Performance evaluation of metal-foam baffle exhaust heat exchanger for waste heat recovery

In this study, a novel metal-foam baffle cut shell and tube heat exchanger for waste heat recovery system is presented to recover heat in the exhaust gas. A 3D numerical model is established to investigate the thermal-hydraulic performance of the metal-foam baffle heat exchangers. First, the non-baffle shell and tube heat exchangers and traditional metal baffle shell and tube heat exchangers are simulated as reference for comparison. Then, the velocity distribution, temperature distribution and pressure distribution of three different types of heat exchangers are analyzed. Afterwards, the influences of exhaust gas mass flow rate and baffle thickness on pressure drop and heat transfer performance of metal-foam baffle heat exchangers and traditional ones are evaluated. The results show that, compared with traditional metal baffle heat exchangers, all metal-foam baffle exchangers show better comprehensive performance, and the area goodness factor of metal-foam baffle heat exchangers increases by 151.89%−583.62%. Among the given heat exchangers, the metal-foam baffle heat exchanger with selected metal-foam sample (MF 40.9132) is the optimum one for waste heat recovery. © 2020