Computational and experimental investigation on effective utilization of waste heat from diesel engine exhaust using a fin protracted heat exchanger

The present research investigates the energy recovery capability of exhaust gases in Internal Combustion Engines (ICEs) in order to reap low grade waste heat energy. In order to achieve this aim, a double pipe, Protracted Finned Counter flow Heat Exchanger (PFCHE) was designed, analysed, fabricated and experimented with binary (water-ethanol) mixtures as working fluids. In the current work, as a first step, the theoretical design was completed and the computational simulation of PFCHE was executed. From the experimental investigation and analytical results, a positive notion was observed about the overall efficiency of the heat recovery system. It was proved that when the number of fins increased along with its height, then the heat transfer rate also got increased which further resulted in the improved performance of heat recovery system and increased Brake Thermal Efficiency from 32% to 39.6%. The developed heat recovery system was able to produce 0.35 kW-0.76 kW of power when the turbines were made to run at 1700 rpm to 4800 rpm respectively. Overall, the study concludes that the PFCHE increased the working fluid outlet temperature, effectiveness, heat transfer rate as well as the overall Brake Thermal Efficiency when compared with traditional heat exchangers that lack fins. (C) 2020 Elsevier Ltd. All rights reserved.