Performance of a shell and helically coiled tube heat exchanger with variable inclination angle: Experimental study and sensitivity analysis

Abstract

Experimental study and sensitivity analysis on the heat transfer and pressure drop of a shell and helically coiled tube heat exchanger (SHCTHE) are carried out. The inclination angle (ɵ) is varied from the horizontal direction (0°) to vertical direction (90°) by a step of 10° and the coil Dean number (Dec) is varied from 1540 to 3860. The results indicate that the effectiveness of SHCTHE (ε) at the vertical direction is higher than that of the horizontal direction by 26.3% and 23.1% at Dec of 1540 and 3860, respectively. Maintaining the SHCTHE in the vertical direction reduces the coil pressure drop comparing with that of the horizontal one by 11% and 32.7% for Dec of 3800 and 1800, respectively. Changing the direction of SHCTHE from the horizontal to vertical direction enhances the performance evaluation criteria (PEC) by 15.1% and 19.1% for Dec of 3800 and 1800, respectively. The ANOVA statistical analysis shows that the effects of the independent variables such as the coil Dean number and the inclination angle of SHCTHE are significant on both the thermal performance and pressure drop. In addition, using multiple regression analysis, correlations are presented to evaluate Nuc and ΔPc as functions of Decandθ with standard deviations of ±2% and ±6.6%, respectively.