Energy and exergy analyses of a hydrogen fuelled HCCI combustion engine combined with organic Rankine cycle

Current investigation is persuaded for the energy and exergy analyses of a new hydrogen operated homogeneous charge compression ignition (HCCI) engine bottoming with an organic Rankine cycle (ORC). Results of exergy distribution of hydrogen show that around 44.6% of the total input exergy is destroyed due to irreversibilities in the components, 49.4% was available as a useful exergy output, and 6% was exhaust exergy lost to the environment. Significant variations were observed in the energy and exergy efficiencies of a proposed cycle when both percent excess air and ambient temperature are changed. Comparison of the performance of the HCCI engine with and without the integrated system (ORC), show that, the exergy efficiency increased considerably and there is only a marginal increase in energy efficiency of the engine with the bottoming of ORC. Results clearly show that exergy analysis quantitatively visualises losses within a cycle and gives clear trends for optimization.