阅读说明：本技术 一种带二次翅片的微通道换热器 (Micro-channel heat exchanger with secondary fins ) 是由 李育隆 夏余天逸 周滢 于 2021-08-12 设计创作，主要内容包括：本申请公开了一种带二次翅片的微通道换热器,涉及换热器结构设计领域。本申请中的每一换热器单元包括主翅片基座、主翅片、二次翅片、冷端流道和热端流道,热端流道为常规尺寸通道,冷端通道为微通道。本申请使用二次翅片进行换热,在不过多增重的情况下大幅扩展换热面积,实现充分换热；采用了分离式多流程设计,在不影响紧凑度的前提下提升的换热总量和换热效率。故本申请具有结构紧凑,适应小流量,换热面积大,制造成本低的特点,解决了现有微通道换热器无法与常规体积流量流体换热的问题。(The application discloses take microchannel heat exchanger of secondary fin relates to heat exchanger structural design field. Each heat exchanger unit in this application includes main fin base, main fin, secondary fin, cold junction runner and hot junction runner, and the hot junction runner is conventional size passageway, and the cold junction passageway is the microchannel. The secondary fins are used for heat exchange, so that the heat exchange area is greatly expanded under the condition of not increasing weight too much, and sufficient heat exchange is realized; and a separated multi-flow design is adopted, so that the total heat exchange amount and the heat exchange efficiency are improved on the premise of not influencing the compactness. Therefore, the micro-channel heat exchanger has the characteristics of compact structure, small flow adaptation, large heat exchange area and low manufacturing cost, and solves the problem that the conventional micro-channel heat exchanger cannot exchange heat with conventional volume flow fluid.)

1. A finned microchannel heat exchanger formed in a flow channel, the flow channel having a flow channel outer wall, the finned microchannel heat exchanger comprising at least one heat exchanger unit (10), each heat exchanger unit comprising:

the main fin base (2) is fixed with the outer wall (1) of the flow channel and used as a main bearing part, and grooves are carved in the main fin base to form a cold-end flow channel (3);

a plurality of main fins (5) are connected to the main fin base at intervals;

a plurality of secondary fins (6), wherein each secondary fin is sleeved on the main fin, and the plurality of secondary fins are arranged at intervals;

the main fins, the secondary fins and the outer walls of the runners are matched to form hot end runners (4), the hot end runners are conventional-size channels, and the cold end channels are micro channels.

2. The microchannel heat exchanger with the secondary fins as recited in claim 1, wherein the primary fin base (2) and the outer wall (1) of the flow channel in each heat exchanger unit are tightly connected without any gap;

the main fin base (2) and the main fins (5) in each heat exchanger unit are tightly welded, and thermal contact resistance does not exist between the two;

the primary fins (5) and the secondary fins (6) in each heat exchanger unit are tightly welded, and thermal contact resistance does not exist between the primary fins and the secondary fins.

3. The microchannel heat exchanger with the secondary fins as set forth in claim 1, wherein the number of the heat exchanger units is plural, and the plural heat exchange units are arranged at equal intervals in the axial direction of the outer wall of the flow channel.

4. The microchannel heat exchanger with secondary fins as recited in claim 1, wherein the combined projected area of the primary fin base, the primary fins and the secondary fins is no more than 50% of the flow channel area so as not to block the hot end flow channels.

5. The microchannel heat exchanger of claim 1, wherein the primary fin bases are disposed transversely to the flow channels, each primary fin is perpendicular to the primary fin bases, and each secondary fin is parallel to the primary fin bases such that the hot side flow channels are in a grid pattern.

6. The micro-channel heat exchanger with secondary fins as claimed in claim 1, wherein additional fins are added to the secondary fins.

7. The finless microchannel heat exchanger of claim 1 wherein the cold end flow channel shape is configured to expand flow path without increasing space length.

8. The finned microchannel heat exchanger of claim 7 wherein the cold end flow passages are serpentine, herringbone or zigzag.

9. The finned microchannel heat exchanger of claim 1 wherein the hydraulic diameter of the cold end flow channels is less than 1 mm.

10. The finned microchannel heat exchanger of any one of claims 1 to 9, wherein each primary fin is of round pin fin construction and each secondary fin is a flat sheet.

Technical Field

The application relates to the field of heat exchanger structural design, in particular to a micro-channel heat exchanger with secondary fins.

Background

The development of the heat exchanger structure design tends to be mature and standardized, and relevant manuals and design reference standards can be consulted in various industrial application scenes. On the other hand, however, micro-channel heat exchanger designs on millimeter, micron, and even nanometer scale are still industry shortboards in micro-electro-mechanical (MEMS), aerospace, precision medical devices, and other applications. The ambiguity of the basic theory of heat exchange under the micro scale and the lack of practical application examples cause that the micro-channel heat exchanger has no unified and definite design method.

With the development of science and technology, the requirement for the compactness of the heat exchanger is gradually increased, and a series of micro-channel compact heat exchanger forms such as plate-fin heat exchangers are also developed. However, the existing microchannel heat exchanger focuses on microchannel-microchannel heat exchange, and no suitable heat exchanger form exists for microchannel-conventional size channel heat exchange.

Therefore, a new heat exchanger structure is developed, the heat exchange problem of the micro-channel-conventional-size channel is solved, the further development of the compact heat exchanger is realized, and the heat exchanger has important practical value.

Disclosure of Invention

It is an object of the present application to overcome the above problems or to at least partially solve or mitigate the above problems.

The application provides a take microchannel heat exchanger of secondary fin forms in the runner, and the runner has the runner outer wall, take microchannel heat exchanger of secondary fin includes an at least heat exchanger unit, and each heat exchanger unit includes:

the main fin base is fixed with the outer wall of the flow channel and used as a main bearing part, and a groove is carved in the main fin base to form a cold-end flow channel;

the number of the main fins is multiple, and the main fins are connected to the main fin base at intervals;

the number of the secondary fins is multiple, each secondary fin is sleeved on the main fin, and the secondary fins are arranged at intervals;

the main fins, the secondary fins and the outer walls of the flow channels are matched to form hot end flow channels, the hot end flow channels are conventional-size channels, and the cold end channels are micro-channels.

Optionally, the main fin base in each heat exchanger unit is tightly connected with the outer wall of the flow channel, and no gap exists;

the main fin base in each heat exchanger unit is tightly welded with the main fin, and thermal contact resistance does not exist between the main fin base and the main fin;

the primary fins and the secondary fins in each heat exchanger unit are tightly welded, and thermal contact resistance does not exist between the primary fins and the secondary fins.

Optionally, the number of the heat exchanger units is multiple, and the multiple heat exchange units are arranged at equal intervals along the axial direction of the outer wall of the flow channel.

Optionally, the total projected area of the primary fin base, the primary fins and the secondary fins does not exceed 50% of the area of the flow channel, so as to avoid blocking the hot end flow channel.

Optionally, the primary fin base is transversely disposed in the flow channel, each primary fin is perpendicular to the primary fin base, and each secondary fin is parallel to the primary fin base, so that the hot-end flow channel is in a grid shape.

Optionally, additional fins are added to the secondary fins.

Optionally, the cold end flow passage shape is configured to expand the flow path without increasing the length of the space.

Optionally, the cold end flow passage is serpentine, herringbone or zigzag.

Optionally, the cold end flow passage has a hydraulic diameter of less than 1 mm.

Optionally, each primary fin is a round thick pin fin structure and each secondary fin is a flat thin plate.

The utility model provides a take microchannel heat exchanger of secondary fin, each heat exchanger unit wherein includes main fin base, main fin, secondary fin, cold junction runner and hot junction runner, and the hot junction runner is conventional size passageway, and the cold junction passageway is the microchannel. The secondary fins are used for heat exchange, so that the heat exchange area is greatly expanded under the condition of not increasing weight too much, and sufficient heat exchange is realized; and a separated multi-flow design is adopted, so that the total heat exchange amount and the heat exchange efficiency are improved on the premise of not influencing the compactness. Therefore, the micro-channel heat exchanger has the characteristics of compact structure, small flow adaptation, large heat exchange area and low manufacturing cost, and solves the problem that the conventional micro-channel heat exchanger cannot exchange heat with conventional volume flow fluid.

The above and other objects, advantages and features of the present application will become more apparent to those skilled in the art from the following detailed description of specific embodiments thereof, taken in conjunction with the accompanying drawings.

Drawings

Some specific embodiments of the present application will be described in detail hereinafter by way of illustration and not limitation with reference to the accompanying drawings. The same reference numbers in the drawings identify the same or similar elements or components. Those skilled in the art will appreciate that the drawings are not necessarily drawn to scale. In the drawings:

FIG. 1 is a schematic cross-sectional view of a microchannel heat exchanger with secondary fins according to one embodiment of the present application;

FIG. 2 is an enlarged schematic view of the cross-sectional top view of the microchannel flow channel of the microchannel heat exchanger with secondary fins of FIG. 1;

FIG. 3 is a schematic cross-sectional view taken along section line A-A in FIG. 1, showing a conventional size channel side cross-section of a secondary finned microchannel heat exchanger.

The symbols in the drawings represent the following meanings:

10 a heat exchanger unit, wherein the heat exchanger unit,

the structure comprises a flow channel outer wall 1, a main fin base 2, a cold end flow channel 3, a hot end flow channel 4, a main fin 5 and a secondary fin 6.

Detailed Description

FIG. 1 is a schematic cross-sectional view of a microchannel heat exchanger with secondary fins according to one embodiment of the present application. FIG. 2 is an enlarged schematic top sectional view of the microchannel flow channel of the microchannel heat exchanger with secondary fins of FIG. 1. FIG. 3 is a schematic cross-sectional view taken along section line A-A in FIG. 1, showing a conventional size channel side cross-section of a secondary finned microchannel heat exchanger.

Referring also to fig. 3, as shown in fig. 1, the present application provides a secondary finned microchannel heat exchanger formed in a flow channel having a flow channel outer wall 1, the secondary finned microchannel heat exchanger comprising at least one heat exchanger unit. Each heat exchanger unit comprises: the heat exchanger comprises a main fin base 2, a main fin 5, a secondary fin 6, a cold end runner 3 and a hot end runner 4. The main fin base 2 is fixed with the runner outer wall 1 and used as a main bearing part, and grooves are carved in the main fin base 2 to form a cold end runner 3. The number of the main fins 5 is multiple, and the main fins are connected to the main fin base 2 at intervals. The number of the secondary fins 6 is multiple, each secondary fin 6 is sleeved on the main fin 5, and the secondary fins 6 are arranged at intervals. The main fins 5, the secondary fins 6 and the runner outer wall 1 are matched to form a hot end runner 4. The hot end flow channel 4 is a conventional size channel. The cold end channel is a microchannel.

The working principle of this application does:

1) the low-pressure hot end gas flows into the hot end runner 4 and is mainly contacted with the secondary fins 6 to carry out convective heat transfer. The secondary fins 6 and the primary fins 5 transfer heat laterally from the secondary fins 6 to the primary fins 5 in a heat conductive manner,

2) the primary fins 5 then heat the primary fin base 2 longitudinally in a thermally conductive manner,

3) the inside of the main fin base 2 exchanges heat with the cold end runner 3 in a convection mode. In the whole heat exchange process, the solid structures are all tightly welded, so that the contact thermal resistance can be ignored.

The utility model provides a take microchannel heat exchanger of secondary fin, each heat exchanger unit wherein includes main fin base 2, main fin 5, secondary fin 6, cold junction runner 3 and hot junction runner 4, and hot junction runner 4 is conventional size passageway, and the cold junction passageway is the microchannel. The secondary fins 6 are used for heat exchange, so that the heat exchange area is greatly expanded under the condition of not increasing weight too much, and sufficient heat exchange is realized; and a separated multi-flow design is adopted, so that the total heat exchange amount and the heat exchange efficiency are improved on the premise of not influencing the compactness. Therefore, the micro-channel heat exchanger with the secondary fins is provided on the basis of the structure of the traditional tube-fin heat exchanger, can realize heat exchange between fluid with small flow and fluid with conventional flow, and has the characteristics of compact structure, small flow adaptation, large heat exchange area and low manufacturing cost. The problem of current microchannel heat exchanger can't with the heat transfer of conventional volume flow fluid is solved.

Further, in the present embodiment, as shown in fig. 1, the main fin base 2 in each heat exchanger unit is tightly connected to the outer wall 1 of the flow channel, and no gap exists, so as to serve as a main force-bearing structure; the main fin base 2 and the main fin 5 in each heat exchanger unit are tightly welded, and thermal contact resistance does not exist between the two; the primary fins 5 and the secondary fins 6 in each heat exchanger unit are tightly welded, and no thermal contact resistance exists between the primary fins and the secondary fins.

As shown in fig. 3, the number of the heat exchanger units is multiple, and the heat exchanger units are arranged at equal intervals along the axial direction of the outer wall 1 of the flow channel. In this embodiment, the number of heat exchanger unit is two, and two heat transfer units are arranged along runner outer wall 1 axial equidistance. The structure of each heat exchange unit is the same, the main fin base 2 of each heat exchange unit is fixed on the outer wall 1 of the flow channel, and the cold end flow channel 3 is perpendicular to the angle shown in the figure and leads to the outside of the outer wall and is connected by the bent pipe with the same size and shape of the flow channel.

In a general tube-fin heat exchanger, a tube can be made into a multi-flow channel to increase the flowing distance of fluid and prolong the heat exchange time. However, in microchannel heat exchangers, where the mass flow rates of the conventionally sized flow channels and the microchannel flow channels differ by 2 to 3 orders of magnitude, the temperature of the fluid within the microchannels may vary widely within a single pass. In order to prevent heat exchange among fluids in different processes, the heat exchange amount of the fluid at the final outlet can be improved by dividing each process.

More specifically, in the present embodiment, the total projected area of the primary fin base 2, the primary fins 5, and the secondary fins 6 does not exceed 50% of the flow channel area, so as not to block the hot end flow channel 4.

More specifically, in this embodiment, as shown in fig. 1, the main fin base 2 is transversely disposed in the flow channel, each main fin 5 is perpendicular to the main fin base 2, each secondary fin 6 is parallel to the main fin base 2, so that the hot end flow channel 4 is in a grid shape to expand the heat exchange area and increase the turbulence degree as much as possible,

to expand the heat exchange area of a low-pressure fluid without losing compactness or increasing weight.

Furthermore, the main fin base 2 is used as a main bearing structure, and the main fins 5 and the secondary fins 6 are not stressed, so that the heat exchange area/volume ratio can be increased as thin as possible, and the compactness is enhanced.

Further, the secondary fins 6 can be extended towards the direction of the fluid flow, and the heat exchange area can be increased without increasing the flow resistance obviously.

Further, under the condition that the processing technology allows, a smaller fin can be additionally added on the secondary fin 6, and the heat exchange is further enhanced by adopting the fractal shape design. The added fins are still counted as secondary fins 6.

More specifically, in the present embodiment, each primary fin 5 is a round thick pin fin structure to reduce the heat transfer resistance inside the heat exchanger; each secondary fin 6 is a flat thin plate to increase the heat exchange area between the present application and the fluid.

Specifically, as shown in fig. 2, the cold-end flow passage 3 is shaped and configured to expand the flow path without increasing the length of the space. Further, the cold end flow channel 3 is in a shape of a snake shape, a herringbone shape or a zigzag shape and the like, which can damage the boundary layer, so that the condition that the boundary layer of the flow fully developed section is too thick under the condition of small hydraulic diameter of the micro-channel is relieved, and the heat exchange condition is improved. In this embodiment, the cold end flow passage 3 is located inside the main fin base 2, and is milled into a serpentine channel by a milling cutter, so that the flow path is increased while the structure is kept as compact as possible.

Further, referring to fig. 2, a high-pressure cold-end flow passage 3 is cut between the upper and lower surfaces of the main fin base 2. Through which high pressure fluid flows for heat exchange. Hydraulic diameter D of the cold end flow passage 3_hShould not exceed 1mm in order to maintain the high pressure state of the fluid and prevent it from expanding and causing pressure loss. Hydraulic diameter D_hThe calculation formula of (A) is as follows:

wherein, a is the sectional area of the cold end runner 3 in the embodiment, and S is the wet circumference of the section of the cold end runner 3 in the embodiment.

In conclusion, the secondary fins 6 are adopted to expand the heat exchange area without reducing the compactness, the curved micro-channel flow channels are adopted to destroy the boundary layer formation and maintain the high-pressure state of the fluid, the separated multi-flow channels are adopted to solve the problem of efficiency reduction caused by heat exchange among fluids in different flows, and the heat exchange among the fluids in the micro-channel/conventional-size channel is realized by solving the three problems.

It is to be noted that, unless otherwise specified, technical or scientific terms used herein shall have the ordinary meaning as understood by those skilled in the art to which this application belongs.

In the description of the present application, it is to be understood that the terms "central," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," "circumferential," and the like are used in the orientations and positional relationships indicated in the drawings for convenience in describing the present application and to simplify the description, and are not intended to indicate or imply that the referenced devices or elements must have a particular orientation, be constructed and operated in a particular orientation, and are therefore not to be considered limiting of the present application.

Furthermore, the terms "first", "second", etc. are used for descriptive purposes only and are not to be construed as indicating or implying relative importance or implicitly indicating the number of technical features indicated. In the description of the present application, "a plurality" means two or more unless specifically defined otherwise.

In this application, unless expressly stated or limited otherwise, the terms "mounted," "connected," "secured," and the like are to be construed broadly and can include, for example, fixed connections, removable connections, or integral parts; can be mechanically or electrically connected; either directly or indirectly through intervening media, either internally or in any other relationship. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art as appropriate.

In this application, unless expressly stated or limited otherwise, the first feature "on" or "under" the second feature may be directly contacting the first and second features or indirectly contacting the first and second features through intervening media. Also, a first feature "on," "over," and "above" a second feature may be directly or diagonally above the second feature, or may simply indicate that the first feature is at a higher level than the second feature. A first feature being "under," "below," and "beneath" a second feature may be directly under or obliquely under the first feature, or may simply mean that the first feature is at a lesser elevation than the second feature.

The above description is only for the preferred embodiment of the present application, but the scope of the present application is not limited thereto, and any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope of the present application should be covered within the scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.