Realization of High Thermal Efficiency Near-zero Emissions and Additional Improved Performance by Optimizing Injected Spray Configuration and Injection Timing in Direct Injection Hydrogen Engines

Abstract

The authors have previously proposed PCC (Plume Ignition and Combustion Concept) combustion, in which a hydrogen fuel is directly injected to the combustion chamber in the latter half of the compression stroke and forms a richer mixture plume. By combusting the mixture plume, both cooling losses and NOx formation are reduced. According to the authors, thermal efficiency was substantially improved, and NOx formation was reduced with PCC combustion by optimizing such characteristics as direction and diameter of the jets in combination with combustion of lean mixture. As a result, hydrogen engine which does not emit any CO2 and particulate matter emissions in principle is worth to be called near-zero emission hydrogen engines in both name and reality.