Exergetic and exergoeconomic analyses of a CI engine fueled with diesel-biodiesel blends containing various metal-oxide nanoparticles

Abstract

Comprehensive exergetic and exergoeconomic analyses of a single-cylinder, four-stroke, naturally aspirated compression ignition (CI) diesel engine were conducted in the present paper. Exergy-based sustainability indicators were also determined in the study. The test engine was fueled with diesel fuel (D100), %90 diesel+10% waste cooking oil methyl ester blend (D90B10), D90B10 with Al2O3 nanoparticle of 100 ppm (D90B10Al2O3), D90B10 with TiO2 nanoparticle of 100 ppm (D90B10TiO2), and D90B10 with SiO2 nanoparticle of 100 ppm (D90B10SiO2) nanofuels, separately. The tests were performed at a constant engine speed of 2000 rpm and at varying engine loads from 2.5 to 10 Nm with an increment of 2.5 Nm. As a result, the exergy efficiencies of the test engine for D90B10 and D90B10Al2O3 were determined to be 25.57% and 28.12%, respectively. The lowest cost flow rate of crankshaft work was found to be 0.4247 US$/h at 2.5 Nm, 0.5154 US$/h at 5 Nm for D90B10Al2O3, and 0.6029 US$/h at 7.5 Nm, 0.7253 US$/h at 10 Nm for D90B10SiO2. At 10 Nm, the highest and lowest sustainability index values were determined to be 1.391 for D90B10Al2O3 and 1.344 for D90B10, respectively. From the perspective of exergy and sustainability, D90B10Al2O3 had the best results. Besides, from the perspective of exergoeconomics, D90B10Al2O3 had the best results at lower engine loads. As a conclusion, it can be said that nanofuels showed better performances compared to neat diesel fuel and diesel-biodiesel blend in the terms of in terms of exergy, exergoeconomics, and sustainability analyzes. Considering all analyses together, it is noticed that Al2O3-doped nanofuel is the best test fuel for this study, and then it is followed by SiO2 and TiO2-doped nanofuels, respectively.