CN115264648A

CN115264648A - Multi-split air conditioning system

Info

Publication number: CN115264648A
Application number: CN202210851580.XA
Authority: CN
Inventors: 颜鹏; 韩飞; 郭小惠; 孙杨
Original assignee: Qingdao Hisense Hitachi Air Conditioning System Co Ltd
Current assignee: Qingdao Hisense Hitachi Air Conditioning System Co Ltd
Priority date: 2022-07-19
Filing date: 2022-07-19
Publication date: 2022-11-01

Abstract

The application discloses multi-split air conditioning system relates to household electrical appliances technical field, can let the refrigerant recovery that leaks and utilize more thoroughly. This multi-split air conditioning system includes: outdoor unit, indoor heat exchanger and refrigerant recovery unit. The outdoor unit comprises a compressor, a four-way valve, an outdoor heat exchanger and an outdoor expansion valve; the indoor unit comprises a plurality of indoor units connected in parallel, each indoor unit comprises an indoor heat exchanger and an indoor expansion valve, and the indoor heat exchanger is connected with the four-way valve through a first pipeline; the refrigerant recovery device includes: the first electromagnetic valve, the second electromagnetic valve, the third electromagnetic valve, the first expansion valve and the liquid storage tank; a first opening of the liquid storage tank is connected with the outdoor expansion valve through a first solenoid valve, a second opening of the liquid storage tank is connected with the indoor expansion valve through a second solenoid valve, and a third opening of the liquid storage tank is communicated with the first pipeline through the first expansion valve; the first end of the third electromagnetic valve is connected with the outdoor expansion valve, and the second end of the third electromagnetic valve is connected with the indoor expansion valve.

Description

Multi-split air conditioning system

Technical Field

The application relates to the technical field of household appliances, in particular to a multi-split air conditioning system.

Background

With the development of economic society, air conditioners are more and more widely used in various places such as entertainment, home and work. When a plurality of small areas in the same area need to use air conditioners, a multi-split air conditioning system composed of an outdoor unit and a plurality of indoor units is often adopted to regulate and control the room temperature of multiple areas in consideration of saving of electric energy. In the use process of the multi-split air conditioning system, a heat transfer pipe (such as a copper pipe or an aluminum pipe) on a heat exchanger is required to transfer heat. However, the heat transfer pipe may be corroded by exposure to the outdoor environment for a long time, and thus may cause leakage of the refrigerant.

In order to avoid the risk caused by refrigerant leakage, in the related art, a pair of electronic expansion valves is added at the inlet and the outlet of each indoor unit of the multi-split air conditioning system to block the refrigerant leaked in the indoor unit from flowing into the indoor environment. However, in the above-mentioned related art method, the leaked refrigerant cannot be completely recovered and utilized, and may be directly discharged to the outdoor environment, thereby causing a problem of environmental pollution.

Disclosure of Invention

The embodiment of the application provides a multi-split air conditioning system for let the refrigerant of leaking more thoroughly retrieve and utilize, with the feature of environmental protection and the energy-conservation nature that improve multi-split air conditioning system.

In a first aspect, an embodiment of the present application provides a multi-split air conditioning system, including: the outdoor unit comprises a compressor, a four-way valve, an outdoor heat exchanger and an outdoor expansion valve; the indoor unit comprises a plurality of indoor units connected in parallel, each indoor unit comprises an indoor heat exchanger and an indoor expansion valve, and the indoor heat exchanger is connected with the four-way valve through a first pipeline; refrigerant recovery unit, refrigerant recovery unit includes: the first electromagnetic valve, the second electromagnetic valve, the third electromagnetic valve, the first expansion valve and the liquid storage tank; a first opening of the liquid storage tank is connected with the outdoor expansion valve through a first solenoid valve, a second opening of the liquid storage tank is connected with the indoor expansion valve through a second solenoid valve, a third opening of the liquid storage tank is communicated with the first pipeline through the first expansion valve, and the third opening of the liquid storage tank is arranged at the bottom of the liquid storage tank; the first end of the third solenoid valve is connected to the outdoor expansion valve, and the second end of the third solenoid valve is connected to the indoor expansion valve.

The technical scheme provided by the embodiment of the application at least has the following beneficial effects: in the multi-split air conditioning system, a refrigerant recovery device is arranged between the outdoor unit and the indoor unit. When the refrigerant leaks, the running modes to be entered of the outdoor unit and the indoor unit are combined, the flowing direction of the refrigerant in the multi-split air-conditioning system is controlled by controlling the closing and opening states of the three electromagnetic valves, namely the first electromagnetic valve, the second electromagnetic valve and the third electromagnetic valve, and the closing and opening state of the first expansion valve in the refrigerant recovery device, the refrigerant in the multi-split air-conditioning system is firstly introduced into the liquid storage tank of the refrigerant recovery device from the first opening or the second opening, the leaked refrigerant is completely recovered, the problem that the refrigerant is discharged out of an outdoor environment to cause environmental pollution is avoided, and the environmental friendliness of the multi-split air-conditioning system is improved. Furthermore, after the refrigerant leakage condition is repaired, when the multi-split air-conditioning system enters a normal refrigeration or heating operation mode again, the refrigerant recovered by the refrigerant recovery device is released into the first pipeline of the multi-split air-conditioning system from the third opening, the recovered refrigerant is reasonably utilized, the consumption of refrigerant resources is saved, and the environmental protection performance of the multi-split air-conditioning system is improved.

In order to improve the refrigerant discharge efficiency, the third opening is usually provided at the bottom of the liquid storage tank.

In some embodiments, the multi-split air conditioning system has a plurality of operating modes, wherein the plurality of operating modes include a first refrigerant recovery mode, a second refrigerant recovery mode, and a refrigerant release mode; when the multi-split air conditioning system is in a first refrigerant recovery mode, the outdoor heat exchanger works as a condenser, the indoor heat exchanger works as an evaporator, the first electromagnetic valve is in an open state, the second electromagnetic valve is in a closed state, the third electromagnetic valve is in a closed state, and the first expansion valve is in a closed state; when the multi-split air conditioning system is in a second refrigerant recovery mode, the outdoor heat exchanger works as an evaporator, the indoor heat exchanger works as a condenser, the first electromagnetic valve is in a closed state, the second electromagnetic valve is in an open state, the third electromagnetic valve is in a closed state, and the first expansion valve is in a closed state; when the multi-split air-conditioning system is in a refrigerant release mode, the first electromagnetic valve is in a closed state, the second electromagnetic valve is in a closed state, the third electromagnetic valve is in an open state, the first expansion valve is in an open state, one of the outdoor heat exchanger and the indoor heat exchanger serves as an evaporator, and the other one serves as a condenser.

Based on this, the multi-split air conditioning system may provide an operation mode corresponding to a scene for different scenes. Specifically, when the refrigerant leaked from the indoor unit needs to be recovered, the multi-split air conditioning system may be switched to the first refrigerant recovery mode, and the refrigerant leaked from the indoor unit may be recovered by the refrigerant recovery device. When the refrigerant leaked from the outdoor unit needs to be recovered, the multi-split air conditioning system can be switched to the second refrigerant recovery mode, and the refrigerant leaked from the outdoor unit can be recovered through the refrigerant recovery device. When the refrigerant recovered in the refrigerant recovery device needs to be utilized, the multi-split air-conditioning system can be adjusted to a refrigerant release mode, and the recovered refrigerant is released into the first pipeline so that the multi-split air-conditioning system can use the recovered refrigerant in the refrigeration operation or heating operation process.

It should be noted that the plurality of operation modes further include a cooling mode and a heating mode. Specifically, when cooling is required (e.g., the room temperature is too high), the operation mode of the multi-split air conditioning system is switched to the cooling mode to reduce the indoor ambient temperature. When heating is needed (for example, the room temperature is too low), the operation mode of the multi-split air conditioning system is switched to the heating mode to increase the indoor environment temperature.

In addition, when the multi-split air conditioning system is in a refrigeration working mode and needs to release the recovered refrigerant, the outdoor heat exchanger works as a condenser, the indoor heat exchanger works as an evaporator, the first electromagnetic valve is in a closed state, the second electromagnetic valve is in a closed state, the third electromagnetic valve is in an open state, and the first expansion valve is in an open state. When the multi-split air conditioning system is in a heating working mode and refrigerant recovered by the recovery device needs to be released, the outdoor heat exchanger works as an evaporator, the indoor heat exchanger works as a condenser, the first electromagnetic valve is in a closed state, the second electromagnetic valve is in a closed state, the third electromagnetic valve is in an open state, and the expansion valve is in an open state.

In some embodiments, the refrigerant recovery device further includes a first supercooling heat exchanger, and the first supercooling heat exchanger includes a first channel and a second channel; a third opening of the liquid storage tank is communicated with the first pipeline through a first expansion valve and a first channel of the first supercooling heat exchanger in sequence; and the first end of the third electromagnetic valve is connected with the outdoor expansion valve through the second channel of the first supercooling heat exchanger.

Therefore, the refrigerant flow recovered in the refrigerant recovery device passes through the first channel of the first cold heat exchanger, and the refrigerant flow passes through the second channel of the first cold heat exchanger in the operation process of the multi-split air-conditioning system. The second channel cools the refrigerant flowing through the second channel to release corresponding heat. The first channel heats the recovered refrigerant flowing through the first channel by utilizing the heat released by the second channel, so that the liquid refrigerant in the recovered refrigerant in two-phase state (gas state and liquid state) is converted into the gas refrigerant, the content of the liquid refrigerant in the refrigerant released by the refrigerant recovery device is reduced, the content of the gas refrigerant in the recovered refrigerant released is improved, and the use efficiency of the recovered refrigerant is ensured.

On one hand, in the process of releasing the recovered refrigerant in the refrigeration operation mode of the multi-split air conditioning system, the refrigerant recovery device releases the recovered refrigerant to the compressor of the outdoor unit, and the content of the liquid refrigerant in the refrigerant released by the refrigerant recovery device is reduced, so that the liquid return of the compressor is reduced, and the service life of the compressor is prolonged. On the other hand, in the process of releasing the recovered refrigerant when the multi-split air-conditioning system is in the heating working mode, the refrigerant recovery device releases the recovered refrigerant to an indoor heat exchanger of the indoor unit, the content of the gaseous refrigerant in the released recovered refrigerant is increased, the amount of the refrigerant entering the indoor heat exchanger for recovery is increased, and the utilization rate of the recovered refrigerant is improved.

In some embodiments, the refrigerant recovery device further includes a first temperature sensor, where the first temperature sensor is configured to detect a temperature value of the refrigerant flowing out of the first channel of the first supercooling heat exchanger; the outdoor unit also comprises a gas-liquid separator and a first outdoor pressure sensor, wherein the first outdoor pressure sensor is used for detecting the pressure value of a refrigerant at an inlet of the gas-liquid separator; the multi-split air conditioning system further comprises: a controller configured to: when the multi-split air conditioning system operates in a refrigerant release mode, acquiring a first temperature value detected by a first temperature sensor and a pressure value detected by a first outdoor pressure sensor; if the difference value between the first temperature value and the second temperature value is greater than or equal to a first preset temperature value, controlling the first expansion valve to increase the opening degree, wherein the second temperature value is a saturation temperature value corresponding to the pressure value detected by the first outdoor pressure sensor; or if the difference value between the first temperature value and the second temperature value is greater than a first preset temperature value, controlling the first expansion valve to reduce the opening degree.

In this embodiment, the temperature difference between the first temperature value and the saturation temperature value is obtained by comparing the first temperature value of the refrigerant flowing out of the first channel of the first supercooling heat exchanger with the saturation temperature (i.e., the second temperature value) corresponding to the pressure value of the refrigerant at the inlet of the gas-liquid separator. And controlling the opening degree of the first expansion valve based on the size relation between the temperature difference value and the first preset temperature value so as to ensure that the opening degree of the first expansion valve is in a reasonable range, thereby ensuring that the refrigerant quantity released by the refrigerant recovery device is in a reasonable range. On one hand, the problem that the refrigerant is not processed in time by the multi-split air-conditioning system due to too much refrigerant in the whole multi-split air-conditioning system pipeline caused by too much refrigerant released by the refrigerant recovery device is avoided; on the other hand, the problem that the refrigerant quantity released by the refrigerant recovery device is too small, so that the refrigerant quantity in the pipeline of the whole multi-connected air-conditioning system is too small, and the working efficiency of the multi-connected air-conditioning system is reduced, such as the refrigerating speed or the heating speed is reduced, is avoided.

In some embodiments, the refrigerant recovery device further comprises a throttling device and a second supercooling heat exchanger; the second supercooling heat exchanger comprises a third channel and a fourth channel; the third opening of the liquid storage tank is also communicated with the first pipeline through a third channel of the throttling device and the second supercooling heat exchanger in sequence; and the second end of the third electromagnetic valve is connected with the indoor expansion valve through a fourth channel of the second supercooling heat exchanger.

On the basis, the refrigerant recovered in the refrigerant recovery device flows through a third channel of the supercooling heat exchanger after being throttled by the throttling device; and in the operation process of the multi-split air conditioning system, the refrigerant flows through the fourth channel of the supercooling heat exchanger. The fourth channel cools the refrigerant flowing through the fourth channel to release corresponding heat. The third channel heats the recovered refrigerant flowing through the third channel by using the heat released by the fourth channel, so that the liquid refrigerant in the two-phase (gas and liquid) recovered refrigerant is converted into the gas refrigerant, the content of the liquid refrigerant in the refrigerant released by the refrigerant recovery device is reduced, the content of the gas refrigerant in the released recovered refrigerant is improved, and the use efficiency of the recovered refrigerant is ensured.

In some embodiments, the refrigerant recovery device further includes a second temperature sensor, where the second temperature sensor is configured to detect a temperature value of the refrigerant flowing out of the third channel of the second supercooling heat exchanger; a controller further configured to: when the multi-split air conditioning system operates in a refrigerant release mode, acquiring a third temperature value detected by the second temperature sensor and a pressure value detected by the first outdoor pressure sensor; if the difference value between the third temperature value and the second temperature value is greater than or equal to a second preset temperature value, ending the operation of the refrigerant release mode, wherein the second temperature value is a saturation temperature value corresponding to the pressure value detected by the first outdoor pressure sensor; or if the difference value between the third temperature value and the second temperature value is smaller than a second preset temperature value, continuing to operate the refrigerant release mode.

In this embodiment, a temperature difference between the first temperature value and the saturation temperature value is obtained by comparing the first temperature value of the refrigerant flowing out of the third channel of the second supercooling heat exchanger with the saturation temperature corresponding to the pressure value of the refrigerant at the inlet of the gas-liquid separator, that is, the second temperature value. The releasing process of the refrigerant recovery device is reasonably controlled based on the size relation between the temperature difference value and the second preset temperature value, so that the refrigerant recovery device can release the refrigerant under the condition of sufficient refrigerant, the refrigerant releasing mode is still executed under the condition that no refrigerant exists in the refrigerant recovery device, the refrigerant quantity in the multi-split air-conditioning system is small, and the working efficiency of the multi-split air-conditioning system is reduced.

In some embodiments, the refrigerant recovery device further includes a fourth solenoid valve disposed on the first pipeline, a first end of the fourth solenoid valve is connected to the four-way valve, and a second end of the fourth solenoid valve is connected to the indoor heat exchanger.

Therefore, when the multi-split air conditioning system operates in any one of a refrigeration mode, a heating mode, a first refrigerant recovery mode and a second refrigerant recovery mode, the fourth electromagnetic valve is controlled to be in an open state, so that the refrigerant can circulate in the corresponding pipeline.

It should be noted that the controller is further configured to: under the first refrigerant recovery mode and the second refrigerant recovery mode, when the refrigerant recovery stopping condition is met, the fourth electromagnetic valve is controlled to be closed; the refrigerant recovery stopping condition comprises one or more of the following conditions: the time length of the multi-split air conditioning system operating in the first refrigerant recovery mode or the second refrigerant recovery mode reaches a preset time length; or the pressure of the refrigerant entering the compressor is within a preset pressure range. Based on this, by setting the refrigerant recovery stopping condition, the time for finishing the refrigerant recovery can be determined, so that the refrigerant is recovered when the refrigerant quantity in the pipeline of the multi-split air-conditioning system is in a reasonable range, and the problem that the multi-split air-conditioning system is abnormal or damaged due to the fact that the first refrigerant recovery mode or the second refrigerant recovery mode is still executed under the condition that no refrigerant exists in the pipeline of the multi-split air-conditioning system is avoided, and the safety and the service life of the multi-split air-conditioning system are further improved.

In some embodiments, the refrigerant recovery device further includes a fifth solenoid valve, the fifth solenoid valve is disposed on the first pipeline, a first end of the fifth solenoid valve is connected to a second end of the fourth solenoid valve, and a second end of the fifth solenoid valve is connected to the indoor heat exchanger.

Based on this, when the multi-split air conditioning system is operated in any one of a refrigeration mode, a heating mode, a first refrigerant recovery mode, a second refrigerant recovery mode or a refrigerant release mode, the fifth electromagnetic valve is controlled to be in an open state, so that the refrigerant can circulate in the corresponding pipeline.

It should be noted that the controller is further configured to: under the first refrigerant recovery mode or the second refrigerant recovery mode, when the refrigerant recovery stopping condition is met, controlling the fifth electromagnetic valve to be closed; the refrigerant recovery stopping condition comprises one or more of the following conditions: the time length of the multi-split air conditioning system operating in the first refrigerant recovery mode or the second refrigerant recovery mode reaches the preset time length; or the pressure of the refrigerant entering the compressor is within a preset pressure range. Based on this, the indoor expansion valve corresponding to the indoor unit in which refrigerant leakage occurs in the indoor unit is in a closed state. After the refrigerant is recovered, the fourth electromagnetic valve and the fifth electromagnetic valve are controlled to be closed, so that the indoor units with refrigerant leakage in the indoor unit are freely separated from the refrigerant recovery device and the outdoor unit, the indoor units with refrigerant leakage are convenient to replace without being influenced by the refrigerant recovery device and the outdoor unit, and the convenience of installing or replacing the indoor units is improved.

In some embodiments, the refrigerant recovery device further includes a second expansion valve, a first end of the second expansion valve is connected to the fourth opening of the liquid storage tank, a second end of the second expansion valve is communicated with a second pipeline, and the second pipeline is a pipeline between the fourth solenoid valve and the fifth solenoid valve; or the first end of the second expansion valve is communicated with a third pipeline, the second end of the second expansion valve is communicated with the second pipeline, and the third pipeline is a pipeline between the first electromagnetic valve and the first opening of the liquid storage tank.

In this embodiment, in the refrigerant recovery process, when the amount of refrigerant circulating in the multi-split air conditioning system is smaller and smaller, and the low pressure of the multi-split air conditioning system is closer and closer to the preset pressure range (generally, the atmospheric pressure of the environment where the multi-split air conditioning system is located), the discharge temperature of the compressor is higher and higher, which affects the reliability of the compressor. Based on this, a second expansion valve is added between the first solenoid valve and the fourth solenoid valve, or a second expansion valve is added between the fourth solenoid valve and the liquid storage tank. In the refrigerant recovery process, the second expansion valve is opened, and a part of the refrigerant bypasses the compressor to reduce the exhaust temperature of the compressor, so that the temperature of the compressor is reduced, and the reliability of the compressor in the refrigerant recovery process is ensured.

In addition, in the process of refrigerant recovery, the refrigerant entering the liquid storage tank may be a gas-phase refrigerant and a liquid-phase refrigerant, and under the condition that the refrigerant entering the liquid storage tank is the two-phase refrigerant, the amount of the refrigerant stored in the liquid storage tank can be reduced due to the small average density of the two-phase refrigerant, so that the refrigerant recovery effect is influenced. Therefore, in the process of refrigerant recovery, the expansion valve is opened, and the bypass gaseous refrigerant enters, so that the effect of refrigerant recovery is improved.

In some embodiments, the refrigerant recovery device further includes: the first stop valve is arranged on a pipeline between the four-way valve and the fourth electromagnetic valve, the first end of the first stop valve is connected with the four-way valve through the pipeline, and the second end of the first stop valve is connected with the first end of the fourth electromagnetic valve through the pipeline; the second stop valve is arranged on a pipeline between the fourth electromagnetic valve and the indoor heat exchanger, the first end of the second stop valve is connected with the second end of the fourth electromagnetic valve through a pipeline, and the second end of the second stop valve is connected with the indoor heat exchanger in each indoor unit through a pipeline; the first end of the second stop valve is connected with the second end of the first solenoid valve through a pipeline; and the fourth stop valve is arranged on a pipeline between the second electromagnetic valve and the indoor heat exchanger, the first end of the fourth stop valve is connected with the second end of the second electromagnetic valve through a pipeline, and the second end of the fourth stop valve is connected with the indoor expansion valve in each indoor unit through a pipeline.

In this embodiment, during an operation process of the multi-split air conditioning system in the first refrigerant recovery mode or the second refrigerant recovery mode, the first stop valve, the second stop valve, the third stop valve, and the fourth stop valve are in an open state. After the first refrigerant recovery mode or the second refrigerant recovery mode is completed, the first electromagnetic valve, the second electromagnetic valve and the third electromagnetic valve are in a closed state, and meanwhile, the first stop valve, the second stop valve, the third stop valve and the fourth stop valve are in a closed state, so that the circulation of refrigerants in pipelines corresponding to the stop valves is better prevented.

In some embodiments, the outdoor unit further comprises: the fourth stop valve is arranged on a pipeline between the four-way valve and the first stop valve, the first end of the fourth stop valve is connected with the four-way valve through the pipeline, and the second end of the fourth stop valve is connected with the first end of the first stop valve through the pipeline; and the sixth stop valve is arranged on a pipeline between the outdoor expansion valve and the third stop valve, the first end of the sixth stop valve is connected with the outdoor expansion valve through a pipeline, and the second end of the sixth stop valve is connected with the first end of the third stop valve through a pipeline.

In this embodiment, during an operation of the multi-split air conditioning system in the first refrigerant recovery mode or the second refrigerant recovery mode, the fifth stop valve and the sixth stop valve are in an open state. After the first refrigerant recovery mode or the second refrigerant recovery mode is finished, the fifth electromagnetic valve and the sixth electromagnetic valve are in a closed state, so that the circulation of the refrigerant in the pipeline corresponding to the stop valve is better prevented.

In some embodiments, the outdoor unit further comprises: the fourth electromagnetic valve is arranged on a pipeline between the four-way valve and the fourth stop valve, the first end of the fourth electromagnetic valve is connected with the four-way valve through the pipeline, and the second end of the fourth electromagnetic valve is connected with the first end of the fourth stop valve through the pipeline; and the seventh electromagnetic valve is arranged on a pipeline between the outdoor expansion valve and the sixth stop valve, the first end of the seventh electromagnetic valve is connected with the outdoor expansion valve through a pipeline, and the second end of the seventh electromagnetic valve is connected with the first end of the sixth stop valve through a pipeline.

Based on the sixth electromagnetic valve and the seventh electromagnetic valve, after the refrigerant is recovered, the sixth electromagnetic valve and the seventh electromagnetic valve are controlled to be closed, so that the outdoor unit is freely separated from the refrigerant recovery device and the indoor unit, the outdoor process is not affected by the refrigerant recovery device and the indoor unit, and the convenience of installing or replacing the outdoor unit is improved.

In some embodiments, each indoor unit further includes an indoor refrigerant leakage detection device; the multi-split air conditioning system further includes: the controller is electrically connected with the indoor refrigerant leakage detection device in each indoor unit; the controller is configured to: the method comprises the steps of obtaining a detection result of each indoor refrigerant leakage detection device, wherein the detection result of one indoor refrigerant leakage detection device is used for indicating whether the indoor unit where the refrigerant leakage detection device is located leaks refrigerant or not; determining whether an indoor unit with refrigerant leakage exists in the indoor unit group or not according to the detection result of each indoor refrigerant leakage detection device; and if so, controlling the multi-split air conditioning system to operate in a first refrigerant recovery mode.

Therefore, the multi-split air conditioning system can determine the indoor unit with refrigerant leakage in the indoor unit according to the detection result of the indoor refrigerant leakage detection device. And under the condition that the indoor unit in the indoor unit leaks the refrigerant, controlling the multi-split air conditioning system to switch to a first refrigerant recovery mode for operation, and recovering the refrigerant leaked from the indoor unit into the refrigerant recovery device. On one hand, the risk of the indoor environment caused by the refrigerant of the indoor unit leaking into the indoor environment is avoided, and the safety of the multi-split air-conditioning system is improved; on the other hand, the refrigerant is recovered by the refrigerant recovery device, so that the amount of the refrigerant discharged to the outdoor environment from the outdoor unit is greatly reduced, and the environmental friendliness of the multi-split air-conditioning system is improved.

In some embodiments, the outdoor unit further comprises an outdoor refrigerant leakage detection device, and the controller is electrically connected with the outdoor refrigerant leakage detection device of the outdoor unit; the controller is configured to: acquiring a detection result of an outdoor refrigerant leakage detection device, wherein the detection result of the outdoor refrigerant leakage detection device is used for indicating whether refrigerant leakage occurs in an outdoor unit; and if the detection result of the outdoor refrigerant leakage detection device indicates that the outdoor unit has refrigerant leakage, controlling the multi-split air-conditioning system to operate in a second refrigerant recovery mode.

In this way, the multi-split air conditioning system can determine whether the outdoor unit has refrigerant leakage according to the detection result of the outdoor refrigerant leakage detection device. Under the condition that the outdoor unit leaks refrigerants, the multi-split air-conditioning system is controlled to be switched to the second refrigerant recovery mode to operate, the refrigerants leaked by the outdoor unit are recovered to the refrigerant recovery device, so that the refrigerants are recovered by the refrigerant recovery device, the amount of the refrigerants discharged to the outdoor environment by the refrigerants of the outdoor unit is greatly reduced, and the environmental friendliness of the multi-split air-conditioning system is improved.

In some embodiments, the controller is further configured to: when the multi-split air conditioning system operates in a first refrigerant recovery mode, an indoor expansion valve in an indoor unit, where refrigerant leakage occurs, is closed; and when the multi-split air conditioning system operates in the second refrigerant recovery mode, controlling the outdoor expansion valve to be at the maximum opening value.

In this embodiment, when the multi-split air conditioning system operates in the first refrigerant recovery mode, the indoor expansion valve in the indoor unit where refrigerant leakage occurs is closed to prevent the refrigerant from continuously entering the indoor unit where refrigerant leakage occurs, so that the refrigerant in the indoor unit where refrigerant leakage occurs is prevented from leaking into an indoor environment, and thus, safe use of the multi-split air conditioning system by a user is ensured. When the multi-split air-conditioning system operates in the second refrigerant recovery mode, the outdoor expansion valve is controlled to be in the maximum opening value, so that the refrigerant in the pipeline communicated with the outdoor expansion valve can be more quickly recovered to the refrigerant recovery device through the outdoor unit and the indoor unit, the recovery speed of the refrigerant leaked from the outdoor unit is increased, and the refrigerant recovery efficiency of the multi-split air-conditioning system is ensured.

In a second aspect, an embodiment of the present application provides a control method for a multi-split air conditioning system, which is applied to the multi-split air conditioning system of the first aspect, and the method includes:

and responding to a starting signal of the multi-split air conditioning system, and controlling the multi-split air conditioning system to be in a refrigerant release mode under the condition that a refrigerant is detected to exist in a liquid storage tank of the refrigerant recovery device.

When the multi-split air-conditioning system is in a refrigerant release mode, the first electromagnetic valve is in a closed state, the second electromagnetic valve is in a closed state, the third electromagnetic valve is in an open state, the first expansion valve is in an open state, one of the outdoor heat exchanger and the indoor heat exchanger works as an evaporator, and the other one works as a condenser.

In some embodiments, the refrigerant recycling device further includes: the first supercooling heat exchanger and the outdoor unit further include a gas-liquid separator, and the method includes: acquiring a first temperature value of a refrigerant flowing out of a first channel of the first supercooling heat exchanger and a pressure value of the refrigerant at an inlet of the gas-liquid separator; if the difference value between the first temperature value and the second temperature value is larger than or equal to a first preset temperature value, controlling the first expansion valve to increase the opening degree, wherein the second temperature value is a saturation temperature value corresponding to the pressure value of the refrigerant at the inlet of the gas-liquid separator; or if the difference value between the first temperature value and the second temperature value is greater than a first preset temperature value, controlling the first expansion valve to reduce the opening degree.

In some embodiments, the refrigerant recovery device further includes: a second subcooling heat exchanger; the method further comprises the following steps: when the multi-split air-conditioning system operates in a refrigerant release mode, acquiring a third temperature value of a refrigerant flowing out of a third channel of the second supercooling heat exchanger and a pressure value of the refrigerant at an inlet of the gas-liquid separator; if the difference value between the third temperature value and the second temperature value is greater than or equal to a second preset temperature value, ending the operation of the refrigerant release mode, wherein the second temperature value is a saturation temperature value corresponding to the pressure value of the refrigerant at the inlet of the gas-liquid separator; or if the difference value between the third temperature value and the second temperature value is smaller than a second preset temperature value, continuing to operate the refrigerant release mode.

In a third aspect, an embodiment of the present application provides a control device for a multi-split air conditioning system, including: one or more processors; one or more memories; wherein the one or more memories are for storing computer program code comprising computer instructions which, when executed by the one or more processors, cause the controller to perform the method provided in the second aspect and possible implementations.

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

In a fifth aspect, embodiments of the present application provide a computer program product including computer instructions, which when executed on a computer, cause the computer to perform the method provided in the second aspect and possible implementation manners.

It should be noted that all or part of the computer instructions may be stored on the 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.

For the beneficial effects described in the second aspect to the fifth aspect in the present application, reference may be made to the beneficial effect analysis of the first aspect, which is not described herein again.

Drawings

The accompanying drawings are included to provide a further understanding of the present invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the example serve to explain the principles of the invention and are not intended to limit the invention.

Fig. 1 is a schematic structural view of a multi-split air conditioning system according to some embodiments;

FIG. 2 is a schematic diagram of another multi-split air conditioning system according to some embodiments;

FIG. 3 is a schematic diagram of another multi-split air conditioning system according to some embodiments;

FIG. 4 is a schematic diagram of another multi-split air conditioning system according to some embodiments;

FIG. 5 is a schematic diagram of another multi-split air conditioning system according to some embodiments;

fig. 6 is a control flowchart of a multi-split air conditioning system according to some embodiments;

FIG. 7 is a control flow diagram of another multi-split air conditioning system according to some embodiments;

fig. 8 is a schematic diagram illustrating a refrigerant cycle of a multi-split air conditioning system according to some embodiments;

fig. 9 is a schematic diagram illustrating a refrigerant cycle of another multi-split air conditioning system according to some embodiments;

fig. 10 is a schematic diagram illustrating a refrigerant cycle of another multi-split air conditioning system according to some embodiments;

fig. 11 is a schematic diagram illustrating a refrigerant cycle of another multi-split air conditioning system according to some embodiments;

fig. 12 is a schematic diagram illustrating a refrigerant cycle of another multi-split air conditioning system according to some embodiments;

fig. 13 is a schematic diagram illustrating a refrigerant cycle of another multi-split air conditioning system according to some embodiments;

FIG. 14 is a schematic diagram of another multi-split air conditioning system according to some embodiments;

fig. 15 is a control flow diagram of a multi-split air conditioning system according to some embodiments;

FIG. 16 is a control flow diagram of another multi-split air conditioning system according to some embodiments;

fig. 17 is a hardware configuration diagram of a controller according to some embodiments.

Reference numerals are as follows: 100-a multi-split air conditioning system; 200-outdoor unit: 201-a compressor; 202-four-way valve; 203-outdoor heat exchanger; 204-outdoor expansion valve; 205-gas-liquid separator; 206-an oil separator; 207-oil return capillary; 208-outdoor one-way valve; 209-a first outdoor pressure sensor; 210-a second outdoor pressure sensor; 211-a fifth stop valve; 212-a sixth stop valve; 213-sixth solenoid valve; 214-seventh solenoid valve; 215-outdoor fan; 300-indoor units; 300A-a first indoor unit; 300B-a second indoor unit; 301A-a first indoor heat exchanger; 302A-a first indoor expansion valve; 303A-a first indoor fan; 301B-a second indoor heat exchanger; 302B-a second indoor expansion valve; 303B-a second indoor fan; a seventh stop valve 304; an eighth cut-off valve 305; 400-refrigerant recovery unit; 401-a first solenoid valve; 402-a second solenoid valve; 403-a third solenoid valve; 404-a liquid storage tank; 405-a fourth solenoid valve; 406-a fifth solenoid valve; 407-a first stop valve; 408-a second stop valve; 409-a third stop valve; 410-a fourth stop valve; 411 — first expansion valve; 412-a second expansion valve; 413-a first subcooling heat exchanger; 414-a throttling device; 415-a second subcooling heat exchanger; 416 — a first channel; 417 — a second channel; 418 — a third channel; 419-fourth lane.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the 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.

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 present application, it is to be noted that the terms "connected" and "connected" are to be interpreted broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected, unless explicitly stated or limited otherwise. 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 "connected" are used in this application to have a meaning of conducting. The specific meaning is to be understood in conjunction with the context.

Unless the context requires otherwise, throughout the description and the claims, the term "comprise" and its other forms, such as the third person's singular form "comprising" and the present participle form "comprising" are to be interpreted in an open, inclusive sense, i.e. as "including, but not limited to". In the description of the specification, the terms "one embodiment", "some embodiments", "example", "specific example" or "some examples" and the like are intended to indicate that a particular feature, structure, material, or characteristic associated with the embodiment or example is included in at least one embodiment or example of the present disclosure. The schematic representations of the above terms are not necessarily referring to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics may be included in any suitable manner in any one or more embodiments or examples.

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 "e.g.," 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 concepts related in a concrete fashion.

As background art, in order to avoid the risk caused by refrigerant leakage, a pair of electronic expansion valves is added to the inlet and outlet of each indoor unit of a multi-split air conditioning system in the related art to block the refrigerant leaking from the indoor unit from flowing into the indoor environment. However, in the above-mentioned related art method, the leaked refrigerant cannot be completely recovered and utilized, and may be directly discharged to the outdoor environment, thereby causing environmental pollution.

In view of the above, an embodiment of the present disclosure provides a multi-split air conditioning system, in which a refrigerant recovery device is disposed between an outdoor unit and an indoor unit, when a refrigerant leaks, by controlling the closed and open states of three electromagnetic valves, namely, a first electromagnetic valve, a second electromagnetic valve, and a third electromagnetic valve, and the closed and open states of a first expansion valve in the refrigerant recovery device, and controlling the flowing direction of the refrigerant in the multi-split air conditioning system in combination with the operation modes to be entered by the outdoor unit and the indoor unit, the refrigerant in the multi-split air conditioning system is first introduced into a liquid storage tank of the refrigerant recovery device from the first opening or the second opening, so that the leaked refrigerant is completely recovered, thereby preventing the refrigerant from being discharged into an outdoor environment to cause environmental pollution, and further improving the environmental friendliness of the multi-split air conditioning system. Furthermore, after the refrigerant leakage condition is repaired, when the multi-split air-conditioning system enters the normal refrigeration or heating operation mode again, the refrigerant recovered by the refrigerant recovery device is released into the first pipeline of the multi-split air-conditioning system from the third opening, the recovered refrigerant is reasonably utilized, the consumption of refrigerant resources is saved, and the environmental protection performance of the multi-split air-conditioning system is improved.

To further describe the solution of the present application, fig. 1 is a schematic structural diagram of a multi-split air conditioning system according to an embodiment of the present application.

Outdoor unit 200

Referring to fig. 1, the multi-split air conditioning system 100 includes an outdoor unit 200, a plurality of indoor units (e.g., a first indoor unit 300A and a second indoor unit 300B shown in fig. 1) connected in parallel in an indoor unit 300, and a refrigerant recovery device 400.

The outdoor unit 200 includes: a compressor 201, a four-way valve 202, an outdoor heat exchanger 203, and an outdoor expansion valve 204, which are connected in this order.

In some embodiments, the outdoor unit 200 further comprises a gas-liquid separator 205, an oil separator 206, an oil return capillary tube 207, and an outdoor check valve 208.

Specifically, as shown in fig. 1, an outlet of the compressor 201 is connected to a first end of an oil separator 206 through a pipe, a second end of the oil separator 206 is connected to an outdoor check valve 208 through a pipe, the outdoor check valve 208 is connected to a four-way valve 202 through a pipe, the four-way valve 202 is connected to an outdoor heat exchanger 203 through a pipe, and the outdoor heat exchanger 203 is connected to an outdoor expansion valve 204 through a pipe. Wherein, the third end of the oil separator 206 is connected with the first opening of the gas-liquid separator 205 through a pipeline; a second opening of gas-liquid separator 205 is connected to four-way valve 202 via a pipe.

In other embodiments, the outdoor unit 200 further includes an outdoor refrigerant leakage detecting device (not shown).

In still other embodiments, the outdoor unit 200 further includes a first outdoor pressure sensor 209 and a second outdoor pressure sensor 210, wherein the first outdoor pressure sensor 209 is disposed at the first port of the gas-liquid separator 205 and is used for detecting the pressure of the refrigerant entering the compressor 201, and as shown in fig. 1, the pressure of the refrigerant entering the compressor 201 is represented by detecting the pressure value of the refrigerant at the inlet of the gas-liquid separator through the first outdoor pressure sensor 209; the second outdoor pressure sensor 210 is provided in a line connecting the outdoor check valve 208 and the four-way valve 202, and detects the pressure of the refrigerant flowing out of the compressor 201. Typically, the first outdoor pressure sensor 209 may be a low pressure sensor and the second outdoor pressure sensor 209 may be a high pressure sensor.

In some embodiments, one end of the outdoor heat exchanger 203 is connected to the compressor 201 through the four-way valve 202, and the other end is connected to the refrigerant recovery device 400. The outdoor heat exchanger 203 exchanges heat between the refrigerant flowing through the heat transfer tubes of the outdoor heat exchanger 203 and the outdoor air. The compressor 201 is disposed between the indoor heat exchanger and the outdoor heat exchanger 203, and is configured to provide power for refrigerant circulation. Taking a refrigeration cycle as an example, the compressor 201 sends a compressed refrigerant to the outdoor heat exchanger 203 via the four-way valve 202.

Alternatively, the compressor 201 may be a variable capacity inverter compressor 201 controlled based on the rotation speed of an inverter.

In some embodiments, four ports (i.e., a C port, a D port, an S port, and an E port) of four-way valve 202 in fig. 1 are connected to the discharge port of compressor 201, outdoor heat exchanger 203, the suction port of compressor 201, and the indoor heat exchanger of each indoor unit, respectively. Four-way valve 202 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 outdoor unit 200 further includes an outdoor fan 215, and the outdoor fan 215 generates an airflow of the outdoor air passing through the outdoor heat exchanger 203 to promote heat exchange between the refrigerant flowing in the heat transfer pipes of the outdoor heat exchanger 203 and the outdoor air.

In some embodiments, the outdoor unit 200 further includes an outdoor fan 215 motor (not shown) connected to the outdoor fan 215 for driving or changing the rotation speed of the outdoor fan 215.

In some embodiments, the outdoor unit 200 further includes a high pressure switch (not shown), and the high pressure switch is electrically connected to the controller, and is configured to monitor a pressure of a pipeline of the multi-split air conditioning system, and send an abnormal message to the controller when the pressure of the pipeline of the multi-split air conditioning system is abnormal, so that the controller controls the system to stop, and thus, normal operation of the multi-split air conditioning system is ensured.

Based on the above embodiment, the outdoor unit 200 is further provided with the sixth and seventh

electromagnetic valves

213 and 214. The sixth solenoid valve 213 is disposed on a pipeline between the four-way valve 202 and the fifth stop valve 211, a first end of the sixth solenoid valve 213 is connected to the four-way valve 202 through a pipeline, a second end of the sixth solenoid valve 213 is connected to a first end of the fifth stop valve 211 through a pipeline, the seventh solenoid valve 214 is disposed on a pipeline between the outdoor expansion valve 204 and the sixth stop valve 212, a first end of the seventh solenoid valve 214 is connected to the outdoor expansion valve 204 through a pipeline, and a second end of the seventh solenoid valve 214 is connected to a first end of the sixth stop valve 212 through a pipeline.

Based on the sixth electromagnetic valve 213 and the seventh electromagnetic valve 214, after the refrigerant is recovered, the sixth electromagnetic valve 213 and the seventh electromagnetic valve 214 are controlled to be closed, so that the outdoor unit 200 is freely separated from the refrigerant recovery device 400 and the indoor unit 300, the outdoor unit is not affected by the refrigerant recovery device 400 and the indoor unit 300 during the outdoor replacement process, and the convenience of installing or replacing the outdoor unit 200 is improved.

Based on the above embodiments, in some embodiments, the outdoor unit 200 further includes: a fifth cut-off valve 211 and a sixth cut-off valve 212, wherein the fifth cut-off valve 211 is disposed on a pipeline between the four-way valve 202 and the first cut-off valve 407, a first end of the fifth cut-off valve 211 is connected to the four-way valve 202 through a pipeline, and a second end of the fifth cut-off valve 211 is connected to a first end of the first cut-off valve 407 through a pipeline; the sixth stop valve 212 is provided on a pipe between the outdoor expansion valve 204 and the third stop valve 409, a first end of the sixth stop valve 212 is connected to the outdoor expansion valve 204 via a pipe, and a second end of the sixth stop valve 212 is connected to a first end of the third stop valve 409 via a pipe.

In this embodiment, during an operation of the multi-split air conditioning system in the first refrigerant recovery mode or the second refrigerant recovery mode, the fifth stop valve 211 and the sixth stop valve 212 are in an open state. After the first refrigerant recovery mode or the second refrigerant recovery mode is completed, the fifth stop valve 211 and the sixth stop valve 212 are in a closed state to better prevent the refrigerant in the pipeline corresponding to the stop valves from flowing.

Indoor unit 300

The indoor unit 300 includes: and a plurality of indoor units connected in parallel, each indoor unit including an indoor heat exchanger and an indoor expansion valve. The indoor heat exchanger is connected to the four-way valve 202 of the outdoor unit through a first pipeline, which is exemplarily shown as (14) → (15) → (16) → (17) → (18) in fig. 1.

In some embodiments, the indoor unit 300 further includes an indoor refrigerant leakage detection device corresponding to the indoor units one to one. The indoor refrigerant leakage detection device (not shown) is used for detecting whether the refrigerant of the indoor unit 300 corresponding to the indoor unit leaks. The refrigerant leakage detecting device is generally referred to as a refrigerant leakage detecting sensor.

Illustratively, the first indoor unit 300A includes: a first indoor heat exchanger 301A, a first indoor expansion valve 302A, and a first indoor refrigerant leakage detection device.

In some embodiments, the first indoor unit 300A further includes a first indoor fluid line temperature sensor, a first indoor return air temperature sensor, and a first indoor fan 303A.

In still another example, the second indoor unit 300B includes: a second indoor heat exchanger 301B, a second indoor expansion valve 302B, and a second indoor refrigerant leakage detection device.

In some embodiments, the second indoor unit 300B further includes a second indoor liquid pipe temperature sensor (not shown), a second indoor return air temperature sensor (not shown), and a second indoor fan 303B. The second indoor liquid pipe temperature sensor is used for detecting the temperature of a refrigerant of an indoor unit pipeline; the second indoor return air temperature sensor is used for detecting the return air temperature of the indoor unit.

The functions and the arrangement of the respective components of the indoor unit will be specifically described below.

In some embodiments, the first indoor heat exchanger 301A is configured to exchange heat between the refrigerant flowing through the heat transfer tubes of the first indoor heat exchanger 301A and the indoor air.

In some embodiments, the first indoor expansion valve 302A is disposed between the first indoor heat exchanger 301A and the refrigerant recovery device 400, has a function of expanding and decompressing the refrigerant flowing through the first indoor expansion valve 302A, and may be used to adjust the supply amount of the refrigerant in the pipe.

Alternatively, the multi-split air conditioning system may be provided with a plurality of first indoor expansion valves 302A, such as a plurality of electronic expansion valves. When the opening degree of the first indoor expansion valve 302A is decreased, the flow path resistance of the refrigerant passing through the first indoor expansion valve 302A is increased. When the opening degree of the first indoor expansion valve 302A is increased, the flow path resistance of the refrigerant passing through the first indoor expansion valve 302A is decreased. In this way, even if the state of other components in the circuit does not change, when the opening degree of the first indoor expansion valve 302A changes, the flow rate of the refrigerant flowing to the first indoor heat exchanger 301A or the outdoor heat exchanger 203 changes. It should be noted that the number of indoor expansion valves and the number of outdoor expansion valves 204 shown in fig. 1 are merely examples, and the present application is not limited thereto.

In some embodiments, the first indoor fan 303A generates an airflow of the indoor air passing through the first indoor heat exchanger 301A to promote heat exchange between the refrigerant flowing in the heat transfer pipes of the first indoor heat exchanger 301A and the indoor air.

In some embodiments, the first indoor unit 300A further includes an indoor fan motor (not shown) connected to the indoor fan for driving or changing the rotation speed of the indoor fan.

In some embodiments, the first indoor unit 300A further includes a plurality of capillary tubes (not shown) for reducing the pressure of the refrigerant in the pipes, and for depressurizing the high-pressure refrigerant delivered from the condenser and delivering the depressurized refrigerant to the evaporator.

In some embodiments, the first indoor unit 300A further includes a humidity sensor (not shown) for detecting the relative humidity of the indoor air.

In some embodiments, the first indoor unit 300A further comprises a dew point meter (not shown) for detecting an ambient dew point temperature near the indoor heat exchanger.

In some embodiments, the first indoor unit 300A further includes a display (not shown). The display is electrically connected with the controller. Alternatively, the display may be used to display a control panel of the multi-split air conditioning system, for example, the display may be used to display an indoor temperature or a current operation mode. Optionally, a display is connected to the controller, and a user can perform operations on the control panel through the display to set a program. Optionally, the display further includes a pressure sensor or a temperature sensor, and the display may transmit a user instruction to the control to implement a human-computer interaction function according to a gesture operation of the user, such as pressing a key or the like. Alternatively, the display may be a liquid crystal display, an organic light-emitting diode (OLED) display. The particular type, size, resolution, etc. of the display are not limiting, and those skilled in the art will appreciate that the display may be modified in its performance and configuration as desired.

The number of the indoor units is only an example, and the number of the indoor units of the multi-split air conditioning system shown in the present application may be two or more, which is not limited in the present application.

Refrigerant recovery device 400

As shown in fig. 1, the refrigerant recovery apparatus 400 includes: a first solenoid valve 401, a second solenoid valve 402, a third solenoid valve 403, a first expansion valve 411, and a reservoir tank 404. A first opening of the liquid storage tank 404 is connected with an outdoor expansion valve through a first solenoid valve 401, a second opening of the liquid storage tank 404 is connected with an indoor expansion valve through a second solenoid valve 402, a third opening of the liquid storage tank 404 is communicated with the first pipeline through a first expansion valve 411, and a third opening of the liquid storage tank 404 is arranged at the bottom of the liquid storage tank 404; a first end of the third solenoid valve 403 is connected to the outdoor expansion valve, and a second end of the third solenoid valve 403 is connected to the indoor expansion valve. In some embodiments, the refrigerant recovery device 400 further includes a fourth solenoid valve 405, the fourth solenoid valve 405 is disposed on the first pipeline, a first end of the fourth solenoid valve 405 is connected to the four-way valve, and a second end of the fourth solenoid valve 405 is connected to the indoor heat exchanger.

In some embodiments, the refrigerant recovery device 400 further includes a fifth solenoid valve 406, the fifth solenoid valve 406 is disposed on the first pipeline, a first end of the fifth solenoid valve 406 is connected to a second end of the fourth solenoid valve 405, and a second end of the fifth solenoid valve 406 is connected to the indoor heat exchanger.

Referring to fig. 1, as shown in fig. 2 and 3, in some embodiments, the refrigerant recovery device 400 further includes a second expansion valve 412. As shown in fig. 2, a first end of the second expansion valve 412 is connected to a fourth opening of the reservoir tank 404, and a second end of the second expansion valve 412 is communicated with a second pipe between the fourth solenoid valve 405 and the fifth solenoid valve 406, which is exemplarily a pipe (16) shown in fig. 3. As shown in fig. 3, a first end of the second expansion valve 412 is in communication with a third line, which is a line between the first solenoid valve 401 and the first opening of the reservoir tank 404, a second end of the second expansion valve 412 is in communication with a second line.

The second expansion valve may be installed in two ways as shown in fig. 2 and 3, in which (1) a first end of the second expansion valve 412 is connected to a second end of the fourth solenoid valve 405 through a pipe, and a second end of the second expansion valve 412 is connected to a second end of the first solenoid valve 401 through a pipe. (2) A first end of the second expansion valve 412 is connected to a second end of the fourth solenoid valve 405 via a pipe, and a second end of the second expansion valve 412 is connected to a fourth opening of the reservoir tank 404 via a pipe.

Based on this, in the refrigerant recovery process, the amount of the refrigerant circulating in the multi-split air conditioning system is smaller and smaller, and the low pressure of the multi-split air conditioning system is closer and closer to the preset pressure range (generally, the atmospheric pressure of the environment where the multi-split air conditioning system is located), the exhaust temperature of the compressor 201 is higher and higher, which affects the reliability of the compressor 201. Based on this, a second expansion valve 412 is added between the first solenoid valve 401 and the fourth solenoid valve 405, or the second expansion valve 412 is added between the fourth solenoid valve 405 and the reservoir tank 404. In the refrigerant recovery process, the second expansion valve 412 is opened to allow a portion of the refrigerant to bypass the compressor 201, so as to reduce the exhaust temperature of the compressor 201, thereby reducing the temperature of the compressor 201 and ensuring the reliability of the compressor 201 in the refrigerant recovery process.

In addition, in the refrigerant recovery process, the refrigerant entering the receiver 404 may be a gas-phase refrigerant and a liquid-phase refrigerant, and in the case that the refrigerant entering the receiver 404 is a two-phase refrigerant, since the average density of the two-phase refrigerant is low, the amount of the refrigerant stored in the receiver 404 is reduced, thereby affecting the refrigerant recovery effect. Therefore, during the refrigerant recovery process, the second expansion valve 412 is opened to bypass the gaseous refrigerant to improve the refrigerant recovery effect.

The above-described installation method (1) of the second expansion valve 412 is applied to the first refrigerant recovery mode. The above-described manner (2) of installing the second expansion valve 412 is applicable to both the first refrigerant recovery mode and the second refrigerant recovery mode. Of course, the two modes can also be combined for use, and are specifically started according to specific conditions. The present application does not specifically limit the manner in which the second expansion valve 412 is disposed.

In addition, the arrangement of the second expansion valve 412 in fig. 2 or fig. 3 can be used to improve the refrigerant recovery device 400 in fig. 4 and fig. 5.

Referring to fig. 4 in conjunction with fig. 1, in some embodiments, the refrigerant recovery device 400 further includes a first subcooling heat exchanger 413. Wherein the first subcooling heat exchanger 413 comprises a first passage 416 and a second passage 417; a third opening of the liquid storage tank 404 is communicated with a first pipeline through a first expansion valve 411 and a first channel 416 of a first supercooling heat exchanger 413 in sequence; a first end of the third solenoid valve 403 is connected to the outdoor expansion valve through the second passage 417 of the first supercooling heat exchanger 413.

Referring to fig. 4 in conjunction with fig. 1, in some embodiments, the refrigerant recovery device 400 further includes a first temperature sensor (not shown). Illustratively, the first temperature sensor is disposed on the line (22) as shown in FIG. 4. The first temperature sensor is used to detect a temperature value of the refrigerant flowing out of the first passage 416 of the first supercooling heat exchanger 413.

First outdoor pressure sensor referring to fig. 1, as shown in fig. 5, in some embodiments, the refrigerant recovery device 400 further includes a throttling device 414 and a second subcooling heat exchanger 415. Wherein the second subcooling heat exchanger comprises a third pass 418 and a fourth pass 419; the third opening of the liquid storage tank 404 is also communicated with the first pipeline through a throttling device 414 and a third channel 418 of the second supercooling heat exchanger 415 in sequence; a second end of the third solenoid valve 403 is connected to the indoor expansion valve through a fourth passage 419 of the second supercooling heat exchanger 415.

Referring to fig. 5 in conjunction with fig. 1, in some embodiments, the refrigerant recovery device 400 further includes a second temperature sensor (not shown), which may be disposed at a point c, for detecting a temperature value of the refrigerant flowing out of the third channel of the second supercooling heat exchanger. First outdoor pressure sensor the functions and arrangement of the various components of the refrigerant recovery device 400 will be described in detail below.

The liquid storage tank 404 is configured to store a refrigerant recovered by the multi-split air conditioning system in a refrigerant recovery mode (i.e., a first refrigerant recovery mode and a second refrigerant recovery mode); and releasing the recovered refrigerant.

Based on the first supercooling heat exchanger 413 shown in fig. 4 provided in the above embodiment, the refrigerant recovered in the refrigerant recovery device passes through the first passage 416 of the first supercooling heat exchanger 413, and the refrigerant passes through the second passage 417 of the first supercooling heat exchanger 413 during the operation of the multi-split air conditioning system. The second passage 417 cools the refrigerant flowing through the second passage 417 to release corresponding heat. The first passage 416 heats the recovered refrigerant flowing through the first passage 416 by using heat released by the second passage 417, so that liquid refrigerants in the recovered refrigerants in two phases (gas and liquid) are converted into gas refrigerants, the content of the liquid refrigerants in the refrigerants released by the refrigerant recovery device is reduced, the content of the gas refrigerants in the released recovered refrigerants is increased, and the use efficiency of the recovered refrigerants is ensured.

It should be noted that, based on the first supercooling heat exchanger 413, on one hand, in the process of releasing the recovered refrigerant in the refrigeration operation mode of the multi-split air conditioning system, the refrigerant recovery device releases the recovered refrigerant to the compressor of the outdoor unit 200, and the content of the liquid refrigerant in the refrigerant released by the refrigerant recovery device is reduced, which reduces the liquid returning from the compressor and prolongs the service life of the compressor. On the other hand, in the process of releasing the recovered refrigerant in the heating operation mode of the multi-split air conditioning system, the refrigerant recovery device 400 releases the recovered refrigerant to the indoor heat exchanger of the indoor unit, so that the content of the released and recovered refrigerant in gaseous state is increased, the amount of the refrigerant entering the indoor heat exchanger for recovery is increased, and the utilization rate of the recovered refrigerant is improved.

Based on above-mentioned first temperature sensor, can realize carrying out reasonable control to the aperture of first expansion valve. Exemplarily, step S11 to step S13 in the following flowchart 6.

And S11, when the multi-split air-conditioning system operates in a refrigerant release mode, acquiring a first temperature value detected by a first temperature sensor and a pressure value detected by a first outdoor pressure sensor.

And S12, if the difference value between the first temperature value and the second temperature value is greater than or equal to a first preset temperature value, controlling the first expansion valve to increase the opening degree.

And the second temperature value is a saturation temperature value corresponding to the pressure value detected by the first outdoor pressure sensor.

And S13, if the difference value between the first temperature value and the second temperature value is greater than a first preset temperature value, controlling the first expansion valve to reduce the opening degree.

In this example, the temperature difference between the first temperature value and the saturation temperature value is obtained by comparing the first temperature value of the refrigerant flowing out of the first channel of the first supercooling heat exchanger with the saturation temperature (i.e., the second temperature value) corresponding to the pressure value of the refrigerant at the inlet of the gas-liquid separator. And controlling the opening degree of the first expansion valve based on the size relation between the temperature difference value and the first preset temperature value so as to ensure that the opening degree of the first expansion valve is in a reasonable range, thereby ensuring that the refrigerant quantity released by the refrigerant recovery device is in a reasonable range. On one hand, the problem that the refrigerant is not processed in time by the multi-split air-conditioning system due to too much refrigerant in the whole multi-split air-conditioning system pipeline caused by too much refrigerant released by the refrigerant recovery device is avoided; on the other hand, the problem that the refrigerant quantity released by the refrigerant recovery device is too small, so that the refrigerant quantity in the pipeline of the whole multi-connected air-conditioning system is too small, and the working efficiency of the multi-connected air-conditioning system is reduced, such as the refrigerating speed or the heating speed is reduced, is avoided. Based on the throttling device 414 and the second cooling heat exchanger 415 shown in fig. 5, the refrigerant recovered in the refrigerant recovery device is throttled by the throttling device 414 and then flows through the third channel 418 of the second subcooling heat exchanger 415; during operation of the multi-split air conditioning system, the refrigerant flows through the fourth passage 419 of the second cooling heat exchanger 415. The fourth passage cools the refrigerant flowing through the fourth passage 419 to release corresponding heat. The third channel 418 heats the recovered refrigerant flowing through the third channel 418 by using the heat released by the fourth channel 419, so that the liquid refrigerant in the recovered refrigerant in two-phase state (gas state and liquid state) is converted into the gas refrigerant, the content of the liquid refrigerant in the refrigerant released by the refrigerant recovery device is reduced, the content of the gas refrigerant in the released recovered refrigerant is improved, and the use efficiency of the recovered refrigerant is ensured.

Based on the second temperature sensor in the above embodiment, the releasing process of the refrigerant in the refrigerant recovery device 400 can be reasonably controlled.

Exemplarily, steps S21 to S23 in the following flowchart 7.

And S21, when the multi-split air conditioning system operates in a refrigerant release mode, acquiring a third temperature value detected by the second temperature sensor and a pressure value detected by the first outdoor pressure sensor.

In step S22, if the difference between the third temperature value and the second temperature value is greater than or equal to a second preset temperature value, the operation of the refrigerant releasing mode is ended.

And step S23, if the difference value between the third temperature value and the second temperature value is smaller than a second preset temperature value, continuing to operate the refrigerant release mode.

It should be noted that the second preset temperature value is a very small value.

In addition, the refrigerant discharged from the receiver flows through three points a, b, and c in fig. 5. The refrigerant temperatures of two points a and b in the three points are the same, and the refrigerant temperatures of the two points b and c are changed due to the refrigerant quantity of the refrigerant in the liquid storage tank, specifically, the refrigerant temperatures of the two points b and c are equal or the difference between the refrigerant temperature of the point b and the refrigerant temperature of the point c is not large under the condition that the refrigerant exists in the liquid storage tank; the temperature of the refrigerant at the point c is higher than that of the refrigerant at the point b under the condition that no refrigerant is released in the liquid storage tank.

In this example, the temperature difference between the first temperature value and the saturation temperature value is obtained by comparing the first temperature value of the refrigerant flowing out of the third channel 418 of the second subcooling heat exchanger 415 with the saturation temperature corresponding to the pressure value of the refrigerant at the inlet of the gas-liquid separator, that is, the second temperature value. The releasing process of the refrigerant recovery device is reasonably controlled based on the size relation between the temperature difference value and the second preset temperature value, so that the refrigerant recovery device 400 can release the refrigerant under the condition of sufficient refrigerant, the refrigerant releasing mode is still executed under the condition that no refrigerant exists in the refrigerant recovery device, the refrigerant quantity in the multi-split air-conditioning system is small, and the working efficiency of the multi-split air-conditioning system is reduced.

The fourth solenoid valve 405 of fig. 1 to 5 is used to control whether the refrigerant can flow through the first pipe line connecting the four-way valve 202 of the indoor unit 300 and the outdoor unit 200.

Illustratively, when the multi-split air conditioning system operates in any one of a cooling mode, a heating mode, a first refrigerant recovery mode, a second refrigerant recovery mode or a refrigerant release mode, the fourth electromagnetic valve is controlled to be in an open state, so as to ensure that the refrigerant can circulate in the corresponding pipeline.

The fifth solenoid valve of fig. 1 to 5 is also used to control whether the refrigerant can flow through the first pipeline connecting the four-way valve 202 of the indoor unit 300 and the outdoor unit 200.

It should be noted that the independence of the refrigerant recovery device from the outdoor unit 200 and the indoor unit 300 can be ensured by closing the first solenoid valve 401, the second solenoid valve 402, the third solenoid valve 403, the fourth solenoid valve 405, and the fifth solenoid valve 406.

Illustratively, when the multi-split air conditioning system operates in any one of a cooling mode, a heating mode, a first refrigerant recovery mode, a second refrigerant recovery mode or a refrigerant release mode, the fifth electromagnetic valve is controlled to be in an open state, so as to ensure that the refrigerant can circulate in the corresponding pipeline.

Based on the above embodiment, as shown in fig. 1 to fig. 5, the refrigerant recycling device 400 further includes: a first stop valve 407, the first stop valve 407 being disposed on a pipeline between the four-way valve 202 and the fourth solenoid valve 405, a first end of the first stop valve 407 being connected to the four-way valve 202 through a pipeline, a second end of the first stop valve 407 being connected to a first end of the fourth solenoid valve 405 through a pipeline; a second stop valve 408, the second stop valve 408 being disposed on a pipeline between the fourth electromagnetic valve 405 and the indoor heat exchanger, a first end of the second stop valve 408 being connected to a second end of the fourth electromagnetic valve 405 through a pipeline, a second end of the second stop valve 408 being connected to the indoor heat exchanger in each indoor unit through a pipeline; a third stop valve 409, the third stop valve 409 being disposed on a pipeline between the outdoor expansion valve 204 and the first solenoid valve 401, a first end of the third stop valve 409 being connected to the outdoor expansion valve 204 through a pipeline, and a second end of the third stop valve 409 being connected to a first end of the first solenoid valve 401 through a pipeline; and a fourth cut-off valve 410, the fourth cut-off valve 410 being disposed on a pipe between the second solenoid valve 402 and the indoor heat exchanger, a first end of the fourth cut-off valve 410 being connected to a second end of the second solenoid valve 402 through a pipe, and a second end of the fourth cut-off valve 410 being connected to an indoor expansion valve of each indoor unit through a pipe.

In this embodiment, during the operation of the multi-split air conditioning system in the first refrigerant recovery mode or the second refrigerant recovery mode, the first stop valve 407, the second stop valve 408, the third stop valve 409, and the fourth stop valve 410 are in an open state. After the first refrigerant recovery mode or the second refrigerant recovery mode is completed, the first solenoid valve 401, the second solenoid valve 402, and the third solenoid valve 403 are in a closed state, and the first stop valve 407, the second stop valve 408, the third stop valve 409, and the fourth stop valve 410 are in a closed state, so as to better prevent the refrigerant from flowing through the pipeline corresponding to the stop valves.

It should be noted that the number of the stop valves provided in the multi-split air conditioning system may be according to specific requirements. For example, two stop valves may be respectively disposed at two ends of the indoor unit 300, that is, one stop valve is disposed at one end of the indoor unit 300 communicating with the four-way valve 202, that is, a stop valve is disposed on the pipeline (14) shown in fig. 2 to 7, for example, an eighth stop valve 305 in fig. 14; the other shutoff valve is disposed at one end of the indoor unit 300 and the refrigerant recovery device 400, i.e., the pipe (9) shown in fig. 2 to 5, and is provided with a shutoff valve, such as the eighth shutoff valve 304 in fig. 14.

In some embodiments, the multi-split air conditioning system at least has one or more of the following operation modes: the air conditioner comprises a cooling mode, a heating mode, a first refrigerant recovery mode, a second refrigerant recovery mode and a refrigerant release mode. The above operation modes are described in detail below.

1. Refrigeration mode

When the multi-split air conditioning system is in a refrigeration mode, the outdoor heat exchanger 203 serves as a condenser to work, the indoor heat exchanger serves as an evaporator to work, the first electromagnetic valve 401 is in a closed state, the second electromagnetic valve 402 is in a closed state, and the third electromagnetic valve 403 is in an open state; the first expansion valve 411 is in a closed state.

In some embodiments, four-way valve 202 may be a four-way reversing valve.

The operation cycle of the cooling mode of the air conditioning system will be described in detail by taking as an example that both the first indoor unit 300A and the second indoor unit 300B are indoor units requiring cooling. With reference to fig. 1, as shown in fig. 8, a D port of the four-way reversing valve is connected to a C port, and an E port is connected to an S port; the first solenoid valve 401, the second solenoid valve 402, and the first expansion valve 411 are closed, the third solenoid valve 403 and the fourth solenoid valve 405 are opened, and the other solenoid valves, the indoor expansion valve, the outdoor expansion valve, the expansion valve, and the stop valves are opened.

The refrigerant circuit flowing through the first indoor unit 300A of the indoor unit 300 is: (1) → (2) → (3) → (4) → (5) → (6) → (7) → (8) → (9) → (10) → (12) → (14) → (15) → (16) → (17) → (18) → (19) → (1).

The refrigerant circuit flowing through the second indoor unit 300B of the indoor unit 300 is: (1) → (2) → (3) → (4) → (5) → (6) → (7) → (8) → (9) → (11) → (13) → (14) → (15) → (16) → (17) → (18) → (19) → (1).

It should be noted that (14) → (15) → (16) → (17) are just an example, and the (14) → (15) → (16) → (17) shown in the present application may be replaced with a single pipe or a plurality of pipes. For example by replacing it with a line (16) which has only the fourth solenoid valve 405 or the fourth solenoid valve 405 and the first stop valve 407. The number of the electromagnetic valves and the number of the stop valves arranged on the section of pipeline are set according to specific requirements.

Specifically, the high-temperature and high-pressure gaseous refrigerant discharged from the compressor 201 enters the oil separator 206, and the refrigerant entering the oil separator 206 is divided into two parts. Wherein, a part of the oil enters the inlet of the gas-liquid separator 205 through an oil return capillary 207; the other part of the high-temperature and high-pressure gaseous refrigerant passing through the oil separator 206 enters the outdoor heat exchanger 203 through the check valve and the four-way valve 202. The high-temperature and high-pressure gaseous refrigerant is condensed into a medium-temperature and high-pressure liquid refrigerant in the outdoor heat exchanger 203. Further, the medium-temperature and high-pressure liquid refrigerant sequentially passes through the outdoor electronic expansion valve and the third electromagnetic valve 403 of the refrigerant recovery device 400, and is then split into two parts, wherein one part of the medium-temperature and high-pressure liquid refrigerant flows into the first indoor electromagnetic valve of the first indoor unit 300A to form a low-temperature and low-pressure liquid refrigerant, and then flows into the first indoor heat exchanger 301A, and is evaporated into a low-temperature and low-pressure gaseous refrigerant by the first indoor heat exchanger 301A; after another part of the refrigerant flows into the second indoor solenoid valve of the second indoor unit 300B to form a low-temperature and low-pressure liquid refrigerant, the low-temperature and low-pressure liquid refrigerant flows into the second indoor heat exchanger 301B again and is evaporated into a low-temperature and low-pressure gas refrigerant by the second indoor heat exchanger 301B. The low-temperature and low-pressure gaseous refrigerants evaporated by the first indoor heat exchanger 301A and the second indoor heat exchanger 301B are converged, and then enter the four-way reversing valve through the fourth electromagnetic valve 405, and the low-temperature and low-pressure gaseous refrigerants enter the gas-liquid separator 205; the low-temperature and low-pressure gaseous refrigerant flowing out of the gas-liquid separator 205 enters a suction port of the compressor 201, and the low-temperature and low-pressure gaseous refrigerant is compressed into a high-temperature and high-pressure gaseous refrigerant by the compressor 201 and discharged from the compressor 1, so that the refrigeration operation of the air conditioning system is completed.

2. Heating mode

When the multi-split air conditioning system is in a heating mode, the outdoor heat exchanger 203 works as an evaporator, the indoor heat exchanger works as a condenser, the first solenoid valve 401 is in a closed state, the second solenoid valve 402 is in a closed state, the third solenoid valve 403 is in an open state, and the first expansion valve 411 is in an open state.

The operation cycle of the heating mode of the air conditioning system will be described in detail, taking as an example that the first indoor unit 300A and the second indoor unit 300B are both indoor units that require heating. With reference to fig. 1, as shown in fig. 9, the S port of the four-way reversing valve is connected to the C port, and the E port is connected to the D port; the first solenoid valve 401, the second solenoid valve 402, and the first expansion valve 411 are closed, the third solenoid valve 403 and the fourth solenoid valve 405 are opened, and the other solenoid valves, the expansion valve, and the shutoff valves are opened.

The refrigerant circuit flowing through the first indoor unit 300A of the indoor unit 300 is: (1) → (2) → (18) → (17) → (16) → (15) → (14) → (12) → (10) → (9) → (8) → (7) → (6) → (5) → (4) → (3) → (19) → (1).

The refrigerant circuit flowing through the second indoor unit 300B of the indoor unit 300 is: (1) → (2) → (18) → (17) → (16) → (15) → (14) → (13) → (11) → (9) → (8) → (7) → (6) → (5) → (4) → (3) → (19) → (1).

Note that (14) → (15) → (16) → (17) are just one example, and this (14) → (15) → (16) → (17) shown in the present application may be replaced with a single pipe or a plurality of pipes. For example, by replacing it with a line (16) which has only the fourth solenoid valve 405 or the fourth solenoid valve 405 and the first stop valve 407. The number of the electromagnetic valves and the number of the stop valves arranged on the section of pipeline are set according to specific requirements.

Specifically, the high-temperature and high-pressure gaseous refrigerant discharged from the compressor 201 enters the oil separator 206. The refrigerant entering the oil separator 206 is divided into two portions. Wherein, a part of the oil enters the inlet of the gas-liquid separator 205 through the oil return capillary 207; the other part of the high-temperature and high-pressure gaseous refrigerant, which passes through the oil separator 206, is sequentially split by the check valve, the four-way valve 202 and the fourth solenoid valve 405 and enters the first indoor heat exchanger 301A of the first indoor unit 300A and the second indoor heat exchanger 301B of the second indoor unit 300B. The first indoor heat exchanger 301A and the second indoor heat exchanger 301B respectively condense the high-temperature and high-pressure gas refrigerant, and condense the refrigerant into a medium-temperature and high-pressure liquid refrigerant. The condensed medium-temperature and high-pressure liquid refrigerant passes through the first indoor expansion valve 302A and the second indoor expansion valve 302B, respectively, and then is merged. The merged refrigerant passes through the third solenoid valve 403 and the outdoor expansion valve 204 in sequence, and is throttled to form a low-temperature and low-pressure liquid refrigerant. The low-temperature low-pressure liquid refrigerant is evaporated into a low-temperature low-pressure gaseous refrigerant by the outdoor heat exchanger 203, and the low-temperature low-pressure gaseous refrigerant enters the gas-liquid separator 205; the low-temperature and low-pressure gaseous refrigerant flowing out of the gas-liquid separator 205 enters a suction port of the compressor 201; the low-temperature low-pressure gaseous refrigerant is compressed into a high-temperature high-pressure gaseous refrigerant by the compressor 201, and is discharged from the compressor 201 1, so that the heating mode operation of the air conditioning system is completed.

3. First refrigerant recovery mode

When the multi-split air conditioning system is in the first refrigerant recovery mode, the outdoor heat exchanger 203 operates as a condenser, the indoor heat exchanger operates as an evaporator, the first solenoid valve 401 is in an open state, the second solenoid valve 402 is in a closed state, the third solenoid valve 403 is in a closed state, and the first expansion valve 411 is in a closed state.

As a possible embodiment, when refrigerant leakage in the indoor unit is detected, regardless of whether the multi-split air conditioning system is in the cooling mode or the heating mode, the multi-split air conditioning system is switched to the cooling mode while the first solenoid valve 401 is controlled to be in the open state, the second solenoid valve 402 is controlled to be in the closed state, and the third solenoid valve 403 is controlled to be in the closed state.

The operation cycle of the first refrigerant recovery mode of the air conditioning system will be described in detail, taking the case where the refrigerant in the first indoor unit 300A leaks and the refrigerant in the second indoor unit 300B does not leak, as an example. Referring to fig. 2, as shown in fig. 10, the D port of the four-way reversing valve is connected to the C port, and the E port is connected to the S port; the first indoor expansion valve 302A is closed, the second solenoid valve 402 is closed, and the third solenoid valve 403 is closed, the first solenoid valve 401 and the fourth solenoid valve 405 are both opened, and the other solenoid valves, the other expansion valves, and the shutoff valves are all opened.

The refrigerant flowing through the outdoor unit 200 has the following flow directions: (1) → (2) → (3) → (4) → (5) → (6) → (20).

The flow direction of the refrigerant flowing through the second indoor unit 300B of the indoor unit 300 is: (8) → (9) → (11) → (13) → (14) → (15) → (16) → (17) → (18) → (19) → (1) → (2) → (3) → (4) → (5) → (6) → (20).

The refrigerant in the pipe line (8) and the pipe line (9) can be run to the compressor 201 through the second indoor unit 300B (indoor unit in which refrigerant leakage does not occur), and discharged or recovered to the refrigerant recovery device 400 by the compressor 201.

Specifically, the high-temperature and high-pressure gaseous refrigerant discharged from the compressor 201 enters the oil separator 206, and the refrigerant entering the oil separator 206 is divided into two parts. Wherein, a part of the oil enters the inlet of the gas-liquid separator 205 through the oil return capillary 207; the other part of the high-temperature and high-pressure gaseous refrigerant passing through the oil separator 206 enters the outdoor heat exchanger 203 through the check valve and the four-way valve 202. The high-temperature and high-pressure gaseous refrigerant is condensed into a medium-temperature and high-pressure liquid refrigerant in the outdoor heat exchanger 203. Further, after the medium-temperature and high-pressure liquid refrigerant sequentially passes through the outdoor electronic expansion valve and the first solenoid valve 401 of the refrigerant recovery device 400, the medium-temperature and high-pressure liquid refrigerant is stored in the liquid storage tank 404. After the low-temperature and low-pressure liquid refrigerant in the pipeline (8) and the pipeline (9) flows into the second indoor solenoid valve of the second indoor unit 300B to form the low-temperature and low-pressure liquid refrigerant, the low-temperature and low-pressure liquid refrigerant flows into the second indoor heat exchanger 301B again and is evaporated into the low-temperature and low-pressure gaseous refrigerant by the second indoor heat exchanger 301B. The low-temperature low-pressure gaseous refrigerant enters the four-way reversing valve through the fourth electromagnetic valve 405, and the low-temperature low-pressure gaseous refrigerant enters the gas-liquid separator 205; the low-temperature low-pressure gaseous refrigerant flowing out of the gas-liquid separator 205 enters a suction port of the compressor 201, and the low-temperature low-pressure gaseous refrigerant is compressed into a high-temperature high-pressure gaseous refrigerant by the compressor 201 and is discharged from the compressor 1, so that the operation in the first refrigerant recovery mode of the air conditioning system is completed.

Optionally, in the operation process of the first refrigerant recovery mode, the indoor expansion valve corresponding to the indoor unit with refrigerant leakage is closed, and meanwhile, the opening degree of the indoor expansion valve corresponding to the indoor unit without refrigerant leakage is opened to the maximum opening degree.

For example, when the refrigerant of the first indoor unit 300A leaks and the refrigerant of the second indoor unit 300B does not leak, the opening degree of the second indoor expansion valve 302B is increased to the maximum value while the first indoor expansion valve 302A is closed.

4. Second refrigerant recovery mode

When the multi-split air conditioning system is in the second refrigerant recovery mode, the outdoor heat exchanger 203 works as an evaporator, the indoor heat exchanger works as a condenser, the first electromagnetic valve 401 is in a closed state, the second electromagnetic valve 402 is in an open state, and the third electromagnetic valve 403 is in a closed state.

Taking the leakage of the outdoor unit 200 as an example, as a possible implementation manner, when the leakage of the refrigerant of the outdoor unit 200 is detected, the multi-split air-conditioning system is switched to the heating mode operation while the first electromagnetic valve 401 is controlled to be in the closed state, the second electromagnetic valve 402 is controlled to be in the open state, and the third electromagnetic valve 403 is controlled to be in the closed state, regardless of whether the multi-split air-conditioning system is in the cooling mode or the heating mode.

The operation cycle of the second refrigerant recovery mode of the air conditioning system will be described in detail. Referring to fig. 1, as shown in fig. 11, the S port of the four-way reversing valve is connected to the C port, and the E port is connected to the D port; the first solenoid valve 401, the third solenoid valve 403, and the first expansion valve 411 are closed, the second solenoid valve 402 and the fourth solenoid valve 405 are opened, and the other solenoid valves, the expansion valve, and the stop valves are opened.

The refrigerant flowing through the first indoor unit 300A of the indoor unit 300 has the following flow directions: (1) → 2 → 18 → 17 → 16 → 15 → 14 → 12 → 10 → 9 → 21.

The flow direction of the refrigerant flowing through the second indoor unit 300B of the indoor unit 300 is: (1) → (2) → (18) → (17) → (16) → (15) → (14) → (13) → (11) → (9) → (21).

Refrigerant flow direction of the outdoor unit 200: (3) → (19) → (1).

Specifically, the high-temperature and high-pressure gaseous refrigerant discharged from the compressor 201 enters the oil separator 206. The refrigerant entering the oil separator 206 is divided into two portions. Wherein, a part of the oil enters the inlet of the gas-liquid separator 205 through the oil return capillary 207; the other part of the high-temperature and high-pressure gaseous refrigerant passing through the oil separator 206 is sequentially split by the check valve, the four-way valve 202 and the fourth solenoid valve 405 and enters the first indoor heat exchanger 301A of the first indoor unit 300A and the second indoor heat exchanger 301B of the second indoor unit 300B. The first indoor heat exchanger 301A and the second indoor heat exchanger 301B respectively condense the high-temperature and high-pressure gas refrigerant, and condense the refrigerant into a medium-temperature and high-pressure liquid refrigerant. The condensed medium-temperature and high-pressure liquid refrigerant passes through the first indoor expansion valve 302A and the second indoor expansion valve 302B, respectively, and then is merged. The merged refrigerant is stored in the accumulator 404 through the second solenoid valve 402. The refrigerant in the outdoor unit 200 is evaporated into a low-temperature and low-pressure gaseous refrigerant by the outdoor heat exchanger 203, and the low-temperature and low-pressure gaseous refrigerant enters the gas-liquid separator 205; the low-temperature and low-pressure gas refrigerant flowing out of the gas-liquid separator 205 enters a suction port of the compressor 201; the low-temperature low-pressure gaseous refrigerant is compressed into a high-temperature high-pressure gaseous refrigerant by the compressor 201, and is discharged from the compressor 201 1, so that the operation of the second refrigerant recovery mode of the air conditioning system is completed.

5. Refrigerant release pattern

When the multi-split air conditioning system is in the refrigerant release mode, the first solenoid valve 401 is in a closed state, the second solenoid valve 402 is in a closed state, the third solenoid valve 403 is in an open state, the first expansion valve 411 is in an open state, and one of the outdoor heat exchanger 203 and the indoor heat exchangers (e.g., 301A and 301B) operates as an evaporator and the other operates as a condenser.

The following two application scenarios are specific: 1. when the multi-split air conditioning system is in a refrigeration working mode and needs to release the recovered refrigerant, the outdoor heat exchanger works as a condenser, the indoor heat exchanger works as an evaporator, the first electromagnetic valve is in a closed state, the second electromagnetic valve is in a closed state, the third electromagnetic valve is in an open state, and the first expansion valve is in an open state. 2. When the multi-split air conditioning system is in a heating working mode and refrigerant recovered by the recovery device needs to be released, the outdoor heat exchanger works as an evaporator, the indoor heat exchanger works as a condenser, the first electromagnetic valve is in a closed state, the second electromagnetic valve is in a closed state, the third electromagnetic valve is in an open state, and the expansion valve is in an open state.

In scenario 1, as shown in fig. 12, the outdoor heat exchanger 203 operates as a condenser, the indoor heat exchanger operates as an evaporator, the first solenoid valve 401 is in a closed state, the second solenoid valve 402 is in a closed state, and the third solenoid valve 403 is in an open state; the first expansion valve 411 is in an open state. The operation cycle of the refrigerant release mode of the air conditioning system will be described in detail, taking as an example that both the first indoor unit 300A and the second indoor unit 300B are indoor units requiring cooling. Referring to fig. 1, as shown in fig. 12, a D port of the four-way reversing valve is connected to a C port, and an E port is connected to an S port; the first solenoid valve 401 and the second solenoid valve 402 are closed, the third solenoid valve 403, the fourth solenoid valve 405, and the first expansion valve 411 are opened, and the other solenoid valves, the indoor expansion valve, the outdoor expansion valve, the expansion valve, and the stop valves are opened.

The refrigerant branch flowing through the outdoor unit is as follows: (15) → 16 → 17 → 18 → 19 → 1 → 2 → 3 → 4 → and 22 → 17 → 18 → 19 → 1 → 2 → 3 → 4.

Specifically, the high-temperature and high-pressure gaseous refrigerant discharged from the compressor 201 enters the oil separator 206, and the refrigerant entering the oil separator 206 is divided into two parts. Wherein, a part of the oil enters the inlet of the gas-liquid separator 205 through an oil return capillary 207; the other part of the high-temperature and high-pressure gaseous refrigerant, which has passed through the oil separator 206, enters the outdoor heat exchanger 203 through the check valve and the four-way valve 202. The high-temperature and high-pressure gaseous refrigerant is condensed into a medium-temperature and high-pressure liquid refrigerant in the outdoor heat exchanger 203. Further, the medium-temperature and high-pressure liquid refrigerant sequentially passes through the outdoor electronic expansion valve and the third electromagnetic valve 403 of the refrigerant recovery device 400, and is then split into two parts, wherein one part of the medium-temperature and high-pressure liquid refrigerant flows into the first indoor electromagnetic valve of the first indoor unit 300A to form a low-temperature and low-pressure liquid refrigerant, and then flows into the first indoor heat exchanger 301A, and is evaporated into a low-temperature and low-pressure gaseous refrigerant by the first indoor heat exchanger 301A; after another part of the refrigerant flows into the second indoor solenoid valve of the second indoor unit 300B to form a low-temperature and low-pressure liquid refrigerant, the low-temperature and low-pressure liquid refrigerant flows into the second indoor heat exchanger 301B again and is evaporated into a low-temperature and low-pressure gas refrigerant by the second indoor heat exchanger 301B. The low-temperature and low-pressure gaseous refrigerants evaporated by the first indoor heat exchanger 301A and the second indoor heat exchanger 301B are merged, meanwhile, the liquid refrigerants stored in the liquid storage tank 404 are throttled into low-temperature and low-pressure refrigerants by the first expansion valve 411, the low-temperature and low-pressure refrigerants are merged with the refrigerants merged and flowed out from each indoor unit of the indoor unit again, pass through the fourth electromagnetic valve 405 and enter the four-way reversing valve, and the low-temperature and low-pressure gaseous refrigerants enter the gas-liquid separator 205; the low-temperature and low-pressure gaseous refrigerant flowing out of the gas-liquid separator 205 enters a suction port of the compressor 201, and the low-temperature and low-pressure gaseous refrigerant is compressed into a high-temperature and high-pressure gaseous refrigerant by the compressor 201 and discharged from the compressor 1, so that the refrigeration operation of the air conditioning system is completed.

In scenario 2, as shown in fig. 13, the outdoor heat exchanger 203 operates as an evaporator, the indoor heat exchanger operates as a condenser, the first solenoid valve 401 is in a closed state, the second solenoid valve 402 is in a closed state, the third solenoid valve 403 is in an open state, and the first expansion valve 411 is in an open state.

The operation cycle of the refrigerant release mode of the air conditioning system will be described in detail, taking as an example that both the first indoor unit 300A and the second indoor unit 300B are indoor units that require heating. Referring to fig. 1, as shown in fig. 13, the S port of the four-way reversing valve is connected to the C port, and the E port is connected to the D port; the first solenoid valve 401 and the second solenoid valve 402 are closed, the first expansion valve 411 is opened, the third solenoid valve 403 and the fourth solenoid valve 405 are opened, and the other solenoid valves, the expansion valve, and the stop valve are opened.

The refrigerant circuit flowing through the first indoor unit 300A of the indoor unit 300 is: (1) → (2) → (18) → (17) → (16) → (15) → (14) → (12) → (10) → (9) → (8) → (7) → (6) → (5) → (4) → (3) → (19) → (1) and (22) → (15) → (14) → (12) → (10) → (9) → (8) → (7) → (6) → (5) → (4) → (3) → (19) → (1).

The refrigerant circuit flowing through the second indoor unit 300B of the indoor unit 300 is: (1) → (2) → (18) → (17) → (16) → (15) → (14) → (13) → (11) → (9) → (8) → (7) → (6) → (5) → (4) → (3) → (19) → (1) and (22) → (15) → (14) → (13) → (11) → (9) → (8) → (7) → (6) → (5) → (4) → (3) → (19) → (1).

Specifically, the high-temperature and high-pressure gaseous refrigerant discharged from the compressor 201 enters the oil separator 206. The refrigerant entering the oil separator 206 is divided into two portions. Wherein, a part of the oil enters the inlet of the gas-liquid separator 205 through the oil return capillary 207; the other part of the high-temperature and high-pressure gaseous refrigerant which passes through the oil separator 206 passes through the check valve, the four-way valve 202 and the fourth solenoid valve 405 in sequence. Meanwhile, the liquid refrigerant stored in the accumulator 404 is throttled into a low-temperature and low-pressure refrigerant by the first expansion valve 411. The high-temperature and high-pressure gaseous refrigerant sequentially passing through the four-way valve 202 and the fourth solenoid valve 405 is merged with the refrigerant throttled by the first expansion valve 411 to have a low temperature and a low pressure, and then is branched into the first indoor heat exchanger 301A of the first indoor unit 300A and the second indoor heat exchanger 301B of the second indoor unit 300B. The first indoor heat exchanger 301A and the second indoor heat exchanger 301B condense the high-temperature and high-pressure gas refrigerant, respectively, and condense the refrigerant into a medium-temperature and high-pressure liquid refrigerant. The condensed medium-temperature and high-pressure liquid refrigerants respectively pass through the first indoor expansion valve 302A and the second indoor expansion valve 302B and then are merged. The merged refrigerant passes through the third solenoid valve 403 and the outdoor expansion valve 204 in sequence, and is throttled to form a low-temperature and low-pressure liquid refrigerant. The low-temperature low-pressure liquid refrigerant is evaporated into a low-temperature low-pressure gaseous refrigerant by the outdoor heat exchanger 203, and the low-temperature low-pressure gaseous refrigerant enters the gas-liquid separator 205; the low-temperature and low-pressure gaseous refrigerant flowing out of the gas-liquid separator 205 enters a suction port of the compressor 201; the low-temperature and low-pressure gaseous refrigerant is compressed into a high-temperature and high-pressure gaseous refrigerant by the compressor 201, and is discharged from the compressor 201 1, so that the heating mode operation of the air conditioning system is completed. It should be noted that the above two scenarios are only examples, and not all scenarios. The flow direction of the released refrigerant can also be adjusted in combination with other application scenarios, for example, the cooling mode and the heating mode in the

above scenarios

1 and 2 are changed into other working modes, such as a dehumidification mode and a drying mode. Or starting the refrigerant release mode to completely release the refrigerant in the refrigerant recovery device and then operating other working modes (such as a refrigeration mode, a heating mode, a dehumidification mode and a drying mode) under the condition of detecting that the refrigerant exists in the refrigerant recovery device

Based on the five different operation modes, the multi-split air conditioning system can provide the operation modes corresponding to the scenes aiming at different scenes. Specifically, when cooling is required (e.g., the room temperature is too high), the operation mode of the multi-split air conditioning system is switched to the cooling mode to reduce the indoor ambient temperature. When heating is needed (for example, the room temperature is too low), the operation mode of the multi-split air conditioning system is switched to the heating mode to increase the indoor environment temperature. When the refrigerant leaked from the indoor unit needs to be recovered, the multi-split air conditioning system may be switched to the first refrigerant recovery mode, and the refrigerant leaked from the indoor unit is recovered by the refrigerant recovery device 400. When it is necessary to recover the refrigerant leaked from the outdoor unit 200, the multi-split air conditioning system may be switched to the second refrigerant recovery mode, and the refrigerant leaked from the outdoor unit 200 may be recovered by the refrigerant recovery device 400. When the refrigerant recovered in the refrigerant recovery device 400 needs to be utilized, the multi-split air conditioning system may be adjusted to the refrigerant release mode, and the recovered refrigerant is released to the first pipeline, so that the multi-split air conditioning system uses the recovered refrigerant in the cooling operation or heating operation process. In some embodiments, the multi-split air conditioning system 100 further includes a controller (not shown in fig. 1).

In some embodiments, the controller refers to a device that can generate an operation control signal according to the command operation code and the timing signal, and instruct the multi-split air conditioning system to execute the control command. For example, the controller 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 controller 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.

Although not shown in fig. 1, the multi-split air conditioning system may further include a power supply device (e.g., a battery and a power management chip) for supplying power to each component, and the battery may be logically connected to the controller through the power management chip, so as to implement functions such as power consumption management of the multi-split air conditioning system through the power supply device.

In some embodiments, the controller is electrically connected with the indoor refrigerant leakage detection device in each indoor unit; the controller is configured to: the method comprises the steps of obtaining a detection result of each indoor refrigerant leakage detection device, wherein the detection result of one indoor refrigerant leakage detection device is used for indicating whether refrigerant leakage occurs in an indoor unit where the refrigerant leakage detection device is located; determining whether an indoor unit 300 having refrigerant leakage exists according to a detection result of each indoor refrigerant leakage detection device; and if so, controlling the multi-split air conditioning system to operate in a first refrigerant recovery mode.

In this way, the multi-split air conditioning system can determine the indoor unit having refrigerant leakage in the indoor unit 300 according to the detection result of the indoor refrigerant leakage detection device. When the indoor unit 300 has a refrigerant leakage, the multi-split air conditioning system is controlled to switch to the first refrigerant recovery mode to recover the refrigerant leaked from the indoor unit to the refrigerant recovery device 400. On one hand, the risk of the indoor environment caused by the refrigerant of the indoor unit leaking into the indoor environment is avoided, and the safety of the multi-split air-conditioning system is improved; on the other hand, the refrigerant is recovered by the refrigerant recovery device 400, so that the amount of the refrigerant discharged from the outdoor unit 200 to the outdoor environment is greatly reduced, and the environmental friendliness of the multi-split air conditioning system is improved.

In some embodiments, the controller is further configured to: and when the multi-split air conditioning system operates in the first refrigerant recovery mode, closing an indoor expansion valve in the indoor unit with refrigerant leakage.

In this embodiment, when the multi-split air conditioning system operates in the first refrigerant recovery mode, the indoor expansion valve in the indoor unit with refrigerant leakage is closed to prevent the refrigerant from continuing to enter the indoor unit with refrigerant leakage, so that the refrigerant in the indoor unit with refrigerant leakage is prevented from leaking into an indoor environment, and the safe use of the multi-split air conditioning system by a user is ensured.

Optionally, when the multi-split air conditioning system operates in the first refrigerant recovery mode, the opening degree of the indoor expansion valve of the indoor unit without refrigerant leakage in the indoor unit 300 is adjusted to the maximum opening degree value, so that the refrigerant in the pipeline communicated with the indoor expansion valve of the indoor unit with refrigerant leakage is more quickly recovered to the refrigerant recovery device 400 through the indoor unit and the outdoor unit 200, thereby increasing the recovery speed of the refrigerant leaked from the indoor unit and ensuring the refrigerant recovery efficiency of the multi-split air conditioning system.

In some embodiments, the controller is further configured to: in the first refrigerant recovery mode, when a refrigerant recovery stop condition is satisfied, the fourth electromagnetic valve 405 is controlled to be closed; the refrigerant recovery stopping condition comprises one or more of the following conditions: the time length of the multi-split air conditioning system in the first refrigerant recovery mode reaches a preset time length; alternatively, the pressure of the refrigerant entering the compressor 201 is within a preset pressure range.

It should be noted that the preset pressure range is determined according to the atmospheric pressure of the outdoor environment.

Alternatively, the pressure of the refrigerant in the compressor 201 may be detected by a first outdoor pressure sensor 209 disposed at an inlet of the compressor 201 as shown in fig. 2.

Based on this, by setting the refrigerant recovery stopping condition, the time for finishing the refrigerant recovery can be determined, so that the refrigerant is recovered when the refrigerant quantity in the pipeline of the multi-split air-conditioning system is in a reasonable range, the first refrigerant recovery mode is still executed under the condition that no refrigerant exists in the pipeline of the multi-split air-conditioning system, the abnormality or damage of the multi-split air-conditioning system is avoided, and the safety and the service life of the multi-split air-conditioning system are further improved.

Based on the above embodiment, the refrigerant recovery device 400 is further provided with a fifth electromagnetic valve 406, a first end of the fifth electromagnetic valve 406 is connected to a second end of the fourth electromagnetic valve 405 through a pipeline, and a second end of the fifth electromagnetic valve 406 is connected to the indoor heat exchangers in the indoor units through pipelines; when the multi-split air conditioning system is in a cooling mode, a heating mode, and a first refrigerant recovery mode, the fifth electromagnetic valve 406 is in an open state.

Based on the above embodiment, the controller is further configured to: in the first refrigerant recovery mode, when the refrigerant recovery stop condition is met, the fifth electromagnetic valve 406 is controlled to be closed; the refrigerant recovery stopping condition comprises one or more of the following conditions: the time length of the multi-split air conditioning system operating in the first refrigerant recovery mode reaches a preset time length; alternatively, the pressure of the refrigerant entering the compressor 201 is within a preset pressure range.

In some embodiments, the outdoor unit 200 controller is electrically connected to the outdoor refrigerant leakage detecting device of the outdoor unit 200; the controller is configured to: acquiring a detection result of an outdoor refrigerant leakage detection device, wherein the detection result of the outdoor refrigerant leakage detection device is used for indicating whether refrigerant leakage occurs in the outdoor unit 200 or not; and if the detection result of the outdoor refrigerant leakage detection device indicates that the outdoor unit 200 has refrigerant leakage, controlling the multi-split air-conditioning system to operate in a second refrigerant recovery mode.

In this way, the multi-split air conditioning system can determine whether the outdoor unit 200 has refrigerant leakage according to the detection result of the outdoor refrigerant leakage detection device. Under the condition that the outdoor unit 200 leaks the refrigerant, the multi-split air conditioning system is controlled to be switched to the second refrigerant recovery mode to operate, and the refrigerant leaked from the outdoor unit 200 is recovered to the refrigerant recovery device 400, so that the refrigerant is recovered by the refrigerant recovery device 400, the amount of the refrigerant discharged from the outdoor unit 200 to the outdoor environment is greatly reduced, and the environmental friendliness of the multi-split air conditioning system is improved.

In some embodiments, the outdoor expansion valve 204 is controlled to be at the maximum opening degree value when the multi-split air conditioning system operates in the second refrigerant recovery mode.

In this embodiment, when the multi-split air-conditioning system operates in the second refrigerant recovery mode, the outdoor expansion valve 204 is controlled to be at the maximum opening value, so that the refrigerant in the pipeline communicated with the outdoor expansion valve 204 is more quickly recovered to the refrigerant recovery device 400 through the outdoor unit 200 and the indoor unit, thereby increasing the recovery speed of the refrigerant leaked from the outdoor unit 200 and ensuring the refrigerant recovery efficiency of the multi-split air-conditioning system.

In some embodiments, the controller is further configured to: in the second refrigerant recovery mode, when the refrigerant recovery stop condition is satisfied, the fourth electromagnetic valve 405 is controlled to be closed; the refrigerant recovery stopping condition comprises one or more of the following conditions: the time for the multi-split air conditioning system to operate in the second refrigerant recovery mode reaches the preset time; alternatively, the pressure of the refrigerant entering the compressor 201 is within a preset pressure range.

Based on this, the timing for finishing the refrigerant recovery can be determined by setting the refrigerant recovery stopping condition, so that the refrigerant is recovered when the refrigerant quantity in the pipeline of the multi-split air-conditioning system is in a reasonable range, the problem that the multi-split air-conditioning system is abnormal or damaged due to the fact that the second refrigerant recovery mode is still executed under the condition that no refrigerant exists in the pipeline of the multi-split air-conditioning system is avoided, and the safety and the service life of the multi-split air-conditioning system are further improved.

Based on the above embodiment, the controller is further configured to: in the second refrigerant recovery mode, when the refrigerant recovery stop condition is met, the fifth electromagnetic valve 406 is controlled to be closed; the refrigerant recovery stopping condition comprises one or more of the following conditions: the time length of the multi-split air conditioning system operating the second refrigerant recovery mode reaches a preset time length; alternatively, the pressure of the refrigerant entering the compressor 201 is within a preset pressure range.

In this embodiment, the indoor expansion valve corresponding to the indoor unit in which refrigerant leakage occurs in the indoor unit 300 is in a closed state. After the refrigerant is recovered, the fourth electromagnetic valve 405 and the fifth electromagnetic valve 406 are controlled to be closed, so that the indoor units with refrigerant leakage in the indoor unit 300 are freely separated from the refrigerant recovery device 400 and the outdoor unit 200, the indoor units with refrigerant leakage are not affected by the refrigerant recovery device 400 and the outdoor unit 200 in the process of replacing the indoor units with refrigerant leakage, and the convenience of installing or replacing the indoor units is improved.

A refrigerant recovery process will be described in an exemplary manner with reference to a control flowchart of the multi-split air conditioning system shown in fig. 15.

And S141, detecting the leakage condition of the refrigerant in the indoor unit and the outdoor unit.

And S142, controlling the multi-split air conditioning system to operate in a first refrigerant recovery mode under the condition that the indoor unit with refrigerant leakage is detected in the indoor unit.

And S143, controlling the multi-split air conditioning system to operate in a second refrigerant recovery mode under the condition that refrigerant leakage of the outdoor unit is detected.

And S144, keeping the original operation mode to operate under the condition that the refrigerant in the indoor unit and the outdoor unit is detected to be not leaked.

The original operation mode may be a mode in which the air conditioning system is operated, such as a cooling mode, a heating mode, and a dehumidification mode.

When the multi-split air conditioning system is in a first refrigerant recovery mode, the outdoor heat exchanger works as a condenser, the indoor heat exchanger works as an evaporator, the first electromagnetic valve is in an open state, the second electromagnetic valve is in a closed state, and the third electromagnetic valve is in a closed state; when the multi-split air conditioning system is in the second refrigerant recovery mode, the outdoor heat exchanger works as an evaporator, the indoor heat exchanger works as a condenser, the first electromagnetic valve is in a closed state, the second electromagnetic valve is in an open state, and the third electromagnetic valve is in a closed state.

Further, the control process of the multi-split air conditioning system in the first refrigerant recovery mode is as follows.

(1) The method comprises the steps of detecting that an indoor unit with refrigerant leakage exists in the indoor unit group. The indoor unit with refrigerant leakage usually sends out early warning information. The early warning information is used for indicating that the indoor unit has refrigerant leakage. The early warning information can be early warning in the form of voice, characters or light.

(2) And judging whether the multi-split air conditioning system is in a refrigeration mode or not.

(3) If not, after the multi-split air conditioning system is switched to the refrigerating mode, the indoor expansion valve corresponding to the indoor unit with refrigerant leakage is controlled to be in a closed state, the first electromagnetic valve is in an open state, the second electromagnetic valve is in a closed state, and the third electromagnetic valve is in a closed state.

(4) If yes, controlling the first electromagnetic valve to be in an opening state, and controlling an indoor expansion valve corresponding to the indoor unit with refrigerant leakage to be in a closing state, the first electromagnetic valve to be in an opening state, the second electromagnetic valve to be in a closing state and the third electromagnetic valve to be in a closing state.

(5) When the time length of the multi-split air-conditioning system running in the first refrigerant recovery mode reaches the preset time length; or when the pressure of the refrigerant entering the compressor is within a preset pressure range, the fourth electromagnetic valve is controlled to be closed, and first replacement information is sent. The first replacement information is used for prompting a user to replace the indoor unit with refrigerant leakage.

(6) And controlling the multi-split air conditioner system to stop running.

Further, the control process that the multi-split air conditioning system is in the second refrigerant recovery mode is described as follows.

(1) And detecting the refrigerant leakage of the outdoor unit. The outdoor unit will typically send out warning information. The early warning information is used for indicating that the outdoor unit has refrigerant leakage. The early warning information can be early warning in the form of voice, characters or light.

(2) And judging whether the multi-split air conditioner system is in a heating mode or not.

(3) If not, the multi-split air-conditioning system is switched to a heating mode, then the first electromagnetic valve is controlled to be in a closed state, the second electromagnetic valve is in an open state, and the third electromagnetic valve is in a closed state.

(4) If yes, the first electromagnetic valve is controlled to be in a closed state, the second electromagnetic valve is controlled to be in an open state, and the third electromagnetic valve is controlled to be in a closed state.

(5) When the time length of the multi-split air conditioning system in the second refrigerant recovery mode reaches the preset time length; or when the pressure of the refrigerant entering the compressor is within the preset pressure range, the fourth electromagnetic valve is controlled to be closed, and second replacement information is sent. The second replacement information is used for prompting the user to replace the outdoor unit.

(6) And controlling the multi-split air conditioner system to stop running.

As shown in the control flowchart of the multi-split air conditioning system shown in fig. 16, a refrigerant releasing process will be described.

And S151, under the condition that the first refrigerant recovery mode or the second refrigerant recovery mode is completed, if an operation signal for indicating that the multi-split air-conditioning system operates in the refrigeration mode is received, controlling the multi-split air-conditioning system in the first refrigerant release mode.

When the multi-split air conditioning system is in the first refrigerant release mode, the outdoor heat exchanger works as a condenser, the indoor heat exchanger works as an evaporator, the first electromagnetic valve is in a closed state, the second electromagnetic valve is in a closed state, the third electromagnetic valve is in an open state, and the first expansion valve is in an open state.

And S152, under the condition that the first refrigerant recovery mode or the second refrigerant recovery mode is finished, if an operation signal for indicating that the multi-split air-conditioning system operates in the heating mode is received, controlling the multi-split air-conditioning system to be in the second refrigerant release mode.

When the multi-split air conditioning system is in the second refrigerant release mode, the outdoor heat exchanger works as an evaporator, the indoor heat exchanger works as a condenser, the first electromagnetic valve is in a closed state, the second electromagnetic valve is in a closed state, the third electromagnetic valve is in an open state, and the expansion valve is in an open state.

In addition, the embodiment of the present application provides 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.

As shown in fig. 17, the controller 2000 includes a processor 2001, and optionally, a memory 2002 and a communication interface 2003, which are connected to the processor 2001. The processor 2001, memory 2002 and communication interface 2003 are connected by a bus 2004.

The processor 2001 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 2001 may also be any other means having a processing function such as a circuit, device or software module. The processor 2001 may also include a plurality of CPUs, and the processor 2001 may be one 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 (e.g., computer program instructions).

The memory 2002 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 disk read-only memory (CD-ROM) or other optical disk storage, optical disk storage (including compact disk, laser disk, optical disk, digital versatile disk, blu-ray disk, etc.), a magnetic disk 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 are not limited by the embodiments of the present application. The memory 2002 may be separate or integrated with the processor 2001. The memory 2002 may include, among other things, computer program code. The processor 2001 is configured to execute the computer program code stored in the memory 2002, thereby implementing the control method provided by the embodiment of the present application.

Communication interface 2003 may be used to communicate with other devices or communication networks (e.g., an Ethernet, radio Access Network (RAN), wireless Local Area Network (WLAN), etc.. Communication interface 2003 may be a module, circuitry, transceiver, or any other device capable of communicating.

The bus 2004 may be a Peripheral Component Interconnect (PCI) bus, an Extended Industry Standard Architecture (EISA) bus, or the like. The bus 2004 may be divided into an address bus, a data bus, a control bus, and the like. For ease of illustration, only one thick line is shown in FIG. 17, but this does not mean only one bus or one type of bus.

Embodiments of the present invention also provide a computer-readable storage medium, where the computer-readable storage medium includes computer-executable instructions, and when the computer-executable instructions are executed on a computer, the computer is caused to execute the method provided in the foregoing embodiments.

The embodiment of the present invention further provides a computer program product, which can be directly loaded into the memory and contains software codes, and after being loaded and executed by the computer, the computer program product can implement the method provided by the above embodiment.

Those skilled in the art will recognize that, in one or more of the examples described above, the functions described in this invention may be implemented in hardware, software, firmware, or any combination thereof. When implemented in software, the functions may be stored on or transmitted over as one or more instructions or code on a computer-readable medium. Computer-readable media includes both computer storage media and communication media including any medium that facilitates transfer of a computer program from one place to another. A storage media may be any available media that can be accessed by a general purpose or special purpose computer.

Through the above description of the embodiments, it is clear to those skilled in the art that, for convenience and simplicity of description, the foregoing division of the functional modules is merely used as an example, and in practical applications, the above function distribution may be completed by different functional modules according to needs, that is, the internal structure of the device may be divided into different functional modules to complete all or part of the above described functions.

In the several embodiments provided in the present application, it should be understood that the disclosed apparatus and method may be implemented in other ways. For example, the above-described embodiments of the apparatus are merely illustrative, and for example, a module or a unit may be divided into only one logic function, and another division may be implemented in practice. For example, multiple modules or components may be combined or may be integrated into another device, or some features may be omitted, or not implemented. In addition, the shown or discussed mutual coupling or direct coupling or communication connection may be an indirect coupling or communication connection through some interfaces, devices or modules, and may be in an electrical, mechanical or other form. Modules described as separate components may or may not be physically separate, and components shown as modules may be one physical module or multiple physical modules, may be located in one place, or may be distributed in multiple different places. Some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.

In addition, functional units in the embodiments of the present invention may be integrated into one processing unit, or each unit may exist alone physically, or two or more units are integrated into one unit. The integrated unit can be realized in a form of hardware, and can also be realized in a form of a software functional unit. The integrated unit, if implemented in the form of a software functional unit and sold or used as a stand-alone product, may be stored in a readable storage medium. Based on such understanding, the technical solutions of the embodiments of the present application may be essentially or partially contributed to by the prior art, or all or part of the technical solutions may be embodied in the form of a software product, where the software product is stored in a storage medium and includes several instructions to enable a device (which may be a single chip, a chip, or the like) or a processor (processor) to execute all or part of the steps of the methods according to the embodiments of the present invention. And the aforementioned storage medium includes: various media capable of storing program codes, such as a U disk, a removable hard disk, a ROM, a RAM, a magnetic disk, or an optical disk.

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 disclosed in the present application should be covered within 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. A multi-split air conditioning system, comprising:

the outdoor unit comprises a compressor, a four-way valve, an outdoor heat exchanger and an outdoor expansion valve;

the indoor unit comprises a plurality of indoor units connected in parallel, each indoor unit comprises an indoor heat exchanger and an indoor expansion valve, and the indoor heat exchanger is connected with the four-way valve through a first pipeline;

refrigerant recovery unit, refrigerant recovery unit includes: the first electromagnetic valve, the second electromagnetic valve, the third electromagnetic valve, the first expansion valve and the liquid storage tank; a first opening of the liquid storage tank is connected with the outdoor expansion valve through the first electromagnetic valve, a second opening of the liquid storage tank is connected with the indoor expansion valve through the second electromagnetic valve, a third opening of the liquid storage tank is communicated with the first pipeline through the first expansion valve, and the third opening of the liquid storage tank is arranged at the bottom of the liquid storage tank; and the first end of the third electromagnetic valve is connected with the outdoor expansion valve, and the second end of the third electromagnetic valve is connected with the indoor expansion valve.

2. A multi-split air conditioning system as claimed in claim 1, wherein the multi-split air conditioning system has a plurality of operation modes, and the plurality of operation modes include a first refrigerant recovery mode, a second refrigerant recovery mode, and a refrigerant release mode;

when the multi-split air conditioning system is in a first refrigerant recovery mode, the outdoor heat exchanger works as a condenser, the indoor heat exchanger works as an evaporator, the first electromagnetic valve is in an open state, the second electromagnetic valve is in a closed state, the third electromagnetic valve is in a closed state, and the first expansion valve is in a closed state;

when the multi-split air conditioning system is in a second refrigerant recovery mode, the outdoor heat exchanger works as an evaporator, the indoor heat exchanger works as a condenser, the first electromagnetic valve is in a closed state, the second electromagnetic valve is in an open state, the third electromagnetic valve is in a closed state, and the first expansion valve is in a closed state;

3. A multi-split air conditioning system as set forth in claim 2,

the refrigerant recovery device also comprises a first supercooling heat exchanger, and the first supercooling heat exchanger comprises a first channel and a second channel; a third opening of the liquid storage tank is communicated with the first pipeline through the first expansion valve and a first channel of the first supercooling heat exchanger in sequence; and the first end of the third electromagnetic valve is connected with the outdoor expansion valve through the second channel of the first supercooling heat exchanger.

4. A multi-split air conditioning system as set forth in claim 3,

the refrigerant recovery device also comprises a first temperature sensor, wherein the first temperature sensor is used for detecting the temperature value of the refrigerant flowing out of the first channel of the first supercooling heat exchanger;

the outdoor unit also comprises a gas-liquid separator and a first outdoor pressure sensor, wherein the first outdoor pressure sensor is used for detecting the pressure value of a refrigerant at an inlet of the gas-liquid separator;

the multi-split air conditioning system further includes: a controller configured to:

when the multi-split air conditioning system operates in a refrigerant release mode, acquiring a first temperature value detected by the first temperature sensor and a pressure value detected by the first outdoor pressure sensor;

if the difference value between the first temperature value and the second temperature value is greater than or equal to a first preset temperature value, controlling the first expansion valve to increase the opening degree, wherein the second temperature value is a saturation temperature value corresponding to the pressure value detected by the first outdoor pressure sensor; alternatively, the first and second electrodes may be,

and if the difference value between the first temperature value and the second temperature value is greater than a first preset temperature value, controlling the first expansion valve to reduce the opening degree.

5. A multi-split air conditioning system as claimed in claim 4,

the refrigerant recovery device also comprises a throttling device and a second supercooling heat exchanger; the second subcooling heat exchanger comprises a third pass and a fourth pass; a third opening of the liquid storage tank is communicated with the first pipeline sequentially through a third channel of the throttling device and the second supercooling heat exchanger; and the second end of the third electromagnetic valve is connected with the indoor expansion valve through a fourth channel of the second supercooling heat exchanger.

6. A multi-split air conditioning system as set forth in claim 5,

the refrigerant recovery device also comprises a second temperature sensor, wherein the second temperature sensor is used for detecting the temperature value of the refrigerant flowing out of a third channel of the second supercooling heat exchanger;

the controller further configured to:

when the multi-split air conditioning system operates in a refrigerant release mode, acquiring a third temperature value detected by the second temperature sensor and a pressure value detected by the first outdoor pressure sensor;

if the difference value between the third temperature value and the second temperature value is greater than or equal to a second preset temperature value, ending the operation of the refrigerant release mode, wherein the second temperature value is a saturation temperature value corresponding to the pressure value detected by the first outdoor pressure sensor; alternatively, the first and second electrodes may be,

and if the difference value between the third temperature value and the second temperature value is smaller than the second preset temperature value, continuing to operate the refrigerant release mode.

7. A multi-split air conditioning system as set forth in claim 1,

the refrigerant recovery device further comprises a fourth electromagnetic valve, the fourth electromagnetic valve is arranged on the first pipeline, the first end of the fourth electromagnetic valve is connected with the four-way valve, and the second end of the fourth electromagnetic valve is connected with the indoor heat exchanger.

8. A multi-split air conditioning system as set forth in claim 7,

the refrigerant recovery device further comprises a fifth electromagnetic valve, the fifth electromagnetic valve is arranged on the first pipeline, a first end of the fifth electromagnetic valve is connected with a second end of the fourth electromagnetic valve, and a second end of the fifth electromagnetic valve is connected with the indoor heat exchanger.

9. A multi-split air conditioning system as set forth in claim 8,

the refrigerant recovery device also comprises a second expansion valve;

a first end of the second expansion valve is connected with a fourth opening of the liquid storage tank, a second end of the second expansion valve is communicated with a second pipeline, and the second pipeline is a pipeline between the fourth electromagnetic valve and the fifth electromagnetic valve; alternatively, the first and second electrodes may be,

the first end of the second expansion valve is communicated with a third pipeline, the second end of the second expansion valve is communicated with the second pipeline, and the third pipeline is a pipeline between the first electromagnetic valve and the first opening of the liquid storage tank.

10. A multi-split air conditioning system as set forth in claim 8,

the refrigerant recovery device further comprises:

the first stop valve is arranged on a pipeline between the four-way valve and the fourth electromagnetic valve, the first end of the first stop valve is connected with the four-way valve through a pipeline, and the second end of the first stop valve is connected with the first end of the fourth electromagnetic valve through a pipeline;

the second stop valve is arranged on a pipeline between the fourth electromagnetic valve and the indoor heat exchangers, a first end of the second stop valve is connected with a second end of the fourth electromagnetic valve through a pipeline, and a second end of the second stop valve is connected with the indoor heat exchangers in the indoor units through pipelines;

a third stop valve disposed on a pipeline between the outdoor expansion valve and the first solenoid valve, a first end of the third stop valve being connected to the outdoor expansion valve through a pipeline, and a second end of the third stop valve being connected to the first end of the first solenoid valve through a pipeline;

and the fourth stop valve is arranged on a pipeline between the second electromagnetic valve and the indoor heat exchanger, the first end of the fourth stop valve is connected with the second end of the second electromagnetic valve through a pipeline, and the second end of the fourth stop valve is connected with each indoor expansion valve in the indoor unit through a pipeline.

11. A multi-split air conditioning system as set forth in claim 10,

the outdoor unit further includes:

the fifth stop valve is arranged on a pipeline between the four-way valve and the first stop valve, the first end of the fifth stop valve is connected with the four-way valve through a pipeline, and the second end of the fifth stop valve is connected with the first end of the first stop valve through a pipeline;

and the sixth stop valve is arranged on a pipeline between the outdoor expansion valve and the third stop valve, the first end of the sixth stop valve is connected with the outdoor expansion valve through a pipeline, and the second end of the sixth stop valve is connected with the first end of the third stop valve through a pipeline.

12. A multi-split air conditioning system as set forth in claim 11,

the outdoor unit further includes:

the sixth electromagnetic valve is arranged on a pipeline between the four-way valve and the fifth stop valve, the first end of the sixth electromagnetic valve is connected with the four-way valve through a pipeline, and the second end of the sixth electromagnetic valve is connected with the first end of the fifth stop valve through a pipeline;

and the seventh electromagnetic valve is arranged on a pipeline between the outdoor expansion valve and the sixth stop valve, the first end of the seventh electromagnetic valve is connected with the outdoor expansion valve through a pipeline, and the second end of the seventh electromagnetic valve is connected with the first end of the sixth stop valve through a pipeline.