Heat storage type two-phase loop heat dissipation device

Abstract

The invention discloses a heat storage type two-phase loop heat dissipation device which comprises a two-phase loop heat transfer unit, a closed cavity structure is arranged in the two-phase loop heat transfer unit, an annular net structure and a heat storage unit are arranged in the cavity, and the heat storage unit is filled with a phase change material. In the invention, through combination of the multi-stage fractal tree-shaped channel structure and the heat storage unit, heat generated by the electronic device can be quickly and efficiently dissipated, and compared with a traditional heat dissipation mode, the multi-stage fractal tree-shaped channel structure utilizes the phase change characteristic of a working medium, so that the heat dissipation efficiency can be remarkably improved, stable operation of the electronic device in a high-temperature environment is ensured, and the service life of the electronic device is prolonged. The phase-change material absorbs heat when the temperature of the equipment rises and releases heat when the temperature drops, so that temperature fluctuation of the equipment is balanced, the characteristic effectively prevents the equipment from being overheated or overcooled, the temperature stability of the equipment is ensured, and the service life of the equipment is prolonged.

Description

Technical Field

[0001] The present invention relates to the technical field of electronic device thermal management, and more specifically to a heat storage type two-phase loop heat dissipation device. Background Art

[0002] Electronic devices and high-power electronic devices play a vital role in modern military and aerospace applications. These devices generate a lot of heat during operation. If they cannot be dissipated in a timely and effective manner, it will lead to device performance degradation, unstable operation, and even possible device damage. Especially in electronic devices, the space is limited and the environment is complex. Traditional cooling methods such as air cooling and water cooling may not work effectively in some special environments. Therefore, it is particularly important to develop an efficient and reliable thermal management device.

[0003] Heat pipes are highly efficient heat transfer elements that use the evaporation and condensation phase change of working fluids to achieve heat transfer. Although heat pipe technology has improved thermal management efficiency to a certain extent, the heat transfer capacity of a single heat pipe is limited, and it is difficult to achieve uniform heat dissipation over a large area of ​​heat source.

[0004] The patent document with the patent publication number CN 113154922 A discloses a bionic phase change energy storage steam chamber module, which includes a tree-like steam chamber and a phase change container. The tree-like steam chamber includes at least one steam chamber plate, a columnar steam chamber and multiple groups of branch steam chamber structures. One side of the steam chamber plate is in contact with the heat source, so that the heat concentrated by the heat source is evenly diffused to the surface of the steam chamber plate, and the other side of the steam chamber plate is encapsulated with the outer surface of the phase change container; the columnar steam chamber is connected to the steam chamber plate, and multiple groups of branch steam chambers are arranged around the columnar steam chamber and each has more than two branch steam chamber branches extending into the space; multiple groups of branch steam chambers are connected by multiple layers of annular steam chamber ribs; the internal channels of the above steam chamber plates, columnar steam chambers, branch steam chambers and annular steam chamber ribs are interconnected, the internal space is filled with phase change working fluid, and the inner surface is arranged with porous capillary structures. The above-mentioned tree-like steam chamber structure is arranged in the phase change container, and the other parts inside are filled with phase change materials.

[0005] For the three-dimensional tree-like microchannel it uses, it adopts a uniform fin structure, and the condensed fluid returns to the heat source through gravity, and the heat dissipation efficiency is low. Summary of the invention

[0006] The technical problem to be solved by the present invention is how to achieve efficient and stable heat dissipation.

[0007] The present invention solves the above technical problems through the following technical means: a heat storage type two-phase loop heat dissipation device, including a two-phase loop heat transfer unit, a closed cavity structure is provided in the two-phase loop heat transfer unit, an annular mesh structure and a heat storage unit are provided in the cavity, the heat storage unit is filled with phase change material, the annular mesh structure includes a multi-level fractal tree-like channel branching step by step along the center of the cavity, the planes where the multi-level fractal tree-like channels are located are located in the same plane, the multi-level fractal tree-like channels are provided with fluid working medium, the heat storage unit is filled with phase change material, and the inner wall of the multi-level fractal channel is provided with porous material, and the porous material can drive the fluid working medium to flow back to the center of the cavity.

[0008] As a preferred technical solution, the annular network structure further includes at least one annular channel, which is connected to the fractal tree-like channels of the same level in the multi-level fractal tree-like channels and can cause the fluid working medium to be uniformly input into the multi-level fractal tree-like channels.

[0009] As a preferred technical solution, each level of the fractal tree-like channel includes a number of micro-grooves, each micro-groove is divided into a number of micro-grooves at the next level, and a number of micro-grooves form the next level of fractal tree-like channels, and the micro-grooves at each level have the same bifurcation angle at the bifurcation, and the bifurcation angle is between 0° and 180°.

[0010] As a preferred technical solution, the length ratio and hydraulic diameter ratio of the k-th micro-channel to the k+1-th micro-channel satisfy the following relationship:

[0011]

[0012] Among them, D and Δ are the length fractal dimension and hydraulic diameter fractal dimension, respectively.

[0013] As a preferred technical solution, each micro-channel is divided into two micro-channels at the next level.

[0014] As a preferred technical solution, the multi-level fractal tree-like channel includes a primary fractal tree-like channel, a secondary fractal tree-like channel, and a tertiary fractal tree-like channel that are connected in sequence.

[0015] As a preferred technical solution, the heat storage unit is formed in the area between the outer side of the annular mesh structure and the cavity.

[0016] As a preferred technical solution, the two-phase loop heat transfer unit includes an upper shell and a lower shell, the upper shell is embedded in the lower shell, the upper shell and the lower shell are welded and fixed to form the cavity structure, and the plane where the top of the upper shell is located is on the same plane as the plane where the top of the lower shell is located.

[0017] As a preferred technical solution, the local heat source is located at the center of the cavity.

[0018] As a preferred technical solution, the phase change material can absorb or release heat at a specific temperature, and the porous material is made of a capillary force material.

[0019] The beneficial effects of the present invention are:

[0020] (1) In the present invention, by combining a multi-level fractal tree-like channel structure and a heat storage unit, the heat generated by the electronic device can be quickly and efficiently dissipated. Compared with the traditional heat dissipation method, the multi-level fractal tree-like channel structure utilizes the phase change characteristics of the working fluid, which can significantly improve the heat dissipation efficiency and ensure the stable operation of the electronic device in a high temperature environment. The phase change material is used as a cold source to absorb heat when the temperature of the device rises and release heat when the temperature drops, thereby balancing the temperature fluctuation of the device. This characteristic effectively prevents the device from overheating or overcooling, ensures the stability of the device temperature, and extends the service life of the device.

[0021] (2) In the present invention, the annular channel connects the multi-level fractal tree-like channel structure to form a fluid transmission network, which can evenly distribute the fluid working medium to each branch of the multi-level fractal tree-like channel structure, thereby improving the overall transmission efficiency of the heat storage type two-phase loop heat dissipation device and avoiding problems such as local overload or uneven fluid flow rate. The annular channel can also effectively buffer and disperse the pressure fluctuations generated by the fluid during the transmission process, reduce the impact on the multi-level fractal tree-like channel structure, and enhance the stability and durability of the heat storage type two-phase loop heat dissipation device.

[0022] (3) In the present invention, by setting up porous materials, there is no need for complicated piping and pump systems, which reduces the weight of the equipment and the difficulty of maintenance, and improves the adaptability and reliability of the system; at the same time, the device has a simple structure and does not require the use of refrigerants and other environmentally harmful substances, thus having good environmental performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 A schematic diagram of an explosion structure provided by an embodiment of the present invention;

[0024] Figure 2 A schematic diagram of a three-dimensional structure provided by an embodiment of the present invention;

[0025] Figure 3 A schematic diagram of filling a phase change material provided in an embodiment of the present invention;

[0026] Figure 4 A schematic diagram of the internal structure of a multi-level fractal tree-like channel structure provided by an embodiment of the present invention;

[0027] Figure 5 A schematic diagram of the working principle of a local heat source in the working phase and the non-working phase provided by an embodiment of the present invention;

[0028] Figure 6 A schematic diagram of a multi-level fractal tree-like channel structure provided by an embodiment of the present invention;

[0029] Figure numbers: 1. two-phase loop heat transfer unit; 2. fractal tree-like channel; 3. heat storage unit; 4. annular channel; 5. upper cover plate; 6. local heat source; 7. porous material; 8. primary fractal tree-like channel; 9. secondary fractal tree-like channel; 10. tertiary fractal tree-like channel; 11. phase change material; 12. lower shell. DETAILED DESCRIPTION

[0030] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described in combination with the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0031] See also Figure 1 , Figure 2 , Figure 3 A heat storage type two-phase loop heat dissipation device comprises a two-phase loop heat transfer unit 1, a heat storage unit 3, an annular channel 4 and a local heat source 6. The two-phase loop heat transfer unit 1 comprises a shell and an annular mesh structure, a fluid medium and a porous material 7 arranged in a cavity of the shell. The annular mesh structure comprises a multi-level fractal tree-like channel 2 branching step by step along the center of the cavity. The shell comprises an upper shell and a lower shell 12 fixed by welding, wherein the upper shell is an upper cover plate 5. In this embodiment, the local heat source 6 is located at the center of the upper cover plate 5, and the lower shell 12 is a box structure with an open top and closed circumference and bottom. In this embodiment, taking a flat cylindrical structure as an example, the multi-level fractal tree-like channel 2 is fixedly connected to the inner wall of the bottom of the lower shell 12; the multi-level fractal tree-like channel 2 branches step by step from its center to form a tree-like channel structure;

[0032] Of course, the multi-level fractal tree-like channel 2 and the lower shell 12 can also be cut and formed as one piece, and the multi-level fractal tree-like channel 2 is filled with a working medium that is fluid under normal conditions. The inner wall of the multi-level fractal tree-like channel 2 is provided with a porous material 7, and the porous material 7 is used to provide capillary suction force for the working medium. In addition to the area of ​​the multi-level fractal tree-like channel 2 in the lower shell 12, a heat storage unit 3 is formed, and the heat storage unit 3 is filled with a phase change material 11. The multi-level fractal tree-like channel 2 is also connected through an annular channel 4 to form a fluid transmission network, which can evenly distribute the fluid working medium to each branch of the multi-level fractal tree-like channel 2, thereby improving the overall transmission efficiency of the heat storage type two-phase loop heat dissipation device and avoiding local overload or uneven fluid flow rate. In addition, the annular channel 4 can effectively buffer and disperse the pressure fluctuations generated by the fluid during the transmission process, reduce the impact on the multi-level fractal tree-like channel 2, and enhance the stability and durability of the heat storage type two-phase loop heat dissipation device.

[0033] See also Figure 4 , Figure 6 The multi-level fractal tree-like channel 2 includes a primary fractal tree-like channel 8, a secondary fractal tree-like channel 9, and a tertiary fractal tree-like channel 10 which are sequentially connected and diffuse outward along the local heat source 6. The primary fractal tree-like channel 8 includes a plurality of primary micro-grooves centered on the local heat source 6 and diffuse outward and are evenly distributed. The secondary fractal tree-like channel 9 includes a plurality of secondary micro-grooves. The tertiary fractal tree-like channel 10 includes a plurality of tertiary micro-grooves. Each level of the fractal tree-like channel 2 includes a plurality of micro-grooves. In this embodiment, each micro-groove is divided into two micro-grooves at the next level, and a plurality of micro-grooves form the next level of fractal tree-like channel 2. The bifurcation angles of the micro-grooves at each level are the same, and the angles are between 0° and 180°.

[0034] The length ratio and hydraulic diameter ratio of the k-th micro-channel to the k+1-th micro-channel satisfy the following relationship:

[0035]

[0036] Among them, D and Δ are the length fractal dimension and hydraulic diameter fractal dimension respectively. Finally, by continuously cycling according to the above rules, a multi-level fractal tree channel 2 can be obtained.

[0037] See also Figure 1 , Figure 4In this embodiment, two annular channels 4 with different diameters are provided, wherein a plurality of primary micro-grooves are connected through one annular channel 4, and a plurality of secondary micro-grooves are connected through another annular channel 4. The plane where the top of the annular channel 4 is located is coplanar with the plane where the tops of the primary fractal tree-shaped channel 8, the secondary fractal tree-shaped channel 9, and the tertiary fractal tree-shaped channel 10 are located. The plane where the bottom of the upper cover plate 5 is located is coplanar with the plane where the top of the annular channel 4 is located. The plane where the top of the upper cover plate 5 is located is coplanar with the plane where the top of the lower shell 12 is located. The upper cover plate 5 is embedded in the top opening of the lower shell 12 and is welded and fixed to the lower shell 12. The upper cover plate 5 and the lower shell 12 enclose the above-mentioned inner cavity.

[0038] It should be noted that in the actual process, the phase change material 11 with a suitable melting point and volume can be selected according to the temperature control range of the equipment. The phase change material 11 can be a material with a moderate melting point, including but not limited to paraffin, low melting point metal alloys, etc., to ensure effective operation within the operating temperature range of the equipment; the porous material 7 is made of a high capillary force material, including but not limited to porous metal, sintered powder, fiber material, etc.; the pore structure and size are designed to ensure that sufficient capillary force can be provided while ensuring the smooth flow of the fluid.

[0039] Working principle:

[0040] See also Figure 5 When the local heat source 6 generates heat, the heat diffuses from point to surface through the multi-level fractal tree-like channel 2, and the fluid working medium in the multi-level fractal tree-like channel 2 absorbs heat and evaporates at the local heat source 6. This part of the heat diffuses evenly and quickly to the surroundings through the multi-level fractal tree-like channel 2, realizing the diffusion path of heat from surface to body; the evaporated fluid working medium carries the heat and diffuses to the surroundings along the multi-level fractal tree-like channel 2; in this process, the fluid working medium transfers the heat to the phase change material 11 outside the multi-level fractal tree-like channel 2, and the phase change material 11 absorbs heat and begins to melt; the condensed liquid working medium returns to the local heat source 6 through the suction force of the porous material 7 under the action of capillary suction force, completing a cycle, and the capillary action of the porous material 7 can ensure that the liquid working medium can be quickly and evenly distributed to the two-phase loop heat transfer unit 1 to maintain a continuous heat transfer cycle;

[0041] When the temperature of the local heat source 6 decreases or stops working, the external phase change material 11 of the multi-level fractal tree-like channel structure 2 releases the stored heat to keep the temperature of the equipment stable and achieve a temperature control effect.

[0042] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A heat storage type two-phase circuit heat dissipation device, characterized in that: It comprises a two-phase loop heat transfer unit, wherein a closed cavity structure is provided in the two-phase loop heat transfer unit, an annular mesh structure and a heat storage unit are provided in the cavity, the heat storage unit is filled with phase change material, the annular mesh structure comprises a multi-level fractal tree-like channel branching step by step along the center of the cavity, the planes where the multi-level fractal tree-like channels are located are located in the same plane, the multi-level fractal tree-like channels are provided with fluid working medium, the heat storage unit is filled with phase change material, the inner wall of the multi-level fractal channel is provided with porous material, and the porous material can drive the fluid working medium to flow back to the center of the cavity.

2. A heat storage type two-phase circuit heat dissipation device according to claim 1, characterized in that: The annular network structure also includes at least one annular channel, which is connected to the fractal tree-like channels of the same level in the multi-level fractal tree-like channels and can cause the fluid working medium to be uniformly input into the multi-level fractal tree-like channels.

3. A heat storage type two-phase circuit heat dissipation device according to claim 1, characterized in that: Each level of the fractal tree-like channel includes a number of micro-grooves, each micro-groove is divided into a number of micro-grooves at the next level, and a number of micro-grooves form the next level of fractal tree-like channel. The micro-grooves at each level have the same bifurcation angle at the bifurcation, and the bifurcation angle is between 0° and 180°.

4. A heat storage type two-phase circuit heat dissipation device according to claim 3, characterized in that: The length ratio and hydraulic diameter ratio of the k-th microchannel to the k+1-th microchannel satisfy the following relationship: Among them, D and Δ are the length fractal dimension and hydraulic diameter fractal dimension respectively.

5. A heat storage type two-phase circuit heat dissipation device according to claim 3, characterized in that: Each microchannel is divided into two microchannels at the next level.

6. A heat storage type two-phase circuit heat dissipation device according to claim 3, characterized in that: The multi-level fractal tree-like channel includes a primary fractal tree-like channel, a secondary fractal tree-like channel, and a tertiary fractal tree-like channel which are connected in sequence.

7. A heat storage type two-phase circuit heat dissipation device according to claim 1, characterized in that: The heat storage unit is formed in the area between the outer side of the annular network structure and the cavity.

8. A heat storage type two-phase circuit heat dissipation device according to claim 1, characterized in that: The two-phase loop heat transfer unit includes an upper shell and a lower shell, the upper shell is embedded in the lower shell, the upper shell and the lower shell are welded and fixed to form the cavity structure, and the plane where the top of the upper shell is located is in the same plane as the plane where the top of the lower shell is located.

9. A heat storage type two-phase circuit heat dissipation device according to claim 1, characterized in that: A local heat source is located at the center of the cavity.

10. A heat storage type two-phase circuit heat dissipation device according to claim 1, characterized in that: The phase change material can absorb or release heat at a specific temperature, and the porous material is made of a capillary force material.

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