A phase change heat storage device

Abstract

The application provides a phase change heat storage device, which comprises an upper negative pressure tank, a heat releasing finned tube, a phase change heat transfer pipeline, a heat dissipation fin, a lower negative pressure tank, a heat storage finned tube, a refrigerant medium, a heat storage tank and paraffin wax. The upper negative pressure tank and the lower negative pressure tank are respectively fixedly installed at the upper and lower ends of the heat storage tank and are fixedly connected by a phase change heat transfer pipeline through a sealing joint. The lower end of the phase change heat transfer pipeline is in sealing communication with the lower negative pressure tank, the heat storage finned tube is distributed in the lower negative pressure tank, the upper end of the phase change heat transfer pipeline is in sealing communication with the upper negative pressure tank, the heat releasing finned tube is distributed in the upper negative pressure tank, the paraffin wax is stored in the heat storage tank, and the refrigerant medium is filled into a sealed cavity formed by the upper negative pressure tank, the lower negative pressure tank and the phase change heat transfer pipeline in a negative pressure mode. The structure improves the heat storage and heat releasing efficiency, reduces the heat exchange area and heat loss, reduces the operation and maintenance cost, and avoids the damage of the heat storage device caused by the fact that the phase change heat transfer pipeline cannot be cleaned due to pipeline blockage.

Description

Technical Field

[0001] This invention relates to the field of thermal energy storage technology, and in particular to a phase change thermal energy storage device. Background Technology

[0002] Phase change thermal energy storage technology utilizes the property of phase change materials to absorb or release a large amount of latent heat during the phase change process, thereby achieving the storage and release of thermal energy. It has advantages such as high thermal density and small temperature fluctuations. Currently, phase change thermal energy storage devices are widely used in industrial production, building heating, solar power generation, and other fields.

[0003] However, existing phase change thermal energy storage devices generally suffer from low heat transfer efficiency and high investment costs. On the one hand, the limited contact area between the phase change material and the heat transfer pipes leads to insufficient heat transfer; on the other hand, the scheme of directly transferring heat to the phase change material without the conversion of the cold medium will cause scaling and blockage of the phase change heat transfer pipes over time, which cannot be cleaned and will eventually lead to the scrapping of the phase change thermal energy storage device, resulting in waste. Therefore, there is an urgent need to design a phase change thermal energy storage device with a reasonable structure, high heat transfer efficiency, and good reliability. Summary of the Invention

[0004] According to an objective of the present invention, and in light of the problems raised in the background, the present invention provides a dual phase change thermal storage device that combines a heat transfer medium and a heat storage medium, in order to solve the problems of low heat transfer efficiency and scaling and clogging in existing phase change thermal storage devices.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a phase change heat storage device, comprising an upper negative pressure tank, a heat dissipation finned tube, a phase change heat transfer pipe, a heat sink, a lower negative pressure tank, a heat storage finned tube, a cooling medium, a heat storage tank, and paraffin wax. The upper and lower negative pressure tanks are respectively fixedly installed at the upper and lower ends of the heat storage tank, and are sealed and fixedly connected in the middle by the phase change heat transfer pipe through a sealing joint. The lower end of the phase change heat transfer pipe is sealed and connected to the lower negative pressure tank, and the heat storage finned tubes are distributed inside the lower negative pressure tank. The upper end of the phase change heat transfer pipe is sealed and connected to the upper negative pressure tank, and the heat dissipation finned tubes are distributed inside the upper negative pressure tank.

[0006] Furthermore, the heat storage tank is a sealed cavity structure with an atmospheric balance hole, and is filled with paraffin as a phase change heat storage material. During the phase change process, paraffin can absorb or release a large amount of latent heat, thereby realizing the storage and release of thermal energy.

[0007] Furthermore, the cold medium filled inside the upper negative pressure tank, lower negative pressure tank, and phase change heat transfer pipe is in a negative pressure state. The magnitude of the negative pressure can control the temperature of the phase change of the cold medium, ensuring that the cold medium absorbs and releases heat during the phase change, and ensuring the stable operation of the device.

[0008] Furthermore, the phase change heat transfer pipes are evenly distributed in the paraffin in a serpentine pattern. This uniform arrangement design increases the contact area between the phase change heat transfer pipes and the paraffin, thereby improving heat transfer efficiency.

[0009] Furthermore, the heat sink is located on the outside of the phase change heat transfer pipe and is fixedly connected to the outer wall of the phase change heat transfer pipe. Multiple heat sinks are evenly distributed along the length of the phase change heat transfer pipe to further expand the heat transfer area and accelerate the transfer of heat between the paraffin and the phase change heat transfer pipe.

[0010] Furthermore, the heat sink is provided with paraffin flow holes to ensure that the paraffin melts and forms convection, facilitating uniform heat transfer.

[0011] Furthermore, the upper part of the heat storage tank is provided with an atmospheric balance hole to balance the volume expansion of the paraffin wax after it changes from a solid to a liquid state.

[0012] Furthermore, the negative pressure inside the negative pressure tank can vary depending on the selected refrigerant, so as to control the phase change temperature of the refrigerant between 50°C and 80°C.

[0013] Furthermore, the outer wall of the heat storage tank is provided with an insulation layer, which is made of rock wool or polyurethane insulation material, which can effectively reduce heat loss and improve the heat storage efficiency of the device.

[0014] Furthermore, the heat-releasing finned tube and the heat-storing finned tube are finned tubes, which can improve heat exchange efficiency.

[0015] This invention provides a phase change thermal energy storage device. Through a dual-medium phase change process involving a cold medium and paraffin wax, and a serpentine arrangement of phase change heat transfer pipes, combined with external heat sinks, the contact area with the phase change material is significantly increased, accelerating heat transfer and improving thermal storage and release efficiency. Because the cold medium flowing within the serpentine phase change heat transfer pipes operates in a closed loop, despite the complex pipe shape, scaling and blockages do not occur, avoiding the problem of the thermal energy storage device becoming unusable due to unrecoverable blockages. Attached Figure Description

[0016] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0017] Figure 1 This is a structural schematic diagram of an embodiment of the present invention;

[0018] Figure 2 yes Figure 1 A sectional view;

[0019] Figure 3 This is an arrangement diagram of phase change heat transfer pipes;

[0020] Figure 4 This is another arrangement diagram of phase change heat transfer pipes;

[0021] In the diagram: 1. Upper negative pressure tank; 2. Heat dissipation finned tube; 3. Phase change heat transfer pipe; 4. Heat sink; 5. Lower negative pressure tank; 6. Heat storage finned tube; 7. Cold medium; 8. Heat storage tank; 9. Paraffin wax; 10. Atmospheric balance hole; 11. Paraffin wax flow hole. Detailed Implementation

[0022] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. 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.

[0023] In the description of this invention, it should be understood that the terms "center", "upper", "lower", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0024] Example 1

[0025] like Figure 1 As shown, a phase change heat storage device includes an upper negative pressure tank 1, a heat dissipation finned tube 2, a phase change heat transfer pipe 3, a heat sink 4, a lower negative pressure tank 5, a heat storage finned tube 6, a cold medium 7, a heat storage tank 8, and paraffin wax 9. The upper negative pressure tank 1 and the lower negative pressure tank 5 are respectively fixedly installed at the upper and lower ends of the heat storage tank 8, and are sealed and fixedly connected in the middle by the phase change heat transfer pipe 3 through a sealing joint. The lower end of the phase change heat transfer pipe 3 is sealed and connected to the lower negative pressure tank 5. The heat storage finned tube 6 is distributed inside the lower negative pressure tank 5. The upper end of the phase change heat transfer pipe 3 is sealed and connected to the upper negative pressure tank 1. The heat dissipation finned tube 2 is distributed inside the upper negative pressure tank 1.

[0026] The heat storage tank 8 is a sealed cavity structure with an atmospheric balance hole 10, and is filled with paraffin wax 9 as a phase change heat storage material. During the phase change process, paraffin wax 9 can absorb or release a large amount of latent heat, realizing the storage and release of thermal energy.

[0027] The cold medium 7 filled inside the upper negative pressure tank 1, the lower negative pressure tank 5, and the phase change heat transfer pipe 3 is normally in a negative pressure state. The magnitude of the negative pressure can control the phase change temperature of the cold medium 7, ensuring that the cold medium 7 absorbs and releases heat during the phase change, and ensuring the stable operation of the device.

[0028] The phase change heat transfer pipes 3 are evenly distributed in the paraffin wax 9 in a serpentine pattern. The uniform arrangement design can increase the contact area between the phase change heat transfer pipes 3 and the paraffin wax 9 and improve the heat transfer efficiency.

[0029] The heat sink 4 is located on the outside of the phase change heat transfer pipe 3 and is fixedly connected to the outer wall of the phase change heat transfer pipe 3. Multiple heat sinks 4 are evenly distributed along the length of the phase change heat transfer pipe 3 to further expand the heat transfer area and accelerate the transfer of heat between the paraffin 9 and the phase change heat transfer pipe 3.

[0030] The outer wall of the heat storage tank 8 is provided with an insulation layer, which is made of rock wool or polyurethane insulation material, which can effectively reduce heat loss and improve the heat storage efficiency of the device.

[0031] The negative pressure inside the upper negative pressure tank 1, the phase change heat transfer tube 3, and the lower negative pressure tank 5 can vary depending on the selected cooling medium 7, so as to control the phase change temperature of the cooling medium 7 between 50℃ and 80℃.

[0032] The heat-releasing finned tube 3 and the heat-storing finned tube 6 are finned tubes, which can improve heat exchange efficiency.

[0033] During normal heat storage, the cold medium 7 absorbs heat from the heat storage finned tube 6 in the lower negative pressure tank 5 and changes from liquid to gas. It then flows from the lower negative pressure tank 5 to the upper negative pressure tank 1 along the phase change heat transfer pipe 3, transferring heat from the heat storage finned tube 6 to the heat release finned tube 2. During this flow, the heat in the gaseous cold medium 7 is simultaneously transferred to the heat storage material paraffin 9. The paraffin 9 absorbs the heat and changes from solid to liquid, completing the heat storage. At the same time, the cold medium 7, having lost heat, changes from gas to liquid and flows back to the lower negative pressure tank 5 along the phase change heat transfer pipe 3. It then absorbs heat from the heat storage finned tube 6 and vaporizes again, continuously transferring heat to the paraffin 9.

[0034] During normal heat release, the cold medium 7 is mainly stored in the upper negative pressure tank 1 in a gaseous state. When cold water flows through the heat-releasing finned tube 2, it absorbs the heat of the cold medium 7 in the upper negative pressure tank 1. After losing heat, the cold medium 7 changes from a gaseous state to a liquid state and flows downward along the phase change heat transfer pipe 3. During the downward flow, it absorbs the heat stored in the liquid paraffin 9 through the phase change heat transfer pipe 3, and then vaporizes and rises again. The heat is then transferred to the heat-releasing finned tube 2 again, and so on, to achieve heat release.

[0035] The heat transfer process involves a phase change of two media. Furthermore, the phase change heat transfer pipes 3 are arranged in a serpentine pattern, and with the external heat sinks 4, the contact area with the phase change material is significantly increased, accelerating heat transfer and improving heat storage and release efficiency. Because the cold medium 7 flowing within the serpentine phase change heat transfer pipes 3 is in a closed loop, despite the complex pipe shape, scaling and blockage will not occur, avoiding the problem of the heat storage device being scrapped due to unrecoverable blockages.

[0036] Among them, the heat-exothermic finned tubes, phase change heat transfer tubes, and heat storage finned tubes can be made of copper, stainless steel, or aluminum depending on the cost and heat transfer efficiency.

[0037] It should be noted that, in order to ensure the heat exchange and convection effect, the phase change heat transfer pipe 3 can be connected upwards from both sides of the circumference of the lower negative pressure tank 5 to the lower circumference of the upper negative pressure tank 1, such as... Figure 3 As shown; similarly, the phase change heat transfer pipe 3 can be connected from the upper circumference of the lower negative pressure tank 5 to both sides of the circumference of the upper negative pressure tank 1, as shown. Figure 4 As shown, they can be arranged in a row as a whole. Figure 3 As shown in the arrangement, the next row can be arranged as follows: Figure 4 Alternating arrangement.

[0038] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A phase change thermal energy storage device, characterized in that, The system includes an upper negative pressure tank, heat-dissipating finned tubes, a phase change heat transfer pipe, heat sinks, a lower negative pressure tank, heat storage finned tubes, a cooling medium, a heat storage tank, and paraffin wax. The upper and lower negative pressure tanks are respectively fixedly installed at the upper and lower ends of the heat storage tank, and are connected in the middle by a phase change heat transfer pipe through a sealing joint. The lower end of the phase change heat transfer pipe is sealed and connected to the lower negative pressure tank. The heat storage finned tubes are distributed inside the lower negative pressure tank. The upper end of the phase change heat transfer pipe is sealed and connected to the upper negative pressure tank. The heat-dissipating finned tubes are distributed inside the upper negative pressure tank.

2. The phase change thermal energy storage device according to claim 1, characterized in that, The heat storage tank is a sealed cavity structure with an atmospheric balance hole, and is filled with paraffin as a phase change heat storage material.

3. The phase change thermal storage device according to claim 1, characterized in that, The cold medium filled inside the upper negative pressure tank, lower negative pressure tank, and phase change heat transfer pipeline is in a negative pressure state.

4. The phase change thermal storage device according to claim 1, characterized in that, The phase change heat transfer pipes are evenly distributed in a serpentine pattern within the paraffin wax.

5. A phase change thermal energy storage device according to claim 1, characterized in that, The heat sink is located on the outside of the phase change heat transfer pipe and is fixedly connected to the outer wall of the phase change heat transfer pipe. Multiple heat sinks are evenly distributed along the length of the phase change heat transfer pipe.

6. The phase change thermal storage device according to claim 1, characterized in that, The heat sink is provided with paraffin flow holes.

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