Spiral cascade phase change heat storage module
By adopting a spiral step phase change heat storage module in the heat storage device, the structural design of Nautilus has been used to solve the shortcomings in heat transfer performance and thermal stress distribution, and the energy storage efficiency and service life are significantly improved.
Patent Information
- Application Number
- CN202421501153.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-06-28
- Publication Date
- 2025-04-04
- Estimated Expiration
- 2034-06-28
AI Technical Summary
The existing partition wall heat storage has shortcomings in heat transfer performance and thermal stress distribution, resulting in poor heat transfer performance and concentrated thermal stress, affecting energy storage efficiency and service life.
The spiral cascade phase change heat storage module is adopted to draw on the spiral connecting pipe and arc-shaped diaphragm structure of Nautilus, and an equiangular spiral heat exchange fluid channel and closed fin are designed to strengthen the convection heat transfer performance of the heat exchange fluid and the thermal conductivity of the phase change material. At the same time, heat is uniformly transferred through the spiral volute structure to reduce thermal stress concentration.
The heat transfer performance and thermal stress uniformity of the heat accumulator were improved, the heating power was increased by 45.6%, the temperature uniformity of the phase change material was increased by 19.97%, and the thermal design was optimized, and the proportion of efficient heat transfer intervals in the heat charging process increased by 53.3%.
Smart Images
Figure CN222718765U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of heat accumulators, in particular to a spiral step phase change heat storage module. Background Art
[0002] In order to balance the supply and demand of the power grid (realize "peak shifting and valley filling") and to absorb new energy represented by wind and solar energy, the research on energy storage technology has attracted increasing attention. Among the many energy storage technologies, heat storage technology has gradually become one of the mainstream technologies for energy storage due to its low construction and maintenance costs and high environmental performance. Heat storage systems can be divided into three forms. Compared with sensible heat storage and thermochemical heat storage, latent heat storage systems represented by cascade phase change heat storage have attracted the attention of scholars due to their higher energy storage density and relatively simple structure.
[0003] Reasonable structural form is the basis of cascade phase change heat accumulator. The partition wall heat accumulator has the characteristics of simple structure, large effective volume, mature technology, etc., and is one of the mainstream structural forms used for cascade phase change heat accumulator. However, the heat transfer path of the phase change material in the partition wall heat accumulator is long, which exacerbates the challenge of improving the heat transfer performance caused by the low thermal conductivity of the phase change material.
[0004] In order to solve the above problems, scholars have developed many methods (such as new configurations and their optimization, adding thermal conductivity enhancers and phase change microcapsules, etc.) to enhance the heat transfer performance of heat accumulators. Among them, the exploration of new configurations and their structural optimization are one of the most challenging enhancement technologies. In this context, scholars have conducted many studies on the structural design and optimization of partition-type heat accumulators. However, the current structure of phase change heat accumulators still has problems such as limited volume-specific surface area and obvious anisotropy of heat transfer. At the same time, there is still a certain heat transfer mismatch between the heat exchange fluid and the phase change material. This not only hinders the maximization of the charging / discharging performance of the heat accumulator, but also leads to the concentration of thermal stress inside the heat accumulator, which shortens its service life. Therefore, the development of new heat accumulator structures to further improve heat transfer performance, optimize thermal design and reduce thermal stress concentration has become a technical problem that needs to be solved urgently by technicians in this field.
[0005] After millions of years of evolution, natural organisms have developed a variety of efficient heat and mass transfer systems and structures. Inspired by this, scholars began to combine biological sciences with engineering technology to develop bionic structures for various applications. At present, bionic technology has been successfully applied in many fields such as chemical reactions, microfluidics, and heat and mass transfer. Therefore, this patent, in response to existing problems, draws on the structure of the nautilus and develops an innovative configuration of a spiral ladder phase change heat accumulator.
[0006] In order to solve the problem of poor heat transfer performance during the charging / discharging process, the heat accumulator draws on the spiral connecting tube and arc-shaped diaphragm structure of the nautilus to simultaneously enhance the convective heat transfer performance of the heat exchange fluid and the thermal conductivity of the phase change material inside. In order to solve the problem of thermal stress concentration, the heat accumulator draws on the spiral volute structure of the nautilus to transfer heat to the heat accumulator more evenly, prevent the concentration of thermal stress, and improve the mechanical properties of the heat accumulator. Regarding the thermal design of the heat accumulator, this patent, based on the bionic nautilus structure, utilizes the change in the spiral radius of the heat exchange fluid channel to enhance the heat transfer performance of the low heat exchange temperature difference area, realizes the spatial matching of the high heat transfer coefficient area and the low heat exchange temperature difference area, and obtains a better thermal design of the heat accumulator. Utility Model Content
[0007] The utility model aims to provide a spiral step phase change heat storage module, so as to improve the heat transfer performance of the heat storage device and disperse the thermal stress more evenly, so as to obtain a better thermal design of the heat storage device.
[0008] In order to solve the above technical problems, the utility model provides a spiral step phase change heat storage module, which includes an outer shell and a fluid channel arranged in the outer shell along a spiral trajectory; the outer shell is filled with a phase change material, and the phase change material is wrapped around the outside of the fluid channel; a diversion partition is provided in the fluid channel, and the diversion partition separates the fluid channel to form an enclosed channel, the end of the enclosed channel in the flow direction is an enclosed structure, and a diversion hole is provided in the space enclosed by the enclosed channel.
[0009] In one of the embodiments, a plurality of chambers arranged along a spiral trajectory are provided in the shell, the plurality of chambers are filled with the phase change material, and the fluid channel passes through the plurality of chambers in sequence along the spiral trajectory.
[0010] In one embodiment, adjacent chambers are separated by metal fins, and the fluid channel passes through a plurality of the metal fins.
[0011] In one embodiment, along the flow direction of the fluid in the fluid channel, different phase change materials are filled in each of the chambers in order of the melting temperatures of the phase change materials from high to low.
[0012] In one of the embodiments, the enclosed channel is arranged close to the inner wall of the fluid channel; or the enclosed channel is arranged close to the outer wall of the fluid channel.
[0013] In one embodiment, the diverter baffle is an L-shaped structure formed by connecting long and short plates, the long plate of the diverter baffle is arranged in a manner consistent with the flow trajectory of the fluid channel, and the short plate of the diverter baffle is connected to the side wall of the fluid channel.
[0014] In one embodiment, the phase change material is a solid-liquid organic phase change material or a composite phase change material.
[0015] In one embodiment, the phase change material is paraffin, erythritol or acetic acid.
[0016] The beneficial effects of the utility model are as follows:
[0017] The above-mentioned spiral step phase change heat storage module can be used alone to utilize the change in the spiral radius of the heat exchange fluid channel to enhance the heat transfer performance of the low heat transfer temperature difference area and achieve spatial matching between the high heat transfer coefficient area and the low heat transfer temperature difference area.
[0018] In addition, multiple spiral step phase change heat storage modules can be combined into a plate-type phase change heat storage device with a bionic nautilus structure. At this time, some spiral step phase change heat storage modules can be used as gas separation units, and some spiral step phase change heat storage modules can be used as liquid separation units, so as to give full play to the structural advantages of the bionic nautilus shell and obtain beneficial effects in three aspects: heat transfer performance, thermal stress and thermal design:
[0019] 1. In terms of heat transfer performance, the heat accumulator is designed with equiangular spiral heat exchange fluid channels and a series of closed fins by referring to the spiral connecting tube and arc diaphragm structure of the Nautilus, while strengthening the convective heat transfer performance of the heat exchange fluid and the thermal conductivity of the phase change material. It has been verified that compared with the existing optimization scheme, the charging power of the phase change heat accumulator with the bionic Nautilus structure is increased by 45.6%;
[0020] 2. In response to thermal stress, the heat accumulator is designed with a spiral plate heat storage unit shell by referring to the spiral volute structure of the nautilus, which transfers heat to the heat accumulator more evenly. It has been verified that compared with the existing optimization scheme, the temperature uniformity of the phase change material in the phase change heat accumulator with the bionic nautilus structure is improved by 19.97%, effectively preventing the concentration of thermal stress;
[0021] 3. Regarding thermal design, based on the bionic nautilus structure, this solution can use the spiral stepped phase change heat storage module as a gas and liquid separation unit, and reasonably design the flow channels between the heat storage units to achieve the matching of the high heat transfer performance area and the high phase change material thermal resistance area, thereby obtaining a better thermal design of the heat accumulator. It has been verified that compared with the existing optimization scheme, the proportion of the efficient heat transfer area of the bionic nautilus structure phase change heat storage device in the charging process is increased by 53.3%. BRIEF DESCRIPTION OF THE DRAWINGS
[0022] In order to more clearly illustrate the technical solution of the present invention, the drawings required for use in the implementation mode will be briefly introduced below. Obviously, the drawings described below are only some implementation modes of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.
[0023] Figure 1 It is a structural schematic diagram provided by the first embodiment of the utility model;
[0024] Figure 2 It is a structural schematic diagram provided by the second embodiment of the utility model;
[0025] Figure 3 It is a schematic diagram of the combined application of the spiral step phase change thermal storage module provided in the embodiment of the utility model.
[0026] The reference numerals are as follows:
[0027] 10. Shell; 11. Fluid channel; 12. Phase change material; 13. Diverter baffle; 14. Enclosed channel; 15. Diverter hole; 16. Chamber; 17. Metal fin;
[0028] 21. Gas separation unit; 22. Liquid separation unit. DETAILED DESCRIPTION
[0029] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention.
[0030] The utility model provides a spiral step phase change heat storage module, which is implemented as follows: Figures 1 to 3 As shown, the spiral step phase change heat storage module includes a shell 10, and a fluid channel 11 arranged in the shell 10 along a spiral trajectory; the shell 10 is filled with a phase change material 12, and the phase change material 12 is wrapped around the outside of the fluid channel 11; a diversion baffle 13 is provided in the fluid channel 11, and the diversion baffle 13 separates the fluid channel 11 to form an enclosed channel 14, and the end of the flow direction of the enclosed channel 14 is an enclosed structure, and a diversion hole 15 is provided in the space enclosed by the enclosed channel 14.
[0031] The above-mentioned spiral step phase change heat storage module can be used alone to utilize the change in the spiral radius of the heat exchange fluid channel to enhance the heat transfer performance of the low heat exchange temperature difference area, achieve spatial matching between the high heat transfer coefficient area and the low heat exchange temperature difference area, and obtain a better thermal design of the heat accumulator.
[0032] In addition, multiple spiral step phase change heat storage modules can be combined to form a plate-type phase change heat storage device with a bionic nautilus structure. At this time, some of the spiral step phase change heat storage modules can be used as gas separation units 21, and some of the spiral step phase change heat storage modules can be used as liquid separation units 22 to achieve gas-liquid separation of the two-phase working fluid; for example, when the spiral step phase change heat storage module is used as the gas separation unit 21, the gas phase working fluid can flow out through the diversion hole 15, and when the spiral step phase change heat storage module is used as the liquid separation unit 22, the liquid phase working fluid can flow out through the diversion hole 15.
[0033] Specifically, Figure 1 and Figure 3 As shown, if the spiral step phase change heat storage module is desired to be used as the gas separation unit 21, the enclosed channel 14 can be arranged close to the inner wall of the fluid channel 11. At this time, if the heat exchange fluid flows in a spiral trajectory in the fluid channel 11, the centrifugal force can concentrate the rich liquid working medium with higher density on the outer wall of the fluid channel 11, while the rich gas working medium with lower density can be concentrated on the inner wall of the fluid channel 11. Therefore, once the heat exchange fluid reaches the enclosed channel 14 arranged on the inner wall, the rich gas working medium can be concentrated into the enclosed channel 14 for collection and transportation to the next spiral step phase change heat storage module for heat exchange, while the rich liquid working medium will continue to flow along the transportation path of the fluid channel 11.
[0034] Similarly, if Figure 2 and Figure 3 As shown, if the spiral step phase change heat storage module is desired to be used as the liquid separation unit 22, the enclosed channel 14 can be arranged close to the outer wall of the fluid channel 11. At this time, if the heat exchange fluid flows in a spiral trajectory in the fluid channel 11, the centrifugal force will also concentrate the liquid-rich working medium with a larger density on the outer wall of the fluid channel 11, and the gas-rich working medium with a smaller density on the inner wall of the fluid channel 11. Therefore, once the heat exchange fluid reaches the enclosed channel 14 provided on the outer wall, the liquid-rich working medium can be concentrated into the enclosed channel 14 for collection and transportation to the next spiral step phase change heat storage module for heat exchange, while the gas-rich working medium will continue to flow along the transportation path of the fluid channel 11.
[0035] In order to realize the function of diversion and collection of the enclosed channel 14, Figure 1 and Figure 2 As shown, in this embodiment, the diverter baffle 13 is configured as an L-shaped structure composed of long and short plates. The long plate of the diverter baffle 13 is arranged in a manner consistent with the flow trajectory of the fluid channel 11, and the short plate of the diverter baffle 13 is connected to the side wall of the fluid channel 11.
[0036] After adopting this setting method, the long plate of the diverter partition 13 is equivalent to dividing the interior of the fluid channel 11 into two channels, one of which will flow to the short plate of the diverter partition 13, thereby forming an enclosed channel 14. Therefore, once one of the working fluids after diversion enters the enclosed channel 14, it will be blocked and collected by the short plate of the diverter partition 13.
[0037] In addition, if Figure 1 and Figure 2 As shown, in this embodiment, a plurality of chambers 16 arranged along a spiral track are arranged in the housing 10, and the plurality of chambers 16 are filled with a phase change material 12, and a fluid channel 11 sequentially passes through the plurality of chambers 16 along the spiral track; and in order to separate the chambers 16, in this embodiment, metal fins 17 are provided between adjacent chambers 16 to separate them, and the fluid channel 11 passes through the plurality of metal fins 17.
[0038] After adopting the above configuration, a partition structure can be provided for the stepped phase change material 12, while the thermal conductivity of the heat storage unit is improved and additional structural strength is provided for the heat storage unit.
[0039] It should also be pointed out that the phase change material 12 can be a series of solid-liquid phase change materials 12 with different melting temperatures, which are sequentially filled in each chamber 16 in the order of melting temperature from high to low along the flow direction of the heat exchange fluid in the fluid channel 11, forming a stepped arrangement of the phase change material 12. Compared with a single-stage arrangement of the phase change material 12, the stepped phase change material 12 can optimize the heat exchange matching of the heat accumulator, increase the heat exchange temperature difference, and improve the energy storage density of the heat accumulator.
[0040] Furthermore, in this embodiment, the phase change material 12 is configured as a solid-liquid organic phase change material 12 or a composite phase change material 12. For example, the phase change material 12 can be configured as paraffin, erythritol or acetic acid.
[0041] It should also be pointed out that the above spiral step phase change thermal storage module can be used individually or in combination, such as Figures 1 to 3 As shown, during application, part of the spiral step phase change heat storage modules can be used as gas separation units 21, and part of the spiral step phase change heat storage modules can be used as liquid separation units 22. Multiple gas separation units 21 and liquid separation units 22 are alternately stacked and connected to each other. In addition to the connection through the fluid channel 11, adjacent spiral step phase change heat storage modules also need to use the diversion hole 15 to connect with the fluid channel 11 of the adjacent spiral step phase change heat storage module below, so as to ensure that the diverted working fluid can be transported to the adjacent fluid channel 11 below.
[0042] The above is a preferred embodiment of the present invention. It should be pointed out that a person skilled in the art can make several improvements and modifications without departing from the principle of the present invention. These improvements and modifications are also considered to be within the protection scope of the present invention.
Claims
1. A spiral step phase change thermal storage module, characterized in that: The spiral step phase change heat storage module includes an outer shell and a fluid channel arranged in the outer shell along a spiral trajectory; the outer shell is filled with a phase change material, and the phase change material is wrapped around the outside of the fluid channel; a diversion partition is provided in the fluid channel, and the diversion partition separates the fluid channel to form an enclosed channel, and the end of the flow direction of the enclosed channel is an enclosed structure, and a diversion hole is provided in the space enclosed by the enclosed channel.
2. The spiral step phase change thermal storage module according to claim 1, characterized in that: A plurality of chambers arranged along a spiral track are provided in the shell, the plurality of chambers are filled with the phase change material, and the fluid channel passes through the plurality of chambers in sequence along the spiral track.
3. The spiral step phase change thermal storage module according to claim 2, characterized in that: Adjacent chambers are separated by metal fins, and the fluid channel passes through a plurality of the metal fins.
4. The spiral step phase change thermal storage module according to claim 2, characterized in that: Along the flow direction of the fluid in the fluid channel, different phase change materials are filled in each of the chambers in order of the melting temperatures of the phase change materials from high to low.
5. The spiral step phase change thermal storage module according to claim 1, characterized in that: The enclosed channel is arranged close to the inner side wall of the fluid channel; Or the enclosed channel is arranged close to the outer side wall of the fluid channel.
6. The spiral step phase change thermal storage module according to claim 1, characterized in that: The diverter baffle is an L-shaped structure formed by connecting long and short plates. The long plate of the diverter baffle is arranged in a manner consistent with the flow trajectory of the fluid channel, and the short plate of the diverter baffle is connected to the side wall of the fluid channel.
7. The spiral step phase change thermal storage module according to claim 1, characterized in that: The phase change material is a solid-liquid organic phase change material or a composite phase change material.
8. The spiral step phase change thermal storage module according to claim 7, characterized in that: The phase change material is paraffin, erythritol or acetic acid.