Simulation of Turbulent Combustion in a Large Pulverized Coal Boiler Based on Turbulent Radiation Interaction and the Modified Soot Model.

Abstract

A combustion heat transfer model suitable for engineering combustion simulation was developed. Using the model, pulverized coal combustion and the soot generation process were simulated in a 300 MW tangentially fired pulverized coal furnace. Here, we proposed a soot evolution model which includes the nucleation, growth, agglomeration, and oxidation processes in the pulverized coal combustion process based on the population balance method. In the process of heat transfer, the absorption coefficient is refined by considering the coal particles and soot radiation. Furthermore, turbulent radiation interaction (TRI) was introduced to the combustion model. Then, pulverized coal combustion and soot and NOX generation processes in a 300 MW tangentially fired pulverized coal furnace under different loads were studied. The results show that the simulated temperature field considering the effect of TRI is lower than that without TRI, and the simulation results considering the effect of TRI are closer to results from the field test. The error between the simulation results and the field tests is within 0.56%. The soot fraction is negatively correlated with temperature. The higher the temperature, the smaller the soot fraction. Taking into account the impact of TRI, the predicted soot production increased.