Oil return control method and air conditioning system

Abstract

This application discloses an oil return control method and an air conditioning system. The air conditioning system includes a compressor, an outdoor unit assembly, an indoor unit assembly, and a gas-liquid separator. The compressor's discharge pipe is connected to the inlet of the outdoor unit assembly, the outdoor unit assembly's output port is connected to the inlet of the indoor unit assembly, and the indoor unit assembly's output port is connected to the gas-liquid separator. At least a portion of the compressor's suction pipe is located in the gas-liquid separator, and the suction pipe has an oil return hole. A stirring motor is located at the bottom of the gas-liquid separator. The method includes: executing a corresponding control strategy based on the compressor's current operating condition. The control strategy includes at least controlling the stirring motor to enable the compressor to reach a target operating condition. Under the target operating condition, the current lubricating oil parameters of the compressor meet the requirements for normal compressor operation. In this way, rapid oil return can be achieved using the stirring motor, avoiding wear caused by compressor oil shortage, thereby improving the compressor's operational safety.

Description

Technical Field

[0001] This application relates to the field of air conditioning system technology, and more specifically, to an oil return control method and an air conditioning system. Background Technology

[0002] To improve compressor efficiency and safety, air conditioning systems often use lubricating oil to assist compressor operation. However, during compressor operation, some lubricating oil is discharged from the compressor along with the refrigerant, entering the system condenser, piping, and evaporator. If the discharged lubricating oil cannot return to the compressor, it may cause compressor wear and failure due to insufficient oil. Summary of the Invention

[0003] This application provides an oil return control method and an air conditioning system.

[0004] The oil return control method of this application is applied to an air conditioning system, which includes a compressor, an outdoor unit assembly, an indoor unit assembly, and a gas-liquid separator. The exhaust pipe of the compressor is connected to the inlet of the outdoor unit assembly, the outlet of the outdoor unit assembly is connected to the inlet of the indoor unit assembly, and the outlet of the indoor unit assembly is connected to the gas-liquid separator. At least a portion of the compressor's suction pipe is located in the gas-liquid separator, the suction pipe is provided with an oil return hole, and a stirring motor is provided at the bottom of the gas-liquid separator. The method includes: executing a corresponding control strategy based on the current operating condition of the compressor, the control strategy including at least controlling the stirring motor to make the compressor reach a target operating condition, under which the current lubricating oil parameters of the compressor meet the requirements for normal operation of the compressor.

[0005] The air conditioning system of this application includes a compressor, an outdoor unit assembly, an indoor unit assembly, a gas-liquid separator, a processor, a memory, and a computer program. The compressor's exhaust pipe is connected to the input port of the outdoor unit assembly, the outdoor unit assembly's output port is connected to the input port of the indoor unit assembly, and the indoor unit assembly's output port is connected to the gas-liquid separator. At least a portion of the compressor's suction pipe is located within the gas-liquid separator, the suction pipe has an oil return hole, and a stirring motor is located at the bottom of the gas-liquid separator. The computer program is stored in the memory and executed by the processor. The computer program includes instructions for executing an oil return control method. The oil return control method includes executing a corresponding control strategy based on the compressor's current operating condition. The control strategy at least includes controlling the stirring motor to make the compressor reach a target operating condition, under which the compressor's current lubricating oil parameters meet the requirements for normal compressor operation.

[0006] The oil return control method and air conditioning system of this application include a stirring motor in the gas-liquid separator. The stirring motor can improve the miscibility efficiency of liquid refrigerant and lubricating oil, preventing stratification. The current operating condition can be used to determine if the compressor is short of oil. During the operation of the air conditioning system, a corresponding control strategy can be executed based on the current operating condition, where the control strategy includes at least controlling the stirring motor. For example, if the compressor is short of oil, the stirring motor can be controlled to increase the likelihood of lubricating oil entering the oil return hole and the compressor, thereby improving the oil return efficiency. This allows the compressor to quickly reach the target operating condition after the stirring motor starts running, ensuring safe operation. If the compressor is not short of oil, the stirring motor can be stopped. Thus, this application can selectively control the stirring motor based on the current operating condition, enabling rapid oil return when lubrication is insufficient and the compressor is short of oil. This quickly improves the lubrication effect of the lubricating oil on the compressor, preventing wear caused by insufficient oil and improving the operational safety of the compressor.

[0007] Additional aspects and advantages of embodiments of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of embodiments of this application. Attached Figure Description

[0008] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, wherein:

[0009] Figure 1 This is a schematic diagram of the structure of an air conditioning system according to certain embodiments of this application;

[0010] Figure 2 This is a flowchart illustrating the oil return control method according to certain embodiments of this application;

[0011] Figure 3 This is a flowchart illustrating the oil return control method according to certain embodiments of this application;

[0012] Figure 4 This is a flowchart illustrating the oil return control method according to certain embodiments of this application;

[0013] Figure 5 This is a flowchart illustrating the oil return control method according to certain embodiments of this application;

[0014] Figure 6 This is a flowchart illustrating the oil return control method according to certain embodiments of this application;

[0015] Figure 7 This is a flowchart illustrating the oil return control method according to certain embodiments of this application;

[0016] Figure 8 This is a flowchart illustrating the oil return control method according to certain embodiments of this application;

[0017] Figure 9 This is a flowchart illustrating the oil return control method according to certain embodiments of this application;

[0018] Figure 10 This is a flowchart illustrating the oil return control method according to certain embodiments of this application;

[0019] Figure 11 This is a flowchart illustrating the oil return control method according to certain embodiments of this application;

[0020] Figure 12 This is a schematic diagram of the return oil control device according to certain embodiments of this application;

[0021] Figure 13 This is a partial structural schematic diagram of an air conditioning system according to certain embodiments of this application;

[0022] Figure 14 This is a schematic diagram illustrating the connection state of a non-volatile computer-readable storage medium and a processor in certain embodiments of this application.

[0023] Explanation of key component symbols:

[0024] 100. Air conditioning system;

[0025] 10. Compressor; 11. Suction pipe; 111. Oil return hole; 12. Oil level sensor; 20. Outdoor unit assembly; 21. Outdoor unit; 22. Fan; 30. Indoor unit assembly; 31. Indoor unit; 32. Electronic expansion valve; 40. Gas-liquid separator; 41. Agitator motor; 50. Oil separator; 60. Four-way valve; 70. Regulating valve. Detailed Implementation

[0026] The embodiments of this application are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the embodiments of this application, and should not be construed as limiting the embodiments of this application.

[0027] To improve compressor efficiency and safety, air conditioning systems often use lubricating oil to assist compressor operation. However, during compressor operation, some lubricating oil is discharged from the compressor along with the refrigerant, entering the system condenser, piping, and evaporator. If the discharged lubricating oil cannot return to the compressor, it may cause oil shortage and wear failure. This is especially true in multi-split systems, where there are many indoor units, long piping, large refrigerant charge, and significant elevation differences. The discharged lubricating oil is prone to stagnating in the piping and failing to return to the compressor, leading to oil shortages.

[0028] Common oil return methods include oil separator oil return, gas-liquid separator oil return hole oil return, and fixed-time oil return. Regarding the gas-liquid separator oil return hole method, due to the large refrigerant charge in the air conditioning system, the liquid level in the gas-liquid separator is high when only the indoor unit is running or at minimum load. Because the density of lubricating oil and liquid refrigerant is different, the lubricating oil often lies on top of the liquid refrigerant, resulting in stratification. However, the oil return hole of the gas-liquid separator is located at the bottom, causing more liquid refrigerant to return to the compressor through the oil return hole. This results in extremely poor oil return efficiency of the gas-liquid separator, diluting the compressor lubricating oil with the refrigerant, rendering it ineffective for lubrication, and ultimately leading to compressor wear and failure due to insufficient oil.

[0029] To address the above problems, this application provides a method for controlling oil return, which will be described in detail below:

[0030] Please see Figure 1 and Figure 2 This application provides an oil return control method applied to an air conditioning system 100. The air conditioning system 100 includes a compressor 10, an outdoor unit assembly 20, an indoor unit assembly 30, and a gas-liquid separator 40. The exhaust pipe of the compressor 10 is connected to the inlet of the outdoor unit assembly 20, the outlet of the outdoor unit assembly 20 is connected to the inlet of the indoor unit assembly 30, and the outlet of the indoor unit assembly 30 is connected to the gas-liquid separator 40. At least a portion of the suction pipe 11 of the compressor 10 is located in the gas-liquid separator 40. The suction pipe 11 of the compressor 10 is provided with an oil return hole 111. A stirring motor 41 is provided at the bottom of the gas-liquid separator 40. The oil return control method includes:

[0031] Step 011: Execute the corresponding control strategy based on the current operating condition of the compressor 10. The control strategy includes at least controlling the stirring motor 41 so that the compressor 10 reaches the target operating condition. Under the target operating condition, the current lubricating oil parameters of the compressor 10 meet the requirements for normal operation of the compressor 10.

[0032] Specifically, the compressor 10 is the core component of the air conditioning refrigeration system, mainly responsible for compressing and transmitting refrigerant vapor. It releases the energy in the refrigerant as heat by changing its state (from gaseous to liquid), thus achieving a cooling effect. The outdoor unit assembly 20 includes an outdoor unit 21 and a fan 22. The outdoor unit 21 is mainly responsible for transferring indoor heat to the outdoor environment through the refrigerant and dissipating the heat in the refrigerant into the atmosphere through the condenser. The fan 22 helps dissipate heat from the outdoor unit 21 by accelerating airflow, thereby ensuring the effective operation of the air conditioning system 100. The indoor unit assembly 30 includes an indoor unit 31 and a corresponding electronic expansion valve 32. The indoor unit 31 is mainly responsible for absorbing indoor heat and transferring it to the outdoor unit 21 through the refrigerant. Simultaneously, it changes the refrigerant from liquid to gaseous through the evaporator, absorbing a large amount of heat in the process, thus achieving indoor cooling. The electronic expansion valve 32 can automatically adjust the refrigerant flow and pressure according to indoor temperature and pressure signals to ensure the normal operation of the air conditioning system 100. The gas-liquid separator 40 is mainly used to separate and store the liquid portion of the refrigerant to prevent the liquid refrigerant from directly entering the compressor 10 and causing liquid slugging.

[0033] The discharge pipe of compressor 10 is connected to the inlet of outdoor unit assembly 20, the outlet of outdoor unit assembly 20 is connected to the inlet of indoor unit assembly 30, and the outlet of indoor unit assembly 30 is connected to gas-liquid separator 40. At least a portion of the suction pipe 11 of compressor 10 is located in gas-liquid separator 40. The portion of suction pipe 11 of compressor 10 located in gas-liquid separator 40 is U-shaped. The bottom of suction pipe 11 of compressor 10 is provided with oil return hole 111, and the top of suction pipe 11 of compressor 10 is provided with air hole. Gaseous refrigerant can enter suction pipe 11 of compressor 10 through air hole. Gaseous refrigerant can move within suction pipe 11 of compressor 10, causing a pressure difference to be formed between the inside of suction pipe 11 of compressor 10 and the inside of gas-liquid separator 40. Under the action of pressure difference, liquid refrigerant and lubricating oil in gas-liquid separator 40 enter oil return hole 111 and re-enter compressor 10 along suction pipe 11 of compressor 10. The bottom of the gas-liquid separator 40 is equipped with a stirring motor 41, which can be used to stir the liquid refrigerant and lubricating oil to improve the mutual solubility efficiency of the liquid refrigerant and lubricating oil and prevent them from separating.

[0034] At this point, the mixture of lubricating oil and refrigerant, after being discharged from the exhaust pipe of compressor 10, can move to outdoor unit assembly 20 for heat exchange. After passing through outdoor unit assembly 20, the mixture of lubricating oil and refrigerant enters indoor unit assembly 30. After being processed by indoor unit assembly 30, the liquid refrigerant evaporates into gaseous refrigerant. When only the indoor unit is running or cooling at a small load, the evaporation efficiency is low, and some liquid refrigerant cannot evaporate. Therefore, the refrigerant discharged from indoor unit assembly 30 may be gaseous refrigerant, or a mixture of liquid and gaseous refrigerant. At the same time, the lubricating oil moves with the refrigerant to the gas-liquid separator 40. In the gas-liquid separator 40, the gaseous refrigerant can return to compressor 10 through the suction pipe 11 of compressor 10, while the liquid refrigerant and lubricating oil can enter the suction pipe 11 of compressor 10 through the oil return hole 111 and then enter compressor 10. It should be noted that the diameter of the oil return hole 111 is usually small, and the amount of liquid entering the oil return hole 111 is usually small. Therefore, even if lubricating oil and liquid refrigerant enter the compressor 10 through the oil return hole 111 and the suction pipe 11 of the compressor 10, liquid slugging will not occur. In this way, the return of lubricating oil can be achieved.

[0035] In some embodiments, the air conditioning system 100 also includes an oil separator 50 and a four-way valve 60. The oil separator 50 is located on the exhaust side of the compressor 10, and its main function is to effectively trap the lubricating oil in the exhaust and return it to the compressor 10, ensuring the recycling of the lubricating oil. This reduces the deposition of lubricating oil in other components of the system, prevents system blockage and scale problems, and thus improves the performance of the entire refrigeration system. The four-way valve 60 is an important control component in the air conditioning system 100, mainly used to change the flow direction of the refrigerant and switch between cooling and heating functions.

[0036] The discharge pipe of compressor 10 is connected to the inlet of oil separator 50; the first outlet of oil separator 50 is connected to four-way valve 60, and through four-way valve 60 is connected to the inlet of outdoor unit assembly 20; the second outlet of oil separator 50 is connected to the suction pipe 11 of compressor 10; the outlet of indoor unit assembly 30 is connected to four-way valve 60, and through four-way valve 60 is connected to gas-liquid separator 40. The movement path of lubricating oil in air conditioning system 100 is as follows: After the mixture of lubricating oil and refrigerant is discharged from the discharge pipe of compressor 10, it moves to oil separator 50 for refrigerant and lubricating oil separation. Most of the lubricating oil is separated and returns to compressor 10 through the second outlet of oil separator 50. A small portion of the unseparated lubricating oil moves with the refrigerant through the first outlet of oil separator 50 to four-way valve 60, and then through four-way valve 60 to outdoor unit assembly 20 for heat exchange. After passing through outdoor unit assembly 20, the mixture of lubricating oil and refrigerant enters indoor unit assembly 30. Simultaneously, the lubricating oil moves along with the refrigerant into the four-way valve 60, and then through the four-way valve 60 into the gas-liquid separator 40. In the gas-liquid separator 40, the gaseous refrigerant can return to the compressor 10 through the suction pipe 11 of the compressor 10, while the liquid refrigerant and lubricating oil can enter the suction pipe 11 of the compressor 10 through the oil return hole 111 and then enter the compressor 10.

[0037] The stirring motor 41 can be used to promote the mutual solubility of liquid refrigerant and lubricating oil, and avoid their separation, so as to increase the possibility of lubricating oil entering the oil return hole 111, thereby improving the oil return efficiency, avoiding the separation of liquid refrigerant and lubricating oil, and preventing the situation where more liquid refrigerant enters the oil return hole 111, thereby avoiding the compressor 10 from lacking oil and improving the operating stability of the compressor 10.

[0038] The lubricating oil parameters may include at least one of oil level and oil release rate, where oil release rate refers to the proportion of lubricating oil in the oil sump of compressor 10, and oil level refers to the height of the liquid in the oil sump. Preset oil level thresholds and preset oil release rate thresholds can be set according to the requirements of compressor 10 during normal operation. The preset oil level threshold is determined based on the oil level at which compressor 10 can operate safely, and the preset oil release rate threshold is determined based on the oil release rate when the oil level is the preset oil level threshold and the lubrication effect of the liquid in the oil sump is optimal.

[0039] The current operating condition can be determined by the current lubricating oil parameters of the compressor 10. For example, the compressor 10 may include an oil level sensor 12, which can be used to obtain the current oil level and current oil release rate of the compressor 10. Based on the current oil level and current oil release rate of the compressor 10 obtained by the oil level sensor 12, the current operating condition can be determined according to a preset oil level threshold, a preset oil release rate threshold, the current oil level, and the current oil release rate. The current operating condition includes the following cases: the current oil level is greater than the preset oil level threshold and the current oil release rate is greater than the preset oil release rate threshold; the current oil level is greater than the preset oil level threshold and the current oil release rate is less than the preset oil release rate threshold; the current oil level is less than the preset oil level threshold and the current oil release rate is greater than the preset oil release rate threshold; and the current oil level is less than the preset oil level threshold and the current oil release rate is less than the preset oil release rate threshold.

[0040] Therefore, the current operating condition can be used to determine whether the compressor 10 is short of oil and whether the lubricating oil is sufficiently effective, i.e., whether the current lubricating oil parameters of the compressor 10 meet the requirements for normal operation. Under the target operating condition, the current lubricating oil parameters of the compressor 10 meet the requirements for normal operation, enabling the compressor 10 to operate normally under the target condition. Therefore, based on the current operating condition of the compressor 10, a corresponding control strategy is executed. The control strategy includes at least controlling the stirring motor 41 to enable the compressor 10 to reach the target operating condition. The control method for the stirring motor 41 may differ under different operating conditions.

[0041] For example, if the current oil level is greater than the preset oil level threshold and the current oil release rate is greater than the preset oil release rate threshold, it can be confirmed that the compressor 10 is not short of oil. The current operating condition of the compressor 10 is the target operating condition. At this time, even if only a small amount of lubricating oil returns to the compressor 10 from the gas-liquid separator 40, it will not affect the operation of the compressor 10. Therefore, the stirring motor 41 can be controlled to stop running to reduce unnecessary wear and tear on the stirring motor 41.

[0042] For example, if the current oil level is higher than the preset oil level threshold and the current oil release rate is lower than the preset oil release rate threshold, the lubrication effect of the lubricating oil can be considered insufficient. In this case, more lubricating oil needs to be obtained from the gas-liquid separator 40. Therefore, the stirring motor 41 can be controlled to run to increase the possibility of lubricating oil entering the oil return hole 111 and improve the oil return efficiency. After the stirring motor 41 runs, the lubricating oil index parameters of the compressor 10 can rise rapidly until the current lubricating oil index parameters of the compressor 10 meet the requirements for normal operation of the compressor 10, so that the operating condition of the compressor 10 can quickly reach the target operating condition.

[0043] When controlling the operation of the stirring motor 41, the operating power of the stirring motor 41 can be determined based on the magnitude of the lubricating oil index parameters. Taking the oil level as an example, a mapping relationship between the oil level and the operating power of the stirring motor 41 can be preset; the lower the oil level, the higher the operating power of the stirring motor 41. Subsequently, when controlling the operation of the stirring motor 41, the operating power of the stirring motor 41 can be determined based on the mapping relationship, so that while ensuring that the oil level of the compressor 10 can quickly rise to the preset oil level threshold, the energy consumption of the stirring motor 41 can be minimized as much as possible. Alternatively, the stirring motor 41 can be directly controlled to operate at maximum power to maximize the stirring efficiency of the stirring motor 41, so that the oil level of the compressor 10 can quickly rise to the preset oil level threshold.

[0044] The gas-liquid separator 40 of the oil return control method in this embodiment is equipped with a stirring motor 41. The stirring motor 41 can be used to improve the miscibility efficiency of liquid refrigerant and lubricating oil, preventing them from separating. The current operating condition can be used to detect whether the compressor 10 is short of oil. During the operation of the air conditioning system 100, a corresponding control strategy can be executed based on the current operating condition, wherein the control strategy includes at least controlling the stirring motor 41. For example, when the compressor 10 is short of oil, the stirring motor 41 can be controlled to operate, thereby increasing the possibility of lubricating oil entering the oil return hole 111 and entering the compressor 10, thus improving the oil return efficiency. After the stirring motor 41 operates, the compressor 10 can quickly reach the target operating condition, ensuring the safe operation of the compressor 10. When the compressor 10 is not short of oil, the stirring motor 41 can be controlled to stop operating. Thus, this application can control the operation of the stirring motor 41 in a targeted manner according to the current working conditions, so that when the lubrication effect is insufficient and the compressor 10 is short of oil, the stirring motor 41 can be used to achieve rapid oil return, so as to improve the lubrication effect of the lubricating oil on the compressor 10 as soon as possible, thereby avoiding wear caused by the lack of oil in the compressor 10, and thus improving the operational safety of the compressor 10.

[0045] Please see Figure 1 and Figure 3 In some embodiments, step 011: Execute a corresponding control strategy based on the current operating condition of the compressor 10. The control strategy includes at least controlling the stirring motor 41, including:

[0046] Step 0111: Based on the preset mapping relationship and the current working condition, obtain the target operating parameters corresponding to the current working condition, so as to control the operation of the stirring motor 41 according to the target operating parameters. The preset mapping relationship is used to characterize the corresponding operating parameters under different working conditions.

[0047] Specifically, a preset mapping relationship can be set according to the operating parameters of the agitator motor 41 when the compressor 10 can achieve rapid oil return under different operating conditions. The preset mapping relationship is used to characterize the corresponding operating parameters under different operating conditions. For example, the operating parameters may include the operating gear or speed. When the current gear indicates that the compressor 10 is less oily, the operating gear or speed should be higher. During the operation of the air conditioning system 100, the target operating parameters can be determined based on the preset mapping relationship and the current operating conditions, and the operation of the agitator motor 41 can be controlled according to the target operating parameters to ensure that the compressor 10 can achieve rapid oil return on the one hand, and reduce the energy consumption of the agitator motor 41 on the other hand.

[0048] In one embodiment, the operating parameters include operating gears, and the compressor 10 can operate at multiple operating gears. The preset mapping relationship includes a first mapping relationship, which characterizes the operating gears corresponding to different operating conditions. It can be understood that the higher the gear, the greater the stirring power of the stirring motor 41. Based on the oil shortage situation corresponding to different operating conditions, the power of different operating gears, and the operating gear corresponding to the stirring motor 41 when the compressor 10 can achieve rapid oil return under different operating conditions, operating gears corresponding to different operating conditions are set to generate the first mapping relationship. For example, the operating gears can be set to three levels, and the oil shortage situation can be divided into mild oil shortage, moderate oil shortage, and severe oil shortage. The corresponding oil shortage situation can be determined according to the lubricating oil index parameters corresponding to different operating conditions, where the gear corresponding to mild oil shortage is level one, the gear corresponding to moderate oil shortage is level two, and the gear corresponding to severe oil shortage is level three. During the operation of the air conditioning system 100, the target operating gear corresponding to the current operating condition can be obtained based on the first mapping relationship and the current operating condition, and then the stirring motor 41 is controlled to operate according to the target operating gear.

[0049] In another embodiment, the operating parameters include rotational speed, and the compressor 10 can operate at multiple speeds. The preset mapping relationship includes a second mapping relationship, which characterizes the rotational speed corresponding to different operating conditions. It can be understood that the higher the rotational speed, the greater the stirring power of the agitator motor 41. Based on the oil shortage situation corresponding to different operating conditions, and the rotational speed of the agitator motor 41 when the compressor 10 can achieve rapid oil return under different operating conditions, the rotational speeds corresponding to different operating conditions are set to generate the second mapping relationship. During the operation of the air conditioning system 100, the target rotational speed corresponding to the current operating condition can be obtained based on the second mapping relationship and the current operating condition, and the agitator motor 41 can be controlled to operate according to the target rotational speed.

[0050] Thus, during the operation of the air conditioning system 100, the corresponding target operating parameters can be determined according to the preset mapping relationship and the current operating conditions. After the stirring motor 41 operates according to the target operating parameters, the compressor 10 can achieve rapid oil return, and the energy consumption of the stirring motor 41 can be reduced, so that the stirring motor 41 does not need to operate at maximum power in every operating condition.

[0051] Please see Figure 1 and Figure 4 In some implementations, when the current operating condition is that the current oil level is greater than a preset oil level threshold and the current oil release rate is greater than a preset oil release rate threshold, step 011: Execute the corresponding control strategy based on the current operating condition of the compressor 10, including:

[0052] Step 0112: Stop the stirring motor 41 from running;

[0053] Step 0113: Control the compressor 10, outdoor unit assembly 20 and indoor unit assembly 30 to maintain the current operating parameters.

[0054] Specifically, under the current operating condition where the current oil level is greater than the preset oil level threshold and the current oil release rate is greater than the preset oil release rate threshold, it can be assumed that the compressor 10 is not short of oil and the lubricating oil has a good lubrication effect. At this time, a lower oil return efficiency will not affect the normal operation of the compressor 10, so the agitator motor 41 can be stopped to reduce its energy consumption. Simultaneously, the compressor 10, oil separator 50, four-way valve 60, outdoor unit assembly 20, and indoor unit assembly 30 can all maintain their current operating parameters without special operation, thereby ensuring that the cooling effect of the entire air conditioning system 100 meets the current demand.

[0055] Please see Figure 1 and Figure 5 In some embodiments, the stirring motor 41 includes multiple operating positions. When the current oil level is greater than a preset oil level threshold and the current oil release rate is less than a preset oil release rate threshold, step 011: Execute the corresponding control strategy based on the current operating condition of the compressor 10, including:

[0056] Step 0114: Control the stirring motor 41 to operate at the preset operating speed;

[0057] Step 0115: Reduce the speed of compressor 10 according to the preset adjustment ratio;

[0058] Step 0116: Reduce the opening degree of the electronic expansion valve 32 of the indoor unit component 30, which is in the open state, according to the first adjustment value;

[0059] Step 0117: Maintain the operation of the indoor unit component 30, which is in the off state.

[0060] Specifically, the stirring motor 41 may include multiple operating speeds, such as three, four, or seven speeds. The higher the operating speed, the greater the stirring power of the stirring motor 41. Under the current operating condition where the current oil level is higher than a preset oil level threshold and the current oil release rate is lower than a preset oil release rate threshold, it is considered that the lubricating effect of the lubricating oil is insufficient, and the liquid refrigerant content in the compressor 10 is relatively high.

[0061] If the lubricating oil's lubrication effect is insufficient, the compressor 10 may be at risk of damage. Furthermore, the compressor 10's rotational speed affects the amount of refrigerant drawn in; the higher the speed, the greater the amount of refrigerant drawn in. Therefore, the compressor 10's rotational speed can be reduced according to a preset adjustment ratio, for example, a preset adjustment ratio of 80%, reducing the compressor 10's rotational speed to 80% of its current speed. This reduces both the amount of refrigerant drawn in and the risk of compressor 10 damage. Simultaneously, the stirring motor 41 can be controlled to operate at a preset operating level. This preset operating level can correspond to a higher stirring power, such as the highest or second-highest operating level, to quickly improve the miscibility efficiency of the refrigerant and lubricating oil, thereby facilitating a rapid increase in oil return efficiency. A low oil release rate can be attributed to excessive liquid refrigerant in the gas-liquid separator 40. Therefore, the opening of the electronic expansion valve 32 of the indoor unit component 30 in the open state can be reduced according to the first adjustment value. For example, the opening of the electronic expansion valve 32 of the open indoor unit 31 can be reduced by 40 steps, while the indoor unit component 30 in the closed state is kept running. This reduces the flow rate of liquid refrigerant into the indoor unit component 30, allowing the indoor unit component 30 to fully evaporate the liquid refrigerant and ensuring that the refrigerant flowing out of the indoor unit component 30 is gaseous. This reduces the amount of liquid refrigerant flowing into the gas-liquid separator 40, thereby improving the oil release rate of the gas-liquid separator 40.

[0062] Thus, when the current oil level is greater than the preset oil level threshold and the current oil release rate is less than the preset oil release rate threshold, i.e., the oil release rate is low, the operating status of the stirring motor 41, the compressor 10 and the indoor unit component 30 can be adjusted accordingly. Under the combined action of the stirring motor 41, the compressor 10 and the indoor unit component 30, the oil release rate and oil return efficiency can be improved, thereby avoiding wear caused by prolonged oil shortage in the compressor 10, and thus improving the operational safety of the compressor 10.

[0063] Please see Figure 1 and Figure 6 In some embodiments, the stirring motor 41 includes multiple operating positions. When the current operating condition is that the current oil level is lower than a preset oil level threshold and the current oil release rate is greater than a preset oil release rate threshold, and when the current operating condition is that the current oil level is lower than a preset oil level threshold and the current oil release rate is lower than a preset oil release rate threshold, step 011: Execute the corresponding control strategy based on the current operating condition of the compressor 10, including:

[0064] Step 0118: Control the stirring motor 41 to run according to the preset operating speed;

[0065] Step 0119: Control the compressor 10 to run according to the preset speed;

[0066] Step 0120: Control the opening degree of the electronic expansion valve 32 of the indoor unit component 30 according to the first preset opening degree.

[0067] Specifically, the preset speed is the fixed oil return speed, which can be calculated based on the refrigerant flow rate when the gaseous refrigerant can drive the lubricating oil in the pipeline to move quickly to the gas-liquid separator 40. The first preset opening degree is the opening degree of the electronic expansion valve 32 when the refrigerant can quickly pass through the indoor unit component 30. For example, the first preset opening degree can be the maximum opening degree of the electronic expansion valve 32.

[0068] If the current oil level is lower than the preset oil level threshold and the current oil release rate is higher than the preset oil release rate threshold, it can be assumed that the compressor 10 is short of oil. This indicates that there is a large amount of lubricating oil remaining in the pipeline or a large amount of lubricating oil stored in the gas-liquid separator 40. If the current oil level is lower than the preset oil level threshold and the current oil release rate is lower than the preset oil release threshold, it can be assumed that the compressor 10 is short of oil and the oil release rate is low. This indicates that there is a large amount of lubricating oil remaining in the pipeline or a large amount of lubricating oil stored in the gas-liquid separator 40, and a high content of liquid refrigerant in the gas-liquid separator 40.

[0069] In both of the above scenarios, the compressor 10 can be controlled to operate according to a preset speed to ensure that the lubricating oil in the pipeline can quickly move into the gas-liquid separator 40. Next, the opening of the electronic expansion valve 32 of the indoor unit assembly 30 can be controlled according to a first preset opening degree to increase the flow rate of the refrigerant flowing in the pipeline, further ensuring that the lubricating oil in the pipeline can be quickly driven to the gas-liquid separator 40 by the refrigerant. It should be noted that the opening degrees of both the open and closed indoor unit assembly 30 can be controlled simultaneously to maximize the flow rate of the refrigerant flowing in the pipeline. Simultaneously, the stirring motor 41 can be controlled to operate at a preset speed to quickly improve the miscibility efficiency of the refrigerant and lubricating oil, thereby facilitating a rapid increase in oil return efficiency.

[0070] In this way, the flow rate and volume of refrigerant in the pipeline can be increased by controlling the compressor 10 and the electronic expansion valve 32, ensuring that the lubricating oil in the pipeline can quickly move to the gas-liquid separator 40, thereby facilitating an increase in oil release rate. At the same time, the operation of the stirring motor 41 can improve the oil return efficiency, thereby increasing the flow rate of liquid delivered from the gas-liquid separator 40 to the compressor 10, especially the flow rate of lubricating oil, ensuring that the oil level and oil release rate of the compressor 10 can quickly rise to the corresponding threshold, thereby avoiding wear caused by prolonged oil shortage in the compressor 10, and thus improving the operational safety of the compressor 10.

[0071] Please see Figure 1 and Figure 7In some embodiments, after step 011: executing the corresponding control strategy based on the current operating condition of the compressor 10, the oil return control method further includes:

[0072] Step 013: When the current oil level is greater than the preset oil level threshold and the current oil release rate is greater than the preset oil release rate threshold, the electronic expansion valve 32 of the compressor 10 and the indoor unit component 30 is restored to the operating conditions before the control strategy was executed.

[0073] Step 015: Gradually reduce the operating speed according to the current oil release rate and the preset oil release rate threshold until the stirring motor 41 stops running.

[0074] Specifically, under the control strategy corresponding to the current operating condition, the current oil level and current oil release rate can be detected in real time. If the current oil level is lower than the preset oil level threshold or the current oil release rate is lower than the preset oil release rate threshold, the compressor 10, indoor unit component 30 and stirring motor 41 can continue to operate according to the control strategy to increase the current oil level or current oil release rate as quickly as possible.

[0075] When the current oil level is greater than the preset oil level threshold and the current oil release rate is greater than the preset oil release rate threshold, it can be considered that the compressor 10 has reached the target operating condition. Therefore, the electronic expansion valve 32 of the compressor 10 and the indoor unit component 30 can resume normal control, that is, control the compressor 10 and the electronic expansion valve 32 to return to the operating condition before the control strategy was executed. At the same time, the agitator motor 41 can be directly shut off, or the operating level can be gradually reduced according to the current oil release rate and the preset oil release rate threshold. For example, the operating level corresponding to the difference between the current oil release rate and the preset oil release rate threshold can be preset when the current oil release rate is greater than the preset oil release rate threshold. The larger the difference, the lower the corresponding operating level. Then, the difference is calculated according to the current oil release rate and the preset oil release rate threshold, and the agitator motor 41 is controlled to run according to the operating level corresponding to the difference until the agitator motor 41 stops running. Of course, when directly controlling the operation of the agitator motor 41 according to the speed, the speed corresponding to the difference between the current oil release rate and the preset oil release rate threshold can be preset when the current oil release rate is greater than the preset oil release rate threshold. The larger the difference, the lower the corresponding speed. Then, the difference between the current oil release rate and the preset oil release rate threshold is calculated, and the stirring motor 41 is controlled to run according to the running gear corresponding to the difference until the stirring motor 41 stops running.

[0076] Thus, after implementing the control strategy corresponding to the current operating condition, the next control strategy can be determined based on the current oil level and the current oil release rate. If the current oil level is greater than the preset oil level threshold and the current oil release rate is greater than the preset oil release rate threshold, the electronic expansion valve 32 of the compressor 10 and the indoor unit component 30 can be restored to the operating condition before the control strategy was implemented. At the same time, the stirring motor 41 can be controlled to gradually reduce its operating speed to slow down the stratification of liquid refrigerant and lubricating oil, ensuring that the current oil release rate will not drop below the preset oil release rate threshold for at least a period of time after the stirring motor 41 stops running.

[0077] Please see Figure 1 and Figure 8 In some embodiments, the stirring motor 41 has three operating speeds. The higher the operating speed, the higher the stirring efficiency of the stirring motor 41. The preset operating speed is three. Step 015: Gradually reduce the operating speed according to the current oil release rate and the preset oil release rate threshold until the stirring motor 41 stops running, including:

[0078] Step 0151: When the current oil level is greater than the preset oil level threshold and the current oil release rate is greater than the preset oil release rate threshold but less than the first preset threshold, control the stirring motor 41 to run at the second gear.

[0079] Step 0152: When the current oil level is greater than the preset oil level threshold and the current oil release rate is greater than the first preset threshold and less than the second preset threshold, control the stirring motor 41 to run at the first gear.

[0080] Step 0153: When the current oil level is greater than the preset oil level threshold and the current oil release rate is greater than the second preset threshold, control the stirring motor 41 to stop running.

[0081] Specifically, with three operating speeds, a preset oil release rate threshold can be used as the base value, and two additional safety thresholds can be set: a first preset threshold and a second preset threshold. If the current oil release rate is greater than the first preset threshold and less than the second preset threshold, the probability of the current oil release rate dropping below the preset oil release rate threshold in a short period is low. If the current oil release rate is greater than the second preset threshold and less than the second preset threshold, the probability of the current oil release rate dropping below the preset oil release rate threshold in a short period is extremely low. For example, the first preset threshold is 12%, and the second preset threshold is 24%.

[0082] The preset operating levels in the control strategy can be three, allowing the agitator motor 41 to agitate the liquid refrigerant and lubricating oil at maximum power to maximize oil return efficiency. After executing the corresponding control strategy based on the current operating condition of the compressor 10, the current oil level and current oil release rate can be detected in real time. If the current oil level is lower than the preset oil level threshold or the current oil release rate is lower than the preset oil release rate threshold, the compressor 10, indoor unit component 30, and agitator motor 41 are still controlled to operate according to the control strategy, with the agitator motor 41 operating at the preset operating level, i.e., the maximum level. If the current oil level is higher than the preset oil level threshold and the current oil release rate is higher than the preset oil release threshold but lower than the first preset threshold, it can be considered that the compressor 10 has reached the target operating condition. Therefore, the electronic expansion valve 32 of the compressor 10 and indoor unit component 30 can resume normal control, i.e., the compressor 10 and electronic expansion valve 32 are restored to the operating conditions before the control strategy was executed, while the agitator motor 41 is reduced to operate at level two. If the current oil level is higher than the preset oil level threshold, and the current oil release rate is higher than the first preset threshold but lower than the second preset threshold, the speed of the stirring motor 41 is reduced again, controlling the stirring motor 41 to operate at speed one. If the current oil level is higher than the preset oil level threshold, and the current oil release rate is higher than the second preset threshold, the stirring motor 41 is controlled to stop operating.

[0083] Thus, when the current oil level is greater than the preset oil level threshold and the current oil release rate is greater than the preset oil release rate threshold, the electronic expansion valve 32 of the compressor 10 and the indoor unit assembly 30 can be restored to the operating conditions before the control strategy was executed, to ensure the cooling effect of the air conditioning system 100. At the same time, the operating speed of the agitator motor 41 can be gradually reduced to reduce the energy consumption of the agitator motor 41 and slow down the rate of stratification of liquid refrigerant and lubricating oil, ensuring that the current oil release rate will not drop below the preset oil release rate threshold for at least a period of time after the agitator motor 41 stops operating.

[0084] Please see Figure 1 and Figure 9 In some embodiments, when the control strategy corresponds to the situation where the current oil level is less than a preset oil level threshold and the current oil release rate is less than a preset oil release rate threshold, after step 011: executing the corresponding control strategy based on the current operating condition of the compressor 10, the oil return control method further includes:

[0085] Step 017: When the current oil level is greater than the preset oil level threshold and the oil release rate is less than the preset oil release rate threshold, control the compressor 10 and the electronic expansion valve 32 to return to the operating conditions before the control strategy was executed, and control the stirring motor 41 to run at the preset operating level.

[0086] Step 019: Real-time detection of current oil release rate;

[0087] Step 021: When the current oil level is greater than the preset oil level threshold and the current oil release rate is greater than the preset oil release rate threshold, the operating gear is gradually reduced according to the current oil release rate and the preset oil release rate threshold until the stirring motor 41 stops running.

[0088] Specifically, after implementing the control strategy corresponding to the current working condition that the current oil level is less than the preset oil level threshold and the current oil release rate is less than the preset oil release rate threshold, the current oil level and the current oil release rate can be detected.

[0089] When the current oil level is greater than the preset oil level threshold and the current oil release rate is greater than the preset oil release rate threshold, all devices in the air conditioning system 100 can resume normal control. That is, the indoor unit 30, the agitator motor 41, and the compressor 10 can all return to their operating conditions before the control strategy was implemented. Alternatively, the operating speed of the agitator motor 41 can be gradually reduced. For details, please refer to the description of gradually reducing the operating speed of the agitator motor 41 above; it will not be repeated here. When the current oil level is less than the preset oil level threshold and the current oil release rate is greater than the preset oil release threshold, or when the current oil level is less than the preset oil level threshold and the current oil release rate is less than the preset oil release threshold, it is considered that the oil level is still not up to standard. In this case, the air conditioning system 100 needs to continue operating according to the control strategy.

[0090] When the current oil level is higher than the preset oil level threshold and the oil release rate is lower than the preset oil release rate threshold, the oil level of compressor 10 can be considered to have met the standard. However, most of the liquid delivered from the gas-liquid separator 40 to compressor 10 is liquid refrigerant. Since the current oil level is lower than the preset oil level threshold and the current oil release rate is lower than the preset oil release rate threshold, the corresponding control strategy may cause a large amount of refrigerant to flow into the gas-liquid separator 40. Therefore, at this time, compressor 10 and electronic expansion valve 32 can be controlled to return to the operating conditions before the control strategy was implemented to reduce the flow rate of refrigerant in the system and prevent a large amount of refrigerant from continuously flowing into the gas-liquid separator 40, thereby improving the oil release rate in the gas-liquid separator 40. Simultaneously, because the current oil release rate is low, it is necessary to continue controlling the stirring motor 41 to operate at the preset operating level to improve the miscibility efficiency of liquid refrigerant and lubricating oil, avoid stratification, and thus increase the probability of lubricating oil entering the oil return hole 111 and entering compressor 10, thereby facilitating an increase in the oil release rate of compressor 10.

[0091] At this point, it is necessary to continue monitoring the current oil release rate. If the current oil level is greater than the preset oil level threshold and the current oil release rate is greater than the preset oil release threshold, the operating speed is gradually reduced based on the current oil release rate and the preset oil release threshold until the stirring motor 41 stops operating. This slows down the stratification of the liquid refrigerant and lubricating oil, ensuring that the current oil release rate does not drop below the preset oil release threshold for at least a period of time after the stirring motor 41 stops operating. The specific method can be found in the description of gradually reducing the operating speed of the stirring motor 41 above, and will not be repeated here.

[0092] Thus, after implementing the control strategy corresponding to the current working condition where the current oil level is less than the preset oil level threshold and the current oil release rate is less than the preset oil release rate threshold, the subsequent control method can be determined based on the current oil level and the current oil release rate to ensure that the current oil level can eventually rise to the preset oil level threshold and the current oil release rate can rise to the preset oil release rate threshold.

[0093] Please see the following: Figure 1 , Figure 10 and Figure 11 In some embodiments, the air conditioning system 100 further includes a regulating valve 70, which is installed on the suction pipe 11 of the compressor 10. During normal operation of the air conditioning system 100, the opening degree of the regulating valve 70 is a second preset opening degree. When the current operating condition is that the current oil level is greater than a preset oil level threshold and the current oil release rate is less than a preset oil release rate threshold, and when the current operating condition is that the current oil level is less than a preset oil level threshold and the current oil release rate is less than a preset oil release rate threshold, step 011: Executing the corresponding control strategy based on the current operating condition of the compressor 10 further includes:

[0094] Step 0121: Reduce the opening of regulating valve 70 according to the second adjustment value.

[0095] Specifically, an adjustable regulating valve 70, such as an electric ball valve, can be installed on the suction pipe 11 of the compressor 10. The adjustable step size of the electric ball valve is 3000P. By reducing the opening of the regulating valve 70, the flow rate of gaseous refrigerant in the suction pipe 11 of the compressor 10 can be increased, thereby increasing the pressure difference in the suction pipe 11 of the compressor 10 and thus improving the oil return power difference. During normal operation of the air conditioning system 100, the opening of the regulating valve 70 is a second preset opening. The second preset opening is the opening of the regulating valve 70 when both gas and liquid in the gas-liquid separator 40 can flow smoothly and a large amount of gaseous refrigerant can flow into the suction pipe 11 of the compressor 10. The second adjustment value is the difference between the opening of the regulating valve 70 and the second preset opening when both gas and liquid can flow smoothly and quickly, for example, the second adjustment value is 1000P.

[0096] When the current oil release rate is less than a preset oil release rate threshold, the control strategy may further include reducing the opening of the regulating valve 70 according to a second adjustment value. That is, when the current oil level is greater than a preset oil level threshold and the current oil release rate is less than a preset oil release rate threshold, the control strategy includes controlling the stirring motor 41 to operate at a preset operating level, reducing the speed of the compressor 10 according to a preset adjustment ratio, reducing the opening of the electronic expansion valve 32 of the indoor unit component 30 (which is in the open state) according to a first adjustment value, maintaining the operation of the indoor unit component 30 (which is in the closed state), and reducing the opening of the regulating valve 70 according to the second adjustment value. When the current oil level is less than a preset oil level threshold and the current oil release rate is less than a preset oil release threshold, the control strategy includes controlling the stirring motor 41 to operate at a preset operating level, controlling the compressor 10 to operate at a preset speed, controlling the opening of the electronic expansion valve 32 of the indoor unit component 30 according to a first preset opening, and reducing the opening of the regulating valve 70 according to the second adjustment value.

[0097] Thus, when the current oil release rate is lower than the preset oil release rate threshold, the return oil power difference can be increased by adjusting the valve, so that the lubricating oil can be quickly drawn into the return oil hole 111 and quickly moved into the compressor 10 through the suction pipe 11 of the compressor 10, thereby improving the return oil efficiency of the lubricating oil in the gas-liquid separator 40, so that the current oil release rate can be quickly increased to the preset oil release rate threshold.

[0098] Please see Figure 1 , Figure 10 and Figure 11 In some embodiments, after executing the corresponding control strategy based on the current operating condition of the compressor 10, the oil return control method further includes:

[0099] Step 023: When the current oil level is greater than the preset oil level threshold and the current oil release rate is greater than the preset oil release rate threshold, adjust the current opening of the regulating valve 70 according to the second preset opening.

[0100] Specifically, when the control strategy includes controlling the regulating valve 70, after executing the control strategy, the current opening degree of the regulating valve 70 can be adjusted according to the current oil level and the current oil release rate. If the current oil level is less than a preset oil level threshold, or the current oil release rate is less than a preset oil release rate threshold, the regulating valve 70 can continue to be controlled according to the control strategy. If the current oil level is greater than the preset oil level threshold and the current oil release rate is greater than the preset oil release threshold, the current opening degree of the regulating valve 70 is adjusted according to the second preset opening degree to facilitate the flow of liquid in the gas-liquid separator 40 and liquid in the suction pipe 11 of the compressor 10, while also ensuring that a large amount of liquid refrigerant can smoothly enter the regulating valve 70, thereby ensuring the normal operation of the air conditioning system 100.

[0101] Please see Figure 1 and Figure 12 To facilitate better implementation of the oil return control method of this application, this application also provides an oil return control device 80. This oil return control device 80 is applied to an air conditioning system 100, which includes a compressor 10, an outdoor unit assembly 20, an indoor unit assembly 30, and a gas-liquid separator 40. The exhaust pipe of the compressor 10 is connected to the inlet of the outdoor unit assembly 20, the outlet of the outdoor unit assembly 20 is connected to the inlet of the indoor unit assembly 30, and the outlet of the indoor unit assembly 30 is connected to the gas-liquid separator 40. At least a portion of the suction pipe 11 of the compressor 10 is located in the gas-liquid separator 40, and the suction pipe 11 of the compressor 10 is provided with an oil return hole 111. A stirring motor 41 is provided at the bottom of the gas-liquid separator 40. The oil return control device 80 may include a control module 81. The acquisition module 11 is used to execute a corresponding control strategy based on the current operating condition of the compressor 10. The control strategy includes at least controlling the stirring motor 41 so that the compressor 10 reaches the target operating condition. Under the target operating condition, the current lubricating oil index parameters of the compressor 10 meet the requirements of the compressor 10 during normal operation.

[0102] The control module 81 is specifically used to obtain the target operating parameters corresponding to the current operating condition based on the preset mapping relationship and the current operating condition, so as to control the operation of the stirring motor 41 according to the target operating parameters. The preset mapping relationship is used to characterize the corresponding operating parameters under different operating conditions.

[0103] The control module 81 is specifically used to control the stirring motor 41 to stop running; and to control the compressor 10, oil separator 50, four-way valve 60, outdoor unit assembly 20 and indoor unit assembly 30 to maintain the current operating parameters.

[0104] The control module 81 is specifically used to control the stirring motor 41 to operate at a preset operating level; reduce the speed of the compressor 10 according to a preset adjustment ratio; reduce the opening of the electronic expansion valve 32 of the indoor unit component 30 in the open state according to a first adjustment value; and maintain the operating state of the indoor unit component 30 in the closed state.

[0105] The control module 81 is specifically used to control the operation of the stirring motor 41 according to the preset operating level; to control the operation of the compressor 10 according to the preset speed; and to control the opening of the electronic expansion valve 32 of the indoor unit component 30 according to the first preset opening degree.

[0106] The oil return control device 80 also includes a recovery module 82. The recovery module 82 is used to control the electronic expansion valve 32 of the compressor 10 and the indoor unit component 30 to return to the operating conditions before the control strategy was executed when the current oil level is greater than the preset oil level threshold and the current oil release rate is greater than the preset oil release rate threshold. The recovery module 82 is used to control the electronic expansion valve 32 of the compressor 10 and the indoor unit component 30 to return to the operating conditions before the control strategy was executed. The recovery module 82 gradually reduces the operating level according to the current oil release rate and the preset oil release rate threshold until the stirring motor 41 stops running.

[0107] The recovery module 82 is specifically used to control the stirring motor 41 to operate at level two when the current oil level is greater than the preset oil level threshold and the current oil release rate is greater than the preset oil release rate threshold but less than the first preset threshold; to control the stirring motor 41 to operate at level one when the current oil level is greater than the preset oil level threshold and the current oil release rate is greater than the first preset threshold but less than the second preset threshold; and to control the stirring motor 41 to stop operating when the current oil level is greater than the preset oil level threshold and the current oil release rate is greater than the second preset threshold.

[0108] The recovery module 82 is specifically used to control the compressor 10 and electronic expansion valve 32 to return to the operating conditions before the execution of the control strategy when the current oil level is greater than the preset oil level threshold and the oil release rate is less than the preset oil release rate threshold, and to control the stirring motor 41 to run at the preset operating level; to detect the current oil release rate in real time; and to gradually reduce the operating level according to the current oil release rate and the preset oil release rate when the current oil level is greater than the preset oil level threshold and the current oil release rate is greater than the preset oil release rate threshold, until the stirring motor 41 stops running.

[0109] The control module 81 is specifically used to reduce the opening of the regulating valve 70 according to the second adjustment value.

[0110] The recovery module 82 is specifically used to control the regulating valve 70 to return to the operating conditions before the execution of the control strategy when the current oil level is greater than the preset oil level threshold and the oil release rate is greater than the preset oil release rate threshold.

[0111] The oil return control device 80 also includes a determination module 83. The determination module 83 is used to obtain the current oil level and current oil release rate of the compressor 10 based on the oil level sensor 12; and to determine the current operating condition based on the preset oil level threshold, the preset oil release rate threshold, the current oil level, and the current oil release rate.

[0112] The oil return control device 80 has been described above from the perspective of functional modules, with reference to the accompanying drawings. This functional module can be implemented in hardware, in software instructions, or in a combination of hardware and software modules. Specifically, the steps of the method embodiments in this application can be completed by integrated logic circuits in the processor's hardware and / or by software instructions. The steps of the method disclosed in this application can be directly manifested as execution by a hardware encoding processor, or by a combination of hardware and software modules in the encoding processor. Optionally, the software module can reside in a mature storage medium in the art, such as random access memory, flash memory, read-only memory, programmable read-only memory, electrically erasable programmable memory, or registers. This storage medium is located in memory, and the processor reads information from the memory and, in conjunction with its hardware, completes the steps in the above method embodiments.

[0113] Please see the following: Figure 1 and Figure 13 The air conditioning system 100100 of this application includes a compressor 10, an outdoor unit assembly 20, an indoor unit assembly 30, a gas-liquid separator 40, a processor 90, a memory 110, and a computer program. The exhaust pipe of the compressor 10 is connected to the input port of the outdoor unit assembly 20, the output port of the outdoor unit assembly 20 is connected to the input port of the indoor unit assembly 30, and the output port of the indoor unit assembly 30 is connected to the gas-liquid separator 40. At least a portion of the suction pipe 11 of the compressor 10 is located in the gas-liquid separator 40, the suction pipe 11 of the compressor 10 is provided with an oil return hole 111, and a stirring motor 41 is provided at the bottom of the gas-liquid separator 40. The computer program is stored in the memory 110 and executed by the processor 90. The computer program includes instructions for executing the oil return control method of any of the above embodiments.

[0114] Please see Figure 14 This application also provides a computer-readable storage medium 300 storing a computer program 310. When the computer program 310 is executed by the processor 320, it implements the steps of the oil return control method of any of the above embodiments. For the sake of brevity, these steps will not be described in detail here.

[0115] In the description of this specification, the references to terms such as "some embodiments," "in one example," "exemplarily," etc., indicate that a specific feature, structure, material, or characteristic described in connection with an embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0116] Any process or method described in the flowchart or otherwise herein can be understood as representing a module, segment, or portion of code comprising one or more executable instructions for implementing a particular logical function or process, and the scope of the preferred embodiments of this application includes additional implementations in which functions may be performed not in the order shown or discussed, including substantially simultaneously or in reverse order depending on the function involved, as will be understood by those skilled in the art to which embodiments of this application pertain.

[0117] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. An oil return control method characterized by, The application is applied to an air conditioning system, which comprises a compressor, an outdoor unit assembly, an indoor unit assembly and a gas-liquid separator, an exhaust pipe of the compressor is connected with an input port of the outdoor unit assembly, an output port of the outdoor unit assembly is connected with an input port of the indoor unit assembly, and an output port of the indoor unit assembly is connected with the gas-liquid separator; at least part of a suction pipe of the compressor is located in the gas-liquid separator, the suction pipe is provided with an oil return hole, and a bottom of the gas-liquid separator is provided with a stirring motor; The method comprises: Based on the current working condition of the compressor, a corresponding control strategy is executed, which at least comprises controlling the stirring motor to make the compressor reach a target working condition, in which a current lubricating oil index parameter of the compressor meets the requirement of normal operation of the compressor; the oil return control method further comprises: acquiring the current oil level and the current oil release rate of the compressor according to the oil level sensor; setting a preset oil level threshold and a preset oil release rate threshold according to the requirement of normal operation of the compressor; The air conditioning system further comprises an adjusting valve, which is installed on the suction pipe; during normal operation of the air conditioning system, the opening degree of the adjusting valve is a second preset opening degree; in the case that the current working condition is that the current oil level is greater than the preset oil level threshold and the current oil release rate is less than the preset oil release rate threshold, and in the case that the current working condition is that the current oil level is less than the preset oil level threshold and the current oil release rate is less than the preset oil release rate threshold, the execution of the corresponding control strategy based on the current working condition of the compressor further comprises: According to a second adjustment value, the opening degree of the adjusting valve is reduced, the second adjustment value is the difference between the opening degree of the adjusting valve and the second preset opening degree when gas and liquid can flow smoothly and quickly; and The oil return control method further comprises: In the case that the current oil level is greater than the preset oil level threshold and the oil release rate is greater than the preset oil release rate threshold, the adjusting valve is controlled to return to the operating condition before the execution of the control strategy.

2. The oil return control method according to claim 1, characterized by, In the case that the current working condition is that the current oil level is greater than the preset oil level threshold and the current oil release rate is greater than the preset oil release rate threshold, the compressor reaches the target working condition, and the execution of the corresponding control strategy based on the current working condition of the compressor comprises: The stirring motor is controlled to stop operating; The compressor, the outdoor unit assembly and the indoor unit assembly are controlled to maintain the current operating parameters.

3. The oil return control method according to claim 1, characterized by, The stirring motor comprises a plurality of operating gears; in the case that the current working condition is that the current oil level is greater than the preset oil level threshold and the current oil release rate is less than the preset oil release rate threshold, the execution of the corresponding control strategy based on the current working condition of the compressor comprises: The stirring motor is controlled to operate at a preset operating gear; The rotating speed of the compressor is reduced according to a preset adjustment ratio; The opening degree of an electronic expansion valve of an indoor unit assembly in an open state is reduced according to a first adjustment value; The operating state of an indoor unit assembly in a closed state is maintained.

4. The oil return control method according to claim 1, characterized by, The stirring motor comprises a plurality of operation gears, and the control strategy corresponding to the current working condition of the compressor is executed in the following two cases: in the case that the current oil level is less than the preset oil level threshold and the current oil release rate is greater than the preset oil release rate threshold; and in the case that the current oil level is less than the preset oil level threshold and the current oil release rate is less than the preset oil release rate threshold, and the control strategy comprises the following steps: controlling the stirring motor to operate according to a preset operation gear; controlling the compressor to operate according to a preset rotating speed; controlling the opening degree of the electronic expansion valve of the indoor unit assembly according to a first preset opening degree.

5. The oil return control method according to any one of claims 3-4, characterized by, After the control strategy corresponding to the current working condition of the compressor is executed, the oil return control method further comprises the following steps: in the case that the current oil level is greater than the preset oil level threshold and the current oil release rate is greater than the preset oil release rate threshold, controlling the compressor and the electronic expansion valve of the indoor unit assembly to return to the operation condition before the control strategy is executed; gradually reducing the operation gear according to the current oil release rate and the preset oil release rate threshold until the stirring motor stops operating.

6. The oil return control method according to claim 4, characterized by, In the case that the control strategy corresponds to the case that the current oil level is less than the preset oil level threshold and the current oil release rate is less than the preset oil release rate threshold, after the control strategy corresponding to the current working condition of the compressor is executed, the oil return control method further comprises the following steps: in the case that the current oil level is greater than the preset oil level threshold and the oil release rate is less than the preset oil release rate threshold, controlling the compressor and the electronic expansion valve to return to the operation condition before the control strategy is executed, and controlling the stirring motor to operate at a preset operation gear; detecting the current oil release rate in real time; in the case that the current oil level is greater than the preset oil level threshold and the current oil release rate is greater than the preset oil release rate threshold, gradually reducing the operation gear according to the current oil release rate and the preset oil release rate threshold until the stirring motor stops operating.

7. The oil return control method according to claim 1, characterized by, determining the current working condition according to the preset oil level threshold, the preset oil release rate threshold, the current oil level and the current oil release rate.

8. An air conditioning system characterized by, comprise: a compressor, an outdoor unit assembly, an indoor unit assembly and a gas-liquid separator, an exhaust pipe of the compressor is connected with an input port of the outdoor unit assembly, an output port of the outdoor unit assembly is connected with an input port of the indoor unit assembly, and an output port of the indoor unit assembly is connected with the gas-liquid separator; at least part of a suction pipe of the compressor is located in the gas-liquid separator, the suction pipe is provided with an oil return hole, and a bottom of the gas-liquid separator is provided with a stirring motor; a processor and a memory; and a computer program, wherein the computer program is stored in the memory and executed by the processor, and the computer program comprises instructions for executing the oil return control method according to any one of claims 1 to 7.

9. The air conditioning system of claim 8, wherein, Also comprising an oil separator and a four-way valve, an exhaust pipe of the compressor is connected with an input port of the oil separator; a first output port of the oil separator is connected with the four-way valve and connected with an input port of the outdoor unit assembly through the four-way valve, a second output port of the oil separator is connected with a suction pipe of the compressor; an output port of the indoor unit assembly is connected with the four-way valve and connected with the gas-liquid separator through the four-way valve.

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