柴油-麻风树生物柴油混合燃油的微爆特性研究

Simulation Investigation of Turbulent Flow Characteristics in Constant Volume Combustion Bomb

为探明柴油-麻风树生物柴油混合燃油的蒸发过程与机理,达到生物柴油与柴油混合用于柴油机缸内稳定燃烧的目的,在723和873 K环境温度下将麻风树生物柴油(JME)和柴油混合,JME所占比例分别为10%、20%和50%(质量分数)。采用热电偶挂滴技术,高速摄像机及Halcon软件代码处理液滴图像,分析柴油-麻风树生物柴油混合燃油(JME10、JME20和JME50)的微爆特性。实验研究得出:不同混合比例的混合燃油与液滴微爆强度大小呈类似于抛物线的函数关系,JME20为最好混合比例的混合油,在此情况下,混合比例的增减都会影响液滴微爆效果,JME20的液滴微爆存在微爆延迟时间最小值,有利于燃油与空气的充分混合。环境温度的提高,对JME10、JME20、JME50的燃油液滴微爆质量的提高均有促进作用,均能缩短蒸发时间。

In order to explore the evaporation process and mechanism of diesel-Jatropha biodiesel hybrid fuel and achieve the purpose of mixing biodiesel and diesel for stable combustion in diesel engine cylinders,Jatropha biodiesel and diesel were mixed at ambient temperatures of 723 and 873 K,and the proportion of Jatropha biodiesel was 10%,20%and 50%,respectively.The micro-explosion characteristics of diesel-Jatropha biodiesel hybrid fuel(JME10,JME20,JME50)were analyzed using thermocouple hanging drop technology,high-speed camera and Halcon software code processes droplet images.It was concluded that the diesel-Jatropha biodiesel with different mixing ratios and the droplet microburst intensity had a function relationship similar to parabola,and JME20 was the best mixing ratio.In this case,the increase or decrease of the mixing ratio would affect the droplet microburst effect,and the droplet microburst under this ratio had a minimum microburst delay time,which was conducive to the full mixing of fuel and air.The increase of ambient temperature can promote the improvement of fuel droplet microburst quality of JME10,JME20 and JME50,and can shorten the evaporation time.