The enhanced heat transfer characteristics of trapezoidal channel heat exchangers under different inclination angles and fin parameters

Abstract

The study of the heat exchangers in the trapezoidal channels and the rectangular channels were carried out. The trapezoidal channel has smaller friction resistance than the rectangular channel with equal section, and the friction factor (f) decreases gradually with the increase of inclination angle, when β= 25 °, the f is the smallest, which is reduced by nearly 22.6% compared to the rectangular channel with equal cross-section; when , the heat transfer factor (j) and comprehensive heat transfer performance of the trapezoidal channel are greater than those of the rectangular channel with the same section, and when , those increase by 8% and 20%, respectively. The height and length of fins have a significant impact on heat transfer performance, increased by 17.65% and 20.85% respectively; By analyzing the comprehensive performance of the trapezoidal channel, the # 8 structure (Fh=10.5mm, β=5°, Sf=3mm, Lf=45mm, tf=0.3mm) has the optimal performance.