CN115264643A

CN115264643A - Air conditioning system and control method thereof

Info

Publication number: CN115264643A
Application number: CN202210841895.6A
Authority: CN
Inventors: 吕金鹏; 李君飞; 辛电波; 蒋茂灿; 郭斌
Original assignee: Qingdao Hisense Hitachi Air Conditioning System Co Ltd
Current assignee: Qingdao Hisense Hitachi Air Conditioning System Co Ltd
Priority date: 2022-07-18
Filing date: 2022-07-18
Publication date: 2022-11-01

Abstract

The application provides an air conditioning system and a control method thereof, and particularly relates to the technical field of air conditioners. This air conditioning system includes: an indoor heat exchanger; an outdoor heat exchanger; a compressor; the outlet of the gas-liquid separator is connected with the inlet of the compressor; the economizer is provided with a first refrigerant channel and a second refrigerant channel, one end of the first refrigerant channel is connected with the indoor heat exchanger, and the other end of the first refrigerant channel is connected with the outdoor heat exchanger; one end of the second refrigerant channel is communicated with a pipeline of the first refrigerant channel for connecting the outdoor heat exchanger through an expansion valve, and the other end of the second refrigerant channel is connected with an inlet of the gas-liquid separator; and the controller is configured to correspondingly adjust the opening degree of the expansion valve when the exhaust temperature of the current detection period is greater than the target exhaust temperature, and at the moment, if the liquid level height of the gas-liquid separator is greater than the preset liquid level height corresponding to the target temperature condition, the opening degree of the expansion valve is reduced until the liquid level height of the gas-liquid separator is less than or equal to the preset liquid level height.

Description

Air conditioning system and control method thereof

Technical Field

The application relates to the technical field of air conditioners, in particular to an air conditioning system and a control method thereof.

Background

In recent years, with the continuous improvement of the living standard of people and the continuous development of the real estate industry, more and more air-conditioning products have large-capacity units, and the corresponding compressor discharge capacity is also larger and larger. Meanwhile, as urban population increases, outdoor environment becomes more and more complex and diversified, and higher requirements are put forward on stable and reliable operation of the air conditioner outdoor unit.

The compressor is a core component of the outdoor unit of the air conditioner, causes problems of the compressor, can cause damage to the compressor due to overhigh exhaust temperature, and can cause liquid-carrying operation of the compressor when liquid refrigerant enters the compressor, thereby causing damage to the compressor. For the problem of liquid-carrying operation of the compressor caused by the liquid refrigerant entering the compressor, a gas-liquid separator with corresponding specification is generally designed to separate the liquid refrigerant.

However, during the actual operation of the air conditioning system, the measures taken to solve the problem of the excessive discharge temperature of the compressor may also cause the liquid level of the gas-liquid separator to rise. When the liquid level of the gas-liquid separator is too high, the liquid refrigerant in the gas-liquid separator flows into the compressor, and the compressor is damaged.

Disclosure of Invention

The embodiment of the application provides an air conditioning system and a control method thereof, which are used for solving the problem that the liquid level of a gas-liquid separator is too high and then the compressor is damaged due to measures taken when the exhaust temperature of the compressor is reduced.

In a first aspect, an embodiment of the present application provides an air conditioning system, including:

an indoor heat exchanger;

an outdoor heat exchanger;

a compressor;

the outlet of the gas-liquid separator is connected with the inlet of the compressor;

the economizer is provided with a first refrigerant channel and a second refrigerant channel, one end of the first refrigerant channel is connected with the indoor heat exchanger, and the other end of the first refrigerant channel is connected with the outdoor heat exchanger; one end of the second refrigerant channel is communicated with a pipeline of the first refrigerant channel connecting the outdoor heat exchanger through an expansion valve, and the other end of the second refrigerant channel is connected with an inlet of the gas-liquid separator;

a controller configured to:

under the condition that the exhaust temperature of the current detection period is greater than the target exhaust temperature, determining a target temperature condition met by the air conditioning system from at least one temperature condition;

adjusting the opening degree of the expansion valve according to an adjustment strategy corresponding to the target temperature condition;

after the opening degree of the expansion valve is adjusted, if the liquid level height of the gas-liquid separator is larger than the preset liquid level height corresponding to the target temperature condition, the opening degree of the expansion valve is reduced until the liquid level height of the gas-liquid separator is smaller than or equal to the preset liquid level height.

The technical scheme provided by the embodiment of the application at least has the following beneficial effects: in the operation process of the air conditioning system, if the compressor continuously operates at high frequency, the exhaust temperature is too high, and the compressor can be damaged. Therefore, the air conditioning system provided by the embodiment of the application is provided with the economizer and the expansion valve, the economizer is provided with two refrigerant channels, and one end of one refrigerant channel is connected with the inlet of the gas-liquid separator through the expansion valve. Therefore, when the exhaust temperature of the compressor is higher than the target exhaust temperature, the opening degree of the expansion valve can be adjusted according to the target temperature condition met by the air conditioning system so as to increase the flow rate of the refrigerant entering the compressor and reduce the exhaust temperature of the compressor. However, if the opening degree of the expansion valve is too large, the liquid refrigerant in the gas-liquid separator is more and more, and at the moment, if the compressor cannot discharge the refrigerant in the gas-liquid separator in time, the compressor can suck the liquid refrigerant to cause the problem of liquid-carrying operation of the compressor, so that the compressor is damaged. To this, this application embodiment still monitors through the liquid level to vapour and liquid separator, and when vapour and liquid separator's liquid level was higher than and predetermines the liquid level height, finely tune the aperture in order to reduce the aperture of expansion valve to make vapour and liquid separator's liquid level height be less than or equal to and predetermine the liquid level height, prevent that the liquid refrigerant from getting into the compressor and causing the damage to the compressor.

In some embodiments, the at least one temperature condition comprises 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 period is greater than or equal to a first preset temperature, and the difference value between the exhaust temperature of the current detection period and the exhaust temperature of the last detection period is greater than or equal to a first preset value and smaller than a second preset value; the second temperature condition includes: the exhaust temperature of the current detection period is greater than or equal to a first preset temperature, and the difference value between the exhaust temperature of the current detection period and the exhaust temperature of the last detection period is greater than a second preset value; the third temperature condition includes: the exhaust temperature of the current detection period is greater than or equal to a second preset temperature, and the difference between the exhaust temperature of the current detection period and the exhaust temperature of the last detection period is greater than or equal to a third preset value; the fourth temperature condition includes: the exhaust temperature of the current detection period is greater than or equal to a third preset temperature, the opening degree of the expansion valve is greater than or equal to a preset opening degree, and the difference between the exhaust temperature of the current detection period and the exhaust temperature of the last detection period is greater than or equal to a fourth preset value; the first preset temperature, the second preset temperature and the third preset temperature are all larger than the target exhaust temperature, the first preset temperature is smaller than the second preset temperature, and the second preset temperature is smaller than the third preset temperature.

It can be understood that the exhaust temperatures of the compressors are different, and the exhaust temperatures of the compressors need to be cooled with different forces, so that the exhaust temperatures of the compressors are divided into at least one temperature condition, and corresponding measures are taken according to the target temperature condition met by the actually detected exhaust temperatures of the compressors. Therefore, the efficiency of reducing the exhaust temperature of the compressor is improved, and the single temperature reduction measure is prevented from being inconsistent with the reasonable adjustment of the actual exhaust temperature of the compressor.

In some embodiments, the controller of the air conditioning system is configured to adjust the opening degree of the expansion valve according to a target temperature condition satisfied by the air conditioning system, and specifically performs the following steps: and if the target temperature condition is the first temperature condition, controlling the expansion valve to increase from the first opening degree to the second opening degree, wherein 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. In this way, when the discharge temperature of the compressor meets the first temperature condition, the opening degree of the expansion valve is correspondingly increased to increase the flow rate of the refrigerant, and the discharge temperature of the compressor is reduced.

In some embodiments, the controller of the air conditioning system is configured to adjust the opening degree of the expansion valve according to a target temperature condition satisfied by the air conditioning system, and specifically performs the following steps: and if the target temperature condition is a second temperature condition, controlling the expansion valve to increase from the first opening degree to a third opening degree, wherein 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 larger than the first preset ratio.

It can be understood that the difference between the discharge temperature of the current detection period of the compressor and the discharge temperature of the previous detection period in the second temperature condition is greater than the difference between the discharge temperature of the current detection period of the compressor and the discharge temperature of the previous detection period in the first temperature condition, so that the increase of the opening degree of the expansion valve when the second temperature condition is satisfied is greater than the increase of the opening degree of the expansion valve when the first temperature condition is satisfied, thereby achieving the purpose of faster temperature reduction

In some embodiments, the controller of the air conditioning system is configured to adjust the opening degree of the expansion valve according to a target temperature condition satisfied by the air conditioning system, and specifically performs the following steps: and if the target temperature condition is the third temperature condition, adjusting the opening degree of the expansion valve to be a preset opening degree.

In some embodiments, the preset opening degree is determined by an actual operating frequency value of the compressor, an ambient temperature, a discharge temperature of a current detection period, and an operating mode of the air conditioning system.

It will be appreciated that the higher the actual operating frequency of the compressor, the higher the discharge temperature of the compressor, and the higher the ambient temperature. The opening degree of the expansion valve should be different according to the exhaust temperature of the current detection cycle. Meanwhile, the exhaust temperatures of the compressors are different in different operation modes of the air conditioning system, so that the preset opening is determined according to the actual operation frequency value of the compressor, the ambient temperature, the exhaust temperature of the current detection period and the operation mode of the air conditioning system, so that the preset opening is more accurate, and the exhaust temperature is more efficiently reduced to a reasonable range.

In some embodiments, the controller of the air conditioning system is configured to adjust the opening degree of the expansion valve according to a target temperature condition satisfied by the air conditioning system, and specifically performs the following steps: if the target temperature condition is the fourth temperature condition, the opening degree of the expansion valve is adjusted to the maximum opening degree. In this way, when the exhaust temperature of the compressor reaches a very high value, the opening degree of the expansion valve is adjusted to the maximum opening degree, and the flow rate of the refrigerant can be adjusted to the maximum amount, so that the temperature of the compressor is reduced at the highest speed, and the possibility of damage to the compressor is reduced.

In some embodiments, the controller of the air conditioning system is configured to decrease the opening degree of the expansion valve until the liquid level height of the gas-liquid separator is less than or equal to a preset liquid level height, and specifically perform the following steps: and gradually reducing the opening degree of the expansion valve by a preset adjustment value until the liquid level height of the gas-liquid separator is less than or equal to the preset liquid level height.

It will be appreciated that when the discharge temperature of the compressor is within a reasonable range, the liquid level of the gas-liquid separator is also at a reasonable height. When the exhaust temperature of the compressor is higher than the reasonable range, the flow rate of the refrigerant is increased due to the increase of the opening degree of the expansion valve, and the liquid level in the gas-liquid separator is further increased. When the liquid level in the gas-liquid separator is higher than the preset liquid level, the compressor may be operated with liquid, and the compressor may be damaged. Therefore, the opening degree of the expansion valve needs to be increased and the liquid level of the gas-liquid separator needs to be monitored, and the liquid level of the gas-liquid separator needs to be adjusted in time when the liquid level is higher than the preset liquid level. The opening degree of the expansion valve is gradually reduced by a preset adjustment value to reduce the flow of the refrigerant until the liquid level height of the gas-liquid separator is less than or equal to the preset liquid level height. If the liquid level height of the gas-liquid separator is less than or equal to the preset liquid level height, the situation that the current refrigerant flow cannot cause liquid-carrying operation is demonstrated temporarily, and therefore the opening degree of the current expansion valve can be maintained until the exhaust temperature is reduced to a reasonable range.

In a second aspect, an embodiment of the present application provides a control method of an air conditioning system, including:

In a third aspect, an embodiment of the present application provides a controller, including: one or more processors; one or more memories; wherein the one or more memories are used to store computer program code comprising computer instructions which, when executed by the one or more processors, cause the controller to perform the control method provided by the second aspect.

In a fourth aspect, embodiments of the present application provide a computer-readable storage medium including computer instructions that, when controlled on a computer, cause the computer to perform the method provided in the second aspect and possible implementation manners.

In a fifth aspect, embodiments of the present invention provide a computer program product, which is directly loadable into a memory and contains software code, and which, when loaded and executed by a computer, is able to carry out the method as provided in the second aspect and possible implementations.

It should be noted that the computer instructions may be stored in whole or in part on a computer-readable storage medium. The computer readable storage medium may be packaged with or separately from a processor of the controller, which is not limited in this application.

The beneficial effects described in the second aspect to the fifth aspect in the present application may refer to the beneficial effect analysis of the first aspect, and are not described herein again.

Drawings

Fig. 1 is a schematic structural diagram of an air conditioning system according to an embodiment of the present disclosure;

fig. 2 is a schematic structural diagram of another air conditioning system provided in an embodiment of the present application;

fig. 3 is a schematic hardware structure diagram of a controller according to an embodiment of the present disclosure;

fig. 4 is a schematic hardware structure diagram of another controller provided in an embodiment of the present application;

fig. 5 is a schematic diagram of a refrigeration cycle of an air conditioning system according to an embodiment of the present disclosure;

fig. 6 is a schematic view illustrating a heating cycle of an air conditioning system according to an embodiment of the present disclosure;

fig. 7 is a flowchart illustrating a control method of an air conditioning system according to an embodiment of the present disclosure;

fig. 8 is a schematic flowchart of another control method for an air conditioning system according to an embodiment of the present disclosure;

fig. 9 is a schematic flowchart of another control method for an air conditioning system according to an embodiment of the present disclosure;

fig. 10 is a schematic hardware structure diagram of a controller according to an embodiment of the present disclosure.

Reference numerals are as follows: 11-an air conditioning system; 100-indoor unit; 200-an outdoor unit; 300-connecting piping; 400-a remote controller; 101-indoor heat exchanger; 2011-first stop valve; 2012-a second stop valve; 202-a four-way reversing valve; 203-a gas-liquid separator; 204-a compressor; 205-outdoor heat exchanger; 206-an economizer; 2071-a first expansion valve; 2072 — a second expansion valve; 208-a temperature sensor; 209-level sensor. 210-a controller; 2101-outdoor control module; 2102-indoor control module; 2103-a processor; 2104-memory; 2105 a communication interface; 2106 a bus.

Detailed Description

The technical solutions in the embodiments of the present application will be described clearly and completely with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only some embodiments of the present application, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

In the description of the present invention, it is to be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of description and simplicity of description, and do not indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and thus, are not to be construed as limiting the present invention.

The terms "first", "second" and "first" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of the present application, "a plurality" means two or more unless otherwise specified.

In the description of the embodiments of the present application, it should be noted that the terms "connected" and "connected" are to be construed broadly and may be, for example, fixedly connected, detachably connected, or integrally connected unless otherwise specifically stated or limited. The specific meaning of the above terms in the present application can be understood in a specific case by those of ordinary skill in the art. In addition, when a pipeline is described, the terms "connected" and "connecting" are used in this application to mean conducting. The specific meaning is to be understood in conjunction with the context.

In the embodiments of the present application, words such as "exemplary" or "for example" are used to mean serving as an example, instance, or illustration. Any embodiment or design described herein as "exemplary" or "such as" is not necessarily to be construed as preferred or advantageous over other embodiments or designs. Rather, use of the word "exemplary" or "such as" is intended to present relevant concepts in a concrete fashion.

As described in the background art, in the operation process of an air conditioner, when the exhaust temperature of a compressor is too high, the opening degree of an expansion valve is increased to increase the flow rate of a refrigerant, so as to achieve the effect of reducing the exhaust temperature of the compressor, but the increase of the opening degree of the expansion valve also causes the height of liquid in a gas-liquid separator to exceed a reasonable range, thereby causing the problem that the compressor is damaged by the liquid-carrying operation of the compressor.

In order to solve the above technical problem, embodiments of the present invention provide an air conditioning system and a control method thereof, where the control method periodically detects the discharge temperature of a compressor, and when the discharge temperature of the compressor is too high, controls the opening degree of an expansion valve to increase. The method is characterized in that the exhaust temperature of the compressor is divided into at least one temperature condition, and the opening degree of the expansion valve is increased by corresponding opening degree according to the temperature condition met by the exhaust temperature detected in the current detection period, so that the exhaust temperature of the compressor is rapidly reduced. Meanwhile, the refrigerant flow is increased due to the increase of the opening degree of the expansion valve, so that the opening degree of the expansion valve can be finely adjusted and reduced when the liquid level of the gas-liquid separator exceeds the liquid level height corresponding to the temperature condition through monitoring the liquid level of the gas-liquid separator, and the phenomenon that the compressor is in liquid-carrying operation due to the fact that too much refrigerant in the gas-liquid separator enters the compressor is prevented, and the compressor is in fault.

The air conditioning system provided by the embodiment of the application can be a cabinet air conditioner, an on-hook air conditioner, a water air conditioner, a window air conditioner, a central air conditioner and a multi-connected air conditioner. The air conditioning system provided by the embodiment of the present application may have one compressor or a plurality of compressors, and the embodiment of the present application does not limit this.

To further describe the technical solution of the embodiment of the present application, fig. 1 is a structural diagram of an air conditioning system provided in the embodiment of the present application.

Referring to fig. 1, the air conditioning system 11 includes: the indoor unit 100, the outdoor unit 200, the connection pipe 300, and the remote controller 400 are, for example, an indoor unit (shown in fig. 1) which is usually attached to an indoor wall surface WL or the like. For another example, an indoor unit (not shown in fig. 1) is also an indoor unit type of the indoor unit.

In some embodiments, the connection pipe 300 is disposed between the indoor unit 100 and the outdoor unit 200, and is used to connect the indoor unit 100 and the outdoor unit 200 to form a refrigerant circuit for circulating a refrigerant.

In some embodiments, the remote control 400 is an accessory to the air conditioning system 11, and has functionality to communicate with the controller, for example, using infrared or other communication means. The remote controller 400 is used to realize interaction between a user and the air conditioning system, and the user can perform operations such as on/off of the air conditioning system, temperature setting, wind direction setting, and air volume setting through a display device and buttons on the remote controller.

In some embodiments, as shown in fig. 2, the indoor unit 100 includes an indoor heat exchanger 101.

And an indoor heat exchanger 101 disposed in the indoor unit 100, for exchanging heat with indoor air to cool or heat the indoor air.

In some embodiments, continuing with fig. 2, the outdoor unit 200 includes: a first stop valve 2011, a second stop 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.

In some embodiments, the outdoor unit 200 is generally disposed outdoors to assist heat exchange in indoor environment. The following is a detailed description of the arrangement and functions of the components of the outdoor unit 200.

In some embodiments, the first stop valve 2011 and the second stop valve 2012 are disposed on a refrigerant passage in the outdoor unit 200, and are respectively connected to two ends of the indoor heat exchanger 101 for preventing the refrigerant from flowing backwards, and after the air conditioning system is installed, the first stop valve 2011 and the second stop valve 2012 are kept in a normally closed state.

In some embodiments, the four-way reversing valve 202 has four ports respectively connected to the discharge port of the compressor 204, the indoor heat exchanger 101, the suction port of the compressor 204, and the outdoor heat exchanger 205, and is used for switching between the cooling mode and the heating mode by changing the flow direction of the refrigerant in the system pipeline.

In some embodiments, the outlet of the gas-liquid separator 203 is connected to the suction port of the compressor 204 for receiving the refrigerant in the liquid return portion of the refrigerant channel, thereby preventing liquid impact on the compressor 204.

In some embodiments, the discharge port of the compressor 204 is connected to the outdoor heat exchanger 205 through the four-way reversing valve 202 for powering the refrigerant cycle. Optionally, the compressor 204 may be one or more.

In some embodiments, the outdoor heat exchanger 205 is disposed in the outdoor unit 200, and is configured to exchange heat between the refrigerant flowing through the heat transfer pipes of the outdoor heat exchanger 205 and the outdoor air.

In some embodiments, the first expansion valve 2071 is disposed between the outdoor heat exchanger 205 and the economizer 206, and has an effect of expanding the refrigerant flowing through the first expansion valve 2071 to achieve decompression, so as to adjust the flow rate of the refrigerant in the refrigerant passage. Alternatively, the first expansion valve 2071 may be an electronic expansion valve. When the opening degree of the first expansion valve 2071 is decreased, the flow path resistance of the refrigerant passing through the first expansion valve 2071 is increased. When the opening degree of the first expansion valve 2071 is increased, the flow path resistance of the refrigerant passing through the first expansion valve 2071 is decreased. As described above, even if the state of other components in the circuit is not changed, the flow rate of the refrigerant flowing through the indoor heat exchanger 101 or the outdoor heat exchanger 205 is changed when the opening degree of the first expansion valve 2071 is changed.

In some embodiments, the economizer 206 has a first refrigerant channel and a second refrigerant channel, and the first refrigerant channel is connected to the indoor heat exchanger 101 at one end and the outdoor heat exchanger 205 at the other end. One end of the second refrigerant channel is communicated with the pipeline of the first refrigerant channel connection outdoor heat exchanger 205 through the second expansion valve 2072, and the other end is connected with the inlet of the gas-liquid separator 203.

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

In some embodiments, a temperature sensor 208 is disposed at the discharge of the compressor 204 for detecting the discharge temperature of the compressor 204.

In some embodiments, a liquid level sensor is disposed within the gas-liquid separator 203 for detecting the height of liquid within the gas-liquid separator 203.

As shown in fig. 3, the air conditioning system further includes a controller 210, and the controller 210 is electrically connected to the indoor heat exchanger 101, the first cut-off valve 2011, the second cut-off valve 2012, the four-way selector valve 202, the gas-liquid separator 203, the compressor 204, the outdoor heat exchanger 205, the economizer 206, the first expansion valve 2071, the second expansion valve 2072, the temperature sensor 208, and the liquid level sensor 209.

In some embodiments, the controller 210 refers to a device that can generate an operation control signal according to the command operation code and the timing signal, and instruct the air conditioning system to execute the control command. Illustratively, the controller 210 may 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. The controller 210 may also be other devices with processing functions, such as a circuit, a device, or a software module, which is not limited in any way by the embodiments of the present application.

In addition, the controller 210 may be configured to control operations of various components of the air conditioning system 11, so that the various components of the air conditioning system 11 operate to implement various predetermined functions of the air conditioning system.

Fig. 4 is a schematic structural diagram of a controller 210 according to an embodiment of the present disclosure. As shown in fig. 4, 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 with the outdoor control module 2101 by wired or wireless communication. The outdoor control module 2101 may be installed in an outdoor unit, or may be independent from the outdoor unit, and is configured to control the outdoor unit to perform related operations. The indoor control module 2102 may be installed in the indoor unit, or may be independent of the indoor unit and used to control components of the indoor unit. It should be understood that the above division of modules is only a division of functionality, and the outdoor control module 2101 and the indoor control module 2102 may also be integrated in one module. The first memory and the second memory may also be integrated into one memory.

In some embodiments, the first storage is used to store applications and data related to the outdoor unit, and the outdoor control module 2101 performs various functions of the air conditioning system and data processing by operating the applications and data stored in the storage. The first memory mainly includes a program storage area and a data storage area, wherein the program storage area may store an operating system, and application programs required by at least one function (for example, adjustment programs for the first expansion valve 2071 and the second expansion valve 2072 of the outdoor unit, etc.); the storage data area may store data (such as opening degrees of the outdoor unit first expansion valve 2071 and the second expansion valve 2072, etc.) created according to the use of the air conditioning system. Further, the first memory may include a high speed random access memory, and may also include a non-volatile memory, such as a magnetic disk storage device, a flash memory device, or other volatile solid state storage device.

In some embodiments, the second memory is used to store applications and data related to the indoor unit and the plurality of first and

second expansion valves

2071 and 2072, and the indoor control module 2102 executes various functions and data processing of the air conditioning system by executing the applications and data stored in the memory. The second memory mainly includes a program storage area and a data storage area, wherein the program storage area may store an operating system, and application programs required by at least one function (for example, an adjustment program for the first expansion valve 2071 and the second expansion valve 2072 of the indoor unit, etc.); the storage data area may store data (such as opening degrees of the indoor unit first expansion valve 2071 and the second expansion valve 2072, etc.) created according to the use of the multi-split air conditioning system. In some examples, the second memory is also used to store correspondence between addresses of the indoor units and addresses of the first and

second expansion valves

2071 and 2072.

In some embodiments, the outdoor control module 2101 is in communication with an outdoor unit, and is configured to control the outdoor unit to perform related operations according to a user instruction or a system default instruction. Alternatively, the outdoor control module 2101 may control the opening degrees of the outdoor unit first expansion valve 2071 and the outdoor unit second expansion valve 2072 according to the discharge superheat degree of the compressor. Optionally, the outdoor control module 2101 may further obtain an outdoor temperature according to a user instruction or a system instruction, and store the obtained outdoor temperature in the first memory. Optionally, the outdoor control module 2101 may also control the four-way reversing valve 202 in the outdoor unit 200 to rotate according to the air conditioner operation mode selected by the user, so as to implement the selection of the cooling or heating mode. Alternatively, the outdoor control module 2101 may also control an operation mode of the outdoor unit, a compressor frequency, and the like in the address correction process.

In some embodiments, the indoor control module 2102 is communicatively coupled to the indoor unit for controlling the indoor unit to perform related operations according to a user command or a default system command. Alternatively, the indoor control module 2102 controls the opening degrees of the first and

second expansion valves

2071 and 2072 of the indoor unit according to the degree of superheat of the compressor discharge air.

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

The cooling mode and the heating mode are respectively described below with reference to the drawings of the specification.

1. Refrigeration mode

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

Illustratively, this is illustrated in connection with the air conditioning system 11 shown in FIG. 5.

When the air conditioning system 11 is in the cooling mode, the end d of the four-way reversing valve 202 is connected to the end c, and the end a is connected to the end b. The compressor 204 discharges high-temperature and high-pressure gaseous refrigerant, the gaseous refrigerant starts from the discharge port of the compressor 204, passes through the d end and the c end of the four-way reversing valve 202 to reach the outdoor heat exchanger 205, is fully heat-exchanged in the outdoor heat exchanger 205 to become high-temperature and high-pressure supercooled liquid refrigerant, and then passes through the first expansion valve 2071 to reach the economizer 206. Part of the refrigerant sequentially passes through the second stop valve 2012 through the first refrigerant channel of the economizer 206 to reach the indoor heat exchanger 101, undergoes heat exchange in the indoor heat exchanger 101, is evaporated into a low-temperature and low-pressure superheated gaseous refrigerant, then flows into the gas-liquid separator 203 through the first stop valve 2011 and the a end and the b end of the four-way reversing valve 202, and is sucked by the compressor 204 through the suction port of the compressor 204, so that the refrigeration cycle is completed. Another part of the refrigerant passes through the second refrigerant passage of the economizer 206 and sequentially passes through the second expansion valve 2072 to flow into the gas-liquid separator 203, and then passes through the suction port of the compressor 204 to be sucked into the compressor 204.

2. Heating mode

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

Illustratively, this is illustrated in connection with the air conditioning system 11 shown in FIG. 6.

When the air conditioning system 11 is in the heating mode, the end a of the four-way reversing valve 202 is connected with the end d, and the end b is connected with the end c. The compressor 204 discharges high-temperature and high-pressure gaseous refrigerant, the gaseous refrigerant starts from an exhaust port of the compressor 204, sequentially passes through the end d and the end a of the four-way reversing valve 202 and the first stop valve 2011 to reach the indoor heat exchanger 101, heat exchange is performed in the indoor heat exchanger 101, heat is released and condensed into low-temperature and high-pressure supercooled liquid refrigerant, and the refrigerant enters the economizer 206 through the second stop valve 2012. Part of the refrigerant sequentially passes through the first expansion valve 2071 through the first refrigerant channel of the economizer 206 and enters the outdoor heat exchanger 205 to complete heat exchange, and is evaporated into a low-temperature and low-pressure superheated gaseous refrigerant, and the superheated gaseous refrigerant enters the gas-liquid separator 203 through the c end and the b end of the four-way reversing valve, and is then sucked into the compressor 204 through the suction port of the compressor 204 to complete the heating cycle. Another part of the refrigerant passes through the second refrigerant passage of the economizer 206 and sequentially passes through the second expansion valve 2072 to flow into the gas-liquid separator 203, and then passes through the suction port of the compressor 204 to be sucked into the compressor 204.

The embodiments of the present application will be described in detail below with reference to the accompanying drawings.

As shown in fig. 7, an embodiment of the present application provides a control method of an air conditioning system, which is applied to a controller of the air conditioning system, and the method includes the following steps:

s101, under the condition that the exhaust temperature of the current detection period is larger than the target exhaust temperature, determining a target temperature condition met by the air conditioning system from at least one temperature condition.

Wherein the target discharge temperature is an ideal discharge temperature of the compressor at the current operating condition of the air conditioning system.

Optionally, the at least one temperature condition comprises one or more of a first temperature condition, a second temperature condition, a third temperature condition, or a fourth temperature condition.

The first temperature condition includes: the exhaust temperature of the current detection period is greater than or equal to a first preset temperature, and the difference between the exhaust temperature of the current detection period and the exhaust temperature of the last detection period is greater than or equal to the first preset value and smaller than a second preset value.

Illustratively, the first temperature condition may be expressed in the form of:

td (n) is more than or equal to 95 ℃, and A is less than or equal to Td (n) -Td (n-1) < B.

Wherein Td (n) is the exhaust temperature of the current detection period; td (n-1) is the exhaust temperature of the last detection period; A. b is a specific number and B > A.

The second temperature condition includes: the exhaust temperature of the current detection period is greater than or equal to a first preset temperature, and the difference between the exhaust temperature of the current detection period and the exhaust temperature of the last detection period is greater than a second preset value.

Illustratively, the second temperature condition may be expressed in the form of:

td (n) is more than or equal to 95 ℃, and Td (n) -Td (n-1) is more than or equal to B.

The third temperature condition includes: the exhaust temperature of the current detection period is greater than or equal to a second preset temperature, and the difference between the exhaust temperature of the current detection period and the exhaust temperature of the last detection period is greater than or equal to a third preset value.

Illustratively, the third temperature condition may be expressed in the form of:

td (n) ≥ 100 deg.C, and Td (n) -Td (n-1) ≥ C. Wherein C is a specific numerical value.

The fourth temperature condition includes: the exhaust temperature of the current detection period is greater than or equal to a third preset temperature, the opening degree of the expansion valve is greater than or equal to a preset opening degree, and the difference between the exhaust temperature of the current detection period and the exhaust temperature of the last detection period is greater than or equal to a fourth preset value.

Illustratively, the fourth temperature condition may be expressed in the form of:

td (n) ≥ 110 deg.C, and Td (n) -Td (n-1) ≥ D. Wherein D is a specific number, and D > C.

As a specific implementation manner, the preset opening K is determined by an actual operating frequency value of the compressor, an ambient temperature, an exhaust temperature of a current detection period, and an operating mode of the air conditioning system.

Exemplarily, K = F × K1 × K2 × K3.

Wherein F is the frequency value of the actual operation of the compressor.

K1 is a parameter related to the operation state of the outdoor unit and the ambient temperature, and the value range of K1 is shown in table 1:

TABLE 1

Outdoor machine operating state	Value of K1
		Ta > E ℃ and refrigeration	1.5
Heating operation	1.0
		Other than the above notes	1.2

Wherein Ta in table 1 represents ambient temperature.

K2 is a parameter related to the exhaust temperature of the compressor, and the value range of K2 is more than or equal to 1 and less than or equal to K2

1.8, and K2 is in positive correlation with the exhaust temperature of the compressor.

K3 is a parameter related to the ambient temperature, the value range of K3 is more than or equal to 1.0 and less than or equal to 1.5, and K3 is in positive correlation with the ambient temperature.

The first preset temperature, the second preset temperature and the third preset temperature are all larger than the target exhaust temperature, the first preset temperature is smaller than the second preset temperature, and the second preset temperature is smaller than the third preset temperature.

It should be understood that the difference between the exhaust temperature of the current detection period and the exhaust temperature of the last detection period may be used to reflect the trend of the exhaust temperature. When the difference value between the exhaust temperature of the current detection period and the exhaust temperature of the last detection period is larger than the preset value, the trend of the change of the exhaust temperature is indicated to be an increasing trend. Therefore, the air conditioning system needs to take timely adjustment measures to avoid the exhaust temperature from being too high.

And S102, adjusting the opening degree of the second expansion valve according to the adjustment strategy corresponding to the target temperature condition.

As a possible implementation, if the target temperature condition is the first temperature condition, the second expansion valve is controlled to increase from the first opening degree to the second opening degree, and a ratio of a difference between the second opening degree and the first opening degree to the first opening degree is equal to a first preset ratio. The first opening degree of the second expansion valve is the opening degree of the expansion valve in the previous detection period, and the second opening degree is the opening degree of the expansion valve after corresponding adjustment. For example, the first predetermined ratio may be 25%.

As another possible implementation manner, if the target temperature condition is the second temperature condition, the second expansion valve is controlled to increase from the first opening degree to the third opening degree, a ratio of a 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. Illustratively, the second predetermined ratio may be 50%.

As another possible implementation manner, if the target temperature condition is the third temperature condition, the opening degree of the second expansion valve is adjusted to a preset opening degree.

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

S103, after the opening degree of the second expansion valve is adjusted, if the liquid level height of the gas-liquid separator is larger than the preset liquid level height corresponding to the target temperature condition, the opening degree of the second expansion valve is reduced until the liquid level height of the gas-liquid separator is smaller than or equal to the preset liquid level height.

In some embodiments, as shown in fig. 8, step S103 may be implemented as the following steps:

and S1031, detecting the liquid level of the gas-liquid separator, and judging whether the liquid level height of the gas-liquid separator is greater than a preset liquid level height corresponding to the target temperature condition.

If yes, executing the following step S1032;

if not, the current opening degree of the expansion valve is maintained until the exhaust temperature is reduced to a reasonable range, for example, the current opening degree of the expansion valve is maintained until the exhaust temperature is less than 95 ℃.

Illustratively, 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, wherein a is greater than 0 and less than b and c is less than d.

And S1032, reducing the opening degree of the second expansion valve by a preset adjusting value.

For example, the preset adjustment value may be 1%.

And S1033, judging whether the liquid level height of the current gas-liquid separator is less than or equal to a preset liquid level height.

If not, S1032 is continuously executed, and the opening degree of the second expansion valve is reduced by the preset adjusting value.

If yes, the following step S1034 is executed.

S1034, the adjustment of the opening degree of the second expansion valve is finished.

The embodiment shown in fig. 7 brings at least the following advantages: in the operation process of the air conditioning system, if the compressor continuously operates at high frequency, the exhaust temperature is too high, and the compressor can be damaged. Therefore, the opening degree of the second expansion valve can be increased according to the exhaust temperature of the compressor so as to increase the flow rate of the refrigerant entering the compressor, thereby reducing the exhaust temperature of the compressor. However, if the opening degree of the second expansion valve is too large, the liquid refrigerant in the gas-liquid separator increases and the liquid refrigerant flows into the compressor more. This application embodiment is through monitoring vapour and liquid separator's liquid level, when vapour and liquid separator's liquid level is higher than the preset liquid level height that the exhaust temperature of compressor corresponds, finely tune the aperture in order to reduce the aperture of second expansion valve to make vapour and liquid separator's liquid level height be less than or equal to preset liquid level height, and then avoid liquid refrigerant to get into the compressor and cause the damage to the compressor.

In some embodiments, if the outdoor unit includes a plurality of compressors, an embodiment of the present application further provides an air conditioning system control method, including: when the maximum value of the exhaust temperature of the current detection period is larger than the target exhaust temperature, determining a target temperature condition met by the air conditioning system from at least one temperature condition; adjusting the opening degree of the expansion valve according to an adjustment strategy corresponding to the target temperature condition; after the opening degree of the expansion valve is adjusted, if the liquid level height of the gas-liquid separator is larger than the preset liquid level height corresponding to the target temperature condition, the opening degree of the expansion valve is reduced until the liquid level height of the gas-liquid separator is smaller than or equal to the preset liquid level height.

The maximum value of the exhaust temperature of one detection period is the maximum value of the exhaust temperatures of the compressors in the detection period.

Accordingly, the at least one temperature condition may include: one or more of a fifth temperature condition, a sixth temperature condition, a seventh temperature condition, and an eighth temperature condition.

The fifth temperature condition comprises that the maximum value of the exhaust temperature of the current detection period is greater than or equal to a first preset temperature, and the difference value between the maximum value of the exhaust temperature of the current detection period and the maximum value of the exhaust temperature of the last detection period is greater than or equal to a first preset value and smaller than a second preset value.

The sixth temperature condition includes that the maximum value of the exhaust temperature of the current detection period is greater than or equal to the first preset temperature, and the difference between the maximum value of the exhaust temperature of the current detection period and the maximum value of the exhaust temperature of the last detection period is greater than the second preset value.

The seventh temperature condition includes that the maximum value of the exhaust temperature of the current detection period is greater than or equal to the second preset temperature, and the difference between the maximum value of the exhaust temperature of the current detection period and the maximum value of the exhaust temperature of the last detection period is greater than or equal to the third preset value.

The eighth temperature condition includes that the maximum value of the exhaust temperature of the current detection period is greater than or equal to a third preset temperature, the opening degree of the expansion valve is greater than or equal to a preset opening degree, and the difference between the maximum value of the exhaust temperature of the current detection period and the maximum value of the exhaust temperature of the previous detection period is greater than or equal to a fourth preset value.

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

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.

A control method of an air conditioning system provided in an embodiment of the present application is described below with reference to fig. 9:

as shown in fig. 9, it is determined from Td (n) that the temperature condition to be satisfied is a first temperature condition, a second temperature condition, a third temperature condition, or a fourth temperature condition.

When a first temperature condition is met, executing valve opening measure 1, then judging whether the liquid level of the gas-liquid separator is less than or equal to a, if so, maintaining the opening of the second expansion valve until Td (n) is reduced to a reasonable range; if not, the opening degree of the second expansion valve is reduced in a fine adjustment mode until the liquid level height of the gas-liquid separator is less than or equal to a, and the current opening degree is maintained until Td (n) is reduced to a reasonable range.

When a second temperature condition is met, executing a valve opening measure 2, then judging whether the liquid level of the gas-liquid separator is less than or equal to b, if so, maintaining the opening of the second expansion valve until Td (n) is reduced to a reasonable range; if not, the opening degree of the second expansion valve is reduced in a fine adjustment mode until the liquid level height of the gas-liquid separator is less than or equal to b, and the current opening degree is maintained until Td (n) is reduced to a reasonable range.

When a first temperature condition is met, executing a valve opening measure 3, then judging whether the liquid level of the gas-liquid separator is less than or equal to c, if so, maintaining the opening of the second expansion valve until Td (n) is reduced to a reasonable range; if not, the opening degree of the second expansion valve is reduced in a fine adjustment mode until the liquid level height of the gas-liquid separator is less than or equal to c, and the current opening degree is maintained until Td (n) is reduced to a reasonable range.

When a first temperature condition is met, executing a valve opening measure 4, then judging whether the liquid level of the gas-liquid separator is less than or equal to d, if so, maintaining the opening of the second expansion valve until Td (n) is reduced to a reasonable range; if not, the opening degree of the second expansion valve is reduced in a fine adjustment mode until the liquid level height of the gas-liquid separator is smaller than or equal to d, and then the current opening degree is maintained until Td (n) is reduced to a reasonable range.

It can be seen that the foregoing describes the solution provided by the embodiments of the present application primarily from a methodological perspective. In order to implement the above functions, the embodiments of the present application provide a hardware structure and/or a software module corresponding to each function. Those of skill in the art will readily appreciate that the various illustrative modules and algorithm steps described in connection with the embodiments disclosed herein may be implemented as hardware or combinations of hardware and computer software. Whether a function is performed as hardware or computer software drives hardware depends upon the particular application and design constraints imposed on the solution. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present invention.

In the embodiment of the present application, the controller may be divided into the functional modules according to the above method example, for example, each functional module may be divided corresponding to each function, or two or more functions may be integrated into one processing module. The integrated module can be realized in a hardware mode, and can also be realized in a software functional module mode. Optionally, in the embodiment of the present application, the division of the module is schematic, and is only one logic function division, and another division manner may be provided in actual implementation.

The embodiment of the present application further provides a schematic diagram of a hardware structure of a controller, as shown in fig. 10, the controller 210 further includes a processor 2103, and optionally, further includes a memory 2104 and a communication interface 2105, which are connected to the processor 2103. The processor 2103, memory 2104, and communication interface 2105 are connected by a bus 2106.

The processor 2103 may be a Central Processing Unit (CPU), a general purpose processor Network (NP), a Digital Signal Processor (DSP), a microprocessor, a microcontroller, a Programmable Logic Device (PLD), or any combination thereof. The processor 2103 may also be any other device having a processing function, such as a circuit, a device, or a software module. The processor 2103 may also include multiple CPUs, and the processor 2103 may be a single-core (single-CPU) processor or a multi-core (multi-CPU) processor. A processor herein may refer to one or more devices, circuits, or processing cores that process data, such as computer program instructions.

The memory 2104 may be a read-only memory (ROM) or other type of static storage device that can store static information and instructions, a Random Access Memory (RAM) or other type of dynamic storage device that can store information and instructions, 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 compact disc, laser disc, optical disc, digital versatile disc, blu-ray disc, etc.), a magnetic disc storage medium or other magnetic storage device, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer, which is not limited by the embodiments of the present application. The memory 2104 may be separate or integrated with the processor 2103. The memory 2104 may have computer program code embodied therein. The processor 2103 is configured to execute the computer program code stored in the memory 2104, so as to implement the control method provided by the embodiment of the present application.

Communication interface 2105 may be used for communicating with other devices or communication networks (e.g., ethernet, radio Access Network (RAN), wireless Local Area Networks (WLAN), etc.) communication interface 2105 may be a module, circuitry, transceiver, or any other device capable of communicating.

The bus 2106 may be a Peripheral Component Interconnect (PCI) bus, an Extended Industry Standard Architecture (EISA) bus, or the like. The bus 2106 may be divided into an address bus, a data bus, a control bus, and so on. For ease of illustration, only one thick line is shown in FIG. 10, but this is not intended to represent only one bus or type of bus.

The embodiment of the present application further provides a computer-readable storage medium, which includes computer-executable instructions, and when the computer-executable instructions run on a computer, the computer is enabled to execute any one of the control methods of the air conditioning system provided in the foregoing embodiments.

Embodiments of the present application further provide a computer program product containing computer execution instructions, which when run on a computer, causes the computer to execute any one of the control methods of the air conditioning system provided in the foregoing embodiments.

In the above embodiments, the implementation may be wholly or partially realized by software, hardware, firmware, or any combination thereof. When implemented using a software program, it may be implemented in whole or in part in the form of a computer program product. The computer program product includes one or more computer-executable instructions. The processes or functions according to the embodiments of the present application are generated in whole or in part when the computer-executable instructions are loaded and executed on a computer. The computer may be a general purpose computer, a special purpose computer, a network of computers, or other programmable device. The computer executable instructions may be stored on a computer readable storage medium or transmitted from one computer readable storage medium to another, for example, the computer executable instructions may be transmitted from one website, computer, server, or data center to another website, computer, server, or data center via wire (e.g., coaxial cable, fiber optic, digital Subscriber Line (DSL)) or wireless (e.g., infrared, wireless, microwave, etc.). Computer-readable storage media can be any available media that can be accessed by a computer or data storage device including one or more available media integrated servers, data centers, and the like. The usable medium may be a magnetic medium (e.g., floppy disk, hard disk, magnetic tape), an optical medium (e.g., DVD), or a semiconductor medium (e.g., solid State Disk (SSD)), among others.

While the present application is described in connection with various embodiments, other variations to the disclosed embodiments can be understood and effected by those skilled in the art in practicing the claimed application, from a review of the drawings, the disclosure, and the appended claims. In the claims, the word "comprising" does not exclude other elements or steps, and the word "a" or "an" does not exclude a plurality. A single processor or other unit may fulfill the functions of several items recited in the claims. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

Although the present application has been described in conjunction with specific features and embodiments thereof, it will be evident that various modifications and combinations can be made thereto without departing from the spirit and scope of the application. Accordingly, the specification and figures are merely exemplary of the present application as defined in the appended claims and are intended to cover any and all modifications, variations, combinations, or equivalents within the scope of the present application. It will be apparent to those skilled in the art that various changes and modifications may be made in the present application without departing from the spirit and scope of the application. Thus, if such modifications and variations of the present application fall within the scope of the claims of the present application and their equivalents, the present application is intended to include such modifications and variations as well.

The above description is only an embodiment of the present application, but the scope of the present application is not limited thereto, and any changes or substitutions within the technical scope of the present disclosure should be covered by the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. An air conditioning system, comprising:

an indoor heat exchanger;

an outdoor heat exchanger;

a compressor;

the economizer is provided with a first refrigerant channel and a second refrigerant channel, one end of the first refrigerant channel is connected with the indoor heat exchanger, and the other end of the first refrigerant channel is connected with the outdoor heat exchanger; one end of the second refrigerant channel is communicated with a pipeline of the first refrigerant channel connected with the outdoor heat exchanger through an expansion valve, and the other end of the second refrigerant channel is connected with an inlet of the gas-liquid separator;

a controller configured to:

when the exhaust temperature of the current detection period is larger than the target exhaust temperature, determining a target temperature condition met by the air conditioning system from at least one temperature condition;

2. The air conditioning system of claim 1, wherein the 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 comprises: the exhaust temperature of the current detection period is greater than or equal to a first preset temperature, and the difference value between the exhaust temperature of the current detection period and the exhaust temperature of the last detection period is greater than or equal to a first preset value and smaller than a second preset value;

the second temperature condition includes: the exhaust temperature of the current detection period is greater than or equal to a first preset temperature, and the difference value between the exhaust temperature of the current detection period and the exhaust temperature of the last detection period is greater than a second preset value;

the third temperature condition includes: the exhaust temperature of the current detection period is greater than or equal to a second preset temperature, and the difference between the exhaust temperature of the current detection period and the exhaust temperature of the last detection period is greater than or equal to a third preset value;

the fourth temperature condition includes: the exhaust temperature of the current detection period is greater than or equal to a third preset temperature, the opening degree of the expansion valve is greater than or equal to a preset opening degree, and the difference between the exhaust temperature of the current detection period and the exhaust temperature of the previous detection period is greater than or equal to a fourth preset value;

3. The air conditioning system of claim 2,

the controller is configured to adjust the opening degree of the expansion valve according to a target temperature condition met by the air conditioning system, and specifically execute the following steps:

and if the target temperature condition is a first temperature condition, controlling the expansion valve to increase from a first opening degree to a second opening degree, wherein 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.

4. The air conditioning system of claim 3,

and if the target temperature condition is a second temperature condition, controlling the expansion valve to increase from a first opening degree to a third opening degree, wherein 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 larger than the first preset ratio.

5. The air conditioning system of claim 2,

and if the target temperature condition is a third temperature condition, adjusting the opening degree of the expansion valve to the preset opening degree.

6. The air conditioning system as claimed in claim 5, wherein the preset opening degree is determined by an actual operating frequency value of the compressor, an ambient temperature, a discharge temperature of a current detection period, and an operating mode of the air conditioning system.

7. The air conditioning system of claim 2,

and if the target temperature condition is a fourth temperature condition, adjusting the opening degree of the expansion valve to be the maximum opening degree.

8. The air conditioning system of claim 1,

the controller is configured to reduce the opening degree of the expansion valve until the liquid level height of the gas-liquid separator is less than or equal to the preset liquid level height, and specifically execute the following steps:

and gradually reducing the opening degree of the expansion valve by a preset adjustment value until the liquid level height of the gas-liquid separator is less than or equal to the preset liquid level height.

9. A control method of an air conditioning system, characterized in that, applied to the air conditioning system of any one of the preceding claims 1-8, the method comprises:

determining a target temperature condition satisfied by the air conditioning system from at least one temperature condition under the condition that the exhaust temperature of the current detection period is greater than the target exhaust temperature;

10. The method of claim 9, wherein the reducing the opening degree of the expansion valve until the liquid level height of the gas-liquid separator is less than or equal to the preset liquid level height comprises: