Control method of air conditioner, air conditioner and storage medium

Abstract

The invention discloses a control method of an air conditioner, the air conditioner and a storage medium. In the air conditioner, an exhaust port of a compressor communicates with an inlet of an oil separator, an air return port of the compressor is connected with a gas-liquid separator, the two ends of a first oil return branch communicate with inlet pipelines of the oil separator and the gas-liquid separator correspondingly, and the first oil return branch is provided with an oil return valve; the control method of the air conditioner comprises the following steps that when the air conditioner receives a shutdown instruction in a preset mode, a four-way valve is controlled to be switched to a valve position corresponding to a refrigeration mode; outdoor environment parameters and operation parameters of the air conditioner are obtained, and whether the outdoor environment parameters and the operation parameters meet a first preset condition or not is determined; and when the outdoor environment parameters and the operation parameters meet the first preset condition, the compressor is controlled to operate at the frequency smaller than the preset frequency, and the oil return valve is controlled to be opened. The invention aims to reduce the amount of lubricating oil migrated in the shutdown stage of the compressor and improve the reliability of the air conditioner.

Description

Technical Field

[0001] The present invention relates to the technical field of air conditioning, and in particular to a control method of an air conditioner, an air conditioner and a storage medium. Background Art

[0002] When air conditioners, especially multi-split units, are shut down for short periods of time in low-temperature environments, the system takes a long time and is slow to balance pressure due to long, high-resistance piping. At low temperatures, the compressor's lubricating oil dissolves a large amount of refrigerant, resulting in poor oil viscosity and an inability to seal the compressor's cylinder clearances. The resulting pressure differential within the compressor and refrigerant evaporation can cause the lubricating oil to migrate from the return air pipe into the gas-liquid separator. This can cause the compressor to start without lubricant the next time the air conditioner is turned on, leading to cylinder wear or even rupture, posing a serious reliability risk. Summary of the Invention

[0003] The main purpose of the present invention is to provide a control method for an air conditioner, an air conditioner and a storage medium, aiming to reduce the amount of lubricating oil migrated during the compressor shutdown phase and improve the reliability of the air conditioner.

[0004] To achieve the above-mentioned object, the present invention provides a control method for an air conditioner, the air conditioner comprising a compressor, an oil separator, a gas-liquid separator, a first oil return branch, a four-way valve, an outdoor heat exchanger, a refrigerant regulating device, and an indoor heat exchanger, wherein the exhaust port of the compressor is connected to the inlet of the oil separator, the return port of the compressor is connected to the gas-liquid separator, the two ends of the first oil return branch are respectively connected to the oil separator and the inlet pipeline of the gas-liquid separator, and the first oil return branch is provided with an oil return valve. The control method for the air conditioner comprises the following steps:

[0005] When the air conditioner receives a shutdown command in a preset mode, the four-way valve is controlled to switch to a valve position corresponding to the cooling mode;

[0006] Acquiring outdoor environmental parameters and operating parameters of the air conditioner, and determining whether the outdoor environmental parameters and the operating parameters meet a first preset condition;

[0007] When the outdoor environmental parameter and the operating parameter meet a first preset condition, the compressor is controlled to operate at a frequency less than a preset frequency, and the oil return valve is controlled to open.

[0008] Optionally, the outdoor environmental parameter includes an outdoor environmental temperature, the operating parameter includes an operating time of the compressor in a preset mode, and the first preset condition includes:

[0009] The outdoor ambient temperature is lower than the preset ambient temperature;

[0010] The running time is shorter than the preset time.

[0011] Optionally, before the step of controlling the compressor to operate at a frequency lower than a preset frequency, the method further comprises:

[0012] The preset frequency is determined according to the outdoor ambient temperature and / or the operating time.

[0013] Optionally, the four-way valve, the indoor heat exchanger, the outdoor heat exchanger, and the refrigerant regulating device are connected in sequence to form a refrigerant main path, and both ends of the refrigerant main path are respectively connected to the oil separator and the gas-liquid separator. The process of controlling the compressor to operate at a low frequency and controlling the oil return valve to open further includes:

[0014] The refrigerant regulating device is controlled to operate so that the refrigerant flowing out of the oil separator is transported to and stays in the refrigerant main path.

[0015] Optionally, the refrigerant regulating device includes an indoor electronic expansion valve and an outdoor electronic expansion valve, the outdoor heat exchanger, the outdoor electronic expansion valve, the indoor electronic expansion valve, and the indoor heat exchanger are connected in sequence, and the step of controlling the operation of the refrigerant regulating device so that the refrigerant flowing out of the oil separator is transported to and remains in the refrigerant main circuit includes:

[0016] The outdoor electronic expansion valve is controlled to open, and the indoor electronic expansion valve is controlled to close.

[0017] Optionally, after the steps of controlling the compressor to operate at a low frequency and controlling the oil return valve to open, the method further includes:

[0018] When the air conditioner operates to meet a second preset condition, the compressor is controlled to be turned off, and the outdoor electronic expansion valve is controlled to be closed.

[0019] Optionally, the second preset condition includes that the compressor operates at a low frequency and the oil return valve is opened for a duration reaching a set duration;

[0020] And / or, after the steps of controlling the compressor to shut down and controlling the outdoor electronic expansion valve to shut down, the method further includes: controlling the oil return valve to shut down.

[0021] Optionally, the preset mode includes a heating mode.

[0022] In addition, to achieve the above-mentioned objectives, the present application further provides an air conditioner, comprising a control device, a compressor, an oil separator, a gas-liquid separator, a first oil return branch, a four-way valve, an outdoor heat exchanger, a refrigerant regulating device, and an indoor heat exchanger, wherein the exhaust port of the compressor is connected to the inlet of the oil separator, the return air port of the compressor is connected to the gas-liquid separator, the two ends of the first oil return branch are respectively connected to the inlet pipeline of the oil separator and the gas-liquid separator, and the first oil return branch is provided with an oil return valve;

[0023] The compressor, the four-way valve and the return oil valve are all connected to the control device, which includes: a memory, a processor and an air conditioner control program stored in the memory and runnable on the processor. When the air conditioner control program is executed by the processor, the steps of the air conditioner control method described in any one of the above items are implemented.

[0024] In addition, in order to achieve the above-mentioned purpose, the present application also proposes a storage medium, on which a control program of an air conditioner is stored. When the control program of the air conditioner is executed by a processor, the steps of the control method of the air conditioner as described in any of the above items are implemented.

[0025] The present invention proposes a control method for an air conditioner. When a shutdown command is received in a preset mode, the method first switches to a refrigeration valve position through a four-way valve, and then, when the outdoor environmental parameters and the operating parameters of the air conditioner meet a first preset condition, controls the compressor to operate at a low frequency and controls the return oil valve to open, so that a pressure difference is formed between the gas-liquid separator and the return air port of the compressor, and the lubricating oil migrated to the gas-liquid separator is promptly transported back to the compressor, thereby effectively reducing the amount of lubricating oil migrated during the compressor shutdown phase, ensuring that there is sufficient lubricating oil in the compressor when the compressor is started next time, and effectively improving the reliability of the air conditioner. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 A schematic diagram of the system structure of an air conditioner according to an embodiment of the present invention;

[0027] Figure 2 Schematic diagram of the hardware structure involved in the operation of an air conditioner according to an embodiment of the present invention;

[0028] Figure 3 A flow chart of an embodiment of a method for controlling an air conditioner according to the present invention;

[0029] Figure 4 FIG. 4 is a flow chart of another embodiment of a method for controlling an air conditioner according to the present invention.

[0030] The purpose, features and advantages of the present invention will be further described with reference to the accompanying drawings and in conjunction with the embodiments. DETAILED DESCRIPTION

[0031] It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0032] An embodiment of the present invention provides an air conditioner. In this embodiment, the air conditioner is a multi-split air conditioner. In other embodiments, the air conditioner may also be a split air conditioner, an all-in-one air conditioner, or other types of air conditioners.

[0033] In the embodiment of the present invention, referring to Figure 1 and Figure 2 The air conditioner includes a control device 1, a compressor 2, an oil separator 3, a gas-liquid separator 4, a first oil return branch 01, and a main refrigerant circuit. The exhaust port of the compressor 2 is connected to the inlet of the oil separator 3, and the return port of the compressor 2 is connected to the gas-liquid separator 4. The two ends of the first oil return branch 01 are connected to the inlet pipelines of the oil separator 3 and the gas-liquid separator 4, respectively. The first oil return branch 01 is provided with an oil return valve 5. The main refrigerant circuit includes an indoor heat exchanger 6, an outdoor heat exchanger 7, and a refrigerant regulating device 8. The two ends of the main refrigerant circuit are connected to the inlet pipeline of the gas-liquid separator 4 and the oil separator 3, respectively. The refrigerant regulating device 8, the oil return valve 5, and the compressor 2 are all connected to the control device 1.

[0034] It should be noted that no throttling component is provided on the first oil return branch 01.

[0035] In this embodiment, the air conditioner further includes a second oil return branch 02 , and an oil return capillary is provided on the second oil return branch 02 .

[0036] The oil separator 3 has an inlet, an oil outlet, and a refrigerant outlet. The inlet of the oil separator 3 is connected to the exhaust port of the compressor 2, and the oil outlet of the oil separator 3 is connected to the inlet pipeline of the gas-liquid separator 4. The refrigerant outlet of the oil separator 3 is connected to one of the indoor heat exchanger 6 and the outdoor heat exchanger 7, and the inlet pipeline of the gas-liquid separator 4 is connected to the other of the indoor heat exchanger 6 and the outdoor heat exchanger 7.

[0037] The gas-liquid separator 4 separates the gaseous refrigerant from the liquid refrigerant, so that the refrigerant flowing into the compressor 2 is the gaseous refrigerant. The oil separator 3 separates the lubricating oil discharged from the compressor 2 from the refrigerant. The lubricating oil can flow back to the compressor 2, and the refrigerant in the oil separator 3 can flow into the indoor heat exchanger 6 or the outdoor heat exchanger 7 to participate in the refrigerant heat exchange cycle.

[0038] In this embodiment, the refrigerant conditioning device 8 includes a throttling device disposed between the indoor heat exchanger 6 and the outdoor heat exchanger 7. In this embodiment, the throttling device includes an outdoor electronic expansion valve 81 and an indoor electronic expansion valve 82. The outdoor heat exchanger 7, the outdoor electronic expansion valve 81, the indoor electronic expansion valve 82, and the indoor heat exchanger 6 are sequentially connected. In this embodiment, the air conditioner is a multi-split air conditioner, with at least two indoor heat exchangers 6 connected in parallel, and one indoor electronic expansion valve 82 provided for each indoor heat exchanger 6. In other embodiments, the refrigerant conditioning device 8 may also include control valves disposed at both ends of the indoor heat exchanger 6 and the outdoor heat exchanger 7.

[0039] In this embodiment, the refrigerant main circuit further includes a reversing assembly 9 , and the exhaust port of the compressor 2 , the return air port of the compressor 2 , the outdoor heat exchanger 7 and the indoor heat exchanger 6 are all connected to the reversing assembly 9 .

[0040] The reversing assembly 9 includes a four-way valve. In other embodiments, the reversing assembly 9 may also be a combination of multiple one-way valves, or a combination of a one-way valve and a multi-way valve, etc. The reversing assembly 9 has a first operating state and a second operating state. When the reversing assembly 9 operates in the first operating state, the exhaust port of the compressor 2 communicates with the indoor heat exchanger 6, and the return air port of the compressor 2 communicates with the outdoor heat exchanger 7. When the reversing assembly 9 operates in the second operating state, the exhaust port of the compressor 2 communicates with the outdoor heat exchanger 7, and the return air port of the compressor 2 communicates with the indoor heat exchanger 6.

[0041] By cooperating with the reversing assembly and the throttling device 3, the air conditioner has at least the following two modes:

[0042] In the first mode, such as the heating mode, the reversing assembly 9 operates in the first operating state, the throttling device is in the throttling state, and when the compressor 2 is turned on, the refrigerant discharged from the compressor 2 flows through the indoor heat exchanger 6, the throttling device, and the outdoor heat exchanger in sequence and then flows back to the compressor 2.

[0043] In the second mode, such as the cooling mode, the reversing component 9 operates in the second operating state, the throttling device is in the throttling state, and when the compressor 2 is turned on, the refrigerant discharged from the compressor 2 flows through the outdoor heat exchanger 7, the throttling device, and the indoor heat exchanger 6 in sequence and then flows back to the compressor 2.

[0044] In other embodiments, the air conditioner may not be equipped with the reversing component 9, and the exhaust port of the compressor 2, the oil separator 3, the indoor heat exchanger 6, the throttling device, the outdoor heat exchanger 7, the gas-liquid separator 4, and the return air port of the compressor 2 are connected in sequence. When the compressor 2 is turned on, the refrigerant discharged from the compressor 2 flows through the indoor heat exchanger 6, the throttling device, and the outdoor heat exchanger 7 in sequence and then flows back to the compressor 2.

[0045] Further, refer to Figure 2The air conditioner may further include an environment detection module 101, which is connected to the control device 1. The environment detection module 101 can be used to detect the ambient temperature of the environment where the compressor 2 is located. In this embodiment, the compressor 2 is located in an outdoor environment, and the environment detection module 101 is set in the outdoor environment.

[0046] In the embodiment of the present invention, referring to Figure 2 The air conditioner control device 1 includes a processor 1001, such as a CPU, a memory 1002, and a timer 1003. These components communicate with each other via a communication bus. The memory 1002 can be a high-speed RAM memory or a non-volatile memory, such as a disk drive. Alternatively, the memory 1002 can be a storage device independent of the processor 1001.

[0047] Those skilled in the art will understand that Figure 2 The device structure shown in the figure does not constitute a limitation of the device, and may include more or fewer components than shown in the figure, or combine certain components, or arrange the components differently.

[0048] like Figure 2 As shown, the memory 1002 as a computer storage medium may include a control program for the air conditioner.

[0049] exist Figure 2 In the device shown, the processor 1001 can be used to call the air conditioner control program stored in the memory 1002 and execute the relevant steps of the air conditioner control method in the following embodiments.

[0050] An embodiment of the present invention further provides a method for controlling an air conditioner, which is applied to the above-mentioned air conditioner.

[0051] Reference Figure 3 , an embodiment of a control method for an air conditioner of the present application is proposed. In this embodiment, the control method for an air conditioner includes:

[0052] Step S10, when the air conditioner receives a shutdown command in a preset mode, controlling the four-way valve to switch to a valve position corresponding to the cooling mode;

[0053] In the preset mode, the compressor is in the on state and the four-way valve is in the first operating state. In this embodiment, the preset mode is the heating mode.

[0054] The valve position corresponding to the cooling mode is the second operating state mentioned above.

[0055] In this embodiment, the air conditioner controls the compressor to shut down when a shutdown command is received while the air conditioner is operating in a preset mode. The air conditioner is a multi-split air conditioner. Here, the compressor shutdown signal includes a user shutdown signal, a user switching to another mode such as defrost mode or air supply mode, or a signal automatically generated by the air conditioner when all indoor heat exchangers are depleted.

[0056] Step S20, obtaining outdoor environmental parameters and operating parameters of the air conditioner, and determining whether the outdoor environmental parameters and the operating parameters meet a first preset condition;

[0057] The first preset condition indicates that there is a risk that the lubricating oil in the compressor will migrate to the gas-liquid separator.

[0058] The outdoor environmental parameters may include at least one of the following: outdoor environmental temperature, outdoor air pressure, etc.

[0059] The operating parameters of the air conditioner may include at least one of the following: operating state parameters of the compressor, state parameters of the gas-liquid separator, state parameters of the oil separator, and the like.

[0060] The first preset condition may include a preset quantitative relationship that the outdoor environmental parameter and the operating parameter need to satisfy when the lubricating oil migrates to the gas-liquid separator after the compressor stops, or a target parameter range that the outdoor environmental parameter and the operating parameter need to reach respectively.

[0061] Step S30: When the outdoor environmental parameter and the operating parameter meet a first preset condition, the compressor is controlled to operate at a frequency less than a preset frequency, and the oil return valve is controlled to open.

[0062] The preset frequency is specifically the maximum frequency allowed for the compressor to operate under current operating conditions without causing migration of lubricating oil after the compressor stops. In this embodiment, the preset frequency is 10 Hz. In other embodiments, the preset frequency may also be determined based on the actual operating conditions of the air conditioner.

[0063] In this embodiment, the air conditioner includes a first oil return branch and a second oil return branch. During the compressor startup process, the oil return valve is closed, and lubricating oil in the oil separator flows back to the compressor through the second oil return branch. When the compressor receives a shutdown signal and shuts down, the oil return valve remains closed. When a first preset condition is met, the oil return valve can be controlled to switch from a closed state to an open state. At this time, the resistance of the first oil return branch is low, and the resistance of the second oil return branch is high. During low-frequency operation of the compressor, most or all of the lubricating oil flows through the first oil return branch into the gas-liquid separator, while a small portion or no lubricating oil flows through the second oil return branch into the gas-liquid separator. In other implementations, the air conditioner may include the first oil return branch but not the second oil return branch. During the compressor startup process, the oil return valve may be opened at a throttled opening. When the compressor receives a shutdown signal and shuts down, the oil return valve switches from an open state to a closed state. When the first preset condition is met, the oil return valve can be controlled to open at its maximum opening.

[0064] After step S30, when a second preset condition is met, the compressor is controlled to stop, and the second preset condition indicates that the amount of lubricating oil in the compressor has reached the minimum amount of oil required for starting.

[0065] An embodiment of the present invention proposes a control method for an air conditioner. When a shutdown command is received in a preset mode, the method first switches to a refrigeration valve position through a four-way valve, and then, when the outdoor environmental parameters and the operating parameters of the air conditioner meet a first preset condition, controls the compressor to operate at a low frequency and controls the return oil valve to open, so that a pressure difference is formed between the gas-liquid separator and the return air port of the compressor, and the lubricating oil migrated to the gas-liquid separator is promptly transported back to the compressor, thereby effectively reducing the amount of lubricating oil migrated during the compressor shutdown phase, ensuring that there is sufficient lubricating oil in the compressor when the compressor is started next time, and effectively improving the reliability of the air conditioner.

[0066] Furthermore, in this embodiment, the outdoor environmental parameter includes the outdoor environmental temperature, the operating parameter includes the operating time of the compressor in the preset mode, and the first preset condition includes at least one of the following:

[0067] Condition 1: the outdoor ambient temperature is lower than the preset ambient temperature;

[0068] Condition 2: The running time is less than the preset time.

[0069] In this embodiment, the compressor is in an outdoor environment, and the ambient temperature is the outdoor ambient temperature.

[0070] The preset ambient temperature and preset duration can be pre-set fixed parameters, or can be parameters determined based on the actual operating conditions of the air conditioner, such as the shutdown duration of the compressor and / or the operating status parameters of the compressor in the preset mode before shutdown, etc.

[0071] For example, the preset ambient temperature may be -10°C, the preset duration may be 15 minutes, the preset exhaust temperature may be 20°C, and so on.

[0072] In this embodiment, because the ambient temperature of the compressor is too low, the exhaust superheat is difficult to establish, and the refrigerant dissolved in the compressor's lubricating oil is not easy to evaporate, resulting in low oil viscosity. The lower the oil viscosity, the greater the risk of oil migration. At the same time, the risk of refrigerant condensing at low temperatures and migrating to the compressor also increases. Therefore, when condition 1 is met, the compressor restarts and operates in the above-described manner, thereby ensuring that the compressor has sufficient lubricating oil and sufficient refrigerant in the refrigerant main circuit when it is next started, thereby ensuring system reliability and ensuring the heat exchange effect of the system at startup. In addition, if the operating time is too short, the exhaust superheat ΔT is not established, and the refrigerant dissolved in the oil is not easy to evaporate, resulting in low oil viscosity. The lower the oil viscosity, the greater the risk of oil migration. Therefore, when condition 2 is met, the compressor restarts and operates in the above-described manner, thereby ensuring system reliability and ensuring the heat exchange effect of the system at startup.

[0073] Furthermore, in this embodiment, before the step of controlling the compressor to operate at a frequency lower than a preset frequency, the method further includes: determining the preset frequency according to the outdoor ambient temperature and / or the operating time.

[0074] Different ambient temperatures and / or different continuous on-times correspond to different preset frequencies. In this embodiment, the ambient temperature and the preset frequency are positively correlated; the lower the ambient temperature, the lower the preset frequency. The continuous on-time is also positively correlated with the preset frequency; the shorter the continuous on-time, the lower the preset frequency.

[0075] Furthermore, in this embodiment, the preset frequency is determined in combination with the ambient temperature and the continuous on time. Specifically, the temperature range of the ambient temperature and the duration range of the continuous on time can be determined, and the preset frequency is determined based on the temperature range and the duration range.

[0076] In this embodiment, the preset frequency is determined by the ambient temperature and / or the continuous opening time, which is conducive to ensuring that the operating frequency of the compressor will not be too high. It can ensure that the compressor operates at a frequency not greater than the preset frequency and when the return oil valve is opened and then shuts down again, the lubricating oil of the compressor can remain in the compressor after shutdown, further improving the reliability of the compressor.

[0077] Furthermore, based on the above embodiment, another embodiment of the control method of the air conditioner of the present application is proposed. In this embodiment, referring to Figure 4The four-way valve, the indoor heat exchanger, the outdoor heat exchanger, and the refrigerant regulating device are connected in sequence to form a refrigerant main path, and the two ends of the refrigerant main path are respectively connected to the oil separator and the gas-liquid separator. The process of controlling the compressor to operate at a low frequency and controlling the oil return valve to open further includes:

[0078] Step S40: Control the refrigerant regulating device to operate so that the refrigerant flowing out of the oil separator is transported to and stays in the refrigerant main path.

[0079] The refrigerant regulating device here operates according to target parameters. In addition to ensuring that the refrigerant flowing out of the oil separator stays in the main refrigerant circuit and does not accumulate in the gas-liquid separator and the compressor, the target parameters can also block the refrigerant circulation, thereby effectively improving the oil return efficiency of the compressor.

[0080] In this embodiment, the refrigerant regulating device includes an indoor electronic expansion valve and an outdoor electronic expansion valve. The outdoor heat exchanger, the outdoor electronic expansion valve, the indoor electronic expansion valve, and the indoor heat exchanger are sequentially connected. The step of controlling the operation of the refrigerant regulating device so that the refrigerant flowing out of the oil separator is transported to and retained in the main refrigerant circuit includes: controlling the outdoor electronic expansion valve to open and controlling the indoor electronic expansion valve to close. In this embodiment, the coordination of the outdoor and indoor electronic expansion valves enables the air conditioner to form a semi-closed system. The power generated by the low-frequency operation of the compressor is used to transport the refrigerant separated by the oil separator to and retain it in the pipeline before the indoor electronic expansion valve.

[0081] In this embodiment, the above-mentioned method can reduce the risk of liquid refrigerant migrating into the compressor and causing hydraulic pressure during startup, thereby further improving the reliability of the air conditioner.

[0082] In other embodiments, when the indoor heat exchanger is connected to the refrigerant outlet of the oil separator, and the outdoor heat exchanger is connected to the inlet pipeline of the gas-liquid separator, the outdoor electronic expansion valve can also be controlled to close and the indoor electronic expansion valve can be controlled to open.

[0083] In other embodiments, the refrigerant regulating device may also include a first stop valve provided at one end of the outdoor heat exchanger away from the indoor heat exchanger and a second stop valve provided at one end of the indoor heat exchanger away from the outdoor heat exchanger. When the air conditioner is in a preset state, the first stop valve can be controlled to open and the second stop valve can be controlled to close.

[0084] Furthermore, in this embodiment, after the steps of controlling the compressor to operate at low frequency and controlling the oil return valve to open, the method further includes: when the air conditioner operates to meet a second preset condition, controlling the compressor to shut down and controlling the outdoor electronic expansion valve to close.

[0085] The second preset condition indicates that the amount of lubricating oil in the compressor has reached the minimum required for startup. In this embodiment, the second preset condition includes the compressor operating at a low frequency and the oil return valve being open for a set duration. For example, the set duration is 2 minutes.

[0086] In this embodiment, the outdoor electronic expansion valve is closed when the compressor is shut down, which can block the refrigerant in the pipeline between the indoor electronic expansion valve and the outdoor electronic expansion valve, thereby avoiding a large amount of liquid refrigerant migrating to the compressor during long-term shutdown, thereby reducing the risk of liquid compression when the compressor is subsequently started, and further improving the reliability of the air conditioner.

[0087] In other embodiments, the second preset condition may also include the oil level of the compressor reaching a preset height, the oil level of the gas-liquid separator being lower than a preset height, or the pressure of the gas-liquid separator being lower than a preset pressure, and so on.

[0088] Furthermore, in this embodiment, after the steps of controlling the compressor to shut down and controlling the outdoor electronic expansion valve to shut down, the method further includes: controlling the oil return valve to shut down.

[0089] In this embodiment, the compressor is first controlled to be turned off, and after the compressor is turned off for a first period of time, the outdoor electronic expansion valve is controlled to be closed, and after the outdoor electronic expansion valve is closed for a second period of time, the oil return valve is controlled to be closed.

[0090] The above method is helpful to ensure that the system can quickly reach pressure balance after the compressor stops, so as to further reduce the amount of oil migration after the compressor stops, and further improve the operating stability of the air conditioner.

[0091] In addition, an embodiment of the present invention further provides a storage medium on which a control program for an air conditioner is stored. When the control program for the air conditioner is executed by a processor, the relevant steps of any embodiment of the above-mentioned method for controlling an air conditioner are implemented.

[0092] It should be noted that, in this document, the terms "comprises," "includes," or any other variations thereof are intended to encompass non-exclusive inclusion, such that a process, method, article, or system comprising a series of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or system. In the absence of further limitations, an element defined by the phrase "comprising a ..." does not exclude the presence of other identical elements in the process, method, article, or system comprising the element.

[0093] The serial numbers of the above embodiments of the present invention are for description only and do not represent the advantages or disadvantages of the embodiments.

[0094] Through the description of the above embodiments, those skilled in the art can clearly understand that the above embodiment methods can be implemented by means of software plus the necessary general hardware platform, and of course can also be implemented by hardware, but in many cases the former is a better embodiment. Based on this understanding, the technical solution of the present invention is essentially or the part that contributes to the prior art can be embodied in the form of a software product, which is stored in a storage medium (such as ROM / RAM, magnetic disk, optical disk) as described above, and includes a number of instructions for enabling a terminal device (which can be a mobile phone, computer, server, air conditioner, or network device, etc.) to execute the methods described in each embodiment of the present invention.

[0095] The above are only preferred embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention description and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A method for controlling an air conditioner, characterized in that: The air conditioner includes a compressor, an oil separator, a gas-liquid separator, a first oil return branch, a four-way valve, an outdoor heat exchanger, a refrigerant regulating device, and an indoor heat exchanger. The exhaust port of the compressor is connected to the inlet of the oil separator, and the return port of the compressor is connected to the gas-liquid separator. The two ends of the first oil return branch are respectively connected to the oil separator and the inlet pipeline of the gas-liquid separator. The first oil return branch is provided with an oil return valve. The control method of the air conditioner includes the following steps: When the air conditioner receives a shutdown command in a preset mode, the four-way valve is controlled to switch to a valve position corresponding to the cooling mode; Acquiring outdoor environmental parameters and operating parameters of the air conditioner, and determining whether the outdoor environmental parameters and the operating parameters meet a first preset condition; When the outdoor environmental parameter and the operating parameter meet a first preset condition, the compressor is controlled to operate at a frequency less than a preset frequency, and the oil return valve is controlled to open.

2. The air conditioner control method according to claim 1, wherein: The outdoor environmental parameter includes the outdoor environmental temperature, the operating parameter includes the operating time of the compressor in the preset mode, and the first preset condition includes: The outdoor ambient temperature is lower than the preset ambient temperature; The running time is shorter than the preset time.

3. The air conditioner control method according to claim 1, wherein: Before the step of controlling the compressor to operate at a frequency lower than a preset frequency, the method further includes: The preset frequency is determined according to the outdoor ambient temperature and / or the operating time.

4. The air conditioner control method according to claim 1, wherein: The four-way valve, the indoor heat exchanger, the outdoor heat exchanger, and the refrigerant regulating device are sequentially connected to form a refrigerant main path, and the two ends of the refrigerant main path are respectively connected to the oil separator and the gas-liquid separator. The process of controlling the compressor to operate at a low frequency and controlling the oil return valve to open further includes: The refrigerant regulating device is controlled to operate so that the refrigerant flowing out of the oil separator is transported to and stays in the refrigerant main path.

5. The air conditioner control method according to claim 4, wherein: The refrigerant regulating device includes an indoor electronic expansion valve and an outdoor electronic expansion valve, the outdoor heat exchanger, the outdoor electronic expansion valve, the indoor electronic expansion valve, and the indoor heat exchanger are connected in sequence, and the step of controlling the operation of the refrigerant regulating device so that the refrigerant flowing out of the oil separator is transported to and stays in the refrigerant main circuit includes: The outdoor electronic expansion valve is controlled to open, and the indoor electronic expansion valve is controlled to close.

6. The air conditioner control method according to claim 5, wherein: After the steps of controlling the compressor to operate at a low frequency and controlling the oil return valve to open, the method further includes: When the air conditioner operates to meet a second preset condition, the compressor is controlled to be turned off, and the outdoor electronic expansion valve is controlled to be closed.

7. The air conditioner control method according to claim 6, wherein: The second preset condition includes that the compressor operates at a low frequency and the oil return valve is opened for a duration that reaches a set duration; And / or, after the steps of controlling the compressor to shut down and controlling the outdoor electronic expansion valve to shut down, the method further includes: controlling the oil return valve to shut down.

8. The air conditioner control method according to any one of claims 1 to 7, characterized in that: The preset mode includes a heating mode.

9. An air conditioner, characterized in that: The air conditioner includes a control device, a compressor, an oil separator, a gas-liquid separator, a first oil return branch, a four-way valve, an outdoor heat exchanger, a refrigerant regulating device and an indoor heat exchanger, the exhaust port of the compressor is connected to the inlet of the oil separator, the return air port of the compressor is connected to the gas-liquid separator, the two ends of the first oil return branch are respectively connected to the oil separator and the inlet pipeline of the gas-liquid separator, and the first oil return branch is provided with an oil return valve; The compressor, the four-way valve and the oil return valve are all connected to the control device, which includes: a memory, a processor and a control program for the air conditioner stored in the memory and runnable on the processor. When the control program for the air conditioner is executed by the processor, the steps of the control method for the air conditioner as described in any one of claims 1 to 8 are implemented.

10. A storage medium, characterized in that: The storage medium stores a control program for the air conditioner, and when the control program for the air conditioner is executed by the processor, the steps of the control method for the air conditioner according to any one of claims 1 to 8 are implemented.

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