A hydrogen fueled experimental single cylinder engine with cylinder displacement 375 cm3 was tested in steady state operation on an engine test bed. The engine was operated in a low-temperature combustion mode with a lean mixture with the air excess ratio between 2.6 and 3.0. In this way, the engine was able to operate free of irregular combustion phenomena. At the same time, the engine reaches high thermal efficiency. Molar fraction of NOx below 10 ppm was achieved within the whole range of operational points. Low-temperature combustion therefore shows a potential to comply with contemporary as well as future limits of NOx emission without exhaust gas aftertreatment. Specific emission of CO2 even involving the CO2 inflow into the intake air was lowered by 2 to 3 orders of magnitude compared to state-of-the-art automotive diesel engines. Emissions of other gaseous pollutants as well as the emission of particulate matter were negligible.

Mr. Jiri Vavra, Czech Technical University in Prague, Faculty of Mechanical Engineering, CZECH REPUBLIC Mr. Zbyněk Syrovátka, Czech Technical University in Prague, Faculty of Mechanical Engineering, CZECH REPUBLIC Mr. Michal Takáts, Czech Technical University in Prague, Faculty of Mechanical Engineering, CZECH REPUBLIC