Elliptical tube-and-fin heat exchanger with streamlined variable-amplitude sine/cosine corrugated fins

Abstract

Disclosed is a streamline variable-amplitude sine-cosine corrugated fin for an elliptical tube and fin heat exchanger. According to the requirements for expanding the surface of a fin and guiding flowing of fluid, from an air inlet to an air outlet, complete streamline convex corrugations 4 and concave corrugations 5, each which has a sine-cosine cross section, are made on the fin by stamping; a line of same trough and peak is a streamline, which allows no reflow to occur to the tail, which the fin 1 corresponds to, of a flat-fin side passage of the tube and fin heat exchanger along the tube axial center section. The longitudinal amplitude of the convex corrugations 4 and that of the concave corrugations 5 change in a moderate waveform 16; the transverse amplitudes change in a moderate waveform 17, including corrugation troughs and peaks. The streamline variable-amplitude sine-cosine corrugated fin has the advantages that flow streamline form of the fluid can be effectively improved, flow resistance is reduced, the surface convex / concave corrugations of the fin allow large fin surface area, heat transfer resistance is reduced, and heat exchange capability of the fin is improved.

Description

technical field [0001] The invention relates to an elliptical tube-fin heat exchanger fin, in particular to a streamline variable-amplitude positive / cosine corrugated fin of the elliptical tube-fin heat exchanger. Background technique [0002] The elliptical tube-fin heat exchanger generally flows liquid working medium inside the tube and air flows outside the tube. The heat transfer coefficient of the air side of the tube-fin heat exchanger is much smaller than that of the liquid working medium side, so reducing the thermal resistance of the air side is very important to improve the overall heat transfer performance of the heat exchanger. The heat transfer performance of the heat exchanger can be improved by increasing the heat transfer area of ​​the fins and strengthening the air flow turbulence on the air side. Therefore, reinforced fins of various shapes, such as louvers, slots, transverse corrugations, vortex generators, etc., are more and more widely used in oval tube...

AI Technical Summary

Problems solved by technology

[0003] Elliptical tube-and-fin heat exchangers have certain streamline characteristics compared with circular tubes due to their tube geometry, but when the tube size becomes larger or the flow rate increases, its streamlines become worse, and the flow of the fluid passing through the elliptical tube The detachment causes a large flow pressure loss, and forms a recirculation zone at the end of the oval tube that is not conducive to heat transfer

Existing fins do not improve fluid flow through the fin side

Therefore, the heat transfer performance of the fin surface of the elliptical tube-fin heat exchanger needs to be further improved.

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