Multi-connected heat pump system

Abstract

The invention discloses a multi-connected heat pump system. The multi-connected heat pump system comprises a main machine heat exchange device and a tail end heat exchange device and communicates with the main machine heat exchange device. The tail end heat exchange equipment comprises at least two tail end heat exchange assemblies, at least two gas side refrigerant pressure adjusting assemblies and at least two liquid side refrigerant pressure adjusting assemblies. The at least two gas side refrigerant pressure adjusting assemblies and the at least two tail end heat exchange assemblies are arranged in a one-to-one correspondence mode. The at least two liquid side refrigerant pressure adjusting assemblies and the at least two tail end heat exchange assemblies are arranged in a one-to-one correspondence mode, and one of the liquid side refrigerant pressure adjusting assemblies and the air side refrigerant pressure adjusting assemblies is configured to adjust the excess redundancy of refrigerants flowing out of the corresponding tail end heat exchange assemblies. And the other one is configured to adjust the temperature of the refrigerant flowing into the corresponding tail end heat exchange assembly to the target temperature. The multi-connected heat pump system provided by the invention is relatively good in comfort.

Description

Technical Field

[0001] This application relates to the technical field of heat exchange, and more particularly to a multi-unit heat pump system. Background Technology

[0002] The Tianfu-based multi-split heat pump system is a multi-supply system integrating air conditioning, underfloor heating, and domestic hot water production. It is widely used in residential and commercial buildings where year-round heating, cooling, and hot water supply are required. The multi-split heat pump system provides cooling to different rooms through multiple indoor units, meeting users' personalized indoor temperature needs. It also heats rooms through underfloor heating coils while simultaneously producing domestic hot water.

[0003] However, multi-split heat pump systems offer relatively poor comfort. Summary of the Invention

[0004] This application provides a multi-split heat pump system with good comfort.

[0005] This application provides a multi-split heat pump system, including:

[0006] Main heat exchange equipment;

[0007] Terminal heat exchange equipment, connected to the main heat exchange equipment, includes:

[0008] At least two end heat exchange components;

[0009] At least two gas-side refrigerant pressure regulating components are set up one-to-one with at least two terminal heat exchange components;

[0010] At least two liquid-side refrigerant pressure regulating components are configured to correspond one-to-one with at least two terminal heat exchange components. One of the liquid-side refrigerant pressure regulating components and the gas-side refrigerant pressure regulating components is configured to regulate the superheat or subcooling of the refrigerant flowing out of the corresponding terminal heat exchange component, and the other is configured to regulate the temperature of the refrigerant flowing into the corresponding terminal heat exchange component to the target temperature.

[0011] It is understood that a multi-split heat pump system includes a main heat exchange unit and terminal heat exchange units, which are connected to the main heat exchange unit. The terminal heat exchange units include at least two terminal heat exchange components, at least two gas-side refrigerant pressure regulating components, and at least two liquid-side refrigerant pressure regulating components. The at least two gas-side refrigerant pressure regulating components are configured to correspond one-to-one with the at least two terminal heat exchange components; the at least two liquid-side refrigerant pressure regulating components are also configured to correspond one-to-one with the at least two terminal heat exchange components. One of the liquid-side and gas-side refrigerant pressure regulating components is configured to regulate the superheat or subcooling of the refrigerant flowing out of the corresponding terminal heat exchange component, while the other is configured to regulate the temperature of the refrigerant flowing into the corresponding terminal heat exchange component to the target temperature. This allows for different evaporation temperatures, enabling different outlet air temperatures under cooling conditions to suit different user load requirements. It also allows for different condensation temperatures; during multi-split operation, higher water temperatures can be produced when heating at lower indoor temperatures, thus improving comfort.

[0012] In some embodiments, a controller is also included, and both the liquid-side refrigerant pressure regulating component and the liquid-side refrigerant pressure regulating component are electrically connected to the controller;

[0013] The controller is configured as follows:

[0014] The difference between the set temperature and the actual temperature of the terminal heat exchange component is obtained, and the corresponding target temperature is obtained based on the difference;

[0015] The operating frequency of the compressor in the main heat exchange equipment is controlled based on a standard temperature; where the standard temperature is one of the target temperatures.

[0016] Based on the corresponding target temperature and standard temperature, control the opening of one of the gas-side refrigerant pressure regulating components and the liquid-side refrigerant pressure regulating components to match the different target temperature requirements of different terminal heat exchange components.

[0017] Control the opening degree of the other of the gas-side refrigerant pressure regulating component and the liquid-side refrigerant pressure regulating component so that the superheat or subcooling of the refrigerant flowing out of the corresponding terminal heat exchange component reaches the preset value.

[0018] In this way, by coordinating the gas-side and liquid-side refrigerant pressure regulating components, different evaporation temperatures can be achieved, resulting in different outlet air temperatures under cooling conditions to suit different user load requirements. Different condensation temperatures can also be achieved, allowing for the production of higher water temperatures while maintaining lower indoor heating temperatures during multi-generational power supply operation. Furthermore, it can meet the requirements for superheating or subcooling.

[0019] In some embodiments, it also includes:

[0020] At least two liquid-side temperature detectors are provided, and at least two liquid-side temperature detectors are set one-to-one with at least two terminal heat exchange components. The liquid-side temperature detectors are located on the side of the liquid-side refrigerant pressure regulating component facing the corresponding terminal heat exchange component. The liquid-side temperature detectors are electrically connected to the controller and are configured to detect the temperature of the refrigerant on the liquid side of the corresponding terminal heat exchange component.

[0021] At least two gas-side temperature detectors are provided, and at least two gas-side temperature detectors are set one-to-one with at least two terminal heat exchange components. The gas-side temperature detectors are located on the side of the gas-side refrigerant pressure regulating component facing the corresponding terminal heat exchange component. The gas-side temperature detectors are electrically connected to the controller and are configured to detect the temperature of the refrigerant on the gas side of the corresponding terminal heat exchange component.

[0022] This allows for real-time monitoring of the refrigerant temperature.

[0023] In some embodiments, the controller is configured to:

[0024] When the terminal heat exchanger is in its first operating state, the target temperature is the target evaporation temperature, and the standard temperature is the standard evaporation temperature.

[0025] The standard evaporation temperature is the minimum of the target evaporation temperatures.

[0026] In this way, the standard evaporation temperature is the minimum value among the target evaporation temperatures, which helps to ensure that the cooling of the entire area meets the standard, reduce ineffective energy consumption, and stabilize the system operation.

[0027] In some embodiments, the controller is configured to:

[0028] When the target evaporation temperature equals the standard evaporation temperature, the opening degree of one of the corresponding liquid-side refrigerant pressure regulating components and gas-side refrigerant pressure regulating components is controlled to 100%; the opening degree of the other of the liquid-side refrigerant pressure regulating components and gas-side refrigerant pressure regulating components is controlled so that the difference between the temperature of the refrigerant on the gas side of the terminal heat exchange component and the temperature of the refrigerant on the liquid side of the terminal heat exchange component reaches the preset value.

[0029] When the target evaporation temperature is higher than the standard evaporation temperature, the opening of the corresponding liquid-side refrigerant pressure regulating component is controlled until the evaporation temperature of the terminal heat exchange component reaches the target evaporation temperature; wherein, the evaporation temperature of the terminal heat exchange component is the temperature of the refrigerant on the liquid side of the terminal heat exchange component; the opening of the gas-side refrigerant pressure regulating component is controlled so that the difference between the temperature of the refrigerant on the gas side of the terminal heat exchange component and the temperature of the refrigerant on the liquid side of the terminal heat exchange component reaches a preset value.

[0030] This allows for the adjustment of both the liquid-side refrigerant pressure regulating component and the gas-side refrigerant pressure regulating component.

[0031] In some embodiments, it also includes:

[0032] The exhaust temperature detector is electrically connected to the controller and is configured to detect the exhaust temperature of the compressor in the main heat exchange equipment.

[0033] This allows for real-time monitoring of the compressor's exhaust temperature.

[0034] In some embodiments, the controller is configured to:

[0035] When the terminal heat exchanger is in the second operating state, the target temperature is the target condensing temperature, and the standard temperature is the standard condensing temperature.

[0036] The standard condensing temperature is the maximum value among the target condensing temperatures.

[0037] In this way, the standard condensing temperature is the maximum value among the target condensing temperatures, which helps to ensure that high-demand terminal heating meets the standards, improves the energy efficiency of the heating system, and stabilizes the heating operation.

[0038] In some embodiments, when the target condensing temperature is equal to the standard condensing temperature, the opening degree of the corresponding gas-side refrigerant pressure regulating component is controlled to 100%; the opening degree of the liquid-side refrigerant pressure regulating component is controlled so that the difference between the target condensing temperature and the temperature of the refrigerant on the liquid side of the corresponding terminal heat exchange component reaches a preset value.

[0039] When the target condensing temperature is lower than the standard condensing temperature, the opening of the corresponding gas-side refrigerant pressure regulating component is controlled until the temperature of the refrigerant on the gas side of the terminal heat exchange component reaches the difference between the exhaust temperature and the standard condensing temperature and the target condensing temperature; the opening of the liquid-side refrigerant pressure regulating component is controlled so that the difference between the target condensing temperature and the temperature of the refrigerant on the liquid side of the corresponding terminal heat exchange component reaches the preset value.

[0040] This allows for the adjustment of both the liquid-side refrigerant pressure regulating component and the gas-side refrigerant pressure regulating component.

[0041] In some embodiments, the controller is configured to:

[0042] Determine the operating status of the terminal heat exchange equipment;

[0043] When the terminal heat exchange components are not in operation, the corresponding gas-side refrigerant pressure regulating components and liquid-side refrigerant pressure regulating components are in the off state.

[0044] This effectively prevents refrigerant bypass, allowing refrigerant flow to bypass the terminal heat exchange components that are not in operation, thus reducing energy loss.

[0045] In some embodiments, a first pressure detector is also included, which is electrically connected to the controller and configured to detect the inlet pressure of the four-way valve in the host heat exchanger.

[0046] When the terminal heat exchange equipment is in the second operating state, some terminal heat exchange components are in operation, and some terminal heat exchange components are in non-operation state; the controller is configured as follows:

[0047] Based on the subcooling and inlet pressure of the terminal heat exchange components in operation, the system controls the storage and release of refrigerant in the non-operational terminal heat exchange components.

[0048] This allows for adjustment of the refrigerant volume, improving system efficiency. Attached Figure Description

[0049] Figure 1 This is a schematic diagram of the structure of a multi-unit heat pump system provided in an embodiment of this application;

[0050] Figure 2 A schematic diagram of refrigerant flow during indoor heating, underfloor heating, and hot water preparation in a multi-split heat pump system provided in this application embodiment;

[0051] Figure 3 A schematic diagram of refrigerant flow during indoor cooling in a multi-split heat pump system provided in this application embodiment;

[0052] Figure 4 A schematic diagram of the structure of the gas-side refrigerant pressure regulating component in the multi-unit heat pump system provided in this application embodiment;

[0053] Figure 5 This is a schematic diagram of the structure of the liquid-side refrigerant pressure regulating component in a multi-unit heat pump system provided in an embodiment of this application;

[0054] Figure 6 A control principle diagram of a multi-unit heat pump system provided in the embodiments of this application;

[0055] Figure 7 A schematic flowchart illustrating the control method for a multi-unit heat pump system provided in an embodiment of this application;

[0056] Figure 8 A schematic diagram of the process for controlling different evaporation temperatures in a multi-unit heat pump system provided in the embodiments of this application;

[0057] Figure 9 A schematic diagram of the process for controlling different condensing temperatures in a multi-unit heat pump system provided in the embodiments of this application;

[0058] Figure 10 This is another schematic flowchart illustrating the control method for a multi-unit heat pump system provided in an embodiment of this application.

[0059] Explanation of reference numerals in the attached figures:

[0060] 100 - Main heat exchange equipment; 110 - Compressor; 120 - Four-way valve; 130 - Outdoor heat exchanger; 140 - First pressure detector; 150 - Second pressure detector; 160 - Exhaust temperature detector;

[0061] 200 - Terminal heat exchange equipment; 210 - Indoor unit; 220 - Underfloor heating module; 230 - Water tank module; 240 - Terminal heat exchange component; 250 - Gas-side refrigerant pressure regulating component; 251 - Gas-side electronic expansion valve; 252 - Gas-side filter; 260 - Liquid-side refrigerant pressure regulating component; 261 - Liquid-side electronic expansion valve; 262 - Liquid-side filter;

[0062] 300-Controller;

[0063] 400-Liquid-side temperature detector;

[0064] 500-Air-side temperature detector. Detailed Implementation

[0065] To make the objectives and implementation methods of this application clearer, the exemplary implementation methods of this application will be clearly and completely described below with reference to the accompanying drawings of the exemplary embodiments of this application. Obviously, the exemplary embodiments described are only some embodiments of this application, and not all embodiments.

[0066] It should be noted that the brief descriptions of terms in this application are only for the convenience of understanding the embodiments described below, and are not intended to limit the embodiments of this application. Unless otherwise stated, these terms should be understood in their ordinary and common meaning.

[0067] The terms "first," "second," "third," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish similar or related objects or entities, and do not necessarily imply a specific order or sequence, unless otherwise specified. It should be understood that such terms are interchangeable where appropriate.

[0068] The terms “comprising” and “having”, and any variations thereof, are intended to cover but not exclude inclusion, for example, a product or device that includes a range of components is not necessarily limited to all of the components that are clearly listed, but may include other components that are not clearly listed or that are inherent to such product or device.

[0069] Among related technologies, the Tianfu-based underfloor heating and Tianfu-based hot water multi-split heat pump system can provide rapid cooling in summer and heating in winter using underfloor heating coils, meeting the human body's comfort needs of "warm feet and a cool head," and can also provide hot water. Its market prospects are broad, especially in areas along the Yangtze River where there is no centralized heating.

[0070] However, during the summer cooling season, different rooms have different load requirements. Multi-split heat pump systems only provide the same evaporation temperature, resulting in low air outlet temperatures in rooms with low load requirements and poor comfort.

[0071] In winter heating mode, a single condensing temperature is provided. In multi-split operation (where air conditioning and underfloor heating or air conditioning and hot water are running simultaneously), the multi-split heat pump system only provides one condensing temperature, which cannot meet diverse needs. For example, when the room temperature is low, the high pressure on the hot water side is limited, preventing the hot water temperature from rising.

[0072] When only the underfloor heating or hot water is running, the indoor unit's electronic expansion valve is at a slight opening, which will bypass a certain flow of refrigerant, resulting in heat dissipation and reduced energy efficiency of the multi-split heat pump system.

[0073] This invention proposes a multi-split heat pump system that achieves different evaporation and condensation temperatures, thereby improving room comfort. Furthermore, when only underfloor heating or hot water is running, the indoor unit can store or release refrigerant, thus regulating the amount of refrigerant used and achieving high efficiency and energy saving in the multi-split heat pump system.

[0074] Figure 1 This is a schematic diagram of the structure of a multi-unit heat pump system provided in an embodiment of this application. Figure 2 This is a schematic diagram of the refrigerant flow during indoor heating, underfloor heating, and hot water preparation in a multi-split heat pump system provided in this application embodiment. Figure 3 This is a schematic diagram of the refrigerant flow during indoor cooling in a multi-split heat pump system provided in an embodiment of this application.

[0075] See Figures 1 to 3 As shown, this application provides a multi-split heat pump system, including a main heat exchanger 100. The main heat exchanger 100 can be an outdoor unit.

[0076] The main heat exchanger 100 includes a compressor 110. The compressor 110 is used to draw refrigerant from the low-pressure side, compress it to increase its temperature and pressure, and then push it to the high-pressure side, thus forming a continuous cycle. The compressor 110 plays an important role in this process, acting as a suction, compression, and circulation pump.

[0077] In some embodiments, the main heat exchanger 100 includes a four-way valve 120. The four-way valve 120 is used to change the flow path of the refrigerant.

[0078] Specifically, the four-way valve 120 includes a first port, a second port, a third port, and a fourth port. In some states, the first port and the second port are connected, and the third port and the fourth port are connected. In other states, the first port and the fourth port are connected, and the second port and the third port are connected.

[0079] It should be noted that the first, second, third, and fourth ports can be arranged counterclockwise in the diagram. Specifically, the first port of the four-way valve 120 is connected to the discharge end of the compressor 110. The third port of the four-way valve 120 is connected to the suction end of the compressor 110.

[0080] In some embodiments, the main heat exchange device 100 includes an outdoor heat exchanger 130, which may be located outdoors and is used for heat exchange with the outdoor environment. The outdoor heat exchanger 130 is connected to the fourth port of the four-way valve 120.

[0081] In some embodiments, the host heat exchanger 100 includes a first pressure detector 140, which is used to detect the inlet pressure of the four-way valve 120. The first pressure detector 140 can be a pressure sensor.

[0082] In some embodiments, the host heat exchanger 100 includes a second pressure detector 150 for detecting the suction pressure of the compressor 110. The second pressure detector 150 may be a pressure sensor.

[0083] In some embodiments, the host heat exchanger 100 includes an exhaust temperature detector 160, which is configured to detect the exhaust temperature of the compressor 110. The exhaust temperature detector 160 may be a temperature sensor.

[0084] See Figures 1 to 3 As shown, the multi-split heat pump system includes a terminal heat exchange device 200, which is connected to the main heat exchange device 100.

[0085] In some embodiments, the terminal heat exchange device 200 includes an indoor unit 210. The indoor unit 210 is connected to the second port of the four-way valve 120 and the outdoor heat exchanger 130, respectively.

[0086] The number of indoor units 210 is at least one. For example, the number of indoor units 210 can be three. All three indoor units 210 are connected to the second port of the four-way valve 120. Furthermore, all three indoor units 210 are connected to the outdoor heat exchanger 130.

[0087] In some embodiments, the terminal heat exchange device 200 includes a floor heating module 220. The floor heating module 220 is connected to the exhaust end of the compressor 110 and the outdoor heat exchanger 130, respectively.

[0088] The number of underfloor heating modules 220 is at least one. For example, the number of underfloor heating modules 220 can be one.

[0089] In some embodiments, the terminal heat exchange device 200 includes a water tank module 230. The water tank module 230 is connected to the exhaust end of the compressor 110 and the outdoor heat exchanger 130, respectively.

[0090] The number of water tank modules 230 is at least one. For example, the number of water tank modules 230 can be one.

[0091] See Figures 1 to 3 As shown, in some embodiments, the terminal heat exchange device 200 includes at least two terminal heat exchange components 240.

[0092] It should be noted that the terminal heat exchange component 240 can be the heat exchange component in the indoor unit 210, the heat exchange component in the underfloor heating module 220, or the heat exchange component in the water tank module 230.

[0093] Specifically, the number of terminal heat exchange components 240 can be five. The five terminal heat exchange components 240 include heat exchange components in three indoor units 210, heat exchange components in one underfloor heating module 220, and heat exchange components in one water tank module 230.

[0094] Figure 4 This is a schematic diagram of the structure of the gas-side refrigerant pressure regulating component in a multi-unit heat pump system provided in an embodiment of this application.

[0095] See Figure 1 , Figure 2 and Figure 4 As shown, in some embodiments, the terminal heat exchanger 200 includes at least two gas-side refrigerant pressure regulating components 250. The gas-side refrigerant pressure regulating components 250 are used to regulate the pressure of the gas-side refrigerant in the terminal heat exchanger 240. In heating mode, the gas-side refrigerant pressure regulating components 250 are used to regulate the pressure of the refrigerant flowing into the terminal heat exchanger 240. In cooling mode, the gas-side refrigerant pressure regulating components 250 are used to regulate the pressure of the refrigerant discharged from the terminal heat exchanger 240.

[0096] Among them, at least two gas-side refrigerant pressure regulating components 250 are set in a one-to-one correspondence with at least two terminal heat exchange components 240.

[0097] Specifically, the number of gas-side refrigerant pressure regulating components 250 can be 5.

[0098] In some embodiments, the gas-side refrigerant pressure regulating assembly 250 includes a gas-side electronic expansion valve 251. The gas-side electronic expansion valve 251 is used to regulate the pressure of the refrigerant.

[0099] In some embodiments, the gas-side refrigerant pressure regulating assembly 250 includes two gas-side filters 252 located on opposite sides of the gas-side electronic expansion valve 251. The gas-side filters 252 are used to filter impurities in the refrigerant, thereby reducing damage to the gas-side electronic expansion valve 251.

[0100] Figure 5 This is a schematic diagram of the liquid-side refrigerant pressure regulating component in a multi-unit heat pump system provided in this application embodiment.

[0101] See Figure 1 , Figure 2 and Figure 5 As shown, in some embodiments, the terminal heat exchanger 200 includes at least two liquid-side refrigerant pressure regulating components 260. The liquid-side refrigerant pressure regulating components 260 are used to regulate the pressure of the liquid-side refrigerant in the terminal heat exchanger 240. In heating mode, the liquid-side refrigerant pressure regulating components 260 are used to regulate the pressure of the refrigerant discharged from the terminal heat exchanger 240. In cooling mode, the liquid-side refrigerant pressure regulating components 260 are used to regulate the pressure of the refrigerant flowing into the terminal heat exchanger 240.

[0102] Among them, at least two liquid-side refrigerant pressure regulating components 260 are set in a one-to-one correspondence with at least two terminal heat exchange components 240.

[0103] Specifically, the number of liquid-side refrigerant pressure regulating components 260 can be 5.

[0104] In some embodiments, one of the liquid-side refrigerant pressure regulating component 260 and the gas-side refrigerant pressure regulating component 250 is configured to regulate the excess refrigerant flowing out of the corresponding terminal heat exchange component 240. It should be noted that the excess refrigerant can be superheat or subcooling.

[0105] In heating mode, the subcooling of the refrigerant flowing out of the corresponding terminal heat exchange component 240 is adjusted. A higher subcooling results in a lower enthalpy of the liquid refrigerant before throttling, allowing it to release more heat upon entering the terminal heat exchange component 240, directly increasing the heating capacity per unit mass of refrigerant. Furthermore, the subcooled liquid refrigerant in the liquid-side electronic expansion valve is less likely to prematurely vaporize and generate flash gas during the throttling process, reducing refrigerant waste and improving system heat exchange efficiency. Increasing the subcooling also prevents "air carryover" at the outlet of the terminal heat exchange component 240 due to insufficient refrigerant or load fluctuations, ensuring that the inlet of the liquid-side electronic expansion valve is always pure liquid refrigerant, effectively preventing a sudden drop in heating performance or system malfunctions.

[0106] In cooling mode, the superheat of the refrigerant flowing out of the corresponding terminal heat exchange component 240 is adjusted. This ensures that only a completely gaseous refrigerant enters the compressor 110, preventing the direct intake of liquid refrigerant and thus protecting core components such as the compressor 110 valves, extending their service life. Furthermore, excessively low superheat can lead to underutilization of the heat exchange area of ​​the terminal heat exchange component 240. A properly increased superheat allows for more efficient heat exchange in the evaporator, resulting in a more stable cooling capacity. Appropriately increasing the superheat also reduces "ineffective circulation" of the refrigerant within the terminal heat exchange component 240, allowing a unit mass of refrigerant to absorb more heat, indirectly improving the system's cooling efficiency.

[0107] One of the liquid-side refrigerant pressure regulating component 260 and the gas-side refrigerant pressure regulating component 250 is configured to regulate the temperature of the refrigerant flowing into the corresponding terminal heat exchange component 240 to the target temperature. This allows different terminal heat exchange components 240 to have different evaporation or condensation temperatures, meeting different usage needs and thus improving comfort.

[0108] Specifically, different evaporation temperatures can be achieved, resulting in different outlet air temperatures under cooling conditions to suit different user load requirements. Different condensation temperatures can also be achieved, allowing for the production of higher water temperatures when heating is being carried out at lower indoor temperatures during multi-generational power supply operation.

[0109] In some embodiments, the liquid-side refrigerant pressure regulating assembly 260 includes a liquid-side electronic expansion valve 261. The liquid-side electronic expansion valve 261 is used to regulate the pressure of the refrigerant.

[0110] In some embodiments, the liquid-side refrigerant pressure regulating assembly 260 includes two liquid-side filters 262 located on opposite sides of the liquid-side electronic expansion valve 261. The liquid-side filters 262 are used to filter impurities in the refrigerant, thereby reducing damage to the liquid-side electronic expansion valve 261.

[0111] Figure 6 A control principle diagram of a multi-unit heat pump system provided in an embodiment of this application.

[0112] See Figure 6 As shown, in some embodiments, the multi-split heat pump system also includes a controller 300. Both the liquid-side refrigerant pressure regulating assembly 260 and the liquid-side refrigerant pressure regulating assembly 260 are electrically connected to the controller 300.

[0113] Controller 300 is configured as follows:

[0114] The difference between the set temperature and the actual temperature of the terminal heat exchange component 240 is obtained, and the corresponding target temperature is obtained based on the difference.

[0115] Specifically, when the indoor unit 210 is in cooling mode, the target evaporation temperature TL_(n) of the terminal heat exchange components 240 in each room is determined based on different room set temperatures Ts_(n) and actual room temperatures Tr_(n). The room set temperature can be input by the user. The actual room temperature can be detected by a temperature sensor.

[0116] For example, TL_(n) = TL_set + △Tsr_(n),

[0117] Where: TL_set is the default value. The value range of TL_set can be 8-15℃. △Tsr_(n) is the difference between the set temperature and the actual temperature of each room, △Tsr_(n)=Ts_(n)-Tr_(n).

[0118] In heating mode, such as when indoor unit 210 is heating, underfloor heating module 220 is heating, and water tank module 230 is producing domestic hot water, the required condensing temperature for each terminal is different. If the unit only provides one condensing temperature, it cannot meet the needs of each terminal; therefore, different condensing pressure controls will be implemented.

[0119] The required condensing temperature needs to be calculated for different terminal heat exchange components 240. The condensing temperature of different terminals is calculated from the set temperature and the actual temperature.

[0120] Indoor unit 210: Tcr_(n) = Tc_set + △Tsr_(n).

[0121] Wherein, Tcr_set is the room temperature set by the user, and the value range of Tcr_set is 16-32℃. △Tsr_(n) is the difference between the set temperature and the actual temperature of each room, △Tsr_(n)=Ts_(n)-Tr_(n), and the value range of △Tsr_(n) is 0-10℃.

[0122] Underfloor heating module 220: Tcw_(n) = Tcw_set + △Tsw_(n).

[0123] Wherein, Tcw_set is the temperature set by the user for the underfloor heating module 220, and the value range of Tcw_set is 25-55℃. △Tsw_(n) is the difference between the set water temperature and the actual outlet water temperature of the underfloor heating module 220, △Tsw_(n)=Ts_(n)-Tw_(n).

[0124] The value of △Tsw_(n) ranges from 0 to 20℃.

[0125] Water tank module 230: Tch_(n) = Tch_set + △Tsh_(n).

[0126] Among them, Tch_set is the user-defined water tank module temperature 230, and the value range of Tch_set is 25-60℃.

[0127] △Tsh_(n) is the difference between the set water temperature and the actual outlet water temperature for each water module. △Tsh_(n) = Ts_(n) - Th_(n), and the value range of △Tsh_(n) is 0-30℃.

[0128] The operating frequency of the compressor 110 in the main heat exchanger 100 is controlled based on a standard temperature. The standard temperature is one of the target temperatures.

[0129] Specifically, see Figure 4 As shown, when the indoor unit 210 is in cooling mode, the target temperature is the target evaporation temperature, and the standard temperature is the standard evaporation temperature. The standard evaporation temperature can be the minimum value among the target evaporation temperatures. Alternatively, the standard evaporation temperature can be the maximum value among the target evaporation temperatures. Or, the standard evaporation temperature can be an intermediate value among the target evaporation temperatures.

[0130] See Figure 3 As shown, in heating mode, such as when indoor unit 210 is heating, floor heating module 220 is heating, and water tank module 230 is producing domestic hot water, the target temperature is the target condensing temperature, and the standard temperature is the standard condensing temperature. The standard condensing temperature can be the maximum value among the target condensing temperatures. Alternatively, the standard condensing temperature can be the minimum value among the target condensing temperatures. Or, the standard condensing temperature can be the average value among the target condensing temperatures.

[0131] Based on the corresponding target temperature and standard temperature, the opening degree of one of the gas-side refrigerant pressure regulating component 250 and the liquid-side refrigerant pressure regulating component 260 is controlled to match the different target temperature requirements of different terminal heat exchange components 240.

[0132] Control the opening degree of the other of the gas-side refrigerant pressure regulating component 250 and the liquid-side refrigerant pressure regulating component 260 so that the superheat or subcooling of the refrigerant flowing out of the corresponding terminal heat exchange component 240 reaches a preset value.

[0133] For example, the preset value can be 1 to 10°C.

[0134] Understandably, by cooperating with the gas-side refrigerant pressure regulating component 250 and the liquid-side refrigerant pressure regulating component 260, different evaporation temperatures can be achieved, resulting in different outlet air temperatures under cooling conditions to suit different user load requirements. Different condensation temperatures can also be achieved, allowing for the production of higher water temperatures while maintaining lower indoor heating temperatures during multi-generational power supply operation. Furthermore, it can meet the requirements for superheating or subcooling.

[0135] See Figure 1As shown, in some embodiments, the terminal heat exchanger 200 includes at least two liquid-side temperature detectors 400. The liquid-side temperature detectors 400 are used to detect the temperature of the refrigerant at the port of the terminal heat exchanger 200 where the refrigerant is in a liquid state. For example, the temperature of the refrigerant at the inlet or outlet.

[0136] At least two liquid-side temperature detectors 400 are configured in a one-to-one correspondence with at least two terminal heat exchange components 240, with the liquid-side temperature detectors 400 located on the side of the liquid-side refrigerant pressure regulating component 260 facing the corresponding terminal heat exchange component 240.

[0137] The liquid-side temperature detector 400 is electrically connected to the controller 300, and the liquid-side temperature detector 400 is configured to detect the temperature of the refrigerant on the liquid side of the corresponding terminal heat exchange component 240.

[0138] Specifically, the liquid-side temperature detector 400 can be a temperature sensor. The number of liquid-side temperature detectors 400 can be up to 5.

[0139] In some embodiments, the terminal heat exchanger 200 includes at least two gas-side temperature detectors 500. The gas-side temperature detectors 500 are used to detect the temperature of the refrigerant at the port of the terminal heat exchanger 200 where the refrigerant is in a gaseous state. For example, the temperature of the refrigerant at the inlet or outlet.

[0140] At least two gas-side temperature detectors 500 are configured in a one-to-one correspondence with at least two terminal heat exchange components 240, with the gas-side temperature detectors 500 located on the side of the gas-side refrigerant pressure regulating component 250 facing the corresponding terminal heat exchange component 240.

[0141] The gas-side temperature detector 500 is electrically connected to the controller 300, and the gas-side temperature detector 500 is configured to detect the temperature of the refrigerant on the gas side of the corresponding terminal heat exchange component 240.

[0142] Specifically, the air-side temperature detector 500 can be a temperature sensor. The number of air-side temperature detectors 500 can be up to five.

[0143] See Figure 3 As shown, in some embodiments, the controller 300 is configured to:

[0144] When the terminal heat exchanger 200 is in its first operating state, the target temperature is the target evaporation temperature, and the standard temperature is the standard evaporation temperature. The standard evaporation temperature is the minimum value among the target evaporation temperatures.

[0145] It should be noted that the first operating state is that the terminal heat exchanger 200 is on the low-pressure side, that is, the indoor unit 210 is in the cooling state.

[0146] Understandably, selecting the minimum target evaporation temperature of the terminal heat exchange components 240 in each room as the control target for the operating frequency of the compressor 110 is beneficial for ensuring that the cooling performance of the entire area meets the standards. Using the minimum target evaporation temperature as a benchmark ensures that the rooms with the most urgent needs (requiring lower temperatures) meet their cooling requirements, avoiding excessively high temperatures in some rooms. Furthermore, it helps reduce ineffective energy consumption, effectively preventing the compressor 110 from blindly operating at high frequencies due to high demand in a single room. Matching the load to the minimum value reduces energy waste and improves the system's energy efficiency ratio. Moreover, it helps stabilize the system's operating status. The minimum evaporation temperature determines the system's minimum operating temperature threshold, effectively preventing frequent start-stops or large frequency fluctuations of the compressor 110, extending the service life of the compressor 110 and piping components.

[0147] In some embodiments, the controller 300 is configured to:

[0148] When the target evaporation temperature equals the standard evaporation temperature, the opening degree of one of the corresponding liquid-side refrigerant pressure regulating component 260 and gas-side refrigerant pressure regulating component 250 is controlled to 100%.

[0149] The opening degree of the other of the liquid-side refrigerant pressure regulating component 260 and the gas-side refrigerant pressure regulating component 250 is controlled so that the temperature difference between the gas-side refrigerant of the terminal heat exchange component 240 and the liquid-side refrigerant of the terminal heat exchange component 240 reaches a preset value.

[0150] Specifically, when the target evaporation temperature equals the standard evaporation temperature, the opening degree of the corresponding gas-side refrigerant pressure regulating component 250 can be controlled to 100%. The opening degree of the corresponding liquid-side refrigerant pressure regulating component 260 is also controlled, thereby achieving Tg-TL=5℃. Here, Tg is the detection value of the gas-side temperature detector 500, and TL is the detection value of the liquid-side temperature detector 400.

[0151] When the target evaporation temperature is higher than the standard evaporation temperature, the opening of the corresponding liquid-side refrigerant pressure regulating component 260 is controlled until the evaporation temperature of the terminal heat exchange component 240 reaches the target evaporation temperature. The evaporation temperature of the terminal heat exchange component 240 is the temperature of the refrigerant on the liquid side of the terminal heat exchange component 240.

[0152] The opening degree of the gas-side refrigerant pressure regulating component 250 is controlled so that the temperature difference between the gas-side refrigerant of the terminal heat exchange component 240 and the liquid-side refrigerant of the terminal heat exchange component 240 reaches a preset value.

[0153] Specifically, the high-pressure liquid refrigerant enters the indoor unit 210 and first flows through the liquid-side electronic expansion valve 261. The liquid-side electronic expansion valve 261 throttles the refrigerant to the target evaporation temperature, meaning that the liquid-side temperature sensor 400's reading is adjusted to approach the target evaporation temperature by regulating the liquid-side electronic expansion valve 261. The control target of the gas-side electronic expansion valve 251 is superheat, i.e., Tg - TL_(n) = 5℃. Here, Tg is the reading from the gas-side temperature sensor 500, and TL is the reading from the liquid-side temperature sensor 400.

[0154] It should be noted that both the liquid-side electronic expansion valve 261 and the gas-side electronic expansion valve 251 can function as throttling valves. The liquid-side electronic expansion valve 261 is the primary valve, while the gas-side electronic expansion valve 251 is secondary.

[0155] For example, there are three indoor units 210, and three rooms. The target evaporation temperatures for the three rooms are 8°C, 10°C, and 12°C, respectively, with a minimum value TL_min = 8°C.

[0156] The saturation temperature corresponding to the suction pressure of compressor 110, as detected by the second pressure detector 150, is 8°C, controlled by the operating frequency of compressor 110.

[0157] If the target evaporation temperature in room 1 is the same as the minimum value, then the gas-side electronic expansion valve 251 is 100% open, and the liquid-side electronic expansion valve 261 controls the difference between Tg and TL to be 5℃.

[0158] If the target evaporation temperature in room 2 is different from the minimum value, the opening of the liquid-side electronic expansion valve 261 is controlled until the refrigerant temperature detected by the liquid-side temperature detector 400 reaches 10℃, and the gas-side electronic expansion valve 251 controls the difference between Tg and TL to be 5℃.

[0159] Room 3 is controlled similarly to Room 2.

[0160] In some embodiments, the multi-split heat pump system further includes an exhaust temperature detector 160. The exhaust temperature detector 160 is electrically connected to the controller 300 and is configured to detect the exhaust temperature of the compressor 110 in the main heat exchanger 100.

[0161] See Figure 4 As shown, in some embodiments, the controller 300 is configured to:

[0162] When the terminal heat exchanger 200 is in the second operating state, the target temperature is the target condensing temperature, and the standard temperature is the standard condensing temperature. The standard condensing temperature is the maximum value among the target condensing temperatures.

[0163] It should be noted that the second operating state is when the terminal heat exchanger 200 is on the high-pressure side, that is, when the indoor unit 210 is in heating mode, or the floor heating module 220 is heating, or the water tank module 230 is producing hot water, or when the cooling heat recovery is producing hot water.

[0164] Understandably, the condensing temperature of the terminal heat exchange components 240 is directly related to the heat supply during heating. Using the maximum value as a benchmark ensures that the terminal with the highest heat demand (such as in low-temperature environments or large spaces) is met, effectively preventing insufficient temperature in some terminal heat exchange components 240. Matching the compressor 110 frequency to the maximum condensing temperature ensures sufficient heating power without wasting energy due to excessively high frequency, allowing the system to operate within its efficient range suitable for the load. The maximum value clearly defines the highest threshold for system heating, effectively preventing the compressor 110 from frequently adjusting its frequency due to differences in the heat demand of each terminal heat exchange component 240, reducing equipment start-up and shutdown losses, and extending the lifespan of the compressor 110 and piping components.

[0165] Specifically, the maximum target condensing temperature of each terminal heat exchange component 240 is selected as the control target for the operating frequency of the compressor 110.

[0166] In some embodiments, when the target condensing temperature is equal to the standard condensing temperature, the opening degree of the corresponding gas-side refrigerant pressure regulating component 250 is controlled to be 100%.

[0167] The opening of the liquid-side refrigerant pressure regulating component 260 is controlled so that the difference between the target condensation temperature and the temperature of the refrigerant on the liquid side of the corresponding terminal heat exchange component 240 reaches a preset value.

[0168] When the target condensing temperature is lower than the standard condensing temperature, the opening of the corresponding gas-side refrigerant pressure regulating component 250 is controlled until the temperature of the refrigerant on the gas side of the terminal heat exchange component 240 reaches the difference between the exhaust temperature and the standard condensing temperature and the target condensing temperature.

[0169] The opening of the liquid-side refrigerant pressure regulating component 260 is controlled so that the difference between the target condensation temperature and the temperature of the refrigerant on the liquid side of the corresponding terminal heat exchange component 240 reaches a preset value.

[0170] Specifically, when the target condensing temperature of the indoor unit 210 is the same as the maximum value, the opening degree of the gas-side electronic expansion valve 251 is 100%. The control target of the liquid-side electronic expansion valve 261 is a subcooling degree of 5°C for the terminal heat exchange assembly 240.

[0171] It should be noted that the actual subcooling is equal to the saturation temperature corresponding to the detection pressure of the first pressure detector 140 minus the detection value of the liquid side temperature detector 400.

[0172] When the target condensing temperature of the indoor unit 210 is lower than the maximum value, the gas-side electronic expansion valve 251 needs to perform a certain throttling function to achieve the corresponding target condensing temperature. At this time, the exhaust temperature detector 160 can obtain the exhaust temperature of the compressor 110. The first pressure detector 140 can detect the intake pressure of the four-way valve 120 and obtain the saturation temperature based on the intake pressure.

[0173] Given that the difference between the target condensing temperature and the maximum value of the indoor unit 210 is Tc_max - Tc_(n), the control target of the gas-side electronic expansion valve 251 is that the detection value of the gas-side temperature detector 500 of the terminal heat exchange component 240 reaches the difference between the exhaust temperature and the standard condensing temperature and the target condensing temperature, which is Td - (Tc_max - Tc_(n)). The control target of the liquid-side electronic expansion valve 261 is the subcooling of the indoor unit 210, i.e., Tc_(n) - TL = 5℃.

[0174] The target condensing temperature for the indoor unit 210 in room 1 is 40℃, the target condensing temperature for the underfloor heating module 220 is 45℃, and the target condensing temperature for the water tank module 230 is 50℃.

[0175] At this time, the target operating frequency of compressor 110 is that the pressure value detected by the first pressure detector 140 corresponds to a saturation temperature of 50℃. At this time, the exhaust temperature Td detected by exhaust temperature detector 160 is 80℃.

[0176] For water tank module 230, the target condensation temperature is the same as the maximum value, and the opening degree of gas-side electronic expansion valve 251 is 100%. The control target of liquid-side electronic expansion valve 261 is a difference of 5°C between the corresponding saturation temperature of 50°C and the detection value of liquid-side temperature detector 400.

[0177] For room 1 heating, if the target condensing temperature of indoor unit 210 is lower than the maximum value and the difference is 10℃, then the control target of gas-side electronic expansion valve 251 is the value detected by gas-side temperature detector 500 as Td-10℃, which is 70℃. The control target of liquid-side electronic expansion valve 261 is the difference between the corresponding saturation temperature of 40℃ and the value detected by gas-side temperature detector 500 as 5℃.

[0178] The control of the underfloor heating module 220 is similar to that of the indoor unit 210.

[0179] In some embodiments, the controller 300 is configured to:

[0180] Determine the operating status of the terminal heat exchanger 200.

[0181] When the terminal heat exchange component 240 is not in operation, the corresponding gas-side refrigerant pressure regulating component 250 and liquid-side refrigerant pressure regulating component 260 are in the closed state.

[0182] Understandably, when the terminal heat exchange component 240 is not in operation, the corresponding gas-side refrigerant pressure regulating component 250 and liquid-side refrigerant pressure regulating component 260 are in a closed state, which can effectively prevent the refrigerant from entering, thereby reducing refrigerant bypass and energy dissipation.

[0183] Specifically, it determines whether the terminal heat exchange component 240 is on the low-pressure side, that is, whether the terminal heat exchange component 240 in the indoor unit 210 is in a cooling state.

[0184] If so, it is determined whether the terminal heat exchange component 240 is in the off state. Specifically, in the off state, the liquid-side electronic expansion valve 261 and the gas-side pressure regulating valve of the terminal heat exchange component 240 of the indoor unit 210 are both closed. In the on state, the terminal heat exchange component 240 of the indoor unit 210 performs different target evaporation pressure control.

[0185] If not, it indicates that the terminal heat exchange component 240 is on the high-pressure side, i.e., during heating, underfloor heating, hot water production, or hot water production via heat recovery. Then, it is determined whether the terminal heat exchange component 240 is in the closed state. Specifically, when the terminal heat exchange component 240 is in the closed state, both the liquid-side electronic expansion valve 261 and the gas-side pressure regulating valve are closed. When the terminal heat exchange component 240 is in the open state, it performs different target condensing pressure controls.

[0186] In some embodiments, a first pressure detector 140 is also included, which is electrically connected to the controller 300 and is configured to detect the inlet pressure of the four-way valve 120 in the host heat exchanger 100.

[0187] When the terminal heat exchanger 200 is in the second operating state, some terminal heat exchange components 240 are in the operating state, and some terminal heat exchange components 240 are in the non-operating state.

[0188] In heating mode, such as when only underfloor heating or only hot water is running, the indoor unit 210 is in a stopped state. At this time, with the electronic expansion valve of the indoor unit 210 slightly open, high-temperature, high-pressure refrigerant flows through the indoor unit 210, causing heat dissipation and increasing the unit's energy consumption. The terminal heat exchange component 240 of the stopped indoor unit 210 can be used as high-pressure side refrigerant storage. During normal operation, both the gas-side expansion valve and the liquid-side electronic expansion valve 261 corresponding to the terminal heat exchange component 240 of the stopped indoor unit 210 are closed (2%). This embodiment allows for refrigerant quantity determination based on operating parameters.

[0189] Controller 300 is configured as follows:

[0190] Based on the subcooling and inlet pressure of the terminal heat exchange component 240 in operation, the terminal heat exchange component 240 in non-operation state is controlled to store and release refrigerant.

[0191] Specifically, if the difference between the saturation temperature corresponding to the intake pressure and the temperature of the refrigerant on the liquid side of the terminal heat exchange component 240 in operation is not less than a third preset value and is maintained for a first preset time, and the intake pressure is not less than the corresponding target pressure and is maintained for a second preset time, then the gas-side refrigerant pressure regulating component 250 corresponding to the terminal heat exchange component 240 in non-operation state is controlled to open for a third preset time, and the corresponding liquid-side refrigerant pressure regulating component 260 remains closed to retain some refrigerant.

[0192] If the difference between the saturation temperature corresponding to the intake pressure and the temperature of the refrigerant on the liquid side of the terminal heat exchange component 240 in operation is not greater than the fourth preset value and is maintained for the fourth preset time, and the intake pressure is not greater than the corresponding target pressure and is maintained for the fifth preset time, then the liquid side refrigerant pressure regulating component 260 corresponding to the terminal heat exchange component 240 in non-operation state is controlled to open for the sixth preset time, and the corresponding gas side refrigerant pressure regulating component 250 remains closed to release some refrigerant.

[0193] The target pressure is related to the corresponding target condensing temperature. In other words, the target pressure will be different when the target condensing temperatures of different terminal heat exchange components 240 are different.

[0194] Specifically, if the subcooling of the terminal heat exchange component 240 during operation (calculated as the difference between the saturation temperature corresponding to the intake pressure detected by the first pressure sensor and the value detected by the liquid-side temperature detector 400) remains high (e.g., ≥10℃ for 10 minutes), and the actual operating intake pressure remains high (e.g., intake pressure ≥ target intake pressure + margin for 10 minutes), it indicates that there is too much refrigerant in the system. It is necessary to open the gas-side electronic expansion valve 251 corresponding to the terminal heat exchange component 240 of the indoor unit 210 that has stopped operating, storing a portion of the refrigerant in the terminal heat exchange component 240 of the indoor unit 210, and specify the opening time (e.g., 2 minutes). At this time, the corresponding liquid-side electronic expansion valve 261 remains closed (2%).

[0195] If the subcooling of the terminal heat exchange component 240 remains low (e.g., ≤3℃ for 10 minutes) and the actual operating intake pressure (detected by the first pressure sensor) remains low (e.g., intake pressure ≤ target intake pressure + margin for 10 minutes), it indicates that the amount of refrigerant in the system is insufficient. It is necessary to open the liquid-side electronic expansion valve 261 corresponding to the terminal heat exchange component 240 of the stopped indoor unit 210 to release the refrigerant stored in the terminal heat exchange component 240 of the stopped indoor unit 210, with a specified opening time (e.g., 2 minutes). At this time, the gas-side electronic expansion valve 251 remains closed (2%).

[0196] The target intake pressure can be obtained from the table showing the correspondence between target condensation temperature and intake pressure, which will not be elaborated here. The margin can be 0 to 1, for example, 0.3.

[0197] It is understandable that by controlling the gas-side electronic expansion valve 251 and liquid-side electronic expansion valve 261 corresponding to the terminal heat exchange component 240 that has stopped operating, the refrigerant quantity can be continuously adjusted, thereby improving the system's operating energy efficiency.

[0198] Figure 7 This is a flowchart illustrating the control method for a multi-unit heat pump system provided in an embodiment of this application.

[0199] See Figure 7 As shown, in some embodiments, this application provides a control method for a multi-split heat pump system, including:

[0200] S101. Obtain the difference between the set temperature and the actual temperature of the terminal heat exchange component, and obtain the corresponding target temperature based on the difference.

[0201] S102. Control the operating frequency of the compressor in the main heat exchanger based on the standard temperature. The standard temperature is one of the target temperatures.

[0202] S103. Based on the corresponding target temperature and standard temperature, control the opening degree of one of the gas-side refrigerant pressure regulating components and the liquid-side refrigerant pressure regulating components to match the different target temperature requirements of different terminal heat exchange components.

[0203] S104. Control the opening degree of the other of the gas-side refrigerant pressure regulating component and the liquid-side refrigerant pressure regulating component so that the superheat or subcooling of the refrigerant flowing out of the corresponding terminal heat exchange component reaches the preset value.

[0204] Figure 8 This is a schematic diagram illustrating the process of controlling different evaporation temperatures in a multi-unit heat pump system provided in an embodiment of this application.

[0205] See Figure 8As shown, based on the corresponding target temperature and standard temperature, the opening degree of one of the gas-side refrigerant pressure regulating components and the liquid-side refrigerant pressure regulating component is controlled to match the different target temperature requirements of different terminal heat exchange components. The opening degree of the other of the gas-side and liquid-side refrigerant pressure regulating components is controlled to ensure that the superheat or subcooling of the refrigerant flowing out of the corresponding terminal heat exchange component reaches a preset value. This includes:

[0206] When the target evaporation temperature equals the standard evaporation temperature, the opening degree of one of the corresponding liquid-side refrigerant pressure regulating components and gas-side refrigerant pressure regulating components is controlled to 100%; the opening degree of the other of the liquid-side refrigerant pressure regulating components and gas-side refrigerant pressure regulating components is controlled so that the difference between the temperature of the refrigerant on the gas side of the terminal heat exchange component and the temperature of the refrigerant on the liquid side of the terminal heat exchange component reaches the preset value.

[0207] When the target evaporation temperature is higher than the standard evaporation temperature, the opening of the corresponding liquid-side refrigerant pressure regulating component is controlled until the evaporation temperature of the terminal heat exchange component reaches the target evaporation temperature; wherein, the evaporation temperature of the terminal heat exchange component is the temperature of the refrigerant on the liquid side of the terminal heat exchange component; the opening of the gas-side refrigerant pressure regulating component is controlled so that the difference between the temperature of the refrigerant on the gas side of the terminal heat exchange component and the temperature of the refrigerant on the liquid side of the terminal heat exchange component reaches a preset value.

[0208] Figure 9 This is a schematic diagram illustrating the process of controlling different condensing temperatures in a multi-unit heat pump system provided in an embodiment of this application.

[0209] See Figure 9 As shown, based on the corresponding target temperature and standard temperature, the opening degree of one of the gas-side refrigerant pressure regulating components and the liquid-side refrigerant pressure regulating component is controlled to match the different target temperature requirements of different terminal heat exchange components. The opening degree of the other of the gas-side and liquid-side refrigerant pressure regulating components is controlled to ensure that the superheat or subcooling of the refrigerant flowing out of the corresponding terminal heat exchange component reaches a preset value. This includes:

[0210] When the target condensing temperature equals the standard condensing temperature, the opening degree of the corresponding gas-side refrigerant pressure regulating component is controlled to 100%; the opening degree of the liquid-side refrigerant pressure regulating component is controlled so that the difference between the target condensing temperature and the temperature of the refrigerant on the liquid side of the corresponding terminal heat exchange component reaches the preset value.

[0211] When the target condensing temperature is lower than the standard condensing temperature, the opening of the corresponding gas-side refrigerant pressure regulating component is controlled until the temperature of the refrigerant on the gas side of the terminal heat exchange component reaches the difference between the exhaust temperature and the standard condensing temperature and the target condensing temperature; the opening of the liquid-side refrigerant pressure regulating component is controlled so that the difference between the target condensing temperature and the temperature of the refrigerant on the liquid side of the corresponding terminal heat exchange component reaches the preset value.

[0212] Figure 10 This is another schematic flowchart illustrating the control method for a multi-unit heat pump system provided in an embodiment of this application.

[0213] See Figure 10 As shown, in some embodiments, the control method for a multi-split heat pump system includes:

[0214] Determine if the terminal heat exchanger is in the first state. That is, determine if the terminal heat exchanger is on the low-pressure side.

[0215] If yes, determine whether the terminal heat exchange component is in the on state; if yes, execute different target evaporation temperature control; if no, control the corresponding refrigerant pressure regulating component and liquid-side refrigerant pressure regulating component to be in the off state.

[0216] If not, determine whether the terminal heat exchange component is in the open state; if yes, execute different target condensing temperature control; if no, control the corresponding refrigerant pressure regulating component and liquid-side refrigerant pressure regulating component to be in the closed state, and control the non-operating terminal heat exchange component to store and release refrigerant according to the subcooling degree and inlet pressure of the terminal heat exchange component in the operating state.

[0217] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

[0218] For ease of explanation, the above description has been provided in conjunction with specific embodiments. However, the above exemplary discussion is not intended to be exhaustive or to limit the embodiments to the specific forms disclosed above. Various modifications and variations can be obtained based on the above teachings. The selection and description of the above embodiments are for the purpose of better explaining the principles and practical applications, thereby enabling those skilled in the art to better utilize the described embodiments and various different variations of embodiments suitable for specific use considerations.

Claims

1. A multi-split heat pump system, characterized in that, include: Main heat exchange equipment (100); A terminal heat exchange device (200) is connected to the main heat exchange device (100), and the terminal heat exchange device (200) includes: At least two end heat exchange components (240); At least two gas-side refrigerant pressure regulating components (250) are provided in a one-to-one correspondence with the at least two terminal heat exchange components (240); At least two liquid-side refrigerant pressure regulating components (260) are provided in a one-to-one correspondence with the at least two terminal heat exchange components (240). One of the liquid-side refrigerant pressure regulating components (260) and the gas-side refrigerant pressure regulating components (250) is configured to regulate the superheat or subcooling of the refrigerant flowing out of the corresponding terminal heat exchange component (240), and the other is configured to regulate the temperature of the refrigerant flowing into the corresponding terminal heat exchange component (240) to the target temperature.

2. The multi-unit heat pump system according to claim 1, characterized in that, It also includes a controller (300), and both the liquid-side refrigerant pressure regulating component (260) and the liquid-side refrigerant pressure regulating component (260) are electrically connected to the controller (300); The controller (300) is configured to: The difference between the set temperature and the actual temperature of the terminal heat exchange component (240) is obtained, and the corresponding target temperature is obtained based on the difference; The operating frequency of the compressor in the main heat exchanger (100) is controlled based on a standard temperature; wherein the standard temperature is one of the target temperatures. Based on the corresponding target temperature and standard temperature, the opening degree of one of the gas-side refrigerant pressure regulating component (250) and the liquid-side refrigerant pressure regulating component (260) is controlled to match the different target temperature requirements of different terminal heat exchange components (240); Control the opening degree of the other of the gas-side refrigerant pressure regulating component (250) and the liquid-side refrigerant pressure regulating component (260) so that the superheat or subcooling of the refrigerant flowing out of the corresponding terminal heat exchange component (240) reaches a preset value.

3. The multi-unit heat pump system according to claim 2, characterized in that, Also includes: At least two liquid-side temperature detectors (400) are provided, each corresponding to one of the at least two terminal heat exchange components (240). The liquid-side temperature detectors (400) are located on the side of the liquid-side refrigerant pressure regulating component (260) facing the corresponding terminal heat exchange component (240). The liquid-side temperature detectors (400) are electrically connected to the controller (300) and are configured to detect the temperature of the refrigerant on the liquid side of the corresponding terminal heat exchange component (240). At least two gas-side temperature detectors (500) are provided, each corresponding to one of the at least two terminal heat exchange components (240). The gas-side temperature detectors (500) are located on the side of the gas-side refrigerant pressure regulating component (250) facing the corresponding terminal heat exchange component (240). The gas-side temperature detectors (500) are electrically connected to the controller (300) and are configured to detect the temperature of the refrigerant on the gas side of the corresponding terminal heat exchange component (240).

4. The multi-unit heat pump system according to claim 3, characterized in that, The controller (300) is configured to: When the terminal heat exchanger (200) is in the first operating state, the target temperature is the target evaporation temperature, and the standard temperature is the standard evaporation temperature; The standard evaporation temperature is the minimum value among the target evaporation temperatures.

5. The multi-unit heat pump system according to claim 4, characterized in that, The controller (300) is configured to: When the target evaporation temperature is equal to the standard evaporation temperature, the opening degree of one of the corresponding liquid-side refrigerant pressure regulating component (260) and gas-side refrigerant pressure regulating component (250) is controlled to 100%; the opening degree of the other of the liquid-side refrigerant pressure regulating component (260) and gas-side refrigerant pressure regulating component (250) is controlled so that the difference between the temperature of the refrigerant on the gas side of the terminal heat exchange component (240) and the temperature of the refrigerant on the liquid side of the terminal heat exchange component (240) reaches the preset value; When the target evaporation temperature is greater than the standard evaporation temperature, the opening degree of the corresponding liquid-side refrigerant pressure regulating component (260) is controlled until the evaporation temperature of the terminal heat exchange component (240) reaches the target evaporation temperature; wherein, the evaporation temperature of the terminal heat exchange component (240) is the temperature of the refrigerant on the liquid side of the terminal heat exchange component (240); the opening degree of the gas-side refrigerant pressure regulating component (250) is controlled so that the difference between the temperature of the refrigerant on the gas side of the terminal heat exchange component (240) and the temperature of the refrigerant on the liquid side of the terminal heat exchange component (240) reaches the preset value.

6. The multi-unit heat pump system according to claim 3, characterized in that, Also includes: An exhaust temperature detector (160) is electrically connected to the controller (300) and is configured to detect the exhaust temperature of the compressor in the host heat exchanger (100).

7. The multi-unit heat pump system according to claim 6, characterized in that, The controller (300) is configured to: When the terminal heat exchanger (200) is in the second operating state, the target temperature is the target condensing temperature, and the standard temperature is the standard condensing temperature; The standard condensing temperature is the maximum value among the target condensing temperatures.

8. The multi-unit heat pump system according to claim 7, characterized in that, When the target condensing temperature is equal to the standard condensing temperature, the opening degree of the corresponding gas-side refrigerant pressure regulating component (250) is controlled to be 100%; the opening degree of the liquid-side refrigerant pressure regulating component (260) is controlled so that the difference between the target condensing temperature and the temperature of the refrigerant on the liquid side of the corresponding terminal heat exchange component (240) reaches the preset value. When the target condensing temperature is less than the standard condensing temperature, the opening of the corresponding gas-side refrigerant pressure regulating component (250) is controlled until the temperature of the refrigerant on the gas side of the terminal heat exchange component (240) reaches the difference between the exhaust temperature and the standard condensing temperature and the target condensing temperature; the opening of the liquid-side refrigerant pressure regulating component (260) is controlled so that the difference between the target condensing temperature and the temperature of the refrigerant on the liquid side of the corresponding terminal heat exchange component (240) reaches the preset value.

9. The multi-unit heat pump system according to any one of claims 2 to 8, characterized in that, The controller (300) is configured to: Determine the operating status of the terminal heat exchanger (200); When the terminal heat exchange component (240) is in a non-operating state, the corresponding gas-side refrigerant pressure regulating component (250) and liquid-side refrigerant pressure regulating component (260) are controlled to be in a closed state.

10. The multi-unit heat pump system according to any one of claims 2 to 8, characterized in that, It also includes a first pressure detector (140), which is electrically connected to the controller (300) and is configured to detect the inlet pressure of the four-way valve (120) in the host heat exchanger (100); When the terminal heat exchanger (200) is in the second operating state, some terminal heat exchange components (240) are in the operating state, and some terminal heat exchange components (240) are in the non-operating state; the controller (300) is configured to: Based on the subcooling of the terminal heat exchange component (240) in the operating state and the inlet pressure, the terminal heat exchange component (240) in the non-operating state is controlled to store and release refrigerant.

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