Experimental investigation on the effect of diesel-ethanol blends for a constant-speed diesel engine

Abstract

ABSTRACT Keeping the need for energy security and the world’s transition to a thriving low-carbon economy in mind, the research, on the feasibility of diesel ethanol blends, has gained momentum. The present work is related to comparing the performance and emission characteristics of pure diesel [D100] with 4 diesel-ethanol blends [D90E10, D85E15, D80E20 and D75E25]. The single-cylinder 4-stroke un-modified diesel engine running at constant 1500 rpm was used for experimentation which ran at different loads. Experimental results showed that with the addition of ethanol in blends, the brake thermal efficiency (BTE) and exhaust gas temperature (EGT) reduced while brake-specific fuel consumption (BSFC) increased. The addition of ethanol shortened the combustion duration. Hence, D75E25 showed a rapid rise in combustion pressure and heat release rate (HRR). As the concentration of ethanol increases in blends, the oxide of nitrogen (NOx) is reduced and carbon monoxide and hydrocarbon (HC) are increased. Thus, D75E5 was good blend producing less NOx with the penalty of fuel consumption on an unmodified diesel engine. In the long run, the effect of blends on the engine should be checked to make ethanol a feasible fuel for diesel engines. Abbreviations: CA: Crank Angle; ATDC: After Top Dead Centre; BMEP: Brake Mean Effective Pressure; BSFC: Brake Specific Fuel Consumption; BTE: Brake Thermal Efficiency; BTDC: Before Top Dead Centre; CO: Carbon Monoxide; COV: Coefficient of Variation; D100: 100% Diesel + 0% Ethanol, Pure petroleum diesel; D90E10: 90% Diesel + 10% Ethanol; D85E15: 85% Diesel + 15% Ethanol; D80E20: 80% Diesel + 20% Ethanol; D75E25: 75% Diesel + 25% Ethanol; HC: Hydrocarbon; IMEP: Indicated Mean Effective Pressure; LHV: Lower Heating Value; NOx: Nitric Oxide.