摘要
为了探明麻疯树生物柴油(JME)燃料的蒸发过程,通过碱性酯交换反应制备了JME,并采用热电偶挂滴技术研究了在673 K和873 K的环境温度下JME单液滴的膨化和蒸发特性,分析了环境温度对JME液滴蒸发过程的影响.结果表明,JME液滴的蒸发过程分为瞬时加热阶段、波动蒸发阶段和平衡蒸发阶段;在 673 K 和873 K下JME液滴的蒸发特性不同,673 K 下液滴的蒸发只存在膨胀过程,没有发生微爆,液滴寿命较长,而873 K下液滴出现了微爆现象,液滴寿命较短;环境温度的升高可以提高JME液滴的蒸发速率,这是因为JME中挥发性成分较多,其挥发后形成气泡,在高温下液滴发生膨化和微爆,这样可以更好地实现空气-燃料混合,提高柴油机的燃烧效率.
Abstract
Jatropha curcas biodiesel(JME)fuel was prepared by an alkaline transesterification reaction.The ex-pansion and evaporation characteristics of JME single droplets at ambient temperatures of 673 K and 873 K were studied using the thermocouple hanging drop technique,and the influence of the ambient temperature on the evapo-ration process of JME droplets was analyzed.The results show that the evaporation of JME droplets is divided into an instantaneous heating stage,a fluctuating evaporation stage and an equilibrium evaporation stage.The evapora-tion characteristics of JME droplets at 673 K and 873 K are significantly different.The evaporation of droplets at 673 K only has an expansion process with no micro-explosion,and the life of the droplets is longer.At 873 K,the droplet undergoes a micro-explosion,and the droplet life is shorter.An increase in ambient temperature increases the evaporation rate of JME droplets because there are many volatile components in JME,which form bubbles after volatilization,and the droplets expand and explode at high temperatures.In this way,better air-fuel mixtures can be obtained and the combustion efficiency of diesel engines can be improved.
基金项目
江苏省研究生创新基金项目(SJCX22_1930)
维普
万方数据