Electric water heater

Abstract

The utility model discloses an electric water heater, including heating rod and gall bladder, gall bladder includes phase change gall bladder and water gall bladder, and heating rod sets up in water gall bladder, and phase change gall bladder has phase change material, and phase change gall bladder still includes the first heat exchanger who communicates with water gall bladder, and the electric water heater still includes the circulation pipeline who communicates water gall bladder and the first heat exchanger, and the circulation pipeline includes first circulation pipeline and second circulation pipeline, and first circulation pipeline has first water inlet and first water outlet, and first water inlet is located in water gall bladder, and first water outlet is located in phase change gall bladder, and second circulation pipeline has second water inlet and second water outlet, and second water inlet is located in phase change gall bladder, and second water outlet is located in water gall bladder, and the water in water gall bladder can circulate and flow between phase change gall bladder and water gall bladder through first circulation pipeline and second circulation pipeline. The electric water heater provided in the application embodiment can effectively improve the heat exchange efficiency of the heat storage stage, shorten the heat storage duration while simplifying the system, effectively reducing the overall cost and reducing the energy consumption.

Description

Technical Field

[0001] This utility model relates to the field of water heater technology, and in particular to an electric water heater. Background Technology

[0002] Traditional storage-type electric water heaters use water as the heat storage medium, and due to the limitation of water's specific heat capacity, the amount of hot water supplied is limited. Increasing the water volume requires a larger tank, taking up more indoor space. Furthermore, as hot water is released, the water temperature inside the tank gradually decreases, resulting in insufficient hot water temperature and volume to meet user needs. Overall, traditional storage-type electric water heaters, constrained by their size, have limited heat storage capacity and suffer from insufficient hot water supply.

[0003] To improve the heat storage capacity of electric water heaters and increase the hot water supply, phase change water heaters have emerged in existing technology. These phase change water heaters rely on the physical state transformation of phase change materials to achieve heat storage and release. Before water is used, the phase change material absorbs heat from the heat source for heat storage; when water is used, the phase change material releases the stored energy to heat the water flowing through the heat exchange components.

[0004] A typical phase change water heater includes a phase change tank filled with phase change material and a heater (e.g., a heating rod) installed inside the phase change tank. During the heat storage stage, the heating rod is activated to directly heat the phase change material.

[0005] However, the above methods objectively have the following problems: the thermal conductivity of phase change materials is generally low, the heat transfer distance of the heating rod is limited, which will cause uneven temperature between phase change materials, low heat exchange efficiency, slow heating efficiency, and a long time required for the entire heat storage process. More seriously, the materials near the heating rod may carbonize or dehydrate due to the high temperature on the surface of the heating rod, thus causing the energy storage function to fail.

[0006] Another typical phase change water heater uses a method where a heat exchanger is installed within the phase change material. During the heat storage phase, a heater heats the water, and a circulating pump drives the heated water into the heat exchanger. This allows the hot water circulating within the heat exchanger to exchange heat with the phase change material, achieving heat storage. However, this method of using a circulating pump to drive water flow for heat exchange has several drawbacks: the circulating pump inevitably consumes energy (e.g., electricity) and generates noise, resulting in a poor user experience; the addition of a circulating pump increases the cost and installation size of the water heater; and the increased number of components, including the circulating pump, reduces the overall reliability of the unit.

[0007] Therefore, it is necessary to propose an electric water heater that solves at least one of the above problems.

[0008] It should be noted that the above introduction to the technical background is only for the purpose of providing a clear and complete explanation of the technical solutions of this application and facilitating understanding by those skilled in the art. It should not be assumed that these technical solutions are known to those skilled in the art simply because they have been described in the background section of this application. Utility Model Content

[0009] In view of the shortcomings of the existing technology, this utility model provides an electric water heater that can effectively improve the heat exchange efficiency during the heat storage stage and shorten the heat storage time while simplifying the system, effectively reducing the overall cost and energy consumption.

[0010] The specific technical solution of this utility model embodiment is as follows:

[0011] An electric water heater, the electric water heater comprising:

[0012] The electric water heater includes a heating rod and a tank. The tank includes a phase change tank and a water tank. The heating rod is disposed in the water tank and is used to heat the water in the water tank. The phase change tank is filled with a phase change material for heat storage and release. The phase change tank also includes a first heat exchanger connected to the water tank. Water flowing through the first heat exchanger can conduct heat to the phase change material. The electric water heater also includes a circulation pipeline connecting the water tank and the first heat exchanger. The circulation pipeline includes a first circulation pipeline and a second circulation pipeline. The first circulation pipeline has a first inlet end and a first outlet end. The first inlet end is located in the water tank, and the first outlet end is located in the phase change tank. The second circulation pipeline has a second inlet end and a second outlet end. The second inlet end is located in the phase change tank, and the second outlet end is located in the water tank. When the heating rod is working, the water in the water tank can circulate between the phase change tank and the water tank through the first circulation pipeline and the second circulation pipeline.

[0013] In a preferred embodiment, a portion of the outer wall of the phase change tank wraps around or adheres to a portion of the outer wall of the water tank; the heat of the water in the water tank can be simultaneously conducted to the phase change tank through both the outer wall of the water tank and the outer wall of the phase change tank.

[0014] In a preferred embodiment, a portion of the outer wall surface of the phase change tank wraps around or adheres to a portion of the outer wall surface of the water tank from top to bottom.

[0015] In a preferred embodiment, a heat-conducting medium or heat-conducting structure is provided between the outer wall surface of the partial phase change tank and / or the outer wall surface of the partial water tank and / or the outer wall surface of the partial phase change tank and the outer wall surface of the partial water tank.

[0016] In a preferred embodiment, the number of heating rods is one, and the heating rod is disposed in the middle, upper or bottom of the water tank. Alternatively, the heating rod includes a first heating rod and a second heating rod, with the first heating rod disposed in the lower part of the water tank and the second heating rod disposed in the middle, upper or bottom of the water tank.

[0017] In a preferred embodiment, the heating rod includes a first heating rod and a second heating rod, and the water tank also includes a water outlet pipe. The water inlet of the water outlet pipe is located at the upper part of the water tank, and the second heating rod is positioned closer to the water inlet of the water outlet pipe than the first heating rod.

[0018] In a preferred embodiment, the lateral dimension of the phase change tank is not less than the lateral dimension of the water tank, or the lateral dimension of the phase change tank is less than the lateral dimension of the water tank.

[0019] In a preferred embodiment, the phase change tank further includes a second heat exchanger for absorbing heat from the phase change material. One end of the second heat exchanger is connected to a water source or the water tank, and the other end of the second heat exchanger is connected to the water tank. Water in the water source or the water tank can absorb heat from the phase change material through the second heat exchanger and then flow into the water tank.

[0020] In a preferred embodiment, the first heat exchanger and the second heat exchanger are arranged independently of each other and are not connected.

[0021] In a preferred embodiment, the phase change tank further includes a second heat exchanger for absorbing heat from the phase change material. One end of the second heat exchanger is connected to a water source or the water tank. Water in the water source or the water tank can absorb heat from the phase change material through the second heat exchanger and the first heat exchanger and then flow into the water tank.

[0022] In a preferred embodiment, the first heat exchanger and the second heat exchanger are connected in series.

[0023] In a preferred embodiment, the second heat exchanger includes a first heat exchange section and a second heat exchange section, wherein the first heat exchange section is located upstream of the first heat exchanger and the second heat exchange section is located downstream of the first heat exchanger; or, the second heat exchanger is located upstream or downstream of the first heat exchanger.

[0024] In a preferred embodiment, the electric water heater further includes a water supply pipeline, one end of which is connected to a water source, and the other end of which is connected to the second heat exchanger. The first heat exchanger and the second heat exchanger are connected, and a switch device is provided on the first circulation pipeline and / or the second circulation pipeline.

[0025] In a preferred embodiment, a portion of the outer wall of the phase change tank wraps around or adheres to a portion of the outer wall of the water tank.

[0026] In a preferred embodiment, the circulation pipeline is provided with an insulation layer.

[0027] In a preferred embodiment, the position of the first water inlet end in the water tank is higher or lower than the position of the second water outlet end in the water tank, and the position of the first water outlet end in the phase change tank is higher or lower than the position of the second water inlet end in the phase change tank; or, the position of the first water inlet end in the water tank is higher or lower than the position of the second water outlet end in the water tank, and the position of the first water outlet end in the phase change tank is level with the position of the second water inlet end in the phase change tank; or, the position of the first water inlet end in the water tank is level with the position of the second water outlet end in the water tank, and the position of the first water outlet end in the phase change tank is higher or lower than the position of the second water inlet end in the phase change tank; or, the position of the first water inlet end in the water tank is level with the position of the second water outlet end in the water tank, and the position of the first water outlet end in the phase change tank is level with the position of the second water inlet end in the phase change tank.

[0028] In a preferred embodiment, the first water inlet is located in the lower, middle, or upper part of the water tank; and / or, the first water outlet is located in the lower, middle, or upper part of the phase change tank; and / or, the second water inlet is located in the lower, middle, or upper part of the phase change tank; and / or, the second water outlet is located in the lower, middle, or upper part of the water tank.

[0029] In a preferred embodiment, the first heat exchanger includes at least a heat exchange box with a cavity, the water inlet of the heat exchange box being connected to the first water outlet, and the water outlet of the heat exchange box being connected to the second water inlet.

[0030] In a preferred embodiment, the first heat exchanger includes at least a first heat exchange box having a first cavity and a second heat exchange box having a second cavity. The first heat exchange box and the second heat exchange box are connected by a water passage structure. The water inlet of the first heat exchange box is connected to the first water outlet, and the water outlet of the first heat exchange box is connected to the second water inlet.

[0031] In a preferred embodiment, the water-passing structure includes an upper water-passing structure and a lower water-passing structure. The upper water-passing structure connects the upper part of the first heat exchange box and the upper part of the second heat exchange box. The lower water-passing structure connects the lower part of the first heat exchange box and the lower part of the second heat exchange box. The upper water-passing structure has an upper water inlet port connected to the first cavity of the first heat exchange box and an upper water outlet port connected to the second cavity of the second heat exchange box. The upper water inlet port is lower than or level with the upper water outlet port in height. The lower water-passing structure has a lower water outlet port connected to the first cavity of the first heat exchange box and a lower water inlet port connected to the second cavity of the second heat exchange box. The lower water inlet port is higher than or level with the lower water outlet port in height.

[0032] In a preferred embodiment, the upper water-passing structure connects the upper part of the first heat exchange box and the upper end of the second heat exchange box, or the upper water-passing structure connects the upper end of the first heat exchange box and the upper end of the second heat exchange box; the lower water-passing structure connects the lower end of the first heat exchange box and the lower end of the second heat exchange box, or the lower water-passing structure connects the lower part of the first heat exchange box and the lower end of the second heat exchange box.

[0033] In a preferred embodiment, the first heat exchanger includes at least one first heat exchange box and a plurality of second heat exchange boxes; a portion of the plurality of second heat exchange boxes is disposed on a first side of the first heat exchange box, and another portion of the plurality of second heat exchange boxes is disposed on a second side of the first heat exchange box opposite to the first side.

[0034] In a preferred embodiment, the first heat exchange box and at least one second heat exchange box constitute a heat exchange box group, and the first heat exchanger includes at least one group of the heat exchange box groups.

[0035] In a preferred embodiment, the upper end of the first heat exchange box is lower than the upper end of the second heat exchange box, and / or the lower end of the first heat exchange box is lower than the lower end of the second heat exchange box.

[0036] In a preferred embodiment, the first heat exchange box and the second heat exchange box are connected in parallel in the water flow path.

[0037] In a preferred embodiment, the water tank is located below the phase change tank.

[0038] In a preferred embodiment, the longitudinal section of the phase change chamber is saddle-shaped or inverted U-shaped, and the first heat exchanger has a predetermined distance from the inner surface of the lower outer wall of the phase change chamber.

[0039] The technical solution of this utility model has the following significant beneficial effects:

[0040] In this embodiment, a heating rod is installed in the water tank. When the heating rod is activated, the hot water heated by the heating rod in the water tank is sent to the first heat exchanger of the phase change tank through a first circulation pipe using natural convection. Simultaneously, the cold water in the first heat exchanger returns to the water tank through a second circulation pipe. Thus, the water circulates between the first heat exchanger of the phase change tank and the water tank. During this circulation process, the heat generated by the energized heating rod in the water tank can raise not only the water temperature in the water tank but also the water temperature in the first heat exchanger. The heat from the water in the first heat exchanger can be transferred through the shell of the first heat exchanger to the phase change material in contact with it, allowing the phase change material to absorb and store heat. During the heating rod startup process, no additional power source is required to achieve natural water circulation, which simplifies the system, reduces energy consumption, effectively controls the overall cost, and does not generate noise that disturbs users. Moreover, by directly allowing the heated water from the water tank to flow into the first heat exchanger, this method of storing heat in the phase change material improves the heat exchange efficiency during the heat storage stage, shortens the heat storage time, and enhances the user experience compared to the existing method of setting heating components in the phase change tank.

[0041] Furthermore, for example, in the case where the phase change tank and the water tank are arranged vertically, since the phase change tank is positioned above the water tank and heat is transferred upwards, heat exchange can occur between the phase change tank and the water tank (this heat exchange can take the form of thermal radiation and / or heat transfer). Taking heat transfer as an example, when the two can be in direct or indirect contact, the heat from the hot water in the water tank can also be transferred to the phase change material of the phase change tank through the shell of the water tank and the shell of the phase change tank. Taking thermal radiation as an example, the phase change tank and the water tank can be placed in the same shell, in which case the heat from the water tank can be radiated to the phase change tank. In summary, the embodiments of this application are equivalent to transferring heat to the phase change material in the phase change tank simultaneously through two different methods, thereby effectively improving the heat exchange efficiency during the heat storage stage, shortening the heat storage time, and enhancing the user experience.

[0042] Specific embodiments of the present invention are disclosed in detail with reference to the following description and accompanying drawings, indicating how the principles of the present invention can be adopted. It should be understood that the embodiments of the present invention are not limited in scope. Within the spirit and scope of the appended claims, embodiments of the present invention include many changes, modifications, and equivalents. Features described and / or shown for one embodiment may be used in the same or similar manner in one or more other embodiments, combined with features in other embodiments, or substituted for features in other embodiments. Attached Figure Description

[0043] The accompanying drawings described herein are for illustrative purposes only and are not intended to limit the scope of this invention in any way. Furthermore, the shapes and proportions of the components in the drawings are merely illustrative to aid in understanding the invention and do not specifically limit the shapes and proportions of the components. Those skilled in the art, under the guidance of this invention, can select various possible shapes and proportions to implement this invention according to specific circumstances.

[0044] Figure 1 This is a front view of the first type of electric water heater provided in the embodiments of this application;

[0045] Figure 2 This is one of the side views of the first type of electric water heater provided in the embodiments of this application;

[0046] Figure 3 This is a front view of the second type of electric water heater provided in the embodiments of this application;

[0047] Figure 4 This is a side view of the second type of electric water heater provided in the embodiments of this application;

[0048] Figure 5 This is a second side view of the first type of electric water heater provided in the embodiments of this application;

[0049] Figure 6 This is the third side view of the first type of electric water heater provided in the embodiments of this application;

[0050] Figure 7 This is the fourth side view of the first type of electric water heater provided in the embodiments of this application;

[0051] Figure 8 This is the fifth side view of the first type of electric water heater provided in the embodiments of this application;

[0052] Figure 9 for Figure 8 One of the schematic diagrams showing the water circuit connection status of an electric water heater;

[0053] Figure 10 for Figure 8 The second schematic diagram of the water circuit connection status of the electric water heater in the picture;

[0054] Figure 11 This is the sixth side view of the first type of electric water heater provided in the embodiments of this application.

[0055] Figure 12 This is a schematic diagram of the structure of the third type of electric water heater provided in the embodiments of this application;

[0056] Figure 13 for Figure 12 A schematic diagram of water flow in the heat storage mode of an electric water heater provided in the embodiments of this application;

[0057] Figure 14 for Figure 12 A schematic diagram of water flow in the water usage mode of an electric water heater provided in the embodiments of this application;

[0058] Figure 15 This is a schematic diagram of the structure of the fourth type of electric water heater provided in the embodiments of this application;

[0059] Figure 16 for Figure 15 A schematic diagram of water flow in the water usage mode of an electric water heater provided in the embodiments of this application;

[0060] Figure 17 This is a structural schematic diagram of the fifth type of electric water heater provided in the embodiments of this application;

[0061] Figure 18 This is a schematic diagram of the structure of the sixth type of electric water heater provided in the embodiments of this application;

[0062] Figure 19 This is a structural schematic diagram of the seventh type of electric water heater provided in the embodiments of this application;

[0063] Figure 20 This is a schematic diagram of the structure of the eighth type of electric water heater provided in the embodiments of this application;

[0064] Figure 21 for Figure 20 A schematic diagram of water flow in the heat storage mode of an electric water heater provided in the embodiments of this application;

[0065] Figure 22 for Figure 20 One of the water flow diagrams of an electric water heater in water usage mode provided in the embodiments of this application;

[0066] Figure 23 for Figure 20 A second schematic diagram of water flow in the water usage mode of an electric water heater provided in the embodiments of this application;

[0067] Figure 24 for Figure 20 The third schematic diagram of water flow in the water usage mode of the electric water heater provided in the embodiments of this application;

[0068] Figure 25 This is a structural schematic diagram of the ninth type of electric water heater provided in the embodiments of this application.

[0069] Reference numerals in the figures of this application:

[0070] 1. Phase change cylinder;

[0071] 2. Water tank;

[0072] 3. Heating rod;

[0073] 31. First heating rod;

[0074] 32. Second heating rod;

[0075] 41. First circulation pipeline;

[0076] 411. First water inlet end;

[0077] 412. First water outlet;

[0078] 42. Second circulation pipeline;

[0079] 421. Second water inlet;

[0080] 422. Second water outlet;

[0081] 5. First heat exchanger;

[0082] 50. Heat exchanger box body;

[0083] 51. First heat exchange box body;

[0084] 52. Second heat exchange box body;

[0085] 61. Upper water passage structure;

[0086] 62. Lower water passage structure;

[0087] 7. Second heat exchanger;

[0088] 71. First connecting part;

[0089] 72. Second connecting part;

[0090] 811, First connecting port;

[0091] 812. Second connecting port;

[0092] 813. Third connecting port;

[0093] 824. Fourth connecting port;

[0094] 825. Fifth connecting port;

[0095] 826. The sixth connecting port;

[0096] 921, First Port;

[0097] 922, Second Port;

[0098] 923, Third Port;

[0099] 94. Flow regulating device;

[0100] 81. Water supply pipelines;

[0101] 82. Water outlet pipe;

[0102] 83. Water inlet pipe;

[0103] 91. Check valve;

[0104] 92. Switching device;

[0105] 93. Insulation layer;

[0106] X, horizontal;

[0107] Y, the height direction;

[0108] Z, forward and backward direction. Detailed Implementation

[0109] The technical solution of this utility model will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that these embodiments are only used to illustrate this utility model and are not intended to limit the scope of this utility model. After reading this utility model, any modifications of this utility model in various equivalent forms by those skilled in the art will fall within the scope defined by the appended claims.

[0110] It should be noted that when an element is referred to as being "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0111] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. The term "and / or" as used herein includes any and all combinations of one or more of the associated listed items.

[0112] This utility model provides an electric water heater that can effectively improve the heat exchange efficiency during the heat storage stage and shorten the heat storage time; at the same time, it can simplify the system, reduce energy consumption, effectively control the overall cost, and improve the user experience.

[0113] Please refer to the following for comprehensive information. Figures 1 to 7 This application specification provides an electric water heater, which includes a heating rod 3 and a tank. The tank includes a phase change tank 1 and a water tank 2. The heating rod 3 is disposed in the water tank 2 and is used to heat the water in the water tank 2. The phase change tank 1 has a phase change material for heat storage and release. The phase change tank 1 also includes a first heat exchanger 5 connected to the water tank 2. The water flowing through the first heat exchanger 5 can conduct heat to the phase change material. The electric water heater also includes a circulation pipe connecting the water tank 2 and the first heat exchanger 5. The circulation pipe includes a first circulation pipe 41 and a second circulation pipe 42. The first circulation pipe 41 has a first inlet 411 and a first outlet 412, with the first inlet 411 located in the water tank 2 and the first outlet 412 located in the phase change tank 1. The second circulation pipe 42 has a second inlet 421 and a second outlet 422, with the second inlet 421 located in the phase change tank 1 and the second outlet 422 located in the water tank 2. When the heating rod 3 is working, the water in the water tank 2 can circulate between the phase change tank 1 and the water tank 2 through the first circulation pipe 41 and the second circulation pipe 42.

[0114] In this embodiment, the electric water heater may include a phase change tank 1 and a water tank 2. The water tank 2 may be located below the phase change tank 1, meaning the phase change tank 1 and water tank 2 may be arranged vertically. Of course, the relative positional relationship between the water tank 2 and the phase change tank 1 can be other than that. The description and drawings of the embodiments in this application mainly use the vertical arrangement of the phase change tank 1 and water tank 2 as an example for illustration; other positional relationships can be referred to by analogy with the embodiments provided in this application.

[0115] The phase change tank 1 contains a phase change material for heat storage and release, hence the name "phase change tank". The phase change material's physical state can change, thus switching between its heat storage and heat release states. The specific material of the phase change material can be inorganic water and salt with added nucleating agents, or it can be in other forms; this application does not impose specific limitations here. In this embodiment, taking a phase change material capable of switching between solid and liquid states as an example, when the phase change material changes from solid to liquid, it is in a heat storage state, absorbing and storing external heat; when it changes from liquid to solid, it is in a heat release state, releasing the stored heat. The phase change tank 1 is internally equipped with a first heat exchanger 5, which is connected to the water tank 2.

[0116] The water tank 2 is a water tank with an internal water storage cavity. A heating rod 3 is installed in the water tank 2. The phase change tank 1 may not have a heating element, or for the phase change tank 1 with a heating element, it may not need to be activated when storing heat for the phase change material. When the phase change material in the phase change tank 1 needs heat storage, this can be achieved using the heat from the water heated by the heating rod 3 in the water tank 2.

[0117] To allow the heated hot water in water tank 2 to flow into phase change tank 1 via natural convection, a first circulation pipe 41 and a second circulation pipe 42 are provided between the first heat exchanger 5 of phase change tank 1 and water tank 2. These first and second circulation pipes connect water tank 2 to the first heat exchanger 5 of phase change tank 1. In other words, the first heat exchanger 5 is effectively interconnected with water tank 2 via the first and second circulation pipes 41 and 42.

[0118] When the heating rod 3 is working, the hot water in the water tank 2 heated by the heating rod 3 expands due to heat. The hot water with lower density flows upward and enters the first heat exchanger 5 through the first circulation pipe 41. The water with lower temperature and lower density in the first heat exchanger 5 returns to the water tank 2 through the second circulation pipe 42. In this way, the water flows in a circulation between the first heat exchanger 5 and the water tank 2 of the phase change tank 1.

[0119] During the aforementioned circulation process, the heat generated by energizing the heating rod 3 can raise the water temperature in the water tank 2, and also raise the water temperature in the first heat exchanger 5. The heat from the water in the first heat exchanger 5 can be transferred through the shell of the first heat exchanger 5 to the phase change material in contact with it, allowing the phase change material to absorb heat and store energy.

[0120] In this embodiment, a heating rod 3 is installed in the water tank 2. When the heating rod 3 is activated, the hot water heated by the heating rod 3 in the water tank 2 is sent to the first heat exchanger 5 of the phase change tank 1 through the first circulation pipe 41 using natural convection. At the same time, the cold water in the first heat exchanger 5 returns to the water tank 2 through the second circulation pipe 42. Thus, the water flows in a circulation between the first heat exchanger 5 of the phase change tank 1 and the water tank 2. During the above circulation process, the heat generated by the energized heating rod 3 in the water tank 2 can not only raise the water temperature in the water tank 2, but also raise the water temperature in the first heat exchanger 5. The heat of the water in the first heat exchanger 5 can be transferred through the shell of the first heat exchanger 5 to the phase change material in contact with it, allowing the phase change material to absorb heat and store energy. During the startup of heating rod 3, no additional power source is required to achieve natural water circulation, simplifying the system, reducing energy consumption, effectively controlling overall costs, and eliminating noise disturbance to users. Furthermore, this method of directly feeding the heated water from water tank 2 into the first heat exchanger 5 for heat storage of the phase change material is superior to existing methods that incorporate heating elements within the phase change tank. For example, existing methods with heating elements in the heat exchanger of the phase change tank have limited volume, typically less than 3L. During the heat storage phase, the heating element with higher heating power heats a limited volume of water. When heating water is used, it is in a state of frequent start-stop, and the working time of the heating component is limited each time it is started. As a result, the heat generated by each heating is small, which leads to an increase in heat storage time and poor heat exchange efficiency. However, in the embodiment of this application, the water tank 2 is connected to the first heat exchanger 5. The water in the water tank 2, which has a large volume (at least 10L), can be heated and circulated with the first heat exchanger 5 through the circulation pipeline. This helps to reduce the heating frequency of the heating rod 3, increase the heat generated by each heating, thereby improving the heat exchange efficiency during the heat storage stage, shortening the heat storage time, and improving the user experience.

[0121] Furthermore, because the phase change tank 1 is positioned above the water tank 2, and heat is transferred upwards, heat exchange can occur between the phase change tank 1 and the water tank 2 (this heat exchange can take the form of thermal radiation and / or thermal transfer). For example, with thermal transfer, when the two are in direct or indirect contact, the heat from the hot water in the water tank 2 can be transferred to the phase change material of the phase change tank 1 through the shell of the water tank 2 and the shell of the phase change tank 1. With thermal radiation, since the phase change tank 1 and the water tank 2 are housed in the same shell, the heat from the water tank 2 can be radiated to the phase change tank 1. In summary, this embodiment of the application effectively transfers heat to the phase change material in the phase change tank 1 through two different methods simultaneously, thereby improving the heat exchange efficiency during the heat storage stage, shortening the heat storage time, and enhancing the user experience.

[0122] In one embodiment, a portion of the outer wall of the phase change tank 1 wraps around or adheres to a portion of the outer wall of the water tank 2; the heat of the water in the water tank 2 can be simultaneously conducted to the phase change tank 1 through the outer wall of the portion of the water tank 2 and the outer wall of the portion of the phase change tank 1.

[0123] In this embodiment, a portion of the outer wall surface of the phase change tank 1 can contact a portion of the outer wall surface of the water tank 2. Specifically, the method by which the portion of the outer wall surface of the phase change tank 1 wraps around or adheres to the portion of the outer wall surface of the water tank 2 can be as follows: the portion of the outer wall surface of the phase change tank 1 can be contoured to the portion of the outer wall surface of the water tank 2. The portion of the outer wall surface of the phase change tank 1 and the portion of the outer wall surface of the water tank 2 can be in partial contact or completely adhered. This wrapping can be a covering relationship between curved surfaces, and the adherence can be a contact relationship between planes, planes and curved surfaces, or curved surfaces.

[0124] For example, such as Figure 2 or Figure 4 As shown, the longitudinal section of the water tank 2 can be circular or near-circular, and the longitudinal section of the upper portion of the outer wall of the water tank 2 has an arc-shaped structure. The lower outer wall of the phase change tank 1 can include an arc-shaped structure that matches the partially annular outer wall of the water tank 2. The arc-shaped structure of the lower part of the phase change tank 1 wraps around the arc-shaped structure of the upper part of the water tank 2, thereby increasing the heat exchange area between the phase change tank 1 and the water tank 2. This facilitates the transfer of heat from the hot water heated by the heating rod 3 in the water tank 2 to the phase change material in the phase change tank 1, improving the heat transfer and heat exchange efficiency of the phase change material during the heat storage stage and shortening the heat storage time.

[0125] Furthermore, when a portion of the outer wall of the phase change tank 1 wraps around or adheres to a portion of the outer wall of the water tank 2 from top to bottom, it is equivalent to extending a portion of the phase change tank 1 towards the water tank 2. The lowest point of the phase change tank 1 is lower than the highest point of the water tank 2, meaning the lower part of the phase change tank 1 extends to the upper part of the water tank 2, covering part of the space outside the phase change tank 1. This helps to fully utilize the limited space within the electric water heater casing, increasing the volume of the phase change tank 1 and the volume of the phase change material within it, thereby increasing heat storage and ultimately improving the hot water supply of the electric water heater. Additionally, because a portion of the outer wall of the phase change tank 1 wraps around or adheres to a portion of the outer wall of the water tank 2 from top to bottom, it increases the heat exchange area between the two, allowing the lower part of the phase change tank 1 to better adhere to the upper part of the water tank 2 under gravity.

[0126] In one embodiment, the longitudinal section of the phase change chamber 1 is saddle-shaped or inverted U-shaped, and the first heat exchanger 5 has a predetermined distance from the inner surface of the lower outer wall of the phase change chamber 1.

[0127] In this embodiment, the lower wall of the longitudinal section of the phase change tank 1 can be configured to mimic the upper wall of the longitudinal section of the water tank 2. For example, when the longitudinal section of the water tank 2 is circular, the longitudinal section of the phase change tank 1 can be saddle-shaped or inverted U-shaped.

[0128] When the longitudinal section of the phase change tank 1 has the above-described structure, the bottom of the phase change tank 1 has a structure that is high in the middle and low on both sides, and a predetermined gap is formed between the first heat exchanger 5 and the inner surface of the lower outer wall of the phase change tank 1. Specifically, this predetermined gap can be the height difference between the lowest point of the first heat exchanger 5 and the lowest position of the lower inner surface of the phase change tank 1 in the height direction Y. In the phase change tank 1, the area between the lowest point of the first heat exchanger 5 and the lowest position of the lower inner surface of the phase change tank 1 is prone to form a region with poor heat transfer of the phase change material, causing the phase change material in this region to be unable to store heat sufficiently.

[0129] Since part of the outer wall of the phase change tank 1 wraps around or adheres to part of the outer wall of the water tank 2, the phase change material in the area with poor heat exchange can be stored by the hot water in the water tank 2 through the heat transfer between the shell of the water tank 2 and the phase change tank 1. This allows the phase change material to be fully stored, thereby increasing the heat storage capacity and thus improving the hot water supply of the electric water heater.

[0130] In one embodiment, a heat-conducting medium or heat-conducting structure is provided between the outer wall surface of the partial phase change tank 1 and / or the outer wall surface of the partial water tank 2 and / or the outer wall surface of the partial phase change tank 1 and the outer wall surface of the partial water tank 2.

[0131] In this embodiment, for cases where the phase change tank 1 and the water tank 2 are not in direct contact, a heat-conducting medium or heat-conducting structure can be provided between the phase change tank 1 and the water tank 2, which is beneficial to increasing the heat exchange area and heat exchange efficiency between the phase change tank 1 and the water tank 2.

[0132] For example, the heat-conducting medium or structure can be disposed on the outer wall surface of a portion of the phase change tank 1, or on the outer wall surface of a portion of the water tank 2, or simultaneously on both the outer wall surface of the phase change tank 1 and the outer wall surface of the water tank 2. The heat-conducting medium or structure can be liquid and / or solid. When the heat-conducting medium or structure includes a liquid, it is relatively more conducive to heat transfer and improves heat exchange efficiency.

[0133] In one embodiment, the position of the first water inlet 411 in the water tank 2 is higher than the position of the second water outlet 422 in the water tank 2, and the position of the first water outlet 412 in the phase change tank 1 is higher than the position of the second water inlet 421 in the phase change tank 1.

[0134] In this embodiment, the position of the first water inlet 411 in the water tank 2 is higher than the position of the second water outlet 422 in the water tank 2, and the position of the first water outlet in the phase change tank 1 is higher than the position of the second water inlet 421 in the phase change tank 1. With this arrangement, when the heating rod 3 is started, the water with a higher temperature in the upper part of the water tank 2 can enter the first circulation pipe 41 through the first water inlet 411 earlier, and then flow into the first heat exchanger 5 through the first water outlet 412. The water with a lower temperature in the first heat exchanger 5 flows out through the second water inlet 421, and then flows into the lower position of the water tank 2 from the second water outlet 422 through the second circulation pipe 42.

[0135] Specifically, the first water inlet 411 can be located at the upper part of the water tank 2, the first water outlet 412 can be located at the upper part of the phase change tank 1, the second water inlet 421 can be located at the lower part of the phase change tank 1, and the second water outlet 422 can be located at the lower part of the water tank 2.

[0136] With this configuration, the heated hot water can enter the first heat exchanger 5 with a shorter path and faster speed, thereby storing heat in the phase change material and enabling the phase change tank 1 to complete the heat storage process as soon as possible, thus shortening the heat storage time. In addition, since the lower-temperature water flowing out of the first heat exchanger 5 flows into the lower part of the water tank 2, this configuration can prevent the lower-temperature water from disturbing the decreasing water temperature from top to bottom in the water tank 2 during the early stage of heat storage. It also helps to ensure that the higher-temperature water can stably pass through the first circulation pipe 41 into the first heat exchanger 5 in the upper part, thereby storing heat in the phase change material in the phase change tank 1.

[0137] Of course, in other embodiments of this application, it is not excluded that the position of the first water inlet 411 in the water tank 2 may be lower than the position of the second water outlet 422 in the water tank 2, and the position of the first water outlet 412 in the phase change tank 1 may be lower than the position of the second water inlet 421 in the phase change tank 1.

[0138] Alternatively, the position of the first water inlet 411 in the water tank 2 is higher or lower than the position of the second water outlet 422 in the water tank 2, and the position of the first water outlet 412 in the phase change tank 1 is flush with the position of the second water inlet 421 in the phase change tank 1. Alternatively, the position of the first water inlet 411 in the water tank 2 is flush with the position of the second water outlet 422 in the water tank 2, and the position of the first water outlet 412 in the phase change tank 1 is higher or lower than the position of the second water inlet 421 in the phase change tank 1. Alternatively, the position of the first water inlet 411 in the water tank 2 is flush with the position of the second water outlet 422 in the water tank 2, and the position of the first water outlet 412 in the phase change tank 1 is flush with the position of the second water inlet 421 in the phase change tank 1.

[0139] like Figure 7 As shown, the position of the first water inlet 411 in the water tank 2 is lower than the position of the second water outlet 422 in the water tank 2. The functions of the first water inlet 411 and the second water outlet 422 can vary depending on the working state of the electric water heater, the water circuit connection relationship, etc.

[0140] For example, during the water usage phase, after the heating rod 3 is activated, high-level water can be replenished through the second water outlet, which is located at a higher position. This ensures that the relatively high-temperature water can be concentrated in the upper part of the water tank 2 for heating and then output to the user terminal, thereby improving the hot water supply capacity of the electric water heater.

[0141] Taking a specific application scenario as an example, for the case where only the heating rod 3 is installed in the water tank 2 of the water heater, when the user is using a small amount of water, and the phase change material in the phase change tank 1 has not yet stored energy or in order not to utilize the heat of the phase change material in the phase change tank 1, in order to ensure the user's water supply, the heating rod 3 can be used first to concentrate the water temperature in the upper part of the water tank 2 to reach the outlet water temperature. Subsequently, the heated hot water can be supplied to the user first through the outlet pipe 82, that is, to ensure that the water tank 2 has the ability to prioritize supplying hot water to the user.

[0142] Alternatively, in another usage state, when the first water inlet 411 is located at the lower part of the water tank 2, hot water circulation can be achieved through the second water outlet 422, the second circulation pipe 42, the first heat exchanger 5, and the first circulation pipe 41 during the heat storage stage.

[0143] In one embodiment, the first water outlet 412 is located in the lower, middle or upper part of the phase change tank 1; and / or, the second water inlet 421 is located in the lower, middle or upper part of the phase change tank 1.

[0144] When the first water outlet 412 is located at the upper part of the phase change tank 1, and the second water inlet 421 is located at the lower part of the phase change tank 1, the hot water with a higher temperature flowing into the first heat exchanger 5 from the first circulation pipe 41 can be discharged from the first heat exchanger 5 from top to bottom under the action of gravity, and then flow into the water tank 2 through the second circulation pipe 42. Overall, this is beneficial for rapidly raising the water temperature in the first heat exchanger 5, thereby facilitating efficient heat exchange between the first heat exchanger 5 and the phase change medium in the phase change tank 1, improving the heat exchange effect, and shortening the heat storage time. Of course, in other embodiments of this application, such as Figure 7 As shown, it is also possible that the first water outlet 412 is located at the lower part of the phase change tank 1, and the second water inlet 421 is located at the upper part of the phase change tank 1.

[0145] In some cases, when the second water outlet 422 is located at the upper part of the water tank 2, that is, when the lower temperature water flowing out from the first heat exchanger 5 of the phase change tank 1 flows into the higher temperature part of the water tank 2, it can be fully mixed with the water in the water tank 2.

[0146] In some scenarios, when a heating element is installed in a phase change chamber, taking heating rod 3 as an example, its general operation is as follows: Heating rod 3 is activated, and during the heating process, it gradually raises the temperature of the surrounding phase change medium. It is difficult to ensure that phase change materials farther from heating rod 3 are also adequately heated. Furthermore, heating elements typically have a protection mechanism; if the temperature of the surrounding phase change medium reaches a preset temperature after a period of operation, heating may stop. However, at this time, the temperature of the phase change material farther from heating rod 3 may still be far below the preset temperature. This leads to uneven heat storage.

[0147] In the embodiments of this application, since the heating rod 3 simultaneously stores heat in the heat storage material in the phase change tank 1 while heating the water in the water tank 2, when the water in the water tank 2 is heated to a predetermined temperature or above, the water in the water tank 2 can circulate with the water in the first heat exchanger 5 through the circulation pipe in a natural convection manner. Specifically, the first heat exchanger 5 includes at least a heat exchange box 50 with a cavity, the water inlet of the heat exchange box 50 is connected to the first water outlet 412, and the water outlet of the heat exchange box 50 is connected to the second water inlet 421.

[0148] In this embodiment, the first heat exchanger 5 can be in the form of a heat exchange box 50 with a certain volume. The heat exchange box 50 has an inlet and an outlet. The inlet is connected to the first outlet 412, so as to receive hot water flowing into the water tank 2 from the first circulation pipe 41. The outlet is connected to the second inlet 421, so as to allow water in the heat exchange box 50 to flow into the water tank 2 through the second circulation pipe 42.

[0149] The heat exchange box 50 can specifically be a box-shaped structure with certain dimensions. Overall, the construction of the heat exchange box 50 can be adapted to the cross-sectional shape of the phase change tank 1. For example, it has certain length, width, and thickness dimensions. The length dimension can be adapted to the length of the phase change tank 1, extending along the transverse direction X; for example, the length of the heat exchange box 50 can be slightly less than the length of the phase change tank 1. The width of the heat exchange box 50 can be adapted to the height of the phase change tank 1; for example, in the height direction Y, the width of the heat exchange box 50 can be slightly less than the height of the phase change tank 1. The thickness dimension can extend along the front-rear direction Z of the phase change tank 1. The thickness of the heat exchange box 50 can vary depending on the construction of the phase change tank 1, the internal component arrangement of the phase change tank 1, and the composition of the first heat exchanger 5 itself, etc. This application does not impose specific numerical limitations here.

[0150] When the first heat exchanger 5 adopts the above-mentioned heat exchange box 50 structure, not only is the medium flowing inside the heat exchange box 50, i.e., the hot water provided in the water tank 2, continuously above the predetermined temperature, which is beneficial for storing heat in the phase change material, but also the surface area of ​​the heat exchange box 50 itself is much larger than the surface area of ​​the heating rod 3, which is beneficial for improving the uniformity of heating the phase change material in the phase change tank 1.

[0151] In one embodiment, the first heat exchanger 5 includes at least a first heat exchange box 51 having a first cavity and a second heat exchange box 52 having a second cavity. The first heat exchange box 51 and the second heat exchange box 52 are connected by a water passage structure. The water inlet of the first heat exchange box 51 is connected to the first water outlet 412, and the water outlet of the first heat exchange box 51 is connected to the second water inlet 421. The water passage structure has a water inlet port connected to the first cavity of the first heat exchange box 51 and a water outlet port connected to the second cavity of the second heat exchange box 52. The water inlet port is lower than or level with the water outlet port in height.

[0152] In this embodiment, the first heat exchanger 5 may include at least two heat exchange boxes 50. For example, the first heat exchanger 5 may include a first heat exchange box 51 and a second heat exchange box 52, which can be connected in series via a water passage structure or in parallel via a water passage structure.

[0153] For example, when the first heat exchange box 51 and the second heat exchange box 52 are connected in series via a water-passing structure, the water inlet of the water-passing structure is connected to the first cavity of the first heat exchange box 51, and the water outlet of the water-passing structure is connected to the second cavity of the second heat exchange box 52. The first heat exchange box 51, the water-passing structure, and the second heat exchange box 52 essentially form a complete heat exchange cavity. The water inlet of the first heat exchange box 51 is connected to the first water outlet 412, and the water outlet of the first heat exchange box 51 is connected to the second water inlet 421. In use, the water flowing out of the water tank 2 sequentially passes through the first circulation pipe 41, the first heat exchange box 51, the water-passing structure, the second heat exchange box 52, and the second circulation pipe 42 before returning to the water tank 2.

[0154] The water inlet of the water-passing structure is lower or flush with the water outlet, which facilitates the smooth flow of hot water with higher temperature and lower density between adjacent heat exchange boxes 50, improving the heat exchange efficiency between the heat exchange boxes 50 and the phase change material. The water-passing structure can be in the form of a hollow pipe, or it can have other structures. The water-passing structure can be detachably and sealed to the first heat exchange box 51 and the second heat exchange box 52, or it can be integrally formed with the first heat exchange box 51 and the second heat exchange box 52. Specifically, this application does not impose specific limitations here.

[0155] like Figure 5 As shown, in one embodiment, the water passage structure includes an upper water passage structure 61 and a lower water passage structure 62. The upper water passage structure 61 is used to connect the upper part of the first heat exchange box 51 and the upper part of the second heat exchange box 52. The lower water passage structure 62 is used to connect the lower part of the first heat exchange box 51 and the lower part of the second heat exchange box 52. The upper water passage structure 61 has an upper water inlet port that communicates with the first cavity of the first heat exchange box 51 and an upper water outlet port that communicates with the second cavity of the second heat exchange box 52. The upper water inlet port is lower than or level with the upper water outlet port in height.

[0156] In this embodiment, the first heat exchange box 51 and the second heat exchange box 52 are arranged at intervals along the thickness direction. The water passage structure may include an upper water passage structure 61 and a lower water passage structure 62 arranged vertically. The upper water passage structure 61 is located at the upper part of the phase change tank 1 and is used to connect the upper part of the first heat exchange box 51 and the upper part of the second heat exchange box 52. The lower water passage structure 62 is located at the lower part of the phase change tank 1 and is used to connect the lower parts of the second heat exchange box 52 to each other.

[0157] The upper water-passing structure 61 has an upper water inlet port communicating with the first cavity of the first heat exchange box 51 and an upper water outlet port communicating with the second cavity of the second heat exchange box 52. The upper water inlet port is lower than or level with the upper water outlet port in height. When the upper water inlet port of the upper water-passing structure 61 is not higher than the upper water outlet port, it is beneficial to allow hot water flowing out of the first heat exchange box 51 to flow smoothly from the first heat exchange box 51 into the second heat exchange box 52 through the upper water-passing structure 61 with low resistance.

[0158] The lower water passage structure 62 has a lower water outlet port communicating with the first cavity of the first heat exchange box 51 and a lower water inlet port communicating with the second cavity of the second heat exchange box 52. The lower water inlet port is higher than or level with the lower water outlet port. When the lower water inlet port of the lower water passage structure 62 is not lower than the lower water outlet port, it is beneficial for the cooler water flowing out of the second heat exchange box 52 to flow smoothly into the first heat exchange box 51 under the action of gravity through the lower water passage structure 62.

[0159] In one specific embodiment, the upper water-passing structure 61 connects the upper part of the first heat exchange box 51 and the upper end of the second heat exchange box 52, or the upper water-passing structure 61 connects the upper end of the first heat exchange box 51 and the upper end of the second heat exchange box 52. The lower water-passing structure 62 connects the lower end of the first heat exchange box 51 and the lower end of the second heat exchange box 52, or the lower water-passing structure 62 connects the lower part of the first heat exchange box 51 and the lower end of the second heat exchange box 52.

[0160] When the upper water-passing structure 61 is connected to the upper end of the second heat exchange box 52 and the lower water-passing structure 62 is connected to the lower end of the second heat exchange box 52, it is beneficial to completely displace the lower-temperature water in the second heat exchange box 52 from the top of the first heat exchange box 51 to the bottom under the action of gravity. This effectively improves the flow of water in the second heat exchange box 52, avoids stagnant water at the lower end of the second heat exchange box 52, and thus improves the heat exchange efficiency between the second heat exchange box 52 and the surrounding phase change material.

[0161] like Figure 6As shown, in one embodiment, the first heat exchanger 5 includes at least one first heat exchange box 51 and a plurality of second heat exchange boxes 52; a portion of the plurality of second heat exchange boxes 52 is disposed on a first side of the first heat exchange box 51, and another portion of the plurality of second heat exchange boxes 52 is disposed on a second side of the first heat exchange box 51 opposite to the first side.

[0162] In this embodiment, when the first heat exchanger 5 includes three or more heat exchange boxes 50, the first heat exchange box 51 can be located in the middle relative to each other in the longitudinal section of the phase change chamber 1, and the second heat exchange box 52 can be located on the left and right sides of the first heat exchange box 51.

[0163] When the first heat exchanger 5 includes a first heat exchange box 51 and two second heat exchange boxes 52, the two second heat exchange boxes 52 can be distributed at a predetermined distance on both sides of the first heat exchange box 51.

[0164] The second heat exchange boxes 52 located on both sides of the first heat exchange box 51 can be connected to the first heat exchange box 51 through an upper water passage structure and a lower water passage structure, respectively. Specifically, the second heat exchange box 52 and the upper and lower water passage structures on one side of the first heat exchange box 51 can be symmetrically arranged with the second heat exchange box 52 and the upper and lower water passage structures on the other side of the first heat exchange box 51.

[0165] The specific configuration of the upper and lower water-passing structures located on both sides of the first heat exchange box 51 can be referred to the detailed description in the above embodiments, and will not be described further here. It should be noted that, in order to reduce the number of openings on the first heat exchange box 51, the upper water inlet port of the upper water-passing structure connected to the upper side of the first heat exchange box 51 can share the same connection position of the first heat exchange box 51.

[0166] In addition, the lower water inlet ports of the lower water passage structures located on both sides of the lower part of the first heat exchange box 51 can be connected to the lower part of the first heat exchange box 51. Specifically, they can share the same connection position of the first heat exchange box 51, thereby reducing the number of openings on the first heat exchange box 51.

[0167] In one embodiment, the first heat exchange box 51 and at least one second heat exchange box 52 constitute a heat exchange box group, and the first heat exchanger 5 includes at least one group of the heat exchange box groups.

[0168] In this embodiment, the first heat exchange box 51 and at least one second heat exchange box 52 constitute a heat exchange box group. The number of heat exchange box groups can be one or more. Specifically, the number of heat exchange box groups can vary depending on the specific size and structure of the phase change tank 1, and this application does not impose a unique limitation. When there are multiple heat exchange box groups, these groups can be connected in series or in parallel in the water path.

[0169] In one embodiment, the upper end of the first heat exchange box 51 is lower than the upper end of the second heat exchange box 52, and / or, the lower end of the first heat exchange box 51 is lower than the lower end of the second heat exchange box 52.

[0170] In this embodiment, when the upper end of the first heat exchange box 51 is lower than the upper end of the second heat exchange box 52, when an upper water passage structure is provided between the upper ends of the first heat exchange box 51 and the second heat exchange box 52, the upper water passage structure is inclined from bottom to top between the upper end of the first heat exchange box 51 and the upper end of the second heat exchange box 52, which facilitates the smooth flow of water with higher temperature and lower density in the first heat exchange box 51 into the second heat exchange box 52 through the upper water passage structure. When the lower end of the first heat exchange box 51 is lower than the lower end of the second heat exchange box 52, and a lower water passage structure is provided between the lower ends of the first and second heat exchange boxes 51 and 52, the lower water passage structure is inclined from top to bottom from the lower end of the second heat exchange box 52 to the lower end of the first heat exchange box 51. This facilitates the smooth flow of water with lower temperature and higher density from the second heat exchange box 52 into the first heat exchange box 51 through the lower water passage structure. Overall, this improves the heat exchange efficiency between the first heat exchanger 5 and the phase change material.

[0171] In one embodiment, the first heat exchange box 51 and the second heat exchange box 52 are connected in parallel in the water flow path.

[0172] In this embodiment, the first heat exchange box 51 and the second heat exchange box 52 in the first heat exchanger 5 can also be connected in parallel in the water flow path. When the first heat exchange box 51 and the second heat exchange box 52 are connected in parallel, it is equivalent to the second heat exchange box 52 being directly connected to the first circulation pipe 41 and the second circulation pipe 42 through the flow channel. For example, two multi-port structures can be provided. The inlet end of one multi-port structure is connected to the first outlet end of the first circulation pipe 41, and the outlet end is connected to the upper ends of the first heat exchange box 51 and the second heat exchange box 52 respectively; the inlet end of the other multi-port structure is connected to the lower ends of the first heat exchange box 51 and the second heat exchange box 52 respectively, and the outlet end is connected to the second inlet end of the second circulation pipe 42 respectively.

[0173] The first heat exchange box 51 and the second heat exchange box 52, which are set in parallel, can exchange heat with the phase change material in the phase change tank 1 in a timely manner by allowing the hot water flowing into the water tank 2 through the first circulation pipe 41 at a higher temperature. This is beneficial to improving heat exchange efficiency and shortening the heat storage time.

[0174] Please refer to the following: Figure 1 and Figure 2 as well as Figure 3 and Figure 4 In one embodiment, the number of heating rods 3 is one, and the heating rod 3 is disposed in the middle or upper part of the water tank 2. Alternatively, the heating rod 3 includes a first heating rod 31 and a second heating rod 32, with the first heating rod 31 disposed in the lower part of the water tank 2 and the second heating rod 32 disposed in the middle or upper part of the water tank 2.

[0175] like Figure 1 and Figure 2 As shown, in one embodiment, the number of heating rods 3 can be one. When there is only one heating rod 3, it is located in the middle or upper part of the water tank 2.

[0176] When the heating rod 3 is located in the middle or upper part of the water tank 2, after the heating rod 3 is activated, it can efficiently concentrate the heat from the energized heating rod 3 to heat the water in the upper part of the water tank 2 (i.e., the water near and above the heating rod 3), allowing this part of the water to quickly reach a higher temperature. Thus, during the heat storage stage, after the water temperature in the upper part of the heating rod 3 is rapidly increased, as the water temperature rises and the density decreases, the hot water can enter the first heat exchanger 5 of the phase change tank 1 through the first circulation pipe 41 via natural convection. After exchanging heat with the phase change material in the phase change tank 1, it returns to the water tank 2 through the second circulation pipe 42, thus forming a cycle. Furthermore, when the heating rod 3 preferentially heats the water in the upper part of the water tank 2, a large temperature difference is formed between the upper part of the water tank 2 and the phase change tank 1. This facilitates efficient heat exchange from the upper part of the water tank 2 to the phase change material in the lower part of the phase change tank 1, thereby significantly improving heat exchange efficiency and shortening the heat exchange time.

[0177] In particular, the longitudinal section of the water tank 2 is circular, while the longitudinal section of the phase change tank 1 can be saddle-shaped or inverted U-shaped. The first heat exchanger 5 and the inner surface of the lower outer wall of the phase change tank 1 have a predetermined distance. Specifically, when designing the contour of the lower part of the phase change tank 1 in contact with the upper part of the water tank 2, the lower shape of the phase change tank 1 is irregular. At the lower position of the phase change tank 1, it is difficult for the first heat exchanger 5 to be fully positioned. Figure 6As shown, taking the first heat exchanger 5, which includes a first heat exchange box 51 in the middle and a second heat exchange box 52 located on both sides of the first heat exchange box 51, as an example, the lower end of the second heat exchange box 52 is at a predetermined distance from the bottom wall of the water tank 2. Therefore, the heat exchange of the phase change material at the bottom of the phase change tank 1 is poor, and even a heat exchange dead zone may occur.

[0178] When the heating rod 3 is placed in the middle or upper part of the water tank 2, the heat generated by the heating rod 3 after it is turned on can reach the lower part of the phase change tank 1 quickly and efficiently with a shorter heat transfer path, so as to fully store the heat of the phase change material in the lower part of the phase change tank 1, thereby making the heat storage of the phase change material in the entire phase change tank 1 uniform, which is beneficial to improving the hot water output of the electric water heater.

[0179] In addition, during the water usage phase, when the heating rod 3 is positioned high (located in the middle or upper part of the water tank 2), the heating rod 3 can be used to concentrate the heating of the water above the middle of the water tank 2, which is beneficial to improve the heat replenishment effect and thus increase the hot water output of the electric water heater.

[0180] Overall, by installing only one heating rod 3 in the water tank 2, and placing this heating rod 3 in the middle or upper part of the water tank 2 at a relatively high position, efficient heat transfer can be achieved during the heat storage stage. This ensures that the phase change material in the lower part of the phase change tank 1 stores heat evenly and sufficiently, which is beneficial to increasing the hot water output of the electric water heater. When using a small amount of water, the higher heating rod 3 can be used to concentrate the heating of the water in the upper part of the water tank 2, achieving rapid hot water output. Alternatively, in the later stages of using a large amount of water, the higher heating rod 3 can be used to concentrate the heating of the water in the upper part of the water tank 2, further increasing the hot water output of the electric water heater. In addition, installing only one heating rod 3, compared to installing two heating rods 3, can reduce the number of parts and lower costs. Furthermore, it can also reduce the number of openings on the water tank 2, improving the pressure resistance of the water tank 2.

[0181] like Figure 3 and Figure 4 As shown, in another embodiment, the number of heating rods 3 can be two. The heating rods 3 may include a first heating rod 31 and a second heating rod 32, with the first heating rod 31 disposed at the lower part of the water tank 2 and the second heating rod 32 disposed at the middle or upper part of the water tank 2.

[0182] In this embodiment, the main difference from the above embodiment is that the number of heating rods 3 can include two. In addition to one heating rod 3 (second heating rod 32) located in the middle or upper part of the water tank 2, another heating rod 3 (first heating rod 31) is located in the lower part of the water tank 2. During the heat storage stage, only the second heating rod 32 can be activated. When the heating power of the second heating rod 32 is the same as or similar to the heating power of the first heating rod 3, the technical effect of using only one heating rod 3 can be achieved.

[0183] For the embodiment with two electric heating rods 3, different operating modes can be provided to the user based on the activation conditions of the electric heating rods 3. Operating mode one involves activating only the second heating rod 32 during the heat storage phase, as described above. Operating mode two involves activating both the first heating rod 31 and the second heating rod 32 during the heat storage phase and the process of raising the water temperature in the water tank 2. This helps to uniformly raise the water temperature in the water tank 2 to the predetermined temperature, thereby shortening the user's waiting time for water. For example, when the user's most urgent need is to shorten the waiting time between two water usage intervals, operating mode two can be used without considering energy consumption. The heating power of the first heating rod 31 and the second heating rod 32 can be the same or different; this application does not specify specific numerical values.

[0184] In other embodiments, the number of heating rods 3 can be one, two, or more. At least one heating rod 3 is located at the bottom of the water tank 2. When a heating rod 3 is located at the bottom of the water tank 2, the temperature of the water in the entire tank can be raised to a higher temperature before circulation or dispensing. Especially in scenarios where the water tank 2 itself has a small volume, having a heating rod 3 at the bottom of the water tank 2 ensures that sufficient heat is provided to the phase change material during heat storage, and that a sufficient amount of hot water is provided to the user during water use.

[0185] In the case where the heating rod 3 includes a first heating rod 31 and a second heating rod 32, the water tank 2 may further include a water outlet pipe 82. The inlet end of the water outlet pipe 82 is located at the upper part of the water tank 2, and the second heating rod 32 is positioned closer to the inlet end of the water outlet pipe 82 than the first heating rod 31. During supplemental heating, the first heating rod 31 and the second heating rod 32 can be activated simultaneously. The first heating rod 31 heats the water above the lower part of the water tank 2, while the second heating rod 32 concentrates on heating the water in the middle and upper parts, thereby increasing the water output of the water heater.

[0186] In one embodiment, the dimension of the phase change tank 1 in the horizontal X direction is not less than the dimension of the water tank 2 in the horizontal X direction.

[0187] In this embodiment, both the phase change tank 1 and the water tank 2 can extend along the transverse x-length. The transverse x-dimensional dimension of the phase change tank 1 is equal to or greater than that of the water tank 2, which increases the volume of the phase change tank 1, thereby increasing the amount of phase change material filling the phase change tank 1 and thus improving its heat storage capacity. This, in turn, helps to increase the hot water supply of the electric water heater. Furthermore, as the volume of the phase change tank 1 increases, the contact area between the phase change tank 1 and the water tank 2 also increases accordingly, increasing the heat transfer area. This, in turn, helps to improve the heat storage efficiency of the phase change material in the phase change tank 1 during the heat storage stage.

[0188] Alternatively, in another embodiment, the phase change tank 1 has a smaller dimension in the horizontal direction (X) than the water tank 2 has in the horizontal direction (X).

[0189] In this embodiment, both the phase change tank 1 and the water tank 2 can extend along the transverse X-axis. The transverse X-axis dimension of the phase change tank 1 is smaller than that of the water tank 2. Thus, in the transverse X-axis (i.e., axial direction), the projection of the water tank 2 onto the phase change tank 1 can completely cover the phase change tank 1. When the phase change material in the phase change tank 1 needs to store heat using hot water heated by the heating rod 3 in the water tank 2, the upper part of the water tank 2, which has a larger transverse dimension, can axially cover and conduct heat to the lower part of the phase change tank 1. Combined with the natural convection characteristics of the hot water in the water tank 2, efficient heat exchange can be carried out in the contact area between the two, reliably ensuring the heat exchange effect between the upper part of the water tank 2 and the lower part of the phase change tank 1, thereby improving the heat storage efficiency of the phase change material in the phase change tank 1.

[0190] In one embodiment, the electric water heater further includes a housing and a functional device, the functional device including a switch and an electronic control board, the switch being disposed on the circulation pipe, the phase change tank 1, the water tank 2 and the functional device being installed inside the housing, and the functional device being disposed within the accommodating space enclosed between the housing and the phase change tank 1 and the water tank 2.

[0191] The electric water heater also includes a casing, within which the phase change tank 1 and the water tank 2 are installed. Since the lateral dimension of the phase change tank 1 is smaller than that of the water tank 2, a space is formed between the end of the phase change tank 1 and the casing and the water tank 2. This space can be used to install functional devices, such as a switch device 92, an electronic control board, and other components. This allows for compact installation of components without increasing the size of the casing, through efficient use of the internal space.

[0192] In one embodiment, the phase change tank 1 further includes a second heat exchanger 7 for absorbing heat from the phase change material. One end of the second heat exchanger 7 is connected to a water source or the water tank 2, and the other end of the second heat exchanger 7 is connected to the water tank 2. Water in the water source or the water tank 2 can absorb heat from the phase change material through the second heat exchanger 7 and then flow into the water tank 2.

[0193] In this embodiment, a second heat exchanger 7 may also be provided in the phase change tank 1. This second heat exchanger 7 is used to allow water to flow through it, which exchanges heat with the phase change material. The second heat exchanger 7 can be in the form of a heat exchange tube, or it can be in other forms. In this embodiment, the second heat exchanger 7 is illustrated by an example comprising a reciprocating heat exchange tube. The water to be heated flows through this heat exchange tube. When the cooler water flows through the second heat exchanger 7 through the phase change tank 1, it absorbs heat from the phase change material, thereby increasing its temperature.

[0194] Specifically, the second heat exchanger 7 has two opposing ends, one of which is the inlet end. The inlet end of the second heat exchanger 7 can be connected to a water source or the water tank 2. For example, when the electric water heater is equipped with a water supply pipe 81, the second heat exchanger 7 is connected to the water source through the water supply pipe 81. When the user uses water, water from the water source can flow into the second heat exchanger 7 through the water supply pipe 81, and the phase change material in the phase change tank 1 heats the water flowing through the second heat exchanger 7.

[0195] The other end of the second heat exchanger 7 is an outlet end, which can be connected to the water tank 2. The water tank 2 of the electric water heater is equipped with a water outlet pipe 82, which is used to output water from the electric water heater to the user terminal. When the user uses water, the water heated by the phase change material in the phase change tank 1 flows into the water tank 2. The hot water in the water tank 2 that meets the user's set temperature requirement is then output to the user terminal through the water outlet pipe 82.

[0196] In one embodiment, the first heat exchanger 5 and the second heat exchanger 7 are independently arranged without being connected. When the first heat exchanger 5 and the second heat exchanger 7 are not connected, that is, when they are relatively independently arranged, the water from the external water source entering through the inlet pipe will not flow through the first heat exchanger 5, which has a relatively small pipe resistance, or the first circulation pipe 41 into the water tank 2 during its flow into the second heat exchanger 7 of the phase change tank 1. This ensures that all the water from the external water source entering through the inlet pipe can flow into the second heat exchanger 7 and fully exchange heat with the phase change material in the phase change tank 1, without being disturbed by the water stored in the first heat exchanger 5, thus ensuring the heat exchange efficiency with the phase change material.

[0197] In one embodiment, the phase change tank 1 further includes a second heat exchanger 7 for absorbing heat from the phase change material. One end of the second heat exchanger 7 is connected to a water source or the water tank 2. Water in the water source or the water tank 2 can absorb heat from the phase change material through the second heat exchanger 7 and the first heat exchanger 5 before flowing into the water tank 2. The first heat exchanger 5 and the second heat exchanger 7 are connected in series.

[0198] In this embodiment, when the second heat exchanger 7 is connected in series with the first heat exchanger 5, the second heat exchanger 7 is located upstream or downstream of the first heat exchanger 5, or the first heat exchanger 5 can be connected to the heat exchange tube of the second heat exchanger 7. Specifically, the second heat exchanger 7 includes a first heat exchange section and a second heat exchange section, the first heat exchange section being located upstream of the first heat exchanger 5, and the second heat exchange section being located downstream of the first heat exchanger 5.

[0199] Please refer to the following: Figure 6 and Figure 7 In one embodiment, the electric water heater further includes a water supply pipe 81, one end of which is connected to a water source and the other end of which is connected to the second heat exchanger 7. The first heat exchanger 5 and the second heat exchanger 7 are connected, and a switch device 92 is provided on the first circulation pipe 41 and / or the second circulation pipe 42.

[0200] In this embodiment, the electric water heater may further include a water supply pipe 81, which may be disposed between the water source and the second heat exchanger 7, for introducing water supplied from the external water source into the second heat exchanger 7. When the first heat exchanger 5 and the second heat exchanger 7 are connected, the first heat exchanger 5 is simultaneously connected to the first circulation pipe 41 and the second circulation pipe 42.

[0201] During the water usage phase, when ambient temperature water flows into the second heat exchanger 7 through the water supply pipe 81, since the first heat exchanger 5 is connected to the second heat exchanger 7, this relatively cool water may flow into the middle or upper part of the water tank 2, where the water temperature is higher, through the first circulation pipe 41 or the second circulation pipe 42, thus affecting the water temperature in the middle and upper parts of the water tank 2. Furthermore, the inlet end of the outlet pipe 82 of the water tank 2 is located at the upper part of the water tank 2. When cool water mixes into the upper part of the water tank 2, it will negatively interfere with the outlet water temperature, failing to meet the user's current outlet water temperature requirements, resulting in a poor user experience.

[0202] like Figure 6As shown, when the first inlet 411 of the first circulation pipe 41 is located at the upper part of the water tank 2, a one-way valve 91 can be installed in the first circulation pipe 41. The one-way valve 91 is unidirectionally open from bottom to top. This one-way valve 91 prevents water supplied from an external water source from flowing into the upper part of the water tank 2 through the first inlet 411 of the first circulation pipe 41, thereby ensuring the stability of the water temperature at the upper part of the water tank 2 and ensuring that hot water meeting the user's outlet temperature requirements is provided, thus guaranteeing the user's experience. The one-way valve 91 can be a form of a switching device 92, which can specifically be a solenoid valve with a switching function. During the heat storage stage, when the switching device 92 is a solenoid valve, it can be in the open state (first state, making the circulation pipe connected). During the water usage stage, it can be in the closed state (second state, the circulation pipe is disconnected), thereby disconnecting the first circulation pipe 41.

[0203] like Figure 7 As shown, when the second outlet 422 of the second circulation pipe 42 is located at the upper part of the water tank 2, a switch device 92 can be installed in the second circulation pipe 42. During the heat storage stage, the switch device 92 can be in the open state; during the water usage stage, the switch device 92 can be in the closed state, thereby disconnecting the second circulation pipe 42. During the water usage stage, disconnecting the second circulation pipe 42 using the switch device 92 prevents water supplied from an external water source from flowing into the upper part of the water tank 2 through the second outlet 422, thus ensuring the stability of the water temperature at the upper part of the water tank 2 and ensuring that hot water meeting the user's temperature requirements is provided, thus guaranteeing the user's experience.

[0204] like Figures 8 to 10 As shown, in one embodiment, a switch device 92 can be provided in the first circulation pipe 41 and the second circulation pipe 42, the second water outlet 422 is located at the lower part of the water tank 2, and the first water inlet 411 of the first circulation pipe 41 is located at the upper part of the water tank 2.

[0205] like Figure 8 As shown, during the heat storage stage, the switching device 92 in the first circulation pipe 41 and the second circulation pipe 42 can be in a closed state. During the water use stage, the water circuit connection of the electric water heater can vary depending on the water temperature changes in the water tank 2 and the different water temperatures supplied to the water tank 2.

[0206] For example, in the initial stage of use, when the water temperature in water tank 2 is relatively high, such as Figure 9As shown, the switch device 92 in the first circulation pipeline 41 is in the open state, and the switch device 92 in the second circulation pipeline 42 is in the closed state. The water supplied from the external water source passes through the water supply pipeline 81, the second heat exchanger 7, and the first heat exchanger 5, and then enters the lower part of the water tank 2 through the second circulation pipeline 42. This allows the water that has exchanged heat with the phase change material in the phase change tank 1 to be sent to the lower part of the water tank 2, preventing the water with a temperature lower than the current water temperature of the water tank 2 from disturbing the water temperature of the water tank 2, ensuring the stability of the outlet water temperature, and at the same time, ensuring that the water with a higher temperature in the water tank 2 is efficiently output.

[0207] In the later stages of water use, when the water temperature in water tank 2 has dropped significantly, and the heating rod 3 located in the middle or above is activated for supplemental heating, the water temperature below the heating rod 3 may already be lower than the water temperature after heat exchange with the phase change material in phase change tank 1. To utilize the heating rod 3 to concentrate the incoming water with a temperature above the predetermined temperature and capable of reaching the required outlet temperature after supplemental heating, and to prevent this portion of incoming water with a certain amount of heat from entering the lower, colder space where the heat is dispersed and fails to contribute to increasing the hot water volume, the location of the incoming water can be switched.

[0208] like Figure 10 As shown, at this time, the switch device 92 in the first circulation pipe 41 is in the closed state, and the switch device 92 in the second circulation pipe 42 is in the open state. The water supplied by the external water source passes through the water supply pipe 81, the second heat exchanger 7, and the first heat exchanger 5, and then enters the upper part of the water tank 2 through the first circulation pipe 41. The water that has exchanged heat with the phase change material in the phase change tank 1 is sent to the upper part of the water tank 2, realizing high-level water intake of the water tank 2. The heating rod 3 in the middle or upper part of the water tank 2 is used to centrally heat this part of water that has been preheated to a predetermined temperature, so that this part of water can reach the outlet water temperature set by the user after being heated, thereby maximizing the water output of the electric water heater.

[0209] For the phase change tank 1, the phase change material inside has a certain service life and will fail after reaching a predetermined number of phase changes. In order to extend the service life of the electric water heater, the phase change tank can be activated according to different water usage volumes. For example, when using a large volume of water, the heat stored in the phase change material of the tank can be activated, while when using a small volume of water, only the water tank 2 equipped with the heating rod 3 can be used.

[0210] To meet the different water consumption needs of users, such as Figure 11 As shown, a water inlet pipe 83 can be installed in the water tank 2.

[0211] For example, when a user needs a large amount of water, in the initial stage of water use, such as Figure 9As shown, water supplied from an external water source passes through water supply pipe 81, second heat exchanger 7, and first heat exchanger 5, and then enters the lower part of water tank 2 through the first circulation pipe 41. This allows water that has exchanged heat with the phase change material in phase change tank 1 to be sent to the lower part of water tank 2, preventing water with a temperature lower than the current water temperature of water tank 2 from disturbing the water temperature of water tank 2, ensuring the stability of the outlet water temperature, and at the same time ensuring that the higher temperature water in water tank 2 is efficiently output.

[0212] In the later stages of water use, such as Figure 10 As shown, at this time, the switch device 92 in the first circulation pipe 41 is in the closed state, and the switch device 92 in the second circulation pipe 42 is in the open state. The water supplied by the external water source passes through the water supply pipe 81, the second heat exchanger 7, and the first heat exchanger 5, and then enters the upper part of the water tank 2 through the first circulation pipe 41. The water that has exchanged heat with the phase change material in the phase change tank 1 is sent to the upper part of the water tank 2, realizing high-level water intake of the water tank 2. The heating rod 3 in the middle or upper part of the water tank 2 is used to centrally heat this part of water that has been preheated to a predetermined temperature, so that this part of water can reach the outlet water temperature set by the user after being heated, thereby maximizing the water output of the electric water heater.

[0213] When users only need a small amount of water, such as Figure 11 As shown, water can be supplied not from the water supply pipe 81, but from the water inlet pipe 83 installed in the water tank 2. For example, in scenarios where users need to wash their hands or use a small amount of water during periods of low water usage (such as non-bathing periods), the heat in the phase change material in the phase change tank 1 can be left unused. When the heat in the water tank 2 is insufficient after multiple uses, the heating rod 3 in the water tank 2 can be used to meet the needs of a small amount of water usage.

[0214] By activating the water supply pipe 81, which is directly connected to the phase change tank 1, or the water inlet pipe 83, which is directly connected to the water tank 2, to supply water according to the different water consumption needs of users, it is beneficial to reduce the phase change frequency of the phase change material in the phase change tank 1, extend its service life, and reduce the user's operating costs while ensuring the user's user experience.

[0215] In one embodiment, an insulation layer 93 is provided outside the circulation pipeline.

[0216] In this embodiment, an insulation layer 93 is provided outside the circulation pipeline for heat preservation and isolation. The first circulation pipeline 41 carries heated water from the water tank 2. The insulation layer 93 helps maintain a higher temperature in the hot water before it is introduced into the first heat exchanger 5 of the phase change tank 1, facilitating efficient heat exchange between the higher-temperature water and the phase change material in the phase change tank 1, thereby improving heat exchange efficiency and shortening the heat storage time.

[0217] The electric water heater also includes a casing, inside which the phase change tank 1 and the water tank 2 are installed. When the heating rod 3 is activated, the water temperature in the water tank 2 and the casing temperature rise, and the air temperature in the gap between the casing and the phase change tank 1 and the water tank 2 is also increased accordingly.

[0218] For the second circulation pipe 42, by setting the insulation layer 93, on the one hand, when the water temperature flowing out from the first heat exchanger 5 is low in the early stage of heat storage, it can prevent the low-temperature second circulation pipe 42 from directly contacting the high-temperature air and generating condensate outside the second circulation pipe 42; on the other hand, when the water temperature flowing out from the first heat exchanger 5 is high in the later stage of heat storage, it can keep the water in the second circulation pipe 42 warm, reduce the heating time required by the heating rod 3, and save energy.

[0219] Please refer to the following: Figures 12 to 17 This application specification provides an electric water heater, which may include: a water tank 2 and a phase change tank 1. The phase change tank 1 has a phase change material for heat storage and release. The phase change tank 1 also includes a second heat exchanger 7 for communication with the water tank 2. The electric water heater further includes a water supply pipe 81 and a circulation pipe. The circulation pipe is used to connect the water tank 2 and the second heat exchanger 7. One side of the water supply pipe 81 can be connected to a water source, and the other side of the water supply pipe 81 can be connected to the second heat exchanger 7 and / or the circulation pipe and / or the water tank 2. A switching device 92 is provided on the circulation pipe, and the switching device 92 has a first state and a second state. In the first state, the circulation pipeline is open, and the water in the water tank 2 can circulate between the water tank 2 and the second heat exchanger 7; or, the water in the water tank 2 cannot circulate between the water tank 2 and the second heat exchanger 7, and the water in the water supply pipeline 81 can only flow into the water tank 2. In the second state, the water in the water tank 2 cannot circulate between the water tank 2 and the second heat exchanger 7, and the water in the water supply pipeline 81 can flow into the second heat exchanger 7 and the water tank 2 in sequence; or, the water in the water supply pipeline 81 can flow into the water tank 2 and the second heat exchanger 7 in sequence.

[0220] In this embodiment, the electric water heater may include a phase change tank 1, a water tank 2, a water supply pipe 81, and a circulation pipe, etc.

[0221] The phase change chamber 1 contains a phase change material for heat storage and release. The phase change material's physical state can change, thereby switching between its heat storage and heat release states. The specific material of the phase change material can be inorganic water and salt with added nucleating agents, or it can be in other forms; this application does not impose specific limitations here. In the embodiments of this application, taking a phase change material capable of switching between solid and liquid states as an example, when the phase change material changes from solid to liquid, it is in a heat storage state, absorbing and storing external heat; when the phase change material changes from liquid to solid, it is in a heat release state, releasing the stored heat to the outside.

[0222] The phase change material tank 1 is internally equipped with a second heat exchanger 7. Cold water flowing through the second heat exchanger 7 can absorb heat from the phase change material, achieving preheating; hot water flowing through the second heat exchanger 7 can release heat to the phase change material, achieving heat storage of the phase change material. Specifically, the second heat exchanger 7 can be in the form of a heat exchange tube, which can extend entirely in the height direction Y and reciprocate in the left-right direction. Alternatively, the second heat exchanger 7 can also take other forms; in the embodiments and accompanying drawings of this application, the second heat exchanger 7 is mainly illustrated using the form of a heat exchange tube.

[0223] The water tank 2 has a water storage cavity inside. Generally, the volume of the water tank 2 is at least 10 liters. When the volume of the water tank 2 is 10 liters or more, it can reliably provide the heat required for heat storage to the phase change material in the phase change tank 1, ensuring that the phase change material can store heat efficiently. In addition, when the volume of the water tank 2 is large, water can be supplied to the water terminal at a relatively stable water temperature using the water tank 2. Of course, the use of a small-capacity water tank is not excluded in this application. In some special cases (such as scenarios with limited installation space), the volume of the water tank 2 may be less than 10L.

[0224] In some embodiments, the water tank 2 and the phase change tank 1 can be arranged vertically. For example, the water tank 2 can be located above or below the phase change tank 1. The phase change tank 1 and the water tank 2 can be installed horizontally, with their axes extending along the horizontal direction (lateral X). In this case, the axes of the phase change tank 1 and the water tank 2 can be arranged vertically. Of course, in the embodiments of this application, vertical installation of the water tank 2 and the phase change tank 1 is also possible. If the water tank 2 and the phase change tank 1 are installed vertically, their axes extend along the vertical direction (Y). In this case, the axes of the phase change tank 1 and the water tank 2 are arranged horizontally.

[0225] The electric water heater also includes a heating element, which can be used to heat the water in the water tank 2. The heating element can be an electric heating element, such as a heating rod 3. Of course, the heating element can also take other forms; in this embodiment, the heating rod 3 is mainly used as an example. The heating rod can be installed inside the water tank 2, or it can be located outside the water tank 2, such as on the outer surface of the water tank 2, or it can be installed in the circulation pipe, etc. In the embodiments and accompanying drawings of this application, the heating element is mainly illustrated as a heating rod 3 installed in the water tank 2. When the heating element is installed in the water tank 2, it can not only heat the water in the water tank 2, but also heat the water in the circulation pipe, providing heat to the water in the circulation pipe for use in the phase change material.

[0226] The phase change tank 1 may or may not have a heating element. In the case where the phase change material in the phase change tank 1 does not have a heating element, it can absorb heat from the water heated by the heating rod 3 in the water tank 2 when heat storage is required. In this embodiment, the example is provided where the water tank 2 has a heating element and the phase change tank 1 does not.

[0227] The electric water heater also includes a circulation pipe, one function of which is to connect the water tank 2 and the second heat exchanger 7. When the second heat exchanger 7 needs to exchange heat with the phase change material using the heated water in the water tank 2, i.e., when heat storage of the phase change material is required, the electric water heater can enter the heat storage mode. During the heat storage stage, the heated hot water in the water tank 2 can be flowed into the second heat exchanger 7 through the circulation pipe. As the hot water flows through the second heat exchanger 7, it releases heat to the phase change material in contact with the second heat exchanger 7, thus achieving heat storage of the phase change material.

[0228] The electric water heater may also include a water supply pipe 81, one side of which can be connected to a water source, and the other side of which can be connected to any one of the second heat exchanger 7, the circulation pipe, and the water tank 2. The electric water heater has a water usage mode. When the water usage mode is activated, during the water usage phase, water supplied from an external water source can be supplied to the second heat exchanger 7 through the water supply pipe 81. As the supplied water flows through the second heat exchanger 7, it absorbs heat from the phase change material in contact with the second heat exchanger 7, thereby raising the water temperature and achieving the effect of preheating the incoming water. The preheated water then flows into the water tank 2.

[0229] A switching device 92 is installed on the circulation pipeline, which is mainly used to control the on / off state of the circulation pipeline. Specifically, the state of the switching device 92 can include a first state and a second state. When the switching device 92 is in the first state, it indicates that the water flow in the circulation pipeline where the switching device 92 is located is in a flowable state. At this time, the circulation pipeline is conductive, and the water in the water tank 2 can circulate between the water tank 2 and the second heat exchanger 7. For example, in the heat storage stage, when the water in the water tank 2 is heated to hot water, some of the hot water can flow to the second heat exchanger 7 through the circulation pipeline, and the water in the second heat exchanger 7 can then return to the water tank 2 through the circulation pipeline, thus achieving circulation.

[0230] Alternatively, in another scenario, the water in the water tank 2 cannot circulate between the water tank 2 and the second heat exchanger 7, and the water in the water supply pipe 81 can flow directly into the water tank 2. For example, during the water usage phase, this part of the circulation pipe can be used as a connecting pipe between the water supply pipe 81 and the water tank 2. Water supplied from an external water source can flow into the water tank 2 through the water supply pipe 81 and part of the circulation pipe. In this case, the phase change tank 1 can be short-circuited using this part of the circulation pipe, so that the water flowing into the water supply pipe 81 is only supplied into the water tank 2.

[0231] When the switching device 92 is in the second state, a complete water flow circulation cannot be formed between the circulation pipeline, the water tank 2, and the second heat exchanger 7. The water in the water tank 2 cannot circulate between the water tank 2 and the second heat exchanger 7. For example, during the water usage phase, the water in the water supply pipeline 81 can flow sequentially into the second heat exchanger 7 and the water tank 2, or the water in the water supply pipeline 81 can flow sequentially into the water tank 2 and the second heat exchanger 7. This water can then be supplied to the water-using terminal through the outlet pipe 82.

[0232] During the aforementioned water usage phase, when the other side of the water supply pipe 81 is connected to the circulation pipe, this portion of the circulation pipe can also be used as a connecting pipe between the water supply pipe 81 and the water tank 2 or the second heat exchanger 7. In specific use, water in the water supply pipe 81 flows sequentially through a portion of the circulation pipe, the second heat exchanger 7, and the water tank 2, and then flows out through the outlet pipe 82; alternatively, water in the water supply pipe 81 flows sequentially through a portion of the circulation pipe, the water tank 2, and the second heat exchanger 7, and then flows out through the outlet pipe 82. The supplied water flow can follow a predetermined path, preventing short circuits in the circulation pipe and thus avoiding cross-contamination and other problems.

[0233] In this embodiment, the specific form of the switching device 92 can include various types. For example, it can include a switching valve that controls the on / off state of the circulation pipeline it is in, a one-way valve that controls the unidirectional flow of the circulation pipeline it is in, a switching valve that is installed between the circulation pipeline and the water supply pipeline 81, or other forms that can realize water flow control. By setting the switching device 92 on the circulation pipeline, the connection relationship of the water path can be switched, ensuring that the water in the circulation pipeline circulates and stores heat during the heat storage stage, achieving efficient heat storage. During the water use stage, the water supplied by the external water source can flow through the second heat exchanger 7, part of the circulation pipeline, and the water tank 2 before being output to the outside, preventing the circulation pipeline from interfering with the water supplied by the external water source during the water use stage, such as short-circuiting the water supplied by the external water source.

[0234] In this embodiment, a heating rod 3 is installed in the water tank 2. When the heating rod 3 is activated, the hot water heated by the heating rod 3 in the water tank 2 is sent to the second heat exchanger 7 of the phase change tank 1 through a circulation pipe. At the same time, the cold water in the second heat exchanger 7 returns to the water tank 2 through the circulation pipe. Thus, the water flows in a circulation between the second heat exchanger 7 of the phase change tank 1 and the water tank 2. During the above circulation process, the heat generated by the energized heating rod 3 in the water tank 2 can not only raise the water temperature in the water tank 2, but also raise the water temperature in the second heat exchanger 7. The heat of the water in the second heat exchanger 7 can be transferred through the shell of the second heat exchanger 7 to the phase change material in contact with it, so that the phase change material in the phase change tank 1 absorbs heat and stores energy.

[0235] The method of directly feeding the heated water from the water tank 2 into the second heat exchanger 7 to store heat in the phase change material has significant advantages over existing implementation methods:

[0236] For example, compared to directly setting the heating element in the phase change tank 1, it can improve heat exchange efficiency and avoid premature failure of materials near the heating rod 3.

[0237] For heat exchangers, the types include: single water box type, single heat exchange tube type, and combination type of water box and heat exchange tube.

[0238] For the second heat exchanger 7 being a separate heat exchange tube, compared to setting a heating element in a heat exchanger (e.g., a water box) inside the phase change tank 1, since the volume of the water second heat exchanger 7 box is limited, usually within 3L, during the heat storage stage, when the heating element with a large heating power heats the limited volume of water, it is in a state of frequent start-stop. The duration of each start-up of the heating element is limited, so the heat generated by a single heating is small, resulting in an increased heat storage time and poor heat exchange efficiency.

[0239] For example, compared to electric water heaters that have a water box in the phase change tank 1 connected to the water tank 2 via a circulation pipe, this application directly eliminates the water box structure, effectively reducing manufacturing costs and complexity. The number of water boxes is easily limited by installation space and cost, making it impossible to distribute them evenly within the phase change material. In this application, the second heat exchanger 7 directly exchanges heat with the phase change material. Since the second heat exchanger 7 can be evenly distributed within the phase change material of the phase change tank 1, it further improves the heat exchange efficiency and heating uniformity between the two materials. Furthermore, compared to the method of setting a water box in the phase change tank 1, the inner surface of the water box is prone to scaling during use, thus affecting the heat exchange effect. In this application, the second heat exchanger 7 is directly used as a carrier for circulating hot water to store heat in the phase change material. Because the hot water has a certain flow velocity when flowing in the second heat exchanger 7, it can effectively flush the pipe wall, thus effectively reducing the rate of scaling on the pipe wall of the second heat exchanger 7, thereby ensuring a better heat exchange effect.

[0240] Furthermore, by installing a switch device 92 in the circulation pipeline, and combining the different working states of the switch device 92, water circuits with different flow paths can be formed inside the electric water heater, thereby meeting the connection requirements of different water circuits during the heat storage stage and the water use stage. For example, during the heat storage stage, the phase change material in the phase change tank 1 can be stored by establishing a connected circulation pipeline; during the water use stage, part of the circulation pipeline can be shielded as needed to prevent cross-contamination and realize the second heat exchanger 7 and the water tank 2 in series for water supply; or, according to the user's needs, part of the circulation pipeline can be connected to realize the function of water tank 2 supplying water independently.

[0241] In summary, in this embodiment, a circulation pipe equipped with a switching device 92 connects the water tank 2 to the second heat exchanger 7. During the heat storage phase, the switching device 92 is in a first state, the circulation pipe is open, and the heated water in the water tank 2 flows into the second heat exchanger 7 through the circulation pipe, and then returns to the water tank 2, thus achieving circulation. During the above circulation process, the second heat exchanger 7, which carries the hot water from the water tank 2, exchanges heat with the phase change material in the phase change tank 1, which can improve the heat exchange efficiency between the second heat exchanger 7 and the phase change material and the uniformity of heating the phase change material; it can improve the heat exchange efficiency during the heat storage phase, shorten the heat storage time, shorten the user's waiting time, and improve the user experience.

[0242] During the water usage phase, the switch device 92 can be in the second state, where water in the water tank 2 cannot circulate between the water tank 2 and the second heat exchanger 7. Water in the water supply pipe 81 can flow between the second heat exchanger 7 and the water tank 2 in series (either flowing into the second heat exchanger 7 and the water tank 2 in sequence, or flowing into the water tank 2 and the second heat exchanger 7 in sequence). Overall, by simply switching the state of the switch device 92, a rapid switch between the electric water heater's own heat storage and the user's water usage can be achieved. The water circuit design is ingenious, and the pipe structure is simple. In addition, since all water supplied from the external water source flows through the water tank 2, the water temperature of the incoming water can be evenly increased, thereby ensuring a relatively stable outlet water temperature and thus providing a stable and comfortable water supply to the user. Especially when the water flows through the second heat exchanger 7 first and then through the water tank 2, the second heat exchanger 7 can be used to preheat the incoming water before it flows into the water tank 2. After mixing with the water in the water tank 2, the water is heated and output, which maximizes the utilization of the heat in the electric water heater and effectively increases the amount of hot water.

[0243] Regarding the connection of the other side of the water supply pipe 81 to the circulation pipe, a clever design has been implemented for the circulation pipe equipped with the switching device 92. This design allows for multi-functional reuse at different stages. For example, during the heat storage stage, this circulation pipe serves as a connecting pipe between the water tank 2 and the second heat exchanger 7. During the water usage stage, this part of the circulation pipe can cooperate with the water supply pipe 81 to supply water to either the water tank 2 or the second heat exchanger 7. When supplying water, switching the switching device 92 to the second state can prevent cross-flow of water from short-circuiting the second heat exchanger 7, thus meeting the demand for large water volumes. Furthermore, during water supply, the switching device 92 can be switched to the first state to short-circuit the second heat exchanger 7, thereby supplying water only to the water tank 2 to meet the demand for small water volumes. Through the above-mentioned clever design of the water circuit, while achieving the functions of different stages, it can also effectively reduce manufacturing costs, shrink the size, and meet the different water volume needs of users.

[0244] As shown in 12, in some embodiments, the switching device 92 can be in the form of a switching valve. For example, the switching device 92 can specifically be in the form of a solenoid valve with switching function.

[0245] During the heat storage phase, the switching device 92 can be in the first state, enabling the circulation pipeline to be open. For example... Figure 3 As shown, the water heated in the upper part of the water tank 2 can flow into the second heat exchanger 7 through the first circulation pipe 41, and after flowing from top to bottom through the second heat exchanger 7, it returns to the lower part of the water tank 2 through the second circulation pipe 42, thereby achieving efficient heat storage of the phase change material in the phase change tank 1.

[0246] During the water usage phase, when the switching device 92 is in the second state, the water in the water tank 2 cannot circulate between the water tank 2 and the second heat exchanger 7, thereby placing the circulation pipeline in a non-conductive state.

[0247] In this embodiment, during the heat storage stage, a circulation pipeline is used to introduce the heated water in the water tank 2 into the second heat exchanger 7 of the phase change tank 1, thereby achieving water circulation between the water tank 2 and the second heat exchanger 7 and storing heat for the phase change material in the phase change tank 1. During the water use stage, the circulation pipeline is used to allow the water in the second heat exchanger 7 of the phase change tank 1, after heat exchange with the phase change material, to flow into the water tank 2. During the operation of the electric water heater, the circulation pipeline is reused for multiple functions, which can effectively reduce the number and length of pipelines, reduce the risk of leakage, and also reduce manufacturing and maintenance costs.

[0248] like Figure 14 As shown, when the switch device 92 is installed in the first circulation pipeline 41, the other side of the water supply pipeline 81 can be connected to the second heat exchanger 7 and / or the first circulation pipeline 41, and the water supplied by the water source can enter the water tank 2 through the water supply pipeline 81, the second heat exchanger 7, and the second circulation pipeline 42.

[0249] Taking the other side of the water supply pipeline 81 as connected to the first circulation pipeline 41 as an example, the water supplied by the water source can enter the water tank 2 after passing through the water supply pipeline 81, part of the first circulation pipeline 41, the second heat exchanger 7, and the second circulation pipeline 42.

[0250] During this water usage phase, the first circulation pipe 41 and all of the second circulation pipe 42 are reused. Furthermore, since the supplied water first passes through the second heat exchanger 7 before entering the water tank 2, the phase change material in the phase change tank 1 can exchange heat with the cold water flowing through the second heat exchanger 7, thereby preheating the cold water supplied from the external water source. This increases the total hot water supply of the electric water heater, meeting the user's demand for large water usage.

[0251] Furthermore, the electric water heater may also include a water outlet pipe 82, one end of which is connected to the circulation pipe, and / or the water outlet pipe 82 passes through the water tank 2.

[0252] In this embodiment, one end of the water outlet pipe 82 can be connected to the circulation pipeline, for example, as... Figure 13As shown, one end of the water outlet pipe 82 can be connected to the first circulation pipe 41. When one end of the water outlet pipe 82 is connected to the first circulation pipe 41, it is located upstream of the switching device 92. Specifically, one end of the water outlet pipe 82 can be connected to the first circulation pipe 41 via a second connecting part 72. This second connecting part 72 can be a T-junction, but its form is not limited to the example described above. The second connecting part 72 can be located upstream of the switching device 92 along the direction of circulating water flow. Furthermore, when the second connecting part 72 is integrated with the switching device 92, one end of the water outlet pipe 82 can be connected to the circulation pipe via the switching device 92.

[0253] During the water usage phase, the water supplied by the water source can enter the water tank 2 after passing through the water supply pipeline 81, part of the first circulation pipeline 41, the second heat exchanger 7, and the second circulation pipeline 42, and then be supplied to the water terminal through part of the first circulation pipeline 41 and the water outlet pipe 82.

[0254] Since the first inlet end 411 of the first circulation pipe 41 is located at the upper part of the water tank 2, this part of the first circulation pipe 41 functions as the outlet pipe 82, allowing hot water at a higher temperature at the upper part of the water tank 2 to be discharged from the water tank 2. In addition, during this water usage phase, the portion of the first circulation pipe 41 upstream of the second connection 72 (used as the inlet pipe of the water supply pipe 81) and the portion of the first circulation pipe 41 downstream of the first connection 71 (used as the outlet pipe of the outlet pipe 82) are fully reused, further improving the utilization rate of the circulation pipe.

[0255] In this embodiment, the water outlet pipe 82, which is connected to the circulation pipeline at one end, is located entirely outside the water tank 2. This arrangement eliminates the need to create a separate opening in the water tank 2 for installing the water outlet pipe 82, thereby improving the reliability of the water tank 2 during use, reducing the risk of leakage, and lowering manufacturing costs.

[0256] In other embodiments, it is also possible that the water tank 2 is equipped with a water outlet pipe 82. For example, when upgrading an existing water tank 2, the existing water outlet pipe 82 can be retained. Alternatively, in some high-water-volume scenarios, the water outlet pipe 82 can also be used to dispense water simultaneously.

[0257] like Figure 15As shown, the switch device 92 can be installed in the second circulation pipeline 42, and the other side of the water supply pipeline 81 can be connected to the second circulation pipeline 42 and / or the water tank 2. The water supplied by the water source can enter the second heat exchanger 7 through the water supply pipeline 81, the water tank 2, and the first circulation pipeline 41.

[0258] like Figure 16 As shown, taking the other end of the water supply pipeline 81 as being connected to the second circulation pipeline 42 as an example, the water supplied by the water source can pass through the water supply pipeline 81, part of the second circulation pipeline 42, the water tank 2, and the first circulation pipeline 41, and enter the second heat exchanger 7.

[0259] When the switch device 92 is installed on the second circulation pipe 42, one end of the outlet pipe 82 is connected to the second circulation pipe 42 located upstream of the switch device 92, or one end of the outlet pipe 82 is connected to the second circulation pipe 42 through the switch device 92. The outlet pipe 82 is located outside the water tank 2.

[0260] Specifically, the water supply pipe 81 connects to the second circulation pipe 42 at the first connection point 71, and the other end of the outlet pipe 82 connects to the second circulation pipe 42 at the second connection point 72. The first connection point 71 can be located downstream of the second connection point 72. The first connection point 71 and the second connection point 72 can be in the form of a tee structure, or integrated with the switch device 92; however, this application does not impose any specific limitations. When the second connection point 72 is integrated with the switch device 92, one end of the outlet pipe 82 can be connected to the circulation pipe through the switch device 92.

[0261] When the electric water heater enters the water use mode, that is, when it is in use, the water supplied by the external water source enters the water tank 2 through the water supply pipe 81 and part of the second circulation pipe 42, and then enters the second heat exchanger 7 through the first circulation pipe 41. The water flowing out of the second heat exchanger 7 flows out through part of the second circulation pipe 42 and then flows out from the outlet pipe 82 to supply the water terminal.

[0262] During this water usage phase, the portion of the second circulation pipeline 42 downstream of the first connection 71 (used as the inlet pipeline of the water supply pipeline 81) and the portion of the pipeline upstream of the second connection 72 (used as the outlet pipeline of the water outlet 82) are fully reused, further improving the utilization rate of the circulation pipeline.

[0263] In this embodiment, the water outlet pipe 82, which is connected to the circulation pipeline at one end, is located entirely outside the water tank 2. This arrangement eliminates the need to create a separate opening in the water tank 2 for installing the water outlet pipe 82, thereby improving the reliability of the water tank 2 during use, reducing the risk of leakage, and lowering manufacturing costs.

[0264] like Figure 17 As shown, in the third type of embodiment, the switching device 92 can be a multi-way valve, for example, a switching valve.

[0265] The switching device 92 has at least a first port 921, a second port 922, and a third port 923. The first port 921 is used to connect to the other side of the water supply pipe 81. The second port 922 and the third port 923 are connected to the first circulation pipe 41 or the second circulation pipe 42. The second port 922 is located downstream of the third port 923. When the switching device 92 is in the first state, the second port 922 and the third port 923 are connected. When the switching device 92 is in the second state, the first port 921 and the second port 922 are connected.

[0266] In this embodiment, the switch device 92 can be located at the position where the water supply pipe 81 is connected to the circulation pipe. Specifically, the switch device 92 can include multiple ports, wherein the first port 921 can be used as a water inlet port, and the second port 922 and the third port 923 can be connected in the circulation pipe.

[0267] by Figure 17 Taking the switching device 92 installed in the first circulation pipe 41 as an example, during the heat storage stage, when the switching device 92 is in the first state, the second port 922 and the third port 923 are connected, and the heated water in the water tank 2 returns to the water tank 2 through the first circulation pipe 41, the second heat exchanger 7, and the second circulation pipe 42. During the water use stage, when the switching device 92 is in the second state, the first port 921 and the second port 922 are connected, and water supplied from an external water source enters the water tank 2 through the water supply pipe 81, part of the first circulation pipe 41, the second heat exchanger 7, and the second circulation pipe 42. Subsequently, the water in the water tank 2 can flow out of the water tank 2 through part of the first circulation pipe 41 and the outlet pipe 82.

[0268] During the water usage phase, the externally supplied water flows sequentially through the second heat exchanger 7 and the water tank 2. The two are connected in series, which can provide the user with the maximum hot water supply, thereby meeting the user's demand for large water consumption.

[0269] Please refer to the following: Figures 18 to 25This application specification provides an electric water heater, which may include: a water tank 2 and a phase change tank 1. The phase change tank 1 has a phase change material for heat storage and release. The phase change tank 1 also includes a second heat exchanger 7 connected to the water tank 2, and the second heat exchanger 7 and the water tank 2 are connected in parallel. The electric water heater also includes a water supply pipe 81 and a circulation pipe. The circulation pipe is used to connect the water tank 2 and the second heat exchanger 7. One side of the water supply pipe 81 can be connected to a water source, and the other side of the water supply pipe 81 can be connected to the second heat exchanger 7 and / or the circulation pipe and / or the water tank 2. Tank 2 is connected; a switch device 92 is provided on the circulation pipeline, the switch device 92 has a first state and a second state. When the switch device 92 is in the first state, the circulation pipeline is open, and the water in the water tank 2 can circulate between the water tank 2 and the second heat exchanger 7. When the switch device 92 is in the second state, the water in the water tank 2 cannot circulate between the water tank 2 and the second heat exchanger 7, and the water in the water supply pipeline 81 can flow into the second heat exchanger 7 and the water tank 2, or flow into the second heat exchanger 7, or flow into the water tank 2.

[0270] In this embodiment, the parallel connection of the second heat exchanger 7 and the water tank 2 mainly refers to the existence of a parallel pipeline structure in the water circuit connection. Using this parallel pipeline structure, the second heat exchanger 7 and the water tank 2 can be connected to the water supply pipeline 81 respectively to input water supplied from an external water source and to output water respectively.

[0271] This electric water heater has a water usage mode. When the water usage mode is activated, during the water usage phase, water supplied from an external water source can be supplied to the second heat exchanger 7 and / or the water tank 2 through the water supply pipe 81. For example, as the water flows through the second heat exchanger 7, it can absorb heat from the phase change material in contact with the second heat exchanger 7, thereby raising the water temperature and achieving the effect of heating the incoming water; or, the water supplied to the water tank 2 can be heated by the heating rod 3 in the water tank 2, thereby outputting water at the user's set temperature to the water terminal; or, it can be supplied to both the second heat exchanger 7 and the water tank 2 simultaneously, and both simultaneously output water at the user's set temperature to the user terminal.

[0272] A switching device 92 is installed on the circulation pipeline, which is mainly used to control the on / off state of the circulation pipeline. Specifically, the state of the switching device 92 can include a first state and a second state. When the switching device 92 is in the first state, it indicates that the water flow in the circulation pipeline where the switching device 92 is located is in a flowable state. At this time, the circulation pipeline is conductive, and the water in the water tank 2 can circulate between the water tank 2 and the second heat exchanger 7. For example, in the heat storage stage, when the water in the water tank 2 is heated to hot water, some of the hot water can flow to the second heat exchanger 7 through the circulation pipeline, and the water in the second heat exchanger 7 can then return to the water tank 2 through the circulation pipeline, thus achieving circulation.

[0273] When the switching device 92 is in the second state, a complete water flow circulation cannot be formed between the circulation pipeline, the water tank 2, and the second heat exchanger 7. Water in the water tank 2 cannot circulate between the water tank 2 and the second heat exchanger 7. For example, during the water usage phase, water in the water supply pipeline 81 can flow into the second heat exchanger 7 and / or the water tank 2, and this water can subsequently be supplied to the water-using terminal through the outlet pipe 82.

[0274] During the aforementioned water usage phase, when the other side of the water supply pipe 81 is connected to the circulation pipe, this portion of the circulation pipe can also be used as a connecting pipe between the water supply pipe 81 and the water tank 2 or the second heat exchanger 7. In specific use, the water in the water supply pipe 81 can flow out through the outlet pipe 82 after passing through a portion of the circulation pipe, the second heat exchanger 7, and / or the water tank 2. When it is necessary to supply water using the phase change tank 1 or the water tank 2 separately, the supplied water can flow along a predetermined path to prevent short circuits in the circulation pipe and problems such as cross-contamination.

[0275] In this embodiment, the specific form of the switching device 92 can include various types. For example, it can include a switching valve that controls the on / off state of the circulation pipeline it is located in, a switching valve set between the circulation pipeline and the water supply pipeline 81, or other forms that can realize water circuit on / off control. By setting the switching device 92 on the circulation pipeline to switch the connection relationship of the water circuit, it is possible to ensure that the water in the circulation pipeline circulates during the heat storage stage, achieving efficient heat storage. During the water use stage, the water supplied by the external water source can switch to work in the corresponding part of the circulation pipeline according to different water use needs, supplying water to any one or a combination of the phase change tank 1 and the water tank 2, thereby better meeting different water use needs and improving the performance of the electric water heater.

[0276] The method of directly feeding the heated water from the water tank 2 into the second heat exchanger 7 to store heat in the phase change material has significant advantages over existing implementation methods:

[0277] For example, compared to directly setting the heating element in the phase change tank 1, it can improve heat exchange efficiency and avoid premature failure of materials near the heating rod 3.

[0278] The second heat exchanger 7 includes: a separate water box, a separate heat exchange tube, and a combination of a water box and a heat exchange tube.

[0279] For the second heat exchanger 7, which is a separate heat exchange tube, compared to setting a heating element in a heat exchanger (e.g., a water box) inside the phase change tank 1, since the volume of the water box is limited, usually less than 3L, during the heat storage stage, the heating element with a large heating power is in a state of frequent start-stop when heating the limited volume of water. The duration of each start-up of the heating element is limited, so the heat generated by a single heating is small, which leads to an increase in the heat storage time and poor heat exchange efficiency.

[0280] For example, compared to electric water heaters that have a water box in the phase change tank 1 connected to the water tank 2 via a circulation pipe, this application directly eliminates the water box structure, effectively reducing manufacturing costs and complexity. The number of water boxes is easily limited by installation space and cost, making it impossible to distribute them evenly within the phase change material. In this application, the second heat exchanger 7 directly exchanges heat with the phase change material. Since the second heat exchanger 7 can be evenly distributed within the phase change material of the phase change tank 1, it further improves the heat exchange efficiency and heating uniformity between the two materials. Furthermore, compared to the method of setting a water box in the phase change tank 1, the inner surface of the water box is prone to scaling during use, thus affecting the heat exchange effect. In this application, the second heat exchanger 7 is directly used as a carrier for circulating hot water to store heat in the phase change material. Because the hot water has a certain flow velocity when flowing in the second heat exchanger 7, it can effectively flush the pipe wall, thus effectively reducing the rate of scaling on the pipe wall of the second heat exchanger 7, thereby ensuring a better heat exchange effect.

[0281] Furthermore, by setting a switch device 92 in the circulation pipeline, and combining the different working states of the switch device 92, water circuits with different flow paths can be formed inside the electric water heater, thereby meeting the connection requirements of different water circuits during the heat storage stage and the water use stage. For example, during the heat storage stage, the phase change material in the phase change tank 1 can be stored by establishing a connected circulation pipeline; during the water use stage, the second heat exchanger 7 and / or the water tank 2 can be connected as needed to achieve separate water supply for the phase change tank 1 equipped with the second heat exchanger 7, or separate water supply for the water tank 2 equipped with the heating rod 3, or parallel water supply for the phase change tank 1 and the water tank 2, etc.

[0282] In summary, in this embodiment, a circulation pipeline equipped with a switching device 92 connects the water tank 2 to the second heat exchanger 7. During the heat storage phase, the switching device is in the first state, and the circulation pipeline is open. The heated water in the water tank 2 can flow into the second heat exchanger 7 through the circulation pipeline and then return to the water tank 2, thus achieving circulation. During the above circulation process, the second heat exchanger 7, which carries hot water from the water tank 2, exchanges heat with the phase change material in the phase change tank 1, which can improve the heat exchange efficiency between the second heat exchanger 7 and the phase change material and the uniformity of heating the phase change material; it can improve the heat exchange efficiency during the heat storage phase, shorten the heat storage time, shorten the user's waiting time, and improve the user experience. During the water usage phase, the switching device 92 is in the second state, and the water in the water tank 2 cannot circulate between the water tank 2 and the second heat exchanger 7. The water in the water supply pipeline 81 can flow into the second heat exchanger 7 and the water tank 2, or it can flow into the heat exchanger 8, or it can flow into the water tank 2.

[0283] Overall, by switching the state of the switch device 92, a rapid switch between the water heater's own heat storage and the user's water usage can be achieved. The water circuit design is ingenious, and the pipe structure is simple. Furthermore, during the water usage phase, depending on the user's actual needs, water tank 2 and the phase change tank equipped with the second heat exchanger 7 can be connected in parallel to output water, or water tank 2 can output water alone, or phase change tank 1 equipped with the second heat exchanger 7 can output water alone, which can meet the user's water usage needs in different scenarios.

[0284] Specifically, for the case where the other side of the water supply pipe 81 is connected to the circulation pipe, the circulation pipe is multifunctionally reused through the clever cooperation between the switch device 92 and the circulation pipe. During the heat storage stage, the circulation pipe is used to connect the water tank 2 and the second heat exchanger 7. Under different water usage conditions, the circulation pipe can cooperate with the water supply pipe 81 to supply water to the water tank 2 and / or the second heat exchanger 7. In some embodiments of this application, the phase change tank 1 can be located above the water tank 2. In this embodiment, when the phase change tank 1 is located above the water tank 2, no additional power source is required during the start-up process of the heating rod 3, which can better realize the natural circulation of water flow, simplify the system, reduce energy consumption, effectively control the overall cost, and avoid noise interference to users.

[0285] In order to allow the heated hot water in water tank 2 to flow into phase change tank 1 by natural convection, a circulation pipe can be installed between the second heat exchanger 7 of phase change tank 1 and water tank 2. The water supply pipe 81 can be connected to the circulation pipe.

[0286] Specifically, the circulation pipe may include: a first circulation pipe 41 and a second circulation pipe 42. The first circulation pipe 41 has a first water inlet 411 and a first water outlet 412. The first water inlet 411 is located in the water tank 2, and the first water outlet 412 is located in the phase change tank 1. The second circulation pipe 42 has a second water inlet 421 and a second water outlet 422. The second water inlet 421 is located in the phase change tank 1, and the second water outlet 422 is located in the water tank 2. The switching device 92 is disposed on the first circulation pipe 41 or the second circulation pipe 42.

[0287] The water tank 2 can be connected to the second heat exchanger 7 of the phase change tank 1 through the first circulation pipe 41 and the second circulation pipe 42. When the heating rod 3 is working, the hot water in the water tank 2 heated by the heating rod 3 expands due to heat. The less dense hot water flows upward and enters the second heat exchanger 7 through the first circulation pipe 41. The less dense water in the second heat exchanger 7 returns to the water tank 2 through the second circulation pipe 42. In this way, the water flow circulates between the second heat exchanger 7 of the phase change tank 1 and the water tank 2.

[0288] During the aforementioned circulation process, the heat generated by energizing the heating rod 3 can raise the water temperature in the water tank 2, and simultaneously raise the water temperature in the second heat exchanger 7. The heat from the water in the second heat exchanger 7 can be transferred through its shell to the phase change material in contact with it, allowing the phase change material to absorb heat and store energy. To ensure that, during the heat storage phase, without additional driving force, the hot water flowing from the water tank 2 into the second heat exchanger 7 in the phase change tank 1 can smoothly return to the water tank 2 from top to bottom along the circulation pipe, at least a portion of the second heat exchanger 7 is arranged from top to bottom along the water flow direction in the height direction Y of the phase change tank 1. If the water flowing from the water tank 2 into the phase change tank 1 flows entirely from bottom to top along the height direction Y, due to the combined effects of internal pipe resistance in the second heat exchanger 7, gravity, and a drop in water temperature, the hot water in the water tank 2 will stop flowing after traveling a certain distance upwards, making it difficult to return to the water tank 2 without external driving force.

[0289] In one embodiment, the first water inlet 411 is located at the upper part of the water tank 2, the first water outlet 412 is located at the upper part of the phase change tank 1, the second water inlet 421 is located at the lower part of the phase change tank 1, and the second water outlet 422 is located at the lower part of the water tank 2.

[0290] When the first inlet end 411 of the first circulation pipe 41 is located at the upper part of the water tank 2, the water that is preferentially heated at the upper part of the water tank 2 can enter the second heat exchanger 7 at a faster speed and with a shorter path, thereby storing heat in the phase change material. This allows the phase change material in the phase change tank 1 to complete the heat storage process as soon as possible and shortens the heat storage time. In addition, since the lower temperature water flowing out of the second heat exchanger 7 flows into the lower part of the water tank 2 through the second outlet end 422, this setting can prevent the lower temperature water from disturbing the decreasing water temperature of the water tank 2 from top to bottom in the early stage of heat storage. It also helps to ensure that the higher temperature water can stably pass through the first circulation pipe 41 into the second heat exchanger 7 at the upper part, thereby storing heat in the phase change material in the phase change tank 1.

[0291] The first water outlet 412 is located at the upper part of the phase change tank 1, and the second water inlet 421 is located at the lower part of the phase change tank 1. This facilitates the smooth flow of hot water flowing into the second heat exchanger 7 through the first circulation pipe 41 under the action of gravity. In other words, even without an external drive, the water flowing out of the water tank 2 can reliably flow through the second heat exchanger 7 to achieve circulation.

[0292] Of course, in the embodiments of this application, it is not excluded that the positions of the first water inlet 411, the first water outlet 412, the second water inlet 421 and the second water outlet 422 may be changed according to actual design requirements in other embodiments.

[0293] In some embodiments, the other side of the water supply pipe 81 can be connected to the circulation pipe. When the water supply pipe 81 is connected to the circulation pipe, it is possible to avoid separately setting an opening for connecting the water supply pipe 81 on the water tank 2 or in the second heat exchanger 7, which helps to ensure the overall reliability of the water tank 2 and the second heat exchanger 7, reduce manufacturing difficulty and cost, and improve the integration of the pipeline.

[0294] The other side of the water supply pipe 81 can be connected to the first circulation pipe 41 or directly or indirectly to the second circulation pipe 42, thereby achieving connectivity. Connectivity at other locations in this embodiment can also be understood as direct or indirect connection.

[0295] like Figure 18 As shown, in one embodiment, the other side of the water supply pipeline 81 has a first connection port 811 and a second connection port 812, which are respectively used to connect to the second circulation pipeline 42. One side of the water supply pipeline 81 has a third connection port 813, which is used to connect to a water source. The switch device 92 is located between the first connection port 811 and the second connection port 812.

[0296] Taking the connection of the other side of the water supply pipe 81 to the second circulation pipe 42 as an example, the other side of the water supply pipe 81 may have a first connecting port 811 and a second connecting port 812. The first connecting port 811 and the second connecting port 812 are respectively used to connect to the second circulation pipe 42, and the switching device 92 is located between the first connecting port 811 and the second connecting port 812. The switching device 92 can be in the form of a switching valve or a switching valve. Of course, in other embodiments, the switching device 92 can also be integrated into the first connection portion 71 between the other end of the water supply pipe 81 and the second circulation pipe 42.

[0297] When the switch device 92 is in the first state, the first connection port 811 and the second connection port 812 are connected, and the circulation pipeline can be connected. During the heat storage stage, the hot water heated by the heating rod 3 in the water tank 2 can flow through the first circulation pipeline 41, through the second heat exchanger 7, and then return to the water tank 2 through the second circulation pipeline 42, thereby forming a circulating flow path to store heat for the phase change material in the phase change tank 1.

[0298] When the switching device 92 is in the second state, the water in the water tank 2 cannot circulate between the water tank 2 and the second heat exchanger 7. Water supplied from the water source can be diverted to the water tank 2 and the second heat exchanger 7 through the first connecting port 811 and the second connecting port 812 of the water supply pipe 81. Furthermore, the electric water heater also includes a water outlet pipe 82, which is connected to the first circulation pipe 41, allowing water flowing out from the water tank 2 and the second heat exchanger 7 to flow out through the first circulation pipe 41 and the water outlet pipe 82.

[0299] More specifically, during the water usage phase, water supplied from an external water source flows into the water supply pipeline 81 through the third connection port 813. Part of the water flows into the water tank 2 through the first connection port 811 and part of the second circulation pipeline 42, and then flows out through the outlet pipe 82 through part of the first circulation pipeline 41. Part of the water flows into the second heat exchanger 7 through the second connection port 812 and part of the second circulation pipeline 42, and then flows out through the outlet pipe 82 through part of the first circulation pipeline 41.

[0300] The water outlet pipe 82 can be specifically connected to the first circulation pipe 41. The connection between the water outlet pipe 82 and the first circulation pipe 41 can form a second connection part 72. The second connection part 72 can be a three-way structure, but it can also be in other forms. This application does not make a unique limitation here.

[0301] Furthermore, the water supply pipeline 81 also has a flow regulating device 94, which is disposed between the first connecting port 811, the second connecting port 812 and the third connecting port 813. The flow regulating device 94 is used to regulate the flow rate between the first connecting port 811 and the third connecting port 813 and / or the flow rate between the second connecting port 812 and the third connecting port 813.

[0302] In this embodiment, a flow regulating device 94 can also be installed on the water supply pipeline 81. The specific form of the flow regulating device 94 can be a flow regulating valve or other forms. Specifically, this application does not make a unique limitation. The flow regulating device 94 can regulate the flow rate between the first connecting port 811 and the third connecting port 813 and / or the flow rate between the second connecting port 812 and the third connecting port 813, thereby distributing the water supplied from the external water source between the water tank 2 and the second heat exchanger 7 to adapt to different operating conditions in the phase change tank 1 and the water tank 2, so that the output water temperature and hot water volume better meet the user's needs.

[0303] In specific adjustments, the flow regulating device 94 can individually adjust the flow rates of the first connecting port 811 and the third connecting port 813, i.e., control the flow rate of cold water flowing into the water tank 2; it can also individually adjust the flow rates of the second connecting port 812 and the third connecting port 813, i.e., control the flow rate of cold water flowing into the second heat exchanger 7; or it can simultaneously adjust the flow rates of the first connecting port 811 and the third connecting port 813, and the flow rates of the second connecting port 812 and the third connecting port 813, i.e., control the flow rates of cold water flowing into the water tank 2 and the second heat exchanger 7. It should be noted that, for the above-mentioned individual adjustments, given a fixed flow rate of cold water supplied from the external water source, adjusting one of the parallel-connected water tank 2 and the second heat exchanger 7 is equivalent to adaptively adjusting the other.

[0304] like Figure 19 As shown, in one embodiment, the first water inlet 411 is located at the upper part of the water tank 2, the first water outlet 412 is located at the upper part of the phase change tank 1, the second water inlet 421 is located at the lower part of the phase change tank 1, and the second water outlet 422 is located at the lower part of the water tank 2. The water supply pipe 81 is connected to the second circulation pipe 42. The electric water heater also includes a water outlet pipe 82. One side of the water outlet pipe 82 has a fourth connecting port 824 and a fifth connecting port 825, which are respectively connected to the first circulation pipe 41. The other side of the water outlet pipe 82 has a sixth connecting port 826, which is used to connect to a water terminal. The switch device 92 is located between the fourth connecting port 824 and the fifth connecting port 825.

[0305] One side of the water supply pipe 81 is used to connect to an external water source, and the other side of the water supply pipe 81 can be connected to the second circulation pipe 42. The other side of the water supply pipe 81 can be connected to the second circulation pipe 42 directly or indirectly. For example, the other side of the water supply pipe 81 can be connected to the second circulation pipe 42 through a first connecting part 71. The first connecting part 71 can be in the form of a tee connector, or it can be in other forms. This application does not make a unique limitation.

[0306] In this embodiment, one side of the water outlet pipe 82 has a fourth connection port 824 and a fifth connection port 825, which are respectively connected to the first circulation pipe 41. The other side of the water outlet pipe 82 has a sixth connection port 826, which is used to connect to the water terminal.

[0307] The switching device 92 can be located between the fourth connecting port 824 and the fifth connecting port 825. The switching device 92 can be in the form of a switching valve or a switching valve. Alternatively, in other embodiments, the switching device 92 can be integrated into the second connection portion 72 between the water outlet pipe 82 and the second circulation pipe 42.

[0308] When the switch device 92 is in the first state, the fourth connection port 824 and the fifth connection port 825 are connected, and the circulation pipeline can be opened. During the heat storage stage, the hot water heated by the heating rod 3 in the water tank 2 can flow through the first circulation pipeline 41, through the second heat exchanger 7, and then return to the water tank 2 through the second circulation pipeline 42, thereby forming a circulating flow path to store heat for the phase change material in the phase change tank 1.

[0309] When the switching device 92 is in the second state, the water in the water tank 2 cannot circulate between the water tank 2 and the second heat exchanger 7. The water supplied by the water source can be diverted to the water tank 2 and the second heat exchanger 7 through the water supply pipeline 81; the water flowing out from the water tank 2 and the second heat exchanger 7 can flow out through the first circulation pipeline 41 and the outlet pipe 82.

[0310] More specifically, during the water usage phase, water supplied from an external water source flows into the water tank 2 and the second heat exchanger 7 through the water supply pipe 81. Water in the upper part of the water tank 2 can flow out through part of the first circulation pipe 41 and the outlet pipe 82 to the water terminal. Water flowing into the second heat exchanger 7 can also flow out through part of the first circulation pipe 41 and the outlet pipe 82 to the water terminal.

[0311] Furthermore, the water outlet pipe 82 may also have a flow regulating device 94, which is disposed between the fourth connecting port 824, the fifth connecting port 825 and the sixth connecting port 826. The flow regulating device 94 is used to regulate the flow rate between the fourth connecting port 824 and the sixth connecting port 826 and / or the flow rate between the fifth connecting port 825 and the sixth connecting port 826.

[0312] In this embodiment, a flow regulating device 94 can also be installed on the water outlet pipe 82. The specific form of the flow regulating device 94 can be a flow regulating valve or other forms. Specifically, this application does not make a unique limitation. The flow regulating device 94 can regulate the flow rate between the fourth connecting port 824 and the sixth connecting port 826 and / or the flow rate between the fifth connecting port 825 and the sixth connecting port 826, thereby distributing the heated water output from the water tank 2 and the second heat exchanger 7 to the outside to adapt to different operating conditions in the phase change tank 1 and the water tank 2, so that the output water temperature and hot water volume better meet the user's needs.

[0313] In specific adjustments, the flow regulating device 94 can individually adjust the flow rates of the fourth connecting port 824 and the sixth connecting port 826, i.e., control the flow rate of hot water flowing out of the water tank 2; it can also individually adjust the flow rates of the fifth connecting port 825 and the sixth connecting port 826, i.e., control the flow rate of hot water flowing out of the second heat exchanger 7; or it can simultaneously adjust the flow rates of the fourth connecting port 824 and the sixth connecting port 826, and the fifth connecting port 825 and the sixth connecting port 826, i.e., control the flow rate of hot water flowing out of the water tank 2 and the flow rate of hot water flowing into the second heat exchanger 7. It should be noted that, for the above-mentioned individual adjustments, given a fixed flow rate of cold water supplied from the external water source, adjusting one of the parallel-connected water tank 2 and the second heat exchanger 7 is equivalent to adaptively adjusting the other.

[0314] Please refer to the following: Figures 20 to 24 In one embodiment, the switching device 92 has at least a first port 921, a second port 922, and a third port 923. The first port 921 is used to connect to the other side of the water supply pipe 81. The second port 922 and the third port 923 are connected to the second circulation pipe 42. The second port 922 is located downstream of the third port 923. When the switching device 92 is in the first state, the second port 922 and the third port 923 are connected. When the switching device 92 is in the second state, the first port 921 is connected to the second port 922 and / or the first port 921 is connected to the third port 923.

[0315] In this embodiment, the switching device 92 can be a multi-way valve, for example, a switching valve.

[0316] like Figure 20 As shown, the switch device 92 can be installed at the location where the water supply pipe 81 is connected to the circulation pipe. Specifically, the switch device 92 can include multiple ports, wherein the first port 921 can be used as a water inlet port, and the second port 922 and the third port 923 can be connected to the circulation pipe.

[0317] like Figure 21 As shown, during the heat storage stage, when the switching device 92 is in the first state, the second port 922 and the third port 923 are connected. The heated water in the water tank 2 returns to the water tank 2 through the first circulation pipe 41, the second heat exchanger 7, and the second circulation pipe 42.

[0318] like Figure 22 As shown, in the first water usage condition, when the switch device 92 is in the second state, the first port 921 and the second port 922 are connected. Water supplied from an external water source enters the water tank 2 through the water supply pipe 81 and part of the second circulation pipe 42. Subsequently, water in the water tank 2 can flow out of the water tank 2 through part of the first circulation pipe 41 and the outlet pipe 82. In the first water usage condition, water is supplied only by the water tank 2, which can meet the needs of frequent water use in low-flow scenarios without activating the phase change tank 1, thereby extending the service life of the phase change material in the phase change tank 1.

[0319] like Figure 23 As shown, in the second water usage condition, when the switching device 92 is in the second state, the first port 921 and the second port 922 are connected. Water supplied from an external water source enters the second heat exchanger 7 through the water supply pipe 81, part of the second circulation pipe 42, and then through the water tank 2. Subsequently, water in the second heat exchanger 7 can flow out of the water tank 2 through part of the first circulation pipe 41 and the outlet pipe 82. In the second water usage condition, only the phase change tank 1 is used for water supply.

[0320] like Figure 24 As shown, in the third water usage stage, when the switch device 92 is in the second state, the first port 921 is connected to the second port 922 and the third port 923.

[0321] During this water usage phase, the externally supplied water flows into the second heat exchanger 7 and the water tank 2, which are connected in parallel. This increases the water flow rate and provides the user with the maximum hot water supply, thus meeting the user's large water consumption needs. The water supplied from the external source flows through the water supply pipeline 81 and is diverted by the switching device 92, then flows into the water tank 2 and the second heat exchanger 7 through a portion of the second circulation pipeline 42. The water flowing out of the water tank 2 and the second heat exchanger 7 can each flow out through a portion of the first circulation pipeline 41 and the outlet pipe 82.

[0322] In the third water usage scenario, the simultaneous supply of water by water tank 2 and phase change tank 1 helps to increase the hot water volume of the electric water heater and meet the user's demand for large water usage.

[0323] Overall, because the electric water heater can switch between different combinations of tanks for water supply using different connection relationships of the switch device 92, it can meet the different water needs of users while ensuring its own reliability and extending its service life.

[0324] like Figure 25 As shown, in one embodiment, the switching device 92 has at least a first port 921, a second port 922, and a third port 923. The electric water heater also includes a water outlet pipe 82. The first port 921 is used to connect to the water outlet pipe 82. The second port 922 and the third port 923 are connected to the first circulation pipe 41. The second port 922 is located downstream of the third port 923. When the switching device 92 is in the first state, the second port 922 and the third port 923 are connected. When the switching device 92 is in the second state, the first port 921 is connected to the second port 922 and / or the first port 921 is connected to the third port 923.

[0325] In this embodiment, the switching device 92 can be a multi-way valve, for example, a switching valve.

[0326] The switch device 92 can be installed at the location where the water supply pipe 81 is connected to the circulation pipe. Specifically, the switch device 92 can include multiple ports, wherein the first port 921 can be used as a water outlet port, and the second port 922 and the third port 923 can be connected in the circulation pipe.

[0327] Taking the switch device 92 as an example, when it is installed in the first circulation pipeline 41, during the heat storage stage, when the switch device 92 is in the first state, the second port 922 and the third port 923 are connected, and the heated water in the water tank 2 returns to the water tank 2 through the first circulation pipeline 41, the second heat exchanger 7, and the second circulation pipeline 42.

[0328] In the first water usage condition, when the switch device 92 is in the second state, the first port 921 and the third port 923 are connected, and the water supplied by the external water source flows out from the outlet pipe 82 after passing through the water supply pipe 81, part of the second circulation pipe 42, the water tank 2, and part of the first circulation pipe 41.

[0329] In the first water usage scenario, water is supplied using only water tank 2, which can meet the needs of frequent water use in low-flow scenarios without activating phase change tank 1, thereby extending the service life of the phase change material in phase change tank 1.

[0330] In the second water usage condition, when the switch device 92 is in the second state, the first port 921 and the second port 922 are connected. Water supplied from the external water source flows out from the outlet pipe 82 after passing through the water supply pipe 81, part of the second circulation pipe 42, the second heat exchanger 7, and part of the first circulation pipe 41.

[0331] In the third water usage condition, when the switch device 92 is in the second state, the first port 921 is connected to the second port 922 and the third port 923.

[0332] During this water usage phase, the externally supplied water flows into the second heat exchanger 7 and the water tank 2, which are connected in parallel to provide the user with the maximum hot water supply, thereby meeting the user's large water consumption needs. The water supplied from the external water source is diverted through the water supply pipeline 81 and flows into the water tank 2 and the second heat exchanger 7 through a portion of the second circulation pipeline 42; the water flowing out of the water tank 2 and the second heat exchanger 7 can each flow out through a portion of the first circulation pipeline 41 and the outlet pipe 82.

[0333] In the third water usage scenario, the simultaneous supply of water by water tank 2 and phase change tank 1 helps to increase the hot water volume of the electric water heater and meet the user's demand for large water usage.

[0334] Overall, because the electric water heater can switch between different combinations of tanks for water supply using different connection relationships of the switch device 92, it can meet the different water needs of users while ensuring its own reliability and extending its service life.

[0335] It should be noted that in the description of this application, the terms "first," "second," etc., are used only for descriptive purposes and to distinguish similar objects; there is no order between them, nor should they be construed as indicating or implying relative importance. Furthermore, in the description of this application, unless otherwise stated, "multiple" means two or more.

[0336] The various embodiments described in this specification are presented in a progressive manner. The same or similar parts between the embodiments can be referred to each other. Each embodiment focuses on the differences from other embodiments.

[0337] The above are merely a few embodiments of this utility model. Although the embodiments disclosed in this utility model are as described above, the content is only for the purpose of facilitating understanding of this utility model and is not intended to limit this utility model. Any person skilled in the art to which this utility model pertains may make any modifications and changes in the form and details of the embodiments without departing from the spirit and scope disclosed in this utility model. However, the patent protection scope of this utility model shall still be determined by the scope defined in the appended claims.

Claims

1. An electric water heater, characterized in that, The electric water heater includes a heating rod and a tank. The tank includes a phase change tank and a water tank. The heating rod is disposed in the water tank and is used to heat the water in the water tank. The phase change tank has a phase change material for heat storage and heat release, and the phase change tank also includes a first heat exchanger connected to the water tank, through which water flowing through the first heat exchanger can conduct heat to the phase change material. The electric water heater further includes a circulation pipeline connecting the water tank and the first heat exchanger. The circulation pipeline includes a first circulation pipeline and a second circulation pipeline. The first circulation pipeline has a first water inlet and a first water outlet. The first water inlet is located in the water tank and the first water outlet is located in the phase change tank. The second circulation pipeline has a second water inlet and a second water outlet. The second water inlet is located in the phase change tank and the second water outlet is located in the water tank. When the heating rod is working, the water in the water tank can circulate between the phase change tank and the water tank through the first circulation pipe and the second circulation pipe.

2. The electric water heater according to claim 1, characterized in that, Part of the outer wall of the phase change chamber wraps around or adheres to part of the outer wall of the water chamber. The heat from the water in the water tank can be simultaneously conducted to the phase change tank through the outer wall of part of the water tank and the outer wall of part of the phase change tank.

3. The electric water heater according to claim 2, characterized in that, The outer wall of the phase change chamber partially wraps around or adheres to the outer wall of the water chamber from top to bottom.

4. The electric water heater according to claim 2, characterized in that, A heat-conducting medium or heat-conducting structure is provided between the outer wall surface of the partial phase change tank and / or the outer wall surface of the partial water tank and / or the outer wall surface of the partial phase change tank and the outer wall surface of the partial water tank.

5. The electric water heater according to claim 1, characterized in that, The number of heating rods is one, and the heating rod is located in the middle, upper part or bottom of the water tank. or, The heating element includes a first heating element and a second heating element. The first heating element is disposed at the lower part of the water tank, and the second heating element is disposed at the middle, upper or bottom of the water tank.

6. The electric water heater according to claim 1, characterized in that, The heating element includes a first heating element and a second heating element. The water tank also includes a water outlet pipe. The water inlet of the water outlet pipe is located at the upper part of the water tank. The second heating element is positioned closer to the water inlet of the water outlet pipe than the first heating element.

7. The electric water heater according to claim 1, characterized in that, The lateral dimension of the phase change tank is not less than the lateral dimension of the water tank, or the lateral dimension of the phase change tank is less than the lateral dimension of the water tank.

8. The electric water heater according to claim 1, characterized in that, The phase change tank also includes a second heat exchanger for absorbing heat from the phase change material. One end of the second heat exchanger is connected to a water source or the water tank, and the other end of the second heat exchanger is connected to the water tank. Water in the water source or the water tank can absorb heat from the phase change material through the second heat exchanger and then flow into the water tank.

9. The electric water heater according to claim 8, characterized in that, The first heat exchanger and the second heat exchanger are set up independently without being connected.

10. The electric water heater according to claim 1, characterized in that, The phase change tank also includes a second heat exchanger for absorbing heat from the phase change material. One end of the second heat exchanger is connected to a water source or the water tank. Water in the water source or the water tank can absorb heat from the phase change material through the second heat exchanger and the first heat exchanger and then flow into the water tank.

11. The electric water heater according to claim 10, characterized in that, The first heat exchanger and the second heat exchanger are connected in series.

12. The electric water heater according to claim 11, characterized in that, The second heat exchanger includes a first heat exchange section and a second heat exchange section, wherein the first heat exchange section is located upstream of the first heat exchanger and the second heat exchange section is located downstream of the first heat exchanger; or, The second heat exchanger is located upstream or downstream of the first heat exchanger.

13. The electric water heater according to claim 10, characterized in that, The electric water heater also includes a water supply pipeline, one end of which is connected to a water source, and the other end of which is connected to the second heat exchanger. The first heat exchanger and the second heat exchanger are connected, and a switch device is provided on the first circulation pipeline and / or the second circulation pipeline.

14. The electric water heater according to claim 1, characterized in that, The outer wall of the phase change chamber partially wraps around or adheres to the outer wall of the water chamber.

15. The electric water heater according to claim 1, characterized in that, The circulation pipeline is equipped with an insulation layer.

16. The electric water heater according to claim 1, characterized in that, The position of the first water inlet in the water tank is higher or lower than the position of the second water outlet in the water tank, and the position of the first water outlet in the phase change tank is higher or lower than the position of the second water inlet in the phase change tank. or, The position of the first water inlet in the water tank is higher or lower than the position of the second water outlet in the water tank, and the position of the first water outlet in the phase change tank is level with the position of the second water inlet in the phase change tank. or, The position of the first water inlet end in the water tank is level with the position of the second water outlet end in the water tank, and the position of the first water outlet end in the phase change tank is higher or lower than the position of the second water inlet end in the phase change tank. or, The position of the first water inlet in the water tank is flush with the position of the second water outlet in the water tank, and the position of the first water outlet in the phase change tank is flush with the position of the second water inlet in the phase change tank.

17. The electric water heater according to claim 1, characterized in that, The first water inlet is located in the lower, middle or upper part of the water tank; And / or, The first water outlet is located in the lower, middle or upper part of the phase change tank; And / or, The second water inlet is located in the lower, middle or upper part of the phase change tank; And / or, The second water outlet is located in the lower, middle or upper part of the water tank.

18. The electric water heater according to claim 1, characterized in that, The first heat exchanger includes at least a heat exchange box body with a cavity. The water inlet of the heat exchange box is connected to the first water outlet. The outlet of the heat exchange box is connected to the second water inlet.

19. The electric water heater according to claim 1, characterized in that, The first heat exchanger includes at least a first heat exchange box having a first cavity and a second heat exchange box having a second cavity, the first heat exchange box and the second heat exchange box being connected by a water-passing structure. The water inlet of the first heat exchange box is connected to the first water outlet. The outlet of the first heat exchange box is connected to the second water inlet.

20. The electric water heater according to claim 19, characterized in that, The water passage structure includes an upper water passage structure and a lower water passage structure. The upper water passage structure is used to connect the upper part of the first heat exchange box and the upper part of the second heat exchange box. The lower water passage structure is used to connect the lower part of the first heat exchange box and the lower part of the second heat exchange box. The upper water passage structure has an upper water inlet port communicating with the first cavity of the first heat exchange box and an upper water outlet port communicating with the second cavity of the second heat exchange box. The upper water inlet port is lower than or level with the upper water outlet port in height. The lower water passage structure has a lower water outlet port that communicates with the first cavity of the first heat exchange box and a lower water inlet port that communicates with the second cavity of the second heat exchange box. The lower water inlet port is higher than or level with the lower water outlet port in height.

21. The electric water heater according to claim 20, characterized in that, The upper water passage structure connects the upper part of the first heat exchange box and the upper end of the second heat exchange box, or the upper water passage structure connects the upper end of the first heat exchange box and the upper end of the second heat exchange box. The lower water passage structure connects the lower end of the first heat exchange box and the lower end of the second heat exchange box, or the lower water passage structure connects the lower part of the first heat exchange box and the lower end of the second heat exchange box.

22. The electric water heater according to claim 19, characterized in that, The first heat exchanger includes at least one first heat exchange box and multiple second heat exchange boxes; A portion of the multiple second heat exchange boxes are disposed on the first side of the first heat exchange box, and another portion of the multiple second heat exchange boxes are disposed on the second side of the first heat exchange box opposite to the first side.

23. The electric water heater according to claim 19, characterized in that, The first heat exchange box and at least one second heat exchange box constitute a heat exchange box group, and the first heat exchanger includes at least one group of the heat exchange box groups.

24. The electric water heater according to claim 19, characterized in that, The upper end of the first heat exchange box is lower than the upper end of the second heat exchange box. And / or, The lower end of the first heat exchange box is lower than the lower end of the second heat exchange box.

25. The electric water heater according to claim 19, characterized in that, The first heat exchange box and the second heat exchange box are connected in parallel in the water flow path.

26. The electric water heater according to any one of claims 1 to 25, characterized in that, The water tank is located below the phase change tank.

27. The electric water heater according to claim 26, characterized in that, The phase change chamber has a longitudinal cross-section that is saddle-shaped or inverted U-shaped, and the first heat exchanger has a predetermined distance from the inner surface of the lower outer wall of the phase change chamber.

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