Abstract：
This study focuses on effectively utilizing the biodiesel extracted from Azolla (third-generation biofuel), which is regarded as a renewable energy source, for fueling diesel engines. Biodiesel is unique due to its increased viscosity and different fatty acid composition, which proved difficult to attain better engine performance with a mechanical type injection system. This study expands on the previous investigation in modifying the fuel system when using Azolla biodiesel by using a common rail fuel injection system with wider injection flexibility. Considering the lack of more engine optimization studies for Azolla biodiesel, a parametric study is conducted by changing the fuel injection pressure in the range between 300 bar and 900 bar for diesel engine fueled by B20 (20% Azolla +80% diesel) blend. The experimental engine study revealed that the physical properties of the fuel adversely affect the in-cylinder combustion, which leads to poor engine performance and higher emissions at lower injection pressure (300 bar) for B20 when compared to diesel. As the injection pressure increases, the fuel atomization and other spray characteristics are enhanced and thereby improve the combustion. The Brake Thermal Efficiency (BTE) for B20 at 900 bar injection pressure is 3% higher than the diesel fuel at 300 bar injection pressure under full load conditions. The HC, CO, and smoke emission in the engine exhaust for B20 at 900 bar injection pressure was reduced by 13.3%, 28.5%, and 12.3%, respectively, when compared to diesel. Overall, this study recommends the operation of Azolla biodiesel blend in diesel at 900 bar fuel injection pressure to attain improved engine characteristics.
摘要：
这项研究的重点是有效利用从Azolla（第三代生物燃料）中提取的生物柴油，它被认为是一种可再生能源，为柴油发动机加油。生物柴油因其粘度增加和不同的脂肪酸组成而独特，事实证明，使用机械式喷射系统很难获得更好的发动机性能。这项研究扩展了先前的研究，即通过使用具有更宽喷射灵活性的共轨燃油喷射系统来使用Azolla生物柴油来修改燃油系统。考虑到Azolla生物柴油缺乏更多的发动机优化研究，通过将B20（20％Azolla80％柴油）混合燃料的柴油发动机的燃油喷射压力在300bar至900bar之间的范围内进行参数研究。发动机实验研究表明，燃料的物理性质会对缸内燃烧产生不利影响，与柴油相比，B20在较低的喷射压力（300bar）下导致发动机性能较差，排放较高。随着注射压力的增加，燃料雾化和其他喷雾特性增强，从而改善燃烧。在满负荷条件下,在900巴喷射压力下B20的制动热效率(BTE)比在300巴喷射压力下的柴油燃料高3%。HC,CO,在900巴喷射压力下，B20的发动机排气中的烟雾排放减少了13.3%，28.5%,12.3%，分别,与柴油相比。总的来说,这项研究建议Azolla生物柴油混合柴油在900bar燃油喷射压力下运行，以改善发动机特性。
