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

In this study, combination of PCC (Plume Ignition and Combustion Concept) combustion, in which plume of fairly rich air-fuel mixture is ignited and burned immediately after completion of injection in the latter half of the compression stroke of the in-cylinder direct injection hydrogen engine proposed by the authors so far, with optimized hydrogen jet configuration such as the direction of the jet flow, diameter of nozzle hole and injection timing and combustion in the lean air-fuel mixture region markedly improved thermal efficiency and reduced NOx emissions at the same time. 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.