Effect of ignition timining on performance and emission characteristics of a single cylinder four sroke cycle petrol engine using hydrogen and petrol as alternative fuels

This paper presents the computational investigations carried out on a single cylinder four stroke cycle petrol engine with hydrogen as an alternative fuel. The software named BOOST software from AVL Austria has been used to carry out the investigations. The engine model is created by joining the various elements available in the software in the graphical user interface. The thermodynamic properties are evaluated by applying the first law of thermodynamics to the engine as an open system when valves are open and engine as a closed system when valves are closed. In order to include the effects of gas exchange in the intake and exhaust manifolds when the valves are open, the conservation equations for mass, momentum and energy have been applied. The engine geometry fixes the design parameters. In the operating variables the speed was maintained constant while the ignition timing besides the corresponding air-fuel ratio were varied for both petrol and hydrogen engines to carry out the investigations. The mapping of the engine was done by using conventional petrol as fuel. The investigations were repeated with data for proposed hydrogen engine and its performance and emissions characteristics were studied. Results showed that in comparison with the conventional petrol fuel the power output of the engine was decreased with hydrogen. However the brake specific fuel consumption was lower with hydrogen fuel. The CO and HC emissions were reduced with hydrogen while as there was increase in NOx emissions.

It is concluded that hydrogen can successfully replace petrol as an alternative future fuel in spark ignition engines.