A fluidic microchannel heat sink

Abstract

This invention discloses a jet microchannel heat sink, comprising a shell, which is divided into a lower microchannel layer and an upper jet generating layer by a layered plate. Several pairs of first ribs are spaced apart in each microchannel to enhance the disturbance of the fluid on the wall and near the jet orifice. A pair of second ribs is also provided between adjacent first ribs to disturb the fluid between adjacent jet orifices, resulting in a higher fluid velocity near the second ribs and helping to reduce the temperature in the middle region between adjacent jet orifices. The jet generating layer also includes several jet dispersing ribs to disturb the fluid flowing in through the jet inlet, solving the problem of uneven jet distribution. Furthermore, the structure of this invention can incorporate crossflow, and by improving the jet orifice diameter distribution, the fluid in the latter half of the microchannel still has a high velocity after the crossflow mixes with the jet, carrying away more heat and making the temperature distribution of the microchannel more uniform.

Description

Technical Field

[0001] This invention relates to a heat sink structure, specifically a microchannel heat sink structure. Background Technology

[0002] With the continuous development of electronic devices, their integration level is increasing, and their power density is constantly rising, leading to increasingly prominent heat generation issues. If electronic devices are kept at high temperatures for extended periods during operation, it can result in performance degradation, shortened lifespan, and even device damage. Therefore, it is necessary to develop efficient heat sinks to address the high heat flux density problems caused by electronic devices.

[0003] The development of microchannel technology began in the 1980s, initially primarily applied in fields such as chemical engineering and biomedicine, and later gradually extended to heat dissipation in electronic devices. The main principle of microchannel heat sinks is to bring the heat-generating element into contact with a microchannel, allowing the fluid within the microchannel to carry away the heat, thus achieving heat dissipation. Jet microchannel heat sinks, on the other hand, are a novel heat dissipation technology combining microchannel and jet technologies. Their main principle is to pass a high-speed fluid through the microchannel, forming a jet that rapidly transfers heat to the cooling medium. The jet enhances the heat transfer between the cooling medium and the microchannel, thereby improving heat dissipation efficiency. Jet microchannel heat sinks offer advantages such as high efficiency, portability, and reliability, and have a wide range of applications, effectively solving heat dissipation problems in electronic devices. With the continuous development and application of microfluidic technology, jet microchannel heat sinks will find increasingly widespread use in electronic product design.

[0004] Currently, existing jet microchannel heat sinks generally suffer from the following problems:

[0005] 1. Uneven jet distribution. The diameter of the jet inlet is much smaller than the distribution range of the jet orifices. The jet velocity is higher in the jet orifices within the jet inlet range and lower in the jet orifices outside the range. The jet orifices at the edge of the range can hardly form a jet.

[0006] 2. After the jet enters the microchannel layer through the jet hole, the fluid velocity in the area near the jet hole is relatively high, while the fluid velocity in the middle area between adjacent jet holes is relatively low, resulting in poor heat dissipation in the middle area. Summary of the Invention

[0007] Purpose of the invention: To address the aforementioned issues in the prior art, this invention proposes a jet microchannel heat sink with turbulence ribs, which solves the problems of uneven jet distribution and poor heat dissipation in the middle region corresponding to adjacent jet holes within the microchannel.

[0008] Technical solution: A jet microchannel heat sink includes a shell, which is divided into a lower microchannel layer and an upper jet generating layer by a plate; a jet inlet is provided at the center of the top of the shell, and a microchannel outlet is provided on the side wall of the shell located on the microchannel layer; the jet generating layer is provided with a plurality of jet dispersing ribs for disturbing the fluid flowing in through the jet inlet;

[0009] The microchannel layer is divided into several parallel microchannels by a partition at the bottom of the vertical shell; within each microchannel, several pairs of first ribs are evenly spaced along the length of the microchannel, each pair of first ribs consists of two ribs arranged at relative intervals, and one vertical side of each pair of ribs is connected to the partition or the shell respectively; within adjacent microchannels, each pair of first ribs is staggered along the length of the microchannel.

[0010] The layer plate is provided with a number of jet holes, each jet hole being directly opposite the center point between each pair of first ribs in the microchannel layer below; in each microchannel, a pair of second ribs are provided directly below the middle of adjacent jet holes, each pair of second ribs being composed of two ribs arranged at relative intervals.

[0011] Furthermore, a crossflow inlet is provided on one side wall of the housing facing the end of each microchannel; from the crossflow inlet toward the outlet of the microchannel, the diameter of the corresponding jet hole at the top of each microchannel gradually decreases.

[0012] Furthermore, the jet dispersing ribs are located directly below the jet inlet and include four third ribs parallel to the length direction of the microchannel and four fourth ribs perpendicular to it; the fourth ribs are arranged in pairs parallel to each other, and the third ribs are located in pairs between the two sets of fourth ribs arranged in pairs parallel to each other; and the distance between adjacent third ribs is equal to the width of the third rib, and the distance between adjacent fourth ribs is less than the length of the fourth rib.

[0013] Furthermore, the width of the second rib is smaller than the width of the first rib, and the distance between the two ribs in each pair of second ribs is smaller than the width of the second rib.

[0014] Furthermore, the height of the jet dispersing rib is 1 / 2 of the height of the jet generating layer cavity.

[0015] Furthermore, the height of both the first rib and the second rib is 1 / 2 of the height of the microchannel.

[0016] Beneficial effects: 1. The addition of jet dispersion ribs 302 helps to solve the problem of uneven jet distribution. Most of the jet holes 301 can generate better jet velocity, especially the jet velocity generated by the jet holes 301 outside the range of jet inlet 101 and the jet holes 301 at the edge of the range of jet generation layer 3 is significantly increased.

[0017] 2. The first rib 202 enhances the disturbance of the fluid near the wall and jet orifice, changing the fluid distribution near the jet orifice 301 and improving the overall heat transfer of the microchannel. Simultaneously, the staggered distribution of the first ribs in adjacent microchannels enhances heat transfer at the wall surface of the first rib 202 and reduces the high temperature in the zero-velocity region caused by the added ribs. The second rib 203 disturbs the fluid between adjacent jet orifices 301, resulting in a higher fluid velocity near the second rib 203, which helps reduce the temperature in the middle region between adjacent jet orifices within the microchannel.

[0018] 3. After the crossflow is introduced, the diameter of the jet orifices 301 in the same row can gradually decrease from left to right. The jet velocity produced by the smaller diameter jet orifice 301 is greater than that produced by the larger diameter jet orifice 301. After the crossflow is mixed with the jet, the fluid in the latter half of the microchannel still has a higher velocity, which can carry away more heat, making the temperature distribution of the microchannel more uniform and reducing device damage caused by excessive wall temperature gradient. Attached Figure Description

[0019] Figure 1 This is a schematic diagram of the microchannel heat sink structure of the present invention;

[0020] Figure 2 This is a schematic diagram of the microchannel heat sink plane of the present invention;

[0021] Figure 3 This is a partial cross-sectional view of the microchannel heat sink of the present invention;

[0022] Figure 4 This is a schematic diagram of the microchannel layer structure;

[0023] Figure 5 This is a schematic diagram of the jet generation layer;

[0024] Figure 6 This is a comparative structural schematic diagram of the present invention;

[0025] Figure 7 This is a schematic diagram of the structure of Embodiment 2 of the present invention;

[0026] Figure 8 This is a comparison diagram of the jet distribution between a conventional jet microchannel heat sink and an embodiment of the present invention;

[0027] Figure 9These are temperature comparison cloud maps of a conventional microchannel and Embodiment 1 of the present invention, as well as a comparative example;

[0028] Figure 10 The above are fluid velocity comparison cloud diagrams of a conventional microchannel and Embodiment 1 of the present invention, which are comparative examples. Implementation

[0029] The invention will now be further explained with reference to the accompanying drawings. Example

[0030] A jet microchannel heat sink, such as Figures 1-5 As shown, the device includes a housing 1, which is divided into a lower microchannel layer 2 and an upper jet generating layer 3 by a layer plate. A jet inlet 101 is provided at the center of the top of the housing 1, and a microchannel outlet 103 is provided on the side wall of the housing 1 located on the microchannel layer 2.

[0031] The microchannel layer 2 is divided into nine parallel microchannels by a partition 201 at the bottom of the vertical housing 1. Within each microchannel, several pairs of first ribs 202 are evenly spaced along the length of the microchannel. Each pair of first ribs 202 consists of two ribs spaced apart, with one vertical side of each rib perpendicularly connected to the partition 201 or the housing 1. In adjacent microchannels, the pairs of first ribs 202 are staggered along the length of the microchannel. Several jet holes 301 are distributed on the layer, each jet hole 301 directly opposite the center point between each pair of first ribs 202 in the lower microchannel layer 2. Within each microchannel, directly below the center of adjacent jet holes 301, a pair of second ribs 203 are also provided, each pair of second ribs 203 consisting of two ribs spaced apart.

[0032] The first rib 202 is used to agitate the fluid near the jet orifice 301, enhancing heat transfer in the vicinity of the microchannel directly opposite the jet orifice 301. The first ribs 202 in adjacent microchannels are staggered, enhancing heat transfer on the wall surface at the first rib 202 and reducing the high temperature in the zero-velocity region caused by the added ribs. The second rib 203 agitates the fluid between adjacent jet orifices 301, increasing the fluid velocity in the middle region of the jet orifice, thereby enhancing heat transfer. Similarly, the second ribs 203 in adjacent microchannels are also staggered.

[0033] In this embodiment, in the three adjacent microchannels, the number of pairs of first ribs 202 are 8, 7, and 8, respectively, and the number of pairs of second ribs 203 are 7, 8, and 7, respectively, corresponding to 8, 7, and 8 jet holes 301. The diameter of the jet hole 301 is much smaller than the spacing between a pair of first ribs 202. The height of both the first ribs 202 and the second ribs 203 is half the height of the microchannel. The width of the second rib 203 is smaller than the width of the first rib 202, and the spacing between the two ribs in each pair of second ribs 203 is smaller than the width of the second rib 203.

[0034] The jet generating layer 3 is further provided with several jet dispersing ribs 302 for agitating the fluid flowing into the jet inlet 101. The height of the jet dispersing ribs 302 is half the height of the jet generating layer 3 cavity, and they are located directly below the jet inlet 101. Each rib includes four third ribs parallel to the length direction of the microchannel and four fourth ribs perpendicular to it. The fourth ribs are arranged in pairs, parallel to each other, and the third ribs are located in pairs between the two sets of parallel fourth ribs. Furthermore, the spacing between adjacent third ribs is equal to the width of the third rib, and the spacing between adjacent fourth ribs is less than the length of the fourth rib. Figure 2 As can be seen, in this embodiment, the eight jet dispersion ribs 302 are symmetrical about the horizontal and vertical directions.

[0035] The microchannel heat sink material is copper, but other metals with good thermal conductivity can also be used. During operation, fluid enters through the jet inlet 101 and is agitated by the jet dispersing fins 302, allowing the fluid to enter each jet hole 301 more evenly to form a jet. After the jet enters a single microchannel, the first fin 202 agitates the fluid near the area below the jet hole 301, enhancing heat transfer in the vicinity of the microchannel directly opposite the jet hole 301. Simultaneously, the first fins 202 of adjacent microchannels are staggered along the length of the microchannel, enhancing heat transfer on the wall of the partition 201 at the first fin 202 and reducing the high temperature in the zero-velocity region caused by the added fins. The second fin 203 agitates the fluid between adjacent jet holes 301, increasing the velocity of the fluid in the middle region between adjacent jet holes 301, thereby enhancing heat transfer. The fluid within the microchannel moves to both sides and finally flows out from the microchannel outlets 103 located at both ends of the microchannel. Example

[0036] The structure in this embodiment is used to introduce crossflow, such as Figure 7 As shown, compared to Example 1, the microchannel outlet 103 at one end is replaced with a crossflow inlet 102, and the diameter of the corresponding jet orifice 301 at the top of each microchannel gradually decreases from the crossflow inlet 102 to the microchannel outlet 103 at the other end. The jet velocity generated by the smaller diameter jet orifice 301 is greater than that generated by the larger diameter jet orifice 301. After adding crossflow, the microchannel crossflow flows in from the crossflow inlet 102 and mixes with the jet entering from above in each microchannel, resulting in better heat transfer. At the same time, due to the variable diameter structure of the jet orifice 301, the jet fluid velocity in the latter half of each microchannel is greater than that in the first half along its length. Therefore, the situation where the crossflow velocity decreases with the microchannel length is improved. After the crossflow mixes with the jet, the fluid in the latter half of each microchannel still has a large velocity, which can carry away more heat. Compared to Example 1, the temperature distribution of the microchannel is more uniform, reducing device damage caused by excessive wall temperature gradient.

[0037] Comparative example:

[0038] like Figure 6 As shown, the only difference from Example 1 is that the second rib 203 in the microchannel is removed from the comparative structure.

[0039] Simulation software was used to model and simulate the structures of Example 1, the comparative example, and a typical microchannel. For example... Figure 8 As shown, the left side represents the jet distribution of a conventional jet microchannel without the jet dispersing ribs 302, while the right side represents the jet distribution in the structure of Example 1 with the addition of the jet dispersing ribs 302. The fluid velocity at the jet inlet 101 is set to 0.5 m / s. In the structure of Example 1, most of the jet holes 301 have a relatively high fluid velocity, and the jet holes 301 at the edges far from the jet inlet 101 also have a relatively high fluid velocity. The black areas in the figure represent jet holes 301 with lower fluid velocities, and their number is far less than that of the conventional jet microchannel structure. This indicates that the addition of the jet dispersing ribs 301 helps to solve the problem of uneven jet distribution. Even the jet holes 301 outside the jet inlet range still have a relatively high jet velocity, and the jet holes 301 at the edge of the jet generation layer 3 also have a good jetting effect.

[0040] like Figure 9 As shown, the simulation calculations compare the temperature contour plots of a conventional microchannel, Embodiment 1 of the present invention, and a comparative example. The jet velocity was 0.5 m / s, and no other flow was observed; only the temperature change of the microchannel caused by the fluid generated by the jet orifice 301 was verified. The calculation results show that the highest temperature of the conventional microchannel is 329.43 K, the highest temperature of the comparative example is 323.28 K, and the highest temperature of Embodiment 1 is 321.82 K. The temperature of the conventional microchannel increases from the center of the jet orifice 301 outwards, with some areas of high temperature near the jet orifice. The high-temperature area of ​​Embodiment 1 is significantly reduced, with the highest temperature occurring near the first rib 202. The temperature near the jet orifice 301 is significantly lower than that of the conventional microchannel, and the temperature in the area between the jet orifice 301 and the second rib 203 in Embodiment 1 is lower than that in the comparative example, indicating that adding the second rib 302 helps to reduce the temperature in the middle region between adjacent jet orifices.

[0041] See Figure 10The simulation calculations compared the velocity contour plots of a conventional microchannel, Embodiment 1 of the present invention, and a comparative example. Similarly, the jet velocity was 0.5 m / s, with no other flow; only the velocity change of the fluid generated by the jet orifice 301 was verified. In a conventional microchannel, there are areas with low or even zero velocity around the jet orifice. The velocity contour plots of the embodiments show that the first rib 202 disturbs the nearby fluid, causing a change in the fluid distribution near the jet orifice 301. The second rib 203 disturbs the fluid between adjacent jet orifices 301. Compared to the comparative example, the velocity near the second rib 203 in Embodiment 1 is greater, producing the following effect: Figure 9 As shown, in Example 1, the temperature between the jet holes 301 is lower, and the overall temperature of the microchannel is also significantly reduced.

[0042] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A jet microchannel heat sink, characterized in that, The device includes a housing (1), which is divided into a lower microchannel layer (2) and an upper jet generating layer (3) by a layer plate; a jet inlet (101) is provided at the center of the top of the housing (1), and a microchannel outlet (103) is provided on the side wall of the housing (1) located in the microchannel layer (2); the jet generating layer (3) is provided with a plurality of jet dispersing ribs (302) for disturbing the fluid flowing in from the jet inlet (101). The microchannel layer (2) is divided into several parallel microchannels by a partition (201) at the bottom of the vertical shell (1); in each microchannel, several pairs of first ribs (202) are evenly spaced along the length of the microchannel, and each pair of first ribs (202) is composed of two ribs arranged at relative intervals, and one vertical side of the two ribs is connected to the partition (201) or the shell (1); in adjacent microchannels, each pair of first ribs (202) is staggered along the length of the microchannel; The layer plate is provided with a plurality of jet holes (301), each jet hole (301) being directly opposite to the center point between each pair of first ribs (202) in the microchannel layer (2) below; in each microchannel, a pair of second ribs (203) are provided directly below the middle of adjacent jet holes (301), each pair of second ribs (203) being composed of two ribs arranged at relative intervals; The jet dispersion ribs (302) are located directly below the jet inlet (101) and include four third ribs parallel to the length direction of the microchannel and four fourth ribs perpendicular to it; the fourth ribs are arranged in pairs parallel to each other, and the third ribs are located in pairs between the two sets of fourth ribs arranged in pairs parallel to each other; and the distance between adjacent third ribs is equal to the width of the third rib, and the distance between adjacent fourth ribs is less than the length of the fourth rib.

2. The jet microchannel heat sink according to claim 1, characterized in that, The housing (1) is also provided with a crossflow inlet (102) on one side wall facing the end of each microchannel; from the crossflow inlet (102) to the microchannel outlet (103), the diameter of the corresponding jet hole (301) at the top of each microchannel gradually decreases.

3. The jet microchannel heat sink according to claim 1 or 2, characterized in that, The width of the second rib (203) is less than the width of the first rib (202), and the distance between the two ribs in each pair of second ribs (203) is less than the width of the second rib (203).

4. The jet microchannel heat sink according to claim 1, characterized in that, The height of the jet dispersion rib (302) is 1 / 2 of the height of the cavity of the jet generation layer (3).

5. The jet microchannel heat sink according to claim 3, characterized in that, The height of the first rib (202) and the second rib (203) is half the height of the microchannel.

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