An enhanced phase change thermal energy storage device

Abstract

An enhanced phase change thermal energy storage device, belonging to the technical field of phase change thermal energy storage equipment, solves the technical problems of solid-liquid stratification and low heat storage and release rates during the heat storage and release processes of traditional phase change thermal energy storage units. The solution is as follows: a heat transfer fluid inlet, a heat transfer fluid outlet, a shell, a central heat exchange tube, and an inner sleeve are coaxially arranged. The inner sleeve is installed inside the shell, and an insulation material layer is placed in the annular gap between the inner sleeve and the shell. The heat transfer fluid inlet and outlet respectively penetrate the end face of the shell and extend into the cavity of the shell. The central heat exchange tube is located between the heat transfer fluid inlet and outlet, and heat dissipation fins are provided on the tube wall. The space between the outer wall of the central heat exchange tube and the inner wall of the inner sleeve is filled with phase change material. This invention increases the heat exchange area between the phase change material and the heat transfer fluid, significantly improving its heat exchange efficiency, accelerating the melting and solidification rate of PCM, improving heat storage capacity, and making heat storage and release more uniform.

Description

Technical Field

[0001] This utility model belongs to the technical field of phase change heat storage equipment, specifically relating to an enhanced phase change heat storage device. Background Technology

[0002] Traditional energy supply methods are facing severe challenges. Thermal energy storage technology, as an efficient and clean energy storage solution, can effectively balance supply and demand fluctuations, improve energy utilization efficiency, and reduce carbon emissions. It is of great significance for promoting energy transformation and achieving sustainable development.

[0003] Phase change thermal energy storage technology features high energy density and high temperature stability, making it widely used in energy storage, especially for balancing the intermittency of renewable energy sources and improving overall system energy efficiency. Therefore, phase change thermal energy storage units have become a research hotspot. However, traditional horizontal coaxial phase change thermal energy storage units have several drawbacks in practical applications:

[0004] (1) During heat storage and melting, due to the difference in solid and liquid density, solid-liquid stratification is likely to occur, causing solid PCM to deposit at the bottom of the ring side, which deteriorates the heat storage efficiency.

[0005] (2) During solidification and heat release, the liquid phase PCM floats on the top of the ring side, affecting the energy release utilization and reducing the heat storage and release rate.

[0006] To address the aforementioned issues, there is an urgent need to design a new type of phase change thermal storage device to improve its heat storage and release capacity. Utility Model Content

[0007] The main purpose of this utility model is to overcome the shortcomings of the existing technology and solve the technical problems of solid-liquid stratification and low heat storage and release rate in the heat storage and release process of traditional phase change heat storage units. This utility model provides an enhanced phase change heat storage device.

[0008] This utility model is achieved through the following technical solution: an enhanced phase change thermal energy storage device, comprising a heat transfer fluid inlet, a heat transfer fluid outlet, a central heat exchange tube, an inner sleeve, and a shell, wherein:

[0009] The interior of the shell is configured as a cavity, and the inner sleeve is fixedly installed in the shell. A closed annular gap is formed between the outer wall of the inner sleeve and the inner wall of the shell, and a layer of heat insulation material is placed in the annular gap. Through holes are respectively provided at the center position of the left and right end faces of the shell. The heat transfer fluid inlet and the heat transfer fluid outlet pass through the through holes and extend into the cavity of the shell. In the cavity of the shell, the heat transfer fluid inlet is connected to one end of the central heat exchange tube, and the heat transfer fluid outlet is connected to the other end of the central heat exchange tube. A phase change material is filled between the outer wall of the central heat exchange tube and the inner wall of the inner sleeve.

[0010] The heat exchange fins include a plurality of high heat dissipation fins and low heat dissipation fins, which are evenly arranged along the circumferential direction of the outer wall of the central heat exchange tube, and the high heat dissipation fins and low heat dissipation fins are alternately arranged. Arc-shaped heat dissipation fins are provided at the outer ends of the high heat dissipation fins and low heat dissipation fins, and the curvature of the arc-shaped heat dissipation fins is equal to the central angle at the corresponding position of the inner sleeve.

[0011] Furthermore, the heat transfer fluid inlet, heat transfer fluid outlet, shell, central heat exchange tube, and inner sleeve are coaxially arranged.

[0012] Furthermore, four high-heat-dissipation fins and four low-heat-dissipation fins are evenly distributed along the circumference of the central heat exchange tube.

[0013] The beneficial effects of this utility model are as follows: In this utility model, high-heat-dissipation fins and low-heat-dissipation fins are alternately arranged on the outer wall of the central heat exchange tube to form a radial and stepped heat dissipation structure, which increases the heat exchange area between the phase change material and the heat transfer fluid, thus significantly improving its heat exchange efficiency; On this basis, arc-shaped heat dissipation fins are respectively arranged at the ends of the high-heat-dissipation fins and low-heat-dissipation fins to form multiple heat dissipation fins with different curved surfaces, which accelerates the melting and solidification rate of PCM, improves the heat storage capacity, and makes heat storage and release more uniform. Attached Figure Description

[0014] Figure 1 This is a partial cross-sectional three-dimensional structural schematic diagram of the present invention;

[0015] Figure 2 This is a schematic diagram of the longitudinal section of the present invention;

[0016] Figure 3 for Figure 2 Schematic diagram of the structure viewed by rotating the AA plane.

[0017] In the figure, 1 is the heat transfer fluid inlet, 2 is the heat transfer fluid outlet, 3 is the shell, 4 is the central heat exchange tube, 5 is the heat exchange fins, 6 is the inner sleeve, 7 is the insulation material layer, and 8 is the phase change material. Detailed Implementation

[0018] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments.

[0019] like Figures 1 to 3 The illustrated enhanced phase change thermal energy storage device includes a heat transfer fluid inlet 1, a heat transfer fluid outlet 2, a central heat exchange tube 4, an inner sleeve 6, and a shell 3. Both the central heat exchange tube 4 and the inner sleeve 6 are metal tubes.

[0020] The interior of the shell 3 is set as a cavity, and the inner sleeve 6 is fixedly installed in the shell 3. A closed annular gap is set between the outer wall of the inner sleeve 6 and the inner wall of the shell 3. A heat insulation material layer 7 is set in the annular gap. Through holes are respectively set at the center position of the left and right end faces of the shell 3. The heat transfer fluid inlet 1 and the heat transfer fluid outlet 2 pass through the through holes and extend into the cavity of the shell 3. In the cavity of the shell 3, the heat transfer fluid inlet 1 is connected to one end of the central heat exchange tube 4, and the heat transfer fluid outlet 2 is connected to the other end of the central heat exchange tube 4. The heat transfer fluid inlet 1, the heat transfer fluid outlet 2, the shell 3, the central heat exchange tube 4 and the inner sleeve 6 are arranged coaxially. A phase change material 8 is filled between the outer wall of the central heat exchange tube 4 and the inner wall of the inner sleeve 6.

[0021] The heat exchange fins 5 include several high-heat-dissipation fins and low-heat-dissipation fins. In this embodiment, four high-heat-dissipation fins and four low-heat-dissipation fins are evenly distributed along the circumference of the central heat exchange tube 4, and the high-heat-dissipation fins and low-heat-dissipation fins are alternately arranged. Arc-shaped heat-dissipation fins are provided at the outer ends of the high-heat-dissipation fins and low-heat-dissipation fins. The curvature of the arc-shaped heat-dissipation fins is equal to the central angle at the corresponding position of the inner sleeve 6. The heat exchange fins 5 can increase the contact area between the phase change material 8 and the heat transfer fluid, improve the heat exchange efficiency, and optimize the heat flow distribution by utilizing the radial expansion characteristics of the multi-curved surface, reducing the dead angle of heat transfer.

[0022] The working principle of this utility model is as follows:

[0023] During heat storage, the heat fluid enters the central heat exchange tube 4 of the enhanced phase change heat storage device through the heat transfer fluid inlet 1. The heat from the heat fluid is transferred to the phase change material 8 through the tube wall. The phase change material 8 gradually melts from a solid state starting from the wall of the central heat exchange tube 4. Under the action of high and low heat dissipation fins and the arc-shaped heat dissipation fins, the rate at which the phase change material 8 changes from solid to liquid is accelerated, and the overall melting is more uniform. The thermal energy of the heat fluid is converted into the latent heat of the phase change material 8. The solid phase change heat storage continuously transforms into a liquid state until complete transformation, at which point the heat storage capacity reaches saturation. The heat fluid after heat exchange flows out through the heat transfer fluid outlet 2.

[0024] During heat release, the cold fluid enters the central heat exchange tube 4 of the enhanced phase change thermal storage device along the heat transfer fluid inlet 1. The latent heat stored in the phase change material 8 is transferred to the cold fluid through the heat dissipation fins and the tube wall of the central heat exchange tube 4. The phase change material 8 gradually changes from liquid to solid at the tube wall. Under the action of the high and low heat dissipation fins and the arc-shaped heat dissipation fins, the speed at which the phase change material 8 changes from liquid to solid is accelerated, and the heat release process is more uniform. Until all the liquid phase change material 8 has changed to solid, the enhanced phase change thermal storage device no longer releases heat, and the heat transfer fluid flows out from the heat transfer fluid outlet 2.

[0025] In summary, the heat storage and release processes of this invention can be repeated, achieving efficient heat exchange between cold and hot fluids and solid-liquid phase change materials.

[0026] The above description is merely a specific embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in this utility model should be included within the protection scope of this utility model. Therefore, the protection scope of this utility model should be determined by the protection scope of the claims.

Claims

1. An enhanced phase change thermal energy storage device, comprising a heat transfer fluid inlet (1), a heat transfer fluid outlet (2), a central heat exchange tube (4), heat exchange fins (5), an inner sleeve (6), and a shell (3), characterized in that: The interior of the shell (3) is set as a cavity, and the inner sleeve (6) is fixedly installed in the shell (3). The outer wall of the inner sleeve (6) and the inner wall of the shell (3) are set as a closed annular gap, and the heat insulation material layer (7) is set in the annular gap. Through holes are respectively set at the core position of the left and right end faces of the shell (3). The heat transfer fluid inlet (1) and the heat transfer fluid outlet (2) pass through the through holes and extend into the cavity of the shell (3). In the cavity of the shell (3), the heat transfer fluid inlet (1) is connected to one end of the central heat exchange tube (4), and the heat transfer fluid outlet (2) is connected to the other end of the central heat exchange tube (4). The phase change material (8) is filled between the outer wall of the central heat exchange tube (4) and the inner wall of the inner sleeve (6). The heat exchange fins (5) include high heat dissipation fins and low heat dissipation fins. Four high heat dissipation fins and four low heat dissipation fins are evenly distributed along the circumference of the central heat exchange tube (4). The high heat dissipation fins and the low heat dissipation fins are alternately arranged. Arc-shaped heat dissipation fins are provided at the outer ends of the high heat dissipation fins and the low heat dissipation fins. The curvature of the arc-shaped heat dissipation fins is equal to the central angle at the corresponding position of the inner sleeve (6).

2. An enhanced phase change thermal reservoir according to claim 1, wherein: The heat transfer fluid inlet (1), heat transfer fluid outlet (2), shell (3), central heat exchange tube (4) and inner sleeve (6) are coaxially arranged.

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