CN116847628A - Jet flow micro-channel heat sink - Google Patents

Abstract

The invention discloses a jet flow micro-channel heat sink which comprises a shell, wherein the shell is divided into a micro-channel layer on the lower layer and a jet flow generation layer on the upper layer by a laminate. A plurality of pairs of first ribs are arranged in each microchannel at intervals and used for strengthening the disturbance of the fluid near the wall surface and the jet holes. And a second rib pair is arranged between the adjacent first ribs and used for disturbing fluid between the adjacent jet holes, so that the fluid velocity near the second ribs is higher, and the temperature of the middle area of the adjacent jet holes is reduced. The jet flow generating layer is also internally provided with a plurality of jet flow dispersing ribs for disturbing the fluid flowing in from the jet inlet, so that the problem of uneven jet flow distribution is solved. In addition, the structure of the invention can also add cross flow, and through improving the distribution of the jet flow diameter, the fluid at the latter half part of the micro-channel still has larger speed after the cross flow is mixed with the jet flow, and more heat can be taken away, so that the temperature distribution of the micro-channel is more uniform.

Description

Jet flow micro-channel heat sink

Technical Field

The invention relates to a radiator structure, in particular to a micro-channel heat sink structure.

Background

With the continuous development of electronic devices, the integration level of the electronic devices is higher and higher, and the power density of the electronic devices is continuously improved, so that the heating problem of the electronic devices is increasingly outstanding. If the electronic device is in a high temperature state for a long time in the working process, the performance of the device is reduced, the service life is shortened, and even the device is damaged. Therefore, there is a need to develop efficient heat sinks to address the high heat flux problems caused by electronics.

The development of micro-channel technology starts in the 80 s of the 20 th century, is mainly applied to the fields of chemical industry, biomedicine and the like at first, and is gradually applied to the field of heat dissipation of electronic devices later. The main principle of the micro-channel heat sink is that a heating element is contacted with a micro-channel, and heat is taken away by fluid in the micro-channel, so that the heat dissipation effect is realized. The jet flow micro-channel heat sink is a novel heat dissipation technology combining micro-channel technology and jet flow technology, and the main principle is that high-speed fluid passes through the micro-channel to form jet flow so as to quickly transfer heat into a cooling medium. Through the jet flow, the heat transfer effect between the cooling medium and the micro-channel can be enhanced, so that the heat dissipation efficiency is improved. The jet micro-channel heat sink has the advantages of high efficiency, portability, reliability and the like, has wide application range, and can well solve the heat dissipation problem of electronic devices. With the continuous development and application of microfluidic technology, jet micro-channel heat sinks will be increasingly used in electronic product design.

At present, the following problems generally exist in the existing jet micro-channel heat sink:

1. the jet is unevenly distributed. The diameter of the jet inlet is far smaller than the distribution range of jet holes, the jet speed of the jet holes in the jet inlet range is larger, the jet speed of the jet holes outside the range is smaller, and jet holes at the edge of the range almost cannot form jet.

2. After the jet flows through the jet holes and enters the micro-channel layer, the fluid velocity of the area near the jet holes is higher, and the fluid velocity of the middle area of the adjacent jet holes is lower, so that the heat dissipation of the middle area is poorer.

Disclosure of Invention

The invention aims to: aiming at the prior art, a jet flow micro-channel heat sink with turbulence ribs is provided, and the problems of uneven jet flow distribution and poor heat dissipation of the middle area corresponding to the adjacent jet flow holes in the micro-channel in the existing structure are solved.

The technical scheme is as follows: a jet flow micro-channel heat sink comprises a shell, wherein the shell is divided into a micro-channel layer on the lower layer and a jet flow generation layer on the upper layer by a laminate; a jet inlet is arranged in the center of the top of the shell, and a microchannel outlet is arranged on the side wall of the shell, which is positioned on the microchannel layer; a plurality of jet flow dispersing ribs for disturbing fluid flowing in from the jet flow inlet are arranged in the jet flow generating layer;

the microchannel layer is divided into a plurality of parallel microchannels by a baffle plate at the bottom of the vertical shell; a plurality of pairs of first ribs are uniformly arranged in each microchannel at intervals along the length direction of the microchannel, each pair of first ribs consists of two ribs which are oppositely arranged at intervals, and one vertical side edge of each rib is respectively connected with the partition plate or the shell; in the adjacent micro-channels, each pair of first ribs are distributed in a staggered manner along the length direction of the micro-channel;

a plurality of jet holes are distributed on the laminate, and each jet hole is respectively right opposite to the center point between each pair of first ribs in the microchannel layer below; and each pair of second ribs is arranged in each microchannel and right below the middle of the adjacent jet holes, and each pair of second ribs consists of two ribs which are oppositely arranged at intervals.

Further, a lateral flow inlet is also arranged on one side wall of the shell, which is opposite to the end part of each micro-channel; and the diameter of one jet hole corresponding to the top of each micro-channel is gradually reduced from the cross flow inlet to the micro-channel outlet.

Further, the jet flow dispersing rib is positioned right below the jet flow inlet and comprises four third ribs parallel to the length direction of the micro-channel and four perpendicular fourth ribs; the fourth ribs are arranged in parallel in pairs, and the third ribs are arranged between the two groups of the fourth ribs which are arranged in parallel in pairs; and the interval between the adjacent third ribs is equal to the width of the third ribs, and the interval between the adjacent fourth ribs is smaller than the length of the fourth ribs.

Further, the width of the second ribs is smaller than the width of the first ribs, and the distance between two ribs in each pair of the second ribs is smaller than the width of the second ribs.

Further, the height of the jet flow dispersing ribs is 1/2 of the height of the cavity of the jet flow generating layer.

Further, the height of the first rib and the second rib is 1/2 of the height of the micro-channel.

The beneficial effects are that: 1. the addition of jet dispersion ribs 302 helps to solve the problem of maldistribution of the jet, and most of the jet holes 301 can produce better jet flow rates, especially the jet flow rates of jet holes 301 outside the range of jet inlets 101 and jet holes 301 at the edge of the range of jet generation layer 3 are obviously increased.

2. The first rib 202 enhances the turbulence of the fluid on the wall and near the orifice, which changes the distribution of the fluid near the orifice 301 and enhances the heat transfer of the overall microchannel. Meanwhile, the first ribs of the adjacent micro-channels are distributed in a staggered mode in the channel direction, so that heat transfer of the wall surface at the first rib 202 can be enhanced, and high temperature in a fluid zero-speed area caused by adding the ribs is reduced. The second rib 203 perturbs the fluid between adjacent jet holes 301 such that the velocity of the fluid near the second rib 203 is greater, helping to reduce the temperature of the intermediate region of adjacent jet holes in the microchannel.

3. After adding cross flow, the diameter of the jet holes 301 in the same row from left to right can be gradually reduced, and the jet flow generated by the jet holes 301 with smaller diameter has a velocity greater than that of the jet flow generated by the jet holes 301 with larger diameter. After the cross flow is mixed with jet flow, the fluid in the second half part of the micro channel still has a higher speed, and more heat can be taken away, so that the temperature distribution of the micro channel is more uniform, and the damage to devices caused by overlarge temperature gradient of the wall surface is reduced.

Drawings

FIG. 1 is a schematic view of a microchannel heat sink structure of the present invention;

FIG. 2 is a schematic plan view of a microchannel heat sink of the present invention;

FIG. 3 is a partial cross-sectional view of a microchannel heat sink of the invention;

FIG. 4 is a schematic structural view of a microchannel layer;

FIG. 5 is a schematic structural view of a jet generating layer;

FIG. 6 is a schematic view of the structure of a comparative example of the present invention;

fig. 7 is a schematic structural view of embodiment 2 of the present invention;

FIG. 8 is a comparison of a generic jet microchannel heat sink and jet distribution of an embodiment of the invention;

FIG. 9 is a temperature versus cloud plot of a generic microchannel and example 1 of the invention, comparative example;

fig. 10 is a fluid velocity vs. cloud for a generic microchannel and example 1 of the invention, comparative example.

Description of the embodiments

The invention is further explained below with reference to the drawings.

Examples

A jet microchannel heat sink, as shown in fig. 1-5, comprises a housing 1, the housing 1 being divided by a laminate into a lower microchannel layer 2 and an upper jet generating layer 3. The center of the top of the shell 1 is provided with a jet inlet 101, and the side wall of the shell 1, which is positioned on the microchannel layer 2, is provided with a microchannel outlet 103.

The microchannel layer 2 is divided into 9 parallel microchannels by a partition 201 perpendicular to the bottom of the housing 1. In each microchannel, a plurality of pairs of first ribs 202 are uniformly arranged at intervals along the length direction of the microchannel, each pair of first ribs 202 is composed of two ribs which are oppositely arranged at intervals, and one vertical side edge of each rib is respectively and vertically connected with a baffle 201 or a shell 1. Within adjacent microchannels, each pair of first ribs 202 may be staggered along the length of the microchannel. A plurality of jet holes 301 are distributed on the laminate, and each jet hole 301 is respectively opposite to the center point between each pair of first ribs 202 in the lower micro-channel layer 2. In each microchannel, there are also two pairs of second ribs 203 respectively provided immediately below the middle of the adjacent jet holes 301, each pair of second ribs 203 being constituted by two ribs arranged at an opposite interval.

The first rib 202 is used for disturbing fluid near the jet hole 301 and enhancing heat transfer of the jet hole 301 to a position near the micro channel; the first ribs 202 in adjacent microchannels are staggered to enhance heat transfer to the walls at the first ribs 202, reducing the high temperatures in the zero velocity region of the fluid due to the increased ribs. The second rib 203 perturbs the fluid between adjacent jet holes 301, enhancing the fluid velocity in the middle region of the jet holes, and thus enhancing heat transfer. Likewise, the second ribs 203 in adjacent microchannels are also staggered.

In the three adjacent microchannels of this embodiment, the number of pairs of first ribs 202 is 8, 7, 8, respectively, the number of pairs of second ribs 203 is 7, 8, 7, respectively, and the number of corresponding jet holes 301 is 8, 7, 8, respectively. The diameter of jet aperture 301 is much smaller than the spacing between a pair of first ribs 202. Wherein the height of the first rib 202 and the second rib 203 is 1/2 of the height of the micro-channel. The width of the second ribs 203 is smaller than the width of the first ribs 202, and the spacing of two ribs in each pair of second ribs 203 is smaller than the width of the second ribs 203.

Also provided in the jet generating layer 3 are jet dispersion ribs 302 for disturbing the fluid flowing in from the jet inlet 101. The jet dispersion rib 302 has a height of 1/2 of the height of the jet generation layer 3 cavity and is located directly below the jet inlet 101, and includes four third ribs parallel to the length direction of the microchannel and four fourth ribs perpendicular thereto. Wherein, the fourth ribs are arranged in parallel in pairs, and the third ribs are arranged between the two groups of fourth ribs which are arranged in parallel in pairs; and the interval between the adjacent third ribs is equal to the width of the third ribs, and the interval between the adjacent fourth ribs is smaller than the length of the fourth ribs. As can be seen in FIG. 2, in this embodiment, 8 jet dispersion ribs 302 are symmetrical about both the horizontal and vertical directions.

The micro-channel heat sink material is copper, and can also be other metals with better heat conductivity. In operation, fluid enters from the jet inlet 101 and passes through the turbulence of the jet dispersion rib 302, causing the fluid to more uniformly enter each jet aperture 301 to form a jet. After the jet flow enters a single microchannel, the first ribs 202 disturb the fluid near the lower part of the jet hole 301, so that the heat transfer of the jet hole 301 to the position near the microchannel is enhanced, meanwhile, the first ribs 202 of adjacent microchannels are distributed in a staggered manner along the length direction of the microchannel, the heat transfer of the wall surface of the baffle 201 at the first ribs 202 is enhanced, and the high temperature of a fluid zero-speed region caused by the addition of the ribs is reduced. The second rib 203 disturbs the fluid between adjacent jet holes 301, enhancing the velocity of the fluid in the middle region of adjacent jet holes 301, thereby enhancing heat transfer. The fluid in the micro-channel moves to two sides and finally flows out from the micro-channel outlets 103 respectively arranged at two ends of the micro-channel.

Examples

The structure of this embodiment is used to introduce cross flow, as shown in fig. 7, and compared with embodiment 1, the micro-channel outlet 103 at one end is changed into the cross flow inlet 102, and the diameter of the jet hole 301 corresponding to the top of each micro-channel is gradually reduced from the cross flow inlet 102 to the micro-channel outlet 103 at the other end. The velocity of the jet produced by the smaller diameter jet holes 301 is greater than the velocity of the jet produced by the larger diameter jet holes 301. After the cross flow is added, the cross flow of the micro channels flows in from the cross flow inlet 102, and is mixed with jet flow entering from the upper part in each micro channel, so that better heat transfer effect is generated. Meanwhile, the variable diameter structure of the jet holes 301 causes the jet fluid velocity of the rear half part of each micro-channel in the length direction to be greater than that of the front half part, so that the condition that the cross flow velocity is reduced along with the length of the micro-channel is improved, and after the cross flow mixes the jet, the fluid of the rear half part of each micro-channel still has a greater velocity, and more heat can be taken away. Compared with the embodiment 1, the temperature distribution of the micro-channel is more uniform, and the damage to the device caused by the overlarge temperature gradient of the wall surface is reduced.

Comparative example:

as shown in fig. 6, the only difference from embodiment 1 is that the present comparative example structure removes the second rib 203 in the microchannel.

Modeling simulation calculations were performed on example 1, comparative example, and common microchannel structures using simulation software. As shown in fig. 8, the left side is the jet distribution of a conventional jet microchannel without the jet dispersion rib 302, and the right side is the jet distribution of the added jet dispersion rib 302 in the structure of embodiment 1. The fluid velocity of the jet inlet 101 was set to 0.5m/s, and most of the jet holes 301 in the structure of example 1 had a larger fluid velocity, and the jet holes 301 at the edges farther from the jet inlet 101 also had a larger fluid velocity. The black part in the figure is the jet holes 301 with smaller fluid velocity, the number of the jet holes is far less than that of a common jet micro-channel structure, and the increase of the jet flow dispersing ribs 301 helps to solve the problem of uneven jet flow distribution, even if jet flows of the jet holes 301 outside the range of the jet flow inlet still have larger velocity, and the jet holes 301 at the edge of the range of the jet flow generating layer 3 also have better jet flow effect.

As shown in fig. 9, a temperature versus cloud for the general microchannel and example 1 of the present invention and comparative example was calculated for simulation. The jet velocity was 0.5m/s and no other flow was present, only verifying the resulting microchannel temperature change of the fluid generated by jet orifice 301. The results after calculation showed that the maximum temperature of the ordinary microchannel was 329.43K, the maximum temperature of the comparative example was 323.28K, and the maximum temperature of example 1 was 321.82K. The temperature of the general micro channel increases from the middle of the jet hole 301 to the periphery, wherein a part of a region with higher temperature exists near the jet hole. The high temperature area of example 1 was significantly reduced, the highest temperature was present near first rib 202, the temperature near jet orifice 301 was significantly lower than for the conventional microchannel, and the area between jet orifice 301 and second rib 203 of example 1 was lower than for the comparative example, indicating that adding second rib 302 helps reduce the temperature in the middle area of the adjacent jet orifice.

Referring to fig. 10, a velocity comparison cloud for a generic microchannel and example 1 of the present invention and comparative example was calculated for simulation. Likewise, the jet velocity was 0.5m/s, and no other flow was present, only the jet orifice 301 was verified to produce a change in velocity of the fluid. The upper part and the lower part around the jet hole of the common micro-channel are respectively provided with a region with small part speed and even 0. As can be seen from the velocity cloud of the embodiment, first rib 202 perturbs the fluid in the vicinity, causing a change in the fluid distribution in the vicinity of jet aperture 301. The second ribs 203 disturb the fluid between adjacent jet holes 301, and the velocity near the second ribs 203 of example 1 is higher than that of the comparative example, resulting in the effect shown in fig. 9, that the jet holes 301 of example 1 have a lower temperature, and the overall temperature of the micro channel is significantly reduced.

The foregoing is merely a preferred embodiment of the present invention and it should be noted that modifications and adaptations to those skilled in the art may be made without departing from the principles of the present invention, which are intended to be comprehended within the scope of the present invention.

Claims (6)

1. The jet flow micro-channel heat sink is characterized by comprising a shell (1), wherein the shell (1) is divided into a micro-channel layer (2) at the lower layer and a jet flow generation layer (3) at the upper layer by a laminate; a jet inlet (101) is formed in the center of the top of the shell (1), and a microchannel outlet (103) is formed in the side wall of the shell (1) positioned on the microchannel layer (2); a plurality of jet flow dispersing ribs (302) for disturbing the fluid flowing in from the jet flow inlet (101) are arranged in the jet flow generating layer (3);

the microchannel layer (2) is divided into a plurality of parallel microchannels by a baffle plate (201) at the bottom of the vertical shell (1); a plurality of pairs of first ribs (202) are uniformly arranged in each microchannel at intervals along the length direction of the microchannel, each pair of first ribs (202) consists of two ribs which are oppositely arranged at intervals, and one vertical side edge of each rib is respectively connected with the partition plate (201) or the shell (1); in the adjacent micro-channels, each pair of first ribs (202) are distributed in a staggered manner along the length direction of the micro-channel;

a plurality of jet holes (301) are distributed on the laminate, and each jet hole (301) is respectively right opposite to the center point between each pair of first ribs (202) in the micro-channel layer (2) below; and each pair of second ribs (203) is arranged in each microchannel under the middle of the adjacent jet holes (301), and each pair of second ribs (203) is composed of two opposite ribs arranged at intervals.

2. The jet micro-channel heat sink according to claim 1, wherein a lateral flow inlet (102) is further provided on one side wall of the housing (1) facing each micro-channel end; the diameter of a corresponding jet hole (301) at the top of each micro channel gradually decreases from the cross flow inlet (102) to the micro channel outlet (103).

3. The jet microchannel heat sink according to claim 1 or 2, characterized in that the jet dispersion rib (302) is located directly below the jet inlet (101), comprising four third ribs parallel to the microchannel length direction and four fourth ribs perpendicular thereto; the fourth ribs are arranged in parallel in pairs, and the third ribs are arranged between the two groups of the fourth ribs which are arranged in parallel in pairs; and the interval between the adjacent third ribs is equal to the width of the third ribs, and the interval between the adjacent fourth ribs is smaller than the length of the fourth ribs.

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

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

6. The fluidic microchannel heat sink of claim 4 wherein the first fin (202) and the second fin (203) each have a height of 1/2 of the height of the microchannel.