CFD analysis of innovative protracted finned counter flow heat exchanger for diesel engine exhaust waste heat recovery

Abstract

This article explores the numerical analysis of innovative heat exchanger to recover the heat energy from the diesel engines exhaust. The theoretical design and computational fluid dynamics(CFD) simulation of the Protracted Finned Counter Flow Heat Exchanger (PFCHE) was conducted in order to obtain an optimized design for fin protrusions. In this investigation, heat exchanger’s geometric parameters such as fin number and protrusions height have been varied and their subsequent effect on thermal effectiveness was compared. The results of various fin configurations were post-processed and compared in order to obtain better heat transfer rate from the exhaust gases. The contours of temperature distribution, pressure distribution and velocity distribution of exhaust gas with heat exchanger fins and inner pipe surfaces are discussed in detail for different cases of heat exchangers. From the numerical simulation, the PFCHE protrusion fin of 30 mm height revealed the maximum heat recovery rate and exhaust gas temperature reduction rate in comparison with the base heat exchanger model without fins. The simulation result also confirms that the PFCHE with 12 fins of 30mm height is the finest configuration to enhances heat recovery from the diesel engine exhaust gas.