Numerical Simulation Of NO_x Reduction Of Utility Boiler With Micronized Coal

NOx emission of utility boiler is main source of atmosphere pollution. Micronized coal reburning technology can lower NOx emission effectively.In this paper, the 3# boiler of Yuanbaoshan power plant as an example, NOx emission difference between the cases with and without the micronized coal reburning technology was simulated. It adopts Pdf model. The structured grids were clustered with the zonal approach. It enchances the convergence, and reduces the false difffusion. Simulating results show that Micronized coal reburning technology lowers NOx emission 50 percent comparing with the general combustion. The distributions of furnace temperature, LOI and NOx have been obtained. Analysis indicates that the optimum low NOx emission is when Micronized coal is at a rate corresponding to 15 percent of the total heat input, and excess air coefficient in the reburn zone is 0.905. The simulating results are reference and guidance for the reburning schemes.