Thermodynamic-CFD analysis of waste heat recovery from homogeneous charge compression ignition (HCCI) engine by Recuperative organic Rankine Cycle (RORC): Effect of operational parameters

Beside the percent of fuel, which is burnt to produce power by combustion, the rest of the fuel energy is waste heat that can be recovered. In the present study, a thermodynamic-computational fluid dynamics (CFD) analysis was performed to recover waste heat from the coolant system (water jacket) in a six-cylinder homogeneous charge compression ignition (HCCI) engine by Recuperative organic Rankine cycle (RORC). The CFD simulations were used to estimate the waste heat at different operating conditions and to investigate the effect of the important parameters including intake temperature, intake pressure, equivalence ratio, and engine speed. Thermodynamic study was performed for the RORC, in which the inlet heat in the evaporator of a cycle was calculated based on the CFD analysis, and then the power produced in RORC was obtained. Results indicate that the improvement in thermal performance of the hybrid system in the HCCI engine can be as high as 27.94%. (C) 2020 Elsevier Ltd. All rights reserved.