A phase change water heater

Abstract

The application discloses a phase change water heater, which comprises a shell and a phase change inner container. The phase change inner container is arranged in the shell and comprises a first shell body. The first shell body is filled with a phase change material, and a first heat exchange pipe is arranged in the first shell body. The phase change material is wrapped around the periphery of the first heat exchange pipe. The two ends of the first heat exchange pipe are respectively provided with a first water inlet and a first water outlet. The first heat exchange pipe comprises a forward heat exchange pipe connected with the first water inlet and a return heat exchange pipe connected with the first water outlet. The forward heat exchange pipe and the return heat exchange pipe are connected in series to form an integrated structure. The end of the forward heat exchange pipe close to the first water inlet and the end of the return heat exchange pipe close to the first water outlet are alternately arranged. The phase change water heater reduces the shrinkage of the phase change material during heat release through heat supplement, avoids the generation of a gap between the phase change material and the first heat exchange pipe, and thus guarantees the heat exchange efficiency.

Description

Technical Field

[0001] This invention belongs to the field of water heater technology, and specifically relates to a phase change water heater. Background Technology

[0002] Water heaters mainly include gas water heaters, solar water heaters, air source heat pump water heaters, and electric water heaters. Among them, electric water heaters use electricity as an energy source for heating. Most electric water heaters use storage-type heating, which includes a water storage tank and an electric heating element. The electric heating element heats the water in the tank for the user's use.

[0003] However, storage-type electric water heaters have the following drawbacks: First, the water in the inner tank is repeatedly heated, which can easily breed bacteria and affect the user's water safety; Second, it takes a long time to heat a large amount of water in the inner tank to the set temperature, and the amount of hot water used is limited by the capacity of the inner tank, resulting in long preheating time and insufficient hot water supply, which affects the user's experience; Third, storage-type electric water heaters are large in size, take up a lot of space, and are inconvenient to transport and install.

[0004] To address the aforementioned issues, related technologies disclose the use of phase change materials (PCMs) to exchange heat with water within heat exchange tubes, achieving the goal of outputting hot water and ensuring user safety. However, when cold water is input into the heat exchange tubes, the low temperature of the cold water causes the PCM to rapidly release heat to the cold water inside the tubes. This can easily lead to rapid contraction and solidification of the PCM, creating gaps between the PCM and the heat exchange tubes and affecting subsequent heat exchange efficiency. Summary of the Invention

[0005] The purpose of this invention is to disclose a phase change water heater that reduces the shrinkage of the phase change material when it releases heat by supplementing heat, and avoids the formation of gaps between the phase change material and the first heat exchange tube, thereby ensuring heat exchange efficiency.

[0006] To achieve the above objectives, the present invention discloses a phase change water heater, comprising: shell; The phase change inner liner is located inside the outer shell. The phase change inner liner includes a first shell, which is filled with phase change material. A first heat exchange tube is provided inside the first shell. The phase change material covers the periphery of the first heat exchange tube. A first water inlet and a first water outlet are respectively provided at both ends of the first heat exchange tube. The first heat exchange tube includes a process heat exchange tube connected to the first inlet and a return heat exchange tube connected to the first outlet. The process heat exchange tube and the return heat exchange tube are connected in series to form a single structure. The process heat exchange tube near the first inlet and the return heat exchange tube near the first outlet are arranged alternately.

[0007] As an optional implementation, the first inlet and the first outlet are arranged close to each other on the same side, the process heat exchange tube is coiled away from the first inlet, the return heat exchange tube is coiled away from the first outlet, the far end of the process heat exchange tube and the far end of the return heat exchange tube are connected in series, and the process heat exchange tube and the return heat exchange tube are coiled alternately along the same path.

[0008] As an optional implementation, the outer shell is provided with a liquid storage tank, which includes a second shell. The second shell is filled with heat exchange fluid and a second heat exchange tube is provided inside the second shell. The heat exchange fluid covers the periphery of the second heat exchange tube. The two ends of the second heat exchange tube are respectively provided with a second inlet and a second outlet. The second inlet and the first outlet are connected by a connecting pipe. The first inlet is used to input cold water and the second outlet is used to output hot water.

[0009] As an optional implementation, the side walls of the first housing and the second housing are fitted together, and a heating element is provided inside the second housing for heating the heat exchange fluid.

[0010] As an alternative implementation, the first housing covers at least the two adjacent outer sidewalls of the second housing.

[0011] As an optional implementation, both the first shell and the second shell are square structures, with the first shell covering the four adjacent outer side walls of the second shell.

[0012] As an optional implementation, the second heat exchange tube includes an inner heat exchange tube and an outer heat exchange tube connected in series. The inner heat exchange tube and the outer heat exchange tube are both coiled up and down. The outer heat exchange tube is located around the inner heat exchange tube. The ends of the inner heat exchange tube and the outer heat exchange tube that are far apart from each other are respectively provided with a second water inlet and a second water outlet.

[0013] As an optional implementation, the inner heat exchange tube is coiled from top to bottom, and the outer heat exchange tube is coiled from bottom to top around the inner heat exchange tube. The lower ends of the inner heat exchange tube and the lower ends of the outer heat exchange tube are connected in series to form an integral structure, and the two ends of the integral structure are respectively connected to the second water inlet and the second water outlet.

[0014] As an optional implementation, the second inlet is connected to the upper end of the inner heat exchange tube, the second outlet is connected to the upper end of the outer heat exchange tube, the heating element is located below the second heat exchange tube, and the heating element is located within the vertical projection area of ​​the inner heat exchange tube.

[0015] As an optional implementation, the heating element includes a first heating tube, a second heating tube, and a temperature probe. The first heating tube and the second heating tube are spaced apart on the same horizontal plane, and the temperature probe is used to detect the temperature of the heat exchange fluid.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: In the phase change water heater of the present invention, the intermediate heat exchange tubes near the first inlet and the return heat exchange tubes near the first outlet are arranged alternately. When cold water is input into the first heat exchange tube, the cold water temperature in the intermediate heat exchange tube near the first inlet is the lowest, and the phase change material around it quickly releases heat to the cold water. Meanwhile, the water in the return heat exchange tube near the first outlet has a higher temperature after flowing and exchanging heat throughout the entire first heat exchange tube. It can replenish heat to the surrounding phase change material, thereby reducing the contraction of the phase change material when releasing heat and avoiding gaps between the phase change material and the first heat exchange tube, thus ensuring heat exchange efficiency. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the phase change water heater of the present invention; Figure 2 This is a schematic diagram of the inner tank structure of the phase change water heater of the present invention; Figure 3 This is a schematic diagram of the phase change inner liner of the present invention; Figure 4 This is a top sectional view of the phase change inner liner of the present invention; Figure 5 This is an exploded view of the phase change inner liner of the present invention; Figure 6 This is a schematic diagram of the structure of the liquid storage liner of the present invention; Figure 7 This is a top sectional view of the liquid storage liner of the present invention; Figure 8 This is an exploded view of the liquid storage liner of the present invention; Figure 9 This is a schematic diagram of the structure of the second heat exchange tube of the present invention; Figure 10 This is a schematic diagram of the structure of the first heat exchange tube of the present invention; Figure 11 This is a schematic diagram of the structure of the series heat exchanger tube of the present invention.

[0019] Explanation of key figure labels: 1. Outer shell; 2. Phase change inner liner; 21. First shell; 22. Phase change material; 23. First heat exchange tube; 231. First inlet; 232. First outlet; 233. Process heat exchange tube; 234. Return heat exchange tube; 3. Liquid storage inner liner; 31. Second shell; 32. Second heat exchange tube; 321. Second inlet; 322. Second outlet; 323. Inner heat exchange tube; 324. Outer heat exchange tube; 4. Connecting pipe; 5. Heating element; 51. First heating tube; 52. Second heating tube; 53. Temperature probe. Detailed Implementation

[0020] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0021] In this invention, the terms "upper," "lower," "left," "right," "front," "rear," "top," "bottom," "inner," "outer," "middle," "vertical," "horizontal," "lateral," and "longitudinal" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. These terms are primarily for the purpose of better describing the invention and its embodiments, and are not intended to limit the indicated devices, elements, or components to having a specific orientation, or to be constructed and operated in a specific orientation.

[0022] Furthermore, some of the aforementioned terms, besides indicating direction or positional relationships, may also have other meanings. For example, the term "above" may, in certain circumstances, indicate a dependency or connection. Those skilled in the art can understand the specific meaning of these terms in this invention based on the specific circumstances.

[0023] Furthermore, the terms "installation," "setup," "equipped with," "connection," and "linked" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral structure; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium, or an internal connection between two devices, components, or parts. Those skilled in the art can understand the specific meaning of these terms in this invention based on the specific circumstances.

[0024] Furthermore, the terms "first," "second," etc., are primarily used to distinguish different devices, components, or parts (which may be the same or different in specific type and construction), and are not intended to indicate or imply the relative importance or quantity of the indicated devices, components, or parts. Unless otherwise stated, "a plurality of" means two or more.

[0025] The technical solution of the present invention will be further described below with reference to the embodiments and accompanying drawings.

[0026] Please see Figure 1 and Figure 3-5 As shown in the figure, this application provides a phase change water heater, including an outer shell 1 and a phase change inner tank 2. The phase change inner tank 2 is disposed inside the outer shell 1. The phase change inner tank 2 includes a first shell 21, which is filled with a phase change material 22. A first heat exchange tube 23 is provided inside the first shell 21. The phase change material 22 covers the periphery of the first heat exchange tube 23. A first water inlet 231 and a first water outlet 232 are respectively provided at both ends of the first heat exchange tube 23.

[0027] The outer shell 1 is used to support the water heater inner tank and water circuit components. The water heater inner tank is located inside the outer shell 1 and is used to heat cold water. The water circuit components are located inside the outer shell 1 to connect to the water heater inner tank, and the water circuit components extend out of the outer shell 1 to connect to external water pipes, thereby realizing the input of cold water into the water heater inner tank for heating, and outputting hot water to the user.

[0028] The water heater inner tank includes a phase change inner tank 2. The first shell 21 of the phase change inner tank 2 is fixed inside the outer shell 1. The phase change material 22 and the first heat exchange tube 23 are disposed inside the first shell 21. The phase change material 22 can be an inorganic phase change material or an organic phase change material, selected according to the heat exchange requirements of the water heater. The first inlet 231 of the first heat exchange tube 23 is used to connect to the water circuit assembly to input cold water, and the first outlet 232 of the first heat exchange tube 23 is used to connect to the water circuit assembly to output hot water. The phase change material 22 completely covers the periphery of the first heat exchange tube 23. After cold water enters the first heat exchange tube 23 through the first inlet 231, the phase change material 22 releases heat to the cold water in the first heat exchange tube 23. As the cold water flows in the first heat exchange tube 23, it continuously absorbs heat and its temperature rises to obtain hot water, which is then output to the water circuit assembly through the first outlet 232 and then supplied to the user.

[0029] To ensure the heat exchange efficiency between the phase change material 22 and the water in the first heat exchange tube 23, the phase change material 22 needs to completely cover the first heat exchange tube 23. However, when cold water is initially introduced into the first heat exchange tube 23, especially near the first inlet 231, the temperature of the cold water in the first heat exchange tube 23 is the lowest. The phase change material 22 around the first heat exchange tube 23 at this location will quickly release heat to the cold water in the first heat exchange tube 23. This can easily cause the phase change material 22 around the first heat exchange tube 23 at this location to rapidly shrink and solidify, creating a gap between the phase change material 22 and the first heat exchange tube 23, thereby affecting the heat exchange effect between the phase change material 22 and the water in the first heat exchange tube 23.

[0030] The first heat exchange tube 23 in this embodiment includes a process heat exchange tube 233 connected to the first inlet 231 and a return heat exchange tube 234 connected to the first outlet 232. The process heat exchange tube 233 and the return heat exchange tube 234 are connected in series to form an integral structure. The end of the process heat exchange tube 233 near the first inlet 231 and the end of the return heat exchange tube 234 near the first outlet 232 are arranged alternately.

[0031] One end of the process heat exchange tube 233 is connected to the first inlet 231, and one end of the return heat exchange tube 234 is connected to the first outlet 232. The other end of the process heat exchange tube 233 is connected to the other end of the return heat exchange tube 234. After cold water is input from the first inlet 231, it first flows in the process heat exchange tube 233 to exchange heat with the phase change material 22 around the process heat exchange tube 233, and then flows into the return heat exchange tube 234 to exchange heat with the phase change material 22 around the return heat exchange tube 234. Finally, hot water is output from the first outlet 232. Therefore, it can be seen that the water temperature in the process heat exchange tube 233 is lower than that in the return heat exchange tube 234. In particular, there is a significant difference between the water temperature in the process heat exchange tube 233 near the first inlet 231 and the water temperature in the return heat exchange tube 234 near the first outlet 232. The water temperature in the process heat exchange tube 233 near the first inlet 231 is the lowest, and the water temperature in the return heat exchange tube 234 near the first outlet 232 is the highest. The process heat exchange tube 233, with its end near the first inlet 231, and the return heat exchange tube 234, with its end near the first outlet 232, are arranged alternately. This allows the heat from the water in the return heat exchange tube 234 near the first outlet 232 to replenish the phase change material 22 surrounding the process heat exchange tube 233 near the first inlet 231. This reduces the contraction of the phase change material 22 when it releases heat, preventing gaps between the phase change material 22 and the first heat exchange tube 23, especially the process heat exchange tube 233, thus ensuring heat exchange efficiency. This alternating arrangement eliminates the need for an additional heater in the first housing 21 to heat the phase change material 22, achieving the goal of preventing rapid contraction of the phase change material 22 when it releases heat and creating gaps with the first heat exchange tube 23. It also helps to extend the length of the first heat exchange tube 23, improving heat exchange efficiency, and is easy to assemble.

[0032] See Figure 3 and Figure 10 The first inlet 231 and the first outlet 232 are set close to each other on the same side. The process heat exchange tube 233 is coiled away from the first inlet 231, and the return heat exchange tube 234 is coiled away from the first outlet 232. The far end of the process heat exchange tube 233 and the far end of the return heat exchange tube 234 are connected in series, and the process heat exchange tube 233 and the return heat exchange tube 234 are coiled alternately along the same path.

[0033] Both the first inlet 231 and the first outlet 232 can be located on the right or left side wall of the first housing 21, which facilitates water circuit installation and allows the first inlet 231 and the first outlet 232 to be positioned close together. In this way, the end of the process heat exchange tube 233 near the first inlet 231 and the end of the return heat exchange tube 234 near the first outlet 232 can be positioned close together, which facilitates the transfer of heat from the water in the return heat exchange tube 234 near the first outlet 232 to the phase change material 22 around the process heat exchange tube 233 near the first inlet 231.

[0034] The process heat exchange tube 233 is coiled gradually away from the first inlet 231 within the first housing 21, and the return heat exchange tube 234 is coiled gradually away from the first outlet 232 within the first housing 21. The distant ends of the two tubes are connected to form the first heat exchange tube 23. Figure 10 As shown, the process heat exchange tube 233 can gradually spiral towards the left inner wall of the first shell 21 from the first inlet 231 in an upward, backward, downward and forward direction. Similarly, the return heat exchange tube 234 can gradually spiral towards the left inner wall of the first shell 21 from the first outlet 232 in an upward, backward, downward and forward direction. The ends of the two tubes near the left inner wall of the first shell 21 are connected to form the first heat exchange tube 23. Thus, the left and right sides of each loop of process heat exchange tube 233 are both return heat exchange tubes 234, and the left and right sides of each loop of return heat exchange tube 234 are both process heat exchange tubes 233. This allows the heat from the water in each return heat exchange tube 234 to replenish the phase change material 22 around the corresponding process heat exchange tube 233. This allows all the phase change material 22 in the first shell 21 to reduce heat release and contraction through heat replenishment. Consequently, all the phase change material 22 is tightly wrapped around the periphery of the first heat exchange tube 23, ensuring the heat exchange efficiency between the phase change material 22 and the water in the first heat exchange tube 23.

[0035] Generally, the first half of the process heat exchange tube 233 near the first inlet 231 is prone to rapid heat release from the surrounding phase change material 22 due to the lower temperature of the cold water, while the water temperature in the return heat exchange tube 234 near the first outlet 232 is higher due to heat exchange. Therefore, in practical applications, the heat exchange tube 233 near the first inlet 231 and the return heat exchange tube 234 near the first outlet 232 can be alternately arranged to complete the heat replenishment of the phase change material 22, and the other parts can be freely arranged.

[0036] Based on the above structure, see [link / reference] Figure 1-2 , Figure 6-8 and Figure 11The outer shell 1 is provided with a liquid storage tank 3. The liquid storage tank 3 includes a second shell 31, which is filled with heat exchange liquid and has a second heat exchange tube 32 inside. The heat exchange liquid covers the periphery of the second heat exchange tube 32. The two ends of the second heat exchange tube 32 are respectively provided with a second inlet 321 and a second outlet 322. The second inlet 321 and the first outlet 232 are connected by a connecting pipe 4. The first inlet 231 is used to input cold water, and the second outlet 322 is used to output hot water.

[0037] The water heater inner tank includes not only the phase change inner tank 2, but also the liquid storage inner tank 3. The second shell 31 of the liquid storage inner tank 3 is fixed inside the outer shell 1. The heat exchange liquid and the second heat exchange tube 32 are located inside the second shell 31. The heat exchange liquid can be water, oil, etc. The second inlet 321 of the second heat exchange tube 32 is used to input water, and the second outlet 322 of the second heat exchange tube 32 is used to output water. The heat exchange liquid completely covers the periphery of the second heat exchange tube 32 so as to efficiently exchange heat with the water in the second heat exchange tube 32 through the high temperature heat exchange liquid.

[0038] Within the entire water heater tank, the first inlet 231 of the first heat exchange tube 23 is used to connect to the water circuit assembly for cold water input. The first outlet 232 of the first heat exchange tube 23 is connected to the second inlet 321 of the second heat exchange tube 32 via the connecting pipe 4. The second outlet 322 of the second heat exchange tube 32 is used to connect to the water circuit assembly for hot water output. Thus, after the water heater is started, cold water first enters the first heat exchange tube 23 through the first inlet 231 to exchange heat with the phase change material 22, then enters the second heat exchange tube 32 through the first outlet 232, the connecting pipe, and the second inlet 321 to exchange heat with the heat exchange fluid, and finally, hot water is output to the user through the second outlet 322 and the water circuit assembly. Phase change material 22 has a large heat storage capacity, and it can exchange heat with a large amount of cold water with a small volume. Combined with the secondary heat exchange of the heat exchange liquid, it is beneficial to extend the length of the heat exchange tube and the heat exchange time of the water, thereby further increasing the temperature of the water in the heat exchange tube and realizing a large amount of hot water output. It has the characteristics of high heat exchange efficiency and small size, which is conducive to providing users with a good water experience and facilitating the transportation and installation of water heaters.

[0039] Furthermore, the hot water output by this water heater to users is flowing, live water that has undergone heat exchange, rather than water that has been repeatedly heated and stored in the inner tank of the water heater. This makes it less prone to bacterial growth, which helps improve the quality of the hot water output by the water heater and ensures the safety of users' water use.

[0040] The heat exchange tube is divided into three sections. The first heat exchange tube 23 is independently installed in the first shell 21, and the second heat exchange tube 32 is independently installed in the second shell 31. The first heat exchange tube 23 and the second heat exchange tube 32 are connected by a connecting pipe 4, which facilitates the assembly of the water heater.

[0041] See Figure 2The first shell 21 and the second shell 31 are fitted together on their sidewalls. A heating element 5 is installed inside the second shell 31 to heat the heat exchange fluid. This sidewall fitting structure provides a large contact area between the first shell 21 and the second shell 31. With the phase change material 22 filling the first shell 21 and the heat exchange fluid filling the second shell 31, heat exchange can occur between the phase change material 22 and the heat exchange tubes. Thus, by simply installing the heating element 5 inside the second shell 31 to heat the heat exchange fluid, and utilizing the heat exchange between the heat exchange fluid and the phase change material 22, the phase change material 22 and the heat exchange fluid can be stored. This design is characterized by low cost, simple structure, and small size. Since the temperature of the phase change material 22 is difficult to control by direct heating, this structure avoids direct heating of the phase change material 22, thereby ensuring its excellent heat storage performance.

[0042] The bonding structure of the first shell 21 and the second shell 31 can be one side wall of the two shells bonded together, or two or more side walls bonded together. This is beneficial to increase the contact area to improve the heat exchange effect between the phase change material 22 and the heat exchange liquid, and to extend the length of the heat exchange tube to further improve the heat exchange efficiency and the amount of hot water produced.

[0043] In a preferred embodiment, the first housing 21 covers at least two adjacent outer sidewalls of the second housing 31. The design of the two adjacent outer sidewalls facilitates the stable and smooth arrangement of the first heat exchange tube 23 within the first housing 21, and improves the integration of the first heat exchange tube 23, reducing the space occupied by the first heat exchange tube 23 while ensuring its effective heat exchange length.

[0044] More preferably, both the first shell 21 and the second shell 31 are square structures, with the first shell 21 covering the four adjacent outer side walls of the second shell 31. The square structure design offers high space utilization, reducing the size of the water heater and facilitating the bonding structure design between the first shell 21 and the second shell 31, thus improving the integration of the phase change inner tank 2 and the liquid storage inner tank 3. The first shell 21 is attached to the outer sides of all four side walls of the second shell 31, allowing for a larger internal space within the first shell 21 to accommodate more phase change material 22 and to lay a longer first heat exchange tube 23. This further extends the heat exchange time of the water within the first heat exchange tube 23, improving heat exchange efficiency and ensuring sufficient heat exchange with the phase change material 22, avoiding heat waste. The selection of the four adjacent side walls can be determined according to assembly requirements; simply select four adjacent side walls from the front, back, left, right, top, and bottom of the second shell 31.

[0045] In this embodiment, the first shell 21 covers the outer sides of the front wall, bottom wall, rear wall, and top wall of the second shell 31. The first shell 21 is attached to the outer sides of the front, rear, top, and bottom circumferences of the second shell 31, allowing for stable installation of the first shell 21 without the need for a fixing structure. This also allows for a larger internal space within the first shell 21 to accommodate more phase change material 22 and to allow for the placement of a longer first heat exchange tube 23, further extending the heat exchange time of the water within the first heat exchange tube 23 and increasing the volume of hot water. Furthermore, the phase change material 22 completely covers the outer side of the second shell 31, enabling sufficient heat exchange with the heat exchange liquid and preventing heat waste.

[0046] See Figure 7-9 The second heat exchange tube 32 includes an inner heat exchange tube 323 and an outer heat exchange tube 324 connected in series. The inner heat exchange tube 323 and the outer heat exchange tube 324 are both coiled up and down. The outer heat exchange tube 324 is located around the inner heat exchange tube 323. The ends of the inner heat exchange tube 323 and the outer heat exchange tube 324 that are far apart from each other are respectively provided with a second water inlet 321 and a second water outlet 322.

[0047] The second heat exchange tube 32 is divided into two parts, with an inner and outer covering and coiled structure. The combination of the inner heat exchange tube 323 and the outer heat exchange tube 324 can greatly extend the length of the second heat exchange tube 32 within the second shell 31. This helps to extend the heat exchange time between the water in the second heat exchange tube 32 and the heat exchange liquid in the second shell 31, making full use of the heat of the heat exchange liquid to achieve efficient heat exchange of the living water. This is beneficial to further increase the output of hot water and ensure the hot water temperature, thereby significantly reducing the heat waste of the heat exchange liquid.

[0048] The inner heat exchange tube 323 is coiled from top to bottom, and the outer heat exchange tube 324 is coiled from bottom to top around the inner heat exchange tube 323. The lower end of the inner heat exchange tube 323 and the lower end of the outer heat exchange tube 324 are connected in series to form an integral structure. The two ends of the integral structure are respectively connected to the second inlet 321 and the second outlet 322.

[0049] The second heat exchange tube 32 is divided into two parts that are covered internally and externally and coiled in opposite directions in the vertical direction. During heat exchange, the water in the second heat exchange tube 32 can complete two vertical flows, which is conducive to efficient heat exchange in terms of heat exchange path and space. The inner heat exchanger tube 323 and the outer heat exchanger tube 324 are connected in series. The two ends of this series structure are respectively connected to the second inlet 321 and the second outlet 322. The second inlet 321 can be located at the end of the inner heat exchanger tube 323, and the second outlet 322 can be located at the end of the outer heat exchanger tube 324. In this way, after water enters the second heat exchanger tube 32 through the second inlet 321, it first exchanges heat through the inner heat exchanger tube 323, then through the outer heat exchanger tube 324, and then hot water is output through the second outlet 322. Alternatively, the second inlet 321 can be located at the end of the outer heat exchanger tube 324, and the second outlet 322 can be located at the end of the inner heat exchanger tube 323. In this way, after water enters the second heat exchanger tube 32 through the second inlet 321, it first exchanges heat through the outer heat exchanger tube 324, then through the inner heat exchanger tube 323, and then hot water is output through the second outlet 322.

[0050] Preferably, the second inlet 321 is connected to the upper end of the inner heat exchange tube 323, the second outlet 322 is connected to the upper end of the outer heat exchange tube 324, the heating element 5 is located below the second heat exchange tube 32, and the heating element 5 is located in the vertical projection area of ​​the inner heat exchange tube 323.

[0051] After water enters the second heat exchange tube 32 through the second inlet 321, it first flows from top to bottom in the inner heat exchange tube 323 to the bottom, and then enters the outer heat exchange tube 324 and flows from bottom to top. After completing the heat exchange, hot water is output from the second outlet 322. When the heating element 5 heats the heat exchange fluid, since the density of the hot heat exchange fluid is less than that of the cold heat exchange fluid, the heat exchange fluid directly below the inner heat exchange tube 323 heated by the heating element 5 flows upward, while the cold heat exchange fluid in the upper part of the vertical area where the inner heat exchange tube 323 is located flows downward. This process is repeated to ensure that the heat exchange fluid in the vertical area where the inner heat exchange tube 323 is located is heated first. Because water enters the inner heat exchange tube 323 first for heat exchange, rapid and efficient heat exchange can be achieved. Then the heat exchange fluid diffuses to the edge. Since the heating element 5 is at the bottom, the heat exchange fluid at the bottom of the periphery of the inner heat exchange tube 323 is heated first, and then extends to other areas above to achieve a uniform temperature distribution of the heat exchange fluid in the entire second shell 31. At this time, the water flows into the outer heat exchange tube 324, which can also ensure the heat exchange effect of the cold water. Based on this, the water in the second heat exchange tube 32 first flows from top to bottom through the inner heat exchange tube 323, and then flows from bottom to top through the outer heat exchange tube 324. When the water heater is initially started, the flow path of the water in the second heat exchange tube 32 corresponds to the area where the heat exchange liquid in the second shell 31 has been heated. This ensures that the water can also exchange heat efficiently when it first enters the second heat exchange tube 32, thereby shortening the time for the water heater to discharge cold water during initial use and quickly obtaining hot water for users, which is beneficial to improving the user experience.

[0052] See Figure 6-8 The heating element 5 includes a first heating tube 51, a second heating tube 52 and a temperature probe 53. The first heating tube 51 and the second heating tube 52 are spaced apart on the same horizontal plane, and the temperature probe 53 is used to detect the temperature of the heat exchange fluid.

[0053] Heating element 5 is connected to the control unit of the water heater. The control unit controls the first heating element 51 and the second heating element 52 to start heating the heat exchange fluid. Temperature probe 53 is used to detect the temperature of the heat exchange fluid and feed it back to the control unit. When the temperature reaches the target, the first heating element 51 and the second heating element 52 stop heating. During the use of the water heater, the temperature of the heat exchange fluid will decrease due to heat exchange with the water in the second heat exchange tube 32. Therefore, the first heating element 51 and the second heating element 52 can be turned on intermittently to ensure the heat storage of the heat exchange fluid.

[0054] The first heating tube 51 and the second heating tube 52 are spaced apart below the inner heat exchange tube 323. The mounting portions of the first heating tube 51, the second heating tube 52, and the temperature probe 53 are all fixed to the side wall of the second housing 31, and their main bodies extend to the bottom of the second heat exchange tube 32 inside the second housing 31 and are located within the vertical projection area of ​​the inner heat exchange tube 323. The two heating tubes are spaced apart along the width direction of the second housing 31, which is beneficial to improving the heating efficiency and heating uniformity of the heat exchange fluid.

[0055] The technical means disclosed in this invention are not limited to those disclosed in the above embodiments, but also include technical solutions composed of any combination of the above technical features. It should be noted that those skilled in the art can make various improvements and modifications without departing from the principles of this invention, and these improvements and modifications are also considered within the scope of protection of this invention.

Claims

1. A phase change water heater, characterized in that, include: shell; A phase change inner liner is disposed inside the outer shell. The phase change inner liner includes a first shell, which is filled with a phase change material and has a first heat exchange tube inside. The phase change material covers the periphery of the first heat exchange tube, and the two ends of the first heat exchange tube are respectively provided with a first water inlet and a first water outlet. The first heat exchange tube includes a process heat exchange tube connected to the first inlet and a return heat exchange tube connected to the first outlet. The process heat exchange tube and the return heat exchange tube are connected in series to form an integral structure. The end of the process heat exchange tube near the first inlet and the end of the return heat exchange tube near the first outlet are arranged alternately.

2. The phase change water heater according to claim 1, characterized in that: The first inlet and the first outlet are located close to each other on the same side. The process heat exchange tube is coiled away from the first inlet, and the return heat exchange tube is coiled away from the first outlet. The far end of the process heat exchange tube and the far end of the return heat exchange tube are connected in series, and the process heat exchange tube and the return heat exchange tube are coiled alternately along the same path.

3. The phase change water heater according to claim 1 or 2, characterized in that: The outer shell is provided with a liquid storage tank, which includes a second shell. The second shell is filled with heat exchange fluid and has a second heat exchange tube inside. The heat exchange fluid covers the periphery of the second heat exchange tube. The two ends of the second heat exchange tube are respectively provided with a second inlet and a second outlet. The second inlet and the first outlet are connected by a connecting pipe. The first inlet is used to input cold water, and the second outlet is used to output hot water.

4. The phase change water heater according to claim 3, characterized in that: The first housing and the sidewall of the second housing are fitted together. The second housing is provided with a heating element for heating the heat exchange fluid.

5. The phase change water heater according to claim 4, characterized in that: The first housing covers at least the two adjacent outer sidewalls of the second housing.

6. The phase change water heater according to claim 5, characterized in that: Both the first shell and the second shell are square structures, with the first shell covering the four adjacent outer side walls of the second shell.

7. The phase change water heater according to claim 4, characterized in that: The second heat exchange tube includes an inner heat exchange tube and an outer heat exchange tube connected in series. The inner heat exchange tube and the outer heat exchange tube are coiled up and down. The outer heat exchange tube is located around the inner heat exchange tube. The second water inlet and the second water outlet are respectively provided at the ends of the inner heat exchange tube and the outer heat exchange tube that are far apart from each other.

8. The phase change water heater according to claim 7, characterized in that: The inner heat exchange tube is coiled from top to bottom, and the outer heat exchange tube is coiled from bottom to top around the inner heat exchange tube. The lower end of the inner heat exchange tube and the lower end of the outer heat exchange tube are connected in series to form an integral structure. The two ends of the integral structure are respectively connected to the second water inlet and the second water outlet.

9. The phase change water heater according to claim 8, characterized in that: The second inlet is connected to the upper end of the inner heat exchange tube, the second outlet is connected to the upper end of the outer heat exchange tube, the heating element is located below the second heat exchange tube, and the heating element is located within the vertical projection area of ​​the inner heat exchange tube.

10. The phase change water heater according to claim 4, characterized in that: The heating element includes a first heating tube, a second heating tube, and a temperature probe. The first heating tube and the second heating tube are spaced apart on the same horizontal plane, and the temperature probe is used to detect the temperature of the heat exchange fluid.

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