Emission experiment of intake air humidification of a port fuel injected spark ignition engine

Abstract

In this study, experimental analysis was carried out to investigate the effect of humidified air induction on emissions of a single cylinder, four stroke, air cooled, Royal Enfield Bullet engine 350cc, with modifications made to assist port fuel injection. Tests have been performed on test engine fuelled with gasoline over a range of engine loads and at rated speed for 75 % and 95 % relative humidity with water injection. The outcomes of the experimental analysis reveal that increasing the intake air humidity from 75 % to 95 % decreased the exhaust emissions of NOx, CO, HC and CO2 at 95% rated load of the engine without much or less impact on the thermal brake efficiency.