PERFORMANCE AND STRUCTURE OPTIMIZATION OF TORSIONAL FLOW HEAT EXCHANGER WITH ORTHOGONAL DROP-SHAPED TUBE

Abstract

As a novel adaptation of shell-and-tube heat exchanger, the torsional flow heat exchanger holds promising application prospects. Drop-shaped tubes are employed to enhance fluid flow velocity, distribution, and overall heat transfer performance. This study presents a torsional flow heat exchanger featuring orthogonal drop-shaped tubes on the shell side, aiming to combine the advantages of both designs. Three numerical models of torsional flow heat exchangers are established with identical structures but varying axial ratios of the heat transfer tubes. The fluid flow and heat transfer characteristics on the shell side are analyzed numerically. The response surface method is utilized to optimize a shell-side structure. The results show that the torsional flow heat exchangers with orthogonal drop-shaped tubes of three axial ratios show reductions in pressure drop by 9.26-14.49%, increases in heat transfer coefficient by 0.65-11.57%, and improvements in comprehensive performance by 14.18-27.23% within the Reynolds number range from 5000 to 13,000, compared to those with common round tubes. The optimum structure of the torsional flow heat exchanger with orthogonal drop-shaped tubes is predicted using Minitab, resulting in a 17.19% improvement in the heat transfer coefficient and an 18.63% improvement in comprehensive performance. The study provides a reference for the exploration and improvement of torsional flow heat exchangers with enhanced tubes.