Performance and emission studies on Bio diesel using different combustion chambers in ci engine

Abstract

The fossil fuels are depleting and their prices are going up day by newlineday. Moreover, the environmental issues concerned with the exhaust gases newlineemission by the usage of fossil fuels are also increasing steadily. In this newlinecontext, there has been growing interest on alternative fuels such as biodiesel newlineto provide a suitable diesel oil substitute for internal combustion engines. newlineVarious researchers have shown that biodiesel fuel exhibits physical, newlinechemical and thermodynamic properties which are similar or even better than newlinethat of petroleum based diesel fuel (PBDF). However certain properties such newlineas viscosity, calorific value, density and isothermal compressibility of newlinebiodiesel differ from PBDF. These properties strongly affect injection, airfuel newlinemixing and thereby combustion characteristics of biodiesel in a diesel newlineengine. A number of experimental investigations were carried out on the newlineperformance and emission characteristics of biodiesel fuelled diesel engines, newlinewithout any modification to the engines. These investigations have reported newlinethat, the use of neat biodiesel and its blends in the diesel engine, increased newlinebrake specific fuel consumption, decreased brake thermal efficiency and newlinebrake mean effective pressure compared to PBDF. In addition, increased newlineexhaust emission levels of oxides of nitrogen (NOx) have also been reported. The poor performance of biodiesel operated diesel engine in comparison with newlinePBDF fuelled diesel engine is mainly due to change in fuel properties, engine newlinedesign and operating parameters. Although transesterification reduces newlineviscosity of biodiesel, the viscosity of biodiesel was found to be 60-85% newlinehigher than PBDF. The high viscosity of biodiesel affects injection newlinecharacteristics, particularly atomization of the fuel. Poor atomization, newlineinsufficient in-cylinder air motion and low volatility of biodiesel lead to newlinedifficulty in the air-fuel mixing.