Air conditioning system and control method thereof

Abstract

The invention relates to air conditioners, in particular to an air conditioning system and a control method, and aims to solve the problem that a control valve of an existing air conditioning system occupies a large space. The air conditioning system comprises a first heat exchanger, a low-pressure air pipe, a high-pressure air pipe and an air control valve. The gas control valve comprises a first channel, a second channel and a third channel, the high-pressure gas pipe is connected to the first channel, the low-pressure gas pipe is connected to the second channel, and the first heat exchanger is connected to the third channel; the gas control valve is configured to control an opening degree of the first channel and the second channel. One control valve can simultaneously control on-off and circulation flow of the low-pressure air pipe and the high-pressure air pipe and the first heat exchanger, compared with the mode that control valves are arranged on the high-pressure air pipe and the low-pressure air pipe respectively, the system structure is simplified, the occupied size of the valve device is reduced, and therefore the size of a valve box provided with the air control valve is reduced, and the cost is reduced. And the installation space requirement can be met.

Description

Technical Field

[0001] The present invention relates to the technical field of air conditioners, and specifically provides an air conditioning system and a control method. Background Art

[0002] With the development of the times and the improvement of the quality of life, air conditioning systems have been fully integrated into various fields such as home and commercial use. The air conditioning system consists of an outdoor part and an indoor part. The outdoor part is used to dissipate heat and provide refrigerant to the indoor part.

[0003] The outdoor part includes a compressor. The indoor part includes an indoor unit, a liquid pipe and an air pipe. The indoor unit is provided with a first heat exchanger, and the first heat exchanger is connected to the air pipe connection pipe. A liquid control valve is provided on the liquid pipe, and the liquid control valve is an automatic valve that can control the flow of the refrigerant flowing through the liquid pipe. An air control valve is provided on the air pipe, and the air control valve is an automatic valve that can control the flow of the refrigerant flowing through the liquid pipe. The air pipe includes a high-pressure air pipe and a low-pressure air pipe. The air control valve includes a low-pressure air control valve and a high-pressure air control valve. The low-pressure air control valve is arranged on the low-pressure air pipe, and the high-pressure air control valve is arranged on the high-pressure air pipe. When the air conditioning system is heating, the high-pressure air control valve is opened, the low-pressure air control valve is closed, and the high-temperature and high-pressure gaseous refrigerant flowing out of the compressor outlet flows into the first heat exchanger through the high-pressure air pipe to heat. When the air conditioning system is cooling, the high-pressure air control valve is closed, the low-pressure air control valve is opened, and the low-pressure air control valve is opened, and the low-temperature and low-pressure gaseous refrigerant flowing out of the first heat exchanger flows back to the compressor through the low-pressure air pipe.

[0004] Liquid control valves, low-pressure control valves and high-pressure control valves are generally installed in valve boxes, which are generally installed in equipment rooms of buildings. Both low-pressure gas pipes and high-pressure gas pipes need to be equipped with corresponding control valves, which occupies a large space, making the valve box larger in size, which is not conducive to its arrangement in equipment rooms with limited space.

[0005] Therefore, there is an urgent need for an air-conditioning system and a control method for the air-conditioning system to solve the problem that the control valve of the existing air-conditioning system occupies a large space. Summary of the invention

[0006] The present invention aims to solve the above technical problem, that is, to solve the problem that the control valve of the existing air-conditioning system occupies a large space.

[0007] In a first aspect, the present invention provides an air-conditioning system, comprising an indoor part, the indoor part comprising: a first heat exchanger; a low-pressure air pipe capable of communicating with the first heat exchanger; a high-pressure air pipe capable of communicating with the first heat exchanger; an air control valve, comprising a first channel, a second channel and a third channel forming a three-way, the high-pressure air pipe being connected to the first channel, the low-pressure air pipe being connected to the second channel, and the first heat exchanger being connected to the third channel; the air control valve being configured to control the opening of the first channel and the second channel.

[0008] In a specific embodiment of the above-mentioned air-conditioning system, the air-conditioning system also includes: a liquid pipe, which is connected to the first heat exchanger; a liquid safety valve, which is arranged on the liquid pipe and is configured to open or disconnect the connection between the liquid pipe and the first heat exchanger; and a gas safety valve, which is arranged between the low-pressure gas pipe, the high-pressure gas pipe or the gas control valve and the first heat exchanger, and is configured to open or disconnect the connection between the low-pressure gas pipe and the high-pressure gas pipe and the first heat exchanger.

[0009] In a specific embodiment of the above-mentioned air-conditioning system, the air-conditioning system also includes a first inspection valve and a second inspection valve, the first inspection valve is arranged on the liquid pipe, and the second inspection valve is arranged on the gas pipe connecting the gas safety valve and the first heat exchanger, and the first inspection valve and the second inspection valve are configured to be able to evacuate the refrigerant of the first heat exchanger from the first inspection valve and the second inspection valve.

[0010] In a specific embodiment of the above-mentioned air-conditioning system, the air-conditioning system also includes an outdoor part, which is configured to provide refrigerant to the indoor part, and the outdoor part includes: a compressor for compressing the refrigerant; a second heat exchanger, the first heat exchanger and the second heat exchanger are connected through the liquid pipe; a second expansion valve, the second expansion valve is arranged on the liquid pipe; a reversing valve group, which is configured to switch the refrigerant flowing out of the compressor to flow to the first heat exchanger or the second heat exchanger.

[0011] In a specific implementation of the above air-conditioning system, the indoor part further includes a refrigerant detection module, and the refrigerant detection module is configured to detect the concentration of the refrigerant in the air.

[0012] In a specific implementation of the above air-conditioning system, the air-conditioning system further comprises a backup power supply, and the backup power supply can supply power to the gas control valve.

[0013] In a specific implementation of the above air conditioning system, the liquid safety valve and the gas safety valve are manually controlled valves.

[0014] In a second aspect, the present invention provides a control method for an air-conditioning system, wherein the indoor part includes an indoor unit, and the first heat exchanger is arranged in the indoor unit. The method is characterized in that the control method for the air-conditioning system includes: obtaining an operating mode of the indoor unit; and controlling the air control valve according to the operating mode of the indoor unit to control the opening of the first channel and the second channel.

[0015] In a specific implementation of the control method of the above-mentioned air-conditioning system, "controlling the air control valve according to the operating mode of the indoor unit" includes: if the operating mode of the indoor unit is cooling operation, the air control valve controls the first channel to be closed and the second channel to be connected, so that the low-pressure air pipe is connected to the first heat exchanger, and the high-pressure air pipe is disconnected from the first heat exchanger.

[0016] In a specific implementation of the control method of the above-mentioned air-conditioning system, "controlling the air control valve according to the operating mode of the indoor unit" also includes: if the operating mode of the indoor unit is cooling standby, the air control valve controls both the first channel and the second channel to be closed, so that the low-pressure air pipe is disconnected from the first heat exchanger, and the high-pressure air pipe is disconnected from the first heat exchanger.

[0017] In a specific implementation of the control method of the above-mentioned air-conditioning system, "controlling the air control valve according to the operating mode of the indoor unit" also includes: if the operating mode of the indoor unit is heating operation or heating standby, the air control valve controls the first channel to be conductive and the second channel to be closed, so that the low-pressure air pipe is disconnected from the first heat exchanger, and the high-pressure air pipe is connected to the first heat exchanger.

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] The air-conditioning system provided by the present invention is provided with a three-way air control valve, and the high-pressure air pipe and the low-pressure air pipe are both connected to the air control valve, so that the on-off and flow rate of the low-pressure air pipe and the high-pressure air pipe with the first heat exchanger can be controlled simultaneously through one control valve. Compared with respectively providing control valves on the high-pressure air pipe and the low-pressure air pipe, the system structure is simplified, the volume occupied by the valve device is reduced, thereby reducing the volume of the valve box where the air control valve is provided, which is conducive to meeting the installation space requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The preferred embodiments of the present invention are described below in conjunction with the accompanying drawings, in which:

[0021] Figure 1 It is a piping diagram of the air conditioning system provided by the present invention;

[0022] Figure 2 It is a piping diagram of the indoor part of the air conditioning system provided by the present invention;

[0023] Figure 3 It is a flow chart of the main steps of the control method of the air conditioning system provided by the present invention;

[0024] Figure 4 It is a flow chart of detailed steps of the control method of the air conditioning system provided by the present invention.

[0025] Description of reference numerals:

[0026] 1. Indoor unit; 11. First heat exchanger; 12. Liquid pipe connection pipe; 13. Gas pipe connection pipe; 14. First expansion valve; 2. Liquid pipe; 21. Liquid control valve; 3. Low-pressure gas pipe; 4. High-pressure gas pipe; 41. Gas control valve; 5. Liquid transition pipe; 51. Liquid safety valve; 52. First inspection valve; 6. Gas transition pipe; 61. Gas safety valve; 62. Second inspection valve; 7. Compressor; 71. Gas-liquid separator; 72. Oil separator; 8. Second heat exchanger; 81. Second expansion valve; 91. First reversing valve; 92. Second reversing valve. DETAILED DESCRIPTION

[0027] The preferred embodiments of the present invention are described below with reference to the accompanying drawings. It should be understood by those skilled in the art that these embodiments are only used to explain the technical principles of the present invention and are not intended to limit the protection scope of the present invention.

[0028] It should be noted that in the description of the present invention, the terms "upper", "lower", "left", "right", "inner", "outer" and the like indicating directions or positional relationships are based on the directions or positional relationships shown in the drawings, which are only for the convenience of description, and do not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0029] In addition, it should be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "installation", "setting", and "connection" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, an indirect connection through an intermediate medium, or the internal connection of two components. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0030] In order to solve the problem that the control valve of the existing air conditioning system occupies a large space, the present invention provides an air conditioning system. The air conditioning system includes an indoor part and an outdoor part, and the outdoor part can supply refrigerant to the indoor part to achieve indoor cooling or heating.

[0031] like Figure 1 and Figure 2As shown, the indoor part includes an indoor unit 1, a liquid pipe 2 and an air pipe. The indoor unit 1 is provided with a first heat exchanger 11, and the inlet and outlet of the first heat exchanger 11 are respectively connected with a liquid pipe connection pipe 12 and an air pipe connection pipe 13. A liquid control valve 21 is provided on the liquid pipe 2, and the liquid control valve 21 is an automatic valve that can control the flow of the refrigerant flowing through the liquid pipe 2. An air control valve 41 is provided on the air pipe, and the air control valve 41 is an automatic valve that can control the flow of the refrigerant flowing through the liquid pipe 2. The liquid control valve 21 and the air control valve 41 are arranged in a valve box. During the operation of the indoor part, the refrigerant enters from the liquid pipe 2 or the air pipe and flows through the first heat exchanger 11, and heat is exchanged at the first heat exchanger 11 to achieve cooling or heating.

[0032] In an embodiment of the present invention, the air pipe includes a low-pressure air pipe 3 and a high-pressure air pipe 4. The air control valve 41 includes a first channel, a second channel and a third channel forming a three-way connection, the high-pressure air pipe 4 is connected to the first channel, the low-pressure air pipe 3 is connected to the second channel, and the air pipe connection pipe 13 is connected to the third channel. The end of the low-pressure air pipe 3 away from the air control valve 41 is connected to the air pipe connection pipe 13 of the indoor unit 1, and the end of the high-pressure air pipe 4 away from the air control valve 41 is connected to the air pipe connection pipe 13 of the indoor unit 1. A first valve plate is provided in the first channel, and the first valve plate can control the opening of the first channel. A second valve plate is provided in the second channel, and the second valve plate can control the opening of the second channel. By setting a three-way air control valve 41 and connecting both the high-pressure air pipe 4 and the low-pressure air pipe 3 to the air control valve 41, the on-off and flow rate of the low-pressure air pipe 3 and the high-pressure air pipe 4 and the air pipe connecting pipe 13 can be controlled simultaneously through one air control valve 41, thereby reducing the volume occupied by the valve device, thereby reducing the volume of the valve box in which the air control valve 41 is set, which is conducive to meeting the installation space requirements.

[0033] In addition, since the volume occupied by the air control valve 41 in the air conditioning system of the present invention is small, when the air conditioning system is provided with multiple indoor units 1, when the air control valves 41 and the liquid control valves 21 corresponding to the multiple indoor units 1 are centrally arranged in one valve box, the volume occupied by the valve box is small. In the same volume of the installation space, the valve box of the air conditioning system provided by the present invention can separate more indoor units 1.

[0034] The gas control valve 41 of the present invention includes but is not limited to a structure in which a valve plate is arranged in a channel, and may also include other valve structures such as a ball valve that may realize a three-way function, all of which belong to the scope of the present invention.

[0035] Regarding the control of the first channel and the second channel, taking the valve plate structure inside the air control valve as an example, if the operation mode of the indoor unit 1 is cooling operation, the air control valve 41 controls the first valve plate to be closed and the second valve plate to be opened, so that the low-pressure air pipe 3 is connected to the air pipe connection pipe 13, and the high-pressure air pipe 4 is disconnected from the air pipe connection pipe 13. If the operation mode of the indoor unit 1 is cooling standby, the air control valve 41 controls both the first valve plate and the second valve plate to be closed, so that the low-pressure air pipe 3 is disconnected from the air pipe connection pipe 13, and the high-pressure air pipe 4 is disconnected from the air pipe connection pipe 13. If the operation mode of the indoor unit 1 is heating operation or heating standby, the air control valve 41 controls the first valve plate to be opened and the second valve plate to be closed, so that the low-pressure air pipe 3 is disconnected from the air pipe connection pipe 13, and the high-pressure air pipe 4 is connected to the air pipe connection pipe 13. When the operation mode of the indoor unit 1 is heating standby, the opening of the first valve plate is small, so that the refrigerant can flow from the first valve plate to the first heat exchanger 11 at a slower speed, ensuring that the first heat exchanger 11 always maintains a certain temperature.

[0036] The liquid pipe 2, the low-pressure gas pipe 3 and the high-pressure gas pipe 4 are all provided with stop valves to control whether the liquid pipe 2, the low-pressure gas pipe 3 and the high-pressure gas pipe 4 are put into use. When the air conditioning system is heating, the stop valves on the liquid pipe 2 and the high-pressure gas pipe 4 are opened, and the stop valve on the low-pressure gas pipe 3 is closed, so that the liquid pipe 2 and the high-pressure gas pipe 4 are put into use. When the air conditioning system is cooling, the stop valves on the liquid pipe 2 and the low-pressure gas pipe 3 are opened, and the stop valve on the high-pressure gas pipe 4 is closed, so that the liquid pipe 2 and the low-pressure gas pipe 3 are put into use.

[0037] The indoor part also includes a liquid safety valve 51 and a gas safety valve 61. The liquid pipe connection pipe 12 is connected to the liquid pipe 2 through the liquid transition pipe 5, and the liquid safety valve 51 is arranged on the liquid transition pipe 5, and the liquid safety valve 51 can open or disconnect the liquid transition pipe to open or disconnect the connection between the liquid pipe 2 and the liquid pipe connection pipe 12. The gas pipe connection pipe 13 is connected to the gas pipe through the gas transition pipe 6, and the gas safety valve 61 is arranged on the gas transition pipe 6, and the gas safety valve 61 can open or disconnect the gas transition pipe to open or disconnect the connection between the gas pipe and the gas pipe connection pipe 13.

[0038] The liquid transition pipe 5 is a portion extending from the liquid pipe 2. In a broad sense, the liquid transition pipe 5 can also be regarded as a part of the liquid pipe 2. The gas transition pipe 6 is a portion extending from the gas pipe after the low-pressure gas pipe 3 and the high-pressure gas pipe 4 are connected in parallel. In a broad sense, the gas transition pipe 6 can also be regarded as a part of the gas pipe.

[0039] Regarding the setting positions of the liquid safety valve 51 and the gas safety valve 61, it should be noted that although in the present invention, the liquid safety valve 51 and the gas safety valve 61 are respectively set on the liquid transition pipe 5 and the gas transition pipe 6, this is not a specific limitation of the present invention. Without departing from the principles of the present invention, in other embodiments, those skilled in the art may also set the liquid safety valve 51 at any position on the liquid pipe 2 and the gas safety valve 61 at any position on the gas pipe.

[0040] There are two conditions for opening the liquid control valve 21 and the gas control valve 41: the refrigerant in the indoor part has not leaked (that is, the refrigerant content in the indoor air is lower than the preset value), and the indoor unit 1 is powered on and is in an online state. In the case of a failure of the indoor unit 1, the online state of the indoor unit 1 will generally be disconnected. At this time, the air conditioning system cannot search for the indoor unit 1, and the liquid control valve 21 and the gas control valve 41 corresponding to the indoor unit 1 will be closed to facilitate the staff to repair the indoor unit 1. In addition, the indoor part also includes a refrigerant detection module for detecting the concentration of refrigerant in the air. Once the refrigerant concentration in the air at the location of a certain indoor unit 1 exceeds the standard, it means that the refrigerant in the indoor unit 1 has leaked, and the air conditioning system will control the liquid control valve 21 and the gas control valve 41 corresponding to the indoor unit 1 to be closed to facilitate the staff to repair. During the repair process of the indoor unit 1, once the indoor unit 1 is in an online state and powered on, and the refrigerant content in the air is lower than the preset value, the air conditioning system will automatically open the liquid control valve 21 and the gas control valve 41. After the liquid safety valve 51 and the gas safety valve 61 are set, if the indoor unit 1 fails and needs to be disassembled, the liquid control valve 21 and the gas control valve 41 are automatically controlled to be closed first, and then the liquid safety valve 51 and the gas safety valve 61 are closed. As a double guarantee, even if the maintenance personnel make an operating error and open the liquid control valve 21 or the gas control valve 41, the liquid safety valve 51 and the gas safety valve 61 can intercept the refrigerant to prevent the air-conditioning system from misjudging the liquid control valve 21 and the gas control valve 41 and causing refrigerant injection leakage.

[0041] The liquid safety valve 51 and the gas safety valve 61 are manually controlled valves, specifically mechanical valves or automatic valves controlled by manual switches. During the maintenance of the indoor unit 1, the liquid safety valve 51 and the gas safety valve 61 are always in a closed state through manual operation to prevent the refrigerant in the air conditioning system from leaking through the liquid pipe 2 or the gas pipe.

[0042] In a possible implementation of the present invention, a backup power supply is also provided in the valve box where the liquid control valve 21 and the gas control valve 41 are provided, and the backup power supply can supply power to the liquid control valve 21 and the gas control valve 41. After the air conditioning system is powered off, the backup power supply can also supply power to the liquid control valve 21 and the gas control valve 41, so that the liquid control valve 21 and the gas control valve 41 are actuated and the liquid pipe 2 and the gas pipe are closed. The backup power supply can be a battery or an emergency energy source.

[0043] In a possible implementation of the present invention, the indoor part further includes a first inspection valve 52 and a second inspection valve 62. The first inspection valve 52 is arranged on the liquid pipe 2, specifically between the liquid safety valve 51 and the first heat exchanger 11. The second inspection valve 62 is arranged on the gas pipe, specifically between the gas safety valve 61 and the first heat exchanger 11. During the inspection process, the staff can use tools to extract the air in the pipeline of the first heat exchanger 11 at the first inspection valve 52 and the second inspection valve 62 to perform the evacuation operation, and then replenish the refrigerant to the first heat exchanger 11 from the first inspection valve 52 and the second inspection valve 62 to ensure that the air-conditioning system has sufficient refrigerant after the indoor unit 1 is inspected, and that air will not be mixed into the refrigerant, and the air-conditioning system does not need to replace the refrigerant as a whole.

[0044] After the maintenance of the indoor unit 1 is completed, the liquid safety valve 51 and the gas safety valve 61 are opened, and the indoor unit 1 of the air-conditioning system is powered on and connected in parallel. The air-conditioning system will search for the indoor unit 1, the outdoor unit and the valve box to determine whether the number of the indoor unit 1, the outdoor unit and the valve box is correct. If the number of indoor units 1 and valve boxes is inconsistent, the valve box corresponding to the missing indoor unit 1 remains closed, and the staff is prompted to check. If the number of indoor units 1 and valve boxes is consistent and matches each other, the liquid control valve 21, the first valve plate and the second valve plate in the control valve box are opened or closed according to the operation mode of the indoor unit 1.

[0045] The outdoor part includes a compressor 7, a second heat exchanger 8, a second expansion valve 81 and a reversing valve group. The second heat exchanger 8, the second expansion valve 81 and the first heat exchanger 11 are connected in sequence through a pipeline formed by a combination of a liquid pipe 2 and a liquid pipe connection pipe 12. The outlet and inlet of the compressor 7 are both connected to the reversing valve group, and the second heat exchanger 8 and the first heat exchanger 11 are also connected to the reversing valve group. The low-temperature and low-pressure gaseous refrigerant can be compressed into a high-temperature and high-pressure gaseous refrigerant after the compressor 7 does work, and is transported from the outlet of the compressor 7 to the reversing valve group, and is switched by the reversing valve group to control the refrigerant to flow to the first heat exchanger 11 or the second heat exchanger 8.

[0046] If the reversing valve group is switched to make the refrigerant flow to the first heat exchanger 11, the high-temperature and high-pressure gaseous refrigerant will be liquefied into medium-temperature and medium-pressure liquid refrigerant at the first heat exchanger 11, and release heat at the first heat exchanger 11 to perform heating; the medium-temperature and medium-pressure liquid refrigerant flowing out of the first heat exchanger 11 enters the second expansion valve 81 for throttling to form low-temperature and low-pressure liquid refrigerant, and then passes through the second evaporator to absorb heat, causing the low-temperature and low-pressure liquid refrigerant to evaporate to form low-temperature and low-pressure gaseous refrigerant, and then flows to the inlet of the compressor 7 through the reversing valve group, forming a refrigerant circulation. If the reversing valve group is switched to make the refrigerant flow to the second heat exchanger 8, the high-temperature and high-pressure gaseous refrigerant will be liquefied into medium-temperature and medium-pressure liquid refrigerant at the second heat exchanger 8, and release heat at the second heat exchanger 8; the medium-temperature and medium-pressure liquid refrigerant flowing out of the second heat exchanger 8 enters the second expansion valve 81 for throttling to form a low-temperature and low-pressure liquid refrigerant, absorbs heat when flowing through the first evaporator to perform refrigeration, and evaporates the low-temperature and low-pressure liquid refrigerant to form a low-temperature and low-pressure gaseous refrigerant, and then flows to the inlet of the compressor 7 through the reversing valve group, forming a refrigerant circulation.

[0047] In an embodiment of the present invention, the reversing valve group includes a first reversing valve 91 and a second reversing valve 92. The first reversing valve 91 is arranged corresponding to the second heat exchanger 8, and each second heat exchanger 8 corresponds to a first reversing valve 91. The pipeline connected to the first reversing valve 91 is the interface of the second heat exchanger 8, the outlet of the compressor 7 and the inlet of the compressor 7. The first reversing valve 91 can be switched to make the interface of the second heat exchanger 8 communicate with the outlet of the compressor 7 or the inlet of the compressor 7. The pipeline connected to the second reversing valve 92 is the high-pressure gas pipe 4 and the outlet of the compressor 7. The second reversing valve 92 can be switched to make the high-pressure gas pipe 4 communicate with or disconnect the outlet of the compressor 7. When the air conditioning system is heating, the second reversing valve 92 is switched to connect the outlet of the compressor 7 with the high-pressure gas pipe 4, and the first reversing valve 91 is switched to connect the interface of the second heat exchanger 8 with the inlet of the compressor 7. The flow path of the refrigerant is: the outlet of the compressor 7 - the second reversing valve 92 - the high-pressure gas pipe 4 - the first heat exchanger 11 - the first expansion valve 14 - the liquid pipe 2 - the second expansion valve 81 - the second heat exchanger 8 - the first reversing valve 91 - the inlet of the compressor 7. When the air conditioning system is cooling, the first reversing valve 91 is switched to connect the interface of the second heat exchanger 8 with the outlet of the compressor 7, and the second reversing valve 92 is switched to disconnect the high-pressure gas pipe 4 from the outlet of the compressor 7. The flow path of the refrigerant is: the outlet of the compressor 7 - the first reversing valve 91 - the second heat exchanger 8 - the second expansion valve 81 - the liquid pipe 2 - the first expansion valve 14 - the first heat exchanger 11 - the low-pressure gas pipe 3 - the inlet of the compressor 7.

[0048] It should be noted that the reversing valve group of the present invention is not limited to the above-mentioned reversing valve group. Without departing from the principle of the present invention, in other embodiments, those skilled in the art may also set the reversing valve group to a four-way valve, which is respectively connected to the inlet of the compressor 7, the outlet of the compressor 7, the interface of the second heat exchanger 8 and the air pipe. The four-way valve can be switched so that the inlet of the compressor 7 is connected to the interface of the second heat exchanger 8 and the outlet of the compressor 7 is connected to the air pipe, or the inlet of the compressor 7 is connected to the air pipe and the outlet of the compressor 7 is connected to the interface of the second heat exchanger 8.

[0049] A gas-liquid separator 71 is provided at the inlet of the compressor 7, which can separate the liquid refrigerant or liquid impurities in the refrigerant to prevent the liquid from hitting the compressor 7, thereby ensuring the safe operation of the compressor 7. An oil separator 72 is provided at the outlet of the compressor 7, which can separate the lubricating oil in the high-pressure refrigerant discharged from the compressor 7, thereby ensuring the safe and efficient operation of the air-conditioning system.

[0050] For some large-area residences or office buildings, multiple indoor units 1 are generally required to be installed in the indoor part, and each indoor unit 1 is provided with a corresponding liquid pipe 2, a gas pipe, a liquid control valve 21, a gas control valve 41, a liquid safety valve 51, a gas safety valve 61, a first inspection valve 52 and a second inspection valve 62. The liquid pipe 2 corresponding to each indoor unit 1 is connected to the liquid pipe 2 of the outdoor part, and the gas pipe corresponding to each indoor unit 1 is connected to the gas pipe of the outdoor part.

[0051] In addition, each indoor unit 1 is provided with a first expansion valve 14, which is located between the first heat exchanger 11 and the second heat exchanger 8, and the first expansion valve 14 is located near the first heat exchanger 11. Specifically, the first expansion valve 14 is provided on the liquid pipe connection pipe 12. When the air-conditioning system is heating or cooling, the first expansion valve 14 and the second expansion valve 81 can both work, and the pressure of the liquid refrigerant between the first expansion valve 14 and the second expansion valve 81 can be adjusted by controlling the opening of the first expansion valve 14 and the second expansion valve 81. At the same time, by controlling the opening of the first expansion valve 14, the refrigeration effect of the indoor unit 1 corresponding to the first expansion valve 14 can be controlled. The larger the opening of the first expansion valve 14, the larger the refrigerant flow rate flowing through the indoor unit 1 corresponding to the first expansion valve 14, and the better the refrigeration effect.

[0052] For some high-power air conditioning systems, multiple second heat exchangers 8 are provided, and multiple second heat exchangers 8 are connected in parallel to improve the heat exchange efficiency between the second heat exchanger 8 and the outside. Each second heat exchanger 8 is provided with a corresponding second expansion valve 81 to individually control the flow of the refrigerant flowing through the single second heat exchanger 8. In the case of a high-power air conditioning system, the more second heat exchangers 8 are put into operation, the larger the opening of the corresponding second expansion valve 81.

[0053] like Figure 3 As shown, the present invention also provides a control method for an air conditioning system, which mainly includes the following steps:

[0054] S1. Obtaining the operation mode of the indoor unit 1. The operation mode of the indoor unit 1 mainly includes a cooling operation mode, a cooling standby mode, a heating operation mode, and a heating standby mode.

[0055] S2. Control the gas control valve 41 according to the operation mode of the indoor unit 1. Specifically, if the operation mode of the indoor unit 1 is cooling operation, the gas control valve 41 controls the first channel to be closed and the second channel to be connected, so that the low-pressure gas pipe 3 is connected to the gas pipe connection pipe 13, and the high-pressure gas pipe 4 is disconnected from the gas pipe connection pipe 13. At this time, the medium-temperature and medium-pressure refrigerant flowing out of the second heat exchanger 8 flows from the liquid pipe 2 to the first heat exchanger 11, and the refrigerant releases heat at the first heat exchanger 11 to form a low-temperature and low-pressure gaseous refrigerant, which flows from the gas pipe connection pipe 13 to the low-pressure gas pipe 3, and finally flows back to the compressor 7. If the operation mode of the indoor unit 1 is cooling standby, the gas control valve 41 controls the first channel and the second channel to be closed at the same time, so that the low-pressure gas pipe 3 is disconnected from the gas pipe connection pipe 13, and the high-pressure gas pipe 4 is disconnected from the gas pipe connection pipe 13. At this time, the refrigerant will not flow through the first heat exchanger 11, and the first heat exchanger 11 will not exchange heat with the air flowing through the first heat exchanger 11, thereby stopping cooling; if the operation mode of the indoor unit 1 is heating operation or heating standby, the gas control valve 41 controls the first channel to be connected and the second channel to be closed, so that the low-pressure gas pipe 3 is disconnected from the gas pipe connection pipe 13, and the high-pressure gas pipe 4 is connected to the gas pipe connection pipe 13. At this time, the high-temperature and high-pressure gaseous refrigerant flowing out of the compressor 7 flows to the first heat exchanger 11 through the high-pressure gas pipe 4 and the gas pipe connection pipe 13. The refrigerant releases heat at the first heat exchanger 11 and forms a medium-temperature and medium-pressure liquid refrigerant, which flows from the liquid pipe connection pipe 12 to the liquid pipe 2, and finally flows to the second heat exchanger 8. Among them, when the operation mode of the indoor unit 1 is heating standby, the opening degree of the first channel is small, reducing the flow rate of the refrigerant flowing through the first heat exchanger 11, ensuring that the first heat exchanger 11 always maintains a certain temperature to maintain the room temperature.

[0056] like Figure 4 As shown, the control method of the air conditioning system provided by the present invention specifically includes the following steps:

[0057] S1. Determine whether the air conditioning system is powered off. If the air conditioning system is powered off, execute step S11; if the air conditioning system is not powered off, execute step S12.

[0058] S11, start the backup power supply to supply power to the liquid control valve 21 and the gas control valve 41, so that the first channel and the second channel of the liquid control valve 21 and the gas control valve 41 are closed.

[0059] S12. Obtaining the refrigerant concentration of a portion of indoor air.

[0060] S2, determine whether the refrigerant concentration is greater than a preset value. If the refrigerant concentration is greater than the preset value, it means that there is a refrigerant leak in the indoor part, and execute step S3; if the refrigerant concentration is not greater than the preset value, execute step S6.

[0061] S3, an alarm is sounded to remind the staff to perform maintenance, and the first channel and the second channel of the liquid control valve 21 and the gas control valve 41 are closed. At the same time, the fan of the indoor unit 1 is controlled to run at a high speed, and the exhaust equipment in the building is linked to exhaust air forcefully, so as to eliminate the safety hazard of explosion caused by excessive refrigerant concentration as soon as possible.

[0062] S4, acquiring the opening and closing states of the first channel and the second channel of the liquid control valve 21, the liquid safety valve 51, the gas safety valve 61 and the gas control valve 41.

[0063] S5. Determine whether the first channel and the second channel of the liquid control valve 21, the liquid safety valve 51, the gas safety valve 61, and the gas control valve 41 are all closed. If the first channel and the second channel of the liquid control valve 21, the liquid safety valve 51, the gas safety valve 61, and the gas control valve 41 are all closed, execute step S51; if the first channel and the second channel of the liquid control valve 21, the liquid safety valve 51, the gas safety valve 61, and the gas control valve 41 are not all closed, there may be a safety hazard, and execute step S52.

[0064] S51. The indoor unit 1 can be removed for maintenance.

[0065] S52: The indoor unit 1 cannot be dismantled for maintenance, and a worker is required to check the liquid control valve 21, the liquid safety valve 51, the gas safety valve 61, and the first channel and the second channel of the gas control valve 41.

[0066] S6, obtaining the current opening and closing states of the liquid control valve 21 and the gas control valve 41. It should be noted that if one of the first channel and the second channel is connected, the opening and closing state of the gas control valve 41 is the open state. If neither the first channel nor the second channel is connected, the opening and closing state of the gas control valve 41 is the closed state.

[0067] S7, determine whether the current opening and closing states of the liquid control valve 21 and the gas control valve 41 are closed. If the current opening and closing states of the liquid control valve 21 and the gas control valve 41 are closed, execute step S8; if the current opening and closing states of the liquid control valve 21 and the gas control valve 41 are open, execute step S9.

[0068] S8. Keep the control liquid control valve 21 and the gas control valve 41 closed, and remind the staff to open them manually.

[0069] S9, the control liquid control valve 21 and the gas control valve 41 remain open.

[0070] S10, obtaining the operation mode of the indoor unit 1. The operation mode of the indoor unit 1 mainly includes a cooling operation mode, a cooling standby mode, a heating operation mode and a heating standby mode.

[0071] S101. Control the gas safety valve 61 according to the operation mode of the indoor unit 1. Specifically, if the operation mode of the indoor unit 1 is cooling operation, the gas control valve 41 controls the first channel to be closed and the second channel to be connected, so that the low-pressure gas pipe 3 is connected to the gas pipe connection pipe 13, and the high-pressure gas pipe 4 is disconnected from the gas pipe connection pipe 13. At this time, the medium-temperature and medium-pressure refrigerant flowing out of the second heat exchanger 8 flows from the liquid pipe 2 to the first heat exchanger 11. The refrigerant releases heat at the first heat exchanger 11 and forms a low-temperature and low-pressure gaseous refrigerant, which flows from the gas pipe connection pipe 13 to the low-pressure gas pipe 3 and finally flows back to the compressor 7. If the operation mode of the indoor unit 1 is cooling standby, the gas control valve 41 controls both the first channel and the second channel to be closed, so that the low-pressure gas pipe 3 and the gas pipe connection pipe are connected. 13 is disconnected, and the high-pressure gas pipe 4 is disconnected from the gas pipe connection pipe 13. At this time, the refrigerant will not flow through the first heat exchanger 11; if the operation mode of the indoor unit 1 is heating operation or heating standby, the gas control valve 41 controls the first channel to be connected and the second channel to be closed, so that the low-pressure gas pipe 3 is disconnected from the gas pipe connection pipe 13, and the high-pressure gas pipe 4 is connected to the gas pipe connection pipe 13. At this time, the high-temperature and high-pressure gas refrigerant flowing out of the compressor 7 flows to the first heat exchanger 11 through the high-pressure gas pipe 4 and the gas pipe connection pipe 13. The refrigerant releases heat at the first heat exchanger 11 and forms a medium-temperature and medium-pressure liquid refrigerant, which flows from the liquid pipe connection pipe 12 to the liquid pipe 2, and finally flows to the second heat exchanger 8. Among them, when the operation mode of the indoor unit 1 is heating standby, the opening of the first channel is small, reducing the flow of the refrigerant flowing through the first heat exchanger 11, ensuring that the first heat exchanger 11 always maintains a certain temperature to maintain the room temperature.

[0072] So far, the technical solutions of the present invention have been described in conjunction with the preferred embodiments shown in the accompanying drawings. However, it is easy for those skilled in the art to understand that the protection scope of the present invention is obviously not limited to these specific embodiments. Without departing from the principle of the present invention, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will fall within the protection scope of the present invention.

Claims

1. An air conditioning system, comprising an indoor part, characterized in that: The indoor part includes: A first heat exchanger (11); A low-pressure gas pipe (3) capable of being in communication with the first heat exchanger (11); A high-pressure gas pipe (4) capable of being in communication with the first heat exchanger (11); The gas control valve (41) comprises a first channel, a second channel and a third channel forming a three-way connection, the high-pressure gas pipe (4) is connected to the first channel, the low-pressure gas pipe (3) is connected to the second channel, and the first heat exchanger (11) is connected to the third channel; The gas control valve (41) is configured to control the opening degrees of the first passage and the second passage.

2. The air conditioning system according to claim 1, characterized in that: The air conditioning system further comprises: a liquid pipe (2), the liquid pipe (2) being connected to the first heat exchanger (11); a liquid safety valve (51), arranged on the liquid pipe (2), configured to open or disconnect the connection between the liquid pipe (2) and the first heat exchanger (11); An air safety valve (61) is arranged between the low-pressure air pipe (3), the high-pressure air pipe (4) or the air control valve (41) and the first heat exchanger (11), and is configured to open or disconnect the connection between the low-pressure air pipe (3) and the high-pressure air pipe (4) and the first heat exchanger (11).

3. The air conditioning system according to claim 2, characterized in that: The air conditioning system further comprises a first inspection valve (52) and a second inspection valve (62), wherein the first inspection valve (52) is arranged on the liquid pipe (2), and the second inspection valve (62) is arranged on the gas pipe connecting the gas safety valve (61) and the first heat exchanger (11); The first inspection valve (52) and the second inspection valve (62) are configured to be able to evacuate the refrigerant of the first heat exchanger (11) from the first inspection valve (52) and the second inspection valve (62).

4. The air conditioning system according to claim 1, characterized in that: The air conditioning system further includes an outdoor part, which is configured to provide a refrigerant to the indoor part, and the outdoor part includes: A compressor (7) for compressing a refrigerant; a second heat exchanger (8), wherein the first heat exchanger (11) and the second heat exchanger (8) are connected via the liquid pipe (2); a second expansion valve (81), the second expansion valve (81) being arranged on the liquid pipe (2); The reversing valve group is configured to switch the refrigerant flowing out of the compressor (7) to flow to the first heat exchanger (11) or the second heat exchanger (8).

5. The air conditioning system according to claim 1, characterized in that: The indoor part also includes a refrigerant detection module, and the refrigerant detection module is configured to detect the concentration of the refrigerant in the air.

6. The air conditioning system according to claim 1, characterized in that: The air conditioning system further comprises a backup power supply, which is capable of supplying power to the gas control valve (41).

7. The air conditioning system according to claim 2, characterized in that: The liquid safety valve (51) and / or the gas safety valve (61) are manually controlled valves.

8. A control method for an air conditioning system according to any one of claims 1 to 7, wherein the indoor part comprises an indoor unit (1), characterized in that: The control method of the air conditioning system comprises: Obtaining the operating mode of the indoor unit (1); The air control valve (41) is controlled according to the operation mode of the indoor unit (1) to control the opening degrees of the first passage and the second passage.

9. The control method of the air conditioning system according to claim 8, characterized in that: “Controlling the gas control valve (41) according to the operating mode of the internal machine (1)” includes: If the operation mode of the indoor unit (1) is cooling operation, the gas control valve (41) controls the first channel to be closed and the second channel to be open, so that the low-pressure gas pipe (3) is connected to the first heat exchanger (11), and the high-pressure gas pipe (4) is disconnected from the first heat exchanger (11).

10. The control method of the air conditioning system according to claim 8, characterized in that: “Controlling the gas control valve (41) according to the operating mode of the internal machine (1)” also includes: If the operation mode of the indoor unit (1) is cooling standby, the gas control valve (41) controls both the first channel and the second channel to be closed, so that the low-pressure gas pipe (3) is disconnected from the first heat exchanger (11), and the high-pressure gas pipe (4) is disconnected from the first heat exchanger (11).

Images