CN113531781B

CN113531781B - Method for controlling self-cleaning in indoor heat exchanger

Info

Publication number: CN113531781B
Application number: CN202110777930.8A
Authority: CN
Inventors: 罗荣邦; 魏冉冉
Original assignee: Qingdao Haier Air Conditioner Gen Corp Ltd; Haier Smart Home Co Ltd
Current assignee: Qingdao Haier Air Conditioner Gen Corp Ltd; Haier Smart Home Co Ltd
Priority date: 2021-07-09
Filing date: 2021-07-09
Publication date: 2023-03-24
Anticipated expiration: 2041-07-09
Also published as: CN113531781A; WO2023279610A1

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 indoor heat exchanger. This application aims at solving the problem of how to realize the intraductal automatically cleaning of indoor heat exchanger. To this end, the air conditioner of this application includes the recovery pipeline, and its one end and the import intercommunication of outdoor heat exchanger, the other end and compressor induction port intercommunication are provided with the on-off valve on the recovery pipeline, and control method includes: responding to a received command of self-cleaning in the pipe, and entering a self-cleaning mode in the pipe; controlling the throttling device to be closed to the minimum opening degree; controlling the compressor to adjust to a self-cleaning frequency; acquiring the exhaust temperature and the exhaust pressure of a compressor and/or the temperature of an indoor coil at intervals of a first interval; judging whether a valve opening condition is satisfied or not; when the valve opening condition is established, the throttle device and the on-off valve are controlled to be opened. Through the control mode, the control method can realize self-cleaning of the indoor heat exchanger, and solves the problem of pipe filth blockage of the indoor heat exchanger.

Description

Method for controlling self-cleaning in indoor 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 indoor heat exchanger.

Background

After the air conditioner is used for a period of time, the cooling and heating effects become poor. There are many factors affecting the cooling and heating effects, and the dirty blockage of the heat exchanger is one of the main reasons. For an indoor heat exchanger, filth blockage of the indoor heat exchanger mainly comprises pipe filth blockage and pipe filth blockage, and the pipe filth blockage mainly influences air supply effect due to fin gaps of the heat exchanger accumulated by indoor dust impurities and the like, so that heat exchange coefficient outside the pipe is reduced, and heat exchange effect between the heat exchanger and air is deteriorated. The heat exchange coefficient between the refrigerant and the coil pipe of the heat exchanger is reduced, so that the energy of the refrigerant in the pipe is influenced to be transmitted outwards. The main factor influencing the filth blockage in the pipe is refrigerating machine oil, the refrigerating machine oil in the compressor flows to a hairpin pipe of the heat exchanger along with a refrigerant, the flow of the refrigerating machine oil is influenced because the existing hairpin pipe is an internal thread copper pipe, and in addition, the centrifugal force action of the flowing refrigerant causes that part of the refrigerating machine oil cannot return to the inside of the compressor in time and stays on the inner wall of the threaded copper pipe, so that the heat transfer between the refrigerant and the coil pipe is blocked, the heat transfer temperature difference is reduced, and the refrigerating and heating effects of the air conditioner are poor.

The surface dust and impurities can be removed by manually cleaning regularly or performing air conditioner frosting operation, but the pipe inside filth blockage is one of the main factors influencing the refrigerating and heating effects of the air conditioner and cannot be cleaned manually. Therefore, how to clean the indoor heat exchanger in the tube becomes an urgent problem to be solved by air conditioner manufacturers.

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

Disclosure of Invention

In order to solve at least one problem in the prior art, namely to solve the problem of how to realize the in-pipe self-cleaning of the indoor heat exchanger, the application provides a control method for the in-pipe self-cleaning of the indoor heat exchanger, which is applied to an air conditioner, the air conditioner comprises a compressor, the 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, one end of the recovery pipeline is communicated with an inlet of the outdoor heat exchanger, the other end of the recovery pipeline is communicated with an air suction port of the compressor, an on-off valve is arranged on the recovery pipeline, and the on-off valve is a normally-closed valve,

the method for controlling self-cleaning in the pipe comprises the following steps:

responding to a received instruction for carrying out in-pipe self-cleaning on the indoor heat exchanger, and entering an in-pipe self-cleaning mode;

controlling the throttling device to be closed to a minimum opening degree;

controlling the compressor to adjust to a preset self-cleaning frequency;

acquiring the exhaust temperature, the exhaust pressure and/or the indoor coil temperature of the compressor at intervals of a first interval;

judging whether a valve opening condition is met or not based on the acquired exhaust temperature, the acquired exhaust pressure and/or the acquired indoor coil temperature;

and controlling the throttle device and the on-off valve to be opened when the valve opening condition is satisfied.

In a preferred embodiment of the method for controlling self-cleaning in a tube of an indoor heat exchanger, the valve opening condition includes at least one of the following conditions:

the exhaust temperature is greater than or equal to an exhaust temperature threshold value and lasts for a first set time;

the exhaust pressure is greater than or equal to an exhaust pressure threshold value and lasts for a second set time;

the indoor coil temperature is greater than or equal to the coil temperature threshold value and lasts for a third set time.

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

and controlling the indoor fan to stop running before acquiring the exhaust temperature, the exhaust pressure and/or the indoor coil temperature of the compressor.

and controlling the indoor fan to start running at the same time or after the throttle device and the on-off valve are controlled to be opened.

and controlling the outdoor fan to keep the current running state.

In a preferred embodiment of the method for controlling self-cleaning in a tube of an indoor heat exchanger, the step of "controlling the throttle device to open" further includes:

and controlling the throttle device to be opened to the maximum opening degree.

and after the throttling device and the on-off valve are opened and continue for a fourth set time, the self-cleaning mode in the pipe is exited.

In a preferred embodiment of the method for controlling self-cleaning in a tube of an indoor heat exchanger, the step of exiting the self-cleaning mode in the tube further includes:

controlling the compressor to resume a frequency prior to entering the in-pipe self-cleaning mode;

controlling the throttling device to maintain the maximum opening degree;

and controlling the on-off valve to close.

and after controlling the throttling device to maintain the maximum opening degree for a fifth set time, controlling the throttling device to return to the opening degree before entering the in-pipe self-cleaning mode.

In the preferable technical scheme of the method for controlling self-cleaning in the tube of the indoor heat exchanger, the self-cleaning frequency is the maximum limit frequency corresponding to the outdoor environment temperature.

It should be noted that, in the preferred technical scheme of this application, the air conditioner includes compressor, indoor heat exchanger, throttling arrangement, the outdoor heat exchanger that connects gradually through the refrigerant pipeline, and the air conditioner still includes the recovery pipeline, and the one end of recovery pipeline communicates with the import of outdoor heat exchanger, and the other end of recovery pipeline communicates with the induction port of compressor, is provided with the on-off valve on the recovery pipeline, and the on-off valve is the normally closed valve, and intraductal automatically cleaning control method includes: responding to a received instruction for carrying out in-pipe self-cleaning on the indoor heat exchanger, and entering an in-pipe self-cleaning mode; controlling the throttling device to be closed to the minimum opening degree; controlling the compressor to adjust to a preset self-cleaning frequency; acquiring the exhaust temperature and the exhaust pressure of a compressor and/or the temperature of an indoor coil at intervals of a first interval; judging whether a valve opening condition is met or not based on the acquired exhaust temperature, exhaust pressure and/or indoor coil temperature; and when the valve opening condition is met, the throttling device and the on-off valve are controlled to be opened.

Through the control mode, the control method can realize self-cleaning of the indoor heat exchanger, and solves the problem of pipe filth blockage of the indoor heat exchanger. Specifically, the throttling device is controlled to be closed to the minimum opening degree, so that the refrigerant discharged from the compressor is accumulated in the indoor heat exchanger, the temperature and the pressure of the refrigerant are rapidly increased in a short time, the throttling device and the on-off valve are opened when the condition of opening the valve is judged to be met based on the exhaust temperature, the exhaust pressure and/or the indoor coil temperature of the compressor, the inside of the coil of the indoor heat exchanger can be effectively washed by utilizing the rapid flow of the high-temperature and high-pressure refrigerant, oil stains on the inner wall of the coil are washed away and directly return to the inside of the compressor along with the refrigerant through a recovery pipeline, and self-cleaning of the indoor heat exchanger is realized. In addition, through setting up the recovery pipeline, can realize directly retrieving in bringing the compressor with the greasy dirt back at the automatically cleaning in-process, reduce the flow stroke of high temperature refrigerant, reduce the pressure drop of refrigerant, improve the automatically cleaning effect, practice thrift the automatically cleaning time, guarantee user experience.

Drawings

The in-tube self-cleaning control method of the indoor 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 an air conditioner of the present application;

FIG. 2 is a flow chart of a method for controlling self-cleaning in a tube of an indoor heat exchanger according to the present application;

fig. 3 is a logic diagram of a possible implementation process of the in-tube self-cleaning control method for the indoor 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. an on-off valve; 9. 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 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 the terms "first," "second," and "third" in the description of the present application are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

It should also be noted that, in the description of the present application, unless explicitly stated or limited otherwise, the term "connected" is to be understood broadly, for example, it may be a fixed connection, a detachable connection, or an integral connection; 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 application.

As shown in fig. 1, in one possible embodiment, the air conditioner includes a compressor 1, a four-way valve 2, an outdoor heat exchanger 3, a throttle device 4, an indoor heat exchanger 5, and an accumulator 9. The gas 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 9, the export of reservoir 9 passes through pipeline and compressor 1' S induction port intercommunication. Throttle device 4 is the electronic expansion valve preferably in this application, is provided with the filter screen in the reservoir 9, and reservoir 9 can play and store refrigerant, refrigerant gas-liquid separation, greasy dirt filtration, amortization and refrigerant buffering etc. effect.

The air conditioner further comprises a recovery pipeline 7 and an on-off valve 8, the recovery pipeline 7 is a copper pipe with a smooth inner wall, the first end of the copper pipe is arranged on a refrigerant pipeline 6 between the throttling device 4 and the inlet of the outdoor heat exchanger 3, and the second end of the copper pipe is arranged on the refrigerant pipeline 6 between the S interface of the four-way valve 2 and the inlet of the liquid reservoir 9. The on-off valve 8 is preferably a solenoid valve which is a normally closed valve and is arranged on the recovery pipeline 7, and the solenoid valve is in communication connection with a controller of the air conditioner to receive opening and closing signals sent by the controller. Of course, the on-off valve 8 may be an electrically controlled valve such as an electronic expansion valve.

The method for controlling self-cleaning in the tube of the indoor 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 air conditioner, for example, one or both of the four-way valve 2 and the accumulator 9 may be omitted, or other components may be added on the basis of the structure of the air conditioner.

The method for controlling self-cleaning in the tube of the indoor heat exchanger according to the present application will be described with reference to fig. 1 and 2. Fig. 2 is a flowchart of a method for controlling self-cleaning in a tube of an indoor heat exchanger according to the present application.

As shown in fig. 2, in order to solve the problem of how to implement in-tube self-cleaning of an indoor heat exchanger, the in-tube self-cleaning control method of an indoor heat exchanger according to the present application includes:

s101, responding to a received command for carrying out in-pipe self-cleaning on the indoor heat exchanger, and entering an in-pipe self-cleaning mode.

In a possible implementation, the instruction of carrying out intraductal automatically cleaning to indoor heat exchanger can be sent by user's initiative, if send the instruction to the air conditioner through the button on the remote controller, perhaps send the instruction through the terminal with air conditioner communication connection, wherein the terminal can be the APP of installation on the smart machine, and the APP directly or through sending the instruction to the air conditioner to high in the clouds. The intelligent device comprises but is not limited to a mobile phone, a tablet personal computer, an intelligent sound box, an intelligent watch and the like, and the intelligent device is in communication connection with the air conditioner or the cloud end and comprises but is not limited to wifi, bluetooth, infrared, 3G/4G/5G and the like. After receiving an instruction of self-cleaning in the pipe of the indoor heat exchanger, the air conditioner switches the operation mode to the self-cleaning in the pipe, and starts to self-clean in the pipe of the coil pipe of the indoor heat exchanger. The self-cleaning mode in the pipe can be a computer program which is stored in the air conditioner in advance, and when the mode is operated, the air conditioner controls the operation of each part of the air conditioner according to the steps set by the program.

Of course, the self-cleaning command may also be automatically issued when the air conditioner reaches certain entry conditions, such as issuing a command for performing in-tube self-cleaning on the indoor heat exchanger when the accumulated operating time of the air conditioner reaches a preset time, where the preset time may be, for example, 20h to 40h.

And S103, controlling the throttle device to be closed to the minimum opening degree.

In one possible embodiment, the electronic expansion valve is controlled to close to the minimum opening degree, that is, the opening degree is 0, at which time the electronic expansion valve realizes complete throttling and the refrigerant cannot flow through the electronic expansion valve. Referring to fig. 1, in the case of the air conditioner operating heating mode before entering the in-tube self-cleaning mode, since the on-off valve is a normally closed valve and the electronic expansion valve is closed to a minimum opening degree, all the refrigerant discharged from the compressor is accumulated in the indoor heat exchanger and a part of the refrigerant pipeline.

And S105, controlling the compressor to adjust to a preset self-cleaning frequency.

In one possible embodiment, the self-cleaning frequency is a frequency determined by experiments in advance, the frequency can be close to or reach the highest operation frequency of the compressor, and when the compressor operates at a higher frequency, the pressure and the temperature of the refrigerant discharged from the air outlet of the compressor are higher, so that the temperature and the pressure of the refrigerant discharged from the compressor can be raised quickly. Preferably, the self-cleaning frequency is a maximum frequency corresponding to the outdoor ambient 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 compressor is provided with a protection mechanism, and the maximum limit frequency is correspondingly set under different outdoor environment temperatures, the self-cleaning frequency of the self-cleaning type air conditioner is the maximum limit frequency of the compressor under the current outdoor environment temperature, and under the frequency limit, the compressor can realize the discharge and accumulation of the refrigerant in the shortest time. The manner of acquiring the outdoor ambient temperature is a conventional means in the art, and is not described herein again.

It should be noted that, although specific numerical values are not listed in the present application to describe the self-cleaning frequency, this does not mean that the control method of the present application cannot be implemented, and the self-cleaning frequency may be different in different models of air conditioners and under different environmental conditions, so that a person skilled in the art may set the self-cleaning frequency based on a specific application scenario as long as the frequency is set to enable the refrigerant discharged by the compressor to have a higher pressure and a higher temperature.

And S107, acquiring the exhaust temperature, the exhaust pressure and/or the indoor coil temperature of the compressor at intervals of a first interval.

In a possible embodiment, the discharge temperature of the compressor may be obtained by arranging a temperature sensor at the discharge port of the compressor, the discharge pressure may be obtained by arranging a pressure sensor at the discharge port of the compressor, and the temperature of the indoor coil may be obtained by arranging a temperature sensor on the coil of the indoor heat exchanger. The first interval may be any value from 1s to 5s, selected in relation to the rate of rise of the discharge temperature, discharge pressure and/or indoor coil temperature, and the control accuracy to be achieved by the present application. If the self-cleaning frequency is relatively large, the rising speed of the exhaust temperature, the exhaust pressure and/or the indoor coil temperature is high, or the application needs to achieve high control accuracy, the first interval time can be selected to be 1s, 2s or shorter, and if the self-cleaning frequency is relatively small, the rising speed of the exhaust temperature, the exhaust pressure and/or the indoor coil temperature is low, or the control method does not need to achieve high accuracy, the first interval time can be selected to be 4s, 5s or even longer.

In the present application, the first interval time is preferably selected to be 1s, and the exhaust temperature, the exhaust pressure and the indoor coil temperature are simultaneously obtained during the operation. That is, after the compressor reaches the self-cleaning frequency, the discharge temperature, the discharge pressure and the indoor coil temperature of the compressor are simultaneously obtained every 1 s.

Of course, in other non-preferred embodiments, only one of the three parameters may be acquired. Further, the discharge temperature, discharge pressure, and indoor coil temperature are not necessarily obtained exclusively, and may be adjusted by those skilled in the art without departing from the principles of the present application, for example, by providing a temperature sensor, a pressure sensor, etc. on the coil of the outdoor heat exchanger.

And S109, judging whether the valve opening condition is met or not based on the acquired exhaust temperature, exhaust pressure and/or indoor coil temperature.

In a possible embodiment, the valve-open condition comprises at least one of the following conditions: (1) The exhaust temperature is greater than or equal to an exhaust temperature threshold value and lasts for a first set time; (2) The exhaust pressure is greater than or equal to the exhaust pressure threshold value and lasts for a second set time; (3) And the indoor coil temperature is greater than or equal to the coil temperature threshold value and lasts for a third set time. When the exhaust temperature is greater than or equal to the exhaust temperature threshold value and lasts for the first set time, the refrigerant accumulated after the exhaust port of the compressor reaches a relatively high temperature. Similarly, when the exhaust pressure is greater than or equal to the exhaust pressure threshold value and lasts for a second set time, the refrigerant accumulated after the exhaust port of the compressor is proved to have reached a quite high pressure, and when the temperature of the indoor coil is greater than or equal to the coil temperature threshold value, the refrigerant in the indoor heat exchanger is proved to have reached a high temperature state.

It is to be understood that the valve opening conditions described above are merely preferred embodiments in the present application, and those skilled in the art can adjust the valve opening conditions described above without departing from the principle of the present application, provided that the adjusted conditions can accurately determine the state of the refrigerant accumulated after the compressor. For example, the valve-open condition may include only one or two of the above three conditions; alternatively, the valve-opening condition may include only the judgment of the temperature/pressure, and the judgment of the duration may be omitted.

And S111, controlling the throttle device and the on-off valve to be opened when the valve opening condition is met.

In one possible embodiment, the throttle device and the on-off valve are controlled to be opened when any of the above conditions (1) to (3) is satisfied. At this time, as shown by arrows in fig. 1, the high-temperature and high-pressure refrigerant accumulated between the discharge port of the compressor and the electronic expansion valve flows back to the accumulator through the recovery pipeline, and is then discharged through the discharge port again under compression of the compressor, thereby realizing circulation of the refrigerant. In the circulation process, the quick flowing of the high-temperature and high-pressure refrigerant is used for impacting and cleaning oil stains attached to the inner wall of the coil pipe of the indoor heat exchanger, and the washed oil stains are directly recovered into the liquid storage device through the recovery pipeline to realize oil stain filtration and engine oil recovery. Preferably, 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 pressure drop in the flowing process of the refrigerant is reduced, and the self-cleaning effect in the pipe is improved.

It can be seen that the electronic expansion valve is controlled to be closed to the minimum opening degree, so that the refrigerant discharged from the compressor is accumulated in the indoor heat exchanger and part of refrigerant pipelines, the temperature and the pressure of the refrigerant are rapidly increased in a short time, when the condition that the valve opening condition is established is judged based on the exhaust temperature, the exhaust pressure and the indoor coil temperature of the compressor, the throttling device and the on-off valve are opened, the inside of the coil of the indoor heat exchanger can be effectively washed by utilizing the rapid flow of the high-temperature and high-pressure refrigerant, oil stains on the inner wall of the coil are washed away and directly return to the inside of the liquid storage device along with the refrigerant through the recovery pipeline, and self-cleaning of the indoor heat exchanger is realized.

In addition, through setting up the recovery pipeline in the air conditioner, this application can be in the intraductal automatically cleaning in-process of executing to indoor heat exchanger, utilize the recovery pipeline to realize the recovery to refrigerator oil, realize that high temperature high pressure refrigerant is after scouring away indoor heat exchanger, need not to pass through outdoor heat exchanger once more, but directly take the greasy dirt back to and retrieve in the reservoir and filter, then again through compressor compression discharge circulation, the flow stroke of having reduced the high temperature refrigerant, reduce along journey pressure drop, improve intraductal automatically cleaning effect. Through the setting of reservoir, can filter the refrigerator oil of retrieving, avoid the impurity in the refrigerator oil to continue to participate in the refrigerant circulation.

In one possible embodiment, the in-tube self-cleaning control method further comprises: and controlling the indoor fan to stop running before acquiring the exhaust temperature, the exhaust pressure and/or the indoor coil temperature of the compressor. Specifically, after entering the in-pipe self-cleaning mode, the indoor fan is controlled to stop running to reduce the heat exchange effect between the indoor heat exchanger and air, so that the temperature and pressure of the refrigerant can be increased, and the control method can achieve the valve opening condition as soon as possible.

In one possible embodiment, the in-tube self-cleaning control method further comprises: and controlling the indoor fan to start running at the same time or after the throttle device and the on-off valve are controlled to be opened. In the process of self-cleaning in the pipe, the refrigerant discharged by the compressor directly returns to the inside of the compressor without passing through the outdoor heat exchanger, so that the temperature in the compressor is gradually increased, and the risk of high-temperature protection and shutdown of the compressor exists. In order to ensure the smooth operation of self-cleaning in the pipe, the inventor finds out through repeated calculation, test, observation and comparison that the refrigerant discharged by the compressor is in the temperature and pressure range which accords with the self-cleaning condition while avoiding the high-temperature protection shutdown of the compressor by starting the indoor fan at the same time or after the throttle device and the on-off valve are opened. The rotating speed of the indoor fan can be controlled by referring to a heating mode control mode, and can also be controlled by adopting a fixed rotating speed mode, but in general, the premise of controlling the operation of the indoor fan is to avoid high-temperature protection shutdown and to have the smallest influence on the operation of the pipe self-cleaning mode. In addition, although the indoor fan is started to enable part of refrigerants to be subjected to heat exchange liquefaction, under the action of high temperature and high pressure, the liquefied refrigerants can be completely recovered through the liquid storage device, and the self-cleaning process in the pipe is not substantially influenced.

In one possible embodiment, the method for controlling self-cleaning in a tube further comprises: and in the operation process of the self-cleaning mode in the pipe, controlling the outdoor fan to keep the current operation state. Specifically, after the self-cleaning in the pipe is executed, the heating mode needs to be switched back to continue to operate, so that in order to ensure user experience, the outdoor fan is controlled to keep the current operation state, hot air is provided indoors as soon as possible after the operation of the self-cleaning mode in the pipe is finished, operation fluctuation is reduced, and the operation stability of the air conditioner is improved.

In one possible embodiment, the in-tube self-cleaning control method further comprises: and after the throttling device and the on-off valve are opened and continue for a fourth set time, the self-cleaning mode in the pipe is exited. The fourth setting time can be any value from 3min to 10min, and is preferably 5min in the application. When the opening time of the throttling device and the on-off valve lasts for 5min, the high-temperature and high-pressure refrigerant circulates for many times to generate a better self-cleaning effect in the pipe, so that the self-cleaning mode in the pipe is exited when the throttling device and the on-off valve are opened for 5min.

Specifically, the step of exiting the in-tube self-cleaning mode further comprises: controlling the frequency of the compressor before the compressor returns to the self-cleaning mode in the pipe, controlling the throttling device to keep the maximum opening degree, and controlling the on-off valve to be closed. After the self-cleaning process in the air conditioner is finished, the air conditioner needs to be restored to the operation mode before the self-cleaning in the air conditioner so as to continuously adjust the indoor temperature. Still taking the heating mode of the air conditioner before entering the in-tube cleaning mode as an example, after the in-tube self-cleaning mode is executed, the heating mode needs to be switched back to operate. At this time, the compressor is controlled to recover from the self-cleaning frequency to the frequency before entering the pipe for self-cleaning, the electronic expansion valve is controlled to keep the maximum opening degree, and the on-off valve is controlled to be closed, so that the refrigerant flows in the flow direction of the normal heating mode. The throttling device keeps the maximum opening degree, and most of refrigerants circulate between the compressor and the indoor heat exchanger when the refrigerant is in self-cleaning mode operation in the pipe, so that refrigerant in the outdoor heat exchanger is lost, the throttling device keeps the maximum opening degree, the refrigerant is enabled to fill the outdoor heat exchanger quickly, and normal circulation of the refrigerant is achieved as soon as possible.

Accordingly, after the control throttle device maintains the maximum opening degree for the fifth set time, the control throttle device is returned to the opening degree before entering the in-pipe self-cleaning mode. The fifth set time can be any value within 1-5 min, the application is preferably 3min, after the electronic expansion valve keeps the maximum opening degree to operate for 3min, the refrigerant circulation tends to be stable, and at the moment, the electronic expansion valve is controlled to recover to the opening degree before entering the in-pipe self-cleaning mode, so that the air conditioner completely recovers the refrigeration parameters before entering the in-pipe self-cleaning mode to continue to operate.

Of course, the manner of exiting the in-duct 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 in-duct self-cleaning mode. For example, all the components may be directly controlled to return to the operating state before entering the in-tube self-cleaning mode, or one or more components may be first controlled to return to the operating state before entering the in-tube self-cleaning mode, and then all the components may be gradually returned to the operating state before entering the in-tube self-cleaning mode.

One possible implementation of the present application is described below with reference to fig. 3. Fig. 3 is a logic diagram of a possible implementation process of the method for controlling self-cleaning in a tube of an indoor heat exchanger according to the present application.

As shown in fig. 3, in a possible implementation process, when the air conditioner operates in the heating mode, a user sends an instruction for performing in-tube self-cleaning on the indoor heat exchanger to the air conditioner through a remote controller key:

firstly, step S201 is executed, the air conditioner enters a self-cleaning mode in the pipe, that is, the electronic expansion valve is controlled to be closed to a minimum opening, the compressor is controlled to be increased to a maximum limit frequency corresponding to the outdoor environment temperature, the indoor fan is controlled to stop running, and the outdoor fan is controlled to maintain the current rotating speed.

Step S203 is executed next, and the discharge air temperature Td and the discharge air pressure Pd of the compressor, and the indoor coil temperature Tp of the indoor heat exchanger are acquired.

Next, step S205 is executed to determine whether at least one of Td ≧ T1, pd ≧ P, and Tp ≧ T2 is true, where T1 is the exhaust temperature threshold, P is the exhaust pressure threshold, and T2 is the coil temperature threshold. And when at least one judgment result is satisfied, executing the step S207, otherwise, when none of the three judgment conditions is satisfied, returning to execute the step S203.

And S207, controlling the electromagnetic valve to be opened, controlling the electronic expansion valve to be opened to the maximum opening degree, and simultaneously controlling the indoor fan to be opened.

Step S209 is executed next, and whether the duration t1 of the joint opening of the electronic expansion valve and the electromagnetic valve is more than or equal to 5min is judged; if the determination result is true, step S211 is executed, otherwise, if the determination result is false, the process returns to continue to execute step S209.

S211, exiting the self-cleaning mode in the pipe, specifically, controlling the electronic expansion valve to keep the maximum opening, controlling the compressor to recover to the frequency before entering the self-cleaning mode in the pipe, and controlling the electromagnetic valve to close.

Step S213 is executed next, and whether the duration time t2 for keeping the maximum opening of the electronic expansion valve is more than or equal to 3min is judged; if the determination result is true, go to step S215; otherwise, if the determination result is false, the process returns to continue to step S213.

S215, controlling the electronic expansion valve to recover to the opening degree before entering the in-pipe self-cleaning mode, and then recovering the air conditioner to the refrigerating mode before entering the in-pipe self-cleaning mode to operate.

Those skilled in the art will appreciate that the above described air conditioner may also include other well known structures such as processors, controllers, memories, etc., wherein the memories include, but are not limited to, ram, flash, rom, prom, volatile, non-volatile, serial, parallel, or registers, etc., and the processors include, but are not limited to, CPLD/FPGA, DSP, ARM processor, 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. For example, although the above-mentioned step S205 is described in connection with the simultaneous determination of Td ≧ T1, pd ≧ P, and Tp ≧ T2, those skilled in the art will appreciate that the above-mentioned three conditions may be determined sequentially.

It should be noted that, although the above embodiments are described with reference to the air conditioner running heating mode before entering the in-duct self-cleaning mode, this is not intended to limit the scope of the present application, and when the air conditioner runs in other modes, if an instruction to enter the in-duct self-cleaning mode is received, the four-way valve is controlled to perform corresponding power on/off switching. For example, on the premise of the air conditioner running in the cooling mode, when an instruction of entering the in-pipe self-cleaning mode is received, the four-way valve is controlled to be switched to the heating mode in an electrified mode, and then the in-pipe self-cleaning mode is executed according to the control mode.

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 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 indoor heat exchanger is applied to an air conditioner and is characterized in that the air conditioner comprises a compressor, the 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, one end of the recovery pipeline is arranged on the refrigerant pipeline between the throttling device and an inlet of the outdoor heat exchanger, the other end of the recovery pipeline is communicated with an air suction port of the compressor, an on-off valve is arranged on the recovery pipeline, the on-off valve is a normally-closed valve,

controlling the throttling device to be closed to a minimum opening degree;

controlling the compressor to adjust to a preset self-cleaning frequency;

2. The in-tube self-cleaning control method of an indoor heat exchanger as claimed in claim 1, wherein the valve-open condition includes at least one of the following conditions:

3. The in-tube self-cleaning control method of an indoor heat exchanger according to claim 1, further comprising:

4. The in-tube self-cleaning control method of an indoor heat exchanger according to claim 3, further comprising:

and controlling the indoor fan to start running at the same time or after the throttling device and the on-off valve are controlled to be opened.

5. The in-tube self-cleaning control method of an indoor heat exchanger according to claim 1, further comprising:

and controlling the outdoor fan to keep the current running state.

6. The method of controlling self-cleaning in a tube of an indoor heat exchanger as claimed in claim 1, wherein the step of controlling the throttle device to be opened further comprises:

and controlling the throttle device to be opened to the maximum opening degree.

7. The method of controlling self-cleaning in a tube of an indoor heat exchanger as claimed in claim 6, further comprising:

8. The in-tube self-cleaning control method of an indoor heat exchanger according to claim 7, wherein the step of exiting the in-tube self-cleaning mode further comprises:

controlling the throttling device to maintain the maximum opening degree;

and controlling the on-off valve to be closed.

9. The in-tube self-cleaning control method of an indoor heat exchanger according to claim 8, further comprising:

10. The method for controlling self-cleaning in a tube of an indoor heat exchanger as claimed in claim 1, wherein the self-cleaning frequency is a maximum frequency corresponding to an outdoor ambient temperature.