Three-dimensional simulation of the pulverized coal combustion inside blast furnace tuyere

A three-dimensional multi-phase model using Eulerian approach has been developed to simulate the coal heat transfer, devolatilization and combustion process inside a blast furnace tuyere. The information including velocity field, temperature distribution and combustion characteristics has been obtained in details and the effect of coal particle diameter, coal type and coal injection angle on the pulverized coal combustion process has been presented. The predicted results show that the coal combustion process inside tuyere are affected by coal particle size, coal type and coal injection angle. For the smaller coal particle diameter, the volatile matter released from the coal more rapidly, this results in a higher coal burnout at the exit of the tuyere. The coal burnout is depended on the coal volatile matter content; a higher coal burnout will be obtained for the coal with a higher volatile matter content. The coal injection angle affects the flow patter inside the tuyere, which results in a different mixing and burning process of the pulverized coal. When the coal diameter changes from 30 μm to 90 μm, the coal burnout decreases from 51.03% to 44.21%; when the coal volatile matter is reduced from 34.32% to 19.95%, the coal burnout decreases from 46.04% to 35.02% and for the coal injection with an angle, the coal burnout is 46.04%, a little bit higher than that of 44.51% without injection angle.