Combustion and performance characteristics of a small spark ignition engine fuelled with HCNG

Due to environmental concerns and fossil fuel depletion,large scale researches were carried out involving the use of natural gas in internal combustion engines. natural gas is a clean burning fuel that is available from large domestic natural reserve. when it is used as a fuel in si engines,it reduces emissions to meet euro-iii norms with carburettors and euro-iv norms with manifold injection. countries like india with fewer natural fossil fuel reserves depend heavily on oil imported from middle east asian countries and on the other hand combustion of fossil fuel has negative impact on air quality in urban areas. use of cng as a fuel in internal combustion engines can reduce the intensiveness of these pervasive problems. the performance of cng can further be improved by addition of small percentages of hydrogen to it to overcome the drawbacks like lower energy density of the fuel,drop in engine power and engine out exhaust emissions. when hydrogen is added to cng it is called as hythane or hydrogen enriched compressed natural gas (hcng). this can be considered as a first step towards promotion of hydrogen in automobiles. in this study,the effects of mixing hydrogen with cng on a small air cooled four stroke si engine’s performance,emissions and heat release rate was analyzed. a comparison of performance and emission by running engine separately on gasoline,hydrogen,cng and hcng was done. the results show a significant decrease in hc,co and nox emissions and marginal increase in specific energy consumption when fuelled with hcng. © school of engineering,taylor’s university.