Effects of Elastic Walls on the Thermal Performance of a Counterflow Heat Exchanger

Abstract

Using elastic plates in combination with counterflow heat exchangers is an innovative aspect of thermal energy storage systems (TES). The incorporation of elastic plates dramatically enhances heat transfer. However, prior studies have yet to thoroughly investigate the effects of exerting force on these elastic plates. The flow and heat transfer in a counterflow plate heat exchanger with elastic parts on the lower and upper plates are numerically investigated in the current study. The study employs fluid–structure interaction (FSI) modeling to account for the elastic behavior of these plates, with external forces applied downward on the upper plate and upward on the lower plate. The analysis focuses on five different heat exchanger configurations, each with elastic plates positioned at varying locations. The results indicate that heat exchangers with elastic plates outperform their rigid counterparts, achieving efficiency improvements ranging from 17% to 140%, with the highest performance observed in configuration B, where the elastic plates are symmetrically placed in the center of the exchanger. Heat transfer rates for this configuration are up to 30% higher than in other designs. Additionally, a tripling of the Reynolds number results in a 47% increase in efficiency for configuration B, while doubling the applied external force increases the heat transfer rate by only 4%. These findings highlight the potential of elastic plate designs to enhance the efficiency of heat exchangers, with promising applications for condensers, evaporators, and boilers.