CN113587262B

CN113587262B - Outdoor unit, air conditioning system and control method thereof

Info

Publication number: CN113587262B
Application number: CN202110846856.0A
Authority: CN
Inventors: 张仕强; 陈敏
Original assignee: Gree Electric Appliances Inc of Zhuhai
Current assignee: Gree Electric Appliances Inc of Zhuhai
Priority date: 2021-07-26
Filing date: 2021-07-26
Publication date: 2022-07-08
Anticipated expiration: 2041-07-26
Also published as: CN113587262A

Abstract

The application relates to an outdoor unit, an air conditioning system and a control method of the air conditioning system. This off-premises station includes: the system comprises a compressor, a gas-liquid separator, a four-way valve, an outdoor heat exchanger, a heating throttling device, a liquid storage tank, a liquid storage inlet valve, a liquid storage outlet valve and a liquid storage throttling element. The compressor, the gas-liquid separator, the four-way valve, the outdoor heat exchanger, the heating throttling device and the indoor unit form a refrigerant circulation loop. The liquid storage tank is provided with a liquid storage inlet and a liquid storage outlet, the liquid storage inlet is connected between the outdoor heat exchanger and the heating throttling device through a liquid storage inlet valve, and the liquid storage throttling element is connected with one end of the liquid storage outlet and one end of the liquid storage outlet valve. And in the heating mode, the other end of the liquid storage outlet valve is connected with the inlet end of the gas-liquid separator, and the liquid storage outlet and the gas-liquid separator are switched on or off. This application can reduce the stock solution volume in the vapour and liquid separator, and then avoid because of the too big liquid impact problem that arouses the compressor and take liquid to cause of the stock solution volume in the vapour and liquid separator.

Description

Outdoor unit, air conditioning system and control method thereof

Technical Field

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

Background

Along with the increase of the design cold quantity of the air conditioning system, the adjustable refrigerant quantity span of the air conditioning unit is increased. In order to prevent the compressor from still reliably running when the refrigerant is incompletely evaporated for use, the design volume of the gas-liquid separator is increased. Because the gas-liquid separator is arranged on the suction side of the compressor, excessive liquid storage easily causes the problem of liquid impact caused by suction and liquid entrainment of the compressor.

Disclosure of Invention

The application aims at the problem that liquid impact is caused by the fact that a compressor easily absorbs air and carries liquid in the existing air conditioning system, and provides an outdoor unit, an air conditioning system and a control method of the outdoor unit, the air conditioning system and the control method of the air conditioning system.

An outdoor unit comprises a compressor, a gas-liquid separator, a four-way valve, an outdoor heat exchanger, a heating throttling device, a liquid storage tank, a liquid storage inlet valve, a liquid storage outlet valve and a liquid storage throttling element, wherein the compressor and the indoor unit form a refrigerant circulation loop;

the liquid storage tank is provided with a liquid storage inlet and a liquid storage outlet, the liquid storage inlet is connected between the outdoor heat exchanger and the heating throttling device through the liquid storage inlet valve, and the liquid storage throttling element is connected with the liquid storage outlet and one end of the liquid storage outlet valve;

and in the heating mode, the other end of the liquid storage outlet valve is connected with the inlet end of the gas-liquid separator, and the liquid storage outlet and the gas-liquid separator are communicated or cut off.

In one embodiment, the reservoir outlet comprises a second reservoir outlet, the reservoir throttle comprises a second reservoir throttle, and the reservoir outlet valve comprises a second reservoir outlet valve;

the second stock solution outlet is located the top of liquid storage pot, the one end of second stock solution outlet valve is connected the second stock solution outlet, second stock solution choke piece is connected the second stock solution outlet with the one end of second stock solution outlet valve, the other end of second stock solution outlet valve is connected the entry end of vapour and liquid separator.

In one embodiment, the reservoir outlet comprises a first reservoir outlet, the reservoir throttle comprises a first reservoir throttle, and the reservoir outlet valve comprises a first reservoir outlet valve;

the first liquid storage outlet is located at the bottom of the liquid storage tank, one end of the first liquid storage outlet valve is connected with the first liquid storage outlet, the first liquid storage throttling piece is connected with the first liquid storage outlet and one end of the first liquid storage outlet valve, and the other end of the first liquid storage outlet valve is connected to a pipeline between the outdoor heat exchanger and the four-way valve.

In one embodiment, the device further comprises a pressurization valve, the liquid storage tank is also provided with a pressurization port, and the pressurization port is positioned at the top of the liquid storage tank; the pressurizing valve is connected with the pressurizing port and the exhaust end of the compressor.

In one embodiment, the air conditioner further comprises a liquid discharge valve, one end of the liquid discharge valve is connected to the side, away from the outdoor heat exchanger, of the heating throttling device, and the other end of the liquid discharge valve is connected to a pipeline between the first liquid storage outlet and the first liquid storage outlet.

In one embodiment, the outdoor heat exchanger further comprises a first temperature sensor and a first pressure sensor, wherein the first temperature sensor is arranged at one end of the outdoor heat exchanger close to the four-way valve, and the first pressure sensor is arranged at a suction end of the compressor.

In one embodiment, the device further comprises a second temperature sensor and a third temperature sensor, wherein the second temperature sensor is arranged at the outlet end of the gas-liquid separator, and the third temperature sensor is arranged at the inlet end of the gas-liquid separator.

In one embodiment, the system further comprises a second pressure sensor, a fourth temperature sensor, a liquid level sensor or a fifth temperature sensor;

the second pressure sensor is arranged at the exhaust end of the compressor, the fourth temperature sensor is used for detecting the outdoor environment temperature, the liquid level sensor is arranged in the liquid storage tank, and the fifth temperature sensor is arranged at the bottom of the liquid storage tank.

In addition, an embodiment of the present application further provides an air conditioning system, including a compressor, a gas-liquid separator, a four-way valve, an outdoor heat exchanger, a heating throttling device, a refrigerating throttling device, an indoor heat exchanger, a liquid storage tank, a liquid storage inlet valve, a liquid storage outlet valve, and a liquid storage throttling element, which form a refrigerant circulation loop;

In addition, an embodiment of the present application further provides a control method of an air conditioning system, including the following steps:

in the heating mode, a heating throttling device is started, and the working state of an outdoor heat exchanger is detected, wherein the working state of the outdoor heat exchanger comprises an evaporation complete state and an evaporation incomplete state;

when the outdoor heat exchanger is in the incomplete evaporation state, opening a liquid storage inlet valve and a liquid storage outlet valve;

and when the outdoor heat exchanger is in the evaporation complete state, closing the liquid storage inlet valve and the liquid storage outlet valve.

In one embodiment, the step of opening the liquid storage inlet valve and the liquid storage outlet valve when the outdoor heat exchanger is in the incomplete evaporation state specifically includes:

when the outdoor heat exchanger is in the incomplete evaporation state, opening the liquid storage inlet valve, and opening a first liquid storage outlet valve and/or a second liquid storage outlet valve;

correspondingly, when the outdoor heat exchanger is in the evaporation complete state, the step of closing the liquid storage inlet valve and the liquid storage outlet valve specifically includes:

and when the outdoor heat exchanger is in the evaporation complete state, closing the liquid storage inlet valve, the first liquid storage outlet valve and/or the second liquid storage outlet valve.

In one embodiment, the step of detecting the working state of the outdoor heat exchanger specifically includes:

acquiring detection values of a first temperature sensor and a first pressure sensor, and judging whether the detection value of the first temperature sensor is larger than a saturation temperature value corresponding to the detection value of the first pressure sensor;

if yes, judging that the outdoor heat exchanger is in a complete evaporation state;

if not, judging that the outdoor heat exchanger is in an incomplete evaporation state.

acquiring detection values of a second temperature sensor and a third temperature sensor, and judging whether a difference value between the detection value of the second temperature sensor and the detection value of the third temperature sensor is greater than a first threshold value or not;

In one embodiment, after the step of closing the liquid storage inlet valve and the liquid storage outlet valve when the outdoor heat exchanger is in the evaporation complete state, the method further comprises:

in the heating mode, judging whether the air-conditioning system meets a heating liquid drainage condition, wherein the heating liquid drainage condition is used for indicating that a refrigerant participating in heating of the air-conditioning system is insufficient;

if yes, opening the pressurizing valve and the first liquid storage outlet valve;

if not, the pressurizing valve and the first liquid storage outlet valve are closed.

In one embodiment, the step of determining whether the air conditioning system meets a heating liquid discharge condition specifically includes:

acquiring a detection value of a second pressure sensor and a detection value of a fourth temperature sensor, and acquiring a detection value of the liquid level sensor or the fifth temperature sensor;

judging whether the difference between the saturation temperature value corresponding to the detection value of the second pressure sensor and the detection value of the fourth temperature sensor is smaller than a third threshold value, and whether the difference between the detection value of the liquid level sensor and the second threshold value is larger than the second threshold value or the difference between the detection value of the fifth temperature sensor and the detection value of the fourth temperature sensor is smaller than a fourth threshold value is met;

if yes, the air conditioning system is judged to meet the heating liquid drainage condition.

In one embodiment, the method further comprises the following steps:

and in a refrigerating mode, opening a liquid storage inlet valve and a liquid discharge valve, and closing a heating throttling device and the liquid storage outlet valve.

In one embodiment, after the steps of opening the liquid storage inlet valve and the liquid discharge valve, and closing the heating throttling device and the liquid storage outlet valve, the method further comprises the following steps:

judging whether the air-conditioning system meets a refrigeration liquid discharge condition, wherein the refrigeration liquid discharge condition is used for indicating that a refrigerant participating in refrigeration in the air-conditioning system is insufficient;

if so, closing the liquid storage inlet valve and the liquid storage outlet valve, and opening the liquid discharge valve and the heating throttling device.

In one embodiment, the step of determining whether the air conditioning system meets the cooling liquid discharge condition specifically includes:

acquiring a temperature difference value of an inlet pipe and an outlet pipe of an indoor heat exchanger, an opening value of a refrigeration throttling device and a detection value of a fourth temperature sensor, and acquiring a detection value of a liquid level sensor or a detection value of a fifth temperature sensor;

judging whether the temperature difference value of an inlet pipe and an outlet pipe of the indoor heat exchanger is larger than a sixth threshold value, the opening value of the refrigeration throttling device is larger than a seventh threshold value, and the detection value of the liquid level sensor is larger than a second threshold value or the difference value between the detection value of the fifth temperature sensor and the detection value of the fourth temperature sensor is smaller than a fourth threshold value;

if yes, the air conditioning system is judged to meet the refrigeration liquid drainage condition.

When the refrigerant in the outdoor heat exchanger is not completely evaporated, the liquid storage inlet valve and the liquid storage outlet valve of the outdoor unit are opened. The refrigerant entering the heating throttling device is divided into two paths, one path enters the outdoor heat exchanger, is changed into a gaseous refrigerant by evaporation and heat absorption and enters the gas-liquid separator, and the other path enters the liquid storage tank through the liquid storage inlet valve and the liquid storage inlet. A part of refrigerant is stored in the liquid storage tank, and a part of refrigerant enters the gas-liquid separator after passing through the liquid storage outlet, the liquid storage outlet valve and the liquid storage throttling piece. Because part of the liquid refrigerant enters the liquid storage tank and is stored, the content of the liquid refrigerant entering the outdoor heat exchanger is reduced, and the liquid refrigerant in the outdoor heat exchanger can be basically and completely evaporated into a gaseous refrigerant. Therefore, the content of the liquid refrigerant in the refrigerant entering the gas-liquid separator is reduced, the liquid storage amount in the gas-liquid separator is reduced, and the liquid impact problem caused by the liquid carrying of the air suction of the compressor due to the overlarge liquid storage amount in the gas-liquid separator is avoided.

Drawings

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

FIG. 2 is a schematic structural diagram of an air conditioning system according to another embodiment of the present application;

FIG. 3 is an initial state diagram of the air conditioning system of FIG. 1 in a heating mode;

FIG. 4 is a liquid storage state diagram of the air conditioning system shown in FIG. 1 in a heating mode;

FIG. 5 is a liquid storage state diagram of the air conditioning system shown in FIG. 2 in a heating mode;

FIG. 6 is a liquid discharge state diagram of the air conditioning system of FIG. 1 in a heating mode;

FIG. 7 is a liquid storage state diagram of the air conditioning system of FIG. 1 in a cooling mode;

FIG. 8 is a liquid discharge state diagram of the air conditioning system of FIG. 1 in a cooling mode;

FIG. 9 is a schematic diagram of an air conditioning system according to another embodiment of the present application;

FIG. 10 is a logic control diagram of an air conditioning system according to an embodiment of the present application;

fig. 11 is a flowchart illustrating a control method of an air conditioning system according to an embodiment of the present application.

Description of reference numerals:

01. an outdoor unit; 02. an indoor unit; a. a liquid storage inlet; b. a pressurizing port; c. a first reservoir outlet; d. a second reservoir outlet;

1. a gas-liquid separator; 2. a compressor; 3. a four-way valve; 4. an outdoor heat exchanger; 5. a heating throttling device; 6. a subcooling throttling device; 7. a subcooling heat exchanger; 8. a heating throttling device; 9. an indoor heat exchanger; 10. a liquid storage tank; 11. a liquid storage inlet valve; 12. a first reservoir outlet valve; 13. a drain valve; 14. a pressurization valve; 15. a first reservoir restriction; 16. a second reservoir restriction; 17. a second reservoir outlet valve; 19. a first temperature sensor; 20. a first pressure sensor; 21. a second temperature sensor; 22. a third temperature sensor; 23. a second pressure sensor; 24. a fourth temperature sensor; 25. a liquid level sensor; 26. and a fifth temperature sensor.

Detailed Description

In order to make the aforementioned objects, features and advantages of the present application more comprehensible, embodiments accompanying the present application are described in detail below with reference to the accompanying drawings. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present application. This application is capable of embodiments in many different forms than those described herein and that modifications may be made by one skilled in the art without departing from the spirit and scope of the application and it is therefore not intended to be limited to the specific embodiments disclosed below.

In the description of the present application, it is to be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," "circumferential," and the like are used in the orientations and positional relationships indicated in the drawings for convenience in describing the present application and for simplicity in description, and are not intended to indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and are therefore not to be considered limiting of the present application.

Furthermore, 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 at least one such feature. In the description of the present application, "plurality" means at least two, e.g., two, three, etc., unless specifically limited otherwise.

In this application, unless expressly stated or limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can include, for example, fixed connections, removable connections, or integral parts; can be mechanically or electrically connected; they may be directly connected or indirectly connected through intervening media, or they may be connected internally or in any other suitable relationship, unless expressly stated otherwise. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art as appropriate.

In this application, unless expressly stated or limited otherwise, the first feature "on" or "under" the second feature may be directly contacting the first and second features or indirectly contacting the first and second features through intervening media. Also, a first feature "on," "above," and "over" a second feature may be directly on or obliquely above the second feature, or simply mean that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.

It will be understood that when an element is referred to as being "secured to" or "disposed on" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and the like as used herein are for illustrative purposes only and do not denote a unique embodiment.

An air conditioning system generally includes a compressor, a gas-liquid separator, a four-way valve, an outdoor heat exchanger, a heating throttle device, a cooling throttle device, and an indoor heat exchanger, which form a refrigerant circulation circuit. The four-way valve is provided with four connecting ports, namely a first connecting port, a second connecting port, a third connecting port and a fourth connecting port. Under the action of the internal switching device of the four-way valve, the first connecting port is selectively communicated with one of the second connecting port and the fourth connecting port, and the third connecting port is selectively communicated with the other one of the second connecting port and the fourth connecting port. The air suction end of the compressor is connected with the outlet end of the gas-liquid separator, the inlet end of the gas-liquid separator is connected with the first connecting port, the exhaust end of the compressor is connected with the third connecting port, the outdoor heat exchanger is connected with the second connecting port, and the indoor heat exchanger is connected with the fourth connecting port. The heating throttling device is arranged between the outdoor heat exchanger and the refrigerating throttling device and used for carrying out pressure reduction and throttling treatment on the refrigerant entering the outdoor heat exchanger (the throttling and pressure reduction effect is mainly achieved in the heating mode), and the refrigerating throttling device is arranged between the heating throttling device and the indoor heat exchanger and used for carrying out pressure reduction and throttling treatment on the refrigerant entering the indoor heat exchanger and outputting (the throttling and pressure reduction effect is mainly achieved in the refrigerating mode).

In the heating mode, the first connecting port is communicated with the fourth connecting port, the third connecting port is communicated with the second connecting port, and high-temperature gaseous refrigerant generated by the compressor sequentially flows through the indoor heat exchanger, the refrigerating throttling device, the heating throttling device, the outdoor heat exchanger and the gas-liquid separator to return into the compressor. In a refrigeration mode, the first connecting port is communicated with the third connecting port, the third connecting port is communicated with the fourth connecting port, and high-temperature gaseous refrigerant generated by the compressor is discharged through the exhaust end of the compressor and then sequentially returns to the compressor through the outdoor heat exchanger, the heating throttling device, the refrigeration throttling device, the indoor heat exchanger and the gas-liquid separator.

Generally, an outdoor unit of an air conditioning system is configured by a compressor, an outdoor heat exchanger, a heating throttle device, a gas-liquid separator, a four-way valve, and the like, and an indoor unit of the air conditioning system is configured by an indoor heat exchanger, a cooling throttle device, and the like. Generally, the outdoor unit is installed outdoors (naturally, not limited to outdoors), and the indoor unit is installed indoors (naturally, not limited to indoors).

This application is to the problem that the compressor easily inhales among the current air conditioning system and takes liquid to cause the liquid to hit, provides an outdoor unit at first. The outdoor unit provided by the present application will be described in detail below.

Referring to fig. 1 and 2, in an embodiment of the present invention, an outdoor unit 01 is provided, which includes a compressor 2, a gas-liquid separator 1, a four-way valve 3, an outdoor heat exchanger 4, a heating throttling device 5, a liquid storage tank 10, a liquid storage inlet valve 11, a liquid storage outlet valve, and a liquid storage throttling element. The compressor 2, the gas-liquid separator 1, the four-way valve 3, the outdoor heat exchanger 4, the heating throttling device 5 and the indoor unit 02 form a refrigerant circulation loop. The liquid storage tank 10 is provided with a liquid storage inlet a and a liquid storage outlet, the liquid storage inlet a is connected between the outdoor heat exchanger 4 and the heating throttling device 5 through a liquid storage inlet valve 11, and the liquid storage throttling element is connected with one end of the liquid storage outlet and one end of the liquid storage outlet valve. And in the heating mode, the other end of the liquid storage outlet valve is connected with the inlet end of the gas-liquid separator 1, and the liquid storage outlet and the gas-liquid separator 1 are communicated or cut off.

In the outdoor unit 01, in the heating mode, the outdoor heat exchanger 4 is conducted with the gas-liquid separator 1, the high-temperature gaseous refrigerant generated by the compressor 2 releases heat through the indoor unit 02, and then the refrigerant is changed into a liquid state or a gas-liquid mixed state, the liquid refrigerant evaporates and absorbs heat in the outdoor heat exchanger 4 of the outdoor unit 01, and then the liquid refrigerant is changed into the gaseous refrigerant, enters the gas-liquid separator 1, and then returns to the compressor 2, so that a refrigerant cycle is completed. When the refrigerant in the outdoor heat exchanger 4 is not completely evaporated, the refrigerant is in a gas-liquid mixed state, and the refrigerant in the gas-liquid mixed state enters the gas-liquid separator 1, so that the content of the liquid refrigerant stored in the gas-liquid separator 1 is increased.

In actual operation, in the heating mode, referring to fig. 3, the heating throttle device 5 is always in an open state. Referring to fig. 4 and 5, when the refrigerant in the outdoor heat exchanger 4 is not completely evaporated, the liquid storage inlet valve 11 and the liquid storage outlet valve are opened. The refrigerant entering the heating throttling device 5 is divided into two paths, one path enters the outdoor heat exchanger 4, is changed into a gaseous refrigerant by evaporation and heat absorption and enters the gas-liquid separator 1, and the other path enters the liquid storage tank 10 through the liquid storage inlet valve 11 and the liquid storage inlet a. A part of refrigerant is stored in the liquid storage tank 10, and a part of refrigerant enters the gas-liquid separator 1 after passing through a liquid storage outlet, a liquid storage outlet valve and a liquid storage throttling piece. Because part of the liquid refrigerant enters the liquid storage tank 10 and is stored, the content of the liquid refrigerant entering the outdoor heat exchanger 4 is reduced, and the liquid refrigerant in the outdoor heat exchanger 4 can be basically and completely evaporated into the gaseous refrigerant. Therefore, the content of the liquid refrigerant in the refrigerant entering the gas-liquid separator 1 is reduced, the liquid storage amount in the gas-liquid separator 1 is reduced, and the liquid impact problem caused by the liquid suction and carrying of the compressor 2 due to the overlarge liquid storage amount in the gas-liquid separator 1 is avoided.

Fig. 3 is a diagram illustrating an initial state of the air conditioning system in the heating mode. The heating initial state means that the air conditioning system just starts to enter a heating mode or the outdoor heat exchanger 4 is in a complete evaporation state.

It can be understood that, in the heating mode of the outdoor unit 01, when the refrigerant can be completely evaporated in the outdoor heat exchanger 4, the liquid storage inlet valve 11 and the liquid storage outlet valve are in a closed state. In addition, the liquid storage throttling element is used for carrying out pressure reduction treatment on the medium-pressure refrigerant discharged from the liquid storage tank 10, so that the refrigerant entering the gas-liquid separator 1 is the low-pressure refrigerant.

Wherein, the liquid storage throttling element can be a throttling orifice plate, a Venturi tube, a capillary tube and the like, and is not limited specifically.

In one embodiment, referring to FIG. 2, the reservoir outlet comprises a second reservoir outlet d, the reservoir throttle comprises a second reservoir throttle 16, and the reservoir outlet valve comprises a second reservoir outlet valve 17. The second liquid storage outlet d is located at the top of the liquid storage tank 10, the second liquid storage throttling piece 16 is connected with one ends of the second liquid storage outlet d and the second liquid storage outlet valve 17, and the other end of the second liquid storage outlet valve 17 is connected with the inlet end of the gas-liquid separator 1.

In this embodiment, referring to fig. 5, when the refrigerant in the outdoor heat exchanger 4 is not completely evaporated, the liquid storage inlet valve 11 and the second liquid storage outlet valve 17 are opened. The refrigerant flowing out through the heating throttling device 5 is divided into two paths, one path of the refrigerant enters the outdoor heat exchanger 4, is changed into a gaseous refrigerant through evaporation and heat absorption and enters the gas-liquid separator 1, the other path of the refrigerant enters the liquid storage tank 10 through the liquid storage inlet valve 11 and the liquid storage inlet a, the liquid refrigerant can be completely stored in the liquid storage tank 10, and the gaseous refrigerant directly enters the gas-liquid separator 1 through the second liquid storage outlet d and the second liquid storage outlet valve 17. So, greatly reduced the stock solution volume that gets into in the vapour and liquid separator 1, to avoiding arousing the liquid problem of hitting that the compressor 2 takes liquid to cause because of the stock solution volume is too big in the vapour and liquid separator 1 and have showing the effect.

In another embodiment, referring to fig. 1, the liquid storage outlet includes a first liquid storage outlet c, the liquid storage throttle includes a first liquid storage throttle 15, the liquid storage outlet includes a first liquid storage outlet valve 12, the first liquid storage outlet c is located at the bottom of the liquid storage tank 10, the first liquid storage throttle 15 is connected to the first liquid storage outlet c and one end of the first liquid storage outlet valve 12, and the other end of the first liquid storage outlet valve 12 is connected to a pipeline between the outdoor heat exchanger 4 and the four-way valve 3.

In this embodiment, referring to fig. 4, when the refrigerant in the outdoor heat exchanger 4 is incompletely evaporated, the liquid storage inlet valve 11 and the first liquid storage outlet valve 12 are opened. The refrigerant entering the outdoor unit 01 is divided into two paths, one path enters the outdoor heat exchanger 4, is changed into a gaseous refrigerant by evaporation and heat absorption and enters the gas-liquid separator 1, the other path enters the liquid storage tank 10 through the liquid storage inlet valve 11 and the liquid storage inlet a, a part of the refrigerant is stored in the liquid storage tank 10 along with the continuous entering of the refrigerant, and a part of the refrigerant enters the gas-liquid separator 1 through the first liquid storage outlet c and the first liquid storage outlet valve 12 and then enters the four-way valve 3. So for reduce the refrigerant content that gets into in vapour and liquid separator 1, and then avoided the stock solution volume in enterprise separator 1, and then avoided because of the too big liquid impact problem that arouses compressor 2 and take liquid to cause of stock solution volume in vapour and liquid separator 1.

Understandably, in the process of storing the refrigerant in the liquid storage tank 10, since the liquid refrigerant at the top of the liquid storage tank 10, which is located at the second liquid storage outlet d, is basically and completely stored in the liquid storage tank 10, the liquid refrigerant at the bottom of the liquid storage tank 10, which is located at the first liquid storage outlet c, flows back to the gas-liquid separator 1 through the first liquid storage outlet c, and the external refrigerant discharged from the second liquid storage outlet d is utilized to be more favorable for the storage of the liquid refrigerant in the liquid storage tank 10 than the external refrigerant discharged from the first liquid storage outlet c.

In some embodiments, referring to fig. 2, the reservoir outlet comprises both said first reservoir outlet c and said second reservoir outlet d, and the reservoir outlet valve comprises both said first reservoir outlet valve 12 and said second reservoir outlet valve 17. In the heating mode, when the refrigerant in the outdoor heat exchanger 4 is not completely evaporated, the liquid refrigerant in the liquid storage tank 10 can be stored by opening the first liquid storage outlet valve 12 and/or the second liquid storage outlet valve 17 to reduce the amount of the liquid refrigerant stored in the gas-liquid separator 1.

In some embodiments, referring to fig. 1 and 2, the outdoor unit 01 further includes a pressurization valve 14, the liquid storage tank 10 further has a pressurization port b, the pressurization port b is located at the top of the liquid storage tank 10, and the pressurization valve 14 is connected to the pressurization port b and the discharge end of the compressor 2.

In the multi-split air conditioning system, due to the unfixed matching of the outdoor unit 01 and the indoor unit 02 and the influence of engineering installation factors, the requirements of refrigerants participating in the circulation of the air conditioning system are inconsistent. In the present embodiment, in the heating mode, when the amount of refrigerant participating in heating of the air conditioning system is insufficient, the refrigerant stored in the liquid storage tank 10 is discharged into the refrigerant circulation circuit for use by the air conditioning system.

Specifically, referring to fig. 6, the reservoir inlet valve 11 is closed and the first reservoir outlet valve 12 and pressurizing valve 14 are opened. At this time, all the refrigerant entering the outdoor unit 01 enters the outdoor heat exchanger 4, passes through the four-way valve 3, and then enters the gas-liquid separator 1. Meanwhile, the liquid storage tank 10 is communicated with the exhaust end of the compressor 2 through the pressure valve 14, part of high-temperature and high-pressure refrigerant discharged by the compressor 2 enters the liquid storage tank 10 through the pressure valve 14, when the high-temperature and high-pressure refrigerant enters the liquid storage tank 10, low-temperature liquid refrigerant stored in the liquid storage tank 10 is heated and evaporated, and liquid discharge pressure is supplemented to enable the refrigerant in the liquid storage tank 10 to flow out through the first liquid storage outlet c and then enter the gas-liquid separator 1 through the first liquid storage outlet valve 12, so that the air suction amount of the air suction end of the compressor 2 is increased, the refrigerant content participating in circulation of an air conditioning system is increased, and the heating effect of the air conditioning system is improved.

In the heating mode, after the pressurization valve 14 is opened, the first liquid storage outlet valve 12 is opened, and the second liquid storage outlet valve 17 is also opened at the same time, so that the gaseous refrigerant in the liquid storage tank 10 can be discharged to the gas-liquid separator 1 through the second liquid storage outlet d.

In some embodiments, referring to fig. 1, the outdoor unit 01 further includes a liquid discharge valve 13, one end of the liquid discharge valve 13 is connected to a side of the heating throttle device 5 facing away from the outdoor heat exchanger 4, and the other end of the liquid discharge valve 13 is connected to a pipeline between the first liquid storage outlet c and the first liquid storage outlet 12.

When the air conditioning system is in a refrigeration mode, the outdoor heat exchanger 4 is not communicated with the gas-liquid separator 1, the gas-liquid separator 1 is communicated with the indoor unit 02, a high-temperature and high-pressure refrigerant generated by the compressor 2 passes through the heat radiator of the outdoor heat exchanger 4, then becomes a liquid state or a gas-liquid mixed state, evaporates and absorbs heat in the indoor heat exchanger 9 of the indoor unit 02, turns into a gas state refrigerant, then enters the gas-liquid separator 1, and then returns to the compressor 2, so that a refrigerant cycle is completed. Generally, the refrigerant content required by the air conditioning system in the cooling mode is lower than the refrigerant content required by the air conditioning system in the heating mode. Therefore, it is necessary to reduce the amount of refrigerant involved in cooling.

In this embodiment, in actual operation, when the air conditioning system enters the cooling mode, the reservoir inlet valve 11 and the drain valve 13 are opened, and the heating throttle device 5, the pressurizing valve 14, and the reservoir outlet valve (including the first reservoir outlet valve 12 and the second reservoir outlet valve 17, both of which are closed), are closed, see fig. 7. At this time, the high-temperature and high-pressure refrigerant discharged by the compressor 2 sequentially passes through the outdoor heat exchanger 4, the liquid storage inlet valve 11, the liquid storage tank 10 and the liquid discharge valve 13 and then enters the indoor unit 02, then enters the gas-liquid separator 1 from the indoor unit 02, and finally returns to the compressor 2. When the refrigerant enters the liquid storage tank 10, part of liquid refrigerant is stored in the liquid storage tank 10, so that the refrigerant quantity flowing through the indoor heat exchanger 9 is reduced, the refrigerant content participating in the refrigeration of the air conditioning system is reduced, the liquid refrigerant entering the gas-liquid separator 1 and causing the liquid storage quantity in the gas-liquid separator 1 due to incomplete evaporation of excessive refrigerant in the indoor heat exchanger 9 is avoided, and the probability of liquid impact caused by liquid absorption of the compressor 2 is reduced.

In the cooling mode, when the amount of refrigerant circulating in the air conditioning system is insufficient, a certain amount of refrigerant is discharged from the liquid storage tank 10 to circulate in the air conditioning system, so as to improve the cooling effect.

Specifically, referring to fig. 8, the reservoir inlet valve 11 and the reservoir outlet valve (including the first reservoir outlet valve 12 and the second reservoir outlet valve 17) are closed, and the heating throttle device 5, the drain valve 13 and the pressurizing valve 14 are opened. At this time, the pressurizing valve 14 communicates the pressurizing port b with the compressor 2. The refrigerant flowing out of the outdoor heat exchanger 4 enters the indoor unit 02 through the heating throttling device 5, and the refrigerant stored in the liquid storage tank 10 is discharged from the liquid storage tank 10 under the action of the high-temperature and high-pressure refrigerant discharged from the compressor 2, passes through the liquid discharge valve 13, and then joins the refrigerant flowing out of the heating throttling device 5 to flow into the indoor unit 02. Therefore, the content of refrigerant participating in refrigeration in the indoor unit 02 is increased, and the refrigeration effect is improved.

In some embodiments, referring to fig. 1 and 2, the outdoor unit 01 further includes a supercooling heat exchanger 7 and a cooling throttling element 6, the supercooling heat exchanger 7 includes a first flow passage and a second flow passage which are independent of each other, one end of the first flow passage is used for connecting the indoor unit 02 and particularly connecting one end of the cooling throttling element 8 of the indoor unit 02, which is away from the indoor heat exchanger 9, the other end of the first flow passage is connected in parallel with the cooling throttling element 6 to the heating throttling device 5, the drain valve 13 is located between the heating throttling device 5 and the parallel connection of the first flow passage and the cooling throttling element 6, one end of the second flow passage is connected to one end of the cooling throttling element 6, which is away from the heating throttling device 5, and the other end of the second flow passage is connected to the inlet end of the gas-liquid separator 1. In actual operation, a part of liquid refrigerant generated by the outdoor heat exchanger 4 is introduced into the cold throttling element 6 through the supercooling heat exchanger 7 and the cold throttling element 6 and then enters the second flow channel, the other part of liquid refrigerant enters the first flow channel and then enters the indoor unit 02, the refrigerant entering the cold throttling element 6 is throttled and depressurized by the cold throttling element 6 and then subcools the refrigerant in the first flow channel in the second flow channel, and the supercooling method is favorable for improving the supercooling amount of the whole air conditioning system.

In the heating mode, the outdoor heat exchanger 4 has two operating states, i.e., a complete evaporation state and an incomplete evaporation state. In the evaporation complete state, the refrigerant in the outdoor heat exchanger 4 is completely evaporated, otherwise, the refrigerant is not completely evaporated. The air conditioning system needs to judge whether the refrigerant in the outdoor heat exchanger 4 is completely evaporated, and controls the liquid storage tank 10 to store liquid according to the result so as to adjust the liquid storage amount in the liquid-gas separator 1.

In some embodiments, referring to fig. 9, the outdoor unit 01 further includes a first temperature sensor 19 and a first pressure sensor 20, the first temperature sensor 19 is disposed at one end of the outdoor heat exchanger 4 near the four-way valve 3, and the first pressure sensor 20 is disposed at a suction end of the compressor 2.

The first temperature sensor 19 is configured to detect a temperature of a refrigerant outflow side of the outdoor heat exchanger 4 in the heating mode, and the first pressure sensor 20 is configured to detect a temperature of a suction side of the compressor 2.

In the present embodiment, the air conditioning system determines the operating state of the outdoor heat exchanger 4 by determining the magnitude relationship between the saturation temperature value corresponding to the detection value of the first temperature sensor 19 and the detection value of the first pressure sensor 20. When the detection value of the first temperature sensor 19 is greater than the saturation temperature value corresponding to the detection value of the first pressure sensor 20, the air conditioning system determines that the outdoor heat exchanger 4 is in a complete evaporation state, and at this time, the liquid storage tank 10 does not need to be controlled to store liquid, that is, the states of closing both the liquid storage inlet valve 11 and the liquid storage outlet valve are kept. On the contrary, when the detection value of the first temperature sensor 19 is less than or equal to the saturation temperature value corresponding to the detection value of the first pressure sensor 20, the air conditioning system determines that the outdoor heat exchanger 4 is in an incomplete evaporation state, and at this time, the liquid storage tank 10 needs to be controlled to store liquid, and the liquid storage inlet valve 11 and the liquid storage outlet valve are both controlled to be opened.

In other embodiments, referring to fig. 9, the outdoor unit 01 further includes a second temperature sensor 21 and a third temperature sensor 22, the second temperature sensor 21 is disposed at the outlet end of the gas-liquid separator 1, and the third temperature sensor 22 is disposed at the inlet end of the gas-liquid separator 1.

Wherein the second temperature sensor 21 is used for detecting the temperature at the outlet end of the gas-liquid separator 1, and the third temperature sensor 22 is used for detecting the temperature at the inlet end of the gas-liquid separator 1.

In the present embodiment, the air conditioning system determines the operating state of the outdoor heat exchanger 4 by the detection value of the second temperature sensor 21 and the detection value of the third temperature sensor 22. When the difference value between the detection value of the second temperature sensor 21 and the detection value of the third temperature sensor 22 is greater than the first threshold value, the air conditioning system judges that the outdoor heat exchanger 4 is in a complete evaporation state, and at the moment, the liquid storage tank 10 does not need to be controlled to store liquid, namely, the states that the liquid storage inlet valve 11 and the liquid storage outlet valve are both closed are maintained. When the difference value between the detection value of the second temperature sensor 21 and the detection value of the third temperature sensor 22 is smaller than or equal to the first threshold value, the air conditioning system judges that the outdoor heat exchanger 4 is in an incomplete evaporation state, and at the moment, the liquid storage tank 10 needs to be controlled to store liquid, and the liquid storage inlet valve 11 and the liquid storage outlet valve are controlled to be opened.

In some embodiments, referring to fig. 9, the outdoor unit 01 further includes a second pressure sensor 23 and a fourth temperature sensor 24, and includes a liquid level sensor 25 or a fifth temperature sensor 26. The second pressure sensor 23 is disposed at the exhaust end of the compressor 2, the fourth temperature sensor 24 is used for detecting the outdoor ambient temperature, the liquid level sensor 25 is disposed in the liquid storage tank 10, and the fifth temperature sensor 26 is disposed at the bottom of the liquid storage tank 10. Here, the outdoor environment refers to an environment in which the outdoor unit 01 is located. The specific installation manner of the fourth temperature sensor 2 is not limited as long as it can detect the external environment temperature of the outdoor unit 01, and for example, the fourth temperature sensor 24 is installed outside the outdoor unit 01.

The liquid level sensor 25 is used for detecting the liquid level in the liquid storage tank 10, the second pressure sensor 23 is used for detecting the pressure at the exhaust side of the compressor 2, and the fifth temperature sensor 26 is used for detecting the temperature at the bottom of the liquid storage tank 10.

In the heating mode, when the outdoor evaporator 4 is in the evaporation complete state, both the liquid storage inlet valve 11 and the liquid storage outlet valve are closed. The air conditioning system also needs to judge whether the amount of the self-circulation refrigerant is enough according to the working condition so as to determine whether the self-circulation refrigerant meets the heating and liquid drainage condition. When the condition that the refrigerant self meets the heating and liquid discharging condition is judged, the insufficient amount of the circulating refrigerant of the air conditioning system is indicated, the pressure valve 14 and the first liquid storage outlet valve 12 are opened, the refrigerant in the liquid storage tank 10 is evaporated by the high-temperature and high-pressure refrigerant generated by the compressor 2 and is pushed out to the gas-liquid separator 1 through the first liquid storage outlet c, and the content of the circulating refrigerant is further increased. When the air conditioner does not meet the heating and liquid discharging conditions, the air conditioner system is indicated to be sufficient in circulating refrigerant consumption, and the liquid storage inlet valve 11 and the liquid storage outlet valve are kept closed.

In the heating mode, after the pressurization valve 14 is opened, the second reservoir outlet valve 17 may be opened in addition to the first reservoir outlet valve 12, so that the gas refrigerant in the reservoir tank 10 may be discharged to the gas-liquid separator 1 through the second reservoir outlet d.

In the present embodiment, the air conditioning system determines whether it satisfies the heating and liquid discharging condition according to the saturation temperature value corresponding to the detection of the second pressure sensor 23, the detection value of the fourth temperature sensor 24, and the detection value of the liquid level sensor 25 or the detection value of the fifth temperature sensor 26. Specifically, when the difference between the saturation temperature value corresponding to the detection value of the second pressure sensor 23 and the detection value of the fourth temperature sensor 24 is smaller than the third threshold, and the detection value of the liquid level sensor 25 is larger than the second threshold, or the difference between the detection value of the fifth temperature sensor 26 and the detection value of the fourth temperature sensor 24 is smaller than the fourth threshold, the air conditioning system determines that the heating and liquid draining condition is satisfied, otherwise, the air conditioning system does not satisfy the heating and liquid draining condition.

In the cooling mode, the air conditioning system may determine whether or not it satisfies the cooling and liquid draining conditions based on the opening degree values of the liquid level sensor 25, the fifth temperature sensor 26, the fourth temperature sensor 24, the heating and air-conditioning throttling device 5, the temperature difference value of the inlet and outlet pipes of the indoor heat exchanger 9, and the opening degree value of the cooling and air-conditioning device 8. Specifically, when the opening value of the heating throttling device 5 is greater than a fifth threshold, the temperature difference value of the inlet and outlet pipes of the indoor heat exchanger 9 is greater than a sixth threshold, and the opening value of the cooling throttling device 8 is greater than a seventh threshold, and the detection value of the liquid level sensor 25 is greater than a second threshold or the difference value between the detection value of the fifth temperature sensor 26 and the detection value of the fourth temperature sensor 24 is less than a fourth threshold, the air conditioning system determines that the air conditioning system satisfies the cooling liquid drainage condition, otherwise, the air conditioning system does not satisfy the cooling liquid drainage condition.

In an embodiment, the outdoor unit 01 further includes the compressor 2, the gas-liquid separator 1, the four-way valve 3, the outdoor heat exchanger 4, the heating throttling device 5, the liquid storage tank 10, the liquid storage inlet valve 11, the first liquid storage outlet valve 12, the pressurization valve 14, the liquid discharge valve 13, and the first liquid storage throttling element 15, and the liquid storage tank 10 includes a liquid storage inlet a, a first liquid storage outlet c, and a pressurization port b.

In the present embodiment, when the air conditioning system is in the heating mode, the heating throttle device 5 is turned on, and the reservoir inlet valve 11, the first reservoir outlet valve 12, the pressurizing valve 14, and the drain valve 13 are closed. And judging the working state of the outdoor heat exchanger 4, and keeping the states of all the valves unchanged when the outdoor heat exchanger 4 is in a complete evaporation state. When the outdoor heat exchanger 4 is in the complete evaporation state, the liquid storage inlet valve 11 and the first liquid storage outlet valve 12 are opened until the outdoor heat exchanger 4 returns to the complete evaporation state, and the liquid storage inlet valve and the first liquid storage outlet valve are closed, so that the liquid storage tank 10 stores liquid. And judging whether the air conditioning system meets heating liquid drainage conditions or not when the outdoor heat exchanger 4 is in a complete evaporation state, and if so, opening the first liquid storage outlet valve 12 and the pressurizing valve 14 to discharge the refrigerant in the liquid storage tank 10 into a refrigerant circulation loop. When the air conditioning system is in a cooling mode, the heating throttling device 5 is closed, the liquid storage inlet valve 11 and the liquid discharge valve 13 are opened, and the first liquid storage outlet valve 12 and the pressurizing valve 4 are closed, so that the liquid storage tank 10 stores liquid. And judging that the air conditioning system can meet the refrigeration liquid drainage condition, if so, keeping the liquid drainage valve 13 open, opening the heating throttling device 5 and the pressurizing valve 14, and closing the liquid storage inlet valve 11 and the first liquid storage outlet valve 12 to discharge the refrigerant in the liquid storage tank 10 into the refrigerant circulation loop.

Referring to fig. 10, a control logic diagram of the air conditioning system is shown, and details are not repeated herein. In the initial flow path control in the heating mode, the heating throttle device 5 is opened, and the liquid storage inlet valve 11, the liquid storage outlet valve, the pressurizing valve 14, and the liquid discharge valve 13 are all closed. When the heating mode liquid storage pipe stores the control flow path, the heating throttling device 5, the liquid storage inlet valve 11 and the liquid storage outlet valve are opened, and the pressurizing valve 14 and the liquid discharge valve 13 are closed. When the heating mode liquid storage tank liquid drainage control flow path is heated, the heating throttling device 5, the pressurizing valve 14 and the liquid storage outlet valve are opened, and the liquid storage inlet valve 11 is closed. When the refrigerating mode liquid storage tank stores the control flow path, the heating throttling device 5, the liquid storage outlet valve and the pressurizing valve 14 are closed, and the liquid storage inlet valve 11 and the liquid discharge valve 13 are opened. When the liquid storage tank liquid drainage control flow path is in the refrigeration mode, the heating throttling device 5, the liquid drainage valve 13 and the pressurization valve 14 are opened, and the liquid storage inlet valve 11 and the liquid storage outlet valve are closed.

The outdoor unit 01 provided in the embodiment of the application can reduce the liquid storage amount in the gas-liquid separator 1 in the heating mode, and avoids the liquid impact problem caused by the liquid suction of the compressor 2 due to the overlarge liquid storage amount in the gas-liquid separator 1. Meanwhile, through the liquid discharge control of the liquid storage tank 10, the circulating refrigerant quantity of the system during heating is increased, and the problem of poor heating capacity caused by insufficient refrigerant circulation is solved. In addition, when the refrigeration operation, utilize the liquid storage pot 10 to deposit liquid, the refrigerant demand under the different operating modes of effect adjustment, solve on the one hand and heat the unmatched problem of refrigeration refrigerant, on the other hand adjusts refrigerant demand under the different operating modes, improves refrigeration effect.

In addition, the embodiment of the present application further provides an air conditioning system, which includes a compressor 2, a gas-liquid separator 1, a four-way valve 3, an outdoor heat exchanger 4, a heating throttling device 5, a refrigerating throttling device 8, an indoor heat exchanger 9, a liquid storage tank 10, a liquid storage inlet valve 11, a liquid storage outlet valve, and a liquid storage throttling element, which form a refrigerant circulation loop. The liquid storage tank 10 is provided with a liquid storage inlet a and a liquid storage outlet, the liquid storage inlet a is connected between the outdoor heat exchanger 4 and the heating throttling device 5 through a liquid storage inlet valve 11, and the liquid storage throttling element is connected with one end of the liquid storage outlet and one end of the liquid storage outlet valve. In the heating mode, the other end of the liquid storage outlet valve is connected with the inlet end of the gas-liquid separator 1, and the liquid storage outlet and the gas-liquid separator 1 are switched on or off.

In the air conditioning system, in the actual operation, the heating throttle device 5 is always in the open state in the heating mode. When the refrigerant in the outdoor heat exchanger 4 is not completely evaporated, the liquid storage inlet valve 11 and the liquid storage outlet valve are opened. The refrigerant entering the heating throttling device 5 is divided into two paths, one path enters the outdoor heat exchanger 4, is changed into a gaseous refrigerant by evaporation and heat absorption and enters the gas-liquid separator 1, and the other path enters the liquid storage tank 10 through the liquid storage inlet valve 11 and the liquid storage inlet a. A part of refrigerant is stored in the liquid storage tank 10, and a part of refrigerant enters the gas-liquid separator 1 after passing through a liquid storage outlet, a liquid storage outlet valve and a liquid storage throttling piece. Because part of the liquid refrigerant enters the liquid storage tank 10 and is stored, the content of the liquid refrigerant entering the outdoor heat exchanger 4 is reduced, and the liquid refrigerant in the outdoor heat exchanger 4 can be basically and completely evaporated into the gaseous refrigerant. Therefore, the content of the liquid refrigerant in the refrigerant entering the gas-liquid separator 1 is reduced, the liquid storage amount in the gas-liquid separator 1 is reduced, and the problem of liquid impact caused by air suction and liquid carrying of the compressor 2 due to the fact that the liquid storage amount in the gas-liquid separator 1 is too large is avoided.

In addition, the air conditioning system further includes the structure and structure of the outdoor unit 01 provided in any of the embodiments, which are described in the above embodiments and not described herein again.

Preferably, the air conditioning system comprises a split indoor unit 02 and an outdoor unit 01, the indoor unit 02 comprises the compressor 2, the gas-liquid separator 1, the four-way valve 3, the outdoor heat exchanger 4 and the heating throttling device 5, and the indoor unit 02 comprises the cooling throttling device 8 and the indoor heat exchanger 9. Of course, the indoor unit 02 may be the indoor unit 02 in any embodiment of the indoor unit 02 provided in the present application.

In addition, referring to fig. 11, an embodiment of the present application further provides a control method of an air conditioning system, including:

s1, under the heating mode, starting the heating throttling device 5, and detecting the working state of the outdoor heat exchanger 4, wherein the working state of the outdoor heat exchanger 4 comprises an evaporation complete state and an evaporation incomplete state;

s2, when the outdoor heat exchanger 4 is in an incomplete evaporation state, opening the liquid storage inlet valve 11 and the liquid storage outlet valve;

and S3, when the outdoor heat exchanger 4 is in the evaporation complete state, closing the liquid storage inlet valve 11 and the liquid storage outlet valve.

In this embodiment, the air conditioning system includes a compressor 2, a gas-liquid separator 1, a four-way valve 3, an outdoor heat exchanger 4, a heating throttle device 5, a cooling throttle device 8, an indoor heat exchanger 9, a liquid storage tank 10, a liquid storage inlet valve 11, a liquid storage outlet valve, and a liquid storage throttle. The compressor 2, the gas-liquid separator 1, the four-way valve 3, the outdoor heat exchanger 4, the heating throttling device 5, the refrigerating throttling device 8 and the indoor heat exchanger 9 form a refrigerant circulation loop. Liquid storage pot 10 has stock solution import an and stock solution export, and stock solution import a passes through stock solution import valve 11 to be connected in outdoor heat exchanger 4 and heat between the throttling arrangement 5, and stock solution throttling element connects the one end of stock solution export and stock solution outlet valve. In the heating mode, the other end of the liquid storage outlet valve is connected with the inlet end of the gas-liquid separator 1, and the liquid storage outlet and the gas-liquid separator 1 are switched on or off.

When the air conditioning system is in the heating mode, the heating throttling device 5 is firstly started, all the valve pieces are closed, and the refrigerant circulation loop is conducted, so that the air conditioning system is in the heating initial state. Then, the operating state of the outdoor heat exchanger 4 is detected. The outdoor heat exchanger 4 has two operating states, i.e., a complete evaporation state and an incomplete evaporation state. In the evaporation complete state, the refrigerant in the outdoor heat exchanger 4 is completely evaporated, otherwise, the refrigerant is not completely evaporated. The air conditioning system needs to judge whether the refrigerant in the outdoor heat exchanger 4 is completely evaporated, and controls the liquid storage tank 10 to store liquid according to the result so as to adjust the amount of the liquid stored in the gas-liquid separator 1.

When the outdoor heat exchanger 4 is in the evaporation complete state, the heating throttling device 5 is kept open, and the valves are kept closed. When the outdoor heat exchanger 4 is in an incomplete evaporation state, the liquid storage inlet valve 11 and the liquid storage outlet valve are opened, so that the refrigerant entering the heating throttling device 5 is divided into two paths, one path enters the outdoor heat exchanger 4, is changed into a gaseous refrigerant through evaporation and heat absorption, enters the gas-liquid separator 1, and the other path enters the liquid storage tank 10 through the liquid storage inlet valve 11 and the liquid storage inlet a. A part of refrigerant is stored in the liquid storage tank 10, and a part of refrigerant enters the gas-liquid separator 1 after passing through a liquid storage outlet, a liquid storage outlet valve and a liquid storage throttling piece. Because part of the liquid refrigerant enters the liquid storage tank 10 and is stored, the content of the liquid refrigerant entering the outdoor heat exchanger 4 is reduced, and the liquid refrigerant in the outdoor heat exchanger 4 can be basically and completely evaporated into the gaseous refrigerant. Therefore, the content of the liquid refrigerant in the refrigerant entering the gas-liquid separator 1 is reduced, the liquid storage amount in the gas-liquid separator 1 is reduced, and the liquid impact problem caused by the liquid suction and carrying of the compressor 2 due to the overlarge liquid storage amount in the gas-liquid separator 1 is avoided.

In specific embodiments, the reservoir outlet comprises a second reservoir outlet d, the reservoir throttle comprises a second reservoir throttle 16, and the reservoir outlet valve comprises a second reservoir outlet valve 17. The second liquid storage outlet d is positioned at the top of the liquid storage tank 10, the second liquid storage throttling element 16 is connected with the second liquid storage outlet d and one end of a second liquid storage outlet valve 17, and the other end of the second liquid storage outlet valve 17 is connected with the inlet end of the gas-liquid separator 1;

and/or, the stock solution export includes first stock solution export c, and the stock solution throttling element includes first stock solution throttling element 15, and the stock solution outlet valve includes first stock solution outlet valve 12, and first stock solution export c is located the bottom of liquid storage pot 10, and first stock solution throttling element 15 connects the one end of first stock solution export c and first stock solution outlet valve 12, and the other end of first stock solution outlet valve 12 is connected to the pipeline between outdoor heat exchanger 4 and the cross valve 3.

In this case, step S2 specifically includes:

and S21, when the outdoor heat exchanger 4 is in an incomplete evaporation state, opening the liquid storage inlet valve 11, and opening the first liquid storage outlet c and/or the second liquid storage outlet d.

Step S3 specifically includes:

and S31, when the outdoor heat exchanger 4 is in the evaporation complete state, closing the liquid storage inlet valve 11, the first liquid storage outlet c and/or the second liquid storage outlet d.

In the present embodiment, when the outdoor heat exchanger 4 is in the evaporation complete state, each valve element is closed. When the outdoor heat exchanger 4 is in an incomplete evaporation state, after the liquid storage inlet valve 11 is opened, the first liquid storage outlet valve 12 is opened, so that the refrigerant enters the liquid storage tank 10 through the liquid storage inlet valve 11 to be stored in the liquid refrigerant, and the gaseous refrigerant or a part of the liquid refrigerant returns to the gas-liquid separator 1 through the first liquid storage outlet c and the four-way valve 3. Or the second liquid storage outlet valve 17 may be opened to allow the refrigerant to enter the liquid storage tank 10 through the liquid storage inlet valve 11 to store the liquid refrigerant, and then the gaseous refrigerant directly enters the gas-liquid separator 1 through the second liquid storage outlet d. It is also possible that both the first reservoir outlet valve 12 and the second reservoir outlet valve 17 are open. It is understood that when the outdoor heat exchanger 4 is in the evaporation complete state, only one of the liquid storage outlet valves needs to be closed when the outdoor unit 01 includes only the first liquid storage outlet valve 12 or the second liquid storage outlet valve 17, and both of the liquid storage outlet valves need to be closed when the outdoor unit 01 includes the first liquid storage outlet valve 12 and the second liquid storage outlet valve 17.

In the specific embodiment, the air conditioning system further includes a first temperature sensor 19 and a first pressure sensor 20, the first temperature sensor 19 is disposed at one end of the outdoor heat exchanger 4 close to the four-way valve 3, and the first pressure sensor 20 is disposed at a suction end of the compressor 2. The first temperature sensor 19 is configured to detect a temperature of a refrigerant outflow side of the outdoor heat exchanger 4 in the heating mode, and the first pressure sensor 20 is configured to detect a temperature of a suction side of the compressor 2.

In this case, step S1 specifically includes:

s11, obtaining detection values of the first temperature sensor 19 and the first pressure sensor 20, and determining whether the detection value of the first temperature sensor 19 is greater than a saturation temperature value corresponding to the detection value of the first pressure sensor 20;

s12, if yes, judging that the outdoor heat exchanger 4 is in a complete evaporation state;

and S13, if not, judging that the outdoor heat exchanger 4 is in an incomplete evaporation state.

In the present embodiment, the operating state of the outdoor heat exchanger 4 is determined by determining the magnitude relationship between the saturation temperature values corresponding to the detection values of the first temperature sensor 19 and the first pressure sensor 20. When the detection value of the first temperature sensor 19 is greater than the saturation temperature value corresponding to the detection value of the first pressure sensor 20, it is determined that the outdoor heat exchanger 4 is in a complete evaporation state, and at this time, the liquid storage tank 10 does not need to be controlled to store liquid, that is, the states of closing both the liquid storage inlet valve 11 and the liquid storage outlet valve are maintained. On the contrary, when the detection value of the first temperature sensor 19 is less than or equal to the saturation temperature value corresponding to the detection value of the first pressure sensor 20, the air conditioning system determines that the outdoor heat exchanger 4 is in an incomplete evaporation state, and at this time, the liquid storage tank 10 needs to be controlled to store liquid, and the liquid storage inlet valve 11 and the liquid storage outlet valve are both controlled to be opened.

In another embodiment, the air conditioning system further includes a second temperature sensor 21 and a third temperature sensor 22, the second temperature sensor 21 is disposed at the outlet end of the gas-liquid separator 1, and the third temperature sensor 22 is disposed at the inlet end of the gas-liquid separator 1. Wherein the second temperature sensor 21 is used for detecting the temperature at the outlet end of the gas-liquid separator 1, and the third temperature sensor 22 is used for detecting the temperature at the inlet end of the gas-liquid separator 1.

In this case, step S1 specifically includes:

s11', obtaining the detection values of the second temperature sensor 21 and the third temperature sensor 22, and determining whether the difference between the detection value of the second temperature sensor 21 and the detection value of the third temperature sensor 22 is greater than a first threshold;

s12', if yes, judging that the outdoor heat exchanger 4 is in a complete evaporation state;

s13', if not, it is determined that the outdoor heat exchanger 4 is in an incomplete evaporation state.

In the present embodiment, the operating state of the outdoor heat exchanger 4 is determined by the detection value of the second temperature sensor 21 and the detection value of the third temperature sensor 22. When the difference value between the detection value of the second temperature sensor 21 and the detection value of the third temperature sensor 22 is greater than the first threshold value, it is determined that the outdoor heat exchanger 4 is in a complete evaporation state, and it is not necessary to control the liquid storage tank 10 to store liquid at this time, that is, the states of closing both the liquid storage inlet valve 11 and the liquid storage outlet valve are maintained. When the difference value between the detection value of the second temperature sensor 21 and the detection value of the third temperature sensor 22 is smaller than or equal to the first threshold value, the air conditioning system judges that the outdoor heat exchanger 4 is in an incomplete evaporation state, and at the moment, the liquid storage tank 10 needs to be controlled to store liquid, and the liquid storage inlet valve 11 and the liquid storage outlet valve are controlled to be opened.

In some embodiments, after step S3, the method further includes:

s4, judging whether the air conditioning system meets a heating liquid drainage condition in the heating mode, wherein the heating liquid drainage condition is used for indicating that the air conditioning system is insufficient in refrigerant participating in heating;

s5, if yes, opening the pressurizing valve 14 and the first liquid storage outlet valve 12;

s6, if not, closing the pressurizing valve 14 and the first reservoir outlet valve 12.

In this embodiment, the air conditioning system further includes a pressure valve 14, the liquid storage tank 10 further has a pressure port b located at the top of the liquid storage tank 10, and the pressure valve 14 connects the pressure port b and the exhaust end of the compressor 2.

After the outdoor heat exchanger 4 is in a complete evaporation state, whether the amount of the circulating refrigerant of the air conditioning system is enough or not needs to be judged according to the working condition so as to determine whether the air conditioning system meets the heating and liquid drainage condition or not. When the air conditioning system is judged to meet the heating and liquid drainage conditions, and the using amount of the circulating refrigerant of the air conditioning system is insufficient, the pressure valve 14 and the first liquid storage outlet valve 12 are opened, the refrigerant in the liquid storage tank 10 is evaporated and pushed out to the gas-liquid separator 1 by using the high-temperature and high-pressure refrigerant generated by the compressor 2, and the content of the circulating refrigerant is further increased. When the air-conditioning system is judged not to meet the heating and liquid discharging conditions, the air-conditioning system is indicated to have enough circulating refrigerant consumption, and the liquid storage inlet valve 11 and the liquid storage outlet valve are kept closed. Therefore, the content of the circulating refrigerant can be adjusted in time, and the heating effect is ensured.

In an embodiment, step S4 specifically includes:

s41, acquiring the detection value of the second pressure sensor 23 and the detection value of the fourth temperature sensor 24, and acquiring the detection value of the liquid level sensor 25 or the fifth temperature sensor 26;

s42, determining whether a difference between a saturation temperature value corresponding to the detection value of the second pressure sensor 23 and the detection value of the fourth temperature sensor 24 is smaller than a third threshold, and whether the detection value of the liquid level sensor 25 is larger than the second threshold or the difference between the detection value of the fifth temperature sensor 26 and the detection value of the fourth temperature sensor 24 is smaller than a fourth threshold;

s43, if yes, judging that the air conditioning system meets the heating liquid discharge condition;

and S44, if not, judging that the air conditioning system does not meet the heating liquid discharge condition.

In the present embodiment, the air conditioning system further includes a second pressure sensor 23 and a fourth temperature sensor 24, and includes a liquid level sensor 25 or a fifth temperature sensor 26. The second pressure sensor 23 is disposed at the discharge end of the compressor 2, the fourth temperature sensor 24 is used for detecting the outdoor temperature environment, the liquid level sensor 25 is disposed in the liquid storage tank 10, and the fifth temperature sensor 26 is disposed at the bottom of the liquid storage tank 10.

In the present embodiment, whether or not the liquid heater and the liquid discharge condition are satisfied is determined based on the saturation temperature value corresponding to the detection of the second pressure sensor 23, the detection value of the fourth temperature sensor 24, and the detection value of the liquid level sensor 25 or the detection value of the fifth temperature sensor 26. Specifically, when the difference between the saturation temperature value corresponding to the detection value of the second pressure sensor 23 and the detection value of the fourth temperature sensor 24 is smaller than the third threshold, and the detection value of the liquid level sensor 25 is larger than the second threshold, or the difference between the detection value of the fifth temperature sensor 26 and the detection value of the fourth temperature sensor 24 is smaller than the fourth threshold, the air conditioning system determines that the heating and liquid draining condition is satisfied, otherwise, the air conditioning system does not satisfy the heating and liquid draining condition.

In some embodiments, the control method of the air conditioning system further includes:

p1, in cooling mode, opening the liquid storage inlet valve 11 and the liquid discharge valve 13, and closing the heating throttling device 5 and the liquid

storage outlet valves

12 and 17.

In this embodiment, the air conditioning system further includes a liquid discharge valve 13, one end of the liquid discharge valve 13 is connected to a side of the heating and throttling device 5 away from the outdoor heat exchanger 4, and the other end of the liquid discharge valve 13 is connected to a pipeline between the first liquid storage outlet c and the first liquid storage outlet valve 12.

Generally, the refrigerant content required by the air conditioning system in the cooling mode is lower than the refrigerant content required by the air conditioning system in the heating mode. Therefore, it is necessary to reduce the amount of refrigerant involved in cooling.

In this embodiment, when the air conditioning system enters the cooling mode, the liquid storage inlet valve 11 and the liquid discharge valve 13 are opened, and the heating throttling device 5 and the liquid storage outlet valve are closed, and the high-temperature and high-pressure refrigerant discharged by the compressor 2 sequentially passes through the outdoor heat exchanger 4, the liquid storage inlet valve 11, the liquid storage tank 10 and the liquid discharge valve 13, enters the indoor unit 02, then enters the gas-liquid separator 1 from the indoor unit 02, and finally returns to the compressor 2. When the refrigerant enters the liquid storage tank 10, part of liquid refrigerant is stored in the liquid storage tank 10, so that the refrigerant quantity flowing through the indoor heat exchanger 9 is reduced, the refrigerant content participating in the refrigeration of the air conditioning system is reduced, the liquid refrigerant entering the gas-liquid separator 1 and causing the liquid storage quantity in the gas-liquid separator 1 due to incomplete evaporation of excessive refrigerant in the indoor heat exchanger 9 is avoided, and the probability of liquid impact caused by liquid absorption of the compressor 2 is reduced.

Specifically, in an embodiment, after step P1, the method further includes:

p2, judging whether the air conditioning system meets a refrigeration liquid discharge condition, wherein the refrigeration liquid discharge condition is used for indicating that a refrigerant participating in refrigeration in the air conditioning system is insufficient;

p3, if yes, closing the liquid storage inlet valve 11 and the liquid storage outlet valve, and opening the liquid discharge valve 13 and the heating throttling device 5.

In this embodiment, the amount of refrigerant used is different according to different conditions of the air conditioning system. After entering the refrigeration mode, the liquid storage tank 10 may store the refrigerant continuously, which may result in insufficient refrigerant usage in a certain working condition, thereby reducing the refrigeration effect. When the system meets the refrigeration and liquid drainage conditions, the insufficient amount of the circulating refrigerant is judged, and at the moment, the refrigerant in the liquid storage tank 10 needs to be utilized to increase the amount of the circulating refrigerant.

Specifically, the reservoir inlet valve 11 and the reservoir outlet valve (including the first reservoir outlet valve 12 and the second reservoir outlet valve 17) are closed, and the heating throttle device 5, the drain valve 13, and the pressurizing valve 14 are opened. At this time, the pressurizing valve 14 communicates the pressurizing port b with the compressor 2. The refrigerant flowing out of the outdoor heat exchanger 4 enters the indoor unit 02 through the heating and throttling device 5, and meanwhile, the refrigerant stored in the liquid storage tank 10 is discharged from the liquid storage tank 10 under the action of the high-temperature and high-pressure refrigerant discharged from the compressor 2, and then flows into the indoor unit 02 after passing through the liquid discharge valve 13 and being merged with the refrigerant flowing out of the heating and throttling device 5. Therefore, the content of refrigerant participating in refrigeration in the indoor unit 02 is increased, and the refrigeration effect is improved.

Specifically, in the embodiment, step P2 specifically includes:

p21, acquiring the temperature difference value of the inlet and outlet pipes of the indoor heat exchanger 9, the opening value of the refrigeration throttling device 8 and the detection value of the fourth temperature sensor 24, and acquiring the detection value of the liquid level sensor 25 or the detection value of the fifth temperature sensor 26;

p22, judging whether the difference between the temperature of the inlet and outlet pipes of the indoor heat exchanger 9 is greater than a sixth threshold, the opening degree of the refrigeration throttling device 8 is greater than a seventh threshold, and the difference between the detection value of the liquid level sensor 25 and the second threshold or the detection value of the fifth temperature sensor 26 and the detection value of the fourth temperature sensor 24 is less than a fourth threshold;

and P23, if yes, judging that the air conditioning system meets the refrigeration liquid discharge condition.

In the embodiment, the condition that the air conditioning system meets the refrigeration liquid drainage condition comprises two conditions. In the first case, the opening degree of the heating throttle device 5 is greater than the fifth threshold, the temperature difference between the inlet and outlet pipes of the indoor heat exchanger 9 is greater than the sixth threshold, the opening degree of the cooling throttle device 8 is greater than the seventh threshold, and the detection value of the liquid level sensor 25 is greater than the second threshold. In another case, the opening degree value of the heating throttle device 5 is greater than the fifth threshold, the temperature difference value of the inlet/outlet pipe of the indoor heat exchanger 9 is greater than the sixth threshold, the opening degree value of the cooling throttle device 8 is greater than the seventh threshold, and the difference value between the detection value of the fifth temperature sensor 26 and the detection value of the fourth temperature sensor 24 is smaller than the fourth threshold.

When either of the two conditions is satisfied, it is determined that the air conditioning system satisfies the cooling liquid discharge condition, and step P3 is executed. If the air conditioner does not meet the refrigerating and liquid discharging conditions, the air conditioner system is judged to not meet the refrigerating and liquid discharging conditions, and all the parts keep the current state.

Further, the method also comprises the step of obtaining an opening value of the heating throttling device 5, and when the step P22 is not met and the opening value of the heating throttling device 5 is less than or equal to a fifth threshold value, it indicates that the refrigerant quantity of the air conditioning system is sufficient, and at this time, the method switches to a cooling and liquid storage state, namely, the heating throttling device 5 is closed, the liquid storage inlet valve 11 and the liquid discharge valve 13 are opened, and the heating throttling device 5 and the liquid storage outlet valve are closed.

All possible combinations of the technical features in the above embodiments may not be described for the sake of brevity, but should be considered as being within the scope of the present disclosure as long as there is no contradiction between the combinations of the technical features.

The above-mentioned embodiments only express several implementation modes of the present application, and the description thereof is specific and detailed, but not construed as limiting the scope of the claims. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the concept of the present application, and these are all within the scope of protection of the present application. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. An outdoor unit is characterized by comprising a compressor (2) forming a refrigerant circulation loop with an indoor unit (02), a gas-liquid separator (1), a four-way valve (3), an outdoor heat exchanger (4), a heating throttling device (5), a liquid storage tank (10), a liquid storage inlet valve (11), a liquid storage outlet valve and a liquid storage throttling element;

the liquid storage tank (10) is provided with a liquid storage inlet (a) and a liquid storage outlet, the liquid storage inlet (a) is connected between the outdoor heat exchanger (4) and the heating throttling device (5) through the liquid storage inlet valve (11), and the liquid storage throttling element is connected with one end of the liquid storage outlet and one end of the liquid storage outlet valve;

in the heating mode, the other end of the liquid storage outlet valve is connected with the inlet end of the gas-liquid separator (1), and the liquid storage outlet and the gas-liquid separator (1) are communicated or cut off;

the outdoor unit (01) further comprises a pressurization valve (14), the liquid storage tank (10) is further provided with a pressurization port (b), and the pressurization port (b) is positioned at the top of the liquid storage tank (10); the pressurization valve (14) is connected with the pressurization port (b) and the exhaust end of the compressor (2).

2. The outdoor unit of claim 1, wherein the liquid storage outlet comprises a second liquid storage outlet (d), the liquid storage restriction comprises a second liquid storage restriction (16), and the liquid storage outlet valve comprises a second liquid storage outlet valve (17);

the second stock solution export (d) is located the top of liquid storage pot (10), the one end of second stock solution outlet valve (17) is connected second stock solution export (d), second stock solution choke piece (16) is connected second stock solution export (d) with the one end of second stock solution outlet valve (17), the other end of second stock solution outlet valve (17) is connected the entry end of vapour and liquid separator (1).

3. The outdoor unit of claim 1 or 2, wherein the liquid storage outlet comprises a first liquid storage outlet (c), the liquid storage restriction comprises a first liquid storage restriction (15), and the liquid storage outlet valve comprises a first liquid storage outlet valve (12);

the first liquid storage outlet (c) is located at the bottom of the liquid storage tank (10), one end of the first liquid storage outlet valve (12) is connected with the first liquid storage outlet (c), the first liquid storage throttling piece (15) is connected with the first liquid storage outlet (c) and one end of the first liquid storage outlet valve (12), and the other end of the first liquid storage outlet valve (12) is connected to a pipeline between the outdoor heat exchanger (4) and the four-way valve (3).

4. The outdoor unit of claim 3, further comprising a liquid discharge valve (13), wherein one end of the liquid discharge valve (13) is connected to a side of the heating throttle device (5) facing away from the outdoor heat exchanger (4), and the other end of the liquid discharge valve (13) is connected to a pipeline between the first liquid storage outlet (c) and the first liquid storage outlet valve (12).

5. The outdoor unit of claim 1, further comprising a first temperature sensor (19) and a first pressure sensor (20), wherein the first temperature sensor (19) is disposed at an end of the outdoor heat exchanger (4) close to the four-way valve (3), and the first pressure sensor (20) is disposed at a suction end of the compressor (2).

6. The outdoor unit of claim 1, further comprising a second temperature sensor (21) and a third temperature sensor (22), wherein the second temperature sensor (21) is disposed at an outlet end of the gas-liquid separator (1), and the third temperature sensor (22) is disposed at an inlet end of the gas-liquid separator (1).

7. The outdoor unit of claim 1, further comprising a second pressure sensor (23) and a fourth temperature sensor (24), and comprising a liquid level sensor (25) or a fifth temperature sensor (26);

the second pressure sensor (23) is arranged at the exhaust end of the compressor (2), the fourth temperature sensor (24) is used for detecting the outdoor environment temperature, the liquid level sensor (25) is arranged in the liquid storage tank (10), and the fifth temperature sensor (26) is arranged at the bottom of the liquid storage tank (10).

8. An air conditioning system is characterized by comprising a compressor (2), a gas-liquid separator (1), a four-way valve (3), an outdoor heat exchanger (4), a heating throttling device (5), a refrigerating throttling device (8) and an indoor heat exchanger (9) which form a refrigerant circulation loop, and further comprising a liquid storage tank (10), a liquid storage inlet valve (11), a liquid storage outlet valve and a liquid storage throttling element;

the air conditioning system further comprises a pressurization valve (14), the liquid storage tank (10) is further provided with a pressurization port (b), and the pressurization port (b) is positioned at the top of the liquid storage tank (10); the pressurization valve (14) is connected with the pressurization port (b) and the exhaust end of the compressor (2).

9. A control method of an air conditioning system is characterized by comprising the following steps:

in the heating mode, a heating throttling device (5) is started, the working state of an outdoor heat exchanger (4) is detected, and the working state of the outdoor heat exchanger (4) comprises an evaporation complete state and an evaporation incomplete state;

when the outdoor heat exchanger (4) is in the incomplete evaporation state, a liquid storage inlet valve (11) and a liquid storage outlet valve are opened;

when the outdoor heat exchanger (4) is in the evaporation complete state, closing the liquid storage inlet valve (11) and the liquid storage outlet valve;

after the step of closing the liquid storage inlet valve (11) and the liquid storage outlet valve when the outdoor heat exchanger (4) is in the evaporation complete state, the method further comprises the following steps:

if yes, opening the pressurizing valve (14) and the first liquid storage outlet valve (12);

if not, the pressurizing valve (14) and the first liquid storage outlet valve (12) are closed.

10. The control method of an air conditioning system according to claim 9, wherein the step of opening the reservoir inlet valve (11) and the reservoir outlet valve when the outdoor heat exchanger (4) is in the incomplete evaporation state specifically comprises:

when the outdoor heat exchanger (4) is in the incomplete evaporation state, opening the liquid storage inlet valve (11), and opening a first liquid storage outlet valve (12) and/or a second liquid storage outlet valve (17);

correspondingly, when the outdoor heat exchanger (4) is in the evaporation complete state, the step of closing the liquid storage inlet valve (11) and the liquid storage outlet valve specifically comprises the following steps:

when the outdoor heat exchanger (4) is in the evaporation complete state, the liquid storage inlet valve (11), the first liquid storage outlet valve (12) and/or the second liquid storage outlet valve (17) are/is closed.

11. The control method of an air conditioning system according to claim 9, wherein the step of detecting the operating state of the outdoor heat exchanger (4) specifically comprises:

acquiring detection values of a first temperature sensor (19) and a first pressure sensor (20), and judging whether the detection value of the first temperature sensor (19) is larger than a saturation temperature value corresponding to the detection value of the first pressure sensor (20);

if yes, judging that the outdoor heat exchanger (4) is in a complete evaporation state;

if not, judging that the outdoor heat exchanger (4) is in an incomplete evaporation state.

12. The control method of an air conditioning system according to claim 9, wherein the step of detecting the operating state of the outdoor heat exchanger (4) specifically comprises:

acquiring detection values of a second temperature sensor (21) and a third temperature sensor (22), and judging whether a difference value between the detection value of the second temperature sensor (21) and the detection value of the third temperature sensor (22) is greater than a first threshold value;

13. The method as claimed in claim 9, wherein the step of determining whether the air conditioning system satisfies a heating and drainage condition includes:

acquiring a detection value of a second pressure sensor (23) and a detection value of a fourth temperature sensor (24), and acquiring a detection value of a liquid level sensor (25) or a fifth temperature sensor (26);

judging whether the difference between the saturation temperature value corresponding to the detection value of the second pressure sensor (23) and the detection value of the fourth temperature sensor (24) is smaller than a third threshold value, and whether the difference between the detection value of the liquid level sensor (25) and the second threshold value or the difference between the detection value of the fifth temperature sensor (26) and the detection value of the fourth temperature sensor (24) is smaller than a fourth threshold value is met;

14. The control method of an air conditioning system according to claim 9, further comprising:

and in a refrigerating mode, a liquid storage inlet valve (11) and a liquid discharge valve (13) are opened, and a heating throttling device (5) and a liquid storage outlet valve are closed.

15. The control method of an air conditioning system according to claim 14, further comprising, after the steps of opening the liquid storage inlet valve (11) and the liquid discharge valve (13), and closing the heating throttle device (5) and the liquid storage outlet valve:

judging whether the air conditioning system meets a refrigeration liquid discharge condition, wherein the refrigeration liquid discharge condition is used for indicating that a refrigerant participating in refrigeration in the air conditioning system is insufficient;

if yes, the liquid storage inlet valve (11) and the liquid storage outlet valve are closed, and the liquid discharge valve (13) and the heating throttling device (5) are opened.

16. The method as claimed in claim 15, wherein the step of determining whether the air conditioning system satisfies a cooling drain condition comprises:

acquiring a temperature difference value of an inlet pipe and an outlet pipe of the indoor heat exchanger (9), an opening value of the refrigerating throttling device (8) and a detection value of a fourth temperature sensor (24), and acquiring a detection value of a liquid level sensor (25) or a detection value of a fifth temperature sensor (26);

judging whether the temperature difference value of an inlet pipe and an outlet pipe of the indoor heat exchanger (9) is larger than a sixth threshold value, the opening value of the refrigeration throttling device (8) is larger than a seventh threshold value, and the detection value of the liquid level sensor (25) is larger than a second threshold value or the difference value of the detection value of the fifth temperature sensor (26) and the detection value of the fourth temperature sensor (24) is smaller than a fourth threshold value;