Control method for air conditioner, computer readable storage medium and air conditioner

Abstract

The invention relates to a control method for an air conditioner, a computer readable storage medium and the air conditioner. The air conditioner comprises a compressor, an indoor heat exchanger and a throttling component correspondingly connected with the indoor heat exchanger, a liquid distributor is arranged between the throttling component and the indoor heat exchanger, the liquid distributor is provided with a liquid inlet and a plurality of liquid outlets, the liquid inlet and the liquid outlets are connected with the throttling component, and each liquid outlet is connected with a corresponding coil pipe of the indoor heat exchanger. The control method comprises the steps that when the air conditioner is in a refrigeration mode, a first temperature difference value between the multiple liquid outlets in the liquid separator is obtained; comparing the first temperature difference value with a first preset temperature difference value; and selectively controlling the compressor to execute an oil return mode based on the comparison result. Whether the liquid outlet of the liquid separator is blocked or refrigerant bias flow occurs or not can be accurately known, the compressor is controlled in time to execute the oil return mode, lubricating oil in the liquid separator is discharged in time, and the heat exchange efficiency of the indoor heat exchanger is guaranteed.

Description

Technical Field

[0001] The present invention relates to the technical field of air conditioners, and particularly to a control method for an air conditioner, a computer-readable storage medium, and an air conditioner. Background Art

[0002] An air conditioner refers to a refrigeration cycle system composed of one or several outdoor units connected to several indoor units of different or the same types and capacities, which can provide processed air to one or several areas. The air conditioner has many advantages such as high energy efficiency, space saving, flexible design, and reliable operation, and is widely used in places such as shopping malls, hospitals, schools, and residences.

[0003] An air conditioner generally includes a compressor, an outdoor heat exchanger, a plurality of parallel indoor heat exchangers, and a throttling component corresponding to each indoor heat exchanger. A liquid distributor is usually provided between each throttling component and the corresponding indoor heat exchanger. The liquid distributor has an inlet connected to the throttling component and outlets corresponding to and connected to a plurality of coils of the indoor heat exchanger. When some indoor units in the air conditioner (for example, only 1 indoor unit) are turned on, the compressor usually operates at a low frequency, the flow rate of the refrigerant medium in the refrigeration cycle system is slow, and the lubricating oil doped in the refrigerant medium is likely to block some of the outlets, resulting in uneven distribution of the refrigerant amount in each coil of the indoor heat exchanger, which greatly affects the heat exchange efficiency of the indoor heat exchanger.

[0004] Therefore, a new technical solution is needed in this field to solve the above problems. Summary of the Invention

[0005] In order to solve or to some extent improve the technical problem that the liquid distributor of the air conditioner in the prior art is prone to uneven flow, the present invention provides a control method for an air conditioner. The air conditioner includes a compressor, an indoor heat exchanger, and a throttling component corresponding to the indoor heat exchanger. A liquid distributor is provided between the throttling component and the corresponding indoor heat exchanger. The liquid distributor has an inlet connected to the throttling component and a plurality of outlets, and each outlet is connected to a corresponding coil of the indoor heat exchanger. And the control method includes: when the air conditioner is in the cooling mode, obtaining a first temperature difference between a plurality of the outlets in the liquid distributor; comparing the first temperature difference with a first preset temperature difference; and selectively controlling the compressor to execute an oil return mode based on the comparison result.

[0006] Those skilled in the art will appreciate that when the air conditioner is in cooling mode, the control method for an air conditioner according to the present invention first obtains a first temperature difference between the multiple liquid outlets in the liquid distributor, then compares the actual first temperature difference with a first preset temperature difference, and then selectively controls the compressor to execute an oil return mode based on the comparison result. Therefore, by detecting the first temperature difference between the liquid outlets of the distributor, it is possible to accurately determine whether the liquid outlets are clogged or the refrigerant is flowing in an unbalanced manner. Furthermore, by appropriately controlling the compressor to execute the oil return mode, the lubricating oil retained in the liquid distributor can be promptly discharged, allowing the refrigerant to flow evenly through each liquid outlet of the liquid distributor, thereby ensuring the heat exchange efficiency of the indoor heat exchanger.

[0007] In the preferred technical solution of the control method for air conditioning described above, the step of selectively controlling the compressor to execute the oil return mode based on the comparison result includes: when the first temperature difference is greater than or equal to the first preset temperature difference, controlling the compressor to execute the oil return mode; when the first temperature difference is less than the first preset temperature difference, not controlling the compressor to execute the oil return mode. When the first temperature difference between the multiple liquid outlets in the liquid distributor is greater than or equal to the first preset temperature difference, it indicates that the multiple liquid outlets have a refrigerant bias flow or even some of the liquid outlets are blocked, so the compressor is controlled to execute the oil return mode, thereby discharging the lubricating oil in the liquid distributor in time. Correspondingly, when the first temperature difference between the multiple liquid outlets in the liquid distributor is less than the first preset temperature difference, it indicates that the possibility of refrigerant bias flow between the multiple liquid outlets is low, so the compressor is not controlled to execute the oil return mode.

[0008] In the preferred technical solution of the above-mentioned control method for an air conditioner, when the first temperature difference is less than the first preset temperature difference, the control method includes: obtaining the outlet temperature of the refrigerant after it flows through the indoor heat exchanger, and obtaining a second temperature difference between each of the liquid outlets and the outlet temperature; comparing the second temperature difference with a second preset temperature difference; when the second temperature difference is greater than or equal to the second preset temperature difference, controlling the compressor to execute the oil return mode; and when the second temperature difference is less than the second preset temperature difference, not controlling the compressor to execute the oil return mode. By introducing the second temperature difference between the liquid outlet and the outlet temperature, it is possible to more accurately determine whether the refrigerant has experienced a flow deviation, thereby more accurately controlling the timing of the compressor executing the oil return mode.

[0009] In the above preferred technical solution of the control method for an air conditioner, the steps for the compressor to execute the oil return mode include: obtaining the operating frequency of the compressor; comparing the operating frequency with a preset oil return frequency; when the operating frequency is less than the preset oil return frequency, controlling the compressor to operate at the preset oil return frequency; when the operating frequency is greater than or equal to the preset oil return frequency, controlling the compressor to operate at the current operating frequency. Through the above settings, the compressor can perform efficient oil return at a relatively high operating frequency.

[0010] In the above preferred technical solution of the control method for an air conditioner, when the compressor executes the oil return mode, the control method further includes: adjusting the opening degree of the throttling component to a preset maximum opening degree. Adjusting the opening degree of the throttling component to the preset maximum opening degree can increase the refrigerant flow rate and ensure the oil return efficiency.

[0011] In the above preferred technical solution of the control method for an air conditioner, the air conditioner further includes a four-way valve; and after the compressor executes the oil return mode, the control method further includes: after a preset time period, re-obtaining the first temperature difference; comparing the re-obtained first temperature difference with the first preset temperature difference; when the re-obtained first temperature difference is greater than or equal to the first preset temperature difference, controlling the four-way valve to change direction so that the air conditioner executes the heating mode; when the re-obtained first temperature difference is less than the first preset temperature difference, not controlling the four-way valve to change direction to keep the air conditioner executing the cooling mode. After a preset time period, if the re-obtained first temperature difference is greater than or equal to the first preset temperature difference, by controlling the four-way valve to change direction, the air conditioner can be switched to the heating mode, which can significantly increase the pressure of the refrigerant in the liquid distributor, thereby quickly and efficiently discharging the lubricating oil in the liquid distributor. Correspondingly, after a preset time period, if the re-obtained first temperature difference is less than the first preset temperature difference, it indicates that the possibility of refrigerant flow deviation is relatively low at this time, so the four-way valve is not controlled to change direction.

[0012] In the preferred technical solution of the above control method for an air conditioner, when the newly obtained first temperature difference is less than the first preset temperature difference, the control method includes: obtaining the outlet temperature of the refrigerant flowing through the indoor heat exchanger, and obtaining the second temperature difference between each liquid outlet and the outlet temperature; comparing the second temperature difference with a second preset temperature difference; when the second temperature difference is greater than or equal to the second preset temperature difference, controlling the four-way valve to change direction so that the air conditioner executes the heating mode; when the second temperature difference is less than the second preset temperature difference, not controlling the four-way valve to change direction to keep the air conditioner executing the cooling mode. By introducing the second temperature difference between the liquid outlet and the outlet temperature, it is possible to more accurately determine whether the refrigerant has a flow deviation, thereby more accurately controlling the timing of the four-way valve to change direction.

[0013] In the preferred technical solution of the above control method for an air conditioner, the air conditioner includes an indoor fan opposite to the indoor heat exchanger; and when the four-way valve is controlled to change direction so that the air conditioner executes the heating mode, the control method further includes: controlling the indoor fan to stop. By controlling the indoor fan to stop, the pressure of the refrigerant in the indoor heat exchanger can be increased, thereby further improving the oil return efficiency in the liquid distributor.

[0014] In the preferred technical solution of the above control method for an air conditioner, when the air conditioner is in the heating mode, the control method includes: obtaining the running duration and running frequency of the compressor; comparing the running duration and the running frequency with a preset running duration and a preset running frequency respectively; when the running duration is greater than the preset running duration and the running frequency is less than or equal to the preset running frequency, controlling the compressor to run at a preset oil return frequency, where the preset oil return frequency is greater than the preset running frequency. When the air conditioner is in the heating mode, if the running duration of the compressor is greater than the preset running duration and the running frequency is less than or equal to the preset running frequency, the lubricating oil in the liquid distributor is discharged in time by controlling the compressor to run at the preset oil return frequency.

[0015] In the preferred technical solution of the above control method for an air conditioner, the liquid outlet includes an upper liquid outlet and a lower liquid outlet spaced apart from each other in the vertical direction; and the temperature difference is equal to the temperature of the lower liquid outlet minus the temperature of the upper liquid outlet. The setting of the upper liquid outlet and the lower liquid outlet can prevent a large difference in temperature between the liquid outlets due to too many liquid outlets.

[0016] In the preferred technical solution of the above control method for an air conditioner, the liquid distributor includes: an inner cylinder, one end of the inner cylinder forms the liquid inlet, and a plurality of liquid through holes spaced from each other are formed on the circumferential wall of the inner cylinder; and an outer cylinder, the outer cylinder is sleeved on the inner cylinder and forms a sealed connection with the inner cylinder, and the upper liquid outlet and the lower liquid outlet are formed on the circumferential wall of the outer cylinder. Through the above arrangement, the liquid distributor can have a reliable structure. In addition, by adjusting the number, size and arrangement position of the liquid through holes in the inner cylinder, the flow rate of the refrigerant flowing out of the liquid outlet can be flexibly adjusted to match indoor heat exchangers of different specifications.

[0017] To solve or to some extent improve the technical problem that the liquid distributor of an air conditioner in the prior art is prone to uneven flow, the present invention provides a computer-readable storage medium. A computer program is stored in the computer-readable storage medium, and the computer program can be executed by a processor to implement the control method for an air conditioner according to any one of the above.

[0018] To solve or to some extent improve the technical problem that the liquid distributor of an air conditioner in the prior art is prone to uneven flow, the present invention provides an air conditioner. The control method for an air conditioner according to any one of the above is executed in the air conditioner, and the air conditioner includes a compressor, an indoor heat exchanger and a throttling component correspondingly connected to the indoor heat exchanger. A liquid distributor is provided between the throttling component and the indoor heat exchanger. The liquid distributor has a liquid inlet connected to the throttling component and a plurality of liquid outlets, and each liquid outlet is connected to a corresponding coil of the indoor heat exchanger. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The preferred embodiments of the present invention will be described below with reference to the drawings, in which:

[0020] Figure 1 is a system configuration diagram of an embodiment of the air conditioner of the present invention;

[0021] Figure 2 is a structural schematic diagram of an embodiment of the distributor in the air conditioner of the present invention;

[0022] Figure 3 is a flowchart of the control method for an air conditioner of the present invention;

[0023] Figure 4 is a first partial flowchart of the first embodiment of the control method for an air conditioner of the present invention;

[0024] Figure 5 is a flowchart of the process of executing the oil return mode in the first embodiment of the control method for an air conditioner of the present invention;

[0025] Figure 6It is a schematic diagram of the second part of the process in the first embodiment of the control method for an air conditioner according to the present invention;

[0026] Figure 7 It is a schematic diagram of the process of the second embodiment of the control method for an air conditioner according to the present invention.

[0027] List of reference numerals:

[0028] 100. Air conditioner; 110. Outdoor unit; 111. Compressor; 112. Outdoor heat exchanger; 113. Outdoor fan; 114. Four-way valve; 120. Indoor unit; 121. Indoor heat exchanger; 1211. Coil; 122. Indoor fan; 123. Throttling component; 124. Liquid distributor; 1241. Inner cylinder; 12411. Liquid inlet; 12412. Liquid passage hole; 1242. Outer cylinder; 12421. Liquid outlet; 124211. Upper liquid outlet; 124212. Lower liquid outlet; 125. Temperature detector. Detailed implementation manners

[0029] The preferred implementation manners of the present invention will be described below with reference to the accompanying drawings. Those skilled in the art should understand that these implementation manners are only used to explain the technical principle of the present invention and are not intended to limit the protection scope of the present invention. It should be noted that in the description of the present invention, the terms "first" and "second" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0030] To solve or to some extent improve the technical problem that the liquid distributor of an air conditioner in the prior art is prone to uneven flow, the present invention provides a control method for an air conditioner 100. The air conditioner 100 includes a compressor 111, an indoor heat exchanger 121, and a throttling component 123 correspondingly connected to the indoor heat exchanger 121. A liquid distributor 124 is provided between the throttling component 123 and the corresponding indoor heat exchanger 121. The liquid distributor 124 has a liquid inlet 12411 connected to the throttling component 123 and a plurality of liquid outlets 12421. Each liquid outlet 12421 is connected to a corresponding coil 1211 of the indoor heat exchanger 121. And the control method includes: when the air conditioner 100 is in the cooling mode, obtaining a first temperature difference between a plurality of liquid outlets 12421 in the liquid distributor 124 (step S1); comparing the first temperature difference with a first preset temperature difference (step S2); selectively controlling the compressor 111 to execute an oil return mode based on the comparison result (step S3).

[0031] Figure 1 It is a system configuration diagram of an embodiment of the air conditioner according to the present invention. As Figure 1As shown, in one or more embodiments, the air conditioner 100 of the present invention includes an outdoor unit 110 (which is generally arranged in an outdoor environment) and three parallel indoor units 120 (which are generally arranged indoors or in a room). Alternatively, the number of indoor units 120 can also be set to other suitable numbers more or less than three, such as 1 unit, 2 units, 4 units, etc. According to actual needs, the configurations of multiple indoor units 120 can be the same or different.

[0032] As Figure 1 shown, in one or more embodiments, the outdoor unit 110 includes components such as a compressor 111, a four-way valve 114, an outdoor heat exchanger 112, and an outdoor fan 113. The compressor 111 can be, but is not limited to, a variable-frequency compressor 111. The number of compressors 111 can be one or more. The four-way valve 114 has a first port connected to the exhaust port of the compressor 111, a second port connected to the outdoor heat exchanger 112, a third port connected to the indoor heat exchanger 121 of the indoor unit 120, and a fourth port connected to the suction port of the compressor 111. The setting of the four-way valve 114 enables the air conditioner 100 to conveniently switch between a heating mode and a cooling mode. The outdoor heat exchanger 112 can be, but is not limited to, a finned coil 1211 type heat exchanger. The outdoor fan 113 is opposite to the outdoor heat exchanger 112 to improve the heat exchange efficiency between the external air and the outdoor heat exchanger 112.

[0033] As Figure 1 shown, in one or more embodiments, each indoor unit 120 includes components such as an indoor heat exchanger 121, an indoor fan 122, a throttling component 123, and a liquid distributor 124. Among them, the indoor heat exchanger 121 includes a plurality of coils 1211 spaced apart from each other. The indoor fan 122 is opposite to the indoor heat exchanger 121 to improve the heat exchange efficiency between the indoor air and the indoor heat exchanger 121. Each indoor heat exchanger 121 is respectively connected to a throttling component 123. The throttling component 123 can be, but is not limited to, an electronic expansion valve. A liquid distributor 124 is provided between each throttling component 123 and the corresponding indoor heat exchanger 121.

[0034] Figure 2 is a schematic structural diagram of an embodiment of the distributor in the air conditioner of the present invention. As Figure 2 shown, in one or more embodiments, the liquid distributor has a liquid inlet 12411 connected to the throttling component 123 and a plurality of liquid outlets 12421. Among them, each liquid outlet 12421 can be connected to a corresponding one of the coils 1211 in the indoor heat exchanger 121. In one or more embodiments, the liquid distributor includes an inner cylinder 1241 and an outer cylinder 1242 sleeved on the inner cylinder 1241. Based on Figure 2In the orientation shown, a liquid inlet 12411 is formed at the upper end of the inner cylinder 1241. Four liquid through holes 12412 spaced from each other are formed on the circumferential wall of the inner cylinder 1241. Among them, two liquid through holes 12412 are close to the liquid inlet 12411, while the other two liquid through holes 12412 are far from the liquid inlet 12411. The outer cylinder 1242 is hermetically connected to the inner cylinder 1241. An upper liquid outlet 124211 and a lower liquid outlet 124212 spaced from each other in the vertical direction are formed on the circumferential wall of the outer cylinder 1242. Among them, the upper liquid outlet 124211 is substantially opposite to the two liquid through holes 12412 located on the upper side, and the lower liquid outlet 124212 is substantially opposite to the two liquid through holes 12412 located on the lower side. It should be noted that the number, size, and arrangement position of the liquid through holes 12412 can be adjusted according to actual needs. Further, the number of the liquid outlets 12421 can also be set to 3, 4, or other appropriate numbers. In one or more embodiments, a temperature detector 125 is provided on each of the upper liquid outlet 124211 and the lower liquid outlet 124212 to detect the real-time temperature of the refrigerant medium. The temperature detector 125 can be, but is not limited to, a resistive temperature sensor.

[0035] Next, in combination with the attached Figures 3 - 7 The control method of the present invention for the air conditioner 100 will be introduced in detail. It should be noted that the control method of the present invention for the air conditioner 100 can be executed in the air conditioner 100 of any of the above embodiments, or can be applied to other suitable air conditioners 100.

[0036] Figure 3 is a schematic flow chart of the control method of the present invention for the air conditioner 100. As Figure 3 shown, in one or more embodiments, when the control method of the present invention for the air conditioner 100 starts, step S1 is first executed, that is, when the air conditioner 100 is in the cooling mode, the first temperature difference between multiple liquid outlets 12421 in the liquid distributor 124 is obtained. Then, step S2 is executed to compare the temperature difference with the first preset temperature difference. Then, based on the comparison result, the compressor 111 is selectively controlled to execute the oil return mode (step S3).

[0037] Figure 4 is a schematic flow chart of the first part of the first embodiment of the control method of the present invention for the air conditioner 100. As Figure 4As shown, in one or more embodiments, after the control method of the present invention for the air conditioner 100 starts, step S11 is first executed, that is, when the air conditioner 100 is in the cooling mode, the first temperature difference between multiple liquid outlets 12421 in the liquid distributor 124 is obtained. In one or more embodiments, the liquid outlets 12421 include an upper liquid outlet 124211 and a lower liquid outlet 124212 that are spaced apart from each other in the vertical direction, and the first temperature difference is equal to the temperature difference between the temperature T1 of the lower liquid outlet 124212 and the temperature T2 of the upper liquid outlet 124211. That is, the first temperature difference is the absolute value between T1 and T2. Alternatively, the liquid outlets 12421 include an upper liquid outlet 124211, a middle liquid outlet (not shown in the figure), and a lower liquid outlet 124212 that are spaced apart from each other in the vertical direction. The first temperature difference can be the temperature difference between any two liquid outlets 12421 (for example, the temperature difference between the upper liquid outlet 124211 and the lower liquid outlet 124212, the temperature difference between the middle liquid outlet and the upper liquid outlet 124211, the temperature difference between the middle liquid outlet and the lower liquid outlet 124212), or it can be the difference between the temperature of any one liquid outlet 12421 and the average temperature of the other two liquid outlets 12421 (for example, the difference between the temperature of the lower liquid outlet 124212 and the average temperature of the upper liquid outlet 124211 and the middle liquid outlet, etc.). Alternatively, the number of liquid outlets 12421 can also be set to 4, 5, or other suitable numbers. The temperature of each liquid outlet 12421 can be measured by a temperature detector 125 arranged at the corresponding liquid outlet 12421. Then, the control method executes step S12, that is, it is judged whether the first temperature difference is greater than or equal to the first preset temperature difference. In one or more embodiments, the first preset temperature difference is 5°C. Alternatively, the first preset temperature difference can also be set to other suitable temperatures higher or lower than 5°C, such as 4°C, 6°C, etc. When the judgment result is negative, it indicates that the refrigerant amounts of the liquid outlets 12421 in the liquid distributor 124 are not very different, and there is no need to intervene, so step S11 is repeatedly executed to continue obtaining the temperature difference between the multiple liquid outlets 12421 in the liquid distributor 124. When the judgment result is positive, it indicates that the refrigerant amounts between the liquid outlets 12421 in the liquid distributor 124 are quite different, and the refrigerant amount in a certain liquid outlet 12421 is less or even blocked. Therefore, the control method executes step S13, that is, controls the compressor 111 to execute the oil return mode.

[0038] In one or more embodiments, when the first temperature difference is less than the first preset temperature difference, the control method performs the following steps: obtaining the outlet temperature T3 of the refrigerant flowing through the indoor heat exchanger 121, and obtaining the second temperature difference between each of the liquid outlet 12421 and the outlet temperature T3; comparing the second temperature difference with the second preset temperature difference; when the second temperature difference is greater than or equal to the second preset temperature difference, controlling the compressor 111 to execute the oil return mode; when the second temperature difference is less than the second preset temperature difference, not controlling the compressor 111 to execute the oil return mode. Among them, the outlet temperature T3 can be measured by a suitable temperature detector provided on the air pipe downstream of the indoor heat exchanger 121. The second preset temperature difference can be 6°C, 7°C, 8°C or other suitable temperature values. By introducing the second temperature difference, it is possible to more accurately determine whether the refrigerant has a flow deviation, thereby more accurately controlling the timing of the compressor 111 to execute the oil return mode.

[0039] Figure 5 FIG. is a schematic flow chart of executing the oil return mode in the first embodiment of the control method for an air conditioner according to the present invention. As Figure 5 shown, in one or more embodiments, when controlling the compressor 111 to execute the oil return mode, the control method first executes step S21, that is, obtaining the operating frequency of the compressor 111. Then, it is determined whether the operating frequency is greater than or equal to the preset oil return frequency. In one or more embodiments, the preset oil return frequency is 75 Hz (i.e., Hertz). Alternatively, the preset oil return frequency can also be set to other suitable frequencies higher or lower than 75 Hz. When the determination result is no, the control method executes step S23, that is, controlling the compressor 111 to operate at the preset oil return frequency. Correspondingly, when the determination result is yes, the control method executes step S24, that is, controlling the compressor 111 to operate at the current operating frequency. Through the above settings, it can be ensured that the compressor 111 always returns oil at a relatively high operating frequency, thereby ensuring the oil return efficiency.

[0040] In one or more embodiments, when controlling the compressor 111 to execute the oil return mode, the control method of the present invention further performs the following steps: adjusting the opening degree of the corresponding throttling component 123 to the preset maximum opening degree. By adjusting the opening degree of the throttling component 123 to the preset maximum opening degree, the flow rate of the refrigerant can be increased, further ensuring the oil return efficiency. The preset maximum opening degree can be determined according to the specific model of the throttling component 123. For example, if the opening degree range of the throttling component 123 is 200 pls - 480 pls, then the preset maximum opening degree of the throttling component 123 is 480 pls.

[0041] Figure 6 FIG. is a schematic diagram of the second part of the flow in the first embodiment of the control method for the air conditioner 100 according to the present invention. As Figure 6As shown, in one or more embodiments, after the compressor 111 executes the oil return mode, the control method of the present invention proceeds to step S31, that is, after a preset time period, the first temperature difference is obtained again. In one or more embodiments, the preset time period is 5 min (i.e., minutes). Alternatively, the preset time period can also be set to other suitable times longer or shorter than 5 min. Then, the control method executes step S32, that is, the newly obtained first temperature difference is compared with the first preset temperature difference. Then, based on the comparison result, the four-way valve 114 is selectively controlled to change its direction so that the air conditioner 100 executes the heating mode.

[0042] In one or more embodiments, when the judgment result is yes, that is, when the newly obtained first temperature difference is still greater than or equal to the first preset temperature difference, the four-way valve 114 is controlled to change its direction so that the air conditioner 100 executes the heating mode (i.e., step S33). By controlling the four-way valve 114 to change its direction so that the air conditioner 100 switches to the heating mode, the pressure of the refrigerant in the liquid distributor 124 can be significantly increased, thereby quickly and efficiently discharging the lubricating oil in the liquid distributor 124. Then, after a preset time period (such as 5 min), the four-way valve 114 is controlled to change its direction so that the air conditioner 100 executes the cooling mode (step S34). When step S34 is completed, the control method ends. In one or more embodiments, the air conditioner 100 includes an indoor fan 122 opposite to the indoor heat exchanger 121; and when the four-way valve 114 changes its direction so that the air conditioner 100 executes the heating mode, the control method further executes the following steps: controlling the indoor fan 122 to stop running to further increase the pressure in the liquid distributor 124.

[0043] Continue to refer to Figure 6 , in one or more embodiments, after executing step S32, when the judgment result is no, it means that the newly obtained first temperature difference is already less than the first preset temperature difference, then the control method ends.

[0044] In one or more embodiments, when the newly obtained first temperature difference is less than the first preset temperature difference, the control method includes: obtaining the outlet temperature of the refrigerant after flowing through the indoor heat exchanger 121, and obtaining the second temperature difference between each liquid outlet 12421 and the outlet temperature; comparing the second temperature difference with the second preset temperature difference; when the second temperature difference is greater than or equal to the second preset temperature difference, controlling the four-way valve 114 to change its direction so that the air conditioner 100 executes the heating mode; when the second temperature difference is less than the second preset temperature difference, not controlling the four-way valve 114 to change its direction to keep the air conditioner 100 executing the cooling mode. By introducing the second temperature difference, it is possible to more accurately determine whether the refrigerant has a flow deviation, and thus more accurately control the timing of the four-way valve 114 to change its direction.

[0045] Figure 7It is a schematic flowchart of the second embodiment of the control method for an air conditioner according to the present invention. As Figure 7 shown, in one or more embodiments, when the air conditioner 100 is in the heating mode, the control method of the present invention first executes step S41, that is, obtains the running duration and running frequency of the compressor 111. Then, step S42 is executed, that is, it is judged whether the running duration is greater than the preset running duration. In one or more embodiments, the preset running duration is 10h (i.e., hours). Alternatively, the preset running duration can also be set to other suitable times longer or shorter than 10h. When the judgment result is yes, the control method proceeds to step S43, that is, it is judged whether the running frequency is less than or equal to the preset running frequency. In one or more embodiments, the preset running frequency is 50Hz. Alternatively, the preset running frequency can also be set to other suitable frequencies higher or lower than 50Hz. If the judgment result is yes, the compressor 111 is controlled to run at the preset oil return frequency, where the preset oil return frequency is greater than the preset running frequency. In one or more embodiments, the preset oil return frequency is 75Hz (i.e., Hertz). Alternatively, the preset oil return frequency can also be set to other suitable frequencies higher or lower than 75Hz.

[0046] Continue to refer to Figure 7 , when executing step S42 and step S43, if the judgment result is no, the control method will re-execute step S41, that is, re-obtain the running duration and running frequency of the compressor 111.

[0047] It should be noted that the parts not mentioned in the second embodiment can be configured the same as those in the first embodiment, and will not be elaborated here.

[0048] The present invention also provides a computer-readable storage medium (not shown in the figure). A computer program is stored on the computer-readable storage medium, and the computer program can be executed by a processor to implement the control method for the air conditioner 100 according to any one of the above embodiments.

[0049] So far, the technical solution of the present invention has been described in combination with the preferred embodiments shown in the drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the protection scope of the present invention.

Claims

1. A control method for an air conditioner, characterized in that, The air conditioner includes a compressor, an indoor heat exchanger, and a throttling component correspondingly connected to the indoor heat exchanger. A liquid distributor is provided between the throttling component and the indoor heat exchanger. The liquid distributor has a liquid inlet connected to the throttling component and a plurality of liquid outlets. Each liquid outlet is connected to a corresponding coil of the indoor heat exchanger, and the control method includes: When the air conditioner is in the cooling mode, obtain a first temperature difference between a plurality of the liquid outlets in the liquid distributor; Compare the first temperature difference with a first preset temperature difference; Based on the comparison result, selectively control the compressor to execute an oil return mode.

2. The control method for an air conditioner according to claim 1, wherein, The step of selectively controlling the compressor to execute the oil return mode based on the comparison result includes: When the first temperature difference is greater than or equal to the first preset temperature difference, control the compressor to execute the oil return mode; When the first temperature difference is less than the first preset temperature difference, do not control the compressor to execute the oil return mode.

3. The control method for an air conditioner according to claim 2, wherein, When the first temperature difference is less than the first preset temperature difference, the control method further includes: Obtain the outlet air temperature after the refrigerant flows through the indoor heat exchanger, and obtain a second temperature difference between each liquid outlet and the outlet air temperature; Compare the second temperature difference with a second preset temperature difference; When the second temperature difference is greater than or equal to the second preset temperature difference, control the compressor to execute the oil return mode; When the second temperature difference is less than the second preset temperature difference, do not control the compressor to execute the oil return mode.

4. The control method for an air conditioner according to any one of claims 1-3, wherein The step of the compressor executing the oil return mode includes: obtaining the operating frequency of the compressor; comparing the operating frequency with a preset oil return frequency; when the operating frequency is less than the preset oil return frequency, controlling the compressor to operate at the preset oil return frequency; when the operating frequency is greater than or equal to the preset oil return frequency, controlling the compressor to operate at the current operating frequency; and / or When the compressor executes the oil return mode, the control method further includes: adjusting the opening degree of the throttling component to a preset maximum opening degree.

5. The control method for an air conditioner according to any one of claims 1 to 3, characterized in that, The air conditioner further includes a four-way valve; and after the compressor executes the oil return mode, the control method further includes: After a preset time period, obtain the first temperature difference again; Compare the newly obtained first temperature difference with the first preset temperature difference; When the newly obtained first temperature difference is greater than or equal to the first preset temperature difference, control the four-way valve to change direction so that the air conditioner executes the heating mode; When the newly obtained first temperature difference is less than the first preset temperature difference, do not control the four-way valve to change direction to keep the air conditioner executing the cooling mode.

6. The control method for an air conditioner according to claim 5, wherein When the newly obtained first temperature difference is less than the first preset temperature difference, the control method includes: obtaining the outlet temperature of the refrigerant flowing through the indoor heat exchanger, and obtaining the second temperature difference between each of the liquid outlet and the outlet temperature; comparing the second temperature difference with a second preset temperature difference; when the second temperature difference is greater than or equal to the second preset temperature difference, controlling the four-way valve to change direction so that the air conditioner executes the heating mode; when the second temperature difference is less than the second preset temperature difference, not controlling the four-way valve to change direction to keep the air conditioner executing the cooling mode; and / or The air conditioner includes an indoor fan opposite to the indoor heat exchanger; and when the four-way valve is controlled to change direction so that the air conditioner executes the heating mode, the control method further includes: controlling the indoor fan to stop operating.

7. The control method for an air conditioner according to claim 1, wherein When the air conditioner is in the heating mode, the control method includes: obtaining the running duration and running frequency of the compressor; comparing the running duration and the running frequency with a preset running duration and a preset running frequency respectively; when the running duration is greater than the preset running duration and the running frequency is less than or equal to the preset running frequency, controlling the compressor to run at a preset oil return frequency, wherein the preset oil return frequency is greater than the preset running frequency.

8. The control method for an air conditioner according to claim 1, wherein the liquid outlets include an upper liquid outlet and a lower liquid outlet spaced apart from each other in the vertical direction, and the temperature difference is equal to the temperature of the lower liquid outlet minus the temperature of the upper liquid outlet; and / or the liquid distributor includes: an inner cylinder, one end of the inner cylinder forms the liquid inlet, and a plurality of liquid through holes spaced apart from each other are formed on the circumferential wall of the inner cylinder; and an outer cylinder, the outer cylinder is sleeved on the inner cylinder and forms a sealed connection with the inner cylinder, and the upper liquid outlet and the lower liquid outlet are formed on the circumferential wall of the outer cylinder.

9. A computer-readable storage medium, characterized in that, A computer program is stored on the computer-readable storage medium, and the computer program can be executed by a processor to implement the control method for an air conditioner according to any one of claims 1-8.

10. An air conditioner, characterized in that, The control method for an air conditioner according to any one of claims 1-8 is executed in the air conditioner, and the air conditioner includes a compressor, an indoor heat exchanger, and a throttling component correspondingly connected to the indoor heat exchanger. A liquid distributor is provided between the throttling component and the indoor heat exchanger. The liquid distributor has a liquid inlet connected to the throttling component and a plurality of liquid outlets, and each of the liquid outlets is connected to a corresponding coil of the indoor heat exchanger.

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