Heat pump system

Abstract

The utility model discloses a heat pump system which comprises a compressor, a low-pressure gas-liquid separator, an outdoor heat exchanger, an indoor unit, a high-pressure gas-liquid separator and a heat recovery branch. And an outlet of the low-pressure gas-liquid separator is connected with an inlet of the compressor. The outdoor heat exchanger comprises a first refrigerant port and a second refrigerant port which are communicated, and the first refrigerant port is connected with an outlet of the compressor and an inlet of the low-pressure gas-liquid separator. The indoor unit comprises a third refrigerant port and a fourth refrigerant port which are communicated, the third refrigerant port is connected with the second refrigerant port, and the fourth refrigerant port is connected with an outlet of the compressor and an inlet of the low-pressure gas-liquid separator. The high-pressure gas-liquid separator comprises a first refrigerant inlet and a first refrigerant outlet which are communicated with each other, the first refrigerant outlet is used for outputting a liquid refrigerant after gas-liquid separation, the first refrigerant inlet is connected with an outlet of the compressor, and one path of the first refrigerant outlet is connected with the second refrigerant port and the third refrigerant port; and the other path is connected with an inlet of the low-pressure gas-liquid separator through a heat recovery branch. The pressure balance of the system can be improved.

Description

Technical Field

[0001] This utility model relates to the field of heat pump technology, and in particular to a heat pump system. Background Technology

[0002] In order to increase the stability of the system, HVAC equipment with related technologies may consider adding a high-pressure gas-liquid separator. However, after adding a high-pressure gas-liquid separator, problems such as oil accumulation or refrigerant migration may occur. Utility Model Content

[0003] The technical problem to be solved by this utility model is to address at least one defect in the related technologies mentioned in the background: after adding a high-pressure gas-liquid separator to the HVAC equipment of the related technologies, problems such as oil accumulation and refrigerant migration may occur, and to provide a heat pump system.

[0004] The technical solution adopted by this utility model to solve its technical problem is: to construct a heat pump system, including:

[0005] The compressor is used to compress refrigerant;

[0006] A low-pressure gas-liquid separator, the outlet of which is connected to the inlet of the compressor;

[0007] An outdoor heat exchanger includes a first refrigerant port and a second refrigerant port, the first refrigerant port being connected to the second refrigerant port, and the first refrigerant port being connected to the outlet of the compressor and the inlet of the low-pressure gas-liquid separator, respectively.

[0008] At least one indoor unit, the indoor unit including a third refrigerant port and a fourth refrigerant port, the third refrigerant port being connected to the fourth refrigerant port, the third refrigerant port being connected to the second refrigerant port, and the fourth refrigerant port being connected to the outlet of the compressor and the inlet of the low-pressure gas-liquid separator respectively;

[0009] The high-pressure gas-liquid separator includes a first refrigerant inlet and a first refrigerant outlet. The first refrigerant inlet is connected to the first refrigerant outlet and is connected to the outlet of the compressor. One path of the first refrigerant outlet is used to output liquid refrigerant after gas-liquid separation. Another path of the first refrigerant outlet is connected to the second refrigerant port and the third refrigerant port respectively. The other path of the first refrigerant outlet is connected to the inlet of the low-pressure gas-liquid separator via the heat recovery branch.

[0010] In some embodiments, at least a portion of the heat recovery branch is a capillary tube; and / or, at least a portion of the pipeline in the first refrigerant outlet branch is a capillary tube.

[0011] In some embodiments, the heat pump system further includes:

[0012] A branch valve is provided on the heat recovery branch.

[0013] In some embodiments, the heat pump system further includes:

[0014] A filter device is installed on the pipeline of the first refrigerant outlet, and the filter device is used to filter impurities.

[0015] In some embodiments, the high-pressure gas-liquid separator further includes a second refrigerant outlet, the first refrigerant inlet is connected to the second refrigerant outlet, and the second refrigerant outlet is used to output the gaseous refrigerant after gas-liquid separation;

[0016] The heat pump system also includes:

[0017] A heat recovery heat exchanger is used to realize heat exchange between refrigerant and heat storage medium for heat storage. The heat recovery heat exchanger includes a second refrigerant inlet and a third refrigerant outlet, and the second refrigerant inlet and the third refrigerant outlet are connected.

[0018] The compressor outlet is connected to the second refrigerant inlet, the third refrigerant outlet is connected to the first refrigerant inlet, and the second refrigerant outlet is connected to both the first refrigerant port and the fourth refrigerant port.

[0019] In some embodiments, the heat pump system further includes:

[0020] The first switching valve connects one outlet of the compressor to the second refrigerant inlet, and the other outlet of the compressor is connected to the first refrigerant port and the fourth refrigerant port respectively.

[0021] In some embodiments, the heat pump system further includes:

[0022] The first reversing valve connects the second refrigerant outlet to the first refrigerant port and the fourth refrigerant port, respectively.

[0023] In some embodiments, the heat pump system further includes:

[0024] The first refrigerant flow regulating device connects the first refrigerant outlet to the second refrigerant port and the third refrigerant port respectively.

[0025] In some embodiments, the heat pump system further includes:

[0026] The second refrigerant flow regulating device and the heat exchanger include a fifth refrigerant port, a sixth refrigerant port, a seventh refrigerant port, and an eighth refrigerant port; the fifth refrigerant port and the sixth refrigerant port are connected to form an enthalpy-increasing main path; one end of the second refrigerant flow regulating device is connected to the pipeline between the third refrigerant port and the fifth refrigerant port, and the other end of the second refrigerant flow regulating device is connected to the eighth refrigerant port via the seventh refrigerant port to form an enthalpy-increasing auxiliary path, and the eighth refrigerant port is connected to the inlet of the low-pressure gas-liquid separator.

[0027] In some embodiments, the heat pump system further includes:

[0028] The second and third switching valves are connected to the inlet of the low-pressure gas-liquid separator via the second switching valve, and the other end of the eighth refrigerant port is connected to the enthalpy-increasing port of the compressor via the third switching valve.

[0029] By implementing this utility model, the following beneficial effects can be achieved:

[0030] This invention provides a heat recovery branch between the first refrigerant outlet of the high-pressure gas-liquid separator and the inlet of the low-pressure gas-liquid separator. This heat recovery branch allows for the return of oil accumulated in the high-pressure gas-liquid separator and the release of refrigerant that has migrated into the high-pressure gas-liquid separator, thus relieving pressure and improving the system's pressure balance. Attached Figure Description

[0031] The present invention will be further described below with reference to the accompanying drawings and embodiments. In the accompanying drawings:

[0032] Figure 1 This is a schematic diagram of the heat pump system of this utility model;

[0033] Figure 2 This is a schematic diagram of the refrigerant flow direction in the heat pump system of this utility model, which produces hot water through a total heat recovery mode while cooling.

[0034] Figure 3 This is a schematic diagram of the flow direction of the first refrigerant in the heat pump system of this utility model, which produces hot water through waste heat recovery while cooling.

[0035] Figure 4 This is a schematic diagram of the flow direction of the second refrigerant in the heat pump system of this utility model, which produces hot water through waste heat recovery while cooling.

[0036] Figure 5 This is a schematic diagram of the flow direction of the first refrigerant in the heat pump system of this utility model, which produces hot water while heating.

[0037] Figure 6 This is a schematic diagram showing the flow direction of the second refrigerant in the heat pump system of this utility model, which produces hot water while heating.

[0038] Figure 7 This is a schematic diagram of the refrigerant flow direction in the heat pump system of this utility model when it is purely preparing hot water;

[0039] Figure 8 This is a schematic diagram of the refrigerant flow direction during cooling in the heat pump system of this utility model;

[0040] Figure 9 This is a schematic diagram of the refrigerant flow direction during heating in the heat pump system of this utility model. Detailed Implementation

[0041] To provide a clearer understanding of the technical features, objectives, and effects of this utility model, the specific embodiments of this utility model will now be described in detail with reference to the accompanying drawings.

[0042] It should be noted that, unless otherwise specified, the embodiments and features described in these embodiments can be combined with each other.

[0043] In the description of this utility model, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model. Furthermore, the terms "first," "second," etc., 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. Thus, features defined with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more.

[0044] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installed," "connected," "linked," "located in," and "located in" 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 mechanical connection or a chemical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal communication between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0045] It should be noted that the connections between ports, between ports and components, or between components described below are only physical structural connections and do not uniquely define the connectivity or refrigerant flow relationship.

[0046] like Figure 1 As shown, some embodiments of this utility model disclose a heat pump system, including a compressor 11, a low-pressure gas-liquid separator 12, an outdoor heat exchanger 13, at least one indoor unit 14, a high-pressure gas-liquid separator 15, and a heat recovery branch 16. It is understood that the "at least one" unit can be one, two, three, or any number of units. The specific details of this heat pump system are as follows:

[0047] The compressor 11 is used to compress the refrigerant. The low-pressure gas-liquid separator 12 is used to separate gaseous refrigerant and liquid refrigerant, and the outlet of the low-pressure gas-liquid separator 12 is connected to the inlet of the compressor 11.

[0048] The outdoor heat exchanger 13 is used to realize heat exchange between the refrigerant and the outside air. The outdoor heat exchanger 13 includes a first refrigerant port 131 and a second refrigerant port 132. The first refrigerant port 131 is connected to the second refrigerant port 132. The first refrigerant port 131 is connected to the outlet of the compressor 11 and the inlet of the low-pressure gas-liquid separator 12.

[0049] The indoor unit 14 is used to realize heat exchange between refrigerant and indoor air. The indoor unit 14 includes a third refrigerant port 141 and a fourth refrigerant port 142. The third refrigerant port 141 is connected to the fourth refrigerant port 142. The third refrigerant port 141 is connected to the second refrigerant port 132. The fourth refrigerant port 142 is connected to the outlet of the compressor 11 and the inlet of the low-pressure gas-liquid separator 12.

[0050] The high-pressure gas-liquid separator 15 is used to separate gaseous refrigerant and liquid refrigerant. The high-pressure gas-liquid separator 15 includes a first refrigerant inlet 151 and a first refrigerant outlet 152. The first refrigerant inlet 151 is connected to the first refrigerant outlet 152 and is connected to the outlet of the compressor 11. One path of the first refrigerant outlet 152 is used to output the liquid refrigerant after gas-liquid separation. One path of the first refrigerant outlet 152 is connected to the second refrigerant port 132 and the third refrigerant port 141 respectively. The other path of the first refrigerant outlet 152 is connected to the inlet of the low-pressure gas-liquid separator 12 via the heat recovery branch 16.

[0051] In this embodiment, a heat recovery branch 16 is provided between the first refrigerant outlet 152 of the high-pressure gas-liquid separator 15 and the inlet of the low-pressure gas-liquid separator 12. The heat recovery branch 16 can realize the return of oil accumulated in the high-pressure gas-liquid separator 15 on the one hand, and release the refrigerant that has migrated into the high-pressure gas-liquid separator 15 to relieve pressure, thereby improving the pressure balance of the system.

[0052] Furthermore, the gas-liquid separation function of the high-pressure gas-liquid separator 15 enables automatic refrigerant flow during mode switching, thereby improving system stability.

[0053] For example, the outdoor heat exchanger 13 is a finned heat exchanger, and the indoor unit 14 is a ducted air conditioner, which includes an indoor heat exchanger (such as a finned heat exchanger) and a fan. The finned heat exchanger and the ducted air conditioner mentioned here are just examples and are not intended to limit this application. Other types are also possible.

[0054] In some embodiments, such as Figure 1 As shown, the heat pump system also includes a branch valve 17, which is located on the heat recovery branch 16. Depending on the system operation, the branch valve 17 is opened to return oil or adjust the system pressure balance. For example, the branch valve 17 is a solenoid valve; however, this solenoid valve is merely an example and not intended to limit the scope of this application, and other types may also be used.

[0055] It should be noted that the branch valve 17 is not only open when the refrigerant is in a gaseous state, but can also be opened when the refrigerant is not in a gaseous state. That is, the branch valve 17 can be opened according to the system conditions, such as refrigerant migration, system pressure, and the oil return requirements of the compressor 11.

[0056] In some embodiments, such as Figure 1 As shown, at least a portion of the heat recovery branch 16 is a capillary tube, i.e. Figure 1 As shown in Figure 161, due to the high resistance of the capillary tube, it can be used to control the amount of refrigerant entering the low-pressure gas-liquid separator 12, preventing excessive refrigerant leakage into the low-pressure gas-liquid separator 12 after the branch valve 17 is opened. And / or, in some other embodiments, at least a portion of the pipeline of the first refrigerant outlet 152 is a capillary tube, i.e. Figure 1 As shown in 44. It can be understood that at least part can be partial or all.

[0057] In some embodiments, the heat pump system further includes a filter device located on a pipeline of the first refrigerant outlet 152, the filter device being used to filter impurities, absorb moisture, and prevent blockages.

[0058] In some embodiments, such as Figure 1 As shown, the high-pressure gas-liquid separator 15 also includes a second refrigerant outlet 153. The first refrigerant inlet 151 is connected to the second refrigerant outlet 153, and the second refrigerant outlet 153 is used to output the gaseous refrigerant after gas-liquid separation.

[0059] The heat pump system further includes a heat recovery heat exchanger 18, which is used to realize heat exchange between the refrigerant and the heat storage medium for heat storage. In some embodiments, it is used to realize heat exchange between the refrigerant and water to produce domestic hot water. In other embodiments, the heat recovery heat exchanger 18 is a heat storage device with heat storage material. The heat recovery heat exchanger 18 includes a second refrigerant inlet 181 and a third refrigerant outlet 182, and the second refrigerant inlet 181 and the third refrigerant outlet 182 are connected.

[0060] The compressor 11 has its outlet connected to the second refrigerant inlet 181, the third refrigerant outlet 182 connected to the first refrigerant inlet 151, and the second refrigerant outlet 153 connected to the first refrigerant port 131 and the fourth refrigerant port 142, respectively.

[0061] When the heat pump system includes the heat recovery heat exchanger 18, the system has multiple operating modes (see below for details). The high-pressure gas-liquid separator 15 can realize the automatic flow of refrigerant when switching between modes (mainly the cooling and total heat recovery domestic hot water mode and the cooling and waste heat recovery domestic hot water mode), thereby improving the stability of the system. However, oil accumulation and refrigerant migration problems are prone to occur in the high-pressure gas-liquid separator 15. Therefore, in the triple heat pump system with the heat recovery heat exchanger 18 and the high-pressure gas-liquid separator 15, adding the heat recovery branch 16 is crucial for the oil return and pressure stability of the triple heat pump system.

[0062] For example, the heat recovery heat exchanger 18 is a shell-and-tube heat exchanger. The shell-and-tube heat exchanger mentioned here is only an example and is not intended to limit this application. Other types are also possible.

[0063] In some embodiments, such as Figure 1 As shown, the heat recovery heat exchanger 18 further includes a first water inlet 183 and a first water outlet 184, with the first water inlet 183 and the first water outlet 184 connected together. The heat pump system also includes a domestic water tank 19, which includes a cold water inlet 191, a first water outlet 192, a first water return outlet 193, and a hot water outlet 194. The first water outlet 192 is connected to the first water inlet 183, and the first water outlet 184 is connected to the first water return outlet 193.

[0064] In some embodiments, such as Figure 1As shown, the heat pump system also includes a first water pump 20, which is installed in the inlet pipe (i.e., the pipe connecting the first outlet 192 and the first water inlet 183) or the outlet pipe (i.e., the pipe connecting the first water outlet 184 and the first return water inlet 193) of the heat recovery heat exchanger 18. The first water pump 20 is used to provide power for the water circulation between the heat recovery heat exchanger 18 and the domestic water tank 19.

[0065] In some embodiments, such as Figure 1 As shown, the heat recovery heat exchanger 18, the domestic water tank 19, and the first water pump 20 can be integrated into a domestic hot water module, which can be assembled by the user according to actual needs.

[0066] In some embodiments, such as Figure 1 As shown, the heat pump system also includes a first switching valve 21. One outlet of the compressor 11 is connected to the second refrigerant inlet 181 via the first switching valve 21, and the other outlet of the compressor 11 is connected to the first refrigerant port 131 and the fourth refrigerant port 142 respectively. When hot water needs to be prepared, the first switching valve 21 can be opened. For example, the first switching valve 21 is a two-way valve. The two-way valve mentioned here is only an example and is not intended to limit this application; other types are also possible.

[0067] In some embodiments, such as Figure 1 As shown, the heat pump system further includes a first reversing valve 22, and the second refrigerant outlet 153 is connected to the first refrigerant port 131 and the fourth refrigerant port 142 via the first reversing valve 22. Furthermore, another outlet of the compressor 11 is connected to the first refrigerant port 131 and the fourth refrigerant port 142 via the first reversing valve 22.

[0068] The first reversing valve 22 includes a first valve port 221, a second valve port 222, and a third valve port 223. The first valve port 221 is connected to the second refrigerant outlet 153, the second valve port 222 is connected to the first refrigerant port 131 and the fourth refrigerant port 142, and the third valve port 223 is connected to the outlet of the compressor 11. For example, the first reversing valve 22 is a three-way valve. The three-way valve mentioned here is only an example and is not intended to limit this application; other valves are also possible.

[0069] When in the cooling and waste heat recovery domestic hot water production mode and the heating and domestic hot water production mode, the first valve port 221 is connected to the second valve port 222, that is, the second refrigerant outlet 153 is connected to the first refrigerant port 131 or the fourth refrigerant port 142.

[0070] In cooling and heating modes, the third valve port 223 is connected to the second valve port 222, meaning the outlet of the compressor 11 is connected to either the first refrigerant port 131 or the fourth refrigerant port 142. Understandably, when it is necessary to regulate the amount of refrigerant entering the heat recovery heat exchanger 18 in cooling and waste heat recovery for domestic hot water production, or in heating and domestic hot water production, the third valve port 223 can also be connected to the second valve port 222.

[0071] In some embodiments, such as Figure 1 As shown, the heat pump system further includes a second reversing valve 23. The outlet of the compressor 11 is connected to the first refrigerant port 131 and the fourth refrigerant port 142 via the second reversing valve 23. The inlet of the low-pressure gas-liquid separator is connected to the first refrigerant port 131 and the fourth refrigerant port 142 via the second reversing valve 23. The third refrigerant outlet 182 is connected to the first refrigerant port 131 and the fourth refrigerant port 142 via the second reversing valve 23.

[0072] Specifically, the outlet of the compressor 11 is connected to the first refrigerant port 131 and the fourth refrigerant port 142 via the first reversing valve 22 and the second reversing valve 23, respectively. The third refrigerant outlet 182 is connected to the first refrigerant port 131 and the fourth refrigerant port 142 via the first refrigerant inlet 151, the second refrigerant outlet 153, the first reversing valve 22, and the second reversing valve 23, respectively.

[0073] The second reversing valve 23 includes a fourth valve port 231, a fifth valve port 232, a sixth valve port 233, and a seventh valve port 234. The fourth valve port 231 is connected to the compressor 11 (specifically, the second valve port 222 of the first reversing valve 22), the fifth valve port 232 is connected to the first refrigerant port 131, the sixth valve port 233 is connected to the inlet of the low-pressure gas-liquid separator 12, and the seventh valve port 234 is connected to the fourth refrigerant port 142. For example, the second reversing valve 23 is a four-way valve. The four-way valve mentioned here is only an example and is not intended to limit this application; other valves are also possible.

[0074] When the domestic hot water is in cooling and total heat recovery mode, the seventh valve port 234 is connected to the sixth valve port 233.

[0075] When in cooling and waste heat recovery domestic hot water mode and in cooling mode, the fourth valve port 231 is connected to the fifth valve port 232, and the seventh valve port 234 is connected to the sixth valve port 233.

[0076] When in heating plus domestic hot water mode and in heating mode, the fourth valve port 231 is connected to the seventh valve port 234, and the fifth valve port 232 is connected to the sixth valve port 233.

[0077] When in pure hot water mode, the fifth valve port 232 is connected to the sixth valve port 233.

[0078] In some embodiments, such as Figure 1 As shown, the heat pump system further includes a first refrigerant flow regulating device 24. The first refrigerant outlet 152 is connected via the first refrigerant flow regulating device 24 to the second refrigerant port 132 and the third refrigerant port 141, respectively. For example, the first refrigerant flow regulating device 24 can be an electronic expansion valve or a thermostatic expansion valve. The electronic expansion valve and the thermostatic expansion valve mentioned here are merely examples and are not intended to limit this application; other types are also possible.

[0079] In some embodiments, such as Figure 1 As shown, the heat pump system also includes a second refrigerant flow regulating device 25 and a heat exchanger 26, the heat exchanger 26 including a fifth refrigerant port 261, a sixth refrigerant port 262, a seventh refrigerant port 263 and an eighth refrigerant port 264.

[0080] The fifth refrigerant port 261 and the sixth refrigerant port 262 are connected to form an enthalpy-increasing main path. One end of the second refrigerant flow regulating device 25 is connected to the pipeline between the third refrigerant port 141 and the fifth refrigerant port 261, and the other end of the second refrigerant flow regulating device 25 is connected to the eighth refrigerant port 264 via the seventh refrigerant port 263 to form an enthalpy-increasing auxiliary path. The eighth refrigerant port 264 is connected to the inlet of the low-pressure gas-liquid separator 12.

[0081] In this embodiment, the heat pump system, by installing the heat exchanger 26 and the second refrigerant flow regulating device 25 at the outlet of the outdoor heat exchanger 13, allows the refrigerant from the outdoor heat exchanger 13 to enter the indoor unit 14 via the enthalpy-increasing main path (i.e., the sixth refrigerant port 262 and the fifth refrigerant port 261), and via the enthalpy-increasing auxiliary path (i.e., the second refrigerant flow regulating device 25, the seventh refrigerant port 263 and the eighth refrigerant port 264). 64) After the refrigerant is throttled and cooled by the second refrigerant flow regulating device 25 in the enthalpy-increasing auxiliary circuit, it can more efficiently absorb the heat from the refrigerant in the enthalpy-increasing main circuit in the heat exchanger 26. After absorbing heat, the refrigerant vaporizes and enters the inlet of the low-pressure gas-liquid separator 12. At the same time, the subcooling degree of the refrigerant after releasing heat in the enthalpy-increasing main circuit is increased, and the temperature of the refrigerant entering the indoor unit 14 is lower, thereby improving the cooling effect in summer.

[0082] For example, the second refrigerant flow regulating device 25 is an electronic expansion valve or a thermal expansion valve. The electronic expansion valve and the thermal expansion valve mentioned here are just examples and are not intended to limit this application. Other types are also possible.

[0083] The heat pump system also includes a second switching valve 27 and a third switching valve 28. One of the eighth refrigerant ports 264 is connected to the inlet of the low-pressure gas-liquid separator 12 via the second switching valve 27, and the other of the eighth refrigerant ports 264 is connected to the enthalpy-increasing port 113 of the compressor 11 via the third switching valve 28.

[0084] For example, the second switching valve 27 and the third switching valve 28 are solenoid valves. The solenoid valves mentioned here are just examples and are not intended to limit this application. They can also be other types.

[0085] In this embodiment, the heat pump system, by installing the heat exchanger 26 and the second refrigerant flow regulating device 25 at the outlet of the indoor unit 14, allows the refrigerant from the indoor unit 14 to enter the outdoor heat exchanger 13 via the enthalpy-increasing main path (i.e., the fifth refrigerant port 261 and the sixth refrigerant port 262), and via the enthalpy-increasing auxiliary path (i.e., the second refrigerant flow regulating device 25, the seventh refrigerant port 263 and the eighth refrigerant port 264) to enter the enthalpy-increasing port 113 of the compressor 11. After the refrigerant is throttled and cooled by the second refrigerant flow regulating device 25 in the enthalpy-increasing auxiliary path, it can more efficiently absorb the heat from the refrigerant in the enthalpy-increasing main path in the heat exchanger 26. After absorbing heat, the refrigerant vaporizes and enters the enthalpy-increasing port 113 of the compressor 11, thereby improving the performance of the compressor 11. Meanwhile, the subcooling of the refrigerant after the heat release through the enthalpy-increasing main circuit is increased, and the temperature of the refrigerant entering the outdoor heat exchanger 13 is lower. Especially in cold winters, the temperature of the refrigerant can be lower than the outdoor temperature, thereby improving the heat absorption performance of the outdoor heat exchanger 13 in low-temperature environments and enhancing the subsequent heating effect.

[0086] In some embodiments, under the cooling and total heat recovery domestic hot water production mode, the refrigerant exiting the compressor 11 passes through the second refrigerant inlet 181, the third refrigerant outlet 182, the first refrigerant inlet 151, the first refrigerant outlet 152, and the enthalpy-increasing main path, and then splits into two paths. One path returns to the inlet of the low-pressure gas-liquid separator 12 via the third refrigerant port 141 and the fourth refrigerant port 142, while the other path returns to the inlet of the low-pressure gas-liquid separator 12 via the enthalpy-increasing auxiliary path and the second switching valve 27. Simultaneously, all the heat of the refrigerant is exchanged in the heat recovery heat exchanger 18.

[0087] In the cooling and waste heat recovery mode for domestic hot water production, the refrigerant exiting the compressor 11 passes through the second refrigerant inlet 181, the third refrigerant outlet 182, the first refrigerant inlet 151, the second refrigerant outlet 153, the first refrigerant port 131, the second refrigerant port 132, and the enthalpy-increasing main path, and then splits into two paths. One path returns to the inlet of the low-pressure gas-liquid separator 12 via the third refrigerant port 141 and the fourth refrigerant port 142, while the other path returns to the inlet of the low-pressure gas-liquid separator 12 via the enthalpy-increasing auxiliary path and the second switching valve 27. Simultaneously, some of the heat from the refrigerant is exchanged in the heat recovery heat exchanger 18.

[0088] In the heating and domestic hot water mode, the refrigerant exiting the compressor 11 passes through the second refrigerant inlet 181, the third refrigerant outlet 182, the first refrigerant inlet 151, the second refrigerant outlet 153, the fourth refrigerant port 142, and the third refrigerant port 141, and then splits into two paths. One path passes through the enthalpy-increasing main path, the second refrigerant port 132, and the first refrigerant port 131, and then returns to the inlet of the low-pressure gas-liquid separator 12. The other path passes through the enthalpy-increasing auxiliary path and the third switching valve 28, and returns to the enthalpy-increasing port 113 of the compressor 11. At the same time, part of the heat of the refrigerant is exchanged in the heat recovery heat exchanger 18.

[0089] In cooling mode, the refrigerant exits from the compressor 11 and splits into two paths after passing through the first refrigerant port 131, the second refrigerant port 132, and the enthalpy-increasing main path. One path returns to the inlet of the low-pressure gas-liquid separator 12 via the third refrigerant port 141 and the fourth refrigerant port 142, while the other path returns to the inlet of the low-pressure gas-liquid separator 12 via the enthalpy-increasing auxiliary path and the second switching valve 27.

[0090] In heating mode, the refrigerant exits from the compressor 11 and is split into two paths after passing through the fourth refrigerant port 142 and the third refrigerant port 141. One path passes through the enthalpy-increasing main path, the second refrigerant port 132 and the first refrigerant port 131 and returns to the inlet of the low-pressure gas-liquid separator 12. The other path passes through the enthalpy-increasing auxiliary path and the third switching valve 28 and returns to the enthalpy-increasing port 113 of the compressor 11.

[0091] It should be noted that "all the heat is exchanged in the heat recovery heat exchanger 18" means that the refrigerant is completely formed into liquid refrigerant after heat exchange in the heat recovery heat exchanger 18, while "part of the heat is exchanged in the heat recovery heat exchanger 18" means that the refrigerant is formed into gaseous refrigerant after heat exchange in the heat recovery heat exchanger 18.

[0092] In some embodiments, such as Figure 1 As shown, the heat pump system further includes a third refrigerant flow regulating device 29, and the second refrigerant port 132 is connected to the sixth refrigerant port 262 via the third refrigerant flow regulating device 29. For example, the third refrigerant flow regulating device 29 is an electronic expansion valve or a thermostatic expansion valve. The electronic expansion valve and the thermostatic expansion valve mentioned here are merely examples and are not intended to limit this application; other types are also possible.

[0093] The temperature of the refrigerant entering the outdoor heat exchanger 13 can be further reduced by the third refrigerant flow regulating device 29.

[0094] Furthermore, the heat pump system also includes a one-way valve 30. One path of the second refrigerant port 132 is connected to the sixth refrigerant port 262 via the third refrigerant flow regulating device 29, and the other path of the second refrigerant port 132 is connected to the sixth refrigerant port 262 via the one-way valve 30. The one-way valve 30 is oriented towards the sixth refrigerant port 262. It should be noted that the orientation of the one-way valve 30 refers to the direction of refrigerant flow, not its spatial orientation.

[0095] In some embodiments, such as Figure 1 As shown, the heat pump system also includes an oil separator 31 and an oil return pipe 32. The oil separator 31 is located at the outlet end of the compressor 11. The oil separator 31 is used to separate the lubricating oil from the compressor 11 mixed in the refrigerant and return it to the compressor 11 through the oil return pipe 32.

[0096] In some embodiments, such as Figure 1 As shown, the heat pump system also includes a fourth refrigerant flow regulating device 33 corresponding to each indoor unit 14. The third refrigerant port 141 is connected to the fifth refrigerant port 261 and one end of the second refrigerant flow regulating device 25 via the fourth refrigerant flow regulating device 33. For example, the fourth refrigerant flow regulating device 33 is an electronic expansion valve or a thermostatic expansion valve. The electronic expansion valve and the thermostatic expansion valve mentioned here are only examples and are not intended to limit this application; other types are also possible.

[0097] In this embodiment, the subcooling of the refrigerant after the heat release through the enthalpy-increasing main circuit is improved, and the temperature of the refrigerant entering the indoor unit 14 is lower, thereby reducing the throttling noise of the fourth refrigerant flow regulating device 33 during summer cooling.

[0098] In some embodiments, such as Figure 1 As shown, the heat pump system also includes a fresh air module (not shown in the figure), which is provided for each indoor unit 14 and is used to introduce fresh outdoor air and exhaust stale indoor air.

[0099] In some embodiments, such as Figure 1As shown, the heat pump system also includes at least two indoor units 14, a gas pipe 34, and a liquid pipe 35. In each indoor unit 14, the fourth refrigerant port 142 is connected to the corresponding branch port in the gas pipe 34, and the third refrigerant port 141 is connected to the corresponding branch port in the liquid pipe 35. The main port of the liquid pipe 35 is connected to the fifth refrigerant port 261 and one end of the second refrigerant flow regulating device 25, respectively. The main port of the gas pipe 34 (specifically, the main port of the gas pipe 34 via the second reversing valve 23) is connected to the outlet of the compressor 11 and the inlet of the low-pressure gas-liquid separator 12, respectively.

[0100] In some embodiments, such as Figure 1 As shown, the heat pump system further includes a fourth switching valve 36, a fifth switching valve 37, a sixth switching valve 38, and a seventh switching valve 39. The fourth switching valve 36 is located on the pipeline between the first switching valve 21 and the second refrigerant inlet 181. The fifth switching valve 37 is located on the pipeline between the third refrigerant outlet 182 and the first refrigerant inlet 151. One end of the sixth switching valve 38 is connected to the fifth refrigerant port 261 and one end of the second refrigerant flow regulating device 25, and the other end of the sixth switching valve 38 is connected to the main interface end of the liquid pipe 35. The seventh switching valve 39 is located on the pipeline between the main interface end of the gas pipe 34 and the second reversing valve 23 (specifically, the seventh valve port 234 of the second reversing valve).

[0101] For example, the fourth switching valve 36, the fifth switching valve 37, the sixth switching valve 38 and the seventh switching valve 39 are shut-off valves. The shut-off valves mentioned here are just examples and are not intended to limit this application. They can also be other types.

[0102] In some embodiments, such as Figure 1 As shown, the compressor 11, the low-pressure gas-liquid separator 12, the outdoor heat exchanger 13, the high-pressure gas-liquid separator 15, the first switching valve 21, the first reversing valve 22, the second reversing valve 23, the first refrigerant flow regulating device 24, the second refrigerant flow regulating device 25, the heat exchanger 26, the second switching valve 27, the third switching valve 28, the third refrigerant flow regulating device 29, the oil separator 31, the oil return pipe 32, the fourth switching valve 36, the fifth switching valve 37, the sixth switching valve 38, and the seventh switching valve 39 are all integrated into the outdoor unit. It can be understood that at least one of the fourth switching valve 36, the fifth switching valve 37, the sixth switching valve 38, and the seventh switching valve 39 can be located inside or on the outer surface of the outdoor unit.

[0103] In some embodiments, such as Figure 1 As shown, the heat pump system further includes at least one heat exchanger 40, which is used to realize heat exchange between the refrigerant and the water in the terminal 42. The heat exchanger 40 includes a ninth refrigerant port 401 and a tenth refrigerant port 402, which are connected to each other. The ninth refrigerant port 401 is connected to the corresponding branch end in the gas pipe 34, and the tenth refrigerant port 402 is connected to the corresponding branch end in the liquid pipe 35. It can be understood that at least one can be one, two, three, or any number.

[0104] In some embodiments, such as Figure 1 As shown, the heat pump system further includes a fifth refrigerant flow regulating device 41, which is used to throttle and cool the refrigerant. The tenth refrigerant port 402 is connected to the corresponding branch port in the liquid pipe 35 via the fifth refrigerant flow regulating device 41. For example, the fifth refrigerant flow regulating device 41 can be an electronic expansion valve or a thermostatic expansion valve. These examples are merely illustrative and not intended to limit the scope of this application; other types are also possible.

[0105] In some embodiments, such as Figure 1 As shown, the heat exchanger 40 further includes a second water inlet 403 and a second water outlet 404, which are connected in communication. The heat pump system also includes the terminal 42, which includes a second water outlet 421 and a second water return outlet 422. The second water outlet 421 is connected to the second water inlet 403, and the second water outlet 404 is connected to the second water return outlet 422. For example, the terminal 42 may be a ground pipe, which achieves underfloor heating or cooling effects through heat exchange with the heat exchanger 40. If there are multiple ground pipes, a manifold can also be installed at the terminal. The ground pipe mentioned here is only an example and is not intended to limit this application; other types are also possible.

[0106] In some embodiments, such as Figure 1 As shown, the heat pump system further includes a second water pump 43, which is disposed in the inlet pipe (i.e., the pipe connecting the second outlet 421 and the second water inlet 403) or the outlet pipe (i.e., the pipe connecting the second water outlet 404 and the second return water inlet 422) of the terminal 42. The second water pump 43 is used to provide power for the water circulation between the heat exchanger 40 and the terminal 42.

[0107] In some embodiments, such as Figure 1As shown, the heat exchanger 40, the fifth refrigerant flow regulating device 41, and the second water pump 43 can be integrated into a hydraulic module, which can be installed on the gas pipe 34 and the liquid pipe 35 according to the user's needs. Furthermore, the indoor unit 14 and the hydraulic module can operate independently or simultaneously.

[0108] Completely, in some embodiments, such as Figure 1 As shown, the connection relationships between the components in the heat pump system are as follows:

[0109] One outlet of the compressor 11 is connected to the second refrigerant inlet 181 via the first switching valve 21 and the fourth switching valve 36. The other outlet of the compressor 11 is connected to the third valve port 223 of the first reversing valve 22. The third refrigerant outlet 182 is connected to the first refrigerant inlet 151 of the high-pressure gas-liquid separator 15 via the fifth switching valve 37. The second refrigerant outlet 153 of the high-pressure gas-liquid separator 15 is connected to the first valve port 221 of the first reversing valve 22. One outlet of the first refrigerant outlet 152 of the high-pressure gas-liquid separator 15 is connected to the sixth refrigerant port 262 of the heat exchanger 26 via the first refrigerant flow regulating device 24. The other outlet of the first refrigerant outlet 152 of the high-pressure gas-liquid separator 15 is connected to the inlet of the low-pressure gas-liquid separator 12 via the heat recovery branch 16. The second valve port 222 of the first reversing valve 22 is connected to the fourth valve port 231 of the second reversing valve 23. The fifth port 232 of the second reversing valve 23 is connected to the first refrigerant port 131 of the outdoor heat exchanger 13. The sixth port 233 of the second reversing valve 23 is connected to the inlet of the low-pressure gas-liquid separator 12, and the outlet of the low-pressure gas-liquid separator 12 is connected to the inlet of the compressor 11. The seventh port 234 of the second reversing valve 23 is connected to the main interface of the gas pipe 34 via the seventh switching valve 39. The main interface of the liquid pipe 35 is connected, via the sixth switching valve 38, one path to the fifth refrigerant port 261 of the heat exchanger 26, and the other path of the main interface of the liquid pipe 35 is connected via the sixth switching valve 38 to the seventh refrigerant port 263 of the heat exchanger 26 via the second refrigerant flow regulating device 25. The sixth refrigerant port 262 of the heat exchanger 26 is connected via the third refrigerant flow regulating device 29 to the second refrigerant port 132 of the outdoor heat exchanger 13. The other end of the sixth refrigerant port 262 is connected via the one-way valve 30 to the same port, with the one-way valve 30 oriented towards the sixth refrigerant port 262 of the heat exchanger 26. The eighth refrigerant port 264 of the heat exchanger 26 is connected via the second switching valve 27 to the inlet of the low-pressure gas-liquid separator 12. The other end of the eighth refrigerant port 264 is connected via the third switching valve 28 to the enthalpy-increasing port 113 of the compressor 11.

[0110] The first outlet 192 of the domestic water tank 19 is connected to the first water inlet 183 of the heat recovery heat exchanger 18 via the first water pump 20, and the first water outlet 184 of the heat recovery heat exchanger 18 is connected to the first return water inlet 193 of the domestic water tank 19.

[0111] The fourth refrigerant port 142 of the indoor unit 14 is connected to the corresponding branch port in the gas pipe 34, and the third refrigerant port 141 of the indoor unit 14 is connected to the corresponding branch port in the liquid pipe 35 via the fourth refrigerant flow regulating device 33.

[0112] The ninth refrigerant port 401 of the heat exchanger 40 is connected to the corresponding branch port in the gas pipe 34, and the tenth refrigerant port 402 of the heat exchanger 40 is connected to the corresponding branch port in the liquid pipe 35 via the fifth refrigerant flow regulating device 41. The second water outlet 421 of the terminal 42 is connected to the second water inlet 403 of the heat exchanger 40 via the second water pump 43, and the second water outlet 404 of the heat exchanger 40 is connected to the second return water port 422 of the terminal 42.

[0113] Under different circumstances, the heat pump system will be connected to different valve ports, which will be described below. Figure 1 The diagram illustrates the refrigerant flow direction for each mode of the heat pump system. It should be noted that components not explicitly marked as "on" are considered off, as detailed below:

[0114] like Figure 2As shown, in the cooling and total heat recovery domestic hot water mode, the first refrigerant flow regulating device 24, the fourth refrigerant flow regulating device 33, the fifth refrigerant flow regulating device 41, the first switching valve 21, the second switching valve 27, the fourth switching valve 36, the fifth switching valve 37, the sixth switching valve 38, and the seventh switching valve 39 are open. The first valve port 221 of the first reversing valve 22 is connected to or not connected to the second valve port 222. The seventh valve port 234 of the second reversing valve 23 is connected to the sixth valve port 233. That is, when hot water needs to be prepared quickly in cooling mode, the high-temperature gaseous refrigerant output from the compressor 11 enters the second refrigerant inlet 181 of the heat recovery heat exchanger 18 after passing through the first switching valve 21 and the fourth switching valve 36. The high-temperature gaseous refrigerant exchanges heat with the water in the domestic water tank 19 in the heat recovery heat exchanger 18, and becomes a medium-temperature liquid refrigerant after preparing hot water. The medium-temperature liquid refrigerant output from the third refrigerant outlet 182 of the heat recovery heat exchanger 18 enters the first refrigerant inlet 151 of the high-pressure gas-liquid separator 15 through the fifth switching valve 37, and undergoes further gas-liquid separation in the high-pressure gas-liquid separator 15 to ensure that the refrigerant output from the first refrigerant outlet 152 is pure liquid. The medium-temperature liquid refrigerant output from the first refrigerant outlet 152 is throttled and cooled by the first refrigerant flow regulating device 24, becoming a lower-temperature liquid refrigerant. It then enters the enthalpy-increasing main circuit (i.e., the sixth refrigerant port 262 and the fifth refrigerant port 261). One path of the low-temperature liquid refrigerant output from the enthalpy-increasing main circuit enters the liquid pipe 35 via the sixth switching valve 38. The other path of the low-temperature liquid refrigerant output from the enthalpy-increasing main circuit of the heat exchanger 26 enters the enthalpy-increasing auxiliary circuit (i.e., the...). The second refrigerant flow regulating device 25, the seventh refrigerant port 263, and the sixth refrigerant port 262) allow the low-temperature liquid refrigerant to be throttled and cooled in the enthalpy-increasing auxiliary circuit. After this cooling, the liquid refrigerant can absorb heat from the main enthalpy-increasing circuit more efficiently in the heat exchanger 26, becoming a low-temperature gaseous refrigerant. The low-temperature gaseous refrigerant output from the enthalpy-increasing auxiliary circuit returns to the inlet of the compressor 11 after passing through the second switching valve 27 and the low-pressure gas-liquid separator 12. The low-temperature liquid refrigerant in the enthalpy-increasing main circuit is cooled down by heat exchange and becomes an even lower-temperature liquid refrigerant. The low-temperature liquid refrigerant enters the fourth refrigerant flow regulating device 33 in the liquid pipe 35. After being throttled and cooled by the fourth refrigerant flow regulating device 33, it becomes an even lower-temperature liquid refrigerant and then enters the third refrigerant port 141 of the indoor unit 14. The low-temperature liquid refrigerant exchanges heat with the indoor air in the indoor unit 14. After absorbing the heat from the indoor air, the low-temperature liquid refrigerant evaporates and becomes a low-temperature gaseous refrigerant. The indoor unit 14 blows out cold air, and the low-temperature gaseous refrigerant output from the fourth refrigerant port 142 of the indoor unit 14 enters the gas pipe 34.Furthermore, the low-temperature liquid refrigerant enters the fifth refrigerant flow regulating device 41 within the liquid pipe 35. After being throttled and cooled by the fifth refrigerant flow regulating device 41, it becomes an even lower-temperature liquid refrigerant, which then enters the tenth refrigerant port 402 of the heat exchanger 40. In the heat exchanger 40, the low-temperature liquid refrigerant exchanges heat with the water at the terminal 42. The low-temperature liquid refrigerant absorbs heat from the water and evaporates into low-temperature gaseous refrigerant, turning the water in the terminal 42 into cold water. The low-temperature gaseous refrigerant output from the ninth refrigerant port 401 of the heat exchanger 40 enters the gas pipe 34. The low-temperature gaseous refrigerant output from the gas pipe 34 passes through the seventh switching valve 39, the seventh valve port 234 and the sixth valve port 233 of the second reversing valve 23, and the low-pressure gas-liquid separator 12 before returning to the inlet of the compressor 11, in a continuous cycle.

[0115] The heat recovery heat exchanger 18 is connected to the domestic water tank 19, thereby recovering and utilizing all the condensation heat originally used for heat exchange with the air in the outdoor heat exchanger 13 during cooling. This avoids heat waste caused by heat exchange between the outdoor heat exchanger 13 and the air. The recovered heat is then exchanged with the water in the domestic water tank 19 in the heat recovery heat exchanger 18, quickly producing hot water, improving energy efficiency and increasing the speed of hot water production. Furthermore, by configuring the heat exchanger 40 and the terminal 42, ground cooling and other effects can be achieved simultaneously, further improving energy efficiency.

[0116] like Figure 3As shown, when the domestic hot water reaches a certain temperature, it can be switched to a cooling and waste heat recovery domestic hot water mode. In the cooling and waste heat recovery domestic hot water mode, the fourth refrigerant flow regulating device 33, the fifth refrigerant flow regulating device 41, the first switching valve 21, the second switching valve 27, the fourth switching valve 36, the fifth switching valve 37, the sixth switching valve 38, and the seventh switching valve 39 are opened. The first valve port 221 of the first reversing valve 22 is connected to the second valve port 222. The fourth valve port 231 of the second reversing valve 23 is connected to the fifth valve port 232. The seventh valve port 234 of the second reversing valve 23 is connected to the sixth valve port 233. That is, when hot water needs to be prepared in cooling mode, the high-temperature gaseous refrigerant output from the outlet of the compressor 11 enters the second refrigerant inlet 181 of the heat recovery heat exchanger 18 after passing through the first switching valve 21 and the fourth switching valve 36. The high-temperature gaseous refrigerant exchanges heat with the water in the domestic water tank 19 in the heat recovery heat exchanger 18, and becomes a medium-temperature gaseous refrigerant after preparing hot water. The medium-temperature gaseous refrigerant output from the third refrigerant outlet 182 of the heat recovery heat exchanger 18 enters the first refrigerant inlet 151 of the high-pressure gas-liquid separator 15 through the fifth switching valve 37, and undergoes further gas-liquid separation in the high-pressure gas-liquid separator 15 to ensure that the refrigerant output from the second refrigerant outlet 153 is pure gas. The medium-temperature gaseous refrigerant output from the second refrigerant outlet 153 enters the first refrigerant port 131 of the outdoor heat exchanger 13 after passing through the first valve port 221 and the second valve port 222 of the first reversing valve 22, and the fourth valve port 231 and the fifth valve port 232 of the second reversing valve 23. The medium-temperature gaseous refrigerant condenses and releases heat in the outdoor heat exchanger 13, becoming a medium-temperature liquid refrigerant. The medium-temperature liquid refrigerant output from the second refrigerant port 132 of the outdoor heat exchanger 13 enters the enthalpy-increasing main circuit (i.e., the sixth refrigerant port 262 and the fifth refrigerant port 261) through the one-way valve 30. One path of the medium-temperature liquid refrigerant output from the enthalpy-increasing main circuit enters the liquid pipe 35 through the sixth switching valve 38. Another path of the medium-temperature liquid refrigerant output from the enthalpy-increasing main circuit of the heat exchanger 26 enters the enthalpy-increasing auxiliary circuit (i.e., the second refrigerant flow regulating device). 25. The medium-temperature liquid refrigerant (the seventh refrigerant port 263 and the sixth refrigerant port 262) is throttled and cooled by the second refrigerant flow regulating device 25 in the enthalpy-increasing auxiliary circuit. It can then absorb heat from the refrigerant in the heat exchanger 26 more efficiently and become a low-temperature gaseous refrigerant. The low-temperature gaseous refrigerant output from the enthalpy-increasing auxiliary circuit returns to the inlet of the compressor 11 after passing through the second switching valve 27 and the low-pressure gas-liquid separator 12.The medium-temperature liquid refrigerant in the enthalpy-increasing main circuit is cooled down by heat exchange and becomes a lower-temperature liquid refrigerant. One path of the low-temperature liquid refrigerant output from the enthalpy-increasing main circuit enters the liquid pipe 35 through the sixth switching valve 38. Another path of the low-temperature liquid refrigerant output from the enthalpy-increasing main circuit of the heat exchanger 26 enters the enthalpy-increasing auxiliary circuit. The medium-temperature or low-temperature liquid refrigerant enters the fourth refrigerant flow regulating device 33 in the liquid pipe 35. After being throttled and cooled by the fourth refrigerant flow regulating device 33, it becomes a lower-temperature liquid refrigerant and then enters the third refrigerant port 141 of the indoor unit 14. The low-temperature liquid refrigerant exchanges heat with the indoor air in the indoor unit 14. After absorbing heat from the indoor air, the low-temperature liquid refrigerant evaporates and becomes a low-temperature gaseous refrigerant. The indoor unit 14 blows out cold air, and the low-temperature gaseous refrigerant output from the fourth refrigerant port 142 of the indoor unit 14 enters the gas pipe 34. Furthermore, the medium-temperature or low-temperature liquid refrigerant enters the fifth refrigerant flow regulating device 41 within the liquid pipe 35. After being throttled and cooled by the fifth refrigerant flow regulating device 41, it becomes an even lower-temperature liquid refrigerant, which then enters the tenth refrigerant port 402 of the heat exchanger 40. The low-temperature liquid refrigerant exchanges heat with the water at the terminal 42 within the heat exchanger 40. The low-temperature liquid refrigerant absorbs heat from the water and evaporates into a low-temperature gaseous refrigerant, turning the water in the terminal 42 into cold water. The low-temperature gaseous refrigerant output from the ninth refrigerant port 401 of the heat exchanger 40 enters the gas pipe 34. The low-temperature gaseous refrigerant output from the gas pipe 34 passes through the seventh switching valve 39, the seventh valve port 234 and the sixth valve port 233 of the second reversing valve 23, and the low-pressure gas-liquid separator 12 before returning to the inlet of the compressor 11, in a continuous cycle.

[0117] The heat recovery heat exchanger 18 is connected to the domestic water tank 19, thereby recovering at least a portion of the condensation heat originally used for heat exchange with the air in the outdoor heat exchanger 13 during cooling. This avoids heat waste due to heat exchange between the outdoor heat exchanger 13 and the air. The recovered heat is exchanged with the water in the domestic water tank 19 in the heat recovery heat exchanger 18, quickly producing hot water, improving energy efficiency and increasing the speed of hot water production. Furthermore, by configuring the heat exchanger 40 and the terminal 42, ground cooling and other effects can be achieved simultaneously, further improving energy efficiency.

[0118] Specifically, Figure 3 and Figure 2 The difference in the illustrated embodiment is that, Figure 3 In order to recover and reuse at least a portion of the condensation heat originally used by the outdoor heat exchanger 13 for heat exchange with the air, Figure 2 In order to recover and utilize all the condensed heat originally used by the outdoor heat exchanger 13 for heat exchange with the air.

[0119] like Figure 4As shown, in the cooling and waste heat recovery domestic hot water production mode, the fourth refrigerant flow regulating device 33, the fifth refrigerant flow regulating device 41, the first switching valve 21, the second switching valve 27, the fourth switching valve 36, the fifth switching valve 37, the sixth switching valve 38, and the seventh switching valve 39 are opened. The second valve port 222 of the first reversing valve 22 is connected to the first valve port 221 and the third valve port 223. The fourth valve port 231 of the second reversing valve 23 is connected to the fifth valve port 232. The seventh valve port 234 of the second reversing valve 23 is connected to the sixth valve port 233. That is, when hot water needs to be prepared in cooling mode, the high-temperature gaseous refrigerant output from the outlet of the compressor 11 enters the second refrigerant inlet 181 of the heat recovery heat exchanger 18 after passing through the first switching valve 21 and the fourth switching valve 36. The high-temperature gaseous refrigerant output from the outlet of the compressor 11 also enters the first refrigerant port 131 of the outdoor heat exchanger 13 after passing through the third valve port 223 and the second valve port 222 of the first reversing valve 22, and the fourth valve port 231 and the fifth valve port 232 of the second reversing valve 23. High-temperature gaseous refrigerant exchanges heat with water in the domestic water tank 19 in the heat recovery heat exchanger 18 to produce hot water, which then becomes medium-temperature gaseous refrigerant. The medium-temperature gaseous refrigerant output from the third refrigerant outlet 182 of the heat recovery heat exchanger 18 enters the first refrigerant inlet 151 of the high-pressure gas-liquid separator 15 via the fifth switching valve 37, where further gas-liquid separation is performed to ensure that the refrigerant output from the second refrigerant outlet 153 is pure gas. The medium-temperature gaseous refrigerant output from the second refrigerant outlet 153 enters the first refrigerant port 131 of the outdoor heat exchanger 13 after passing through the first valve port 221 and the second valve port 222 of the first reversing valve 22, and the fourth valve port 231 and the fifth valve port 232 of the second reversing valve 23. The medium-temperature gaseous refrigerant condenses and releases heat in the outdoor heat exchanger 13, becoming medium-temperature liquid refrigerant. The medium-temperature liquid refrigerant output from the second refrigerant port 132 of the outdoor heat exchanger 13 enters the enthalpy-increasing main circuit (i.e., the sixth refrigerant port 262 and the fifth refrigerant port 261) via the one-way valve 30. One path of the medium-temperature liquid refrigerant output from the enthalpy-increasing main circuit enters the liquid pipe 35 via the sixth switching valve 38. Another path of the medium-temperature liquid refrigerant output from the enthalpy-increasing main circuit of the heat exchanger 26 enters the enthalpy-increasing auxiliary circuit (i.e., the second refrigerant flow regulating device). 25. The medium-temperature liquid refrigerant (the seventh refrigerant port 263 and the sixth refrigerant port 262) is throttled and cooled by the second refrigerant flow regulating device 25 in the enthalpy-increasing auxiliary circuit. It can then absorb heat from the refrigerant in the heat exchanger 26 more efficiently and become a low-temperature gaseous refrigerant. The low-temperature gaseous refrigerant output from the enthalpy-increasing auxiliary circuit returns to the inlet of the compressor 11 after passing through the second switching valve 27 and the low-pressure gas-liquid separator 12.The medium-temperature liquid refrigerant in the enthalpy-increasing main circuit is cooled down by heat exchange and becomes a lower-temperature liquid refrigerant. One path of the low-temperature liquid refrigerant output from the enthalpy-increasing main circuit enters the liquid pipe 35 through the sixth switching valve 38. Another path of the low-temperature liquid refrigerant output from the enthalpy-increasing main circuit of the heat exchanger 26 enters the enthalpy-increasing auxiliary circuit. The medium-temperature or low-temperature liquid refrigerant enters the fourth refrigerant flow regulating device 33 in the liquid pipe 35. After being throttled and cooled by the fourth refrigerant flow regulating device 33, it becomes a lower-temperature liquid refrigerant and then enters the third refrigerant port 141 of the indoor unit 14. The low-temperature liquid refrigerant exchanges heat with the indoor air in the indoor unit 14. After absorbing heat from the indoor air, the low-temperature liquid refrigerant evaporates and becomes a low-temperature gaseous refrigerant. The indoor unit 14 blows out cold air, and the low-temperature gaseous refrigerant output from the fourth refrigerant port 142 of the indoor unit 14 enters the gas pipe 34. Furthermore, the medium-temperature or low-temperature liquid refrigerant enters the fifth refrigerant flow regulating device 41 within the liquid pipe 35. After being throttled and cooled by the fifth refrigerant flow regulating device 41, it becomes an even lower-temperature liquid refrigerant, which then enters the tenth refrigerant port 402 of the heat exchanger 40. The low-temperature liquid refrigerant exchanges heat with the water at the terminal 42 within the heat exchanger 40. The low-temperature liquid refrigerant absorbs heat from the water and evaporates into a low-temperature gaseous refrigerant, turning the water in the terminal 42 into cold water. The low-temperature gaseous refrigerant output from the ninth refrigerant port 401 of the heat exchanger 40 enters the gas pipe 34. The low-temperature gaseous refrigerant output from the gas pipe 34 passes through the seventh switching valve 39, the seventh valve port 234 and the sixth valve port 233 of the second reversing valve 23, and the low-pressure gas-liquid separator 12 before returning to the inlet of the compressor 11, in a continuous cycle.

[0120] Specifically, Figure 4 and Figure 3 The difference in the illustrated embodiment is that, Figure 4 In the illustrated embodiment, an additional refrigerant path enters the outdoor heat exchanger 13 via the third and second valve ports 223 and 222 of the first reversing valve 22, and the fourth and fifth valve ports 231 and 232 of the second reversing valve 23. This allows for better control of the amount of refrigerant entering the heat recovery heat exchanger 18. Furthermore, the path where the refrigerant from the compressor 11 directly reaches the second reversing valve 23 ensures that it is in a pure gaseous state. This pure gaseous state further ensures that the second reversing valve 23 has sufficient pressure differential for reversing, thus reducing pressure loss in the refrigerant pipeline.

[0121] like Figure 5As shown, in the heating and domestic hot water mode, the second refrigerant flow regulating device 25, the fourth refrigerant flow regulating device 33, the third refrigerant flow regulating device 29, the fifth refrigerant flow regulating device 41, the first switching valve 21, the third switching valve 28, the fourth switching valve 36, the fifth switching valve 37, the sixth switching valve 38, and the seventh switching valve 39 are open. The first valve port 221 of the first reversing valve 22 is connected to the second valve port 222. The fourth valve port 231 of the second reversing valve 23 is connected to the seventh valve port 234. The fifth valve port 232 of the second reversing valve 23 is connected to the sixth valve port 233. That is, when hot water needs to be prepared in heating mode, the high-temperature gaseous refrigerant output from the outlet of the compressor 11 enters the second refrigerant inlet 181 of the heat recovery heat exchanger 18 after passing through the first switch valve 21 and the fourth switch valve 36. The high-temperature gaseous refrigerant exchanges heat with the water in the domestic water tank 19 in the heat recovery heat exchanger 18, and becomes a medium-temperature gaseous refrigerant after preparing hot water. The medium-temperature gaseous refrigerant output from the third refrigerant outlet 182 of the heat recovery heat exchanger 18 enters the first refrigerant inlet 151 of the high-pressure gas-liquid separator 15 through the fifth switch valve 37, and undergoes further gas-liquid separation in the high-pressure gas-liquid separator 15 to ensure that the refrigerant output from the second refrigerant outlet 153 is pure gas. The medium-temperature gaseous refrigerant output from the second refrigerant outlet 153 enters the gas pipe 34 via the first valve port 221 and the second valve port 222 of the first reversing valve 22, the fourth valve port 231 and the seventh valve port 234 of the second reversing valve 23, and the seventh switching valve 39. The medium-temperature gaseous refrigerant enters the fourth refrigerant port 142 of the indoor unit 14 within the gas pipe 34. The medium-temperature gaseous refrigerant exchanges heat with the indoor air in the indoor unit 14. After releasing heat into the indoor air, the medium-temperature gaseous refrigerant condenses into medium-temperature liquid refrigerant, and the indoor unit 14 blows out hot air. The medium-temperature liquid refrigerant output from the third refrigerant port 141 of the indoor unit 14 is throttled and cooled by the fourth refrigerant flow regulating device 33, becoming low-temperature liquid refrigerant. Then, the low-temperature liquid refrigerant output from the fourth refrigerant flow regulating device 33 enters the liquid pipe 35. Furthermore, the medium-temperature gaseous refrigerant enters the ninth refrigerant port 401 of the heat exchanger 40 through the gas pipe 34. After heat exchange with the water in the terminal 42 in the heat exchanger 40, the medium-temperature gaseous refrigerant becomes a medium-temperature liquid refrigerant, while the water in the terminal 42 becomes hot water. The medium-temperature liquid refrigerant output from the tenth refrigerant port 402 of the heat exchanger 40 is throttled and cooled by the fifth refrigerant flow regulating device 41, becoming a low-temperature liquid refrigerant. Then, the low-temperature liquid refrigerant output from the fifth refrigerant flow regulating device 41 enters the liquid pipe 35.The low-temperature liquid refrigerant output from the liquid pipe 35 enters the enthalpy-increasing main circuit (i.e., the fifth refrigerant port 261 and the sixth refrigerant port 262) through the sixth switching valve 38, and enters the enthalpy-increasing auxiliary circuit (i.e., the second refrigerant flow regulating device 25, the seventh refrigerant port 263 and the sixth refrigerant port 262) through the sixth switching valve 38. After being throttled and cooled by the second refrigerant flow regulating device 25 in the enthalpy-increasing auxiliary circuit, the low-temperature liquid refrigerant can absorb heat from the refrigerant in the enthalpy-increasing main circuit more efficiently in the heat exchanger 26, becoming low-temperature gaseous refrigerant. The low-temperature gaseous refrigerant output from the enthalpy-increasing auxiliary circuit returns to the enthalpy-increasing port 113 of the compressor 11 through the third switching valve 28. The low-temperature liquid refrigerant in the enthalpy-increasing main path, after heat exchange to lower its temperature, becomes an even lower-temperature liquid refrigerant. It then enters the third refrigerant flow regulating device 29 for throttling and cooling, becoming an even lower-temperature liquid refrigerant before entering the second refrigerant port 132 of the outdoor heat exchanger 13. In the outdoor heat exchanger 13, the low-temperature liquid refrigerant evaporates and absorbs heat, becoming a low-temperature gaseous refrigerant. The low-temperature gaseous refrigerant output from the first refrigerant port 131 of the outdoor heat exchanger 13 passes through the fifth valve port 232 and the sixth valve port 233 of the second reversing valve 23, and the low-pressure gas-liquid separator 12 before returning to the inlet of the compressor 11, repeating the cycle. This heat pump system can produce hot water and provide underfloor heating while simultaneously providing heating, thus improving energy efficiency.

[0122] like Figure 6As shown, in the heating and domestic hot water mode, the second refrigerant flow regulating device 25, the fourth refrigerant flow regulating device 33, the third refrigerant flow regulating device 29, the fifth refrigerant flow regulating device 41, the first switching valve 21, the third switching valve 28, the fourth switching valve 36, the fifth switching valve 37, the sixth switching valve 38, and the seventh switching valve 39 are open. The second valve port 222 of the first reversing valve 22 is connected to the first valve port 221 and the third valve port 223. The fourth valve port 231 of the second reversing valve 23 is connected to the seventh valve port 234. The fifth valve port 232 of the second reversing valve 23 is connected to the sixth valve port 233. That is, when hot water needs to be prepared in heating mode, the high-temperature gaseous refrigerant output from the outlet of the compressor 11 enters the second refrigerant inlet 181 of the heat recovery heat exchanger 18 after passing through the first switching valve 21 and the fourth switching valve 36. The high-temperature gaseous refrigerant output from the outlet of the compressor 11 also enters the gas pipe 34 through the third valve port 223 and the second valve port 222 of the first reversing valve 22, the fourth valve port 231 and the seventh valve port 234 of the second reversing valve 23, and the seventh switching valve 39. The high-temperature gaseous refrigerant exchanges heat with the water in the domestic water tank 19 in the heat recovery heat exchanger 18 to prepare hot water, and then becomes a medium-temperature gaseous refrigerant. The medium-temperature gaseous refrigerant output from the third refrigerant outlet 182 of the heat recovery heat exchanger 18 enters the first refrigerant inlet 151 of the high-pressure gas-liquid separator 15 through the fifth switching valve 37, and undergoes further gas-liquid separation in the high-pressure gas-liquid separator 15 to ensure that the refrigerant output from the second refrigerant outlet 153 is pure gas. The medium-temperature gaseous refrigerant output from the second refrigerant outlet 153 enters the gas pipe 34 via the first valve port 221 and the second valve port 222 of the first reversing valve 22, the fourth valve port 231 and the seventh valve port 234 of the second reversing valve 23, and the seventh switching valve 39. The medium-temperature gaseous refrigerant enters the fourth refrigerant port 142 of the indoor unit 14 within the gas pipe 34. The medium-temperature gaseous refrigerant exchanges heat with the indoor air in the indoor unit 14. After releasing heat into the indoor air, the medium-temperature gaseous refrigerant condenses into medium-temperature liquid refrigerant, and the indoor unit 14 blows out hot air. The medium-temperature liquid refrigerant output from the third refrigerant port 141 of the indoor unit 14 is throttled and cooled by the fourth refrigerant flow regulating device 33, becoming low-temperature liquid refrigerant. Then, the low-temperature liquid refrigerant output from the fourth refrigerant flow regulating device 33 enters the liquid pipe 35.Furthermore, the medium-temperature gaseous refrigerant enters the ninth refrigerant port 401 of the heat exchanger 40 through the gas pipe 34. After heat exchange with the water in the terminal 42 in the heat exchanger 40, the medium-temperature gaseous refrigerant becomes a medium-temperature liquid refrigerant, while the water in the terminal 42 becomes hot water. The medium-temperature liquid refrigerant output from the tenth refrigerant port 402 of the heat exchanger 40 is throttled and cooled by the fifth refrigerant flow regulating device 41, becoming a low-temperature liquid refrigerant. Then, the low-temperature liquid refrigerant output from the fifth refrigerant flow regulating device 41 enters the liquid pipe 35. The low-temperature liquid refrigerant output from the liquid pipe 35 enters the enthalpy-increasing main circuit (i.e., the fifth refrigerant port 261 and the sixth refrigerant port 262) through the sixth switching valve 38, and enters the enthalpy-increasing auxiliary circuit (i.e., the second refrigerant flow regulating device 25, the seventh refrigerant port 263 and the sixth refrigerant port 262) through the sixth switching valve 38. After being throttled and cooled by the second refrigerant flow regulating device 25 in the enthalpy-increasing auxiliary circuit, the low-temperature liquid refrigerant can absorb heat from the refrigerant in the enthalpy-increasing main circuit more efficiently in the heat exchanger 26, becoming low-temperature gaseous refrigerant. The low-temperature gaseous refrigerant output from the enthalpy-increasing auxiliary circuit returns to the enthalpy-increasing port 113 of the compressor 11 through the third switching valve 28. The low-temperature liquid refrigerant in the enthalpy-increasing main circuit is cooled down by heat exchange and becomes an even lower-temperature liquid refrigerant. It then enters the third refrigerant flow regulating device 29 for throttling and cooling, becoming an even lower-temperature liquid refrigerant. It then enters the second refrigerant port 132 of the outdoor heat exchanger 13. The low-temperature liquid refrigerant evaporates and absorbs heat in the outdoor heat exchanger 13, becoming a low-temperature gaseous refrigerant. The low-temperature gaseous refrigerant output from the first refrigerant port 131 of the outdoor heat exchanger 13 passes through the fifth valve port 232 and the sixth valve port 233 of the second reversing valve 23 and the low-pressure gas-liquid separator 12 before returning to the inlet of the compressor 11, repeating the cycle.

[0123] Specifically, Figure 6 and Figure 5 The difference in the illustrated embodiment is that, Figure 6 In the illustrated embodiment, an additional path leads from the third and second valve ports 223 and 222 of the first reversing valve 22, the fourth and seventh valve ports 231 and 234 of the second reversing valve 23, and the sixth switching valve 38 into the gas pipe 34. This allows for better control of the amount of refrigerant entering the heat recovery heat exchanger 18. Furthermore, the path from the compressed refrigerant directly to the second reversing valve 23 ensures that the refrigerant is in a gaseous state. The pure gaseous refrigerant further ensures that the second reversing valve 23 has sufficient pressure differential for reversing, thus minimizing pressure loss in the refrigerant pipeline.

[0124] like Figure 7As shown, in pure hot water mode, the first refrigerant flow regulating device 24, the third refrigerant flow regulating device 29, the first switching valve 21, the fourth switching valve 36 and the fifth switching valve 37 are open, the first valve port 221 of the first reversing valve 22 is connected to or not connected to the second valve port 222, and the fifth valve port 232 of the second reversing valve 23 is connected to the sixth valve port 233. That is, when only hot water needs to be produced, the high-temperature gaseous refrigerant output from the outlet of the compressor 11 enters the second refrigerant inlet 181 of the heat recovery heat exchanger 18 after passing through the first switching valve 21 and the fourth switching valve 36. The high-temperature gaseous refrigerant exchanges heat with the water in the domestic water tank 19 in the heat recovery heat exchanger 18, and becomes a medium-temperature liquid refrigerant after producing hot water. The medium-temperature liquid refrigerant output from the third refrigerant outlet 182 of the heat recovery heat exchanger 18 enters the first refrigerant inlet 151 of the high-pressure gas-liquid separator 15 through the fifth switching valve 37, and undergoes further gas-liquid separation in the high-pressure gas-liquid separator 15 to ensure that the refrigerant output from the first refrigerant outlet 152 is pure liquid. The medium-temperature liquid refrigerant output from the first refrigerant outlet 152 is throttled and cooled by the first refrigerant flow regulating device 24, becoming a lower-temperature liquid refrigerant. It then enters the third refrigerant flow regulating device 29 for further throttling and cooling, becoming an even lower-temperature liquid refrigerant. It then enters the second refrigerant port 132 of the outdoor heat exchanger 13. The low-temperature liquid refrigerant evaporates and absorbs heat in the outdoor heat exchanger 13, becoming a low-temperature gaseous refrigerant. The low-temperature gaseous refrigerant output from the first refrigerant port 131 of the outdoor heat exchanger 13 passes through the fifth valve port 232 and the sixth valve port 233 of the second reversing valve 23 and the low-pressure gas-liquid separator 12 before returning to the inlet of the compressor 11, repeating the cycle.

[0125] like Figure 8As shown, in cooling mode, the second refrigerant flow regulating device 25, the fourth refrigerant flow regulating device 33, the fifth refrigerant flow regulating device 41, the second switching valve 27, the sixth switching valve 38, and the seventh switching valve 39 are open. The third valve port 223 of the first reversing valve 22 is connected to the second valve port 222, the fourth valve port 231 of the second reversing valve 23 is connected to the fifth valve port 232, and the seventh valve port 234 of the second reversing valve 23 is connected to the sixth valve port 233. That is, during summer cooling, the high-temperature gaseous refrigerant output from the compressor 11 enters the first refrigerant port 131 of the outdoor heat exchanger 13 after passing through the third valve port 223 and the second valve port 222 of the first reversing valve 22, and the fourth valve port 231 and the fifth valve port 232 of the second reversing valve 23. The medium-temperature gaseous refrigerant condenses and releases heat in the outdoor heat exchanger 13, becoming a medium-temperature liquid refrigerant. The medium-temperature liquid refrigerant output from the second refrigerant port 132 of the outdoor heat exchanger 13 enters the enthalpy-increasing main circuit (i.e., the sixth refrigerant port 262 and the fifth refrigerant port 261) via the one-way valve 30. One path of the medium-temperature liquid refrigerant output from the enthalpy-increasing main circuit enters the liquid pipe 35 via the sixth switching valve 38. Another path of the medium-temperature liquid refrigerant output from the enthalpy-increasing main circuit of the heat exchanger 26 enters the enthalpy-increasing auxiliary circuit (i.e., the second refrigerant flow regulating device). 25. The medium-temperature liquid refrigerant (the seventh refrigerant port 263 and the sixth refrigerant port 262) is throttled and cooled by the second refrigerant flow regulating device 25 in the enthalpy-increasing auxiliary circuit. It can then absorb heat from the refrigerant in the heat exchanger 26 more efficiently and become a low-temperature gaseous refrigerant. The low-temperature gaseous refrigerant output from the enthalpy-increasing auxiliary circuit returns to the inlet of the compressor 11 after passing through the second switching valve 27 and the low-pressure gas-liquid separator 12. The medium-temperature liquid refrigerant in the enthalpy-increasing main circuit is cooled down by heat exchange and becomes a lower-temperature liquid refrigerant. One path of the low-temperature liquid refrigerant output from the enthalpy-increasing main circuit enters the liquid pipe 35 through the sixth switching valve 38. Another path of the low-temperature liquid refrigerant output from the enthalpy-increasing main circuit of the heat exchanger 26 enters the enthalpy-increasing auxiliary circuit. The medium-temperature or low-temperature liquid refrigerant enters the fourth refrigerant flow regulating device 33 in the liquid pipe 35. After being throttled and cooled by the fourth refrigerant flow regulating device 33, it becomes a lower-temperature liquid refrigerant and then enters the third refrigerant port 141 of the indoor unit 14. The low-temperature liquid refrigerant exchanges heat with the indoor air in the indoor unit 14. After absorbing heat from the indoor air, the low-temperature liquid refrigerant evaporates and becomes a low-temperature gaseous refrigerant. The indoor unit 14 blows out cold air, and the low-temperature gaseous refrigerant output from the fourth refrigerant port 142 of the indoor unit 14 enters the gas pipe 34.Furthermore, the medium-temperature or low-temperature liquid refrigerant enters the fifth refrigerant flow regulating device 41 within the liquid pipe 35. After being throttled and cooled by the fifth refrigerant flow regulating device 41, it becomes an even lower-temperature liquid refrigerant, which then enters the tenth refrigerant port 402 of the heat exchanger 40. The low-temperature liquid refrigerant exchanges heat with the water at the terminal 42 within the heat exchanger 40. The low-temperature liquid refrigerant absorbs heat from the water and evaporates into a low-temperature gaseous refrigerant, turning the water in the terminal 42 into cold water. The low-temperature gaseous refrigerant output from the ninth refrigerant port 401 of the heat exchanger 40 enters the gas pipe 34. The low-temperature gaseous refrigerant output from the gas pipe 34 passes through the seventh switching valve 39, the seventh valve port 234 and the sixth valve port 233 of the second reversing valve 23, and the low-pressure gas-liquid separator 12 before returning to the inlet of the compressor 11, repeating the cycle. This heat pump system can achieve both cooling and ground cooling effects, improving energy efficiency.

[0126] like Figure 9As shown, in heating mode, the second refrigerant flow regulating device 25, the third refrigerant flow regulating device 29, the fourth refrigerant flow regulating device 33, the fifth refrigerant flow regulating device 41, the third switching valve 28, the sixth switching valve 38, and the seventh switching valve 39 are open. The second valve port 222 of the first reversing valve 22 is connected to the third valve port 223. The fourth valve port 231 of the second reversing valve 23 is connected to the seventh valve port 234. The fifth valve port 232 of the second reversing valve 23 is connected to the sixth valve port 233. That is, when heating is required in winter, the high-temperature gaseous refrigerant output from the compressor 11 enters the gas pipe 34 through the third valve port 223 and the second valve port 222 of the first reversing valve 22, the fourth valve port 231 and the seventh valve port 234 of the second reversing valve 23, and the seventh switching valve 39. The medium-temperature gaseous refrigerant enters the fourth refrigerant port 142 of the indoor unit 14 in the gas pipe 34. The medium-temperature gaseous refrigerant exchanges heat with the indoor air in the indoor unit 14. After releasing heat into the indoor air, the medium-temperature gaseous refrigerant condenses into medium-temperature liquid refrigerant. The indoor unit 14 blows out hot air. The medium-temperature liquid refrigerant output from the third refrigerant port 141 of the indoor unit 14 is throttled and cooled by the fourth refrigerant flow regulating device 33 and becomes low-temperature liquid refrigerant. Then, the low-temperature liquid refrigerant output from the fourth refrigerant flow regulating device 33 enters the liquid pipe 35. Furthermore, the medium-temperature gaseous refrigerant enters the ninth refrigerant port 401 of the heat exchanger 40 through the gas pipe 34. After heat exchange with the water in the terminal 42 in the heat exchanger 40, the medium-temperature gaseous refrigerant becomes a medium-temperature liquid refrigerant, while the water in the terminal 42 becomes hot water. The medium-temperature liquid refrigerant output from the tenth refrigerant port 402 of the heat exchanger 40 is throttled and cooled by the fifth refrigerant flow regulating device 41, becoming a low-temperature liquid refrigerant. Then, the low-temperature liquid refrigerant output from the fifth refrigerant flow regulating device 41 enters the liquid pipe 35. The low-temperature liquid refrigerant output from the liquid pipe 35 enters the enthalpy-increasing main circuit (i.e., the fifth refrigerant port 261 and the sixth refrigerant port 262) through the sixth switching valve 38, and enters the enthalpy-increasing auxiliary circuit (i.e., the second refrigerant flow regulating device 25, the seventh refrigerant port 263 and the sixth refrigerant port 262) through the sixth switching valve 38. After being throttled and cooled by the second refrigerant flow regulating device 25 in the enthalpy-increasing auxiliary circuit, the low-temperature liquid refrigerant can absorb heat from the refrigerant in the enthalpy-increasing main circuit more efficiently in the heat exchanger 26, becoming low-temperature gaseous refrigerant. The low-temperature gaseous refrigerant output from the enthalpy-increasing auxiliary circuit returns to the enthalpy-increasing port 113 of the compressor 11 through the third switching valve 28.The low-temperature liquid refrigerant in the enthalpy-increasing main circuit, after being cooled by heat exchange, becomes an even lower-temperature liquid refrigerant. It then enters the third refrigerant flow regulating device 29 for throttling and cooling, becoming an even lower-temperature liquid refrigerant before entering the second refrigerant port 132 of the outdoor heat exchanger 13. In the outdoor heat exchanger 13, the low-temperature liquid refrigerant evaporates and absorbs heat, becoming a low-temperature gaseous refrigerant. The low-temperature gaseous refrigerant output from the first refrigerant port 131 of the outdoor heat exchanger 13 passes through the fifth valve port 232 and the sixth valve port 233 of the second reversing valve 23, and the low-pressure gas-liquid separator 12 before returning to the inlet of the compressor 11, in a continuous cycle. This heat pump system can provide heating while also achieving effects such as underfloor heating, improving energy efficiency.

[0127] It should be noted that the terms high, medium, and low temperatures mentioned above are only relative descriptions, and gaseous refrigerant can also refer to a two-phase state of gas and liquid or a gaseous state, which is not limited here.

[0128] By implementing this utility model, the following beneficial effects can be achieved:

[0129] This invention provides a heat recovery branch 16 between the first refrigerant outlet 152 of the high-pressure gas-liquid separator 15 and the inlet of the low-pressure gas-liquid separator 12. The heat recovery branch 16 can, on the one hand, return the oil accumulated in the high-pressure gas-liquid separator 15, and on the other hand, release the refrigerant that has migrated into the high-pressure gas-liquid separator 15 and relieve pressure, thereby improving the pressure balance of the system.

[0130] It is understood that the above embodiments only illustrate some implementation methods of this utility model, and their descriptions are relatively specific and detailed, but they should not be construed as limiting the scope of this utility model patent. It should be noted that those skilled in the art can freely combine the above embodiments or technical features without departing from the concept of this utility model, and can also make several modifications and improvements, all of which fall within the protection scope of this utility model. That is, the embodiments described "in some embodiments" can be freely combined with any of the preceding and following embodiments. Therefore, all equivalent transformations and modifications made within the scope of the claims of this utility model should fall within the coverage of the claims of this utility model.

Claims

1. A heat pump system, characterized in that, include: The compressor is used to compress refrigerant; A low-pressure gas-liquid separator, the outlet of which is connected to the inlet of the compressor; An outdoor heat exchanger includes a first refrigerant port and a second refrigerant port, the first refrigerant port being connected to the second refrigerant port, and the first refrigerant port being connected to the outlet of the compressor and the inlet of the low-pressure gas-liquid separator, respectively. At least one indoor unit, the indoor unit including a third refrigerant port and a fourth refrigerant port, the third refrigerant port being connected to the fourth refrigerant port, the third refrigerant port being connected to the second refrigerant port, and the fourth refrigerant port being connected to the outlet of the compressor and the inlet of the low-pressure gas-liquid separator respectively; The high-pressure gas-liquid separator includes a first refrigerant inlet and a first refrigerant outlet. The first refrigerant inlet is connected to the first refrigerant outlet and is connected to the outlet of the compressor. One path of the first refrigerant outlet is used to output liquid refrigerant after gas-liquid separation. Another path of the first refrigerant outlet is connected to the second refrigerant port and the third refrigerant port respectively. The other path of the first refrigerant outlet is connected to the inlet of the low-pressure gas-liquid separator via the heat recovery branch.

2. The heat pump system according to claim 1, characterized in that, At least a portion of the heat recovery branch is a capillary tube; and / or, at least a portion of the pipeline of the first refrigerant outlet is a capillary tube.

3. The heat pump system according to claim 1, characterized in that, The heat pump system also includes: A branch valve is provided on the heat recovery branch.

4. The heat pump system according to claim 1, characterized in that, The heat pump system also includes: A filter device is installed on the pipeline of the first refrigerant outlet, and the filter device is used to filter impurities.

5. The heat pump system according to any one of claims 1-4, characterized in that, The high-pressure gas-liquid separator also includes a second refrigerant outlet, and the first refrigerant inlet is connected to the second refrigerant outlet. The second refrigerant outlet is used to output the gaseous refrigerant after gas-liquid separation. The heat pump system also includes: A heat recovery heat exchanger is used to realize heat exchange between refrigerant and heat storage medium for heat storage. The heat recovery heat exchanger includes a second refrigerant inlet and a third refrigerant outlet, and the second refrigerant inlet and the third refrigerant outlet are connected. The compressor outlet is connected to the second refrigerant inlet, the third refrigerant outlet is connected to the first refrigerant inlet, and the second refrigerant outlet is connected to both the first refrigerant port and the fourth refrigerant port.

6. The heat pump system according to claim 5, characterized in that, The heat pump system also includes: The first switching valve connects one outlet of the compressor to the second refrigerant inlet, and the other outlet of the compressor is connected to the first refrigerant port and the fourth refrigerant port respectively.

7. The heat pump system according to claim 5, characterized in that, The heat pump system also includes: The first reversing valve connects the second refrigerant outlet to the first refrigerant port and the fourth refrigerant port, respectively.

8. The heat pump system according to claim 5, characterized in that, The heat pump system also includes: The first refrigerant flow regulating device connects the first refrigerant outlet to the second refrigerant port and the third refrigerant port respectively.

9. The heat pump system according to claim 5, characterized in that, The heat pump system also includes: The second refrigerant flow regulating device and the heat exchanger include a fifth refrigerant port, a sixth refrigerant port, a seventh refrigerant port, and an eighth refrigerant port; the fifth refrigerant port and the sixth refrigerant port are connected to form an enthalpy-increasing main path; one end of the second refrigerant flow regulating device is connected to the pipeline between the third refrigerant port and the fifth refrigerant port, and the other end of the second refrigerant flow regulating device is connected to the eighth refrigerant port via the seventh refrigerant port to form an enthalpy-increasing auxiliary path, and the eighth refrigerant port is connected to the inlet of the low-pressure gas-liquid separator.

10. The heat pump system according to claim 9, characterized in that, The heat pump system also includes: The second and third switching valves are connected to the inlet of the low-pressure gas-liquid separator via the second switching valve, and the other end of the eighth refrigerant port is connected to the enthalpy-increasing port of the compressor via the third switching valve.

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