Air conditioning system and control method thereof

Abstract

The invention relates to an air conditioning system and a control method thereof, and the air conditioning system comprises a refrigerant circulation loop; the liquid storage container is used for storing a refrigerant and is provided with a liquid inlet and a liquid outlet; the liquid inlet pipeline is provided with a liquid inlet valve, the first end of the liquid inlet pipeline is communicated with the liquid inlet, and the second end of the liquid inlet pipeline is communicated with at least one of the low-pressure side pipeline, the medium-pressure side pipeline and the high-pressure side pipeline; the liquid discharging pipeline is provided with a liquid discharging valve, the first end of the liquid discharging pipeline is communicated with the liquid outlet, and the second end of the liquid discharging pipeline is communicated with at least one of the low-pressure side pipeline, the medium-pressure side pipeline and the high-pressure side pipeline; under the condition that the liquid inlet valve is in the on state, the pressure of the first end of the liquid inlet branch is smaller than that of the second end of the liquid inlet branch, and therefore the refrigerant is stored in the liquid storage container through the pressure difference. And under the condition that the drain valve is in the on state, the pressure of the first end of the drain branch is larger than that of the second end of the drain branch, so that the refrigerant in the liquid storage container is discharged through the pressure difference.

Description

Technical Field

[0001] The present disclosure relates to the field of refrigeration technology, and in particular to an air-conditioning system and a control method thereof. Background Art

[0002] A multi-split air conditioning system is an outdoor unit that can connect to multiple indoor units. Its refrigeration system is an outdoor unit that can transport refrigerant liquid to several indoor units through pipelines. By controlling the refrigerant circulation volume of the compressor and the refrigerant flow entering each indoor heat exchanger, the indoor cooling and heating load requirements can be met in a timely manner.

[0003] The current multi-split air conditioning system can only realize conventional cooling mode and heating mode, and the heat exchange effect is poor. Summary of the invention

[0004] Some embodiments of the present disclosure provide an air-conditioning system and a control method thereof, which can enable the air-conditioning system to achieve a better heat exchange effect.

[0005] A first aspect of the present disclosure provides an air conditioning system, comprising:

[0006] The refrigerant circulation loop is provided with a compressor, an evaporator and a condenser. The high-pressure side pipeline is between the exhaust port of the compressor and the condenser, the medium-pressure side pipeline is between the condenser and the evaporator, and the low-pressure side pipeline is between the evaporator and the air intake port of the compressor;

[0007] A liquid storage container, used for storing refrigerant and having a liquid inlet and a liquid outlet;

[0008] a liquid inlet pipeline, on which a liquid inlet valve having an on state and an off state is provided, a first end of the liquid inlet pipeline is connected to the liquid inlet port, and a second end of the liquid inlet pipeline is connected to at least one of the low-pressure side pipeline, the medium-pressure side pipeline and the high-pressure side pipeline; and

[0009] A liquid discharge pipeline, on which a liquid discharge valve having an on state and an off state is provided, a first end of the liquid discharge pipeline is connected to the liquid outlet, and a second end of the liquid discharge pipeline is connected to at least one of the low-pressure side pipeline, the medium-pressure side pipeline and the high-pressure side pipeline;

[0010] Among them, when the liquid inlet valve is in the on state, the pressure at the first end of the liquid inlet branch is lower than the pressure at the second end, so that the refrigerant in the refrigerant circulation loop can be stored in the liquid storage container by utilizing the pressure difference; when the liquid discharge valve is in the on state, the pressure at the first end of the liquid discharge branch is higher than the pressure at the second end, so that the refrigerant in the liquid storage container can be discharged into the refrigerant circulation loop by utilizing the pressure difference.

[0011] In some embodiments, the liquid storage container further has a pressure regulating port, and the air conditioning system further comprises:

[0012] A pressure relief branch, on which a balancing valve having an on state and an off state is provided, and a first end of the pressure relief branch is connected to the pressure regulating port;

[0013] When the balancing valve is in the on state, the pressure in the liquid storage container is released through the pressure relief branch.

[0014] In some embodiments, the liquid storage container further has a pressure regulating port, and the air conditioning system further comprises:

[0015] A pressurizing branch, on which a pressurizing valve having an on state and an off state is provided, a first end of the pressurizing branch is connected to the pressure regulating port, and a second end of the pressurizing branch is connected to the high-pressure side pipeline;

[0016] When the pressurizing valve is in the on state, the high-pressure side pipeline pressurizes the liquid storage container.

[0017] In some embodiments, the liquid inlet pipeline includes a first liquid inlet branch, a second end of the first liquid inlet branch is connected to the medium-pressure side pipeline, and the liquid inlet valve includes a first liquid inlet valve provided on the first liquid inlet branch; and

[0018] The drain pipeline includes a first drain branch, the second end of the first drain branch is configured to communicate with the low-pressure side pipeline in the cooling mode and to communicate with the high-pressure side pipeline in the heating mode, and the drain valve includes a first drain valve arranged on the first drain branch.

[0019] In some embodiments, the refrigerant circulation loop further includes a four-way reversing valve and a gas-liquid separator, the four-way reversing valve is used to switch between the cooling mode and the heating mode, and the gas-liquid separator is arranged on the pipeline between the four-way reversing valve and the compressor suction port;

[0020] Among them, the air-conditioning system also includes a pressurization branch, the second end of the first liquid discharge branch is connected to the pipeline between the four-way reversing valve and the evaporator, the second end of the pressurization branch is connected to the pipeline between the exhaust port of the compressor and the four-way reversing valve, and the second end of the pressure relief branch is connected between the inlet of the gas-liquid separator and the four-way reversing valve.

[0021] In some embodiments, the liquid inlet and the pressure regulating port are arranged in the upper area of ​​the liquid storage container, and the liquid outlet is arranged in the lower area of ​​the liquid storage container.

[0022] In some embodiments,

[0023] The liquid inlet pipeline includes a second liquid inlet branch, a second end of the second liquid inlet branch is connected to the low-pressure side pipeline, and the liquid inlet valve also includes a second liquid inlet valve arranged on the second liquid inlet branch; and / or

[0024] The liquid discharge pipeline includes a second liquid discharge branch, a second end of the second liquid discharge branch is communicated with the medium-pressure side pipeline, and the liquid discharge valve also includes a second liquid discharge valve arranged on the second liquid discharge branch.

[0025] In some embodiments, the refrigerant circulation loop further includes a four-way reversing valve and a gas-liquid separator, the four-way reversing valve is used to switch between the cooling mode and the heating mode, and the gas-liquid separator is arranged on the pipeline between the four-way reversing valve and the compressor suction port;

[0026] The second end of the second liquid inlet branch is connected between the four-way reversing valve and the inlet of the gas-liquid separator.

[0027] In some embodiments, a main pipeline section is formed between the four-way reversing valve and the second end of the second liquid inlet branch, a branch pipeline section is formed between the second end of the second liquid inlet branch and the inlet of the gas-liquid separator, and the main pipeline section is connected to the second liquid inlet branch and the branch pipeline section;

[0028] Among them, the refrigerant flow resistance of the branch pipe section is greater than the refrigerant flow resistance of the second liquid inlet branch.

[0029] In some embodiments, the height of the second liquid inlet branch is lower than the length section of the branch pipe section close to the second end of the second liquid inlet branch; and / or

[0030] A resistance increasing portion is provided on the branch pipeline section, and the resistance increasing portion is configured to increase the refrigerant flow resistance of the branch pipeline section.

[0031] In some embodiments, the liquid inlet pipeline includes a second liquid inlet branch and a pressurizing branch, the second end of the second liquid inlet branch is connected to the low-pressure side pipeline, and the liquid inlet valve includes a second liquid inlet valve provided on the second liquid inlet branch; a pressurizing valve having an on state and an off state is provided on the pressurizing branch, the first end of the pressurizing branch is connected to the pressure regulating port of the liquid storage container, and the second end of the pressurizing branch is connected to the high-pressure side pipeline;

[0032] The drain pipeline includes a first drain branch and a second drain branch, the second end of the first drain branch is configured to communicate with the low-pressure side pipeline in the cooling mode and communicate with the high-pressure side pipeline in the heating mode; the second end of the second drain branch is communicated with the medium-pressure side pipeline; the drain valve includes a first drain valve provided on the first drain branch and a second drain valve provided on the second drain branch;

[0033] A second control valve is provided on the pipeline section between the second end of the second liquid inlet branch and the air intake port of the compressor in the refrigerant circulation loop; the liquid storage container has an air outlet, and the air-conditioning system also includes a first control valve, the first end of the first control valve is connected to the air outlet, and the second end of the first control valve is connected to the pipeline section between the second control valve and the air intake port of the compressor.

[0034] A second aspect of the present disclosure provides a control method for an air conditioning system based on the above embodiment, comprising:

[0035] Liquid collection mode: the liquid inlet valve is turned on, and the pressure at the first end of the liquid inlet pipeline is lower than the pressure at the second end, so that the refrigerant in the refrigerant circulation loop is stored in the liquid storage container;

[0036] Discharge mode: When the refrigerant in the liquid storage container needs to be discharged to the refrigerant circulation loop, the discharge valve is turned on and the pressure at the first end of the discharge pipeline is greater than the pressure at the second end.

[0037] In some embodiments, the air conditioning system further comprises a pressure relief branch and a pressurization branch, wherein a balancing valve is provided on the pressure relief branch, and a first end of the pressure relief branch is connected to a pressure regulating port of the liquid storage container; a pressurization valve is provided on the pressurization branch, a first end of the pressurization branch is connected to the pressure regulating port, and a second end of the pressurization branch is connected to a high-pressure side pipeline;

[0038] The liquid inlet pipeline includes a first liquid inlet branch, the second end of the first liquid inlet branch is connected to the medium pressure side pipeline, and the liquid inlet valve includes a first liquid inlet valve arranged on the first liquid inlet branch;

[0039] The liquid collection mode includes: a cooling liquid collection mode and a heating liquid collection mode. In the cooling liquid collection mode and the heating liquid collection mode, the drain valve and the pressurizing valve are both in the disconnected state, the first liquid inlet valve is in the connected state, and when the pressure difference across the first liquid inlet valve is less than a preset threshold, the balancing valve is in the connected state to release the pressure in the liquid storage container.

[0040] In some embodiments, the drain pipeline includes a first drain branch, the second end of the first drain branch is configured to communicate with the low-pressure side pipeline in the cooling mode, and to communicate with the high-pressure side pipeline in the heating mode, the drain valve includes a first drain valve provided on the first drain branch; the drain mode also includes a cooling drain mode and a heating drain mode,

[0041] In the refrigeration discharge mode, the first discharge valve is in the on state, and the first inlet valve and the balancing valve are both in the off state;

[0042] In the heating and liquid discharge mode, the first liquid inlet valve is first placed in the on state, and when the pressure in the liquid storage container reaches the pressure at the second end of the first liquid inlet branch, the first liquid inlet valve is placed in the off state; thereafter, the compressor is reduced in frequency or stopped, and at this time the first liquid discharge valve is placed in the on state.

[0043] In some embodiments, the air conditioning system further comprises a pressurizing branch, on which a pressurizing valve is provided, a first end of the pressurizing branch is connected to the pressure regulating port, and a second end of the pressurizing branch is connected to the high-pressure side pipeline; the drain pipeline comprises a first drain branch, a second end of the first drain branch is configured to be connected to the low-pressure side pipeline in the cooling mode, and to be connected to the high-pressure side pipeline in the heating mode, and the drain valve comprises a first drain valve provided on the first drain branch;

[0044] The drainage modes include: a first cooling drainage mode, a second cooling drainage mode, a first heating drainage mode, and a second heating drainage mode; wherein,

[0045] In the first refrigeration liquid discharge mode, the first liquid discharge valve is in the on state, and when the internal pressure of the liquid storage container drops to the same level as the low-pressure side pipeline, the pressurizing valve is in the on state, and the first liquid inlet valve and the balancing valve are both in the off state;

[0046] In the second refrigeration liquid discharge mode, the balancing valve is in the on state, and the first liquid inlet valve, the first liquid discharge valve and the pressurizing valve are all in the off state;

[0047] In the first heating liquid discharge mode, the pressurizing valve is in an on state, so that the pressure inside the liquid storage container is increased to the pressure at the second end of the pressurizing branch, and the first liquid discharge valve is in an on state;

[0048] In the second heating and liquid discharge mode, the pressurizing valve is first placed in the on state, and when the pressure inside the liquid storage container rises to the pressure at the second end of the pressurizing branch, the pressurizing valve is switched to the off state; thereafter, the compressor is reduced in frequency or stopped, and at this time the first liquid discharge valve is placed in the on state.

[0049] In some embodiments, the liquid inlet pipeline includes a second liquid inlet branch, the second end of the second liquid inlet branch is connected to the low-pressure side pipeline, and the liquid inlet valve also includes a second liquid inlet valve provided on the second liquid inlet branch; the liquid discharge pipeline includes a second liquid discharge branch, the second end of the second liquid discharge branch is connected to the medium-pressure side pipeline, and the liquid discharge valve also includes a second liquid discharge valve provided on the second liquid discharge branch; a branch pipeline section is formed between the second end of the second liquid inlet branch and the inlet of the gas-liquid separator;

[0050] The liquid collection mode also includes: a cooling low-pressure side liquid collection mode and a heating low-pressure side liquid collection mode. In the cooling low-pressure side liquid collection mode and the heating low-pressure side liquid collection mode, the second liquid inlet valve is in an on state, and when the pressure in the liquid storage container increases to a point where the refrigerant flow resistance of the second liquid inlet branch is greater than that of the branch pipe section, the balancing valve is opened; and / or

[0051] The discharge mode also includes: a refrigeration medium-pressure side discharge mode. In the refrigeration medium-pressure side discharge mode, the pressurizing valve is first placed in an on state. When the pressure in the liquid storage container rises to the pressure at the second end of the pressurizing branch, the pressurizing valve is switched to a disconnected state; thereafter, the second discharge valve is opened.

[0052] In some embodiments, the liquid inlet pipeline includes a second liquid inlet branch and a pressurizing branch, the second end of the second liquid inlet branch is connected to the low-pressure side pipeline, and the liquid inlet valve includes a second liquid inlet valve provided on the second liquid inlet branch; a pressurizing valve is provided on the pressurizing branch, the first end of the pressurizing branch is connected to the pressure regulating port of the liquid storage container, and the second end of the pressurizing branch is connected to the high-pressure side pipeline;

[0053] The drain pipeline includes a first drain branch and a second drain branch, the second end of the first drain branch is configured to communicate with the low-pressure side pipeline in the cooling mode and communicate with the high-pressure side pipeline in the heating mode; the second end of the second drain branch is communicated with the medium-pressure side pipeline; the drain valve includes a first drain valve provided on the first drain branch and a second drain valve provided on the second drain branch;

[0054] The refrigerant circulation loop is provided with a second control valve on the pipeline section between the second end of the second liquid inlet branch and the air intake port of the compressor; the liquid storage container has an exhaust port, and the air conditioning system also includes a first control valve, the first end of the first control valve is connected to the exhaust port, and the second end of the first control valve is connected to the pipeline section between the second control valve and the air intake port of the compressor;

[0055] The liquid collection mode includes a cooling low-pressure side liquid collection mode and a heating low-pressure side liquid collection mode. In the cooling low-pressure side liquid collection mode and the heating low-pressure side liquid collection mode, the second liquid inlet valve and the first control valve are in an on state.

[0056] In some embodiments, the liquid discharge mode includes a cooling medium-pressure side liquid discharge mode and a heating high-pressure side liquid discharge mode.

[0057] In the refrigeration medium-pressure side liquid discharge mode, the first control valve is in the disconnected state, and the second control valve is in the connected state, then the pressurizing valve is in the connected state to increase the pressure in the liquid storage container, and the second liquid discharge valve is in the connected state;

[0058] In the heating high-pressure side liquid discharge mode, the first control valve is in the disconnected state and the second control valve is in the connected state. Then, the pressurizing valve is in the connected state to increase the pressure inside the liquid storage container and the first liquid discharge valve is in the connected state.

[0059] Based on the above technical solution, the present disclosure has at least the following beneficial effects:

[0060] A liquid storage container is added to the air-conditioning system of the embodiment of the present disclosure, and is connected to at least one of the low-pressure side pipeline, medium-pressure side pipeline and high-pressure side pipeline in the system through a liquid inlet valve and a liquid discharge valve that can realize the on-off function. On the basis of realizing the conventional refrigerant mode and the heating mode, the excess refrigerant in the refrigerant circulation loop can be collected from a specific pressure side by using the pressure difference according to the actual heat exchange demand of the air-conditioning system, or the refrigerant in the liquid storage container can be discharged into the refrigerant circulation loop for replenishment according to the actual refrigerant demand, so as to achieve the best heat exchange effect and improve the heat exchange efficiency of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0061] The drawings described herein are used to provide a further understanding of the present disclosure and constitute a part of the present application. The illustrative embodiments of the present disclosure and their descriptions are used to explain the present disclosure and do not constitute an improper limitation on the present disclosure. In the drawings:

[0062] Figure 1 is a schematic diagram of the first embodiment of the air conditioning system of the present disclosure in a conventional cooling mode;

[0063] Figure 2 is a schematic diagram of the first embodiment of the air conditioning system of the present disclosure in a conventional heating mode;

[0064] Figure 3 It is a principle diagram of the first embodiment of the air conditioning system of the present disclosure in the cooling and liquid collecting mode;

[0065] Figure 4 It is a principle diagram of the first embodiment of the air conditioning system of the present disclosure in the first refrigeration and liquid discharge mode;

[0066] Figure 5 It is a principle diagram of the first embodiment of the air conditioning system of the present disclosure in the second refrigeration and liquid discharge mode;

[0067] Figure 6 It is a principle diagram of the first embodiment of the air conditioning system of the present disclosure in the heating and liquid collecting mode;

[0068] Figure 7 It is a principle diagram of the first embodiment of the air conditioning system of the present disclosure in the first heating and liquid discharge mode;

[0069] Figure 8 This is a schematic diagram of the first embodiment of the air conditioning system disclosed herein being in the second heating and liquid discharge mode, with the pressurizing valve being opened first;

[0070] Fig. 9 It is a principle diagram of the first drain valve being opened when the first embodiment of the air conditioning system of the present disclosure is in the second heating drain mode;

[0071] Fig.10 is a schematic diagram of a second embodiment of the air conditioning system of the present disclosure in a conventional cooling mode;

[0072] Fig.11 is a schematic diagram of the second embodiment of the air conditioning system of the present disclosure in a conventional heating mode;

[0073] Fig.12 It is a principle diagram of the second embodiment of the air conditioning system of the present disclosure in the cooling and liquid collecting mode;

[0074] Fig.13 It is a schematic diagram of the second embodiment of the air conditioning system of the present disclosure in the cooling and liquid discharge mode;

[0075] Fig.14It is a principle diagram of the second embodiment of the air conditioning system of the present disclosure in the heating and liquid collecting mode;

[0076] Fig.15 This is a schematic diagram of the first liquid inlet valve being opened when the second embodiment of the air conditioning system of the present disclosure is in a heating and liquid discharge mode;

[0077] Fig.16 This is a schematic diagram of the second embodiment of the air conditioning system disclosed herein, when the first drain valve is opened in the heating drain mode;

[0078] Fig.17 is a schematic diagram of a third embodiment of the air conditioning system of the present disclosure in a conventional cooling mode;

[0079] Fig.18 is a schematic diagram of a third embodiment of the air conditioning system of the present disclosure in a conventional heating mode;

[0080] Fig.19 It is a principle diagram of the third embodiment of the air conditioning system of the present disclosure in the cooling low-pressure side liquid collection mode;

[0081] Fig. 20 It is a principle diagram of the third embodiment of the air conditioning system of the present disclosure in the refrigeration medium-pressure side liquid discharge mode;

[0082] Fig.21 It is a principle diagram of the third embodiment of the air conditioning system of the present disclosure in the heating and liquid collecting mode;

[0083] Fig. 22 for Fig.21 A in the enlarged view;

[0084] Fig.23 for Fig. 22 A schematic diagram of a modified example of ;

[0085] Fig.24 for Fig. 22 A schematic diagram of another variation of ;

[0086] Fig.25 It is a principle diagram of the third embodiment of the air conditioning system of the present disclosure in the heating and liquid discharge mode;

[0087] Fig.26 is a schematic diagram of a fourth embodiment of the air conditioning system of the present disclosure in a conventional cooling mode;

[0088] Fig. 27 is a schematic diagram of a fourth embodiment of the air conditioning system of the present disclosure in a conventional heating mode;

[0089] Fig.28 It is a schematic diagram of the fourth embodiment of the air conditioning system of the present disclosure in the cooling low-pressure side liquid collection mode;

[0090] Fig.29 It is a schematic diagram of the fourth embodiment of the air conditioning system of the present disclosure in the cooling medium-pressure side liquid discharge mode;

[0091] Fig.30 It is a schematic diagram of the fourth embodiment of the air conditioning system of the present disclosure in the heating low-pressure side liquid collection mode;

[0092] Fig.31 It is a schematic diagram of the fourth embodiment of the air conditioning system of the present disclosure in the heating high-pressure side liquid discharge mode;

[0093] Fig.32 is a schematic diagram of a fifth embodiment of the air conditioning system of the present disclosure in a conventional cooling mode;

[0094] Fig.33 is a schematic diagram of a fifth embodiment of the air conditioning system of the present disclosure in a conventional heating mode;

[0095] Fig.34 It is a principle diagram of the fifth embodiment of the air conditioning system of the present disclosure in the cooling low-pressure side liquid collection mode;

[0096] Fig.35 It is a principle diagram of the fifth embodiment of the air conditioning system of the present disclosure in the cooling medium-pressure side liquid discharge mode;

[0097] Fig.36 It is a principle diagram of the fifth embodiment of the air conditioning system of the present disclosure in the heating low-pressure side liquid collection mode;

[0098] Fig.37 This is a schematic diagram of the fifth embodiment of the air-conditioning system disclosed herein in a heating high-pressure side liquid discharge mode.

[0099] It should be understood that the size of each part shown in the accompanying drawings is not drawn according to the actual proportional relationship. In addition, the same or similar reference numerals represent the same or similar components.

[0100] Description of Reference Numerals

[0101] 101, compressor; 102, first pressure sensor; 103, four-way reversing valve; 104, outdoor heat exchanger; 105, outdoor unit throttling element; 106, liquid pipe valve; 107, gas pipe valve; 108, second pressure sensor; 109, gas-liquid separator; 110, liquid storage container; 111, pressurizing valve; 112, balancing valve; 113, first liquid inlet valve; 114, unloading valve; 115, first liquid discharge valve; 116, first non-return valve; 117, second liquid discharge valve; 118, second non-return valve; 119, second liquid inlet valve; 120, first control valve; 121, second control valve; 122, indoor heat exchanger;

[0102] 1. The first liquid inlet branch; 2. The first liquid discharge branch; 3. The pressure relief branch; 4. The pressurization branch; 5. The second liquid inlet branch; 6. The second liquid discharge branch; 10. The resistance increasing part. DETAILED DESCRIPTION

[0103] Various exemplary embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. The description of the exemplary embodiments is merely illustrative and is in no way intended to limit the present disclosure and its application or use. The present disclosure can be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are provided to make the present disclosure thorough and complete and to fully express the scope of the present disclosure to those skilled in the art. It should be noted that unless otherwise specifically stated, the relative arrangement of the components and steps, the composition of the materials, the numerical expressions and the numerical values ​​set forth in these embodiments should be interpreted as being merely exemplary and not as limiting.

[0104] The words "first", "second" and similar words used in this disclosure do not indicate any order, quantity or importance, but are only used to distinguish different parts. The words "include" or "comprise" and similar words mean that the elements before the word include the elements listed after the word, and do not exclude the possibility of including other elements. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0105] In the present disclosure, when a specific device is described as being located between a first device and a second device, there may or may not be an intermediate device between the specific device and the first device or the second device. When a specific device is described as being connected to other devices, the specific device may be directly connected to the other device without an intermediate device, or may not be directly connected to the other device but have an intermediate device.

[0106] All terms (including technical terms or scientific terms) used in the present disclosure have the same meanings as those understood by ordinary technicians in the field to which the present disclosure belongs, unless otherwise specifically defined. It should also be understood that terms defined in general dictionaries, such as general dictionaries, should be interpreted as having meanings consistent with their meanings in the context of the relevant technology, and should not be interpreted in an idealized or extremely formal sense, unless explicitly defined herein.

[0107] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered part of the specification.

[0108] Based on the above-mentioned embodiments of the present disclosure, in the absence of explicit negation or conflict, the technical features of one embodiment may be beneficially combined with one or more other embodiments.

[0109] The present disclosure provides an air conditioning system, such as Figures 1 to 37 As shown, five different types of embodiments are illustrated. In some embodiments, the air conditioning system includes:

[0110] A refrigerant circulation loop is provided with a compressor 101, an evaporator and a condenser. A high-pressure side pipeline is provided between the exhaust port of the compressor 101 and the condenser, a medium-pressure side pipeline is provided between the condenser and the evaporator, and a low-pressure side pipeline is provided between the evaporator and the air intake port of the compressor 101;

[0111] The liquid storage container 110 is used to store the refrigerant and has a liquid inlet A and a liquid outlet B;

[0112] a liquid inlet pipeline, on which a liquid inlet valve having an on state and an off state is provided, a first end of the liquid inlet pipeline is connected to the liquid inlet port A, and a second end of the liquid inlet pipeline is connected to at least one of the low-pressure side pipeline, the medium-pressure side pipeline and the high-pressure side pipeline; and

[0113] A liquid discharge pipeline, on which a liquid discharge valve having an on state and an off state is provided, a first end of the liquid discharge pipeline is connected to the liquid outlet B, and a second end of the liquid discharge pipeline is connected to at least one of the low-pressure side pipeline, the medium-pressure side pipeline and the high-pressure side pipeline;

[0114] Among them, when the liquid inlet valve is in the on state, the pressure at the first end of the liquid inlet branch is lower than the pressure at the second end, so that the refrigerant in the refrigerant circulation loop can be stored in the liquid storage container 110 by utilizing the pressure difference; when the liquid discharge valve is in the on state, the pressure at the first end of the liquid discharge branch is higher than the pressure at the second end, so that the refrigerant in the liquid storage container 110 can be discharged to the refrigerant circulation loop by utilizing the pressure difference.

[0115] Specifically, a compressor 101, an evaporator and a condenser are provided on the refrigerant circulation circuit. Figure 1 As shown, from the perspective of the installation position, the refrigerant circulation loop includes a compressor 101, an outdoor heat exchanger 104 and an indoor heat exchanger 122. The indoor heat exchanger 122 is only Figure 1 As shown in the figure, the number can be one or more, and the indoor heat exchanger 122 is omitted in other figures. In the cooling state, the indoor heat exchanger 122 serves as an evaporator, and the outdoor heat exchanger 104 serves as a condenser. An outdoor unit throttling element 105 can also be provided at the downstream position of the outlet of the outdoor heat exchanger 104 to throttle and cool the refrigerant; in the heating state, the indoor heat exchanger 122 serves as a condenser, and the outdoor heat exchanger 104 serves as an evaporator. The cooling state and the heating state are switched by a four-way reversing valve 103. The liquid storage container 110 can be a liquid storage tank, etc., for temporarily storing the refrigerant in the refrigerant circulation loop. For example, the outdoor unit system can be a multi-split outdoor unit.

[0116] For example, the liquid storage container 110 may be provided in the external system, or may be provided between the internal system and the external system.

[0117] For example, the refrigerant circulation loop also includes a four-way reversing valve 103 and a gas-liquid separator 109. The four-way reversing valve 103 is used to switch between the cooling mode and the heating mode. The gas-liquid separator 109 is arranged on the pipeline between the four-way reversing valve 103 and the suction port of the compressor 101.

[0118] For such a system, Figure 1 As shown, in the cooling mode, the high-pressure side pipeline is the pipeline between the exhaust port of the compressor 101 to the condenser (outdoor heat exchanger 104), the medium-pressure side pipeline is the pipeline between the condenser (outdoor heat exchanger 104) and the evaporator (indoor heat exchanger), and the low-pressure side pipeline includes: from the evaporator (indoor heat exchanger) through the four-way reversing valve 103 to the inlet of the gas-liquid separator 109, and the pipeline between the outlet of the gas-liquid separator 109 and the air inlet of the compressor 101.

[0119] like Figure 2 As shown, in the heating mode, the high-pressure side pipeline is the pipeline between the exhaust port of the compressor 101 to the condenser (indoor heat exchanger), the medium-pressure side pipeline is the pipeline between the condenser (indoor heat exchanger) and the evaporator (outdoor heat exchanger 104), and the low-pressure side pipeline includes: from the evaporator (outdoor heat exchanger 104) through the four-way reversing valve 103 to the inlet of the gas-liquid separator 109, and the pipeline between the outlet of the gas-liquid separator 109 and the air inlet of the compressor 101.

[0120] The second end of the liquid inlet pipeline can be connected to one, two or three of the low-pressure side pipeline, medium-pressure side pipeline and high-pressure side pipeline of the external unit system as needed, so as to collect the refrigerant from different pressure sides into the liquid storage container 110 under different working modes. When collecting liquid, it is necessary to establish a pressure difference between the two ends of the liquid inlet branch so that the pressure at the first end of the liquid inlet branch is less than the pressure at the second end, so as to utilize the pressure difference to allow at least part of the refrigerant in the refrigerant circulation loop to enter the liquid storage container 110.

[0121] The second end of the discharge pipeline can be connected to one, two or three of the low-pressure side pipeline, medium-pressure side pipeline and high-pressure side pipeline of the external unit system as needed, so as to collect the refrigerant from different pressure sides into the liquid storage container 110, which is conducive to realizing different liquid collection modes. When collecting liquid, it is necessary to establish a pressure difference at both ends of the liquid inlet branch so that the pressure at the first end of the liquid inlet branch is less than the pressure at the second end, so as to utilize the pressure difference to make at least part of the refrigerant in the refrigerant circulation loop enter the liquid storage container 110.

[0122] The second end of the liquid inlet pipeline is connected to one, two or three of the low-pressure side pipeline, the medium-pressure side pipeline and the high-pressure side pipeline, so that the refrigerant in the liquid storage container 110 can be discharged to different pressure sides, which is conducive to realizing different discharge modes, so that the pressure at the first end of the discharge branch is greater than the pressure at the second end, so as to utilize the pressure difference to discharge at least part of the refrigerant in the liquid storage container 110 into the refrigerant circulation loop.

[0123] For example, the high-pressure side pipeline can be called the first pressure side pipeline, the medium-pressure side pipeline can be called the second pressure side pipeline, and the low-pressure side pipeline can be called the third pressure side pipeline, wherein the first pressure interval is higher than the second pressure interval, and the second pressure interval is higher than the third pressure interval.

[0124] This embodiment adds a liquid storage container 110 to the air-conditioning system, and is connected to at least one of the low-pressure side pipeline, medium-pressure side pipeline and high-pressure side pipeline in the system through a liquid inlet valve and a liquid discharge valve that can realize the on-off function. On the basis of realizing the conventional refrigerant mode and the heating mode, the pressure difference can be used to collect excess refrigerant in the refrigerant circulation loop from a specific pressure side according to the actual heat exchange demand of the air-conditioning system, or the refrigerant in the liquid storage container 110 can be discharged into the refrigerant circulation loop for replenishment according to the actual refrigerant demand, so as to achieve the best heat exchange effect and improve the heat exchange efficiency of the system.

[0125] Through this system, the refrigerant adjustment function and the refrigerant transfer function can be realized at the same time.

[0126] In the refrigerant adjustment function, the refrigerant is stored and released through the liquid storage container 110, and the amount of refrigerant in different operating modes is controlled, so that the system refrigerant circulation amount is consistent with the refrigerant demand in different operating modes, thereby achieving the best heat exchange effect.

[0127] In the refrigerant transfer function, the problem of system refrigerant accumulating on the outdoor low-pressure side after defrosting can be solved. The liquid refrigerant is stored in the liquid storage container 110 during defrosting. After defrosting is completed and switched to heating mode, the liquid refrigerant is discharged by relying on the high-pressure refrigerant on the exhaust side, so that the refrigerant can quickly participate in the heating cycle, reducing the time for the heating capacity to recover to the maximum output after defrosting and improving the heating capacity.

[0128] In some embodiments, Figure 1 As shown, the liquid storage container 110 also has a pressure regulating port C, and the air-conditioning system also includes: a pressure relief branch 3, on which is provided a balancing valve 112 with an on state and a off state, and the first end of the pressure relief branch 3 is connected to the pressure regulating port C. For example, the second end of the pressure relief branch 3 is connected to the low-pressure side pipeline, which is more conducive to liquid discharge, or it can also be connected to the medium-pressure side pipeline or other positions, as long as the pressure at the connected position is lower than the pressure in the liquid storage container 110; wherein, when the balancing valve 112 is in the on state, the pressure in the liquid storage container 110 is released through the pressure relief branch 3.

[0129] Specifically, the refrigerant circulation loop also includes a four-way reversing valve 103 and a gas-liquid separator 109. The four-way reversing valve 103 is used to switch between the cooling mode and the heating mode, and the gas-liquid separator 109 is arranged on the pipeline between the four-way reversing valve 103 and the air intake of the compressor 101. Based on this, the second end of the pressure relief branch 3 is connected to the pipeline at the inlet of the gas-liquid separator 109, and the gaseous refrigerant discharged through the pressure relief branch 3 can first enter the gas-liquid separator 109 for gas-liquid separation, and then the gas enters the compressor 101 to prevent the compressor 101 from sucking liquid with liquid and causing liquid hammer.

[0130] This embodiment provides a pressure relief branch 3 for the liquid storage container 110. When the pressure in the liquid storage container 110 is high and liquid cannot be collected normally, the pressure in the liquid storage container 110 can be released to the low-pressure side pipeline by connecting the balancing valve 112, thereby ensuring a pressure difference at both ends of the liquid inlet valve, which is beneficial to the subsequent smooth liquid collection and realizes efficient storage of the refrigerant.

[0131] In some embodiments, Figure 1 As shown, the liquid storage container 110 also has a pressure regulating port C, and the air-conditioning system also includes: a pressurizing branch 4, on which is provided a pressurizing valve 111 with an on state and an off state, and the first end of the pressurizing branch 4 is connected to the pressure regulating port C; wherein, when the pressurizing valve 111 is in the on state, the high-pressure side pipeline pressurizes the liquid storage container 110.

[0132] Preferably, the second end of the pressurizing branch 4 is connected to the high-pressure side pipeline to provide more sufficient pressure in the liquid storage container to facilitate smooth discharge. Optionally, the second end of the pressurizing branch 4 can also be connected to the medium-pressure side pipeline or a pipeline at another position, as long as the pressure is higher than that in the liquid storage container 110.

[0133] Specifically, the second end of the pressurizing branch 4 is connected to the pipeline between the exhaust port of the compressor 101 and the four-way reversing valve 103 .

[0134] This embodiment sets a pressurizing branch 4 for the liquid storage container 110. When the pressure in the liquid storage container 110 is low and the liquid cannot be discharged normally, the pressurizing valve 111 can be turned on to lead the high pressure of the exhaust port of the compressor 101 into the liquid storage container 110, thereby ensuring that a pressure difference is established at both ends of the discharge valve, which is conducive to smooth discharge of the liquid, so that the refrigerant in the liquid storage container 110 can be discharged efficiently, the discharge efficiency can be improved, the amount of refrigerant remaining in the liquid storage container 110 can be reduced, the larger refrigerant demand in the system can be met, and the heat exchange effect can be optimized.

[0135] In some embodiments, Figure 1As shown, the liquid inlet pipeline includes a first liquid inlet branch 1, the second end of the first liquid inlet branch 1 is connected to the medium-pressure side pipeline, and the liquid inlet valve includes a first liquid inlet valve 113 provided on the first liquid inlet branch 1; and

[0136] The drain pipeline includes a first drain branch 2, the second end of the first drain branch 2 is configured to be connected to the low-pressure side pipeline in the cooling mode and to be connected to the high-pressure side pipeline in the heating mode, and the drain valve includes a first drain valve 115 arranged on the first drain branch 2.

[0137] In this embodiment, the second end of the first liquid inlet branch 1 is connected to the medium-pressure side pipeline. Since the medium-pressure side pipeline contains liquid refrigerant and has a relatively high pressure, it is beneficial to collect the liquid refrigerant in the medium-pressure side pipeline into the liquid storage container 110, thereby achieving smooth liquid collection. The second end of the first liquid discharge branch 2 is connected to the low-pressure side pipeline in the cooling mode, so that the refrigerant discharged from the liquid storage container 110 can be merged with the refrigerant flowing out of the evaporator; the second end of the first liquid discharge branch 2 is connected to the high-pressure side pipeline in the heating mode, so that the refrigerant adjustment and refrigerant transfer functions can be realized simultaneously using the same liquid storage container 110. When realizing the refrigerant transfer function, after defrosting and heating operation are completed, the refrigerant in the liquid storage container 110 is discharged into the high-pressure side pipeline, so that the supplementary refrigerant can directly participate in the heat exchange on the indoor side, thereby improving the heating efficiency.

[0138] In some embodiments, Figure 1 As shown, the refrigerant circulation circuit also includes a four-way reversing valve 103 and a gas-liquid separator 109. The four-way reversing valve 103 is used to switch between the cooling mode and the heating mode. The gas-liquid separator 109 is arranged on the pipeline between the four-way reversing valve 103 and the air intake port of the compressor 101;

[0139] Among them, the air-conditioning system also includes a pressurizing branch 4, the second end of the first liquid discharge branch 2 is connected to the pipeline between the four-way reversing valve 103 and the evaporator, the second end of the pressurizing branch 4 is connected to the pipeline between the exhaust port of the compressor 101 and the four-way reversing valve 103, and the second end of the pressure relief branch 3 is connected between the inlet of the gas-liquid separator 109 and the four-way reversing valve 103.

[0140] In this embodiment, the second end of the first drain branch 2 is connected to the pipeline between the four-way reversing valve 103 and the evaporator. When draining in the cooling mode, the refrigerant discharged from the first drain branch 2 can flow to the four-way reversing valve 103 together with the refrigerant flowing out of the evaporator, and then enter the gas-liquid separator 109 for separation and then replenish the gaseous refrigerant to the compressor; when draining in the heating mode, the refrigerant flowing out of the compressor 101 through the four-way reversing valve 103 is combined with the refrigerant discharged from the first drain branch 2 and can enter the condenser for heat exchange, thereby achieving a larger heat exchange capacity.

[0141] The second end of the pressurizing branch 4 is connected to the pipeline between the exhaust port of the compressor 101 and the four-way reversing valve 103. The larger pressure at the exhaust port of the compressor 101 can be used to pressurize the liquid storage container 110 so that the refrigerant in the liquid storage container 110 can be discharged smoothly.

[0142] The second end of the pressure relief branch 3 is connected between the inlet of the gas-liquid separator 109 and the four-way reversing valve 103. When the pressure in the liquid storage container 110 is too high to continue collecting liquid, the gaseous refrigerant discharged through the pressure relief branch 3 can first enter the gas-liquid separator 109 for gas-liquid separation, and then the gas can enter the compressor 101 to prevent liquid hammer caused by the compressor 101 sucking in liquid.

[0143] In some embodiments, Figure 1 As shown, the liquid inlet A and the pressure regulating port C are arranged in the upper area of ​​the liquid storage container 110, and the liquid outlet B is arranged in the lower area of ​​the liquid storage container 110.

[0144] Among them, the liquid storage container 110 includes a top wall, a bottom wall and a side wall, and can be, for example, cylindrical or prismatic. The "upper area" includes the area above the top wall and the side wall, and the "lower area" includes the area below the bottom wall and the side wall. For example, the liquid inlet A can be arranged on the top wall, and after the refrigerant is introduced through the liquid inlet pipeline, it can directly fall into the bottom of the liquid storage container 110 from above, and gas-liquid separation is not easy to occur; the liquid outlet B can be arranged in the bottom area of ​​the side wall, and when the storage amount is small, the refrigerant inside the liquid storage container 110 can also be discharged smoothly; the pressure regulating port C is arranged in the upper area of ​​the side wall, which is convenient for pressure regulation by discharging gaseous refrigerant or passing high-pressure gaseous refrigerant. Optionally, the liquid inlet A can also be arranged in the lower area.

[0145] In this embodiment, the liquid inlet A can be arranged in the upper area of ​​the liquid storage container 110. After the refrigerant is introduced through the liquid inlet pipeline, it can fall directly from the top to the bottom of the liquid storage container 110 with less resistance, and the liquid can be collected smoothly. The pressure regulating port C is arranged in the upper area of ​​the liquid storage container 110, which is convenient for adjusting the pressure inside the liquid storage container 110 by releasing the gaseous refrigerant or introducing the high-pressure gaseous refrigerant. The liquid outlet B is arranged in the lower area of ​​the liquid storage container 110, so that the refrigerant inside the liquid storage container 110 can be discharged smoothly when the amount of stored liquid is small.

[0146] In some embodiments, Fig.17 As shown, the liquid inlet pipeline includes a second liquid inlet branch 5, the second end of the second liquid inlet branch 5 is connected to the low-pressure side pipeline, and the liquid inlet valve also includes a second liquid inlet valve 119 provided on the second liquid inlet branch 5; and / or

[0147] The liquid discharge pipeline includes a second liquid discharge branch 6 , a second end of the second liquid discharge branch 6 is communicated with the medium-pressure side pipeline, and the liquid discharge valve also includes a second liquid discharge valve 117 arranged on the second liquid discharge branch 6 .

[0148] In this embodiment, optionally, only the second liquid inlet branch 5 may be provided in the air-conditioning system, or both the first liquid inlet branch 1 and the second liquid inlet branch 5 may be provided.

[0149] This embodiment Figure 1 On the basis of , a second liquid inlet branch 5 and a second liquid discharge branch 6 are added. On the basis that the air-conditioning system has the functions of collecting liquid from the medium-pressure side pipeline, discharging liquid to the low-pressure side in cooling and discharging liquid to the high-pressure side pipeline in heating mode, it can also realize collecting liquid from the low-pressure side in cooling and heating mode, and discharging liquid to the medium-pressure side pipeline in cooling and heating mode. Thus, the liquid collection and discharge modes of the air-conditioning system are expanded, and liquid can be collected from different pressure areas, or the refrigerant in the liquid storage container 110 can be discharged to different pressure areas of the system. According to the actual heat exchange requirements of the air-conditioning system, the appropriate liquid collection or discharge mode can be flexibly selected to achieve the best heat exchange effect.

[0150] In some embodiments, Fig.17 As shown, the refrigerant circulation circuit also includes a four-way reversing valve 103 and a gas-liquid separator 109. The four-way reversing valve 103 is used to switch between the cooling mode and the heating mode. The gas-liquid separator 109 is arranged on the pipeline between the four-way reversing valve 103 and the suction port of the compressor 101; the second end of the second liquid inlet branch 5 is connected between the four-way reversing valve 103 and the inlet of the gas-liquid separator 109.

[0151] In this embodiment, a low-pressure side pipeline is provided between the four-way reversing valve 103 and the inlet of the gas-liquid separator 109, thereby allowing the second end of the second liquid inlet branch 5 to be connected to the low-pressure side pipeline to collect liquid from the low-pressure side in the cooling or heating mode. Moreover, the second end of the second liquid inlet branch 5 is connected to a position before the inlet of the gas-liquid separator 109, and this pipeline section contains more liquid refrigerant, facilitating liquid collection.

[0152] In some embodiments, Fig.21 and Fig. 22 As shown, a main pipeline section a is formed between the four-way reversing valve 103 and the second end of the second liquid inlet branch 5, and a branch pipeline section b is formed between the second end of the second liquid inlet branch 5 and the inlet of the gas-liquid separator 109. The main pipeline section a is connected to the second liquid inlet branch 5 and the branch pipeline section b. The second liquid inlet branch 5 is Fig. 22 The branch pipe section c.

[0153] Among them, the refrigerant flow resistance of the branch pipe section b is greater than the refrigerant flow resistance of the second liquid inlet branch 5.

[0154] This embodiment takes into account that when collecting liquid from the low-pressure side pipeline, the pressure difference between the low-pressure side pipeline and the liquid storage container 110 is relatively small. By making the refrigerant flow resistance of the branch pipeline section b greater than the refrigerant flow resistance of the second liquid inlet branch 5, the refrigerant in the main pipeline section a can flow preferentially to the second liquid inlet branch 5 for liquid collection, thereby smoothly realizing liquid collection on the low-pressure side.

[0155] In some embodiments, Figure 22 to Figure 24 , the height of the second liquid inlet branch 5 is lower than the length section of the branch pipe section b close to the second end of the second liquid inlet branch 5; and / or

[0156] The branch pipe section b is provided with a resistance increasing portion 10, which is configured to increase the refrigerant flow resistance of the branch pipe section b.

[0157] Among them, Fig. 22 As shown, the main pipeline section a and the branch pipeline section b are arranged horizontally and flush, and the branch pipeline section c is bent downward to form an L-shaped pipeline. The horizontal section of the L-shaped pipeline is lower than the branch pipeline section b. By setting the height difference, the refrigerant preferentially flows into the lower second liquid inlet branch 5.

[0158] like Fig.24 As shown, the main pipeline section a bends upward to form an L-shaped pipeline, and the second liquid inlet branch 5 bends downward to form an L-shaped pipeline. The horizontal section of the main pipeline section a is higher than the horizontal section of the second liquid inlet branch 5, and the refrigerant preferentially flows into the lower second liquid inlet branch 5.

[0159] like Fig.23 As shown, a resistance increasing portion 10 is provided on the branch pipe section b. For example, the resistance increasing portion 10 is a throttle or a curved pipe, which can increase the flow resistance of the refrigerant in the branch pipe section b, so that the refrigerant preferentially flows into the lower second liquid inlet branch 5.

[0160] The pipeline of this embodiment can make the refrigerant flow resistance of the branch pipeline section b greater than the refrigerant flow resistance of the second liquid inlet branch 5 through different structural forms, so that the refrigerant in the main pipeline section a can flow preferentially to the second liquid inlet branch 5 for liquid collection, so as to smoothly realize the liquid collection on the low-pressure side. Among them, the above resistance relationship is realized by the height difference of the pipeline, and only a specific pipeline position needs to be set when the system is laid out; by setting the resistance increasing part 10, the resistance adjustment can be realized by changing the local structure of the pipeline.

[0161] In some embodiments, Figure 32 to Figure 37As shown, the liquid inlet pipeline includes a second liquid inlet branch 5 and a pressurizing branch 4, the second end of the second liquid inlet branch 5 is connected to the low-pressure side pipeline, and the liquid inlet valve includes a second liquid inlet valve 119 arranged on the second liquid inlet branch 5; the pressurizing branch 4 is provided with a pressurizing valve 111 with an on state and an off state, and the first end of the pressurizing branch 4 is connected to the pressure regulating port C of the liquid storage container 110. For example, the second end of the pressurizing branch 4 is connected to the high-pressure side pipeline, or can also be connected to the medium-pressure side pipeline or other positions, as long as the pressure at the connected position is greater than the pressure inside the liquid storage container 110;

[0162] The liquid discharge pipeline includes a first liquid discharge branch 2 and / or a second liquid discharge branch 6, the second end of the first liquid discharge branch 2 is configured to be connected to the low-pressure side pipeline in the cooling mode, and to be connected to the high-pressure side pipeline in the heating mode; the second end of the second liquid discharge branch 6 is connected to the medium-pressure side pipeline; the liquid discharge valve includes a first liquid discharge valve 115 provided on the first liquid discharge branch 2 and a second liquid discharge valve 117 provided on the second liquid discharge branch 6;

[0163] A second control valve 121 is provided on the pipeline section between the second end of the second liquid inlet branch 5 and the air intake port of the compressor 101 in the refrigerant circulation loop; the liquid storage container 110 has an air outlet D, and the air-conditioning system also includes a first control valve 120, the first end of the first control valve 120 is connected to the air outlet D, and the second end of the first control valve 120 is connected to the pipeline section between the second control valve 121 and the air intake port of the compressor 101.

[0164] The first control valve 120 and the second control valve 121 both have an on state and an off state.

[0165] Optionally, a first liquid inlet branch 1 and a second liquid inlet branch 5 are simultaneously provided in the air-conditioning system. The first liquid inlet branch 1 and the second liquid inlet branch 5 can select one of the branches to realize liquid inlet according to actual needs, or liquid can be inlet through both branches at the same time. At the same time, a first liquid discharge branch 2 or a second liquid discharge branch 6 is provided in the air-conditioning system, thereby having two liquid inlet branches and one liquid discharge branch.

[0166] This embodiment has a low-pressure side liquid collection mode for cooling and heating, a medium-pressure side liquid discharge mode for cooling and a high-pressure side liquid discharge mode for heating. On the basis of realizing the liquid collection and discharge functions, the gas-liquid separator can be omitted, the system structure can be simplified, and the cost can be reduced. The risk of liquid inhalation in the compressor 101 can be prevented through precise control of multiple valves.

[0167] Secondly, the present disclosure provides a control method for an air conditioning system based on the above embodiment, which in some embodiments includes:

[0168] Liquid collection mode: the liquid inlet valve is turned on, and the pressure at the first end of the liquid inlet pipeline is lower than the pressure at the second end, so that the refrigerant in the refrigerant circulation loop is stored in the liquid storage container 110;

[0169] Discharge mode: when the refrigerant in the liquid storage container 110 needs to be discharged to the refrigerant circulation loop, the discharge valve is turned on and the pressure at the first end of the discharge pipeline is greater than the pressure at the second end.

[0170] When the air conditioning system is in load conversion or mode conversion, the load conversion means that the number of indoor units in the multi-split system changes. Since the air conditioning operation state changes greatly, the refrigerant in the refrigerant circulation loop can be adapted to the working demand through the liquid collection mode and the liquid discharge mode. When the air conditioning system has just switched from the defrosting mode to the heating state for a period of time, it is necessary to speed up the liquid discharge to facilitate the rapid entry of liquid refrigerant into the system to participate in the circulation.

[0171] The air-conditioning system control method of this embodiment can be connected to at least one of the low-pressure side pipeline, medium-pressure side pipeline and high-pressure side pipeline in the system through an inlet valve and a drain valve with on-off functions. On the basis of realizing the conventional refrigerant mode and the heating mode, the excess refrigerant in the refrigerant circulation loop can be collected from a specific pressure side by using the pressure difference according to the actual heat exchange demand of the air-conditioning system, or the refrigerant in the liquid storage container 110 can be discharged into the refrigerant circulation loop for replenishment according to the actual refrigerant demand, so as to achieve the best heat exchange effect and improve the heat exchange efficiency of the system.

[0172] In some embodiments, for example Figures 1 to 9 The first embodiment shown, and Figures 10 to 16 In the second embodiment shown, the air conditioning system further includes a pressure relief branch 3 and a pressurization branch 4. The pressure relief branch 3 is provided with a balancing valve 112. The first end of the pressure relief branch 3 is connected to the pressure regulating port C of the liquid storage container 110, and the second end of the pressure relief branch 3 can be connected to the low-pressure side pipeline or the medium-pressure side pipeline; the pressurization branch 4 is provided with a pressurization valve 111. The first end of the pressurization branch 4 is connected to the pressure regulating port C, and the second end of the pressurization branch 4 is connected to the high-pressure side pipeline;

[0173] The liquid inlet pipeline includes a first liquid inlet branch 1, a second end of the first liquid inlet branch 1 is connected to the medium-pressure side pipeline, and the liquid inlet valve includes a first liquid inlet valve 113 provided on the first liquid inlet branch 1;

[0174] The liquid collection mode includes: a cooling liquid collection mode and a heating liquid collection mode. In the cooling liquid collection mode and the heating liquid collection mode, the drain valve and the pressurizing valve 111 are both in the disconnected state, the first liquid inlet valve 113 is in the connected state, and when the pressure difference across the first liquid inlet valve 113 is less than a preset threshold, the balancing valve 112 is in the connected state to release the pressure in the liquid storage container 110.

[0175] in, Figure 3Schematic diagram of the refrigeration liquid collection mode, the first liquid inlet valve 113 is in the on state, and a part of the liquid refrigerant flowing out of the outdoor heat exchanger 104 enters the liquid storage container 110 through the first liquid inlet valve 113 to complete the liquid collection in the refrigeration mode. At the same time, when the pressure P0 in the liquid storage container 110 is high, so that the pressure difference between the two ends of the first liquid inlet valve 113 is small, the balance valve 112 is in the on state, and the second end of the balance valve 112 is connected to the low-pressure side pipeline, which can realize the pressure relief inside the liquid storage container 110 and make the liquid collection process proceed smoothly.

[0176] Figure 6 Schematic diagram of the heating liquid collection mode, the first liquid inlet valve 113 is in the on state, and a part of the liquid refrigerant flowing out of the indoor heat exchanger 122 enters the liquid storage container 110 through the first liquid inlet valve 113 to complete the liquid collection in the heating mode. At the same time, when the pressure P0 in the liquid storage container 110 is high, so that the pressure difference between the two ends of the first liquid inlet valve 113 is small, the balance valve 112 is in the on state, and the second end of the balance valve 112 is connected to the low-pressure side pipeline, which can realize the pressure relief inside the liquid storage container 110 and make the liquid collection process proceed smoothly.

[0177] When collecting liquid in the cooling mode or the heating mode, this embodiment enables the first liquid inlet valve 113 to be in the on state, so that the refrigerant in the medium-pressure side pipeline can enter the liquid storage container 110 to collect liquid, and when the pressure in the liquid storage container 110 is high and liquid cannot be collected normally, by enabling the balancing valve 112 to be in the on state, the pressure in the liquid storage container 110 can be discharged to the low-pressure side pipeline through the pressure relief branch 3, thereby ensuring that a pressure difference is established at both ends of the first liquid inlet valve 113, which is conducive to further smooth liquid collection and efficient storage of the refrigerant.

[0178] In some embodiments, for example Figures 10 to 16 In the second embodiment shown, the drain pipeline includes a first drain branch 2, the second end of the first drain branch 2 is configured to communicate with the low-pressure side pipeline in the cooling mode, and to communicate with the high-pressure side pipeline in the heating mode, and the drain valve includes a first drain valve 115 provided on the first drain branch 2; the drain mode also includes a cooling drain mode and a heating drain mode,

[0179] like Fig.13 As shown, in the refrigeration discharge mode, the first discharge valve 115 is in the on state, at which time the first inlet valve 113 and the balance valve 112 are both in the off state, or the discharge through the first discharge valve 115 and the inlet through the first inlet valve 113 can be performed simultaneously;

[0180] like Fig.15 and Fig.16In the heating and liquid discharge mode, the first liquid inlet valve 113 is first placed in an on state, and when the pressure in the liquid storage container 110 reaches the pressure at the second end of the first liquid inlet branch 1, the first liquid inlet valve 113 is placed in an off state; thereafter, the compressor 101 is reduced in frequency or stopped, and at this time, the first liquid discharge valve 115 is placed in an on state.

[0181] In the heating liquid discharge mode, the pressure at the exhaust port of the compressor 101 is marked as the first pressure point P1, the pressure downstream of the first liquid discharge valve 115 is marked as the second pressure point P2, and the pressure at the second end of the first liquid inlet branch 1 is marked as the third pressure point P3, that is, the position between the external machine throttling element 105 and the liquid pipe valve 106. In the heating mode operation state, P1>P2>P3.

[0182] First, if Fig.15 As shown, after the first liquid inlet valve 113 is in the on state, the pressure in the liquid storage container 110 is adjusted to a medium pressure state, that is, the pressure P0 in the liquid storage container 110 = the third pressure point P3, and then the first liquid inlet valve 113 is switched to the off state. At this time, P1>P2>P3=P0, so that the pressure in the liquid storage container 110 can be maintained.

[0183] Afterwards, if Fig.16 As shown, the compressor 101 is reduced in frequency or stopped. At this time, the pressures at the first pressure point P1, the second pressure point P2 and the third pressure point P3 are reduced, which are recorded as P1', P2' and P3'. At this time, the pressure P0 in the liquid storage container 110 remains unchanged, P0>P1'>P2'>P3'. At this time, the first liquid discharge valve 115 is in the on state, and the refrigerant in the liquid storage container 110 can be discharged.

[0184] In the cooling discharge mode, since the liquid is discharged to the low-pressure side pipeline, the first discharge valve 115 alone can be used to discharge the liquid, and the discharge function can be realized, which can simplify the control method. In the heating discharge mode, since the liquid is discharged to the high-pressure side pipeline, the pressure in the liquid storage container 110 is first increased and maintained through the first inlet valve 113. Since the second end of the first inlet valve 113 is connected to the medium-pressure side pipeline, it is still difficult to discharge the refrigerant. By reducing the frequency or stopping the operation of the compressor 101, the pressure at the second end of the first discharge branch 2 can be reduced, so that the refrigerant in the liquid storage container 110 can be discharged smoothly.

[0185] In some embodiments, for example Figures 1 to 9In the first embodiment shown, the liquid collection mode is consistent with the second embodiment. The air conditioning system further includes a pressurizing branch 4, on which a pressurizing valve 111 is provided, and the first end of the pressurizing branch 4 is connected to the pressure regulating port C; the liquid discharge pipeline includes a first liquid discharge branch 2, and the second end of the first liquid discharge branch 2 is configured to be connected to the low-pressure side pipeline in the cooling mode and to be connected to the high-pressure side pipeline in the heating mode, and the liquid discharge valve includes a first liquid discharge valve 115 provided on the first liquid discharge branch 2;

[0186] The drainage modes include: a first cooling drainage mode, a second cooling drainage mode, a first heating drainage mode, and a second heating drainage mode; wherein,

[0187] like Figure 4 As shown, in the first refrigeration liquid discharge mode, the first liquid discharge valve 115 is in the on state, and when the internal pressure P0 of the liquid storage container 110 drops to the same level as the low-pressure side pipeline, the pressurizing valve 111 is in the on state, and the first liquid inlet valve 113 and the balancing valve 112 are both in the off state;

[0188] like Figure 5 As shown, in the second refrigeration liquid discharge mode, the balancing valve 112 is in the on state, and the first liquid inlet valve 113, the first liquid discharge valve 115 and the pressurizing valve 111 are all in the off state;

[0189] like Figure 7 As shown, in the first heating liquid discharge mode, the pressurizing valve 111 is in the on state, so that the pressure inside the liquid storage container 110 is increased to the pressure at the second end of the pressurizing branch 4, and the first liquid discharge valve 115 is in the on state; the first liquid inlet valve 113 and the balance valve 112 are in the off state. Preferably, the pressurizing valve 111 is first in the on state, and after the pressure inside the liquid storage container 110 is increased to the pressure at the second end of the pressurizing branch 4, the first liquid discharge valve 115 is in the on state, so that the pressure required for liquid discharge can be easily reached. Alternatively, the pressurizing valve 111 and the first liquid discharge valve 115 can be opened at the same time.

[0190] Specifically, the pressure at the exhaust port of the compressor 101 is marked as the first pressure point P1, and the pressure downstream of the first drain valve 115 is marked as the second pressure point P2. In the heating mode, P1>P2. In this state, the pressurizing valve 111 is opened, and the pressure inside the liquid storage container 110 P0=P1>P2. Opening the first drain valve 115 can discharge the refrigerant in the liquid storage container 110.

[0191] like Figure 8 and Fig. 9As shown, in the second heating and liquid discharge mode, the pressurizing valve 111 is first placed in an on state, and when the pressure inside the liquid storage container 110 rises to the pressure at the second end of the pressurizing branch 4, the pressurizing valve 111 is switched to an off state; thereafter, the compressor 101 is reduced in frequency or stopped, and at this time, the first liquid discharge valve 115 is placed in an on state.

[0192] Specifically, first, Figure 8 As shown, after the pressure-adding valve 111 is in the on state, the pressure in the liquid storage container 110 is adjusted to a high pressure state, that is, the pressure P0 in the liquid storage container 110 = the first pressure point P1, that is, P0 = P1; at the same time, P0>P2, that is, P0=P1>P2. Next, the pressure-adding valve 111 and the first liquid discharge valve 115 are in the off state, so that the pressure in the liquid storage container 110 can be maintained.

[0193] Afterwards, if Fig.19 As shown, the compressor 101 is reduced in frequency or stopped. At this time, the pressures at the first pressure point P1 and the second pressure point P2 are reduced, which are denoted as P1' and P2'. At this time, the pressure P0 in the liquid storage container 110 remains unchanged, P0>P1'>P2'. At this time, the first liquid discharge valve 115 is in the on state, and the refrigerant in the liquid storage container 110 can be discharged.

[0194] The air conditioning system of this embodiment has two liquid discharge modes in both cooling and heating modes, and can flexibly select different liquid discharge modes according to needs to optimize the heat exchange effect. Specifically:

[0195] In the first refrigeration discharge mode, the second end of the first discharge branch 2 is connected to the low-pressure side pipeline. After the first discharge valve 115 is opened, the refrigerant can enter the system circulation. When the internal pressure of the liquid storage container 110 drops to a point where it cannot be discharged, the pressure inside the liquid storage container 110 is increased by opening the pressurizing valve 111 for a preset time, so that the refrigerant can continue to be discharged.

[0196] In the second refrigeration discharge mode, since the second end of the balancing valve 112 is connected to the low-pressure side pipeline, the balancing valve 112 is in an on state, and the refrigerant in the liquid storage container 110 can also be discharged into the system circulation. At this time, the refrigerant discharged is gaseous refrigerant, which is suitable for situations where less refrigerant needs to be added to the system.

[0197] In the first heating and drainage mode, since the second end of the first drainage branch 2 is connected to the high-pressure side pipeline, by turning on the pressurizing valve 111 during drainage, the high-pressure pipeline at the exhaust port of the compressor 101 can be used to pressurize the interior of the liquid storage container 110, thereby achieving smooth drainage in the heating mode.

[0198] In the second heating discharge mode, the pressure in the liquid storage container 110 is first increased and maintained through the pressurizing valve 111. Since the second end of the first discharge branch 2 is connected to the high-pressure side pipeline, it is difficult to discharge a large amount of refrigerant, and a lot of refrigerant will remain in the liquid storage container 110. By reducing the frequency or stopping the compressor 101, the pressure at the second end of the first discharge branch 2 can be reduced, so that the refrigerant in the liquid storage container 110 can be discharged smoothly and the discharge amount of the refrigerant can be increased.

[0199] In some embodiments, Figures 17 to 25 In the third embodiment shown, the liquid inlet pipeline includes a second liquid inlet branch 5, the second end of the second liquid inlet branch 5 is connected to the low-pressure side pipeline, and the liquid inlet valve also includes a second liquid inlet valve 119 provided on the second liquid inlet branch 5; the liquid discharge pipeline includes a second liquid discharge branch 6, the second end of the second liquid discharge branch 6 is connected to the medium-pressure side pipeline, and the liquid discharge valve also includes a second liquid discharge valve 117 provided on the second liquid discharge branch 6; a branch pipeline section b is formed between the second end of the second liquid inlet branch 5 and the inlet of the gas-liquid separator 109;

[0200] The liquid collection mode also includes: a cooling low-pressure side liquid collection mode and a heating low-pressure side liquid collection mode. In the cooling low-pressure side liquid collection mode and the heating low-pressure side liquid collection mode, the second liquid inlet valve 119 is in an on state, and when the pressure in the liquid storage container 110 increases to a point where the refrigerant flow resistance of the second liquid inlet branch 5 is greater than that of the branch pipe section b, the balancing valve 112 is opened; and / or

[0201] The discharge mode also includes: a refrigeration medium-pressure side discharge mode. In the refrigeration medium-pressure side discharge mode, the pressurizing valve 111 is first placed in an on state. When the pressure in the liquid storage container 110 rises to the pressure at the second end of the pressurizing branch 4, the pressurizing valve 111 is switched to a disconnected state. Thereafter, the second discharge valve 117 is opened.

[0202] Specifically, Fig.19 As shown, in the refrigeration low-pressure side liquid collection mode, when the second liquid inlet valve 119 is in the on state, the liquid refrigerant flows back to the low-pressure side from the gas pipe valve 107, most of the refrigerant enters the liquid storage container 110 through the second liquid inlet branch 5, and a small part flows through the branch pipe section b through the gas-liquid separator 109 and returns to the low-pressure side pipeline. When the internal pressure P0 of the liquid storage container 110 increases to a value greater than the flow resistance of the branch pipe section c, liquid collection will not be possible. At this time, the balance valve 112 can be opened to reduce the flow resistance of the branch pipe section b.

[0203] like Fig.21 As shown, in the heating low-pressure side liquid collection mode, the valve body action is Fig.19 The refrigeration low-pressure side liquid collection pattern is consistent.

[0204] like Fig. 20As shown, in the refrigeration medium-pressure side discharge mode, the pressurizing valve 111 is first placed in the on state. After the pressure P0 in the liquid storage container 110 rises to the same level as the first pressure point P1, the pressurizing valve 111 is switched to the off state; then the second discharge valve 117 is placed in the on state. At this time, the internal pressure P0 of the liquid storage container 110 is higher than the fourth pressure point P4, and the fourth pressure point P4 is the pressure at the second end of the second discharge branch 6. The refrigerant in the liquid storage container 110 can be discharged through the second discharge valve 117 and enter the medium-pressure side pipeline of the system to participate in the circulation.

[0205] like Fig.25 As shown, in the heating high pressure side liquid discharge mode, the valve body switching mode is consistent with the first heating liquid discharge mode in the first embodiment. In addition, the second heating liquid discharge mode in the first embodiment can also be realized.

[0206] This embodiment adds a second liquid inlet branch 5 and a second liquid discharge branch 6 on the basis of the first embodiment. On the basis that the air-conditioning system has the functions of collecting liquid from the medium-pressure side pipeline, discharging liquid to the low-pressure side in cooling and discharging liquid to the high-pressure side pipeline in heating mode, it can also realize collecting liquid from the low-pressure side in cooling and heating mode, and discharging liquid to the medium-pressure side pipeline in cooling and heating mode. Thus, the liquid collection and discharge modes of the air-conditioning system are expanded, and liquid can be collected from different pressure areas, or the refrigerant in the liquid storage container 110 can be discharged to different pressure areas of the system. According to the actual heat exchange requirements of the air-conditioning system, the appropriate liquid collection or discharge mode can be flexibly selected to achieve the best heat exchange effect.

[0207] In some embodiments, Figure 26 to Figure 31 In the fourth embodiment shown, the first liquid inlet valve 113 is cancelled compared with the third embodiment. The control method of the fourth embodiment in the cooling low-pressure side liquid collection mode, the heating low-pressure side liquid collection mode, the cooling medium-pressure side liquid discharge mode and the heating high-pressure side liquid discharge mode is consistent with that of the third embodiment.

[0208] In some embodiments, Figure 32 to Figure 37 As shown, the liquid inlet pipeline includes a second liquid inlet branch 5 and a pressurizing branch 4, the second end of the second liquid inlet branch 5 is connected to the low-pressure side pipeline, and the liquid inlet valve includes a second liquid inlet valve 119 provided on the second liquid inlet branch 5; the pressurizing branch 4 is provided with a pressurizing valve 111, the first end of the pressurizing branch 4 is connected to the pressure regulating port C of the liquid storage container 110, and the second end of the pressurizing branch 4 is connected to the high-pressure side pipeline;

[0209] The drain pipeline includes a first drain branch 2 and a second drain branch 6, the second end of the first drain branch 2 is configured to be connected to the low-pressure side pipeline in the cooling mode, and to be connected to the high-pressure side pipeline in the heating mode; the second end of the second drain branch 6 is connected to the medium-pressure side pipeline; the drain valve includes a first drain valve 115 provided on the first drain branch 2 and a second drain valve 117 provided on the second drain branch 6;

[0210] The refrigerant circulation loop is provided with a second control valve 121 on the pipeline section between the second end of the second liquid inlet branch 5 and the air intake port of the compressor 101; the liquid storage container 110 has an exhaust port, and the air conditioning system further includes a first control valve 120, the first end of the first control valve 120 is communicated with the exhaust port, and the second end of the first control valve 120 is connected to the pipeline section between the second control valve 121 and the air intake port of the compressor 101;

[0211] The liquid collection mode includes the cooling low-pressure side liquid collection mode and the heating low-pressure side liquid collection mode, such as Fig.34 and Fig.36 As shown, in the cooling low-pressure side liquid collection mode and the heating low-pressure side liquid collection mode, the second liquid inlet valve 119 and the first control valve 120 are in the connected state, and the other valves are in the disconnected state.

[0212] In this embodiment, under the refrigeration low-pressure side liquid collection mode, the high-pressure gaseous refrigerant discharged from the compressor 101 passes through the four-way reversing valve 103, the outdoor heat exchanger 104, the outdoor unit throttling element 105, the indoor heat exchanger 122, the four-way reversing valve 103, and the second liquid inlet valve 119 in sequence and then enters the liquid storage container 110. Subsequently, the gaseous refrigerant is discharged back to the compressor 101 through the first control valve 120. In this process, the liquid storage container 110 becomes a part of the main circulation loop. Since the refrigerant discharged through the first control valve 120 is gaseous and has a slow discharge speed, it is suitable for occasions with a smaller heat exchange requirement.

[0213] In the heating low-pressure side liquid collection mode, the high-pressure gaseous refrigerant discharged from the compressor 101 passes through the four-way reversing valve 103, the indoor heat exchanger 122, the outdoor unit throttling element 105, the outdoor heat exchanger 104, the four-way reversing valve 103, and the second liquid inlet valve 119 and then enters the liquid storage container 110. Subsequently, the gaseous refrigerant is discharged back to the compressor 101 through the first control valve 120. In this process, the liquid storage container 110 becomes a part of the main circulation loop. Since the refrigerant discharged through the first control valve 120 is gaseous and has a slow discharge speed, it is suitable for occasions with a smaller heat exchange requirement.

[0214] This embodiment can omit the gas-liquid separator, simplify the system structure, reduce costs, and prevent the risk of the compressor 101 sucking liquid through precise control of multiple valves.

[0215] In some embodiments, the liquid discharge mode includes a cooling medium-pressure side liquid discharge mode and a heating high-pressure side liquid discharge mode.

[0216] like Fig.35As shown, in the refrigeration medium pressure side liquid discharge mode, the first control valve 120 is in the disconnected state, and the second control valve 121 is in the connected state, then the pressurizing valve 111 is in the connected state to increase the pressure in the liquid storage container 110, and the second liquid discharge valve 117 is in the connected state;

[0217] Preferably, the pressurizing valve 111 is first in the on state, and when the pressure in the liquid storage container 110 rises to the pressure at the second end of the pressurizing branch 4, the pressurizing valve 111 is switched to the off state, and then the second liquid discharge valve 117 is opened. This method makes it easier to achieve pressurization and make the liquid discharge process smooth. Optionally, the pressurizing valve 111 and the second liquid discharge valve 117 can also be opened at the same time.

[0218] like Fig.37 As shown, in the heating high-pressure side liquid discharge mode, the first control valve 120 is in the disconnected state, and the second control valve 121 is in the connected state. Then, the pressurizing valve 111 is in the connected state to increase the pressure inside the liquid storage container 110, and the first liquid discharge valve 115 is in the connected state.

[0219] Preferably, the pressurizing valve 111 is first turned on, and when the pressure inside the liquid storage container 110 rises to the pressure at the second end of the pressurizing branch 4, the pressurizing valve 111 is switched to the off state, and then the first liquid discharge valve 115 is turned on. This method makes it easier to achieve pressurization and make the liquid discharge process smooth. Optionally, the pressurizing valve 111 and the first liquid discharge valve 115 can also be opened at the same time.

[0220] In the cooling medium-pressure side liquid discharge mode of this embodiment, the second control valve 121 is in the on state and connected to the low-pressure side pipeline. Since the second end of the second liquid discharge branch 6 is connected to the medium-pressure side pipeline, it is necessary to increase the pressure in the liquid storage container through the pressurizing valve 111 to facilitate smooth liquid discharge. In the heating high-pressure side liquid discharge mode, since the second end of the first liquid discharge branch 2 is connected to the high-pressure side pipeline, it is necessary to increase the pressure in the liquid storage container through the pressurizing valve 111 to facilitate smooth liquid discharge.

[0221] The five embodiments shown in the accompanying drawings are described in detail below. The valves in each embodiment may be solenoid valves and controlled by a controller.

[0222] 1. First embodiment, as Figures 1 to 9 shown.

[0223] The air conditioning system includes a compressor 101, an outdoor heat exchanger 104, an indoor heat exchanger 122, a first liquid inlet valve 113, a liquid storage container 110, a gas-liquid separator 109, a four-way reversing valve 103, a first liquid discharge valve 115, a pressurizing valve 111 and a balancing valve 112. A liquid pipe valve 106 and a gas pipe valve 107 are respectively arranged at two refrigerant interfaces of the indoor heat exchanger 122. The liquid pipe valve 106 is arranged on the pipeline between the indoor heat exchanger 122 and the outdoor heat exchanger 104, and the gas pipe valve 107 is arranged on the pipeline connected to the four-way reversing valve 103. Further, a first pressure sensor 102 is arranged between the compressor 101 and the four-way reversing valve 103, which is used to detect the refrigerant pressure at the first pressure point P1; a second pressure sensor 108 is arranged between the gas-liquid separator 109 and the four-way reversing valve 103, which is used to detect the pressure at the inlet of the gas-liquid separator 109. The air-conditioning system also includes a unloading valve 114, a first end of the unloading valve 114 is connected to the first liquid inlet branch 1 between the first liquid inlet valve 113 and the liquid inlet A, and a second end of the unloading valve 114 is connected to the inlet of the gas-liquid separator 109 on the pipeline between the four-way reversing valve 103, and is used to relieve pressure when the pressure in the first liquid inlet branch 1 exceeds a safety threshold.

[0224] The air conditioning system of the first embodiment has a conventional cooling mode, such as Figure 1 As shown, the first liquid inlet valve 113, the first liquid discharge valve 115, the pressurizing valve 111 and the balancing valve 112 are all in the disconnected state; and the conventional heating mode, such as Figure 2 As shown, the first liquid inlet valve 113, the first liquid outlet valve 115, the pressurizing valve 111 and the balancing valve 112 are all in the disconnected state.

[0225] In addition, the air conditioning system also has the following liquid collection mode and liquid discharge mode:

[0226] A. Refrigeration and liquid collection mode: Figure 3 As shown, the first liquid inlet valve 113 is in the on state, and the pressurizing valve 111, the balancing valve 112, and the first liquid discharge valve 115 are closed. The position connected to the second end of the first liquid inlet valve 113 is the medium-pressure side of the system. This valve is in the on state, and a part of the refrigerant flowing out of the outdoor heat exchanger 104 is stored in the liquid storage container 110 through the first liquid inlet valve 113 to complete the liquid collection in the cooling mode. At the same time, when the internal pressure P0 is high and the pressure difference between the two ends of the first liquid inlet valve 113 is small, the balancing valve 112 is in the on state, and the position connected to the second end of the balancing valve 112 is the low-pressure side of the system, which can achieve internal pressure relief of the liquid storage container 110.

[0227] B. First refrigeration discharge mode: Figure 4As shown, the pressurizing valve 111 and the first liquid discharge valve 115 are in the on state, and the first liquid inlet valve 113 and the balancing valve 112 are in the off state. The position connected to the second end of the first liquid discharge valve 115 is the low-pressure side of the system. When this valve is in the on state, the refrigerant in the liquid storage container 110 is discharged and enters the system circulation through the first liquid discharge valve 115. When the internal pressure P0 of the liquid storage container 110 drops to the same level as the low pressure and can no longer be discharged, the pressurizing valve 111 can be in the on state for a preset time to increase the internal pressure P0 of the liquid storage container 110.

[0228] C. Second refrigeration discharge mode: Figure 5 As shown, the balancing valve 112 is in the on state, and the pressurizing valve 111, the first liquid inlet valve 113, and the first liquid discharge valve 115 are in the off state. The second end of the balancing valve 112 is connected to the low-pressure side of the system. When this valve is in the on state, the refrigerant in the liquid storage container 110 is discharged and enters the system circulation through the balancing valve 112.

[0229] D. Heating and liquid collection mode: Figure 6 As shown, the same as the cooling liquid collection mode.

[0230] For ease of understanding, two pressure point concepts are introduced. The first pressure point is located after the compressor 101 and before the four-way reversing valve 103, where the pressure is recorded as P1; the second pressure point is located after the four-way reversing valve 103 and before the tracheal valve 107, where the pressure is recorded as P2.

[0231] E. First heating and liquid discharge mode: Figure 7 As shown, the pressurizing valve 111 and the first liquid discharge valve 115 are in the connected state, and the first liquid inlet valve 113 and the balancing valve 112 are in the disconnected state. At this time, the second end of the pressurizing valve 111 is connected to the first pressure point P1; the second end of the first liquid discharge valve 115 is connected to the second pressure point P2, P1>P2. In this mode, the pressurizing valve 111 is in the connected state, and the internal pressure P0 of the liquid storage container 110 is P1>P2, and the first liquid discharge valve 115 is in the connected state, which can realize the discharge of the refrigerant in the liquid storage container 110.

[0232] F. Second heating and drainage mode:

[0233] ①First, if Figure 8 As shown, the liquid storage container 110 is adjusted to a high pressure state by the pressurizing valve 111 in the on state, and then the pressurizing valve 111 is closed. At this time, the internal pressure P0 of the liquid storage container 110 is equal to the first pressure point P1, that is, P0 = P1; at the same time, P0 is higher than the second high pressure P2 of the first end system of the first liquid discharge valve 115, that is, P0>P2. P0=P1>P2.

[0234] ②Afterwards, if Fig. 9As shown, the compressor 101 is reduced in frequency or stopped, and the pressures at the first pressure point and the second pressure point are reduced, which are recorded as P1' and P2'. At this time, the internal pressure P0 of the liquid storage container 110 remains unchanged, P0>P1'>P2', and the first liquid discharge valve 115 is in the on state, and the refrigerant therein can be discharged.

[0235] In different operation modes, each valve body connected to the liquid storage container 110 operates as follows:

[0236] Table 1 Valve body movements in various working modes of the first embodiment

[0237]

[0238]

[0239] Second, the second embodiment, as Figures 10 to 16 shown.

[0240] On the basis of the first embodiment, the pressurizing valve 111 and the pressurizing branch 4 are eliminated, and the other components, the liquid storage container 110, and the valve body connection features remain the same.

[0241] The air conditioning system of the second embodiment has a conventional cooling mode, such as Fig.10 As shown, the first liquid inlet valve 113, the first liquid outlet valve 115 and the balance valve 112 are all in the disconnected state; and the conventional heating mode, such as Fig.11 As shown, the first liquid inlet valve 113, the first liquid outlet valve 115 and the balance valve 112 are all in the disconnected state.

[0242] In addition, the air conditioning system also has the following liquid collection mode and liquid discharge mode:

[0243] A. Refrigeration and liquid collection mode: Fig.12 As shown, it is consistent with the refrigeration liquid collection mode of the first embodiment.

[0244] B. Refrigeration discharge mode: Fig.13 As shown, the first liquid discharge valve 115 is in the on state, and the first liquid inlet valve 113 and the balance valve 112 are in the off state. The position connected to the second end of the first liquid discharge valve 115 is the low-pressure side of the system. When this valve is in the on state, the refrigerant in the liquid storage container 110 is discharged and enters the system circulation through the first liquid discharge valve 115.

[0245] C. Heating and liquid collection mode: Fig.14 As shown, it is consistent with the heating liquid collection mode of the first embodiment.

[0246] For ease of understanding, the concept of the third pressure point is introduced. The third pressure point is located after the air pipe valve 107 in the heating flow direction and before the throttling element 105 of the heating external unit. The pressure here is recorded as P3. In the heating mode, P1>P2>P3.

[0247] D. Heating and draining mode:

[0248] ①First, if Fig.15 As shown, by making the first liquid inlet valve 113 in the on state, the liquid storage container 110 is adjusted to the medium pressure state, that is, the internal pressure P0 of the liquid storage container 110 = the third pressure point P3, and then the first liquid inlet valve 113 is switched to the off state. At this time, P1>P2>P3=P0.

[0249] ②Afterwards, if Fig.16 As shown, the compressor 101 is reduced in frequency or stopped, and the pressures at the first pressure point, the second pressure point, and the third pressure point are reduced, which are recorded as P1', P2', and P3'. At this time, the internal pressure P0 of the liquid storage container remains unchanged, P0>P1'>P2'>P3', and at this time, the first liquid discharge valve 115 is in the on state, and the refrigerant in the liquid storage container 110 can be discharged.

[0250] In different operation modes, each valve body connected to the liquid storage container 110 operates as follows:

[0251] Table 2 Valve body movements in each working mode of the second embodiment

[0252]

[0253] 3. The third embodiment, Figures 17 to 25 shown.

[0254] On the basis of the first embodiment, a second liquid inlet valve 119 and a second liquid discharge valve 117 connected to the low-pressure side pipeline are added. In addition to retaining the first embodiment's liquid collection from the medium-pressure side for cooling / heat, liquid discharge from cooling to the low-pressure side, and liquid discharge from heating to the high-pressure side, it is also possible to collect liquid from the low-pressure side for cooling / heat and discharge liquid from cooling to the medium-pressure side for cooling / heat.

[0255] The second end connected to the second liquid inlet valve 119 is located after the four-way reversing valve 103 in the refrigeration flow direction and before the gas-liquid separator 109, and the first end is a connecting pipeline connected to the liquid storage container 110. The second end connected to the second liquid discharge valve 117 is located after the first end of the second liquid inlet valve 119 in the refrigeration flow direction and before the gas-liquid separator 109, and the first end is a connecting pipeline connected to the liquid storage container 110.

[0256] For ease of understanding, a concept of a pressure point is introduced: The fourth pressure point is located at the second end of the second liquid discharge valve 117, and the pressure here is recorded as P4.

[0257] The air conditioning system of the second embodiment has a conventional cooling mode, such as Fig.17 As shown, the first liquid inlet valve 113, the first liquid outlet valve 115, the balancing valve 112, the second liquid inlet valve 119 and the second liquid outlet valve 117 are all in the disconnected state; and the conventional heating mode, such as Fig.18 As shown, the first liquid inlet valve 113, the first liquid outlet valve 115, the balance valve 112, the second liquid inlet valve 119 and the second liquid outlet valve 117 are all in the disconnected state.

[0258] In addition, the air conditioning system also has the following liquid collection mode and liquid discharge mode:

[0259] A. Refrigeration low pressure side liquid collection mode: Fig.19 As shown, the second liquid inlet valve 119 is in the on state, and the pressurizing valve 111, the balancing valve 112, the first liquid inlet valve 113, the first liquid discharge valve 115, and the second liquid discharge valve 117 are in the off state. After the second liquid inlet valve 119 is in the on state, most of the liquid refrigerant flowing back to the low-pressure side from the gas pipe valve 107 enters the liquid storage container 110 through the second liquid inlet branch 5, and a small part flows through the branch pipe section b through the gas-liquid separator 109 and returns to the low-pressure side. When the internal pressure of the liquid storage container 110 rises to the point where the flow resistance of the second liquid inlet branch 5 is greater than the flow resistance of the main pipe section a, the liquid storage container 110 cannot continue to collect liquid, and the balancing valve 112 can be opened to reduce the flow resistance of the second liquid inlet branch 5.

[0260] B. Refrigeration medium pressure side discharge mode: Fig. 20 As shown, the balancing valve 112, the first liquid inlet valve 113, the first liquid discharge valve 115, and the second liquid inlet valve 119 are in the disconnected state. First, the pressurizing valve 111 is in the connected state, and after the internal pressure P0 of the liquid storage container 110 is increased to the same as the first pressure point P1, the pressurizing valve 111 is disconnected; then the second liquid discharge valve 117 is in the connected state, and at this time, the internal pressure P0 of the liquid storage container 110 is higher than the fourth pressure point P4, and the refrigerant in the liquid storage container 110 can be discharged through the second liquid discharge valve 117 and enter the medium pressure side of the system to participate in the circulation.

[0261] C. Heating low-pressure side liquid collection mode: Fig.21 As shown, the valve body action is consistent with the refrigeration low-pressure side liquid collection mode of the third embodiment.

[0262] D. Heating high pressure side discharge mode: Fig.25 As shown, the action of the valve body is consistent with the first heating liquid discharge and liquid collection mode of the first embodiment.

[0263] In different operation modes, each valve body connected to the liquid storage container 110 operates as follows:

[0264] Table 3 Valve body movements in each working mode of the third embodiment

[0265]

[0266]

[0267] 4. The fourth embodiment, Figure 26 to Figure 31As shown.

[0268] On the basis of the third embodiment, the first liquid inlet valve 113 is cancelled, and the rest remains unchanged, and only the functions of collecting liquid from the low-pressure side for cooling / heating, discharging liquid to the medium-pressure side for cooling, and discharging liquid to the high-pressure side for heating are retained.

[0269] The air conditioning system of the fourth embodiment has a conventional cooling mode, such as Fig.26 As shown, the first liquid inlet valve 113, the first liquid outlet valve 115 and the balance valve 112 are all in the disconnected state; and the conventional heating mode, such as Fig. 27 As shown, the first liquid inlet valve 113, the first liquid outlet valve 115 and the balance valve 112 are all in the disconnected state.

[0270] In addition, the air conditioning system also has the following liquid collection mode and liquid discharge mode:

[0271] A. Refrigeration low pressure side liquid collection mode: Fig.28 As shown, the valve body action is consistent with the refrigeration low-pressure side liquid collection mode of the third embodiment.

[0272] B. Refrigeration medium pressure side discharge mode: Fig.29 As shown, the valve body action is consistent with the refrigeration medium-pressure side liquid discharge mode of the third embodiment.

[0273] C. Heating low-pressure side liquid collection mode: Fig.30 As shown, the valve body action is consistent with the heating low-pressure side liquid collection mode of the third embodiment.

[0274] D. Heating high pressure side discharge mode: Fig.31 As shown, the valve body action is consistent with the heating high-pressure side liquid discharge mode of the third embodiment.

[0275] In different operation modes, each valve body connected to the liquid storage container 110 operates as follows:

[0276] Table 4 Valve body movements in each working mode of the fourth embodiment

[0277]

[0278]

[0279] 5. The fifth embodiment, as Figure 32 to Figure 37 As shown.

[0280] On the basis of the fourth embodiment, the gas-liquid separator 109 and the balancing valve 112 are cancelled, and the first control valve 120 and the second control valve 121 are added to realize the collection of liquid from the low-pressure side and the discharge of liquid to the medium-pressure side for refrigeration, and the collection of liquid from the low-pressure side and the discharge of liquid to the high-pressure side for heating.

[0281] The air conditioning system of the fifth embodiment has a conventional cooling mode, such as Fig.32As shown, the second control valve 121 is in the on state, the second liquid inlet valve 119, the first liquid discharge valve 115, the second liquid discharge valve 117 and the pressurizing valve 111 are all in the off state; and the conventional heating mode, such as Fig.33 As shown, the second control valve 121 is in an on state, and the first liquid inlet valve 113, the first liquid outlet valve 115 and the balance valve 112 are all in an off state.

[0282] In addition, the air conditioning system also has the following liquid collection mode and liquid discharge mode:

[0283] A. Refrigeration low-pressure side liquid collection mode: Fig.34 As shown, the pressurizing valve 111, the first liquid discharge valve 115, the second liquid discharge valve 117, the second liquid inlet valve 119, and the second control valve 121 are in the disconnected state. The second liquid inlet valve 119 and the first control valve 120 are opened, and the refrigerant returning to the low-pressure side from the four-way reversing valve 103 first enters the liquid storage container 110 through the second liquid inlet valve 119, and most of the liquid refrigerant is stored in the liquid storage container 110, and the remaining small part of the gaseous refrigerant returns to the suction side of the compressor 101.

[0284] B. Refrigeration medium pressure side discharge mode: Fig.35 As shown, the first control valve 120 is in the disconnected state, the second control valve 121 is in the connected state, and the actions of the other valve bodies are consistent with the refrigeration medium-pressure side liquid discharge mode of the fourth embodiment.

[0285] C. Heating low pressure side liquid collection mode, such as Fig.36 As shown, the valve body action is consistent with the refrigeration low-pressure side liquid collection mode of the fifth embodiment.

[0286] D. Heating high pressure side discharge mode, such as Fig.37 As shown, the first control valve 120 is in an off state, the second control valve 121 is in an on state, and the actions of the remaining valve bodies are consistent with the heating high-pressure side liquid discharge mode of the fourth embodiment.

[0287] In different operation modes, each valve body connected to the liquid storage container 110 operates as follows:

[0288] Table 5 Valve body movements in each working mode of the fifth embodiment

[0289]

[0290] Although some specific embodiments of the present disclosure have been described in detail by way of examples, it should be understood by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the present disclosure. It should be understood by those skilled in the art that the above embodiments may be modified or some technical features may be replaced by equivalents without departing from the scope and spirit of the present disclosure. The scope of the present disclosure is defined by the appended claims.

Claims

1. An air conditioning system, characterized in that: include: A refrigerant circulation loop is provided with a compressor (101), an evaporator and a condenser, a high-pressure side pipeline is between the exhaust port of the compressor (101) and the condenser, a medium-pressure side pipeline is between the condenser and the evaporator, and a low-pressure side pipeline is between the evaporator and the air intake port of the compressor (101); A liquid storage container (110), used for storing refrigerant and having a liquid inlet (A) and a liquid outlet (B); a liquid inlet pipeline, on which a liquid inlet valve having an on state and an off state is provided, a first end of the liquid inlet pipeline is connected to the liquid inlet port (A), and a second end of the liquid inlet pipeline is connected to at least one of the low-pressure side pipeline, the medium-pressure side pipeline and the high-pressure side pipeline; and a liquid discharge pipeline, on which a liquid discharge valve having an on state and an off state is provided, a first end of the liquid discharge pipeline being in communication with the liquid outlet (B), and a second end of the liquid discharge pipeline being in communication with at least one of the low-pressure side pipeline, the medium-pressure side pipeline and the high-pressure side pipeline; Wherein, when the liquid inlet valve is in an on state, the pressure at the first end of the liquid inlet branch is lower than the pressure at the second end, so that the refrigerant in the refrigerant circulation loop is stored in the liquid storage container (110) by utilizing the pressure difference; when the liquid discharge valve is in an on state, the pressure at the first end of the liquid discharge branch is higher than the pressure at the second end, so that the refrigerant in the liquid storage container (110) is discharged to the refrigerant circulation loop by utilizing the pressure difference.

2. The air conditioning system according to claim 1, characterized in that: The liquid storage container (110) further comprises a pressure regulating port (C), and the air conditioning system further comprises: A pressure relief branch (3) is provided with a balancing valve (112) having an on state and an off state, and a first end of the pressure relief branch (3) is connected to the pressure regulating port (C); Wherein, when the balancing valve (112) is in an on state, the pressure in the liquid storage container (110) is released through the pressure relief branch (3).

3. The air conditioning system according to claim 1 or 2, characterized in that: The liquid storage container (110) further comprises a pressure regulating port (C), and the air conditioning system further comprises: A pressurizing branch (4) is provided with a pressurizing valve (111) having an on state and an off state, and a first end of the pressurizing branch (4) is connected to the pressure regulating port (C); When the pressurizing valve (111) is in an on state, the high-pressure side pipeline pressurizes the liquid storage container (110).

4. The air conditioning system according to claim 1, characterized in that: The liquid inlet pipeline comprises a first liquid inlet branch (1), a second end of the first liquid inlet branch (1) is connected to the medium-pressure side pipeline, and the liquid inlet valve comprises a first liquid inlet valve (113) provided on the first liquid inlet branch (1); and The liquid discharge pipeline comprises a first liquid discharge branch (2), the second end of the first liquid discharge branch (2) being configured to communicate with the low-pressure side pipeline in a cooling mode and to communicate with the high-pressure side pipeline in a heating mode, and the liquid discharge valve comprises a first liquid discharge valve (115) arranged on the first liquid discharge branch (2).

5. The air conditioning system according to claim 4, characterized in that: The refrigerant circulation loop further comprises a four-way reversing valve (103) and a gas-liquid separator (109), wherein the four-way reversing valve (103) is used for reversing when switching between a cooling mode and a heating mode, and the gas-liquid separator (109) is arranged on a pipeline between the four-way reversing valve (103) and an air intake port of the compressor (101); The air conditioning system further comprises a pressurizing branch (4), the second end of the first liquid discharge branch (2) is connected to the pipeline between the four-way reversing valve (103) and the evaporator, the second end of the pressurizing branch (4) is connected to the pipeline between the exhaust port of the compressor (101) and the four-way reversing valve (103), and the second end of the pressure relief branch (3) is connected between the inlet of the gas-liquid separator (109) and the four-way reversing valve (103).

6. The air conditioning system according to claim 3, characterized in that: The liquid inlet (A) and the pressure regulating port (C) are arranged in the upper region of the liquid storage container (110), and the liquid outlet (B) is arranged in the lower region of the liquid storage container (110).

7. The air conditioning system according to any one of claims 1 to 6, characterized in that: The liquid inlet pipeline comprises a second liquid inlet branch (5), a second end of the second liquid inlet branch (5) is connected to the low-pressure side pipeline, and the liquid inlet valve further comprises a second liquid inlet valve (119) arranged on the second liquid inlet branch (5); and / or The liquid discharge pipeline comprises a second liquid discharge branch (6), a second end of the second liquid discharge branch (6) being in communication with the medium-pressure side pipeline, and the liquid discharge valve further comprises a second liquid discharge valve (117) arranged on the second liquid discharge branch (6).

8. The air conditioning system according to claim 7, characterized in that: The refrigerant circulation loop further comprises a four-way reversing valve (103) and a gas-liquid separator (109), wherein the four-way reversing valve (103) is used for reversing when switching between a cooling mode and a heating mode, and the gas-liquid separator (109) is arranged on a pipeline between the four-way reversing valve (103) and an air intake port of the compressor (101); The second end of the second liquid inlet branch (5) is connected between the four-way reversing valve (103) and the inlet of the gas-liquid separator (109).

9. The air conditioning system according to claim 8, characterized in that: A main pipeline section (a) is formed between the four-way reversing valve (103) and the second end of the second liquid inlet branch (5), and a branch pipeline section (b) is formed between the second end of the second liquid inlet branch (5) and the inlet of the gas-liquid separator (109), and the main pipeline section (a) is connected to both the second liquid inlet branch (5) and the branch pipeline section (b); Wherein, the refrigerant flow resistance of the branch pipe section (b) is greater than the refrigerant flow resistance of the second liquid inlet branch (5).

10. The air conditioning system according to claim 9, characterized in that The height of the second liquid inlet branch (5) is lower than the length section of the branch pipe section (b) close to the second end of the second liquid inlet branch (5); and / or The branch pipe section (b) is provided with a resistance increasing portion (10), and the resistance increasing portion (10) is configured to increase the refrigerant flow resistance of the branch pipe section (b).

11. The air conditioning system according to claim 1, characterized in that: The liquid inlet pipeline comprises a second liquid inlet branch (5) and a pressurizing branch (4); the second end of the second liquid inlet branch (5) is in communication with the low-pressure side pipeline; the liquid inlet valve comprises a second liquid inlet valve (119) provided on the second liquid inlet branch (5); the pressurizing branch (4) is provided with a pressurizing valve (111) having an on state and an off state; the first end of the pressurizing branch (4) is in communication with a pressure regulating port (C) of the liquid storage container (110); The liquid discharge pipeline comprises a first liquid discharge branch (2) and / or a second liquid discharge branch (6); the second end of the first liquid discharge branch (2) is configured to communicate with the low-pressure side pipeline in a cooling mode, and to communicate with the high-pressure side pipeline in a heating mode; the second end of the second liquid discharge branch (6) is connected to the medium-pressure side pipeline; the liquid discharge valve comprises a first liquid discharge valve (115) provided on the first liquid discharge branch (2) and a second liquid discharge valve (117) provided on the second liquid discharge branch (6); The refrigerant circulation loop is provided with a second control valve (121) on the pipeline section between the second end of the second liquid inlet branch (5) and the air intake port of the compressor (101); the liquid storage container (110) has an air outlet (D), and the air-conditioning system also includes a first control valve (120), the first end of the first control valve (120) is connected to the air outlet (D), and the second end of the first control valve (120) is connected to the pipeline section between the second control valve (121) and the air intake port of the compressor (101).

12. A control method for an air conditioning system according to any one of claims 1 to 11, characterized in that: include: Liquid collection mode: the liquid inlet valve is in an on state, and the pressure at the first end of the liquid inlet pipeline is made lower than the pressure at the second end, so that the refrigerant in the refrigerant circulation loop is stored in the liquid storage container (110); Discharge mode: when it is necessary to discharge the refrigerant in the liquid storage container (110) to the refrigerant circulation circuit, the discharge valve is turned on and the pressure at the first end of the discharge pipeline is greater than the pressure at the second end.

13. The control method according to claim 12, characterized in that: The air conditioning system further comprises a pressure relief branch (3) and a pressure increase branch (4); the pressure relief branch (3) is provided with a balancing valve (112), and a first end of the pressure relief branch (3) is in communication with a pressure regulating port (C) of the liquid storage container (110); the pressure increase branch (4) is provided with a pressure increase valve (111), and a first end of the pressure increase branch (4) is in communication with the pressure regulating port (C); The liquid inlet pipeline comprises a first liquid inlet branch (1), a second end of the first liquid inlet branch (1) is connected to the medium-pressure side pipeline, and the liquid inlet valve comprises a first liquid inlet valve (113) arranged on the first liquid inlet branch (1); The liquid collection mode comprises: a cooling liquid collection mode and a heating liquid collection mode. In the cooling liquid collection mode and the heating liquid collection mode, the drain valve and the pressurizing valve (111) are both in an open state, the first liquid inlet valve (113) is in an open state, and when the pressure difference across the first liquid inlet valve (113) is less than a preset threshold, the balancing valve (112) is in an open state to release the pressure in the liquid storage container (110).

14. The control method according to claim 13, characterized in that: The liquid discharge pipeline comprises a first liquid discharge branch (2), the second end of the first liquid discharge branch (2) being configured to communicate with the low-pressure side pipeline in a cooling mode and to communicate with the high-pressure side pipeline in a heating mode, the liquid discharge valve comprising a first liquid discharge valve (115) provided on the first liquid discharge branch (2); the liquid discharge mode further comprises a cooling liquid discharge mode and a heating liquid discharge mode, In the refrigeration liquid discharge mode, the first liquid discharge valve (115) is in an on state, and the first liquid inlet valve (113) and the balancing valve 112 are both in an off state; In the heating and liquid discharge mode, the first liquid inlet valve (113) is first placed in an on state, and when the pressure in the liquid storage container (110) reaches the pressure at the second end of the first liquid inlet branch (1), the first liquid inlet valve (113) is placed in an off state; thereafter, the compressor (101) is reduced in frequency or stopped, and at this time, the first liquid discharge valve (115) is placed in an on state.

15. The control method according to claim 13, characterized in that: The air conditioning system further comprises a pressurizing branch (4), on which a first end of the pressurizing branch (4) is connected to the pressure regulating port (C), and a pressurizing valve (111) is provided on the pressurizing branch (4); the liquid discharge pipeline comprises a first liquid discharge branch (2), a second end of the first liquid discharge branch (2) is configured to be connected to the low-pressure side pipeline in a cooling mode and to be connected to the high-pressure side pipeline in a heating mode, and the liquid discharge valve comprises a first liquid discharge valve (115) provided on the first liquid discharge branch (2); The drainage modes include: a first cooling drainage mode, a second cooling drainage mode, a first heating drainage mode, and a second heating drainage mode; wherein, In the first refrigeration liquid discharge mode, the first liquid discharge valve (115) is in an on state, and when the internal pressure of the liquid storage container (110) drops to the same level as the low-pressure side pipeline, the pressurizing valve (111) is in an on state, and the first liquid inlet valve (113) and the balancing valve (112) are both in an off state; In the second refrigeration liquid discharge mode, the balancing valve (112) is in an on state, and the first liquid inlet valve (113), the first liquid discharge valve (115) and the pressurizing valve (111) are all in an off state; In the first heating liquid discharge mode, the pressurizing valve (111) is in an on state, so that the pressure inside the liquid storage container (110) is increased to the pressure at the second end of the pressurizing branch (4), and the first liquid discharge valve (115) is in an on state; In the second heating and liquid discharge mode, the pressurizing valve (111) is first placed in an on state, and when the pressure inside the liquid storage container (110) rises to the pressure at the second end of the pressurizing branch (4), the pressurizing valve (111) is switched to an off state; thereafter, the compressor (101) is reduced in frequency or stopped, and at this time, the first liquid discharge valve (115) is placed in an on state.

16. The control method according to claim 15, characterized in that: The liquid inlet pipeline comprises a second liquid inlet branch (5), the second end of the second liquid inlet branch (5) is in communication with the low-pressure side pipeline, and the liquid inlet valve further comprises a second liquid inlet valve (119) arranged on the second liquid inlet branch (5); the liquid discharge pipeline comprises a second liquid discharge branch (6), the second end of the second liquid discharge branch (6) is in communication with the medium-pressure side pipeline, and the liquid discharge valve further comprises a second liquid discharge valve (117) arranged on the second liquid discharge branch (6); a branch pipeline section (b) is formed between the second end of the second liquid inlet branch (5) and the inlet of the gas-liquid separator (109); The liquid collection mode also includes: a cooling low-pressure side liquid collection mode and a heating low-pressure side liquid collection mode. In the cooling low-pressure side liquid collection mode and the heating low-pressure side liquid collection mode, the second liquid inlet valve (119) is in an on state, and when the pressure in the liquid storage container (110) rises to a point where the refrigerant flow resistance of the second liquid inlet branch (5) is greater than that of the branch pipe section (b), the balancing valve (112) is opened; and / or The drainage mode also includes: a refrigeration medium-pressure side drainage mode, in which the pressurizing valve (111) is first placed in an on state, and when the pressure in the liquid storage container (110) rises to the pressure at the second end of the pressurizing branch (4), the pressurizing valve (111) is switched to an off state; thereafter, the second drainage valve (117) is opened.

17. The control method according to claim 12, characterized in that: The liquid inlet pipeline comprises a second liquid inlet branch (5) and a pressurizing branch (4); the second end of the second liquid inlet branch (5) is in communication with the low-pressure side pipeline; the liquid inlet valve comprises a second liquid inlet valve (119) provided on the second liquid inlet branch (5); the pressurizing branch (4) is provided with a pressurizing valve (111); the first end of the pressurizing branch (4) is in communication with the pressure regulating port (C) of the liquid storage container (110); The liquid discharge pipeline comprises a first liquid discharge branch (2) and a second liquid discharge branch (6); the second end of the first liquid discharge branch (2) is configured to communicate with the low-pressure side pipeline in a cooling mode, and to communicate with the high-pressure side pipeline in a heating mode; the second end of the second liquid discharge branch (6) is connected to the medium-pressure side pipeline; the liquid discharge valve comprises a first liquid discharge valve (115) provided on the first liquid discharge branch (2) and a second liquid discharge valve (117) provided on the second liquid discharge branch (6); The refrigerant circulation loop is provided with a second control valve (121) on the pipeline section between the second end of the second liquid inlet branch (5) and the air intake port of the compressor (101); the liquid storage container (110) has an exhaust port, and the air conditioning system further comprises a first control valve (120), wherein the first end of the first control valve (120) is connected to the exhaust port, and the second end of the first control valve (120) is connected to the pipeline section between the second control valve (121) and the air intake port of the compressor (101); The liquid collection mode includes a cooling low-pressure side liquid collection mode and a heating low-pressure side liquid collection mode. In the cooling low-pressure side liquid collection mode and the heating low-pressure side liquid collection mode, the second liquid inlet valve (119) and the first control valve (120) are in an on state.

18. The control method according to claim 17, characterized in that: The discharge mode includes a cooling medium-pressure side discharge mode and a heating high-pressure side discharge mode. In the refrigeration medium-pressure side liquid discharge mode, the first control valve (120) is in an off state, and the second control valve (121) is in an on state, and then the pressurizing valve (111) is in an on state to increase the pressure in the liquid storage container (110), and the second liquid discharge valve (117) is in an on state; In the heating high-pressure side liquid discharge mode, the first control valve (120) is in an off state, and the second control valve (121) is in an on state. Then, the pressurizing valve (111) is in an on state to increase the pressure inside the liquid storage container (110), and the first liquid discharge valve (115) is in an on state.

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