Air conditioning system and air treatment system

Abstract

The utility model relates to the technical field of air-conditioning systems, and discloses an air-conditioning system which comprises a compressor, a first air-conditioning system and a second air-conditioning system. Wherein the first compression cylinder is provided with a first air suction port, and the second compression cylinder is provided with a second air suction port; the air supply inlet is formed in a refrigerant main circulation loop of the air conditioning system; the first end of the air supply pipe set communicates with the air supply inlet, and the second end of the air supply pipe set communicates with the first air suction port and / or the second air suction port. In this way, the energy efficiency of the air supply system is improved, the air supply requirements of the two compression cylinders are effectively met, and safe and stable operation of the compressor is guaranteed. The utility model further discloses an air conditioner processing system.

Description

Technical Field

[0001] This application relates to the technical field of air conditioning systems, for example, to an air conditioning system and an air handling system. Background Art

[0002] With the development of technology and the improvement of people's living standards, air conditioners have been widely used, and people's requirements for the use of air conditioners are getting higher and higher, and the performance of air conditioners has been continuously optimized. Among them, the three-pipe air conditioning system has emerged and can be applied in different heat exchange scenarios.

[0003] The related technology discloses a three-pipe air conditioning system, which uses a double-cylinder compressor with double suction and single exhaust. In the process of implementing the embodiments of the present disclosure, it is found that there are at least the following problems in the related technology: the pipeline layout of the three-pipe air conditioning system is relatively complex, and the internal components of the double-cylinder compressor are more complex than those of the single-cylinder compressor, so the requirements for oil return and gas replenishment are relatively high. Therefore, how to improve the performance of the oil return system and the gas replenishment system plays a crucial role in the operation of the double-cylinder compressor.

[0004] It should be noted that the information disclosed in the above background art section is only used to enhance the understanding of the background of the present application, and therefore may include information that does not constitute the prior art known to those of ordinary skill in the art. Summary of the Utility Model

[0005] To have a basic understanding of some aspects of the disclosed embodiments, a simple summary is given below. The summary is not a general review, nor is it intended to identify key / important constituent elements or delineate the protection scope of these embodiments, but rather serves as a preamble to the detailed description below.

[0006] The embodiments of the present disclosure provide an air conditioning system and an air handling system, which solve the problem of improving the performance of the gas replenishment system of the double-cylinder compressor.

[0007] In some embodiments, the air conditioning system includes:

[0008] A compressor, including a first compression cylinder and a second compression cylinder; wherein, the first compression cylinder has a first suction port, and the second compression cylinder has a second suction port;

[0009] A gas replenishment inlet, arranged on the main refrigerant circulation return path of the air conditioning system;

[0010] A gas replenishment pipe group, whose first end is connected to the gas replenishment inlet, and whose second end is connected to the first suction port and / or the second suction port.

[0011] The air conditioning system and the air handling system provided by the embodiments of the present disclosure can achieve the following technical effects:

[0012] An air-conditioning system is provided with a gas supplement inlet on the main refrigerant circulation loop, and the refrigerant can flow from the gas supplement inlet to the gas supplement pipe group. Under the action of the gas supplement pipe group, gas can be supplemented to the first compression cylinder through the first gas supplement port, and / or gas can be supplemented to the second compression cylinder through the second gas supplement port. In this way, the energy efficiency of the gas supplement system is improved, effectively meeting the gas supplement requirements of the two compression cylinders and ensuring the safe and stable operation of the compressor.

[0013] The above general description and the following description are only exemplary and explanatory, and are not used to limit this application. Brief Description of the Drawings

[0014] One or more embodiments are exemplarily illustrated by corresponding drawings. These exemplary illustrations and the drawings do not constitute limitations on the embodiments. Elements with the same reference numerals in the drawings are shown as similar elements. The drawings do not constitute a scale limitation, and among them:

[0015] Figure 1 is a schematic structural diagram of an air-conditioning system provided by an embodiment of the present disclosure;

[0016] Figure 2 is a refrigerant flow diagram of the refrigeration mode of the air-conditioning system provided by an embodiment of the present disclosure;

[0017] Figure 3 is a refrigerant flow diagram of the heating mode of the air-conditioning system provided by an embodiment of the present disclosure;

[0018] Figure 4 is a schematic structural diagram of another air-conditioning system provided by an embodiment of the present disclosure;

[0019] Figure 5 is a schematic structural diagram of a compressor and an oil separator provided by an embodiment of the present disclosure;

[0020] Figure 6 is a schematic diagram of an oil return system provided by an embodiment of the present disclosure. (a) is an oil return diagram to the first compression cylinder, and (b) is an oil return diagram to the second compression cylinder;

[0021] Figure 7 is a schematic diagram of another oil return system provided by an embodiment of the present disclosure. (a) is an oil return diagram to the first compression cylinder, and (b) is an oil return diagram to the second compression cylinder;

[0022] Figure 8 is a schematic diagram of another oil return system provided by an embodiment of the present disclosure. (a) is an oil return diagram to the first compression cylinder, and (b) is an oil return diagram to the second compression cylinder;

[0023] Figure 9 is a schematic diagram of another oil return system provided by an embodiment of the present disclosure. (a) is an oil return diagram to the first compression cylinder, and (b) is an oil return diagram to the second compression cylinder;

[0024] Figure 10 It is a schematic diagram of an air supplement system provided by an embodiment of the present disclosure. (a) is a diagram of direct air supplement, and (b) is a diagram of direct and indirect air supplement;

[0025] Figure 11 It is a schematic diagram of another air supplement system provided by an embodiment of the present disclosure. (a) is a diagram of indirectly supplementing air to the first compression cylinder, and (b) is a diagram of indirectly supplementing air to the second compression cylinder;

[0026] Figure 12 It is a schematic diagram of another air supplement system provided by an embodiment of the present disclosure. (a) is a schematic diagram of the first gas-liquid separator and the second gas-liquid separator, and (b) is a schematic diagram of the first air supplement solenoid valve and the second air supplement solenoid valve;

[0027] Figure 13 It is a schematic diagram of another air supplement system provided by an embodiment of the present disclosure. (a) is a diagram of the connection position of the third air supplement pipeline, and (b) is a schematic diagram of the fourth air supplement solenoid valve;

[0028] Figure 14 It is a refrigerant flow diagram of the reheating and dehumidifying mode of the air conditioning system provided by an embodiment of the present disclosure;

[0029] Figure 15 It is a refrigerant flow diagram of the simultaneous heating and cooling mode of the air conditioning system provided by an embodiment of the present disclosure;

[0030] Figure 16 It is a schematic diagram of the integration of an air supplement system and an oil return system provided by an embodiment of the present disclosure.

[0031] Reference numerals:

[0032] 10. Compressor; 11. First compression cylinder; 12. Second compression cylinder; 13. First suction port; 14. First air supplement port; 15. First exhaust port; 16. Second suction port; 17. Second air supplement port; 18. Second exhaust port;

[0033] 20. Oil separator; 21. First oil return port; 22. Second oil return port; 23. First gas-liquid separator; 24. Second gas-liquid separator; 25. First air supplement accumulator; 26. Second air supplement accumulator; 27. Regulation accumulator;

[0034] 30. Economizer; 31. Primary side; 32. Secondary side; 33. Indoor heat exchange unit; 34. First evaporator; 35. Second evaporator; 36. Four-way valve; 37. Three-way valve;

[0035] 40. Outdoor heat exchange unit; 41. First refrigerant pipeline; 42. Second refrigerant pipeline; 43. Third refrigerant pipeline; 44. First return pipeline; 45. Second return pipeline;

[0036] 50. Air supplement inlet; 51. First air supplement pipeline; 52. Second air supplement pipeline; 53. Third air supplement pipeline; 54. First oil return pipeline; 55. Second oil return pipeline; 56. Air supplement confluence pipe section; 57. Oil return confluence pipe section;

[0037] 60. First throttling element; 61. Second throttling element; 62. Third throttling element; 63. Fourth throttling element; 64. Fifth throttling element; 65. Sixth throttling element; 66. Seventh throttling element;

[0038] 70. First air supplement solenoid valve; 71. Second air supplement solenoid valve; 72. Third air supplement solenoid valve; 73. Fourth air supplement solenoid valve; 74. Oil return solenoid valve; 75. Intermediate solenoid valve. Detailed implementation mode

[0039] In order to be able to understand the features and technical content of the embodiments of the present disclosure in more detail, the implementation of the embodiments of the present disclosure will be described in detail below with reference to the attached drawings. The attached drawings are only for reference and explanation purposes and are not used to limit the embodiments of the present disclosure. In the following technical description, for the sake of explanation, multiple details are provided to fully understand the disclosed embodiments. However, one or more embodiments can still be implemented without these details. In other cases, well-known structures and devices can be shown in a simplified manner to simplify the drawings.

[0040] In the embodiments of the present disclosure, the terms "first", "second", etc. in the description and claims of the present disclosure and the above-mentioned drawings are used to distinguish similar objects and do not have to be used to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so as to describe the embodiments of the present disclosure here. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion.

[0041] In the embodiments of the present disclosure, the orientation or positional relationship indicated by the terms "upper", "lower", "inner", "middle", "outer", "front", "rear", etc. is based on the orientation or positional relationship shown in the drawings. These terms are mainly used to better describe the embodiments of the present disclosure and their embodiments and are not used to limit that the indicated devices, elements or components must have a specific orientation or be constructed and operated in a specific orientation. And, in addition to being able to represent the orientation or positional relationship, some of the above terms may also be used to represent other meanings. For example, the term "upper" may also be used to represent a certain attachment relationship or connection relationship in some cases. For those of ordinary skill in the art, the specific meanings of these terms in the embodiments of the present disclosure can be understood according to specific circumstances.

[0042] In addition, the terms "arranged", "connected", and "fixed" should be understood in a broad sense. For example, "connected" can be a fixed connection, a detachable connection, or an integral structure; it can be a mechanical connection or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or an internal connection between two devices, components, or parts. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present disclosure can be understood according to specific circumstances.

[0043] Unless otherwise specified, the term "plurality" means two or more.

[0044] In the embodiments of the present disclosure, the character " / " indicates that the objects before and after are in an "or" relationship. For example, A / B means: A or B.

[0045] The term "and / or" is an associative relationship describing an object, indicating that there can be three relationships. For example, A and / or B means: A or B, or, the three relationships of A and B.

[0046] It should be noted that, without conflict, the embodiments in the embodiments of the present disclosure and the features in the embodiments can be combined with each other.

[0047] Combined Figure 1-16 As shown, the embodiments of the present disclosure provide an air-conditioning system, the compressor 10 of which is a twin-cylinder compressor, including a first compression cylinder 11 and a second compression cylinder 12. As Figure 5 shown, the first compression cylinder 11 has a first suction port 13 and a first discharge port 15, and the second compression cylinder 12 has a second suction port 16 and a second discharge port 18. After the refrigerant is compressed by the first compression cylinder 11 and / or the second compression cylinder 12, it flows through the first discharge port 15 and / or the second discharge port 18 to the oil separator 20, and then flows to the main refrigerant circulation circuit of the air-conditioning system. As Figure 1 shown, the pipeline layout of the main refrigerant circulation circuit mainly includes a first refrigerant pipeline 41, a second refrigerant pipeline 42, and a third refrigerant pipeline 43, so it is also called a three-pipe air-conditioning system.

[0048] In the refrigeration mode, as Figure 2As shown, the refrigerant of the oil separator 20 flows from the four-way valve 36 to the outdoor heat exchange unit 40, and the refrigerant of the outdoor heat exchange unit 40 flows from the third refrigerant pipeline 43 (high-pressure liquid pipeline) to the first evaporator 34 and the second evaporator 35; moreover, the refrigerant of the first evaporator 34 flows from the first refrigerant pipeline 41 (low-pressure gas pipeline) and the three-way valve 37 to the first return pipeline 44 in sequence, and the refrigerant of the first return pipeline 44 flows to the first compression cylinder 11 (low-pressure cylinder); the refrigerant of the second evaporator 35 flows from the second refrigerant pipeline 42 (medium-pressure gas pipeline) and the four-way valve 36 to the second return pipeline 45 in sequence, and the refrigerant of the second return pipeline 45 flows to the second compression cylinder 12 (medium-pressure cylinder). Here, the a port and the b port of the four-way valve 36 are connected, and the c port and the d port are connected; the g port and the h port of the three-way valve 37 are connected.

[0049] In the heating mode, as Figure 3 shown, the refrigerant of the oil separator 20 flows through the three-way valve 37 to the first refrigerant pipeline 41, and the refrigerant of the first refrigerant pipeline 41 flows to the first evaporator 34; the refrigerant of the oil separator 20 also flows through the four-way valve 36 to the second refrigerant pipeline 42, and the refrigerant of the second refrigerant pipeline 42 flows to the second evaporator 35; moreover, after the refrigerants of the first evaporator 34 and the second evaporator 35 converge, they flow from the third refrigerant pipeline 43 to the outdoor heat exchange unit 40; the refrigerant of the outdoor heat exchange unit 40 flows to the second compression cylinder 12 from the four-way valve 36 and the second return pipeline 45 in sequence. Here, the a port and the d port of the four-way valve 36 are connected, and the b port and the c port are connected; the f port and the g port of the three-way valve 37 are connected.

[0050] Optionally, the first return pipeline 44 and the second return pipeline 45 are connected through an intermediate solenoid valve 75. In the heating mode, when the intermediate solenoid valve 75 is opened, the first return pipeline 44 and the second return pipeline 45 are connected. At this time, the first suction port 13 and the second suction port 16 are in a connected state, and there is no pressure difference between the first compression cylinder 11 and the second compression cylinder 12. When the intermediate solenoid valve 75 is closed, only the second suction port 16 has refrigerant flowing in. At this time, only the second compression cylinder 12 works, which is beneficial to improving the energy efficiency of the air-conditioning system during low-load operation. In the cooling mode, when the intermediate solenoid valve 75 is opened, the first suction port 13 and the second suction port 16 are connected. At this time, there is no pressure difference between the first compression cylinder 11 and the second compression cylinder 12, and the temperatures of the first evaporator 34 and the second evaporator 35 are basically the same. When the intermediate solenoid valve 75 is closed, the first suction port 13 is connected to the first evaporator 34, and the second suction port 16 is connected to the second evaporator 35. At this time, a pressure difference is formed between the first compression cylinder 11 and the second compression cylinder 12. In this way, for the dehumidification mode, the latent heat load can be processed by the first evaporator 34, and the sensible heat load can be processed by the second evaporator 35, thereby effectively improving the energy efficiency of the air-conditioning system.

[0051] Optionally, in the case of having multiple first evaporators 34 and multiple second evaporators 35, each first evaporator 34 is arranged side by side with a second evaporator 35 to form a set of indoor heat exchange units 33. Here, an indoor fan is provided on one side of each set of indoor heat exchange units 33. And, multiple sets of indoor heat exchange units 33 can be used for installation in different spaces.

[0052] Optionally, each evaporator is provided with a corresponding sixth throttling element 65, and a seventh throttling element 66 is provided between the indoor heat exchange unit 33 and the outdoor heat exchange unit 40. In this way, through the arrangement and adjustment of multiple throttling elements, the air conditioning system can achieve multiple modes in addition to the refrigeration mode and the heating mode, such as the reheat dehumidification mode, the simultaneous cooling and heating mode, etc.

[0053] Exemplarily, as Figure 14 shown, in the reheat dehumidification mode, the refrigerant of the oil separator 20 flows through the four-way valve 36 to the outdoor heat exchange unit 40, the refrigerant of the outdoor heat exchange unit 40 flows through the third refrigerant pipeline 43, and the refrigerant of the third refrigerant pipeline 43 throttles and then flows to the second evaporator 35 (for dehumidification); and, the refrigerant of the oil separator 20 also flows through the three-way valve 37 to the first refrigerant pipeline 41, and the refrigerant of the first refrigerant pipeline 41 flows to the first evaporator 34 (for reheating). The refrigerant of the first evaporator 34 throttles and then flows to the second evaporator 35. Then, the refrigerant of the second evaporator 35 sequentially flows through the second refrigerant pipeline 42 and the second return pipeline 45 to the compressor 10. In this way, the first evaporator 34 cools and dehumidifies, and the second evaporator 35 heats to reheat the dehumidified air. Here, the a port and the b port of the four-way valve 36 are connected, and the c port and the d port are connected; the f port and the g port of the three-way valve 37 are connected.

[0054] Another exemplarily, as Figure 15As shown, the air conditioning system has two indoor heat exchange units 33, respectively called the first unit and the second unit. The sixth throttle element 65 corresponding to the second evaporator 35 of the first unit is closed, and the sixth throttle element 65 corresponding to the first evaporator 34 of the second unit is closed. In the simultaneous heating and cooling mode, the refrigerant of the oil separator 20 flows through the four-way valve 36 to the outdoor heat exchange unit 40. The refrigerant of the outdoor heat exchange unit 40 passes through the third refrigerant pipeline 43. After throttling, the refrigerant in the third refrigerant pipeline 43 can only flow to the second evaporator 35 (for refrigeration) of the second unit; and, the refrigerant of the oil separator 20 also flows through the three-way valve 37 to the first refrigerant pipeline 41, and the refrigerant in the first refrigerant pipeline 41 can only flow to the first evaporator 34 (for heating) of the first unit. The refrigerant of the first evaporator 34 of the first unit flows to the second evaporator 35 of the second unit after throttling. Then, the refrigerant of the second evaporator 35 of the second unit flows to the compressor 10 through the second refrigerant pipeline 42 and the second return pipeline 45 in sequence. In this way, the first unit is for heating and the second unit is for refrigeration. Here, the a port and the b port of the four-way valve 36 are connected, and the c port and the d port are connected; the f port and the g port of the three-way valve 37 are connected.

[0055] Optionally, the air conditioning system further includes an economizer 30. Among them, the primary side 31 of the economizer 30 is connected to the refrigerant main circulation loop, the inlet of its secondary side 32 is connected to the gas supplement inlet 50, and the outlet of its secondary side 32 is connected to the gas supplement pipe group; and, a third throttle element 62 is provided between the inlet of the secondary side 32 of the economizer 30 and the gas supplement inlet 50.

[0056] In this embodiment, the primary side 31 and the secondary side 32 of the economizer 30 can exchange heat. The gas supplement inlet 50 is arranged between the indoor heat exchange unit 33 and the seventh throttle element 66. When the third throttle element 62 is opened, a part of the refrigerant enters the secondary side 32 of the economizer 30 and can exchange heat with the refrigerant flowing through the primary side 31. This part of the refrigerant is vaporized after heat exchange and flows to the gas supplement pipe group, and then supplements gas to the compressor 10.

[0057] Optionally, the air conditioning system further includes a regulating liquid receiver 27. The regulating liquid receiver 27 has a liquid storage inlet pipe section and a liquid storage outlet pipe section; among them, the liquid storage inlet pipe section is connected to the refrigerant main circulation loop and is located upstream of the gas supplement inlet 50; the liquid storage outlet pipe section is connected to the secondary side 32 of the economizer 30 and is located between the inlet of the secondary side 32 of the economizer 30 and the third throttle element 62. Here, a fourth throttle element 63 is provided on the liquid storage inlet pipe section, and / or a fifth throttle element 64 is provided on the liquid storage outlet pipe section.

[0058] In this embodiment, the regulating liquid reservoir 27 can store part of the refrigerant and can deliver the refrigerant to the gas supply pipe group. When the refrigerant amount of the air-conditioning system needs to be reduced, the fourth throttling element 63 is opened and the fifth throttling element 64 is closed. At this time, part of the refrigerant in the main refrigerant circulation loop can be stored in the regulating liquid reservoir 27. When the refrigerant amount of the air-conditioning system needs to be increased, the fourth throttling element 63 is closed and the fifth throttling element 64 is opened. At this time, the refrigerant in the regulating liquid reservoir 27 flows to the gas supply pipe group after being heated and vaporized by the secondary side 32 of the economizer 30, and then flows to the compressor 10.

[0059] Optionally, the regulating liquid reservoir 27 is provided with a liquid storage inlet and a liquid storage outlet, and the height of the liquid storage inlet is greater than the height of the liquid storage outlet; wherein, the liquid storage inlet is used to communicate with the liquid storage inlet pipe section, and the liquid storage outlet is used to communicate with the liquid storage discharge pipe section.

[0060] In this embodiment, since the liquid storage inlet is arranged at a higher position and the liquid storage outlet is arranged at a lower position, this helps the natural stratification of the refrigerant in the regulating liquid reservoir 27. The gas accumulates at the top of the regulating liquid reservoir 27, while the liquid deposits at the bottom. In this way, the liquid refrigerant discharged from the liquid storage outlet is purer, reducing the situation of gas-liquid mixing.

[0061] Optionally, the liquid storage inlet is arranged on the side wall of the regulating liquid reservoir 27, and the liquid storage outlet is arranged at the bottom of the regulating liquid reservoir 27.

[0062] Optionally, by controlling the on-off states of the third throttling element 62, the fourth throttling element 63 and the fifth throttling element 64, multiple gas supply modes can be achieved. For example, when the third throttling element 62 is opened and the fifth throttling element 64 is closed, only the refrigerant from the gas supply inlet 50 is used to supply gas to the compressor 10. Another example is that when the third throttling element 62 is closed and the fifth throttling element 64 is opened, only the refrigerant from the regulating liquid reservoir 27 is used to supply gas to the compressor 10. Another example is that when the third throttling element 62 is opened and the fifth throttling element 64 is opened, the refrigerant from both the gas supply inlet 50 and the regulating liquid reservoir 27 is used to supply gas to the compressor 10 at the same time. Here, a suitable gas supply mode is selected according to the gas supply requirement of the compressor 10.

[0063] In some embodiments, the air-conditioning system includes a compressor 10, and the compressor 10 includes a first compression cylinder 11 and a second compression cylinder 12; wherein, the first compression cylinder 11 has a first suction port 13 and a first discharge port 15, and the second compression cylinder 12 has a second suction port 16 and a second discharge port 18; the oil separator 20 has an oil inlet and an oil return port; wherein, both the first discharge port 15 and the second discharge port 18 are communicated with the oil inlet; the first end of the oil return pipe group is communicated with the oil return port, and its second end is communicated with the first suction port 13 and / or the second suction port 16.

[0064] In this embodiment, after the refrigerant is compressed in the first compression cylinder 11 and / or the second compression cylinder 12, it flows to the oil separator 20. And under the action of the oil return pipe group, oil can be returned to the first compression cylinder 11 through the first suction port 13 and / or to the second compression cylinder 12 through the second suction port 16. In this way, the energy efficiency of the oil return system is improved, effectively meeting the oil return requirements of the two compression cylinders and ensuring the safe and stable operation of the compressor 10.

[0065] Optionally, the oil return port includes a first oil return port 21. The oil return pipe group includes a first oil return pipe 54. As Figure 6 (a) shows, the first end of the first oil return pipe 54 is connected to the first oil return port 21, and its second end is connected to the first suction port 13. In this way, oil can be returned to the first compression cylinder 11 through the first oil return pipe 54.

[0066] Optionally, the oil return port includes a first oil return port 21. The oil return pipe group includes a first oil return pipe 54. As Figure 6 (b) shows, the first end of the first oil return pipe 54 is connected to the first oil return port 21, and its second end is connected to the second suction port 16. In this way, oil can be returned to the second compression cylinder 12 through the first oil return pipe 54.

[0067] Optionally, the oil return port includes a first oil return port 21. The oil return pipe group includes a first oil return pipe 54. And, the first end of the first oil return pipe 54 is connected to the first oil return port 21, and its second end is simultaneously connected to the first suction port 13 and the second suction port 16. Here, the second end of the first oil return pipe 54 forms two branch pipes, one branch pipe is connected to the first suction port 13, and the other branch pipe is connected to the second suction port 16. In this way, oil can be returned to the first compression cylinder 11 and the second compression cylinder 12 simultaneously through the first oil return pipe 54.

[0068] Optionally, the first oil return pipe 54 is provided with a first throttling element 60. The flow rate of the refrigerant is adjusted through the first throttling element 60 to reduce the refrigerant throughput and keep the lubricating oil at an appropriate flow rate.

[0069] Optionally, the first throttling element 60 is a capillary tube.

[0070] Optionally, as Figure 7 shown, the oil return pipe group further includes a second oil return pipe 55. The second oil return pipe 55 is connected in parallel to the first oil return pipe 54; and, the second oil return pipe 55 is provided with an oil return solenoid valve 74.

[0071] In this embodiment, adding an oil return pipeline can effectively increase the oil return volume, and here the second oil return pipeline 55 serves as a fast oil return path. The air conditioning system requires a large oil return volume under certain working conditions, such as startup condition, shutdown condition, defrosting condition or working condition switching. At this time, the oil return solenoid valve 74 is opened. In this way, oil is returned to the compressor 10 through the first oil return pipeline 54 and the second oil return pipeline 55 simultaneously to meet the oil return requirement.

[0072] Optionally, the second oil return pipeline 55 is also provided with a second throttling element 61, and the second throttling element 61 is located downstream of the oil return solenoid valve 74. Among them Figure 8 (a) is for returning oil to the first compression cylinder 11, Figure 8 (b) is for returning oil to the second compression cylinder 12.

[0073] In this embodiment, downstream means that the second throttling element 61 is located between the oil return solenoid valve 74 and the suction port. Under the action of the second throttling element 61, the refrigerant flow rate in the second oil return pipeline 55 can be adjusted to reduce the refrigerant throughput. When returning oil, the refrigerant flow rate corresponding to the suction port increases. Under the combined regulation of the first throttling element 60 and the second throttling element 61, it is beneficial to effectively regulate the flow rate corresponding to the suction port and balance the pressure difference between the two compression cylinders. Thus, the stable operation of the air conditioning system is ensured.

[0074] Optionally, the second throttling element 61 is a capillary tube.

[0075] Optionally, as Figure 7 (a) shows, the second end of the second oil return pipeline 55 and the second end of the first oil return pipe are both connected to the first end of the oil return manifold pipe section 57, and the second end of the oil return manifold pipe section 57 is connected to the first suction port 13. In this way, the refrigerants of the two oil return pipes are collected in the oil return manifold pipe section 57 and then return oil to the first compression cylinder 11.

[0076] Optionally, as Figure 7 (b) shows, the second end of the second oil return pipeline 55 and the second end of the first oil return pipe are both connected to the first end of the oil return manifold pipe section 57, and the second end of the oil return manifold pipe section 57 is connected to the second suction port 16. In this way, the refrigerants of the two oil return pipes are collected in the oil return manifold pipe section 57 and then return oil to the second compression cylinder 12.

[0077] Optionally, the second end of the second oil return pipeline 55 and the second end of the first oil return pipe are both connected to the first end of the oil return manifold pipe section 57, and the second end of the oil return manifold pipe section 57 is simultaneously connected to the first suction port 13 and the second suction port 16. In this way, the refrigerants of the two oil return pipes are collected in the oil return manifold pipe section 57 and then return oil to the first compression cylinder 11 and the second compression cylinder 12 simultaneously.

[0078] Optionally, the air conditioner further includes a controller. The controller is electrically connected to the oil return solenoid valve 74; and the controller is configured to: control the oil return solenoid valve 74 to open when the oil level in the compressor 10 is lower than the first oil level; control the oil return solenoid valve 74 to open intermittently when the oil level in the compressor 10 is greater than or equal to the first oil level and lower than the second oil level; and control the oil return solenoid valve 74 to close when the oil level in the compressor 10 is greater than or equal to the second oil level.

[0079] In this embodiment, an oil sump is provided in the compressor 10, and the first oil level is lower than the second oil level. Under certain operating conditions of the air conditioning system, such as startup condition, shutdown condition, defrosting condition or operating condition switching, the oil level in the oil sump is relatively low. At this time, the state of the oil return solenoid valve 74 is controlled according to the oil level in the oil sump. Specifically, when the liquid level in the oil sump is lower than the first oil level, the oil level is extremely low. The controller controls the oil return solenoid valve 74 to open fully, and uses the second oil return pipeline 55 to cooperate with the first oil return pipeline 54 for rapid oil return. When the oil level rises to be greater than or equal to the first oil level and lower than the second oil level, the controller controls the oil return solenoid valve 74 to open intermittently. For example, it opens once every 15s, 30s or 60s. The intermittent opening method can not only make the oil level rise faster, but also avoid a large pressure difference between the two compression cylinders. When the oil level rises to be greater than or equal to the second oil level, the controller controls the oil return solenoid valve 74 to close. At this time, the air conditioning system operates stably, and the oil return demand can be met by using the first oil return pipeline 54 for oil return.

[0080] Optionally, as Figure 5 shown, the oil return port further includes a second oil return port 22, and the horizontal height of the second oil return port 22 is lower than the horizontal height of the first oil return port 21. The oil return pipe group further includes a second oil return pipeline 55. The first end of the second oil return pipeline 55 is connected to the second oil return port 22, and its second end is connected to the first suction port 13 and / or the second suction port 16.

[0081] In this embodiment, since the horizontal height of the second oil return port 22 is lower than that of the first oil return port 21, the lubricating oil is more likely to flow out from the second oil return port 22 under the action of gravity, reducing the oil return resistance, thereby improving the oil return efficiency of the second oil return pipeline 55.

[0082] Optionally, the second end of the second oil return pipeline 55 and the second end of the first oil return pipe are both connected to the first end of the oil return manifold pipe section 57, and the second end of the oil return manifold pipe section 57 is connected to the first suction port 13 and / or the second suction port 16.

[0083] In this embodiment, as Figure 9 (a) shows, when the second end of the oil return manifold pipe section 57 is connected to the first suction port 13, the refrigerant in the two oil return pipes converges in the oil return manifold pipe section 57 and then returns oil to the first compression cylinder 11. As Figure 9As shown in (b), when the second end of the oil return manifold section 57 is connected to the second suction port 16, the refrigerant in the two oil return pipes converges in the oil return manifold section 57 and then returns oil to the second compression cylinder 12. When the second end of the oil return manifold section 57 is simultaneously connected to the first suction port 13 and the second suction port 16, the refrigerant in the two oil return pipes converges in the oil return manifold section 57 and then returns oil to the first compression cylinder 11 and the second compression cylinder 12 simultaneously.

[0084] Optionally, the first oil return port 21 is provided on the side wall of the oil separator 20; the second oil return port 22 is provided at the bottom of the oil separator 20. In this way, the setting position of the second oil return port 22 helps to timely discharge the lubricating oil accumulated at the bottom of the oil separator 20, reducing the risk of failure caused by oil accumulation.

[0085] In some embodiments, the air conditioning system includes a compressor 10. The compressor 10 includes a first compression cylinder 11 and a second compression cylinder 12; wherein, the first compression cylinder 11 has a first air supplement port 14, and the second compression cylinder 12 has a second air supplement port 17; the air supplement inlet 50 is provided on the refrigerant main circulation return path of the air conditioning system; the first end of the air supplement pipe group is connected to the air supplement inlet 50, and its second end is connected to the first air supplement port 14 and / or the second air supplement port 17.

[0086] In this embodiment, an air supplement inlet 50 is provided on the refrigerant main circulation return path of the air conditioning system, and the refrigerant can flow from the air supplement inlet 50 to the air supplement pipe group. Under the action of the air supplement pipe group, air can be supplemented to the first compression cylinder 11 through the first air supplement port 14, and / or air can be supplemented to the second compression cylinder 12 through the second air supplement port 17. In this way, the energy efficiency of the air supplement system is improved, effectively meeting the air supplement requirements of the two compression cylinders and ensuring the safe and stable operation of the compressor 10.

[0087] Optionally, as Figure 10 (a) shown, the air supplement pipe group includes a first air supplement pipeline 51 and a second air supplement pipeline 52. The first end of the first air supplement pipeline 51 is connected to the first air supplement accumulator 25, and its second end is connected to the first air supplement port 14; the first end of the second air supplement pipeline 52 is connected to the first air supplement accumulator 25, and its second end is connected to the second air supplement port 17; and, the first air supplement accumulator 25 is connected to the air supplement inlet 50.

[0088] In this embodiment, the refrigerant flows from the air supplement inlet 50 to the first air supplement accumulator 25, and the refrigerant in the first air supplement accumulator 25 simultaneously supplements air to the first compression cylinder 11 through the first air supplement pipeline 51 and supplements air to the second compression cylinder 12 through the second air supplement pipeline 52.

[0089] Optionally, a first valve component is provided on the first air supply pipeline 51, and the conduction direction of the first valve component is defined as flowing from the first air supply liquid storage device 25 to the first air supply port 14; and / or, a second valve component is provided on the second air supply pipeline 52, and the conduction direction of the second valve component is defined as flowing from the second air supply liquid storage device 26 to the second air supply port 17. In this way, under the action of the first valve component and the second valve component, such as a one-way valve, only the refrigerant is allowed to flow from the first air supply pipeline 51 and the second air supply pipeline 52 to the corresponding air supply ports, thereby avoiding the phenomenon of gas cross-flow in the first compression cylinder 11 and the second compression cylinder 12.

[0090] Optionally, the first suction port 13 of the compressor 10 is communicated with the outlet of the first gas-liquid separator 23. As Figure 11 (a) shows, the air supply pipeline group further includes a third air supply pipeline 53. The first end of the third air supply pipeline 53 is communicated with the air supply inlet 50, and its second end is communicated with the inlet of the first gas-liquid separator 23.

[0091] In this embodiment, the first air supply pipeline 51 and the second air supply pipeline 52 can be regarded as direct air supply, and the third air supply pipeline 53 can be regarded as indirect air supply. The refrigerant flows from the air supply inlet 50 to the third air supply pipeline 53, and the third air supply pipeline 53 is provided with a third air supply solenoid valve 72. When the third air supply solenoid valve 72 is opened, the refrigerant flows to the first gas-liquid separator 23, and then flows to the first compression cylinder 11. In this way, for the first compression cylinder 11, air supply can be carried out through the first air supply pipeline 51 and / or the third air supply pipeline 53. For example, when a large amount of air supply is required for the first compression cylinder 11, the third throttling element 62 is opened and the fifth throttling element 64 is opened. At this time, the refrigerant from the air supply inlet 50 and the regulating liquid storage device 27 is used to supply air to the compressor 10 at the same time. In order to adapt to the air supply volume, the first air supply pipeline 51 and the third air supply pipeline 53 are used to supply air to the first compression cylinder 11 at the same time.

[0092] Optionally, the second suction port 16 of the compressor 10 is communicated with the outlet of the second gas-liquid separator 24. As Figure 11 (b) shows, the air supply pipeline group further includes a third air supply pipeline 53. The first end of the third air supply pipeline 53 is communicated with the air supply inlet 50, and its second end is communicated with the inlet of the second gas-liquid separator 24.

[0093] In this embodiment, the refrigerant flows from the gas replenishing inlet 50 to the third gas replenishing pipeline 53, and the third gas replenishing pipeline 53 is provided with a third gas replenishing solenoid valve 72. When the third gas replenishing solenoid valve 72 is opened, the refrigerant flows to the second gas-liquid separator 24 and then to the second compression cylinder 12. Thus, for the second compression cylinder 12, gas replenishment can be performed through the second gas replenishing pipeline 52 and / or the third gas replenishing pipeline 53. For example, when a large amount of gas replenishment is required for the second compression cylinder 12, the third throttling element 62 is opened and the fifth throttling element 64 is opened. At this time, the refrigerant from the gas replenishing inlet 50 and the regulating liquid reservoir 27 is used to replenish gas to the compressor 10 simultaneously. In order to adapt to the gas replenishment amount, both the second gas replenishing pipeline 52 and the third gas replenishing pipeline 53 are used to replenish gas to the second compression cylinder 12.

[0094] Optionally, the first suction port 13 of the compressor 10 communicates with the outlet of the first gas-liquid separator 23, and the second suction port 16 of the compressor 10 communicates with the outlet of the second gas-liquid separator 24; and, the inlet of the first gas-liquid separator 23 is connected to the inlet of the second gas-liquid separator 24 through an intermediate solenoid valve 75. Here, the inlet of the first gas-liquid separator 23 communicates with the first return pipeline 44, and the inlet of the second gas-liquid separator 24 communicates with the second return pipeline 45. Both ends of the intermediate solenoid valve 75 are respectively connected to the first return pipeline 44 and the second return pipeline 45.

[0095] Optionally, as Figure 10 (b) shows, the gas replenishing pipe group further includes a third gas replenishing pipeline 53. The first end of the third gas replenishing pipeline 53 communicates with the gas replenishing inlet 50, and its second end communicates with the inlet of the first gas-liquid separator 23 or the inlet of the second gas-liquid separator 24; and, the second end of the third gas replenishing pipeline 53 is located upstream of the intermediate solenoid valve 75.

[0096] In this embodiment, the refrigerant flows from the gas replenishing inlet 50 to the third gas replenishing pipeline 53, and the third gas replenishing pipeline 53 is provided with a third gas replenishing solenoid valve 72. When the third gas replenishing solenoid valve 72 is opened, the third gas replenishing pipeline 53 is conducted. When the intermediate solenoid valve 75 is opened, the refrigerant flows to the first gas-liquid separator 23 and the second gas-liquid separator 24 simultaneously. When the intermediate solenoid valve 75 is closed and the second end of the third gas replenishing pipeline 53 communicates with the first gas-liquid separator 23, the refrigerant only replenishes gas to the first compression cylinder 11; when the intermediate solenoid valve 75 is closed and the second end of the third gas replenishing pipeline 53 communicates with the second gas-liquid separator 24, the refrigerant only replenishes gas to the second compression cylinder 12. Thus, by adding the third gas replenishing pipeline 53 and its third gas replenishing solenoid valve 72, the air-conditioning system can more flexibly control the flow direction of the refrigerant according to needs and accurately replenish gas.

[0097] Optionally, a first air replenishing solenoid valve 70 is provided on the first inlet pipe section of the first air replenishing liquid reservoir 25; a third air replenishing solenoid valve 72 is provided on the third air replenishing pipe 53; and the first inlet pipe section is connected to the air replenishing inlet 50 through an air replenishing manifold pipe section 56, and the first end of the third air replenishing pipe 53 is connected to the air replenishing manifold pipe section 56. In this way, the refrigerant at the air replenishing inlet 50 flows towards the air replenishing manifold pipe section 56. When the first air replenishing solenoid valve 70 is opened, the first air replenishing pipe 51 is conducted; when the third air replenishing solenoid valve 72 is opened, the third air replenishing pipe 53 is conducted. Further cooperating with the switching state of the intermediate solenoid valve 75, various air replenishing requirements can be adapted.

[0098] Optionally, as Figure 12 shown, the air replenishing pipe includes a first air replenishing pipe 51 and a second air replenishing pipe 52. Among them, the first end of the first air replenishing pipe 51 is connected to the first air replenishing liquid reservoir 25, and its second end is connected to the first air replenishing port 14; the first end of the second air replenishing pipe 52 is connected to the second air replenishing liquid reservoir 26, and its second end is connected to the second air replenishing port 17; and both the first air replenishing liquid reservoir 25 and the second air replenishing liquid reservoir 26 are connected to the air replenishing inlet 50.

[0099] In this embodiment, as Figure 12 (a) shown, the refrigerant can flow from the air replenishing inlet 50 to the first air replenishing liquid reservoir 25 and the second air replenishing liquid reservoir 26 simultaneously. Then, the refrigerant in the first air replenishing liquid reservoir 25 flows through the first air replenishing pipe 51 to the first compression cylinder 11, and the refrigerant in the second air replenishing liquid reservoir 26 flows through the second air replenishing pipe 52 to the second compression cylinder 12. In this way, by providing two air replenishing liquid reservoirs, compared with providing one air replenishing liquid reservoir, the capacity adjustment ability of the air replenishing system can be significantly improved, so that the range of air replenishing adjustment is larger. And the problem of liquid return of the compressor 10 brought is smaller.

[0100] Optionally, as Figure 12 (b) shown, a first air replenishing solenoid valve 70 is provided on the first inlet pipe section of the first air replenishing liquid reservoir 25; a second air replenishing solenoid valve 71 is provided on the second inlet pipe section of the second air replenishing liquid reservoir 26; and after the first inlet pipe section and the second inlet pipe section converge, they are connected to the air replenishing inlet 50 through an air replenishing manifold pipe section 56.

[0101] In this embodiment, when the first air replenishing solenoid valve 70 is opened, the refrigerant at the air replenishing inlet 50 sequentially flows from the air replenishing manifold pipe section 56 and the first inlet pipe section to the first air replenishing liquid reservoir 25, and then replenishes air to the first compression cylinder 11. When the second air replenishing solenoid valve 71 is opened, the refrigerant at the air replenishing inlet 50 sequentially flows from the air replenishing manifold pipe section 56 and the second inlet pipe section to the second air replenishing liquid reservoir 26, and then replenishes air to the second compression cylinder 12.

[0102] Optionally, the first suction port 13 of the compressor 10 communicates with the outlet of the first gas-liquid separator 23; the gas replenishing pipe group further includes a third gas replenishing pipeline 53, the first end of the third gas replenishing pipeline 53 communicates with the gas replenishing inlet 50, and its second end communicates with the inlet of the first gas-liquid separator 23 or communicates with the inlet of the second gas-liquid separator 24.

[0103] In this embodiment, the first gas replenishing liquid reservoir 25 can replenish gas to the first compression cylinder 11 through the first gas replenishing pipeline 51, and the second gas replenishing liquid reservoir 26 can replenish gas to the second compression cylinder 12 through the second gas replenishing pipeline 52. In the case of having two gas replenishing liquid reservoirs, the second end of the third gas replenishing pipeline 53 is further communicated with the upstream of the intermediate solenoid valve 75. In this way, by controlling the state of the intermediate solenoid valve 75, the third gas replenishing pipeline 53 can replenish gas to the corresponding compression cylinder through the corresponding gas-liquid separator.

[0104] Optionally, the first inlet pipe section of the first gas replenishing liquid reservoir 25 and the second inlet pipe section of the second gas replenishing liquid reservoir 26 converge and then communicate with the gas replenishing inlet 50 through the gas replenishing converging pipe section 56. As Figure 13 (b) shows, the gas replenishing converging pipe section 56 is provided with a fourth gas replenishing solenoid valve 73; and, the third gas replenishing pipeline 53 is provided with a third gas replenishing solenoid valve 72, and the first end of the third gas replenishing pipeline 53 communicates with the gas replenishing converging pipe section 56 and is located upstream of the fourth gas replenishing solenoid valve 73.

[0105] In this embodiment, when the fourth gas replenishing solenoid valve 73 is opened, the refrigerant in the gas replenishing converging pipe section 56 flows to both the first gas replenishing liquid reservoir 25 and the second gas replenishing liquid reservoir 26 simultaneously. When the third gas replenishing solenoid valve 72 is opened, the third gas replenishing pipeline 53 is conducted. And, when the intermediate solenoid valve 75 is further opened, the refrigerant in the third gas replenishing pipeline 53 flows to both the first gas-liquid separator 23 and the second gas-liquid separator 24 simultaneously.

[0106] Optionally, the first inlet pipe section of the first gas replenishing liquid reservoir 25 is provided with a first gas replenishing solenoid valve 70; the second inlet pipe section of the second gas replenishing liquid reservoir 26 is provided with a second gas replenishing solenoid valve 71; the third gas replenishing pipeline 53 is provided with a third gas replenishing solenoid valve 72; as Figure 13 (a) shows, the first inlet pipe section and the second inlet pipe section converge and then communicate with the gas replenishing inlet 50 through the gas replenishing converging pipe section 56, and the first end of the third gas replenishing pipeline 53 communicates with the gas replenishing converging pipe section 56. In this way, when the first gas replenishing solenoid valve 70 is opened, the refrigerant in the gas replenishing converging pipe section 56 flows to the first gas replenishing liquid reservoir 25. When the second gas replenishing solenoid valve 71 is opened, the refrigerant in the gas replenishing converging pipe section 56 flows to the second gas replenishing liquid reservoir 26.

[0107] It should be noted that, without conflict, the above-mentioned multiple embodiments and the features in each embodiment can be combined with each other.

[0108] Optionally, a combined form of an air replenishment system and a refrigerant return system is as follows Figure 16 shown. Here, the oil return manifold section 57 is connected to the first suction port 13 through the first branch pipe section and to the second suction port 16 through the second branch pipe section. The first branch pipe section and the second branch pipe section can be controlled by the controller to be turned on or off

[0109] In the first operating condition, for the air replenishment system: only the refrigerant in the regulating accumulator 27 is needed for air replenishment, and the first compression cylinder 11 requires both direct and indirect air replenishment at the same time, while the second compression cylinder 12 only requires indirect air replenishment. For the oil return system: at the initial stage of the first operating condition, the oil level in the oil sump is lower than the first oil level, and only the first compression cylinder 11 needs rapid oil return

[0110] At this time, the third throttling element 62 is closed and the fifth throttling element 64 is opened, so that only the refrigerant from the regulating accumulator 27 is used to replenish air to the compressor 10. Moreover, the first air replenishment solenoid valve 70 is opened, and air is directly replenished to the first compression cylinder 11 through the first air replenishment pipeline 51. The second air replenishment solenoid valve 71 is closed, the third air replenishment solenoid valve 72 is opened, and the intermediate solenoid valve 75 is opened, so that air is indirectly replenished to the first compression cylinder 11 and the second compression cylinder 12 at the same time through the third air replenishment pipeline 53. Synchronously, the oil return solenoid valve 74 is controlled to be opened, the first branch pipe section is turned on and the second branch pipe section is blocked. As the oil level rises to be greater than or equal to the first oil level, the oil return solenoid valve 74 is controlled to be intermittently opened; when the oil level further rises to be greater than or equal to the second oil level, the oil return solenoid valve 74 is controlled to be closed

[0111] In the second operating condition, for the air replenishment system: only the refrigerant at the air replenishment inlet 50 is needed for air replenishment, and the first compression cylinder 11 only requires direct air replenishment, while the second compression cylinder 12 requires both direct and indirect air replenishment at the same time. For the oil return system: at the initial stage of the first operating condition, the oil level in the oil sump is greater than the first oil level and less than the second oil level, and only the second compression cylinder 12 needs rapid oil return

[0112] At this time, the third throttling element 62 is opened and the fifth throttling element 64 is closed, so that only the refrigerant from the air replenishment inlet 50 is used to replenish air to the compressor 10. Moreover, the first air replenishment solenoid valve 70 is opened, and air is directly replenished to the first compression cylinder 11 through the first air replenishment pipeline 51. The second air replenishment solenoid valve 71 is opened, the third air replenishment solenoid valve 72 is opened, and the intermediate solenoid valve 75 is closed, so that air is replenished to the second compression cylinder 12 through the second air replenishment pipeline 52 and the third air replenishment pipeline 53. Synchronously, the oil return solenoid valve 74 is controlled to be intermittently opened, the first branch pipe section is blocked and the second branch pipe section is turned on. When the oil level further rises to be greater than or equal to the second oil level, the oil return solenoid valve 74 is controlled to be closed

[0113] In summary, the technical solution of the present application optimizes the oil return system and the gas replenishment system of the twin-cylinder compressor, can meet various gas replenishment and oil return requirements, and significantly improves the adaptability and stability of the air-conditioning system.

[0114] The above description and the drawings fully illustrate the embodiments of the present disclosure so that those skilled in the art can practice them. Other embodiments may include structural and other changes. Embodiments represent possible variations. Unless explicitly required, individual components and functions are optional, and the order of operations may vary. Parts and features of some embodiments may be included in or substituted for parts and features of other embodiments. The embodiments of the present disclosure are not limited to the structures described above and shown in the drawings, and various modifications and changes can be made without departing from its scope. The scope of the present disclosure is limited only by the appended claims.

Claims

1. An air conditioning system, characterized in that a compressor (10), comprising a first compression cylinder (11) and a second compression cylinder (12); wherein, the first compression cylinder (11) has a first suction port (13), and the second compression cylinder (12) has a second suction port (16); a gas supplement inlet (50), arranged on the main refrigerant circulation loop of the air conditioning system; a gas supplement pipe group, the first end of which is communicated with the gas supplement inlet (50), and the second end of which is communicated with the first suction port (13) and / or the second suction port (16).

2. The air conditioning system according to claim 1, characterized in that the first suction port (13) of the compressor (10) is communicated with the outlet of the first gas-liquid separator (23), and the second suction port (16) of the compressor (10) is communicated with the outlet of the second gas-liquid separator (24); and, the inlet of the first gas-liquid separator (23) is communicated with the inlet of the second gas-liquid separator (24) through an intermediate solenoid valve (75).

3. The air conditioning system according to claim 2, characterized in that, The gas supplement pipe group includes: a third gas supplement pipeline (53), the first end of which is communicated with the gas supplement inlet (50), and the second end of which is communicated with the inlet of the first gas-liquid separator (23) or the inlet of the second gas-liquid separator (24); and, the second end of the third gas supplement pipeline (53) is located upstream of the intermediate solenoid valve (75).

4. The air conditioning system according to claim 3, characterized in that when the intermediate solenoid valve (75) is opened, the third gas supplement pipeline (53) supplements gas to both the first compression cylinder (11) and the second compression cylinder (12) simultaneously.

5. The air conditioning system according to claim 3, characterized in that when the second end of the third gas supplement pipeline (53) is communicated with the inlet of the first gas-liquid separator (23) and the intermediate solenoid valve (75) is closed, the third gas supplement pipeline (53) only supplements gas to the first compression cylinder (11).

6. The air conditioning system according to claim 3, characterized in that when the second end of the third gas supplement pipeline (53) is communicated with the inlet of the second gas-liquid separator (24) and the intermediate solenoid valve (75) is closed, the third gas supplement pipeline (53) only supplements gas to the second compression cylinder (12).

7. The air conditioning system according to any one of claims 1 to 6, characterized in that, It further includes: an economizer (30), the primary side (31) of which is communicated with the main refrigerant circulation loop, the inlet of the secondary side (32) of which is communicated with the gas supplement inlet (50), and the outlet of the secondary side (32) of which is communicated with the gas supplement pipe group.

8. The air conditioning system according to claim 7, characterized in that a third throttling element (62) is provided between the inlet of the secondary side (32) of the economizer (30) and the gas supplement inlet (50).

9. The air conditioning system according to claim 8, wherein It further includes: a regulating liquid reservoir (27), having a liquid storage inlet pipe section and a liquid storage outlet pipe section; wherein, the liquid storage inlet pipe section is communicated with the main refrigerant circulation loop and is located upstream of the gas supplement inlet (50); the liquid storage outlet pipe section is communicated with the secondary side (32) of the economizer (30) and is located between the inlet of the secondary side (32) of the economizer (30) and the third throttling element (62).

10. The air conditioning system according to claim 9, characterized in that a fourth throttling element (63) is provided in the liquid storage inlet pipe section; and / or, The liquid storage discharge pipe section is provided with a fifth throttling element (64).

11. The air-conditioning system according to any one of claims 1 to 4, characterized in that The first compression cylinder (11) has a first suction port (13), and the second compression cylinder (12) has a second suction port (16); the air conditioning system further includes: An oil separator (20), arranged on the refrigerant main circulation loop of the air conditioning system, including an oil return port; An oil return pipe group, whose first end is communicated with the oil return port, and whose second end is communicated with the first suction port (13) and / or the second suction port (16).

12. An air treatment system, characterized in that, It includes the air conditioning system according to any one of claims 1 to 11.

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