Multiresponse optimization of exhaust thermoelectric generator using Taguchi-based gray relation analysis

The best operating condition of the exhaust thermoelectric generator (ETEG) provides more power output and low-pressure drop (low-PD). So it is required to optimize the operating condition of the ETEG. In the present work, Taguchi's L₁₈(6¹ 3³) orthogonal array was chosen to find the optimal parameters. Analysis of variance was used to determine the percent contribution of the control factors such as engine loads (ELs), different types of heat exchangers (HEs) with and without inserts, water flow rate (WFR), and external load resistance (ELR) on the thermoelectric power output and PD in the HE. The confirmation test was carried out at optimum levels for the regression equations and Taguchi method. Gray relational analysis was performed to find the optimum value of the power output and PD. It is observed that the optimal operating condition is EL₆ HE₁ WFR₃ ELR₂ (EL₆ = 10 kg, HE₁ = G-type test section, WFR₃ = 0.08 kg/s, and ELR₂ = 40 Ω).