A numerical study for the effects of sub-channels on combined thermal and hydrodynamic effectiveness in a plate heat exchanger designed for balanced ventilation

Abstract

In this study, the effects of the number of sub-channels on the thermal and hydrodynamic performance of plate heat exchangers (PHEs) designed to be used in balanced ventilation systems have been investigated numerically. In the design of PHEs, Taguchi method was used for 4 different effective factors (average air flow velocity, channel height, number of sub-channels and plate material) in 3 levels. Numerical analyzes of PHE models were performed with a CFD based package program. In Taguchi analysis, 2 and 6 sub-channels PHE models obtained close results (<1%) in terms of the number of sub-channels according to the selected performance parameter (combined thermal and hydrodynamic effectiveness-CTHE). And thus, the changes in recovered thermal power, pressure drop, flow effectiveness and thermal effectiveness in both PHE models were investigated depending on the average air flow velocity. According to the recovered thermal power and CTHE, it was found that the optimal average air flow velocity for both PHE models was 1.5 m/s. It has been determined that 2 sub-channels model is more advantageous in terms of thermal and hydrodynamic performance, weight and production