Theoretical investigation of a ceramic monolith heat exchanger using silicon carbide and aluminium nitride as heat exchanger material

Abstract

Ceramic heat exchangers are preferred in most high temperature applications due to its high temperature stability and corrosion resistance. This work investigated the performance of a ceramic heat exchanger, evaluating the heat transfer and pressure drop theoretically by ϵ-NTU method by using silicon carbide and aluminium nitride as heat exchanger material. The performances of both the heat exchangers are correlated. The heat exchanger of cross flow type considered for this study entails of rectangular ducts for the passage of exhaust gas, a ceramic core, and the air passage through rectangular ducts. The heat exchangers were studied using conventional ϵ-NTU method with numerous Nusselt analogies to characterize the flow in the rectangular duct. The theoretical analyses reveal that, the performance parameters such as overall heat transfer increased by 4.5-5%, effectiveness by 3% and heat transfer rate by 3% using aluminium nitride as the heat exchanger material relative to silicon carbide.