Heat pump system

Abstract

The utility model discloses a heat pump system. The heat pump system comprises a compressor; a refrigerant-air heat exchanger; a first refrigerant-water heat exchanger fluidly connected to a heat storage device for providing domestic hot water; a second refrigerant-water heat exchanger fluidly connected to a terminal device for space cooling or space heating; a first throttling element fluidly connected to the refrigerant-air heat exchanger; the first refrigerant flow direction switching valve is in fluid connection with the refrigerant-air heat exchanger and the compressor; the second refrigerant flow direction switching valve is in fluid connection with the first refrigerant-water heat exchanger and the compressor; the third refrigerant flow direction switching valve is in fluid connection with the second refrigerant-water heat exchanger and the compressor; the first refrigerant flow direction switching valve, the second refrigerant flow direction switching valve and the third refrigerant flow direction switching valve are used for switching the flow directions of refrigerants, so that the refrigerant-air heat exchanger, the first refrigerant-water heat exchanger and the second refrigerant-water heat exchanger work as condensers or evaporators; according to the invention, multiple modes can be flexibly realized, and user experience is prevented from being sacrificed.

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] Existing heat pump systems can generally provide space cooling, space heating, and domestic hot water.

[0003] However, the three functional modes are implemented alternately. When a user needs a large amount of domestic hot water but the remaining water in the tank is insufficient, the heat pump system can only pause heating or cooling to prioritize meeting the demand for domestic hot water. This results in the indoor temperature not being maintained at the user's set temperature, leading to poor user comfort.

[0004] The information disclosed in this background section is only intended to enhance the understanding of the background technology of this application, and therefore may include prior art that is not known to those skilled in the art. Utility Model Content

[0005] The first aspect of this application provides a heat pump system, comprising: a compressor for compressing a refrigerant; a refrigerant-air heat exchanger for exchanging heat between the refrigerant and air; a first refrigerant-water heat exchanger for exchanging heat between the refrigerant and water, fluidly connected to a heat storage device, the heat storage device being used to provide domestic hot water; a second refrigerant-water heat exchanger for exchanging heat between the refrigerant and water, fluidly connected to a terminal device, the terminal device being used for space cooling or space heating; and a first throttling element fluidly connected to the refrigerant-air heat exchanger. It also includes: a first refrigerant flow direction switching valve, which is fluidly connected to the refrigerant-air heat exchanger and the compressor; a second refrigerant flow direction switching valve, which is fluidly connected to the first refrigerant-water heat exchanger and the compressor; and a third refrigerant flow direction switching valve, which is fluidly connected to the second refrigerant-water heat exchanger and the compressor. The first, second, and third refrigerant flow direction switching valves are used to switch the refrigerant flow direction so that the refrigerant-air heat exchanger and / or the first and / or the second refrigerant-water heat exchanger operate as a condenser or an evaporator.

[0006] The above technical solution has the following advantages or beneficial effects: This application can realize multiple working modes, avoiding the need to pause heating or cooling, which would cause the indoor temperature to fail to maintain the user-set temperature and result in poor user comfort.

[0007] In some embodiments of this application, the heat pump system further includes: a second throttling element fluidly connected to the first refrigerant-water heat exchanger; in space cooling mode, the first refrigerant flow direction switching valve, the second refrigerant flow direction switching valve, and the third refrigerant flow direction switching valve can switch the refrigerant flow direction, such that the refrigerant-air heat exchanger functions as a condenser, the first refrigerant-water heat exchanger functions as an evaporator, and the second refrigerant-water heat exchanger functions as an evaporator to provide chilled water for cooling to the terminal equipment; or in space cooling mode, the first refrigerant flow direction switching valve, the second refrigerant flow direction switching valve, and the third refrigerant flow direction switching valve can switch the refrigerant flow direction, such that the refrigerant-air heat exchanger functions as a condenser, and the second refrigerant-water heat exchanger functions as an evaporator to provide chilled water for cooling to the terminal equipment; the second throttling element remains fully closed to cut off the refrigerant passage of the first refrigerant-water heat exchanger.

[0008] The above technical solution has the following advantages or beneficial effects: through the cooperation of the second throttling element, the first refrigerant flow switching valve, the second refrigerant flow switching valve and the third refrigerant flow switching valve, it can adapt to the space cooling needs of different loads.

[0009] In some embodiments of this application, the heat pump system further includes: a second throttling element fluidly connected to a first refrigerant-water heat exchanger; in a space heating mode, the first refrigerant flow direction switching valve, the second refrigerant flow direction switching valve, and the third refrigerant flow direction switching valve can switch the refrigerant flow direction, such that the refrigerant-air heat exchanger functions as an evaporator, the first refrigerant-water heat exchanger functions as a condenser, and the second refrigerant-water heat exchanger functions as a condenser to provide hot water for heating to the heat storage device; or in a space heating mode, the first refrigerant flow direction switching valve, the second refrigerant flow direction switching valve, and the third refrigerant flow direction switching valve can switch the refrigerant flow direction, such that the refrigerant-air heat exchanger functions as an evaporator, and the second refrigerant-water heat exchanger functions as a condenser to provide hot water for heating to the terminal device; the second throttling element is kept below a set opening to limit the refrigerant flow rate in the first refrigerant-water heat exchanger.

[0010] The above technical solution has the following advantages or beneficial effects: through the cooperation of the second throttling element, the first refrigerant flow switching valve, the second refrigerant flow switching valve and the third refrigerant flow switching valve, it can adapt to the space heating requirements of different loads.

[0011] In some embodiments of this application, the heat pump system further includes: a third throttling element fluidly connected to a second refrigerant-water heat exchanger; in domestic hot water mode, the first refrigerant flow direction switching valve, the second refrigerant flow direction switching valve, and the third refrigerant flow direction switching valve can switch the refrigerant flow direction, such that the refrigerant-air heat exchanger is used as an evaporator, the first refrigerant-water heat exchanger is used as a condenser, and the second refrigerant-water heat exchanger is used as a condenser to provide hot water for heating to the heat storage device; or, the first refrigerant flow direction switching valve, the second refrigerant flow direction switching valve, and the third refrigerant flow direction switching valve can switch the refrigerant flow direction, such that the refrigerant-air heat exchanger is used as an evaporator, the first refrigerant-water heat exchanger is used as a condenser, and the third throttling element is kept below a set opening to limit the refrigerant flow rate in the second refrigerant-water heat exchanger.

[0012] The above technical solution has the following advantages or beneficial effects: through the cooperation of the third throttling element, the first refrigerant flow switching valve, the second refrigerant flow switching valve and the third refrigerant flow switching valve, it can adapt to the domestic hot water demand under different loads.

[0013] In some embodiments of this application, the heat pump system further includes: a second throttling element fluidly connected to a first refrigerant-water heat exchanger; a first refrigerant flow direction switching valve, a second refrigerant flow direction switching valve, and a third refrigerant flow direction switching valve capable of switching the refrigerant flow direction, such that the refrigerant-air heat exchanger functions as an evaporator, the first refrigerant-water heat exchanger functions as a condenser to provide hot water for heating to a heat storage device, and the second refrigerant-water heat exchanger functions as a condenser to provide hot water for heating to a terminal device; or, the first refrigerant flow direction switching valve, the second refrigerant flow direction switching valve, and the third refrigerant flow direction switching valve capable of switching the refrigerant flow direction, such that the refrigerant-air heat exchanger functions as an evaporator, and the first refrigerant-water heat exchanger functions as a condenser to provide hot water for heating to both the heat storage device and the terminal device; the second throttling element is maintained below a set opening to limit the refrigerant flow rate in the first refrigerant-water heat exchanger.

[0014] The above technical solution has the following advantages or beneficial effects: through the cooperation of the second throttling element and the first refrigerant flow switching valve, the second refrigerant flow switching valve and the third refrigerant flow switching valve, the needs for space heating and domestic hot water can be met simultaneously.

[0015] In some embodiments of this application, the first refrigerant flow switching valve, the second refrigerant flow switching valve, and the third refrigerant flow switching valve can switch the refrigerant flow direction, such that the refrigerant-air heat exchanger functions as an evaporator, the first refrigerant-water heat exchanger functions as a condenser to provide hot water for heating to the heat storage device, and the second refrigerant-water heat exchanger functions as an evaporator to provide cold water for cooling to the terminal device; or

[0016] The first refrigerant flow switching valve, the second refrigerant flow switching valve, and the third refrigerant flow switching valve can switch the refrigerant flow direction, so that the refrigerant-air heat exchanger is used as a condenser, the first refrigerant-water heat exchanger is used as a condenser to provide hot water for heating to the heat storage equipment, and the second refrigerant-water heat exchanger is used as an evaporator to provide cold water for cooling to the terminal equipment.

[0017] The above technical solution has the following advantages or beneficial effects: through the cooperation of the first refrigerant flow switching valve, the second refrigerant flow switching valve and the third refrigerant flow switching valve, the needs of space cooling and domestic hot water can be met simultaneously.

[0018] In some embodiments of this application, the first refrigerant flow switching valve, the second refrigerant flow switching valve, and the third refrigerant flow switching valve can switch the refrigerant flow direction, so that the refrigerant-air heat exchanger is used as a condenser to melt the frost layer on the surface of the refrigerant-air heat exchanger, the first refrigerant-water heat exchanger is used as an evaporator, and the second refrigerant-water heat exchanger is used as a condenser to provide hot water for heating to the terminal equipment.

[0019] The above technical solution has the following advantages or beneficial effects: by cooperating with the first refrigerant flow switching valve, the second refrigerant flow switching valve and the third refrigerant flow switching valve, the space heating and defrosting requirements can be met simultaneously.

[0020] In some embodiments of this application, the first refrigerant flow switching valve, the second refrigerant flow switching valve, and the third refrigerant flow switching valve can switch the refrigerant flow direction, such that the refrigerant-air heat exchanger is used as a condenser to melt the frost layer on the surface of the refrigerant-air heat exchanger, the first refrigerant-water heat exchanger is used as a condenser to provide hot water for the heat storage device to generate heat, and the second refrigerant-water heat exchanger is used as an evaporator.

[0021] The above technical solution has the following advantages or beneficial effects: by cooperating with the first refrigerant flow switching valve, the second refrigerant flow switching valve and the third refrigerant flow switching valve, the needs for domestic hot water and defrosting can be met simultaneously.

[0022] In some embodiments of this application, the heat pump system further includes: a second throttling element fluidly connected to a first refrigerant-water heat exchanger; in space cooling mode, a first refrigerant flow switching valve, a second refrigerant flow switching valve, and a third refrigerant flow switching valve can switch the refrigerant flow direction, such that the refrigerant-air heat exchanger is used as a condenser, the first refrigerant-water heat exchanger is used as an evaporator, and the second refrigerant-water heat exchanger is used as an evaporator to provide chilled water for cooling to the terminal equipment; when the indoor temperature is higher than a set indoor temperature threshold, or the outdoor ambient temperature is higher than a set outdoor ambient temperature threshold, the second throttling element switches to a fully closed state to cut off the refrigerant passage of the first refrigerant-water heat exchanger.

[0023] The above technical solution has the following advantages or beneficial effects: through the cooperation of the second throttling element, the first refrigerant flow switching valve, the second refrigerant flow switching valve and the third refrigerant flow switching valve, the compressor is prevented from entering the protection program under high temperature conditions.

[0024] In some embodiments of this application,

[0025] The first water flow direction switching valve has a first port connected to a heat storage device, a second port connected to a first refrigerant-water heat exchanger, and a third port connected to a second refrigerant-water heat exchanger. The first water flow direction switching valve can form a flow path between the first port and the second port, or a flow path between the second port and the third port.

[0026] The second water flow direction switching valve has a first port connected to the terminal equipment, a second port connected to the first water flow direction switching valve and the first refrigerant-water heat exchanger, and a third port connected to the second refrigerant-water heat exchanger and the first water flow direction switching valve. The second water flow direction switching valve can form a flow path between the first port and the second port, a flow path between the first port and the third port, or a flow path between the second port and the third port.

[0027] The third water flow direction switching valve has a first port connected to the heat storage device, a second port connected to the first refrigerant-water heat exchanger, and a third port connected to the terminal equipment; the third water flow direction switching valve can form a flow path between the first port and the second port, or a flow path between the second port and the third port;

[0028] The fourth water flow direction switching valve has its first port connected to the return water end of the heat storage device and the third water flow direction switching valve, its second port connected to the heat storage device and the third water flow direction switching valve, and its third port connected to the second refrigerant-water heat exchanger. The fourth water flow direction switching valve can form a flow path between the first port and the second port, between the first port and the third port, or between the second port and the third port.

[0029] The above technical solution has the following advantages or beneficial effects: by using the first water flow direction switching valve, the second water flow direction switching valve, the third water flow direction switching valve and the fourth water flow direction switching valve, the water circuit can be flexibly configured to meet the needs of multiple modes.

[0030] Other features and advantages of this utility model will become clearer after reading the detailed embodiments of this utility model in conjunction with the accompanying drawings. Attached Figure Description

[0031] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0032] Figure 1 This is a schematic diagram of the refrigeration cycle of a heat pump system provided in some embodiments of the present invention;

[0033] Figure 2 This is a schematic diagram of the refrigeration cycle of a heat pump system under space cooling mode (high load) provided in some embodiments of the present invention;

[0034] Figure 3 This is a schematic diagram of the refrigeration cycle of a heat pump system under space heating mode (high load) provided in some embodiments of the present invention;

[0035] Figure 4 This is a schematic diagram of the refrigeration cycle of a heat pump system under domestic hot water mode (high load) provided in some embodiments of the present invention;

[0036] Figure 5 A schematic diagram of the refrigeration cycle when the heat pump system provided in some embodiments of this utility model simultaneously performs space heating mode and domestic hot water mode (high load);

[0037] Figure 6 A schematic diagram of the refrigeration cycle when the heat pump system provided in some embodiments of this utility model simultaneously performs space cooling mode and domestic hot water mode (domestic hot water demand takes priority);

[0038] Figure 7 A schematic diagram of the refrigeration cycle when the heat pump system provided in some embodiments of this utility model simultaneously executes space cooling mode and domestic hot water mode (space cooling demand takes priority);

[0039] Figure 8 A schematic diagram of the refrigeration cycle when the heat pump system provided in some embodiments of the present invention simultaneously performs space heating mode and defrosting mode;

[0040] Figure 9 A schematic diagram of the refrigeration cycle of a heat pump system provided in some embodiments of the present invention when simultaneously executing domestic hot water mode and defrost mode;

[0041] Figure 10 This is a schematic diagram of the refrigeration cycle of a heat pump system in space cooling mode (low load) provided in some embodiments of the present invention;

[0042] Figure 11This is a schematic diagram of the refrigeration cycle of a heat pump system in a space heating mode (low load) provided in some embodiments of the present invention;

[0043] Figure 12 This is a schematic diagram of the refrigeration cycle of a heat pump system in domestic hot water mode (low load) according to some embodiments of the present invention;

[0044] Figure 13 A schematic diagram of the refrigeration cycle when the heat pump system provided in some embodiments of this utility model simultaneously performs space heating mode and domestic hot water mode (low load);

[0045] Figure 14 A schematic diagram of the refrigeration cycle of a heat pump system under refrigeration overload provided in some embodiments of this utility model;

[0046] Figure 15 This is a schematic diagram of the refrigeration cycle of a heat pump system provided in some embodiments of the present invention;

[0047] Figure 16 This is a schematic diagram of the refrigeration cycle of a heat pump system provided in some embodiments of the present invention;

[0048] Figure 17 This is a schematic diagram of the refrigeration cycle of a heat pump system provided in some embodiments of the present invention;

[0049] Figure 18 and Figure 19 A status table for each component in a heat pump system under different operating modes;

[0050] In the diagram: 1. Gas-liquid separator; 2. Compressor; 3a. First refrigerant flow switching valve; 3b. Second refrigerant flow switching valve; 3c. Third refrigerant flow switching valve; 4. Refrigerant-air heat exchanger; 5a. First throttling element; 5b. Second throttling element; 5c. Third throttling element; 6. First refrigerant-water heat exchanger; 7. Second refrigerant-water heat exchanger; 8. Heat pump fan; 9. Terminal equipment; 10. Thermal storage equipment; 11. Terminal water pump; 12. Hot water storage pump; 13a. First water flow switching valve; 13b. Second water flow switching valve; 14a. Third water flow switching valve; 14b. Fourth water flow switching valve; 15a. First shut-off valve; 15b. Second shut-off valve; 15c. Third shut-off valve; a1, Domestic water tank supply inlet; a2, Domestic water tank return inlet; b1, Water source interface; b2, Water supply interface; O6, First refrigerant-water heat exchanger outlet interface; R6, First refrigerant-water heat exchanger return interface; O7, Second refrigerant-water heat exchanger outlet interface; R7, Second refrigerant-water heat exchanger return interface; O9, Terminal equipment outlet pipe; R9, Terminal equipment return pipe; O10, Heat storage equipment outlet pipe; R10, Heat storage equipment return pipe; P1, First shut-off valve interface; P2, Second shut-off valve interface; P3, Third shut-off valve interface; 100, Outdoor unit; 101, Outdoor unit; 102, Outdoor unit; 200, Indoor unit; 201, Indoor unit; 300, Other parts configured on site. Detailed Implementation

[0051] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0052] In the description of this application, it should be understood that the terms "center", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0053] The terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "multiple" means two or more.

[0054] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0055] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0056] The following disclosure provides many different embodiments or examples for implementing various structures of this invention. To simplify the disclosure, specific examples of components and arrangements are described below. These are merely examples and are not intended to limit the scope of the invention. Furthermore, reference numerals and / or letters may be repeated in different examples; such repetition is for simplification and clarity and does not in itself indicate a relationship between the various embodiments and / or arrangements discussed. In addition, examples of various specific processes and materials are provided in this invention, but those skilled in the art will recognize the application of other processes and / or the use of other materials.

[0057] Heat pump systems are highly efficient heat transfer devices capable of providing heating or cooling under various environmental conditions. They are primarily used for residential heating and cooling, heating domestic hot water, heat recovery in industrial processes, and temperature control. In the residential sector, the most common type of heat pump system is the air-source heat pump system. Air-source heat pump systems extract heat from the air for heating or cooling, representing a highly efficient and environmentally friendly energy utilization method.

[0058] From a thermodynamic perspective, the refrigeration cycle of a heat pump system includes an evaporator, compressor, condenser, and throttling device connected in sequence. The refrigeration cycle involves a series of processes, including compression, condensation, expansion, and evaporation, to cool or heat indoor spaces or to heat domestic water.

[0059] From a thermodynamic perspective, a low-temperature, low-pressure refrigerant enters the compressor, which compresses it into a high-temperature, high-pressure refrigerant gas and discharges the compressed gas. The discharged refrigerant gas flows into the condenser. The condenser condenses the compressed refrigerant into a liquid phase, and heat is released to the surrounding environment through the condensation process.

[0060] The throttling device causes the high-temperature, high-pressure liquid refrigerant that condenses in the condenser to expand into a low-pressure liquid refrigerant. The evaporator evaporates the refrigerant that has expanded in the throttling device, returning the low-temperature, low-pressure refrigerant gas to the compressor. The evaporator achieves its cooling effect by utilizing the latent heat of refrigerant evaporation to exchange heat with the material being cooled.

[0061] From a hardware architecture perspective, refer to the appendix. Figure 1 This application describes some embodiments of the heat pump system provided.

[0062] Figure 1 A schematic diagram of the refrigeration cycle of a heat pump system provided in some aspects of this application.

[0063] In the refrigeration cycle of a heat pump system, compressor 2 is the core component. Compressor 2 is used to compress the refrigerant, changing the refrigerant from a low-pressure state to a high-pressure state, so that the refrigerant can effectively transfer heat in the refrigeration cycle.

[0064] The refrigerant-air heat exchanger 4 is used for heat exchange between refrigerant and air. The refrigerant flows in the refrigerant-air heat exchanger 4, and the air flows on the surface of the refrigerant-air heat exchanger 4 by means of the heat pump fan 8 or natural convection to achieve heat exchange between the two.

[0065] A refrigerant-water heat exchanger is used to exchange heat between refrigerant and water, transferring heat from the refrigerant to the water, causing the water temperature to rise or fall. Water with a higher temperature can be used in terminal equipment 9 such as floor heating and radiators to provide hot water circulation, or in heat storage equipment 10 such as domestic water tanks in domestic hot water supply systems to provide domestic hot water. Water with a lower temperature can be used in terminal equipment 9 to provide cooling water circulation for indoor space cooling.

[0066] In some embodiments of this application, such as Figure 1As shown, the refrigeration cycle of the heat pump system also includes a first refrigerant-water heat exchanger 6. The first refrigerant-water heat exchanger 6 is fluidly connected to a heat storage device 10 (e.g., a domestic water tank). Water heated in the first refrigerant-water heat exchanger 6 enters the heat storage device 10 to provide domestic water. Figure 1 As shown, O6 is the outlet water interface of the first refrigerant-water heat exchanger 6, and R6 is the return water interface of the first refrigerant-water heat exchanger 6. The heat storage device 10 includes a water supply end and a water return end. Taking a domestic water tank as an example of the heat storage device 10, a1 is the water supply port (water supply end) of the domestic water tank, a2 is the water return port (water return end) of the domestic water tank, b1 is the water source interface (e.g., the pipe port connected to the municipal water supply), and b2 is the water supply interface (e.g., the pipe port connected to the user's water terminal).

[0067] In some embodiments of this application, such as Figure 1 As shown, the refrigeration cycle of the heat pump system also includes a second refrigerant-water heat exchanger 7. The second refrigerant-water heat exchanger 7 is fluidly connected to the terminal device 9. Water heated in the second refrigerant-water heat exchanger 7 enters the terminal device 9 (e.g., underfloor heating or radiators) to provide hot water circulation; or, water cooled in the second refrigerant-water heat exchanger 7 enters the terminal device 9 (e.g., the coil of a heat pump fan 8) to provide cooling water circulation for indoor space cooling. Figure 1 As shown, O7 is the outlet water interface of the second refrigerant-water heat exchanger 7, and R7 is the return water interface of the second refrigerant-water heat exchanger 7. The terminal equipment 9 includes a water supply end and a water return end.

[0068] exist Figure 1 In this context, RO represents the water piping of the refrigerant-water heat exchanger (including the first refrigerant-water heat exchanger 6 and the second refrigerant-water heat exchanger 7), and GL represents the refrigerant piping of the refrigerant-water heat exchanger (including the first refrigerant-water heat exchanger 6 and the second refrigerant-water heat exchanger 7). The first refrigerant-water heat exchanger 6 and the second refrigerant-water heat exchanger 7 can be plate heat exchangers.

[0069] In some embodiments of this application, the refrigeration cycle of the heat pump system further includes a first refrigerant flow switching valve 3a, a second refrigerant flow switching valve 3b, and a third refrigerant flow switching valve 3c. The first refrigerant flow switching valve 3a, the second refrigerant flow switching valve 3b, and the third refrigerant flow switching valve 3c are used to switch the refrigerant flow direction, so that the refrigerant-air heat exchanger 4, and / or the first refrigerant-water heat exchanger 6, and / or the second refrigerant-water heat exchanger 7 operate as a condenser or an evaporator, respectively.

[0070] This application can realize multiple working modes, avoiding the problem that the heat pump system needs to stop heating or cooling, which causes the indoor temperature to fail to maintain the user's set temperature and results in poor user comfort.

[0071] In some embodiments of this application, the first refrigerant flow switching valve 3a, the second refrigerant flow switching valve 3b, and the third refrigerant flow switching valve 3c are four-way switching valves. The four-way switching valve has four ports: D, S, C, and E. In one operating state (e.g., OFF state), ports D and C are connected, and ports E and S are connected, forming an internal channel connecting DC and ES. In another operating state (e.g., ON state), ports D and E are connected, and ports C and S are connected, forming an internal channel connecting DE and CS.

[0072] The first refrigerant flow switching valve 3a is fluidly connected to the refrigerant-air heat exchanger 4 and the compressor 2; the second refrigerant flow switching valve 3b is fluidly connected to the first refrigerant-water heat exchanger 6 and the compressor 2; and the third refrigerant flow switching valve 3c is fluidly connected to the second refrigerant-water heat exchanger 7 and the compressor 2.

[0073] In some embodiments of this application, the refrigeration cycle of the heat pump system further includes a first water flow direction switching valve 13a, a second water flow direction switching valve 13b, a third water flow direction switching valve 14a, and a fourth water flow direction switching valve 14b. The first water flow direction switching valve 13a, the second water flow direction switching valve 13b, the third water flow direction switching valve 14a, and the fourth water flow direction switching valve 14b are used to switch the water flow direction in the first refrigerant-water heat exchanger 6, the second refrigerant-water heat exchanger 7, the terminal equipment 9, and the heat storage device 10, so that the water flow path cooperates with the refrigerant flow path to achieve multiple operating modes of the heat pump system.

[0074] In some embodiments of this application, the first water flow direction switching valve 13a, the second water flow direction switching valve 13b, the third water flow direction switching valve 14a, and the fourth water flow direction switching valve 14b are three-way valves.

[0075] The first water flow direction switching valve 13a has its first port T connected to the heat storage device 10, its second port O1 connected to the first refrigerant-water heat exchanger 6, and its third port O2 connected to the second refrigerant-water heat exchanger 7. The first water flow direction switching valve 13a can form a flow path between the first port and the second port (T-O1 path), or a flow path between the second port and the third port (O1-O2 path).

[0076] The second water flow direction switching valve 13b has its first port F connected to the terminal device 9, its second port O1 connected to the first water flow direction switching valve 13a and the first refrigerant-water heat exchanger 6, and its third port O2 connected to the second refrigerant-water heat exchanger 7 and the first water flow direction switching valve 13a. The second water flow direction switching valve 13b can form a flow path between the first port and the second port (F-O1 path), a flow path between the first port and the third port (F-O2 path), or a flow path between the second port and the third port (O1-O2 path).

[0077] The third water flow direction switching valve 14a has its first port T connected to the heat storage device 10, its second port R1 connected to the first refrigerant-water heat exchanger 6, and its third port R2 connected to the terminal device 9. The third water flow direction switching valve 14a can form a flow path between the first port and the second port (T-R1 path), or a flow path between the second port and the third port (R1-R2 path).

[0078] The fourth water flow direction switching valve 14b has its first port F connected to the heat storage device 10 and the third water flow direction switching valve 14a, its second port R1 connected to the heat storage device 10 and the third water flow direction switching valve 14a, and its third port R2 connected to the second refrigerant-water heat exchanger 7. The fourth water flow direction switching valve 14b can form a flow path between the first port and the second port (F-R1 path), a flow path between the first port and the third port (F-R2 path), or a flow path between the second port and the third port (R1-R2 path).

[0079] In other embodiments of this application, the water flow switching functions of the first water flow direction switching valve 13a, the second water flow direction switching valve 13b, the third water flow direction switching valve 14a, and the fourth water flow direction switching valve 14b can also be achieved by other different valve combinations.

[0080] In some embodiments of this application, the heat pump system further includes a first throttling element 5a, a second throttling element 5b, and a third throttling element 5c. The first throttling element 5a is connected to the refrigerant-air heat exchanger 4, the second throttling element 5b is connected to the first refrigerant-water heat exchanger 6, and the third throttling element 5c is connected to the second refrigerant-water heat exchanger 7.

[0081] In some embodiments of this application, the first throttling element 5a, the second throttling element 5b, and the third throttling element 5c are electronic expansion valves.

[0082] In some embodiments of this application, the heat pump system further includes a gas-liquid separator 1. The gas-liquid separator 1 is disposed on the suction side of the compressor 2 and is used to effectively separate the mixed refrigerant gas and liquid to ensure normal system operation. It prevents liquid refrigerant from entering the compressor 2, protecting the compressor 2 from damage.

[0083] In some embodiments of this application, the heat pump system further includes a terminal water pump 11, which circulates water in the terminal device 9 to achieve efficient heat transfer.

[0084] In some embodiments of this application, the heat pump system further includes a hot water storage pump 12, which is used to circulate water in the heat storage device 10 to achieve efficient heat transfer.

[0085] In some embodiments of this application, the gas-liquid separator 1, compressor 2, first refrigerant flow switching valve 3a, second refrigerant flow switching valve 3b, third refrigerant flow switching valve 3c, refrigerant-air heat exchanger 4, first throttling element 5a, second throttling element 5b, third throttling element 5c, first refrigerant-water heat exchanger 6, and second refrigerant-water heat exchanger 7 can be integrated into the outdoor unit. Other components (such as...) Figure 1 The portion shown in section 300 can be configured and installed at the actual usage location.

[0086] In some embodiments of this application, in order to adapt to the space cooling requirements of different loads, in the space cooling mode, the first refrigerant flow switching valve 3a, the second refrigerant flow switching valve 3b, and the third refrigerant flow switching valve 3c can switch the refrigerant flow direction, so that the refrigerant-air heat exchanger 4 is used as a condenser, the first refrigerant-water heat exchanger 6 is used as an evaporator, and the second refrigerant-water heat exchanger 7 is used as an evaporator to provide chilled water to the terminal equipment 9 for cooling; or in the space cooling mode, the first refrigerant flow switching valve 3a, the second refrigerant flow switching valve 3b, and the third refrigerant flow switching valve 3c can switch the refrigerant flow direction, so that the refrigerant-air heat exchanger 4 is used as a condenser, and the second refrigerant-water heat exchanger 7 is used as an evaporator to provide chilled water to the terminal equipment 9 for cooling; the second throttling element 5b remains fully closed to cut off the refrigerant passage of the first refrigerant-water heat exchanger 6.

[0087] In some embodiments of this application, to adapt to different space heating demands, in space heating mode, the first refrigerant flow switching valve 3a, the second refrigerant flow switching valve 3b, and the third refrigerant flow switching valve 3c can switch the refrigerant flow direction, so that the refrigerant-air heat exchanger 4 is used as an evaporator, the first refrigerant-water heat exchanger 6 is used as a condenser, and the second refrigerant-water heat exchanger 7 is used as a condenser to provide hot water for heating to the heat storage device 10; or

[0088] In the space heating mode, the first refrigerant flow switching valve 3a, the second refrigerant flow switching valve 3b, and the third refrigerant flow switching valve 3c can switch the refrigerant flow direction, so that the refrigerant-air heat exchanger 4 is used as an evaporator and the second refrigerant-water heat exchanger 7 is used as a condenser to provide hot water for heating to the terminal equipment 9; the second throttling element 5b is kept below the set opening to limit the refrigerant flow in the first refrigerant-water heat exchanger 6.

[0089] In some embodiments of this application, in order to adapt to different loads of domestic hot water demand and to adapt to different loads, in the domestic hot water mode, the first refrigerant flow switching valve 3a, the second refrigerant flow switching valve 3b and the third refrigerant flow switching valve 3c can switch the refrigerant flow direction, so that the refrigerant-air heat exchanger 4 is used as an evaporator, the first refrigerant-water heat exchanger 6 is used as a condenser and the second refrigerant-water heat exchanger 7 is used as a condenser to provide hot water for heating to the heat storage device 10;

[0090] Alternatively, the first refrigerant flow switching valve 3a, the second refrigerant flow switching valve 3b, and the third refrigerant flow switching valve 3c can switch the refrigerant flow direction, so that the refrigerant-air heat exchanger 4 is used as an evaporator, the first refrigerant-water heat exchanger 6 is used as a condenser, and the third throttling element 5c is kept below the set opening to limit the refrigerant flow in the second refrigerant-water heat exchanger 7.

[0091] In some embodiments of this application, in order to simultaneously meet the needs of space heating and domestic hot water, the first refrigerant flow switching valve 3a, the second refrigerant flow switching valve 3b and the third refrigerant flow switching valve 3c can switch the refrigerant flow direction, so that the refrigerant-air heat exchanger 4 is used as an evaporator, the first refrigerant-water heat exchanger 6 is used as a condenser to provide hot water for heating to the heat storage device 10, and the second refrigerant-water heat exchanger 7 is used as a condenser to provide hot water for heating to the terminal device 9;

[0092] Alternatively, the first refrigerant flow switching valve 3a, the second refrigerant flow switching valve 3b, and the third refrigerant flow switching valve 3c can switch the refrigerant flow direction, so that the refrigerant-air heat exchanger 4 is used as an evaporator, and the first refrigerant-water heat exchanger 6 is used as a condenser to provide hot water for heating to the heat storage device 10 and the terminal device 9; the second throttling element 5b is kept below the set opening to limit the refrigerant flow in the first refrigerant-water heat exchanger 6.

[0093] In some embodiments of this application, in order to simultaneously meet the needs of space cooling and domestic hot water,

[0094] The first refrigerant flow switching valve 3a, the second refrigerant flow switching valve 3b, and the third refrigerant flow switching valve 3c can switch the refrigerant flow direction, so that the refrigerant-air heat exchanger 4 is used as an evaporator, the first refrigerant-water heat exchanger 6 is used as a condenser to provide hot water for heating to the heat storage device 10, and the second refrigerant-water heat exchanger 7 is used as an evaporator to provide cold water for cooling to the terminal device 9.

[0095] Alternatively, the first refrigerant flow switching valve 3a, the second refrigerant flow switching valve 3b, and the third refrigerant flow switching valve 3c can switch the refrigerant flow direction, so that the refrigerant-air heat exchanger 4 is used as a condenser, the first refrigerant-water heat exchanger 6 is used as a condenser to provide hot water to the heat storage device 10 for heating, and the second refrigerant-water heat exchanger 7 is used as an evaporator to provide cold water to the terminal device 9 for cooling.

[0096] In some embodiments of this application, in order to simultaneously meet the needs of space heating and defrosting, the first refrigerant flow switching valve 3a, the second refrigerant flow switching valve 3b, and the third refrigerant flow switching valve 3c can switch the refrigerant flow direction, so that the refrigerant-air heat exchanger 4 is used as a condenser to melt the frost layer on the surface of the refrigerant-air heat exchanger 4, the first refrigerant-water heat exchanger 6 is used as an evaporator, and the second refrigerant-water heat exchanger 7 is used as a condenser to provide hot water for heating to the terminal equipment 9.

[0097] In some embodiments of this application, in order to simultaneously meet the needs of domestic hot water and defrosting, the first refrigerant flow switching valve 3a, the second refrigerant flow switching valve 3b, and the third refrigerant flow switching valve 3c can switch the refrigerant flow direction, so that the refrigerant-air heat exchanger 4 is used as a condenser to melt the frost layer on the surface of the refrigerant-air heat exchanger 4, the first refrigerant-water heat exchanger 6 is used as a condenser to provide hot water to the heat storage device 10 for heating, and the second refrigerant-water heat exchanger 7 is used as an evaporator.

[0098] In some embodiments of this application, in order to prevent the compressor 2 from entering the protection program under high temperature conditions, in the space cooling mode, the first refrigerant flow switching valve 3a, the second refrigerant flow switching valve 3b and the third refrigerant flow switching valve 3c can switch the refrigerant flow direction, so that the refrigerant-air heat exchanger 4 is used as a condenser, the first refrigerant-water heat exchanger 6 is used as an evaporator, and the second refrigerant-water heat exchanger 7 is used as an evaporator to provide cold water to the terminal equipment 9 for cooling;

[0099] When the indoor temperature is higher than the set indoor temperature threshold, or the outdoor ambient temperature is higher than the set outdoor ambient temperature threshold, the second throttling element 5b switches to the fully closed state to cut off the refrigerant passage of the first refrigerant-water heat exchanger 6.

[0100] like Figure 2 The diagram shows the circulation process of a heat pump system in space cooling mode (high load).

[0101] Reference Figure 2 This paper describes the refrigerant flow process in a heat pump system under space cooling mode (high load). When there is only space cooling demand and the cooling load is large, the refrigerant-air heat exchanger 4 acts as a condenser, the first refrigerant-water heat exchanger 6 acts as an evaporator, and the second refrigerant-water heat exchanger 7 acts as an evaporator to provide chilled water cooling for the terminal equipment 9. The first refrigerant flow switching valve 3a is in the OFF state (DC connected, ES connected), the second refrigerant flow switching valve 3b is in the ON state (DE connected, CS connected), and the third refrigerant flow switching valve 3c is in the ON state (DE connected, CS connected).

[0102] Compressor 2 draws low-pressure gaseous refrigerant from gas-liquid separator 1 and compresses it to a high-temperature, high-pressure exhaust state. The refrigerant then passes through the DC passage of the first refrigerant flow switching valve 3a and enters the refrigerant-air heat exchanger 4. There, it exchanges heat with outdoor air, cools, and condenses into a medium-temperature, high-pressure subcooled liquid refrigerant. After passing through the first throttling element 5a, it splits into two paths. The two refrigerant paths are throttled into low-pressure two-phase refrigerant by the second throttling element 5b and the third throttling element 5c, respectively, and then enter the first refrigerant-water heat exchanger 6 and the second refrigerant-water heat exchanger 7, respectively. In the first and second refrigerant-water heat exchangers 6 and 7, the refrigerant exchanges heat with water, absorbing heat from the water and becoming low-pressure superheated refrigerant. Then, it returns to gas-liquid separator 1 through the CS passages of the second and third refrigerant flow switching valves 3b and 3c, respectively.

[0103] Reference Figure 2 The flow process of water is described below. In the first refrigerant-water heat exchanger 6, water exchanges heat with the refrigerant, and its temperature decreases to become low-temperature chilled water. The chilled water after heat exchange flows to the terminal device 9 through the first water flow switching valve 13a (O1-O2 connected). In the second refrigerant-water heat exchanger 7, water exchanges heat with the refrigerant, and its temperature decreases. The chilled water after heat exchange merges with the chilled water from the first water flow switching valve 13a, and flows to the terminal device 9 through the second water flow switching valve 13b (O2-F connected) under the suction of the terminal water pump 11. The chilled water undergoes further heat exchange in the terminal device 9. After cooling is achieved, the return water from the terminal device 9 is divided into two paths. One path returns to the first refrigerant-water heat exchanger 6 through the third water flow switching valve 14a (R2-R1 connected), where it exchanges heat with the refrigerant and is cooled to low-temperature chilled water. The above cycle is then repeated. Another path flows through the fourth water path to the switching valve 14b (F and R2 are connected) and back to the second refrigerant-water heat exchanger 7. In the second refrigerant-water heat exchanger 7, it exchanges heat with the refrigerant and is cooled to a low temperature. Then, the above cycle is repeated. At the same time, the hot water storage pump 12 is turned off.

[0104] like Figure 3 The diagram shows the circulation process of a heat pump system in space heating mode (high load).

[0105] Reference Figure 3 This paper describes the refrigerant flow process in a heat pump system under space heating mode (high load). When there is only space heating demand and the heating load is large, the refrigerant-air heat exchanger 4 acts as an evaporator, the first refrigerant-water heat exchanger 6 acts as a condenser, and the second refrigerant-water heat exchanger 7 acts as a condenser to provide hot water heating to the terminal equipment 9. The first refrigerant flow switching valve 3a is in the ON state (DE connected, CS connected), the second refrigerant flow switching valve 3b is in the OFF state (DC connected, ES connected), and the third refrigerant flow switching valve 3c is in the OFF state (DC connected, ES connected).

[0106] Compressor 2 draws low-pressure gaseous refrigerant from gas-liquid separator 1 and compresses it to a high-temperature, high-pressure exhaust state. The refrigerant is then split into two paths: one through the DC passage of the second refrigerant flow switching valve 3b, and the other through the DC passage of the third refrigerant flow switching valve 3c. Both paths lead into the first refrigerant-water heat exchanger 6 and the second refrigerant-water heat exchanger 7, where they exchange heat with water, are cooled, and condense into a medium-temperature, high-pressure subcooled liquid refrigerant. This medium-temperature, high-pressure subcooled liquid refrigerant further passes through the second throttling element 5b and the third throttling element 5c, and then merges with the second throttling element 5b. After merging, it is further throttled by the first throttling element 5a into a low-pressure two-phase refrigerant, which enters the refrigerant-air heat exchanger 4. There, it absorbs heat from the outdoor air and becomes a low-pressure superheated refrigerant. Finally, it returns to gas-liquid separator 1 through the CS passage of the first refrigerant flow switching valve 3a.

[0107] Reference Figure 3The flow process of water is described below. In the first refrigerant-water heat exchanger 6, water exchanges heat with the refrigerant, and its temperature rises to become high-temperature hot water. The high-temperature hot water after heat exchange flows to the terminal device 9 through the first water flow switching valve 13a (O1-O2 connected). In the second refrigerant-water heat exchanger 7, water exchanges heat with the refrigerant, and its temperature rises. The high-temperature hot water after heat exchange merges with the high-temperature hot water from the first water flow switching valve 13a, and flows to the terminal device 9 through the second water flow switching valve 13b (O2-F connected) under the suction of the terminal water pump 11. The high-temperature hot water undergoes further heat exchange in the terminal device 9. After heating is achieved, the return water from the terminal device 9 is divided into two paths. One path returns to the first refrigerant-water heat exchanger 6 through the third water flow switching valve 14a (R2-R1 connected), where it exchanges heat with the refrigerant and is heated to high-temperature hot water by the high-temperature and high-pressure refrigerant. The above cycle is then repeated. Another path flows through the fourth water path to the switching valve 14b (F and R2 are connected) and back to the second refrigerant-water heat exchanger 7. In the second refrigerant-water heat exchanger 7, it exchanges heat with the refrigerant and is heated into high-temperature hot water by the high-temperature and high-pressure refrigerant, then repeats the above cycle. At the same time, the hot water storage pump 12 is turned off.

[0108] like Figure 4 The diagram shows the circulation process of a heat pump system in domestic hot water mode (high load).

[0109] Reference Figure 4 This paper describes the refrigerant flow process in a heat pump system under domestic hot water mode (high load). When there is only domestic hot water demand and the heating load is large, the refrigerant-air heat exchanger 4 acts as an evaporator, the first refrigerant-water heat exchanger 6 acts as a condenser, and the second refrigerant-water heat exchanger 7 acts as a condenser to provide hot water heating for the heat storage device 10. The first refrigerant flow switching valve 3a is in the ON state (DE connected, CS connected), the second refrigerant flow switching valve 3b is in the OFF state (DC connected, ES connected), and the third refrigerant flow switching valve 3c is in the OFF state (DC connected, ES connected).

[0110] Compressor 2 draws low-pressure gaseous refrigerant from gas-liquid separator 1 and compresses it to a high-temperature, high-pressure exhaust state. The refrigerant is then split into two paths: one through the DC passage of the second refrigerant flow switching valve 3b, and the other through the DC passage of the third refrigerant flow switching valve 3c. Both paths lead into the first refrigerant-water heat exchanger 6 and the second refrigerant-water heat exchanger 7, where they exchange heat with water, are cooled, and condense into a medium-temperature, high-pressure subcooled liquid refrigerant. This medium-temperature, high-pressure subcooled liquid refrigerant further passes through the second throttling element 5b and the third throttling element 5c, and then merges with the second throttling element 5b. After merging, it is further throttled by the first throttling element 5a into a low-pressure two-phase refrigerant, which enters the refrigerant-air heat exchanger 4. There, it absorbs heat from the outdoor air and becomes a low-pressure superheated refrigerant. Finally, it returns to gas-liquid separator 1 through the CS passage of the first refrigerant flow switching valve 3a.

[0111] Reference Figure 4 The flow process of water is described below. In the first refrigerant-water heat exchanger 6, water exchanges heat with the refrigerant, and its temperature rises to become high-temperature hot water. The high-temperature hot water after heat exchange flows to the heat storage device 10 through the first water flow switching valve 13a (O1-T connection). In the second refrigerant-water heat exchanger 7, water exchanges heat with the refrigerant, and its temperature rises. The high-temperature hot water after heat exchange flows to the first refrigerant-water heat exchanger 6 through the second water flow switching valve 13b (O2-O1 connection), and then flows to the heat storage device 10 through the first water flow switching valve 13a (O1-T connection) under the suction of the hot water storage pump 12. The heat storage device 10 is fluidly connected to the water source (e.g., through pipe b1) and the user's water terminal (e.g., through pipe b2). The return water from the heat storage device 10 is divided into two paths. One path flows through the third water path switching valve 14a (T-R1 connection) back to the first refrigerant-water heat exchanger 6, where it exchanges heat with the refrigerant and is heated to high-temperature hot water by the high-temperature, high-pressure refrigerant, then repeats the above cycle. The other path flows through the fourth water path switching valve 14b (R1-R2 connection) back to the second refrigerant-water heat exchanger 7, where it exchanges heat with the refrigerant and is heated to high-temperature hot water by the high-temperature, high-pressure refrigerant, then repeats the above cycle. Simultaneously, the terminal water pump 11 is shut off.

[0112] like Figure 5 The diagram shows the circulation process of a heat pump system operating simultaneously in space heating mode and domestic hot water mode (high load).

[0113] Reference Figure 5This paper describes the refrigerant flow process in a heat pump system operating simultaneously in both space heating and domestic hot water modes (high load). When there is simultaneous demand for space heating and domestic hot water, and the heating load is high, the refrigerant-air heat exchanger 4 acts as an evaporator, the first refrigerant-water heat exchanger 6 acts as a condenser to provide hot water for the heat storage device 10, and the second refrigerant-water heat exchanger 7 acts as a condenser to provide hot water for the terminal device 9. The first refrigerant flow switching valve 3a is in the ON state (DE connected, CS connected), the second refrigerant flow switching valve 3b is in the OFF state (DC connected, ES connected), and the third refrigerant flow switching valve 3c is in the OFF state (DC connected, ES connected).

[0114] Compressor 2 draws low-pressure gaseous refrigerant from gas-liquid separator 1 and compresses it to a high-temperature, high-pressure exhaust state. The refrigerant is then split into two paths: one through the DC passage of the second refrigerant flow switching valve 3b, and the other through the DC passage of the third refrigerant flow switching valve 3c. Both paths lead into the first refrigerant-water heat exchanger 6 and the second refrigerant-water heat exchanger 7, where they exchange heat with water, are cooled, and condense into a medium-temperature, high-pressure subcooled liquid refrigerant. This medium-temperature, high-pressure subcooled liquid refrigerant further passes through the second throttling element 5b and the third throttling element 5c, and then merges with the second throttling element 5b. After merging, it is further throttled by the first throttling element 5a into a low-pressure two-phase refrigerant, which enters the refrigerant-air heat exchanger 4. There, it absorbs heat from the outdoor air and becomes a low-pressure superheated refrigerant. Finally, it returns to gas-liquid separator 1 through the CS passage of the first refrigerant flow switching valve 3a.

[0115] Reference Figure 5 The flow process of water is described below. In the first refrigerant-water heat exchanger 6, water exchanges heat with the refrigerant, and its temperature rises to become high-temperature hot water. After heat exchange, the high-temperature hot water flows through the first water path switching valve 13a (O1-T connection) and, under the suction of the hot water storage pump 12, flows to the heat storage device 10. In the second refrigerant-water heat exchanger 7, water exchanges heat with the refrigerant, and its temperature rises. After heat exchange, the high-temperature hot water flows through the second water path switching valve 13b (O2-F connection) and, under the suction of the terminal water pump 11, flows to the terminal device 9. The return water from the heat storage device 10 returns to the first refrigerant-water heat exchanger 6 through the third water path switching valve 14a (T-R1 connection), where it exchanges heat with the refrigerant and is heated by the high-temperature, high-pressure refrigerant to become high-temperature hot water, and then the above cycle is repeated. The return water from terminal device 9 returns to the second refrigerant-water heat exchanger 7 through the fourth water flow switching valve 14b (F-R2 connection). In the second refrigerant-water heat exchanger 7, it exchanges heat with the refrigerant and is heated into high-temperature hot water by the high-temperature and high-pressure refrigerant, and then repeats the above cycle.

[0116] like Figure 6 The diagram shows the circulation process of the heat pump system when it is running in both space cooling mode and domestic hot water mode, with domestic hot water mode taking priority.

[0117] Reference Figure 6 This paper describes the refrigerant flow process in a heat pump system operating simultaneously in both space cooling and domestic hot water modes, with domestic hot water mode taking priority. When there are simultaneous space cooling and domestic hot water demands, with domestic hot water mode taking priority, the refrigerant-air heat exchanger 4 acts as an evaporator, the first refrigerant-water heat exchanger 6 acts as a condenser to provide hot water heating for the heat storage device 10, and the second refrigerant-water heat exchanger 7 acts as an evaporator to provide chilled water cooling for the terminal device 9. The first refrigerant flow switching valve 3a is in the ON state (DE connected, CS connected), the second refrigerant flow switching valve 3b is in the OFF state (DC connected, ES connected), and the third refrigerant flow switching valve 3c is in the ON state (DE connected, CS connected).

[0118] Compressor 2 draws low-pressure gaseous refrigerant from gas-liquid separator 1 and compresses it to a high-temperature, high-pressure exhaust state. It then passes through the DC passage of the second refrigerant flow switching valve 3b and enters the first refrigerant-water heat exchanger 6, where it exchanges heat with water, cools, and condenses into a medium-temperature, high-pressure subcooled liquid refrigerant. After passing through the second throttling element 5b, the subcooled liquid refrigerant splits into two paths. One path is throttled by the first throttling element 5a into a low-pressure two-phase refrigerant that enters the refrigerant-air heat exchanger 4, where it absorbs heat from the outdoor air and becomes a low-pressure superheated refrigerant. It then passes through the CS passage of the first refrigerant flow switching valve 3a and returns to gas-liquid separator 1. The other path is throttled by the third throttling element 5c into a low-pressure two-phase refrigerant that enters the second refrigerant-water heat exchanger 7, where it absorbs heat from the return water of terminal equipment 9 and becomes a low-pressure superheated refrigerant. It then enters the CS passage of the third refrigerant flow switching valve 3c and returns to gas-liquid separator 1.

[0119] Reference Figure 6The flow process of water is described below. In the first refrigerant-water heat exchanger 6, water exchanges heat with the refrigerant, and its temperature rises to become high-temperature hot water. After heat exchange, the high-temperature hot water flows through the first water path switching valve 13a (O1-T connection) and, under the suction of the hot water storage pump 12, flows to the heat storage device 10. In the second refrigerant-water heat exchanger 7, water exchanges heat with the refrigerant and is cooled to low-temperature cold water. After heat exchange, the low-temperature cold water flows through the second water path switching valve 13b (O2-F connection) and, under the suction of the terminal water pump 11, flows to the terminal device 9. The return water from the heat storage device 10 returns to the first refrigerant-water heat exchanger 6 through the third water path switching valve 14a (T-R1 connection), where it exchanges heat with the refrigerant and is heated to high-temperature hot water by the high-temperature and high-pressure refrigerant, and then the above cycle is repeated. The return water from terminal device 9 returns to the second refrigerant-water heat exchanger 7 via the fourth water flow switching valve 14b (F-R2 connection), where it exchanges heat with the refrigerant. After being cooled to low-temperature cold water, the above cycle is repeated.

[0120] like Figure 7 The diagram shows the circulation process of the heat pump system when both the space cooling mode and the domestic hot water mode are running simultaneously, with the space cooling mode taking priority.

[0121] Reference Figure 7 This paper describes the refrigerant flow process in a heat pump system operating simultaneously in both space cooling and domestic hot water modes, with space cooling mode taking priority. When there are simultaneous demands for both space cooling and domestic hot water, and space cooling mode takes priority, the refrigerant-air heat exchanger 4 acts as a condenser, the first refrigerant-water heat exchanger 6 acts as a condenser to provide hot water heating for the heat storage device 10, and the second refrigerant-water heat exchanger 7 acts as an evaporator to provide chilled water cooling for the terminal device 9. The first refrigerant flow switching valve 3a is in the OFF state (DC connected, ES connected), the second refrigerant flow switching valve 3b is in the OFF state (DC connected, ES connected), and the third refrigerant flow switching valve 3c is in the ON state (DE connected, CS connected).

[0122] The compressor 2 draws low-pressure gaseous refrigerant from the gas-liquid separator 1 and compresses it to a high-temperature and high-pressure exhaust state. The high-temperature and high-pressure refrigerant is divided into two paths, which pass through the DC passage of the first refrigerant flow switching valve 3a and the DC passage of the second refrigerant flow switching valve 3b, respectively, and then enter the first refrigerant-water heat exchanger 6 and the second refrigerant-water heat exchanger 7. In the refrigerant-air heat exchanger 4, the refrigerant exchanges heat with the outdoor air, cools, and condenses to a medium-temperature, high-pressure subcooled liquid refrigerant. In the first refrigerant-water heat exchanger 6, it exchanges heat with water, cools, and condenses to a medium-temperature, high-pressure subcooled liquid refrigerant. The subcooled liquid refrigerant flowing out of the refrigerant-air heat exchanger 4 passes through the first throttling element 5a, and the subcooled liquid refrigerant flowing out of the first refrigerant-water heat exchanger 6 passes through the second throttling element 5b. After the two merge, they are throttled by the third throttling element 5c to become a low-pressure two-phase refrigerant and enter the second refrigerant-water heat exchanger 7. It exchanges heat with the return water of the terminal equipment 9 to become a low-pressure superheated refrigerant, and then flows through the CS passage of the first refrigerant flow to the switching valve 3a, returning to the gas-liquid separator 1.

[0123] Reference Figure 7 The flow process of water is described below. In the first refrigerant-water heat exchanger 6, water exchanges heat with the refrigerant, and its temperature rises to become high-temperature hot water. After heat exchange, the high-temperature hot water flows through the first water path switching valve 13a (O1-T connection) and, under the suction of the hot water storage pump 12, flows to the heat storage device 10. In the second refrigerant-water heat exchanger 7, water exchanges heat with the refrigerant and is cooled to low-temperature cold water. After heat exchange, the low-temperature cold water flows through the second water path switching valve 13b (O2-F connection) and, under the suction of the terminal water pump 11, flows to the terminal device 9. The return water from the heat storage device 10 returns to the first refrigerant-water heat exchanger 6 through the third water path switching valve 14a (T-R1 connection), where it exchanges heat with the refrigerant and is heated to high-temperature hot water by the high-temperature and high-pressure refrigerant, and then the above cycle is repeated. The return water from terminal device 9 returns to the second refrigerant-water heat exchanger 7 via the fourth water flow switching valve 14b (F-R2 connection), where it exchanges heat with the refrigerant. After being cooled to low-temperature cold water, the above cycle is repeated.

[0124] like Figure 8 The diagram shows the circulation process of a heat pump system that operates in both space heating and defrosting modes simultaneously.

[0125] Reference Figure 8This paper describes the refrigerant flow process in a heat pump system when operating in both heating and defrosting modes simultaneously. In both modes, the refrigerant-air heat exchanger 4 acts as a condenser, the first refrigerant-water heat exchanger 6 acts as an evaporator, and the second refrigerant-water heat exchanger 7 acts as a condenser to provide hot water heating to the terminal device 9. The first refrigerant flow switching valve 3a is in the OFF state (DC connected, ES connected), the second refrigerant flow switching valve 3b is in the ON state (DE connected, CS connected), and the third refrigerant flow switching valve 3c is in the OFF state (DC connected, ES connected).

[0126] Compressor 2 draws low-pressure gaseous refrigerant from gas-liquid separator 1 and compresses it to a high-temperature, high-pressure exhaust state. The refrigerant is then split into two paths, flowing through the DC passage of the first refrigerant flow switching valve 3a and the third refrigerant flow switching valve 3c, respectively, before entering the refrigerant-air heat exchanger 4 and the second refrigerant-water heat exchanger 7. The heat pump fan 8 is shut down. In the refrigerant-air heat exchanger 4, the refrigerant exchanges heat with the surface frost layer, cooling and condensing into a subcooled liquid refrigerant at medium temperature and high pressure. In the second refrigerant-water heat exchanger 7, the refrigerant exchanges heat with water, cooling and condensing into a subcooled liquid refrigerant at medium temperature and high pressure. The medium-temperature, high-pressure subcooled liquid refrigerant further passes through the first throttling element 5a and the third throttling element 5c, and then merges after passing through the first throttling element 5a and the third throttling element 5c. After merging, it is further throttled by the second throttling element 5b into a low-pressure two-phase refrigerant, which enters the first refrigerant-water heat exchanger 6, absorbs the heat from the return water of the heat storage device 10, and becomes a low-pressure superheated refrigerant. Then, it flows through the second refrigerant to the CS passage of the switching valve 3b and returns to the gas-liquid separator 1.

[0127] Reference Figure 8The flow process of water is described below. In the first refrigerant-water heat exchanger 6, water exchanges heat with the refrigerant, and the water temperature decreases due to the absorption of heat by the low-pressure two-phase refrigerant. After heat exchange, the water flows through the first water path switching valve 13a (O1-T connected) and, under the suction of the hot water storage pump 12, flows to the heat storage device 10. The return water from the heat storage device 10 flows back to the first refrigerant-water heat exchanger 6 through the third water path switching valve 14a (T-R1 connected), where it exchanges heat with the refrigerant again. This cycle is repeated, thereby achieving defrosting by absorbing heat from the heat storage device 10. In the second refrigerant-water heat exchanger 7, water exchanges heat with the refrigerant, and the temperature rises. The high-temperature hot water after heat exchange flows through the second water path switching valve 13b (O2-F connected) and, under the suction of the terminal water pump 11, flows to the terminal device 9. The return water from terminal device 9 returns to the second refrigerant-water heat exchanger 7 through the fourth water flow switching valve 14b (F-R2 connection). In the second refrigerant-water heat exchanger 7, it exchanges heat with the refrigerant and is heated into high-temperature hot water by the high-temperature and high-pressure refrigerant, and then repeats the above cycle.

[0128] Users can set the priority between the space cooling mode and the domestic hot water mode through the human-computer interaction interface. Alternatively, the priority can be automatically generated based on the deviation between the real-time water temperature and the set water temperature, or the deviation between the real-time room temperature and the set room temperature, to prioritize the most pressing usage needs. The automatic priority generation can employ algorithms disclosed in existing technologies, which are not the focus of this invention and will not be elaborated upon here.

[0129] like Figure 9 The diagram shows the circulation process of a heat pump system operating simultaneously in domestic hot water mode and defrost mode.

[0130] Reference Figure 9 This paper describes the refrigerant flow process in a heat pump system when operating in both domestic hot water and defrost modes simultaneously. In both modes, the refrigerant-air heat exchanger 4 acts as a condenser, the first refrigerant-water heat exchanger 6 acts as a condenser to provide hot water for the heat storage device 10, and the second refrigerant-water heat exchanger 7 acts as an evaporator. The first refrigerant flow switching valve 3a is in the OFF state (DC connected, ES connected), the second refrigerant flow switching valve 3b is in the OFF state (DC connected, ES connected), and the third refrigerant flow switching valve 3c is in the ON state (DE connected, CS connected).

[0131] Compressor 2 draws low-pressure gaseous refrigerant from gas-liquid separator 1 and compresses it to a high-temperature, high-pressure exhaust state. The refrigerant is then split into two paths, flowing through the DC passage of the first refrigerant-to-switching valve 3a and the second refrigerant-to-switching valve 3b, respectively, before entering the refrigerant-air heat exchanger 4 and the first refrigerant-water heat exchanger 6. The heat pump fan 8 is shut down. In the refrigerant-air heat exchanger 4, the refrigerant exchanges heat with the surface frost layer, cooling and condensing into a subcooled liquid refrigerant at medium temperature and high pressure. In the first refrigerant-water heat exchanger 6, the refrigerant exchanges heat with water, cooling and condensing into a subcooled liquid refrigerant at medium temperature and high pressure. The medium-temperature, high-pressure subcooled liquid refrigerant further passes through the first throttling element 5a and the second throttling element 5b, and then merges after passing through the first throttling element 5a and the second throttling element 5b. After merging, it is further throttled by the third throttling element 5c into a low-pressure two-phase refrigerant, which enters the second refrigerant-water heat exchanger 7. It absorbs the heat from the return water of the terminal equipment 9 and becomes a low-pressure superheated refrigerant. Then, it flows through the CS passage of the third refrigerant flow to the switching valve 3c and returns to the gas-liquid separator 1.

[0132] Reference Figure 9 The flow process of water is described below. In the second refrigerant-water heat exchanger 7, water exchanges heat with the refrigerant, and the water temperature decreases due to the absorption of heat by the low-pressure two-phase refrigerant. After heat exchange, the water flows through the second water path switching valve 13b (O2-F connection) and, under the suction of the terminal water pump 11, flows to the terminal device 9. The return water from the terminal device 9 flows back to the second refrigerant-water heat exchanger 7 through the fourth water path switching valve 14b (F-R2 connection), where it exchanges heat with the refrigerant again, repeating the above cycle. This achieves defrosting by absorbing heat from the terminal device 9. In the first refrigerant-water heat exchanger 6, water exchanges heat with the refrigerant, and its temperature rises to become high-temperature hot water. After heat exchange, the high-temperature hot water flows through the first water path switching valve 13a (O1-T connection) and, under the suction of the hot water storage pump 12, flows to the heat storage device 10. The return water from the heat storage device 10 returns to the first refrigerant-water heat exchanger 6 through the third water flow switching valve 14a (T-R1 connection). In the first refrigerant-water heat exchanger 6, it exchanges heat with the refrigerant and is heated into high-temperature hot water by the high-temperature and high-pressure refrigerant. The above cycle is then repeated.

[0133] like Figure 10 The diagram shows the circulation process of a heat pump system in space cooling mode (low load).

[0134] Reference Figure 10This paper describes the refrigerant flow process in a heat pump system under space cooling mode (low load). When there is only space cooling demand and the cooling load is small (e.g., the temperature difference between the return air temperature and the set temperature meets the preset low load setting conditions), the refrigerant-air heat exchanger 4 is used as a condenser, the first refrigerant-water heat exchanger 6 is not used, the second throttling element 5b remains fully closed, and the second refrigerant-water heat exchanger 7 is used as an evaporator to provide chilled water cooling for the terminal equipment 9. The first refrigerant flow direction switching valve 3a is in the OFF state (DC connected, ES connected), the second refrigerant flow direction switching valve 3b is in the ON state (DE connected, CS connected), and the third refrigerant flow direction switching valve 3c is in the ON state (DE connected, CS connected).

[0135] Compressor 2 draws low-pressure gaseous refrigerant from gas-liquid separator 1 and compresses it to a high-temperature, high-pressure exhaust state. The refrigerant then flows through the DC passage of the first refrigerant flow switching valve 3a into the refrigerant-air heat exchanger 4, where it exchanges heat with outdoor air, cools, and condenses into a medium-temperature, high-pressure subcooled liquid refrigerant. This subcooled liquid then passes through the third throttling element 5c, becoming a low-pressure two-phase refrigerant, and enters the second refrigerant-water heat exchanger 7. In the second refrigerant-water heat exchanger 7, the refrigerant exchanges heat with water, absorbing heat from the water and becoming a low-pressure superheated refrigerant. Finally, it flows back to gas-liquid separator 1 through the CS passage of the third refrigerant flow switching valve 3c.

[0136] Reference Figure 10 The flow process of water is described below. In the second refrigerant-water heat exchanger 7, water exchanges heat with the refrigerant, causing its temperature to drop. The cooled water, after heat exchange, flows through the second water flow switching valve 13b (O2-F connected) and, under the suction of the terminal water pump 11, flows to the terminal device 9. The cooled water undergoes further heat exchange in the terminal device 9, and after achieving cooling, it returns to the second refrigerant-water heat exchanger 7 through the fourth water flow switching valve 14b (F and R2 connected). In the second refrigerant-water heat exchanger 7, it exchanges heat with the refrigerant and is cooled to a low temperature, then the above cycle is repeated. At the same time, the hot water storage pump 12 is shut off.

[0137] like Figure 11 The diagram shows the circulation process of a heat pump system in space heating mode (low load).

[0138] Reference Figure 11This paper describes the refrigerant flow process in a heat pump system under space heating mode (low load). When there is only space heating demand and the heating load is small (e.g., the temperature difference between the set temperature and the return air temperature meets the preset low load setting conditions), the refrigerant-air heat exchanger 4 is used as an evaporator, the first refrigerant-water heat exchanger 6 is not used, the second throttling element 5b is kept below the set opening (a small opening) to avoid refrigerant accumulation, and the second refrigerant-water heat exchanger 7 is used as a condenser to provide hot water heating for the terminal equipment 9. The first refrigerant flow direction switching valve 3a is in the ON state (DE connected, CS connected), the second refrigerant flow direction switching valve 3b is in the OFF state (DC connected, ES connected), and the third refrigerant flow direction switching valve 3c is in the OFF state (DC connected, ES connected).

[0139] Compressor 2 draws low-pressure gaseous refrigerant from gas-liquid separator 1 and compresses it to a high-temperature, high-pressure exhaust state. The refrigerant is then divided into two paths, passing through the DC passage of the second refrigerant flow switching valve 3b and the DC passage of the third refrigerant flow switching valve 3c, respectively, and entering the first refrigerant-water heat exchanger 6 and the second refrigerant-water heat exchanger 7. In the first refrigerant-water heat exchanger 6, the refrigerant flow is relatively small, and there is no flowing water to exchange heat with it. It only has natural convection heat exchange with the air and has basically no heating capacity. The refrigerant at the outlet of the first refrigerant-water heat exchanger 6 is in a high-pressure or high-pressure two-phase state. In the second refrigerant-water heat exchanger 7, it exchanges heat with water from terminal equipment 9, is cooled, and condenses into a medium-temperature, high-pressure subcooled liquid refrigerant. The two refrigerants further pass through the second throttling element 5b and the third throttling element 5c respectively, and then merge after passing through the second throttling element 5b and the third throttling element 5c. After merging, they are further throttled by the first throttling element 5a into low-pressure two-phase refrigerant, and enter the refrigerant-air heat exchanger 4. There, they absorb heat from the outdoor air and become low-pressure superheated refrigerant. Then, they flow through the CS passage of the first refrigerant to the switching valve 3a and return to the gas-liquid separator 1.

[0140] Reference Figure 11 The flow process of water is described below. In the second refrigerant-water heat exchanger 7, water exchanges heat with the refrigerant, causing its temperature to rise. The high-temperature hot water, after heat exchange, flows through the second water flow switching valve 13b (O2-F connected) and, under the suction of the terminal water pump 11, flows to the terminal device 9. The high-temperature hot water undergoes further heat exchange in the terminal device 9. After achieving heating, the return water from the terminal device 9 returns to the second refrigerant-water heat exchanger 7 through the fourth water flow switching valve 14b (F and R2 connected). In the second refrigerant-water heat exchanger 7, it exchanges heat with the refrigerant and is heated into high-temperature hot water by the high-temperature, high-pressure refrigerant, thus repeating the above cycle. At the same time, the hot water storage pump 12 is shut off.

[0141] like Figure 12The diagram shows the circulation process of a heat pump system in domestic hot water mode (low load).

[0142] Reference Figure 12 This paper describes the refrigerant flow process in a heat pump system under domestic hot water mode (low load). When there is only domestic hot water demand and the heating load is small (e.g., the temperature difference between the set temperature and the real-time temperature of the water tank meets the preset low load setting conditions), the refrigerant-air heat exchanger 4 acts as an evaporator, the first refrigerant-water heat exchanger 6 acts as a condenser to provide hot water to the heat storage device 10 for heating, the second refrigerant-water heat exchanger 7 is not used, and the third throttling element 5c is kept below the set opening (a small opening) to avoid refrigerant accumulation. The first refrigerant flow direction switching valve 3a is in the ON state (DE connected, CS connected), the second refrigerant flow direction switching valve 3b is in the OFF state (DC connected, ES connected), and the third refrigerant flow direction switching valve 3c is in the OFF state (DC connected, ES connected).

[0143] Compressor 2 draws low-pressure gaseous refrigerant from gas-liquid separator 1 and compresses it to a high-temperature, high-pressure exhaust state. The refrigerant is then split into two paths: one through the DC passage of the second refrigerant flow switching valve 3b, and the other through the DC passage of the third refrigerant flow switching valve 3c. After entering the first refrigerant-water heat exchanger 6, the refrigerant exchanges heat with water, is cooled, and condenses into a subcooled liquid refrigerant at medium temperature and high pressure. In the second refrigerant-water heat exchanger 7, the refrigerant flow is relatively small, and there is no flowing water for heat exchange; it only exchanges heat with air through natural convection, resulting in virtually no heating capacity. The refrigerant at the outlet of the second refrigerant-water heat exchanger 7 is in a high-pressure or high-pressure two-phase state. The refrigerant further passes through the second throttling element 5b and the third throttling element 5c respectively, and then merges after passing through the second throttling element 5b and the third throttling element 5c. After merging, it is further throttled by the first throttling element 5a into a low-pressure two-phase refrigerant, and enters the refrigerant-air heat exchanger 4. It absorbs heat from the outdoor air and becomes a low-pressure superheated refrigerant, and then flows through the CS passage of the first refrigerant flow to the switching valve 3a, and returns to the gas-liquid separator 1.

[0144] Reference Figure 12 The flow process of water is described below. In the first refrigerant-water heat exchanger 6, water exchanges heat with the refrigerant, and its temperature rises to become high-temperature hot water. The high-temperature hot water after heat exchange flows to the heat storage device 10 through the first water flow switching valve 13a (O1-T connection). The return water from the heat storage device 10 returns to the first refrigerant-water heat exchanger 6 through the third water flow switching valve 14a (T-R1 connection), where it exchanges heat with the refrigerant and is heated to high-temperature hot water by the high-temperature and high-pressure refrigerant. The above cycle is then repeated.

[0145] like Figure 13The diagram shows the circulation process of a heat pump system operating simultaneously in space heating mode and domestic hot water mode (low load).

[0146] Reference Figure 13 This paper describes the refrigerant flow process in a heat pump system operating simultaneously in both space heating and domestic hot water modes (low load). When there is simultaneous demand for both space heating and domestic hot water, and the heating load is relatively low (e.g., when the temperature difference between the set temperature and the real-time temperature of the water tank, and the temperature difference between the set temperature and the return air temperature, simultaneously meet the preset low load conditions), the refrigerant-air heat exchanger 4 acts as an evaporator, the first refrigerant-water heat exchanger 6 acts as a condenser to provide hot water for heating to the heat storage device 10 and the terminal device 9, the second refrigerant-water heat exchanger 7 is not used, and the third throttling element 5c is kept below the set opening (a small opening) to avoid refrigerant accumulation. The first refrigerant flow direction switching valve 3a is in the ON state (DE connected, CS connected), the second refrigerant flow direction switching valve 3b is in the OFF state (DC connected, ES connected), and the third refrigerant flow direction switching valve 3c is in the OFF state (DC connected, ES connected).

[0147] Compressor 2 draws low-pressure gaseous refrigerant from gas-liquid separator 1 and compresses it to a high-temperature, high-pressure exhaust state. The refrigerant is then divided into two paths, passing through the DC passage of the second refrigerant flow to switching valve 3b and the DC passage of the third refrigerant flow to switching valve 3c, respectively, and enters the first refrigerant-water heat exchanger 6 and the second refrigerant-water heat exchanger 7. In the first refrigerant-water heat exchanger 6, the refrigerant exchanges heat with water, is cooled, and condenses into a medium-temperature, high-pressure subcooled liquid refrigerant. In the second refrigerant-water heat exchanger 7, the refrigerant flow rate is low, and there is no flowing water to exchange heat with it. It only has natural convection heat exchange with the air and has basically no heating capacity. The refrigerant at the outlet of the second refrigerant-water heat exchanger 7 is in a high-pressure or high-pressure two-phase state. It further passes through the second throttling element 5b and the third throttling element 5c respectively, and then merges after passing through the second throttling element 5b and the third throttling element 5c. After merging, it is further throttled by the first throttling element 5a into a low-pressure two-phase refrigerant, and enters the refrigerant-air heat exchanger 4. It absorbs heat from the outdoor air and becomes a low-pressure superheated refrigerant. Then it flows through the CS passage of the first refrigerant flow to the switching valve 3a and returns to the gas-liquid separator 1.

[0148] Reference Figure 13The flow process of water is described below. In the first refrigerant-water heat exchanger 6, water exchanges heat with the refrigerant, and its temperature rises to become high-temperature hot water. The high-temperature hot water after heat exchange flows through the first water path switching valve 13a (O1-T connection) and flows to the heat storage device 10 under the suction of the hot water storage pump 12. The other path flows through the second water path switching valve 13b (O1-F connection) and flows to the terminal device 9 under the suction of the terminal water pump 11. The return water from the terminal device 9 passes through the fourth water path switching valve 14b (F-R1 connection) and merges with the return water from the heat storage device 10. Then, it passes through the third water path switching valve 14a (T-R1 connection) and returns to the first refrigerant-water heat exchanger 6. In the first refrigerant-water heat exchanger 6, it exchanges heat with the refrigerant and is heated to high-temperature hot water by the high-temperature and high-pressure refrigerant. The above cycle is then repeated.

[0149] During the high temperatures of summer, the cooling operation of heat pump systems is subject to harsh conditions, which mainly leads to two problems: If both indoor and outdoor temperatures are high, the suction and discharge pressures of the heat pump system's compressor 2 will be very high, while the maximum suction and discharge pressures of compressor 2 need to be maintained within a certain range. When the maximum suction or discharge pressure is exceeded, compressor 2 will enter protection control, and the heat pump system will shut down and become unable to operate. If the outdoor temperature is very high, but the indoor temperature is still acceptable, the heat pump system may experience a situation where the discharge pressure exceeds the high-pressure protection value, but the suction pressure is within the tolerable range. In this case, the heat pump system will automatically reduce the frequency of compressor 2 to reduce the high pressure, thereby reducing the capacity of the heat pump system and causing fluctuations in the room temperature or water temperature.

[0150] To address this issue, the heat pump system provided in this application can also operate in a cooling overload mode.

[0151] like Figure 14 The diagram shows the cyclic process of a heat pump system in overload mode.

[0152] Reference Figure 14 This section describes the refrigerant flow process in a heat pump system under overload cooling mode. When the indoor temperature and / or outdoor ambient temperature are within a preset protection range, the heat pump system executes overload cooling mode. In overload cooling mode, the refrigerant-air heat exchanger 4 functions as a condenser, the first refrigerant-water heat exchanger 6 is not used, the second throttling element 5b remains fully closed, and the second refrigerant-water heat exchanger 7 functions as an evaporator to provide chilled water cooling to the terminal equipment 9. The first refrigerant flow direction switching valve 3a is in the OFF state (DC connected, ES connected), the second refrigerant flow direction switching valve 3b is in the ON state (DE connected, CS connected), and the third refrigerant flow direction switching valve 3c is in the ON state (DE connected, CS connected).

[0153] Compressor 2 draws low-pressure gaseous refrigerant from gas-liquid separator 1 and compresses it to a high-temperature, high-pressure exhaust state. The refrigerant then flows through the DC passage of the first refrigerant flow switching valve 3a into the refrigerant-air heat exchanger 4, where it exchanges heat with outdoor air, cools, and condenses into a medium-temperature, high-pressure subcooled liquid refrigerant. This subcooled liquid then passes through the third throttling element 5c, becoming a low-pressure two-phase refrigerant, and enters the second refrigerant-water heat exchanger 7. In the second refrigerant-water heat exchanger 7, the refrigerant exchanges heat with water, absorbing heat from the water and becoming a low-pressure superheated refrigerant. Finally, it flows back to gas-liquid separator 1 through the CS passage of the third refrigerant flow switching valve 3c.

[0154] Reference Figure 14 The flow process of water is described below. In the second refrigerant-water heat exchanger 7, water exchanges heat with the refrigerant, causing its temperature to drop. The cooled water, after heat exchange, flows through the second water flow switching valve 13b (O2-F connected) and, under the suction of the terminal water pump 11, flows to the terminal device 9. The cooled water undergoes further heat exchange in the terminal device 9, and after achieving cooling, it returns to the second refrigerant-water heat exchanger 7 through the fourth water flow switching valve 14b (F and R2 connected). In the second refrigerant-water heat exchanger 7, it exchanges heat with the refrigerant and is cooled to a low temperature, then the above cycle is repeated. At the same time, the hot water storage pump 12 is shut off.

[0155] In the overload mode of cooling, only one refrigerant-water heat exchanger is used as the evaporator to address the first problem. This reduces the evaporation area and lowers the evaporation pressure, which in turn lowers the discharge pressure. This ensures that the suction and discharge pressures are within the acceptable range of compressor 2, thereby expanding the operating range of the unit. To address the second problem, this reduces the evaporation area and lowers the evaporation pressure. The discharge pressure will then be reduced to below the high-pressure protection pressure of compressor 2, preventing compressor 2 from throttling and thus ensuring the cooling capacity of the heat pump system.

[0156] like Figure 15 As shown, in some embodiments of this application, the gas-liquid separator 1, compressor 2, first refrigerant flow switching valve 3a, second refrigerant flow switching valve 3b, third refrigerant flow switching valve 3c, refrigerant-air heat exchanger 4, first throttling element 5a, second throttling element 5b, third throttling element 5c, first refrigerant-water heat exchanger 6, and second refrigerant-water heat exchanger 7 can be integrated into the outdoor unit 100. The first water flow switching valve 13a, second water flow switching valve 13b, third water flow switching valve 14a, fourth water flow switching valve 14b, terminal water pump 11, heat storage device 10, and hot water storage pump 12 can be integrated into the indoor unit 200; the terminal device 9 can be configured and installed at the actual place of use, for example through the water outlet O9 and the water return R9 of the terminal device 9.

[0157] like Figure 16As shown, in some embodiments of this application, the gas-liquid separator 1, compressor 2, first refrigerant flow switching valve 3a, second refrigerant flow switching valve 3b, third refrigerant flow switching valve 3c, refrigerant-air heat exchanger 4, first throttling element 5a, second throttling element 5b, third throttling element 5c, first refrigerant-water heat exchanger 6, second refrigerant-water heat exchanger 7, first water flow switching valve 13a, second water flow switching valve 13b, third water flow switching valve 14a, fourth water flow switching valve 14b, terminal water pump 11, heat storage device 10, and hot water storage pump 12 can be integrated into the outdoor unit 101; the terminal device 9 and the heat storage device 10 can be configured and installed in the actual use location, for example, through the water outlet O9 and the water return R9 of the terminal device 9, and the water outlet O10 and the water return R10 of the heat storage device 10.

[0158] like Figure 17 As shown, in some embodiments of this application, the gas-liquid separator 1, compressor 2, first refrigerant flow switching valve 3a, second refrigerant flow switching valve 3b, third refrigerant flow switching valve 3c, refrigerant-air heat exchanger 4, first throttling element 5a, second throttling element 5b, third throttling element 5c, first refrigerant-water heat exchanger 6, and second refrigerant-water heat exchanger 7 can be integrated into the outdoor unit 201. The first water flow switching valve 13a, second water flow switching valve 13b, third water flow switching valve 14a, fourth water flow switching valve 14b, terminal water pump 11, heat storage device 10, and hot water storage pump 12 can be integrated into the indoor unit 102. The two are designed as separate units, with a first shut-off valve 15a, a second shut-off valve 15b, and a third shut-off valve 15c installed on the outdoor unit side. The first shut-off valve 15a is connected to the second refrigerant flow switching valve 3b, the second shut-off valve 15b is connected to the third refrigerant flow switching valve 3c, and the third shut-off valve 15c is connected to the refrigerant-air heat exchanger 4. The first shut-off valve 15a, the second shut-off valve 15b, and the third shut-off valve 15c ensure installation safety. The terminal equipment 9 can be configured and installed at the actual place of use, for example, through the water outlet O9 and the water return R9 of the terminal equipment 9. Figure 17 In the diagram, P1 is the first shut-off valve port, P2 is the second shut-off valve port, and P3 is the third shut-off valve port.

[0159] In some embodiments of this application, the low load setting conditions can be set according to the actual situation, or other low load setting conditions or other load setting conditions can be selected.

[0160] Figure 18 and Figure 19 This is a table showing the status of different components in the heat pump system under various operating modes of this application.

[0161] In the description of the above embodiments, specific features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.

[0162] The above are merely specific embodiments of this utility model, but the protection scope of this utility model is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the scope of the claims.

Claims

1. Heat pump system, including: A compressor, which is used to compress refrigerant; A refrigerant-air heat exchanger is used to exchange heat between a refrigerant and air. A first refrigerant-water heat exchanger is used for heat exchange between refrigerant and water, and is fluidly connected to a heat storage device that can be used to provide domestic hot water. A second refrigerant-water heat exchanger is used for heat exchange between refrigerant and water, and is fluidly connected to a terminal device that can be used for space cooling or space heating. The first throttling element is fluidly connected to the refrigerant-air heat exchanger; Its characteristic is that it further includes: A first refrigerant flow switching valve is fluidly connected to the refrigerant-air heat exchanger and the compressor; The second refrigerant flow switching valve is fluidly connected to the first refrigerant-water heat exchanger and the compressor; The third refrigerant flow switching valve is fluidly connected to the second refrigerant-water heat exchanger and the compressor; The first refrigerant flow switching valve, the second refrigerant flow switching valve, and the third refrigerant flow switching valve are used to switch the refrigerant flow direction, so that the refrigerant-air heat exchanger, and / or the first refrigerant-water heat exchanger, and / or the second refrigerant-water heat exchanger, can operate as a condenser or an evaporator.

2. The heat pump system according to claim 1, characterized in that, Also includes: The second throttling element is fluidly connected to the first refrigerant-water heat exchanger; In space cooling mode, the first refrigerant flow switching valve, the second refrigerant flow switching valve, and the third refrigerant flow switching valve can switch the refrigerant flow direction, so that the refrigerant-air heat exchanger acts as a condenser, the first refrigerant-water heat exchanger acts as an evaporator, and the second refrigerant-water heat exchanger acts as an evaporator to provide chilled water to the terminal equipment for cooling; or In space cooling mode, the first refrigerant flow switching valve, the second refrigerant flow switching valve, and the third refrigerant flow switching valve can switch the refrigerant flow direction, so that the refrigerant-air heat exchanger is used as a condenser and the second refrigerant-water heat exchanger is used as an evaporator to provide cold water to the terminal equipment for cooling; the second throttling element remains fully closed to cut off the refrigerant passage of the first refrigerant-water heat exchanger.

3. The heat pump system according to claim 1, characterized in that, Also includes: The second throttling element is fluidly connected to the first refrigerant-water heat exchanger; In space heating mode, the first refrigerant flow switching valve, the second refrigerant flow switching valve, and the third refrigerant flow switching valve can switch the refrigerant flow direction, so that the refrigerant-air heat exchanger acts as an evaporator, the first refrigerant-water heat exchanger acts as a condenser, and the second refrigerant-water heat exchanger acts as a condenser to provide hot water for heating to the heat storage device; or In the space heating mode, the first refrigerant flow switching valve, the second refrigerant flow switching valve, and the third refrigerant flow switching valve can switch the refrigerant flow direction, so that the refrigerant-air heat exchanger is used as an evaporator and the second refrigerant-water heat exchanger is used as a condenser to provide hot water for heating to the terminal equipment; the second throttling element is kept below the set opening to limit the refrigerant flow in the first refrigerant-water heat exchanger.

4. The heat pump system according to claim 1, characterized in that, Also includes: The third throttling element is fluidly connected to the second refrigerant-water heat exchanger; In domestic hot water mode, the first refrigerant flow switching valve, the second refrigerant flow switching valve, and the third refrigerant flow switching valve can switch the refrigerant flow direction, so that the refrigerant-air heat exchanger is used as an evaporator, the first refrigerant-water heat exchanger is used as a condenser, and the second refrigerant-water heat exchanger is used as a condenser to provide hot water for heating to the heat storage equipment. Alternatively, the first refrigerant flow switching valve, the second refrigerant flow switching valve, and the third refrigerant flow switching valve can switch the refrigerant flow direction, so that the refrigerant-air heat exchanger is used as an evaporator, the first refrigerant-water heat exchanger is used as a condenser, and the third throttling element is kept below a set opening to limit the refrigerant flow in the second refrigerant-water heat exchanger.

5. The heat pump system according to claim 1, characterized in that: Also includes: The second throttling element is fluidly connected to the first refrigerant-water heat exchanger; The first refrigerant flow switching valve, the second refrigerant flow switching valve, and the third refrigerant flow switching valve can switch the refrigerant flow direction, so that the refrigerant-air heat exchanger is used as an evaporator, the first refrigerant-water heat exchanger is used as a condenser to provide hot water for heating to the heat storage equipment, and the second refrigerant-water heat exchanger is used as a condenser to provide hot water for heating to the terminal equipment. Alternatively, the first refrigerant flow switching valve, the second refrigerant flow switching valve, and the third refrigerant flow switching valve can switch the refrigerant flow direction, so that the refrigerant-air heat exchanger is used as an evaporator and the first refrigerant-water heat exchanger is used as a condenser to provide hot water for heating to the heat storage equipment and terminal equipment; the second throttling element is kept below the set opening to limit the refrigerant flow in the first refrigerant-water heat exchanger.

6. The heat pump system according to claim 1, characterized in that, The first refrigerant flow switching valve, the second refrigerant flow switching valve, and the third refrigerant flow switching valve can switch the refrigerant flow direction, such that the refrigerant-air heat exchanger functions as an evaporator, the first refrigerant-water heat exchanger functions as a condenser to provide hot water for heating to the heat storage device, and the second refrigerant-water heat exchanger functions as an evaporator to provide cold water for cooling to the terminal device; or The first refrigerant flow switching valve, the second refrigerant flow switching valve, and the third refrigerant flow switching valve can switch the refrigerant flow direction, so that the refrigerant-air heat exchanger is used as a condenser, the first refrigerant-water heat exchanger is used as a condenser to provide hot water for heating to the heat storage equipment, and the second refrigerant-water heat exchanger is used as an evaporator to provide cold water for cooling to the terminal equipment.

7. The heat pump system according to claim 1, characterized in that, The first refrigerant flow switching valve, the second refrigerant flow switching valve, and the third refrigerant flow switching valve can switch the refrigerant flow direction, so that the refrigerant-air heat exchanger is used as a condenser to melt the frost layer on the surface of the refrigerant-air heat exchanger, the first refrigerant-water heat exchanger is used as an evaporator, and the second refrigerant-water heat exchanger is used as a condenser to provide hot water for heating to the terminal equipment.

8. The heat pump system according to claim 1, characterized in that, The first refrigerant flow switching valve, the second refrigerant flow switching valve, and the third refrigerant flow switching valve can switch the refrigerant flow direction, so that the refrigerant-air heat exchanger is used as a condenser to melt the frost layer on the surface of the refrigerant-air heat exchanger, the first refrigerant-water heat exchanger is used as a condenser to provide hot water for the heat storage device to generate heat, and the second refrigerant-water heat exchanger is used as an evaporator.

9. The heat pump system according to claim 1, characterized in that, Also includes: The second throttling element is fluidly connected to the first refrigerant-water heat exchanger; In the space cooling mode, the first refrigerant flow switching valve, the second refrigerant flow switching valve, and the third refrigerant flow switching valve can switch the refrigerant flow direction, so that the refrigerant-air heat exchanger is used as a condenser, the first refrigerant-water heat exchanger is used as an evaporator, and the second refrigerant-water heat exchanger is used as an evaporator to provide cold water to the terminal equipment for cooling. When the indoor temperature is higher than the set indoor temperature threshold, or the outdoor ambient temperature is higher than the set outdoor ambient temperature threshold, the second throttling element switches to a fully closed state to cut off the refrigerant passage of the first refrigerant-water heat exchanger.

10. The heat pump system according to any one of claims 1 to 9, characterized in that, Also includes: The first water flow direction switching valve has a first port connected to the heat storage device, a second port connected to the first refrigerant-water heat exchanger, and a third port connected to the second refrigerant-water heat exchanger; the first water flow direction switching valve can form a flow path between the first port and the second port, or a flow path between the second port and the third port; The second water flow direction switching valve has a first port connected to the terminal equipment, a second port connected to the first water flow direction switching valve and the first refrigerant-water heat exchanger, and a third port connected to the second refrigerant-water heat exchanger and the first water flow direction switching valve; the second water flow direction switching valve can form a flow path between the first port and the second port, a flow path between the first port and the third port, or a flow path between the second port and the third port. The third water flow direction switching valve has a first port connected to the heat storage device, a second port connected to the first refrigerant-water heat exchanger, and a third port connected to the terminal device; the third water flow direction switching valve can form a flow path between the first port and the second port, or a flow path between the second port and the third port; The fourth water flow direction switching valve has its first port connected to the return water end of the heat storage device and the third water flow direction switching valve, its second port connected to the heat storage device and the third water flow direction switching valve, and its third port connected to the second refrigerant-water heat exchanger. The fourth water flow direction switching valve can form a flow path between the first port and the second port, between the first port and the third port, or between the second port and the third port.

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