Multi-loop parallel pulsating heat pipe heat dissipation device

Abstract

The utility model provides a multi-loop parallel pulsating heat pipe heat dissipation device, which belongs to the technical field of heat dissipation, and comprises a multi-loop parallel pulsating heat pipe assembly and a plurality of fins, the multi-loop parallel pulsating heat pipe assembly comprises a laminated heat pipe flat pipe assembly and an end connector, the stacked heat pipe flat pipe assembly comprises a plurality of micro-channel heat pipe flat pipes and a plurality of flat pipe expansion pieces, and the flat pipe expansion pieces and the micro-channel heat pipe flat pipes are alternately arranged in the width direction of the micro-channel heat pipe flat pipes to form the stacked heat pipe flat pipe assembly. The stacked heat pipe flat pipe assembly is bent for multiple times to form a snakelike structure with parallel middle pipe sections and opposite head and tail end openings, the end connector is in a fishbone shape, the end connector is connected with the head and tail end openings of the stacked heat pipe flat pipe assembly to form a closed structure, and a plurality of fins are arranged between the parallel middle pipe sections of the stacked heat pipe flat pipe assembly. According to the utility model, the dry-out failure risk of the pulsating heat pipe under high load is reduced, and the heat transfer limit of the heat pipe and the stability and reliability of the heat dissipation device are improved.

Description

Technical Field

[0001] This utility model relates to the field of heat dissipation technology, and in particular to a multi-loop parallel pulsating heat pipe heat dissipation device. Background Technology

[0002] Pulsating heat pipes, also known as oscillating heat pipes, were proposed by Japanese scholar H. Akachi in the 1990s. Their working principle involves heating the evaporation section. When the pipe wall temperature reaches a certain superheat, the working fluid in the evaporation section accumulates energy. At this point, the pressure in the evaporation section is sufficient to overcome the combined effects of gravity and the pressure in the condensation section, propelling the working fluid in an oscillating motion from the evaporation section to the condensation section, thus completing heat transfer. Compared to traditional heat pipes, pulsating heat pipes have advantages such as high heat transfer limit, simple structure, no wick, and low cost. Pulsating heat pipes are generally formed by serpentine bending of copper capillary tubes. However, copper is expensive, and with the trend of aluminum replacing copper in the refrigeration industry, aluminum heat pipes are gradually becoming a new development trend. Furthermore, the circular cross-section of copper capillary tubes is difficult to fit with a planar heat source, making the flat shape of the pulsating heat pipe a better choice. Microchannel flat tubes, as an important component in the manufacture of microchannel heat exchangers, have a relatively mature manufacturing process, and their flat shape allows for good fit with planar heat sources, making them suitable for manufacturing flat pulsating heat pipe heat dissipation devices.

[0003] However, single-loop microchannel flat tube pulsating heat pipes suffer from problems such as small heat transfer area, low heat transfer limit, and susceptibility to burn-out failure. To address these issues, existing technologies generally employ wider flat tubes. This increases the tube width and heat transfer area, and also increases the number of microchannels within the tube, thereby increasing the number of bends in the loop, resulting in a slight improvement in the heat transfer limit. However, this does not fundamentally solve the problem. This is because simply increasing the tube width and the number of internal channels lengthens the pulsation path of the working fluid, weakening its pulsation effect and making it difficult to achieve the desired heat transfer limit. Furthermore, current heat dissipation devices using single-loop microchannel flat tube pulsating heat pipes mostly require auxiliary devices for fixation to the heat source, which typically leads to reduced heat pipe performance, increased manufacturing costs, and installation difficulties. Summary of the Invention

[0004] The purpose of this invention is to provide a multi-loop parallel pulsating heat pipe heat dissipation device, which can reduce the risk of pulsating heat pipe burning out and failing under high load, effectively improve the heat transfer limit, and increase the stability and reliability of the heat dissipation device.

[0005] To achieve the above objectives, this utility model provides the following technical solution:

[0006] A multi-loop parallel pulsating heat pipe heat dissipation device is characterized by comprising a multi-loop parallel pulsating heat pipe assembly and several fins. The multi-loop parallel pulsating heat pipe assembly includes a stacked heat pipe flat tube assembly and an end connector. The stacked heat pipe flat tube assembly includes several microchannel heat pipe flat tubes and several flat tube extensions. The flat tube extensions and microchannel heat pipe flat tubes are alternately arranged in the width direction of the microchannel heat pipe flat tubes to form a stacked heat pipe flat tube assembly. The stacked heat pipe flat tube assembly is formed into a serpentine structure with parallel middle tube sections and opposite ends by multiple bends. The end connector is fishbone shaped and is connected to the first and last ends of the stacked heat pipe flat tube assembly to form a closed structure. Several fins are provided between the parallel middle tube sections of the stacked heat pipe flat tube assembly.

[0007] Furthermore, the microchannel heat pipe flat tube has an odd number of parallel partitions inside, and the microchannel heat pipe flat tube includes a flat tube at one end and a flat tube at the other end. The partitions divide the lumen of the microchannel heat pipe flat tube into an even number of parallel microchannels.

[0008] Furthermore, the surface of the flat tube extension is provided with a number of through holes at intervals.

[0009] Furthermore, the end connector includes two end branches and a middle main trunk. One end branch is provided with several first protruding tubes, and the other end branch is provided with several first protruding tubes and second protruding tubes. The main trunk is provided with interconnected connecting holes and connecting tubes. The end connector is tightly connected to both ends of the stacked heat pipe flat tube assembly through the first protruding tubes and the second protruding tubes.

[0010] Furthermore, each pair of adjacent microchannels in the flat tube is a group from top to bottom, and a recess is provided on the partition wall between each pair of adjacent microchannels in the flat tube so that the adjacent microchannels in the group are connected.

[0011] Except for the two microchannels on the uppermost and lowermost sides, the other two microchannels on the other end of the flat tube are grouped into two adjacent microchannels. The partition wall between each pair of adjacent microchannels on the other end of the flat tube is provided with a recess so that the adjacent microchannels in the group are connected.

[0012] Furthermore, the first protruding tube is inserted into the recess of the partition wall between each group of adjacent microchannels in one end of the flat tube and the other end of the flat tube to connect the adjacent microchannels in series, forming a pulsating heat pipe loop in which the adjacent microchannels are interconnected.

[0013] The second protruding tube is inserted into two microchannels located on the upper and lower sides of the microchannel heat pipe flat tube. The second protruding tube is connected to the connecting tube through the connecting hole, so that each pulsating heat pipe loop is connected in parallel.

[0014] Furthermore, the thickness of the flat tube extension is 0.25 to 1.2 times the thickness of the microchannel heat pipe flat tube, and the width of the flat tube extension is 0.25 to 0.75 times the width of the microchannel heat pipe flat tube.

[0015] Furthermore, the stacked heat pipe flat tube assembly has a serpentine bending structure with a bending spacing of 8mm to 32mm.

[0016] Furthermore, the first and second protruding tubes of the end connector are connected to the stacked heat pipe flat tube assembly by adhesive bonding or welding.

[0017] Furthermore, the outer edge plane of the multi-loop parallel pulsating heat pipe assembly is an evaporation section, which is in contact with the heat source, and several fins are provided between the parallel intermediate tube sections of the stacked heat pipe flat tube assembly to form a condensation section.

[0018] Advantages of this utility model:

[0019] 1. This utility model provides an implementation method to reduce the risk of heat pipe burn-out failure and effectively improve the heat transfer limit. Multiple microchannel heat pipe flat tubes are connected by a flat tube extension, thereby increasing the heat transfer area. The end connector can connect adjacent microchannels in a single pulsed heat pipe loop in series, or connect multiple pulsed heat pipe loops in parallel. When the heat source is too hot and causes the working fluid in one loop to burn out, the working fluid in other loops can be replenished through the connecting pipe in the end connector, reducing the risk of heat pipe burn-out.

[0020] 2. This utility model provides a fixing method for a microchannel flat tube pulsating heat pipe heat dissipation device. This method is simple to operate and low in cost, eliminating the need for heavy aluminum substrates or other auxiliary devices. The flat tube is fixed to the heat source using bolts through pre-drilled holes in the flat tube extension, effectively reducing the contact thermal resistance between the heat source and the heat pipe. This fixing method improves the reliability of the device's fixation and ensures the stability of its heat dissipation effect. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of this utility model;

[0022] Figure 2 This is a schematic diagram of the structure of the mid-layer stacked heat pipe flat tube assembly of this utility model;

[0023] Figure 3 This is a schematic diagram of the cross-sectional view of both ends of the microchannel heat pipe flat tube in this utility model;

[0024] Figure 4 This is a structural schematic diagram of the end connector of this utility model;

[0025] Figure 5This is a schematic diagram illustrating the connection method between the mid-layer stacked heat pipe flat tube assembly and the end connector of this utility model;

[0026] Figure 6 This is a cross-sectional view of the connection method between the mid-layer stacked heat pipe flat tube assembly and the end connector of this utility model;

[0027] In the figure: 1. Multi-loop parallel pulsating heat pipe assembly; 101. Stacked heat pipe flat tube assembly; 1011. Microchannel heat pipe flat tube; 1012. Flat tube extension; 1013. Partition wall; 1014. Recess; 1015. Microchannel; 1016. Through hole; 102. End connector; 1021. First protruding tube; 1022. Second protruding tube; 1023. Connecting hole; 1024. Connecting tube.

[0028] 2. Fins. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model. Therefore, the following detailed description of the embodiments of this utility model provided in the accompanying drawings is not intended to limit the scope of the claimed utility model, but merely to represent selected embodiments of this utility model.

[0030] like Figure 1 As shown, a multi-loop parallel pulsating heat pipe heat dissipation device includes a multi-loop parallel pulsating heat pipe assembly 1 and several fins 2. The multi-loop parallel pulsating heat pipe assembly includes a stacked heat pipe flat tube assembly 101 and end connectors 102; the stacked heat pipe flat tube assembly 101 includes several microchannel heat pipe flat tubes 1011 and several flat tube extensions 1012; the flat tube extensions 1012 and the microchannel heat pipe flat tubes 1011 are alternately arranged in the width direction of the microchannel heat pipe flat tubes 1011, forming the stacked heat pipe flat tube assembly 101. The stacked heat pipe flat tube assembly 101 is formed into a serpentine structure with parallel middle sections and opposite end ports through multiple bends. Figure 4 As shown, the end connector 102 is fishbone shaped. The end connector 102 is connected to the first and last ports of the stacked heat pipe flat tube assembly 101 to form a closed structure. Several fins 2 are provided between the parallel intermediate tube segments of the stacked heat pipe flat tube assembly 101.

[0031] As a preferred embodiment of this utility model, such as Figure 2 and Figure 3 As shown, the microchannel heat pipe flat tube 1011 has an odd number of parallel partitions 1013 inside. The microchannel heat pipe flat tube 1011 includes a flat tube at one end and a flat tube at the other end. The partitions 1013 divide the lumen of the microchannel heat pipe flat tube 1011 into an even number of parallel microchannels 1015.

[0032] In a preferred embodiment of this utility model, the surface of the flat tube extension 1012 is provided with a plurality of through holes 1016 at intervals. The shapes of the through holes include, but are not limited to, circles, oblong shapes, and oblong arc shapes. The through hole design can reduce the material consumption of the flat tube extension and save costs, and it is also beneficial for fixing the heat dissipation device.

[0033] As a preferred embodiment of this utility model, such as Figure 4 As shown, the end connector 102 includes two end branches and a middle main trunk; as Figure 5 and Figure 6 As shown, one end branch has several first protruding tubes 1021, and the other end branch has several first protruding tubes 1021 and second protruding tubes 1022. The main body has interconnected connecting holes 1023 and connecting pipes 1024. The end connector 102 is tightly connected to both ends of the stacked heat pipe flat tube assembly 101 through the first protruding tubes 1021 and the second protruding tubes 1022.

[0034] The flat tube at one end forms a group of two adjacent microchannels 1015 from top to bottom. A recess 1014 is provided on the partition wall 1013 between each pair of adjacent microchannels 1015 in the flat tube at one end so that the adjacent microchannels 1015 in the group are connected.

[0035] Except for the two microchannels 1015 on the uppermost and lowermost sides, each pair of adjacent microchannels 1015 on the other end of the flat tube is a group. A recess 1014 is provided on the partition wall 1013 between each pair of adjacent microchannels 1015 on the other end of the flat tube so that the adjacent microchannels 1015 in the group are connected.

[0036] The first protruding tube 1021 is inserted into the recess 1014 of the partition wall 1013 between each group of adjacent microchannels 1015 of one end flat tube and the other end flat tube, connecting the adjacent microchannels 1015 in series to form a pulsating heat pipe loop in which the adjacent microchannels 1015 are interconnected.

[0037] The second protruding tube 1022 is inserted into two microchannels 1015 located on the upper and lower sides of the microchannel heat pipe flat tube 1011. The second protruding tube 1022 is connected to the connecting tube 1024 through the connecting hole 1023, so that each pulsating heat pipe loop is connected in parallel.

[0038] In a preferred embodiment of the present invention, the thickness of the flat tube extension 1012 is 0.25 to 1.2 times the thickness of the microchannel heat pipe flat tube 1011, and the width of the flat tube extension 1012 is 0.25 to 0.75 times the width of the microchannel heat pipe flat tube 1011.

[0039] In a preferred embodiment of the present invention, the stacked heat pipe flat tube assembly 101 has a serpentine bending structure with a bending spacing of 8mm to 32mm.

[0040] In a preferred embodiment of the present invention, the first protruding tube 1021 and the second protruding tube 1022 of the end connector 102 are connected to the stacked heat pipe flat tube assembly 101 by means of adhesive bonding or welding.

[0041] In a preferred embodiment of the present invention, the outer edge plane of the multi-loop parallel pulsating heat pipe assembly 1 is an evaporation section, which is in contact with the heat source, and a number of fins 2 are provided between the parallel intermediate pipe sections of the stacked heat pipe flat tube assembly 101 to form a condensation section.

[0042] In a preferred embodiment of the present invention, the microchannel heat pipe flat tube 1011 and the flat tube extension 1012 are made of aluminum.

[0043] The working process of this utility model:

[0044] Before operation, the multi-loop parallel pulsating heat pipe assembly 1 needs to be evacuated and filled with working fluid, with the filling volume being 40% to 80% of the heat pipe's internal volume. A non-flammable working fluid with a high saturation temperature-pressure ratio, thermal conductivity, specific heat capacity, and low surface tension and dynamic viscosity is typically selected, which facilitates rapid start-up and efficient heat dissipation of the pulsating heat pipe. During operation, multiple fins 2 (heat dissipation ends) are installed in the middle section of the multi-loop parallel pulsating heat pipe assembly 1, with their outer edge planes contacting the heat source (heat absorption ends). The heat source and radiator can be bolted together using the through holes 1016 on the flat tube extension 1012. The heat generated by the heat source can be directly transferred to the multi-loop parallel pulsating heat pipe assembly 1. Each pulsating heat pipe loop in the multi-loop parallel pulsating heat pipe assembly 1 transfers heat from the heat absorption end to the heat dissipation end through the gas-liquid phase change and vapor-liquid plug oscillation of the working fluid. Then, the heat is carried away by the airflow between the heat pipe and the fins 2, thus achieving the purpose of heat dissipation. When the heat source is too hot and the working fluid in a certain loop burns out, the working fluid in other loops can be replenished to the burned-out area through the connecting pipe in the end connector, so that the gas and liquid in that loop can be restored to circulation, avoiding local dry burning and thus improving the heat transfer limit of the heat pipe.

[0045] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model. Those skilled in the art can still adjust the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Therefore, if these modifications and variations of the present utility model fall within the scope of the claims of the present utility model and their equivalents, the present utility model also intends to include these modifications and variations.

Claims

1. A multi-loop parallel pulsating heat pipe heat dissipation device, characterized in that: The system includes a multi-loop parallel pulsating heat pipe assembly (1) and several fins (2). The multi-loop parallel pulsating heat pipe assembly includes a stacked heat pipe flat tube assembly (101) and an end connector (102). The stacked heat pipe flat tube assembly (101) includes several microchannel heat pipe flat tubes (1011) and several flat tube extensions (1012). The flat tube extensions (1012) and the microchannel heat pipe flat tubes (1011) are located at the same width as the microchannel heat pipe flat tubes (1011). The stacked heat pipe flat tubes are arranged alternately in the direction to form a stacked heat pipe flat tube assembly (101). The stacked heat pipe flat tube assembly (101) is formed by multiple bends to form a serpentine structure with parallel middle tube sections and opposite head and tail ports. The end connector (102) is fishbone shaped. The end connector (102) is connected to the head and tail ports of the stacked heat pipe flat tube assembly (101) to form a closed structure. Several fins (2) are provided between the parallel middle tube sections of the stacked heat pipe flat tube assembly (101).

2. The multi-loop parallel pulsating heat pipe heat dissipation device according to claim 1, characterized in that: The microchannel heat pipe flat tube (1011) has an odd number of parallel partitions (1013) inside. The microchannel heat pipe flat tube (1011) includes a flat tube at one end and a flat tube at the other end. The partitions (1013) divide the lumen of the microchannel heat pipe flat tube (1011) into an even number of parallel microchannels (1015).

3. The multi-loop parallel pulsating heat pipe heat dissipation device according to claim 2, characterized in that: The surface of the flat tube extension (1012) is provided with a plurality of through holes (1016) spaced apart.

4. The multi-loop parallel pulsating heat pipe heat dissipation device according to claim 3, characterized in that: The end connector (102) includes two branch ends and a middle main trunk. One branch end is provided with several first protruding tubes (1021), and the other branch end is provided with several first protruding tubes (1021) and second protruding tubes (1022). The main trunk is provided with interconnected connecting holes (1023) and connecting pipes (1024). The end connector (102) is tightly connected to both ends of the stacked heat pipe flat tube assembly (101) through the first protruding tubes (1021) and the second protruding tubes (1022).

5. The multi-loop parallel pulsating heat pipe heat dissipation device according to claim 4, characterized in that: The flat tube at one end has two adjacent microchannels (1015) arranged as a group from top to bottom. The partition wall (1013) between each two adjacent microchannels (1015) of the flat tube at one end is provided with a recess (1014) so ​​that the adjacent microchannels (1015) in the group are connected. Except for the two microchannels (1015) on the uppermost and lowermost sides, each pair of adjacent microchannels (1015) on the other end of the flat tube is a group. A recess (1014) is provided on the partition wall (1013) between each pair of adjacent microchannels (1015) on the other end of the flat tube so that the adjacent microchannels (1015) in the group are connected.

6. The multi-loop parallel pulsating heat pipe heat dissipation device according to claim 5, characterized in that: The first protruding tube (1021) is inserted into one end of the flat tube and the other end of the flat tube respectively. The recess (1014) of the partition wall (1013) between each group of adjacent microchannels (1015) connects the adjacent microchannels (1015) in series to form a pulsating heat pipe loop in which the adjacent microchannels (1015) are interconnected. The second protruding tube (1022) is inserted into two microchannels (1015) located on the upper and lower sides of the microchannel heat pipe flat tube (1011). The second protruding tube (1022) is connected to the connecting tube (1024) through the connecting hole (1023) to connect each pulsating heat pipe loop in parallel.

7. The multi-loop parallel pulsating heat pipe heat dissipation device according to claim 6, characterized in that: The thickness of the flat tube extension (1012) is 0.25 to 1.2 times the thickness of the microchannel heat pipe flat tube (1011), and the width of the flat tube extension (1012) is 0.25 to 0.75 times the width of the microchannel heat pipe flat tube (1011).

8. The multi-loop parallel pulsating heat pipe heat dissipation device according to claim 7, characterized in that: The stacked heat pipe flat tube assembly (101) has a serpentine bending structure with a bending spacing of 8mm to 32mm.

9. A multi-loop parallel pulsating heat pipe heat dissipation device according to claim 8, characterized in that: The first protruding tube (1021) and the second protruding tube (1022) of the end connector (102) are connected to the stacked heat pipe flat tube assembly (101) by adhesive bonding or welding.

10. A multi-loop parallel pulsating heat pipe heat dissipation device according to claim 9, characterized in that: The outer edge plane of the multi-loop parallel pulsating heat pipe assembly (1) is an evaporation section, which is in contact with the heat source. Several fins (2) are provided between the parallel intermediate pipe sections of the stacked heat pipe flat tube assembly (101) to form a condensation section.

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