CN109640593B - A micro-rib array heat dissipation device and method equipped with a synthetic jet exciter - Google Patents

Abstract

The invention discloses a micro-rib array heat dissipation device and method equipped with a synthetic jet exciter. The device adopts a synthetic jet exciter on the top of a micro-rib array heat sink and arranges micro-holes on the top cover of the micro-rib array heat sink. When the synthetic jet exciter is working, the fluid can be periodically inhaled and ejected through the micro-holes to form a synthetic jet. The synthetic jet generated by the synthetic jet exciter can improve the flow environment in the micro-fin array, and finally achieve the effect of enhancing the heat dissipation performance of the micro-fin array heat sink. The advantages of this heat sink structure are that it is compact in structure, has good heat dissipation effect, and has little effect on the pressure drop before and after the micro-rib array heat sink. Thermal issues and temperature control in modern high-performance electronics offer a new avenue.

Description

A micro-rib array heat dissipation device and method equipped with a synthetic jet exciter

technical field

The invention belongs to the field of heat dissipation with high heat flux density, and in particular relates to a micro-rib array heat dissipation device and method equipped with a synthetic jet exciter.

Background technique

Under the development trend of miniaturization and high performance of electronic products, the heat flux density of electronic products shows a trend of rapid growth, which puts forward extremely high requirements for the thermal design of electronic products. Some traditional passive cooling technologies can no longer meet the requirements. The need for heat dissipation in the case of extremely high heat flux density, and the new generation of active enhanced heat dissipation technology equipped with modern high-efficiency drive and disturbance technology, due to its excellent heat dissipation performance and strong controllability and other significant advantages, has become an electronic heat dissipation technology. Research focus in the field of technology. However, the current existing heat dissipation devices generally have complex structures, and the heat dissipation effect is not satisfactory.

SUMMARY OF THE INVENTION

In order to solve the problem of high heat flux density of modern high-performance electronic products and make up for the deficiency of traditional passive heat dissipation technology, the present invention provides a micro-rib array heat dissipation device and method equipped with a synthetic jet exciter.

A micro-rib array heat dissipation device equipped with a synthetic jet exciter, comprising a heat sink substrate, a micro-rib array structure, a top cover, and a synthetic jet exciter; the heat sink substrate is directly or indirectly connected with a heating part of an electronic device; The micro-rib array structure is located above the heat sink substrate; the top cover plate is located above the micro-rib array structure, and fluid is communicated between the top cover plate and the heat sink substrate; the synthetic jet exciter is open at the bottom The structure is located above the top cover plate and assembled with the top cover plate to form a synthetic jet cavity, and the top cover plate is provided with a micropore array.

In the above technical scheme, the arrangement of the micro-rib array structure can be in order, fork, combined or disordered, and the cross-sectional shape of each rib in the micro-rib array structure can be rectangular, circular, triangular. , or rhombus, etc., the cross-sectional size changes with the height of the rib.

The arrangement of the micro-hole array is usually consistent with the micro-rib array structure, the cross-sectional shape of each micro-hole is rectangle, circle, triangle, or diamond, etc., and the size of the micro-hole changes with the depth of the hole, forming a conical hole. .

The synthetic jet cavity can be a cuboid, a cylinder, or any other shape.

The driving manner of the synthetic jet exciter may be spark, piezoelectric, plasma driving, and the like.

The method of applying the above-mentioned device for heat dissipation is as follows: the heat sink substrate is directly or indirectly connected to the heating part of the electronic device, a fluid is passed between the top cover plate and the heat sink substrate, and the heat sink substrate receives heat from the electronic device through thermal conduction. Part of the heat is transferred to the micro-rib array structure; the micro-rib array structure transfers the heat to the upstream flow through the convective heat transfer effect, and the synthetic jet exciter is activated to enter the active mode; in the active mode, there is no need to change the incoming flow conditions. Adjusting the input parameters of the synthetic jet exciter can control the heat dissipation performance of the micro-rib array heat sink in real time. Specifically, adjusting the input parameters of the synthetic jet exciter makes the pressure in the synthetic jet cavity rise and fall periodically. This pressure change makes The synthetic jet exciter periodically sucks and ejects fluid through the micro-hole array on the top cover to form a synthetic jet; the interaction between the synthetic jet and the fluid from the upstream improves the flow structure and enhances the surface of the micro-rib array structure. The convection heat transfer effect on the upper surface of the heat sink substrate, thereby enhancing the heat dissipation performance.

The beneficial effects of the present invention are as follows: first, the synthetic jet exciter is used as the disturbance device, which has a compact structure and a good effect of disturbing the flow; second, it does not need to change the incoming flow conditions, and only needs to adjust the working parameters of the synthetic jet exciter. Adjusting the heat dissipation performance of the heat sink structure highlights the strong controllability of the heat sink structure equipped with the synthetic jet exciter; thirdly, the micro-rib array structure is used as the basic heat sink structure, which has good heat dissipation effect and is easy to process.

Description of drawings

Fig. 1 is the structural schematic diagram of the micro-rib array heat sink equipped with synthetic jet exciter;

Fig. 2 is three views of the structure of the synthetic jet exciter;

Figure 3 is a schematic diagram of the structure of the micro-rib array heat sink;

Figure 4 is a schematic diagram of the structure of the top cover plate of the micro-rib array heat sink;

FIG. 5 is an explanatory diagram of the cavity structure of the synthetic jet exciter;

Description of reference numerals: 1. Heat sink substrate; 2. Micro-rib array structure; 3. Top cover plate; 4. Synthetic jet actuator; 5. Microwell array; 6. Synthetic jet cavity.

Detailed ways

The present invention will be further described below with reference to the accompanying drawings and embodiments.

As shown in Figure 1, a micro-rib array heat dissipation device equipped with a synthetic jet exciter includes a heat sink substrate 1, a micro-rib array structure 2, a top cover 3, and a synthetic jet exciter 4; the heat sink substrate 1 directly or Indirectly connected to the heat source; the micro-rib array structure 2 is located above the heat sink substrate 1; the top cover plate 3 is located above the micro-rib array structure 2; the bottom of the synthetic jet exciter 4 is an open structure, located above the top cover plate 3 and the top cover plate 3 Assemble to form a synthetic jet cavity 6 .

As shown in FIG. 3 , the heat sink substrate 1 is directly or indirectly connected to the heating part of the electronic device or indirectly through a heat pipe and other devices, so as to receive the heat from the heating part of the electronic device through thermal conduction and transfer it to the micro-rib array structure 2 .

As shown in FIG. 3 , the micro-rib array structure 2 can be designed in a variety of arrangement ways, such as sequential arrangement, fork arrangement, combination arrangement, and disorder arrangement. The cross-sectional shape of each fin in the micro-rib array structure can be designed as Rectangular, circular, triangular, diamond and other shapes, the cross-sectional size of the fins can change with the height of the fins; a fluid flows between the top cover plate and the heat sink substrate, and the micro-rib array receives from the heat sink substrate 1, and transfer the heat to the low temperature fluid from the upstream through the convective heat transfer effect.

As shown in FIG. 4 , the top cover plate 3 has a microwell array 5 arranged on its surface. The cross-sectional shape can be designed into various shapes such as rectangle, circle, triangle, rhombus, etc. The size of the micropore can change with the depth of the hole to form a tapered hole.

As shown in Figures 2 and 5, the synthetic jet exciter 4, its open part is assembled with the top cover plate 3 to form a synthetic jet cavity 6; the synthetic jet cavity 6 of the synthetic jet exciter 4 can be designed as a rectangular parallelepiped , cylinder, special-shaped body and other shapes; the synthetic jet exciter 4 can be driven by various methods such as electric spark, piezoelectric, plasma, etc., as long as the pressure in the synthetic jet cavity can be adjusted.

The working method of the above-mentioned micro-rib array heat sink equipped with a synthetic jet exciter is as follows: the heat sink substrate 1 is directly connected with the heating part of the electronic device or indirectly through a device such as a heat pipe, so as to receive the heat from the heating part of the electronic device through thermal conduction, and transmit the heat. to the micro-rib array structure 2; the micro-rib array structure 2 receives the heat from the heat sink substrate 1, and transfers the heat to the low-temperature fluid from the upstream through the convection heat transfer effect; start the synthetic jet actuator to enter the active mode; in the active mode In the mode, the heat dissipation performance of the micro-rib array heat sink can be adjusted in real time only by adjusting the input parameters of the synthetic jet exciter without changing the incoming flow conditions. Specifically, the pressure in the cavity 6 of the synthetic jet exciter will vary with The change of the input parameters of the exciter changes accordingly, and this pressure change enables the synthetic jet exciter 4 to periodically inhale and eject fluid through the micro-holes on the top cover 3 to form a synthetic jet; the synthetic jet and the fluid from the upstream There is an interaction between them, which improves the flow structure inside the micro-fin array heat sink, and improves the convection heat transfer effect between the surface of the micro-fin array and the upper surface of the heat sink substrate, thereby realizing the enhancement of heat dissipation performance.

Compared with the traditional micro-rib array heat dissipation device, the device of the present invention can increase the global average convective heat transfer coefficient by more than 80% under the condition that the peak velocity of the micro-pore is 3m/s, while the increase of the pressure drop is only 30%. . Through the simulation analysis, it can be seen that under the influence of the synthetic jet exciter, on the one hand, the overall momentum level in the flow stagnation area between the front row of micro-fins and the rear row of micro-fins inside the micro-fin array heat sink has been significantly improved. On the other hand, the synthetic jet has an obvious inhibitory effect on the flow separation phenomenon on the downstream surface of the micro-fins. Under the combined influence of these two effects, the momentum exchange between the flow stagnation area and the main flow area is more frequent, and the convection The heat exchange is more sufficient, and the synthetic jet has a limited influence on the main flow due to the arrangement of the micropores of the synthetic jet in the flow stagnation area, so that the increase in the overall pressure drop loss is small. In addition, compared with the traditional continuous or intermittent jet enhancement technology, the synthetic jet has many advantages such as compact structure, convenient control, and simple maintenance, which makes the synthetic jet have outstanding advantages and broad applications in the field of microstructure heat dissipation. prospect.

Claims (1)

1. A heat dissipation method of a micro-rib array equipped with a synthetic jet actuator is characterized in that: the device is realized by utilizing a micro-rib array heat dissipation device provided with a synthetic jet actuator, and the device comprises a heat sink substrate, a micro-rib array structure, a top cover plate and the synthetic jet actuator; the heat sink substrate is directly or indirectly connected with a heating part of the electronic device; the micro rib array structure is positioned above the heat sink substrate; the top cover plate is positioned above the micro-rib array structure, and fluid is communicated between the top cover plate and the heat sink substrate; the synthetic jet actuator is of a bottom opening structure, is positioned above the top cover plate and is assembled with the top cover plate to form a synthetic jet cavity, and the top cover plate is provided with a micropore array; the method comprises the following steps: fluid is introduced between the top cover plate and the heat sink substrate, and the heat sink substrate receives heat from a heating part of the electronic device through heat conduction and transfers the heat to the micro-rib array structure; the micro-rib array structure transfers heat to upstream incoming flow through a convection heat transfer effect, and a synthetic jet actuator is started to enter an active mode; in an active mode, the heat dissipation performance of the micro-rib array heat sink can be regulated and controlled in real time by regulating input parameters of the synthetic jet actuator without changing inflow conditions, specifically, the pressure in the synthetic jet cavity is periodically raised and lowered by regulating the input parameters of the synthetic jet actuator, and the synthetic jet actuator periodically sucks and ejects fluid through the micro-pore array on the top cover plate by the pressure change to form synthetic jet; interaction occurs between the synthetic jet and fluid from upstream.

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