Thermal performance of diesel engine exhaust heat recovery system using concentric tube heat exchanger inserts with different porous materials

This paper aims to analyse and improve the thermal performance of a concentric tube heat exchanger using porous material inserts. In this method, two different types of porous materials such as cast iron and mild steel were introduced on the outer surface of the inner tube wall of a concentric tube exchanger. The porous particle improves the convective heat transfer coefficient between the tube wall and fluid flow surface. Experimentally, it was found that the inserted porous material enhances the heat exchanger effectiveness by 76% for cast iron and 77% for mild steel. The effect of inserting porous particles on the waste heat recovered from the engine exhaust was also investigated in the present study.