Numerical simulation of NO_x, formation in coal combustion with inlet natural gas burning

A full two-fluid model of reacting gas-particle flows and coal combustion is used to simulate coal combustion with and without inlet natural gas added in the inlet. The simulation results for the case without natural gas burning is in fair agreement with the experimental results reported in references. The simulation results of different natural gas adding positions indicate that the natural gas burning can form lean oxygen combustion environment at the combustor inlet region and the NO_x concentration is reduced. The same result can be obtained from chemical equilibrium analysis.