Combined type circular pipe pipe-fin heat exchanger

Abstract

The invention discloses a combined type circular pipe pipe-fin heat exchanger, relating to the technical field of heat exchangers. The combined type circular pipe pipe-fin heat exchanger comprises circular pipes arranged along a flow direction of gas and fins sleeved on the circular pipes, wherein the fins are provided with holes used for being sleeved with the circular pipes, a flanging boss is arranged on the edge of each hole, a pair of rectangular small wing plane vortex generators is punched at the rear part of each hole, and an oval convex hull is punched at the front part of the hole. The oval convex hulls have better streamline, and when flowing through the oval convex hulls, a fluid changes a flow direction and flows along the convex hulls, thereby the loss of flow resistance caused by directly and vertically washing the circular pipes with the fluid is reduced. Meanwhile, after the fluid flows through the rectangular vortex generators, secondary flow following a mainstream is generated in the fluid. When a part of the fluid flows through the vortex generators, a fluid channel is formed between each circular pipe and each vortex generator and is led to a recirculation region of the circular pipes, thereby the size of the recirculation region at the downstream of the circular pipes is reduced, the heat exchanging performance between the pipe wall at the downstream of the circular pipes as well as the surface of adjacent fins and the fluid is improved, and the consumption of the mechanical energy in the recirculation region is reduced.

Description

technical field [0001] The invention relates to the technical field of heat exchangers, in particular to a combined circular tube-tube-fin heat exchanger. Background technique [0002] Since the round tube fin heat exchanger has a wide range of uses, it is very important to enhance the heat transfer of the round tube fin heat exchanger. Researchers are committed to enhancing the heat transfer capacity of the tube-fin heat exchanger while reducing the increase in resistance loss as much as possible, that is, reducing the operating cost of the tube-fin heat exchanger. Fins are usually installed on the outside of the tube to increase the heat transfer area and reduce thermal resistance, but the area of ​​the fins cannot be increased indefinitely due to the limitation of economy and fin efficiency. In order to further improve the heat transfer performance of the round tube fin heat exchanger, the fin surface is made into various structures. The vortex generator punched out on ...

AI Technical Summary

Problems solved by technology

However, the area with poor heat transfer capacity on the surface of the fin is the area in contact with the wake area of ​​the circular tube. The flow linearity of the fluid flowing through the circular tube is worse than that of the flat tube, that is, the fluid flows through the front end of the circular tube. Large resistance loss near the stagnation point and when flowing through the wake area of ​​the circular tube

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