Electric water heater

Abstract

The utility model discloses an electric water heater, including phase change gall and water gall, be provided with heating rod in water gall, and heating rod is used for heating the water in water gall, the phase change gall has the phase change material for heat storage and heat release, and the phase change gall still includes the heat exchange pipe who communicates with water gall, and the water that flows through heat exchange pipe can absorb heat from phase change material, can also release heat to phase change material, in the height direction of phase change gall, along the flow direction of water, at least partial heat exchange pipe is arranged from top to bottom, and the electric water heater still includes the circulation pipe who communicates water gall and heat exchange pipe, when heating rod works, and the hot water in water gall can circulate and flow between heat exchange pipe and water gall through circulation pipe. The electric water heater provided in the application embodiment can simplify the structure and manufacturing process of electric water heater, reduce manufacturing cost and use cost, realize efficient energy storage simultaneously, in addition, can also maintain the better heat exchange effect in the long term in the use process.

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 currently includes a phase change tank filled with phase change material and a heater (e.g., a heating rod) installed inside the tank. During the heat storage phase, the heating rod is activated to directly heat the phase change material. However, this method objectively has the following problems: the phase change material itself has generally low thermal conductivity, and the heat transfer distance of the heating rod is limited, which can cause uneven temperature distribution among the phase change materials, resulting in low heat exchange efficiency and slow heating efficiency. This leads to a longer time required for the entire heat storage process. More seriously, the material near the heating rod may suffer carbonization and dehydration due to the high temperature on the heating rod surface, thus causing the energy storage function to fail.

[0005] To address the aforementioned problems with phase change water heaters, one approach is to install a water tank with a certain volume within the phase change water heater. A heating rod heats the water in the water tank, and heat exchange occurs between the water tank and the phase change material, thereby improving heat exchange efficiency to some extent and preventing premature failure of materials near the heating rod.

[0006] However, after further research, the inventors of this application discovered that existing water box processes are complex, resulting in high manufacturing costs and difficulties. Furthermore, when water boxes are placed within phase change materials for heat exchange, the limited number of water boxes limits the potential for improvement in heat exchange efficiency and heating uniformity between the water boxes and the phase change material.

[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 simplifies the structure and manufacturing process of the electric water heater, reduces manufacturing and usage costs, achieves efficient energy storage, and maintains a good heat exchange effect for a long time during use.

[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 water heater comprises a phase change tank and a water tank. A heating rod is installed in the water tank to heat the water. The phase change tank contains a phase change material for heat storage and release. It also includes a heat exchange tube connected to the water tank, through which water can absorb heat from and release heat to the phase change material. At least a portion of the heat exchange tube is arranged from top to bottom along the water flow direction in the height direction of the phase change tank. The water heater further includes a circulation pipe connecting the water tank and the heat exchange tube, allowing hot water in the water tank to circulate between the heat exchange tube and the water tank when the heating rod is operating.

[0013] In a preferred embodiment, the electric water heater includes at least one reversing connection for changing the flow direction of water in the heat exchange tube. The reversing connection has an inlet section and an outlet section, with the inlet section being higher than the outlet section in the height direction.

[0014] In a preferred embodiment, the reversing connection further includes a connecting section located between the water inlet section and the water outlet section, the connecting section being used to connect the water inlet section and the water outlet section; at least a portion of the connecting section extends downward or diagonally downward from the water inlet section to the water outlet section.

[0015] In a preferred embodiment, the projection of the connecting segment onto the vertical plane is in the shape of a line segment, an arc, or a broken line.

[0016] In a preferred embodiment, the reversing connection is located outside the phase change tank. The reversing connection includes a connecting pipe, one end of which is the water inlet section and the other end of which is the water outlet section. Alternatively, the reversing connection includes a protrusion on the plate, one side of which has the water inlet section and the other side of which has the water outlet section.

[0017] In a preferred embodiment, the inlet section and the outlet section are respectively connected to the connecting section via an arc transition.

[0018] In a preferred embodiment, the heat exchange tube includes multiple sub-heat exchange tubes connected in series, and the multiple sub-heat exchange tubes are connected through the reversing connection. Alternatively, the heat exchange tube includes heat exchange flow paths connected in series, and the series heat exchange flow path segments include at least a first heat exchange flow path segment and a second heat exchange flow path segment. Both the first heat exchange flow path segment and the second heat exchange flow path segment include multiple sub-heat exchange tubes connected in parallel, and the first heat exchange flow path segment and the second heat exchange flow path segment are connected through the reversing connection.

[0019] In a preferred embodiment, the heat exchange tube includes multiple sub-heat exchange tubes connected in series, which are connected by the reversing connection portion and arranged from high to low in the height direction along the water flow direction.

[0020] In a preferred embodiment, the heat exchange tube includes heat exchange flow sections connected in series. The heat exchange flow sections connected in series include at least a first heat exchange flow section and a second heat exchange flow section. Both the first heat exchange flow section and the second heat exchange flow section include multiple sub-heat exchange tubes connected in parallel. The first heat exchange flow section and the second heat exchange flow section are connected through the reversing connection. Along the water flow direction, water flows sequentially through the first heat exchange flow section and the second heat exchange flow section. The first heat exchange flow section is set higher than the second heat exchange flow section in the height direction.

[0021] In a preferred embodiment, the multiple parallel heat exchange tubes are arranged flush in the height direction.

[0022] In a preferred embodiment, the spacing between two adjacent sub-heat exchange tubes is between 20 mm and 50 mm.

[0023] In a preferred embodiment, the diameter of the heat exchange tube is 10 mm or more.

[0024] In a preferred embodiment, the heat exchange tube includes a heat exchange circular tube and / or a heat exchange flat tube.

[0025] In a preferred embodiment, the heat exchange flat tube is arranged at an angle, horizontally, or vertically.

[0026] In a preferred embodiment, the heat exchange flat tube has a cross-section that is D-shaped, waist-shaped, elliptical, rectangular, or near-rectangular.

[0027] In a preferred embodiment, the electric water heater further includes a water distribution device and a water collection device. The water distribution device is located upstream of the inlet of the heat exchange tube, and the water collection device is located downstream of the outlet of the heat exchange tube. Both the water distribution device and the water collection device are connected to the circulation pipe. The heat exchange tube includes multiple parallel sub-heat exchange tubes. When the heating rod is working, the water in the water tank can circulate through the circulation pipe between the water distribution device, the heat exchange tube, the water collection device, and the water tank.

[0028] In a preferred embodiment, the heat exchange tubes are arranged longitudinally, the water distribution device is located at the upper part of the heat exchange tubes, and the water collection device is located at the lower part of the heat exchange tubes; or, the heat exchange tubes are arranged transversely, in which the water distribution device is located on one side of the heat exchange tubes and the water collection device is located on the other side of the heat exchange tubes.

[0029] 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 the outer wall of the portion of the water tank and the outer wall of the portion of the phase change tank.

[0030] In a preferred embodiment, the number of heating rods is one, and the heating rod is disposed in the middle, upper or lower part 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 or bottom part of the water tank and the second heating rod disposed in the middle or upper part of the water tank.

[0031] In a preferred embodiment, the phase change tank has a smaller lateral dimension than the water tank.

[0032] In a preferred 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, the water tank 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 and the water tank.

[0033] In a preferred embodiment, the heat exchange tube is also used to connect to a water source, through which water can absorb heat from the phase change material and flow into the water tank.

[0034] In a preferred embodiment, the circulation pipe includes a first circulation pipe and a second circulation pipe. The first circulation pipe has a first inlet end and a first outlet end, with the first inlet end located in the water tank and the first outlet end located in the phase change tank. The second circulation pipe has a second inlet end and a second outlet end, with the second inlet end located in the phase change tank and the second outlet end located in the water tank. A switching device is provided on the first circulation pipe and / or the second circulation pipe.

[0035] In a preferred embodiment, water from the water source can flow into the water tank through the heat exchange tube and the second circulation tube; the first water inlet is located at the upper part of the water tank, and the switch device is disposed on the first circulation tube.

[0036] In a preferred embodiment, the electric water heater further includes a water supply pipe, which is connected to the first circulation pipe via a connecting part, and the switching device is located between the connecting part and the first water inlet end, or the water supply pipe is connected to the first circulation pipe via the switching device.

[0037] In a preferred embodiment, the electric water heater further includes a water inlet pipe located in the water tank. The electric water heater has a first water usage state and a second water usage state. In the first water usage state, water supplied from the water source can be supplied to the lower part of the water tank through the water supply pipe, the heat exchange pipe, and the second circulation pipe. In the second water usage state, the water inlet pipe directly supplies water to the lower part of the water tank.

[0038] 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.

[0039] In a preferred embodiment, the inlet of the heat exchange tube is located at the high point of the heat exchange tube, and the outlet of the heat exchange tube is located at the low point of the heat exchange tube. The first inlet end is located at the upper part of the water tank; the first outlet end is located at the upper part of the phase change tank; the second inlet end is located at the lower part of the phase change tank; and the second outlet end is located at the lower part of the water tank.

[0040] In a preferred embodiment, the inlet of the heat exchange tube is located at the high point of the heat exchange tube, the outlet of the heat exchange tube is located at the low point of the heat exchange tube, and an insulation layer is provided outside the circulation tube.

[0041] In a preferred embodiment, the water tank is located below the phase change tank.

[0042] The technical solution of this utility model has the following significant beneficial effects:

[0043] In this embodiment, a circulation pipe connects the water tank and the heat exchange pipe. A heating rod is installed in the water tank, allowing water in the tank to be heated by the heating rod and then flow into the heat exchange pipe through the circulation pipe, subsequently returning to the water tank to achieve circulation. During the heat storage stage, the heat exchange pipe, through which hot water flows, exchanges heat with the phase change material in the phase change tank, improving the heat exchange efficiency between the heat exchange pipe and the phase change material, as well as the uniformity of heating the phase change material. Simultaneously, it reduces the heating frequency of the heating rod, increasing the heat generated per heating cycle, thus improving the heat exchange efficiency during the heat storage stage, shortening the heat storage time, and reducing operating costs. This application further simplifies the structure of the electric water heater, effectively reducing manufacturing costs. Furthermore, during long-term use, the inner wall of the heat exchange pipe is less prone to scaling, ensuring optimal heat exchange performance.

[0044] 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

[0045] 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.

[0046] Figure 1 This is a front view of an electric water heater provided in the embodiments of this application;

[0047] Figure 2 This is one of the left views of an electric water heater provided in the embodiments of this application;

[0048] Figure 3 This is a second left-side view of an electric water heater provided in the embodiments of this application;

[0049] Figure 4 This is a front view of a phase change tank in an electric water heater provided in the embodiments of this application;

[0050] Figure 5 for Figure 4 Sectional view of AA;

[0051] Figure 6 for Figure 5 A magnified view of a portion of point I in the middle;

[0052] Figure 7 This is one of the schematic diagrams showing the connection relationship of the heat exchange tubes in the phase change tank of an electric water heater provided in the embodiments of this application;

[0053] Figure 8 This is the second schematic diagram showing the connection relationship of the heat exchange tubes in the phase change tank of an electric water heater provided in the embodiments of this application;

[0054] Figure 9 This is the third schematic diagram showing the connection relationship of the heat exchange tubes in the phase change tank of an electric water heater provided in the embodiments of this application;

[0055] Figure 10 This is one of the schematic diagrams illustrating the structure of a heat exchange tube in a phase change tank of an electric water heater provided in the embodiments of this application;

[0056] Figure 11 for Figure 10 Schematic diagram of the cross-section of the heat exchanger tube;

[0057] Figure 12 This is a second schematic diagram of the structure of the heat exchange tube in the phase change tank of an electric water heater provided in the embodiments of this application;

[0058] Figure 13 for Figure 12 Schematic diagram of the cross-section of the heat exchanger tube;

[0059] Figure 14 This is a schematic diagram of another electric water heater provided in the embodiments of this application;

[0060] Figure 15 This is a schematic diagram of the structure of another electric water heater provided in the embodiments of this application.

[0061] Reference numerals in the figures of this application:

[0062] 1. Phase change cylinder;

[0063] 2. Water tank;

[0064] 3. Heating rod;

[0065] 41. First circulation pipe;

[0066] 411. First water inlet end;

[0067] 412. First water outlet;

[0068] 42. Second circulation pipe;

[0069] 421. Second water inlet;

[0070] 422. Second water outlet;

[0071] 5. Heat exchanger tubes;

[0072] 50. Sub-heat exchanger tube;

[0073] 51. Reversing connection part;

[0074] 511. Water entry section;

[0075] 512. Water outlet section;

[0076] 513. Connected segment;

[0077] 501, First heat exchange flow section; 502, Second heat exchange flow section; 81, Water supply pipe;

[0078] 82. Water outlet pipe;

[0079] 83. Water inlet pipe;

[0080] 92. Switching device;

[0081] 93. Insulation layer;

[0082] 61. Water distribution device;

[0083] 62. Water collection device;

[0084] X, horizontal;

[0085] Y, the height direction. Detailed Implementation

[0086] 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.

[0087] 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.

[0088] 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.

[0089] This utility model provides an electric water heater that simplifies the structure and manufacturing process of electric water heaters, reduces manufacturing and operating costs, achieves efficient energy storage, and maintains a good heat exchange effect over a long period of time during use.

[0090] Please refer to the following for comprehensive information. Figures 1 to 14 This application specification provides an electric water heater, which may include: a phase change tank 1 and a water tank 2. The water tank 2 is provided with a heating rod 3 for heating 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 heat exchange tube 5 connected to the water tank 2. Water flowing through the heat exchange tube 5 can absorb heat from the phase change material and release heat to the phase change material. In the height direction Y of the phase change tank 1, at least part of the heat exchange tube 5 is arranged from top to bottom along the water flow direction. The electric water heater also includes a circulation pipe connecting the water tank 2 and the heat exchange tube 5. When the heating rod 3 is working, the hot water in the water tank 2 can circulate between the heat exchange tube 5 and the water tank 2 through the circulation pipe.

[0091] 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.

[0092] The phase change chamber 1 contains a phase change material for heat storage and release, hence the name "phase change chamber". 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 chamber 1 is internally equipped with a heat exchange tube 5, which is connected to the water chamber 2. Water flowing through the heat exchange tube 5 can absorb heat from the phase change material and also release heat to it.

[0093] The water tank 2 is a water tank with an internal water storage cavity. Generally, the volume of this water tank is at least 10 liters. A heating rod 3 can be installed in the water tank 2, while the phase change tank 1 does not have a heating element. Alternatively, 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, it can absorb heat from the water heated by the heating rod 3 in the water tank 2.

[0094] The phase change material in the phase change tank 1 is further equipped with a heat exchange tube 5 connected to the water tank 2. During the heat storage stage, the heated hot water in the water tank 2 flows into the heat exchange tube 5, releasing heat to the phase change material in contact with it. During the water use stage, the water supplied from an external water source absorbs heat from the phase change material in contact with the heat exchange tube 5 as it flows through it, thereby raising the water temperature and achieving a preheating effect.

[0095] To facilitate the flow of heated hot water from water tank 2 into the upper phase change tank 1 via natural convection, a circulation pipe is installed between the heat exchange tube 5 of the phase change tank 1 and water tank 2. Specifically, this circulation pipe may include a first circulation pipe 41 and a second circulation pipe 42, which connect water tank 2 and the heat exchange tube 5 of the phase change tank 1. When the heating rod 3 is operating, the heated hot water in water tank 2 expands due to heat, and the less dense hot water flows upward, entering the heat exchange tube 5 through the first circulation pipe 41. The less dense water in the heat exchange tube 5 returns to water tank 2 through the second circulation pipe 42, thus circulating the water flow between the heat exchange tube 5 of the phase change tank 1 and water tank 2.

[0096] 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 heat exchange tube 5. The heat from the water in the heat exchange tube 5 can be transferred through the shell of the heat exchange tube 5 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, the hot water flowing from the water tank 2 into the phase change tank 1 through the heat exchange tube 5 can smoothly return to the water tank 2 from top to bottom along the circulation pipe without additional driving force, at least a portion of the heat exchange tube 5 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 tube resistance of the heat exchange tube 5, 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.

[0097] 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 heat exchange tube 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 heat exchange tube 5 returns to the water tank 2 through the second circulation pipe 42. Thus, the water flows in a circulation between the heat exchange tube 5 of the phase change tank 1 and the water tank 2. During the above circulation process, the heat generated by the 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 heat exchange tube 5. The heat of the water in the heat exchange tube 5 can be transferred through the shell of the heat exchange tube 5 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.

[0098] In this embodiment, firstly, during the start-up process of the heating rod 3, the natural circulation of water can be achieved without setting up an additional power source, which simplifies the system, reduces energy consumption, effectively controls the overall cost, and does not generate noise that disturbs the user.

[0099] Secondly, the method of directly feeding the heated water from the water tank 2 into the heat exchange tube 5 to store heat in the phase change material has significant advantages over existing implementation methods:

[0100] For example, compared to directly placing the heating element in the phase change chamber, it can improve heat exchange efficiency and prevent premature failure of the material near the heating rod 3.

[0101] For example, compared to setting a heating element in the heat exchanger (water box) inside the phase change tank, 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.

[0102] For example, compared to electric water heaters that have a water box in the phase change tank and connect it 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 contrast, this application directly utilizes heat exchange tubes 5 to exchange heat with the phase change material. Since heat exchange tubes 5 can be evenly distributed within the phase change material of the phase change tank 1, it can further improve the heat exchange efficiency and heating uniformity between them and the phase change material.

[0103] Furthermore, compared to methods that involve placing a water box within the phase change tank, the inner surface of the water box is prone to scaling during use, thus affecting the heat exchange efficiency. In this application, the heat exchange tube 5 is directly used as a carrier for circulating hot water to store heat in the phase change material. Since the hot water has a certain flow velocity when flowing in the heat exchange tube 5, it can effectively flush the tube wall, thus effectively slowing down the scaling rate on the tube wall and ensuring a better heat exchange effect.

[0104] In summary, in this embodiment, a circulation pipe connects the water tank 2 to the heat exchange tube 5. A heating rod 3 is only installed in the water tank 2. The water in the water tank 2 is heated by the heating rod 3 and then flows into the heat exchange tube 5 through the circulation pipe, subsequently returning to the water tank 2, thus achieving circulation. During the heat storage stage, the heat exchange tube 5, through which hot water from the water tank 2 flows, exchanges heat with the phase change material in the phase change tank 1. This improves the heat exchange efficiency between the heat exchange tube 5 and the phase change material, as well as the uniformity of heating the phase change material. Simultaneously, it reduces the heating frequency of the heating rod 3, increasing the heat generated per heating cycle, thereby improving the heat exchange efficiency during the heat storage stage, shortening the heat storage time, and reducing operating costs. This application further simplifies the structure of the electric water heater, effectively reducing manufacturing costs. Furthermore, during long-term use, scale does not easily form on the inner wall of the heat exchange tube 5, ensuring better heat exchange performance.

[0105] Please refer to the following: Figure 4 , Figure 5 and Figure 6In one embodiment, the electric water heater includes at least one reversing communication portion 51, which is used to change the flow direction of water in the heat exchange tube 5. The reversing communication portion 51 has a water inlet section 511 and a water outlet section 512, wherein the water inlet section 511 is higher than the water outlet section 512 in the height direction Y.

[0106] In this embodiment, the heat exchange tubes 5 may include multiple tubes, and adjacent heat exchange tubes 5 can be connected by a reversing connection 51. This reversing connection 51 can be used to change the flow direction of water in adjacent heat exchange tubes 5. For example, when two adjacent heat exchange tubes 5 extend along the entire length from the first end of the phase change tank 1 to the second end of the phase change tank 1, if it is necessary to connect the two adjacent heat exchange tubes 5 end-to-end to achieve a large-angle reversal (reversal angle of approximately 180°), this can be achieved by providing the reversing connection 51. Specifically, the reversing connection 51 may include a water inlet section 511 and a water outlet section 512, wherein the water inlet section 511 can be connected to one heat exchange tube 5, and the water outlet section 512 can be connected to another heat exchange tube 5. In the height direction Y, the water inlet section 511 can be higher than the water outlet section 512, so that the water from one heat exchange tube 5 can flow smoothly to the water outlet section 512 under the action of gravity after flowing into the reversing connection part 51 through the water inlet section 511, and then flow into another heat exchange tube 5, thereby realizing the reversal of water flow.

[0107] Furthermore, the reversing connection portion 51 may also include a connecting section 513, which is located between the water inlet section 511 and the water outlet section 512. The connecting section 513 is used to connect the water inlet section 511 and the water outlet section 512. At least a portion of the connecting section 513 extends downward or diagonally downward from the water inlet section 511 to the water outlet section 512.

[0108] In this embodiment, a connecting section 513 may be provided between the water inlet section 511 and the water outlet section 512. The connecting section 513 is connected to both the water inlet section 511 and the water outlet section 512. Since the water inlet section 511 is higher than the water outlet section 512 in terms of height, in order to achieve the connection between the water inlet section 511 and the water outlet section 512, at least part of the connecting section 513 extends downward or diagonally downward from the water inlet section 511 to the water outlet section 512.

[0109] In this embodiment, in order to introduce hot water from water tank 2 into phase change tank 1 without an additional power source, and to achieve natural circulation of water between water tank 2 and phase change tank 1, it is necessary to maintain low flow resistance throughout the circulation channel. The inventors further discovered that the flow resistance of water in the heat exchange tube mainly depends on the flow resistance at the connecting section 51, and therefore optimized the extension direction of the connecting section 513.

[0110] Overall, when at least part of the connecting section 513 extends downward or obliquely downward from the water inlet section 511 to the water outlet section 512, it helps to ensure that the water flow can flow efficiently in the heat exchange tube 5 with less resistance, thereby ensuring that the phase change material in the phase change tank 1 can efficiently store heat during the heat storage stage, thus shortening the heat storage time of the phase change material and improving the user experience.

[0111] For example, in one specific embodiment, all connecting sections 513 can extend downward or diagonally downward from the water inlet section 511 to the water outlet section 512, thereby minimizing the resistance of the entire flow path formed by the heat exchange tube 5 and maximizing the heat storage efficiency of the phase change material.

[0112] like Figure 2 , Figure 3 or Figure 7 , Figure 8 and Figure 9 As shown, in one specific embodiment, the projection of the connecting segment 513 onto the vertical plane is in the shape of a line segment, an arc, or a broken line.

[0113] In this embodiment, the projection of the connecting segment 513 onto the vertical plane can be in the form of a line segment, an arc, or a broken line. When the projection of the connecting segment 513 onto the vertical plane is a broken line, it can be formed by splicing together multiple line segments. When the projection of the connecting segment 513 onto the vertical plane is in the form of a line segment or a broken line, it helps to reduce the installation space required by the connecting segment 513, thus not excessively affecting the size of the electric water heater. Furthermore, the transition between two line segments can also be achieved through an arc, which facilitates smooth water flow and reduces flow resistance.

[0114] When the projection of the connecting segment 513 on the vertical plane is arc-shaped, the connecting segment 513 can be a circular arc-shaped cavity in space (for example, it can be a part of the arc-shaped cavity cut out from a sphere). This setting helps to reduce the resistance of water flowing through the connecting segment 513.

[0115] like Figure 6 As shown, in one embodiment, the reversing communication part 51 is located outside the phase change tank 1. The reversing communication part 51 includes a connecting pipe, one end of which is the water inlet section 511 and the other end of which is the water outlet section 512. Alternatively, the reversing communication part 51 includes a protrusion provided on the plate body, one side of which has the water inlet section 511 and the other side of which has the water outlet section 512.

[0116] In this embodiment, the reversing connection 51 is located on the outside of the phase change tank 1, thereby facilitating installation and maintenance. It also allows for the positioning of the heat exchange tube 5. The reversing connection 51 can take the form of a connecting pipe, a convex hull, or other forms, and is not limited to the above description. Those skilled in the art, inspired by the technical essence of this application, may make other modifications, but as long as the achieved function and effect are the same as or similar to those of this application, they should be covered within the scope of protection of this application.

[0117] Taking the reversing connection part 51 including a connecting pipe as an example, the connecting pipe can be a hollow tubular structure. One end of the connecting pipe is used to form an inlet section 511 connected to a heat exchange tube 5, and the other end is used to form an outlet section 512 connected to another heat exchange tube 5. The middle part of the connecting pipe is a connecting section 513.

[0118] Taking the reversing connection part 51, which includes a protrusion on the plate, as an example, the end of the phase change tube 1 can be provided with an end plate. The end plate is provided with an opening for the heat exchange tube 5 to pass through. The projection of the protrusion toward the end plate can cover the ports of two adjacent heat exchange tubes 5, thereby connecting the two adjacent heat exchange tubes 5. The protrusion can be in the shape of a cover with a certain curvature. One side can have a water inlet section 511 communicating with one heat exchange tube 5, and the other side can have a water outlet section 512 communicating with another heat exchange tube 5. Water flowing out from one heat exchange tube 5 can enter the protrusion through the water inlet end of the protrusion, and then flow into the other heat exchange tube 5 from the water outlet section 512 of the protrusion.

[0119] Specifically, the convex bulge can be a protrusion formed on a mating plate directly opposite the end plate of the phase change chamber 1. This protrusion can be formed by stamping or other methods, and its outer edge can seal against the end plate to form the convex bulge. The protrusion can be arc-shaped or have other structures.

[0120] Overall, when the reversing connection 51 is in the form of the aforementioned convex hull, the cavity of the convex hull adopts a smoothly transitioning arc-shaped structure, allowing water to naturally turn along the cavity wall of the convex hull, avoiding eddies caused by sharp bends, and effectively reducing the resistance coefficient of water within the reversing connection 51.

[0121] Since the water tank 2 is usually a pressurized water tank 2, and the heat exchange tube 5 and the reversing connection part 51 are both connected to the water tank 2, they need to withstand a certain pressure during use. When the convex cavity adopts an integral arc structure with uniform wall thickness and no sharp corners, the stress distribution is more uniform and it can withstand higher working pressure.

[0122] In addition, the smooth inner wall and dead-angle-free design of the convex cavity can keep the fluid in a turbulent state, enhance its self-cleaning ability, reduce the adhesion of impurities, and reduce the risk of clogging and corrosion.

[0123] In one embodiment, the water inlet section 511 and the water outlet section 512 are respectively connected to the connecting section 513 via an arc transition.

[0124] In this embodiment, when the inlet section 51 and the outlet section 51 are connected to the connecting section 513 by an arc surface transition, it is beneficial for the water flow to turn naturally along the arc surface, avoiding large eddies caused by sharp bends, and effectively reducing the resistance coefficient of water in the reversing connecting section 51.

[0125] Please refer to the following: Figures 7 to 9 , Figure 10 and Figure 12 In one embodiment, the heat exchange tube 5 includes multiple sub-heat exchange tubes 50 connected in series, and the multiple sub-heat exchange tubes 50 are connected through the reversing connection part 51. Alternatively, the heat exchange tube 5 includes heat exchange flow segments connected in series, and the heat exchange flow segments connected in series include at least a first heat exchange flow segment 501 and a second heat exchange flow segment 502. The first heat exchange flow segment 501 and the second heat exchange flow segment 502 each include multiple sub-heat exchange tubes 50 connected in parallel, and the first heat exchange flow segment 501 and the second heat exchange flow segment 502 are connected through the reversing connection part 51.

[0126] In this embodiment, the heat exchange tube 5 may include multiple tubes, and the multiple sub-heat exchange tubes 50 may be connected in series and / or in parallel in the water circuit.

[0127] For example, when all the sub-heat exchange tubes 50 are connected in series, two adjacent sub-heat exchange tubes 50 can be connected through the reversing connection part 51 to form a whole heat exchange flow path. The inlet of the heat exchange flow path can be connected to the first circulation pipe 41, and the outlet of the heat exchange flow path can be connected to the second circulation pipe 42. The water entering the heat exchange tube 5 from the inlet can flow back and forth between the two ends of the phase change tank 1 along the vertical direction Y from top to bottom.

[0128] Alternatively, when multiple sub-heat exchanger tubes 50 are connected in series and parallel, each heat exchanger tube 5 may include a series heat exchange flow path, which may itself include at least two heat exchange flow paths, such as a first heat exchange flow path 501 and a second heat exchange flow path 502. Each heat exchange flow path may include multiple sub-heat exchanger tubes 50 connected in parallel. Adjacent heat exchange flow paths can be connected by a reversing flow section.

[0129] Furthermore, the multiple heat exchange tubes 50 can be connected in parallel. Alternatively, the multiple heat exchange tubes 50 can also include other combinations of the series and parallel connections described above.

[0130] like Figure 7 As shown, in one specific embodiment, the heat exchange tube 5 includes multiple sub-heat exchange tubes 50 connected in series. The multiple sub-heat exchange tubes 50 are connected through the reversing communication part 51. Along the water flow direction, the multiple sub-heat exchange tubes 50 are arranged from high to low in the height direction Y.

[0131] In this embodiment, when all the sub-heat exchange tubes 50 are connected in series, adjacent sub-heat exchange tubes 50 can be connected through the reversing connection part 51 to form a complete heat exchange flow path. The inlet of the heat exchange flow path can be connected to the first circulation pipe 41, and the outlet of the heat exchange flow path can be connected to the second circulation pipe 42. The multiple sub-heat exchange tubes 50 are arranged from high to low in the height direction Y. Water entering the heat exchange tube 5 from the inlet can flow back and forth between the two ends of the phase change tank 1 in the height direction Y from top to bottom under the action of gravity until it flows out from the outlet.

[0132] Overall, the multiple sub-heat exchange tubes 50 are connected in series through the reversing connection part 51, so that water needs to flow through each sub-heat exchange tube 50 in sequence, thereby increasing the total flow length, increasing the contact time between water and heat exchange tube 5, and making heat exchange more complete, which is conducive to achieving efficient heat exchange.

[0133] When the heat exchange tubes 5 are arranged from high to low in the height direction Y along the water flow direction, the water can flow naturally by gravity during the flow process, without the need for an additional drive source (such as a pump), which helps to simplify the structure and achieve low energy consumption operation.

[0134] Furthermore, if water enters from the lower heat exchange tube 5, and if gas (such as air) is trapped in the water due to a water outage, the gas, being less dense than water, will automatically migrate upwards and accumulate in the top heat exchange tube 5. If the gas cannot be expelled in time, it will form a closed gas column at a higher position, obstructing the normal flow of water and creating a liquid seal. When the gas column adheres to the wall of the heat exchange tube 5, it forms an insulating layer, significantly reducing heat transfer efficiency. Moreover, if water supply is subsequently restored, the high-speed water flow impacting the gas column may trigger water hammer (liquid hammer), causing pipe vibration. However, if water enters from the top heat exchange tube 5, these problems can be avoided.

[0135] like Figure 8As shown, in one specific embodiment, the heat exchange tube 5 includes heat exchange flow sections connected in series. The heat exchange flow sections connected in series include at least a first heat exchange flow section 501 and a second heat exchange flow section 502. Both the first heat exchange flow section 501 and the second heat exchange flow section 502 include multiple sub-heat exchange tubes 50 connected in parallel. The first heat exchange flow section 501 and the second heat exchange flow section 502 are connected through the reversing connection part 51. Along the water flow direction, water flows sequentially through the first heat exchange flow section 501 and the second heat exchange flow section 502. The first heat exchange flow section 501 is set higher than the second heat exchange flow section 502 in the height direction Y.

[0136] In this embodiment, the heat exchange tube 5 may include at least a first heat exchange flow section 501 and a second heat exchange flow section 502 connected in series, and the first heat exchange flow section 501 is set higher than the second heat exchange flow section 502 in the height direction Y. The above-mentioned multiple heat exchange flow sections are connected in series and arranged vertically in height, which has the technical effect of the above-mentioned multiple sub-heat exchange tubes 50 connected in series. This application will not elaborate further here.

[0137] Unlike the series connection of multiple heat exchange tubes 5, this heat exchange flow path uses multiple heat exchange flow segments connected in series, with each segment including multiple parallel sub-heat exchange tubes 50. Taking the heat storage stage as an example, the heated hot water in the water tank 2 first enters each sub-heat exchange tube 50 in the first heat exchange flow segment 501 through the first circulation pipe 41, then converges through the heat exchange connecting part and flows into each sub-heat exchange tube 50 in the relatively lower second heat exchange flow segment 502, and then converges again before returning to the water tank 2 through the second circulation pipe 42. By using the heat exchange connecting part to force the water in the first heat exchange flow segment 501 to change direction at a large angle, the flow direction of the water can be reversed, which can avoid local short circuits in the multiple parallel sub-heat exchange tubes 50, thus ensuring that all sub-heat exchange tubes 50 participate in heat exchange.

[0138] In one specific embodiment, the multiple parallel heat exchange tubes 50 are arranged flush in the height direction Y.

[0139] In this embodiment, the multiple heat exchange tubes 50 can be connected in parallel. When the multiple heat exchange tubes 50 are connected in parallel, they can be arranged flush in the height direction Y. This helps to ensure that each heat exchange tube 50 has water flow, ensuring uniform water flow distribution. There is no need to set up an additional flow equalization structure, which simplifies the structure and reduces costs.

[0140] In one embodiment, the spacing between two adjacent sub-heat exchange tubes 50 is between 20 mm and 50 mm.

[0141] In this embodiment, the spacing between two adjacent heat exchange tubes 50 needs to be controlled within a reasonable range so that the heat transfer efficiency of the phase change material can be maximized.

[0142] If the spacing between two adjacent sub-heat exchanger tubes 50 is too small, for example, less than 20 mm, the phase change material between the two adjacent sub-heat exchanger tubes 50 may be too thin, leading to localized overheating of the phase change material. It may also cause the sub-heat exchanger tubes 50 to be too densely packed, increasing tube resistance. If the spacing between the sub-heat exchanger tubes 50 is too large, for example, greater than 50 mm, the phase change material between the two adjacent sub-heat exchanger tubes 50 may be too thick, leading to increased thermal resistance and slow phase change in the central region, which is far from both sub-heat exchanger tubes 50.

[0143] Furthermore, during the heat storage stage, taking the phase change material's transition from solid to liquid as an example, a reasonable spacing allows the liquid phase change material to form natural convection under the drive of the temperature gradient, improving heat exchange efficiency. If the spacing is too small, for example, less than 20 mm, convection will be weakened, and heat transfer will rely on thermal conduction, resulting in low efficiency. If the spacing is too large, for example, greater than 50 mm, the convection path will be too long, delaying energy transfer.

[0144] When two adjacent sub-heat exchange tubes 50 are connected by a reversing connection part 51, if the distance between the two adjacent sub-heat exchange tubes 50 is too small, for example, less than 20 mm, the reversing connection part 51 will achieve a large angle (close to 180°) reversal between the two sub-heat exchange tubes 50 within a limited size, which will easily generate turbulence and thus significantly increase the tube resistance.

[0145] Of course, in the embodiments of this application, it is not excluded that the minimum distance between two adjacent sub-heat exchange tubes 50 is slightly less than 20 mm. For example, the minimum distance between two adjacent sub-heat exchange tubes 50 can be 19 mm, 18 mm, etc. When the minimum distance between two adjacent sub-heat exchange tubes 50 is slightly less than 20 mm, its effect on the heat transfer efficiency of the phase change material can also achieve the same effect as the minimum boundary value (20 mm).

[0146] Similarly, in the embodiments of this application, it is not excluded that the maximum distance between two adjacent sub-heat exchange tubes 50 is slightly greater than 50 mm. For example, the maximum distance between two adjacent sub-heat exchange tubes 50 can be 51 mm, 52 mm, etc. When the maximum distance between two adjacent sub-heat exchange tubes 50 is slightly greater than 50 mm, its effect on the heat transfer efficiency of the phase change material can also achieve the same effect as the maximum boundary value of 50 mm.

[0147] In one embodiment, the diameter of the heat exchange tube 5 is 10 mm or more.

[0148] In this embodiment, the diameter of the heat exchange tube 5 needs to be controlled to be above 10 mm. This helps to control the tube resistance of the heat exchange tube 5 within a predetermined range, ensuring that the fluid can flow smoothly in the heat exchange tube 5, while also helping to control the number of heat exchange tubes 5 within a predetermined range.

[0149] Please refer to the following: Figures 10 to 13 In one embodiment, the heat exchange tube 5 includes a heat exchange circular tube and / or a heat exchange flat tube.

[0150] In this embodiment, the heat exchange tube 5 can be a circular heat exchange tube, a flat heat exchange tube, or a combination of both. For example... Figure 10 and Figure 11 For heat exchanger tubes, their cross-section is circular. For example... Figure 12 and Figure 13 For heat exchange flat tubes, their cross-section is flat. Specifically, the cross-section of the heat exchange flat tube can be D-shaped, waist-shaped, elliptical, rectangular, or rectangular-like.

[0151] When the heat exchange tube 5 includes a heat exchange flat tube, its cross-section is flat, which can significantly increase the lateral X surface area. Under the same volume, it provides more heat exchange interfaces than a round tube, thereby improving the heat transfer efficiency.

[0152] For heat exchange flat tubes, they can be installed at an angle, horizontally, or vertically. Specifically, the installation angle of the heat exchange flat tube can vary depending on the actual water circuit connection structure and relationship.

[0153] like Figure 14 As shown, in one embodiment, the electric water heater may further include a water distribution device 61 and a water collection device 62. The water distribution device 61 is located upstream of the inlet of the heat exchange tube 5, and the water collection device 62 is located downstream of the outlet of the heat exchange tube 5. Both the water distribution device 61 and the water collection device 62 are connected to the circulation pipe. The heat exchange tube 5 includes multiple parallel sub-heat exchange tubes 5. When the heating rod 3 is working, the water in the water tank 2 can circulate through the circulation pipe among the water distribution device 61, the heat exchange tube 5, the water collection device 62, and the water tank 2.

[0154] In this embodiment, the electric water heater may further include a water distribution device 61 located upstream of the heat exchange tube 5 and a water collection device 62 located downstream of the heat exchange tube 5. The water distribution device 61 may have a hollow cavity structure, including an inlet and an outlet. The water distribution device 61 may have one inlet, which may be connected to the first outlet 412 of the first circulation pipe 41. The water distribution device 61 may have multiple outlets. When multiple heat exchange tubes 5 are arranged in parallel in the phase change tank 1, the number of outlets of the water distribution device 61 may be adapted to the number of sub-heat exchange tubes 50. The water collection device 62 can be a hollow cavity structure, which can include an inlet and an outlet. The number of inlets of the water collection device 62 can be multiple. When multiple heat exchange tubes 5 are arranged in parallel in the phase change tank 1, the number of inlets of the water collection device 62 can be matched with the number of sub-heat exchange tubes 50. The outlet of the water collection device 62 can be connected to the second inlet 421 of the second circulation pipe 42.

[0155] When the heating rod 3 is working, the water in the water tank 2 can flow into the water distribution device 61 through the first circulation pipe 41, and then flow evenly from the water distribution device 61 to each sub-heat exchange tube 50. After flowing out through each sub-heat exchange tube 50, it enters the water collection device 62 for collection, and finally returns to the water tank 2 through the second circulation pipe 42 to form a closed loop of circulation.

[0156] In this embodiment, the heat exchange tube 5 is arranged longitudinally, the water distribution device 61 is located at the upper part of the heat exchange tube 5, and the water collection device 62 is located at the lower part of the heat exchange tube 5; or, the heat exchange tube 5 is arranged transversely X, and in the transverse X direction, the water distribution device 61 is located on one side of the heat exchange tube 5, and the water collection device 62 is located on the other side of the heat exchange tube 5.

[0157] In the embodiment where the heat exchange tube 5 can be arranged horizontally (X), it also includes two cases: the heat exchange tube 5 is inclined at a certain angle or arranged horizontally.

[0158] like Figure 14 As shown, taking the longitudinal arrangement of the heat exchange tube 5 as an example, the water distribution device 61 can be located at the upper end of the heat exchange tube 5, and the water collection device 62 can be located at the lower end of the heat exchange tube 5. Multiple sub-heat exchange tubes 5 are arranged at intervals along the horizontal direction, and each sub-heat exchange tube 50 is arranged longitudinally along the vertical direction. This arrangement can reduce water flow resistance and simplify the structure, for example, eliminating the need to set multiple reversing connecting parts 51.

[0159] 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.

[0160] 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.

[0161] For example, such as Figure 2 or Figure 3 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.

[0162] 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, the lower part of the phase change tank 1 adheres better to the upper part of the water tank 2 under gravity, thus increasing the heat exchange area between the two.

[0163] 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 3 and a second heating rod 3, with the first heating rod 3 disposed in the lower part of the water tank 2 and the second heating rod 3 disposed in the middle or upper part of the water tank 2.

[0164] 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.

[0165] 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 heat exchange tube 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 created 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.

[0166] 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 heat exchange tubes 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 position where the lower part of the phase change tank 1 contacts the upper part of the water tank 2, the lower shape of the phase change tank 1 is irregular, making it difficult for the heat exchange tubes 5 to be fully distributed in the lower part of the phase change tank 1. For example... Figure 2 or Figure 3 As shown, the lower end of the heat exchange tube 5 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 there may even be a heat exchange dead zone.

[0167] 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.

[0168] 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.

[0169] 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.

[0170] In another embodiment, the number of heating rods 3 can be two. The heating rods 3 may include a first heating rod 3 and a second heating rod 3, with the first heating rod 3 disposed at the lower part of the water tank 2 and the second heating rod 3 disposed at the middle or upper part of the water tank 2.

[0171] 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 (the second heating rod 3) located in the middle or upper part of the water tank 2, another heating rod 3 (the first heating rod 3) is located in the lower part of the water tank 2. During the heat storage stage, only the second heating rod 3 can be activated. When the heating power of the second heating rod 3 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.

[0172] For the implementation 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 3 during the heat storage phase, as described above. Operating mode two involves activating both the first and second heating rods 3 during the heat storage phase and during 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 and second heating rods 3 can be the same or different; this application does not specify a particular numerical value.

[0173] 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.

[0174] The water tank 2 may also include a water outlet pipe 82, with the inlet end of the water outlet pipe 82 located at the upper part of the water tank 2. In the case where the heating rod 3 includes a first heating rod 3 and a second heating rod 3, the second heating rod 3 is positioned closer to the inlet end of the water outlet pipe 82 than the first heating rod 3. During supplemental heating, the first heating rod 3 and the second heating rod 3 can be activated simultaneously. The first heating rod 3 heats the water above the lower part of the water tank 2, while the second heating rod 3 concentrates on heating the water in the middle and upper parts, thereby increasing the water output of the water heater.

[0175] In one embodiment, the size of the phase change tank 1 in the horizontal X direction is smaller than the size of the water tank 2 in the horizontal X direction.

[0176] 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.

[0177] 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.

[0178] 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.

[0179] In one embodiment, the heat exchange tube 5 is also used to connect to a water source, and the water from the water source can absorb heat from the phase change material through the heat exchange tube 5 and then flow into the water tank 2.

[0180] In this embodiment, the heat exchange tube 5 can be connected to a water source. Specifically, the electric water heater can be equipped with a water supply pipe 81, and the heat exchange tube 5 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 heat exchange tube 5 through the water supply pipe 81, and the phase change material in the phase change tank 1 is used to heat the water flowing through the heat exchange tube 5.

[0181] The heat exchange tube 5 is connected to the water tank 2 via the second circulation pipe 42. The water tank 2 of this 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 a user uses water, the water supplied from an external water source flows through the heat exchange tube 5, is heated by the phase change material in the phase change tank 1, and then flows into the water tank 2 through the second circulation pipe 42. 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 in the water tank 2.

[0182] In one embodiment, the circulation pipe includes 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. A switch device 92 is provided on the first circulation pipe 41 and / or the second circulation pipe 42.

[0183] To allow the heated hot water in water tank 2 to flow naturally into the upper phase change tank 1, a first circulation pipe 41 and a second circulation pipe 42 are installed between the heat exchange tube 5 of the phase change tank 1 and water tank 2. The first inlet 411 of the first circulation pipe 41 is located in water tank 2, and the first outlet 412 of the first circulation pipe 41 is located in phase change tank 1. The second inlet 421 of the second circulation pipe 42 is located in phase change tank 1, and the second outlet 422 of the second circulation pipe 42 is located in water tank 2. The water tank 2 is connected to the heat exchange tube 5 of the phase change tank 1 through the first circulation pipe 41 and the second circulation pipe 42. In other words, the heat exchange tube 5 is effectively connected to the water tank 2 via the first circulation pipe 41 and the second circulation pipe 42.

[0184] During the heat storage stage, 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 heat exchange tube 5 of the phase change tank 1 through the first circulation pipe 41 by natural convection. At the same time, the cold water in the heat exchange tube 5 returns to the water tank 2 through the second circulation pipe 42. Thus, the water flows in a circulation between the heat exchange tube 5 of the phase change tank 1 and the water tank 2.

[0185] A switching device 92 is provided on the first circulation pipe 41 and / or the second circulation pipe 42. This switching device 92 may include a switching valve for controlling the on / off state of the circulation pipe it is located in, or a one-way valve for controlling the unidirectional flow of the circulation pipe it is located in. By providing the switching device 92 on the circulation pipe, it is ensured that during the water usage phase, the water supplied from the external water source can flow through the heat exchange pipe 5, the second circulation pipe 42, and the water tank 2 before being output, preventing the circulation pipe from interfering with the water supplied from the external water source during the water usage phase, such as by short-circuiting the water supplied from the external water source.

[0186] In one specific embodiment, water from the water source can flow into the water tank 2 through the heat exchange pipe 5 and the second circulation pipe 42; the first water inlet 411 is located at the upper part of the water tank 2, and the switch device 92 is disposed on the first circulation pipe 41.

[0187] In this embodiment, the electric water heater may further include a water supply pipe 81, which can be installed between the water source and the heat exchange pipe 5 to guide water supplied from the external water source into the heat exchange pipe 5. During the water usage phase, when room temperature water flows into the heat exchange pipe 5 through the water supply pipe 81, since the heat exchange pipe 5 is connected to the water tank 2, this relatively low-temperature water may flow through the first circulation pipe 41 into the middle or upper part of the water tank 2 where the water temperature is higher, thereby affecting the water temperature in the middle and upper part of the water tank 2.

[0188] Furthermore, the inlet end of the water outlet pipe 82 of the water tank 2 is located at the top of the water tank 2. When water with a lower temperature mixes into the top of the water tank 2, it will negatively interfere with the water outlet temperature, causing fluctuations in the water temperature, and may even fail to meet the user's current water outlet temperature requirements, resulting in a poor user experience.

[0189] A switching device 92, such as a one-way valve, can be installed in the first circulation pipe 41. The one-way valve is unidirectionally open from bottom to top. Normal water flow will automatically select the flow path with lower pipe resistance. The pipe resistance of the heat exchange tube 5 is generally greater than that of the first circulation pipe 41. When a one-way valve is installed on the first circulation pipe 41, it can be used to prevent water supplied from the external water source from being short-circuited by the first circulation pipe 41 (i.e., flowing into the water tank 2 through the first water inlet 411 of the first circulation pipe 41 without flowing through the heat exchange tube 5 of the phase change tank 1).

[0190] Specifically, when the first inlet 411 of the first circulation pipe 41 is located at the upper part of the water tank 2, a switching device 92, such as a one-way valve, can be installed in the first circulation pipe 41. This one-way valve allows unidirectional flow from bottom to top. This one-way valve 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 providing users with hot water that meets their outlet temperature requirements, thus ensuring a good user experience. The one-way valve can be replaced with a switching valve; for example, the switching device 92 can be a solenoid valve with a switching function. During the heat storage stage, the switching device 92 can be in the open state; during the water usage stage, the switching device 92 can be in the closed state, thereby disconnecting the first circulation pipe 41.

[0191] In this embodiment, during the heat storage stage, a circulation pipe is used to introduce heated water from the water tank 2 into the heat exchange tube 5 of the phase change tank 1, thereby achieving water circulation between the water tank 2 and the heat exchange tube 5 and storing heat for the phase change material in the phase change tank 1. During the water use stage, the circulation pipe is used to allow water that has exchanged heat with the phase change material in the heat exchange tube 5 of the phase change tank 1 to flow into the water tank 2. During the operation of the electric water heater, the circulation pipe is reused in multiple ways, which can effectively reduce the number and length of pipes, reduce the risk of leakage, and also reduce manufacturing and maintenance costs.

[0192] like Figure 1 As shown, in one specific embodiment, the electric water heater further includes a water supply pipe 91, which is connected to the first circulation pipe 41 via a connecting part. The switching device 92 is located between the connecting part and the first water inlet end 411, or the water supply pipe 81 is connected to the first circulation pipe 41 via the switching device 92.

[0193] The electric water heater may include a water supply pipe 81 connected to an external water source, which can be connected to the first circulation pipe 41. Specifically, the water supply pipe 81 can be connected to the first circulation pipe 41 via a T-connector. Of course, it can also be connected to the first circulation pipe 41 in other ways; however, this application does not make a specific limitation here.

[0194] The switching device 92 can be located on the first circulation pipe 41 between the connection part and the first water inlet 411. Taking the switching device 92 as a solenoid valve as an example, during the heat storage stage, the solenoid valve is in the closed state, and the heated water in the water tank 2 can flow into the upper heat exchange pipe 5 through the first circulation pipe 41, and then return to the water tank 2 through the second circulation pipe 42. During the water use stage, the solenoid valve is in the open state, and the water supplied by the external water source flows in through the water supply pipe 81, passes through part of the first circulation pipe 41, enters the heat exchange pipe 5, exchanges heat with the phase change medium through the heat exchange pipe 5, and then flows into the water tank 2 through the second circulation pipe 42. This arrangement allows the circulation pipes to be highly reused, and the water flow direction is clear, preventing mutual interference between water paths.

[0195] Furthermore, the water supply pipe 81 can be connected to the first circulation pipe 41 via the switching device 92. For example, the switching device 92 can be a switching valve located at the connection between the water supply pipe 81 and the first circulation pipe 41. The switching valve can include a first port, a second port, and a third port. The first port can be connected to the water supply pipe 81, and the second and third ports can be connected to the first circulation pipe 41 respectively. When water is needed, the first port is connected to the second or third port. When heat storage is needed, the second and third ports are connected, thereby opening the circulation pipe.

[0196] In one embodiment, a switch device 92 may be provided in the first circulation pipe 41 and the second circulation pipe 42, with the second outlet 422 of the second circulation pipe 42 located at the lower part of the water tank 2 and the first inlet 411 of the first circulation pipe 41 located at the upper part of the water tank 2.

[0197] During the heat storage phase, 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 usage phase, 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.

[0198] For example, during the water usage phase, when the water temperature in water tank 2 is high, such as... Figure 9As shown, the switch device 92 in the first circulation pipe 41 is in the open state, and the switch device 92 in the second circulation pipe 42 is in the closed state. The water supplied from the external water source passes through the water supply pipe 81 and the heat exchange pipe 5, and then enters the lower part of the water tank 2 through the second circulation pipe 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, thus 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.

[0199] like Figure 15 As shown, in another specific embodiment, the electric water heater further includes a water inlet pipe 83 located in the water tank 2. The electric water heater has a first water usage state and a second water usage state. In the first water usage state, water supplied from the water source can be supplied to the lower part of the water tank 2 through the water supply pipe 81, the heat exchange pipe 5, and the second circulation pipe 42. In the second water usage state, the water inlet pipe 83 directly supplies water to the lower part of the water tank 2.

[0200] For phase change tank 1, the phase change material inside has a certain service life and will fail after reaching a predetermined number of phase change cycles. 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 phase change tank 1 can be activated, while when using a small volume of water, only water tank 2 equipped with heating rod 3 can be used.

[0201] To meet different water consumption needs of users, an inlet pipe 83 can be installed in the water tank 2.

[0202] For example, when a user needs a large amount of water, i.e. when the electric water heater is in the first water usage state, the water supplied from the external water source passes through the water supply pipe 81 and the heat exchange pipe 5, and then enters the lower part of the water tank 2 through the second circulation pipe 42. This sends the water that has exchanged heat with the phase change material in the phase change tank 1 to the lower part of the water tank 2, avoiding the disturbance of the water temperature of the water tank 2 caused by water with a temperature lower than the current water temperature of the water tank 2, ensuring the stability of the outlet water temperature, and at the same time, ensuring that the higher temperature water in the water tank 2 is efficiently output.

[0203] When a user only needs a small amount of water, i.e., when the electric water heater is in its second water usage state, water can be drawn from the inlet pipe 83 in the water tank 2 instead of from the water supply pipe 81 and heat exchange pipe 5. For example, during periods of low water usage (such as non-bathing periods) when the user needs to wash their hands or use other small amounts of water, the heat in the phase change material in the phase change tank 1 can be left unused. After multiple uses, when the heat in the water tank 2 is insufficient, the heating rod 3 in the water tank 2 alone can meet the small water usage needs.

[0204] 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 different user water consumption needs, 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 user operating costs while ensuring user experience.

[0205] In embodiments of this application, the first water inlet 411 is located in the lower, middle, or upper part of the water tank 2; and / or, 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; and / or, the second water outlet 422 is located in the lower, middle, or upper part of the water tank 2.

[0206] In this embodiment, when the heat exchange tube 5 is connected to the water tank 2 through the circulation tube, the hot water heated by the heating rod 3 in the water tank 2 forms a circulating water flow with the heat exchange tube 5 through the circulation tube, thereby storing heat for the phase change material in the phase change tank 1. For the heat exchange tube 5, when the inlet is located at the high point of the heat exchange tube 5, the hot water flowing in from the water tank 2 can flow smoothly downward from the upper part of the phase change tank 1 under the action of gravity, and then flow back to the lower part of the water tank 2 through the circulation tube, thus achieving efficient circulation.

[0207] To ensure efficient circulation between the heat exchange tube 5 and the water tank 2, the inlet of the heat exchange tube 5 is located at the high point of the heat exchange tube 5, and the outlet of the heat exchange tube 5 is located at the low point of the heat exchange tube 5.

[0208] The specific positions of the inlet and outlet of the circulation pipe are illustrated by the following example: the first inlet 411 is located at the upper part of the water tank 2; the first outlet 412 is located at the upper part of the phase change tank 1; the second inlet 421 is located at the lower part of the phase change tank 1; and the second outlet 422 is located at the lower part of the water tank 2.

[0209] The example mainly uses the first water inlet 411 of the first circulation pipe 41 located at the upper part of the water tank 2, the first water outlet 412 located at the upper part of the upper end, the second water inlet 421 of the second circulation pipe 42 located at the lower part of the phase change tank 1, and the second water outlet 422 located at the lower part of the water tank 2 as an example.

[0210] 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 heat exchange pipe 5 at a faster speed and with a shorter path, thereby achieving heat storage of the phase change material. This allows 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 heat exchange pipe 5 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 heat exchange pipe 5 at the upper part, thereby achieving heat storage of the phase change material in the phase change tank 1.

[0211] 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.

[0212] In one embodiment, the inlet of the heat exchange tube 5 is located at the high point of the heat exchange tube 5, the outlet of the heat exchange tube 5 is located at the low point of the heat exchange tube 5, and an insulation layer 93 is provided outside the circulation tube.

[0213] In this embodiment, when the heat exchange tube 5 is connected to the water tank 2 through the circulation tube, the hot water heated by the heating rod 3 in the water tank 2 forms a circulating water flow with the heat exchange tube 5 through the circulation tube, thereby storing heat for the phase change material in the phase change tank 1. For the heat exchange tube 5, when the inlet is located at the high point of the heat exchange tube 5, the hot water flowing in from the water tank 2 can flow smoothly downward from the upper part of the phase change tank 1 under the action of gravity, and then flow back to the lower part of the water tank 2 through the circulation tube, thus achieving efficient circulation.

[0214] Conversely, if hot water enters from the bottom of phase change tank 1, the hot water will flow upward against gravity for a certain distance, but will stop flowing due to the drop in temperature and will not be able to flow to the top of phase change tank 1, thus failing to achieve circulation.

[0215] In addition, an insulation layer 93 is provided on the outside of the circulation pipe for heat preservation and isolation. The first circulation pipe 41 carries heated water from the water tank 2. The insulation layer 93 helps maintain a higher temperature in the hot water within the first circulation pipe 41 before it is introduced into the heat exchange tube 5 of the phase change tank 1. This facilitates efficient heat exchange between the hot water and the phase change material in the phase change tank 1, improving heat exchange efficiency and shortening the heat storage time.

[0216] 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.

[0217] For the second circulation pipe 42, by setting the insulation layer 93, on the one hand, when the water temperature flowing out from the heat exchange pipe 5 is low in the early stage of heat storage, the lower temperature of the second circulation pipe 42 is prevented from directly contacting the higher temperature air and generating condensate on the outside of the second circulation pipe 42; on the other hand, when the water temperature flowing out from the heat exchange pipe 5 is high in the later stage of heat storage, the water in the second circulation pipe 42 can be kept warm, reducing the heating time required by the heating rod 3 and saving energy.

[0218] 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.

[0219] 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.

[0220] 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 phase change tank and a water tank, and a heating rod is installed in the water tank for heating the water in the water tank. The phase change tank has a phase change material for heat storage and heat release. The phase change tank also includes a heat exchange tube connected to the water tank. Water flowing through the heat exchange tube can absorb heat from the phase change material and also release heat to the phase change material. In the height direction of the phase change chamber, along the direction of water flow, at least a portion of the heat exchange tubes are arranged from top to bottom; The electric water heater also includes a circulation pipe connecting the water tank and the heat exchange tube. When the heating rod is working, the hot water in the water tank can circulate between the heat exchange tube and the water tank through the circulation pipe.

2. The electric water heater as described in claim 1, characterized in that, The electric water heater includes at least one reversing connection, which is used to change the flow direction of water in the heat exchange tube. The reversing connection has an inlet section and an outlet section, and the inlet section is higher than the outlet section in the height direction.

3. The electric water heater as described in claim 2, characterized in that, The reversing connection section further includes a connecting section, which is located between the water inlet section and the water outlet section, and is used to connect the water inlet section and the water outlet section; At least a portion of the connecting section extends downward or diagonally downward from the inlet section to the outlet section.

4. The electric water heater as described in claim 3, characterized in that, The projection of the connected segment onto the vertical plane is in the shape of a line segment, an arc, or a broken line.

5. The electric water heater as described in claim 3, characterized in that, The reversing connection is located on the outside of the phase change chamber. The reversing connection includes a connecting pipe, one end of which is the water inlet section, and the other end of which is the water outlet section. or, The reversing communication section includes a protrusion on the plate, with the water inlet section on one side of the protrusion and the water outlet section on the other side of the protrusion.

6. The electric water heater as described in claim 5, characterized in that, The inlet section and the outlet section are respectively connected to the connecting section via an arc surface transition.

7. The electric water heater as described in claim 2, characterized in that, The heat exchange tube comprises multiple sub-heat exchange tubes connected in series, and the multiple sub-heat exchange tubes are connected through the switching communication part. or, The heat exchange tube includes heat exchange flow sections connected in series. The heat exchange flow sections connected in series include at least a first heat exchange flow section and a second heat exchange flow section. Both the first heat exchange flow section and the second heat exchange flow section include multiple sub-heat exchange tubes connected in parallel. The first heat exchange flow section and the second heat exchange flow section are connected through the reversing connection part.

8. The electric water heater as described in claim 7, characterized in that, The heat exchange tube includes multiple sub-heat exchange tubes connected in series. The multiple sub-heat exchange tubes are connected through the reversing connection part and arranged from high to low in the height direction along the water flow direction.

9. The electric water heater as described in claim 7, characterized in that, The heat exchange tube includes heat exchange flow sections connected in series. The heat exchange flow sections connected in series include at least a first heat exchange flow section and a second heat exchange flow section. Both the first heat exchange flow section and the second heat exchange flow section include multiple sub-heat exchange tubes connected in parallel. The first heat exchange flow section and the second heat exchange flow section are connected through the reversing connection part. Along the water flow direction, water flows through the first heat exchange flow section and the second heat exchange flow section in sequence. The first heat exchange flow section is set higher than the second heat exchange flow section in the height direction.

10. The electric water heater as described in claim 9, characterized in that, The multiple heat exchange tubes connected in parallel are arranged horizontally in the height direction.

11. The electric water heater as described in claim 7, characterized in that, The spacing between two adjacent heat exchange tubes is between 20 mm and 50 mm.

12. The electric water heater as described in claim 1 or 11, characterized in that, The diameter of the heat exchange tube is 10 mm or more.

13. The electric water heater as described in claim 1, characterized in that, The heat exchange tubes include heat exchange circular tubes and / or heat exchange flat tubes.

14. The electric water heater as described in claim 13, characterized in that, The heat exchange flat tubes are arranged at an angle, horizontally, or vertically.

15. The electric water heater as described in claim 13, characterized in that, The heat exchange flat tube has a cross-section that is D-shaped, waist-shaped, elliptical, rectangular, or near-rectangular.

16. The electric water heater as described in claim 1, characterized in that, The electric water heater also includes a water distribution device and a water collection device. The water distribution device is located upstream of the water inlet of the heat exchange tube, and the water collection device is located downstream of the water outlet of the heat exchange tube. Both the water distribution device and the water collection device are connected to the circulation pipe. The heat exchange tubes include multiple sub-heat exchange tubes connected in parallel. When the heating rod is working, the water in the water tank can circulate between the water distribution device, the heat exchange tube, the water collection device, and the water tank through the circulation pipe.

17. The electric water heater as described in claim 16, characterized in that, The heat exchange tubes are arranged longitudinally, the water distribution device is located at the upper part of the heat exchange tubes, and the water collection device is located at the lower part of the heat exchange tubes. or, The heat exchange tubes are arranged laterally. In the horizontal direction, the water distribution device is located on one side of the heat exchange tubes, and the water collection device is located on the other side of the heat exchange tubes.

18. 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.

19. 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.

20. The electric water heater according to claim 1 or 18, characterized in that, The phase change tank has a smaller lateral dimension than the water tank.

21. The electric water heater according to claim 20, characterized in that, The electric water heater also includes a housing and a functional device, which includes a switch and an electronic control board. The switch is mounted on the circulation pipe. The phase change tank, the water tank, and the functional device are installed inside the housing. The functional device is located within the accommodating space between the housing and the phase change tank and the water tank.

22. The electric water heater according to claim 1, characterized in that, The heat exchange tube is also used to connect to a water source, through which water can absorb heat from the phase change material and flow into the water tank.

23. The electric water heater according to claim 22, characterized in that, The circulation pipe includes a first circulation pipe and a second circulation pipe. The first circulation pipe 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 pipe 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. A switching device is provided on the first circulation pipe and / or the second circulation pipe.

24. The electric water heater according to claim 23, characterized in that, Water from the water source can flow into the water tank through the heat exchange tube and the second circulation tube; the first water inlet is located at the top of the water tank, and the switch device is installed on the first circulation tube.

25. The electric water heater according to claim 24, characterized in that, The electric water heater also includes a water supply pipe, which is connected to the first circulation pipe via a connecting part. The switching device is located between the connecting part and the first water inlet end, or the water supply pipe is connected to the first circulation pipe via the switching device.

26. The electric water heater according to claim 25, characterized in that, The electric water heater also includes a water inlet pipe, which is located inside the water tank. The electric water heater has a first water usage state and a second water usage state. In the first water usage state, the water supplied by the water source can be supplied to the lower part of the water tank through the water supply pipe, the heat exchange pipe, and the second circulation pipe; In the second water usage state, the water inlet pipe supplies water directly to the lower part of the water tank.

27. The electric water heater according to claim 23, 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.

28. The electric water heater according to claim 23, characterized in that, The inlet of the heat exchange tube is located at the higher part of the heat exchange tube, and the outlet of the heat exchange tube is located at the lower part of the heat exchange tube. The first water inlet is located at the upper part of the water tank. The first water outlet is located at the upper part of the phase change tank. The second water inlet is located at the lower part of the phase change tank. The second water outlet is located at the bottom of the water tank.

29. The electric water heater according to claim 1, characterized in that, The inlet of the heat exchange tube is located at the high point of the heat exchange tube, and the outlet of the heat exchange tube is located at the low point of the heat exchange tube. An insulation layer is provided outside the circulation tube.

30. The electric water heater according to claim 1, characterized in that, The water tank is located below the phase change tank.

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