Effect of Silver Nano-Particle Blended Biodiesel and Swirl on the Performance of Diesel Engine Combustion

Abstract

Increased energy requirement in sectors like transportation, power generation and others coupled with depletion of high energy non-renewable energy resources like petroleum products and their harmful tail pipe emissions has led to search for new alternative and renewable energy resources. Different methods have been adopted to reduce tail pipe emissions and these include engine modification, fuel alteration, and exhaust gas treatment. Low emission characteristics and equivalent energy density of biodiesel are useful for replacement for petroleum fuels in internal combustion engines. Recently addition of catalytic reactivity materials like metal and oxide materials to biodiesel and their effect on engine performance has been reported in the literature. Due to their special properties like higher thermal conductivity, chemical and electrical properties enhanced properties of the base fuel diesel/biodiesel when these additives were used has been reported. In the present work both engine modification as well as fuel alteration techniques have been adopted to study their effect on diesel engine performance and emission characteristics. Engine modification involved provision of tangential slots on the piston crown surface. Fuel modification included addition of metal and metal oxide nano-particles to Honge biodiesel called Honge Oil Methyl Ester (HOME) as an alternative fuel for diesel engine applications. Experimental investigations were carried out to determine performance, emission, and combustion characteristics of diesel engine operated on diesel, HOME and HOME-silver nano-particles blended fuels. The biodiesel was prepared from honge oil called Honge Oil Methyl Ester [HOME]. The silver nano-particles were blended with HOME in the mass fractions of 25ppm and 50ppm using a mechanical homogenizer and an ultrasonicator. Subsequently, the stability characteristics of silver nano-particles blended–biodiesel fuels were analyzed under static conditions for their homogeneity. A considerable enhancement in the brake thermal efficiency with substantial reduction in the harmful pollutants from the engine for the nano-additive biodiesel blends was observed. Maximum brake thermal efficiency was obtained for HOME+ 50SILVER with reduced harmful pollutants compared to HOME+25SILVER blends. With swirl intended slots provided on the piston crown surface the performance was further improved using HOME+50SILVER in general and for 6.5mm slot on the combustion chamber in particular.