Sunflower Oil Fuel For Diesel Engines: An Experimental Investigation And Optimum Engine Setting Evaluation Using A Multi-Criteria Decision Making Approach

An experimental investigation on a diesel engine was conducted to evaluate the performance and exhaust emissions of sunflower oil and three blends with diesel fuel (20, 40, and 70% oil content volumetrically) in comparison to diesel fuel. Three injection timing and three injector protrusion settings were tested to study engine performance and exhaust emissions. The work was conducted in a direct injection agricultural tractor engine. Engine operation with sunflower oil-based fuels was unproblematic during the short-term experiments. Torque, brake-specific fuel consumption and NOx were enhanced as oil content was increased in the tested fuel. Early injection timing improved torque output, reduced BSFC, increased thermal efficiency, and NOx emissions. Deep injector protrusion increased torque release in low oil content fuels and shallow injector protrusion and increased torque in high oil content fuels. The experimental results were evaluated using two multi-criteria decision-making techniques (Analytical Hierarchy Process-AHP and Technique for Order Preference by Similarity to the Ideal Solution-TOPSIS) and the optimal fuel type-injection timing-injector protrusion configuration was selected. AHP and TOPSIS were run for three groups of criteria that were focusing on higher engine performance, lower environmental impact, and a balance between the first two, respectively. The results of the two techniques were compared. AHP and TOPSIS gave the same attribute ranking in all three groups of criteria, but did not give the same classification of Fuel/Injection Timing/Injector Protrusion configuration. The 70% oil content blend was selected from both techniques as optimal in the examined groups of criteria.