Aspects of combustion in diesel engine at hydrogen use-a theoretical approach

Abstract

The use of alternative fuel may be a viable solution in order to ameliorate the engine performance especially in terms of pollutant emissions. Among the alternative fuels that can be use to fuel internal combustion engines hydrogen can be a viable alternative fuel especially due to the advantage of reducing the carbon emission at its use as alternative fuel even for partial substitution of classic fuel. Hydrogen has good combustion properties like higher Lower Heating Value, large inflammability limits, higher combustion speed, which may has a benefic influence on combustion process. The use of hydrogen to diesel engine bring few important issues that must be solved in order to assure the normal engine operation, starting with the fuelling system and engine with the control of the combustion process. The paper presents some results obtained during the theoretical modeling of the in-cylinder process at a diesel engine fuelled with classic fuel and hydrogen. The diesel fuel is energetically substituted by hydrogen in percent’s of 25% and 30%. The influences of hydrogen use on in-cylinder maximum pressure, maximum pressure rise rate, heat release rate, combustion temperature, indicated thermal efficiency and nitrogen oxides and smoke emission levels are shown and analyzed.