for example, the first time interval and the second time interval are both 15min, that is, after the accumulated running time reaches 20h, the average value of the coil temperature is taken as the first average value and the second average value in two 15min time intervals, respectively. More preferably, after the accumulated operation time reaches 20h, the average value of the coil temperature of the first 15min and the average value of the coil temperature of the last 15min of the 1h from the 20 th hour to the operation time reaches 21h can be respectively taken as the first average value and the second average value.

Of course, the specific obtaining manner of the first average value and the second average value is not exclusive, and the above embodiment is only a preferred embodiment, and a person skilled in the art can adjust the above embodiment as long as the first average value and the second average value can be effectively obtained. For example, after the accumulated operation time reaches 20h, the average value of the coil temperature in two consecutive 15min periods can be obtained as the first average value and the second average value.

After the first average value and the second average value are obtained, the step of determining the filth blockage degree of the outdoor heat exchanger based on the operation data further comprises the following steps:

calculating an absolute value of a difference between the first average value and the second average value; when the absolute value of the difference value is smaller than a first threshold value, judging that the outdoor heat exchanger is lightly filthy blocked; when the absolute value of the difference value is greater than or equal to a first threshold value and smaller than a second threshold value, judging that the outdoor heat exchanger is moderately dirty and blocked; and when the absolute value of the difference value is larger than or equal to the second threshold value, judging that the outdoor heat exchanger is heavily filthy-blocked.

In a possible implementation, taking the air conditioner as an example of the heating mode, the more the outdoor heat exchanger is clogged, the worse the heat exchange effect is, and therefore, the lower the coil temperature of the outdoor heat exchanger is. In the present application, the first threshold is smaller than the second threshold, the first threshold may be any value in 1-3 ℃, and the second threshold may be any value in 3-5 ℃. Assuming that the first average value is Tp1, the second average value is Tp2, the first threshold value is 2 ℃, and the second threshold value is 4 ℃, the absolute value of the difference between the first average value and the second average value, i.e., | Tp1-Tp2|, is first calculated, and then the magnitude between the absolute value and the first threshold value and the second threshold value is determined. If the absolute Tp1-Tp2 is less than 2, the outdoor heat exchanger is considered to be slightly dirty and blocked; if the absolute value Tp1-Tp2 is more than or equal to 2 and less than 4, the outdoor heat exchanger is considered to be moderately dirty and blocked; if the absolute Tp1-Tp2 is more than or equal to 4, the outdoor heat exchanger is considered to be severely dirty and blocked.

When the air conditioner runs in a refrigeration mode, the more serious the filth blockage of the outdoor heat exchanger is, the poorer the heat exchange effect of the outdoor heat exchanger is, and therefore, the higher the temperature of the coil pipe of the outdoor heat exchanger is. The process of judging the filth blockage degree of the outdoor heat exchanger based on the operation data is similar to that in the heating mode, and is not repeated.

Example 2

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

acquiring the actual exhaust temperature of the compressor; and when the actual exhaust temperature reaches the target exhaust temperature, acquiring the actual opening degree of the electronic expansion valve.

In a possible embodiment, the actual discharge temperature of the compressor is obtained by a temperature sensor disposed at the discharge port of the compressor, and the obtaining manner is a conventional measure in the art and is not described again. The target exhaust temperature is a common control parameter in air conditioner control, and in the operation process of the air conditioner, the target exhaust temperature is determined firstly, and then the opening degree of the electronic expansion valve is controlled to adjust the actual exhaust temperature, so that the actual exhaust temperature reaches or approaches to the target exhaust temperature as much as possible. There are many ways to determine the target exhaust temperature, such as determining based on a look-up table or a fitting formula between the target exhaust temperature and the outdoor ambient temperature. And in the running process of the air conditioner, the actual exhaust temperature is controlled by adjusting the opening degree of the expansion valve, and when the actual exhaust temperature reaches the target exhaust temperature, the actual opening degree of the electronic expansion valve at the moment is obtained.

After the actual opening degree of the electronic expansion valve is obtained, the step of determining the filth blockage degree of the outdoor heat exchanger based on the operation data further comprises the following steps:

calculating a difference value between the actual opening degree and the target opening degree, and calculating a ratio between the difference value and the target opening degree; when the ratio is greater than the third threshold and less than or equal to the fourth threshold, judging that the outdoor heat exchanger is lightly dirty and blocked; when the ratio is greater than a fourth threshold value and less than or equal to a fifth threshold value, judging that the outdoor heat exchanger is medium filth blockage; when the ratio is greater than a fifth threshold value, judging that the outdoor heat exchanger is severely dirty and blocked;

in one possible embodiment, 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 between the three. In the formula, bset is a target opening degree, i.e., an ideal opening degree when no filth blockage occurs, td is a target exhaust temperature, tao is an outdoor environment temperature, K is a coefficient, and the coefficient K may be determined based on an experiment. As can be seen from the above, when the outdoor heat exchanger is not dirty, each outdoor ambient temperature corresponds to a target exhaust temperature, and the target exhaust temperature and the outdoor ambient temperature together determine the target opening degree of the electronic expansion valve.

The current way of controlling the opening of the electronic expansion valve based on the target exhaust gas temperature is generally as follows: when the exhaust temperature is higher than the target exhaust temperature → the electronic expansion valve is opened greatly → the refrigerant quantity is increased, the temperature of the refrigerant in the evaporator after heat exchange is reduced → the suction temperature and the exhaust temperature of the compressor are reduced. When the exhaust temperature is lower than the target exhaust temperature → the electronic expansion valve is closed to be small → the refrigerant quantity is reduced, the temperature of the refrigerant in the evaporator after heat exchange is improved → the suction temperature and the exhaust temperature of the compressor are increased.

Under the corresponding relationship, the more severe the filth blockage of the outdoor heat exchanger is, the poorer the heat exchange effect is, the higher the suction temperature and the exhaust temperature of the compressor are, and the opening degree of the electronic expansion valve is larger than the target opening degree at the moment. Therefore, whether the outdoor heat exchanger is dirty or not and the degree of the dirty can be determined by comparing the actual opening degree of the electronic expansion valve with the target opening degree thereof.

For example, if it is assumed 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 environment temperature is Bset, at this time, the difference Δ B = B-Bset between the two is calculated, then the ratio of the difference Δ B to the target opening degree Bset is calculated, and the range of the ratio is determined. In the present application, the third threshold, the fourth threshold, and the fifth threshold increase sequentially, where the third threshold is any value from 0.9 to 1.05, the fourth threshold is any value from 1.05 to 1.15, and the fifth threshold is any value from 1.15 to 1.35. In the present application, the third threshold is 1, the fourth threshold is 1.1, and the fifth threshold is 1.2. If delta B/Bset is less than or equal to 1, the filth blockage degree of the outdoor heat exchanger is not large, and self-cleaning is not needed; if 1 & ltdelta B/Bset & gt is less than or equal to 1.1, the outdoor heat exchanger is considered to be lightly filthy blocked; if the delta B/Bset is more than 1.1 and less than or equal to 1.2, the outdoor heat exchanger is considered to be moderately dirty and blocked; if Delta B/Bset is more than 1.2, the outdoor heat exchanger is considered to be severely filtrately blocked.

Example 3

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

the actual discharge temperature of the compressor is obtained. The actual discharge temperature may be obtained based on a temperature sensor provided at the compressor discharge.

After the actual exhaust temperature is obtained, the step of "determining the filth blockage degree of the outdoor heat exchanger based on the operation data" further includes:

calculating a difference between the actual exhaust temperature and the target exhaust temperature, and calculating a ratio between the difference and the target exhaust temperature; when the ratio is greater than a sixth threshold value and less than or equal to a seventh threshold value, judging that the outdoor heat exchanger is lightly filthy blocked; when the ratio is greater than the seventh threshold and less than or equal to the eighth threshold, judging that the outdoor heat exchanger is moderately dirty and blocked; and when the ratio is larger than an eighth threshold value, judging that the outdoor heat exchanger is severely dirty and blocked.

In one possible implementation, the determination of the target exhaust temperature is the same as in example 2 and will not be described again. Because the opening degree of the capillary tube can not be adjusted, the more serious the filth blockage of the outdoor heat exchanger is, the worse the heat exchange effect is, and the higher the suction temperature and the exhaust temperature of the compressor are. Therefore, whether or not the outdoor heat exchanger is dirty and the degree of the dirty can be determined by comparing the actual exhaust temperature with the target exhaust temperature.

For example, after the air conditioner is started and operates stably, the actual exhaust temperature T is obtained, then the difference value delta T between the actual exhaust temperature T and the target exhaust temperature Td is calculated, and the ratio of the difference value delta T to the target exhaust temperature Td is calculated; and finally, judging the range of the ratio, thereby determining the degree of the filth blockage. In the present application, the sixth threshold, the seventh threshold and the eighth threshold are sequentially increased, where the sixth threshold is any value from 0.9 to 1.05, the seventh threshold is any value from 1.05 to 1.15, and the eighth threshold is any value from 1.15 to 1.35. In this application, the sixth threshold is 1, the seventh threshold is 1.1, and the eighth threshold is 1.2. If delta T/Td is less than or equal to 1, the dirty degree of the outdoor heat exchanger is not large, and self-cleaning is not needed; if 1 & ltdelta T/Td & lt 1.1 & gt, the outdoor heat exchanger is considered to be lightly dirty and blocked; if 1.1 < [ delta ] T/Td is less than or equal to 1.2, the outdoor heat exchanger is considered to be moderately dirty and blocked; and if the delta T/Td is more than 1.2, the outdoor heat exchanger is considered to be severely filtrately blocked.

The following describes a specific control process of the self-cleaning mode in each pipe according to the present application, taking a throttling device as an electronic expansion valve as an example. It will be understood by those skilled in the art that when the restriction device is a capillary tube, a control method corresponding to the in-tube self-cleaning mode when the restriction device is a capillary tube may be obtained by adjusting the in-tube self-cleaning mode described below. For example, all the control methods described below for the throttling device may be omitted, thereby obtaining a control method for the in-tube self-cleaning mode in the case of the capillary tube.

In one possible embodiment, 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 temperature of a coil of the outdoor heat exchanger is less than or equal to a first preset temperature; when the temperature of the coil pipe is less than or equal to the first preset temperature and lasts for a first preset time, controlling the air conditioner to be switched into a refrigeration mode; and controlling the second cut-off valve to be opened for a second preset time. The operation parameters comprise the operation frequency of the compressor, the opening of the throttling device, the rotating speed of the indoor fan and the rotating speed of the outdoor fan. In particular, the amount of the solvent to be used,

first, the air conditioner is controlled to operate a heating mode. Switching between the operation modes of the air conditioner may be controlled by controlling the on/off of the four-way valve, for example, when the four-way valve is powered on, the air conditioner operates in a heating mode, and when the four-way valve is powered off, the air conditioner operates in a cooling mode. In the embodiment, after entering the mild self-cleaning mode, if the air conditioner is in the heating mode, the air conditioner is controlled to continue to operate without adjustment; and if the air conditioner is running in the non-heating mode, controlling the air conditioner to switch to the heating mode to run.

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

TABLE 1 comparison table of outdoor ambient temperature and first self-cleaning frequency

Outdoor ambient temperature (. Degree. C.)	First self-cleaning frequency (Hz)
		Tao≤-20	Outer ring temperature frequency limit maximum frequency-5
-20<Tao≤-10	Outer loop temperature limit frequency maximum-5
		-10<Tao≤-5	Outer loop temperature limit frequency maximum-5
-5<Tao≤0	Outer loop temperature frequency limiting maximum frequency
		0<Tao≤5	Outer loop temperature frequency limiting maximum frequency
5<Tao≤10	Outer ring temperature frequency limiting maximum frequency +5
		10<Tao≤16	Outer ring temperature frequency limit maximum frequency +5
Tao>16	Outer ring temperature frequency limiting maximum frequency +5

And then, controlling the outdoor fan to operate at the lowest rotating speed, and controlling the indoor fan to operate at a first preset rotating speed. Specifically, in the mild self-cleaning mode, before the opening degree of the throttling device is adjusted, the outdoor fan is controlled to operate at the lowest rotating speed to reduce the heat exchange effect between the outdoor heat exchanger and air, so that the reduction speed of the temperature of the outdoor coil pipe can be increased, and the self-cleaning efficiency in the pipe is improved. The first preset rotating speed can be a lower rotating speed in the rotating speeds of the indoor fans, such as 400r/min-700r/min, the first preset rotating speed can be 500r/min, the dirty blockage of the outdoor heat exchanger is not serious, and the indoor environment temperature of the air conditioner is being adjusted before the air conditioner enters the slight self-cleaning mode, so that on the basis of ensuring the self-cleaning effect, the outdoor fans are controlled to operate at the lowest rotating speed, and the indoor fans operate at the first preset rotating speed, and certain indoor comfort level can be ensured.

And then, adjusting the opening degree of the throttling device to enable the temperature of the coil of the outdoor heat exchanger to be less than or equal to a first preset temperature. In a possible implementation manner, the temperature of the coil of the outdoor heat exchanger can be detected by the temperature sensor, and the opening degree of the electronic expansion valve is dynamically adjusted, so that the temperature of the coil of the outdoor heat exchanger is less than or equal to a first preset temperature. Because the freezing point of the refrigerating machine oil is far lower than the freezing point of the oil stain, the oil stain can be firstly solidified and separated out when the temperature of the coil is less than or equal to a first preset temperature. The first preset temperature may be set to-1 ℃ to-10 ℃ in the present application, and the first preset temperature may be set to-5 ℃ in the present application. That is, the coil temperature of the outdoor heat exchanger is controlled to be equal to or lower than a first preset temperature, and the coil temperature of the outdoor heat exchanger is always in a state of being equal to or lower than the first preset temperature by adjusting the opening degree of the electronic expansion valve (such as PID adjustment).

Referring to fig. 1, when the air conditioner operates in a heating mode, the temperature of the coil of the outdoor heat exchanger is maintained at a temperature of-5 ℃ or lower, and at this time, oil stains in the outdoor heat exchanger are separated from the refrigerant cycle and attached to the inner wall of the coil of the outdoor heat exchanger.

Of course, in other embodiments, the coil temperature of the outdoor heat exchanger may be set to be equal to or lower than the first preset temperature by adjusting the opening degree of the electronic expansion valve to a fixed opening degree.

And then, when the temperature of the coil pipe is less than or equal to a first preset temperature and lasts for a first preset time, controlling the air conditioner to be switched into a refrigeration mode. The first preset time period can be any value in the range of 5-15 min. Preferably, the first preset time period in this embodiment is 10min, and after the temperature of the coil pipe is less than or equal to-5 ℃ and lasts for 10min, the oil stains in the outdoor heat exchanger are already stripped, and then the stripped oil stains can be cleaned. At this time, the switching between the operation modes of the air conditioner is controlled by controlling the on/off of the four-way valve, for example, the four-way valve is controlled to be powered off, and the air conditioner operates in a cooling mode.

Next, after controlling the air conditioner to switch to the cooling mode, controlling the indoor fan to stop operating. Specifically, when the refrigeration mode is operated, the outlet air temperature of the indoor unit is gradually reduced, and poor use experience can be brought to users. At this moment, the operation of the indoor fan is controlled to stop after 30s, and the influence on user experience due to too low air outlet temperature can be avoided. Of course, the person skilled in the art can adjust the above 30s to any value within 10s-1 min.

And finally, controlling the second on-off valve to be opened, and controlling the throttling device to be opened to the maximum opening degree for a second preset time. The second preset time period can be any value from 3min to 10min, and the application is preferably 5min. And when the operation mode is switched to the refrigeration mode, controlling the second stop valve to be opened and the throttling device to be opened to the maximum opening degree, and keeping the state to continuously operate for 5min. At this time, as shown by the arrow in fig. 2, the high-temperature and high-pressure refrigerant discharged from the compressor flows through the outdoor heat exchanger, the high-temperature and high-pressure refrigerant quickly impacts the coil of the outdoor heat exchanger, the oil stain temporarily stored in the coil is melted, and the high-temperature refrigerant directly flows back to the reservoir through the recovery pipeline to achieve recovery and filtration, so that the purpose of self-cleaning in the pipe of the outdoor heat exchanger is achieved. The throttling device is controlled to be opened to the maximum opening degree, so that high-temperature and high-pressure refrigerants can rapidly pass through, the pressure drop in the flowing process of the refrigerants is reduced, and the self-cleaning effect in the pipe is improved.

In one possible embodiment, the mild self-cleaning mode further comprises: after the step of controlling the air conditioner to switch to the cooling mode, controlling the compressor to adjust to the maximum limit frequency corresponding to the outdoor environment temperature. Generally, the operation frequency of the compressor is affected by the outdoor environment temperature, and cannot be increased without limit, otherwise, the phenomenon of high-temperature protection shutdown of the compressor is easy to occur, and the service life of the compressor is adversely affected. Therefore, the compressors are provided with protection mechanisms, and the maximum limit frequency is correspondingly set under different outdoor environment temperatures. The manner of acquiring the outdoor ambient temperature is a conventional means in the art, and is not described herein again.

In one possible embodiment, the method further comprises: and when entering a slight self-cleaning mode, closing the outdoor anti-freezing protection function and the outdoor environment temperature frequency limiting function. Because the temperature of the coil of the outdoor heat exchanger needs to be reduced to a lower value, in order to achieve the condition as soon as possible, the compressor needs to operate at high frequency, and in the heating operation process, the outdoor anti-freezing protection function and the outdoor environment temperature frequency limiting function are closed, so that the smooth execution of the method is ensured. However, other protection functions are normally started, such as compressor exhaust protection, current overload protection and the like, and the functions are kept started, so that adverse effects on the service life of the air conditioner are prevented.

Of course, the specific control process of the mild self-cleaning mode is not exclusive, and the control mode can be adjusted by those skilled in the art. For example, one or more of the operating frequency of the compressor, the opening degree of the electronic expansion valve, the rotational speed of the indoor fan, and the rotational speed of the outdoor fan in the above control method may be omitted on the premise that the coil temperature of the outdoor heat exchanger can be maintained at the first preset temperature or lower. For another example, after the air conditioner is controlled to switch to the cooling mode, no adjustment may be made to the throttle device.

In one possible embodiment, the method further comprises: and after the second on-off valve is opened and the throttling device is opened to the maximum opening degree for the second preset time, the air conditioner exits from the mild self-cleaning mode and is controlled to be restored to the running state before the air conditioner enters the mild self-cleaning mode. When the time that the second on-off valve is opened and the throttling device is closed lasts for 5min, the high-temperature and high-pressure refrigerant circulates for many times to generate a better self-cleaning effect, so that the mild self-cleaning mode can be exited when the second on-off valve is opened and the throttling device is opened to the maximum opening degree and lasts for 5min.

Specifically, the step of exiting the mild self-cleaning mode further comprises: the air conditioner is controlled to be restored to the running mode before the air conditioner enters the slight self-cleaning mode, the frequency of the compressor before the compressor enters the slight self-cleaning mode is controlled to be restored, the indoor fan is controlled to be started, the air deflector of the indoor unit supplies air upwards, the throttling device is controlled to keep the maximum opening degree, and the second on-off valve is controlled to be closed. After the mild self-cleaning mode is performed, the air conditioner needs to be returned to the operation mode before entering the mild self-cleaning mode to continuously adjust the indoor temperature. In the following, taking the air conditioner running heating mode before entering the mild self-cleaning mode as an example, after the mild self-cleaning mode is executed, the air conditioner needs to be switched back to the heating mode to run. At the moment, the four-way valve is controlled to be electrified to recover the heating mode, the compressor is controlled to recover the frequency from the highest limit frequency to the frequency before entering the mild self-cleaning mode, the indoor fan is controlled to be started, the air deflector of the indoor unit supplies air upwards, the electronic expansion valve is controlled to keep the maximum opening degree, and the second on-off valve is controlled to be closed, so that the refrigerant flows in the flow direction of the normal heating mode. Wherein, indoor fan opens and the aviation baffle of indoor set upwards supplies air, prevents because when the air conditioner just changed into the mode of heating, indoor heat exchanger coil pipe temperature was crossed lowly and the air-out brought not good use experience for the user. The throttling device keeps the maximum opening degree, and refrigerant circulates between the compressor and the outdoor heat exchanger when the refrigerant runs in the mild self-cleaning mode, so that refrigerant in the indoor heat exchanger is lost, the throttling device keeps the maximum opening degree, the refrigerant is enabled to be rapidly filled in the indoor heat exchanger, and normal circulation of the refrigerant is achieved as soon as possible.

Correspondingly, after the indoor fan is controlled to be started and the air guide plate supplies air upwards for the first duration, the indoor fan and the air guide plate are controlled to be restored to the running state before the light self-cleaning mode is entered. The first duration time can be any value within 20s-1min, the time is preferably 30s in the application, after the indoor fan is started and the air deflector supplies air upwards for 30s, the temperature of the coil pipe of the indoor heat exchanger is raised to the temperature matched with the heating mode, and at the moment, the indoor fan and the air deflector are controlled to be restored to the operation mode before the mild self-cleaning mode, so that the heating requirement of a user is met.

Accordingly, after controlling the throttle device to maintain the maximum opening for the second duration, the throttle device is controlled to return to the opening before entering the mild self-cleaning mode. The second duration time can be any value within 1-5min, the application is preferably 3min, when the electronic expansion valve keeps the maximum opening degree and operates for 3min, the refrigerant circulation tends to be stable, and the electronic expansion valve is controlled to be restored to the opening degree before the air conditioner enters the mild self-cleaning mode, so that the air conditioner completely restores the heating parameters before the air conditioner enters the mild self-cleaning mode and continues to operate.

Of course, the manner of exiting the mild self-cleaning mode is not limited to the above-mentioned one, and a person skilled in the art may freely select a specific control manner without departing from the principles of the present application, provided that the air conditioner can be restored to the operating state before entering the mild self-cleaning mode. For example, the outdoor fan may be controlled to return to the operation state before entering the mild self-cleaning mode; for another example, the indoor fan may be controlled to be turned off, and then the indoor fan may be controlled to start operation after the temperature of the coil of the indoor heat exchanger is obtained to be raised to the temperature suitable for the heating mode. As another example, it is also possible to control the components of the air conditioner to directly return to the operating parameters before entering the mild self-cleaning mode.

In one possible embodiment, 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 temperature of a coil of the outdoor heat exchanger is less than or equal to a second preset temperature; when the temperature of the coil pipe is less than or equal to the second preset temperature and lasts for a third preset time, controlling the air conditioner to be switched to a refrigeration mode; controlling the first on-off valve and the second on-off valve to close; and when the first preset condition is met, controlling the second on-off valve to be opened and lasting for a fourth preset time. The operation parameters comprise the operation frequency of the compressor, the opening of the throttling device, the rotating speed of the indoor fan and the rotating speed of the outdoor fan. In particular, the amount of the solvent to be used,

first, the air conditioner is controlled to operate a heating mode. Similarly to the above-described mild self-cleaning mode, switching between the operation modes of the air conditioner can be controlled by controlling the on/off of the four-way valve. In the embodiment, after the medium self-cleaning mode is entered, if the air conditioner is in the heating mode, the air conditioner is controlled to continue to operate without adjustment; and if the air conditioner is running in the non-heating mode, controlling the air conditioner to switch to the heating mode to run.

The compressor is then controlled to adjust to a second self-cleaning frequency. The second self-cleaning frequency is a frequency determined in advance through experiments, and the determination manner can refer to table 1, which is not described herein again. When the compressor is operating at the second self-cleaning frequency, it facilitates implementation of a subsequent control process.

And then, controlling the outdoor fan to operate at the lowest rotating speed, and controlling the indoor fan to operate at a second preset rotating speed. Specifically, in the medium self-cleaning mode, before the opening degree of the throttling device is adjusted, the outdoor fan is controlled to operate at the lowest rotating speed to reduce the heat exchange effect between the outdoor heat exchanger and air, so that the reduction speed of the temperature of the outdoor coil pipe can be increased, and the self-cleaning efficiency in the pipe is improved. The second is preset the rotational speed and can be the highest rotational speed of indoor fan in this application, because outdoor heat exchanger's filth is stifled comparatively seriously, consequently before adjusting throttling arrangement's aperture, through controlling indoor fan with the operation of highest rotational speed, can improve the heat transfer effect between refrigerant and the environment among the indoor heat exchanger to reduce the temperature and the pressure of refrigerant, improve the refrigerant evaporation effect in outdoor heat exchanger, make outdoor coil pipe reduce to the second with faster speed and predetermine the temperature.

And then, adjusting the opening degree of the throttling device to enable the temperature of the coil of the outdoor heat exchanger to be less than or equal to a second preset temperature. Preferably, the second preset temperature is lower than the first preset temperature, so that the oil stains can be solidified and separated out more quickly compared with the mild self-cleaning mode. In this application, the second predetermined temperature may be-10 ℃. That is, the coil temperature of the outdoor heat exchanger is controlled to be equal to or lower than the second preset temperature, and the coil temperature of the outdoor heat exchanger is always in a state of being equal to or lower than the second preset temperature by adjusting the opening degree of the electronic expansion valve (such as PID adjustment).

Referring to fig. 1, when the air conditioner operates in a heating mode, the temperature of the coil of the outdoor heat exchanger is maintained at a temperature of-10 ℃ or lower, and at this time, oil stains in the outdoor heat exchanger are separated from the refrigerant cycle and attached to the inner wall of the coil of the outdoor heat exchanger.

Of course, in other embodiments, the coil temperature of the outdoor heat exchanger may be set to be equal to or lower than the second preset temperature by adjusting the opening degree of the electronic expansion valve to a fixed opening degree.

And then, when the temperature of the coil is less than or equal to a second preset temperature and lasts for a third preset time, controlling the air conditioner to be switched into a refrigeration mode. The third preset time period can be any value in the range of 5-15 min. Preferably, the third preset time period in this embodiment is 10min, and after the temperature of the coil pipe is less than or equal to-10 ℃ and lasts for 10min, the oil stains in the outdoor heat exchanger are already stripped, and then the stripped oil stains may be cleaned. At this time, the switching between the operation modes of the air conditioner is controlled by controlling the on/off of the four-way valve, for example, the four-way valve is controlled to be powered off, and the air conditioner operates in a cooling mode.

Next, after controlling the air conditioner to switch to the cooling mode, controlling the indoor fan to stop operating. Specifically, when the refrigeration mode is operated, the outlet air temperature of the indoor unit is gradually reduced, and poor use experience can be brought to users. At this moment, the operation of the indoor fan is controlled to stop after 30s, and the influence on user experience due to too low air outlet temperature can be avoided. Of course, the adjustment of 30s can be performed by one skilled in the art, such as to any value of 10s-1 min.

And then, after the air conditioner is switched to the cooling mode, controlling the first on-off valve and the second on-off valve to be closed. After the first on-off valve and the second on-off valve are closed, the refrigerant pipeline between the throttling device and the indoor heat exchanger and the recovery pipeline are throttled, and at the moment, as shown in fig. 2, the refrigerants in the indoor heat exchanger and the refrigerant pipeline are discharged by the compressor and are accumulated in the outdoor heat exchanger.

And finally, judging whether a first preset condition is met, and controlling the second stop valve to be opened and the throttling device to be opened to the maximum opening degree when the first preset condition is met, and continuing for a fourth preset time. In this 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 time. Wherein the eighth preset time period is preferably any value from 3s to 10s, and takes 5s in the application. The exhaust temperature may be obtained continuously or at intervals, such as every 1s-5 s. The throttle device is controlled to be opened to the maximum opening degree, so that the high-temperature and high-pressure refrigerant can rapidly pass through the throttle device. The fourth preset time period can be any value from 3min to 10min, and the fourth preset time period is preferably 5min. When the exhaust temperature is greater than or equal to the exhaust temperature threshold value and the eighth preset time is continued, the refrigerant is accumulated in the outdoor heat exchanger, the pressure of the exhaust port of the compressor is increased to a higher value at the moment, the conditions are met, and oil stain cleaning operation can be performed. Therefore, when the above conditions are satisfied, the second cut-off valve is opened, the throttle device is opened to the maximum opening degree, and the operation is continued for 5min while maintaining this state. At this time, as shown by the arrow in fig. 2, the high-temperature and high-pressure refrigerant discharged from the compressor flows through the outdoor heat exchanger, the high-temperature and high-pressure refrigerant quickly impacts the coil pipe of the outdoor heat exchanger, the oil stain temporarily stored in the coil pipe is melted, and the high-temperature refrigerant directly flows back to the liquid reservoir through the recovery pipeline to realize recovery and filtration, so that the purpose of self-cleaning in the pipe of the outdoor heat exchanger is achieved.

In one possible embodiment, the moderate self-cleaning mode further comprises: and after the step of controlling the air conditioner to be switched into the cooling mode, controlling the compressor to adjust to the maximum limit frequency corresponding to the outdoor environment temperature. Generally, the operation frequency of the compressor is affected by the outdoor environment temperature, and cannot be increased without limit, otherwise, the phenomenon of high-temperature protection shutdown of the compressor is easy to occur, and the service life of the compressor is adversely affected. Therefore, the compressors are provided with protection mechanisms, and the maximum limit frequency is correspondingly set under different outdoor environment temperatures. The manner of acquiring the outdoor ambient temperature is a conventional means in the art, and is not described herein again.

In one possible embodiment, the method further comprises: when the air conditioner enters the moderate self-cleaning mode, the outdoor anti-freezing protection function and the outdoor environment temperature frequency limiting function are closed, but other protection functions of the air conditioner are opened as usual. The purpose and implementation of this step are the same as in the light cleaning mode, and therefore are not described in detail.

Of course, the specific control procedure of the moderate self-cleaning mode is not exclusive, and the control mode can be adjusted by those skilled in the art. For example, one or more of the operating frequency of the compressor, the opening degree of the electronic expansion valve, the rotational speed of the indoor fan, and the rotational speed of the outdoor fan in the above control method may be omitted on the premise that the coil temperature of the outdoor heat exchanger can be maintained at the second preset temperature or lower. For another example, after the air conditioner is controlled to switch to the cooling mode, no adjustment may be made to the throttle device.

In one possible embodiment, the method further comprises: and after the second on-off valve is opened and the throttling device is opened to the maximum opening degree for a fourth preset time, the air conditioner exits from the moderate self-cleaning mode and is controlled to be restored to the running state before the air conditioner enters into the moderate self-cleaning mode. When the opening time of the throttling device and the second on-off valve lasts for 5min, the high-temperature and high-pressure refrigerant circulates for many times enough to generate a better self-cleaning effect, so that the moderate self-cleaning mode can be exited when the second on-off valve is opened, and the throttling device is opened to the maximum opening degree and lasts for 5min.

In this application, the same control method as the above-mentioned method for exiting the mild self-cleaning mode may be adopted to achieve the purpose of exiting the moderate self-cleaning mode, and details are not described herein again.

Of course, the manner of exiting the moderate self-cleaning mode is not limited to the same manner as exiting the mild self-cleaning mode, and the skilled person can freely select a specific control manner without departing from the principles of the present application, provided that the air conditioner can be restored to the operation state before entering the moderate self-cleaning mode. For example, the outdoor fan may be controlled to return to the operating state before entering the moderate self-cleaning mode; for another example, the indoor fan may be controlled to be turned off, and then the indoor fan may be controlled to start operation after the temperature of the coil of the indoor heat exchanger is obtained to be raised to the temperature suitable for the heating mode. As another example, the various components of the air conditioner may be controlled to return directly to the operating parameters prior to entering the moderate self-cleaning mode.

In one possible embodiment, 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 temperature of a coil of the outdoor heat exchanger is less than or equal to a third preset temperature; when the temperature of the coil pipe is less than or equal to the third preset temperature and lasts for a fifth preset time, controlling the air conditioner to be switched to a refrigeration mode; controlling the first on-off valve and the second on-off valve to be closed; when a second preset condition is met, controlling a second on-off valve to be opened; after the sixth preset duration, controlling the second on-off valve to close; and when the second preset condition is met again, controlling the second cut-off valve to be opened again and continuing for a seventh preset time. The operation parameters comprise the operation frequency of the compressor, the opening of the throttling device, the rotating speed of the indoor fan and the rotating speed of the outdoor fan. In particular, the amount of the solvent to be used,

first, the air conditioner is controlled to operate a heating mode. The compressor is then controlled to adjust to a third self-cleaning frequency. And then, controlling the outdoor fan to operate at the lowest rotating speed, and controlling the indoor fan to operate at a third preset rotating speed. And then, adjusting the opening degree of the throttling device to enable the temperature of the coil of the outdoor heat exchanger to be less than or equal to a third preset temperature. And then, when the temperature of the coil is less than or equal to a third preset temperature and lasts for a fifth preset time period, controlling the air conditioner to be switched into a refrigeration mode. And then, controlling the first on-off valve and the second on-off valve to be closed, and controlling the second on-off valve to be opened and the throttling device to be opened to the maximum opening degree when a second preset condition is met, and continuing for a sixth preset time. Then after lasting for a sixth preset time, controlling the second on-off valve to close; and when the second preset condition is met again, controlling the second cut-off valve to be opened again and continuing for a seventh preset time.

Preferably, the operation parameters of deep self-cleaning in the present application may be the same as the corresponding parameter settings in the moderate self-cleaning mode, that is, the parameters such as the third self-cleaning frequency, the third preset rotation speed, the third preset temperature, the fifth preset time duration, the second preset condition, and the sixth preset time duration are the same as the moderate self-cleaning. The control process of the deep self-cleaning mode is different from the moderate self-cleaning mode in that:

and when the second preset condition is met, controlling the second on-off valve to be opened for a sixth preset time, not immediately exiting the deep self-cleaning mode, but controlling the second on-off valve to be closed again, then continuously judging whether the second preset condition is met, and opening the second on-off valve again when the second preset condition is met, so that the indoor heat exchanger is self-cleaned and lasts for a seventh preset time. Wherein the seventh preset duration may be any value from 1 to 5min, and 3min is selected in the present application. The second on-off valve is controlled to be closed and opened again, so that the self-cleaning of the outdoor heat exchanger is more thorough, and the self-cleaning effect is more consistent with the filth blockage degree of the current outdoor heat exchanger.

Of course, the control parameter of deep self-cleaning is the same as that of moderate self-cleaning, and is only a preferred embodiment, and in other embodiments, a person skilled in the art may also adjust the control parameter of deep self-cleaning to achieve a better deep self-cleaning effect. For example, the deep self-cleaning mode may be operated for only one cycle, and the third preset temperature may be further decreased than the second preset temperature, the fifth and sixth preset time periods may be increased than the third or fourth preset time periods, and so on.

In one possible embodiment, the deep self-cleaning mode further comprises: after the step of controlling the air conditioner to switch to the cooling mode, controlling the compressor to adjust to the maximum limit frequency corresponding to the outdoor environment temperature.

In one possible embodiment, the method further comprises: when entering the deep self-cleaning mode, the outdoor anti-freezing protection function and the outdoor environment temperature frequency limiting function are closed, but other protection functions of the air conditioner are opened as usual. The purpose and implementation of this step are the same as in the light cleaning mode, and therefore are not described in detail.

Of course, the specific control process of the deep self-cleaning mode is not exclusive, and the control mode can be adjusted by those skilled in the art. For example, one or more of the operating frequency of the compressor, the opening degree of the electronic expansion valve, the rotational speed of the indoor fan, and the rotational speed of the outdoor fan in the above control method may be omitted on the premise that the coil temperature of the outdoor heat exchanger can be maintained at the third preset temperature or lower. For another example, after the air conditioner is controlled to switch to the cooling mode, no adjustment may be made to the throttle device.

In one possible embodiment, the method further comprises: and after the second on-off valve is opened again and lasts for a seventh preset time, the deep self-cleaning mode is exited, and the air conditioner is controlled to be restored to the running state before the deep self-cleaning mode is entered. When the second on-off valve is opened for the second time and lasts for the seventh preset time, the second on-off valve can generate a better self-cleaning effect, and therefore the deep self-cleaning mode can be quitted when the second on-off valve is opened for the second time and lasts for the seventh preset time.

In this application, the same control method as the method for exiting the mild self-cleaning mode may be adopted to achieve the purpose of exiting the deep self-cleaning mode, and details are not described herein.

Of course, the manner of exiting the deep self-cleaning mode is not limited to the same manner as exiting the light self-cleaning mode, and a person skilled in the art may freely select a specific control manner without departing from the principles of the present application, provided that the air conditioner can be restored to the operation state before entering the deep self-cleaning mode. For example, the outdoor fan may be controlled to return to an operation state before entering the deep self-cleaning mode; for another example, the indoor fan may be controlled to be turned off, and then the indoor fan may be controlled to start operation after the temperature of the coil of the indoor heat exchanger is obtained to be raised to the temperature suitable for the heating mode. As another example, the components of the air conditioner may be controlled to directly return to the operating parameters before entering the deep self-cleaning mode.

Generally speaking, the intraductal automatically cleaning mode of three kinds of this application, through the first mode of heating of operation of control air conditioner, and adjust the operating parameter of air conditioner and make the greasy dirt in the coil pipe of outdoor heat exchanger solidify from the refrigerant circulation and peel off, adhere to on the coil pipe inner wall of outdoor heat exchanger, then control air conditioner conversion is the refrigeration mode, and open the second on-off valve or close first on-off valve and second on-off valve earlier and open the second on-off valve when satisfying preset conditions, utilize the quick flow of high temperature high pressure refrigerant to strike the coil pipe of outdoor heat exchanger inside, the greasy dirt of temporary storage inside the coil pipe is melted by high temperature and is directly returned to inside the reservoir along with the refrigerant by the recovery pipeline, realize the intraductal automatically cleaning to outdoor heat exchanger. And the cleaning effect of the light self-cleaning mode, the medium self-cleaning mode and the deep self-cleaning mode in the three types of pipes is sequentially enhanced, so that the cleaning effect is matched with the filth blockage effect, and the intelligent self-cleaning of the outdoor heat exchanger is realized.

In addition, through setting up the recovery pipeline in the air conditioner, this application can utilize the recovery pipeline to realize the recovery to the greasy dirt in the automatically cleaning in-process in carrying out the outdoor heat exchanger, realizes that high temperature high pressure refrigerant is scouring away the back to outdoor heat exchanger, need not to pass through outdoor heat exchanger once more, but directly takes the greasy dirt back to the reservoir and retrieves the filtration, has reduced the flow stroke of high temperature refrigerant, has reduced along the journey pressure drop, improves intraductal automatically cleaning effect.

One possible implementation of the present application is described below with reference to fig. 4. Fig. 4 is a logic diagram of a possible implementation process of the method for controlling self-cleaning in a tube of an outdoor heat exchanger according to the present application.

As shown in fig. 4, the air conditioner is turned on to perform a heating operation, and then the following operations are performed:

step S201 is executed first to acquire the cumulative operation time t of the air conditioner.

Step S203 is executed to determine whether the accumulated time t is greater than or equal to 20h, and if yes, step S205 is executed, otherwise, if not, the operation is ended.

S205, acquiring a first average value Tp1 of the coil temperature of the outdoor heat exchanger within 0-15min and a second average value Tp2 of the coil temperature of the outdoor heat exchanger within 45-60 min within 1h of the next operation.

Step S207 is executed next, and whether | Tp1-Tp2| < 2 is judged; if not, step S209 is executed, otherwise, if yes, step S211 is executed.

S209, judging whether the absolute Tp1-Tp2 is more than or equal to 4; if not, step S213 is performed, otherwise, if yes, step S215 is performed.

And S211, executing a mild self-cleaning mode.

And S213, executing a moderate self-cleaning mode.

And S215, executing a deep self-cleaning mode.

Those skilled in the art will appreciate that the above-described air conditioner may also include other known structures, such as a processor, a controller, a memory, etc., wherein the memory includes, but is not limited to, a random access memory, a flash memory, a read only memory, a programmable read only memory, a volatile memory, a non-volatile memory, a serial memory, a parallel memory or a register, etc., and the processor includes, but is not limited to, a CPLD/FPGA, a DSP, an ARM processor, a MIPS processor, etc. Such well-known structures are not shown in the drawings in order to not unnecessarily obscure embodiments of the present disclosure.

Although the foregoing embodiments describe the steps in the above sequential order, those skilled in the art can understand that, in order to achieve the effect of the present embodiments, the different steps need not be executed in such an order, and may be executed simultaneously (in parallel) or in an inverted order, and these simple changes are all within the scope of protection of the present application.

So far, the technical solutions of the present application have been described in connection with the preferred embodiments shown in the drawings, but it is easily understood by those skilled in the art that the scope of protection of the present application is obviously not limited to these specific embodiments. Equivalent changes or substitutions of related technical features can be made by those skilled in the art without departing from the principle of the present application, and the technical scheme after the changes or substitutions will fall into the protection scope of the present application.

Claims

1. An in-pipe self-cleaning control method of an outdoor heat exchanger is applied to an air conditioner and is characterized in that the air conditioner comprises a compressor, a four-way valve, an indoor heat exchanger, a throttling device and an outdoor heat exchanger which are sequentially connected through a refrigerant pipeline, the air conditioner also comprises a recovery pipeline, a first on-off valve and a second on-off valve, the first on-off valve is arranged on the refrigerant pipeline between the indoor heat exchanger and the throttling device, one end of the recovery pipeline is arranged on the refrigerant pipeline between the first on-off valve and the throttling device, the other end of the recovery pipeline is communicated with an air suction port of the compressor, the second on-off valve is arranged on the recovery pipeline,

the control method comprises the following steps:

acquiring operation data of the air conditioner;

executing a corresponding in-pipe self-cleaning mode based on the filth blockage degree;

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 temperature of a coil of the outdoor heat exchanger is less than or equal to a second preset temperature; when the temperature of the coil pipe is less than or equal to the second preset temperature and lasts for a third preset time, controlling the air conditioner to be switched into a refrigeration mode; controlling the first on-off valve and the second on-off valve to close; when a first preset condition is met, controlling the second on-off valve to be opened and lasting for a fourth preset time;

the deep self-cleaning mode includes: controlling the air conditioner to operate in a heating mode; adjusting the operating parameters of the air conditioner to enable the temperature of a coil of the outdoor heat exchanger to be less than or equal to a third preset temperature; when the temperature of the coil pipe is less than or equal to the third preset temperature and lasts for a fifth preset time, controlling the air conditioner to be switched to a refrigeration mode; controlling the first on-off valve and the second on-off valve to close; when a second preset condition is met, controlling the second on-off valve to be opened; after lasting for a sixth preset time, controlling the second cut-off valve to be closed; when the second preset condition is met again, controlling the second cut-off valve to be opened again for a seventh preset time;

2. The in-tube self-cleaning control method of an outdoor heat exchanger according to claim 1, wherein in the mild self-cleaning mode,

3. The method of controlling self-cleaning in a tube of an outdoor heat exchanger of claim 2, further comprising:

4. The method of controlling self-cleaning in a tube of an outdoor heat exchanger according to claim 1, wherein in the middle self-cleaning mode,

5. The method of controlling self-cleaning in a tube of an outdoor heat exchanger according to claim 4, further comprising:

6. The in-tube self-cleaning control method of an outdoor heat exchanger according to claim 1, wherein in the deep self-cleaning mode,

7. The method of controlling self-cleaning in a tube of an outdoor heat exchanger according to claim 6, further comprising:

8. The in-tube self-cleaning control method of an outdoor heat exchanger according to claim 1, wherein the operation data includes an accumulated operation time of the air conditioner and a coil temperature of the outdoor heat exchanger, and the step of acquiring the operation data of the air conditioner further includes:

acquiring the accumulated running time of the air conditioner;

9. The method as claimed in claim 1, wherein the throttling device is an electronic expansion valve, the operation data includes an actual opening degree of the electronic expansion valve and an actual discharge temperature of the compressor, and the step of obtaining the operation data of the air conditioner further includes:

acquiring an actual exhaust temperature of the compressor;

when the ratio is greater than the fourth threshold and less than or equal to a fifth threshold, judging that the outdoor heat exchanger is the moderate filth blockage;

10. The method of controlling self-cleaning in a tube of an outdoor heat exchanger according to claim 1, wherein the throttling device is a capillary tube, the operation data includes an actual discharge temperature, and the step of acquiring the operation data of the air conditioner further includes:

acquiring an actual exhaust temperature of the compressor;