Discuss on NOx emission from W-flame boiler

W-flame combustion technology was developed for ignition and burn out of the coals with low volatile. Numerical simulation was carried out for the combustion process of a W-flame boiler in certain 600 MW power station. Using steam temperature inside the waterwall and thermal resistance of the waterwall as the thermal boundary conditions, simulation was completed based on the commercial software platform FLUENT. The results show that the heat flux of the waterwall below furnace arch varies little under different loads, and NO_x formation in W-flame boiler is relative high at various loads. Besides, since the flame center moves upwards in the furnace in practical operation of W-flame boiler, condition opposite to the normal regularity occurs, namely NO_x formation increase with the ratio of the overfire air.