Heat Transfer Rate, Effectiveness, and Pressure Drop Using Taguchi Method

This paper presents a systematic experimental investigation and optimisation of a shell-and-tube heat exchanger (STHE) performance using the Taguchi L9 orthogonal array and Analysis of Variance (ANOVA). Four operating parameters — shell-side flow rate, tube-side flow rate, inlet temperature difference, and baffle spacing — were investigated at three levels each. Response variables include heat transfer rate (Q), heat exchanger effectiveness (ε), and shell-side pressure drop (ΔP_s). Water was used as the working fluid on both sides. Signal-to-Noise ratio analysis identified the optimal parameter combination as shell-side flow rate 8 LPM, tube-side flow rate 12 LPM, inlet temperature difference 40°C, and baffle spacing 80 mm. ANOVA revealed tube-side flow rate as the most significant factor with 38.4 percent contribution to heat transfer rate, followed by inlet temperature difference (29.6 percent) and shell-side flow rate (22.8 percent). The optimal configuration achieved heat exchanger effectiveness ε = 0.784 and heat transfer rate Q = 4.82 kW — improvements of 41.6 percent and 38.2 percent respectively over the base condition. NTU-effectiveness method predictions agreed with experimental results within 7.1 percent. Confirmation experiments validated optimal values within 4.6 percent error.