Study on the NOx release rule along the boiler during pulverized coal combustion

Abstract

Numerical simulation and experimental study on NO_x release along the boiler during pulverized coal combustion have been conducted. With the increase of temperature the NO_x emission increased and the peak value of NO_x release moved forward. But when the temperature increased to a certain degree, NO_x emission began to reduce. NO_x emission increased with the increase of nitrogen content of coal. The peak value of NO_x release moved backwards with the increase of coal rank. NO_x emission increased obviously with the increase of stoichiometric ratio. There existed a critical average diameter of the pulverized coal (d_c). If d"dd_c, NO_x emission reduced with the decrease of pulverized coal size. If d>d_c, NO_x emission reduced with the increase of the pulverized coal size. The results showed that the simulation results are in agreement with the experimental results for concentration distribution of NO_x along the axis of the furnace.