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

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 ⩽ d 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.