A manifold micro-jet ultra-high heat flux density heat dissipation assembly

Abstract

The present application relates to a heat dissipation assembly, in particular to a manifold micro-jet ultra-high heat flux density heat dissipation assembly. The present application overcomes the limitations of traditional heat dissipation assemblies in integration and engineering application. The present application comprises a shell, a liquid inflow pipeline, a manifold micro-jet assembly, a micro-channel heat sink and a liquid outflow pipeline in the shell. The micro-channel heat sink is above the manifold micro-jet assembly, and a fluid heat exchange chamber is formed between the two. The heat fluid enters from the liquid inflow pipeline, is ejected out through the manifold micro-jet assembly, enters the fluid heat exchange chamber, and performs convective heat exchange with the back of the micro-channel heat sink, and then is discharged to the liquid outflow pipeline through the backflow hole on the manifold micro-jet assembly. The present application combines the advantages of jet impact on the boundary layer of stagnation area, high convective heat exchange coefficient and micro-channel enhanced convective heat exchange, realizes the heat dissipation of high-power ultra-high heat flux density, greatly shortens the backflow path, and improves the system integration.

Description

TECHNICAL FIELD

[0001] The present application relates to a heat dissipation assembly, in particular to a manifold micro-jet ultra-high heat flux density heat dissipation assembly. BACKGROUND

[0002] With the rapid development of electronic technology and laser technology and the related industries, electronic chips gradually develop towards miniaturization and high integration, and the output power of lasers also increases continuously with the demand, such as high heat flux microprocessors, high-energy lasers, high-power radar systems and high-power microwave systems. These electronic devices and lasers generate high heat during operation, which can reach hundreds or even thousands of watts per square centimeter. If this much heat is not dissipated in time, the local temperature of the heat sink surface will exceed the safe operating temperature, affecting the reliability of electronic devices and the output quality of laser media. Heat dissipation and temperature control have become key issues restricting the long-term development of electronic devices and laser technology.

[0003] Technologies with heat dissipation capacity higher than 500W / cm 2 are called ultra-high heat flux cooling technologies, mainly including jet impingement cooling, micro-channel heat dissipation and spray cooling. Among them, the effect of traditional jet impingement cooling is greatly affected by jet Reynolds number Re, and the increase of working fluid flow demand when dissipating high heat flux of high power increases the overall power consumption and size of the system, which is not conducive to improving the integration; micro-channel heat dissipation technology has large pressure loss and is prone to blockage; and spray cooling is an extremely complex two-phase heat fluid system with many influencing factors. So far, there is still no complete understanding of the heat transfer mechanism and influencing factors of spray cooling. Current research work is still mainly experimental research, supplemented by model research and numerical simulation, and there are almost no successful engineering cases at home and abroad. Therefore, there is an urgent need for an ultra-high heat flux density heat dissipation technology that is mature and highly integrated, to lay the foundation for the development of high-power electronic devices and high-power laser technology. SUMMARY

[0004] The purpose of the present application is to provide a manifold micro-jet ultra-high heat flux density heat dissipation assembly, which can realize the ultra-high heat flux density heat dissipation requirement of 300-1500W / cm 2 of thermal interface, and overcome the limitations of traditional heat dissipation assemblies in integration and engineering application.

[0005] The technical solution of the present application is to provide a manifold micro-jet ultra-high heat flux density heat dissipation assembly, which is characterized by comprising a shell, a liquid inflow pipe located inside the shell, a manifold micro-jet assembly, a micro-channel heat sink and a liquid outflow pipe.

[0006] The manifold micro jet assembly comprises a top plate, a bottom plate and a flow guide pipe arranged integrally between the top plate and the bottom plate; a plurality of groups of jet units are formed on the top plate, each group of jet units comprising a first jet hole and a plurality of return holes arranged around the first jet hole with the first jet hole as the center; a plurality of second jet holes are formed on the bottom plate; the flow guide pipe communicates the first jet hole with the second jet hole;

[0007] The back of the micro channel heat sink is provided with a micro channel; the micro channel heat sink is located above the top plate of the manifold micro jet assembly, and the micro channel of the back of the micro channel heat sink is close to the top plate of the manifold micro jet assembly.

[0008] The micro channel heat sink and the manifold micro jet assembly form a fluid heat exchange chamber;

[0009] The liquid inlet pipeline is communicated with the fluid heat exchange chamber through the manifold micro jet assembly; one end of the liquid outlet pipeline is communicated with the space formed by the top plate and the bottom plate of the manifold micro jet assembly, and the other end is directed to the outside of the shell.

[0010] The heat fluid enters from the liquid inlet pipeline, is sprayed out of the first jet hole through the second jet hole of the manifold micro jet assembly, enters the fluid heat exchange chamber, performs convective heat exchange with the back of the micro channel heat sink, and then is discharged to the liquid outlet pipeline through the return hole on the manifold micro jet assembly.

[0011] Further, the shapes of the top plate and the bottom plate of the manifold micro jet assembly are adapted to the shape of the micro channel heat sink.

[0012] Further, the top plate of the manifold micro jet assembly is a circular plate, each group of jet units comprises six return holes, the six return holes are arranged in a honeycomb regular hexagon, and each first jet hole is located at the center of each regular hexagon; adjacent jet units share corresponding return holes.

[0013] Further, the top plate of the manifold micro jet assembly is a square plate, each group of jet units comprises four return holes, the four return holes are arranged in a square, and each first jet hole is located at the center of each square; adjacent jet units share corresponding return holes.

[0014] Further, the manifold micro jet ultra-high heat flux heat dissipation assembly further comprises an annular baffle coaxially arranged between the micro channel heat sink and the manifold micro jet assembly.

[0015] Further, the manifold micro jet ultra-high heat flux heat dissipation assembly further comprises a micro jet assembly pressing ring located between the annular baffle and the edge of the top plate of the manifold micro jet assembly, so that the fluid that has performed convective heat exchange with the back of the micro channel heat sink in the fluid heat exchange chamber can only be discharged from the return hole on the manifold micro jet assembly.

[0016] Further, the liquid inflow pipeline is located at the axial center of the shell, and the liquid outflow pipeline is arranged on both sides of the liquid inflow pipeline with the liquid inflow pipeline as the axis of symmetry.

[0017] Further, the liquid outflow pipeline is sleeved on the periphery of the liquid inflow pipeline with the liquid inflow pipeline as the central axis.

[0018] Further, in order to reduce the heat loss caused by heat exchange between the inlet fluid and the outlet fluid, a hollow cavity is further arranged between the liquid outflow pipeline and the liquid inflow pipeline.

[0019] Further, the outlet end of the liquid outflow pipeline is located on the side wall of the shell close to the inlet end of the liquid inflow pipeline.

[0020] Further, in a typical jet flow unit, the diameter of the first jet flow hole is Dj, in order to reduce the backflow resistance of the liquid, the diameter of the backflow hole is generally 1.5-3Dj, and the distance between the centers of the first jet flow hole and the backflow hole is generally 1.5-3Dj; the diameter of the second jet flow hole is equal to that of the first jet flow hole. The diameter of the liquid inflow pipeline is Di, and the outer diameter of the hollow cavity is generally 1.2-1.5Di, and the outer diameter of the entire shell is generally 1.5-2Di. The micro channel on the back of the micro channel heat sink is μm level size. The characteristic size of the needle rib in the micro channel heat sink is rib height 1.5mm and rib spacing 0.3mm.

[0021] The beneficial effects of the present application are:

[0022] 1) The present application adopts the heat dissipation mode of micro-jet flow combined micro channel heat sink, which combines the advantages of jet flow impact on the boundary layer of stagnation zone, high convective heat transfer coefficient, and micro channel enhanced convective heat transfer, and fully utilizes the advantages of multiple porous jet flow in interface temperature uniformity, improves the temperature uniformity of the thermal interface, and can realize the heat dissipation of high power and high heat flux density.

[0023] 2) The micro jet flow assembly of the present application adopts a manifold type flow distribution structure, the backflow holes are arranged in a regular hexagon or square, and the jet flow holes are located at the center of the regular hexagon or square. In this way, on the one hand, the fluid participating in the convective heat transfer of the stagnation zone can directly flow out from around the stagnation zone, avoiding affecting the heat transfer performance of other jet flow units around, and on the other hand, the backflow path is greatly shortened, thereby the pressure loss of the system can be greatly reduced, the power consumption of the system is reduced, and the system integration is improved; at the same time, the design also eliminates the non-uniformity of the temperature and flow distribution on the surface of the heat sink to a certain extent.

[0024] 3) The present application designs a micro channel of μm level size on the back of the micro channel heat sink, thereby greatly enhancing the convective heat transfer between the fluid and the heat sink on the back of the heat sink, and further improving the convective heat transfer effect of the system.

[0025] 4) The hollow cavity between the liquid inlet pipe and the liquid outlet pipe greatly reduces the heat loss caused by the heat exchange between the inlet fluid and the outlet fluid, and the fluid return path is designed to be axisymmetric, thereby ensuring the symmetry and uniformity of the thermal interface temperature and flow. BRIEF DESCRIPTION OF DRAWINGS

[0026] Figure 1 Three-dimensional structure schematic diagram of the manifold micro-jet ultra-high heat flux heat dissipation assembly for the embodiment;

[0027] Figure 2 Three-dimensional structure schematic diagram of the manifold micro-jet ultra-high heat flux heat dissipation assembly for the embodiment;

[0028] Figure 3 Three-dimensional structure schematic diagram of the manifold micro-jet ultra-high heat flux heat dissipation assembly for the embodiment;

[0029] Figure 4 Three-dimensional structure schematic diagram of the manifold micro-jet ultra-high heat flux heat dissipation assembly for the embodiment;

[0030] Figure 5 Three-dimensional structure schematic diagram of the manifold micro-jet ultra-high heat flux heat dissipation assembly for the embodiment;

[0031] Figure 6 Three-dimensional structure schematic diagram of the manifold micro-jet ultra-high heat flux heat dissipation assembly for the embodiment;

[0032] Figure 7 Three-dimensional structure schematic diagram of the manifold micro-jet ultra-high heat flux heat dissipation assembly for the embodiment;

[0033] Figure 8 Three-dimensional structure schematic diagram of the manifold micro-jet ultra-high heat flux heat dissipation assembly for the embodiment;

[0034] The figure shows the following reference signs: 01, nozzle; 02, potential flow core area; 03, free jet area; 04, stagnation area; 05, wall jet area; 06, stagnation point;

[0035] 1, shell; 11, annular baffle; 2, manifold micro-jet assembly; 20, top plate; 21, return hole; 22, first jet hole; 23, flow guide pipe; 24, second jet hole; 25, bottom plate; 3, micro-channel heat sink; 31, micro-channel; 32, needle rib; 4, micro-jet assembly pressure ring; 5, liquid inlet pipe; 6, liquid outlet pipe; 7, fluid heat exchange chamber; 8, hollow cavity. DETAILED DESCRIPTION

[0036] In order to make the above-mentioned objectives, features and advantages of the present application more apparent, the present application will be described in detail below with reference to the accompanying drawings.

[0037] In the following description, a large number of specific details are set forth in order to provide a thorough understanding of the present application, however, the present application can also be implemented in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the concept of the present application, therefore, the present application is not limited to the specific embodiments disclosed below.

[0038] As shown in Figure 1 , the overall shape of the super-high heat flux heat dissipation assembly of the present embodiment is a cylindrical structure, in other embodiments, other structural forms can also be used, the heat fluid enters from the liquid inflow pipe 5, and flows out after heat exchange from the liquid outflow pipe 6. In combination with Figure 2 and Figure 3 , it can be seen that the super-high heat flux heat dissipation assembly of the present embodiment mainly consists of a micro-channel heat sink 3, a manifold micro-jet assembly 2, a liquid inflow pipe 5, a liquid outflow pipe 6 and a shell 1. Through detailed simulation analysis of heat-flow-solid coupling, it is found that the structure can realize the super-high heat flux heat dissipation requirement of 300-1500W / cm 2 . In order to facilitate description, the structure of the super-high heat flux heat dissipation assembly will be described in detail in the orientation shown in Figure 2 , Figure 3 and Figure 4 . As can be seen from the figure, the micro-channel heat sink 3 and the manifold micro-jet assembly 2 are coaxially arranged in the shell 1 from top to bottom along the axial direction of the shell 1, from Figure 3 , it can be seen that the micro-channel heat sink 3 and the manifold micro-jet assembly 2 form a fluid heat exchange chamber 7; in order to ensure that the fluid after heat exchange can only flow out through the manifold micro-jet assembly 2, an annular baffle 11 is coaxially arranged between the micro-channel heat sink 3 and the manifold micro-jet assembly 2, and a micro-jet assembly pressing ring 4 can also be arranged between the annular baffle 11 and the edge of the top plate 20 of the manifold micro-jet assembly 2. The liquid inflow pipe 5 communicates with the fluid heat exchange chamber 7 through the manifold micro-jet assembly 2; one end of the liquid outflow pipe 6 communicates with the space formed by the top plate 20 and the bottom plate 25 of the manifold micro-jet assembly 2, and the other end faces the outside of the shell 1, and can be located on the side wall of the lower half of the shell 1. In other embodiments, in order to ensure the symmetry and uniformity of the heat interface temperature and flow, the liquid inflow pipe 5 is located at the axial center of the shell 1, and the liquid outflow pipe 6 is arranged on both sides of the liquid inflow pipe 5 with the liquid inflow pipe 5 as the axis of symmetry, and a hollow cavity 8 can also be added between the liquid inflow pipe 5 and the liquid outflow pipe 6, thereby greatly reducing the heat loss caused by heat exchange between the inlet fluid and the outlet fluid. The liquid outflow pipe 6 is preferably a pipe that is sleeved around the liquid inflow pipe 5 with the liquid inflow pipe 5 as the center axis.

[0039] In the impinging jet cooling, the boundary layer of the stagnation zone 04 is very thin, so the convective heat transfer coefficient of this zone is also very high. Outside the stagnation zone 04, the heat transfer coefficient decays with the increase of the boundary layer thickness, and the heat transfer coefficient of the stagnation zone 04 is inversely proportional to the diameter of the jet. Therefore, using micro-jet with a diameter less than 1mm, a very high heat transfer coefficient can be achieved in an area roughly the same size as the impinging jet. However, to achieve such a large heat transfer coefficient on a large area, a set of closely arranged array jets is needed, and when the jet array impinges on the target, the cooling liquid is collected around the target, and the performance of each jet is affected by the cross flow of the cooling liquid from the adjacent jets, thereby greatly reducing the heat transfer effect. Figure 5 A schematic diagram of single jet impinging cooling is shown in the figure. The area indicated by 01 is the nozzle, the area indicated by 02 is the potential flow core zone, the area indicated by 03 is the free jet zone, the area indicated by 04 is the stagnation zone, the area indicated by 05 is the wall jet zone, and the area indicated by 06 is the stagnation point.

[0040] Based on the above analysis, the micro-jet assembly of the present application adopts a manifold type flow distribution structure, as shown in the figure. Figure 6 The manifold type micro-jet assembly 2 of the embodiment includes a top plate 20, a bottom plate 25 and a flow guide pipe 23 arranged between the top plate 20 and the bottom plate 25; a plurality of groups of jet units are formed on the top plate 20, each group of jet units includes a first jet hole 22 and a plurality of return holes 21 arranged around the first jet hole 22 with the first jet hole 22 as the center; a plurality of second jet holes 24 are formed on the bottom plate 25; the flow guide pipe 23 communicates the first jet hole 22 and the second jet hole 24. The shape of the top plate 20 and the bottom plate 25 of the manifold type micro-jet assembly 2 is adapted to the shape of the micro-channel heat sink 3, when the micro-channel heat sink 3 is circular, the plurality of groups of jet units on the manifold type micro-jet assembly 2 adopt the mode shown in a1, each group of jet units includes six return holes 21, the six return holes 21 are arranged in a honeycomb regular hexagon, and each first jet hole 22 is located at the center of each regular hexagon; adjacent jet units share corresponding return holes 21. Figure 6 Figure 6 ​As shown in a2, each jet unit includes four return holes 21 arranged in a square. Each first jet hole 22 is located at the center of each square, and adjacent jet units share the corresponding return hole 21. This design allows the fluid participating in the convective heat transfer in the stagnation zone 04 to flow directly out from around the stagnation zone 04, avoiding impact on the heat transfer performance of other surrounding jet units. It also significantly shortens the return path, thereby greatly reducing system pressure loss, power consumption, and improving system integration. Furthermore, this design also eliminates, to some extent, the uneven distribution of heat sink surface temperature and flow. In a typical jet unit, assuming the diameter of the first jet hole 22 is Dj, to reduce liquid return resistance, the diameter of the return hole 21 is typically 1.5–3Dj, and the distance between the centers of the jet hole and the return hole 21 is typically 1.5–3Dj.

[0041] At the same time, such as Figure 7 As shown, in this embodiment, microchannels 31 with a size in the μm range are designed on the back of the microchannel heat sink 3 of this component, thereby greatly enhancing the convective heat transfer between the fluid and the heat sink on the back, and further improving the convective heat transfer effect of the system. In this embodiment, the characteristic dimensions of the needle ribs 32 in the microchannel heat sink 3 are rib height 1.5mm and rib spacing 0.3mm. In other embodiments, the dimensions can be designed according to specific requirements.

[0042] like Figure 8 As shown, the hot fluid enters from the liquid inlet pipe 5, is ejected from the first jet hole 22 through the second jet hole 24 of the manifold microjet assembly 2, enters the fluid heat exchange chamber 7, and undergoes convective heat exchange with the back of the microchannel heat sink 3. Then, it is discharged through the return hole 21 on the manifold microjet assembly 2 to the liquid outlet pipe 6. This achieves ultra-high heat flux density heat dissipation at the microchannel heat sink 3.

Claims

1. A manifolded micro-jet ultra-high heat flux density heat spreading assembly, characterized by: The shell (1) and the liquid inflow pipeline (5), the manifold microjet assembly (2), the microchannel heat sink (3) and the liquid outflow pipeline (6) inside the shell (1); The manifold microjet assembly (2) comprises an integrated top plate (20), a bottom plate (25) and a flow guide pipe (23) between the top plate (20) and the bottom plate (25); a plurality of groups of jet units are formed on the top plate (20), each group of jet units comprising a first jet hole (22) and a plurality of return holes (21) arranged around the first jet hole (22) with the first jet hole (22) as the center; a plurality of second jet holes (24) are formed on the bottom plate (25); the flow guide pipe (23) communicates the first jet hole (22) with the second jet hole (24); The back of the microchannel heat sink (3) is provided with a microchannel (31); the microchannel heat sink (3) is located above the top plate (20) of the manifold microjet assembly (2), and the microchannel (31) at the back of the microchannel heat sink (3) is close to the top plate (20) of the manifold microjet assembly (2); The microchannel heat sink (3) and the manifold microjet assembly (2) form a fluid heat exchange chamber (7); The liquid inflow pipeline (5) communicates with the fluid heat exchange chamber (7) through the manifold microjet assembly (2); one end of the liquid outflow pipeline (6) communicates with the space formed by the top plate (20) and the bottom plate (25) of the manifold microjet assembly (2), and the other end faces the outside of the shell (1); The liquid inflow pipeline (5) is located at the axial center of the shell (1), and the liquid outflow pipeline (6) is sleeved on the periphery of the liquid inflow pipeline (5) with the liquid inflow pipeline (5) as the central axis; The hot fluid enters from the liquid inflow pipeline (5), is sprayed out of the first jet hole (22) through the second jet hole (24) of the manifold microjet assembly (2), enters the fluid heat exchange chamber (7), performs convective heat exchange with the back of the microchannel heat sink (3), and then is discharged to the liquid outflow pipeline (6) through the return hole (21) on the manifold microjet assembly (2) to flow out.

2. The manifolded microfluidic ultra-high heat flux density heat spreading assembly of claim 1, wherein: The shapes of the top plate (20) and the bottom plate (25) of the manifold microjet assembly (2) are adapted to the shape of the microchannel heat sink (3).

3. The manifolded microfluidic ultra-high heat flux density heat spreading assembly of claim 2, wherein: The top plate (20) of the manifold microjet assembly (2) is a circular plate, each group of jet units comprises six return holes (21), the six return holes (21) are arranged in a honeycomb regular hexagon, and each first jet hole (22) is located at the center of each regular hexagon; adjacent jet units share corresponding return holes (21).

4. The manifolded microfluidic ultra-high heat flux density heat spreading assembly of claim 2, wherein: The top plate (20) of the manifold microjet assembly (2) is a square plate, each group of jet units comprises four return holes (21), the four return holes (21) are arranged in a square, each first jet hole (22) is located at the center of each square, and adjacent jet units share corresponding return holes (21).

5. The manifolded microfluidic ultra-high heat flux density heat spreading assembly of any of claims 1-4, wherein: An annular baffle (11) is coaxially arranged between the microchannel heat sink (3) and the manifold microjet assembly (2).

6. The manifolded microfluidic ultra-high heat flux density heat spreading assembly of claim 5, wherein: A microjet assembly pressing ring (4) is arranged between the annular baffle (11) and the edge of the top plate (20) of the manifold microjet assembly (2).

7. The manifolded microfluidic ultra-high heat flux density heat spreading assembly of claim 6, wherein: A hollow cavity (8) is also provided between the liquid outflow pipe (6) and the liquid inflow pipe (5); the outlet end of the liquid outflow pipe (6) is located on the side wall of the shell (1) close to the inlet end of the liquid inflow pipe (5).

8. The manifolded microfluidic ultra-high heat flux density heat spreading assembly of claim 7, wherein: The diameter of the first jet hole (22) is Dj, the diameter of the backflow hole (21) is 1.5-3Dj, the distance between the centers of the first jet hole (22) and the backflow hole (21) is 1.5-3Dj; the diameter of the second jet hole (24) is equal to that of the first jet hole (22); the diameter of the liquid inflow pipe (5) is Di, the outer diameter of the hollow cavity (8) is 1.2-1.5Di, and the outer diameter of the entire shell (1) is 1.5-2Di; the micro-channel (31) provided on the back of the micro-channel heat sink (3) is of μm level size; the characteristic size of the needle rib (32) in the micro-channel heat sink (3) is rib height 1.5mm and rib spacing 0.3mm.

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