Numerical study on reaction-induced force of a coal particle: Effect of temperature gradient in entrained-flow gasifier

The ambient temperature in entrained-flow gasifier varies in the large range, and temperature gradient can reach 60,000 similar to 80,000 K/m in the flame zone. This work numerically studies the effect of temperature gradient on the conversion characteristic and reaction-induced force of a single carbon particle during the gasification process. The single carbon particle is placed in the H2O/CO2 mixture atmosphere with a temperature gradient. The particle size and the average ambient temperature around the particle are considered. The temperature gradient leads to the difference of conversion rate on the particle surface. The net reaction-induced force is formed. The reaction-induced force (F-r) is proportional to d(2) (d is the particle diameter). For small particles (d < 30 mu m), the F-r can reach the same magnitude as the particle gravity. Additionally, F-r increases linearly with the increase of temperature gradient. With the increase of ambient temperature around the particle, the F-r rapidly increases.