An air conditioning system and its control method

Abstract

This application provides an air conditioning system and its control method, particularly relating to the field of air conditioning technology. The air conditioning system includes: an indoor heat exchanger; an outdoor heat exchanger; a compressor; a gas-liquid separator, the outlet of which is connected to the inlet of the compressor; an economizer and an expansion valve. The economizer has a first refrigerant passage and a second refrigerant passage. One end of the first refrigerant passage is connected to the indoor heat exchanger, and the other end is connected to the outdoor heat exchanger. One end of the second refrigerant passage is connected to the pipeline connecting the first refrigerant passage to the outdoor heat exchanger via the expansion valve, and the other end is connected to the inlet of the gas-liquid separator. A controller is configured to adjust the opening of the expansion valve when the exhaust temperature of the current detection cycle is greater than the target exhaust temperature. If the liquid level of the gas-liquid separator is greater than the preset liquid level corresponding to the target temperature condition, the opening of the expansion valve is reduced until the liquid level of the gas-liquid separator is less than or equal to the preset liquid level.

Description

Technical Field

[0001] This application relates to the field of air conditioning technology, and in particular to an air conditioning system and its control method. Background Technology

[0002] In recent years, with the continuous improvement of people's living standards and the continuous development of the real estate industry, more and more air conditioning products have adopted large-capacity units, and the corresponding compressor displacements have also increased. At the same time, due to the increase in urban population and the increasingly complex and diverse outdoor environment, higher requirements have been placed on the stable and reliable operation of air conditioning outdoor units.

[0003] The compressor is the core component of the outdoor unit of an air conditioner. There are many reasons why the compressor might malfunction. Excessively high exhaust temperature can damage the compressor, and liquid refrigerant entering the compressor can cause it to operate with liquid, thus damaging the compressor. To address the problem of liquid refrigerant entering the compressor, a gas-liquid separator of appropriate specifications is typically designed to separate the liquid refrigerant.

[0004] However, in the actual operation of an air conditioning system, measures taken to address the problem of excessively high compressor discharge temperature can also lead to an increase in the liquid level in the gas-liquid separator. When the liquid level in the gas-liquid separator is too high, the liquid refrigerant in the separator flows into the compressor, potentially damaging it. Summary of the Invention

[0005] This application provides an air conditioning system and its control method to solve the problem of excessive liquid level in the gas-liquid separator, which damages the compressor, caused by measures taken to reduce the compressor's exhaust temperature.

[0006] In a first aspect, embodiments of this application provide an air conditioning system, the air conditioning system comprising:

[0007] Indoor heat exchanger;

[0008] Outdoor heat exchanger;

[0009] compressor;

[0010] A gas-liquid separator, the outlet of which is connected to the inlet of the compressor;

[0011] The economizer and expansion valve are included. The economizer has a first refrigerant passage and a second refrigerant passage. One end of the first refrigerant passage is connected to the indoor heat exchanger, and the other end is connected to the outdoor heat exchanger. One end of the second refrigerant passage is connected to the pipeline of the first refrigerant passage connected to the outdoor heat exchanger through the expansion valve, and the other end is connected to the inlet of the gas-liquid separator.

[0012] The controller is configured as follows:

[0013] If the exhaust temperature in the current testing cycle is greater than the target exhaust temperature, determine the target temperature condition that the air conditioning system must meet from at least one temperature condition.

[0014] Adjust the opening of the expansion valve according to the adjustment strategy corresponding to the target temperature conditions;

[0015] After adjusting the opening of the expansion valve, if the liquid level in the gas-liquid separator is higher than the preset liquid level corresponding to the target temperature condition, reduce the opening of the expansion valve until the liquid level in the gas-liquid separator is less than or equal to the preset liquid level.

[0016] The technical solution provided in this application provides at least the following beneficial effects: During the operation of an air conditioning system, if the compressor operates continuously at a high frequency and the exhaust temperature is too high, it will damage the compressor. Therefore, an air conditioning system provided in this application includes an economizer and an expansion valve. The economizer has two refrigerant channels, one end of which is connected to the inlet of a gas-liquid separator through an expansion valve. When the compressor's exhaust temperature is higher than the target exhaust temperature, the opening of the expansion valve can be adjusted according to the target temperature conditions met by the air conditioning system to increase the flow of refrigerant into the compressor, thereby reducing the compressor's exhaust temperature. However, if the expansion valve opening is too large, it will lead to an increase in liquid refrigerant in the gas-liquid separator. If the compressor cannot discharge the refrigerant from the gas-liquid separator in time, it will cause the compressor to draw in liquid refrigerant, resulting in liquid-laden operation and damage to the compressor. In this embodiment, the liquid level of the gas-liquid separator is monitored. When the liquid level of the gas-liquid separator is higher than the preset liquid level, the opening of the expansion valve is finely adjusted to reduce the opening of the expansion valve, so that the liquid level of the gas-liquid separator is less than or equal to the preset liquid level, thereby preventing liquid refrigerant from entering the compressor and causing damage to the compressor.

[0017] In some embodiments, at least one temperature condition includes one or more of a first temperature condition, a second temperature condition, a third temperature condition, or a fourth temperature condition; wherein, the first temperature condition includes: the exhaust temperature of the current detection cycle is greater than or equal to a first preset temperature, and the difference between the exhaust temperature of the current detection cycle and the exhaust temperature of the previous detection cycle is greater than or equal to a first preset value and less than a second preset value; the second temperature condition includes: the exhaust temperature of the current detection cycle is greater than or equal to the first preset temperature, and the difference between the exhaust temperature of the current detection cycle and the exhaust temperature of the previous detection cycle is greater than the second preset value; the third temperature condition... The first preset temperature is greater than or equal to the second preset temperature, and the difference between the exhaust temperature of the current testing cycle and the exhaust temperature of the previous testing cycle is greater than or equal to the third preset value. The fourth temperature condition includes: the exhaust temperature of the current testing cycle is greater than or equal to the third preset temperature, the opening degree of the expansion valve is greater than or equal to the preset opening degree, and the difference between the exhaust temperature of the current testing cycle and the exhaust temperature of the previous testing cycle is greater than or equal to the fourth preset value. Among them, the first preset temperature, the second preset temperature and the third preset temperature are all greater than the target exhaust temperature, and the first preset temperature is less than the second preset temperature, and the second preset temperature is less than the third preset temperature.

[0018] It is understandable that different compressor discharge temperatures require different levels of cooling. Therefore, the compressor discharge temperature is divided into at least one temperature condition, and corresponding measures are taken based on the target temperature condition met by the actually detected compressor discharge temperature. This not only improves the efficiency of reducing the compressor discharge temperature but also prevents a single cooling measure from failing to adequately adjust the actual compressor discharge temperature.

[0019] In some embodiments, the controller of the air conditioning system is configured to adjust the opening of the expansion valve according to the target temperature condition met by the air conditioning system, specifically performing the following steps: if the target temperature condition is a first temperature condition, the expansion valve is controlled to increase from a first opening to a second opening, and the ratio of the difference between the second opening and the first opening to the first opening is equal to a first preset ratio. Thus, when the compressor's discharge temperature meets the first temperature condition, the opening of the expansion valve is increased accordingly to increase the refrigerant flow, thereby reducing the compressor's discharge temperature.

[0020] In some embodiments, the controller of the air conditioning system is configured to adjust the opening of the expansion valve according to the target temperature condition met by the air conditioning system, specifically performing the following steps: if the target temperature condition is a second temperature condition, control the expansion valve to increase from a first opening to a third opening, the ratio of the difference between the third opening and the first opening to the first opening is equal to a second preset ratio, and the second preset ratio is greater than the first preset ratio.

[0021] Understandably, the difference between the compressor's discharge temperature in the current detection cycle and the discharge temperature in the previous detection cycle under the second temperature condition is greater than the difference under the first temperature condition. Therefore, the increase in the expansion valve opening when the second temperature condition is met is greater than the increase in the expansion valve opening when the first temperature condition is met, thus achieving faster cooling.

[0022] In some embodiments, the controller of the air conditioning system is configured to adjust the opening of the expansion valve according to the target temperature condition met by the air conditioning system, specifically performing the following steps: if the target temperature condition is a third temperature condition, the opening of the expansion valve is adjusted to a preset opening.

[0023] In some embodiments, the preset opening degree is determined by the actual operating frequency of the compressor, the ambient temperature, the exhaust temperature of the current detection cycle, and the operating mode of the air conditioning system.

[0024] It is understandable that the higher the actual operating frequency of the compressor, the higher the compressor's discharge temperature; similarly, the higher the ambient temperature, the higher the compressor's discharge temperature. The opening degree of the expansion valve should also vary depending on the discharge temperature during the current testing cycle. Furthermore, the compressor's discharge temperature also varies depending on the operating mode of the air conditioning system. Therefore, determining the preset opening degree based on the compressor's actual operating frequency, ambient temperature, discharge temperature during the current testing cycle, and the air conditioning system's operating mode ensures greater accuracy and more efficient reduction of the discharge temperature to a reasonable range.

[0025] In some embodiments, the controller of the air conditioning system is configured to adjust the opening of the expansion valve according to the target temperature condition met by the air conditioning system, specifically performing the following steps: if the target temperature condition is a fourth temperature condition, the opening of the expansion valve is adjusted to the maximum opening. In this way, when the compressor's exhaust temperature reaches a very high level, adjusting the opening of the expansion valve to the maximum opening allows the refrigerant flow to be adjusted to the maximum amount, thereby cooling the compressor as quickly as possible and reducing the possibility of damage to the compressor.

[0026] In some embodiments, the controller of the air conditioning system is configured to reduce the opening of the expansion valve until the liquid level of the gas-liquid separator is less than or equal to a preset liquid level. Specifically, the following steps are performed: the opening of the expansion valve is reduced by a preset adjustment value one by one until the liquid level of the gas-liquid separator is less than or equal to the preset liquid level.

[0027] Understandably, when the compressor's discharge temperature is within a reasonable range, the liquid level in the gas-liquid separator is also at a reasonable height. When the compressor's discharge temperature exceeds this range, increasing the opening of the expansion valve increases the refrigerant flow, further raising the liquid level in the gas-liquid separator. When the liquid level in the gas-liquid separator exceeds the preset level, it may cause the compressor to operate with liquid, potentially damaging it. Therefore, while increasing the opening of the expansion valve, it is necessary to monitor the liquid level in the gas-liquid separator and adjust it promptly when it exceeds the preset level. Gradually decrease the opening of the expansion valve by the preset adjustment value to reduce the refrigerant flow until the liquid level in the gas-liquid separator is less than or equal to the preset level. If the liquid level in the gas-liquid separator is less than or equal to the preset level, it indicates that the current refrigerant flow will not cause liquid operation for the time being, so the current opening of the expansion valve can be maintained until the discharge temperature drops to a reasonable range.

[0028] Secondly, embodiments of this application provide a control method for an air conditioning system, the method comprising:

[0029] If the exhaust temperature in the current testing cycle is greater than the target exhaust temperature, determine the target temperature condition that the air conditioning system must meet from at least one temperature condition.

[0030] Adjust the opening of the expansion valve according to the adjustment strategy corresponding to the target temperature conditions;

[0031] After adjusting the opening of the expansion valve, if the liquid level in the gas-liquid separator is higher than the preset liquid level corresponding to the target temperature condition, reduce the opening of the expansion valve until the liquid level in the gas-liquid separator is less than or equal to the preset liquid level.

[0032] Thirdly, embodiments of this application provide a controller, including: one or more processors; one or more memories; wherein the one or more memories are used to store computer program code, the computer program code including computer instructions, and when the one or more processors execute the computer instructions, the controller executes the control method provided in the second aspect.

[0033] Fourthly, embodiments of this application provide a computer-readable storage medium including computer instructions that, when controlled on a computer, cause the computer to perform the methods provided in the second aspect and possible implementations.

[0034] Fifthly, embodiments of the present invention provide a computer program product that can be directly loaded into a memory and contains software code. After being loaded and executed by a computer, the computer program product can implement the methods provided in the second aspect and possible implementations.

[0035] It should be noted that the aforementioned computer instructions may be stored, in whole or in part, on a computer-readable storage medium. This computer-readable storage medium may be packaged together with the controller's processor, or it may be packaged separately from the controller's processor; this application does not impose any limitations on this.

[0036] The beneficial effects described in aspects two through five of this application can be referred to the analysis of the beneficial effects of aspect one, and will not be repeated here. Attached Figure Description

[0037] Figure 1 This is a schematic diagram of the structure of an air conditioning system provided in an embodiment of this application;

[0038] Figure 2 This is a schematic diagram of another air conditioning system provided in an embodiment of this application;

[0039] Figure 3 A schematic diagram of the hardware structure of a controller provided in an embodiment of this application;

[0040] Figure 4 A schematic diagram of the hardware structure of another controller provided in an embodiment of this application;

[0041] Figure 5 This application provides a schematic diagram of the refrigeration cycle principle of an air conditioning system.

[0042] Figure 6 A schematic diagram of the heating cycle principle of an air conditioning system provided in this application embodiment;

[0043] Figure 7 A flowchart illustrating a control method for an air conditioning system provided in an embodiment of this application;

[0044] Figure 8 A flowchart illustrating another control method for an air conditioning system provided in an embodiment of this application;

[0045] Figure 9 A flowchart illustrating another control method for an air conditioning system provided in an embodiment of this application;

[0046] Figure 10 This is a schematic diagram of the hardware structure of a controller provided in an embodiment of this application.

[0047] Reference numerals: 11-Air conditioning system; 100-Indoor unit; 200-Outdoor unit; 300-Connecting piping; 400-Remote controller; 101-Indoor heat exchanger; 2011-First shut-off valve; 2012-Second shut-off valve; 202-Four-way reversing valve; 203-Gas-liquid separator; 204-Compressor; 205-Outdoor heat exchanger; 206-Economizer; 2071-First expansion valve; 2072-Second expansion valve; 208-Temperature sensor; 209-Level sensor; 210-Controller; 2101-Outdoor control module; 2102-Indoor control module; 2103-Processor; 2104-Memory; 2105-Communication interface; 2106-Bus. Detailed Implementation

[0048] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of this application.

[0049] In the description of this invention, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0050] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "a plurality of" means two or more.

[0051] In the description of the embodiments of this application, it should be noted that, unless otherwise explicitly specified and limited, the terms "connected" and "connected" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances. Furthermore, when describing pipelines, the terms "connected" and "connected" as used in this application have the meaning of establishing electrical conductivity. The specific meaning needs to be understood in conjunction with the context.

[0052] In the embodiments of this application, the terms "exemplary" or "for example" are used to indicate that something is an example, illustration, or description. Any embodiment or design that is described as "exemplary" or "for example" in the embodiments of this application should not be construed as being more preferred or advantageous than other embodiments or design. Specifically, the use of the terms "exemplary" or "for example" is intended to present the relevant concepts in a specific manner.

[0053] As described in the background section, when the compressor's exhaust temperature is too high during operation, the air conditioner will increase the opening of the expansion valve to increase the refrigerant flow, thereby reducing the compressor's exhaust temperature. However, increasing the opening of the expansion valve will also cause the liquid level in the gas-liquid separator to exceed the reasonable range, resulting in the compressor running with liquid and causing damage to the compressor.

[0054] To address the aforementioned technical problems, this application provides an air conditioning system and its control method. This control method periodically detects the compressor's exhaust temperature and, when the compressor's exhaust temperature is too high, controls the opening of the expansion valve to increase. Specifically, the compressor's exhaust temperature is defined as at least one temperature condition. Based on the temperature condition satisfied by the exhaust temperature detected in the current detection cycle, the opening of the expansion valve is increased accordingly, thereby rapidly reducing the compressor's exhaust temperature. Simultaneously, since increasing the expansion valve opening also increases the refrigerant flow rate, by monitoring the liquid level in the gas-liquid separator, the opening of the expansion valve can be finely adjusted to decrease when the liquid level in the gas-liquid separator exceeds the liquid level height corresponding to the temperature condition. This prevents excessive refrigerant from the gas-liquid separator from entering the compressor, causing the compressor to operate with liquid and leading to compressor malfunction.

[0055] The air conditioning system provided in this application embodiment can be a cabinet air conditioner, a wall-mounted air conditioner, a water-cooled air conditioner, a window air conditioner, a central air conditioner, or a multi-split air conditioner. The air conditioning system provided in this application embodiment can have one compressor or multiple compressors, and this application embodiment does not impose any restrictions on this.

[0056] To further describe the technical solutions of the embodiments of this application, as follows: Figure 1 The diagram shown is a structural diagram of an air conditioning system provided in an embodiment of this application.

[0057] Reference Figure 1 The air conditioning system 11 includes: an indoor unit 100, an outdoor unit 200, connecting pipes 300, and a remote control 400, with the indoor unit being a wall-mounted unit ( Figure 1 For example, as shown in the image, indoor wall-mounted air conditioners are typically installed on indoor walls such as the wall panel (WL). Another example is indoor floor-standing air conditioners (…). Figure 1 (Not yet released) is also a type of indoor unit.

[0058] In some embodiments, the connecting pipe 300 is disposed between the indoor unit 100 and the outdoor unit 200 to connect the indoor unit 100 and the outdoor unit 200 to form a refrigerant circuit for refrigerant circulation.

[0059] In some embodiments, the remote controller 400 is an accessory device to the air conditioning system 11, and has the function of communicating with the controller, for example, using infrared or other communication methods. The remote controller 400 is used to realize the interaction between the user and the air conditioning system. The user can perform operations such as turning the air conditioning system on and off, setting the temperature, setting the airflow direction, and setting the airflow through the display device and buttons on the remote controller.

[0060] In some embodiments, such as Figure 2 As shown, the indoor unit 100 includes an indoor heat exchanger 101.

[0061] The indoor heat exchanger 101 is installed in the indoor unit 100 and is used to exchange heat with the indoor air, thereby achieving cooling or heating of the indoor air.

[0062] In some embodiments, continue as follows Figure 2 As shown, the outdoor unit 200 includes: a first shut-off valve 2011, a second shut-off valve 2012, a four-way reversing valve 202, a gas-liquid separator 203, a compressor 204, an outdoor heat exchanger 205, an economizer 206, a first expansion valve 2071, a second expansion valve 2072, a temperature sensor 208, and a liquid level sensor 209.

[0063] In some embodiments, the outdoor unit 200 is typically installed outdoors to assist in indoor heat exchange. The following is a detailed description of the configuration and functions of the various components of the outdoor unit 200.

[0064] In some embodiments, the first shut-off valve 2011 and the second shut-off valve 2012 are disposed on the refrigerant passage in the outdoor unit 200 and are respectively connected to both ends of the indoor heat exchanger 101 to prevent refrigerant backflow. After the air conditioning system is installed, the first shut-off valve 2011 and the second shut-off valve 2012 remain in a normally closed state.

[0065] In some embodiments, the four-way reversing valve 202 has four ports, which are respectively connected to the exhaust port of the compressor 204, the indoor heat exchanger 101, the suction port of the compressor 204, and the outdoor heat exchanger 205, and are used to switch between cooling mode and heating mode by changing the flow direction of refrigerant in the system pipeline.

[0066] In some embodiments, the outlet of the gas-liquid separator 203 is connected to the suction port of the compressor 204 to accommodate the refrigerant in the refrigerant return section of the refrigerant passage, thereby preventing liquid slugging of the compressor 204.

[0067] In some embodiments, the discharge port of compressor 204 is connected to outdoor heat exchanger 205 via four-way reversing valve 202 to provide power for refrigerant circulation. Optionally, compressor 204 may be one or more.

[0068] In some embodiments, an outdoor heat exchanger 205 is disposed in an outdoor unit 200 for exchanging heat between the refrigerant flowing in the heat transfer tubes of the outdoor heat exchanger 205 and the outdoor air.

[0069] In some embodiments, a first expansion valve 2071 is disposed between the outdoor heat exchanger 205 and the economizer 206, and has the effect of expanding the refrigerant flowing through the first expansion valve 2071 to achieve pressure reduction, thereby regulating the refrigerant flow rate in the refrigerant passage. Optionally, the first expansion valve 2071 can be an electronic expansion valve. If the opening of the first expansion valve 2071 decreases, the flow resistance of the refrigerant through the first expansion valve 2071 increases. If the opening of the first expansion valve 2071 increases, the flow resistance of the refrigerant through the first expansion valve 2071 decreases. Thus, even if the states of other devices in the circuit remain unchanged, the refrigerant flow rate to the indoor heat exchanger 101 or the outdoor heat exchanger 205 will change when the opening of the first expansion valve 2071 changes.

[0070] In some embodiments, the economizer 206 has a first refrigerant passage and a second refrigerant passage. One end of the first refrigerant passage is connected to the indoor heat exchanger 101, and the other end is connected to the outdoor heat exchanger 205. One end of the second refrigerant passage is connected to the pipeline connecting the first refrigerant passage to the outdoor heat exchanger 205 via a second expansion valve 2072, and the other end is connected to the inlet of the gas-liquid separator 203.

[0071] In some embodiments, one end of the second expansion valve 2072 is connected to the economizer 206, and the other end is connected to the outdoor heat exchanger 205 via the first expansion valve 2071, for controlling the flow rate of refrigerant flowing into the gas-liquid separator 203. It is understood that since the refrigerant flows into the gas-liquid separator 203 after passing through the second expansion valve 2072, the flow rate of refrigerant flowing into the gas-liquid separator 203 can be controlled by controlling the opening degree of the second expansion valve 2072.

[0072] In some embodiments, a temperature sensor 208 is disposed at the exhaust port of the compressor 204 to detect the exhaust temperature of the compressor 204.

[0073] In some embodiments, a liquid level sensor is disposed in the gas-liquid separator 203 to detect the height of the liquid in the gas-liquid separator 203.

[0074] like Figure 3As shown, the air conditioning system also includes a controller 210, which is electrically connected to an indoor heat exchanger 101, a first shut-off valve 2011, a second shut-off valve 2012, a four-way reversing valve 202, a gas-liquid separator 203, a compressor 204, an outdoor heat exchanger 205, an economizer 206, a first expansion valve 2071, a second expansion valve 2072, a temperature sensor 208, and a liquid level sensor 209.

[0075] In some embodiments, controller 210 refers to a device that can generate operation control signals according to instruction opcodes and timing signals, instructing the air conditioning system to execute control commands. Exemplarily, controller 210 can be a central processing unit (CPU), a network processor (NP), a digital signal processor (DSP), a microprocessor, a microcontroller, a programmable logic device (PLD), or any combination thereof. Controller 210 can also be other devices with processing functions, such as circuits, devices, or software modules; this application embodiment does not impose any limitations on this.

[0076] In addition, the controller 210 can be used to control the operation of each component in the air conditioning system 11 so that each component of the air conditioning system 11 can perform each predetermined function of the air conditioning system.

[0077] Figure 4 This is a schematic diagram of the structure of a controller 210 provided in an embodiment of this application. Figure 4 As shown, the controller 210 includes an outdoor control module 2101 and an indoor control module 2102. The outdoor control module 2101 includes a first memory, and the indoor control module 2102 includes a second memory. The indoor control module 2102 is connected to the outdoor control module 2101 via wired or wireless communication. The outdoor control module 2101 can be installed in the outdoor unit or independently of the outdoor unit, and is used to control the outdoor unit to perform related operations. The indoor control module 2102 can be installed in the indoor unit or independently of the indoor unit, and is used to control the components of the indoor unit. It should be understood that the above module division is only functional; the outdoor control module 2101 and the indoor control module 2102 can also be integrated into one module. The first memory and the second memory can also be integrated into one memory.

[0078] In some embodiments, the first memory is used to store application programs and data related to the outdoor unit. The outdoor control module 2101 executes various functions and data processing of the air conditioning system by running the application programs and data stored in the memory. The first memory mainly includes a program storage area and a data storage area. The program storage area can store the operating system and application programs required for at least one function (such as the adjustment program of the first expansion valve 2071 and the second expansion valve 2072 of the outdoor unit). The data storage area can store data created based on the use of the air conditioning system (such as the opening degree of the first expansion valve 2071 and the second expansion valve 2072 of the outdoor unit). In addition, the first memory may include high-speed random access memory and may also include non-volatile memory, such as disk storage devices, flash memory devices, or other volatile solid-state storage devices.

[0079] In some embodiments, the second memory is used to store applications and data related to the indoor unit and multiple first expansion valves 2071 and second expansion valves 2072. The indoor control module 2102 executes various functions and data processing of the air conditioning system by running the applications and data stored in the memory. The second memory mainly includes a program storage area and a data storage area. The program storage area can store the operating system and applications required for at least one function (such as the adjustment program for the first expansion valves 2071 and second expansion valves 2072 of the indoor unit). The data storage area can store data created based on the use of the multi-split air conditioning system (such as the opening degree of the first expansion valves 2071 and second expansion valves 2072 of the indoor unit). In some examples, the second memory is also used to store the correspondence between the address of the indoor unit and the addresses of the first expansion valves 2071 and second expansion valves 2072.

[0080] In some embodiments, the outdoor control module 2101 has a communication connection with the outdoor unit and is used to control the outdoor unit to perform relevant operations according to user instructions or system default instructions. Optionally, the outdoor control module 2101 can control the opening degree of the first expansion valve 2071 and the second expansion valve 2072 of the outdoor unit according to the compressor exhaust superheat. Optionally, the outdoor control module 2101 can also acquire the outdoor temperature according to user instructions or system instructions and store the acquired outdoor temperature in a first memory. Optionally, the outdoor control module 2101 can also control the rotation of the four-way reversing valve 202 in the outdoor unit 200 according to the air conditioning operation mode selected by the user to realize the selection of cooling or heating mode. Optionally, the outdoor control module 2101 can also control the operating mode of the outdoor unit, compressor frequency, etc. during address correction.

[0081] In some embodiments, the indoor control module 2102 has a communication connection with the indoor unit and is used to control the indoor unit to perform relevant operations according to user instructions or system default instructions. Optionally, the indoor control module 2102 controls the opening degree of the first expansion valve 2071 and the second expansion valve 2072 of the indoor unit according to the compressor exhaust superheat.

[0082] In some embodiments, the air conditioning system 11 includes a cooling mode and a heating mode.

[0083] The cooling and heating modes described above are explained below with reference to the accompanying drawings.

[0084] 1. Cooling Mode

[0085] When the air conditioning system is in cooling mode, the indoor heat exchanger 101 works as an evaporator and the outdoor heat exchanger 205 works as a condenser.

[0086] For example, in combination Figure 5 The air conditioning system 11 shown is illustrated as an example.

[0087] When the air conditioning system 11 is in cooling mode, the d-end and c-end of the four-way reversing valve 202 are connected, and the a-end and b-end are connected. The compressor 204 discharges high-temperature and high-pressure gaseous refrigerant. The gaseous refrigerant starts from the exhaust port of the compressor 204, passes through the d-end and c-end of the four-way reversing valve 202, and reaches the outdoor heat exchanger 205. After sufficient heat exchange in the outdoor heat exchanger 205, it becomes high-temperature and high-pressure subcooled liquid refrigerant, and then passes through the first expansion valve 2071 to reach the economizer 206. Among them, part of the refrigerant passes through the first refrigerant channel of the economizer 206, passes through the second shut-off valve 2012, and reaches the indoor heat exchanger 101. Heat exchange occurs in the indoor heat exchanger 101, and it evaporates into low-temperature and low-pressure superheated gaseous refrigerant. Then, it flows into the gas-liquid separator 203 through the first shut-off valve 2011, the a-end and b-end of the four-way reversing valve 202, and then is drawn into the compressor 204 through the suction port, completing the refrigeration cycle. Another portion of the refrigerant flows through the second refrigerant passage of the economizer 206, passes through the second expansion valve 2072, flows into the gas-liquid separator 203, and is then drawn into the compressor 204 through the suction port.

[0088] 2. Heating Mode

[0089] When the air conditioner is in heating mode, the indoor heat exchanger 101 works as a condenser and the outdoor heat exchanger 205 works as an evaporator.

[0090] For example, in combination Figure 6 The air conditioning system 11 shown is illustrated as an example.

[0091] When the air conditioning system 11 is in heating mode, terminals a and d of the four-way reversing valve 202 are connected, and terminals b and c are connected. The compressor 204 discharges high-temperature, high-pressure gaseous refrigerant. This gaseous refrigerant originates from the compressor 204's exhaust port, passes sequentially through terminals d and a of the four-way reversing valve 202, and the first shut-off valve 2011 to reach the indoor heat exchanger 101. Heat exchange occurs within the indoor heat exchanger 101, releasing heat and condensing into low-temperature, high-pressure subcooled liquid refrigerant, which then enters the economizer 206 via the second shut-off valve 2012. A portion of the refrigerant passes through the first refrigerant channel of the economizer 206, sequentially through the first expansion valve 2071, and enters the outdoor heat exchanger 205 to complete heat exchange, evaporating into low-temperature, low-pressure superheated gaseous refrigerant. This superheated gaseous refrigerant passes through terminals c and b of the four-way reversing valve into the gas-liquid separator 203, and then is drawn into the compressor 204 through its suction port, completing the heating cycle. Another portion of the refrigerant flows through the second refrigerant passage of the economizer 206, passes through the second expansion valve 2072, flows into the gas-liquid separator 203, and is then drawn into the compressor 204 through the suction port.

[0092] The embodiments of this application will now be described in detail with reference to the accompanying drawings.

[0093] like Figure 7 As shown in the figure, this application provides a control method for an air conditioning system, applied to the controller of an air conditioning system. The method includes the following steps:

[0094] S101. If the exhaust temperature in the current detection cycle is greater than the target exhaust temperature, determine the target temperature condition that the air conditioning system must meet from at least one temperature condition.

[0095] The target exhaust temperature is the ideal exhaust temperature of the compressor under the current operating conditions of the air conditioning system.

[0096] Optionally, at least one temperature condition includes one or more of a first temperature condition, a second temperature condition, a third temperature condition, or a fourth temperature condition.

[0097] The first temperature condition includes: the exhaust temperature of the current detection cycle is greater than or equal to the first preset temperature, and the difference between the exhaust temperature of the current detection cycle and the exhaust temperature of the previous detection cycle is greater than or equal to the first preset value and less than the second preset value.

[0098] For example, the first temperature condition can be expressed in the following form:

[0099] Td(n)≥95℃, and A≤Td(n)-Td(n-1)<B.

[0100] Where Td(n) is the exhaust temperature of the current detection cycle; Td(n-1) is the exhaust temperature of the previous detection cycle; A and B are specific values, and B > A.

[0101] The second temperature condition includes: the exhaust temperature of the current detection cycle is greater than or equal to the first preset temperature, and the difference between the exhaust temperature of the current detection cycle and the exhaust temperature of the previous detection cycle is greater than the second preset value.

[0102] For example, the second temperature condition can be expressed in the following form:

[0103] Td(n)≥95℃, and Td(n)-Td(n-1)≥B.

[0104] The third temperature condition includes: the exhaust temperature of the current detection cycle is greater than or equal to the second preset temperature, and the difference between the exhaust temperature of the current detection cycle and the exhaust temperature of the previous detection cycle is greater than or equal to the third preset value.

[0105] For example, the third temperature condition can be expressed in the following form:

[0106] Td(n)≥100℃, and Td(n)-Td(n-1)≥C. Where C is a specific value.

[0107] The fourth temperature condition includes: the exhaust temperature of the current detection cycle is greater than or equal to the third preset temperature, the opening degree of the expansion valve is greater than or equal to the preset opening degree, and the difference between the exhaust temperature of the current detection cycle and the exhaust temperature of the previous detection cycle is greater than or equal to the fourth preset value.

[0108] For example, the fourth temperature condition can be expressed in the following form:

[0109] Td(n)≥110℃, and Td(n)-Td(n-1)≥D. Where D is a specific value, and D>C.

[0110] As a specific implementation method, the preset opening degree K is determined by the actual operating frequency of the compressor, the ambient temperature, the exhaust temperature of the current detection cycle, and the operating mode of the air conditioning system.

[0111] For example, K = F × K1 × K2 × K3.

[0112] Where F is the actual operating frequency of the compressor.

[0113] K1 is a parameter related to the outdoor unit's operating status and ambient temperature. The value range of K1 is shown in Table 1.

[0114] Table 1

[0115] Outdoor unit operating status The value of K1 Ta > E℃ and cooling 1.5 Heating operation 1.0 Other than the above 1.2

[0116] In Table 1, Ta represents the ambient temperature.

[0117] K2 is a parameter related to the compressor's exhaust temperature, and the value of K2 ranges from 1 to K2.

[0118] 1.8, and K2 is positively correlated with the compressor's exhaust temperature.

[0119] K3 is a parameter related to ambient temperature. The value of K3 is 1.0 ≤ K3 ≤ 1.5, and K3 is positively correlated with ambient temperature.

[0120] The first preset temperature, the second preset temperature, and the third preset temperature are all greater than the target exhaust temperature, and the first preset temperature is less than the second preset temperature, and the second preset temperature is less than the third preset temperature.

[0121] It should be understood that the difference between the exhaust temperature in the current testing cycle and the exhaust temperature in the previous testing cycle can be used to reflect the trend of exhaust temperature change. When the difference between the exhaust temperature in the current testing cycle and the exhaust temperature in the previous testing cycle is greater than a preset value, it indicates that the exhaust temperature is trending upwards. Therefore, the air conditioning system needs to take timely adjustment measures to avoid excessively high exhaust temperatures.

[0122] S102. Adjust the opening of the second expansion valve according to the adjustment strategy corresponding to the target temperature conditions.

[0123] As one possible implementation, if the target temperature condition is a first temperature condition, the second expansion valve is controlled to increase from a first opening degree to a second opening degree. The ratio of the difference between the second opening degree and the first opening degree to the first opening degree is equal to a first preset ratio. Here, the first opening degree of the second expansion valve is the opening degree of the expansion valve in the previous detection cycle, and the second opening degree is the opening degree of the expansion valve after corresponding adjustments. For example, the first preset ratio can be 25%.

[0124] As another possible implementation, if the target temperature condition is a second temperature condition, the second expansion valve is controlled to increase from a first opening degree to a third opening degree. The ratio of the difference between the third opening degree and the first opening degree to the first opening degree is equal to a second preset ratio, and the second preset ratio is greater than the first preset ratio. For example, the second preset ratio can be 50%.

[0125] As another possible implementation, if the target temperature condition is the third temperature condition, the opening of the second expansion valve is adjusted to the preset opening.

[0126] As another possible implementation, if the target temperature condition is the fourth temperature condition, the opening of the second expansion valve is adjusted to the maximum opening.

[0127] S103. After adjusting the opening of the second expansion valve, if the liquid level of the gas-liquid separator is greater than the preset liquid level corresponding to the target temperature condition, reduce the opening of the second expansion valve until the liquid level of the gas-liquid separator is less than or equal to the preset liquid level.

[0128] In some embodiments, such as Figure 8 As shown, step S103 can be specifically implemented as follows:

[0129] S1031. Detect the liquid level of the gas-liquid separator and determine whether the liquid level height of the gas-liquid separator is greater than the preset liquid level height corresponding to the target temperature condition.

[0130] If so, proceed with step S1032 below;

[0131] If not, maintain the current opening of the expansion valve until the exhaust temperature drops to a reasonable range, for example, maintain the current opening of the expansion valve until the exhaust temperature is less than 95°C.

[0132] For example, the preset liquid level height corresponding to the first temperature condition is a, the preset liquid level height corresponding to the second temperature condition is b, the preset liquid level height corresponding to the third temperature condition is c, and the preset liquid level height corresponding to the fourth temperature condition is d, where 0 < a < b < c < d.

[0133] S1032. Reduce the opening of the second expansion valve to a preset adjustment value.

[0134] For example, the preset adjustment value can be 1%.

[0135] S1033. Determine whether the current liquid level of the gas-liquid separator is less than or equal to the preset liquid level.

[0136] If not, continue executing S1032 to reduce the opening of the second expansion valve to the preset adjustment value.

[0137] If so, proceed with step S1034 below.

[0138] S1034. End the adjustment of the opening degree of the second expansion valve.

[0139] Figure 7The illustrated embodiment offers at least the following beneficial effects: During the operation of an air conditioning system, if the compressor operates continuously at a high frequency, the excessively high exhaust temperature can damage the compressor. Therefore, the opening of the second expansion valve can be increased based on the compressor's exhaust temperature to increase the refrigerant flow into the compressor, thereby reducing the compressor's exhaust temperature. However, if the opening of the second expansion valve is too large, it will lead to an increase in liquid refrigerant in the gas-liquid separator, resulting in more liquid refrigerant flowing into the compressor. This embodiment monitors the liquid level in the gas-liquid separator. When the liquid level in the gas-liquid separator is higher than a preset liquid level corresponding to the compressor's exhaust temperature, the opening of the expansion valve is finely adjusted to reduce the opening of the second expansion valve, thereby ensuring that the liquid level in the gas-liquid separator is less than or equal to the preset liquid level, thus preventing liquid refrigerant from entering the compressor and damaging it.

[0140] In some embodiments, if the outdoor unit includes multiple compressors, this application also provides an air conditioning system control method, the method comprising: when the maximum exhaust temperature of the current detection cycle is greater than the target exhaust temperature, determining a target temperature condition satisfied by the air conditioning system from at least one temperature condition; adjusting the opening of the expansion valve according to an adjustment strategy corresponding to the target temperature condition; after adjusting the opening of the expansion valve, if the liquid level of the gas-liquid separator is greater than a preset liquid level corresponding to the target temperature condition, reducing the opening of the expansion valve until the liquid level of the gas-liquid separator is less than or equal to the preset liquid level.

[0141] The maximum exhaust temperature in a detection cycle is the maximum exhaust temperature of each compressor within that detection cycle.

[0142] Accordingly, the above-mentioned at least one temperature condition may include one or more of the following: the fifth temperature condition, the sixth temperature condition, the seventh temperature condition, and the eighth temperature condition.

[0143] The fifth temperature condition includes the maximum exhaust temperature of the current detection cycle being greater than or equal to the first preset temperature, and the difference between the maximum exhaust temperature of the current detection cycle and the maximum exhaust temperature of the previous detection cycle being greater than or equal to the first preset value and less than the second preset value.

[0144] The sixth temperature condition includes the maximum exhaust temperature of the current detection cycle being greater than or equal to the first preset temperature, and the difference between the maximum exhaust temperature of the current detection cycle and the maximum exhaust temperature of the previous detection cycle being greater than the second preset value.

[0145] The seventh temperature condition includes the maximum exhaust temperature of the current detection cycle being greater than or equal to the second preset temperature, and the difference between the maximum exhaust temperature of the current detection cycle and the maximum exhaust temperature of the previous detection cycle being greater than or equal to the third preset value.

[0146] The eighth temperature condition includes the maximum exhaust temperature of the current detection cycle being greater than or equal to the third preset temperature, the opening degree of the expansion valve being greater than or equal to the preset opening degree, and the difference between the maximum exhaust temperature of the current detection cycle and the maximum exhaust temperature of the previous detection cycle being greater than or equal to the fourth preset value.

[0147] It should be noted that the adjustment strategy corresponding to the fifth temperature condition is the same as that corresponding to the first temperature condition, the adjustment strategy corresponding to the sixth temperature condition is the same as that corresponding to the second temperature condition, the adjustment strategy corresponding to the seventh temperature condition is the same as that corresponding to the third temperature condition, and the adjustment strategy corresponding to the eighth temperature condition is the same as that corresponding to the fourth temperature condition.

[0148] The preset liquid level height corresponding to the fifth temperature condition is the same as the preset liquid level height corresponding to the first temperature condition, the preset liquid level height corresponding to the sixth temperature condition is the same as the preset liquid level height corresponding to the second temperature condition, the preset liquid level height corresponding to the seventh temperature condition is the same as the preset liquid level height corresponding to the third temperature condition, and the preset liquid level height corresponding to the eighth temperature condition is the same as the preset liquid level height corresponding to the fourth temperature condition.

[0149] The following is combined with Figure 9 This application describes a control method for an air conditioning system provided in an embodiment:

[0150] like Figure 9 As shown, based on Td(n), it can be determined whether the temperature condition is the first temperature condition, the second temperature condition, the third temperature condition, or the fourth temperature condition.

[0151] When the first temperature condition is met, valve opening measure 1 is executed. Then, it is determined whether the liquid level of the gas-liquid separator is less than or equal to a. If so, the opening of the second expansion valve is maintained until Td(n) drops to a reasonable range. If not, the opening of the second expansion valve is slightly reduced until the liquid level of the gas-liquid separator is less than or equal to a. Then, the current opening is maintained until Td(n) drops to a reasonable range.

[0152] When the second temperature condition is met, valve opening measure 2 is executed. Then, it is determined whether the liquid level of the gas-liquid separator is less than or equal to b. If so, the opening of the second expansion valve is maintained until Td(n) drops to a reasonable range. If not, the opening of the second expansion valve is slightly reduced until the liquid level of the gas-liquid separator is less than or equal to b. Then, the current opening is maintained until Td(n) drops to a reasonable range.

[0153] When the first temperature condition is met, valve opening measure 3 is executed. Then, it is determined whether the liquid level of the gas-liquid separator is less than or equal to c. If so, the opening of the second expansion valve is maintained until Td(n) drops to a reasonable range. If not, the opening of the second expansion valve is slightly reduced until the liquid level of the gas-liquid separator is less than or equal to c. Then, the current opening is maintained until Td(n) drops to a reasonable range.

[0154] When the first temperature condition is met, valve opening measure 4 is executed. Then, it is determined whether the liquid level of the gas-liquid separator is less than or equal to d. If so, the opening of the second expansion valve is maintained until Td(n) drops to a reasonable range. If not, the opening of the second expansion valve is slightly reduced until the liquid level of the gas-liquid separator is less than or equal to d, and then the current opening is maintained until Td(n) drops to a reasonable range.

[0155] As can be seen, the above mainly describes the solutions provided by the embodiments of this application from a methodological perspective. To achieve the above functions, the embodiments of this application provide corresponding hardware structures and / or software modules for executing each function. Those skilled in the art should readily recognize that, in conjunction with the modules and algorithm steps of the various examples described in the embodiments disclosed herein, the embodiments of this application can be implemented in hardware or a combination of hardware and computer software. Whether a function is executed in a hardware or computer software-driven hardware manner depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of this invention.

[0156] This application embodiment can divide the controller into functional modules according to the above method example. For example, each function can be divided into a separate functional module, or two or more functions can be integrated into one processing module. The integrated module can be implemented in hardware or as a software functional module. Optionally, the module division in this application embodiment is illustrative and only represents one logical functional division; other division methods may be used in actual implementation.

[0157] This application also provides a hardware structure diagram of a controller, such as... Figure 10 As shown, the controller 210 also includes a processor 2103, and optionally, a memory 2104 and a communication interface 2105 connected to the processor 2103. The processor 2103, memory 2104 and communication interface 2105 are connected via a bus 2106.

[0158] Processor 2103 may be a central processing unit (CPU), a general-purpose processor, a network processor (NP), a digital signal processor (DSP), a microprocessor, a microcontroller, a programmable logic device (PLD), or any combination thereof. Processor 2103 may also be any other device with processing capabilities, such as a circuit, device, or software module. Processor 2103 may also include multiple CPUs, and processor 2103 may be a single-core processor or a multi-core processor. Here, "processor" may refer to one or more devices, circuits, or processing cores used to process data (e.g., computer program instructions).

[0159] The memory 2104 may be a read-only memory (ROM) or other type of static storage device capable of storing static information and instructions, random access memory (RAM) or other type of dynamic storage device capable of storing information and instructions, or it may be an electrically erasable programmable read-only memory (EEPROM), a compact disc read-only memory (CD-ROM) or other optical disc storage, optical disc storage (including compressed optical discs, laser discs, optical discs, digital universal optical discs, Blu-ray discs, etc.), magnetic disk storage media or other magnetic storage devices, or any other medium capable of carrying or storing desired program code in the form of instructions or data structures and accessible by a computer. This application embodiment does not impose any limitations on this. The memory 2104 may exist independently or may be integrated with the processor 2103. The memory 2104 may contain computer program code. The processor 2103 is used to execute the computer program code stored in the memory 2104, thereby implementing the control method provided in this application embodiment.

[0160] The communication interface 2105 can be used to communicate with other devices or communication networks (such as Ethernet, radio access network (RAN), wireless local area networks (WLAN), etc.). The communication interface 2105 can be a module, circuit, transceiver, or any device capable of communication.

[0161] Bus 2106 can be a Peripheral Component Interconnect (PCI) bus or an Extended Industry Standard Architecture (EISA) bus, etc. Bus 2106 can be divided into address bus, data bus, control bus, etc. For ease of representation, Figure 10 The bus is represented by a single thick line, but this does not mean that there is only one bus or one type of bus.

[0162] This application also provides a computer-readable storage medium including computer-executable instructions that, when run on a computer, cause the computer to execute any of the air conditioning system control methods provided in the above embodiments.

[0163] This application also provides a computer program product containing computer execution instructions, which, when run on a computer, causes the computer to execute any of the air conditioning system control methods provided in the above embodiments.

[0164] In the above embodiments, implementation can be achieved, in whole or in part, through software, hardware, firmware, or any combination thereof. When implemented using software programs, implementation can be, in whole or in part, in the form of a computer program product. This computer program product includes one or more computer-executable instructions. When these computer-executable instructions are loaded and executed on a computer, all or part of the flow or function according to the embodiments of this application is generated. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. The computer-executable instructions can be stored in a computer-readable storage medium or transmitted from one computer-readable storage medium to another. For example, computer-executable instructions can be transmitted from one website, computer, server, or data center to another via wired (e.g., coaxial cable, fiber optic, digital subscriber line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.) means. The computer-readable storage medium can be any available medium accessible to a computer or a data storage device containing one or more servers, data centers, etc., that can be integrated with the medium. The available media can be magnetic media (e.g., floppy disks, hard disks, magnetic tapes), optical media (e.g., DVDs), or semiconductor media (e.g., solid-state disks, SSDs).

[0165] Although this application has been described herein in conjunction with various embodiments, those skilled in the art, by reviewing the accompanying drawings, disclosure, and appended claims, will understand and implement other variations of the disclosed embodiments in carrying out the claimed application. In the claims, the word "comprising" does not exclude other components or steps, and "a" or "an" does not exclude multiple instances. A single processor or other unit can implement several functions listed in the claims. While different dependent claims may recite certain measures, this does not mean that these measures cannot be combined to produce good results.

[0166] Although this application has been described in conjunction with specific features and embodiments, it is obvious that various modifications and combinations can be made thereto without departing from the spirit and scope of this application. Accordingly, this specification and drawings are merely illustrative descriptions of the application as defined by the appended claims, and are considered to cover any and all modifications, variations, combinations, or equivalents within the scope of this application. Clearly, those skilled in the art can make various alterations and modifications to this application without departing from the spirit and scope of this application. Thus, if such modifications and modifications of this application fall within the scope of the claims of this application and their equivalents, this application is also intended to include such modifications and modifications.

[0167] The above description is merely a specific embodiment of this application, but the scope of protection of this application is not limited thereto. Any changes or substitutions within the technical scope disclosed in this application should be included within the scope of protection of this application. Therefore, the scope of protection of this application should be determined by the scope of the claims.

Claims

1. An air conditioning system, characterized in that, include: Indoor heat exchanger; Outdoor heat exchanger; compressor; A gas-liquid separator, the outlet of which is connected to the inlet of the compressor; An economizer and an expansion valve are provided. The economizer has a first refrigerant passage and a second refrigerant passage. One end of the first refrigerant passage is connected to the indoor heat exchanger, and the other end is connected to the outdoor heat exchanger. One end of the second refrigerant passage is connected to the pipeline of the first refrigerant passage connected to the outdoor heat exchanger through the expansion valve, and the other end is connected to the inlet of the gas-liquid separator. The controller is configured as follows: When the exhaust temperature in the current detection cycle is greater than the target exhaust temperature, the target temperature condition that the air conditioning system meets is determined from at least one temperature condition. The at least one temperature condition includes a first temperature condition, which includes: the exhaust temperature in the current detection cycle is greater than or equal to a first preset temperature, and the difference between the exhaust temperature in the current detection cycle and the exhaust temperature in the previous detection cycle is greater than or equal to a first preset value and less than a second preset value. According to the adjustment strategy corresponding to the target temperature condition, the opening degree of the expansion valve is adjusted, including: if the target temperature condition is a first temperature condition, the expansion valve is controlled to increase from a first opening degree to a second opening degree, and the ratio of the difference between the second opening degree and the first opening degree to the first opening degree is equal to a first preset ratio. After adjusting the opening of the expansion valve, if the liquid level of the gas-liquid separator is greater than the preset liquid level corresponding to the target temperature condition, the opening of the expansion valve is reduced until the liquid level of the gas-liquid separator is less than or equal to the preset liquid level.

2. The air conditioning system according to claim 1, characterized in that, The at least one temperature condition further includes one or more of a second temperature condition, a third temperature condition, or a fourth temperature condition; The second temperature condition includes: the exhaust temperature of the current detection cycle is greater than or equal to the first preset temperature, and the difference between the exhaust temperature of the current detection cycle and the exhaust temperature of the previous detection cycle is greater than the second preset value. The third temperature condition includes: the exhaust temperature of the current detection cycle is greater than or equal to the second preset temperature, and the difference between the exhaust temperature of the current detection cycle and the exhaust temperature of the previous detection cycle is greater than or equal to the third preset value. The fourth temperature condition includes: the exhaust temperature of the current detection cycle is greater than or equal to the third preset temperature, the opening degree of the expansion valve is greater than or equal to the preset opening degree, and the difference between the exhaust temperature of the current detection cycle and the exhaust temperature of the previous detection cycle is greater than or equal to the fourth preset value. Wherein, the first preset temperature, the second preset temperature, and the third preset temperature are all greater than the target exhaust temperature, and the first preset temperature is less than the second preset temperature, and the second preset temperature is less than the third preset temperature.

3. The air conditioning system according to claim 2, characterized in that, The controller is configured to adjust the opening of the expansion valve according to the target temperature conditions met by the air conditioning system, specifically by performing the following steps: If the target temperature condition is the second temperature condition, the expansion valve is controlled to increase from the first opening degree to the third opening degree. The ratio of the difference between the third opening degree and the first opening degree to the first opening degree is equal to the second preset ratio, and the second preset ratio is greater than the first preset ratio.

4. The air conditioning system according to claim 1, characterized in that, The controller is configured to adjust the opening of the expansion valve according to the target temperature conditions met by the air conditioning system, specifically by performing the following steps: If the target temperature condition is the third temperature condition, the opening degree of the expansion valve is adjusted to the preset opening degree.

5. The air conditioning system according to claim 4, characterized in that, The preset opening degree is determined by the actual operating frequency of the compressor, the ambient temperature, the exhaust temperature of the current detection cycle, and the operating mode of the air conditioning system.

6. The air conditioning system according to claim 2, characterized in that, The controller is configured to adjust the opening of the expansion valve according to the target temperature conditions met by the air conditioning system, specifically by performing the following steps: If the target temperature condition is the fourth temperature condition, adjust the opening of the expansion valve to the maximum opening.

7. The air conditioning system according to claim 1, characterized in that, The controller is configured to reduce the opening of the expansion valve until the liquid level in the gas-liquid separator is less than or equal to the preset liquid level, specifically by performing the following steps: The opening of the expansion valve is gradually reduced by a preset adjustment value until the liquid level of the gas-liquid separator is less than or equal to the preset liquid level.

8. A control method for an air conditioning system, characterized in that, Applied to the air conditioning system according to any one of claims 1-7, the method comprises: If the exhaust temperature in the current detection cycle is greater than the target exhaust temperature, the target temperature condition that the air conditioning system meets is determined from at least one temperature condition. The at least one temperature condition includes a first temperature condition, which includes: the exhaust temperature in the current detection cycle is greater than or equal to a first preset temperature, and the difference between the exhaust temperature in the current detection cycle and the exhaust temperature in the previous detection cycle is greater than or equal to a first preset value and less than a second preset value. According to the adjustment strategy corresponding to the target temperature condition, the opening degree of the expansion valve is adjusted, including: if the target temperature condition is a first temperature condition, the expansion valve is controlled to increase from a first opening degree to a second opening degree, and the ratio of the difference between the second opening degree and the first opening degree to the first opening degree is equal to a first preset ratio. After adjusting the opening of the expansion valve, if the liquid level of the gas-liquid separator is greater than the preset liquid level corresponding to the target temperature condition, the opening of the expansion valve is reduced until the liquid level of the gas-liquid separator is less than or equal to the preset liquid level.

9. The method according to claim 8, characterized in that, Reducing the opening of the expansion valve until the liquid level in the gas-liquid separator is less than or equal to the preset liquid level includes: The opening of the expansion valve is gradually reduced by a preset adjustment value until the liquid level of the gas-liquid separator is less than or equal to the preset liquid level.

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