Experimental Study on Evaporation Characteristics of Light Cycle Oil Droplet under Various Ambient Conditions

The
authors conducted droplet evaporation experiments of light
cycle oil (LCO) at various ambient temperatures and pressures. Five
kinds of LCO and three kinds of arranged fuels were used. We investigated
the evaporation characteristics of LCO and the relationships between
the evaporation characteristics and the cetane index. In addition
to that, a surrogate fuel composed of four chemical species, which
can simulate the droplet evaporation characteristics of LCO, was suggested.
Experimental results show that the differences in droplet lifetime
between fuel species become larger with decreasing ambient temperature.
This is because the low volatile component made the evaporation rate
outstandingly slow at a low ambient temperature. It was found that
the relationship between droplet lifetime and the late-stage distillation
temperature becomes stronger at low ambient temperature and high ambient
pressure. By an analysis employing the properties of chemical species
in LCO surrogate fuel, it is clarified that the mass evaporation rate
becomes smaller than the internal diffusion, which is the condition
similar to that in the distillation test. Finally, the relationship
between the droplet lifetime and the cetane index was investigated.
It can be concluded that the droplet lifetime is independent of the
cetane index under all conditions tested in this study. The experimental
data obtained by this research can be utilized for the validation
of multicomponent fuel droplet evaporation models in the future.