MODELLING OF NO FORMATION IN CNG ENGINE

Abstract

Due to limited resources, high cost and high level of emissions of gasoline engine, there is need of alternative fuels. CNG is one of the most promising fuel alternatives as it is cheaper, largely available and above all environmental friendly. Natural gas engines generally show very low emission of reactive hydrocarbon, carbon monoxide and particulate matter, but NO formation in these engines may be fairly high. This makes study of NO formation important for evaluation of CNG as a replacement of gasoline. A computer program in turbo C++ has been developed to study the effect of fuel-air equivalence ratio (0), percentage exhaust gas recirculation (% EGR), intake manifold temperature (Ti), engine speed and others have been brought out clearly. The model also takes into account, • The variation in mixture composition during compression stroke • The progressive burning of charge during combustion process and consequent rise of pressure and temperature in the engine cylinder • The kinetics of formation of NO at temperatures and pressures, prevalent in the engine cylinder, during combustion and expansion processes.