Abstract: Abstract:The 600MW tangentially pulverized coalfired boiler in a power plant was taken as research object. The numerical simulation method was adopted. Under the rated condition, the influence of the traditional burner arrangement scheme, the separated overfire air (SOFA) nozzle position and SOFA air rate on the NOx emission concentration was analyzed. The speed distribution, the temperature distribution, the components distribution and the NOx concentration distribution in furnace under different schemes were researched emphatically. The computation results show that to adopt the air staged combustion technology can improve the temperature distribution and the components distribution in furnace, the fullness of air flow in furnace is also improved. The rational arrangement of OFA is useful for reducing NOx emission concentration effectively.

Key words: Keywords:pulverized coalfired boiler, air staged combustion, corner tangential, NOx emission, numerical simulation