Elliptical tube-and-fin heat exchanger with streamlined variable-amplitude parabolic corrugated fins

Abstract

Provided is a streamlined variable amplitude parabolic corrugated fin of an oval tube fin heat exchanger. According to the needs for expanding the surface of the fin and guiding fluid to flow, streamlined convex ripples 4 and streamlined concave ripples 5 are extruded out on the fin from an airflow inlet to an airflow outlet, and the complete cross sections of the convex ripples 4 and the concave ripples 5 are parabolic. The connecting line of the same trough and the connecting line of the same wave peak are streamlines. According to the streamlines, backflow does not happen to a tube tail of a plain fin side channel of the tube fin heat exchanger corresponding to the fin 1 along the tube axial center section. The amplitude of the convex ripples 4 and the concave ripples 5 in the longitudinal direction needs the change of a waveform 14, and the amplitude in the transverse direction needs the change of an envelope ripple trough and peak of a waveform 15. The parabolic streamlined corrugated fin can effectively improve the streamline performance of flowing of fluid, flowing resistance is reduced, the area of the surface of the fin is increased through the convex / concave ripples on the surface of the fin, heat transfer resistance is reduced, and the overall heat exchange capacity of the fin is improved.

Description

technical field [0001] The invention relates to fins of an elliptical tube-and-fin heat exchanger, in particular to a streamlined variable-amplitude parabolic corrugated fin for an elliptical tube-and-fin heat exchanger. Background technique [0002] Tube-fin heat exchangers are widely used. Generally, the liquid working medium flows in the tube, and the gas flows outside the tube. The thermal resistance of the gas side accounts for 70%-90% of the total thermal resistance of this type of heat exchanger, which is the main thermal resistance of the heat transfer link. Reducing the thermal resistance of the air side is very important to improve the overall heat transfer performance of the heat exchanger of. The reinforced fins can increase the heat transfer area of ​​the fins and strengthen the air flow turbulence on the air side, increasing the heat transfer on the air side, thereby improving the heat transfer performance of the heat exchanger. Therefore, enhanced heat exch...

AI Technical Summary

Problems solved by technology

[0003] The elliptical tube-fin heat exchanger has a certain flow linearity compared with the circular tube due to its tube geometry, but when the tube size becomes larger or the flow rate increases, the flow linearity becomes worse, and when the fluid passes through the elliptical tube The detachment of the body 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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