Thermal balancing and exergetic performance evaluation of a compression ignition engine fuelled with waste plastic pyrolytic oil and different fuel additives

Abstract

This study aims at evaluating the heat energy and exergy values of waste plastic oil (WPO) blended diesel mixed with different fractions of fuel additives (ethanol as oxygenated fuel additive and nano graphene as nano additive) with a view to establish the thermal balancing of a diesel engine analytically taking experimental data and comparing with neat diesel oil. The research engine used was a four stroke, constant speed, stationary, direct injected, single cylinder, water-cooled compression ignition engine tested at different loading conditions. The thermal balance was prepared in respect of work output, heat loss in cooling, heat loss in exhaust gas, heat loss in lubrication and additional unaccounted heat losses in order to measure the efficiency of the engine in agreement with thermodynamics energy principles. Three test fuels with same plastic oil and different fuel additives concentration (comprising of 80% Diesel+20%WPO, 60% Diesel + 20%WPO+20% Ethanol and 80%Diesel +20% WPO+100 ppm nano graphene) are prepared for the engine test. The addition of ethanol in WPO blended diesel fuel mixture contributes marginal increase in brake thermal efficiency, decrease in brake specific fuel consumption, higher exhaust gas temperature and lower exergetic efficiency as compared to that of diesel. Nano graphene added to WPO blended diesel enhanced its energy along with exergy efficiency values as compared to other fuel mixtures under higher operating load condition. Fuel exergy for this fuel was increased by 18.57% in comparison to diesel at highest load. However, Exergy destruction and exhaust exergy were decreased by 34.97% and 14.03% respectively in comparison to diesel at highest load. Moreover, exergetic efficiency was enhanced by 18.9% than diesel at maximum load condition.