A phase change film heat storage device and working method

Abstract

The application provides a phase change film heat storage device and a working method. The phase change film heat storage device comprises a sealed cavity with an inlet and an outlet. A cyclone separator is arranged below the inlet and used for separating two-phase working medium with high dryness from the inlet into two-phase working medium with lower dryness offset to one side of the inner wall of the sealed cavity and two-phase working medium with higher dryness gathered in the central area. A variable-pitch wound phase change film is arranged below the cyclone separation space of the cyclone separator and formed by winding the phase change film. The layer spacing of the winding phase change film gradually increases from inside to outside along the radial direction, so that the winding form of the phase change film is formed as being dense in the center and gradually sparse in the periphery. A support framework is filled between the layers of the variable-pitch wound phase change film. The application aims at the problems of heavy structure and slow heat response of the traditional heat storage device, realizes lightweight design, and improves the relief capacity for short-time high heat flow.

Description

Technical Field

[0001] This invention relates to the field of phase change thermal energy storage and thermal management technology, specifically to a lightweight phase change thin film thermal energy storage device for mitigating short-term high heat flux. Background Technology

[0002] Phase change materials (PCMs) possess significant advantages in absorbing transient heat and reducing temperature peaks due to their high latent heat density and near-isothermal phase change process, making them widely used in thermal buffering applications. However, traditional PCM storage units often employ block-filled or shell-and-tube-filled encapsulation structures. While these structures offer substantial heat storage capacity, they also generally suffer from several drawbacks. First, PCMs have low thermal conductivity, leading to slow response times under short-term high heat flux during heat transfer. Second, traditional encapsulation structures often rely on thick walls or large volumes to ensure sealing and strength, increasing ineffective structural mass and hindering lightweight design. Third, conventional uniform channels struggle to balance inlet flow guidance and localized heat transfer uniformity, easily resulting in localized stagnation, flow deviation, or uneven heat load distribution under high heat flux impact and two-phase flow conditions.

[0003] Furthermore, as thermal management targets evolve towards higher power density and miniaturization, thermal storage devices not only need sufficient heat storage capacity but also require higher heat exchange efficiency within limited mass and space. This means that thermal storage units cannot simply rely on increasing the mass of phase change material to improve heat capacity; instead, they should improve heat storage capacity per unit mass and volume through structural optimization and lightweight packaging. However, traditional phase change thermal storage structures often struggle to simultaneously meet lightweight requirements and transient thermal response performance in practical designs, thus limiting their further application in short-term high heat flux scenarios. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a phase change thin film thermal storage device and its working method for improving the ability to rapidly absorb short-term high heat flux.

[0005] To solve the above-mentioned technical problems, the present invention provides the following technical solution: A phase change thin-film thermal energy storage device for mitigating short-term high heat flux includes a sealed cavity with an inlet and an outlet, wherein the following are disposed within the sealed cavity: A cyclone separator, located below the inlet, is used to separate the high-dryness two-phase working fluid flowing in from the inlet into a lower-dryness two-phase working fluid that deflects toward one side of the inner wall of the sealed cavity and a relatively concentrated higher-dryness working fluid in the central region. A variable-pitch wound phase change film is disposed below the cyclone separation space of the cyclone separator; it is formed by winding a phase change film, and the interlayer spacing of the wound phase change film gradually increases from the inside to the outside along the radial direction, thereby forming a winding form that is denser at the center and gradually sparser at the periphery; as well as A honeycomb support skeleton; filled in the interlayer of the variable-pitch wound phase change film to support the variable-pitch wound phase change film.

[0006] The phase change film thermal storage device provided by the present invention for alleviating short-term high heat flux has an outer surface of the variable pitch wound phase change film that is hydrophobic, which is used to improve the working fluid condensation effect and flow state on the film surface.

[0007] The present invention provides a phase change thin film thermal storage device for alleviating short-term high heat flux, wherein the variable pitch wound phase change thin film is a planar helical wound structure.

[0008] The present invention provides a phase change thin film thermal storage device for alleviating short-term high heat flow. The sealed cavity is composed of a shell, an upper cover plate and a lower cover plate. The inlet is located on the upper cover plate and the outlet is located on the lower cover plate.

[0009] The present invention provides a phase change thin film thermal storage device for alleviating short-term high heat flow, wherein the cyclone separator is located directly below the central axis of the upper cover plate inlet and is fixedly connected to the inner wall of the shell through several connecting rods.

[0010] The phase change film thermal storage device provided by the present invention for alleviating short-term high heat flux has a honeycomb support skeleton made of lightweight high-temperature resistant material to reduce structural mass while ensuring support stability.

[0011] The phase change film thermal storage device for alleviating short-term high heat flow provided by the present invention has two variable pitch wound phase change films, which are arranged concentrically and staggered at an angle of 180°.

[0012] Based on the above structural arrangement, the working process of the device of the present invention is as follows: The high-dryness two-phase working fluid enters the shell through the inlet at the top cover plate and first flows through the cyclone separator located directly below the central axis of the inlet. Under the action of the cyclone, the lower-dryness two-phase working fluid shifts towards the inner wall of the shell and then enters the flow channel region formed by the gradually sparser phase change film winding on the periphery; the higher-dryness working fluid is relatively concentrated in the central region and then enters the flow channel region formed by the denser phase change film winding. At the same time, the two-phase working fluid transfers heat to the surface-hydrophobic modified phase change film. The phase change material absorbs heat and undergoes a phase change, thereby buffering the short-term high heat flow. The two-phase working fluid condenses during the flow and heat transfer process, and the working fluid state changes from high-dryness to low-dryness. The low-dryness two-phase working fluid finally flows out through the outlet at the bottom cover plate.

[0013] Compared with the prior art, the beneficial effects of the present invention are as follows: By incorporating a cyclone separator, the high-dryness two-phase working fluid entering the device is swirled and distributed, causing the lower-dryness two-phase working fluid to shift outwards, while a relatively larger portion of the higher-dryness working fluid enters the central region. This, combined with a variable-pitch phase change film (PCC) winding structure that is denser in the center and gradually sparser at the periphery, allows for zoned heat exchange of the working fluid in different states, thereby improving the utilization rate of limited cooling resources. Furthermore, the surface of the PCC is treated with a hydrophobic coating to improve the condensation effect and flow state of the working fluid on the film surface, thus enhancing heat exchange efficiency. By using a lightweight honeycomb support frame, the shape stability of the flexible PCC after winding can be maintained without significantly increasing mass, preventing rebound, unraveling, and localized deformation from adversely affecting the flow channels and heat exchange effect. Therefore, this invention can improve the rapid absorption capacity for short-term high heat flux while reducing structural mass, making it suitable for applications requiring high mass and transient thermal management performance. Attached Figure Description

[0014] Figure 1 This is a radial cross-sectional view of the phase change thin film thermal storage device of the present invention.

[0015] Figure 2 This is a top view of the variable-pitch wound phase change film of the present invention.

[0016] Figure 3 This is a radial cross-sectional view of the variable pitch upper cover plate of the present invention.

[0017] Figure 4 This is a schematic diagram of the radial cross-sectional structure of the variable pitch lower cover plate of the present invention. Detailed Implementation

[0018] The technical solution of the present invention will now be described in detail with reference to the accompanying drawings.

[0019] like Figures 1-3 This invention provides a phase change thin film thermal storage device for mitigating short-term high heat flux, comprising a sealed cavity having an inlet and an outlet, and a component disposed at the top of the sealed cavity: A cyclone separator 4, located below the inlet, is used to separate the high-dryness two-phase working fluid flowing in from the inlet into a lower-dryness two-phase working fluid that deflects toward one side of the inner wall of the sealed cavity and a higher-dryness working fluid that is relatively concentrated in the central region. A variable-pitch wound phase change film 5 is disposed below the cyclone separation space of the cyclone separator 4. It is formed by winding the phase change film, and the interlayer spacing of the wound phase change film gradually increases from the inside to the outside along the radial direction, thereby forming a winding form that is denser in the center and gradually sparser at the periphery. as well as A honeycomb support frame 6 is filled in the interlayer of the variable-pitch wound phase change film 5 to support the variable-pitch wound phase change film 5.

[0020] In one embodiment, the outer surface of the variable-pitch wound phase change film 5 is a hydrophobic surface, which is used to improve the working fluid condensation effect and flow state on the film surface.

[0021] In one embodiment, the variable-pitch wound phase change film 5 is a planar spiral wound structure.

[0022] In one embodiment, the sealed cavity is composed of a housing 1, an upper cover plate 2, and a lower cover plate 3, with the inlet located on the upper cover plate 2 and the outlet located on the lower cover plate 3.

[0023] In one embodiment, the cyclone separator 4 is located directly below the central axis of the upper cover plate inlet and is fixedly connected to the inner wall of the housing 1 by several connecting rods.

[0024] In one embodiment, the support frame 6 is a honeycomb structure made of lightweight, high-temperature resistant material to reduce structural mass while ensuring support stability.

[0025] In one embodiment, there are two variable-pitch wound phase change films 5, which are arranged concentrically and staggered at an angle of 180°.

[0026] The present invention also provides a method for operating a phase change thin film thermal storage device, specifically: After the high-dryness two-phase working fluid enters the shell 1 through inlet 201 at the upper cover plate 2, it first flows through the cyclone separator 4 located directly below the central axis of the inlet. Under the swirling action of the cyclone separator 4, the high-dryness two-phase working fluid is split into a higher-dryness two-phase working fluid and a lower-dryness two-phase working fluid (the higher-dryness two-phase working fluid and the lower-dryness two-phase working fluid are relative, that is, two types of two-phase working fluid with different dryness levels). The lower-dryness two-phase working fluid shifts towards the inner wall of the shell 1, and then... The working fluid enters the flow channel region formed by the gradually thinning phase change film winding at the periphery; the relatively dry working fluid is relatively concentrated in the central region, and then enters the flow channel region formed by the denser phase change film winding; at the same time, the two-phase working fluid transfers heat to the surface hydrophobic modified phase change film, the phase change material absorbs heat and undergoes a phase change, thereby achieving buffering of short-term high heat flux. The two-phase working fluid condenses during the flow and heat transfer process, and the working fluid state changes from high dryness to low dryness. The low dryness two-phase working fluid finally flows out from the outlet at the lower cover plate.

[0027] The above specific embodiments are only for illustrating the technical concept and structural features of the present invention, and are intended to enable those skilled in the art to implement them. However, the above content does not limit the scope of protection of the present invention. Any equivalent changes or modifications made in accordance with the spirit and essence of the present invention should fall within the scope of protection of the present invention.

Claims

1. A phase change thin-film thermal storage device, comprising a sealed cavity having an inlet and an outlet, characterized in that, The sealed cavity is provided with: A cyclone separator (4), located below the inlet, is used to separate the high-dryness two-phase working fluid flowing in from the inlet into a lower-dryness two-phase working fluid that deflects toward one side of the inner wall of the sealed cavity and a higher-dryness working fluid that is relatively concentrated in the central region. Variable pitch wound phase change film (5); disposed below the swirling separation space of the swirling separator (4); formed by winding the phase change film, the interlayer spacing of the wound phase change film gradually increases from the inside to the outside along the radial direction, thereby forming a winding form that is denser in the center and gradually sparser at the periphery; as well as Support skeleton; filled in the interlayer of the variable pitch wound phase change film (5) to support the variable pitch wound phase change film (5).

2. The phase change thin-film thermal storage device according to claim 1, characterized in that, The outer surfaces of the variable-pitch wound phase change film (5) are all hydrophobic surfaces, which are used to improve the working fluid condensation effect and flow state on the film surface.

3. The phase change thin-film thermal storage device according to claim 1, characterized in that, The variable pitch wound phase change film (5) is a planar spiral wound structure.

4. The phase change thin-film thermal storage device according to claim 1, characterized in that, The sealed cavity is composed of a shell (1), an upper cover plate (2) and a lower cover plate (3), with the inlet located on the upper cover plate and the outlet located on the lower cover plate.

5. The lightweight phase change thin film thermal storage device for mitigating short-term high heat flux according to claim 4, characterized in that, The cyclone separator (4) is located directly below the central axis of the upper cover plate inlet and is fixedly connected to the inner wall of the shell (1) by several connecting rods.

6. The phase change thin-film thermal storage device according to claim 1, characterized in that, The supporting frame is a honeycomb supporting frame (6).

7. The phase change thin-film thermal storage device according to claim 6, characterized in that, The honeycomb support frame (6) is a honeycomb structure made of lightweight, high-temperature resistant material to reduce structural mass while ensuring support stability.

8. The phase change thin-film thermal storage device according to claim 1, characterized in that, There are two variable pitch wound phase change films (5), which are arranged concentrically and staggered at an angle of 180°.

9. A method for operating the phase change thin-film thermal storage device according to any one of claims 1-8, characterized in that, After the high-dryness two-phase working fluid enters the sealed cavity, it first flows through the cyclone separator (4). Under the swirling action of the cyclone separator (4), the lower-dryness two-phase working fluid shifts to one side of the inner wall of the sealed cavity and then enters the flow channel area formed by the gradually thinning phase change film winding on the periphery. The higher-dryness working fluid is relatively concentrated in the central area and then enters the flow channel area formed by the denser phase change film winding. At the same time, the two-phase working fluid transfers heat to the surface hydrophobic modified phase change film. The phase change material absorbs heat and undergoes a phase change, thereby achieving a buffer against short-term high heat flow. The two-phase working fluid condenses during the flow and heat transfer process, and the working fluid changes from high-dryness to low-dryness. The low-dryness two-phase working fluid finally flows out of the outlet.

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