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

Abstract

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 d2 law is large below 600 ℃, and the deviation from the d2 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.

Keywords

• evaporation rate
• droplet lifetime
• diesel from direct coal liquefaction
• diesel from indirect coal liquefaction