Air conditioning system and control method thereof

Abstract

The present disclosure relates to an air conditioning system and a control method thereof, wherein the air conditioning system comprises: a refrigerant circulation loop; a liquid storage container for storing refrigerant and having an inlet and an outlet; an inlet branch provided with an inlet valve having an on state and an off state, a first end of the inlet branch being in communication with the inlet, and a second end of the inlet branch being in communication with a medium-pressure side pipeline; and a discharge branch provided with a discharge valve having an on state and an off state, a first end of the discharge branch being in communication with the outlet, and a second end of the discharge branch being in communication with the refrigerant circulation loop; wherein, when the inlet valve is in the on state, the pressure at the first end of the inlet branch is less than the pressure at the second end, so as to store refrigerant in the refrigerant circulation loop into the liquid storage container by means of the pressure difference; and when the discharge valve is in the on state, the pressure at the first end of the discharge branch is greater than the pressure at the second end, so as to discharge refrigerant in the liquid storage container to the refrigerant circulation loop by means of the pressure difference.

Description

Technical Field

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

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

[0003] Current multi-split air conditioning systems can only achieve conventional cooling and heating modes, and their heat exchange efficiency is relatively low. Summary of the Invention

[0004] Some embodiments of this disclosure provide an air conditioning system and its control method, which can improve the energy efficiency of the air conditioning system.

[0005] The first aspect of this disclosure provides an air conditioning system, comprising:

[0006] The refrigerant circulation loop is equipped with a compressor, evaporator and condenser. The high-pressure side pipeline is between the compressor's discharge port 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 compressor's suction port.

[0007] A liquid storage container used to store refrigerant and having an inlet and an outlet;

[0008] The inlet branch is equipped with an inlet valve that has an on and off state. The first end of the inlet branch is connected to the inlet port, and the second end is connected to the medium-pressure side pipeline.

[0009] The drain branch is equipped with a drain valve that has an on and off state. The first end of the drain branch is connected to the liquid outlet, and the second end of the drain branch is connected to the refrigerant circulation loop.

[0010] Specifically, when the inlet valve is in the on state, the pressure at the first end of the inlet branch is less than the pressure at the second end, so as to use the pressure difference to store the refrigerant in the refrigerant circulation loop into the storage container; when the drain valve is in the on state, the pressure at the first end of the drain branch is greater than the pressure at the second end, so as to use the pressure difference to discharge the refrigerant in the storage container into the refrigerant circulation loop.

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

[0012] The pressure relief branch is equipped with a balance valve that has an on and off state, and the 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 second end of the drain branch is configured to be connected to the low-pressure side pipeline in the cooling mode, and the drain valve is configured to be in the on state in the cooling mode.

[0015] In some embodiments, the inlet valve is in the on state in defrosting mode, the drain valve is in the on state in the initial stage of switching to heating mode after defrosting ends, and the second end of the drain branch is configured to be connected to the high-pressure side pipeline in heating mode.

[0016] In some embodiments, the liquid storage container further includes a pressure regulating port, and the air conditioning system further includes:

[0017] A pressurizing branch is equipped with a pressurizing valve that has an on and off state, and the first end of the pressurizing branch is connected to the pressure regulating port.

[0018] When the pressure valve is in the on state, the high-pressure side pipeline pressurizes the liquid storage container.

[0019] In some embodiments, the air conditioning system further includes an auxiliary drain branch, which is provided with an auxiliary drain valve having an on state and an off state. The first end of the auxiliary drain branch is connected to the drain outlet, and the second end of the auxiliary drain branch is connected to the low-pressure side pipeline.

[0020] In some embodiments, the air conditioning system further includes an unloading branch, a first end of which is connected to a liquid inlet, and a second end of which is connected to a low-pressure side pipeline. The unloading branch is provided with an unloading valve having an on state and an off state. The unloading valve is configured to be in the on state when the pressure in the liquid storage container is higher than a preset safety threshold.

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

[0022] 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 when switching between cooling mode and heating mode, and the gas-liquid separator is provided on the pipeline between the four-way reversing valve and the compressor suction port.

[0023] The air conditioning system also includes a pressure relief branch and a pressure boosting branch. The first end of each of the pressure relief branch and the pressure boosting branch is connected to the pressure regulating port of the liquid storage container. The second end of the pressure relief branch is connected to the low-pressure side pipeline, and the second end of the pressure boosting branch is connected to the high-pressure side pipeline.

[0024] The second end of the drain 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 compressor's discharge port 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.

[0025] In some embodiments, the liquid storage container is built into the outdoor unit assembly.

[0026] A second aspect of this disclosure provides a control method for an air conditioning system based on the above embodiments, comprising:

[0027] Liquid collection step: Turn on the liquid inlet valve and make the pressure at the first end of the liquid inlet branch less than the pressure at the second end, so that the refrigerant in the refrigerant circulation loop is stored in the liquid storage container.

[0028] Drainage procedure: When it is necessary to drain the refrigerant in the storage container into the refrigerant circulation loop, turn on the drain valve and make the pressure at the first end of the drain branch greater than the pressure at the second end.

[0029] In some embodiments, the air conditioning system further includes a pressure relief branch and a pressure boosting branch, wherein a balancing valve is provided on the pressure relief branch and a pressure boosting valve is provided on the pressure boosting branch, and the first ends of each of the pressure relief branch and the pressure boosting branch are connected to the pressure regulating port of the liquid storage container; the control method further includes:

[0030] During the liquid collection process, the balancing valve is turned on to reduce the pressure inside the storage container.

[0031] During the drainage process, the pressure valve is turned on to increase the pressure inside the storage container.

[0032] In some embodiments, in the refrigerant adjustment function in cooling and heating modes, the liquid collection step includes:

[0033] The inlet valve is turned on, and when the pressure difference across the inlet valve is less than a preset threshold, the balance valve is turned on, and the drain valve and pressure valve are both turned off.

[0034] In some embodiments, the second end of the drain branch is configured to be connected to the low-pressure side pipeline in cooling mode;

[0035] In the refrigerant adjustment function of cooling mode, the draining step includes: turning on the drain valve and turning off both the inlet valve and the balance valve.

[0036] In some embodiments, the refrigerant adjustment function in cooling mode further includes: when the internal pressure of the liquid storage container drops to the same level as the low-pressure side pipeline, the pressure valve is turned on.

[0037] In some embodiments, the second end of the drain branch is configured to be connected to the high-pressure side pipeline in heating mode;

[0038] In the refrigerant adjustment function of heating mode, the draining step includes: turning on the pressure valve to increase the pressure inside the liquid storage container to the pressure at the second end of the pressure branch, and turning on the drain valve.

[0039] In some embodiments, the second end of the drain branch is configured to connect with the high-pressure side pipeline in heating mode, in the refrigerant transfer function.

[0040] During defrosting, the liquid collection step includes: turning on the inlet valve and turning off the drain valve, balancing valve, and pressurizing valve; and / or

[0041] In the initial stage of switching to heating mode after defrosting, the pressure valve is turned on to increase the pressure inside the liquid storage container to the pressure at the second end of the pressure branch, and the drain valve is turned on.

[0042] Based on the above technical solution, this disclosure has at least the following beneficial effects:

[0043] The air conditioning system of this embodiment is equipped with a liquid storage container, which is connected to the medium-pressure side pipeline through an inlet valve and to the refrigerant circulation loop through a drain valve. In addition to realizing conventional refrigerant mode and heating mode, excess refrigerant in the refrigerant circulation loop can be collected from a specific pressure side using 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, improve the system heat exchange efficiency, improve the energy efficiency of the air conditioning system, and realize the refrigerant adjustment and transfer functions simultaneously through the same liquid storage container, which can simplify the system structure and improve space utilization.

[0044] Furthermore, the collection of excess refrigerant from the medium-pressure side pipeline also provides sufficient pressure to ensure smooth storage of the refrigerant in the liquid storage container. In both cooling and defrosting modes, the connection point at the second end of the liquid inlet branch is located upstream of the gas-liquid separator, allowing for direct collection of excess refrigerant through the liquid storage container. This eliminates the need for the refrigerant to be stored in the gas-liquid separator first, and then released from the liquid storage container when needed, thereby improving heat exchange efficiency. Attached Figure Description

[0045] The accompanying drawings, which are included to provide a further understanding of this disclosure and form part of this application, illustrate exemplary embodiments of this disclosure and are used to explain this disclosure, but do not constitute an undue limitation of this disclosure. In the drawings:

[0046] Figure 1This is a system schematic diagram of some embodiments of the air conditioning system disclosed herein;

[0047] Figure 2 This is a schematic diagram of the flow path of the air conditioning system in conventional cooling mode and defrosting mode of the present disclosure;

[0048] Figure 3 This is a schematic diagram of the flow path of the air conditioning system in conventional heating mode according to the present disclosure;

[0049] Figure 4 A schematic diagram of the flow path in defrosting mode for the air conditioning system of this disclosure to realize the refrigerant transfer function;

[0050] Figure 5 A schematic diagram of the flow path in the initial stage of entering the heating mode after defrosting when the air conditioning system of this disclosure realizes the refrigerant transfer function;

[0051] Figure 6 A schematic diagram of the flow path for storing refrigerant by opening the inlet valve in cooling mode when the air conditioning system of this disclosure implements the refrigerant adjustment function;

[0052] Figure 7 A schematic diagram of the flow path for storing refrigerant by simultaneously opening the inlet valve and the balance valve in cooling mode when the air conditioning system of this disclosure implements the refrigerant adjustment function;

[0053] Figure 8 A schematic diagram of the refrigerant flow path in cooling mode when the air conditioning system of this disclosure implements the refrigerant adjustment function;

[0054] Figure 9 A schematic diagram of the flow path for storing refrigerant by opening the inlet valve in heating mode when the air conditioning system of this disclosure implements the refrigerant adjustment function;

[0055] Figure 10 A schematic diagram of the flow path for simultaneously opening the inlet valve and the balance valve in heating mode when the air conditioning system of this disclosure implements the refrigerant adjustment function;

[0056] Figure 11 A schematic diagram of the refrigerant release path in heating mode when the air conditioning system of this disclosure implements the refrigerant adjustment function;

[0057] Figure 12 This is a schematic diagram of the flow path of the air conditioning system disclosed herein, in heating mode, for releasing refrigerant through an auxiliary drain valve.

[0058] It should be understood that the dimensions of the various parts shown in the accompanying drawings are not drawn to actual scale. Furthermore, the same or similar reference numerals denote the same or similar components.

[0059] Explanation of reference numerals in the attached figures

[0060] 10. Outdoor unit components; 1. Liquid inlet branch; 2. Liquid drain branch; 3. Pressure relief branch; 4. Pressurization branch; 5. Auxiliary drain branch; 6. Unloading branch;

[0061] 101. Compressor; 102. Oil separator; 103. Four-way reversing valve; 104. Outdoor unit heat exchanger; 105. Outdoor unit throttling element; 106. Gas-liquid separator; 107. Liquid storage container; 108. Inlet valve; 109. Drain valve; 110. Pressurizing valve; 111. Balancing valve; 112. Unloading valve; 113. Auxiliary drain valve;

[0062] 20. Indoor unit components; 201. Indoor unit heat exchanger; 202. Indoor unit throttling element. Detailed Implementation

[0063] Various exemplary embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. The descriptions of the exemplary embodiments are merely illustrative and are in no way intended to limit the present disclosure or its application or use. The present disclosure may be implemented in many different forms and is not limited to the embodiments described herein. These embodiments are provided so that the present disclosure will be thorough and complete, and will fully express the scope of the disclosure to those skilled in the art. It should be noted that, unless specifically stated otherwise, the relative arrangement of components and steps, the composition of materials, numerical expressions, and values ​​set forth in these embodiments should be interpreted as exemplary only and not as limiting.

[0064] The terms "first," "second," and similar words used in this disclosure do not indicate any order, quantity, or importance, but are merely used to distinguish different parts. Words such as "including" or "contains" mean that the element preceding the word encompasses the element listed after it, and do not exclude the possibility of encompassing other elements as well. Terms such as "above," "below," "left," and "right" are used only to indicate relative positional relationships; when the absolute position of the described object changes, this relative positional relationship may also change accordingly.

[0065] In this disclosure, when a specific device is described as being located between a first device and a second device, an intermediary device may or may not be present between the specific device and the first or second device. When a specific device is described as being connected to other devices, the specific device may be directly connected to the other devices without an intermediary device, or it may be not directly connected to the other devices but have an intermediary device.

[0066] All terms used in this disclosure (including technical or scientific terms) have the same meaning as understood by one of ordinary skill in the art to which this disclosure pertains, unless otherwise specifically defined. It should also be understood that terms defined in a general dictionary, such as a dictionary, should be interpreted as having a meaning consistent with their meaning in the context of the relevant art, and not as having an idealized or highly formalized meaning, unless expressly defined herein.

[0067] Techniques, methods, and equipment known to those skilled in the art may not be discussed in detail, but where appropriate, they should be considered part of the specification.

[0068] Based on the embodiments disclosed above, in the absence of explicit denial or conflict, the technical features of one embodiment may be advantageously combined with one or more other embodiments.

[0069] This disclosure provides an air conditioning system, such as Figures 1 to 12 As shown, in some embodiments, the air conditioning system includes:

[0070] The refrigerant circulation loop is equipped with a compressor 101, an evaporator and a condenser. The high-pressure side pipeline is between the exhaust port of the compressor 101 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 suction port of the compressor 101.

[0071] The liquid storage container 107 is used to store refrigerant and has a liquid inlet A and a liquid outlet B;

[0072] Liquid inlet branch 1 is equipped with a liquid inlet valve 108 having an on and off state. The first end of liquid inlet branch 1 is connected to liquid inlet A, and the second end of liquid inlet branch 1 is connected to the medium-pressure side pipeline; and

[0073] Drainage branch 2 is equipped with a drain valve 109 having an on state and an off state. The first end of the drainage branch is connected to the outlet B, and the second end of the drainage branch is connected to the refrigerant circulation loop.

[0074] When the inlet valve 108 is in the closed state, the pressure at the first end of the inlet branch 1 is less than the pressure at the second end, so as to use the pressure difference to store the refrigerant in the refrigerant circulation loop into the storage container 107; when the drain valve 109 is in the closed state, the pressure at the first end of the drain branch 2 is greater than the pressure at the second end, so as to use the pressure difference to discharge the refrigerant in the storage container 107 into the refrigerant circulation loop.

[0075] Specifically, the refrigerant circulation loop includes a compressor 101, an evaporator, and a condenser, such as... Figure 1As shown, from the perspective of installation location, the air conditioning system includes an outdoor unit assembly 10 and an indoor unit assembly 20. The outdoor unit assembly 10 includes a compressor 101, an outdoor unit heat exchanger 104 and an outdoor unit throttling element 105. The indoor unit assembly 20 includes an indoor unit heat exchanger 201 and an indoor unit throttling element 202. The number of indoor unit heat exchangers 201 can be one or more.

[0076] In cooling mode, the indoor unit heat exchanger 201 acts as an evaporator, and the outdoor unit heat exchanger 104 acts as a condenser. The outdoor unit throttling element 105 is located downstream of the outlet of the outdoor unit heat exchanger 104, used to throttle and cool the refrigerant. The indoor unit throttling element 202 is located upstream of the inlet of the indoor unit heat exchanger 201. In heating mode, the indoor unit heat exchanger 201 acts as a condenser, and the outdoor unit heat exchanger 104 acts as an evaporator. The cooling and heating modes are switched via a four-way reversing valve 103. The liquid storage container 107 can be a liquid storage tank, etc., used to temporarily store the refrigerant in the refrigerant circulation loop.

[0077] The second end of the liquid inlet branch 1 is connected to the medium-pressure side pipeline to collect refrigerant from the medium-pressure side pipeline into the liquid storage container 107 under different working modes. During liquid collection, a pressure difference needs to be established at both ends of the liquid inlet branch 1 so that the pressure at the first end of the liquid inlet branch 1 is less than the pressure at the second end, so that at least part of the refrigerant in the refrigerant circulation loop can enter the liquid storage container 107 by utilizing the pressure difference.

[0078] The second end of the drain branch 2 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 outdoor unit system as needed, so that the refrigerant in the liquid storage container 107 is discharged to different pressure sides, which is conducive to realizing different drain modes. During draining, the pressure at the first end of the drain branch 2 is greater than the pressure at the second end, so as to use the pressure difference to discharge at least part of the refrigerant in the liquid storage container 107 into the refrigerant circulation loop.

[0079] 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. The first pressure range is higher than the second pressure range, and the second pressure range is higher than the third pressure range.

[0080] For example, the refrigerant circulation loop also includes a four-way reversing valve 103 and a gas-liquid separator 106. The four-way reversing valve 103 is used to switch between cooling mode and heating mode. The gas-liquid separator 106 is located on the pipeline between the four-way reversing valve 103 and the suction port of the compressor 101.

[0081] For this type of system, such as Figure 2As shown, in cooling mode, the high-pressure side pipeline is the pipeline between the discharge port of the compressor 101 and 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 201), and the low-pressure side pipeline includes: the pipeline from the evaporator (indoor heat exchanger 201) through the four-way reversing valve 103 to the inlet of the gas-liquid separator 106, and the pipeline between the outlet of the gas-liquid separator 106 and the air inlet of the compressor 101.

[0082] like Figure 3 As shown, in heating mode, the high-pressure side pipeline is the pipeline between the exhaust port of the compressor 101 and the condenser (indoor heat exchanger 201), the medium-pressure side pipeline is the pipeline between the condenser (indoor heat exchanger 201) and the evaporator (outdoor heat exchanger 104), and the low-pressure side pipeline includes: the pipeline from the evaporator (outdoor heat exchanger 104) through the four-way reversing valve 103 to the inlet of the gas-liquid separator 106, and the pipeline between the outlet of the gas-liquid separator 106 and the air inlet of the compressor 101.

[0083] This embodiment adds a liquid storage container 107 to the air conditioning system and connects it to the medium-pressure side pipeline of the system through an inlet valve 108 that can realize on / off functions. It also connects it to at least one of the low-pressure side pipeline, medium-pressure side pipeline, and high-pressure side pipeline of the system through a drain valve 109 that can realize on / off functions. Based on the conventional refrigerant mode and heating mode, excess refrigerant in the refrigerant circulation loop can be collected from a specific pressure side according to the actual heat exchange demand of the air conditioning system using the pressure difference, or the refrigerant in the liquid storage container 107 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, thereby improving the working energy efficiency of the air conditioning system.

[0084] Moreover, the collection of excess refrigerant from the medium-pressure side pipeline also provides sufficient pressure to allow the refrigerant to be stored smoothly in the liquid storage container 107. In cooling mode and defrosting mode, the connection position of the second end of the liquid inlet branch 1 is located upstream of the gas-liquid separator 106. Excess refrigerant can be collected solely by the liquid storage container 107, thereby adjusting the amount of circulating refrigerant. There is no need to combine it with the gas-liquid separator to store the refrigerant first, and then allow the refrigerant to enter the liquid storage container from the gas-liquid separator and be released from the liquid storage container when needed, which can improve heat exchange efficiency.

[0085] Furthermore, the refrigerant adjustment and refrigerant transfer functions can be realized simultaneously through the same liquid storage container 107, simplifying the system and piping structure, reducing costs, and improving product space utilization.

[0086] In the refrigerant adjustment function, the refrigerant is stored and released through the liquid storage container 107, and the amount of refrigerant in different operating modes is controlled so that the refrigerant circulation volume of the system is consistent with the refrigerant demand in different operating modes, so as to achieve the best heat exchange effect.

[0087] The refrigerant transfer function can solve the problem of refrigerant accumulating on the outdoor low-pressure side after defrosting. During defrosting, liquid refrigerant is directly stored in the liquid storage container 107. After defrosting ends and the system switches to heating mode, the stored refrigerant is released into the refrigerant circulation loop to participate in the heating cycle. This is more conducive to reducing the time for the heating capacity to recover to maximum output after defrosting and improving the heating capacity.

[0088] In traditional solutions, refrigerant is stored in a gas-liquid separator during the defrosting process. Often, a significant amount of liquid refrigerant is stored in the gas-liquid separator only after defrosting has ended and the system enters heating mode. The liquid refrigerant is then transferred to a storage container, which takes a considerable amount of time.

[0089] In some embodiments, such as Figure 1 As shown, the liquid storage container 107 also has a pressure regulating port C, and the air conditioning system also includes:

[0090] The pressure relief branch 3 is equipped with a balance valve 111 with an on state and an off state. 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 drainage. Alternatively, it can be connected to the medium-pressure side pipeline or other locations, as long as the pressure at the connection point is lower than the pressure inside the liquid storage container 107.

[0091] When the balance valve 111 is in the on state, the pressure in the liquid storage container 107 is released through the pressure relief branch 3.

[0092] Specifically, the refrigerant circulation loop also includes a four-way reversing valve 103 and a gas-liquid separator 106. The four-way reversing valve 103 is used to switch between cooling and heating modes. The gas-liquid separator 106 is located on the pipeline between the four-way reversing valve 103 and the suction port 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 106. The gaseous refrigerant discharged through the pressure relief branch 3 can first enter the gas-liquid separator 106 for gas-liquid separation before the gas enters the compressor 101, preventing liquid slugging during compressor suction.

[0093] This embodiment provides a pressure relief branch 3 to the liquid storage container 107. When the pressure inside the liquid storage container 107 is too high to collect liquid normally, the pressure inside the liquid storage container 107 can be released to the low-pressure side pipeline by turning on the balance valve 111. This ensures that a pressure difference is established between the two ends of the liquid inlet valve 108, which is conducive to subsequent smooth liquid collection and achieves efficient storage of refrigerant.

[0094] In some embodiments, such as Figure 8As shown, the second end of the drain branch 2 is configured to be connected to the low-pressure side pipeline in the cooling mode, and the drain valve 109 is configured to be in the on state in the cooling mode.

[0095] Specifically, the second end of the drain branch 2 can be connected between the four-way reversing valve 103 and the inlet of the gas-liquid separator 106.

[0096] In this embodiment, the second end of the first drain branch 2 is connected to the low-pressure side pipeline in the cooling mode, which can reduce the pressure at the second end of the drain branch 2 as much as possible, so that the refrigerant can be released smoothly from the liquid storage container 107. The discharged refrigerant merges with the refrigerant flowing out of the evaporator, increasing the amount of refrigerant in the low-pressure side pipeline, which can improve the heat exchange capacity of the air conditioning system in the cooling mode.

[0097] In some embodiments, such as Figure 4 and Figure 5 As shown, the inlet valve 108 is in the on state in defrosting mode, the drain valve 109 is in the on state in the initial stage of switching to heating mode after defrosting ends, and the second end of the drain branch 2 is configured to be connected to the high-pressure side pipeline in heating mode.

[0098] Among them, such as Figure 4 As shown, in the heating defrosting mode, the inlet valve 108 is in the on state and the drain valve 109 is in the off state. Excess refrigerant in the refrigerant circulation loop is stored in the liquid storage container 107 from the medium-pressure side pipeline during the defrosting process to solve the problem of refrigerant accumulating on the outdoor low-pressure side after defrosting.

[0099] like Figure 5 As shown, in the initial stage of entering the heating mode after the defrosting mode ends, the drain valve 109 is in the on state and the inlet valve 108 is in the off state. The high-pressure refrigerant on the exhaust side can establish a pressure difference between the two ends of the drain branch 2, and discharge the liquid refrigerant in the storage container 107 to the high-pressure side pipeline, directly and quickly participating in the heating cycle, reducing the time for the heating capacity to recover to the maximum output after defrosting, and improving the heating capacity.

[0100] This embodiment configures the second end of the drain branch 2 to connect with the high-pressure side pipeline in heating mode, which can better realize the refrigerant transfer function and enable the air conditioning system to achieve better refrigerant adjustment and transfer effects. During the defrosting process, the refrigerant can be directly stored in the liquid storage container 107 without the need to combine it with the gas-liquid separator 106 for refrigerant storage. In the initial stage of entering the heating mode after the defrosting mode ends, the liquid refrigerant in the liquid storage container 107 is discharged to the high-pressure side pipeline and directly and quickly participates in the heating cycle, reducing the time for the heating capacity to recover to maximum output after defrosting and improving the heating capacity.

[0101] In some embodiments, such as Figure 1As shown, the liquid storage container 107 also has a pressure regulating port C, and the air conditioning system also includes:

[0102] The pressurization branch 4 is equipped with a pressurization valve 110 that has an on state and an off state, and the first end of the pressurization branch 4 is connected to the pressure regulating port C.

[0103] When the pressure valve 110 is in the on state, the high-pressure side pipeline pressurizes the liquid storage container 107.

[0104] Preferably, the second end of the pressurizing branch 4 is connected to the high-pressure side pipeline to provide more sufficient pressure to the liquid storage container, which facilitates smooth drainage. Alternatively, the second end of the pressurizing branch 4 can also be connected to the medium-pressure side pipeline or pipelines at other locations, as long as the pressure is higher than that inside the liquid storage container 107.

[0105] Specifically, the second end of the pressurization branch 4 is connected to the pipeline between the exhaust port of the compressor 101 and the four-way reversing valve 103.

[0106] This embodiment, by setting a pressurization branch 4 in the liquid storage container 107, can keep the pressurization valve 110 in the on state when the pressure in the liquid storage container 107 is too low to drain normally. This allows the high pressure from the exhaust port of the compressor 101 to be led into the liquid storage container 107, ensuring that a pressure difference is established across the drain valve. This facilitates smooth drainage, allows the refrigerant in the liquid storage container 107 to be discharged efficiently, improves drainage efficiency, reduces the amount of refrigerant remaining in the liquid storage container 107, meets the large refrigerant demand in the system, and optimizes the heat exchange effect.

[0107] In some embodiments, such as Figure 12 As shown, the air conditioning system also includes an auxiliary drain branch 5, which is equipped with an auxiliary drain valve 113 having an on state and an off state. The first end of the auxiliary drain branch 5 is connected to the outlet B, and the second end of the auxiliary drain branch 5 is connected to the low-pressure side pipeline.

[0108] Specifically, the second end of the auxiliary drain branch 5 is connected to the pipeline between the four-way reversing valve 103 and the inlet of the gas-liquid separator 106. The liquid refrigerant discharged through the auxiliary drain branch 5 can first enter the gas-liquid separator 106 for gas-liquid separation, and then allow the gas to enter the compressor 101 to prevent liquid slugging from the compressor 101.

[0109] In any operating mode of the air conditioning system, when it is necessary to discharge the refrigerant in the liquid storage container 107 more quickly, the auxiliary drain valve 113 is also turned on. Through the auxiliary drain branch 5 and the drain branch 2, the liquid refrigerant in the liquid storage container 107 is discharged more quickly into the refrigerant circulation loop to participate in the heat exchange cycle, thereby improving the heat exchange capacity.

[0110] In some embodiments, such as Figure 1 As shown, the air conditioning system also includes an unloading branch 6. The first end of the unloading branch 6 is connected to the liquid inlet A, and the second end of the unloading branch 6 is connected to the low-pressure side pipeline. The unloading branch 6 is provided with an unloading valve 112 having an on state and an off state. The unloading valve 112 is configured to be in the on state when the pressure in the liquid storage container 107 is higher than a preset safety threshold.

[0111] Specifically, the second end of the unloading branch 6 is connected to the pipeline between the four-way reversing valve 103 and the inlet of the gas-liquid separator 106. The liquid refrigerant discharged through the unloading branch 6 can first enter the gas-liquid separator 106 for gas-liquid separation, and then allow the gas to enter the compressor 101, preventing liquid slugging during compressor 101 intake. Optionally, the first end of the unloading branch 6 can also be connected to other locations within the liquid storage container 107.

[0112] This embodiment can release pressure to the low-pressure side pipeline through the unloading valve 112 when the refrigerant pressure in the liquid storage container 107 exceeds the preset safety threshold, thereby facilitating the release of pressure in the liquid storage container 107 and improving the safety of the air conditioning system.

[0113] In some embodiments, the inlet A and the pressure regulating port C are located in the upper region of the liquid storage container 107, and the outlet B is located in the lower region of the liquid storage container 107.

[0114] The liquid storage container 107 includes a top wall, a bottom wall, and side walls, and can be cylindrical or prismatic in shape. The "upper region" includes the upper part of the top and side walls, while the "lower region" includes the lower part of the bottom and side walls. For example, the inlet A can be located on the top wall, allowing refrigerant to fall directly into the bottom of the liquid storage container 107 after being introduced through the inlet pipe, minimizing the risk of gas-liquid separation. The outlet B can be located at the bottom of the side wall, allowing for the smooth discharge of refrigerant from the container 107 when the liquid volume is low. The pressure regulating port C is located in the upper part of the side wall, facilitating pressure regulation by releasing gaseous refrigerant or introducing high-pressure gaseous refrigerant. Optionally, the inlet A can also be located in the lower region.

[0115] In this embodiment, the inlet A can be located in the upper region of the liquid storage container 107. After the refrigerant is introduced through the inlet pipe, it can fall directly into the bottom of the liquid storage container 107 from above with less resistance and smooth liquid collection. The pressure regulating port C is located in the upper region of the liquid storage container 107, which facilitates the adjustment of the internal pressure of the liquid storage container 107 by releasing gaseous refrigerant or introducing high-pressure gaseous refrigerant. The outlet B is located in the lower region of the liquid storage container 107, which also allows the refrigerant inside the liquid storage container 107 to be discharged smoothly when the liquid volume is small.

[0116] In some embodiments, such as Figure 1As shown, the refrigerant circulation loop also includes a four-way reversing valve 103 and a gas-liquid separator 106. The four-way reversing valve 103 is used to switch between cooling mode and heating mode. The gas-liquid separator 106 is located on the pipeline between the four-way reversing valve 103 and the suction port of the compressor 101.

[0117] The air conditioning system also includes a pressure relief branch 3 and a pressure boosting branch 4. The first end of each of the pressure relief branch 3 and the pressure boosting branch 4 is connected to the pressure regulating port C of the liquid storage container 107. The second end of the pressure relief branch 3 is connected to the low-pressure side pipeline, and the second end of the pressure boosting branch 4 is connected to the high-pressure side pipeline.

[0118] The second end of the drain branch 2 is connected to the pipeline between the four-way reversing valve 103 and the evaporator. The second end of the pressurization branch 4 is connected to the pipeline between the exhaust port of the compressor 101 and the four-way reversing valve 103. The second end of the pressure relief branch 3 is connected between the inlet of the gas-liquid separator 106 and the four-way reversing valve 103.

[0119] This embodiment is equipped with an inlet valve 108, a drain valve 109, a balance valve 111, and a pressure valve 110. The cooperation of these four valves can achieve different working modes and also has the functions of refrigerant adjustment and transfer. In contrast, the conventional scheme with two liquid storage containers requires seven valves.

[0120] The second end of the drain branch 2 is connected to the pipeline between the four-way reversing valve 103 and the evaporator. When draining in cooling mode, the refrigerant discharged from the drain branch 2 can flow together with the refrigerant flowing out of the evaporator and into the four-way reversing valve 103. After entering the gas-liquid separator 106 for separation, the gaseous refrigerant is replenished to the compressor 101. When draining in heating mode, the refrigerant flowing out of the compressor 101 through the four-way reversing valve 103 and the refrigerant discharged from the drain branch 2 can enter the condenser for heat exchange, achieving a larger heat exchange capacity.

[0121] The second end of the pressurization 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 pressurize the liquid storage container 107 so that the refrigerant in the liquid storage container 107 can be discharged smoothly.

[0122] The second end of the pressure relief branch 3 is connected between the inlet of the gas-liquid separator 106 and the four-way reversing valve 103. When the pressure in the liquid storage container 107 is too high to continue collecting liquid, the gaseous refrigerant discharged through the pressure relief branch 3 can first enter the gas-liquid separator 106 for gas-liquid separation, and then allow the gas to enter the compressor 101 to prevent the compressor 101 from sucking in liquid and causing liquid slugging.

[0123] In some embodiments, the liquid storage container 107 is built into the outdoor unit assembly 10.

[0124] In this embodiment, the liquid storage container 107 is built into the outdoor unit assembly 10, which eliminates the need for additional space during installation and reduces the overall installation difficulty of the air conditioning system, as the liquid storage container 107 does not need to be installed as a separate accessory. Optionally, the liquid storage container 107 can be installed between the outdoor unit assembly 10 and the indoor unit assembly 20.

[0125] Secondly, this disclosure provides a control method for an air conditioning system based on the above embodiments, which in some embodiments includes:

[0126] Liquid collection step: Turn on the liquid inlet valve 108 and make the pressure at the first end of the liquid inlet branch 1 less than the pressure at the second end, so that the refrigerant in the refrigerant circulation loop is stored in the liquid storage container 107.

[0127] Drainage procedure: When it is necessary to drain the refrigerant in the liquid storage container 107 into the refrigerant circulation loop, the drain valve 109 is turned on and the pressure at the first end of the drain branch 2 is greater than the pressure at the second end.

[0128] When an air conditioning system undergoes load or mode switching, the number of indoor units in a multi-split system changes. Due to the significant change in the air conditioning's operating state, the refrigerant in the refrigerant circulation loop can be adjusted to meet operational requirements through liquid collection and drainage modes. When the air conditioning system has just switched from defrosting mode to heating mode, it is necessary to accelerate liquid drainage to facilitate the rapid entry of liquid refrigerant into the system for circulation.

[0129] The air conditioning system control method of this embodiment connects to the medium-pressure side pipeline of the system via an inlet valve 108 that can be switched on and off, and connects to at least one of the low-pressure side pipeline, medium-pressure side pipeline, and high-pressure side pipeline of the system via a drain valve 109 that can be switched on and off. Based on the implementation of conventional refrigerant mode and heating mode, it can collect excess refrigerant from the refrigerant circulation loop from a specific pressure side according to the actual heat exchange demand of the air conditioning system, or discharge the refrigerant in the liquid storage container 107 to 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, thereby improving the working energy efficiency of the air conditioning system.

[0130] Moreover, the collection of excess refrigerant from the medium-pressure side pipeline also provides sufficient pressure to allow the refrigerant to be stored smoothly in the liquid storage container 107. In cooling mode and defrosting mode, the connection position of the second end of the liquid inlet branch 1 is located upstream of the gas-liquid separator 106. Excess refrigerant can be collected solely by the liquid storage container 107, thereby adjusting the amount of circulating refrigerant. There is no need to combine it with the gas-liquid separator to store the refrigerant first, and then allow the refrigerant to enter the liquid storage container from the gas-liquid separator and be released from the liquid storage container when needed, which can improve heat exchange efficiency.

[0131] In some embodiments, the air conditioning system further includes a pressure relief branch 3 and a pressure boosting branch 4. The pressure relief branch 3 is equipped with a balancing valve 111, and the pressure boosting branch 4 is equipped with a pressure boosting valve 110. The first ends of both the pressure relief branch 3 and the pressure boosting branch 4 are connected to the pressure regulating port C of the liquid storage container 107. The second end of the pressure relief branch 3 can be connected to a low-pressure side pipeline or a medium-pressure side pipeline, and the second end of the pressure boosting branch 4 is connected to a high-pressure side pipeline. The control method further includes:

[0132] During the liquid collection step, the balance valve 111 is turned on to reduce the pressure inside the liquid storage container 107.

[0133] During the drainage step, the pressure valve 110 is turned on to increase the pressure inside the storage container 107.

[0134] In this embodiment, during the liquid collection step, when the pressure inside the liquid storage container 107 is too high to collect liquid normally, the pressure inside the liquid storage container 107 is released to the low-pressure side pipeline by closing the balance valve 111. This ensures a pressure difference is established across the inlet valve 108, which facilitates subsequent smooth liquid collection and achieves efficient refrigerant storage. During the liquid drainage step, when the pressure inside the liquid storage container 107 is too low to drain normally, the pressure valve 110 is closed to draw the high pressure from the compressor 101 exhaust port into the liquid storage container 107. This ensures a pressure difference is established across the drain valve, facilitating smooth drainage and efficient discharge of refrigerant from the liquid storage container 107. This improves drainage efficiency, reduces the amount of refrigerant remaining in the liquid storage container 107, meets the system's large refrigerant demand, and optimizes heat exchange.

[0135] In some embodiments, such as Figure 6 , Figure 7 and Figure 9 , Figure 10 As shown, in the refrigerant adjustment function of cooling and heating modes, the liquid collection step includes:

[0136] The inlet valve 108 is turned on, and when the pressure difference across the inlet valve 108 is less than a preset threshold, the balance valve 111 is turned on, and the drain valve 109 and the pressure valve 110 are both turned off.

[0137] in, Figure 6 This is a schematic diagram of refrigerant storage in cooling mode during refrigerant transfer. The inlet valve 108 is in the closed state, and a portion of the liquid refrigerant flowing from the outdoor unit heat exchanger 104 enters the liquid storage container 107 through the inlet valve 108, completing the liquid collection in cooling mode. Figure 7As shown, when the pressure inside the liquid storage container 107 is high, making the pressure difference across the liquid inlet valve 108 small, the balance valve 111 is turned on. The second end of the balance valve 111 is connected to the low-pressure side pipeline, which can realize the internal pressure relief of the liquid storage container 107 and make the refrigerant storage process proceed smoothly.

[0138] Figure 9 This is a schematic diagram of refrigerant storage in heating mode during refrigerant transfer. With the inlet valve 108 closed, a portion of the liquid refrigerant flowing from the indoor unit heat exchanger 201 enters the storage container 107 through the inlet valve 108, completing the liquid collection process in heating mode. Figure 10 As shown, when the pressure inside the liquid storage container 107 is high, making the pressure difference across the liquid inlet valve 108 small, the balance valve 111 is turned on. The second end of the balance valve 111 is connected to the low-pressure side pipeline, which can realize the internal pressure relief of the liquid storage container 107 and make the refrigerant storage process proceed smoothly.

[0139] In this embodiment, when collecting liquid in cooling or heating modes, the inlet valve 108 is turned on, allowing the refrigerant in the medium-pressure side pipeline to enter the liquid storage container 107 for collection. If the pressure in the liquid storage container 107 is too high to collect liquid normally, the balance valve 111 is turned on, allowing the pressure in the liquid storage container 107 to be released to the low-pressure side pipeline through the pressure relief branch 3. This ensures that a pressure difference is established across the inlet valve 108, which is beneficial for subsequent smooth liquid collection and achieves efficient storage of refrigerant.

[0140] In some embodiments, such as Figure 8 As shown, the second end of the drain branch 2 is configured to connect to the low-pressure side pipeline in cooling mode;

[0141] In the refrigerant adjustment function in cooling mode, the draining step includes: turning on the drain valve 109 and turning off both the inlet valve 108 and the balance valve 111.

[0142] In this embodiment, in the refrigeration drain mode, since the drain is directed to the low-pressure side pipeline, the drain valve 109 alone can be used to drain the liquid, which simplifies the control method.

[0143] In some embodiments, the refrigerant adjustment function in cooling mode further includes the following step: when the internal pressure of the liquid storage container 107 drops to the same level as the low-pressure side pipeline, the pressure valve 110 is turned on. During this process, both the balance valve 111 and the inlet valve 108 are turned off.

[0144] In this embodiment, the second end of the drain branch 2 is connected to the low-pressure side pipeline. After the drain valve 109 is opened, the refrigerant can enter the system for circulation. When the internal pressure of the liquid storage container 107 drops to the point where it cannot be drained, the internal pressure of the liquid storage container 107 can be increased by opening the pressurization valve 110 for a preset time, so that the refrigerant can continue to be drained. This allows the refrigerant in the cooling mode of the refrigerant adjustment function to be drained smoothly.

[0145] In some embodiments, such as Figure 11 As shown, the second end of the drain branch 2 is configured to connect to the high-pressure side pipeline in heating mode;

[0146] In the refrigerant adjustment function of the heating mode, the draining step includes: turning on the pressure valve 110 to increase the pressure inside the liquid storage container 107 to the pressure at the second end of the pressure branch 4, and turning on the drain valve 109.

[0147] Preferably, the pressure valve 110 is first turned on to raise the pressure inside the liquid storage container 107 to the pressure at the second end of the pressure branch 4, and then the drain valve 109 is opened to easily reach the pressure required for draining; or the pressure valve 110 and the drain valve 109 can be opened simultaneously. During this process, the inlet valve 108 and the balance valve 111 are turned off.

[0148] Specifically, the pressure at the discharge port of compressor 101 is marked as the first pressure point P1, and the pressure downstream of drain valve 109 is marked as the second pressure point P2. In heating mode, P1 > P2. In this state, when pressurization valve 110 is opened, the pressure inside liquid storage container 107 is P0 = P1 > P2. Opening the first drain valve 115 allows the refrigerant inside liquid storage container 107 to be discharged.

[0149] In this embodiment, during the refrigerant adjustment function in heating mode, since the second end of the drain branch 2 is connected to the high-pressure side pipeline, the pressurization valve 110 is turned on during draining, and the high-pressure pipeline of the compressor 101 exhaust port can be used to pressurize the inside of the liquid storage container 107, thereby achieving smooth draining in heating mode.

[0150] Optionally, in the heating mode of the refrigerant adjustment function, the pressure valve 110 is first turned on, and when the pressure inside the liquid storage container 107 rises to the pressure at the second end of the pressure branch 4, the pressure valve 110 is switched to the off state; then, the compressor 101 is reduced in frequency or stopped, and the drain valve 109 is turned on.

[0151] This control method first increases and maintains the pressure in the liquid storage container 107 by pressurizing valve 110. Since the second end of the drain 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 107. By reducing the frequency of the compressor 101 or stopping its operation, the pressure at the second end of the drain branch 2 can be reduced, thereby allowing the refrigerant in the liquid storage container 107 to be discharged smoothly and increasing the amount of refrigerant discharged.

[0152] In some embodiments, the second end of the drain branch 2 is configured to connect with the high-pressure side pipeline in heating mode, in the refrigerant transfer function.

[0153] During the defrosting process, such as Figure 4 and Figure 5 As shown, the liquid collection step includes: turning on the inlet valve 108 and turning off the drain valve 109, the balancing valve 111, and the pressurizing valve 110; and / or

[0154] In the initial stage of switching to heating mode after defrosting, the pressure valve 110 is first turned on to increase the pressure inside the liquid storage container 107 to the pressure at the second end of the pressure branch 4, and then the drain valve 109 is turned on.

[0155] Among them, such as Figure 4 As shown, in the heating defrosting mode, the inlet valve 108 is in the on state and the drain valve 109 is in the off state. Excess refrigerant in the refrigerant circulation loop is stored in the liquid storage container 107 from the medium-pressure side pipeline during the defrosting process to solve the problem of refrigerant accumulating on the outdoor low-pressure side after defrosting.

[0156] like Figure 5 As shown, in the initial stage of entering the heating mode after the defrosting mode ends, the drain valve 109 is in the on state and the inlet valve 108 is in the off state. The high-pressure refrigerant on the exhaust side can establish a pressure difference between the two ends of the drain branch 2, and discharge the liquid refrigerant in the storage container 107 to the high-pressure side pipeline, directly and quickly participating in the heating cycle, reducing the time for the heating capacity to recover to the maximum output after defrosting, and improving the heating capacity.

[0157] This embodiment configures the second end of the drain branch 2 to connect with the high-pressure side pipeline in heating mode, which can better realize the refrigerant transfer function and enable the air conditioning system to achieve better refrigerant adjustment and transfer effects. During the defrosting process, the refrigerant can be directly stored in the liquid storage container 107 without the need to combine it with the gas-liquid separator 106 for refrigerant storage. In the initial stage of entering the heating mode after the defrosting mode ends, the liquid refrigerant in the liquid storage container 107 is discharged to the high-pressure side pipeline and directly and quickly participates in the heating cycle, reducing the time for the heating capacity to recover to maximum output after defrosting and improving the heating capacity.

[0158] The following is in conjunction with the appendix Figures 1 to 11 The embodiments given in the present disclosure illustrate the working principle of the air conditioning system. The valves in the above embodiments can all be solenoid valves and are controlled by a controller.

[0159] The air conditioning system includes a compressor 101, an outdoor unit heat exchanger 104, an indoor unit heat exchanger 201, an inlet valve 108, a liquid storage container 107, a gas-liquid separator 106, a four-way reversing valve 103, a drain valve 109, a pressurizing valve 110, and a balancing valve 111. Further, an oil separator 102 can be installed downstream of the compressor 101. The inlet of the oil separator 102 is connected to the exhaust port of the compressor 101, the outlet is connected to the four-way reversing valve 103, and the oil outlet is connected to the inlet port of the compressor 101. The air conditioning system also includes an unloading valve 112. The first end of the unloading valve 112 is connected to the inlet branch 1 between the inlet valve 108 and the inlet port A, and the second end of the unloading valve 112 is connected to the pipeline between the inlet of the gas-liquid separator 106 and the four-way reversing valve 103, used to release pressure when the pressure in the inlet branch 1 exceeds a safety threshold.

[0160] The air conditioning system in this embodiment has a conventional cooling mode and a defrosting mode:

[0161] like Figure 2 In the conventional cooling and defrosting modes shown, when there is no need to adjust the refrigerant circulation, the inlet valve 108, outlet valve 109, pressurization valve 110, and balance valve 111 are all in the open state. The refrigerant is discharged from the compressor 101, passes through the oil separator 102 and the four-way reversing valve 103, enters the outdoor unit heat exchanger 104 for condensation, then passes through the outdoor unit throttling element 105 and the indoor unit throttling element 202 for throttling, enters the indoor unit heat exchanger 201 for evaporation, and finally flows through the four-way reversing valve 103 into the gas-liquid separator 106, returning to the suction port of the compressor 101.

[0162] like Figure 3 In the conventional heating mode shown, when there is no need to adjust the refrigerant circulation, the inlet valve 108, outlet valve 109, pressurization valve 110, and balance valve 111 are all in the open state. The refrigerant is discharged from the compressor 101, passes through the oil separator 102 and the four-way reversing valve 103, then enters the indoor unit heat exchanger 201 for condensation. After being throttled by the indoor unit throttling element 202 and the outdoor unit throttling element 105, it enters the outdoor unit heat exchanger 104 for evaporation. Finally, it flows through the four-way reversing valve 103 into the gas-liquid separator 106, returning to the compressor 101's suction port. For example, the throttling element can be an electronic expansion valve or a capillary tube, etc.

[0163] In addition, the air conditioning system also has refrigerant transfer and adjustment functions:

[0164] 1. Refrigerant transfer function:

[0165] like Figure 4 As shown, the inlet valve 108 is in the on state, while the pressure valve 110, balance valve 111, and drain valve 109 are closed. The second end of the inlet valve 108 is connected to the medium-pressure side of the system. When this valve is in the on state, a portion of the excess refrigerant flowing from the outdoor unit heat exchanger 104 and the outdoor unit throttling element 105 is stored in the liquid storage container 107 through the inlet valve 108, completing the storage of refrigerant during the defrosting process. This solves the problem of refrigerant accumulating on the outdoor low-pressure side after defrosting, while the remaining portion continues to flow to the inner side, maintaining the defrosting circulation path.

[0166] Optionally, when the internal pressure is high and the pressure difference across the liquid inlet valve 108 is small, the balance valve 111 is in the on state. The second end of the balance valve 111 is connected to the low-pressure side of the system, which can realize the internal pressure relief of the liquid storage container 107.

[0167] like Figure 5 As shown, in the initial stage of transitioning from defrosting mode to heating mode, the pressurization valve 110 is first turned on, raising the pressure inside the liquid storage container 107 to the pressure at the second end of the pressurization branch 4, and then the drain valve 109 is opened. During this process, the inlet valve 108 and the balance valve 111 are turned off. Thus, the high-pressure refrigerant discharged from the oil separator 102 establishes a pressure difference across the drain branch 2, discharging the liquid refrigerant in the liquid storage container 107 to the high-pressure side pipeline, allowing it to directly and quickly participate in the heating cycle, reducing the time required for the heating capacity to recover to maximum output after defrosting, and improving the heating capacity.

[0168] 2. Refrigerant adjustment function:

[0169] like Figure 6 The diagram shows the refrigerant storage in cooling mode during refrigerant adjustment. In this mode, the inlet valve 108 is open; the drain valve 109, pressurization valve 110, and balancing valve 111 are closed. A portion of the medium-pressure refrigerant flowing from the outdoor unit heat exchanger 104 and the outdoor unit throttling element 105 enters the liquid storage container 107 through the inlet valve 108, thus storing excess refrigerant in the liquid storage container 107 and reducing the amount of refrigerant circulating in the system.

[0170] Based on this, such as Figure 7 As shown, as the amount of refrigerant stored in the liquid storage container 107 increases, the internal pressure of the liquid storage container 107 gradually rises. When the pressure difference across the liquid inlet valve 108 decreases to the point where the liquid inlet power is insufficient, the balance valve 111 needs to be opened simultaneously to release pressure so that the refrigerant can continue to be stored in the liquid storage container 107.

[0171] like Figure 8The diagram shows the refrigerant release in cooling mode during the refrigerant adjustment function. In this mode, the drain valve 109 is open, and the pressure valve 110, inlet valve 108, and balance valve 111 are closed. The refrigerant inside the liquid storage container 107 can return to the system through the drain valve 109 to participate in the circulation.

[0172] like Figure 9 The diagram shows the refrigerant flow path in heating mode during refrigerant adjustment. In this mode, the inlet valve 108 is open; the drain valve 109, pressurization valve 110, and balancing valve 111 are closed. A portion of the medium-pressure refrigerant flowing from the indoor unit heat exchanger 201 and the indoor unit throttling element 202 enters the storage container 107 through the inlet valve 108, storing excess refrigerant in the storage container 107 and reducing the amount of refrigerant circulating in the system. The remaining refrigerant continues to flow to the outdoor unit heat exchanger 104, maintaining the circulation path.

[0173] exist Figure 9 On the basis of, such as Figure 10 As shown, as the amount of refrigerant stored in the liquid storage container 107 increases, the internal pressure of the liquid storage container 107 gradually rises. When the pressure difference across the liquid inlet valve 108 decreases to the point where the liquid inlet power is insufficient, the balance valve 111 needs to be opened simultaneously to release pressure so that the refrigerant can continue to be stored in the liquid storage container 107.

[0174] like Figure 11 The diagram shows the refrigerant flow path in the heating mode of the refrigerant adjustment function. In this mode, the drain valve 109 and the pressurization valve 110 are open; the inlet valve 108 and the balance valve 111 are closed. The high-temperature, high-pressure refrigerant discharged from the oil separator 102 enters the liquid storage container 107 through the pressurization valve 110, causing the refrigerant in the liquid storage container 107 to be discharged through the drain valve 109.

[0175] While specific embodiments of this disclosure have been described in detail by way of examples, those skilled in the art should understand that the examples are for illustrative purposes only and not intended to limit the scope of this disclosure. Those skilled in the art should understand that modifications can be made to the above embodiments or equivalent substitutions can be made to some technical features without departing from the scope and spirit of this disclosure. The scope of this disclosure is defined by the appended claims.

Claims

1. An air conditioning system, characterized in that, include: The refrigerant circulation loop is equipped with a compressor (101), an evaporator and a condenser. The discharge port of the compressor (101) and the condenser are connected by a high-pressure side pipeline, the condenser and the evaporator are connected by a medium-pressure side pipeline, and the evaporator and the suction port of the compressor (101) are connected by a low-pressure side pipeline. A liquid storage container (107) for storing refrigerant and having an inlet (A) and an outlet (B); A liquid inlet branch (1) is provided with a liquid inlet valve (108) having an on state and an off state. The first end of the liquid inlet branch (1) is connected to the liquid inlet (A), and the second end of the liquid inlet branch (1) is connected to the medium-pressure side pipeline; and A drain branch (2) is provided with a drain valve (109) having an on state and an off state. The first end of the drain branch is connected to the outlet (B), and the second end of the drain branch is connected to the refrigerant circulation loop. When the inlet valve (108) is in the closed state, the pressure at the first end of the inlet branch (1) is less than the pressure at the second end, so as to use the pressure difference to store the refrigerant in the refrigerant circulation loop into the storage container (107); when the drain valve (109) is in the closed state, the pressure at the first end of the drain branch (2) is greater than the pressure at the second end, so as to use the pressure difference to discharge the refrigerant in the storage container (107) into the refrigerant circulation loop; The inlet valve (108) is in the on state in defrosting mode, the drain valve (109) is in the on state in the initial stage of switching to heating mode after defrosting, and the second end of the drain branch (2) is configured to be connected to the high-pressure side pipeline in heating mode.

2. The air conditioning system as described in claim 1, characterized in that, The liquid storage container (107) also has a pressure regulating port (C), and the air conditioning system further includes: The pressure relief branch (3) is equipped with a balance valve (111) having an on state and an off state, and the first end of the pressure relief branch (3) is connected to the pressure regulating port (C); When the balance valve (111) is in the on state, the pressure in the liquid storage container (107) is released through the pressure relief branch (3).

3. The air conditioning system as described in claim 1, characterized in that, The second end of the drain branch (2) is configured to be connected to the low-pressure side pipeline in the cooling mode, and the drain valve (109) is configured to be in the on state in the cooling mode.

4. The air conditioning system as described in claim 1, characterized in that, The liquid storage container (107) also has a pressure regulating port (C), and the air conditioning system further includes: A pressurizing branch (4) is provided with a pressurizing valve (110) having an on state and an off state, and the first end of the pressurizing branch (4) is connected to the pressure regulating port (C); When the pressure valve (110) is in the on state, the high-pressure side pipeline pressurizes the liquid storage container (107).

5. The air conditioning system as described in claim 1, characterized in that, It also includes an auxiliary drainage branch (5), which is equipped with an auxiliary drainage valve (113) having an on state and an off state. The first end of the auxiliary drainage branch (5) is connected to the outlet (B), and the second end of the auxiliary drainage branch (5) is connected to the low-pressure side pipeline.

6. The air conditioning system as described in claim 1, characterized in that, It also includes an unloading branch (6), the first end of which is connected to the liquid inlet (A), and the second end of which is connected to the low-pressure side pipeline. The unloading branch (6) is provided with an unloading valve (112) having an on state and an off state. The unloading valve (112) is configured to be in the on state when the pressure in the liquid storage container (107) is higher than a preset safety threshold.

7. The air conditioning system as described in claim 2, characterized in that, The inlet (A) and the pressure regulating port (C) are located in the upper region of the liquid storage container (107), and the outlet (B) is located in the lower region of the liquid storage container (107).

8. The air conditioning system as described in claim 1, characterized in that, The refrigerant circulation loop also includes a four-way reversing valve (103) and a gas-liquid separator (106). The four-way reversing valve (103) is used to switch between cooling mode and heating mode. The gas-liquid separator (106) is located on the pipeline between the four-way reversing valve (103) and the suction port of the compressor (101). The air conditioning system also includes a pressure relief branch (3) and a pressure boosting branch (4). The first end of each of the pressure relief branch (3) and the pressure boosting branch (4) is connected to the pressure regulating port (C) of the liquid storage container (107). The second end of the pressure relief branch (3) is connected to the low-pressure side pipeline, and the second end of the pressure boosting branch (4) is connected to the high-pressure side pipeline. The second end of the drain branch (2) is connected to the pipeline between the four-way reversing valve (103) and the evaporator. The second end of the pressurization branch (4) is connected to the pipeline between the exhaust port of the compressor (101) and the four-way reversing valve (103). The second end of the pressure relief branch (3) is connected between the inlet of the gas-liquid separator (106) and the four-way reversing valve (103).

9. The air conditioning system according to any one of claims 1 to 8, characterized in that, The liquid storage container (107) is built into the outdoor unit assembly (10).

10. A control method for an air conditioning system according to any one of claims 1 to 9, characterized in that, include: Liquid collection step: Turn on the liquid inlet valve (108) and make the pressure at the first end of the liquid inlet branch (1) less than the pressure at the second end, so that the refrigerant in the refrigerant circulation loop is stored in the liquid storage container (107). Drainage procedure: When it is necessary to drain the refrigerant in the liquid storage container (107) into the refrigerant circulation loop, the drain valve (109) is turned on and the pressure at the first end of the drain branch (2) is greater than the pressure at the second end.

11. The control method as described in claim 10, characterized in that, The air conditioning system further includes a pressure relief branch (3) and a pressure boosting branch (4). The pressure relief branch (3) is equipped with a balancing valve (111), and the pressure boosting branch (4) is equipped with a pressure boosting valve (110). The first ends of the pressure relief branch (3) and the pressure boosting branch (4) are connected to the pressure regulating port (C) of the liquid storage container (107). The control method further includes: In the liquid collection step, the balance valve (111) is turned on to reduce the pressure inside the liquid storage container (107); During the drainage step, the pressure valve (110) is turned on to increase the pressure inside the liquid storage container (107).

12. The control method as described in claim 11, characterized in that, In the refrigerant adjustment function of cooling and heating modes, the liquid collection step includes: The inlet valve (108) is turned on, and when the pressure difference across the inlet valve (108) is less than a preset threshold, the balance valve (111) is turned on, and the drain valve (109) and the pressure valve (110) are both turned off.

13. The control method as described in claim 11, characterized in that, The second end of the drain branch (2) is configured to be connected to the low-pressure side pipeline in the cooling mode; In the refrigerant adjustment function in the cooling mode, the draining step includes: turning the drain valve (109) on, and turning the inlet valve (108) and the balance valve (111) off.

14. The control method as described in claim 13, characterized in that, In the refrigerant adjustment function in the cooling mode, the draining step further includes: when the internal pressure of the liquid storage container (107) drops to the same level as the low-pressure side pipeline, the pressure valve (110) is turned on.

15. The control method as described in claim 11, characterized in that, The second end of the drain branch (2) is configured to be connected to the high-pressure side pipeline in heating mode; In the refrigerant adjustment function under heating mode, the draining step includes: turning on the pressure valve (110) to increase the pressure inside the liquid storage container (107) to the pressure at the second end of the pressure branch (4), and turning on the drain valve (109).

16. The control method according to any one of claims 11 to 15, characterized in that, The second end of the drain branch (2) is configured to connect with the high-pressure side pipeline in heating mode, in the refrigerant transfer function, During the defrosting process, the liquid collection step includes: turning on the inlet valve (108) and turning off the drain valve (109), the balancing valve (111), and the pressure valve (110); and / or In the initial stage of switching to heating mode after defrosting, the pressure valve (110) is turned on so that the pressure inside the liquid storage container (107) rises to the pressure at the second end of the pressure branch (4), and the drain valve (109) is turned on.

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