Design method of embedded micro-grid-micro-channel combined enhanced heat sink structure

Abstract

The invention discloses an embedded micro-grid-micro-channel combined enhanced heat sink structure design method, and relates to the technical field of micro-nano-scale flow and heat exchange, and the method comprises the following steps: 1, building a combined enhanced heat sink structure based on a principle that a bubble nucleation position in a transfer boiling process improves CHF, and building a three-dimensional geometric model; 2, preparing a combined enhanced heat sink structure, wherein the combined enhanced heat sink structure comprises a substrate, a micro-channel and an embedded micro-grid; 3, the surfaces of the micro-channel and the embedded micro-net are coated with functional coatings; and step 4, embedding the embedded micro-grid into the micro-channel, and connecting the micro-channel with the embedded micro-grid. According to the design method of the embedded micro-grid-micro-channel combined enhanced heat sink structure, the combined enhanced heat sink structure is constructed through the design method, the cooling capacity of the micro-channel heat dissipation technology can be greatly improved through the constructed combined enhanced heat sink structure, and the requirement of a laser protection structure for ultrahigh heat flux density cooling is met.

Description

Technical Field

[0001] The present invention relates to the field of micro-nanoscale flow and heat exchange technology, and in particular to a design method for an embedded microgrid-microchannel combined enhanced heat sink structure. Background Art

[0002] Microchannel cooling technology has been widely used in thermal management of (ultra) high heat flux density equipment such as aerospace, power electronics, solar photovoltaic / thermal systems, and large-scale lithium-ion battery packs due to its extremely high heat transfer performance. However, current laser protection structures are mostly designed with the idea of ​​passive thermal insulation of ablation-resistant materials, and there are few reports on the use of efficient active cooling technology based on microchannels for laser protection structures.

[0003] At present, there are many reports on the relevant research of microchannels. For microchannel heat sinks that use the boiling phase change process to transfer heat, the critical heat flux (CHF) is often improved by optimizing the microchannel wall structure. However, bubbles in the phase change process still nucleate and grow at the wall, and the microchannel wall is still facing the risk of local evaporation due to insufficient liquid replenishment. In order to solve this problem, an embedded microgrid-microchannel combined enhanced heat sink structure is designed. This technology can not only transfer the bubble nucleation position from the bottom of the microchannel to the microgrid as much as possible, but also strengthen the disturbance of the convective flow boundary layer and the thermal boundary layer to increase the convective heat transfer coefficient (Heat Transfer Coefficient, HTC), which greatly improves the comprehensive performance of the heat sink. Summary of the invention

[0004] The purpose of the present invention is to provide a design method for an embedded microgrid-microchannel combination enhanced heat sink structure to solve the problems raised by the above-mentioned background technology and meet the current demand for efficient thermal protection of laser protection structures.

[0005] To achieve the above object, the present invention provides a method for designing an embedded microgrid-microchannel combined enhanced heat sink structure, comprising the following steps:

[0006] Step 1: Based on the principle of increasing CHF by shifting the bubble nucleation position during boiling, a combined enhanced heat sink structure is constructed and a three-dimensional geometric model is established;

[0007] Step 2: preparing a combined enhanced heat sink structure, the combined enhanced heat sink structure comprising a substrate, a microchannel and an embedded microgrid;

[0008] Step 3: coating the surface of the microchannel and the embedded microgrid with a functional coating;

[0009] Step 4: embed the embedded microgrid into the microchannel, and connect the microchannel and the embedded microgrid.

[0010] Preferably, a gap is provided between the embedded microgrid and the bottom surface of the microchannel.

[0011] Preferably, in the step 2, the microchannel plate is obtained by chemical etching according to the established three-dimensional geometric model.

[0012] Preferably, in step three, a high thermal emissivity coating is plated on the bottom surface of the microchannel, and a high thermal absorption ratio coating is plated on the embedded microgrid.

[0013] Preferably, in step 4, a vacuum electron beam welding method is used to connect the microchannel plate, the microgrid and the substrate.

[0014] Therefore, the present invention adopts the above-mentioned embedded microgrid-microchannel combined enhanced heat sink structure design method, and constructs a combined enhanced heat sink structure through the design method. The constructed combined enhanced heat sink structure can greatly improve the cooling capacity of the microchannel heat dissipation technology and meet the laser protection structure's demand for ultra-high heat flux density cooling.

[0015] The technical solution of the present invention is further described in detail below through the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a flow chart of an embodiment of a method for designing an embedded microgrid-microchannel combined enhanced heat sink structure of the present invention;

[0017] Figure 2 A geometric model diagram of a combined enhanced heat sink structure constructed by a design method for an embedded microgrid-microchannel combined enhanced heat sink structure of the present invention;

[0018] Figure 3 A processing geometric model diagram of a microchannel plate constructed by a design method for an embedded microgrid-microchannel combined enhanced heat sink structure of the present invention;

[0019] Figure 4 A schematic diagram of the connection of a microchannel plate, a microgrid, and a substrate constructed by a design method for an embedded microgrid-microchannel combination enhanced heat sink structure of the present invention;

[0020] Figure 5 A schematic diagram of the connection and cutting of a microchannel plate, a microgrid, and a substrate constructed by a design method for an embedded microgrid-microchannel combination enhanced heat sink structure of the present invention;

[0021] Figure numerals: 1. microchannel; 2. embedded microgrid; 3. substrate; 4. microchannel plate. DETAILED DESCRIPTION

[0022] The technical solution of the present invention is further described below through the accompanying drawings and embodiments.

[0023] Unless otherwise defined, the technical terms or scientific terms used in the present invention should be understood by people with ordinary skills in the field to which the present invention belongs. The words "first", "second" and similar words used in the present invention do not indicate any order, quantity or importance, but are only used to distinguish different components. "Include" or "comprise" and similar words mean that the elements or objects appearing before the word include the elements or objects listed after the word and their equivalents, without excluding other elements or objects. "Connect" or "connected" and similar words are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Up", "down", "left", "right" and the like are only used to indicate relative positional relationships. When the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0024] Example

[0025] See also Figure 1-5 The present invention provides a method for designing an embedded microgrid-microchannel combined enhanced heat sink structure, comprising the following steps:

[0026] Step 1: Based on the principle of increasing CHF by transferring the bubble nucleation position during boiling, a combined enhanced heat sink structure is constructed and a three-dimensional geometric model is established, such as Figure 2 shown.

[0027] Step 2: prepare a combined enhanced heat sink structure, which includes a substrate 3, a microchannel 1 and an embedded microgrid 2. The microchannel 1 is composed of a number of rectangular channels with equal spacing, and the embedded microgrid 2 is composed of a number of long strip embedded microgrids 2 with equal width.

[0028] According to the established three-dimensional geometric model, two rectangular microchannel plates 4 of the same size are processed by chemical etching, as shown in FIG. Figure 3 shown.

[0029] Step three: grow a graphene coating with a thickness of less than 10 μm on the bottom surface of the microchannel 1 by plasma enhanced chemical vapor deposition. The coating has high thermal emission characteristics and high thermal conductivity, and radiates the heat on the bottom surface of the microchannel 1 as much as possible through radiation heat exchange. A high heat absorption ratio coating is plated on the embedded microgrid 2 by electroplating. The coating has high heat absorption characteristics and can effectively absorb the radiated heat from the bottom surface of the microchannel 1, thereby realizing the transfer of the hot spot position in the heat sink structure. Subsequently, a heat exchange fluid such as deionized water is introduced into the microchannel 1 to realize the coupling of the two heat transfer modes of radiation heat exchange and convection heat exchange.

[0030] Step 4: Connect the two microchannel plates 4, the embedded microgrid 2, and the substrate 3 by vacuum electron beam welding technology. Figure 4 Finally, the microchannel plate 4 is cut according to the actual size requirements, as shown in FIG. Figure 5 As shown, the heat sink structure can be obtained.

[0031] Therefore, the present invention adopts the above-mentioned embedded microgrid-microchannel combined enhanced heat sink structure design method, and constructs a combined enhanced heat sink structure through the design method. The constructed combined enhanced heat sink structure can greatly improve the cooling capacity of the microchannel heat dissipation technology and meet the laser protection structure's demand for ultra-high heat flux density cooling.

[0032] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that they can still modify or replace the technical solution of the present invention with equivalents, and these modifications or equivalent replacements cannot cause the modified technical solution to deviate from the spirit and scope of the technical solution of the present invention.

Claims

1. A method for designing an embedded microgrid-microchannel combined enhanced heat sink structure, characterized in that: The following steps are involved: Step 1: Based on the principle of increasing CHF by shifting the bubble nucleation position during boiling, a combined enhanced heat sink structure is constructed and a three-dimensional geometric model is established; Step 2: preparing a combined enhanced heat sink structure, the combined enhanced heat sink structure comprising a substrate, a microchannel and an embedded microgrid; Step 3: coating the surface of the microchannel and the embedded microgrid with a functional coating; Step 4: embed the embedded microgrid into the microchannel, and connect the microchannel and the embedded microgrid.

2. The method for designing an embedded microgrid-microchannel combined enhanced heat sink structure according to claim 1, characterized in that: A gap is arranged between the embedded microgrid and the bottom surface of the microchannel.

3. The method for designing an embedded microgrid-microchannel combined enhanced heat sink structure according to claim 1, characterized in that: In the step 2, the microchannel plate is obtained by chemical etching according to the established three-dimensional geometric model.

4. The method for designing an embedded microgrid-microchannel combined enhanced heat sink structure according to claim 1, characterized in that: In the step three, a high thermal emissivity coating is plated on the bottom surface of the microchannel, and a high thermal absorption ratio coating is plated on the embedded microgrid.

5. The method for designing an embedded microgrid-microchannel combined enhanced heat sink structure according to claim 1, characterized in that: In the step 4, the microchannel plate, the microgrid and the substrate are connected by a vacuum electron beam welding method.

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