TY - JOUR TI - Performance comparison between hydrogen and gasoline fuelled S.I. engine AU - Negurescu Niculae AU - Pana Constantin AU - Popa Marcel Ginu AU - Cernat Alexandru JN - Thermal Science PY - 2011 VL - 15 IS - 4 SP - 1155 EP - 1164 PT - Article AB - Due to its combustion properties, the hydrogen has a great potential in energetic improvement and emission performance of spark ignition (SI) engine. In this respect, the paper presents comparative results of the experimental researches carried on SI single cylinder engine fuelled with gasoline or only hydrogen, at some engine speeds and full load. Direct injection hydrogen fuelled engine power is greater with almost 30% comparative to gasoline engine due to cycle heat release increasing. The hydrogen direct injection method in the engine cylinder at the beginning of the compression stroke after the intake valve closed has been chosen to avoid reducing the power output per litre. Using this fuelling method was possible to avoid the uncontrolled burning process for all engine operating regimes. Hydrogen supply system used is original and offers great flexibility in operation to establish the adjustments. The obtained results show that the engine fuelled with hydrogen offers the possibility of qualitative load adjustment using for the engine performance improvement especially at partial loads. The paper presents a strategy for combining qualitative and quantitative setting adjustment in order to optimize engine operation at all regimens.