CN116481345A

CN116481345A - Microchannel heat exchanger

Info

Publication number: CN116481345A
Application number: CN202310673339.7A
Authority: CN
Inventors: 汤凯; 郭元东; 林贵平; 苗建印; 张红星; 黄金印; 谢永奇
Original assignee: Beihang University
Current assignee: Beihang University
Priority date: 2023-06-07
Filing date: 2023-06-07
Publication date: 2023-07-25

Abstract

The invention provides a microchannel heat exchanger, and relates to the technical field of efficient heat transfer. The microchannel heat exchanger comprises a cover plate, a manifold liquid-dividing plate and a microchannel substrate; the manifold liquid-dividing plate is provided with a liquid inlet and a plurality of heat exchange units, each heat exchange unit comprises a manifold liquid inlet channel and a manifold liquid outlet, and the manifold liquid inlet channel is communicated with the liquid inlet; one side of the microchannel substrate is provided with a plurality of microchannel units, each microchannel unit is provided with a heat exchange channel, and the manifold liquid inlet channel is communicated with the manifold liquid outlet through the heat exchange channels; the manifold liquid distribution plate or the cover plate is provided with a communication working medium outlet, and the manifold liquid outlet is communicated with the working medium outlet. Compared with the traditional straight liquid inlet design, the design of the manifold liquid inlet flow channels on the manifold liquid distribution plate can more uniformly distribute the heat exchange working medium into the whole micro-channel unit, so that the flow length of the heat exchange working medium is effectively reduced, the flow resistance of the heat exchange working medium is reduced, and the uniformity of flow distribution in the heat exchange unit is improved.

Description

Microchannel heat exchanger

Technical Field

The invention relates to the technical field of efficient heat transfer, in particular to a microchannel heat exchanger.

Background

With the continuous development of integrated circuit technology, the integration level of electronic chips is higher and higher, and the input power and power loss are also improved, which leads to the rapid increase of the heat dissipation requirements of electronic devices. In a part of the 3D integrated chip, the power density can be as high as 1000W/cm2. In addition, the functionality of electronic devices is increasingly complex, and the size of electronic systems such as data centers is increasingly large, which has prompted the shift in heat dissipation requirements from a single heat source to multiple heat source arrays.

In current engineering practice, single-phase liquid cooling or air cooling is generally used for heat dissipation, and compared with the traditional technical means, the microchannel cooling technology has higher heat dissipation efficiency and a more compact and light structure. Numerous researchers have extensively explored the heat transfer flow characteristics of microchannel cooling technology, manufacturing techniques, and applications in electronic devices. However, many researches have been conducted to heat a single small-area heat source.

The problems faced by multiple heat sources are more complex and severe than single heat source heat dissipation. On one hand, the heat dissipation requirement of multiple heat sources objectively increases the area of the heat exchanger, so that the length of the flow channel inside the heat exchanger is increased, and the flow resistance is greatly increased. On the other hand, uneven heat source distribution, different heat source power, different interface thermal resistance and the like can cause uneven heat flow distribution of a radiating surface, so that uneven distribution of working medium flow and different temperature levels of the radiating surface are caused, and the caused problems of thermal stress and the like bring great risks to safe operation of equipment such as electronic devices and the like.

Disclosure of Invention

The invention aims to solve the problem of large flow resistance when the existing microchannel cooling technology is applied to multi-heat source heat dissipation.

The invention provides the following technical scheme:

a microchannel heat exchanger comprises a cover plate, a manifold liquid-dividing plate and a microchannel substrate which are sequentially laminated;

the manifold liquid distribution plate is provided with a liquid inlet, one side of the manifold liquid distribution plate, facing the microchannel substrate, is provided with a plurality of heat exchange units, each heat exchange unit comprises a plurality of manifold liquid inlet channels and manifold liquid outlet ports which are alternately arranged, and each manifold liquid inlet channel is communicated with each liquid inlet port;

the side, facing the manifold liquid separation plate, of the microchannel substrate is provided with a plurality of microchannel units corresponding to the heat exchange units, each microchannel unit is provided with a heat exchange channel, and the manifold liquid inlet channel is communicated with the manifold liquid outlet through the heat exchange channels;

the manifold liquid separation plate or the cover plate is provided with working medium outlets, and each manifold liquid outlet is communicated with the working medium outlet.

As a further alternative to the microchannel heat exchanger, a side of the manifold liquid-dividing plate facing the microchannel substrate and/or a side of the microchannel substrate facing the manifold liquid-dividing plate are provided with liquid-dividing flow channels;

the manifold liquid distribution plate is provided with a working medium collecting cavity towards one side of the cover plate, the working medium collecting cavity is communicated with the working medium outlet, and each manifold liquid outlet is communicated with the working medium collecting cavity.

As a further alternative to the microchannel heat exchanger, the split flow channel includes a main flow channel and a plurality of secondary flow channels, the main flow channel is communicated with the liquid inlet, one end of the secondary flow channel is communicated with the main flow channel, and the other end of the secondary flow channel is communicated with the manifold liquid inlet.

As a further alternative to the microchannel heat exchanger, at least part of the secondary flow channels have throttling slits; or alternatively

At least part of the secondary flow passage is internally provided with a resistance increasing piece.

As a further alternative scheme of the microchannel heat exchanger, a side of the manifold liquid-dividing plate facing the microchannel substrate is provided with the liquid-dividing flow channel, a side of the manifold liquid-dividing plate facing the cover plate is provided with a main flow channel back rib, and the main flow channel back rib is arranged corresponding to the main flow channel.

As a further alternative to the microchannel heat exchanger, a support column is arranged in the working medium collecting chamber, and the support column is connected with the cover plate.

As a further alternative scheme for the micro-channel heat exchanger, the heat exchange unit further comprises a liquid inlet cavity, and the inner wall of the liquid inlet cavity is provided with a diversion inclined plane;

each manifold liquid inlet runner is communicated with the liquid inlet through the liquid inlet cavity, and the inlet of each manifold liquid inlet runner faces the diversion inclined plane.

As a further alternative scheme of the microchannel heat exchanger, the microchannel unit comprises a groove and a plurality of heat exchange pieces arranged on the bottom surface of the groove in an array manner, and the heat exchange channels are formed between the heat exchange pieces.

As a further alternative to the microchannel heat exchanger, the heat exchange elements are arranged in a needle-like or strip-like arrangement.

As a further alternative scheme of the micro-channel heat exchanger, the cover plate is provided with a working medium inlet and a working medium outlet, the liquid inlet penetrates through the manifold liquid distribution plate, and the liquid inlet is communicated with the working medium inlet.

The embodiment of the invention has the following beneficial effects:

when the micro-channel heat exchanger is used, heat exchange working media enter the liquid inlet of the manifold liquid distribution plate and are then distributed into the liquid inlet channels of the manifolds. Then, the heat exchange working medium flows towards the micro-channel unit along the direction vertical to the micro-channel substrate and flows into the heat exchange channel, so that the micro-channel cooling heat exchange is realized. And finally, the heat exchange working medium flows back to the micro-channel unit along the direction vertical to the micro-channel substrate, reversely turns back to the manifold liquid outlet and flows out from the working medium outlet. The heat exchange units are matched with the micro-channel units which are correspondingly arranged, so that the heat sources can be cooled and exchanged. Compared with the traditional straight liquid inlet design, the design of the manifold liquid inlet flow channels on the manifold liquid distribution plate can more uniformly distribute the heat exchange working medium into the whole micro-channel unit, so that the flow length of the heat exchange working medium is effectively reduced, the flow resistance of the heat exchange working medium is reduced, and the uniformity of flow distribution in the heat exchange unit is improved. In addition, the heat exchange working medium enters the heat exchange channel of the micro-channel unit from the manifold liquid inlet channel in a vertical mode, so that the heat exchange effect can be greatly improved.

In order to make the above objects, features and advantages of the present invention more comprehensible, preferred embodiments accompanied with figures are described in detail below.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings that are needed in the embodiments will be briefly described below, it being understood that the following drawings only illustrate some embodiments of the present invention and therefore should not be considered as limiting the scope, and other related drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

Fig. 1 shows an exploded schematic view of a microchannel heat exchanger according to an embodiment of the present invention;

fig. 2 shows an exploded schematic view of a microchannel heat exchanger according to an embodiment of the present invention at another view angle;

FIG. 3 is a schematic cross-sectional view of a cover plate in a microchannel heat exchanger according to an embodiment of the present invention;

FIG. 4 shows a schematic view of a B-side of a manifold liquid distribution plate in a microchannel heat exchanger according to an embodiment of the present invention;

FIG. 5 shows an enlarged schematic view at C in FIG. 4;

fig. 6 shows a schematic structural diagram of a microchannel substrate in a microchannel heat exchanger according to an embodiment of the present invention;

FIG. 7 shows an enlarged schematic view at D in FIG. 6;

fig. 8 is a schematic structural diagram of a microchannel unit in a microchannel heat exchanger according to another embodiment of the present invention;

fig. 9 is a schematic structural diagram of a microchannel unit in a microchannel heat exchanger according to another embodiment of the present invention;

fig. 10 is a schematic structural diagram of a microchannel unit in a microchannel heat exchanger according to another embodiment of the present invention;

fig. 11 is a schematic structural diagram of a microchannel unit in a microchannel heat exchanger according to another embodiment of the present invention;

fig. 12 shows a schematic view of an a-plane of a manifold liquid separation plate in a microchannel heat exchanger according to an embodiment of the present invention.

Description of main reference numerals:

100-cover plate; 110-a first joint; 111-working medium inlet; 120-second linker; 121-a working medium outlet; 200-manifold liquid separation plate; 210-a liquid inlet; 220-a liquid separation flow channel; 221-a main runner; 222-secondary flow channel; 222 a-a throttle slit; 230-a heat exchange unit; 231-a liquid inlet cavity; 231 a-a diversion ramp; 232-manifold inlet flow channel; 233-manifold drain; 240-working medium collecting cavity; 241-support columns; 250-main runner back ribs; 300-microchannel substrate; 310-microchannel unit; 311-heat exchange channels; 312-grooves; 313-heat exchange member.

Detailed Description

Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein like or similar reference numerals refer to like or similar elements or elements having like or similar functions throughout. The embodiments described below by referring to the drawings are illustrative only and are not to be construed as limiting the invention.

It will be understood that when an element is referred to as being "fixed to" another element, it can be directly on the other element or intervening elements may also be present. When an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. In contrast, when an element is referred to as being "directly on" another element, there are no intervening elements present. The terms "vertical," "horizontal," "left," "right," and the like are used herein for illustrative purposes only.

In the present invention, unless explicitly specified and limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally formed; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communicated with the inside of two elements or the interaction relationship of the two elements. The specific meaning of the above terms in the present invention can be understood by those of ordinary skill in the art according to the specific circumstances.

Furthermore, the terms "first," "second," and the like, are used for descriptive purposes only and are not to be construed as indicating or implying a relative importance or implicitly indicating the number of technical features indicated. Thus, a feature defining "a first" or "a second" may explicitly or implicitly include one or more such feature. In the description of the present invention, the meaning of "a plurality" is two or more, unless explicitly defined otherwise.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the templates herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The term "and/or" as used herein includes any and all combinations of one or more of the associated listed items.

Example 1

Referring to fig. 1 and 2 together, the present embodiment provides a microchannel heat exchanger, which includes a cover plate 100, a manifold liquid-dividing plate 200 and a microchannel substrate 300 stacked in order.

Referring to fig. 4 and 5, the manifold plate 200 is provided with a liquid inlet 210, and a side of the manifold plate 200 facing the microchannel substrate 300 is provided with a plurality of heat exchange units 230. The heat exchange unit 230 includes a plurality of manifold inlet channels 232 and manifold drain ports 233 alternately arranged, each manifold inlet channel 232 communicating with the inlet port 210.

Referring to fig. 6 and 7, accordingly, the side of the microchannel substrate 300 facing the manifold liquid distribution plate 200 is provided with a plurality of microchannel units 310 corresponding to the plurality of heat exchange units 230. The microchannel unit 310 has a heat exchange channel 311, and the manifold liquid inlet channel 232 communicates with a manifold liquid outlet 233 through the heat exchange channel 311.

Referring to fig. 3, in addition, a working fluid outlet 121 is disposed on the manifold liquid-dividing plate 200 or the cover plate 100, and each of the manifold liquid-draining ports 233 is communicated with the working fluid outlet 121.

When the microchannel heat exchanger is used, heat exchange working media enter the liquid inlet 210 of the manifold liquid distribution plate 200 and are then split into the liquid inlet channels 232 of the manifolds. Subsequently, the heat exchange medium flows toward the microchannel unit 310 in a direction perpendicular to the microchannel substrate 300 and flows into the heat exchange channels 311, thereby achieving microchannel cooling heat exchange. Finally, the heat exchanging medium flows back to the micro-channel unit 310 in a direction perpendicular to the micro-channel substrate 300, and flows back to the manifold drain 233 and flows out of the medium outlet 121. The heat exchange units 230 are matched with the micro-channel units 310, so as to perform cooling heat exchange on the heat sources.

Compared with the traditional straight liquid inlet design, the design of the manifold liquid inlet channels 232 on the manifold liquid distribution plate 200 can more uniformly distribute the heat exchange working medium into the whole micro-channel unit 310, so that the flow length of the heat exchange working medium is effectively reduced, the flow resistance of the heat exchange working medium is reduced, and the uniformity of flow distribution in the heat exchange unit 230 is improved. In addition, the heat exchange working medium enters the heat exchange channel 311 of the micro-channel unit 310 from the manifold liquid inlet channel 232 in a vertical mode, so that the heat exchange effect can be greatly improved.

Example 2

Referring to fig. 1 and fig. 2 together, the present embodiment provides a microchannel heat exchanger, specifically a microchannel heat exchanger for a multi-heat source array. The microchannel heat exchanger consists of a cover plate 100, a manifold liquid-dividing plate 200 and a microchannel substrate 300, wherein the cover plate 100, the manifold liquid-dividing plate 200 and the microchannel substrate 300 are sequentially laminated and fixedly connected.

In production, the cover plate 100, the manifold liquid-dividing plate 200 and the micro-channel substrate 300 are made of various materials which are suitable for processing and have good heat conduction effect, such as copper, aluminum, stainless steel, silicon and the like, and then are connected by welding, bonding and the like.

In this embodiment, the cover plate 100 is used for connecting with an external pipeline to carry inflow and outflow of heat exchange medium. The manifold liquid-dividing plate 200 is used for uniformly distributing heat exchange working medium and collecting the heat exchange working medium. The micro-channel substrate 300 is used for absorbing the heat of the multi-heat source array, and further transmitting the heat from each heat source to the multi-strand heat exchange working medium uniformly distributed by the manifold liquid-dividing plate 200, and taking away the heat by the heat exchange working medium.

Referring to fig. 3, specifically, the cover plate 100 is a flat rectangular sheet. The bottom surface of apron 100 and manifold divides liquid board 200 fixed connection, and the top surface one end of apron 100 is provided with first joint 110, and the other end is provided with second joint 120, and first joint 110 and second joint 120 are connected with outside pipeline respectively. The first joint 110 is provided with a working medium inlet 111, the second joint 120 is provided with a working medium outlet 121, and the working medium inlet 111 and the working medium outlet 121 are both communicated to the bottom surface of the cover plate 100.

In some embodiments, both the first joint 110 and the second joint 120 are integrally formed with the cover plate 100.

Referring to fig. 4, in particular, the manifold distribution plate 200 is also a flat rectangular sheet having an a-side facing the cover plate 100 and a B-side facing the microchannel substrate 300.

Wherein, the B surface of the manifold liquid separation plate 200 is provided with a liquid inlet 210, a liquid separation channel 220 and a plurality of heat exchange units 230. Opposite to the liquid separation channel 220 on the manifold liquid separation plate 200, the side of the micro-channel substrate 300 facing the manifold liquid separation plate 200 is also provided with the liquid separation channel 220, and the liquid inlet 210 is communicated with the plurality of heat exchange units 230 through the liquid separation channel 220.

After the manifold and micro-channel substrates 200 and 300 are fixedly connected, the fluidic channels 220 on the manifold and micro-channel substrates 200 and 300 form a complete flow path. Meanwhile, the liquid distribution channels 220 are arranged on the manifold liquid distribution plate 200 and the micro-channel substrate 300, so that the thickness space of the micro-channel substrate 300 can be fully utilized, and the thickness dimension of the whole micro-channel heat exchanger can be smaller.

In another embodiment of the present application, the liquid separation flow channel 220 may be provided only on the B surface of the manifold liquid separation plate 200, or the liquid separation flow channel 220 may be provided only on the side of the microchannel substrate 300 facing the manifold liquid separation plate 200.

In this embodiment, the liquid inlet 210 penetrates to the a-plane of the manifold liquid-dividing plate 200 in the thickness direction of the manifold liquid-dividing plate 200, and communicates with the working medium inlet 111. When in use, the heat exchange working medium in the external pipeline flows into the first joint 110, and then enters the liquid inlet 210 through the working medium inlet 111 on the first joint 110.

In another embodiment of the present application, the first connector 110 may also be directly disposed on the manifold liquid-dividing plate 200, so that the working medium inlet 111 on the first connector 110 communicates with the liquid inlet 210.

In the present embodiment, the liquid separation flow passage 220 is composed of a main flow passage 221 and a plurality of sub flow passages 222. Wherein the main flow channel 221 communicates with the liquid inlet 210. One end of the secondary flow passage 222 communicates with the primary flow passage 221, and the other end of the secondary flow passage 222 communicates with the plurality of heat exchange units 230.

The cross-section of the main flow channel 221 and the secondary flow channel 222 may be rectangular, circular, V-shaped, trapezoidal, or the like.

In some embodiments, the secondary flow path 222 is divided into a secondary flow path and a tertiary flow path … … N-stage flow path, N being an integer greater than 2, and the stages of flow paths being connected in sequence.

Wherein the number of the secondary flow channels is two. Both secondary flow channels are communicated with one end of the main flow channel 221 away from the liquid inlet 210, and are symmetrically arranged about the main flow channel 221.

Similarly, the number of tertiary channels is four. Every two tertiary runners are communicated with one end of one secondary runner far away from the main runner 221 and are symmetrically arranged relative to the corresponding secondary runner.

Similarly, the number of N-level channels is 2 (N-1). In addition, one end of the N-stage flow channel is communicated with the N-1 stage flow channel, and the other end of the N-stage flow channel is communicated with the heat exchange unit 230.

Optionally, n=5, and the number of corresponding heat exchange units 230 is 16.

At this time, taking a three-stage flow passage as an example, one end of the three-stage flow passage is communicated with the main flow passage 221 through the two-stage flow passage, and the other end of the three-stage flow passage is communicated with the heat exchange unit 230 through the four-stage flow passage and the five-stage flow passage.

In other embodiments, the secondary flow channels 222 may be arranged in parallel, where one end of each of the secondary flow channels 222 is simultaneously connected to the primary flow channel 221, and the other end is respectively connected to different heat exchange units 230.

Further, in the present embodiment, at least part of the secondary flow passage 222 has a throttle slit 222a.

The throttling slit 222a has larger flow resistance, so that uneven flow distribution caused by uneven flow resistance of each heat exchange unit 230 can be reduced to a certain extent, and the heat exchange working medium can be uniformly distributed to each heat exchange unit 230.

Taking the above-described sequentially connected flow channels of each stage as an example, the throttle slits 222a may be provided in each of the four three-stage flow channels. In addition, the five-stage flow passage is designed to be smaller in flow passage size, and the flow resistance can be appropriately increased as well.

In another embodiment of the present application, a resistance increasing member, such as a rib, a microcolumn, a porous medium, or the like, may be disposed in at least a portion of the secondary flow passage 222, which can also have a throttling and resistance increasing effect.

It should be noted that the location where the throttle slit 222a or the resistance increasing member is provided is not unique. In addition to the three-stage flow channel, the throttle slit 222a or the resistance increasing member may be provided in the second-stage flow channel, the fourth-stage flow channel or the fifth-stage flow channel, or the throttle slit 222a or the resistance increasing member may be provided in multiple stages or all stages of the flow channels.

Further, the liquid separation channel 220 is designed according to the principle that the hydraulic diameter is reduced step by step, and meanwhile, the flow area of the heat exchange working medium is ensured not to be reduced, so that excessive pressure loss in the liquid separation channel 220 is avoided.

Taking the above-mentioned sequentially connected channels of each stage as an example, the hydraulic diameter of the main channel 221 is larger than that of the secondary channel, and the hydraulic diameter of the secondary channel is larger than that of the tertiary channel, and so on.

In addition, the sum of the cross-sectional areas of the two secondary flow channels is not smaller than the cross-sectional area of the primary flow channel 221, the sum of the cross-sectional areas of the four tertiary flow channels is not smaller than the sum of the cross-sectional areas of the two secondary flow channels, and so on.

Referring to fig. 5, in the present embodiment, the heat exchange unit 230 includes a liquid inlet chamber 231, a manifold liquid inlet channel 232 and a manifold liquid outlet 233.

Wherein, the liquid inlet cavity 231 is communicated with the secondary flow channel 222, and the inner wall of the liquid inlet cavity 231 is provided with diversion inclined planes 231a in pairs.

The manifold liquid inlet channel 232 and the manifold liquid outlet 233 are provided in plurality, the manifold liquid inlet channel 232 and the manifold liquid outlet 233 are alternately arranged in a direction away from the secondary channel 222, and the manifold liquid inlet channel 232 and the manifold liquid outlet 233 are not directly communicated. The manifold inlet channels 232 are simultaneously in communication with the inlet chamber 231 and in turn in communication with the secondary channels 222 through the inlet chamber 231.

When in use, the heat exchange working media evenly distributed by the liquid distribution channels 220 respectively flow into the corresponding liquid inlet cavities 231, and are further distributed into the manifold liquid inlet channels 232 in the liquid inlet cavities 231.

In addition, the manifold inlet channel 232 has two inlets facing the two diversion slopes 231a, respectively. In the direction away from the secondary flow channel 222, the distance between the diversion inclined plane 231a and each manifold inlet flow channel 232 gradually decreases, which is beneficial to uniformly diverting the heat exchange working medium into the manifold inlet flow channels 232.

Referring to fig. 6 and 7, specifically, the side of the microchannel substrate 300 facing the manifold liquid separation plate 200 is provided with a plurality of microchannel units 310. Each microchannel unit 310 corresponds to one heat exchange unit 230, and the microchannel units 310 are directly opposite to the manifold inlet channels 232 and the manifold drain 233 in the corresponding heat exchange unit 230.

Further, the microchannel unit 310 has a heat exchange channel 311, and the manifold liquid inlet channel 232 communicates with the manifold liquid outlet 233 through the heat exchange channel 311.

Because the manifold inlet flow channel 232 and the manifold drain 233 are not directly communicated, the heat exchange working medium entering the manifold inlet flow channel 232 can only flow to the heat exchange channel 311, impact the microchannel substrate 300 to participate in heat exchange, and realize microchannel cooling heat exchange in cooperation with the microchannel unit 310. Then, the heat exchange medium turns back to the manifold drain 233, taking away the heat generated by the heat source.

When in use, one side of the micro-channel substrate 300, which is away from the manifold liquid separation plate 200, is attached to a chip or other equipment, continuously absorbs heat generated by a heat source, and directly transmits the heat to the micro-channel unit 310, so that the heat resistance is smaller, and the heat dissipation effect is more outstanding.

In this embodiment, the microchannel unit 310 includes a recess 312 and a plurality of heat exchange members 313.

The grooves 312 are formed on the surface of the microchannel substrate 300, and the grooves 312 are opposite to the manifold inlet channels 232 and the manifold drain ports 233 in the corresponding heat exchange units 230.

The array of heat exchange pieces 313 is disposed on the bottom surface of the groove 312, and one end of the heat exchange piece 313 away from the bottom surface of the groove 312 is flush with the surface of the microchannel substrate 300, and heat exchange channels 311 are formed between the heat exchange pieces 313.

Referring to fig. 8 and 9, in some embodiments, the heat exchange member 313 is in a needle shape, and the cross section of the heat exchange member 313 may be square or a parallelogram other than square. When the cross section of the heat exchange member 313 is square, the sides of the square may be parallel to the side walls of the groove 312 or may form an included angle with the side walls of the groove 312.

Referring to fig. 10 and 11, in other embodiments, the heat exchange member 313 is disposed in a strip shape. The long sides of the heat exchanging pieces 313 are parallel to one side wall of the groove 312, and the respective heat exchanging pieces 313 are arranged in a direction parallel to the other side wall of the groove 312. The long side of the heat exchanger 313 may be a flat side or may be a concave-convex structure.

Referring to fig. 12, specifically, a face a of the manifold plate 200 is provided with a working fluid collection chamber 240. The manifold drain ports 233 of the heat exchange units 230 are all communicated with the manifold liquid distribution plate 200 along the thickness direction, and then are communicated with the working medium collecting cavity 240, and the working medium collecting cavity 240 is communicated with the working medium outlet 121.

When in use, the heat exchange working medium returned to the manifold liquid outlet 233 is collected in the working medium collecting cavity 240 and finally discharged from the working medium outlet 121.

Further, a plurality of support columns 241 are disposed within the working fluid collection chamber 240. The support column 241 is provided in the thickness direction of the manifold liquid separation plate 200, and one end of the support column 241 is fixedly connected to the manifold liquid separation plate 200.

When the manifold liquid separation plate 200 is fixedly connected with the cover plate 100, the other end of the supporting column 241 is also fixedly connected with the cover plate 100, so that the structural strength of the working medium collecting cavity 240 can be increased.

Further, the a-side of the manifold liquid separation plate 200 is provided with a main flow passage back rib 250, and the main flow passage back rib 250 is provided corresponding to the main flow passage 221.

In the case where the main flow passage back rib 250 is provided, the main flow passage 221 located on the B-side of the manifold liquid separation plate 200 may have a depth large enough to reduce the flow resistance of the heat exchange medium. In addition, when the manifold liquid separation plate 200 is fixedly connected with the cover plate 100, the main runner back rib 250 is also fixedly connected with the cover plate 100, so that the structural strength of the working medium collecting cavity 240 can be increased.

In summary, when the microchannel heat exchanger is used, the heat exchange medium flows in through the medium inlet 111 and flows through the liquid inlet 210 and the liquid separation channel 220 in sequence. After being evenly distributed by the liquid separation flow channels 220, the heat exchange working medium flows into the manifold liquid inlet flow channels 232 of the heat exchange units 230 respectively. Subsequently, the heat exchange medium flows toward the microchannel unit 310 in a direction perpendicular to the microchannel substrate 300 and flows into the heat exchange channels 311, thereby achieving microchannel cooling heat exchange. Finally, the heat exchange medium flows back to the microchannel unit 310 along the direction perpendicular to the microchannel substrate 300, and reversely flows back to the manifold drain port 233, is collected in the medium collection chamber 240, and flows out from the medium outlet 121. The heat exchange units 230 are matched with the micro-channel units 310, so as to perform cooling heat exchange on the heat sources.

Taking a 10mm x 10mm range as an example, in a conventional straight liquid feed design, the heat exchange medium flows from one side of the region to the other side. No matter how many flow channels are provided in this region, the total width of the cross section of each flow channel does not exceed 10mm, irrespective of the wall thickness between adjacent flow channels. In the case of a flow channel depth of 0.5mm, the total area of the cross section of each flow channel does not exceed 5mm ² . In contrast, the flow length of the heat exchange medium is 10mm.

In the microchannel heat exchanger, the flow direction of the heat exchange medium is perpendicular to the plane of the heat exchange unit 230. The total area of the cross-section of each manifold inlet channel 232 may be up to half the area of the area, i.e., 50mm, regardless of the wall thickness between the manifold inlet channel 232 and the manifold drain 233 ² . In contrast, in the case where the depths of the manifold liquid inlet channel 232, the heat exchange channel 311 and the manifold liquid outlet 233 are all 0.5mm, the flow length of the heat exchange medium is the sum of the depth of the manifold liquid inlet channel 232, the depth of the heat exchange channel 311, the depth of the manifold liquid outlet 233 and the average distance between the manifold liquid inlet channel 232 and the manifold liquid outlet 233, which is significantly smaller than the dimension of the region in a certain direction.

The average distance between the manifold inlet channel 232 and the manifold outlet 233 is understood as the distance between the central axis of the manifold inlet channel 232 and the central axis of the manifold outlet 233. The greater the number of manifold inlet channels 232 disposed in this region, the smaller the distance.

In addition, in the flow channel design after the manifold drain 233, compared with the conventional confluence channel with the same structure and opposite flow direction as the split flow channel 220, the working medium collecting cavity 240 can maximize the flow area, so that the flow resistance of the heat exchange working medium in the confluence process is greatly reduced, and the smooth flow of the heat exchange working medium is ensured under the conditions of the increase of the area of the whole micro-channel heat exchanger and the increase of the length of the internal flow channel. Compared with single-phase heat exchange, the micro-channel heat exchanger has more outstanding heat exchange performance under the two-phase flow working condition. However, the heat exchange working medium absorbs heat and vaporizes during two-phase operation, and the volume flow is greatly increased. The advantage of the working substance collection chamber 240 in reducing flow resistance is particularly pronounced compared to conventional converging channel designs. In addition, the outlets of all the heat exchange units 230 are directly communicated by the working medium collecting cavity 240, so that the outlet pressures of all the heat exchange units 230 are relatively consistent, and the phase transition saturation temperatures of the working mediums in the heat exchange units 230 tend to be consistent, thereby improving the uniformity of heat dissipation temperatures among the heat exchange units 230. Therefore, the microchannel heat exchanger has the advantages of good heat exchange capacity and small flow resistance when carrying out heat exchange and cooling on the multi-heat source array.

Furthermore, through the arrangement of the throttling slit 222a or the resistance increasing piece, and the design of the five-stage runner with smaller runner size, the throttling effect can be achieved, the flow resistance of the split runner 220 is properly increased, the negative influence of the difference of flow resistance of the downstream heat exchange unit 230 on the overall flow distribution is weakened, the flow distribution uniformity of the micro-channel heat exchanger is finally good, and the temperature consistency among multiple heat sources is improved.

Finally, the microchannel heat exchanger has high unitization characteristic, the number of the heat exchange units 230 can be changed according to actual requirements, and the microchannel heat exchanger suitable for different scenes (such as the number of heat sources) can be designed after the liquid separation flow channel 220 is adjusted, so that the microchannel heat exchanger has wider adaptability.

Any particular values in all examples shown and described herein are to be construed as merely illustrative and not a limitation, and thus other examples of exemplary embodiments may have different values.

It should be noted that: like reference numerals and letters denote like items in the following figures, and thus once an item is defined in one figure, no further definition or explanation thereof is necessary in the following figures.

The above examples merely represent a few embodiments of the present invention, which are described in more detail and are not to be construed as limiting the scope of the present invention. It should be noted that it will be apparent to those skilled in the art that several variations and modifications can be made without departing from the spirit of the invention, which are all within the scope of the invention.

Claims

1. The microchannel heat exchanger is characterized by comprising a cover plate, a manifold liquid-dividing plate and a microchannel substrate which are sequentially laminated;

2. The microchannel heat exchanger according to claim 1, wherein a side of the manifold liquid distribution plate facing the microchannel substrate and/or a side of the microchannel substrate facing the manifold liquid distribution plate is provided with liquid distribution channels;

3. The microchannel heat exchanger of claim 2 wherein the split flow channel comprises a primary flow channel and a plurality of secondary flow channels, the primary flow channel being in communication with the inlet, one end of the secondary flow channel being in communication with the primary flow channel, the other end of the secondary flow channel being in communication with the manifold inlet flow channel.

4. A microchannel heat exchanger according to claim 3, wherein at least part of the secondary flow channels have throttling slits; or alternatively

5. A microchannel heat exchanger according to claim 3, wherein the side of the manifold liquid distribution plate facing the microchannel substrate is provided with the liquid distribution channel, the side of the manifold liquid distribution plate facing the cover plate is provided with a main channel back rib, and the main channel back rib is provided corresponding to the main channel.

6. The microchannel heat exchanger of claim 2 wherein a support column is disposed within the working fluid collection chamber, the support column being connected to the cover plate.

7. The microchannel heat exchanger according to any one of claims 1 to 6, wherein the heat exchange unit further comprises a liquid inlet chamber, the inner wall of the liquid inlet chamber being provided with a diversion slope;

8. The microchannel heat exchanger according to any one of claims 1 to 6, wherein the microchannel unit comprises a groove and a plurality of heat exchange members arranged on the bottom surface of the groove in an array, and the heat exchange channels are formed between the heat exchange members.

9. The microchannel heat exchanger of claim 8, wherein the heat exchange elements are in a needle-like arrangement or a strip-like arrangement.

10. The microchannel heat exchanger of any one of claims 1-6, wherein the cover plate is provided with a working fluid inlet and a working fluid outlet, the liquid inlet extends through the manifold liquid distribution plate, and the liquid inlet is in communication with the working fluid inlet.