CN108548437B

CN108548437B - Bionic-based fishbone-type micro-staggered alveolar heat exchanger core and heat exchanger

Info

Publication number: CN108548437B
Application number: CN201810590275.3A
Authority: CN
Inventors: 王俊伟
Original assignee: Shaanxi Yixin Weichuang Intelligent Technology Co ltd
Current assignee: Shaanxi Yixin Weichuang Intelligent Technology Co ltd
Priority date: 2018-06-08
Filing date: 2018-06-08
Publication date: 2023-11-03
Anticipated expiration: 2038-06-08
Also published as: CN108548437A

Abstract

The invention discloses a bionic-based fishbone type micro-staggered alveolar heat exchanger core, which comprises a shell, wherein the core is divided into two layers by a heat exchange plate, two layers of fishbone type rib combinations are arranged in each layer of cavity, each layer of fishbone type rib combination consists of a plurality of rows of fishbone type ribs which are parallel to each other, each row of fishbone type ribs consists of a plurality of pairs of short ribs which are arranged in a splayed shape, and the shapes, angles and intervals of the short ribs in the same row are the same; the two layers of fishbone ribs are not contacted; two layers of fishbone ribs are respectively fixed on the inner wall of the medium flow cavity. The bionic elements are fused into the design of the heat exchanger, and the micro staggered alveolus heat exchanger is designed, so that the structure improves the performance of the heat exchanger in terms of heat transfer coefficient and heat transfer area, is light and simple, and is suitable for the heat exchanger for aerospace.

Description

Bionic-based fishbone-type micro-staggered alveolar heat exchanger core and heat exchanger

Technical Field

The invention belongs to the technical field of heat exchange equipment, and particularly relates to a bionic-based fishbone-type micro-staggered alveolar heat exchanger core and a heat exchanger.

Background

The heat exchanger has wide application in industry, and the design of the advanced heat exchanger is to be realized with low energy consumption and high efficiency operation of equipment in the fields of power, chemical industry, ships, refrigeration, machinery and the like. To improve the heat exchange capacity of the heat exchanger, there are generally three means: the heat transfer temperature difference is improved, the heat transfer area is increased, and the convection heat transfer coefficient is increased. In heat exchangers without phase change, the increase of the heat transfer temperature difference is usually achieved by reasonably arranging flow channels, such as countercurrent flow of cold and hot fluids, increasing the heat exchange area means increasing the total volume of the heat exchanger or reducing the channel cross section to arrange more flow channels, and increasing the convective heat transfer coefficient can be achieved by turbulent flow. The most widely used heat exchanger designs are shell and tube heat exchangers and plate heat exchangers. The shell-and-tube heat exchanger is shown in fig. 1, and is difficult to apply to occasions requiring a light-weight and small-volume heat exchanger due to the large volume and low heat exchange efficiency. Typical fin forms for plate-fin heat exchangers are shown in fig. 2, where the flow in a conventional straight channel plate-fin heat exchanger lacks sufficient turbulence, and the corrugated fin or like channel design in turn causes more swirl and dead space to the flow, resulting in increased flow shape resistance and more pumping work consumption.

In the aerospace heat exchanger, the heat exchange efficiency is pursued, and meanwhile, the reliability of the heat exchanger needs to be ensured, namely, the heat exchanger is convenient to maintain and reliable to operate. When the fluid flowing in the heat exchanger is corrosive or sedimenting and chippings, it must be ensured that the heat exchanger is not prone to clogging, and therefore the channels of the heat exchanger cannot be too small.

In order to improve the heat exchange effect, some heat exchangers are overlarge in design volume, so that the operation weight is overlarge, some heat exchangers are designed into bionic micro-channels, but thought is limited to tree-shaped bifurcation, and the heat exchangers cannot meet the high-efficiency heat exchange requirements in high-end equipment in the field of aerospace, the field of electronic chips and the like at present. Meanwhile, the heat exchange capability of the traditional shell-and-tube heat exchanger is insufficient to meet the current heat exchange requirement. At present, some heat exchangers applied to the high-end field also need good reliability, and a way of simply reducing the heat exchanger channels to increase the heat exchange area-volume ratio is hindered, namely heat exchange enhancement cannot be realized by simply reducing the channel size.

Disclosure of Invention

The invention aims to provide a bionic-based fishbone-type micro-staggered alveolus heat exchanger core, which improves the performance of a heat exchanger by referring to staggered and cavity interval structures of alveoli of organisms, can reduce the volume of the heat exchanger core, and solves the problem that the high heat exchange performance and the micro volume of the traditional heat exchanger core are difficult to be compatible.

It is another object of the present invention to provide a heat exchanger having the heat exchanger core as described above.

The invention adopts the technical scheme that the bionic-based fishbone type micro-staggered alveolar heat exchanger core comprises a shell, wherein the core is divided into two layers by a heat exchange plate, two layers of fishbone type rib combinations are arranged in each layer of cavity, each layer of fishbone type rib combination consists of a plurality of rows of fishbone type ribs which are parallel to each other, each row of fishbone type ribs consists of a plurality of pairs of short ribs which are arranged in a splayed manner, and the shapes, angles and intervals of the short ribs in the same row are the same; the two layers of fishbone ribs are not contacted; two layers of fishbone ribs are respectively fixed on the inner wall of the medium flow cavity.

The invention is also characterized in that:

further, the distance between each pair of the short ribs is 0.1-2 times the length of the short ribs themselves.

Further, the direction of each row of the fishbone-shaped ribs forms a certain staggered angle with the medium flow direction.

Further, the height of each layer of fishbone type rib combination is 1/2 of that of the medium flow cavity.

Further, the two layers of fishbone type rib combinations are provided with intervals in height, and the intervals are 0.1-1 times of the rib heights.

Further, one or more baffles are arranged in each layer of the medium flow cavity along the medium flow direction or at an angle with the medium flow direction.

The invention also provides a heat exchanger, which is provided with any bionic-based fishbone type micro-staggered alveolus heat exchanger core.

The arrangement of the fishbone structure enables a plurality of staggered tiny flow cavities, namely bionic staggered alveoli, to be formed in the medium flow cavity. When fluid flows in the flow cavity, the fluid flows around the fishbone structure, and is repeatedly mixed between the two rows of flow channels to generate disturbance beneficial to heat exchange; the gap between the upper fishbone structure and the lower fishbone structure can make the flow become more complex, is favorable for the generation of vortex, and simultaneously the fluid is blocked by the wall surface at the boundary and is folded and overturned, so that the fluid generates vortex and secondary flow and enhances heat exchange in a later flow channel. The fishbone structure can greatly enhance the mixing degree of fluid, increase the heat exchange coefficient, and the secondary surface energy formed by the ribs can increase the heat exchange area. The structure can improve the performance of the heat exchanger from the two aspects of increasing the heat exchange coefficient and increasing the heat exchange area.

The invention has the beneficial effects that the bionic elements are fused into the design of the heat exchanger, the micro staggered alveolus heat exchanger is designed, the structure improves the performance of the heat exchanger from the two aspects of heat transfer coefficient and heat transfer area,

the heat exchange power per unit area is more than 7 times of that of the traditional tube-sheet type heat exchanger and the shell-and-tube type heat exchanger, and the performance of the heat exchanger is similar to that of a micro-channel heat exchanger and exceeds that of a common laminated plate type heat exchanger. Meanwhile, the internal channel does not reach the size range of the micro-channel, and the fishbone structure arrangement also ensures that secondary flow and various disturbance in the flowing process are more, so that the problem of blockage can be avoided to a great extent. Because the heat exchange effect per unit volume is stronger, the same heat exchange requirement can be realized by using smaller volume, thereby realizing the purpose of reducing the volume of the heat exchanger. Meanwhile, the volume of the internal cavity is reduced greatly compared with that of the traditional heat exchanger, so that the working medium required under the same heat exchange requirement is also reduced, namely the running weight of the heat exchanger can be reduced by about 1/2.

Drawings

FIG. 1 is a schematic view of a conventional shell-and-tube heat exchanger;

FIG. 2 is a schematic diagram of a typical fin structure of a conventional plate-fin heat exchanger;

FIG. 3 is a schematic diagram of the structure of a fishbone type micro-staggered alveolar heat exchanger core of the present invention;

FIGS. 4a-4c are schematic views of the structure of the fishbone rib of the invention;

FIG. 5 is a schematic view of a screenshot of a two-layer fishbone rib;

FIG. 6 is a schematic diagram of the media flow according to the present invention;

fig. 7 is a schematic view of a separator of the present invention.

In the figure, 1, a shell, 2, a heat exchange plate, 3, linear ribs and 4, a baffle plate.

Detailed Description

The invention will be described in further detail with reference to the drawings and the detailed description, but the invention is not limited to these embodiments.

The structure of the bionic-based fishbone type micro-staggered alveolus heat exchanger core is shown in fig. 3, the core comprises a shell 1, the core is divided into two layers by a heat exchange plate 2, the two layers are respectively used as medium flow cavities for cold and hot medium fluid to flow, and heat exchange is carried out by the heat exchange plate 2. Two layers of fishbone rib combinations are arranged in each layer of cavity, each layer of fishbone rib combination consists of a plurality of rows of fishbone ribs which are parallel to each other, each row of fishbone ribs consists of a plurality of pairs of splayed short ribs 3, and the shapes, angles and intervals of the short ribs in the same row are the same, so that the fishbone rib is formed. The two layers of fishbone ribs are not contacted. Two layers of fishbone ribs are respectively fixed on the inner wall of the medium flow cavity.

One layer of the fishbone rib assembly is shown in fig. 4a, each row of the fishbone ribs is arranged in an inverted splayed shape, and the other layer of the fishbone rib assembly is shown in fig. 4b, and each row of the fishbone ribs is arranged in a positive splayed shape. The two ribs are assembled alternately, and the upper rib and the lower rib are parallel to each other, but have no contact points, as shown in fig. 4c. The distance between each pair of short ribs is preferably 0.1-2 times the length of the short ribs themselves.

The height of each layer of the fishbone rib assembly may be 1/2 of the medium flow cavity, i.e. the two layers of the fishbone rib assembly are not spaced in height. The two layers of fishbone rib combinations may also have a spacing in height, as shown in fig. 5, preferably 0.1-1 times the rib height.

The direction of each row of fishbone ribs can be parallel to the medium flow direction, or can form a certain staggered angle with the medium flow direction (namely, form a certain staggered angle with the side wall of the heat exchanger core).

The cross-section of the fishbone rib includes, but is not limited to, the parallelogram, rectangle, triangle, cut ellipse, cross, L-shape, hexagon, etc. in fig. 6, i.e., the rib cross-section formed by polygons, arcs, and combinations thereof is calculated as the rib cross-section form of the staggered alveolus structure.

In fig. 7, in order to further improve the heat exchange performance, a baffle 4 is further disposed in each layer of the medium flow cavity along the medium flow direction or in a direction forming a certain angle with the medium flow direction, the baffle divides the linear rib row into a plurality of groups, and the presence of the baffle increases the turn-back times of the medium in the staggered rib cores, changes the flow path, and enhances the heat exchange capability. The baffles can be set to n (n.gtoreq.1) so as to divide the basin into 1/(n+1). n is specifically determined by the shape and the size of the medium flow cavity, generally n=2, 3 and 4 can reduce the flow resistance, increase the fluid disturbance and enhance the heat exchange; when fluid flows through the cavity formed by the rib combination, the fluid is blocked by the baffle plate and is turned back, so that heat exchange is enhanced. When the baffle plates are arranged, the volumes of the heat exchangers can be 10-200 mm as intervals, the denser the baffle plates are, the more the fluid is folded frequently, the stronger the heat exchange is, and the higher the pressure drop is. The overall dimension, the form and the thickness of the partition plate, the form of the inlet and the outlet and the parameters of the cross section of the rib are determined according to the required heat exchange power and volume requirements, the parameters are more and the change is relatively more random, and no fixed value is given here.

Taking the fishbone type micro-staggered alveolus heat exchanger core as an example, the heat exchange performance is calculated.

The number of the fishbone-shaped rib combination layers is 2, no space exists between the two layers, the height of a single row of ribs of a fluid channel is 1mm, the spacing between the short ribs is 2mm, the length of a single short rib is 10mm, no baffle plate exists, the included angle of each pair of splayed short ribs is 60 degrees, the cross section of each short rib takes a rectangle, the widths of the top and the bottom of the rib are 0.8mm, namely the cross section area of the rib is 0.8mm ² 。

The heat exchanger of this example was calculated to have a heat flux density of about 8.8W/cm when the average logarithmic temperature difference of the cold and hot fluid was about 35℃ ² The heat exchange power per unit area reaches more than 7 times of that of the traditional tube-sheet type heat exchanger and the shell-and-tube type heat exchanger, and reaches and exceeds the performance of the common laminated plate type heat exchanger, which is close to the performance of the micro-channel heat exchanger. Meanwhile, the internal channel does not reach the size range of the micro-channel, and the fishbone structure arrangement also ensures that secondary flow and various disturbance in the flowing process are more, so that the problem of blockage can be avoided to a great extent. Because the heat exchange effect per unit volume is stronger, the same heat exchange requirement can be realized by using smaller volume, thereby realizing the purpose of reducing the volume of the heat exchanger. Meanwhile, the volume of the internal cavity is reduced greatly compared with that of the traditional heat exchanger, so that the working medium required under the same heat exchange requirement is also reduced, namely the running weight of the heat exchanger can be reduced by about 1/2.

Meanwhile, from the view of a plurality of geometric variations and geometric dimensional changes which possibly exist in the staggered alveoli of the heat exchanger, the invention provides a large number of bionic design forms and ideas, and can further develop the application of the bionic design in the actual heat exchanger.

Claims

1. The bionic fishbone type micro staggered alveolus heat exchanger core is characterized in that the core comprises a shell, the core is divided into two layers through a heat exchange plate, two layers of fishbone type rib combinations are arranged in each layer of cavity, each layer of fishbone type rib combination is composed of a plurality of fishbone type ribs which are parallel to each other, each row of fishbone type rib is composed of a plurality of pairs of short ribs which are arranged in a splayed mode, the shapes, angles and intervals of the short ribs in the same row are the same, one layer of fishbone type rib in the two layers of fishbone type ribs is arranged in a regular splayed mode, the other layer of fishbone type rib is arranged in an inverted splayed mode and is mutually inserted and combined together, the upper layer of rib and the lower layer of rib are parallel to each other without contact points, the distance between each pair of short ribs is 0.1-2 times of the length of the short ribs, the two layers of fishbone type rib combinations are not contacted, the two layers of fishbone type ribs are respectively fixed on the inner wall of a medium flow cavity, the height of each layer of fishbone type rib combination is 1/2 of the medium flow cavity, the direction of the fishbone type rib and the medium flow direction is in a certain angle of the medium flow direction is 60 degrees, and the medium baffle is arranged in each layer of the medium flow direction is in the medium flow direction and is in a certain direction of the medium baffle to be 4 degrees.

2. The bionic-based fishbone micro-interleaved alveolar heat exchanger core of claim 1, wherein the two layers of fishbone rib combinations have a spacing in height of 0.1-1 times the rib height.

3. A heat exchanger having a bionic-based fishbone micro-interlaced alveolar heat exchanger core as defined in any of claims 1-2.