Multi-connected system

Abstract

The application discloses a multi-connected system. The multi-connected system comprises a four-way valve, a mode converter, an indoor heat exchanger, an outdoor heat exchanger, a first control valve, a second control valve, a branch pipe, and a fifth pipe.

Description

Technical Field

[0001] This application relates to the field of multi-split air conditioning technology, and more specifically, to a multi-split system that can simultaneously provide cooling and heating. Background Technology

[0002] In related technologies, multi-split air conditioning systems with simultaneous cooling and heating functions typically employ dual four-way valves and multiple electromagnetic or electric valves to allow different indoor units to simultaneously operate in cooling / heating modes and switch freely, as well as to circulate the system. This results in a congested internal piping layout and increased control complexity. Conversely, multi-split systems using a single four-way valve suffer from significant refrigerant stagnation in cooling mode. Summary of the Invention

[0003] This application provides a multi-unit system.

[0004] The multi-split air conditioning system of this application includes a compressor, a four-way valve, a mode converter, an indoor heat exchanger, an outdoor heat exchanger, a first control valve, and a second control valve.

[0005] The four-way valve has a first valve port, a second valve port, a third valve port, and a fourth valve port. When the first valve port and the second valve port are connected, the third valve port and the fourth valve port are disconnected. When the first valve port and the second valve port are disconnected, the third valve port and the fourth valve port are connected. The first valve port of the four-way valve is connected to the discharge port flow path of the compressor through a first pipeline.

[0006] The mode converter is connected to the second valve port of the four-way valve via a second pipeline and to the third valve port of the four-way valve via a third pipeline.

[0007] The indoor heat exchanger is connected to the mode converter.

[0008] One end of the outdoor heat exchanger is connected to the mode converter via the fourth pipeline, and the other end of the outdoor heat exchanger is connected to the fourth valve port of the four-way valve.

[0009] The first control valve is located on the second pipeline. A branch pipe is connected between the second pipeline and the compressor's exhaust port. A fifth pipeline is connected between the second pipeline and the third pipeline. The second control valve is located on the fifth pipeline.

[0010] In the multi-split air conditioning system of this application embodiment, the switching of multiple functions and modes can be controlled by adjusting the four-way valve, the first control valve, and the second control valve. In addition, the flow rate of refrigerant in the second pipeline can be controlled by the first control valve, effectively controlling the cooling and heating effects of the multi-split air conditioning system and improving reliability. The second control valve can open the fifth pipeline in the full cooling mode, thereby connecting the second and third pipelines. Refrigerant is discharged through the two low-pressure sides of the second and third pipelines, improving unit performance and avoiding large amounts of refrigerant accumulation.

[0011] In some implementations, the multi-split system has a first operating mode in which the first and fourth ports of the four-way valve are connected, and the compressor delivers refrigerant to the outdoor heat exchanger; the first control valve is disconnected, the second control valve is opened, and the mode converter delivers refrigerant to the indoor heat exchangers so that all indoor heat exchangers are operating in cooling mode.

[0012] Thus, by connecting the first and fourth valve ports, disconnecting the first control valve, and opening the second control valve, the multi-split system can be switched to the first operating mode, enabling the multi-split system to cool the environment where the indoor heat exchanger is located. Furthermore, opening the second control valve connects the fifth pipe, which in turn connects the second and third pipes, allowing the second pipe to deliver refrigerant to the compressor for recycling, thus preventing large amounts of refrigerant from accumulating.

[0013] In some implementations, the multi-split system has a second operating mode in which the first and fourth ports of the four-way valve are connected. The compressor delivers a portion of the refrigerant to the outdoor heat exchanger and another portion to the second pipeline. The first control valve opens and the second control valve closes. The fourth and second pipelines deliver refrigerant to the mode converter, which then delivers refrigerant to multiple indoor heat exchangers so that the indoor heat exchangers connected to the fourth pipeline operate in cooling mode and the indoor heat exchangers connected to the second pipeline operate in heating mode.

[0014] Thus, by controlling the connection between the first valve port and the fourth valve port, opening the first control valve, and disconnecting the second control valve, the multi-split system can be switched to the second working mode. In the second working mode, the multi-split system can meet the simultaneous cooling and heating needs of multiple indoor heat exchangers in different environments.

[0015] In some implementations, in the second operating mode, the indoor heat exchanger operating in heating mode delivers the condensed refrigerant to the indoor heat exchanger operating in cooling mode via a mode converter, and the indoor heat exchanger operating in cooling mode delivers the evaporated refrigerant to the compressor via a third pipeline.

[0016] Thus, in the second operating mode, the multi-split system can transfer some of the heat exchange energy in the space to other spaces within the system for utilization, thereby realizing the rational transfer and recovery of energy within the multi-split system, improving energy utilization efficiency, and saving energy.

[0017] In some implementations, in the second operating mode, the first control valve controls at least one of the indoor heat exchangers in heating operation to maintain heating operation, and at least one indoor heat exchanger is shut down for oil return or defrosting operation.

[0018] In this way, the multi-split system can achieve continuous heating while performing oil return or defrosting.

[0019] In some implementations, the multi-split system has a third operating mode in which the third and fourth ports of the four-way valve are connected, the first control valve is opened, the compressor delivers refrigerant to the second pipeline, and the second control valve is closed; the second pipeline delivers refrigerant to the mode converter, and the mode converter delivers refrigerant to the indoor heat exchangers so that all indoor heat exchangers are operating in heating mode.

[0020] Thus, by connecting the third and fourth valve ports, opening the first control valve, and disconnecting the second control valve, the multi-split system can be controlled to switch to the third operating mode, enabling the multi-split system to heat the environment where the indoor heat exchanger is located, thereby improving the reliability of the multi-split system in controlling the switching between different operating modes.

[0021] In some implementations, the multi-split system has a fourth operating mode. In this fourth operating mode, the third and fourth ports of the four-way valve are connected, the first control valve is opened, the compressor delivers refrigerant to the second pipeline, and the second control valve is disconnected. The second pipeline delivers refrigerant to the mode converter, which then delivers refrigerant to the indoor heat exchanger to enable the indoor heat exchanger connected to the second pipeline to operate in heating mode. The indoor heat exchanger operating in heating mode delivers refrigerant to the indoor heat exchanger connected to the fourth pipeline via the mode converter to enable the indoor heat exchanger connected to the fourth pipeline to operate in cooling mode.

[0022] Thus, by connecting the third and fourth valve ports of the four-way valve, opening the first control valve, and disconnecting the second control valve, the multi-split system can be controlled to switch to the fourth working mode. In the fourth working mode, the multi-split system can meet the simultaneous cooling and heating needs of multiple indoor heat exchangers in different environments.

[0023] In some implementations, the first control valve is a flow regulating valve.

[0024] Thus, in the second operating mode, adjusting the first control valve can control the refrigerant flow in the second passage, thereby controlling the ratio of refrigerant flowing to the heating direction and refrigerant flowing to the cooling direction. In the case of a multi-split system simultaneously cooling and heating, adjusting the first control valve can control the ratio of heating capacity to cooling capacity of the multi-split system, maintaining good cooling and heating effects.

[0025] In some implementations, the multi-split system includes an electronic expansion valve and a subcooler, which are located on a fourth piping line.

[0026] In this way, the electronic expansion valve can control the flow rate of the fourth pipeline, throttle and reduce pressure, and the subcooler can improve the subcooling protection of the multi-split system.

[0027] In some implementations, the multi-split system includes a gas-liquid separator, with a first end connected to the compressor's air inlet and a second end connected to a third pipeline and a third valve port.

[0028] In this way, the gas-liquid separator can separate the refrigerant into gas and liquid components, ensuring that the compressor operates normally by drawing in gaseous refrigerant.

[0029] Additional aspects and advantages of embodiments of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of embodiments of this application. Attached Figure Description

[0030] The above and / or additional aspects and advantages of this application will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, wherein:

[0031] Figure 1 This is a schematic diagram of the structure of the multi-unit air conditioning system according to the embodiments of this application;

[0032] Figure 2 This is a schematic diagram of the multi-unit system in the first working mode according to the embodiments of this application;

[0033] Figure 3 This is a schematic diagram of the multi-unit system in the second working mode according to the embodiments of this application;

[0034] Figure 4 This is a schematic diagram of the multi-unit system in the third working mode according to the embodiments of this application;

[0035] Figure 5 This is a schematic diagram of the multi-unit system in the fourth working mode according to the embodiments of this application;

[0036] Figure 6 This is a schematic diagram of the multi-unit system in the fifth working mode according to the embodiments of this application.

[0037] Explanation of key component symbols:

[0038] Multi-split system 100, compressor 10, exhaust port 11, air inlet 12, four-way valve 20, first valve port 21, second valve port 22, third valve port 23, fourth valve port 24, mode converter 30, liquid pipe section 31, indoor heat exchanger 40, outdoor heat exchanger 50, first control valve 101, second control valve 102, first pipeline 61, second pipeline 62, third pipeline 63, fourth pipeline 64, fifth pipeline 65, branch pipe 66, gas-liquid separator 70, electronic expansion valve 80, subcooler 90. Detailed Implementation

[0039] The embodiments of this application are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements throughout.

[0040] Or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0041] In the description of the embodiments of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the stated features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0042] In the description of the embodiments of this application, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in the embodiments of this application according to the specific circumstances.

[0043] The following disclosure provides numerous different embodiments or examples for implementing various structures of the embodiments of this application. To simplify the disclosure of the embodiments of this application, specific examples of components and arrangements are described below. Of course, these are merely examples and are not intended to limit the scope of this application. Furthermore, reference numerals and / or reference letters may be repeated in different examples of the embodiments of this application; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, various specific examples of processes and materials are provided in the embodiments of this application, but those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0044] Please see Figure 1 The multi-split air conditioning system 100 of this application includes a compressor 10, a four-way valve 20, a mode converter 30, an indoor heat exchanger 40, an outdoor heat exchanger 50, a first control valve 101, and a second control valve 102.

[0045] The four-way valve 20 has a first valve port 21, a second valve port 22, a third valve port 23, and a fourth valve port 24. When the first valve port 21 is connected to the second valve port 22, the third valve port 23 is disconnected from the fourth valve port 24. When the first valve port 21 is disconnected from the second valve port 22, the third valve port 23 is connected to the fourth valve port 24. The first valve port 21 of the four-way valve 20 is connected to the discharge port 11 of the compressor 10 through the first pipeline 61.

[0046] The mode converter 30 is connected to the flow path of the second valve port 22 of the four-way valve 20 through the second pipe 62, and is connected to the third valve port 23 of the four-way valve 20 through the third pipe 63.

[0047] The indoor heat exchanger 40 is connected to the mode converter 30. One end of the outdoor heat exchanger 50 is connected to the mode converter 30 through the fourth pipe 64, and the other end of the outdoor heat exchanger 50 is connected to the fourth valve port 24 of the four-way valve 20.

[0048] The first control valve 101 is installed on the second pipeline 62. A branch pipe 66 is connected between the second pipeline 62 and the exhaust port 11 of the compressor 10. A fifth pipeline 65 is connected between the second pipeline 62 and the third pipeline 63. The second control valve 102 is installed on the fifth pipeline 65.

[0049] In the multi-split air conditioning system 100 of this application embodiment, the system can switch between multiple functions and modes by adjusting the four-way valve 20, the first control valve 101, and the second control valve 102. In addition, the first control valve 101 can control the flow rate of refrigerant in the second pipeline 62, effectively controlling the cooling and heating effects of the multi-split air conditioning system 100 and improving reliability. The second control valve 102 can open the fifth pipeline 65 in full cooling mode, thereby connecting the second pipeline 62 and the third pipeline 63. Refrigerant is discharged through the two low-pressure sides of the second pipeline 62 and the third pipeline 63, improving unit performance and avoiding large amounts of refrigerant accumulation.

[0050] Specifically, in the multi-split air conditioning system 100 of this application embodiment, there is one four-way valve 20, at least one outdoor heat exchanger 50, and multiple indoor heat exchangers 40. The compressor 10 is used to compress and drive the refrigerant. The compressor 10 can compress the low-temperature, low-pressure gaseous refrigerant into a high-temperature, high-pressure gaseous refrigerant and pump the refrigerant into the connecting pipeline.

[0051] The four-way valve 20 is used to change the flow direction of the refrigerant. In the four-way valve 20, there is a pressure difference between the section on one side of the first valve port 21 and the section on one side of the fourth valve port 24. When the first valve port 21 and the second valve port 22 are connected and the first control valve 101 is open, the four-way valve 20 connects the discharge port 11 of the compressor 10 and the second pipeline 62. When the first valve port 21 and the fourth valve port 24 are connected, the four-way valve 20 connects the discharge port 11 of the compressor 10 and one end of the outdoor heat exchanger 50, allowing the outdoor heat exchanger 50 to deliver refrigerant to the fourth pipeline 64. When the third valve port 23 and the fourth valve port 24 are connected, the four-way valve 20 connects one end of the outdoor heat exchanger 50 and the flow path of the compressor 10's inlet port 12, allowing the refrigerant to return to the outdoor heat exchanger 50 via the fourth pipeline 64, after which the four-way valve 20 can divert the refrigerant to the compressor 10.

[0052] The second pipe 62 and the third pipe 63 are used to transport refrigerant. The second pipe 62 is mainly used to transport the high-temperature, high-pressure refrigerant discharged from the compressor 10, while the third pipe 63 is mainly used to transport the low-temperature, low-pressure refrigerant returning to the compressor 10. The fourth pipe 64 is used to transport refrigerant. The branch pipe 66 can be a capillary tube. When the first control valve 101 is open, the branch pipe 66 can directly transport the high-temperature, high-pressure refrigerant discharged from the compressor 10 to the second pipe 62.

[0053] Indoor heat exchanger 40 and outdoor heat exchanger 50 exchange heat with their surroundings by utilizing the heat absorption or release properties of the refrigerant during evaporation (vaporization) or condensation (liquefaction). Indoor heat exchanger 40 absorbs heat during refrigerant evaporation, thus lowering the ambient temperature and operating in cooling mode. Indoor heat exchanger 40 condenses the refrigerant, releasing heat during condensation and raising the ambient temperature, thus operating in heating mode. The refrigerant flowing from the compressor 10's exhaust port 11 to the cooling-operating indoor heat exchanger 40 is the cooling-oriented refrigerant, and the refrigerant flowing from the compressor 10's exhaust port 11 to the heating-operating indoor heat exchanger 40 is the heating-oriented refrigerant.

[0054] The mode converter 30 includes a liquid line section 31, a solenoid valve, an expansion valve, a subcooler, etc. The mode converter 30 can be connected to the second pipe 62, the third pipe 63, and the fourth pipe 64 via different connecting pipes, with the liquid line section 31 connecting the fourth pipe 64 and the indoor heat exchanger 40. The mode converter 30 can split the cooling flow to the refrigerant and the heating flow to the refrigerant, controlling the mode switching of the multi-split system 100.

[0055] The first control valve 101 can be an electric ball valve, and the second control valve 102 can be a solenoid valve.

[0056] Please see Figure 2 ,exist Figure 2 In the diagram, thick solid arrows indicate the direction of refrigerant flow. In some embodiments, the multi-split system 100 has a first operating mode in which the first port 21 of the four-way valve 20 is connected to the fourth port 24, and the compressor 10 delivers refrigerant to the outdoor heat exchanger 50; the first control valve 101 is disconnected, the second control valve 102 is opened, and the mode converter 30 delivers refrigerant to the indoor heat exchangers 40 so that all indoor heat exchangers 40 are operating in cooling mode.

[0057] Thus, by connecting the first valve port 21 to the fourth valve port 24, disconnecting the first control valve 101, and opening the second control valve 102, the multi-split system 100 can be switched to the first operating mode, enabling the multi-split system 100 to cool the environment where the indoor heat exchanger 40 is located. Furthermore, opening the second control valve 102 connects to the fifth pipe 65, which in turn connects to the second pipe 62 and the third pipe 63. This allows the second pipe 62 to deliver refrigerant to the compressor 10 for recycling, preventing large amounts of refrigerant from accumulating.

[0058] Specifically, the first port 21 of the four-way valve 20 is connected to the fourth port 24, and the flow path of the compressor 10 discharge port 11, the first pipeline 61, the outdoor heat exchanger 50, and the fourth pipeline 64 are connected. The first control valve 101 is fully closed, and the first pipeline 61 is disconnected from the second pipeline 62. The high-temperature and high-pressure gaseous refrigerant discharged from the compressor 10 enters the outdoor heat exchanger 50 through the first pipeline 61 and the four-way valve 20, where it condenses into liquid refrigerant. The outdoor heat exchanger 50 delivers the liquid refrigerant to the fourth pipeline 64, which in turn delivers it to the mode converter 30. The mode converter 30 then delivers the liquid refrigerant to multiple indoor heat exchangers 40, all of which operate in cooling mode. The refrigerant flowing to the indoor heat exchangers 40 absorbs heat during evaporation. In the first operating mode, the multi-split system 100 cools the environment of all indoor heat exchangers 40.

[0059] The indoor heat exchanger 40 delivers the evaporated refrigerant to the mode converter 30. A portion of the refrigerant enters the second pipe 62, and the remaining portion enters the third pipe 63, ultimately returning to the compressor 10. In related technologies, the refrigerant entering the second pipe is difficult to return to the compressor, resulting in a large amount of refrigerant stagnation. In the multi-split system 100 of this application, the second control valve 102 is opened, connecting to the fifth pipe 65. This allows a portion of the refrigerant entering the second pipe 62 to be collected in the third pipe 63 via the fifth pipe 65. The third pipe 63 then delivers the refrigerant to the inlet 12 of the compressor 10. The compressor 10 draws in the refrigerant from the inlet 12, thus achieving refrigerant circulation within the multi-split system 100. The combined delivery of the returning refrigerant via the second pipe 62 and the third pipe 63 improves the operating performance of the multi-split system 100.

[0060] Please see Figure 3 ,exist Figure 3 In the diagram, thick solid arrows indicate the flow of refrigerant to cooling, while dashed arrows indicate the flow of refrigerant to heating. In some embodiments, the multi-split system 100 has a second operating mode. In this mode, the first port 21 of the four-way valve 20 is connected to the fourth port 24. The compressor 10 delivers a portion of the refrigerant to the outdoor heat exchanger 50 and another portion to the second pipeline 62. The first control valve 101 is opened, and the second control valve 102 is closed. The fourth pipeline 64 and the second pipeline 62 deliver refrigerant to the mode converter 30. The mode converter 30 then delivers refrigerant to multiple indoor heat exchangers 40, causing the indoor heat exchanger 40 connected to the fourth pipeline 64 to operate in cooling mode and the indoor heat exchanger 40 connected to the second pipeline 62 to operate in heating mode.

[0061] Thus, by controlling the connection between the first valve port 21 and the fourth valve port 24, opening the first control valve 101, and disconnecting the second control valve 102, the multi-split system 100 can be switched to the second working mode. In the second working mode, the multi-split system 100 can meet the simultaneous cooling and heating needs of multiple different indoor heat exchangers 40 in their respective environments.

[0062] Specifically, the first port 21 of the four-way valve 20 is connected to the fourth port 24, connecting the compressor 10 discharge port 11 flow path, the first pipeline 61, the outdoor heat exchanger 50, and the fourth pipeline 64. Simultaneously, the first control valve 101 opens, connecting the compressor 10 discharge port 11 flow path, the first pipeline 61, and the branch pipe 66 to the second pipeline 62. The second control valve 102 closes, disconnecting the fifth pipeline 65, and preventing connection between the second pipeline 62 and the third pipeline 63. The compressor 10 discharges high-temperature, high-pressure refrigerant. A portion of this refrigerant is diverted through the four-way valve 20 to the outdoor heat exchanger 50, where it condenses into liquid refrigerant and enters the fourth pipeline 64. The remaining portion of the high-temperature, high-pressure refrigerant is directly transported to the second pipeline 62 via the branch pipe 66.

[0063] The fourth pipe 64 delivers the condensed refrigerant to the mode converter 30, which then delivers the refrigerant to several of the multiple indoor heat exchangers 40. The indoor heat exchangers 40 connected to the fourth pipe 64 operate in cooling mode, absorbing heat during the refrigerant evaporation process to cool the surrounding environment. The total energy absorbed by the indoor heat exchangers operating in cooling mode from the surrounding environment constitutes the cooling capacity.

[0064] The second pipe 62 delivers high-temperature, high-pressure refrigerant to the mode converter 30. The mode converter 30 then delivers the refrigerant to at least one of the multiple indoor heat exchangers 40. The indoor heat exchanger 40 connected to the second pipe 62 operates in heating mode, and this portion of the refrigerant condenses in the indoor heat exchanger 40 operating in heating mode. The total energy released by the indoor heat exchanger operating in heating mode to the surrounding environment is the heating capacity.

[0065] Multiple indoor heat exchangers 40 can be installed in different rooms, so that the multi-split system 100 can simultaneously cool and heat different rooms in the second operating mode. In the second operating mode, the flow rate of refrigerant discharged from the compressor 10 into the fourth pipe 64 is greater than the flow rate into the second pipe 62, and the cooling capacity of the indoor heat exchanger 40 in cooling operation is greater than the heating capacity of the indoor heat exchanger 40 in heating operation.

[0066] The first control valve 101 is installed on the connecting pipe section of the second pipe 62 and the four-way valve 20 and the branch pipe 66. The first control valve 101 can adjust the opening size to control the flow rate of the heating refrigerant entering the second pipe 62, thereby controlling the ratio of the flow rate of the cooling refrigerant to the flow rate of the heating refrigerant in the second working mode, ensuring the effect of simultaneous cooling and heating operation of multiple indoor heat exchangers 40.

[0067] Please continue reading. Figure 3 In some embodiments, in the second operating mode, the indoor heat exchanger 40 operating in heating mode delivers the condensed refrigerant to the indoor heat exchanger 40 operating in cooling mode via the mode converter 30, and the indoor heat exchanger 40 operating in cooling mode delivers the evaporated refrigerant to the compressor 10 via the third pipeline 63.

[0068] Thus, in the second operating mode, the multi-split system 100 can transfer some of the heat exchange energy to other spaces within the system for utilization, thereby achieving reasonable energy transfer and recovery within the multi-split system 100, improving energy utilization efficiency, and saving energy.

[0069] Specifically, in the second operating mode, the indoor heat exchanger 40 operating in heating mode can use the mode converter 30 to transfer the condensed refrigerant to the indoor heat exchanger 40 operating in cooling mode. This portion of the condensed refrigerant evaporates again during the cooling operation of the indoor heat exchanger 40 and is recycled. The indoor heat exchanger 40 operating in cooling mode transfers the evaporated refrigerant to the third pipeline 63. The third pipeline 63 collects the returned low-temperature, low-pressure refrigerant and transfers it to the flow path of the compressor 10 inlet 12.

[0070] In some embodiments, in the second operating mode, the first control valve 101 controls at least one of the indoor heat exchangers 40 in heating operation to maintain heating operation, and at least one indoor heat exchanger 40 stops to perform oil return or defrosting operation.

[0071] In this way, the multi-split system 100 can achieve continuous heating while performing oil return or defrosting.

[0072] Specifically, the multi-split system 100 includes a control module (not shown), which accepts user commands and sets the priority of the indoor heat exchangers 40 according to the user's commands. When the outdoor heat exchanger 50 is frosted, the control module can control the multi-split system 100 to enter a second operating mode, and in conjunction with the first control valve 101 and the mode converter 30, maintain the high-priority indoor heat exchanger 40 in heating operation. The non-high-priority indoor heat exchangers 40 can be in a shutdown state or in cooling operation, so that the outdoor heat exchanger 50 can raise its temperature to perform oil return or defrosting while the indoor heat exchanger 40 continues to heat.

[0073] Please see Figure 4 ,exist Figure 4 In the diagram, dashed arrows indicate the flow direction of high-temperature, high-pressure refrigerant, while thick solid arrows indicate the flow direction of low-temperature, low-pressure refrigerant. In some embodiments, the multi-split system 100 has a third operating mode. In this third operating mode, the third port 23 of the four-way valve 20 is connected to the fourth port 24, the first control valve 101 is opened, the compressor 10 delivers refrigerant to the second pipeline 62, and the second control valve 102 is disconnected. The second pipeline 62 delivers refrigerant to the mode converter 30, which then delivers refrigerant to the indoor heat exchangers 40 so that all indoor heat exchangers 40 operate in heating mode.

[0074] Thus, by connecting the third valve port 23 and the fourth valve port 24, opening the first control valve 101, and disconnecting the second control valve 102, the multi-split system 100 can be controlled to switch to the third working mode, enabling the multi-split system 100 to heat the environment where the indoor heat exchanger 40 is located, thereby improving the reliability of the multi-split system 100 in controlling the switching of different working modes.

[0075] Specifically, the third valve port 23 of the four-way valve 20 is connected to the fourth valve port 24, the first valve port 21 is disconnected from the second valve port 22, the first control valve 101 is fully open, and the flow path of the discharge port 11 of the control compressor 10 is connected to the second pipeline 62 through the branch pipe 66. The second control valve 102 is disconnected, the fifth pipeline 65 is disconnected, and the second pipeline 62 and the third pipeline 63 are not connected. The compressor 10 discharges high-temperature and high-pressure refrigerant and pumps the refrigerant to the second pipeline 62. The second pipeline 62 delivers the high-temperature and high-pressure refrigerant to the mode converter 30, and the mode converter 30 delivers the refrigerant to the indoor heat exchangers 40. All indoor heat exchangers 40 operate in heating mode to condense the refrigerant. In the third operating mode, the multi-split system 100 heats the environment of all indoor heat exchangers 40.

[0076] The condensed refrigerant is delivered to the fourth pipe 64 via the mode converter 30. The fourth pipe 64 then delivers the refrigerant to the outdoor heat exchanger 50, where it evaporates during heating operation. The third port 23 and the fourth port 24 of the four-way valve 20 are connected, linking the outdoor heat exchanger 50 and the compressor inlet 12, thus allowing the evaporated refrigerant to flow back to the compressor 10 via the four-way valve 20.

[0077] A gas-liquid separator 70 can be installed in the flow path of the compressor 10 inlet 12. The gas-liquid separator 70 separates the refrigerant into gas and liquid, thereby ensuring that the compressor 10 does not draw in too much liquid refrigerant.

[0078] Please see Figure 5 ,exist Figure 5 In the diagram, dashed arrows indicate the refrigerant flow direction for heating, while thick solid arrows indicate the refrigerant flow direction for cooling. In some embodiments, the multi-split system 100 has a fourth operating mode. In this fourth operating mode, the third port 23 of the four-way valve 20 is connected to the fourth port 24, the first control valve 101 is opened, the compressor 10 delivers refrigerant to the second pipeline 62, and the second control valve 102 is disconnected. The second pipeline 62 delivers refrigerant to the mode converter 30, which then delivers refrigerant to the indoor heat exchanger 40 to enable the indoor heat exchanger 40 connected to the second pipeline 62 to operate in heating mode. The indoor heat exchanger 40 operating in heating mode then delivers refrigerant through the mode converter 30 to the indoor heat exchanger 40 connected to the fourth pipeline 64 to enable the indoor heat exchanger 40 connected to the fourth pipeline 64 to operate in cooling mode.

[0079] Thus, by connecting the third valve port 23 and the fourth valve port 24 of the four-way valve 20, opening the first control valve 101, and disconnecting the second control valve 102, the multi-split system 100 can be controlled to switch to the fourth working mode. In the fourth working mode, the multi-split system 100 can meet the simultaneous cooling and heating needs of multiple different indoor heat exchangers 40 in their respective environments.

[0080] Specifically, the third valve port 23 of the four-way valve 20 is connected to the fourth valve port 24, the first valve port 21 is disconnected from the second valve port 22, the first control valve 101 is fully open, and the discharge port 11 of the compressor 10 is connected to the second pipeline 62 through the branch pipe 66. It should be noted that when the first control valve 101 is fully open, the refrigerant can flow directly through the first control valve 101 into the second pipeline 62. When the second control valve 102 is disconnected, the fifth pipeline 65 is disconnected, and the second pipeline 62 is not connected to the third pipeline 63. The compressor 10 discharges high-temperature, high-pressure refrigerant and pumps it to the second pipeline 62. The second pipeline 62 delivers the high-temperature, high-pressure refrigerant to the mode converter 30. The mode converter 30 controls the second pipeline 62 to connect with several of the multiple indoor heat exchangers 40, delivering the high-temperature, high-pressure refrigerant to the indoor heat exchangers 40 connected to the second pipeline 62. The indoor heat exchanger 40, which is supplied with high-temperature and high-pressure refrigerant, operates in heating mode to condense the refrigerant.

[0081] The indoor heat exchanger 40, operating in heating mode, delivers the condensed refrigerant to the liquid line section 31 in the mode converter 30. The mode converter 30 delivers a portion of the condensed refrigerant to the fourth line 64, which in turn delivers the refrigerant to the outdoor heat exchanger 50. The outdoor heat exchanger 50 evaporates the returning refrigerant. The third port 23 of the four-way valve 20 is connected to the fourth port 24, and the outdoor heat exchanger 50 is connected to the air inlet 12 of the compressor 10, thus diverting the returning refrigerant to the compressor 10 via the four-way valve 20.

[0082] The mode converter 30 delivers another portion of the condensed refrigerant to at least one of the multiple outdoor heat exchangers 50. The outdoor heat exchanger 50 receiving the condensed refrigerant operates in cooling mode, causing the refrigerant to evaporate. The indoor heat exchanger 40, operating in cooling mode, delivers the evaporated refrigerant to the mode converter 30. The mode converter 30 delivers this portion of the evaporated refrigerant to a third line 63, through which it returns to the compressor 10.

[0083] Multiple indoor heat exchangers 40 can be installed in different rooms, allowing the multi-split system 100 to provide cooling and heating for different rooms in the fourth operating mode. In the fourth operating mode, the multi-split system 100 can transfer the energy exchanged in the space where the outdoor heat exchanger 50 is located during heating operation to the space where the outdoor heat exchanger 50 is located during cooling operation for reuse. This achieves rational energy transfer and recovery within the multi-split system 100, improving energy utilization and saving energy.

[0084] Please see Figure 6 With the cooling capacity accounting for approximately 45% to 55% of all indoor heat exchangers 40, the heat exchange energy of the outdoor heat exchanger 50 operating in heating mode can be largely converted to the outdoor heat exchanger 50 operating in cooling mode for reuse, resulting in high heat exchange efficiency and the multi-split system being in a state of complete heat recovery.

[0085] In some embodiments, the first control valve 101 is a flow regulating valve.

[0086] Thus, in the second working mode, adjusting the first control valve 101 can control the refrigerant flow in the second passage, thereby controlling the ratio of refrigerant flowing to the heating direction and refrigerant flowing to the cooling direction. In this way, when the multi-split system 100 is simultaneously cooling and heating, adjusting the first control valve 101 can control the ratio of the heating capacity to the cooling capacity of the multi-split system 100, maintaining good cooling and heating effects.

[0087] Specifically, the first control valve 101 is a flow regulating valve, such as an electric ball valve or an electronic expansion valve. When the first control valve 101 is open, its opening degree is adjustable; for example, it can be adjusted to 20%, 30%, 50%, 75%, or 100%, with a fully open state of 100%. A larger opening degree of the first control valve 101 allows for a wider flow path for the refrigerant, thus controlling the refrigerant flow rate in the second pipe 62 by adjusting the opening degree of the first control valve 101.

[0088] The first control valve 101 can adjust its opening degree according to the operating conditions of the multi-split system 100. These operating conditions can be expressed as the ratio of cooling to heating capacity in all indoor heat exchangers 40, or the turns ratio of indoor heat exchangers 40 operating in heating mode to those operating in cooling mode. In the second operating mode, adjusting the refrigerant flow rate in the second pipeline 62 according to the actual operating conditions of the multi-split system 100 can improve the operational reliability of the multi-split system 100 and the simultaneous cooling and heating effect. For example, when the turns ratio of indoor heat exchangers 40 operating in heating mode to those operating in cooling mode increases, the opening degree of the first control valve 101 increases, controlling the refrigerant flow rate in the second pipeline 62 to increase, thereby increasing the refrigerant flow rate in the heating direction to match the heating and cooling needs of the indoor heat exchangers 40.

[0089] In some embodiments, the multi-split system 100 includes an electronic expansion valve 80 and a subcooler 90, which are disposed on a fourth line 64.

[0090] Thus, the electronic expansion valve 80 can regulate the flow rate of the refrigerant and reduce the pressure of the refrigerant, while the subcooler 90 can control the subcooling in the fourth pipe 64 and maintain the operating performance of the multi-split system 100.

[0091] Specifically, the electronic expansion valve 80 can be installed at the end of the outdoor heat exchanger 50 that is not connected to the four-way valve 20. It calculates and controls the pressure by detecting the refrigerant pressure difference between the inlet and outlet of the outdoor heat exchanger 50, thereby regulating the refrigerant flow rate in the fourth pipe 64. One end of the subcooler 90 can be connected to the electronic expansion valve 80. The subcooler 90 can further cool the condensed refrigerant, lowering the temperature of the refrigerant entering the electronic expansion valve 80, preventing premature evaporation of the refrigerant, appropriately increasing the subcooling degree of the refrigerant, and ensuring that the refrigerant returning to the outdoor heat exchanger 50 is in a liquid state.

[0092] In some embodiments, the multi-split system 100 includes a gas-liquid separator 70, with a first end connected to the air inlet 12 of the compressor 10 and a second end connected to a third pipeline 63 and a third valve port 23.

[0093] In this way, the gas-liquid separator 70 can separate the refrigerant gas and liquid, ensuring that the compressor 10 can operate normally by drawing in gaseous refrigerant.

[0094] Specifically, in the first, second, and fourth operating modes, the third pipe 63 transports the refrigerant after heat exchange in the indoor heat exchanger 40 back to the outdoor unit of the multi-split system 100. A gas-liquid separator 70 is located between the third pipe 63 and the air inlet 12 of the compressor 10, separating gaseous refrigerant and transporting it to the compressor 10. In the third and fourth operating modes, the refrigerant returning through the fourth pipe 64 evaporates in the outdoor heat exchanger 50, is diverted by the four-way valve 20 into the gas-liquid separator 70, and then returns to the compressor 10 via the gas-liquid separator 70.

[0095] In summary, in the multi-split air conditioning system 100 of this application embodiment, multiple operating modes can be achieved by controlling the connection states of the four-way valve 20, the first control valve 101, and the second control valve 102, as well as the mode converter 30. Simultaneous cooling and heating can be met in both the first and second operating modes. Compared with related technologies, the control process for switching between multiple operating modes is less complex and more reliable. The multi-split air conditioning system 100 exhibits high stability and good cooling / heating performance in multiple modes.

[0096] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with the embodiment or example is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0097] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A multi-split air conditioning system (100), characterized in that, include: Compressor (10); A four-way valve (20) has a first valve port (21), a second valve port (22), a third valve port (23), and a fourth valve port (24). When the first valve port (21) is connected to the second valve port (22), the third valve port (23) is disconnected from the fourth valve port (24). When the first valve port (21) is disconnected from the second valve port (22), the third valve port (23) is connected to the fourth valve port (24). The first valve port (21) of the four-way valve (20) is connected to the discharge port (11) of the compressor (10) through a first pipeline (61). A mode converter (30) is connected to the flow path of the second valve port (22) of the four-way valve (20) via a second pipe (62) and to the third valve port (23) of the four-way valve (20) via a third pipe (63); An indoor heat exchanger (40) is connected to the mode converter (30); An outdoor heat exchanger (50) is provided, one end of which is connected to a mode converter (30) via a fourth pipe (64), and the other end of which is connected to the fourth valve port (24) of the four-way valve (20). A first control valve (101) is provided on the second pipeline (62), a branch pipe (66) is connected between the second pipeline (62) and the exhaust port (11) of the compressor (10), a fifth pipeline (65) is connected between the second pipeline (62) and the third pipeline (63), and a second control valve (102) is provided on the fifth pipeline (65); The multi-split air conditioning system (100) has a first operating mode. In the first operating mode, the first valve port (21) of the four-way valve (20) is connected to the fourth valve port (24), and the compressor (10) delivers refrigerant to the outdoor heat exchanger (50). The first control valve (101) is disconnected, the second control valve (102) is opened, and the mode converter (30) delivers refrigerant to the indoor heat exchanger (40) so that all the indoor heat exchangers (40) are in cooling operation. The multi-split air conditioning system (100) also includes a gas-liquid separator (70), the first end of which is connected to the air inlet (12) of the compressor (10), and the second end of which is connected to the third pipeline (63) and the third valve port (23).

2. The multi-unit air conditioning system (100) according to claim 1, characterized in that, The multi-split system (100) has a second operating mode. In the second operating mode, the first valve port (21) of the four-way valve (20) is connected to the fourth valve port (24). The compressor (10) delivers part of the refrigerant to the outdoor heat exchanger (50) and part of the refrigerant to the second pipeline (62). The first control valve (101) is opened and the second control valve (102) is disconnected. The fourth pipeline (64) and the second pipeline (62) deliver the refrigerant to the mode converter (30). The mode converter (30) delivers the refrigerant to multiple indoor heat exchangers (40) so that the indoor heat exchanger (40) connected to the fourth pipeline (64) operates in cooling mode and the indoor heat exchanger (40) connected to the second pipeline (62) operates in heating mode.

3. The multi-unit air conditioning system (100) according to claim 2, characterized in that, In the second operating mode, the indoor heat exchanger (40) operating in heating mode delivers the condensed refrigerant to the indoor heat exchanger (40) operating in cooling mode through the mode converter (30), and the indoor heat exchanger (40) operating in cooling mode delivers the evaporated refrigerant to the compressor (10) through the third pipeline (63).

4. The multi-unit air conditioning system (100) according to claim 2, characterized in that, In the second working mode, the first control valve (101) controls at least one of the indoor heat exchangers (40) in heating operation to maintain heating operation, and at least one of the indoor heat exchangers (40) stops to perform oil return or defrosting operation.

5. The multi-unit air conditioning system (100) according to claim 1, characterized in that, The multi-split system (100) has a third operating mode in which the third valve port (23) of the four-way valve (20) is connected to the fourth valve port (24), and the compressor (10) delivers refrigerant to the second pipeline (62); the first control valve (101) is opened, and the second control valve (102) is disconnected (the fifth pipeline is disconnected); the second pipeline (62) delivers refrigerant to the mode converter (30), and the mode converter (30) delivers refrigerant to the indoor heat exchangers (40) so that all the indoor heat exchangers (40) are in heating operation.

6. The multi-unit air conditioning system (100) according to claim 1, characterized in that, The multi-split air conditioning system (100) has a fourth operating mode. In the fourth operating mode, the third valve port (23) of the four-way valve (20) is connected to the fourth valve port (24), the first control valve (101) is opened, the compressor (10) delivers refrigerant to the second pipeline (62), and the second control valve (102) is disconnected. The second pipeline (62) delivers refrigerant to the mode converter (30), and the mode converter (30) delivers refrigerant to the indoor heat exchanger (40) so that the indoor heat exchanger (40) connected to the second pipeline (62) operates in heating mode. The indoor heat exchanger (40) operating in heating mode delivers refrigerant to the indoor heat exchanger (40) connected to the fourth pipeline (64) so ​​that the indoor heat exchanger (40) connected to the fourth pipeline (64) operates in cooling mode.

7. The multi-unit air conditioning system (100) according to claim 2, characterized in that, The first control valve (101) is a flow regulating valve.

8. The multi-unit air conditioning system (100) according to claim 1, characterized in that, The multi-split system (100) includes an electronic expansion valve (80) and a subcooler (90), which are disposed on the fourth pipeline (64).

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