CN103267436A - Plate-fin crotch structure heat exchange device for enhancing heat transfer - Google Patents

Abstract

The invention discloses a plate-fin crotch structure heat exchange device for enhancing heat transfer. The plate-fin crotch structure heat exchange device comprises two end sockets, a partition board, flow deflectors and fins. Fluid enters the plate-fin crotch structure heat exchange device through the flow deflector on one side. After being subjected to heat exchange with the fins, the fluid flows out from the other side. The plate-fin crotch structure heat exchange device is characterized in that the fins are crotch-shaped fins, wherein each crotch-shaped fin is composed of a trunk part and a crotch part, and each crotch-shaped fin comprises at least two crotches which are evenly distributed on two side faces of a trunk. The crotches are arranged in a staggered mode on two sides of each trunk in the flowing direction of the fluid. The open direction of each crotch-shaped fin is consistent with the flowing direction of the fluid. The range of an open angle is 10-30 degrees. By means of the plate-fin crotch structure heat exchange device for enhancing the heat transfer, the problem that the temperatures of the fluid in different flow paths of a heat exchanger are not uniform is solved; the turbulence performance of the fluid in the heat exchanger is improved, a thermal boundary layer of the fluid is damaged, the flowing directions of the fluid in the different flow paths are changed, and therefore the heat exchange efficiency is improved; due to a crotch-shaped fin structure of the plate-fin heat exchanger, the thermal boundary layer of the fluid is damaged, and the heat transfer effect of the heat exchanger is enhanced.

Description

A plate-fin tree branch structure heat exchange device with enhanced heat transfer

technical field

The invention relates to a heat exchange device, in particular to a plate-fin type tree branch structure heat exchange device for enhancing heat transfer.

Background technique

The plate-fin heat exchange device is the key equipment in the process of enhancing heat transfer. Its advantages mainly include: (1) High heat transfer efficiency: the partition plate and fin structure in the heat exchanger are usually relatively thin, and both have good heat conduction The performance enables the plate-fin heat exchanger to form a unique secondary heat transfer phenomenon, which improves heat transfer efficiency; (2) Large heat transfer coefficient: the disturbance of the fin structure to the fluid continuously destroys the thermal boundary layer of the fluid, promoting (3) Compact structure: the secondary heat transfer surface of the fin increases the heat transfer area; (4) Lightweight: the plate-fin heat exchanger has many structures such as fins, partitions, and seals. Made of aluminum alloy, it has light weight and high heat transfer efficiency; (5) Wide adaptability: Multiple combinations such as series and parallel connection of multiple heat exchanger units can meet the requirements of gas-liquid, gas-gas, liquid-liquid and other Heat exchange requirements between multiple fluids. Because of its many advantages above, it is widely used in petroleum, chemical industry, shipbuilding, metallurgy, aerospace and other fields.

In the structural units of plate-fin heat exchangers that have been widely used in enterprises, the fin structure still adopts the traditional straight fin, perforated fin, zigzag fin and other structures, and the plate-fin heat exchanger with traditional fin structure is adopted. Heat exchangers have certain disadvantages, mainly reflected in:

(1) In the traditional fin of plate-fin heat exchanger, the fluid flow velocity is too fast, the turbulence effect of the fluid in the flow channel is not obvious, the thermal boundary layer of the fluid cannot be fully destroyed, and the heat of the fluid cannot be exchanged well.

(2) In the plate-fin heat exchanger with traditional fin structure, as the key part of heat exchange, the heat conduction of the partition can only realize the exchange of heat between different layers. The transfer and exchange of fluid heat in the channel is mainly carried out through the heat conduction of the fins, and the heat exchange effect of this method is not as good as that of direct fluid contact.

(3) During the structural design of plate-fin heat exchangers, it is usually assumed that the temperature of the fluid in the same layer of the fins is evenly distributed. There is bound to be a gap in the temperature distribution of the fluid in the inner fluid, so it is unreasonable to assume that the temperature of the fluid in each flow channel is evenly distributed.

(4) The traditional fins of plate-fin heat exchangers are easy to block, and difficult to clean and overhaul. Usually, they can only be used in clean media, not easy to scale, not easy to deposit, and not suitable for clogging.

Contents of the invention

The purpose of the present invention is to provide a plate-fin type branch structure heat exchange device with enhanced heat transfer, which overcomes the inability to completely exchange heat caused by the excessively fast fluid flow in the existing fin structure. The heat exchange effect between fluids in different flow channels is not good.

The technical scheme adopted in the present invention is:

The invention includes two heads, partitions, deflectors and fins, the fluid enters from one side of the deflector, and the fluid flows out from the other side after being heat-exchanged by the fins; it is characterized in that the fins are tree Branch fins, branch fins are composed of a trunk part and a branch part, a branch fin contains at least two branches, and the branches are evenly distributed on both sides of the trunk, and the branches are located on both sides of the trunk along the direction of fluid flow. The sides are staggered, the opening direction of the branch fins is consistent with the flow direction of the fluid, and the opening angle ranges from 10° to 30°.

The shape of the branch is a rectangle.

The beneficial effects that the present invention has are:

1) The fin structure of the tree-branch type plate-fin heat exchanger solves the problem of fluid temperature inhomogeneity in different flow channels of the heat exchanger;

2) Increase the turbulence performance of the fluid in the heat exchanger, destroy the thermal boundary layer of the fluid, and change the flow direction of the fluid in different flow channels to improve the heat exchange efficiency.

3) The branch-shaped fin structure of the plate-fin heat exchanger destroys the thermal boundary layer of the fluid and enhances the heat transfer effect of the heat exchanger.

The invention can be used in an enhanced heat transfer environment with limited heat exchange space but higher requirements on heat exchange efficiency.

Description of drawings

Fig. 1 is a structural unit diagram of a plate-fin type tree-branch structure heat exchange device for enhancing heat transfer in the present invention.

Fig. 2 is a three-dimensional structure diagram of the straight fins of a traditional plate-fin heat exchanger.

Fig. 3 is a three-dimensional structure diagram of a branch-shaped fin of the present invention.

Fig. 4 is a three-view view of the branch part in the single-row branch-shaped fin structure of the present invention.

Fig. 5 is a schematic diagram of fluid flow in the present invention.

In the figure: 1. clapboard, 2. branch-shaped fin, 3. head, 4. deflector, 5. trunk, 6. branch.

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

As shown in Fig. 1 and Fig. 3, the present invention includes two heads 3, partitions 1, guide fins 4 and fins, the fluid enters from the guide fins 4 on one side, and the fluid flows from the other side after heat exchange through the fins. side outflow; the fins are branch-shaped fins 2, the branch-shaped fins 2 are composed of the trunk 5 and the branch 6, the branch-shaped fins contain at least two branches, and the branches are evenly distributed on the trunk 3 On both sides, the branches 6 are alternately arranged on both sides of the trunk along the fluid flow direction, the opening direction of the branch fins is consistent with the fluid flow direction, and the opening angle ranges from 10° to 30°. The shape of the branch is a rectangle. The function of the backbone structure of the fin is to ensure the direction of fluid flow, and the main function of the bifurcation structure of the fin is to promote a slight change in the flow direction of the fluid at the bifurcation, destroy the fluid thermal boundary layer, and increase the fluid turbulence performance at the bifurcation. The opening direction of the bifurcation structure on the branch-shaped fin is consistent with the flow direction of the fluid, and the bifurcation opening direction is alternately distributed along both sides of the main structure of the fin.

Among them, the branch-shaped fins, as the most important heat exchange structure, play a very important role in the heat exchange of the fluid. The bifurcation structures punched out are evenly arranged on both sides of the branch-shaped fin structure, and the bifurcation structures punched out on adjacent fins have the same form. The opening direction of the bifurcation structure is consistent with the flow direction of the fluid, ensuring that the change of the fluid flow state occurs on a two-dimensional plane along the flow direction, and at the same time changing the flow direction of the fluid, so that the fluid in different channels of the same fin structure passes through the bifurcation The opening structure is in direct contact to realize the direct transfer of heat.

Figure 2 shows the traditional straight fins. It can be seen from Figure 2 that the traditional straight fins do not have any bifurcated structure, which cannot destroy the thermal boundary layer of the fluid, and the heat transfer effect of the fluid is low. . The fluid flows along the flow channel, and the heat transfer direction is perpendicular to the flow direction of the fluid, and the heat exchange is mainly realized through fins and partitions. In the traditional flat fin structure, the fluids in different flow channels do not directly contact each other. Due to the difference in the flow velocity and flow rate of the fluid in each flow channel, the temperature distribution of the fluid in different flow channels in the same layer of the heat exchanger is uneven. cause inaccurate calculation results.

Aiming at the problems in Fig. 2, a tree-branched heat exchange fin is designed. The fin structure is shown in Fig. 3. The fluid enters the diversion area from the inlet of the heat exchanger, is redistributed by the diversion area, and reaches the heat exchanger. The hot section performs heat exchange. The branch-shaped fins are mainly distributed in the heat exchange section. When the fluid flows in each flow channel of the heat exchange section, the enhanced heat transfer effect of the branch-shaped fin structure increases the turbulence of the fluid and improves the heat transfer. efficiency.

The bifurcated structure of the fin structure in the present invention can be completed by punching the backbone structure. The bifurcated structure formed after punching not only ensures that the fins destroy the thermal boundary layer of the fluid and increases the turbulence performance of the fluid, but also improves the The temperature distribution of the fluid in different flow channels of the heat exchanger.

The fin structure features of the plate-fin heat exchanger of the present invention are as follows:

The bifurcated structures on the fins are alternately distributed along the flow direction of the fluid on both sides of the backbone structure of the fins.

翅片结构上分叉开口角度θ的范围

如果忽略冲压过程中翅片厚度变化带来的计算误差，则有： $S\∈\[N\sqrt{(L^2-H^2)}+M(N-1),\∞\].$ The length S of the flow channel in the fin, the number of bifurcated structures N in the flow channel along the fluid flow direction, the distance between the bifurcated structures M, the length L of the bifurcated structures, and the value range of the channel width W [0.8mm, 1.2mm], The value range of fin thickness T [0.1mm, 0.2mm], the range of bifurcation structure height H

The range of bifurcation opening angle θ on the fin structure

If the calculation error caused by the change of fin thickness during the stamping process is ignored, then: $S\∈\[N\sqrt{(L^2-h^2)}+m(N-1),\∞\].$

The branch-shaped fin-plate-fin heat exchanger unit is composed of at least two cross-arranged bifurcated structures.

The tree-branched fins are mainly based on the traditional straight fin structure by punching the fins laterally, and then bending the whole. Since the branch-shaped fin structures are distributed on the lateral fins, the punch needs to be milled before bending the whole body, and the size and shape of the milling slots depend on the opening of the branch-shaped fin structures. The fin unit formed after lateral punching contains the bifurcation structure of the fin. The front view, left view and top view of the new fin structure unit formed after punching are shown in Figure 4-a), Figure 4-b), Figure 4-c). The opening directions of the bifurcations on the lateral fin structures are alternately distributed on both sides of the fins, and the distribution of the bifurcation structures on adjacent lateral fins is the same.

As shown in Figure 5, in the X-Y plane, in the traditional fin structure, the fluid flows in one direction in the channel without turbulence. Compared with the traditional fin structure, the fluid in the channel in the branch fin structure The turbulent flow depends on the flow velocity of the fluid, the structural parameters such as the height of the bifurcation structure and the length of the bifurcation. In addition, the branch-shaped fin structure can realize the adjustment of the temperature of the fluid in different flow channels inside the same fin structure of the heat exchanger.

The main part of the branch-shaped fin structure is still made of bent thin aluminum plate, which is similar to the traditional fin production process. After the main body of the fin is completed, the bent fin is then punched laterally. The processing of the fin is simple and convenient. Convenient welding and high heat transfer efficiency, it is suitable for various plate-fin heat exchangers that need heat transfer enhancement.

The plate-fin heat exchanger composed of tree-branch fins has basically the same arrangement of internal fins as the traditional fins. Tree-branch fins are placed between two parallel partitions. The seal structure is set at the place, and the units are welded firmly by vacuum brazing, and finally a complete heat exchanger unit is obtained. By combining different unit bodies, a heat exchanger plate bundle is obtained, and several plate bundles are welded together to obtain a new type of heat exchanger unit composed of a tree-branched fin structure. enhanced heat transfer effect.

The research of the invention solves the problem of enhanced heat transfer of the plate-fin heat exchanger, and realizes the enhanced heat transfer effect of the fluid in the heat exchanger.

Claims (2)

1. the plate-fin crotch structure heat-exchanger rig of an augmentation of heat transfer comprises two end sockets, dividing plate, flow deflector and fins, and fluid enters from a side flow deflector, and fluid flows out from opposite side after the fin heat exchange; It is characterized in that: described fin is the fork type fin, the fork type fin partly is made up of trunk portion and crotch, the fork type fin comprises 2 crotches at least, crotch is evenly distributed on the two sides of trunk, crotch longshore current body flow direction is staggered in the trunk both sides, the opening direction of fork type fin is consistent with the flow direction of fluid, and the opening angle scope is 10 °～30 °.

2. the plate-fin crotch structure heat-exchanger rig of a kind of augmentation of heat transfer according to claim 1, it is characterized in that: described crotch is shaped as rectangle.

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