WO2023284196A1

WO2023284196A1 - Outside-pipe self-cleaning control method for indoor heat exchanger

Info

Publication number: WO2023284196A1
Application number: PCT/CN2021/129806
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: CN113639412A; CN113639412B

Abstract

The present invention relates to the technical field of air conditioner self-cleaning, and in particular to an outside-pipe self-cleaning control method for an indoor heat exchanger. The present application aims at solving the problem that existing self-cleaning control methods cannot control the self-cleaning degree according to the smudginess degree of the indoor heat exchanger. For this objective, an air conditioner of the present application comprises a recycling pipeline, a first on-off valve, and a second on-off valve. The control method comprises: obtaining operation parameters of an indoor fan; determining the dust attachment degree of an indoor heat exchanger on the basis of the operation parameters; and executing a corresponding outside-pipe self-cleaning mode on the basis of the dust attachment degree, the dust attachment degree comprising light attachment, moderate attachment, and heavy attachment, and the outside-pipe self-cleaning mode comprising a light self-cleaning mode, a moderate self-cleaning mode, and a deep self-cleaning mode. According to the present application, the corresponding outside-pipe self-cleaning mode is executed on the basis of the dust attachment degree of the indoor heat exchanger, thereby achieving more intelligent outside-pipe self-cleaning.

Description

Self-cleaning control method outside the tube of indoor heat exchanger

technical field

The invention relates to the technical field of self-cleaning of air conditioners, in particular to a method for controlling the self-cleaning outside the tube of an indoor heat exchanger.

Background technique

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

However, after the current air conditioner enters the self-cleaning mode, the cleaning method is fixed, and the degree of self-cleaning cannot be intelligently controlled according to the dirtiness of the indoor heat exchanger. The self-cleaning time is long when it is light, which affects the user's normal experience, and the self-cleaning is not thorough when the outer surface of the indoor heat exchanger is seriously dirty.

Correspondingly, there is a need in the art for a new control method for self-cleaning outside the tube of the indoor heat exchanger 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, in order to solve the problem that the existing self-cleaning control method cannot control the degree of self-cleaning according to the degree of dirt of the indoor heat exchanger, the application provides a tube for the indoor heat exchanger The external self-cleaning control method is applied to an air conditioner, and the air conditioner includes a compressor connected through a refrigerant pipeline, a four-way valve, an indoor heat exchanger, a throttling device, and an outdoor heat exchanger. The indoor heat exchanger is configured There is an indoor fan, the indoor heat exchanger is equipped with an indoor fan, the air conditioner also includes a recovery pipeline, one end of the recovery pipeline communicates with the outlet of the outdoor heat exchanger, and the other end of the recovery pipeline One end communicates with the suction port of the compressor, and an on-off valve is arranged on the recovery pipeline, and the on-off valve is a normally closed valve.

The control methods include:

Obtain the operating parameters of the indoor fan;

Based on the operating parameters, judging the degree of dust adhesion of the indoor heat exchanger;

Based on the degree of dust adhesion, perform a corresponding self-cleaning mode outside the pipe;

The degree of dust adhesion includes light adhesion, moderate adhesion and heavy adhesion, and the self-cleaning mode outside the pipe includes mild self-cleaning mode, moderate self-cleaning mode and deep self-cleaning mode;

The mild self-cleaning mode includes: controlling the air conditioner to operate in cooling mode; controlling the compressor to adjust to the first self-cleaning frequency; adjusting the opening of the throttling device so that the indoor heat exchanger The coil temperature is less than or equal to the first preset temperature to realize frosting; when the coil temperature is less than or equal to the first preset temperature and lasts for a first preset time, the air conditioner is controlled to switch to the heating mode; Controlling the opening of the second on-off valve for a second preset period of time to achieve defrosting;

The moderate self-cleaning mode includes: controlling the air conditioner to operate in cooling mode; controlling the compressor to adjust to the second self-cleaning frequency; adjusting the opening of the throttling device so that the indoor heat exchanger The coil temperature is less than or equal to the second preset temperature to realize frosting; when the coil temperature is less than or equal to the second preset temperature and lasts for a third preset time, the air conditioner is controlled to switch to the heating mode; Control the first on-off valve to close and the second on-off valve to open; when the first preset condition is met, control the first on-off valve to open for a fourth preset duration to realize defrosting;

The deep self-cleaning mode includes: controlling the air conditioner to operate in cooling mode; controlling the compressor to adjust to the third self-cleaning frequency; adjusting the opening of the throttling device so that the disc of the indoor heat exchanger The tube temperature is less than or equal to the third preset temperature to realize frosting; when 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 the heating mode; control The first on-off valve is closed and the second on-off valve is opened; when the second preset condition is met, the first on-off valve is controlled to open; The first on-off valve is closed; when the second preset condition is met again, the first on-off valve is controlled to open again for a seventh preset period of time to realize defrosting.

In the preferred technical solution of the control method for self-cleaning outside the pipe of the indoor heat exchanger, the mild self-cleaning mode further includes: after controlling the air conditioner to switch to the heating mode, controlling the compressor to adjust to the outdoor The highest limit frequency corresponding to the ambient temperature; and/or

The mild self-cleaning mode further includes: before adjusting the opening degree of the throttling device, controlling the outdoor fan to maintain the current running state, and controlling the indoor fan to run at a preset speed; and/or

The mild self-cleaning mode further includes: controlling the throttling device to close to a minimum opening degree after controlling the air conditioner to switch to a heating mode.

In the preferred technical solution of the above-mentioned external self-cleaning control method of the indoor heat exchanger, the control method also 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 control method for self-cleaning outside the pipe of the indoor heat exchanger, the moderate self-cleaning mode further includes: after controlling the air conditioner to switch to the heating mode, controlling the compressor to adjust to the outdoor The highest limit frequency corresponding to the ambient temperature; and/or

The moderate self-cleaning mode further includes: before adjusting the opening degree of the throttling device, controlling the outdoor fan to run at the highest speed, and controlling the indoor fan to stop running; and/or

The moderate self-cleaning mode further includes: controlling the throttling device to close to a minimum opening degree after controlling the air conditioner to switch to a heating mode.

In the preferred technical scheme of the control method for self-cleaning outside the tube of the above-mentioned indoor heat exchanger, the control method also includes:

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

In the preferred technical solution of the control method for self-cleaning outside the pipe of the indoor heat exchanger, the deep self-cleaning mode further includes: after controlling the air conditioner to switch to the heating mode, controlling the compressor to adjust to the outdoor environment The maximum limit frequency corresponding to the temperature; and/or

The deep self-cleaning mode further includes: before adjusting the opening of the throttling device, controlling the outdoor fan to run at the highest speed, and controlling the indoor fan to stop running; and/or

The deep self-cleaning mode further includes: after controlling the air conditioner to switch to the heating mode, controlling the throttling device to close to a minimum opening.

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

When entering the self-cleaning mode outside the tube, the indoor anti-freezing protection function and the outdoor ambient temperature frequency limiting function are turned off.

In the preferred technical solution of the control method for self-cleaning outside the tube of the indoor heat exchanger, the indoor fan is a DC fan, and the operating parameters include the actual speed and voltage of the indoor fan,

The step of "judging the degree of dust adhesion of the indoor heat exchanger based on the operating parameters" further includes:

determining a theoretical voltage value corresponding to the actual rotational speed;

calculating an absolute value of the difference between the actual voltage value and the theoretical voltage value, and calculating a ratio between the absolute value of the difference and the theoretical voltage value;

When the ratio is greater than the first threshold and less than or equal to the second threshold, it is judged that the indoor heat exchanger is the lightly attached;

When the ratio is greater than the second threshold and less than or equal to a third threshold, it is determined that the indoor heat exchanger is moderately attached;

When the ratio is greater than the third threshold, it is determined that the indoor heat exchanger is heavily attached.

In the preferred technical solution of the control method for self-cleaning outside the tube of the indoor heat exchanger, the indoor fan is an AC fan, and the operating parameters include the actual rotational speed and actual current value of the indoor fan,

determining a theoretical current value corresponding to the actual rotational speed;

calculating an absolute value of the difference between the actual current value and the theoretical current value, and calculating a ratio between the absolute value of the difference and the theoretical current value;

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

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

When the ratio is greater than the sixth threshold, it is determined that the indoor heat exchanger is heavily attached.

By judging the degree of dust adhesion of the indoor heat exchanger according to the operating parameters of the indoor fan, and then operating different self-cleaning modes outside the pipe based on the degree of dust adhesion, the control method of the present application can not only realize the self-cleaning outside the pipe of the indoor heat exchanger, Moreover, it is also possible to implement a matching external-tube self-cleaning mode based on the degree of dust adhesion of the indoor heat exchanger to achieve a more intelligent external-tube self-cleaning.

Description of drawings

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

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

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

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

Fig. 4 is a logic diagram of a possible implementation process of the method for controlling the self-cleaning outside the tube of the indoor 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", and "seventh" are only used for describe purpose and should not be read 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 Figure 1, in a possible implementation, the air conditioner includes a compressor 1, a four-way valve 2, an outdoor heat exchanger 3, a throttling device 4, an indoor heat exchanger 5, and a liquid reservoir 11. The heat exchanger 5 is configured with an indoor fan, and the outdoor heat exchanger 3 is configured with an outdoor fan. The exhaust port of compressor 1 communicates with the P interface of four-way valve 2 through refrigerant pipeline 6, and the C interface of four-way valve 2 communicates with the inlet of outdoor heat exchanger 3 through refrigerant pipeline 6. The outlet communicates with one port of the throttling device 4 through the refrigerant pipeline 6, and the other port of the throttling device 4 communicates with the inlet of the indoor heat exchanger 5 through the refrigerant pipeline 6, and the outlet of the indoor heat exchanger 5 passes through the refrigerant pipeline 6 is in communication with the E port of the four-way valve 2, the S port of the four-way valve 2 is in communication with the inlet of the accumulator 11 through the refrigerant pipeline 6, and the outlet of the accumulator 11 is in communication with the suction port of the compressor 1 through the pipeline . The throttling device 4 is preferably an electronic expansion valve, and a filter is provided in the liquid reservoir 11. The liquid reservoir 11 can store refrigerant, separate gas and liquid of refrigerant, filter oil, eliminate noise, and buffer refrigerant.

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

The method for controlling the self-cleaning outside the tube of the indoor heat exchanger in this embodiment will be described below in conjunction with the structure of the above-mentioned air conditioner, but those skilled in the art can understand that the specific structural composition of the air conditioner is not static, and those skilled in the art can To adjust it, for example, add or delete parts etc. 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 outside the tube of the indoor heat exchanger of the present application will be introduced. Among them, Fig. 2 is a system diagram of the air conditioner of the present application in heating mode; Fig. 3 is a flow chart of the control method for the self-cleaning outside the pipe of the indoor heat exchanger of the present application.

As shown in Figure 3, in order to solve the problem that the existing self-cleaning control method cannot control the degree of self-cleaning according to the degree of dirtiness of the indoor heat exchanger, the external self-cleaning control method of the indoor heat exchanger of the present application includes:

S101. Obtain operating parameters of the indoor fan.

In a possible implementation manner, the operating parameters of the indoor fan include actual rotational speed, actual current value, actual voltage value, etc., and one or more of the above-mentioned operating parameters of the indoor fan is obtained during the operation of the air conditioner. Wherein, the acquisition methods of the above-mentioned operating parameters belong to conventional means in the art, and will not be repeated here.

S103. Based on the operating parameters, determine the degree of dust adhesion of the indoor heat exchanger.

In a possible implementation manner, by reasonably calculating the above operating parameters and comparing them with preset thresholds, the range or size of the operating parameters is determined, and then the dust adhesion degree of the indoor heat exchanger is determined. .

S105. Based on the degree of dust adhesion, execute a corresponding self-cleaning mode outside the tube.

In a possible implementation, the degree of dust adhesion in this application can be divided into light adhesion, moderate adhesion and heavy adhesion. Correspondingly, the self-cleaning mode outside the pipe includes mild self-cleaning mode, medium High self-cleaning mode and deep self-cleaning mode. That is to say, when it is judged that the degree of dust adhesion of the indoor heat exchanger is mild, the air conditioner is controlled to perform a mild self-cleaning mode; when it is judged that the degree of dust adhesion of the indoor heat exchanger is moderate, the air conditioner is controlled to The air conditioner performs a moderate self-cleaning mode; when it is judged that the degree of dust adhesion on the indoor heat exchanger is heavy, the air conditioner is controlled to perform a deep self-cleaning mode.

It can be seen that by judging the degree of dust adhesion of the indoor heat exchanger according to the operating parameters of the indoor fan, and then operating different self-cleaning modes outside the pipe based on the degree of dust adhesion, the control method of the present application can not only realize the control of the indoor heat exchanger. External self-cleaning, and can also implement a corresponding degree of external self-cleaning mode based on the degree of dust adhesion of the indoor heat exchanger, so that the self-cleaning effect can adapt to the degree of dust adhesion, and achieve more intelligent external self-cleaning.

Several possible embodiments of the present application for judging the degree of dust adhesion of the indoor heat exchanger according to the operating parameters of the air conditioner are introduced below.

Example 1

In this embodiment, the indoor fan is a DC fan, and the operating parameters include the actual rotational speed and actual voltage value of the indoor fan. Obtaining the operating parameters of the indoor fan means obtaining the actual rotational speed and actual voltage value of the indoor fan. Wherein, the method of obtaining the actual rotational speed and the actual voltage value of the indoor fan belongs to a conventional method in the field, and will not be repeated here.

After obtaining the actual rotational speed and actual voltage value of the indoor fan, the step of "judging the degree of dust adhesion of the indoor heat exchanger based on the operating parameters" further includes:

Determine the theoretical voltage value corresponding to the actual speed; calculate the absolute value of the difference between the actual voltage value and the theoretical voltage value, and calculate the ratio between the absolute value of the difference and the theoretical voltage value; when the ratio is greater than the first threshold and less than or equal to When the second threshold is reached, it is judged that the indoor heat exchanger is slightly attached; when the ratio is greater than the second threshold and less than or equal to the third threshold, it is judged that the indoor heat exchanger is moderately attached; when the ratio is greater than the third threshold, it is judged that the indoor heat exchanger is The heater is heavily attached.

In a possible implementation manner, the theoretical voltage value is determined based on experiments. Specifically, for different speeds of the indoor fan, under the same load (such as indoor heat exchanger without dust adhesion), the input current value is fixed, and then the bus voltage value at each speed is recorded as the indoor fan at that speed. The theoretical voltage value. During actual operation, due to the dust attached to the indoor heat exchanger, the actual load of the indoor fan changes. When the speed remains unchanged, if it still wants to reach the speed, the air conditioner will automatically adjust the input voltage value of the indoor fan. And the greater the load, the greater the regulated input voltage value. Therefore, the comparison between the actual voltage value of the indoor fan and its theoretical voltage value can be used to determine whether there is dust adhesion in the indoor heat exchanger and the degree of dust adhesion.

For example, assuming that the theoretical voltage corresponding to the acquired actual rotational speed of the indoor fan is Un, and the actual voltage value of the indoor fan is U, first calculate the absolute value of the difference between the two △U=|U-Un| , and then calculate the ratio △U/Un of the difference △U and the theoretical voltage value, and judge the range of the ratio. In this application, the first threshold, the second threshold and the third threshold increase sequentially, wherein the first threshold is any value in 0.9-1.05, the second threshold is any value in 1.05-1.2, and the third threshold is 1.3 Any value from -1.6. In this application, the first threshold value is 1, the second threshold value is 1.1, and the third threshold value is 1.5. If △U/Un≤1, it is considered that the dust adhesion degree of the indoor heat exchanger is not large, and self-cleaning is not required; if 1 <△U/Un≤1.1, the indoor heat exchanger is considered to be slightly attached; if 1.1<△U/Un≤1.5, the indoor heat exchanger is considered to be moderately attached; if △U/Un>1.5, considered to be The indoor heat exchanger is heavily attached.

Example 2

In this embodiment, the indoor fan is an AC fan, and the operating parameters include the actual rotational speed and actual current value of the indoor fan. Obtaining the operating parameters of the indoor fan means obtaining the actual rotational speed and actual current value of the indoor fan. Wherein, the method of obtaining the actual rotational speed and the actual current value of the indoor fan belongs to a conventional method in the field, and will not be repeated here.

After obtaining the actual rotational speed and actual current value of the indoor fan, the step of "judging the degree of dust adhesion of the indoor heat exchanger based on the operating parameters" further includes:

Determine the theoretical current value corresponding to the actual rotational speed; calculate the absolute value of the difference between the actual current value and the theoretical current value, and calculate the ratio between the absolute value of the difference and the theoretical current value; when the ratio is greater than the fourth threshold and less than or equal to At the fifth threshold, it is judged that the indoor heat exchanger is slightly attached; when the ratio is greater than the fifth threshold and less than or equal to the sixth threshold, it is judged that the indoor heat exchanger is moderately attached; when the ratio is greater than the sixth threshold, it is judged that the indoor heat exchanger is The heater is heavily attached.

In a possible implementation manner, the theoretical current value is determined based on experiments. Specifically, for the AC fan, its voltage is a constant voltage, and for different speeds of the indoor fan, under the same load (such as the indoor heat exchanger without dust attached), record the input current value at each speed as the The theoretical current value of the indoor fan at this speed. During actual operation, due to the dust attached to the indoor heat exchanger, the actual load of the indoor fan changes. When the speed remains unchanged, if it still wants to reach the speed, the air conditioner will automatically adjust the input current value of the indoor fan. And the greater the load, the greater the regulated input current value. Therefore, the comparison between the actual current value of the indoor fan and its theoretical current value can be used to determine whether the indoor heat exchanger has dust adhesion and the degree of dust adhesion.

For example, assuming that the theoretical current value corresponding to the obtained actual rotational speed of the indoor fan is In, and the actual current value of the indoor fan is I, at this time, the absolute value of the difference between the two is first calculated ΔI=|I-In| , and then calculate the ratio △I/In of the difference △I and the theoretical current value, and judge the range of the ratio. In this application, the fourth threshold, the fifth threshold and the sixth threshold increase sequentially, wherein the fourth threshold is any value in 0.9-1.05, the fifth threshold is any value in 1.05-1.2, and the sixth threshold is 1.3 Any value from -1.6. In this application, the fourth threshold value is 1, the fifth threshold value is 1.1, and the sixth threshold value is 1.5. If △I/In≤1, it is considered that the dust adhesion degree of the indoor heat exchanger is not large and self-cleaning is not required; if 1 <△I/In≤1.1, the indoor heat exchanger is considered to be slightly attached; if 1.1<△I/In≤1.5, the indoor heat exchanger is considered to be moderately attached; if △I/In>1.5, considered to be The indoor heat exchanger is heavily attached.

The specific control process of each external self-cleaning mode of the present application will be introduced below.

In a possible implementation, the mild self-cleaning mode includes: controlling the air conditioner to operate in cooling mode; controlling the compressor to adjust to the first self-cleaning frequency; adjusting the opening of the throttling device to allow indoor heat exchange The coil temperature of the air conditioner is less than or equal to the first preset temperature to realize frosting on the outer surface of the coil; when the coil temperature is less than or equal to the first preset temperature and lasts for the first preset time, the air conditioner is controlled to switch to the heating mode ; Control the opening of the second on-off valve and the closing of the throttling device to the minimum opening, and last for a second preset time to realize defrosting on the outer surface of the coil. specifically,

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

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

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

室外环境温度(℃)Outdoor ambient temperature (℃)	第一自清洁频率(Hz)The first self-cleaning frequency (Hz)
Tao≤16Tao≤16	5050
16<Tao≤2216<Tao≤22	6060
22<Tao≤2922<Tao≤29	7070
29<Tao≤3529<Tao≤35	8080
35<Tao≤4335<Tao≤43	8585
43<Tao≤5243<Tao≤52	7878
Tao>52Tao>52	7272

Next, the opening degree of the throttling device is adjusted so that the coil temperature of the indoor heat exchanger is less than or equal to the first preset temperature, so as to achieve frosting on the outer surface of the coil. In a possible implementation, the temperature sensor can detect the coil temperature of the indoor heat exchanger, and dynamically adjust the opening of the electronic expansion valve, so that the coil temperature of the indoor heat exchanger is less than or equal to the first preset temperature. Due to the dust attached to the outer surface of the indoor heat exchanger, frosting will appear on the outer surface of the coil after the temperature of the coil drops to a certain temperature and lasts for a certain period of time. The first preset temperature in this application may be set at -1°C to -10°C, and in this application, the first preset temperature may be -5°C. That is to say, the coil temperature of the indoor heat exchanger is less than or equal to the first preset temperature as the control purpose, and by adjusting the opening degree of the electronic expansion valve (such as PID adjustment, etc.), the coil temperature of the indoor heat exchanger is always at The state of being less than or equal to the first preset temperature.

Referring to Fig. 1 , when the air conditioner is running in cooling mode, the coil temperature of the indoor heat exchanger is kept at a state of less than or equal to -5°C, and frost will form on the outer surface of the indoor heat exchanger at this time.

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

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

Finally, the second on-off valve is controlled to open, the throttling device is closed to the minimum opening, and lasts for a second preset time period to realize defrosting. Control the throttling device to close to the minimum opening degree, that is, the state where the opening degree is 0, the throttling device realizes complete throttling, and the refrigerant cannot flow through. The second preset duration can be any value in 3min-10min, preferably 5min in this application. When the operating mode is switched to the heating mode, control the opening of the second on-off valve, close the throttling device to the minimum opening degree, and keep running for 5 minutes in this state. At this time, as shown by the arrow in Figure 2, the high-temperature and high-pressure refrigerant discharged from the compressor flows through the indoor heat exchanger, and the high-temperature and high-pressure refrigerant exchanges heat with the coil of the indoor heat exchanger, melting the frost layer on the outer surface of the indoor heat exchanger , the dust attached to the outer surface of the indoor heat exchanger also flows away with the melted water. The high-temperature refrigerant flows back to the liquid receiver through the recovery pipeline to achieve the purpose of self-cleaning outside the tube of the indoor heat exchanger. Control the throttling device to close to the minimum opening, so that the high-temperature and high-pressure refrigerant can pass quickly, reduce the pressure drop during the refrigerant flow process, and improve the self-cleaning effect outside 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 the heating mode, controlling the compressor to adjust to the highest limit frequency corresponding to the outdoor ambient temperature. Usually, the operating frequency of the compressor is affected by the outdoor ambient temperature and cannot be increased indefinitely, otherwise the phenomenon of high temperature protection shutdown of the compressor will easily occur, which will have a negative impact on the life of the compressor. Therefore, the compressors are all equipped with a protection mechanism. Under different outdoor ambient temperatures, the corresponding maximum frequency limit is set. In this application, after the air conditioner is switched to heating mode, the rating of the compressor is adjusted to the current outdoor environment. The highest limit frequency under the temperature, under this frequency limit, the compressor can increase the temperature and pressure of the refrigerant in the shortest time, thereby improving the self-cleaning effect. Wherein, the manner of obtaining the outdoor ambient temperature is a conventional means in the field, and will not be repeated here.

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

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

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

In a possible implementation, the method further includes: exiting the mild self-cleaning mode and controlling the air conditioner to return to The operating state before entering the light self-cleaning mode. When the second on-off valve is opened and the throttling device is closed to the minimum opening for 5 minutes, the high-temperature and high-pressure refrigerant has circulated several times, which is enough to complete the defrosting operation. Therefore, when the second on-off valve is opened and the throttling device is closed to When the minimum opening is 5 minutes, you can exit the mild self-cleaning mode.

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

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

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

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

In a possible implementation, the moderate self-cleaning mode includes: controlling the air conditioner to run in cooling mode; controlling the compressor to adjust to the second self-cleaning frequency; adjusting the opening of the throttling device so that the coil of the indoor heat exchanger The temperature is less than or equal to the second preset temperature to realize frosting; when the coil temperature is less than or equal to the second preset temperature and lasts for the third preset time, the air conditioner is controlled to switch to the heating mode; the first on-off valve is controlled to close, The second on-off valve is opened; when the first preset condition is met, the first on-off valve is controlled to open, and the throttling device is closed to a minimum opening, and lasts for a fourth preset time period to realize defrosting. specifically,

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

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

Next, the opening degree of the throttling device is adjusted so that the coil temperature of the indoor heat exchanger is less than or equal to the second preset temperature, so as to achieve frosting on the outer surface of the coil. Preferably, the second preset temperature is lower than the first preset temperature. In this application, the second preset temperature may be -10°C. That is to say, the coil temperature of the indoor heat exchanger is set to be less than or equal to the second preset temperature as the control purpose, and the coil temperature of the indoor heat exchanger is always at The state of being less than or equal to the second preset temperature. In this way, the outer surface of the coil can be frosted faster than in the mild self-cleaning mode, and the thickness of the frost layer is thicker.

Referring to Figure 1, when the air conditioner is running in the cooling mode, keep the coil temperature of the indoor heat exchanger at a temperature less than or equal to -10°C. At this time, frost forms on the outer surface of the indoor heat exchanger and the frost layer adheres to the indoor heat exchanger The outer surface of the heater coil.

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

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

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

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

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

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

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

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

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

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

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

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

In a possible implementation, the deep self-cleaning mode includes: controlling the air conditioner to run in cooling mode; controlling the compressor to adjust to the third self-cleaning frequency; adjusting the opening degree of the throttling device so that the coil temperature of the indoor heat exchanger When the temperature is less than or equal to the third preset temperature, frosting is realized; when the coil 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 the heating mode; the first on-off valve is controlled to be closed . The second on-off valve is opened; when the second preset condition is met, the first on-off valve is controlled to open, and the throttling device is closed to the minimum opening; after the sixth preset duration, the first on-off valve is controlled to The valve is closed; when the second preset condition is met again, the first on-off valve is controlled to open again, and lasts for the seventh preset time to realize defrosting. specifically,

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 temperature, the fifth preset duration, the first Parameters such as the second preset condition and the sixth preset duration are the same as the moderate self-cleaning. The difference between the control process of the deep self-cleaning mode and the moderate self-cleaning mode is:

When the second preset condition is met, the first on-off valve is controlled to open, the throttling device is closed to the minimum opening and lasts for the sixth preset time, the deep self-cleaning mode is not immediately exited, but the first on-off valve is controlled Close it again, and then continue to judge whether the second preset condition is met, and if it is met, open the first on-off valve again to defrost the indoor heat exchanger, and last for the seventh preset time. Wherein, the seventh preset duration can be any value in 1-5 minutes in this application, and 3 minutes is selected in this application. By controlling the first on-off valve to close and open again, the defrosting of the indoor heat exchanger is more thorough, and the self-cleaning effect is more in line with the current dust adhesion degree of the indoor heat exchanger.

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

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

In a possible implementation manner, the deep self-cleaning mode further includes: before adjusting the opening degree of the throttling device, controlling the outdoor fan to run at the highest speed, and controlling the indoor fan to stop running. Specifically, in the deep self-cleaning mode, since the indoor heat exchanger is more dirty and clogged, before adjusting the opening of the throttling device, by controlling the outdoor fan to run at the highest speed, the refrigerant in the outdoor heat exchanger and the environment can be improved. The heat exchange effect between them reduces the temperature and pressure of the refrigerant, improves the evaporation effect of the refrigerant in the indoor heat exchanger, and makes the indoor coil reduce to the second preset temperature at a faster speed. Controlling the stop of the indoor fan can reduce the heat exchange effect between the indoor heat exchanger and the air, thereby speeding up the temperature reduction of the indoor coil and improving the self-cleaning efficiency and effect outside the tube.

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

Of course, the specific control process of the deep self-cleaning mode is not unique, and those skilled in the art can adjust the control method. For example, on the premise that the temperature of the coil tube of the indoor heat exchanger can be kept less than or equal to the third preset temperature, the operation frequency of the compressor, the opening degree of the electronic expansion valve, the speed of the indoor fan and the One or more of the rotational speeds of the outdoor fans are omitted. For another example, after the air conditioner is controlled to switch to the heating mode, the throttling device may not be adjusted in any way. For another example, when executing the deep self-cleaning mode, the rotation speed of the outdoor fan may be determined according to the outdoor ambient temperature, and then the operation of the outdoor fan may be controlled.

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

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

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

In general, the three external self-cleaning modes of this application control the air conditioner to run in the cooling mode first, and adjust the opening of the throttling device to make frost on the outer surface of the indoor heat exchanger, and then control the air conditioner to switch In heating mode, open the second on-off valve or close the first on-off valve first and open the first on-off valve when the preset conditions are met, and use high-temperature and high-pressure refrigerant to exchange heat with the coil of the indoor heat exchanger for high-temperature After defrosting, the dust attached to the outer surface of the coil will fall together with the melted water after the frost layer has melted, and the refrigerant will return directly to the inside of the liquid receiver through the recovery pipeline, so as to realize the self-cleaning of the outside of the indoor heat exchanger. In addition, the cleaning effect of the three external self-cleaning modes from mild, moderate to deep self-cleaning mode is enhanced sequentially, which can match the cleaning effect with the dust adhesion effect and realize intelligent self-cleaning of the indoor heat exchanger.

In addition, by setting the recovery pipeline in the air conditioner, the application can use the recovery pipeline to shorten the circulation path of the refrigerant during the self-cleaning process of the indoor heat exchanger outside the tube, and realize the high-efficiency of the high-temperature and high-pressure refrigerant and the indoor heat exchanger. Heat exchange reduces the pressure drop along the way and improves the self-cleaning effect outside the tube.

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 the self-cleaning outside the tube of the indoor heat exchanger of the present application.

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

First, step S201 is executed to acquire the actual rotational speed r and the actual voltage value U of the indoor fan.

Next step S203 is executed, based on the actual rotational speed r, the corresponding theoretical voltage value Un is determined, and ΔU=|U-Un| is calculated.

Next, execute step S205 to determine whether △U/Un≤1 is true, and if true, end the operation; otherwise, when not true, execute step S207, where △U=|U-Un|, Un is the actual speed of the indoor fan The corresponding theoretical voltage value, U is the actual voltage value of the indoor fan.

S207, judging whether 1<ΔU/Un≤1.1 holds; if it holds, execute step S211; otherwise, if not hold, execute step S209.

S209, judging whether 1.1<ΔU/Un≤1.5 holds true; if true, execute step S213; otherwise, if not 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

A self-cleaning control method outside the tube of an indoor heat exchanger, applied to an air conditioner, characterized in that the air conditioner includes a compressor, a four-way valve, an outdoor heat exchanger, and a throttling device sequentially connected through a refrigerant pipeline . An indoor heat exchanger, the indoor heat exchanger is equipped with an indoor fan, 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 on the On the refrigerant pipeline between the throttling device and the indoor heat exchanger, one end of the recovery pipeline is arranged on the refrigerant pipeline between the throttling device and the first on-off valve, and the recovery pipeline The other end of the pipeline communicates with the suction port of the compressor, and the second on-off valve is arranged on the recovery pipeline,

The control methods include:

Obtain the operating parameters of the indoor fan;

Based on the operating parameters, judging the degree of dust adhesion of the indoor heat exchanger;

Based on the degree of dust adhesion, perform a corresponding self-cleaning mode outside the pipe;

The degree of dust adhesion includes light adhesion, moderate adhesion and heavy adhesion, and the self-cleaning mode outside the pipe includes mild self-cleaning mode, moderate self-cleaning mode and deep self-cleaning mode;

The mild self-cleaning mode includes: controlling the air conditioner to operate in cooling mode; controlling the compressor to adjust to the first self-cleaning frequency; adjusting the opening of the throttling device so that the indoor heat exchanger The coil temperature is less than or equal to the first preset temperature to realize frosting; when the coil temperature is less than or equal to the first preset temperature and lasts for a first preset time, the air conditioner is controlled to switch to the heating mode; Controlling the opening of the second on-off valve for a second preset period of time to achieve defrosting;

The moderate self-cleaning mode includes: controlling the air conditioner to operate in cooling mode; controlling the compressor to adjust to the second self-cleaning frequency; adjusting the opening of the throttling device so that the indoor heat exchanger The coil temperature is less than or equal to the second preset temperature to realize frosting; when the coil temperature is less than or equal to the second preset temperature and lasts for a third preset time, the air conditioner is controlled to switch to the heating mode; Control the first on-off valve to close and the second on-off valve to open; when the first preset condition is met, control the first on-off valve to open for a fourth preset duration to realize defrosting;

The deep self-cleaning mode includes: controlling the air conditioner to operate in cooling mode; controlling the compressor to adjust to the third self-cleaning frequency; adjusting the opening of the throttling device so that the disc of the indoor heat exchanger The tube temperature is less than or equal to the third preset temperature to realize frosting; when 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 the heating mode; control The first on-off valve is closed and the second on-off valve is opened; when the second preset condition is met, the first on-off valve is controlled to open; after a sixth preset time period, the second on-off valve is controlled to The first on-off valve is closed; when the second preset condition is met again, the first on-off valve is controlled to open again for a seventh preset time period to realize defrosting.
The self-cleaning control method outside the tube of the indoor heat exchanger according to claim 1, characterized in that,

The mild self-cleaning mode further includes: after controlling the air conditioner to switch to heating mode, controlling the compressor to adjust to the highest limit frequency corresponding to the outdoor ambient temperature; and/or

The mild self-cleaning mode further includes: before adjusting the opening degree of the throttling device, controlling the outdoor fan to maintain the current running state, and controlling the indoor fan to run at a preset speed; and/or

The mild self-cleaning mode further includes: controlling the throttling device to close to a minimum opening degree after controlling the air conditioner to switch to a heating mode.
The method for controlling the self-cleaning outside the tube of the indoor 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 self-cleaning control method outside the tube of the indoor heat exchanger according to claim 1, characterized in that,

The moderate self-cleaning mode further includes: after controlling the air conditioner to switch to heating mode, controlling the compressor to adjust to the highest limit frequency corresponding to the outdoor ambient temperature; and/or

The moderate self-cleaning mode further includes: before adjusting the opening degree of the throttling device, controlling the outdoor fan to run at the highest speed, and controlling the indoor fan to stop running; and/or

The moderate self-cleaning mode further includes: controlling the throttling device to close to a minimum opening degree after controlling the air conditioner to switch to a heating mode.
The method for controlling the self-cleaning outside the tube of the indoor heat exchanger according to claim 4, wherein the control method further comprises:

After the first on-off valve is opened for the fourth preset time period, exit the moderate self-cleaning mode, and control the air conditioner to return to the operating state before entering the moderate self-cleaning mode.
The self-cleaning control method outside the tube of the indoor heat exchanger according to claim 1, characterized in that,

The deep self-cleaning mode further includes: after controlling the air conditioner to switch to heating mode, controlling the compressor to adjust to the highest limit frequency corresponding to the outdoor ambient temperature; and/or

The deep self-cleaning mode further includes: before adjusting the opening of the throttling device, controlling the outdoor fan to run at the highest speed, and controlling the indoor fan to stop running; and/or

The deep self-cleaning mode further includes: after controlling the air conditioner to switch to the heating mode, controlling the throttling device to close to a minimum opening.
The method for controlling the self-cleaning outside the tube of the indoor heat exchanger according to claim 6, wherein the control method further comprises:

After the first on-off valve is opened again for the seventh preset time period, the deep self-cleaning mode is exited, and the air conditioner is controlled to return to the operating state before entering the deep self-cleaning mode.
The method for controlling the self-cleaning outside the tube of the indoor heat exchanger according to claim 1, wherein the control method further comprises:

When entering the self-cleaning mode outside the tube, the indoor anti-freezing protection function and the outdoor ambient temperature frequency limiting function are turned off.
The method for controlling self-cleaning outside the tube of an indoor heat exchanger according to claim 1, wherein the indoor fan is a DC fan, and the operating parameters include the actual speed and voltage of the indoor fan,

The step of "judging the degree of dust adhesion of the indoor heat exchanger based on the operating parameters" further includes:

determining a theoretical voltage value corresponding to the actual rotational speed;

calculating an absolute value of the difference between the actual voltage value and the theoretical voltage value, and calculating a ratio between the absolute value of the difference and the theoretical voltage value;

When the ratio is greater than the first threshold and less than or equal to the second threshold, it is judged that the indoor heat exchanger is the lightly attached;

When the ratio is greater than the second threshold and less than or equal to a third threshold, it is determined that the indoor heat exchanger is moderately attached;

When the ratio is greater than the third threshold, it is determined that the indoor heat exchanger is heavily attached.
The method for controlling self-cleaning outside the tube of an indoor heat exchanger according to claim 1, wherein the indoor fan is an AC fan, and the operating parameters include the actual rotational speed and actual current value of the indoor fan,

The step of "judging the degree of dust adhesion of the indoor heat exchanger based on the operating parameters" further includes:

determining a theoretical current value corresponding to the actual rotational speed;

calculating an absolute value of the difference between the actual current value and the theoretical current value, and calculating a ratio between the absolute value of the difference and the theoretical current value;

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

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

When the ratio is greater than the sixth threshold, it is determined that the indoor heat exchanger is heavily attached.