Refrigerant switching device and HVAC system

Abstract

This application discloses a refrigerant switching device and a heating, ventilation, and air (HVAC) system. The refrigerant switching device includes: a housing; a liquid pipe assembly; a gas pipe assembly; and a pressure relief assembly. The pressure relief assembly includes a main pressure relief pipe, a pressure relief valve, and multiple branch pressure relief pipes. The branch pressure relief pipes are spaced apart along a first direction. One end of each branch pressure relief pipe is connected to either the indoor unit liquid pipe between the liquid shut-off valve and the load unit, or the indoor unit gas pipe between the gas shut-off valve and the load unit. The other end of each branch pressure relief pipe is connected to the main pressure relief pipe, which is connected to a heat source unit. The pressure relief valve is located on either the branch pressure relief pipe or the main pressure relief pipe. This application's technical solution can solve the safety problem caused by refrigerant leakage in current refrigerant switching devices.

Description

Technical Field

[0001] This application relates to the field of air conditioning technology, and in particular to a refrigerant switching device and a heating, ventilation and ventilation system using the refrigerant switching device. Background Technology

[0002] Currently, HVAC systems are widely used in office buildings and shopping malls. An HVAC system generally includes a heat source unit, a refrigerant switching device, and multiple load units. The main function of the refrigerant switching device is to enable the load units to switch between different modes. The heat source unit and each load unit are connected to the refrigerant switching device through liquid and gas pipes, thereby achieving cooling and heating through the exchange of heat exchange media.

[0003] In related technologies, there is a possibility of leakage during the refrigerant transfer process between the refrigerant switching device and the load unit. When the refrigerant leaks, the refrigerant switching device will cut off the refrigerant transfer to the load unit, which will cause the refrigerant pressure on the side connected to the load unit to be too high. If the refrigerant pressure is too high, the pipes or components on the load unit side may not be able to withstand the pressure, thus causing an explosion. Utility Model Content

[0004] This application provides a refrigerant switching device and a heating, ventilation and air conditioning system, which can solve the problem of safety issues caused by refrigerant leakage in current refrigerant switching devices.

[0005] This application embodiment provides a refrigerant switching device located in the refrigerant circuit between a heat source unit and a load unit, the refrigerant switching device comprising: case; A liquid pipe assembly, comprising a plurality of parallel indoor liquid pipes, the plurality of parallel indoor liquid pipes being spaced apart along a first direction, the indoor liquid pipes being at least partially located within the housing space, the indoor liquid pipes being used to communicate with the load unit, and the indoor liquid pipes being provided with liquid shut-off valves, the liquid shut-off valves being used to close / open the communication between the indoor liquid pipes and the load unit; An air hose assembly, comprising multiple indoor air hoses, each indoor air hose being at least partially disposed within the internal space of the housing, the multiple parallel indoor air hoses being spaced apart along the first direction, the indoor air hoses being used to communicate with the load unit, and each indoor air hose being equipped with a gas shut-off valve, the gas shut-off valve closing / opening the communication between the indoor air hose and the load unit; and The pressure relief assembly includes a main pressure relief pipe, a pressure relief valve, and multiple pressure relief branch pipes. The pressure relief branch pipes are spaced apart along the first direction. One end of each pressure relief branch pipe is connected to the indoor unit liquid pipe between the liquid shut-off valve and the load unit, or to the indoor unit gas pipe between the gas shut-off valve and the load unit. The other end of each pressure relief branch pipe is connected to the main pressure relief pipe, which is connected to the heat source unit. The pressure relief valve is located on either the pressure relief branch pipe or the main pressure relief pipe.

[0006] The refrigerant switching device and HVAC system provided in this application embodiment include a pressure relief component in the refrigerant switching device. This pressure relief component includes a pressure relief main pipe, a pressure relief valve, and multiple pressure relief branch pipes. When the refrigerant in the refrigerant switching device leaks, the gas shut-off valve closes the indoor unit gas pipe, causing excessive refrigerant pressure in the section of the indoor unit gas pipe connecting to the load unit. Alternatively, the liquid shut-off valve closes the indoor unit liquid pipe, causing excessive refrigerant pressure in the section of the indoor unit liquid pipe connecting to the load unit. In this case, one end of the pressure relief branch pipe is connected to the indoor unit liquid pipe between the liquid shut-off valve and the load unit, or to the indoor unit gas pipe between the gas shut-off valve and the load unit, and the other end of the pressure relief branch pipe is connected to the pressure relief main pipe. The pressure relief main pipe is connected to the heat source unit, and the pressure relief valve is installed on either the pressure relief branch pipe or the pressure relief main pipe. When the refrigerant pressure exceeds the limit, the pressure relief valve will open, allowing the refrigerant pressure in the indoor unit's liquid pipe or gas pipe to be released through the corresponding pressure relief branch pipe to the main pressure relief pipe, and then discharged to the heat source unit. This prevents the indoor unit's liquid pipe or gas pipe from bursting due to excessive internal pressure, thus meeting the safety requirements for use.

[0007] Meanwhile, by integrating the internal pressure of multiple indoor unit liquid pipes into the same pressure relief main pipe for pressure relief, multiple indoor unit liquid pipes actually share the same pressure relief pipeline for pressure relief. This reduces the pipeline length of each pressure relief branch pipe, thereby effectively reducing costs and solving the problem of high cost of pressure relief structure in refrigerant switching devices, in order to meet the demand for low-cost production.

[0008] Furthermore, by installing the pressure relief valve only on the main pressure relief pipe, the number of pressure relief valves can be effectively reduced. This not only reduces the number of pressure relief valves and lowers costs, but also eliminates the need for the pressure relief valves to be avoided between the gas pipe assembly and the liquid pipe assembly of the refrigerant switching device. This allows the gas pipe assembly and the liquid pipe assembly to be installed close together, resulting in a more compact internal structure of the refrigerant switching device. This saves internal space in the housing, thereby reducing the size requirements of the refrigerant switching device and making it suitable for various installation environments. Attached Figure Description

[0009] To more clearly illustrate the technical solutions in the embodiments of this application or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0010] Figure 1 This is a schematic diagram of the refrigerant transfer switching device located in the refrigerant circuit between the heat source unit and the load unit according to an embodiment of this application; Figure 2 This is a schematic diagram of the refrigerant transfer switching device according to an embodiment of this application; Figure 3 This is an exploded structural diagram of the refrigerant transfer switching device provided in the embodiments of this application; Figure 4 A schematic diagram of the assembly of the pressure relief component, gas pipe component, and liquid pipe component of the refrigerant transfer switching device provided in the embodiments of this application; Figure 5 A partial schematic diagram of the assembly of the pressure relief component, gas pipe component, and liquid pipe component of the refrigerant transfer switching device provided in the embodiments of this application; Figure 6 A schematic diagram of the assembly of the pressure relief component and the gas pipe component of the refrigerant switching device provided in the embodiments of this application; Figure 7 A diagram showing the refrigerant flow direction in the refrigerant switching device provided in this application embodiment when all load units are in cooling mode; Figure 8 A refrigerant flow diagram in a refrigerant switching device provided in another embodiment of this application, wherein all load units are in cooling mode; Figure 9 A schematic diagram of the assembly structure of the gas pipe assembly of the refrigerant switching device provided in this application embodiment, located on the second beam; Figure 10 A partial schematic diagram of the assembly of the pressure relief component, gas pipe component, and liquid pipe component of the refrigerant switching device provided in the embodiments of this application; Figure 11 A schematic diagram of the structure of the refrigerant switching device provided in this application, showing the indoor liquid pipe located inside the housing; Figure 12 A schematic diagram of the assembly structure of the indoor unit liquid pipe and the pressure relief branch pipe of the refrigerant switching device provided in the embodiments of this application; Figure 13 A schematic diagram from another perspective showing the assembly of the pressure relief component, gas pipe component, and liquid pipe component of the refrigerant switching device provided in the embodiments of this application; Figure 14A schematic diagram showing a portion of the structure of the gas pipe assembly of the refrigerant switching device provided in this application embodiment located within the housing; Figure 15 This is an assembly diagram of a portion of the refrigerant switching device provided in an embodiment of this application; Figure 16 A schematic diagram showing the pressure relief assembly of the refrigerant switching device provided in this application embodiment located inside the housing; Figure 17 A schematic diagram of the assembly of the pressure relief component and the subcooling component of the refrigerant switching device provided in the embodiments of this application; Figure 18 This is a schematic diagram of the subcooling component of the refrigerant switching device provided in the embodiments of this application; Figure 19 A partial schematic diagram of the subcooling assembly of the refrigerant switching device provided in the embodiments of this application within the housing; Figure 20 A structural diagram of a first installation method for a heat exchanger in a refrigerant switching device provided in an embodiment of this application; Figure 21 This is a structural diagram of the second installation method of the heat exchanger in the refrigerant switching device provided in the embodiments of this application; Figure 22 This is a structural diagram illustrating a third installation method of the heat exchanger in the refrigerant switching device provided in this application embodiment; Figure 23 This is a structural diagram illustrating a fourth installation method of the heat exchanger in the refrigerant switching device provided in this application embodiment; Figure 24 A diagram showing the refrigerant flow direction in the refrigerant switching device provided in this application embodiment when all load units are in heating mode; Figure 25 A diagram showing the refrigerant flow direction in the load unit when most of the refrigerant switching devices provided in the embodiments of this application are in the cooling state; Figure 26 A diagram showing the refrigerant flow direction in the load unit when most of the refrigerant switching devices provided in the embodiments of this application are in heating mode.

[0011] Explanation of icon numbers: 100. Refrigerant switching device; 10. Shell; 11. Shell body; 111. Top plate; 112. Side plate; 1121. Load-side side plate; 112a. Load-side port; 1121. Heat source-side side plate; 112b. Heat source-side port; 1123. Electrical control-side side plate; 12. Chassis; 13. Support beam; 131. First beam; 132. Second beam; 14. Connecting bracket; 15. Fixing component; 16. Shock-absorbing pad; 20. Liquid pipe assembly; 21. Main liquid pipe; 211. First connecting section; 22. Refrigerant branch liquid pipe; 221. Second connecting section; 23. Heating branch liquid pipe; 24. Indoor unit liquid pipe; 241. Interface end; 242. Liquid shut-off valve; 24a. First transition section; 24b. Second transition section; 24c. Third transition section; 24d. Fourth transition section; 25. Branch liquid pipe 26. Bypass liquid pipe; 30. Gas pipe assembly; 31. Low-pressure gas pipe; 311. Third connecting section; 32. High-pressure gas pipe; 33. Bypass gas pipe; 331. Low-pressure gas valve; 34. Branch gas pipe; 341. High-pressure gas valve; 35. Indoor unit gas pipe; 351. Gas shut-off valve; 352. First pressure relief port; 40. Pressure relief assembly; 41. Pressure relief main pipe; 411. First pipe section; 4111. 412. Pressure relief port; 42. Second pipe section; 43. Pressure relief valve; 44. Pressure relief branch pipe; 45. Second pressure relief port; 46. Connecting pipe; 47. Clearance section; 58. Subcooling assembly; 59. Heat exchanger; 50. Electronic expansion valve; 51. Main inlet pipe; 52. Main outlet pipe; 53. Auxiliary pipe connection; 54. T-junction connection; 65. First check valve; 76. Second check valve; 87. Filter.

[0012] The purpose, features, and advantages of this application will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0013] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in further detail below with reference to the accompanying drawings.

[0014] Where the following description relates to the accompanying drawings, unless otherwise indicated, the same numbers in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this application. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this application as detailed in the appended claims.

[0015] In the description of this application, it should be understood that the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances. Furthermore, in the description of this application, unless otherwise stated, "multiple" refers to two or more. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. The character " / " generally indicates that the preceding and following related objects are in an "or" relationship.

[0016] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of this application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0017] Currently, HVAC systems are widely used in office buildings and shopping malls. An HVAC system generally includes a heat source unit, a refrigerant switching device, and multiple load units. The main function of the refrigerant switching device is to enable the load units to switch between different modes of cooling and heating. The heat source unit and each load unit are connected to the refrigerant switching device through liquid pipes and gas pipes, thereby realizing a refrigerant cooling cycle or a refrigerant heating cycle.

[0018] In related technologies, there is a possibility of leakage during the refrigerant transfer process between the refrigerant switching device and the load unit. When the refrigerant leaks, the refrigerant switching device will cut off the refrigerant transfer to the load unit, which will cause the refrigerant pressure on the side connected to the load unit to be too high. If the refrigerant pressure is too high, the pipes or components on the load unit side may not be able to withstand the pressure, thus causing an explosion.

[0019] Therefore, this application provides a refrigerant switching device 100 and a heating and ventilation system, which solves the problem of safety issues caused by refrigerant leakage in current refrigerant switching devices by setting up a pressure relief component.

[0020] Reference Figure 1 In this embodiment, the refrigerant switching device 100 is located on the refrigerant circuit between the heat source unit and the load unit. The heat source unit can be installed in an outdoor space or an indoor space (such as an equipment room). The load unit is installed in an indoor space that requires temperature control. The refrigerant switching device 100 can be installed in an indoor space that requires temperature control, just like the load unit, or it can be installed in an independent space. Here, there are no specific restrictions on the installation environment of the refrigerant switching device.

[0021] The embodiments of this application will be described in detail below with reference to the accompanying drawings and specific implementation details.

[0022] Reference Figures 2 to 4 This embodiment provides a refrigerant switching device 100, including a housing 10, a liquid pipe assembly 20, a gas pipe assembly 30, and a pressure relief assembly 40.

[0023] The outer contour of the housing 10 can be rectangular. The housing 10 is used to support components such as the liquid pipe assembly 20, the gas pipe assembly 30, and the pressure relief assembly 40. The housing 10 can be made of alloys or metals such as aluminum or steel to meet requirements such as structural strength and long service life. Of course, the housing 10 can also be made of plastic to meet requirements such as lighter weight; this application does not impose any restrictions on this. The housing 10 provides protection and is compatible with the connection structure of the installation environment.

[0024] The liquid pipe assembly 20 includes multiple parallel indoor unit liquid pipes 24, which are spaced apart along a first direction. Each indoor unit liquid pipe 24 is at least partially located within the housing 10 and is used to communicate with a load unit. Each indoor unit liquid pipe 24 is equipped with a liquid shut-off valve 242, which closes or opens the communication between the indoor unit liquid pipe 24 and the load unit, thereby transferring liquid heat exchange medium between the indoor unit liquid pipe 24 and the load unit. It is understood that the number of indoor unit liquid pipes 24 corresponds to the number of load units that the refrigerant switching device 100 can connect to.

[0025] The gas pipe assembly 30 includes multiple parallel indoor unit gas pipes 35, each at least partially located within the housing 10. These parallel indoor unit gas pipes 35 are spaced apart along a first direction and are used to communicate with load units. Each indoor unit gas pipe 35 is equipped with a gas shut-off valve 351, which closes / opens the communication between the indoor unit gas pipe 35 and the load unit, thereby transferring gaseous heat exchange medium between the indoor unit gas pipe 35 and the load unit. Similarly, the number of indoor unit gas pipes 35 corresponds to the number of load units that the refrigerant switching device 100 can connect to.

[0026] Reference Figure 4 and Figure 5 The pressure relief assembly 40 includes a main pressure relief pipe 41, a pressure relief valve 42, and multiple pressure relief branch pipes 43. The multiple pressure relief branch pipes 43 are spaced apart along a first direction. One end of each pressure relief branch pipe 43 is connected to the indoor unit liquid pipe 24 between the liquid shut-off valve 241 and the load unit, or one end of each pressure relief branch pipe 43 is connected to the indoor unit gas pipe 35 between the gas shut-off valve 351 and the load unit. The other end of each pressure relief branch pipe 43 is connected to the main pressure relief pipe 41, which is connected to the heat source unit. The pressure relief valve 42 is located on either the pressure relief branch pipe 43 or the main pressure relief pipe 41. (Refer to...) Figure 6In another structural form, a first pressure relief port 352 can be provided on the indoor air pipe 35 for connection with the pressure relief branch pipe 43.

[0027] The main pressure relief pipe 41 and the branch pressure relief pipe 43 can be made of copper, aluminum alloys or metals, or steel, to meet the requirements of structural strength and long service life, and to ensure pressure relief stability. Figure 7 This is a diagram showing the refrigerant flow direction when the pressure relief valve 42 of the refrigerant switching device is installed in the pressure relief manifold 41, and all load units are in cooling mode. Figure 8 This is a diagram showing the refrigerant flow direction when the pressure relief valve 42 of the refrigerant switching device is installed in the pressure relief branch pipe 43, and all load units are in cooling mode.

[0028] The refrigerant switching device 100 and HVAC system provided in this application embodiment include a pressure relief assembly 40, which comprises a pressure relief main pipe 41, a pressure relief valve 42, and multiple pressure relief branch pipes 43. When refrigerant leaks in the refrigerant switching device 100, the gas shut-off valve 351 closes the indoor unit gas pipe 35, causing excessive refrigerant pressure in the section of the indoor unit gas pipe 35 connecting to the load unit. Alternatively, the liquid shut-off valve closes the indoor unit liquid pipe 24, causing excessive refrigerant pressure in the section of the indoor unit liquid pipe 24 connecting to the load unit. In this case, one end of the pressure relief branch pipe 43 is connected to the indoor unit liquid pipe 24 between the liquid shut-off valve and the load unit, or to the indoor unit gas pipe 35 between the gas shut-off valve 351 and the load unit, while the other end is connected to the pressure relief main pipe 41. The pressure relief main pipe 41 is connected to the heat source unit, and the pressure relief valve 42 is installed on either the pressure relief branch pipe 43 or the pressure relief main pipe 41. When the refrigerant pressure exceeds the limit, the pressure relief valve 42 will open, so that the refrigerant pressure in the indoor unit liquid pipe 24 or indoor unit gas pipe 35 can be relieved through the corresponding pressure relief branch pipe 43 to the pressure relief main pipe 41, and then discharged to the heat source unit, thereby preventing the indoor unit liquid pipe 24 or indoor unit gas pipe 35 from bursting due to excessive internal pressure, and meeting the safety requirements of use.

[0029] Meanwhile, by integrating the internal pressure of multiple indoor unit liquid pipes 24 into the same pressure relief main pipe 41 for pressure relief, the multiple indoor unit liquid pipes 24 actually share the same pressure relief pipeline for pressure relief, thus reducing the pipeline length of each pressure relief branch pipe 43, thereby effectively reducing costs and solving the problem of high cost of the pressure relief structure in the refrigerant switching device 100, so as to meet the demand for low-cost production.

[0030] Optionally, the pressure relief valve 42 is designed to operate within a specific pressure range to ensure the safe operation of the system. Its operation is as follows: when the pressure in the pipeline exceeds a first preset pressure value, the pressure relief valve 42 will open, allowing refrigerant to pass through to relieve the pressure in the pipeline. When the pressure drops below a second preset pressure value, the pressure relief valve 42 will close, stopping the release of refrigerant. This design ensures that the system can release pressure in a timely manner when the pressure rises abnormally, avoiding damage to the system or potential safety hazards caused by excessive pressure. Simultaneously, the setting that the first preset pressure value is greater than the second preset pressure value also ensures that the pressure relief valve 42 can open promptly when necessary, rather than frequently opening and closing. This design of the pressure relief valve 42 helps improve the stability and safety of the system.

[0031] Optionally, the pressure relief valve 42 is configured as a one-way valve, allowing refrigerant to flow unidirectionally from the load unit to the heat source unit. The one-way valve design of the pressure relief valve 42 helps ensure unidirectional refrigerant flow within the system, thereby maintaining normal system operation and pressure balance. Its operation is as follows: when the system pressure exceeds the set value of the pressure relief valve 42, the pressure relief valve 42 will open, allowing refrigerant to flow unidirectionally from the load unit side to the heat source unit side, thus relieving system pressure. When the pressure drops below the set value, the pressure relief valve 42 will close, preventing refrigerant backflow. This design effectively prevents damage to the system due to excessive pressure and maintains stable system operation. Through the one-way valve design, the refrigerant can only flow in a predetermined direction, ensuring that all components and pipes of the system operate according to design requirements. This design improves system reliability and safety, ensuring normal system operation under various working conditions.

[0032] Reference Figure 7 Optionally, the pressure relief valve 42 is installed on the pressure relief main pipe 41. Since installing the pressure relief valve 42 only on the pressure relief main pipe 41 can effectively reduce the number of pressure relief valves 42, it can not only reduce the number of pressure relief valves 42 and reduce costs, but also eliminate the need for the gas pipe assembly 30 and liquid pipe assembly 20 of the refrigerant switching device 100 to avoid the pressure relief valve 42. This allows the gas pipe assembly 30 and liquid pipe assembly 20 to be installed close together, making the internal structure of the refrigerant switching device 100 more compact and saving the internal space of the housing 10. This reduces the size requirement of the refrigerant switching device 100 and makes it suitable for various installation environments.

[0033] Reference Figure 8 Optionally, each pressure relief branch 43 is equipped with a pressure relief valve 42, and each pressure relief branch 43 is connected to the pressure relief main pipe 41 through the pressure relief valve 42. Pressure relief can be performed on the flow path of a specific leaking load unit, thereby achieving precise control of the refrigerant flow path of each load unit.

[0034] Optionally, the refrigerant switching device 100 also includes a refrigerant detection sensor (not shown) and a control module (not shown). The refrigerant detection sensor is used to monitor the amount of refrigerant leakage within the load unit or housing 10. The control module takes appropriate measures based on whether the detected refrigerant leakage exceeds a preset threshold. Once the refrigerant leakage exceeds the preset threshold, the control module will command the liquid shut-off valve 242 and the gas shut-off valve 351 to close to prevent further leakage and protect the safe operation of the system. This refrigerant detection and control mechanism helps to promptly detect and address potential refrigerant leakage problems, thereby minimizing potential safety risks.

[0035] Combined with reference Figures 7 to 9 Regarding the specific composition of the gas pipe assembly 30: The gas pipe assembly 30 includes a gas manifold extending along a first direction. Multiple parallel indoor unit gas pipes 35 converge at the gas manifold. The gas manifold is closer to the heat source unit than each individual indoor unit gas pipe 35. The pressure relief manifold 41 is connected to the heat source unit via the gas manifold. By using a gas manifold to converge multiple parallel indoor unit gas pipes 35, the pipe length of each indoor unit gas pipe 35 is reduced, thereby effectively reducing costs and further addressing the issue of high cost in the refrigerant switching device 100, thus meeting the requirements for low-cost production. It should be noted that, in one embodiment, the gas manifold can be a separate pipeline. In another embodiment, the gas manifold includes a high-pressure gas pipe 32 and a low-pressure gas pipe 31, which branch from the indoor unit gas pipe 35 to form two gas branches, which are respectively defined as a bypass gas pipe 33 and a branch gas pipe 34. The bypass gas pipe 33 is connected to the low-pressure gas pipe 31, and the branch gas pipe 34 is connected to the high-pressure gas pipe 32. One end of the pressure relief branch pipe 43 is connected to the indoor unit gas pipe 35 between the gas shut-off valve 351 and the load unit, and the other end of the pressure relief branch pipe 43 is connected to the pressure relief main pipe 41. The pressure relief main pipe 41 is connected to the heat source unit via the low-pressure gas pipe 31.

[0036] Both the low-pressure air pipe 31 and the high-pressure air pipe 32 are at least partially located within the interior space of the housing 10, and both extend outside the housing 10 to facilitate communication with the heat source unit. Furthermore, the housing 10 includes a fixing member 15, which can hold and fix the high-pressure air pipe 32 and the low-pressure air pipe 31 to improve their stability within the housing 10. The extending direction of the low-pressure air pipe 31 and the high-pressure air pipe 32 is defined as a first direction. Multiple parallel indoor unit liquid pipes 24 are spaced apart along this first direction, as are multiple parallel indoor unit air pipes 35. The high-pressure air pipe 32 is connected to the indoor unit air pipe 35 via a branch air pipe 34, and the indoor unit air pipe 35 is connected to the low-pressure air pipe 31 via a bypass air pipe 33. That is, a bypass air pipe 33 and a branch air pipe 34 converge onto an indoor unit air pipe 35. Meanwhile, the indoor unit gas pipe 35 is used to connect with the load unit. The indoor unit gas pipe 35 is equipped with a gas shut-off valve 351, which closes or opens the connection between the indoor unit gas pipe 35 and the load unit. It can be understood that the high-pressure gas pipe 32 is mainly responsible for receiving the high-pressure gaseous heat exchange medium from the heat source unit, which is then transported to the load unit via the subsequent branch gas pipe 34. The low-pressure gas pipe 31 is responsible for transporting the low-pressure gaseous heat exchange medium from the load unit back to the heat source unit via the bypass gas pipe 33 and the branch gas pipe 34. In a multi-split system, the low-pressure refrigerant generated by each load unit returns to the heat source unit through the low-pressure gas pipe 31, absorbs heat in the evaporator, and is then compressed again by the compressor. This cycle allows the HVAC system to continuously provide cooling.

[0037] It should be noted that the refrigerant switching device 100 also includes multiple filters 80. These filters can be installed in various pipelines, such as the low-pressure gas pipe 31. The filters can prevent impurities, dirt, and other particulate matter from entering the load unit, thus helping to prevent these impurities from damaging the load unit or affecting its performance.

[0038] Combined with reference Figure 7 , Figure 8 as well as Figure 10 Regarding the specific composition of the liquid pipe assembly 20: The liquid pipe assembly 20 also includes a liquid manifold extending along a first direction. Multiple parallel indoor unit liquid pipes 24 converge in the liquid manifold. The liquid manifold is closer to the heat source unit than each individual indoor unit liquid pipe 24. The end of each indoor unit liquid pipe 24 furthest from the liquid manifold forms an interface end 241, which is connected to the load unit. One end of the pressure relief branch pipe 43 is connected between the liquid shut-off valve 242 and the interface end 241, and the other end of the pressure relief branch pipe 43 is connected to the pressure relief main pipe 41. By setting the liquid manifold to converge multiple parallel indoor unit liquid pipes 24, the pipe length of each indoor unit liquid pipe 24 is reduced, thereby effectively reducing costs and further solving the problem of high cost in the refrigerant switching device 100, thus meeting the needs of low-cost production.

[0039] In one structural implementation of the liquid pipe assembly 20, there is only one liquid manifold, and the indoor unit liquid pipe 24 extends from the liquid manifold to the interface end 241. By using a single liquid manifold, the structure of the liquid pipe assembly 20 is simplified, making it easier to install and reducing the size of the refrigerant switching device 100.

[0040] In another structural implementation of the liquid pipe assembly 20, there are three liquid manifolds: a main liquid pipe 21, a cooling branch liquid pipe 22, and a heating branch liquid pipe 23. The main liquid pipe 21 is used to connect to the heat source unit. The cooling branch liquid pipe 22 and the heating branch liquid pipe 23 are branched from the main liquid pipe 21. Two liquid branches are formed from each indoor unit liquid pipe 24, which are defined as a branch liquid pipe 25 and a bypass liquid pipe 26, respectively. Each branch liquid pipe 25 is connected to the heating branch liquid pipe 23 and is configured to flow from the branch liquid pipe 25 to the heating branch liquid pipe 23. Each bypass liquid pipe 26 is connected to the cooling branch liquid pipe 22 and is configured to flow from the cooling branch liquid pipe 22 to the bypass liquid pipe 26.

[0041] The main liquid pipe 21 extends at least partially outside the housing 10 to communicate with the heat source unit. The cooling branch liquid pipe 22 and the heating branch liquid pipe 23 are located inside the housing 10 and are both connected to the main liquid pipe 21. Each indoor unit liquid pipe 24 is connected to both the cooling branch liquid pipe 22 and the heating branch liquid pipe 23. Each indoor unit liquid pipe 24 is connected to the cooling branch liquid pipe 22 via a bypass liquid pipe 26, and each indoor unit liquid pipe 24 is connected to the heating branch liquid pipe 23 via a branch liquid pipe 25. Each indoor unit liquid pipe 24 is also connected to a load unit. Thus, in either the heating or cooling operation of the load unit, the heat source unit and the load unit exchange liquid heat exchange media, which can be refrigerant, through the main liquid pipe 21, cooling branch liquid pipe 22, heating branch liquid pipe 23, and multiple indoor unit liquid pipes 24. Meanwhile, the indoor unit liquid pipe 24 is equipped with a liquid shut-off valve 242, which closes or opens the connection between the indoor unit liquid pipe 24 and the load unit. The other end of the refrigerant branch liquid pipe 22 in the first direction is a closed end, and the other end of the heating branch liquid pipe 23 in the first direction is a closed end, so as to ensure that the refrigerant can only flow to the load unit from the preset pipeline and avoid refrigerant leakage from the end of the branch liquid pipe.

[0042] Reference Figure 11 and Figure 12The indoor unit liquid pipe 24 includes a first transition section 24a, a second transition section 24b, a third transition section 24c, and a fourth transition section 24d arranged sequentially. The two ends of the liquid shut-off valve 242 are connected to the first transition section 24a and the second transition section 24b, respectively. The end of the first transition section 24a furthest from the second transition section 24b is connected to both the branch liquid pipe 25 and the bypass liquid pipe 26. The bypass liquid pipe 26 has a clearance portion 261 to avoid the heating branch liquid pipe 23. Specifically, the clearance portion 261 is partially located on the first horizontal plane V1, and the heating branch liquid pipe 23 is located on the second horizontal plane V2, which is higher than the first horizontal plane V1. This effectively utilizes internal space, making the pipe structure more compact. Furthermore, the second transition section 24b of the indoor unit liquid pipe 24 has a second pressure relief port 431 for communication with the pressure relief branch pipe 43.

[0043] Reference Figure 13 In some structural configurations, the main pressure relief pipe 41 includes a first pipe section 411 and a second pipe section 412 connected together. The end of the second pipe section 412 facing away from the first pipe section 411 is connected to a low-pressure gas pipe 31, which is connected to a heat source unit. The first pipe section 411 and the second pipe section 412 can be an integral structure to ensure the overall stability of the main pressure relief pipe 41, or they can be connected by a detachable method such as screws, allowing for future replacement of both sections. The first pipe section 411 extends along a first direction, and multiple pressure relief branch pipes 43 are arranged at intervals along the first direction and connected to the first pipe section 411. This aligns the arrangement direction of the multiple pressure relief branch pipes 43 with the extension direction of the first pipe section 411 of the main pressure relief pipe 41, thereby optimizing the layout of the multiple pressure relief branch pipes 43 and the pressure relief pipeline and reducing connection difficulty. This layout makes the pressure relief piping more organized and orderly, reducing pipe crossings and clutter. The orderly layout also makes system maintenance more convenient. Technicians can more easily identify and access the main pressure relief pipe 41 and branch pipes 43 during inspections and maintenance, saving maintenance time and costs.

[0044] Combined with reference Figure 14Furthermore, the refrigerant switching device 100 includes a heating mode and a cooling mode. A bypass pipe 33 is equipped with a low-pressure valve 331, and a branch pipe 34 is equipped with a high-pressure valve 341. In heating mode, the high-pressure valve 341 of the pipe assembly 30 is open, the low-pressure valve 331 is closed, and the liquid shut-off valve 242 of the liquid pipe assembly 20 is open. In cooling mode, the high-pressure valve 341 of the pipe assembly 30 is closed, the low-pressure valve 331 is open, and the liquid shut-off valve 242 of the liquid pipe assembly 20 is open. To ensure safety, by providing a low-pressure valve 331 on one side of the bypass pipe 33 and a high-pressure valve 341 on the branch pipe 34, it is ensured that the bypass pipe 33 and the branch pipe 34 are only opened for refrigerant in their respective modes, and remain closed in other situations, thereby improving operational safety.

[0045] Combined with reference Figure 15 The direction perpendicular to the first direction is defined as the second direction, and both the first and second directions are perpendicular to the height direction of the housing 10. In the second direction, the indoor liquid pipe 24 has an interface end 241 for connecting to the load unit, and the first pipe section 411 is located on the side of the indoor liquid pipe 24 away from the interface end 241. By keeping the first pipe section 411 away from the interface end 241, installation interference caused by the first pipe section 411 when connecting the indoor liquid pipe 24 to the load unit is effectively avoided. At the same time, the first pipe section 411 is located at the boundary of the indoor liquid pipe 24 in the second direction, which makes installation and maintenance easier.

[0046] Reference Figure 16 and Figure 17 Optionally, the first pipe section 411 is provided with pressure relief interfaces 4111 corresponding to and connected to multiple pressure relief branch pipes 43, and the multiple pressure relief interfaces 4111 are oriented in the same direction. This allows multiple subsequent pressure relief branch pipes 43 to be connected to the pressure relief interfaces 4111 in the same direction. Specifically, in the height direction of the shell 10, the multiple pressure relief interfaces 4111 can all be oriented upwards. During installation, operators only need to install the multiple pressure relief branch pipes 43 downwards, without needing to consider differences in interface orientation, reducing the risk of incorrect connection, simplifying installation steps, reducing installation complexity and time costs, and improving installation convenience. Moreover, when maintenance or replacement of the pressure relief branch pipes 43 is required, operators can more easily identify and access the pressure relief interfaces 4111 for disassembly, simplifying maintenance operations and improving maintenance efficiency. In addition, the unidirectional arrangement of the pressure relief interfaces 4111 is beneficial for optimizing space utilization. It makes the arrangement of the pressure relief branch pipes 43 more neat and orderly, reduces pipe crossings and clutter, and improves space utilization efficiency.

[0047] Optionally, the first pipe section 411 and the second pipe section 412 are located on the same horizontal plane in the height direction of the housing 10. This not only reduces the bending and twisting of the pressure relief manifold 41, ensuring its structural strength, but also helps optimize space utilization. This design makes the pressure relief manifold 41 occupy less space in the vertical direction, allowing for more efficient use of the space in the housing 10, further reducing the volume requirement of the refrigerant switching device 100. Furthermore, having the first pipe section 411 and the second pipe section 412 on the same horizontal plane makes it easier for technicians to access and operate the system during inspection or maintenance. This simplifies the maintenance process and saves maintenance time and costs.

[0048] Reference Figure 16 and Figure 17 In some structural configurations, the pressure relief assembly 40 further includes a connecting pipe 44, which is located between the second pipe segment 412 and the low-pressure gas pipe 31 in a second direction along the height direction of the housing 10. The connecting pipe 44 includes at least one clearance section 441 that bends along the height direction, defining a clearance area that clears at least a portion of the liquid pipe assembly 20 or at least a portion of the gas pipe assembly 30. Alternatively, the clearance area can clear at least a portion of both the liquid pipe assembly 20 and the gas pipe assembly 30 simultaneously. This design of the clearance section 441 allows the connecting pipe 44 to bend along the height direction, thereby arranging the pipes more efficiently within a limited space, reducing the space occupied by the pipes, and improving space utilization. Furthermore, the clearance area clears portions of the liquid pipe assembly 20 and the gas pipe assembly 30, preventing collisions between the connecting pipe 44 and other components. This helps protect the liquid pipe and gas pipe assembly 30, reduces the risk of damage, and improves the reliability and stability of the system. Furthermore, both the first and second directions are perpendicular to the height of the housing 10. This places the connecting pipe 44 in the second direction between the second pipe section 412 and the low-pressure gas pipe 31, resulting in a clearer and more orderly pipe layout. This design reduces pipe crossings and clutter, improving system reliability and stability. Simultaneously, it ensures that the connecting pipe 44 occupies less space in the second direction, allowing for more efficient use of the housing 10's space, further reducing the size of the refrigerant switching device 100.

[0049] Furthermore, the main pressure relief pipe 41 is connected to the low-pressure gas pipe 31 via a pressure relief valve 42. One port of the pressure relief valve 42 is connected to the second pipe section 412 via a connecting pipe 44, and the other port of the pressure relief valve is connected to the low-pressure gas pipe 31. The pressure relief valve 42, connecting pipe 44, and second pipe section 412 are all located on the same side of the overall structure formed by multiple internal liquid pipes 24 in the first direction. This makes the connection between the pressure relief valve 42, connecting pipe 44, and second pipe section 412 more convenient, allowing operators to more easily connect and disconnect these three components, simplifying the installation and maintenance process. It also helps reduce pipe crossings and clutter. This design makes the pipe layout clearer and more orderly, reducing the possibility of confusion and incorrect connections during pipe connections, improving overall reliability, and making the pipe arrangement more compact, saving installation space. In other embodiments, the pressure relief branch pipe is connected to the pressure relief main pipe via a pressure relief valve. One port of the pressure relief valve is connected to the pressure relief branch pipe, and the other port is connected to a first pipe section. The first pipe section is connected to the low-pressure gas pipe via a second pipe section and a connecting pipe. This allows for changing the installation position of the pressure relief valve, thereby enabling individual control of the pressure on / off of each pressure relief branch pipe. When maintenance or inspection of a particular pressure relief branch is required, the pressure relief valve of that branch can be closed independently without affecting the normal operation of other pressure relief branches.

[0050] Combined with reference Figures 17 to 19 In some structural configurations, the refrigerant switching device 100 further includes a subcooling assembly 50. The subcooling assembly 50 is housed within the casing 10 and is connected to the refrigerant branch pipe 22 and the main pipe 21. The subcooling assembly 50 enhances the subcooling of the refrigerant flowing from the main pipe 21 to the refrigerant branch pipe 22, bringing it closer to saturation, thereby increasing the efficiency of the refrigeration cycle. This allows for greater cooling capacity under the same operating conditions, improving the performance and energy efficiency ratio of the HVAC system.

[0051] The extension direction of the main liquid pipe 21 is defined as the first direction, and the subcooling assembly 50 is located at the same end of the whole formed by the main liquid pipe 21 and the refrigerant branch pipe 22 in the first direction. This makes installation and maintenance more convenient. It reduces the complexity of pipe connections and wiring, lowers the risk of errors during installation, and simplifies maintenance and repair operations.

[0052] Furthermore, the subcooling assembly 50 includes a heat exchanger 51, an electronic expansion valve 52, a main inlet pipe 53, a main outlet pipe 54, an auxiliary pipe 55, and a tee pipe 56. The heat exchanger 51 has a main flow path and an auxiliary flow path. The heat exchange medium in the auxiliary flow path is used to cool the heat exchange medium in the main flow path. By dividing the heat exchanger 51 into a main flow path and an auxiliary flow path, and utilizing the heat exchange medium in the auxiliary flow path to cool the heat exchange medium in the main flow path, the efficiency of the heat exchanger 51 can be effectively improved. This internal circulation design allows the refrigeration system to make fuller use of the refrigerant's heat, improving refrigeration efficiency and thus achieving a faster and more energy-efficient refrigeration process.

[0053] The heat exchanger 51 can be a plate heat exchanger, which has advantages such as high-efficiency heat exchange, flexibility, easy cleaning and maintenance, and corrosion resistance. The inlet end of the main flow path of the heat exchanger 51 is connected to the main liquid pipe 21 through the main inlet pipe 53, and the outlet end of the main flow path of the heat exchanger 51 is connected to the first interface of the three-way connector 56. The second interface of the three-way connector 56 is connected to the inlet end of the second flow path of the heat exchanger 51 through the electronic expansion valve 52. The electronic expansion valve 52 is used to cool the heat exchange medium entering the second flow path. By cooling the heat exchange medium entering the second flow path through the electronic expansion valve 52, the refrigeration system can achieve precise temperature control. This adjustable cooling device can adjust the temperature of the refrigerant according to actual needs, ensuring that the system can provide a stable cooling effect under different operating conditions and meet the user's temperature control requirements. The third interface of the three-way connector 56 is connected to the refrigerant branch liquid pipe 22 through the main outlet pipe 54, and the outlet end of the second flow path of the heat exchanger 51 is connected to the low-pressure gas pipe 31 through the auxiliary pipe 55.

[0054] By connecting the main inlet pipe 53 to the main liquid pipe 21, the main outlet pipe 54 to the refrigerant branch liquid pipe 22, and the auxiliary pipe 55 to the low-pressure gas pipe 31, the effective distribution and recycling of heat within the refrigeration system is achieved. This optimized design ensures a reasonable flow path for the refrigerant within the system, maximizing heat transfer efficiency and thus improving the overall performance of the refrigeration system. Furthermore, the T-junction pipe 56 effectively reduces the number of pipes, allowing for more efficient pipe arrangement within a limited space, reducing pipe footprint and improving space utilization. The connection between the main liquid pipe and the main inlet pipe forms the first connection section, the connection between the refrigerant branch liquid pipe and the main outlet pipe forms the second connection section, and the connection between the low-pressure gas pipe and the auxiliary pipe forms the third connection section. The openings of the first, second, and third connection sections all face the same direction, facilitating standardized pipe connections and mass installation.

[0055] Furthermore, the extension direction of the low-pressure gas pipe 31 is defined as the first direction, and the direction perpendicular to the first direction is defined as the second direction. Both the first and second directions are perpendicular to the height direction of the housing 10. The electronic expansion valve 52 and the heat exchanger 51 are arranged to at least partially overlap in the second direction. This reduces the space occupied by the electronic expansion valve 52 and the heat exchanger 51 in the second direction, thereby effectively saving space in the system. This compact layout also means fewer pipe connections and component installations, reducing system complexity, lowering installation and maintenance costs and difficulties, and improving system reliability and ease of use.

[0056] Combined with reference Figure 3 and Figure 4 In some structural configurations, the housing 10 includes a housing body 11, a chassis 12, and a support beam 13. The chassis 12 is located at the bottom of the housing body 11 and connected to it. The support beam 13 is connected to the housing body 11 to house the liquid pipe assembly 20, the gas pipe assembly 30, and the pressure relief assembly 40. The support beam 13 can be directly connected to the pressure relief assembly 40 so that the pressure relief assembly 40 is supported within the housing body 11. Alternatively, the support beam 13 can also be connected to the liquid pipe assembly 20 and the gas pipe assembly 30. Since the pressure relief assembly 40 is connected to both the liquid pipe assembly 20 and the gas pipe assembly 30, this also allows the pressure relief assembly 40 to be supported within the housing body 11, thereby ensuring that the pressure relief assembly 40 is stably positioned within the housing body 11.

[0057] The shell body 11 has a cover structure and includes a top plate 111 and multiple side plates 112 surrounding the top plate 111. The top plate 111 is disposed opposite to the chassis 12. The multiple side plates 112 define downward-facing openings. The chassis 12 covers the openings and is detachably connected to the shell body 11. The chassis 12 and the shell body 11 together form an installation cavity. It should be noted that the multiple side plates 112 include a load-side side plate 1121, a heat-source-side side plate 1122, and an electrical control-side side plate 1123. A load-side pipe port 112a is provided on the load-side side plate 1121 for a pipe connected to the load unit to pass through, and a heat-source-side pipe port 112b is provided on the heat-source-side side plate 1122 for a pipe connected to the heat-source unit to pass through. The electrical control components of the refrigerant switching device 100 are mounted on the chassis 12 and disposed near the electrical control-side side plate 1123. The detachable connection between the chassis 12 and the shell body 11 can be a connection between the chassis 12 and multiple side plates 112. Specifically, a protruding connecting lug or other structure can be provided on the chassis 12, and the structure can be detachably connected to the chassis 12 by a screw or other threaded structure to achieve a detachable connection between the chassis 12 and the shell body 11.

[0058] Specifically, the refrigerant switching device 100 is defined to have a length direction and a width direction. Multiple side plates 112 may include two first side plates 112 arranged opposite each other along the length direction and two second side plates 112 arranged opposite each other along the width direction. The two second side plates 112 are connected between the ends of the two first side plates 112 to form a downward-facing opening. The chassis 12 is detachably connected to the multiple side plates to cover the opening, thus suspending the pressure relief assembly 40 above the chassis 12. This allows for direct maintenance of the pressure relief assembly 40 when the chassis 12 is disassembled, specifically for the maintenance of the pressure relief valve 42, the main pressure relief pipe 41, and the branch pressure relief pipe 43.

[0059] The heat exchanger 51 of the subcooling assembly 50 can be installed on the shell body 11 or the support beam 13. This ensures that the chassis 12 can be disassembled independently, allowing for easy inspection or maintenance of the gas pipe assembly 30 and liquid pipe assembly 20. This not only increases the efficiency of inspection and maintenance of the gas pipe assembly 30 and liquid pipe assembly 20 but also reduces the cost.

[0060] Reference Figure 20 In the first installation method of the heat exchanger 51, the supporting beam 13 includes a first beam 131 and a second beam 132 spaced apart. The first beam 131 is used to mount the liquid pipe assembly 20, and the second beam 132 is used to mount the gas pipe assembly 30. The heat exchanger 51 is installed on either the first beam 131 or the second beam 132. This allows for a modular design of the heat exchanger 51 and the gas pipe assembly 30, or the heat exchanger 51 and the liquid pipe assembly 20, facilitating the overall installation of the heat exchanger 51 and the gas pipe assembly 30 or the liquid pipe assembly 20. Furthermore, referring to… Figure 14 The housing also includes a shock-absorbing pad 16, which is located between the second beam 132 and the low-pressure valve 331 to reduce hard contact with the low-pressure valve 331.

[0061] Specifically, during the installation of the gas pipe assembly 30, the liquid pipe assembly 20, the heat exchanger 51, and the shell body 11: When the heat exchanger 51 is installed on the first beam 131, the liquid pipe assembly 20 is first installed on the first beam 131, and then the heat exchanger 51 is installed on the first beam 131. After the assembly is completed, the gas pipe assembly 30 is installed on the second beam 132. After the assembly is completed, this part is placed on the structure composed of the already installed liquid pipe assembly 20, heat exchanger 51 and first beam 131. After the placement is completed, it is installed together on the shell body 11. When the heat exchanger 51 is installed on the second beam 132, the liquid pipe assembly 20 is first installed on the first beam 131. After the assembly is completed, the gas pipe assembly 30 is installed on the second beam 132, and the heat exchanger 51 is installed on the second beam 132. After the assembly is completed, this part is placed on the structure composed of the already installed liquid pipe assembly 20 and the first beam 131. After the placement is completed, it is installed together on the shell body 11.

[0062] It should be noted that, since the heat exchanger 51 will be installed on the first beam 131 or the second beam 132, in order to form an installation space to accommodate the heat exchanger 51, when the heat exchanger 51 is installed on the first beam 131, the extension length of the first beam 131 should be greater than the extension length of the second beam 132; when the heat exchanger 51 is installed on the second beam 132, the extension length of the second beam 132 should be greater than the extension length of the first beam 131.

[0063] In another alternative implementation, refer to Figure 21 In the second installation method of heat exchanger 51, when heat exchanger 51 is located inside the mounting cavity, it can also be directly installed on the shell body 11. Specifically, heat exchanger 51 can be fixed to the inner wall of one side plate 112. In a specific embodiment of this invention, heat exchanger 51 can be fixed to the inner wall of the first side plate 112. This arrangement also allows for the separate disassembly of the chassis 12, facilitating the inspection or maintenance of the gas pipe assembly 30 or liquid pipe assembly 20. Furthermore, when heat exchanger 51 is installed on the first side plate 112, the dimensions occupied by heat exchanger 51 in the height direction can overlap to a certain extent with the dimensions occupied by gas pipe assembly 30 or liquid pipe assembly 20, thereby achieving a high degree of structural compactness in the height direction of the refrigerant replacement device.

[0064] In another alternative implementation, refer to Figure 22 In the third installation method of heat exchanger 51, heat exchanger 51 can also be installed outside the shell body 11. In this case, heat exchanger 51 is fixed to the outer wall of one side plate 112, such as the outer wall of the first side plate 112. The side plate has openings for the main inlet pipe, tee pipe and auxiliary pipe communicating with heat exchanger 51 to pass through. That is to say, in this way, heat exchanger 51 can be installed outside the shell body 11, so that chassis 12 can be disassembled independently.

[0065] Regardless of whether the heat exchanger 51 is installed on the support beam 13 or the shell body 11, directly fixing the heat exchanger 51 to the support beam 13 or the shell body 11 is not only costly but may also affect the performance of the heat exchanger 51. Therefore, in this embodiment, an intermediate connecting bracket 14 is required for installing the heat exchanger 51, as shown in the reference... Figure 23In the fourth installation method of heat exchanger 51, heat exchanger 51 is connected to support beam 13 or shell body 11 via connecting bracket 14. In this way, heat exchanger 51 can be installed on support beam 13 or shell body 11, while reducing installation cost and improving performance.

[0066] This embodiment also provides a heating, ventilation, and air conditioning system, including the refrigerant switching device 100 described in the above embodiments. The structure of the refrigerant switching device 100 has been described in detail in the above embodiments and will not be repeated here.

[0067] In addition, the HVAC system provided in this embodiment should also include a heat source unit and multiple load units. The load units may include, but are not limited to, ceiling-mounted units, duct units, wall-mounted air conditioning load units, and floor-standing air conditioning load units, etc. The following describes the refrigerant flow of the HVAC system provided in this embodiment under different modes using four load units as an example.

[0068] Please combine Figure 7 , Figures 24 to 26 , Figure 2 This is a refrigerant flow diagram for each load unit in the HVAC system provided in the embodiments of this application, all in cooling mode. Figure 24 A refrigerant flow diagram for each load unit in the heating system provided in this application embodiment, all in heating mode. Figure 25 This application provides a diagram showing the refrigerant flow direction of a majority of load units in a heating, ventilation, and air conditioning system under cooling conditions, as provided in the embodiments of this application. Figure 26 This is a refrigerant flow diagram for a majority of load units in a heating / ventilation system provided in an embodiment of this application, under heating conditions. For ease of description, [the diagram is shown here]. Figure 7 The operating mode of the load unit shown is called full cooling mode. Figure 24 The operating mode of the load unit shown is called full heating mode. Figure 25 The operating mode of the load unit shown is called the main cooling mode. Figure 26 The operating mode of the load unit shown is called the main heating mode.

[0069] like Figure 7 As shown, in full cooling mode, for each load unit, the first one-way valve 60 in its corresponding branch pipe unit is closed, and the second one-way valve 70 is open. The refrigerant flow direction is: heat source unit → main liquid pipe 21 → heat exchanger 51 → cooling branch liquid pipe 22 → bypass liquid pipe 26 → indoor unit liquid pipe 24 → load unit → indoor unit gas pipe 35 → bypass gas pipe 33 → low-pressure gas pipe 31 → heat source unit. In this way, one cooling cycle is completed.

[0070] like Figure 24As shown, in full heating mode, for each load unit, the first one-way valve 60 in its corresponding branch pipe unit 8 is open, and the second one-way valve 70 is closed. The refrigerant flow direction is: heat source unit → high-pressure gas pipe 32 → branch gas pipe 34 → indoor unit gas pipe 35 → load unit → indoor unit liquid pipe 24 → branch liquid pipe 25 → refrigerant branch liquid pipe 22 → main liquid pipe 21 → heat source unit. In this way, one heating cycle is completed. like Figure 25 As shown, in the main cooling mode, for the load unit in heating mode, its corresponding first check valve 60 is open and the second check valve 70 is closed. The refrigerant flows as follows: heat source unit → high-pressure gas pipe 32 → branch gas pipe 34 → indoor unit gas pipe 35 → load unit → indoor unit liquid pipe 24 → branch liquid pipe 25 → refrigerant branch liquid pipe 22 → main liquid pipe 21 → heat source unit. This completes one heating cycle. For the load unit in cooling mode, its corresponding first check valve 60 is closed and the second check valve 70 is open. The refrigerant flows in the following direction: heat source unit → main liquid pipe 21 → heat exchanger 51 → refrigerant branch liquid pipe 22 → bypass liquid pipe 26 → branch liquid pipe 25 → indoor unit liquid pipe 24 → load unit → indoor unit gas pipe 35 → bypass gas pipe 33 → low-pressure gas pipe 31 → heat source unit. After the refrigerant flows out of the heat exchanger 51, a portion will be diverted along the electronic expansion valve 52 → auxiliary pipe 55 → low-pressure gas pipe 31 → heat source unit. In this way, one cooling cycle is completed.

[0071] like Figure 26 As shown, in the main heating mode, for the load unit in heating mode, its corresponding first one-way valve 60 is open and the second one-way valve 70 is closed. The refrigerant flow direction is: heat source unit → high-pressure gas pipe 32 → branch gas pipe 34 → indoor unit gas pipe 35 → load unit → indoor unit liquid pipe 24 → branch liquid pipe 25 → refrigerant branch liquid pipe 22 → main liquid pipe 21 → heat source unit. In this way, one heating cycle is completed. For the load unit in cooling mode, during operation in heating mode, when the refrigerant flows to the main liquid pipe 21, a portion is diverted to the heat exchanger 51. The refrigerant flow direction is: heat exchanger 51 → refrigerant branch liquid pipe 22 → bypass liquid pipe 26 → branch liquid pipe 25 → indoor unit liquid pipe 24 → load unit → indoor unit gas pipe 35 → bypass gas pipe 33 → low-pressure gas pipe 31 → heat source unit. After flowing out of the heat exchanger 51, a portion of the refrigerant flows along the electronic expansion valve 52 → auxiliary pipe 55 → low-pressure gas pipe 31 → heat source unit. This completes one refrigeration cycle.

[0072] It should be noted that, taking the four load units in this embodiment as an example, in the main cooling mode, three load units can be cooling and one load unit can be heating; in the main heating mode, three load units can be heating and one load unit can be cooling. Here, no specific restrictions are placed on the number of load units or the actual cooling mode.

[0073] In the accompanying drawings of this embodiment, the same or similar reference numerals correspond to the same or similar components. In the description of this application, it should be understood that if terms such as "upper," "lower," "left," and "right" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, they are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, the terms used to describe positional relationships in the accompanying drawings are only for illustrative purposes and should not be construed as limiting this patent. For those skilled in the art, the specific meaning of the above terms can be understood according to the specific circumstances.

[0074] The above are merely preferred embodiments of this application and are not intended to limit this application. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. A refrigerant switching device, located in the refrigerant circuit between a heat source unit and a load unit, characterized in that, The refrigerant switching device includes: case; A liquid pipe assembly, comprising a plurality of parallel indoor liquid pipes, the plurality of parallel indoor liquid pipes being spaced apart along a first direction, the indoor liquid pipes being at least partially located within the housing space, the indoor liquid pipes being used to communicate with the load unit, and the indoor liquid pipes being provided with liquid shut-off valves, the liquid shut-off valves being used to close / open the communication between the indoor liquid pipes and the load unit; An air duct assembly, comprising multiple parallel indoor air ducts, each indoor air duct being at least partially disposed within the internal space of the housing, the multiple parallel indoor air ducts being spaced apart along the first direction, each indoor air duct being used to communicate with the load unit, and each indoor air duct being equipped with a gas shut-off valve, the gas shut-off valve closing / opening the communication between the indoor air duct and the load unit; and The pressure relief assembly includes a main pressure relief pipe, a pressure relief valve, and multiple pressure relief branch pipes. The multiple pressure relief branch pipes are spaced apart along the first direction. One end of each pressure relief branch pipe is connected to the indoor unit liquid pipe between the liquid shut-off valve and the load unit, or to the indoor unit gas pipe between the gas shut-off valve and the load unit. The other end of each pressure relief branch pipe is connected to the main pressure relief pipe, which is connected to the heat source unit. The pressure relief valve is located on the pressure relief branch pipe or the main pressure relief pipe.

2. The refrigerant switching device as described in claim 1, characterized in that, The airway assembly includes a low-pressure airway and a high-pressure airway, as well as a plurality of bypass airways connected to the low-pressure airway and a plurality of branch airways connected to the high-pressure airway. The extension direction of the low-pressure airway and the high-pressure airway is the first direction. The plurality of bypass airways are arranged at intervals along the first direction, and the plurality of branch airways are arranged at intervals along the first direction. One bypass airway and one branch airway converge into one indoor airway. The main pressure relief pipe includes a first pipe section and a second pipe section that are connected to each other. The first pipe section extends along the first direction. A plurality of the pressure relief branch pipes are arranged at intervals along the first direction and are connected to the first pipe section. The end of the second pipe section opposite to the first pipe section is connected to the low-pressure gas pipe. The low-pressure gas pipe is connected to the heat source unit.

3. The refrigerant switching device as described in claim 2, characterized in that, The refrigerant switching device includes a heating mode and a cooling mode. One of the bypass gas pipes is equipped with a low-pressure gas valve, and one of the branch gas pipes is equipped with a high-pressure gas valve. In the heating mode, the high-pressure gas valve of the gas pipe assembly is open, the low-pressure gas valve is closed, and the liquid shut-off valve of the liquid pipe assembly is open. In the cooling mode, the high-pressure gas valve of the gas pipe assembly is closed, the low-pressure gas valve is open, and the liquid shut-off valve of the liquid pipe assembly is open.

4. The refrigerant switching device as described in claim 1, characterized in that, The refrigerant switching device also includes a refrigerant detection sensor and a control module. The refrigerant detection sensor is used to detect the refrigerant leakage of the load unit or the refrigerant leakage in the housing. The control module closes the liquid shut-off valve and the gas shut-off valve when the refrigerant leakage exceeds a preset threshold.

5. The refrigerant switching device as described in claim 1, characterized in that, The pressure relief valve is configured to open when the pressure exceeds a first preset pressure value and close when the pressure is below a second preset pressure value, wherein the first preset pressure value is greater than the second preset pressure value.

6. The refrigerant switching device as described in claim 1, characterized in that, The pressure relief valve is configured as a one-way valve, allowing refrigerant to flow unidirectionally from the load unit to the heat source unit.

7. The refrigerant switching device as described in claim 2, characterized in that, The direction perpendicular to the first direction is defined as the second direction. Both the first direction and the second direction are perpendicular to the height direction of the housing. In the second direction, the internal liquid pipe has an interface end connected to the load unit. The first pipe segment is located on the side of the internal liquid pipe away from the interface end. And / or, the first pipe section is provided with a pressure relief port that is connected to the plurality of pressure relief branches, and the plurality of pressure relief ports are oriented in the same direction; And / or, in the height direction of the housing, the first pipe segment and the second pipe segment are located on the same horizontal plane.

8. The refrigerant switching device as described in claim 7, characterized in that, The pressure relief assembly also includes a connecting pipe, which is located between the second pipe section and the low-pressure gas pipe in a second direction in the height direction of the housing, and the second direction is perpendicular to the first direction; The connecting tube includes at least one clearance section that bends along the height direction, the clearance section defining a clearance area in the height direction, the clearance area being used to avoid at least a portion of the liquid tubing assembly and / or at least a portion of the gas tubing assembly.

9. The refrigerant switching device as described in claim 8, characterized in that, The main pressure relief pipe is connected to the low-pressure gas pipe through the pressure relief valve, wherein one port of the pressure relief valve is connected to the second pipe section through the connecting pipe, and the other port of the pressure relief valve is connected to the low-pressure gas pipe; The pressure relief valve, the connecting pipe, and the second pipe section are all located on the same side of the entire assembly of the multiple internal liquid pipes in the first direction.

10. The refrigerant switching device as described in claim 8, characterized in that, The pressure relief branch pipe is connected to the pressure relief main pipe through the pressure relief valve. One port of the pressure relief valve is connected to the pressure relief branch pipe, and the other port of the pressure relief valve is connected to the first pipe section. The first pipe section is connected to the low-pressure gas pipe via the second pipe section and the connecting pipe.

11. The refrigerant switching device as described in claim 1, characterized in that, The air pipe assembly includes an air manifold that extends along the first direction. Multiple parallel indoor air pipes converge at the air manifold. The air manifold is closer to the heat source unit than each of the indoor air pipes. The pressure relief manifold is connected to the heat source unit via the air manifold.

12. The refrigerant switching device as described in claim 11, characterized in that, The gas manifold includes a high-pressure gas pipe and a low-pressure gas pipe. It branches off from the indoor unit gas pipe to form two gas branches, which are defined as a bypass gas pipe and a branch gas pipe, respectively. The bypass gas pipe is connected to the low-pressure gas pipe, and the branch gas pipe is connected to the high-pressure gas pipe. One end of the pressure relief branch pipe is connected to the indoor unit gas pipe between the gas shut-off valve and the load unit, and the other end of the pressure relief branch pipe is connected to the pressure relief main pipe. The pressure relief main pipe is connected to the heat source unit via the low-pressure gas pipe.

13. The refrigerant switching device as described in claim 11, characterized in that, The liquid pipe assembly also includes a liquid manifold extending along the first direction. Multiple parallel indoor unit liquid pipes converge at the liquid manifold. The liquid manifold is closer to the heat source unit than each individual indoor unit liquid pipe. The end of each indoor unit liquid pipe furthest from the liquid manifold forms an interface end, which is connected to the load unit. One end of the pressure relief branch pipe is connected between the liquid shut-off valve and the interface end, and the other end of the pressure relief branch pipe is connected to the pressure relief main pipe.

14. The refrigerant switching device as described in claim 13, characterized in that, The number of liquid manifolds is one, and the indoor liquid pipe extends from the liquid manifold to the interface end.

15. The refrigerant switching device as described in claim 13, characterized in that, The number of liquid manifolds is three: a main liquid manifold, a cooling branch liquid manifold, and a heating branch liquid manifold. The main liquid manifold is used to connect to the heat source unit. The cooling branch liquid manifold and the heating branch liquid manifold are formed from the main liquid manifold. Two liquid branches are formed from each of the indoor unit liquid manifolds, which are defined as a branch liquid manifold and a bypass liquid manifold, respectively. Each branch liquid manifold is connected to the heating branch liquid manifold and is configured to flow from the branch liquid manifold to the heating branch liquid manifold. Each bypass liquid manifold is connected to the cooling branch liquid manifold and is configured to flow from the cooling branch liquid manifold to the bypass liquid manifold.

16. The refrigerant switching device as described in claim 15, characterized in that, One end of the main liquid pipe in the first direction is connected to one end of the refrigeration branch pipe in the first direction via a subcooling assembly. The refrigerant flowing from the main liquid pipe to the refrigeration branch pipe has its subcooling increased via the subcooling assembly. The other end of the refrigeration branch pipe in the first direction is a closed end; and / or The other end of the main liquid pipe in the first direction is connected to one end of the heating branch liquid pipe in the first direction, and the other end of the heating branch liquid pipe in the first direction is a closed end.

17. The refrigerant switching device as described in any one of claims 1 to 16, characterized in that, The housing includes a housing body, a chassis, and a support beam. The chassis is located at the bottom of the housing body and connected to the housing body. The support beam is connected to the housing body to accommodate the liquid pipe assembly, the gas pipe assembly, and the pressure relief assembly.

18. The refrigerant switching device as described in claim 17, characterized in that, The shell body includes a top plate and a plurality of side plates surrounding the top plate. The opposite ends of the supporting beam are respectively connected to two oppositely arranged side plates. The plurality of side plates define a downwardly facing opening. The chassis is detachably connected to the plurality of side plates to cover the opening.

19. The refrigerant switching device as described in any one of claims 1 to 12, characterized in that, The liquid pipe assembly also includes a main liquid pipe, a cooling branch liquid pipe, and a heating branch liquid pipe. The main liquid pipe is used to connect to the heat source unit. The heating branch liquid pipe is connected to the main liquid pipe. Each of the indoor unit liquid pipes is connected to the cooling branch liquid pipe and the heating branch liquid pipe. The refrigerant switching device further includes a subcooling component, which is disposed within the housing and is connected to the refrigerant branch pipe and the main pipe. The subcooling component is used to increase the subcooling degree of the refrigerant flowing from the main pipe to the refrigerant branch pipe. The extension direction of the main pipe is defined as a first direction, and the subcooling component is located at the same end of the whole formed by the main pipe and the refrigerant branch pipe in the first direction.

20. The refrigerant switching device as described in claim 19, characterized in that, The gas pipe assembly includes a low-pressure gas pipe, and the subcooling assembly includes a heat exchanger, an electronic expansion valve, a main inlet pipe, a main outlet pipe, an auxiliary pipe connection, and a tee connection. The heat exchanger has a main flow path and an auxiliary flow path, and the heat exchange medium in the auxiliary flow path is used to cool the heat exchange medium in the main flow path. The inlet end of the main flow path of the heat exchanger is connected to the main liquid pipe through the main inlet pipe, and the outlet end of the main flow path of the heat exchanger is connected to the first interface of the three-way connector. The second interface of the three-way connector is connected to the inlet end of the second flow path of the heat exchanger through the electronic expansion valve. The electronic expansion valve is used to cool the heat exchange medium entering the second flow path. The third interface of the three-way connector is connected to the refrigeration branch liquid pipe through the main outlet pipe, and the outlet end of the second flow path of the heat exchanger is connected to the low-pressure gas pipe through the auxiliary pipe.

21. The refrigerant switching device as described in claim 20, characterized in that, The main liquid pipe has a first connecting section that communicates with the main inlet pipe, the refrigeration branch liquid pipe has a second connecting section that communicates with the main outlet pipe, and the low-pressure gas pipe has a third connecting section that communicates with the auxiliary pipe. The openings of the first connecting section, the second connecting section, and the third connecting section have the same orientation.

22. The refrigerant switching device as described in claim 20, characterized in that, The direction perpendicular to the first direction is defined as the second direction, and both the first direction and the second direction are perpendicular to the height direction of the shell; The electronic expansion valve and the heat exchanger are arranged to overlap at least partially in the second direction.

23. The refrigerant switching device as described in claim 20, characterized in that, The housing includes a housing body, a chassis, and a support beam. The chassis is disposed at the bottom of the housing body and connected to the housing body. The support beam is connected to the housing body for mounting the liquid tubing assembly. The heat exchanger is installed on the shell body or the supporting crossbeam.

24. The refrigerant switching device as described in claim 23, characterized in that, The supporting beam includes a first beam and a second beam that are spaced apart; The first beam is used to mount the liquid pipe assembly, and the second beam is used to mount the gas pipe assembly; wherein the heat exchanger is installed on either the first beam or the second beam.

25. The refrigerant switching device as described in claim 23, characterized in that, The shell body includes a top plate and a plurality of side plates surrounding the periphery of the top plate, the plurality of side plates defining a downwardly facing opening; The two ends of the supporting beam are respectively connected to two oppositely arranged side plates, wherein the heat exchanger is fixed to the inner wall surface of one of the side plates.

26. The refrigerant switching device as described in claim 23, characterized in that, The shell body includes a top plate and a plurality of side plates surrounding the periphery of the top plate, the plurality of side plates defining a downwardly facing opening; The heat exchanger is fixed to the outer wall of a side plate, and the side plate has an opening through which the main inlet pipe, the three-way connector and the auxiliary pipe, which are connected to the heat exchanger, pass.

27. The refrigerant switching device as described in claim 23, characterized in that, It also includes a connecting bracket, through which the heat exchanger is connected to the supporting beam or the shell body.

28. A heating, ventilation, and air conditioning system, characterized in that, include: Heat source unit; Multiple load units; as well as The refrigerant switching device as described in any one of claims 1 to 27, wherein the heat source unit and the plurality of load units are all connected to the refrigerant switching device.

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