煤直接、间接液化柴油及其混合燃料液滴的蒸发特性

Droplets Evaporation Characteristics of Diesel from Direct and Indirect Coal Liquefaction and Their Blends

为研究煤直接和间接液化柴油(DDCL、DICL)及其混合燃料液滴在不同环境温度下(500、600和700℃)的蒸发特性,利用基于悬挂法的液滴蒸发试验装置,采用交叉石英丝悬挂液滴,通过燃料设计方法,将DDCL和DICL按29∶21的质量比混合后可获得与柴油理化特性非常相近的燃料.研究显示,DDCL、DICL及其混合燃料液滴蒸发规律与柴油相似,均呈现两阶段蒸发.在600℃以下与经典d^(2)定律(d为液滴直径)存在较大偏差,随环境温度的升高,与d^(2)定律的偏差逐渐缩小.在以上3种环境温度下,混合燃料液滴均表现出的蒸发性能优于柴油,分别比柴油的平均蒸发速率高27.2%、46.3%和19.6%.研究结果为煤液化柴油在柴油机上的应用提供支撑数据.

To study the evaporation characteristics of diesel from direct coal liquefaction(DDCL),diesel from indirect coal liquefaction(DICL),and their blended fuel droplets at different ambient temperatures(500,600 and 700℃),a droplet evaporation test apparatus based on the suspension method was used to suspend droplets using crossed quartz wires,and a fuel with very similar physicochemical properties to diesel was obtained by blending of DDCL and DICL at a mass ratio of 29∶21 by using the fuel design method.It is shown that the evaporation pattern of DDCL,DICL,and their blended fuel droplets is similar to that of diesel fuel,and they all show a two-stage evaporation.The deviation from the classical d^(2)law is large below 600℃,and the deviation from the d^(2)law gradually decreases with the increase of ambient temperature.At all three ambient temperatures,the blended fuel droplets exhibit a better evaporation performance than diesel,with 27.2%,46.3%,and 19.6%higher average evaporation rates than diesel,respectively,providing supporting data for the application of coal liquefied diesel in diesel engines.