Energy and exergy analysis of a hydrogen-fueled HCCI engine

Abstract

Nowadays, engines design technology tends toward less fuel consumption and emission besides higher efficiency. Hydrogen as a clean fuel has been a point of interest for long time, but in recent years due to fossil fuel increasing prices and stringent environmental laws, more considerations have been made. In addition to the challenges of producing and storing hydrogen as a fuel for internal combustion engines, the engine performance should be independently evaluated. Simultaneous investigation of energy and exergy brings better analysis of internal combustion engines performance and helps researchers to propose more efficient ways for engines development. In this work, energy and exergy analysis of a hydrogen-fueled homogeneous charge compression ignition engine has been done to investigate the effects of engine input parameters on its performance. Considered input parameters are engine speed, inlet pressure and temperature, equivalence ratio and exhaust gas recirculation. To achieve this goal, a single-zone thermodynamic model considering detailed chemical kinetics has been employed which is able to estimate engine performance qualitatively. Results show inlet valve closing (IVC) pressure and equivalence ratio have the greatest impact on irreversibility and exergy terms, while engine speed is the least effective parameter on irreversibility production. Both power and irreversibility increase by IVC pressure enhancement, and furthermore IVC temperature increase reduces charge chemical exergy by engine volumetric efficiency decrease.