Heat pump water heater

Abstract

The utility model belongs to the technical field of heat supply, and particularly discloses a heat pump water heater. The heat pump water heater comprises a compressor, a water storage tank, a first heat exchanger, a second heat exchanger and a throttling device, the first heat exchanger is provided with a refrigerant channel and a water channel, a water inlet of the water channel is used for being connected with a cold water supply pipe, and a water outlet of the water channel is communicated with a water tank inlet of the water storage tank; the second heat exchanger is mounted in the water storage tank and used for exchanging heat with water in the water storage tank; the outlet end of the compressor can selectively communicate with an inlet of the refrigerant channel or an inlet of the second heat exchanger, an outlet of the refrigerant channel can selectively communicate with an inlet of the second heat exchanger or an inlet of the throttling device, an outlet of the second heat exchanger communicates with an inlet of the throttling device, and an outlet of the throttling device communicates with an inlet of the compressor. According to the heat pump water heater, the heating efficiency can be improved, meanwhile, the energy consumption is reduced, and the use flexibility and the use experience of the heat pump water heater are improved.

Description

Technical Field

[0001] The utility model relates to the technical field of heating, in particular to a heat pump water heater. Background Art

[0002] Water heaters are household appliances that are commonly used in people's daily lives. According to the heating method, they can be divided into electric heaters, gas water heaters and heat pump water heaters.

[0003] A heat pump water heater usually includes a water tank and a compressor, a condenser, a throttling device and an evaporator connected in sequence by a refrigerant pipeline. The condenser is arranged inside the water tank or coiled outside the water tank so that the refrigerant flowing through the condenser can heat the water inside the water tank.

[0004] In order to meet the heat storage demand, the heat pump water heaters provided by the existing technology usually require a relatively large water tank, which makes the overall size of the heat pump water heater relatively large and difficult to meet the miniaturization demand of the heat pump water heater; at the same time, since the condenser needs to insulate the water inside the water tank, the energy consumption required for insulation is relatively high; furthermore, when the water temperature in the water tank does not meet the water demand and the user needs to use hot water, the user's waiting time will be increased or the water outlet temperature of the water tank will be lower than the user's required temperature, affecting the user experience of the heat pump water heater. Utility Model Content

[0005] The technical problem solved by the present utility model is to provide a heat pump water heater, which can effectively solve the problems of existing heat pump water heaters such as large water tank size requirements, high energy consumption required for insulation and inability to meet instant heating needs, reduce the overall energy consumption of the heat pump water heater, and improve the user experience of the heat pump water heater.

[0006] The above technical problems are solved by the following technical solutions:

[0007] A heat pump water heater comprises a compressor, a water tank, a first heat exchanger, a second heat exchanger and a throttling device, wherein the first heat exchanger has a refrigerant channel and a water channel, the water inlet of the water channel is used to be connected to a cold water supply pipe, the water outlet of the water channel is connected to the water tank inlet of the water tank, and the water tank outlet of the water tank is used to be connected to a water end, and the second heat exchanger is installed in the water tank and is used to exchange heat with the water in the water tank;

[0008] The outlet end of the compressor can be selectively connected to the inlet of the refrigerant channel or the inlet of the second heat exchanger, the outlet of the refrigerant channel can be selectively connected to the inlet of the second heat exchanger or the inlet of the throttling device, the outlet of the second heat exchanger is connected to the inlet of the throttling device, and the outlet of the throttling device is connected to the inlet of the compressor.

[0009] Compared with the prior art, the heat pump water heater of the present invention has the following advantages: since the user can achieve secondary heating of water through the first heat exchanger and the second heat exchanger when using water, the outlet water temperature at the water-using end can be quickly brought to the preset outlet water temperature, reducing user waiting time and avoiding the situation where the outlet water temperature is lower than the preset outlet water temperature, thereby improving the user's water use experience; when the water temperature in the water storage tank is higher than the preset water temperature or the inlet water temperature of the water channel is relatively high, the water can be heated only by the first heat exchanger, thereby reducing the operating energy consumption of the heat pump water heater; at the same time, since the water flow can be heated by the first heat exchanger before entering the water storage tank, the water temperature entering the water storage tank can be increased, while meeting the user's demand for large amounts of hot water, the volume requirement of the water storage tank is reduced, thereby reducing the space occupied by the entire heat pump water heater, and facilitating the installation of the heat pump water heater in small houses; furthermore, since the required volume of the water storage tank is reduced, the energy consumption required to use the second heat exchanger to keep the water in the water storage tank warm can be reduced, thereby reducing the operating cost of the heat pump water heater.

[0010] In one embodiment, the heat pump water heater includes a four-way reversing valve, the four-way reversing valve having ports A, B, C, and D, wherein port A is connected to the outlet of the compressor, port B is connected to the inlet of the refrigerant channel, port C is connected to the inlet of the second heat exchanger, and port D is connected to the inlet of the compressor;

[0011] The four-way reversing valve has a first conducting state in which the port A is connected to the port B and the port C is connected to the port D, and a second conducting state in which the port A is connected to the port C and the port B is connected to the port D.

[0012] In one embodiment, the outlet of the throttling device is connected to the inlet of the compressor through a refrigerant return pipe, a bypass return pipe is connected between the D port and the refrigerant return pipe, and a reflux check valve is provided on the bypass return pipe. The reflux check valve only allows the refrigerant to flow from the D port to the refrigerant return pipe.

[0013] In one embodiment, the outlet of the compressor is connected to a refrigerant outlet pipe, the inlet of the refrigerant channel is connected to a first heat exchange branch, the inlet of the second heat exchanger is connected to a second heat exchange branch, and the refrigerant outlet pipe can be selectively connected to the first heat exchange branch or the second heat exchange branch; the outlet of the refrigerant channel can be selectively connected to the second heat exchange branch or the inlet of the throttling device.

[0014] In one embodiment, the second heat exchange branch has an inlet point connected to the refrigerant channel, and the second heat exchange branch is provided with a first one-way valve, which is located between the inlet end of the second heat exchange branch and the inlet point. The first one-way valve only allows the refrigerant to flow from the inlet of the second heat exchange branch to the inlet point.

[0015] In one embodiment, the heat pump water heater includes an electrically controlled three-way valve, a first port of the electrically controlled three-way valve is connected to the outlet of the refrigerant channel, a second port of the electrically controlled three-way valve is connected to the second heat exchange branch, a third port of the electrically controlled three-way valve is connected to the inlet of the throttling device, and the first port is connected to the second port or the third port.

[0016] In one embodiment, the second port is connected to the second heat exchange branch through a heat exchange bypass pipe, and a second one-way valve is provided on the heat exchange bypass pipe. The second one-way valve only allows the refrigerant to flow from the second port to the heat exchange bypass pipe.

[0017] In one embodiment, the third port is connected to the throttling device via a first throttling inlet pipe, and a third one-way valve is provided on the first throttling inlet pipe, and the third one-way valve only allows the refrigerant to flow from the electronically controlled three-way valve to the throttling device;

[0018] And / or, the outlet of the second heat exchanger is connected to the inlet of the throttling device through a second throttling inlet pipe, and a fourth one-way valve is provided on the second throttling inlet pipe, and the fourth one-way valve only allows the refrigerant to flow from the second heat exchanger to the throttling device.

[0019] In one embodiment, the heat pump water heater includes a controller and a water storage temperature sensor, the water storage temperature sensor is used to detect the temperature of water in the water storage tank, and the water storage temperature sensor is communicatively connected to the controller;

[0020] And / or, the heat pump water heater includes a controller and a water inlet temperature sensor, the water inlet temperature sensor is used to detect the temperature of water entering the water channel, and the water inlet temperature sensor is communicatively connected to the controller.

[0021] In one embodiment, the first heat exchanger includes an inner tube and an outer tube spaced apart and sleeved outside the inner tube, the inner cavity of the inner tube forms an inner flow channel, and an interlayer flow channel is formed between the inner tube and the outer tube, one of the inner flow channel and the interlayer flow channel is the water channel, and the other is the refrigerant channel;

[0022] And / or, the second heat exchanger is a microchannel heat exchanger arranged around the water storage tank. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A schematic diagram of the refrigerant flow of the heat pump water heater provided by an embodiment of the present utility model in the first heating mode;

[0024] Figure 2 A schematic diagram of the refrigerant flow of the heat pump water heater provided by an embodiment of the present invention in the second heating mode;

[0025] Figure 3 A schematic diagram of the refrigerant flow in the heat pump water heater provided in the heat storage mode according to an embodiment of the present invention.

[0026] Description of labels:

[0027] 1. Compressor; 2. Four-way reversing valve; 3. First heat exchanger; 4. Second heat exchanger; 5. Electric three-way valve; 6. Water storage tank; 7. Throttling device; 8. Evaporator; 9. Cooling fan; 10. Gas-liquid separator; 20. Flow switch;

[0028] 101, refrigerant outlet pipe; 102, first heat exchange branch pipe; 103, second heat exchange branch pipe; 104, first throttle inlet pipe; 105, second throttle inlet pipe; 106, refrigerant return pipe; 107, bypass return pipe; 108, water inlet pipe; 109, heat exchange outlet pipe; 110, heat exchange bypass pipe;

[0029] 201, first one-way valve; 202, second one-way valve; 203, third one-way valve; 204, fourth one-way valve; 205, backflow one-way valve. DETAILED DESCRIPTION

[0030] The following will be combined with the drawings in the embodiments of this application to clearly and completely describe the technical solutions in the embodiments of this application. Obviously, the embodiments described are only part of the embodiments of this application, not all of the embodiments. Based on the embodiments in this application, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of this application.

[0031] In the description of this application, it should be understood that the terms "center", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position 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, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application.

[0032] 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 the technical features being referred to. Thus, a feature specified as "first" or "second" may explicitly or implicitly include one or more of such features. Throughout this application, unless otherwise specified, "plurality" means two or more.

[0033] In the description of this application, it should be noted that, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on the specific circumstances.

[0034] The utility model provides a heat pump water heater, which can meet the needs of rapid water supply and heat preservation, reduce the overall size of the heat pump water heater, and improve the user experience of the heat pump water heater.

[0035] like Figures 1 to 3 As shown, specifically, the heat pump water heater includes a compressor 1, a water tank 6, a first heat exchanger 3, a second heat exchanger 4, and a throttling device 7. The first heat exchanger 3 has a water channel and a refrigerant channel for exchanging heat with each other. The outlet of the compressor 1 can selectively communicate with the inlet of the refrigerant channel or the inlet of the second heat exchanger 4; the outlet of the refrigerant channel can selectively communicate with the inlet of the second heat exchanger 4 or the inlet of the throttling device 7, and the outlet of the second heat exchanger 4 is connected to the inlet of the throttling device 7. The inlet of the water channel is connected to the cold water supply pipe, and the outlet of the water channel is connected to the water tank inlet of the water tank 6. The outlet of the water tank 6 is connected to the water supply pipeline. The second heat exchanger 4 is mounted on the water tank 6 and is used to exchange heat with the water in the water tank 6. The outlet of the throttling device 7 is connected to the inlet of the compressor 1.

[0036] The heat pump water heater provided by the present invention has the following configurations:

[0037] When the heat pump water heater is in the first heating mode, the outlet of the compressor 1 is connected to the inlet of the refrigerant channel, the outlet of the refrigerant channel is connected to the inlet of the throttling device 7, and the inlet of the second heat exchanger 4 is disconnected from the refrigerant channel and the outlet of the compressor 1. The high-temperature and high-pressure refrigerant flowing out of the compressor 1 flows into the refrigerant channel of the first heat exchanger 3, exchanges heat with the cold water in the water channel, and the refrigerant condenses and cools to form a high-pressure, medium-temperature or low-temperature liquid before flowing to the throttling device 7. After being throttled by the throttling device 7, the refrigerant becomes a low-temperature and low-pressure liquid refrigerant and flows back to the compressor 1 to form a refrigerant flow cycle; the water in the water channel is converted into hot water after heat exchange with the high-temperature refrigerant in the refrigerant channel. The hot water flows to the water storage tank 6 and mixes with the water in the water storage tank 6. The water in the water storage tank 6 flows to the water use end.

[0038] When the heat pump water heater is in the second heating mode, the inlet of compressor 1 communicates with the inlet of the refrigerant channel, and the outlet of the refrigerant channel communicates with the inlet of the second heat exchanger 4. The high-temperature, high-pressure gaseous refrigerant, compressed and ejected from compressor 1, flows into the refrigerant channel in first heat exchanger 3, where it exchanges heat with the water in the water channel. The refrigerant condenses and cools to form a high-pressure, medium-temperature, or low-temperature liquid. The medium-temperature refrigerant then flows into second heat exchanger 4, where it exchanges heat with the water in water storage tank 6, further condensing and cooling the refrigerant and heating the water in water storage tank 6. The refrigerant flowing out of second heat exchanger 4 is throttled and cooled by throttling device 7 before returning to compressor 1.

[0039] When the heat pump water heater is in heat storage mode, the inlet of compressor 1 is connected to the inlet of second heat exchanger 4. The high-temperature, high-pressure gaseous refrigerant, compressed by compressor 1, flows to second heat exchanger 4, where it heats the water in water storage tank 6. The water in water storage tank 6 is heated to maintain its temperature and store heat. After heat exchange and cooling in second heat exchanger 4, the refrigerant flows to throttling device 7 and, after being throttled, flows back to compressor 1.

[0040] That is, the heat pump water heater provided in this embodiment has a first heating mode in which only the first heat exchanger 3 heats water, a second heating mode in which the first heat exchanger 3 and the second heat exchanger 4 are connected in series to heat water successively, and a heat storage mode in which only the second heat exchanger 4 heats water in the water storage tank 6, so that the heat pump water heater can be switched to different operating modes according to different needs:

[0041] When the water end needs water and the water temperature in the water storage tank 6 is higher than the preset water temperature or the ambient temperature is higher than the preset ambient temperature, the heat pump water heater can be switched to the first heating mode to meet the hot water supply demand of the preset water outlet temperature, while reducing the required refrigerant flow rate and reducing the energy consumption of the heat pump water heater;

[0042] When the user needs water and the water temperature in the water storage tank 6 is lower than the preset water temperature, the heat pump water heater can switch to the second heating mode, so that the water entering the water channel is heated by the first heat exchanger 3 and the second heat exchanger 4 in sequence, while meeting the preset water outlet temperature of the user, improving the heating efficiency and meeting the demand for rapid supply of hot water at the preset water outlet temperature;

[0043] When the water-using end does not need water and the water temperature in the water tank 6 is lower than the preset insulation temperature, the heat pump water heater can switch to the heat storage mode to heat the water in the water tank 6 through the second heat exchanger 4 to meet the insulation requirements.

[0044] That is, the heat pump water heater provided in this embodiment can realize secondary heating of water through the first heat exchanger 3 and the second heat exchanger 4 when the user uses water, so that the outlet water temperature of the water-using end can quickly reach the preset outlet water temperature, reducing the user's waiting time and avoiding the situation where the outlet water temperature is lower than the preset outlet water temperature, thereby improving the user's water use experience; when the water temperature in the water storage tank 6 is higher than the preset water temperature or the inlet water temperature of the water channel is relatively high, the water can be heated only by the first heat exchanger 3, thereby reducing the operating energy consumption of the heat pump water heater; and Since the water flow can be heated by the first heat exchanger 3 before entering the water tank 6, the water temperature entering the water tank 6 can be increased. While meeting the user's demand for large amounts of hot water, the volume requirement of the water tank 6 is reduced, thereby reducing the footprint of the entire heat pump water heater, which is conducive to meeting the installation requirements of the heat pump water heater in small-sized houses; furthermore, since the required volume of the water tank 6 is reduced, the energy consumption required for using the second heat exchanger 4 to keep the water in the water tank 6 warm can be reduced, thereby reducing the use cost of the heat pump water heater.

[0045] The outlet of the throttling device 7 is connected to the inlet of the compressor 1 via a refrigerant return pipe 106. An evaporator 8 and a gas-liquid separator 10 are sequentially arranged on the refrigerant return pipe 106 along the refrigerant flow direction. That is, the low-temperature, low-pressure liquid refrigerant formed by throttling and cooling the throttling device 7 is throttled and cooled by the evaporator 8 to form a low-temperature, low-pressure gaseous refrigerant, which is then separated from the gas and liquid and returned to the compressor 1. The throttling device 7 preferably, but not limited to, employs an existing throttling structure such as an electronic expansion valve.

[0046] Furthermore, the heat pump water heater further includes a heat dissipation fan 9 , which is arranged facing the evaporator 8 to dissipate heat from the evaporator 8 .

[0047] In one embodiment, the heat pump water heater includes a four-way reversing valve 2, which has a port A, a port B, a port C and a port D. Port A is connected to the outlet of the compressor 1, port B is connected to the inlet of the refrigerant channel, port C is connected to the inlet of the second heat exchanger 4, and port D is connected to the inlet of the compressor 1; the four-way reversing valve 2 has a first conducting state in which port A is connected to port B and port C is connected to port D, and a second conducting state in which port A is connected to port C and port B is connected to port D.

[0048] That is, when the heat pump water heater is in the first heating mode and the second heating mode, the four-way reversing valve 2 is in the first conduction state; when the heat pump water heater is in the heat storage mode, the four-way reversing valve 2 is in the second conduction state, which is conducive to realizing the flow reversal of the refrigerant; at the same time, because when port A is connected to port B, port C is connected to port D, and when port A is connected to port C, port B is connected to port D, it is conducive to pumping the refrigerant in the heat pump water heater pipeline back to the compressor 1, which is conducive to regulating the amount of refrigerant in the pipeline of the heat pump water heater, and better ensuring the reliability of the use of the heat pump water heater.

[0049] In one embodiment, a bypass return pipe 107 is connected between port D and the refrigerant return pipe 106. A return check valve 205 is provided on bypass return pipe 107, which only allows refrigerant to flow from port D to the refrigerant return pipe 106. This simplifies the piping configuration of the heat pump water heater while preventing refrigerant from the refrigerant return pipe 106 from flowing back through bypass return pipe 107 to the four-way reversing valve 2. Specifically, the return bypass pipe is connected between the evaporator 8 and the gas-liquid separator 10 to separate the refrigerant flowing out of the return bypass pipe into gas and liquid before returning it to the compressor 1.

[0050] Furthermore, the outlet of the compressor 1 is connected to a refrigerant outlet pipe 101, which is connected to port A. The inlet of the refrigerant channel is connected to a first heat exchange branch pipe 102, whose inlet end is connected to port B. The inlet of the second heat exchanger 4 is connected to a second heat exchange branch pipe 103, whose inlet end is connected to port C. Thus, the outlet of the refrigerant outlet pipe 101 is selectively connected to the first heat exchange branch pipe 102 and the second heat exchange branch pipe 103 through the four-way reversing valve 2.

[0051] In one embodiment, the outlet of the refrigerant channel can be selectively connected to the inlet of the throttling device 7 or the second heat exchange branch pipe 103, thereby simplifying the piping arrangement of the heat pump water heater and reducing costs.

[0052] To simplify the structure, the heat pump water heater also includes an electrically controlled three-way valve 5. The first port of the electrically controlled three-way valve 5 is connected to the outlet of the refrigerant channel, the second port of the electrically controlled three-way valve 5 is connected to the second heat exchange branch 103, and the third port of the electrically controlled three-way valve 5 is connected to the inlet of the throttling device 7. The first port is connected to either the second port or the third port. Thus, the electrically controlled three-way valve 5 enables selective communication between the outlet of the refrigerant channel, the second heat exchange branch 103, and the throttling device 7, reducing control difficulty.

[0053] Specifically, the outlet of the refrigerant channel is connected to the first port through the heat exchange outlet pipe 109, the second port is connected to the second heat exchange branch pipe 103 through the heat exchange bypass pipe 110, and the third port is connected to the inlet of the throttling device 7 through the first throttling inlet pipe 104.

[0054] In other embodiments, control valves may be respectively provided on the heat exchange bypass pipe 110 and the first throttling inlet pipe 104 to respectively control the on-off of the two heat exchange bypass pipes 110 and the first throttling inlet pipe 104, thereby realizing selective conduction between the heat exchange outlet pipe 109 and the inlet of the throttling device 7 and the inlet of the second heat exchanger 4.

[0055] In one embodiment, the second heat exchange branch 103 has a confluence point connected to the refrigerant channel. A first one-way valve 201 is installed on the second heat exchange branch 103, located between the inlet of the second heat exchange branch 103 and the confluence point. The first one-way valve 201 only allows refrigerant to flow from the inlet of the second heat exchange branch 103 to the confluence point. This prevents refrigerant flowing out of the heat exchange bypass pipe 110 from flowing through the second heat exchange branch 103 to the refrigerant outlet pipe 101 or the first heat exchange branch 102, ensuring reliable refrigerant flow. Specifically, the confluence point is the point where the second heat exchange branch 103 connects to the heat exchange bypass pipe 110.

[0056] A second one-way valve 202 is provided on the heat exchange bypass pipe 110. The second one-way valve 202 only allows the refrigerant to flow from the electric three-way valve 5 to the second heat exchange branch 103. This can prevent the refrigerant flowing into the inlet end of the second heat exchange branch 103 from flowing to the electric three-way valve 5 when the heat pump water heater is in the heat storage mode, and ensure that the refrigerant flowing into the second heat exchange branch 103 can flow to the second heat exchanger 4, thereby avoiding the loss of cooling capacity of the refrigerant and improving the operating reliability of the heat pump water heater.

[0057] The outlet of the second heat exchanger 4 is connected to the inlet of the throttling device 7 via the second throttling inlet pipe 105. The first throttling inlet pipe 104 is provided with a third one-way valve 203. The third one-way valve 203 only allows the refrigerant to flow from the third port to the throttling device 7, thereby preventing the refrigerant flowing out of the second throttling inlet pipe 105 from flowing through the first throttling inlet pipe 104 to the electrically controlled three-way valve 5. The second throttling inlet pipe 105 is provided with a fourth one-way valve 204, thereby preventing the refrigerant entering and exiting the first throttling inlet pipe 104 from flowing back through the second throttling inlet pipe 105 to the second heat exchanger 4.

[0058] In one embodiment, to enhance the water heating efficiency of the first heat exchanger 3, the first heat exchanger 3 is a double-tube heat exchanger. Specifically, the first heat exchanger 3 comprises an inner tube and an outer tube spaced apart and sheathed outside the inner tube. The inner tube's lumen forms an inner flow channel that is open at both ends, and a sandwich flow channel that is open at both ends is formed between the inner and outer tubes. One of the inner and sandwich flow channels is a refrigerant channel, and the other is a water channel. This structure of the first heat exchanger 3 effectively increases the heat exchange area between the water and the refrigerant while avoiding oversizing the first heat exchanger 3, thereby improving the heat exchange efficiency.

[0059] In one embodiment, the inner flow channel is a water channel and the interlayer flow channel is a refrigerant channel. In other embodiments, the inner flow channel may be a refrigerant channel and the interlayer flow channel may be a water channel.

[0060] In one embodiment, the second heat exchanger 4 is disposed around the outside of the water tank 6, thereby reducing the volume requirement of the water tank 6 and facilitating the pipe connection between the second heat exchanger 4 and other structures. In other embodiments, the second heat exchanger 4 can also be disposed inside the water tank 6.

[0061] To reduce the size of the second heat exchanger 4, a microchannel heat exchanger is provided surrounding the water storage tank 6. This miniaturizes the second heat exchanger 4, further reducing the overall footprint of the heat pump water heater. The specific structure of the microchannel heat exchanger can be configured with reference to existing technologies and is not limited or elaborated upon in this embodiment.

[0062] To enhance the heat pump water heater's automated control, the water channel's inlet is connected to a water inlet pipe 108. This pipe is equipped with a flow rate sensor, which is communicatively connected to the heat pump water heater's controller. The flow rate sensor detects the water flow rate entering the water inlet pipe 108, thereby determining whether water is being consumed at the water-using end.

[0063] In one embodiment, a water inlet temperature sensor is provided in the water inlet pipe 108 and / or a water storage temperature sensor is provided at the water storage tank 6, wherein the water inlet temperature sensor is used to detect the water inlet temperature of the water inlet pipe 108, and the water storage temperature sensor is used to detect the water temperature of the water in the water storage tank 6, so as to determine whether the heat pump water heater should switch to the first heating mode or the second heating mode when a user uses water, and determine whether the water in the water storage tank 6 needs to be preheated when the user does not need to use water.

[0064] That is, when the flow rate detected by the flow switch 20 is greater than or equal to the preset flow rate, and the temperature detected by the water inlet temperature sensor is higher than or equal to the preset water inlet temperature or the temperature detected by the water storage temperature sensor is equal to or higher than the preset water storage temperature, the controller controls the heat pump water heater to switch to the first heating mode;

[0065] When the flow rate detected by the flow switch 20 is greater than or equal to the preset flow rate, and the temperature detected by the water inlet temperature sensor is lower than the preset water inlet temperature and the temperature detected by the water storage temperature sensor is lower than the preset water storage temperature, the controller controls the heat pump water heater to switch to the second heating mode;

[0066] When the flow rate detected by the flow switch 20 is less than the preset flow rate and the temperature detected by the water storage temperature sensor is lower than the preset insulation temperature, the controller controls the heat pump water heater to switch to the heat storage mode;

[0067] When the flow rate detected by the flow switch 20 is less than the preset flow rate and the temperature detected by the water storage temperature sensor is equal to or higher than the preset insulation temperature, the heat pump water heater remains in the standby state.

[0068] In the specific contents of the above-mentioned specific implementation methods, the various technical features can be combined in any non-contradictory manner. In order to make the description concise, not all possible combinations of the above-mentioned technical features are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0069] The specific contents of the above-mentioned specific embodiments only express several embodiments of the present invention. Although the description is relatively specific and detailed, it should not be construed as limiting the scope of the present invention. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of the present invention, and these modifications and improvements fall within the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be based on the appended claims.

Claims

1. A heat pump water heater, characterized in that: The invention comprises a compressor (1), a water storage tank (6), a first heat exchanger (3), a second heat exchanger (4) and a throttling device (7), wherein the first heat exchanger (3) has a refrigerant channel and a water channel, the water inlet of the water channel is used to be connected to a cold water supply pipe, the water outlet of the water channel is communicated with a water tank inlet of the water storage tank (6), the water tank outlet of the water storage tank (6) is used to be communicated with a water use end, and the second heat exchanger (4) is installed in the water storage tank (6) and is used to exchange heat with the water in the water storage tank (6); The outlet end of the compressor (1) can be selectively connected to the inlet of the refrigerant channel or the inlet of the second heat exchanger (4), the outlet of the refrigerant channel can be selectively connected to the inlet of the second heat exchanger (4) or the inlet of the throttling device (7), the outlet of the second heat exchanger (4) is connected to the inlet of the throttling device (7), and the outlet of the throttling device (7) is connected to the inlet of the compressor (1).

2. The heat pump water heater according to claim 1, characterized in that The heat pump water heater comprises a four-way reversing valve (2), the four-way reversing valve (2) having an A port, a B port, a C port and a D port, the A port being connected to the outlet of the compressor (1), the B port being connected to the inlet of the refrigerant channel, the C port being connected to the inlet of the second heat exchanger (4), and the D port being connected to the inlet of the compressor (1); The four-way reversing valve (2) has a first conducting state in which the A port is connected to the B port and the C port is connected to the D port, and a second conducting state in which the A port is connected to the C port and the B port is connected to the D port.

3. The heat pump water heater according to claim 2, characterized in that: The outlet of the throttling device (7) is connected to the inlet of the compressor (1) through a refrigerant return pipe (106), and a bypass return pipe (107) is connected between the D port and the refrigerant return pipe (106). A return check valve (205) is provided on the bypass return pipe (107), and the return check valve (205) only allows the refrigerant to flow from the D port to the refrigerant return pipe (106).

4. The heat pump water heater according to claim 1, characterized in that The outlet of the compressor (1) is connected to a refrigerant outlet pipe (101), the inlet of the refrigerant channel is connected to a first heat exchange branch pipe (102), and the inlet of the second heat exchanger (4) is connected to a second heat exchange branch pipe (103). The refrigerant outlet pipe (101) can be selectively connected to the inlet end of the first heat exchange branch pipe (102) or the inlet end of the second heat exchange branch pipe (103); the outlet of the refrigerant channel can be selectively connected to the second heat exchange branch pipe (103) or the inlet of the throttling device (7).

5. The heat pump water heater according to claim 4, characterized in that: The second heat exchange branch (103) has an inlet point connected to the refrigerant channel, and the second heat exchange branch (103) is provided with a first one-way valve (201). The first one-way valve (201) is located between the inlet end of the second heat exchange branch (103) and the inlet point. The first one-way valve (201) only allows the refrigerant to flow from the inlet of the second heat exchange branch (103) to the inlet point.

6. The heat pump water heater according to claim 4, characterized in that The heat pump water heater includes an electrically controlled three-way valve (5), wherein a first port of the electrically controlled three-way valve (5) is connected to the outlet of the refrigerant channel, a second port of the electrically controlled three-way valve (5) is connected to the second heat exchange branch pipe (103), a third port of the electrically controlled three-way valve (5) is connected to the inlet of the throttling device (7), and the first port is connected to the second port or the third port.

7. The heat pump water heater according to claim 6, characterized in that The second port is connected to the second heat exchange branch (103) via a heat exchange bypass pipe (110). A second one-way valve (202) is provided on the heat exchange bypass pipe (110). The second one-way valve (202) only allows the refrigerant to flow from the second port to the heat exchange bypass pipe (110).

8. The heat pump water heater according to claim 6, characterized in that The third port is connected to the throttling device (7) via a first throttling inlet pipe (104), and a third one-way valve (203) is provided on the first throttling inlet pipe (104). The third one-way valve (203) only allows the refrigerant to flow from the electric-controlled three-way valve (5) to the throttling device (7); And / or, the outlet of the second heat exchanger (4) is connected to the inlet of the throttling device (7) through a second throttling inlet pipe (105), and a fourth one-way valve (204) is provided on the second throttling inlet pipe (105), and the fourth one-way valve (204) only allows the refrigerant to flow from the second heat exchanger (4) to the throttling device (7).

9. The heat pump water heater according to any one of claims 1 to 8, characterized in that: The heat pump water heater comprises a controller and a water storage temperature sensor, wherein the water storage temperature sensor is used to detect the temperature of water in the water storage tank (6), and the water storage temperature sensor is communicatively connected to the controller; And / or, the heat pump water heater includes a controller and a water inlet temperature sensor, the water inlet temperature sensor is used to detect the temperature of water entering the water channel, and the water inlet temperature sensor is communicatively connected to the controller.

10. The heat pump water heater according to any one of claims 1 to 7, characterized in that: The first heat exchanger (3) comprises an inner tube and an outer tube spaced apart and sleeved outside the inner tube, the inner cavity of the inner tube forms an inner flow channel, an interlayer flow channel is formed between the inner tube and the outer tube, one of the inner flow channel and the interlayer flow channel is the water channel, and the other is the refrigerant channel; And / or, the second heat exchanger (4) is a microchannel heat exchanger arranged around the water storage tank (6).

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