The effect of tri-fuel blends on engine characteristics of a direct injection diesel engine with exhaust gas recirculation

Biofuels are the most promising alternative to petro-diesel. In this work, the combined effect of mahua biodiesel and 1-Hexanol is studied on the engine characteristics. The concentration of both 1-Hexanol and mahua biodiesel is varied, 10%, 20%, and 30% each with diesel fuel. Common rail direct injection diesel engine is used in this study. Engine load is varied from 20% to 80% in step of 20%, the speed of the engine is constant throughout the experiment. Biofuel blends showed improved cylinder pressure and mean gas temperature at a higher engine load. At 60% load, 10H10M80D (10% 1-Hexanol/10% mahua biodiesel/80% diesel) showed 3.45% lower thermal efficiency and 6.11% higher fuel consumption compared to diesel. At 60% load, all the biofuel blends showed 50% lower carbon monoxide emission. At 60% load, 10H10M80D showed 33.33% lower hydrocarbon emission and 0.96% higher nitrogen oxide emission compared to baseline readings. The biofuel blends are less sensitive to exhaust gas recirculation (EGR) due to the oxygenated nature of biofuels. With 20% EGR, at 60% load, 10H10M80D showed 39.48% lower nitrogen oxide compared to no EGR. The results of 10H10M80D showed the best performance at all loads.生物燃料是当前最具应用前景的石化柴油替代燃料。本研究针对马胡生物柴油（mahua biodiesel）与1-己醇（1-Hexanol）复配使用对发动机特性的影响展开探究。实验中，1-己醇与马胡生物柴油的掺混比例分别设置为10%、20%、30%，并与石化柴油复配使用。本实验采用共轨直喷式柴油发动机，发动机负荷以20%为步长在20%至80%区间内调节，实验全程发动机转速保持恒定。在较高发动机负荷工况下，生物燃料掺混物的气缸压力与平均燃气温度均有所提升。在60%负荷工况下，相较于纯柴油，10H10M80D（10%1-己醇/10%马胡生物柴油/80%柴油）的热效率降低3.45%，燃油消耗量升高6.11%。在60%负荷工况下，所有生物燃料掺混物的一氧化碳排放量均降低50%。在60%负荷工况下，相较于基准工况数据，10H10M80D的碳氢化合物排放量降低33.33%，氮氧化物排放量升高0.96%。由于生物燃料本身的含氧特性，生物燃料掺混物对排气再循环（EGR）的敏感性更低。在60%负荷工况下，搭载20%排气再循环时，10H10M80D的氮氧化物排放量相较于无排气再循环工况降低39.48%。10H10M80D的实验结果显示，其在所有负荷工况下均具备最优性能。