Performance comparison of plate heat exchangers designed using Taguchi method and computational fluid dynamics

Abstract

In this study, thermal and hydraulic performances of cross flow plate heat exchangers, designed using Taguchi method and Computational Fluid Dynamics, in a small capacity (50-200 m(3)/h) air to air heat recovery device were compared. The plate heat exchangers, which are designed to have high flow effectiveness and sensible effectiveness, number of sub-channel, channel height, average air velocity and sheet material variables were determined. The equations for flow effectiveness and recovered thermal power, including variables and second order interactions of variables, were derived by multiple regression analysis for flow effective and thermally effective plate heat exchangers. The performances of 3-dimensional plate heat exchangers using finite volume based ANSYS/Fluent were compared in different volumetric flow rates. The channel height and average air velocity were determined as the most influential variables in the design of plate heat exchanger. It was found that on average 50% more heat was recovered and thermal effectiveness was on average 35% higher in the thermal effective model, while pressure drop was on average 2.5 times less and flow effectiveness was on average 10% higher in the flow effective model When the recovered thermal power at the fresh side and flow effectiveness are evaluated together, the optimum average flow velocities for both models was determined to be range of 1.5-2 m/s (similar to 90 divided by similar to 110 m(3)/h).