Effects of Fuel Injection Angles on Performance of A Two-Stage Coal Gasifier

Numerical simulation of the coal gasification process inside an oxygen-blown, two-stage entrained-flow gasifier are carried out using the commercial CFD solver FLUENT. The 3-D Navier-Stokes equations and seven species transport equations are solved with eddy-breakup combustion model. Simulations are conducted to investigate the effects of coal-slurry injection angles on the performance of a two-stage entrained coal gasifier. The results indicate that the configuration with all injectors positioned horizontally gives the best result. By changing the lower injectors to pointing 30 degrees downward or upward, fuel conversion efficiency is decreased. Altering the upper (second stage) fuel injection directions or eliminating half of the first-stage fuel injectors appears to have an insignificant effect on the gasifier performance. The overall results indicate that the fuel conversion efficiency can be considerably affected by the flow pattern in the gasifier by about 17% in the studied cases