Some Results of Gas Mixture Influence on Combustion Course in Spark Ignition Engine

The presented article deals with the influence of hydrogen blended to a mixture with natural gas and what effect it has on the power and ecological parameters of the engine. The aspect assessed is the impact of the composition of the mixture on the combustion processes in the spark-ignition engine. The experimental measurements have shown that with increasing proportion of hydrogen in the fuel, the power parameters deteriorate because the calorific value of the fuel mixture decreases. The specific fuel consumption decreases with growing proportion of hydrogen due to the decreasing mass fuel consumption. The hydrocarbons and carbon monoxide have a digressive tendency, while nitrogen oxides increase with the proportion of hydrogen due to higher combustion temperatures. The progress of pressure and related data were analysed as indicators of the quality of combustion. The analysis shows that with an increase of the proportion of hydrogen in the fuel, the ignition delay and the total time of the beginning and end of the combustion process become shorter. The maximum cylinder pressure and the maximum pressure rate increase. The proportion of hydrogen in the fuel reduces the coefficient of variation of the maximum pressure and the coefficient of variation of maximum pressure rate increases. These conditions improve the cyclic irregularity of the operation and prolong the overall life of combustion engine.