Assessment of a direct injection diesel engine fumigated with ethanol/water mixtures

Enhancing the combustion process of today's diesel engines necessitates finding practical methods to reduce harmful emissions, with minor modifications on the main structure of the engine. Dual fuel method has been recognized as an effective way that be able to resolve the emissions problems encountered in diesel engines and attain higher performance. An experimental investigation is performed to explore the effects of using ethanol/water mixtures fumigation into the inlet air on the performance and exhaust emissions of a fully instrumented single cylinder diesel engine. Ethanol/water with different mixing ratios (25%, 50%, 75% and 100% by volume) are used as a secondary fuel with diesel as the main fuel. Fuel consumption, exhaust gas temperatures and exhaust emissions such as nitrogen oxides, carbon monoxide and unburned hydrocarbons are measured and compared for both methods of operation. In addition, thermal and exergy efficiencies are calculated and compared. The results indicated that NO emission tend to decrease with mixtures containing water and tend to slightly increase with pure ethanol fumigation. CO, HC emissions and fuel consumption tend to increase while exhaust gas temperatures tend to decrease with all mixtures of ethanol/water fumigation. Slight improvements in thermal and exergy efficiencies with ethanol/water mixtures fumigation are found. Results confirmed the potential use of ethanol/water fumigation in diesel engines for better energy and exergy efficiencies and lower NO emission.