Numerical simulation of the modification of burners for a 200 MW tangentially fired boiler to reduce NO_x emissions

To address such problems as comparatively high NO_x emissions and serious slagging in the 200 MW tangentially fired boiler of a power plant in China, a study has been conducted of the in-furnace combustion process before and after burner modification by using a CFD (computational fluid dynamics) software platform and numerical simulation method. The calculation results show that due to the effect of attached wall jet flow, high-temperature zones are concentrated in the central part of the furnace, effectively preventing boiler slagging. After modification, the furnace had a reducing atmosphere zone even greater than that of a boiler adopting conventional combustion modes, thus suppressing the generation of NO_x emissions and reducing them by 34.6%. The calculation results after the modification correspond quite well with those of test ones. The numerical simulation can well provide a theoretical basis for the design, modification and operation of the boiler in question.