CN111380176A

CN111380176A - Air conditioner and cleaning control method thereof

Info

Publication number: CN111380176A
Application number: CN201811653536.8A
Authority: CN
Inventors: 潘杰; 李川
Original assignee: Daikin Industries Ltd
Current assignee: Daikin Industries Ltd
Priority date: 2018-12-29
Filing date: 2018-12-29
Publication date: 2020-07-07
Anticipated expiration: 2038-12-29
Also published as: CN111380176B

Abstract

The invention relates to an air conditioner, which comprises a heat exchanger, a filter screen cleaning mechanism and a controller, wherein the controller is configured to perform the self-cleaning of the heat exchanger and the self-cleaning of the filter screen simultaneously, the self-cleaning of the heat exchanger comprises a frosting stage and a defrosting stage, wherein the frosting stage is performed in a first period, the defrosting stage is performed in a second period after the first period, the self-cleaning of the filter screen is performed in a third period, and at least one part of the third period is overlapped with the first period. The invention can clean the filter screen during the low rotating speed of the fan in the frosting process of the heat exchanger, thereby saving the time for cleaning the filter screen.

Description

Air conditioner and cleaning control method thereof

Technical Field

The invention relates to the field of air conditioners, in particular to a cleaning control method of an air conditioner.

Background

The air conditioner is liable to accumulate a large amount of dust on some parts such as a heat exchanger and a filter net during use. If the dust is not cleaned in time, the heat exchange performance of the heat exchanger is greatly reduced, and bacteria are easy to breed and mildew is easy to form.

Some air conditioners have a heat exchanger self-cleaning function and a filter screen self-cleaning function, and may be performed when the air conditioner is idle. These two functions are usually performed separately, because the fan turns when the heat exchanger is self-cleaning, and the fan is not recommended to turn when the filter screen is self-cleaning, which may cause dust to be blown out. Thus, it takes much time to complete the self-cleaning of the heat exchanger and the self-cleaning of the filter net.

Disclosure of Invention

The technical problem to be solved by the invention is to provide an air conditioner and a cleaning control method thereof, which can simultaneously perform the self-cleaning function of a heat exchanger and the self-cleaning function of a filter screen so as to save time.

The present invention provides an air conditioner including a heat exchanger, a filter cleaning mechanism, and a controller, wherein the controller is configured to perform self-cleaning of the heat exchanger and self-cleaning of the filter simultaneously, the self-cleaning of the heat exchanger includes a frosting stage and a defrosting stage, the frosting stage is performed during a first period, the defrosting stage is performed during a second period after the first period, the self-cleaning of the filter is performed during a third period, and at least a portion of the third period overlaps the first period. The technical scheme has the advantages that the self-cleaning of the filter screen can be carried out by utilizing the period of low rotating speed of the fan in the frosting process of the heat exchanger, so that the self-cleaning time of the filter screen is saved.

In an embodiment of the invention, the controller is configured to compare the time lengths of the first period and the third period, thereby determining the timing relationship between the first period and the third period. The technical scheme has the advantage that the coordination of the frosting stage of the heat exchanger and the self-cleaning time of the filter screen during working can be determined according to the frosting stage and the self-cleaning time of the filter screen.

In an embodiment of the present invention, the controller is configured to compare start times and time lengths of the first period and the third period, thereby determining a timing relationship of the first period and the third period. The technical scheme has the advantage that the coordination of the frosting stage of the heat exchanger and the self-cleaning starting time and the self-cleaning time of the filter screen on the working time can be determined according to the frosting stage of the heat exchanger and the self-cleaning starting time and the self-cleaning time length of the filter screen.

In an embodiment of the invention, an end time of the third period is equal to or earlier than an end time of the first period.

In an embodiment of the present invention, an end time of the third period is later than an end time of the first period, and a start time of the second period is equal to or later than the end time of the third period.

In an embodiment of the invention, an end time of the third period is later than an end time of the first period, a start time of the second period is earlier than the end time of the third period, and the end time of the second period is later than the end time of the third period.

In an embodiment of the present invention, when the ventilation mode defrosting is used, a ratio of an overlapping time of the third period and the second period to the second period is less than or equal to 1/3. The advantage of this technical scheme is that just accomplish the filter screen clean in the early stage of heat exchanger defrosting to make the dust can pour on the heat exchanger, the water after melting along with the frost is discharged.

In an embodiment of the present invention, when the heating mode defrosting is used, the third period ends when the heat exchanger surface temperature is greater than a preset value. The advantage of this technical scheme is that just accomplish the filter screen clean in the early stage of heat exchanger defrosting to make the dust can pour on the heat exchanger, the water after melting along with the frost is discharged.

In an embodiment of the present invention, the third period includes a first sub-period and a second sub-period which are not consecutive, an end time of the first sub-period is equal to or earlier than an end time of the first period, and a start time of the second sub-period is equal to or later than an end time of the second period. The advantage of this technical scheme is that the filter screen cleaning can be divided into two separate sub-periods, so as not to influence the heat exchanger defrosting.

In an embodiment of the present invention, the filter screen cleaning mechanism includes an electric brush for sweeping the filter screen, and the controller is configured to control the fan rotation speed in the third period not to be higher than a preset rotation speed. The technical scheme has the advantage that the rotating speed of the fan in the self-cleaning process of the filter screen is controlled so as to avoid influencing the self-cleaning of the filter screen.

In an embodiment of the present invention, the filter screen cleaning mechanism includes a motor-driven brush for sweeping the filter screen and a roller for fitting the filter screen, wherein the controller is configured to control the motor-driven brush to sweep the filter screen, then rotate the roller to rotate the filter screen to a side facing the heat exchanger, and turn on a fan of the air conditioner to blow dust on the filter screen onto the heat exchanger during the third period. The advantage of this technical scheme is that the filter screen can rotate to the one side towards heat exchanger to utilize the fan to blow the dust to the heat exchanger on, needn't use electronic brush.

In an embodiment of the present invention, the filter screen cleaning mechanism includes a motor-driven brush for sweeping the filter screen and a roller for fitting the filter screen, wherein the controller is configured to control the motor-driven brush to sweep the filter screen during the first sub-period, then rotate the roller to rotate the filter screen to a side facing the heat exchanger, and turn on a fan of the air conditioner to blow dust on the filter screen onto the heat exchanger. The advantage of this technical scheme is that the filter screen can rotate to the one side towards heat exchanger to utilize the fan to blow the dust to the heat exchanger on, needn't use electronic brush.

In an embodiment of the invention, the filter screen cleaning mechanism comprises an electric brush and a guide member, wherein the controller is configured to control the electric brush to clean the filter screen during the third period, wherein the cleaned dust is guided to the heat exchanger by the guide member. The technical scheme has the advantages that the filter screen is cleaned by the electric brush, and dust is accurately poured onto the heat exchanger through the guide component.

In an embodiment of the invention, the filter screen cleaning mechanism comprises an electric brush and a guide member, wherein the controller is configured to control the electric brush to clean the filter screen during the first sub-period, wherein cleaned dust is directed onto the heat exchanger by the guide member. The technical scheme has the advantages that the filter screen is cleaned by the electric brush, and dust is accurately poured onto the heat exchanger through the guide component.

The invention also provides a cleaning control method of the air conditioner, the air conditioner comprises a heat exchanger, a filter screen and a filter screen cleaning mechanism, and the method comprises the following steps: performing heat exchanger cleaning, the heat exchanger cleaning comprising a frosting stage and a defrosting stage, wherein the frosting stage is performed during a first period and the defrosting stage is performed during a second period after the first period; and performing a filter screen self-cleaning, the filter screen self-cleaning being performed during a third period, at least a portion of the third period overlapping the first period.

In an embodiment of the invention, the method further includes comparing time lengths of the first period and the third period, so as to determine a timing relationship between the first period and the third period.

In an embodiment of the invention, the method further includes comparing start times and time lengths of the first period and the third period, so as to determine a timing relationship between the first period and the third period.

In an embodiment of the present invention, when the ventilation mode defrosting is used, a ratio of an overlapping time of the third period and the second period to the second period is less than or equal to 1/3.

In an embodiment of the present invention, when the heating mode defrosting is used, the third period ends when the heat exchanger surface temperature is greater than a preset value.

In an embodiment of the present invention, the third period includes a first sub-period and a second sub-period which are not consecutive, an end time of the first sub-period is equal to or earlier than an end time of the first period, and a start time of the second sub-period is equal to or later than an end time of the second period.

In an embodiment of the present invention, a start time of the third period is equal to or later than a start time of the first period.

In an embodiment of the invention, the filter cleaning mechanism comprises a motor-driven brush for sweeping the filter, wherein the method comprises controlling the fan speed during the second period not to be higher than a preset speed.

In an embodiment of the invention, the filter screen cleaning mechanism comprises a motor brush for sweeping the filter screen and a roller for fitting the filter screen, the method comprising, during the third period: controlling the electric brush to clean the filter screen; rotating the roller to rotate the filter screen to a side facing the heat exchanger; and starting a fan of the air conditioner to blow dust on the filter screen to the heat exchanger.

In an embodiment of the invention, the filter screen cleaning mechanism comprises a powered brush for sweeping the filter screen and a roller for fitting the filter screen, the method comprising during the first sub-period: controlling the electric brush to clean the filter screen; rotating the roller to rotate the filter screen to a side facing the heat exchanger; and starting a fan of the air conditioner to blow dust on the filter screen to the heat exchanger.

In an embodiment of the invention, the filter cleaning mechanism comprises a roller for fitting the filter, the method comprising during the third period: rotating the roller to rotate a filter screen to a side facing the heat exchanger; and starting a fan of the air conditioner to blow dust on the filter screen onto the heat exchanger.

In an embodiment of the invention, the filter cleaning mechanism comprises a roller for fitting the filter, the method comprising during the first sub-period: rotating the roller to rotate a filter screen to a side facing the heat exchanger; and starting a fan of the air conditioner to blow dust on the filter screen onto the heat exchanger.

In an embodiment of the invention, the filter cleaning mechanism comprises a powered brush and a guide member, the method comprising during the third period: controlling the electric brush to clean the filter screen; and guiding the cleaned dust to the heat exchanger through the guide member.

In an embodiment of the invention, the filter cleaning mechanism comprises a powered brush and a guide member, the method comprising during the first sub-period: controlling the electric brush to clean the filter screen; and guiding the cleaned dust to the heat exchanger through the guide member.

The invention can self-clean the filter screen during the low rotating speed of the fan in the frosting process of the heat exchanger, thereby saving the self-cleaning time of the filter screen. In addition, the invention can further control the rotating speed of the fan in the frosting process of the heat exchanger, so that the invention is more beneficial to self-cleaning of the filter screen. In addition, the invention can introduce the dust with self-cleaning filter screen into the heat exchanger, and flush the dust in the defrosting process of the heat exchanger, thereby saving the part for collecting the dust.

Drawings

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below, wherein:

fig. 1 is a circuit block diagram of an air conditioner according to an embodiment of the present invention.

Fig. 2 is a flowchart illustrating a cleaning control method of an air conditioner according to an embodiment of the present invention.

Fig. 3A is a diagram illustrating a cleaning control process of an air conditioner according to some embodiments of the present invention.

Fig. 3B is a diagram illustrating a cleaning control process of an air conditioner according to another embodiment of the present invention.

Fig. 4A-4C are timing diagrams illustrating a washing control of an air conditioner according to some embodiments of the present invention.

Fig. 5A and 5B are schematic diagrams illustrating cleaning of a filter screen of an air conditioner according to an embodiment of the present invention.

Fig. 6 is a schematic view illustrating cleaning of a filter net of an air conditioner according to another embodiment of the present invention.

Fig. 7 is a schematic view illustrating cleaning of a filter net of an air conditioner according to still another embodiment of the present invention.

Detailed Description

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below.

In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention, but the present invention may be practiced in other ways than those specifically described herein, and thus the present invention is not limited to the specific embodiments disclosed below.

As used in this application and the appended claims, the terms "a," "an," and/or "the" are not intended to be inclusive in the singular, but rather are intended to be inclusive in the plural unless the context clearly dictates otherwise. In general, the terms "comprises" and "comprising" merely indicate that steps and elements are included which are explicitly identified, that the steps and elements do not form an exclusive list, and that a method or apparatus may include other steps or elements.

The embodiment of the invention describes a cleaning control method of an air conditioner, which can enable the self-cleaning function of a heat exchanger and the self-cleaning function of a filter screen to be matched, thereby saving the cleaning time.

Fig. 1 is a circuit block diagram of an air conditioner according to an embodiment of the present invention. Referring to fig. 1, the air conditioner 100 may include a heat exchanger 120, a filter screen cleaning mechanism 130, a fan 140, and a controller 110. Other mechanical components, such as a filter screen, are also included in the air conditioner 100. Components of the air conditioner not relevant to the present invention are not shown in order to avoid obscuring the focus of the present invention. The heat exchanger 120, the filter screen cleaning mechanism 130, and the fan 140 are all electrically connected to the controller 110. The controller 110 may control the actions of the heat exchanger 120, the filter screen cleaning mechanism 130, and the fan 140. The controller 110 controls the heat exchanger 120 to frost during a first period, which is referred to as a frosting phase. The surface of the heat exchanger may be frosted in a cooling mode of the air conditioner. Additionally or alternatively, the air conditioner may also have a dedicated frosting mode in which the surface of the heat exchanger is frosted. In the frosting mode, the fan 140 may be operated at a lower wind speed to have a lower rotational speed. The controller 110 controls the heat exchanger 120 to defrost during a second period, which is referred to as a defrost phase. The air conditioner 100 may be put in a ventilation mode to defrost. For example, the controller 110 may cause the fan 140 to have a higher rotational speed for ventilation. The air conditioner 100 may be in a heating mode to defrost. The controller 110 controls the filter screen cleaning mechanism 130 to clean the filter screen during the third period, which is referred to as filter screen self-cleaning.

The process of heat exchanger self-cleaning may include a frosting stage and a defrosting stage. The end time of the frosting phase is equal to or earlier than the start time of the frosting phase, so that the first period and the second period do not overlap. That is, the self-cleaning process of the heat exchanger is to perform a frosting step to frost the dust on the surface of the heat exchanger 120 together with the moisture in the air, and then perform a defrosting step to make the dust on the surface of the heat exchanger 120 flow down together with the condensed water generated after the frost is melted, so that the heat exchanger 120 is self-cleaned. The condensation frost cleaning technology can remove the scale virtually and keep the heat exchanger clean.

Further, the time period during which the filter screen is self-cleaning (third period) and the time period during which the frost formation occurs (first period) at least partially coincide. That is, the self-cleaning and frosting phases of the filter screen may start at the same time, or the self-cleaning of the filter screen starts earlier than the frosting phase, or the self-cleaning of the filter screen starts later than the frosting phase, but the self-cleaning of the filter screen starts before the end of the frosting phase, so that there is an overlapping time between the self-cleaning of the filter screen and the frosting phase. The air conditioner carries out the self-cleaning frosting stage of the heat exchanger and the self-cleaning of the filter screen at the same time in the overlapped time, thereby achieving the purpose of saving the cleaning time of the air conditioner.

The self-cleaning end time of the filter screen can be earlier than the end time of the frosting stage or later than the end time of the frosting stage. The defrosting stage starts at two starting moments, wherein the first starting moment is that the self-cleaning of the filter screen is started after the frosting stage and the self-cleaning of the filter screen are finished, the second starting moment is that the self-cleaning of the filter screen is not finished when the frosting stage is finished, the self-cleaning of the filter screen is stopped firstly, the defrosting stage is started, and after the defrosting stage is finished, the controller 110 controls the filter screen cleaning mechanism 130 to finish the rest self-cleaning steps of the filter screen.

Fig. 2 is a flowchart illustrating a cleaning control method of an air conditioner according to an embodiment of the present invention. This method may be implemented in the air conditioner 100 shown in fig. 1 or a variation thereof. Referring to fig. 2, the method of the present embodiment includes:

in step 201, a start time relationship is determined.

In this step, the controller 110 determines the relationship between the start timings of the self-cleaning of the heat exchanger and the self-cleaning of the filter net, that is, the relationship between the frosting stage and the start timing of the self-cleaning of the filter net. The results obtained included: the starting time of the frosting stage is the same as the starting time of the self-cleaning of the filter screen, or the starting time of the self-cleaning of the filter screen is later than the starting time of the frosting stage. It is understood that the starting time of the frosting stage and the starting time of the self-cleaning of the filter screen may be set by a user or may be automatically controlled by the controller 110. For example: after a user starts the air conditioner, the self-cleaning function of the heat exchanger is started firstly, and then the self-cleaning function of the filter screen is started; or, the self-cleaning function of the filter screen is started first, and then the self-cleaning function of the heat exchanger is started; alternatively, the user only activates one of the heat exchanger self-cleaning function and the filter screen self-cleaning function, and the controller 110 controls the heat exchanger 120 and the filter screen self-cleaning mechanism 130 to operate simultaneously, so that the heat exchanger self-cleaning function and the filter screen self-cleaning function start simultaneously.

In step 202, a session length relationship is determined.

In this step, the duration (hereinafter, simply referred to as "duration") of the frosting stage, the defrosting stage, and the self-cleaning of the filter screen are respectively defined as T1, T2, and T3, and the controller 110 determines the lengths of T1, T2, and T3, and the obtained results include T3 > T1 or T3 < T1. Generally, T1 and T2 may be fixed values or estimated time periods by the controller 110, and the estimated time periods may be calculated according to the temperature, humidity, etc. of the environment at the time. T3 may be a fixed value, such as 8 minutes, or a time period estimated by the controller 110, and the estimated time period may be calculated according to the amount of dust on the filter 130, the frequency of using the air conditioner, or the time period between the last cleaning and the cleaning.

In step 203, a timing relationship is determined.

At this step, the controller 110 determines the timing relationship between the frosting stage, the defrosting stage, and the filter screen self-cleaning, and the controller 110 controls the actions of the heat exchanger 120 and the filter screen cleaning mechanism 130 according to the determined timing relationship. Here, the timing relationship may represent the interrelation of the frosting stage, the defrosting stage and the filter screen self-cleaning in the execution time, including but not limited to the interrelation of the start time and the interrelation of the end time.

Fig. 3A is a diagram illustrating a cleaning control process of an air conditioner according to some embodiments of the present invention. In these embodiments, the controller 110 determines that the start time of the first period and the start time of the third period are the same, i.e. the heat exchanger self-cleaning function and the filter screen self-cleaning function are activated simultaneously, according to step 201 in fig. 2, as shown in step 310 in fig. 3A. At this time, the controller 110 controls the heat exchanger 120 to be frosted. In the self-cleaning process of the filter screen, the controller 110 may operate the air conditioner at a low wind level, so that the rotation speed of the fan of the air conditioner is not higher than a preset value suitable for self-cleaning the filter screen. For example, the fan speed of the air conditioner is not higher than 300 rpm. In the frosting process of the heat exchanger, as long as the filter screen is not self-cleaned, the rotating speed of the fan can be increased so as to be frosted more quickly.

At step 311, corresponding to step 202 in fig. 2, the controller 110 determines the duration of the frosting phase, the defrosting phase, the filter screen self-cleaning, and compares the duration of the frosting phase T1 with the duration of the filter screen self-cleaning T3. In the steps after step 311, the controller 110 controls the heat exchanger 120 and the filter screen cleaning mechanism 130 in four control modes.

When the result of step 311 is T3 < T1, the controller 110 adopts the first control mode. In a first control mode:

at step 312, after the frosting stage is completed, the controller 110 controls the heat exchanger 120 to directly start the frosting stage.

In step 313, after the defrosting stage is finished, the cleaning process of the entire air conditioner is completed. The control mode has the advantages that the self-cleaning of the filter screen can be finished in the frosting stage with lower rotating speed of the fan, so that the self-cleaning effect of the filter screen is better.

When the result of step 311 is that T3 is greater than or equal to T1, the controller 110 adopts the second control mode, the third control mode or the fourth control mode. In a second control mode:

in step 314, after the filter screen self-cleaning is completed, the controller 110 controls the heat exchanger 120 to start a defrosting phase.

In step 315, after the defrosting stage is finished, the cleaning process of the entire air conditioner is completed. The control mode has the advantages that the self-cleaning of the filter screen can be finished in the frosting stage with lower rotating speed of the fan, so that the self-cleaning effect of the filter screen is better.

In one example, after the frosting stage (T1) is completed and before step 314 begins, the fan 140 may be turned off, so that dust is not easily blown out during the process of cleaning the filter screen, which is more beneficial to self-cleaning the filter screen.

Under a third control mode:

in step 316, when the frosting stage is completed, the self-cleaning of the filter screen is not completed, the controller 110 allows the filter screen cleaning mechanism 130 to continue to work, and the controller 110 controls the heat exchanger 120 to perform the defrosting stage, in which the self-cleaning of the filter screen is completed first. In this control mode, the self-cleaning of the filter screen has partial time overlapping with the defrosting stage. The advantage of this control is that the self-cleaning of the filter takes up a part of the defrosting period, so that the total cleaning time can be reduced when the self-cleaning time of the filter is longer.

In one example, the fan 140 may continue to operate below the preset speed before the filter screen self-cleaning (T3) ends. After the filter screen is self-cleaned, the rotating speed of the fan 140 is increased to accelerate defrosting and shorten defrosting time.

Under a fourth control mode:

in step 318, when the frosting stage is completed, the self-cleaning of the filter screen is not completed, the controller 110 first controls the filter screen cleaning structure 130 to stop working, the controller 110 controls the heat exchanger 120 to perform the defrosting stage first, and then continues the self-cleaning of the filter screen after the defrosting stage is completed.

In step 319, after the self-cleaning of the filter net is finished, the cleaning process of the whole air conditioner is completed.

In one example, the fan 140 may be continuously operated below a predetermined speed during the overlap of the frost formation stage and the filter screen self-cleaning. In the defrosting stage (T2), the rotation speed of the fan 140 is increased to accelerate defrosting and shorten defrosting time. After the defrosting phase is finished, the fan 140 may be operated or stopped below a preset rotation speed.

The control mode has the advantages that the self-cleaning of the filter screen can be carried out in the frosting stage with lower rotating speed of the fan and after the defrosting stage is finished, so that the self-cleaning effect of the filter screen is better.

In actual operation, the controller of the air conditioner can select one control mode according to various parameters, the control is flexible, and the advantages of various control modes are utilized.

Fig. 3B is a diagram illustrating a cleaning control process of an air conditioner according to another embodiment of the present invention. In these embodiments, the controller 110 determines that the third period starts later than the first period according to step 201 in FIG. 2, i.e., the filter self-cleaning function starts later than the heat exchanger self-cleaning function, and starts the filter self-cleaning function after the heat exchanger self-cleaning function has been operated for a time Tn, as shown in step 320 in FIG. 3B.

At step 321, corresponding to step 202 in fig. 2, the controller 110 determines the duration of the frosting phase, the defrosting phase, the filter screen self-cleaning, and compares the remaining duration of the frosting phase (T1-Tn) with the duration of the filter screen self-cleaning T3. The steps after step 321 are similar to those after step 311 in fig. 3A, and the controller 110 divides the control of the heat exchanger 120 and the filter screen cleaning mechanism 130 into the same four control modes.

When the result of step 321 is T3 < (T1-Tn), the controller 110 adopts the first control scheme. In a first control mode:

after the frosting phase is completed, the controller 110 controls the heat exchanger 120 to directly start the frosting phase at step 322.

In step 323, after the defrosting stage is finished, the cleaning process of the entire air conditioner is completed.

When the result of step 321 is T3 ≧ (T1-Tn), the controller 110 employs the second control mode or the third control mode. In a second control mode:

at step 324, after the filter screen self-cleaning is completed, the controller 110 controls the heat exchanger 120 to start a defrosting phase.

In step 325, after the defrosting stage is finished, the cleaning process of the entire air conditioner is completed.

In one example, after the frosting period (T1) is completed and before step 324 begins, the fan 140 may be turned off, so that dust is not easily blown out during the process of cleaning the filter screen, which is more beneficial to self-cleaning the filter screen. Under a third control mode:

at step 326, when the frosting stage is completed, the self-cleaning of the filter net is not completed, the controller 110 allows the filter net self-cleaning mechanism 130 to continue to work, and the controller 110 controls the heat exchanger 120 to perform the defrosting stage, in which the self-cleaning of the filter net is completed first.

At step 327, after the defrosting phase is completed, the cleaning process of the entire air conditioner is completed.

Under a fourth control mode:

in step 328, when the frosting stage is completed, the self-cleaning of the filter screen is not completed, the controller 110 first controls the filter screen cleaning mechanism 130 to stop working, the controller 110 controls the heat exchanger 120 to perform the defrosting stage first, and then continues the self-cleaning of the filter screen after the defrosting stage is completed.

In step 329, after the self-cleaning of the filter net is finished, the cleaning process of the whole air conditioner is completed.

In one example, the fan 140 may be continuously operated below a predetermined speed during the overlap of the frost formation stage and the filter screen self-cleaning. In the defrosting stage, the rotation speed of the fan 140 is increased to accelerate defrosting and shorten defrosting time. After the defrosting phase is finished, the fan 140 may be operated or stopped below a preset rotation speed.

As mentioned above, the filter self-cleaning function may be started earlier than the heat-exchange self-cleaning function, and the control process is similar to that of fig. 2 and will not be described herein.

Fig. 4A-4C are timing diagrams illustrating a washing control of an air conditioner according to some embodiments of the present invention. Corresponding to step 203 in fig. 2, the controller 110 determines the timing relationship between the frosting stage, the defrosting stage, and the filter screen self-cleaning. Twelve timing relationships are listed here. The first timing relationship 401, the second timing relationship 402, the third timing relationship 403, and the fourth timing relationship 404 correspond to the cleaning control process shown in fig. 3A, i.e., the hot-water self-cleaning function and the filter screen self-cleaning function are simultaneously activated. The fifth timing relationship 405, the sixth timing relationship 406, the seventh timing relationship 407, and the eighth timing relationship 408 correspond to the cleaning control process shown in fig. 3B, that is, the filter screen self-cleaning function is started after the hot-water auto-cleaning function operates for the duration Tn. The ninth timing relationship 409, the tenth timing relationship 410, the eleventh timing relationship 411 and the twelfth timing relationship 412 are the case when the self-cleaning function of the filter screen is started earlier than the heat-exchange self-cleaning function.

As shown in FIG. 4A, in the first timing relationship 401, the duration T1 of the frosting period is longer than the duration T3 of the self-cleaning of the filter screen, and the self-cleaning of the filter screen is completed before the frosting period is completed. Thus, after the frosting phase is finished, the controller 110 directly controls the heat exchanger 120 to start the frosting phase process. After the defrosting stage is operated for a time period T2, dust flows down to the drain pan along with condensed water after frost is melted, and therefore the cleaning process of the whole air conditioner is completed. In a first timing relationship, the controller 110 controls the heat exchanger 120 and the filter screen cleaning mechanism 130 in a first control manner. Considering the time after frost is melted until dust flows down to the drain pan along with condensed water, the self-cleaning time of the heat exchanger is more than T1+ T2. Since this time is typically short, e.g., 1-2 minutes in the case of hydrophilic heat exchangers, the heat exchanger self-cleaning time is approximately T1+ T2. In an alternative example, the duration of the defrost stage, T2, may include the time for dust to flow down the drain pan with the condensed water, when the heat exchanger self-cleaning time is approximately T1+ T2. In an alternative example, the duration of the defrost phase, T2, may also include the time to dry the heat exchanger 120. In the following description, unless otherwise specified, it will be exemplified that the period T2 of the defrosting stage includes a time when dust flows down to the drain pan along with the condensed water. Under the second timing relationship 402, the duration T1 of the frosting period is less than the duration T3 of the self-cleaning of the filter screen, and after the frosting period is over, the self-cleaning of the filter screen is not over. At this time, the controller 110 controls the heat exchanger 120 to stop operation, and the controller 110 controls the filter screen cleaning mechanism 130 to continue the filter screen self-cleaning. After the self-cleaning of the filter screen is finished, the controller 110 controls the heat exchanger 120 to start the defrosting stage process. After the defrosting stage is operated for a time period T2, the cleaning process of the whole air conditioner is completed. In the second timing relationship, the controller 110 controls the heat exchanger 120 and the filter screen cleaning mechanism 130 in the second control manner, and the cleaning time of the whole air conditioner is T3+ T2.

Under the third timing relationship 403, the duration T1 of the frosting period is less than the duration T3 of the self-cleaning of the filter screen, and after the frosting period is over, the self-cleaning of the filter screen is not over. At this time, the controller 110 controls the heat exchanger 120 to continue to operate, and controls the filter screen cleaning mechanism 130 to continue the filter screen self-cleaning. And (5) finishing self-cleaning of the filter screen in the defrosting stage process. After the defrosting stage is operated for a time period T2, the cleaning process of the whole air conditioner is completed. In the third timing relationship, the controller 110 controls the heat exchanger 120 and the filter screen cleaning mechanism 130 in the third control manner, and the cleaning time of the whole air conditioner is T1+ T2. Under this timing relationship, if the filter screen is self-cleaned during the defrosting stage, the rotation speed of the fan 140 is first reduced to make it suitable for self-cleaning of the filter screen.

Under the fourth timing relationship 404, the duration T1 of the frosting period is less than the duration T3 of the self-cleaning operation of the filter screen, and the self-cleaning operation of the filter screen is performed for a duration T31 before the frosting period is finished, wherein T31 is less than T3. At this time, the controller 110 controls the filter screen cleaning mechanism 130 to stop operating, and the controller 110 controls the heat exchanger 120 to start the defrosting stage. After the time length T2 elapses in the defrosting stage, the controller 110 controls the filter screen cleaning mechanism 130 to continue the self-cleaning of the filter screen, where the remaining time of the self-cleaning of the filter screen is T32, and T32 is T3-T31. After the self-cleaning operation of the filter screen is finished for a time period T32, the cleaning process of the whole air conditioner is finished. Under the third timing relationship, the controller 110 controls the heat exchanger 120 and the filter screen cleaning mechanism 130 in the fourth control mode, and the cleaning time of the whole air conditioner is T1+ T2+ T32.

As shown in fig. 4B, in the fifth timing relationship 405, the self-cleaning function of the filter screen is started after the frosting stage starts to run for a time duration Tn, at this time, the remaining time duration (T1-Tn) of the frosting stage is greater than the self-cleaning time duration T3 of the filter screen, and before the frosting stage is finished, the self-cleaning of the filter screen is finished. Thus, after the frosting phase is finished, the controller 110 directly controls the heat exchanger 120 to start the frosting phase process. After the defrosting stage is operated for a time period T2, the cleaning process of the whole air conditioner is completed. In the fifth timing relationship, the controller 110 controls the heat exchanger 120 and the filter screen cleaning mechanism 130 in the first control manner, and the cleaning time of the whole air conditioner is T1+ T2.

Under the sixth timing relationship 406, the self-cleaning function of the filter screen is started after the frosting stage starts to run for a time length Tn, at this time, the remaining time length (T1-Tn) of the frosting stage is less than the self-cleaning time length T3 of the filter screen, and after the frosting stage is finished, the self-cleaning of the filter screen is not finished yet. At this time, the controller 110 controls the heat exchanger 120 to stop operation, and the controller 110 controls the filter screen cleaning mechanism 130 to continue the filter screen self-cleaning. After the self-cleaning of the filter screen is finished, the controller 110 controls the heat exchanger 120 to start the defrosting stage process. After the defrosting stage is operated for a time period T2, the cleaning process of the whole air conditioner is completed. Under the sixth timing relationship, the controller 110 controls the heat exchanger 120 and the filter screen cleaning mechanism 130 in the second control mode, and the cleaning time of the whole air conditioner is Tn + T3+ T2.

Under a seventh timing relationship 407, the self-cleaning function of the filter screen is started after the frosting stage starts to run for a time length Tn, at this time, the remaining time length (T1-Tn) of the frosting stage is less than the self-cleaning time length T3 of the filter screen, and after the frosting stage is finished, the self-cleaning of the filter screen is not finished yet. At this time, the controller 110 controls the heat exchanger 120 to continue to operate, and controls the filter screen cleaning mechanism 130 to continue the filter screen self-cleaning. And in the defrosting stage process, self-cleaning of the filter screen is finished. After the defrosting stage is operated for a time period T2, the cleaning process of the whole air conditioner is completed. Under the seventh timing relationship, the controller 110 controls the heat exchanger 120 and the filter screen cleaning mechanism 130 in the third control mode, and the cleaning time of the whole air conditioner is Tn + T3+ T2.

Under the eighth timing relationship 408, the self-cleaning function of the filter screen is started after the frosting stage starts to operate for a time length Tn, at this time, the remaining time length (T1-Tn) of the frosting stage is less than the self-cleaning time length T3 of the filter screen, before the frosting stage is finished, the self-cleaning operation of the filter screen is performed for a time length T31, and T31 is less than T3. At this time, the controller 110 controls the filter screen cleaning mechanism 130 to stop operating, and the controller 110 controls the heat exchanger 120 to start the defrosting stage. After the time length T2 elapses in the defrosting stage, the controller 110 controls the filter screen cleaning mechanism 130 to continue the self-cleaning of the filter screen, where the remaining time of the self-cleaning of the filter screen is T32, and T32 is T3-T31. After the self-cleaning operation of the filter screen is finished for a time period T32, the cleaning process of the whole air conditioner is finished. In the eighth timing relationship, the controller 110 controls the heat exchanger 120 and the filter screen cleaning mechanism 130 in the fourth control manner, and the cleaning time of the whole air conditioner is T1+ T2+ T32.

As shown in fig. 4C, in a ninth timing relationship 409, the filter screen self-cleaning function starts only after a time period Tm elapses, the sum of the time periods T1 and Tm of the frosting period is greater than a time period T3 of the filter screen self-cleaning, and the filter screen self-cleaning is finished before the frosting period is finished. Thus, after the frosting phase is finished, the controller 110 directly controls the heat exchanger 120 to start the frosting phase process. After the defrosting stage is operated for a time period T2, the cleaning process of the whole air conditioner is completed. In the ninth timing relationship, the controller 110 controls the heat exchanger 120 and the filter screen cleaning mechanism 130 in the first control manner, and the cleaning time of the whole air conditioner is Tm + T1+ T2.

Under the tenth timing relationship 410, the self-cleaning function of the filter screen is started only after the running time length Tm, the sum of the time length T1 and Tm of the frosting stage is less than the self-cleaning time length T3 of the filter screen, and after the frosting stage is finished, the self-cleaning filter screen is not finished yet. At this time, the controller 110 controls the heat exchanger 120 to stop operation, and the controller 110 controls the filter screen cleaning mechanism 130 to continue the filter screen self-cleaning. After the self-cleaning of the filter screen is finished, the controller 110 controls the heat exchanger 120 to start the defrosting stage process. After the defrosting stage is operated for a time period T2, the cleaning process of the whole air conditioner is completed. In the tenth timing relationship, the controller 110 controls the heat exchanger 120 and the filter screen cleaning mechanism 130 in the second control manner, and the cleaning time of the whole air conditioner is Tm + T3+ T2.

Under the eleventh time sequence relation 403, the self-cleaning function of the filter screen is started only after the running time length Tm, the sum of the time length T1 and Tm of the frosting stage is less than the self-cleaning time length T3 of the filter screen, and after the frosting stage is finished, the self-cleaning filter screen is not finished yet. At this time, the controller 110 controls the heat exchanger 120 to continue to operate, and controls the filter screen cleaning mechanism 130 to continue the filter screen self-cleaning. And (5) finishing self-cleaning of the filter screen in the defrosting stage process. After the defrosting stage is operated for a time period T2, the cleaning process of the whole air conditioner is completed. Under the eleventh timing relationship, the controller 110 controls the heat exchanger 120 and the filter screen self-cleaning mechanism 130 in the third control mode, and the cleaning time of the whole air conditioner is Tm + T1+ T2. Under this timing relationship, if the filter screen is self-cleaned during the defrosting stage, the rotation speed of the fan 140 is first reduced to make it suitable for self-cleaning of the filter screen.

Under the twelfth timing relationship 404, the self-cleaning function of the filter screen is started only after the time length Tm starts, the sum of the time length T1 and Tm of the frosting stage is less than the self-cleaning time length T3 of the filter screen, before the frosting stage is finished, the self-cleaning filter screen is operated for a time length T31, and T31 is less than T3. At this time, the controller 110 controls the filter screen cleaning mechanism 130 to stop operating, and the controller 110 controls the heat exchanger 120 to start the defrosting stage. After the time length T2 elapses in the defrosting stage, the controller 110 controls the filter screen cleaning mechanism 130 to continue the self-cleaning of the filter screen, where the remaining time of the self-cleaning of the filter screen is T32, and T32 is T3-T31. After the self-cleaning operation of the filter screen is finished for a time period T32, the cleaning process of the whole air conditioner is finished. In the twelfth timing relationship, the controller 110 controls the heat exchanger 120 and the filter screen cleaning mechanism 130 in the fourth control manner, and the cleaning time of the whole air conditioner is T31+ T2+ T32.

In the first to fourth timing relationships, the control of the fan speed is the same as that described above with reference to fig. 3A. In the fifth to eighth timing relationships, the control of the fan speed is the same as that described above with reference to fig. 3B. In the ninth to twelfth timing relationships, the control of the fan speed is the same as that described above with reference to fig. 3A.

From the twelve timing diagrams shown in fig. 4A-4C, it can be seen that the cleaning time of the entire air conditioner is shorter than the time duration T1+ T2+ T3 for the heat exchange cleaning and the filter screen self-cleaning respectively. Therefore, the present invention saves the cleaning time of the air conditioner. Fig. 5A and 5B are schematic diagrams illustrating self-cleaning of a filter screen of an air conditioner according to an embodiment of the present invention. In the present embodiment, the filter screen cleaning mechanism 130 of the air conditioner includes an electric brush 531, two rollers 521 for mounting the filter screen 150, and a dust box 530. As shown in fig. 5A, the dust box 530 and the electric brush 531 constitute a cleaning assembly together. The roller 521 serves as a mechanism for moving the filter screen 150. The controller 110 controls the roller 521 to roll, and moves the screen surface 520 of the screen 150 in the direction indicated by the screen moving direction a. The cleaning assembly is positioned below the filter screen 150, and the electric brush 531 is in contact with the rollers 521 below the filter screen 150, but does not hinder the rolling of the rollers 521 and the movement of the filter screen surface 520. The electric brush 531 may be composed of a brush portion and a brush driving portion. The structure of the brush portion can be as shown in fig. 5A. The brush driving part is used for driving the brush part to rotate, so as to clean dust on the filter screen surface 520. By the arrangement of the filter screen cleaning mechanism 130, automatic filtering and sweeping are realized, a user does not need to manually unpick and wash the filter screen, and convenience and worry are saved.

Before the filter screen self-cleaning function is turned on, as shown in fig. 5A, a certain amount of dust 540 is accumulated on the filter screen surface 520. After the self-cleaning function of the filter screen is turned on, the controller 110 controls the roller 521 to roll, so as to drive the filter screen surface 520 to move along the first direction a, such that the filter screen surface 520 moves from the surface I far away from the heat exchanger 120 to the surface II close to the heat exchanger 120, as shown in fig. 5B. During the rolling of the roller 521, the electric brush 531 of the sweeping assembly brushes off the dust 540 on the filter screen surface 520, and most of the dust 540 falls into the dust box 530. Thereafter, the filter screen 150 may be rotated by the rotation of the roller 521, so that the filter screen surface 520 is positioned at a side close to the heat exchanger 120. At this time, the controller 110 turns on the blower 600 to make the dust 540 on the surface of the filter net II flow together with the sucked air flow and be blown onto the heat exchanger 120, so that the dust 540 can flow out and be discharged together with the condensed water in the defrosting stage. In an alternative embodiment, the fan 600 may be located on the side of the filter screen 150 away from the heat exchanger 120, and when the fan 600 is turned on, the dust 540 on the surface of the filter screen II is blown onto the heat exchanger 120. After the filter screen self-cleaning step is finished, the controller 110 controls the roller 521 to rotate again, so that the filter screen surface 520 returns to a position close to the windward side of the fan 600 along the second direction B.

In another embodiment, the filter screen cleaning mechanism 130 of the air conditioner includes the roller 521 instead of the electric brush and the dust box in the filter screen cleaning mechanism 130. After the self-cleaning function of the filter screen is turned on, the controller 110 controls the roller 521 to roll, so as to move the filter screen surface 520 to a side close to the heat exchanger 120 (refer to fig. 5B), and the controller 110 turns on the blower 600 to blow the dust 540 on the filter screen surface onto the heat exchanger 120, so that the dust 540 can flow out and be discharged together with the condensed water in the defrosting stage.

Fig. 6 is a schematic diagram illustrating a self-cleaning of a filter net of an air conditioner according to another embodiment of the present invention. In the present embodiment, the filter screen cleaning mechanism 130 includes a roller 521, a movable dust box 530, and a power brush 531. After the self-cleaning function of the filter screen is started, the controller 110 controls the roller 521 to roll, so as to drive the filter screen surface 520 to move to a side close to the heat exchanger 120, and then the cleaning assembly composed of the movable dust collection box 530 and the electric brush 531 moves along the filter screen surface 520, while the electric brush 531 rotates clockwise and brushes the dust 540 on the filter screen surface 520 into the dust collection box 530.

Fig. 7 is a schematic diagram illustrating a self-cleaning of a filter net of an air conditioner according to still another embodiment of the present invention. In the present embodiment, the filter screen cleaning mechanism 130 includes a roller 521, a movable guide member 560, and a power brush 531. The guide member 560 is positioned at the same position as the dust box 530 except that it has an opening toward the side of the heat exchanger 120. After the self-cleaning function of the filter screen is started, the controller 110 controls the filter screen surface 520 to move to a side close to the heat exchanger 120 through the roller 521, and then the cleaning assembly moves along the filter screen surface 520 while the electric brush 531 rotates clockwise and brushes dust 540 on the filter screen surface 520 into the guide member 530, and the dust 540 falls on the surface of the heat exchanger 120 through the opening of the guide member. In this way, the dust 540 may flow out and be discharged together with the condensed water in the step of the defrosting stage.

In the various timing relationships in fig. 4A-4C, if the filter screen is self-cleaned by cleaning, the rotation speed of the fan needs to be the rotation speed suitable for self-cleaning of the filter screen during the self-cleaning process of the filter screen, so as to reduce the degree of blowing out the dust. For example, when the filter screen is self-cleaned in the frosting stage, the speed of the fan can be properly reduced when the filter screen is self-cleaned; or when the filter screen is self-cleaned in the defrosting stage, the speed of the fan can be properly reduced when the filter screen is self-cleaned (such as the third and seventh time sequence relations). Since the fan speed is originally low during the frosting phase, in some examples the fan speed does not have to be further reduced to accommodate the filter screen self-cleaning.

In addition, in the third, seventh and eleventh timing relationships, if the self-cleaning manner of the filter screen includes blowing dust onto the heat exchanger, the self-cleaning step of the filter screen needs to be completed at an early stage of melting of frost of the heat exchanger, so as to facilitate taking away the dust during defrosting. In such an example, the time during which the period T3 of the filter screen self-cleaning overlaps the period T2 of the defrosting stage is configured to be less than a predetermined value. Specifically, for ventilation-mode frosting, if the room temperature is below 20 degrees, the time for T3 to overlap T2 is less than or equal to 1/3 of T2, and if the room temperature exceeds 20 degrees, the time for T3 to overlap T2 is less than or equal to 1/4 of T2. Therefore, in the third, seventh and eleventh timing relationships, the room temperature can be determined first, and then the ratio of the time T3 and the time T2 overlapping with each other to T2 can be determined accordingly. For heating mode defrosting, the proportion of the time T3 and T2 overlapping T2 can be determined by detecting the heat exchanger surface temperature, if the heat exchanger surface temperature is less than or equal to-1 ℃, the self-cleaning of the filter screen can be continued, and if the heat exchanger surface temperature is greater than-1 ℃, the self-cleaning of the filter screen is stopped. It is to be understood that the above-mentioned critical temperatures are examples in specific cases. In particular embodiments, those skilled in the art may redetermine the determination from case to case.

Further details of the filter cleaning mechanism can be found in the application No. 201310444679.9 filed on 25.5.2016 and the application No. 200780045150.2, which will not be described in detail herein.

This application uses specific words to describe embodiments of the application. Reference throughout this specification to "one embodiment," "an embodiment," and/or "some embodiments" means that a particular feature, structure, or characteristic described in connection with at least one embodiment of the present application is included in at least one embodiment of the present application. Therefore, it is emphasized and should be appreciated that two or more references to "an embodiment" or "one embodiment" or "an alternative embodiment" in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, some features, structures, or characteristics of one or more embodiments of the present application may be combined as appropriate.

Although the present invention has been described with reference to the present specific embodiments, it will be appreciated by those skilled in the art that the above embodiments are merely illustrative of the present invention, and various equivalent changes and substitutions may be made without departing from the spirit of the invention, and therefore, it is intended that all changes and modifications to the above embodiments within the spirit and scope of the present invention be covered by the appended claims.

Claims

1. An air conditioner comprising a heat exchanger, a filter screen cleaning mechanism, and a controller, wherein the controller is configured to perform heat exchanger self-cleaning and filter screen self-cleaning simultaneously, the heat exchanger self-cleaning comprising a frosting phase and a defrosting phase, wherein the frosting phase is performed during a first period, the defrosting phase is performed during a second period after the first period, characterized in that the filter screen self-cleaning is performed during a third period, at least a portion of the third period overlapping the first period.

2. The air conditioner according to claim 1, wherein the controller is configured to compare time lengths of the first period and the third period, thereby determining a timing relationship of the first period and the third period.

3. The air conditioner according to claim 1, wherein the controller is configured to compare start times and time lengths of the first period and the third period, thereby determining a timing relationship of the first period and the third period.

4. The air conditioner according to claim 1, wherein an end time of the third period is equal to or earlier than an end time of the first period.

5. The air conditioner according to claim 1, wherein an end time of the third period is later than an end time of the first period, and wherein a start time of the second period is equal to or later than the end time of the third period.

6. The air conditioner according to claim 1, wherein an end time of the third period is later than an end time of the first period, wherein a start time of the second period is earlier than the end time of the third period, and the end time of the second period is later than the end time of the third period.

7. The air conditioner as claimed in claim 6, wherein when the ventilation mode defrosting is used, a ratio of an overlapping time of the third period and the second period to the second period is less than or equal to 1/3.

8. The air conditioner as claimed in claim 6, wherein the third period is ended when the heat exchanger surface temperature is greater than a preset value when the heating mode defrosting is used.

9. The air conditioner according to claim 1, wherein the third period includes a first sub-period and a second sub-period which are discontinuous, an end time of the first sub-period is equal to or earlier than an end time of the first period, and a start time of the second sub-period is equal to or later than an end time of the second period.

10. The air conditioner according to any one of claims 4 to 9, wherein the filter screen cleaning mechanism includes a power brush for sweeping the filter screen, and the controller is configured to control the fan rotation speed in the third period not to be higher than a preset rotation speed.

11. The air conditioner according to any one of claims 4 to 8, wherein the filter screen cleaning mechanism includes a motor brush for sweeping the filter screen and a roller for fitting the filter screen, wherein the controller is configured to control the motor brush to sweep the filter screen during the third period, then rotate the roller to rotate the filter screen to a side facing the heat exchanger, and turn on a fan of the air conditioner to blow dust on the filter screen onto the heat exchanger.

12. The air conditioner according to claim 9, wherein the filter screen cleaning mechanism includes a motor brush for sweeping the filter screen and a roller for fitting the filter screen, wherein the controller is configured to control the motor brush to clean the filter screen, then rotate the roller to rotate the filter screen to a side facing the heat exchanger, and turn on a fan of the air conditioner to blow dust on the filter screen onto the heat exchanger during the first sub-period.

13. The air conditioner according to any one of claims 4 to 8, wherein the filter screen cleaning mechanism includes a roller for fitting the filter screen, wherein the controller is configured to rotate the roller to rotate the filter screen to a side facing the heat exchanger and turn on a fan of the air conditioner to blow dust on the filter screen onto the heat exchanger during the third period.

14. The air conditioner according to claim 9, wherein the filter screen cleaning mechanism includes a roller for fitting the filter screen, wherein the controller is configured to rotate the roller to rotate the filter screen to a side facing the heat exchanger during the first sub-period, and turn on a fan of the air conditioner to blow dust on the filter screen onto the heat exchanger.

15. The air conditioner according to any one of claims 4 to 8, wherein the filter screen cleaning mechanism includes an electric brush and a guide member, wherein the controller is configured to control the electric brush to clean the filter screen during the third period, wherein the cleaned dust is guided to the heat exchanger through the guide member.

16. The air conditioner of claim 9, wherein the filter screen cleaning mechanism includes a motor brush and a guide member, wherein the controller is configured to control the motor brush to clean the filter screen during the first sub-period, wherein cleaned dust is directed to the heat exchanger through the guide member.

17. A cleaning control method of an air conditioner, the air conditioner comprises a heat exchanger, a filter screen and a filter screen cleaning mechanism, and the method is characterized by comprising the following steps:

performing heat exchanger cleaning, the heat exchanger cleaning comprising a frosting stage and a defrosting stage, wherein the frosting stage is performed during a first period and the defrosting stage is performed during a second period after the first period; and

performing a filter screen self-cleaning, the filter screen self-cleaning being performed during a third period, at least a portion of the third period overlapping the first period.

18. The method of claim 17, further comprising comparing the time lengths of the first period and the third period to determine a timing relationship of the first period and the third period.

19. The method of claim 17, further comprising comparing the start times and time lengths of the first and third periods to determine the timing relationship of the first and third periods.

20. The method of claim 17, wherein an end time of the third period is equal to or earlier than an end time of the first period.

21. The method of claim 17, wherein an end time of the third period is later than an end time of the first period, wherein a start time of the second period is equal to or later than the end time of the third period.

22. The method of claim 17, wherein an end time of the third period is later than an end time of the first period, wherein a start time of the second period is earlier than the end time of the third period, and wherein the end time of the second period is later than the end time of the third period.

23. The method of claim 22, wherein when using ventilation mode defrosting, a ratio of an overlap time of the third period and the second period to the second period is less than or equal to 1/3.

24. The method of claim 22, wherein the third period ends when the heat exchanger surface temperature is greater than a preset value when heating mode defrosting is used.

25. The method of claim 17, wherein the third period includes a first sub-period and a second sub-period which are discontinuous, an end time of the first sub-period is equal to or earlier than an end time of the first period, and a start time of the second sub-period is equal to or later than an end time of the second period.

26. A method according to any of claims 20-25, wherein the start of the third period is equal to or later than the start of the first period.

27. The method of claim 17, wherein the filter screen cleaning mechanism comprises a powered brush for sweeping the filter screen, and wherein the method comprises controlling the fan speed during the second period to be no higher than a preset speed.

28. A method according to any one of claims 20 to 24, wherein the filter cleaning mechanism comprises a powered brush for sweeping the filter and a roller for fitting the filter, the method comprising, during the third period:

controlling the electric brush to clean the filter screen;

rotating the roller to rotate the filter screen to a side facing the heat exchanger;

and starting a fan of the air conditioner to blow dust on the filter screen to the heat exchanger.

29. The method of claim 25, wherein the filter screen cleaning mechanism includes a powered brush for sweeping the filter screen and a roller for mounting the filter screen, the method including during the first sub-period:

controlling the electric brush to clean the filter screen;

30. A method according to any one of claims 20 to 24, wherein the filter cleaning mechanism comprises a roller for fitting the filter, the method comprising during the third period:

rotating the roller to rotate a filter screen to a side facing the heat exchanger; and

31. The method of claim 25, wherein the filter screen cleaning mechanism includes a roller for assembling the filter screen, the method including during the first sub-period:

32. The method of any of claims 20-24, wherein the screen cleaning mechanism comprises a powered brush and a guide member, the method comprising during the third period:

controlling the electric brush to clean the filter screen; and

the cleaned dust is guided to the heat exchanger by the guide member.

33. The method of claim 25, wherein the screen cleaning mechanism includes a powered brush and a guide member, the method including during the first sub-period:

controlling the electric brush to clean the filter screen; and

the cleaned dust is guided to the heat exchanger by the guide member.