Numerical simulation of thermochemical conversion of a high–ash coal in a low-temperature fluidized bed under pressure

The paper considers a mathematical model, an algorithm, and a program for calculating nonstationary processes of air gasification of a high-ash coal under pressure in a pilot-scale circulating fluidized bed gasifier reactor. The effect of operation parameters on the course of the process is analyzed. It is shown that “hot spots” (short-duration local heatings) can form at various points of the bed, at which maximum temperature can be close or even exceed the fluid slagging point. Possible mechanisms of formation of “hot spots” are analyzed.