阅读说明：本技术 一种具有多级微槽道的微通道换热器及其制造方法 (Microchannel heat exchanger with multistage microchannels and manufacturing method thereof ) 是由 邓大祥 郑剑 张鹏 姚英学 赵晨阳 于 2020-04-30 设计创作，主要内容包括：本发明公开了一种具有多级微槽道的微通道换热器及其制造方法,该微通道换热器由上盖板、下盖板、金属微通道基体组成。所述金属微通道基体包括若干平行间隔阵列排布的微槽道,且微槽道两侧壁面分别具有阵列凸起的二级微槽道结构,二级微槽道对称分布于微槽道内,可显著增大换热面积,增强扰流,实现强化换热。制备方法如下：先在工作辊上加工出具有阵列梯形沟槽,形成V形凸台；改变带沟槽工作辊的轴向平移量与下压深度,进行多道次辊压加工,得到具有多级微沟槽的金属微通道基体；最后将其进行密封封装得到新型微通道换热器。本发明解决了阵列微通道内多级微槽道结构加工成形的难题,具有过程简单,成本低,效率高等优点。(The invention discloses a micro-channel heat exchanger with a multi-stage micro-channel and a manufacturing method thereof. The metal microchannel base body comprises a plurality of microchannels which are arranged in parallel at intervals in an array mode, two side wall surfaces of each microchannel are provided with two-stage microchannel structures with protruding arrays respectively, and the two-stage microchannels are symmetrically distributed in the microchannels, so that the heat exchange area can be remarkably increased, turbulence is enhanced, and heat exchange enhancement is realized. The preparation method comprises the following steps: firstly, processing trapezoidal grooves with arrays on a working roll to form V-shaped bosses; changing the axial translation amount and the pressing depth of the grooved working roll, and performing multi-pass rolling processing to obtain a metal microchannel matrix with multistage microgrooves; and finally, sealing and packaging the heat exchanger to obtain the novel micro-channel heat exchanger. The invention solves the problem of processing and forming the multi-stage micro-channel structure in the array micro-channel, and has the advantages of simple process, low cost, high efficiency and the like.)

1. A microchannel heat exchanger having a plurality of microchannels, comprising a microchannel substrate, wherein: the microchannel base body comprises a plurality of microchannels which are arranged in parallel at intervals in the width direction, the two side wall inclined planes of the microchannels extending in the length direction are symmetrically arranged relative to the long axis of the microchannels, and each side wall inclined plane is respectively provided with a sub-microchannel with an array bulge;

the groove bottom of one sub-micro channel close to the long axis of the micro channel in the two adjacent sub-micro channels is lower than the groove bottom of the other sub-micro channel, and the groove top is higher than the groove bottom of the other sub-micro channel.

2. The microchannel heat exchanger with multi-stage microchannels of claim 1, wherein: the width of the microchannel is 0.4mm-1.0mm, and the depth is 0.4mm-1.0 mm.

3. The microchannel heat exchanger with multi-stage microchannels of claim 1, wherein: the included angle of the inclined planes of the two side walls of the micro-channel extending along the length direction is 30-150 degrees, and the vertex angle of the sub-micro-channel is 30-60 degrees.

4. The microchannel heat exchanger with multi-stage microchannels of claim 1, wherein: the microchannel material is one of pure copper, aluminum, copper alloy, aluminum alloy and magnesium alloy.

5. A method of manufacturing a microchannel heat exchanger having a plurality of microchannels according to any one of claims 1 to 4, comprising the steps of:

(1) cleaning and drying the metal substrate;

(2) processing trapezoidal deep grooves in an array arrangement on a working roller of a roller press, and forming a V-shaped boss between every two adjacent trapezoidal deep grooves;

(3) the metal substrate is positioned and clamped and is arranged between an upper guide roller and a lower guide roller which are vertically symmetrical and two working rollers of a rolling machine;

(4) adjusting the gap between the rollers, carrying out first rolling with the rolling depth of h1, and lifting the rollers after the rolling is finished to obtain a V-shaped micro-channel; moving the rolling die for a set distance along the cross section direction of the microchannel, performing secondary rolling, wherein the rolling depth is h2, and lifting the roller after the rolling is finished to obtain a V-shaped microchannel structure with a certain distance; moving the rolling die for the same set distance along the cross section direction of the microchannel, wherein the rolling depth is h3, and lifting the roller after rolling; similarly proceeding in sequence, thereby forming sub-micro channels arranged in an array on the inclined surface of one side wall of the micro channel;

(5) rolling the other side wall inclined plane of the microchannel by using the method in the step 4;

(6) and welding and packaging the microchannel base body with the multistage microchannel and the upper cover plate, and connecting the microchannel base body with an external connecting pipe and a water pump into a whole to obtain the complete microchannel heat exchanger.

6. The method of manufacturing a microchannel heat exchanger having a plurality of microchannels, according to claim 5, wherein: the two guide rollers of the roller press are smooth rollers.

7. The method of manufacturing a microchannel heat exchanger having a plurality of microchannels, according to claim 5, wherein: and (3) the working roller with the trapezoidal deep groove in the step (2) is a rolling die, and the other vertically symmetrical working roller of the rolling machine is a smooth roller.

8. The method of making a microchannel heat exchanger having a plurality of microchannels according to claim 5, wherein: the rolling depths h1, h2 and h3 are 0.2mm-1 mm.

Technical Field

The invention belongs to the technical field of micro-structure design and manufacture, relates to a micro-channel heat exchanger and a manufacturing method thereof, and particularly relates to a micro-channel heat exchanger with a multistage micro-channel and a manufacturing method thereof.

Background

In recent years, with the rapid development of industries such as electronic information and integrated communication, electronic components have been increasingly miniaturized and integrated. The micro-components enable electronic equipment to be more portable, efficient and popular, but also cause the problems of overhigh heat productivity of unit area and the like, and seriously restrict the further development of the micro-electronic devices. The microchannel heat exchanger is considered to be an effective way for solving the problem of high heat flow density of the miniature components due to the characteristics of light weight, small volume, good heat dissipation performance and the like. The common micro-channel heat exchanger is only provided with a micro-channel array structure with smooth wall surfaces, such as a rectangle, a triangle, a trapezoid and the like, on a metal or silicon substrate, and is coupled with a cover plate for packaging. However, with the increase of power of electronic devices, the common microchannel heat exchanger can not meet the heat dissipation requirement gradually, and the demand for novel microchannel heat exchangers is increasing day by day.

The micro-channel structure with the micro-bulges on the inner wall surface can increase the contact area of the fluid and the solid wall surface, damage the normal flow of the fluid and enhance the turbulent flow, thereby strengthening the heat exchange. However, the preparation of the enhanced heat transfer microstructure in the microchannel has the problems of high processing difficulty, low efficiency and the like, and becomes a key problem restricting the application and popularization of the enhanced heat transfer microstructure.

At present, the micro-channel structure mainly comprises preparation modes such as precision cutting processing, surface stamping, rolling processing and the like. The surface micro-channel obtained by precision cutting has high precision and good surface quality, but has the problems of low efficiency, high cost and the like because only a single micro-channel can be processed. The traditional surface stamping technology has low cost and high forming resolution, but is still poor in machining efficiency, surface microstructure consistency and the like. The rolling processing has small forming force, good section quality, high efficiency and less investment, and is suitable for processing large-area micro-channel arrays. According to the shape of the forming roller, the rolling process is divided into: a roll-to-plate method and a roll-to-roll method. However, when forming a micro-channel array, a method of roll-to-plate requires a micro-channel mold with a large area, which is limited by the mold manufacturing process, and the roll forming efficiency is low. The traditional roll-to-roll method can form the array microchannel structure with high efficiency, but when the method is used for forming the microchannel structure with the microprotrusions on the inner wall surface, the following difficulties are still encountered: firstly, the single-pass processing of the array micro-channel is difficult to realize; secondly, grooves on the working roll are complex, difficult to process and insufficient in strength; and thirdly, a multi-stage micro-channel with a micro-convex enhanced heat transfer structure on the inner wall surface is difficult to machine.

Disclosure of Invention

The invention aims to overcome the defects of the prior art and provide the micro-channel heat exchanger with the multistage micro-channels, which can improve the flow pattern structure, increase the effective heat exchange area and realize the enhanced heat exchange; and provides a manufacturing method of the microchannel heat exchanger with the multistage microchannels, which can be used for processing the heat transfer enhancement microchannel heat exchanger with the multistage microchannels with high efficiency and low cost through a roll-to-roll processing process.

In order to solve the technical problem, the invention provides a microchannel heat exchanger with a multistage microchannel, which comprises a microchannel base body, wherein the microchannel base body comprises a plurality of microchannels which are arranged in parallel at intervals in the width direction, two side wall inclined planes of the microchannels, which extend along the length direction, are symmetrically arranged relative to the long axis of the microchannels, and each side wall inclined plane is respectively provided with a sub-microchannel with an array bulge;

the groove bottom of one sub-micro channel close to the long axis of the micro channel in the two adjacent sub-micro channels is lower than the groove bottom of the other sub-micro channel, and the groove top is higher than the groove bottom of the other sub-micro channel.

In a preferred embodiment: the width of the microchannel is 0.4mm-1.0mm, and the depth is 0.4mm-1.0 mm.

In a preferred embodiment: the included angle of the inclined planes of the two side walls of the micro-channel extending along the length direction is 30-150 degrees, and the vertex angle of the sub-micro-channel is 30-60 degrees.

In a preferred embodiment: the microchannel material is one of pure copper, aluminum, copper alloy, aluminum alloy and magnesium alloy.

The invention also provides a method for manufacturing the microchannel heat exchanger with the multistage microchannels, which comprises the following steps:

(1) cleaning and drying the metal substrate;

(2) processing trapezoidal deep grooves in an array arrangement on a working roller of a roller press, and forming a V-shaped boss between every two adjacent trapezoidal deep grooves;

(3) the metal substrate is positioned and clamped and is arranged between an upper guide roller and a lower guide roller which are vertically symmetrical and two working rollers of a rolling machine;

(4) adjusting the gap between the rollers, carrying out first rolling with the rolling depth of h1, and lifting the rollers after the rolling is finished to obtain a V-shaped micro-channel; moving the rolling die for a set distance along the cross section direction of the microchannel, performing secondary rolling, wherein the rolling depth is h2, and lifting the roller after the rolling is finished to obtain a V-shaped microchannel structure with a certain distance; moving the rolling die for the same set distance along the cross section direction of the microchannel, wherein the rolling depth is h3, and lifting the roller after rolling; similarly proceeding in sequence, thereby forming sub-micro channels arranged in an array on the inclined surface of one side wall of the micro channel;

(5) rolling the other side wall inclined plane of the microchannel by using the method in the step 4;

(6) and welding and packaging the microchannel base body with the multistage microchannel and the upper cover plate, and connecting the microchannel base body with an external connecting pipe and a water pump into a whole to obtain the complete microchannel heat exchanger.

In a preferred embodiment: the two guide rollers of the roller press are smooth rollers.

In a preferred embodiment: and (3) the working roller with the trapezoidal deep groove in the step (2) is a rolling die, and the other vertically symmetrical working roller of the rolling machine is a smooth roller.

In a preferred embodiment: the rolling depths h1, h2 and h3 are 0.2mm-1 mm.

Compared with the prior art, the invention has the following remarkable advantages:

(1) the micro-channel structure of the multi-stage micro-channel structure increases the contact area of the fluid and the solid wall surface, damages the normal flow of the fluid, enhances turbulent flow and remarkably strengthens heat exchange.

(2) According to the rolling forming processing method of the multi-stage micro-channel, the simple and repeated trapezoidal grooves are processed on the working roller, and the processing forming of the multi-stage micro-channel structure can be realized by continuously rolling, so that a complex structure which is complementary with the multi-stage micro-channel structure is prevented from being directly processed on the working roller, and the problem that the multi-stage micro-channel structure in the micro-channel is difficult to form is solved.

(3) The rolling forming processing method of the multi-stage microchannel has the advantages of simple process, easy realization, low equipment requirement and good forming quality, and can efficiently and low-cost manufacture the microchannel array with the inner wall surface provided with the micro-bulge enhanced heat transfer structure, thereby providing a good way for preparing the enhanced heat transfer microchannel heat exchanger.

Drawings

FIG. 1: microchannel heat exchanger with multi-stage microchannels

FIG. 2: microchannel matrix cross-sectional shape schematic with multi-stage microchannels

FIG. 3: micro-channel heat exchanger matrix rolling processing process diagram with multistage micro-channels

FIG. 4: schematic diagram of micro-channel heat exchanger matrix rolling processing device with multistage micro-channels

FIG. 5: schematic cross-sectional shape of rolling die

In the figure: 1. a metal microchannel substrate; 2. an upper guide roller; 3. a grooved work roll; 4. a smooth work roll; 5. a lower guide roller; 6. upper cover plate

Detailed Description

The present invention will be further described with reference to the following examples, but the present invention is not limited thereto.

Referring to fig. 1 and 2, the microchannel heat exchanger with the multistage microchannels of the invention comprises an upper cover plate 7, a lower cover plate 6 and a metal microchannel matrix 1. The metal microchannel substrate 1 is characterized in that a plurality of microchannels are arranged in parallel at intervals in an array mode in the substrate, the two side wall surfaces of each microchannel are respectively provided with sub microchannels which are raised in an array mode, and the sub microchannels are symmetrically distributed in the microchannels. The groove bottom of one sub-micro channel close to the long axis of the micro channel in the two adjacent sub-micro channels is lower than the groove bottom of the other sub-micro channel, and the groove top is higher than the groove bottom of the other sub-micro channel.

One end of the micro-channel heat exchanger is connected with an inlet of a cooling working medium, and the other end of the micro-channel heat exchanger is connected with an outlet of the cooling working medium.

Preferably, the cross-sectional parameters of the metal microchannel substrate 1 are as follows: w is 0.5mm, S is 0.1mm, H1 is 0.311mm, H2 is 0.406mm, H3 is 0.500mm, H is 1.2mm, and θ is 30 °. Wherein W is the width of the micro-channel, S is the distance between the adjacent micro-channels, H1, H2 and H3 are the depths of two sides of the sub-micro-channel respectively, H is the thickness of the metal matrix, and theta is the value of the vertex angle of the groove of the adjacent sub-micro-channel.

In the present embodiment, the plate material of the metal microchannel matrix 1 is preferably Mg — Al alloy. As a simple alternative, the material may be one of pure copper, pure aluminum, a copper alloy, an aluminum alloy, and a magnesium alloy.

With reference to fig. 3, 4 and 5, the present invention provides a method for manufacturing a microchannel heat exchanger with a multi-stage microchannel, comprising the following steps:

(1) designing and manufacturing a rolling die: according to the metal matrix structure and the section parameters of the micro-channel heat exchanger, trapezoidal deep grooves which are repeatedly arranged are precisely cut on a working roller, and the rolling die 3 is manufactured. The section parameters of the rolling die 3 are as follows: h is 0.5mm, a is 0.6mm, theta is 30 degrees, the convex of the die roller 3 is provided with a fillet with the radius r of 0.005mm, the diameters of the working rollers 3 and 4 are both 40mm, and the diameters of the guide rollers 2 and 5 are both 30 mm. 100 isosceles triangle protruding microstructures are arranged on the mold roller 3 at equal intervals and repeatedly, and 100 microchannels can be processed simultaneously.

(2) Installing a metal base plate to be processed: selecting a Mg-Al alloy matrix plate 1 with the length of 200mm, the width of 100mm and the thickness of 1.2mm, cleaning to remove surface stains, wiping and airing, and then positioning and clamping the Mg-Al alloy matrix plate 1 between the upper and lower guide rollers 2 and 5 and the working rollers 3 and 4. During positioning, the grooved working roll 3 is required to be just contacted with the surface of the substrate plate 1 to be processed and is positioned at the axial initial processing position of the micro-channel array to be formed, so that the initial positions of the two pairs of rollers are determined;

(3) and (3) rolling for multiple times: adjusting the size of a gap between the rollers, setting the temperature of the working roller 3 to be 250 ℃, the pressure of the working roller 4 to be 700N, adjusting the rotating speed of the guide rollers 2 and 5 and the rotating speed of the working rollers 3 and 4 to ensure that the rolling speed is 8mm/s, carrying out first rolling, wherein the rolling depth is h 1-0.311 mm, and lifting the rollers after the rolling is finished; moving the working roller 3 to the cross section direction of the microchannel by 0.083mm, setting the temperature of the working roller 3 to be 250 ℃, setting the pressure of the working roller 4 to be 700N, adjusting the rotating speeds of the guide rollers 2 and 5 and the working rollers 3 and 4 to ensure that the rolling speed is 8mm/s, changing the rotating direction of each roller wheel, carrying out secondary rolling, wherein the rolling depth is h 2-0.406 mm, and lifting the roller wheels after the rolling is finished; moving the working roller 3 to the cross section direction of the microchannel by 0.083mm, setting the temperature of the working roller 3 to be 250 ℃, setting the pressure of the working roller 4 to be 700N, adjusting the rotating speeds of the guide rollers 2 and 5 and the working rollers 3 and 4 to ensure that the rolling speed is 8mm/s, changing the rotating direction of each roller, carrying out third rolling, and lifting the roller after the rolling is finished, wherein the rolling depth is h 3-0.500 mm.

(4) And (3) rolling and processing the symmetrical wall surfaces for multiple times: moving the working roller 3 to the symmetrical side wall surface of the micro-channel by 0.083mm along the cross section direction of the micro-channel, setting the temperature of the working roller 3 to be 250 ℃, the pressure of the working roller 4 to be 700N, adjusting the rotating speeds of the guide rollers 2 and 5 and the working rollers 3 and 4 to ensure that the rolling speed is 8mm/s, changing the rotating direction of each roller, carrying out first rolling, and lifting the roller after the rolling is finished, wherein the rolling depth is h 2-0.406 mm. Moving the working roller 3 by 0.083mm along the cross section direction of the microchannel, setting the temperature of the working roller 3 to be 250 ℃, setting the pressure of the working roller 4 to be 700N, adjusting the rotating speeds of the guide rollers 2 and 5 and the working rollers 3 and 4 to enable the rolling speed to be 8mm/s, changing the rotating direction of each roller, performing fifth rolling, setting the rolling depth to be h 1-0.311 mm, and lifting the rollers after the rolling is finished to obtain the metal microchannel substrate 1.

(5) Packaging the micro-channel heat exchanger: matching and attaching the micro-channel metal matrix 1 and the upper cover plate 6, and sealing and packaging through brazing. An external connecting pipe and a water pump are connected to the upper cover plate 6 to form a whole, a forced circulation loop is formed, and the complete micro-channel heat exchanger is obtained.

Through the trapezoidal grooves repeatedly arranged on the working roller 3, 100 identical microchannel structures are simultaneously processed on the metal matrix plate 1 by each rolling; by changing the radial and axial feed amounts of the working roller 3 and simultaneously rolling in different microchannels once to obtain completely same secondary microchannel columns, 100 microchannel heat exchanger metal matrixes which are parallel to each other, have a spacing of 0.1mm and a channel width of 0.5mm and have a multistage microchannel structure are finally formed on the surface of the Mg-Al alloy plate and are packaged to obtain the novel microchannel heat exchanger.

The above description is only an embodiment of the present invention, but the design concept of the present invention is not limited thereto, and any insubstantial modifications made by using the design concept should fall within the scope of infringing the present invention.