Air energy heat pump water heater

Abstract

The utility model provides an air energy heat pump water heater which comprises a vertical container, a coil heat exchanger and an external heat exchange module. The vertical container is provided with a cold water inlet and a hot water outlet, a water pumping port at the bottom and a backflow port on the side surface; the coil heat exchanger is arranged on the vertical container, and an inlet of the coil heat exchanger is used for being connected with an output channel of the air energy heat pump. The external heat exchange module comprises a plate heat exchanger and a water pump; a primary-side inlet of the plate heat exchanger is connected to an outlet of the coil heat exchanger, a primary-side outlet is connected with an input channel of the air energy heat pump, a secondary-side inlet is connected with the water pumping port, and a secondary-side outlet is connected with the backflow port; the water pump is used for conveying water from the pumping port to the backflow port; the external heat exchange module improves the heat exchange efficiency of the heat exchange working medium, reduces the temperature of the heat exchange working medium during backflow, reduces the up-down temperature difference of water in the vertical container, and improves the utilization rate of the total volume.

Description

Technical Field

[0001] The utility model relates to the technical field of water heaters, in particular to an air source heat pump water heater. Background Art

[0002] Existing water heaters with an air source heat pump as the heat source usually include a container and a coil heat exchanger installed inside the container. The air source heat pump delivers a heat transfer medium to the coil heat exchanger to heat the water in the container. Such an air source heat pump water heater has the following problems.

[0003] 1. The air source heat pump is a low-temperature heat source. To improve energy efficiency, the temperature of the heat transfer medium output by the air source heat pump should not be too high, usually not exceeding 55°C. In this case, to improve the heat transfer efficiency, it is necessary to increase the surface area of the coil heat exchanger, that is, increase its number of turns. However, even if the coil heat exchanger fills the internal space of the container, when matching with some main engines with higher heating capacity, especially in summer, it is still possible that the heat in the heat transfer medium cannot be effectively transferred out at the end of the heating cycle, resulting in overpressure protection of the compressor of the air source heat pump.

[0004] 2. Through heat transfer by the coil heat exchanger, the domestic water stored inside the container is in a static state and is heated as a whole under the effect of the thermosiphon effect. At the end of the heating cycle, the temperature of the domestic water rises to close to the target temperature, the temperature difference from the heat transfer medium gradually decreases, and the heat transfer driving force decreases, resulting in an extended time required to prepare domestic hot water.

[0005] 3. In order to adapt to the operating characteristics of large flow rate and small temperature difference at the heating and cooling terminals, the air source heat pump usually circulates the heat transfer medium in a large flow rate in the domestic hot water mode, resulting in that the heat transfer medium cannot be fully cooled after flowing through the coil heat exchanger, and the temperature is too high when flowing back to the air source heat pump. The supply-return temperature difference of the air source heat pump is small, which reduces the energy efficiency of the air source heat pump.

[0006] 4. For a vertical container, its bottom is a protruding end. Due to the limitation of the installation position of the coil heat exchanger, the domestic water at the bottom of the vertical container cannot be heated to the preset target temperature. After a heating cycle is completed, there will be a phenomenon of high temperature at the top and low temperature at the bottom of the water temperature in the vertical container, and the overall volume utilization rate is not high. Summary of the Utility Model

[0007] The utility model provides an air source heat pump water heater to solve the above problems existing in the prior art.

[0008] An air source heat pump water heater provided by the utility model includes:

[0009] A vertical container, which is provided with a cold water inlet and a hot water outlet, a water pumping port is arranged at its bottom, and a return port is arranged on its side;

[0010] A coil heat exchanger is provided on the vertical container, and the inlet of the coil heat exchanger is used to connect to the outlet channel of an air source heat pump.

[0011] An external heat exchange module includes a plate heat exchanger and a water pump; the plate heat exchanger includes a primary side and a secondary side. The inlet of the primary side is connected to the outlet of the coil heat exchanger, and the outlet of the primary side is used to connect to the input channel of the air source heat pump. The inlet of the secondary side is connected to the water intake, and the outlet of the secondary side is connected to the return port; the water pump is connected to the inlet or outlet of the secondary side and is used to convey water flow from the water intake to the return port.

[0012] In an embodiment of the present invention, the inlet of the coil heat exchanger is close to the top of the vertical container, and the outlet of the coil heat exchanger is close to the bottom of the vertical container.

[0013] In an embodiment of the present invention, it further includes an air source heat pump and a circulation pump, and the circulation pump is connected between the input channel of the air source heat pump and the primary side of the plate heat exchanger.

[0014] In an embodiment of the present invention, a first temperature detection element for detecting the water temperature is provided on the vertical container, and the position height of the return port does not exceed the position height of the first temperature detection element.

[0015] In an embodiment of the present invention, the external heat exchange module further includes a water flow detection element, and the water flow detection element is connected to the primary side of the plate heat exchanger and is used to detect the flow state of the heat exchange medium.

[0016] In an embodiment of the present invention, it further includes a control unit. The control unit controls the start and stop of the air source heat pump according to the temperature signal detected by the first temperature detection element, and the control unit controls the start and stop of the water pump according to the water flow signal detected by the water flow detection element.

[0017] In an embodiment of the present invention, the external heat exchange module further includes a second temperature detection element for detecting the temperature of the heat exchange medium inside the primary side of the plate heat exchanger, and the control unit controls the start and stop of the water pump according to the temperature signal detected by the second temperature detection element and the water flow signal detected by the water flow detection element.

[0018] In an embodiment of the present invention, a first water replenishment and drainage valve is provided at the inlet of the secondary side of the plate heat exchanger, and a second water replenishment and drainage valve is provided at the outlet of the secondary side of the plate heat exchanger; a first shut-off valve is provided between the first water replenishment and drainage valve and the water intake, and a second shut-off valve is provided between the second water replenishment and drainage valve and the return port.

[0019] In one embodiment of the present utility model, it further includes a heat preservation housing. The vertical container is arranged inside the heat preservation housing, and the external heat exchange module is arranged outside the heat preservation housing.

[0020] In one embodiment of the present utility model, a bracket is arranged outside the heat preservation housing. A decorative outer cover is detachably connected to the bracket, and the external heat exchange module is installed on the bracket and located inside the decorative outer cover.

[0021] Compared with the prior art, the advantages and positive effects of the present utility model are as follows:

[0022] The air - source heat pump water heater provided by the present utility model, by adding a plate heat exchanger, connects the primary side of the plate heat exchanger to the outlet of the coil heat exchanger and the input channel of the air - source heat pump, and the secondary side is connected to the water extraction port and the return port of the vertical container. And a water pump is used to transport the relatively low - temperature domestic water at the bottom of the vertical container to the secondary side of the plate heat exchanger. After heat exchange with the heat - transfer medium in the primary side, it is sent back into the vertical container, fully utilizing the waste heat of the heat - transfer medium, improving the heat exchange efficiency, reducing the temperature of the heat - transfer medium when it flows back to the air - source heat pump, improving the energy efficiency of the air - source heat pump, and avoiding over - pressure protection of its compressor; in addition, the relatively low - temperature domestic water at the bottom of the vertical container is heated and then flows back, reducing the upper - lower temperature difference of the domestic water inside the vertical container, improving the utilization rate of the overall volume, and increasing the available hot water volume.

[0023] Through the following detailed description of the exemplary embodiments of the present utility model with reference to the accompanying drawings, other features and advantages of the present utility model will become clear. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The drawings incorporated in the specification and constituting a part of the specification illustrate embodiments of the present utility model and, together with the description, are used to explain the principles of the present utility model.

[0025] Figure 1 FIG. 1 is a schematic structural diagram of the first embodiment of the air - source heat pump water heater provided by the present utility model;

[0026] Figure 2 FIG. 2 is a schematic internal structure diagram of the first embodiment of the air - source heat pump water heater provided by the present utility model;

[0027] Figure 3 FIG. 3 is a perspective view of the first embodiment of the air - source heat pump water heater provided by the present utility model;

[0028] Figure 4 FIG. 4 is an exploded view of the first embodiment of the air - source heat pump water heater provided by the present utility model;

[0029] Figure 5It is a schematic structural diagram of the second embodiment of the air - source heat pump water heater provided by the present utility model.

[0030] Figures 1 to 5 The reference numerals of the names of the components in the figure are as follows:

[0031] 1. Vertical container; 101. Cold water inlet; 102. Hot water outlet; 103. Water pumping port; 104. Return port;

[0032] 2. Coil heat exchanger;

[0033] 3. Air - source heat pump; 31. Output channel; 32. Input channel;

[0034] 4. Plate heat exchanger; 41. Primary side; 42. Secondary side;

[0035] 5. Water pump;

[0036] 6. Circulation pump;

[0037] 7. First temperature detection element;

[0038] 8. Water flow detection element;

[0039] 9. Control unit;

[0040] 10. Second temperature detection element;

[0041] 11. First water - replenishing and sewage - draining valve;

[0042] 12. Second water - replenishing and sewage - draining valve;

[0043] 13. First shut - off valve;

[0044] 14. Second shut - off valve;

[0045] 15. Exhaust valve;

[0046] 16. Bracket; 161. Hook;

[0047] 17. Decorative outer cover

[0048] 18. Heat - insulating outer shell. Detailed implementation manners

[0049] Now, various exemplary embodiments of the present utility model will be described in detail with reference to the accompanying drawings. It should be noted that: unless otherwise specifically stated, the relative arrangements of components and steps, numerical expressions and values set forth in these embodiments do not limit the scope of the present utility model.

[0050] The following description of at least one exemplary embodiment is merely illustrative in nature and in no way limits the present utility model, its application or use.

[0051] Techniques, methods, and devices known to those of ordinary skill in the relevant art may not be discussed in detail, but where appropriate, such techniques, methods, and devices shall be regarded as part of the specification.

[0052] In all examples shown and discussed herein, any specific values should be construed as merely exemplary, rather than as limitations. Thus, other examples of the exemplary embodiments may have different values.

[0053] It should be noted that like reference numerals and letters refer to like items in the following figures, and thus, once an item is defined in one figure, further discussion thereof in subsequent figures is not necessary.

[0054] In this document, "upper", "lower", "front", "rear", "top", "bottom", etc. are used only to indicate the relative positional relationship between relevant parts, rather than to define the absolute positions of these relevant parts.

[0055] In this document, "first", "second", etc. are used only for distinction from each other, rather than indicating importance, order, and the premise of mutual existence, etc.

[0056] In this document, "equal", "same", etc. are not strict mathematical and / or geometric limitations, and also include the allowable errors that can be understood by those skilled in the art and are allowed in manufacturing or using, etc.

[0057] In this document, unless otherwise specified, "a plurality of" means two or more. Unless otherwise specified, the numerical ranges in this document include not only the entire range between its two endpoints, but also several sub-ranges included therein.

[0058] In addition, the present utility model provides examples of various specific processes and materials, but those of ordinary skill in the art can be aware of the application of other processes and / or the use of other materials. Embodiment

[0059] Figures 1 to 4 An embodiment of an air source heat pump water heater provided by the present utility model is shown. In this embodiment, the air source heat pump water heater includes a vertical container 1, a coil heat exchanger 2, and an external heat exchange module.

[0060] The coil heat exchanger 2 is disposed on the vertical container 1 for exchanging heat with the water inside the vertical container 1. The vertical container 1 is provided with a cold water inlet 101 and a hot water outlet 102. Domestic water is transported from the cold water inlet 101 into the vertical container 1, heated to hot water through heat exchange with the coil heat exchanger 2, and then output from the hot water outlet 102. A water pumping port 103 is further provided at the bottom of the vertical container 1, and a return port 104 is provided on the side.

[0061] The coil heat exchanger 2 is supplied with a heat transfer medium by an air source heat pump 3. The air source heat pump 3 is provided with an output channel 31 and an input channel 32 for the heat transfer medium. The inlet of the coil heat exchanger 2 is used to connect to the output channel 31 of the air source heat pump 3, and the heat transfer medium is transported to the coil heat exchanger 2 through the output channel 31 to heat the domestic water in the vertical container 1.

[0062] The external heat exchange module includes a plate heat exchanger 4 and a water pump 5 disposed outside the vertical container 1. The plate heat exchanger 4 includes a primary side 41 and a secondary side 42, and the primary side 41 and the secondary side 42 are two separated water channel passages. The inlet of the primary side 41 of the plate heat exchanger 4 is connected to the outlet of the coil heat exchanger 2, and the outlet of the primary side 41 is used to connect to the input channel 32 of the air source heat pump 3. The inlet of the secondary side 42 of the plate heat exchanger 4 is connected to the water extraction port 103, and the outlet of the secondary side 42 is connected to the return port 104.

[0063] The water pump 5 is connected to the inlet or outlet of the secondary side 42 of the plate heat exchanger 4. The water pump 5 is used to transport water flow from the water extraction port 103 to the return port 104. Specifically, the water pump 5 can be connected between the water extraction port 103 and the inlet of the secondary side 42, or between the return port and the outlet of the secondary side 42.

[0064] After the heat transfer medium in the coil heat exchanger 2 exchanges heat with the domestic water inside the vertical container 1, it enters the primary side 41 of the plate heat exchanger 4, and then returns to the air source heat pump 3 through the input channel 32. The air source heat pump 3, the coil heat exchanger 2, and the primary side 41 of the plate heat exchanger 4 form a circulation loop.

[0065] The domestic water at the bottom of the vertical container 1 enters the secondary side 42 of the plate heat exchanger 4 from the water extraction port 103. The waste heat of the heat transfer medium flowing through the primary side 41 causes the domestic water flowing through the secondary side 42 to increase in temperature. The heated domestic water then returns to the vertical container 1 through the return port 104. The secondary side 42 of the plate heat exchanger 4 and the vertical container 1 form a circulation loop.

[0066] After detecting that the domestic water inside the vertical container 1 reaches the target temperature, the air source heat pump water heater completes a heating cycle. At the end of the heating cycle, the domestic water in the vertical container 1 rises to near the target temperature, the temperature difference with the heat transfer medium gradually decreases, and the heat conduction efficiency gradually decreases. At this time, the temperature of the heat transfer medium is still relatively high after passing through the coil heat exchanger 2. After the overheated heat transfer medium returns to the air source heat pump 3, it will cause the compressor of the air source heat pump 3 to operate overload and trigger overpressure protection. The plate heat exchanger 4 utilizes the waste heat of the heat transfer medium to perform secondary heating on the domestic water. The temperature of the heat transfer medium decreases after passing through the primary side 41 of the plate heat exchanger 4, and then returns to the air source heat pump 3, making the temperature difference between the output and input heat transfer media of the air source heat pump 3 larger, thereby ensuring the energy efficiency of the air source heat pump 3 and avoiding overpressure protection of the compressor of the air source heat pump 3.

[0067] The top and bottom of the vertical container 1 are both convex heads. Due to the structure of the vertical container 1 and the installation position of the coil heat exchanger 2, the domestic water at the bottom of the vertical container 1 cannot be heated to the preset target temperature. After completing a heating cycle, the domestic water inside the vertical container 1 will show a phenomenon that the water temperature is higher at the top and lower at the bottom. After the domestic water at the bottom of the vertical container 1 enters the secondary side 42 of the plate heat exchanger 4, it is reheated by the heat transfer medium in the primary side 41 of the plate heat exchanger 4, and then flows back into the vertical container 1, making full use of the waste heat of the heat transfer medium, improving the heat transfer efficiency, being able to shorten the time required to prepare domestic hot water, and being able to reduce the upper and lower temperature difference of the domestic water in the vertical container 1, improving the utilization rate of the overall volume and increasing the available hot water volume.

[0068] In some embodiments of the present utility model, the cold water inlet 101 is close to the bottom of the vertical container 1, and the hot water outlet 102 is close to the top of the vertical container 1. To improve the heat transfer efficiency, the inlet of the coil heat exchanger 2 is close to the top of the vertical container 1, and the outlet of the coil heat exchanger 2 is close to the bottom of the vertical container 1. The heat transfer medium flows downward in the coil heat exchanger 2.

[0069] Specifically, the output channel 31 of the air source heat pump 3 is connected to the inlet of the coil heat exchanger 2 through a pipeline. The inlet of the primary side 41 of the plate heat exchanger 4 is connected to the outlet of the coil heat exchanger 2 through a pipeline, and the outlet of the primary side 41 is connected to the input channel 32 of the air source heat pump 3 through a pipeline. The inlet of the secondary side 42 of the plate heat exchanger 4 is connected to the water pumping port 103 through a pipeline, and the outlet of the secondary side 42 is connected to the return port 104 through a pipeline. The water pump 5 is arranged on the pipeline between the secondary side 42 of the plate heat exchanger 4 and the water pumping port 103, or is arranged on the pipeline between the secondary side 42 of the plate heat exchanger 4 and the return port 104.

[0070] The heat transfer medium and the domestic water participating in heat transfer in the primary side 41 and the secondary side 42 of the plate heat exchanger 4 are both in a flowing state and conduct convective heat transfer, and the flow directions of the two media are opposite. Compared with the heat transfer method where one side flows and the other side is stationary between the vertical container 1 and the coil heat exchanger 2, the heat transfer method of the plate heat exchanger 4 is more efficient.

[0071] The channels of the primary side 41 and the secondary side 42 of the plate heat exchanger 4 are formed by stacking multiple layers of metal discs, and the metal discs are all stamped with herringbone or other shaped patterns. On the one hand, it can increase the heat transfer area, and on the other hand, it can make the medium form turbulence at a lower flow rate. The medium can better release and absorb heat in the turbulent state, improving the heat conduction efficiency.

[0072] The plate heat exchanger 4 can appropriately increase the flow resistance of the heat exchange working medium, thereby reducing the circulation flow rate of the heat exchange working medium, enabling the heat exchange working medium to fully exchange heat with domestic water, and having a lower temperature when returning to the air source heat pump 3, avoiding overpressure protection of the compressor of the air source heat pump 3.

[0073] In one embodiment of the present utility model, as Figure 1 shown, the coil heat exchanger 2 is arranged inside the vertical container 1, with small heat loss. The inlet of the coil heat exchanger 2 extends from the top of the side of the vertical container 1, and the outlet of the coil heat exchanger 2 extends from the bottom of the side of the vertical container 1, with higher heating efficiency for domestic water.

[0074] In another embodiment of the present utility model, the coil heat exchanger 2 is wound around the outside of the vertical container 1, isolated from domestic water, not easily corroded, and has a longer service life. The inlet of the coil heat exchanger 2 is close to the top of the vertical container 1, and the outlet of the coil heat exchanger 2 is close to the bottom of the vertical container 1. To reduce heat loss, the vertical container 1 and the coil heat exchanger 2 can be wrapped in heat insulation materials.

[0075] In some embodiments of the present utility model, as Figure 1 shown, a first temperature detection element 7 for detecting the water temperature is arranged on the vertical container 1. The position of the return port 104 is lower than the position of the first temperature detection element 7. The air source heat pump 3 judges the start and end of the heating cycle according to the water temperature detected by the first temperature detection element 7. When the water temperature does not reach the target temperature, the air source heat pump 3 operates, and after the water temperature reaches the target temperature, the air source heat pump 3 stops running. The first temperature detection element 7 can specifically adopt a thermistor type temperature sensor.

[0076] The external heat exchange module further includes a water flow detection element 8. The water flow detection element 8 is connected to the primary side 41 of the plate heat exchanger 4 and is used to detect the flow state of the heat exchange working medium in the primary side 41. The water pump 5 starts and stops according to the flow state of the heat exchange working medium detected by the water flow detection element 8. When the heat exchange working medium is in a flowing state, the water pump 5 operates, and when the heat exchange working medium is in a static state, the water pump 5 stops running. The water flow detection element 8 can specifically adopt a baffle type water flow switch.

[0077] Furthermore, the air source heat pump water heater further includes a control unit 9. The air source heat pump 3, the water pump 5, the first temperature detection element 7 and the water flow detection element 8 are respectively electrically connected or communicatively connected to the control unit 9. The control unit 9 controls the start and stop of the air source heat pump 3 according to the temperature signal detected by the first temperature detection element 7, and the control unit 9 controls the start and stop of the water pump 5 according to the water flow signal detected by the water flow detection element 8.

[0078] Specifically, the first temperature detection element 7 sends the detected temperature signal to the control unit 9. The control unit 9 sends a control signal to the air source heat pump 3 according to the temperature signal sent by the first temperature detection element 7. When the temperature signal detected by the first temperature detection element 7 does not reach the preset target temperature, the control unit 9 controls the air source heat pump 3 to operate; when the temperature signal detected by the first temperature detection element 7 reaches the preset target temperature, the control unit 9 controls the air source heat pump 3 to stop operating.

[0079] The water flow detection element 8 sends the detected water flow signal to the control unit 9. The control unit 9 sends a control signal to the water pump 5 according to the water flow signal sent by the water flow detection element 8. When the water flow detection element 8 detects the flow of the heat exchange medium, the control unit 9 controls the water pump 5 to start and conveys domestic water from the water pumping port 103 at the bottom of the vertical container 1 to the secondary side 42 of the plate heat exchanger 4. When the water flow detection element 8 detects the stillness of the heat exchange medium, the control unit 9 controls the water pump 5 to stop working.

[0080] Specifically, the water pump 5 starts and stops through the pulse width modulation (PWM) signal of the voltage sent by the control unit 9, which can avoid excessive starting current, protect the electronic and mechanical components of the water pump 5, and extend its service life.

[0081] In some embodiments of the present utility model, as Figure 2 shown, the external heat exchange module further includes a second temperature detection element 10, and the second temperature detection element 10 is used to detect the temperature of the heat exchange medium in the primary side 41 of the plate heat exchanger 4.

[0082] The second temperature detection element 10 is electrically connected or communicatively connected to the control unit 9 and sends the detected temperature signal to the control unit 9. The control unit 9 controls the start and stop of the water pump 5 according to the temperature signal detected by the second temperature detection element 10 and the water flow signal detected by the water flow detection element 8. The second temperature detection element 10 can specifically adopt a thermistor type temperature sensor.

[0083] When the water flow detection element 8 detects that the heat exchange medium in the primary side 41 of the plate heat exchanger 4 does not flow, the control unit 9 controls the water pump 5 to close. After the water flow detection element 8 detects the flow of the heat exchange medium in the primary side 41 of the plate heat exchanger 4, the second temperature detection element 10 delays to detect the temperature T2 of the heat exchange medium in the primary side 41 of the plate heat exchanger 4. The control unit 9 presets a temperature threshold. When the temperature T2 reaches the temperature threshold preset by the control unit 9, the control unit 9 controls the water pump 5 to start; when the temperature T2 is lower than the preset temperature threshold minus the dead band, the control unit 9 controls the water pump 5 to close.

[0084] The process of consuming the domestic water that has been heated to the target temperature in the vertical container 1 is the heat unloading process. During the heat unloading process, the domestic water is divided into upper and lower regions. The upper region is the domestic water that has reached the target temperature, and the lower region is the domestic water that is below the target temperature. When there is a speed reduction and flow stabilization baffle at the cold water inlet 101, the domestic water in the upper and lower regions hardly mixes due to the specific gravity difference, and a clear interface is formed at the position where the two regions are adjacent. As the domestic water is continuously consumed, this interface moves smoothly from bottom to top inside the vertical container. When its position moves above the height of the first temperature detection element 7, the first temperature detection element 7 detects that the temperature of the domestic water is lower than the target temperature minus the return difference, and the control unit 9 controls the air source heat pump 3 to start and begin a new heating cycle. If the heat unloading process is still in progress at this time, the water flow detection element 8 detects that the heat exchange medium is in a flowing state and feeds back a water flow signal to the control unit. The control unit 9 controls the water pump 5 to work, and pumps domestic water from the water extraction port 103 into the plate heat exchanger 4 for heat exchange.

[0085] Since the heat exchange medium in the primary side 41 of the plate heat exchanger 4 is not sufficient to heat the domestic water in the secondary side 42 to the target temperature, if the position of the return port 104 is higher than the position of the first temperature detection element 7, the domestic water that has not reached the target temperature enters the upper region of the domestic water in the vertical container 1, resulting in a decrease in the temperature of the domestic water in the upper region, which is equivalent to reducing the effective utilization rate of the hot water. Therefore, to ensure the effective utilization rate of the hot water, the position height of the return port 104 does not exceed the position height of the first temperature detection element 7.

[0086] As Figure 1 shown in the specific embodiment, the position of the return port 104 is lower than the position of the first temperature detection element 7. The return port 104 and the first temperature detection element 7 can be arranged on opposite sides of the vertical container 1.

[0087] To reduce the disturbance to the domestic water in the upper and lower regions of the vertical container 1, there is a speed reduction and flow stabilization baffle at the return port 104. However, directly injecting the domestic water with too low a temperature into the upper middle part of the vertical container 1 may still damage the thermal stratification of the domestic water in the upper and lower regions. Adding a second temperature detection element 10 can delay the starting time of the water pump 5 and avoid the destruction of the thermal stratification during the continuous consumption of hot water.

[0088] In some embodiments of the present invention, as Figure 2 shown, a first make-up water and blowdown valve 11 is provided at the inlet of the secondary side 42 of the plate heat exchanger 4, and a second make-up water and blowdown valve 12 is provided at the outlet of the secondary side 42 of the plate heat exchanger 4.

[0089] After the equipment has been used for a long time, scale will inevitably form inside the plate heat exchanger 4. Without disassembling the plate heat exchanger 4, the scale inside the secondary side 42 of the plate heat exchanger 4 can be cleaned through the first make-up and drain valve 11 and the second make-up and drain valve 12.

[0090] Furthermore, a first shut-off valve 13 is provided between the first make-up and drain valve 11 and the water pumping port 103, and a second shut-off valve 14 is provided between the second make-up and drain valve 12 and the return port 104.

[0091] During operation, the first shut-off valve 13 and the second shut-off valve 14 are closed to isolate the secondary side 42 of the plate heat exchanger 4 from the water circuit; a hose is used to connect the first make-up and drain valve 11 to the outlet of the self-priming pump, and the inlet of the self-priming pump is immersed in the descaling agent solution; one end of another hose is connected to the second make-up and drain valve 12 and the other end is immersed in the descaling agent solution; the self-priming pump is started to make the descaling agent solution circulate in the secondary side 42 of the plate heat exchanger 4, thereby dissolving the deposited scale inside it.

[0092] In some embodiments of the present utility model, as Figure 2 shown, an exhaust valve 15 is provided at the top of the primary side 41 of the plate heat exchanger 4, and the exhaust valve 15 is used to discharge the gas in the primary side 41 of the plate heat exchanger 4.

[0093] In some embodiments of the present utility model, as Figure 3 shown, the air source heat pump water heater further includes a heat preservation housing 18, and the vertical container 1 is arranged inside the heat preservation housing 18. The external heat exchange module is arranged outside the heat preservation housing 18. The heat preservation housing 18 includes a heat preservation layer made of foamed polyurethane or other heat preservation materials.

[0094] Furthermore, a bracket 16 is provided on the outside of the heat preservation housing 18. The bracket 16 serves as an installation base, and the external heat exchange module is installed on the bracket 16.

[0095] The bracket 16 can be fixedly connected to the pipelines extending from the water pumping port 103 and the return port 104 of the vertical container 1 through fasteners (such as lock nuts). The bracket 16 is located on the outer side of the heat preservation housing 18 and is close to the position of the outlet of the coil heat exchanger 2 and the water pumping port 103. The outlet of the coil heat exchanger 2 is connected to the primary side 41 of the plate heat exchanger 4 through a pipeline passing through the heat preservation housing 18, and the water pumping port 103 is connected to the secondary side 42 of the plate heat exchanger 4 through a pipeline passing through the heat preservation housing 18.

[0096] Specifically, the plate heat exchanger 4 and the water pump 5 are fixed on the bracket 16. The water flow detection element 8, the control unit 9, the second temperature detection element 10, the first make-up and drain valve 11, the second make-up and drain valve 12, the first shut-off valve 13, and the second shut-off valve 14 can all be arranged on the bracket 16.

[0097] The outlet of the primary side 41 of the plate heat exchanger 4 is connected to the input channel 32 of the air source heat pump 3 through a bridging pipe, so that the pipe orifices of all external pipes are located on the back of the vertical container 1, facilitating the arrangement and fixation of the connected pipes along the building wall.

[0098] After the plate heat exchanger 4 and the coil heat exchanger 2 are connected through a bridging pipe, a high point for the flow of the heat transfer medium is formed at the top, and air will inevitably accumulate during the first installation and daily operation. These accumulated gases can be discharged from the closed-loop system of the primary side 41 through the exhaust valve 15 to ensure the smooth circulation of the heat transfer medium.

[0099] In some embodiments of the present invention, such as Figure 3 and Figure 4 shown, a decorative outer cover 17 is detachably connected to the bracket 16, and the replaceable heat exchange module is located inside the decorative outer cover 17. Specifically, the decorative outer cover 17 plays a role in protection and decoration, and components such as the bracket 16 and the plate heat exchanger 4, water pump 5, water flow detection element 8, control unit 9, second temperature detection element 10, first water replenishment and sewage discharge valve 11, second water replenishment and sewage discharge valve 12, first shut-off valve 13, and second shut-off valve 14 installed on the bracket 16 are all covered inside the decorative outer cover 17. For the convenience of maintenance, components such as the plate heat exchanger 4, water pump 5, water flow detection element 8, control unit 9, second temperature detection element 10, first water replenishment and sewage discharge valve 11, second water replenishment and sewage discharge valve 12, first shut-off valve 13, and second shut-off valve 14 are arranged on the side of the bracket 16 away from the vertical container 1.

[0100] Specifically, as Figure 4 shown, a plurality of hooks 161 are provided at the edge of the bracket 16, and the decorative outer cover 17 is hung on the bracket 16 through the hooks 161, which is convenient for disassembly and assembly.

[0101] The air source heat pump water heater provided by the present invention uses the waste heat of the heat transfer medium through the plate heat exchanger 4 to heat the domestic water with a relatively low temperature at the bottom of the vertical container 1, improving the heat exchange efficiency, reducing the temperature of the heat transfer medium when it flows back to the air source heat pump, improving the energy efficiency of the air source heat pump, and thus avoiding overpressure protection of its compressor. And it reduces the upper and lower temperature difference of the domestic water inside the vertical container, improves the utilization rate of the overall volume, and increases the available hot water volume. Components such as the plate heat exchanger 4, water pump 5, water flow detection element 8, control unit 9, second temperature detection element 10, first water replenishment and sewage discharge valve 11, second water replenishment and sewage discharge valve 12, first shut-off valve 13, and second shut-off valve 14 are integrated on the bracket 16, which is convenient for assembly and maintenance. Embodiment

[0102] Figure 5Another embodiment of the air source heat pump water heater provided by the present utility model is shown. The difference from the first embodiment is that the air source heat pump water heater of this embodiment further includes an air source heat pump 3 and a circulation pump 6.

[0103] The air source heat pump 3 is provided with an output channel 31 and an input channel 32 for the heat transfer medium. The output channel 31 is connected to the inlet of the coil heat exchanger 2, and the input channel 32 is connected to the outlet of the primary side 41 of the plate heat exchanger 4. The circulation pump 6 is connected between the input channel 32 of the air source heat pump 3 and the primary side 41 of the plate heat exchanger 4, and conveys the heat transfer medium flowing through the primary side 41 of the plate heat exchanger 4 to the input channel 32 of the air source heat pump 3.

[0104] The control unit 9 can be electrically connected or communicatively connected to the circulation pump 6. The control unit 9 controls the start and stop of the circulation pump 6 according to the temperature signal detected by the first temperature detection element 7. Specifically, when the temperature signal of the first temperature detection element 7 received by the control unit 9 is less than the target temperature, the control unit 9 controls the circulation pump 6 to start; when the temperature signal of the first temperature detection element 7 received by the control unit 9 reaches the preset target temperature, the control unit 9 controls the circulation pump 6 to stop running. The air source heat pump 3 can be connected to a heating and cooling system. Its output channel 31 is connected to the coil heat exchanger 2 and the heating and cooling system through a reversing valve, and the heat transfer medium can be selectively conveyed to the coil heat exchanger 2 or the heating and cooling system through the reversing valve. The heating and cooling system is also connected to the input channel 32 of the air source heat pump 3 to send the heat transfer medium back to the air source heat pump 3. When the temperature signal of the first temperature detection element 7 received by the control unit 9 reaches the preset target temperature, the control unit 9 can control the circulation pump 6 to stop running, or control the reversing valve to change direction and convey the heat transfer medium to the heating and cooling system.

[0105] The embodiments of the present utility model have been described above. The above description is exemplary and not exhaustive, and is not limited to the disclosed embodiments. Many modifications and variations are obvious to those of ordinary skill in the art in the technical field without departing from the scope and spirit of the described embodiments. The selection of the terms used herein is intended to best explain the principles of the embodiments, practical applications, or improvements to the technology in the market, or to enable other ordinary skill in the art in the technical field to understand the disclosed embodiments. The scope of the present utility model is defined by the appended claims.

Claims

1. An air energy heat pump water heater, characterized in that: include: A vertical container is provided with a cold water inlet and a hot water outlet, a water extraction port is provided at the bottom, and a return port is provided at the side; A coil heat exchanger, which is arranged on the vertical container, and the inlet of the coil heat exchanger is used to connect to the output channel of the air energy heat pump; An external heat exchange module comprises a plate heat exchanger and a water pump; the plate heat exchanger comprises a primary side and a secondary side, the inlet of the primary side is connected to the outlet of the coil heat exchanger, the outlet of the primary side is used to connect to the input channel of the air energy heat pump, the inlet of the secondary side is connected to the water pumping port, and the outlet of the secondary side is connected to the return port; the water pump is connected to the inlet or outlet of the secondary side and is used to transport water from the water pumping port to the return port.

2. The air energy heat pump water heater according to claim 1, characterized in that: The inlet of the coil heat exchanger is close to the top of the vertical container, and the outlet of the coil heat exchanger is close to the bottom of the vertical container.

3. The air energy heat pump water heater according to claim 2, characterized in that: It also includes an air energy heat pump and a circulation pump, wherein the circulation pump is connected between the input channel of the air energy heat pump and the primary side of the plate heat exchanger.

4. The air energy heat pump water heater according to claim 1, characterized in that: The vertical container is provided with a first temperature detection element for detecting water temperature, and the height of the reflux port does not exceed the height of the first temperature detection element.

5. The air energy heat pump water heater according to claim 4, characterized in that: The external heat exchange module further includes a water flow detection element, which is connected to the primary side of the plate heat exchanger and is used to detect the flow state of the heat exchange medium.

6. The air energy heat pump water heater according to claim 5, characterized in that: It also includes a control unit, which controls the start and stop of the air-source heat pump according to the temperature signal detected by the first temperature detection element, and controls the start and stop of the water pump according to the water flow signal detected by the water flow detection element.

7. The air energy heat pump water heater according to claim 6, characterized in that: The external heat exchange module also includes a second temperature detection element for detecting the temperature of the heat exchange medium in the primary side of the plate heat exchanger, and the control unit controls the start and stop of the water pump according to the temperature signal detected by the second temperature detection element and the water flow signal detected by the water flow detection element.

8. The air energy heat pump water heater according to claim 1, characterized in that: The secondary side inlet of the plate heat exchanger is provided with a first water replenishment and drainage valve, and the secondary side outlet of the plate heat exchanger is provided with a second water replenishment and drainage valve; A first shut-off valve is arranged between the first water replenishment and sewage discharge valve and the water pumping port, and a second shut-off valve is arranged between the second water replenishment and sewage discharge valve and the reflux port.

9. The air energy heat pump water heater according to any one of claims 1 to 8, characterized in that: It also includes a heat-insulating shell, the vertical container is arranged in the heat-insulating shell, and the external heat exchange module is arranged on the outside of the heat-insulating shell.

10. The air energy heat pump water heater according to claim 9, characterized in that: A bracket is arranged on the outer side of the heat-insulating outer shell, a decorative outer cover is detachably connected to the bracket, and the external heat exchange module is mounted on the bracket and is located inside the decorative outer cover.

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