Air conditioner control method and device and multi-split air conditioner

Abstract

The invention relates to the technical field of air conditioners, in particular to an air conditioner control method and device and a multi-split air conditioner. The multi-split air conditioner aims at solving the problem that when the multi-split air conditioner is shut down in winter, refrigerants can migrate into a gas-liquid separator and a compressor from an air pipe. In order to achieve the purpose, the control method comprises the steps that under the conditions that the air conditioner operates in a heating mode and an outdoor unit needs to be shut down, the current outdoor temperature is obtained; and under the condition that the current outdoor temperature is smaller than the outdoor temperature threshold value, the operation states of the compressor, the indoor unit electronic expansion valve, the outdoor unit electronic expansion valve and the four-way valve are controlled, and refrigerants in the air pipe and the air-liquid separator are transferred into the liquid pipe and the outdoor heat exchanger. According to the control method, the migration amount of the refrigerant to the gas-liquid separator and the compressor after the air conditioner is shut down in winter can be reduced, so that the situation that too much refrigerant in the gas-liquid separator influences heating starting of the air conditioner can be prevented, and lubricating oil in the compressor can also be prevented from being diluted by the refrigerant.

Description

Technical Field

[0001] This application relates to the technical field of air conditioners, and particularly relates to a control method and device for an air conditioner and a multi-connected air conditioner. Background Art

[0002] A multi-connected air conditioner can centrally manage multiple indoor units with only one outdoor unit, and has the advantages of flexible control, energy conservation and environmental protection, easy installation and maintenance, etc. The multi-connected air conditioner includes: an indoor unit, including an indoor electronic expansion valve and an indoor heat exchanger; an outdoor unit, including an outdoor electronic expansion valve, a four-way valve, a gas-liquid separator and an outdoor heat exchanger; an air pipe, connected between the four-way valve and the indoor heat exchanger; a liquid pipe, connected between the outdoor heat exchanger and the indoor heat exchanger. Among them, when the multi-connected air conditioner is shut down, the four-way valve is in a de-energized state, the air pipe and the gas-liquid separator are connected through the four-way valve, and the gas-liquid separator is connected to the suction port of the compressor.

[0003] However, when the multi-connected air conditioner is shut down in winter, the environmental temperature difference between the indoor side and the outdoor side is large, and the refrigerant will migrate from the indoor unit on the high-pressure side to the outdoor unit on the low-pressure side, that is, the refrigerant will migrate from the air pipe to the gas-liquid separator and the compressor. Excessive migration of the refrigerant will cause a large amount of liquid refrigerant to accumulate in the gas-liquid separator and even enter the compressor oil sump, which will not only prevent the compressor from starting for heating, but also damage the compressor.

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

[0005] In order to solve at least one of the above problems in the prior art, that is, to solve the problem that when the multi-connected air conditioner is shut down in winter, the refrigerant will migrate from the air pipe to the gas-liquid separator and the compressor, preventing the compressor from starting for heating and even damaging the compressor.

[0006] This application provides a control method for an air conditioner. The air conditioner includes: an indoor unit, including an indoor electronic expansion valve and an indoor heat exchanger; an outdoor unit, including a compressor, an outdoor electronic expansion valve, a four-way valve, a gas-liquid separator and an outdoor heat exchanger; an air pipe, connected between the four-way valve and the indoor heat exchanger; a liquid pipe, connected between the outdoor heat exchanger and the indoor heat exchanger. The control method includes: when the air conditioner operates in the heating mode and the outdoor unit needs to be shut down, obtaining the current outdoor temperature; when the current outdoor temperature is less than the outdoor temperature threshold, controlling the operating states of the compressor, the indoor electronic expansion valve, the outdoor electronic expansion valve and the four-way valve, so that the refrigerant in the air pipe and the gas-liquid separator is transferred to the liquid pipe and the outdoor heat exchanger.

[0007] In some embodiments, the step of "controlling the operating states of the compressor, the indoor electronic expansion valve, the outdoor electronic expansion valve, and the four-way valve to transfer the refrigerant in the gas pipe and the gas-liquid separator to the liquid pipe and the outdoor heat exchanger" further includes: controlling the operating states of the outdoor electronic expansion valve, the compressor, and the indoor electronic expansion valve to seal part of the refrigerant in the liquid pipe; controlling the four-way valve to be powered off and the operating state of the compressor to transfer the refrigerant in the gas pipe, the gas-liquid separator, and the indoor heat exchanger to the outdoor heat exchanger.

[0008] In some embodiments, the outdoor electronic expansion valve is located at one end of the liquid pipe close to the outdoor heat exchanger, and the indoor electronic expansion valve is located at one end of the liquid pipe close to the indoor and outdoor heat exchangers; the step of "controlling the operating states of the outdoor electronic expansion valve, the compressor, and the indoor electronic expansion valve to seal part of the refrigerant in the liquid pipe" further includes: controlling the outdoor electronic expansion valve to close; controlling the compressor to operate in a first mode to transfer the refrigerant in the outdoor heat exchanger and the gas-liquid separator to the liquid pipe and the indoor heat exchanger; controlling the indoor electronic expansion valve to close so that the refrigerant in the liquid pipe remains in the liquid pipe.

[0009] In some embodiments, the air conditioner further includes an indoor fan, and the step of "controlling the indoor electronic expansion valve to close" further includes: when P a2 < P a ≤ P a1 , controlling the indoor electronic expansion valve to switch to a first opening; when P a ≤ P a2 , controlling the indoor electronic expansion valve to close; where P a is the low-pressure pressure of the compressor, P a2 < P a1 , the first opening is greater than 0; and / or, before the indoor electronic expansion valve closes, the indoor fan is in an operating state, and when the indoor electronic expansion valve closes, the indoor fan turns off.

[0010] In some embodiments, the step of "controlling the four-way valve to be powered off and the operating state of the compressor" further includes: controlling the four-way valve to be powered off, at this time the outdoor electronic expansion valve and the indoor electronic expansion valve are in a closed state; controlling the compressor to operate in a second mode to transfer the refrigerant in the gas pipe, the gas-liquid separator, and the indoor heat exchanger to the outdoor heat exchanger.

[0011] In some embodiments, the step of "controlling the compressor to operate in a second mode" further includes: when P a4<P a ≤P a3 In the case of, control the current output power of the compressor to be W1; when P a5 <T a ≤P a4 In the case of, control the current output power of the compressor to be W2; when P a ≤P a5 In the case of, control the compressor to stop; where P a is the low - pressure of the compressor, P a5 <P a4 <P a3 , W2 < W1.

[0012] In some embodiments, the air conditioner further includes an outdoor fan. While controlling the compressor to operate in the second mode, the control method further includes: adjusting the gear of the outdoor fan according to the current outdoor temperature in an inverse proportion relationship.

[0013] In some embodiments, the step of "adjusting the gear of the outdoor fan according to the current outdoor temperature in an inverse proportion relationship" further includes: when T ao ≥T1, control the gear of the outdoor fan to be the third gear; when T2≤T ao <T1, control the gear of the outdoor fan to be the second gear; when T3≤T ao <T2, control the gear of the outdoor fan to be the first gear; when T ao <T3, control the outdoor fan to stop; where T ao is the current outdoor temperature, T3 < T2 < T1, and the higher the gear of the outdoor fan, the faster the rotation speed of the outdoor fan.

[0014] This application provides an electronic device, including a memory and a processor. A computer program is stored in the memory, and the processor can call and run the computer program to execute the control method of the above - mentioned air conditioner.

[0015] This application provides a multi - split air conditioner, including a controller configured to be able to execute the control method of the above - mentioned air conditioner.

[0016] In the case of adopting the above technical solution, when the outdoor unit of the present application needs to be shut down, through the short-term operation of the air conditioner, most of the refrigerant in the gas pipe and the gas-liquid separator can be transferred to the liquid pipe and the outdoor heat exchanger. In this way, the remaining refrigerant amount in the gas pipe and the gas-liquid separator is less, which can reduce the migration amount of the refrigerant to the gas-liquid separator and the compressor after the air conditioner stops in winter, thereby preventing the excessive refrigerant in the gas-liquid separator from affecting the heating startup of the air conditioner, which is beneficial for the compressor to quickly increase the exhaust temperature and establish the exhaust superheat during the heating startup, and can also prevent the lubricating oil in the compressor from being diluted by the refrigerant, thereby ensuring the lubrication effect of the lubricating oil in the compressor, improving the service life of the compressor and the heating effect of the air conditioner, and being beneficial for improving the user experience. In addition, the present application does not need to additionally increase components such as solenoid valves, refrigerant pipes or liquid storage tanks, which is beneficial for cost reduction. Description of the Drawings

[0017] The present application will be described below with reference to the drawings. In the drawings:

[0018] Figure 1 It is a schematic diagram of the refrigerant flow path of a multi-connected air conditioner under the heating condition;

[0019] Figure 2 It is a schematic diagram of the refrigerant flow path of a multi-connected air conditioner under the cooling condition;

[0020] Figure 3 It is a main step flowchart of the control method provided by the present application;

[0021] Figure 4 It is a detailed step flowchart of the control method provided by the present application;

[0022] Figure 5 It is another detailed step flowchart of the control method provided by the present application. Detailed Embodiments

[0023] The preferred embodiments of the present application will be described below with reference to the drawings. Those skilled in the art should understand that these embodiments are only used to explain the technical principle of the present application and are not intended to limit the protection scope of the present application. It should be noted that although the detailed steps of the method of the present application are described in detail below, on the premise of not deviating from the basic principle of the present application, those skilled in the art can combine, split and change the order of the following steps, and the modified technical solutions do not change the basic concept of the present application, so they also fall within the protection scope of the present application.

[0024] It should be noted that in the description of the present application, the terms "first", "second", "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance. In addition, in the description of the present application, "a plurality of" means at least two.

[0025] A multi-connected air conditioner is a type of central air conditioner, commonly known as "one outdoor unit serving multiple indoor units". It refers to a primary refrigerant air conditioning system where one outdoor unit is connected to two or more indoor units through pipes, with an air-cooled heat exchange form on the outdoor side and a direct evaporation heat exchange form on the indoor side.

[0026] Combined with Figure 1 and Figure 2 As shown, the multi-connected air conditioner includes indoor units, an outdoor unit, a gas pipe 1, and a liquid pipe 2. Among them, the indoor unit includes an indoor unit electronic expansion valve 3 and an indoor heat exchanger 4. The outdoor unit includes an outdoor unit electronic expansion valve 5, a four-way valve 6, a gas-liquid separator 7, an outdoor heat exchanger 8, and a compressor 9. The gas pipe 1 is connected between the four-way valve 6 and the indoor heat exchanger 4. The liquid pipe 2 is connected between the outdoor heat exchanger 8 and the indoor heat exchanger 4.

[0027] Among them, the four-way valve 6 includes a first connection port 61, a second connection port 62, a third connection port 63, and a fourth connection port 64. The first connection port 61 is connected to the exhaust port of the compressor 9, the second connection port 62 is connected to the gas pipe 1, the third connection port 63 is connected to the gas-liquid separator 7, and the fourth connection port 64 is connected to the outdoor heat exchanger 8. When the four-way valve 6 is energized, the first connection port 61 and the second connection port 62 of the four-way valve 6 are connected, and the third connection port 63 and the fourth connection port 64 of the four-way valve 6 are connected; when the four-way valve 6 is not energized, the first connection port 61 and the fourth connection port 64 of the four-way valve 6 are connected, and the second connection port 62 and the third connection port 63 of the four-way valve 6 are connected.

[0028] Figure 1 It is a schematic diagram of the refrigerant flow path when the air conditioner is in the heating mode. When the air conditioner is in the heating mode, the four-way valve 6 is energized, the first connection port 61 and the second connection port 62 of the four-way valve 6 are connected, and the third connection port 63 and the fourth connection port 64 of the four-way valve 6 are connected. The refrigerant flows through the exhaust port of the compressor 9, the four-way valve 6, the gas pipe 1, the indoor heat exchanger 4, the indoor unit electronic expansion valve 3, the liquid pipe 2, the outdoor unit electronic expansion valve 5, the outdoor heat exchanger 8, the four-way valve 6, the gas-liquid separator 7, and the suction port of the compressor in sequence.

[0029] Figure 2 It is a schematic diagram of the refrigerant flow path when the air conditioner is in the cooling mode. When the air conditioner is in the cooling mode, the four-way valve 6 is not energized, the first connection port 61 and the fourth connection port 64 of the four-way valve 6 are connected, and the second connection port 62 and the third connection port 63 of the four-way valve 6 are connected. The refrigerant flows through the exhaust port of the compressor 9, the four-way valve 6, the outdoor heat exchanger 8, the outdoor unit electronic expansion valve 5, the liquid pipe 2, the indoor unit electronic expansion valve 3, the indoor heat exchanger 4, the gas pipe 1, the four-way valve 6, the gas-liquid separator 7, and the suction port of the compressor in sequence.

[0030] When the multi-connected air conditioner is shut down, the four-way valve is in a de-energized state. The gas pipe is connected to the gas-liquid separator through the four-way valve, and the gas-liquid separator is connected to the suction port of the compressor. However, when the multi-connected air conditioner is shut down in winter, the environmental temperature difference between the indoor side and the outdoor side is large, and the refrigerant will migrate from the indoor unit on the high-pressure side to the outdoor unit on the low-pressure side, that is, the refrigerant will migrate from the gas pipe to the gas-liquid separator and the compressor. The pipeline of the multi-connected air conditioner is long, and the amount of refrigerant stored in the pipeline is large. If too much refrigerant migrates to the outdoor side, a large amount of liquid refrigerant will accumulate in the gas-liquid separator and even enter the compressor oil sump. If too much refrigerant migrates into the gas-liquid separator and is stored in the gas-liquid separator in the form of liquid refrigerant, it is not conducive to quickly increasing the exhaust temperature and establishing the exhaust superheat degree, which will prevent the compressor from starting for heating. Further, if the gas-liquid separator is filled with liquid refrigerant, there will be liquid return, resulting in liquid slugging of the compressor. If the refrigerant enters the oil sump of the compressor, the refrigerant will dissolve with the compressor lubricating oil, diluting the lubricating oil, thereby weakening the lubricating effect of the lubricating oil, which may cause wear of the compressor crankshaft and reduce the service life of the compressor.

[0031] Optionally, the outdoor electronic expansion valve 5 is located at one end of the liquid pipe 2 close to the outdoor heat exchanger 8, and the indoor electronic expansion valve 3 is located at one end of the liquid pipe 2 close to the indoor and outdoor heat exchanger 4.

[0032] Optionally, the multi-connected air conditioner further includes an indoor fan 10 and an outdoor fan 11. The indoor fans 10 are respectively arranged on the periphery of the indoor heat exchanger 4 for dissipating heat from the corresponding indoor heat exchanger 4. The outdoor fan 11 is arranged on the periphery of the outdoor heat exchanger 4 for dissipating heat from the outdoor heat exchanger.

[0033] In order to solve the problem that when the multi-connected air conditioner is shut down in winter, the refrigerant will migrate from the gas pipe to the gas-liquid separator and the compressor, preventing the compressor from starting for heating and even damaging the compressor, the present application provides a control method, device and multi-connected air conditioner for an air conditioner.

[0034] In a first aspect, the present application provides a control method for an air conditioner.

[0035] Combined with Figure 3 As shown, the control method provided by the present application includes the following steps:

[0036] S301, when the air conditioner is operating in the heating mode and the outdoor unit needs to be shut down, obtain the current outdoor temperature.

[0037] Wherein, the outdoor unit needs to be shut down, that is, the current is the last indoor unit to be shut down, or all the current indoor units are shut down.

[0038] S302. When the current outdoor temperature is lower than the outdoor temperature threshold, control the operating states of the compressor, the indoor unit electronic expansion valve, the outdoor unit electronic expansion valve, and the four-way valve, so that the refrigerant in the gas pipe and the gas-liquid separator is transferred to the liquid pipe and the outdoor heat exchanger.

[0039] In the case of adopting the above technical solution, when the outdoor unit of the present application needs to be shut down, through the short-term operation of the air conditioner, most of the refrigerant in the gas pipe and the gas-liquid separator can be transferred to the liquid pipe and the outdoor heat exchanger. In this way, the remaining refrigerant volume in the gas pipe and the gas-liquid separator is small, which can reduce the migration amount of the refrigerant to the gas-liquid separator and the compressor after the air conditioner stops operating in winter. Thus, it can prevent the excessive refrigerant in the gas-liquid separator from affecting the heating startup of the air conditioner, which is beneficial for the compressor to quickly increase the exhaust temperature and establish the exhaust superheat during heating startup. It can also prevent the lubricating oil in the compressor from being diluted by the refrigerant, thereby ensuring the lubricating effect of the lubricating oil in the compressor, improving the service life of the compressor and the heating effect of the air conditioner, and being beneficial to improving the user experience. In addition, the present application does not need to additionally increase components such as solenoid valves, refrigerant pipes, or liquid storage tanks, which is beneficial for cost reduction.

[0040] In some embodiments, the step of "controlling the operating states of the compressor, the indoor unit electronic expansion valve, the outdoor unit electronic expansion valve, and the four-way valve, so that the refrigerant in the gas pipe and the gas-liquid separator is transferred to the liquid pipe and the outdoor heat exchanger" (step S302) further includes: controlling the operating states of the outdoor unit electronic expansion valve, the compressor, and the indoor unit electronic expansion valve, so that part of the refrigerant is sealed in the liquid pipe. Control the four-way valve to be powered off and the operating state of the compressor, so that the refrigerant in the gas pipe, the gas-liquid separator, and the indoor heat exchanger is transferred to the outdoor heat exchanger. With such a setting, most of the refrigerant in the gas pipe and the gas-liquid separator can be transferred to the liquid pipe and the outdoor heat exchanger.

[0041] In some embodiments, in combination with Figure 4 as shown, the step of "controlling the operating states of the outdoor unit electronic expansion valve, the compressor, and the indoor unit electronic expansion valve, so that part of the refrigerant is sealed in the liquid pipe" further includes:

[0042] S401. Control the outdoor unit electronic expansion valve to close.

[0043] It can be understood that before this step, the multi-connected air conditioner operates in the heating mode, the compressor operates, the first connection port 61 and the second connection port 62 of the four-way valve 6 are communicated, and the third connection port 63 and the fourth connection port 64 of the four-way valve 6 are communicated. The indoor unit electronic expansion valve and the outdoor unit electronic expansion valve are opened to a certain degree, and the indoor fan and the outdoor fan operate. After executing this step, the outdoor unit electronic expansion valve switches to the closed state, and the indoor unit electronic expansion valve, the four-way valve, the indoor fan, and the outdoor fan maintain their original operating states.

[0044] S402, control the compressor to operate in the first mode to transfer the refrigerant in the outdoor heat exchanger and the gas-liquid separator to the liquid pipe and the indoor heat exchanger.

[0045] S403, control the electronic expansion valve of the indoor unit to close so that the refrigerant in the liquid pipe remains in the liquid pipe.

[0046] In this embodiment, after the electronic expansion valve of the outdoor unit is closed, there is no continuous refrigerant circulation volume in the outdoor unit. At this time, during the operation of the compressor, the compressor continuously transfers the refrigerant in the outdoor heat exchanger and the gas-liquid separator to the indoor heat exchanger and the liquid pipe. After the refrigerant transfer is completed, closing the electronic expansion valve of the indoor unit can achieve that part of the refrigerant remains in the liquid pipe.

[0047] Optionally, the compressor operates in the first mode, including: the compressor operates at the first frequency, and the first frequency is 40% - 60% of the maximum frequency of the compressor. For example, the first frequency is 45%, 48%, 50%, 55% or 58% of the maximum frequency of the compressor, etc. If the first frequency is too large, the pressure of the indoor heat exchanger rises too fast, and the heat dissipation is not timely, which may affect the refrigerant transfer volume. If the first frequency is too small, the refrigerant transfer speed is too slow.

[0048] Optionally, while the electronic expansion valve of the indoor unit is closed, the control method further includes: adjusting the opening degree of all the electronic expansion valves of the indoor unit to the first opening degree, and the first opening degree is 65% - 75% of the maximum opening degree. For example, the first opening degree is 65%, 68%, 70%, 73% or 75% of the maximum opening degree, etc. If the first opening degree is too large, the electronic expansion valve of the indoor unit cannot be quickly cut off. If the first opening degree is too small, it is not conducive to the refrigerant entering the liquid pipe.

[0049] In some embodiments, the step of "control the electronic expansion valve of the indoor unit to close" further includes: when P a2 <P a ≤P a1 , control the electronic expansion valve of the indoor unit to switch to the first opening degree. When P a ≤P a2 , control the electronic expansion valve of the indoor unit to close. Wherein, P a is the low-pressure pressure of the compressor, P a2 <P a1 , and the first opening degree is greater than 0. By reducing the opening degree of the electronic expansion valve of the indoor unit, the refrigerant flow rate entering the indoor evaporator can be reduced, thereby increasing the low-pressure pressure of the compressor, meeting the operating conditions of the compressor, and increasing the refrigerant transfer volume.

[0050] For example, the minimum allowable low-pressure pressure of the compressor is P1, P a1 =P1*125%, P a2= P1 * 115%, and the first opening degree is 5% of the maximum opening degree of the electronic expansion valve of the indoor unit.

[0051] In some embodiments, before the electronic expansion valve of the indoor unit is closed, the indoor fan is in an operating state. When the electronic expansion valve of the indoor unit is closed, the indoor fan is turned off. The indoor fan being in an operating state can be for the indoor heat exchanger to accelerate the liquefaction of the refrigerant in the indoor heat exchanger, which is beneficial for the liquid pipe to store more refrigerant.

[0052] In some embodiments, in combination with Figure 5 As shown, the step of "controlling the power-off of the four-way valve and the operating state of the compressor" further includes:

[0053] S501, control the four-way valve to cut off power, at this time the outdoor unit electronic expansion valve and the indoor unit electronic expansion valve are in a closed state.

[0054] Before controlling the four-way valve to cut off power, the outdoor unit electronic expansion valve and the indoor unit electronic expansion valve are in a closed state, the four-way valve is in a powered-on state, and the compressor is in an operating state. After controlling the four-way valve to cut off power, the four-way valve is in a power-off state, and the outdoor unit electronic expansion valve, the indoor unit electronic expansion valve and the compressor maintain their original operating states.

[0055] S502, control the compressor to operate in a second mode to transfer the refrigerant in the gas pipe, gas-liquid separator and indoor heat exchanger to the outdoor heat exchanger.

[0056] In this embodiment, after both the outdoor unit electronic expansion valve and the indoor unit electronic expansion valve are closed, the compressor continuously transfers the refrigerant in the indoor heat exchanger, gas pipe and gas-liquid separator to the outdoor heat exchanger. After the refrigerant transfer is completed, the remaining refrigerant amount in the gas pipe and gas-liquid separator is small, which can reduce the migration amount of the refrigerant from the gas-liquid separator and the compressor after the air conditioner stops in winter, thereby preventing the excessive refrigerant in the gas-liquid separator from affecting the heating start of the air conditioner and the service life of the compressor.

[0057] In some embodiments, the step of "controlling the compressor to operate in a second mode" further includes: When P a4 < P a ≤ P a3 , control the current output power of the compressor to be W1. When P a5 < T a ≤ P a4 , control the current output power of the compressor to be W2. When P a ≤ P a5 , control the compressor to stop. Wherein, P a is the low-pressure pressure of the compressor, P a5 < P a4 < P a3, W2 < W1. Adjusting the current output power of the compressor according to the low-pressure pressure of the compressor can meet the operating conditions of the compressor and avoid damaging the compressor.

[0058] For example, P a3 = P1 * 125%, where W1 is 30% of the maximum output power of the compressor; P a4 = P1 * 115%, where W2 is the minimum output power of the compressor, and P a5 = P1 * 110%. The first opening degree is 5% of the maximum opening degree of the electronic expansion valve of the indoor unit.

[0059] In some embodiments, while controlling the compressor to operate in the second mode, the control method further includes: adjusting the gear of the outdoor fan according to the current outdoor temperature in an inverse proportion relationship.

[0060] In some embodiments, the step of "adjusting the gear of the outdoor fan according to the current outdoor temperature in an inverse proportion relationship" further includes: when T ao ≥ T1, controlling the gear of the outdoor fan to be the third gear. When T2 ≤ T ao < T1, controlling the gear of the outdoor fan to be the second gear. When T3 ≤ T ao < T2, controlling the gear of the outdoor fan to be the first gear. When T ao < T3, controlling the outdoor fan to stop. Where T ao is the current outdoor temperature, T3 < T2 < T1, and the higher the gear of the outdoor fan, the faster the rotation speed of the outdoor fan. Adjusting the rotation speed of the outdoor fan according to the current outdoor temperature, the higher the current outdoor temperature, the faster the rotation speed of the outdoor fan, which can better dissipate heat for the outdoor heat exchanger, accelerate the liquefaction of the refrigerant in the outdoor heat exchanger, and enable more refrigerant to enter the outdoor heat exchanger. On the contrary, the lower the current outdoor temperature, the slower the rotation speed of the outdoor fan. When the current outdoor temperature is relatively low, it can meet the heat dissipation requirements of the outdoor heat exchanger, and there is no need for the outdoor fan to increase the heat exchange speed.

[0061] Optionally, while controlling the compressor to operate in the second mode, when the high-pressure pressure of the compressor rises to 90% of the high-pressure limit value, the outdoor fan raises 1 gear on the basis of the current gear.

[0062] The present application provides a multi-connected air conditioner, which includes a controller configured to be able to execute the control method of the above-mentioned air conditioner.

[0063] The present application provides a computer-readable storage medium, in which a computer program is stored. When the computer program runs, it executes the control method of the above-mentioned air conditioner.

[0064] The above computer-readable storage medium may be a transient computer-readable storage medium or a non-transient computer-readable storage medium.

[0065] This application provides an electronic device, which includes a memory and a processor. A computer program is stored in the memory, and the processor can call and run the computer program to execute the above air conditioner control method. Optionally, the device may further include a communication interface and a bus. Among them, the processor, the communication interface, and the memory can complete mutual communication through the bus. The communication interface can be used for information transmission. The processor can call the logical instructions in the memory to execute the air conditioner control method in the above embodiments.

[0066] In addition, when the logical instructions in the above memory are implemented in the form of a software functional unit and sold or used as an independent product, they can be stored in a computer-readable storage medium.

[0067] As a computer-readable storage medium, the memory can be used to store software programs and computer-executable programs, such as the program instructions / modules corresponding to the method in the patent embodiment of this application. By running the program instructions / modules stored in the memory, the processor executes functional applications and data processing, that is, implements the air conditioner control method in the above embodiments.

[0068] The memory may include a program storage area and a data storage area. Among them, the program storage area may store an operating system and application programs required for at least one function. The data storage area may store data created according to the use of the terminal device, etc. In addition, the memory may include a high-speed random access memory and may also include a non-volatile memory.

[0069] The technical solution of the embodiment of this application can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes one or more instructions for causing a computer device (which may be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the method of the embodiment of this application. The foregoing storage medium may be a non-transient storage medium, including: various media that can store program codes such as USB flash drives, mobile hard disks, read-only memories (ROM, Read-Only Memory), random access memories (RAM, Random Access Memory), magnetic disks, or optical discs, or may also be a transient storage medium.

[0070] Although the above steps are described in the above sequential order in the above embodiments, those skilled in the art can understand that in order to achieve the effects of this embodiment, different steps do not have to be executed in such an order. They can be executed simultaneously (in parallel) or in a reversed order, and these simple changes are all within the protection scope of this application.

[0071] So far, the technical solution of the present application has been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present application is obviously not limited to these specific embodiments. Without departing from the principle of the present application, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the protection scope of the present application.

Claims

1. A control method for an air conditioner, the air conditioner comprising: The indoor unit includes an indoor electronic expansion valve and an indoor heat exchanger; The outdoor unit includes a compressor, an outdoor electronic expansion valve, a four-way valve, a gas-liquid separator, and an outdoor heat exchanger; The gas pipe is connected between the four-way valve and the indoor heat exchanger; The liquid pipe is connected between the outdoor heat exchanger and the indoor heat exchanger; It is characterized in that the control method includes: When the air conditioner operates in the heating mode and the outdoor unit needs to be shut down, obtain the current outdoor temperature; When the current outdoor temperature is lower than the outdoor temperature threshold, control the operating states of the compressor, the indoor electronic expansion valve, the outdoor electronic expansion valve, and the four-way valve, so that the refrigerant in the gas pipe and the gas-liquid separator is transferred to the liquid pipe and the outdoor heat exchanger.

2. The control method according to claim 1, characterized in that The step of "controlling the operating states of the compressor, the indoor electronic expansion valve, the outdoor electronic expansion valve, and the four-way valve, so that the refrigerant in the gas pipe and the gas-liquid separator is transferred to the liquid pipe and the outdoor heat exchanger" further includes: Control the operating states of the outdoor electronic expansion valve, the compressor, and the indoor electronic expansion valve, so that part of the refrigerant is sealed in the liquid pipe; Control the four-way valve to be powered off and the operating state of the compressor, so that the refrigerant in the gas pipe, the gas-liquid separator, and the indoor heat exchanger is transferred to the outdoor heat exchanger.

3. According to the control method described in claim 2, the outdoor electronic expansion valve is located at one end of the liquid pipe close to the outdoor heat exchanger, and the indoor electronic expansion valve is located at one end of the liquid pipe close to the indoor and outdoor heat exchangers; It is characterized in that, The step of "controlling the operating states of the outdoor electronic expansion valve, the compressor, and the indoor electronic expansion valve, so that part of the refrigerant is sealed in the liquid pipe" further includes: Control the outdoor electronic expansion valve to close; Control the compressor to operate in a first mode to transfer the refrigerant in the outdoor heat exchanger and the gas-liquid separator to the liquid pipe and the indoor heat exchanger; Control the indoor electronic expansion valve to close, so that the refrigerant in the liquid pipe remains in the liquid pipe.

4. According to the control method described in claim 3, the air conditioner further includes an indoor fan, It is characterized in that, The step of "controlling the indoor unit electronic expansion valve to close" further includes: when P a2 <P a ≤P a1 , controlling the indoor unit electronic expansion valve to switch to the first opening degree; when P a ≤P a2 , controlling the indoor unit electronic expansion valve to close; where P a is the low-pressure pressure of the compressor, P a2 <P a1 , the first opening degree is greater than 0; and / or Before the indoor electronic expansion valve is closed, the indoor fan is in an operating state, and when the indoor electronic expansion valve is closed, the indoor fan is turned off.

5. The control method according to any one of claims 2 to 4, characterized in that The step of "controlling the four-way valve to be powered off and the operating state of the compressor" further includes: Control the four-way valve to be powered off, at this time the outdoor electronic expansion valve and the indoor electronic expansion valve are in a closed state; Control the compressor to operate in a second mode to transfer the refrigerant in the gas pipe, the gas-liquid separator, and the indoor heat exchanger to the outdoor heat exchanger.

6. The control method according to claim 5, characterized in that The step of "controlling the compressor to operate in a second mode" further includes: When at P a4 <P a ≤P a3 the current output power of the compressor is controlled to be W1; When at P a5 <T a ≤P a4 the current output power of the compressor is controlled to be W2; When at P a ≤P a5 , control the compressor to shut down; Among them, P a is the low-pressure pressure of the compressor, P a5 < P a4 < P a3 , and W2 < W1.

7. The control method according to claim 5, wherein the air conditioner further comprises an outdoor fan, characterized in that, While controlling the compressor to operate in a second mode, the control method further includes: According to the current outdoor temperature, adjust the gear of the outdoor fan according to an inverse proportional relationship.

8. The control method according to claim 7, characterized in that The step of "adjusting the gear of the outdoor fan according to the inverse proportional relationship based on the current outdoor temperature" further includes: When T ao is greater than or equal to T1, control the gear of the outdoor fan to the third gear; When T2 ≤ T ao < T1, control the outdoor fan to the second gear; When T3 ≤ T ao < T2, control the gear of the outdoor fan to the first gear; When at T ao is less than T3, control the outdoor fan to stop running; where T ao is the current outdoor temperature, T3 < T2 < T1, and the greater the gear of the outdoor fan, the faster the rotation speed of the outdoor fan.

9. An electronic device, comprising a memory and a processor, characterized in that, A computer program is stored in the memory, and the processor can call and run the computer program to execute the control method of the air conditioner according to any one of claims 1 to 8.

10. A multi-connected air conditioner, comprising a controller, characterized in that, The controller is configured to be able to execute the control method of the air conditioner according to any one of claims 1 to 8.

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