The denitrification function of separating over-fired air (SOFA) system in boiler of Taicang Power Plant

the rectifying effect of honrizontal adjustment upon the residual whirling of flue gas in the upper furnace

and the influence of SOFA upon the atmosphere at wall surface in the furnace

as well as upon furnace temperature and boiler efficiency

have been tested and calculated. Results show that the SOFA has certain effect upon decreasing the Nox emission

and rectifying partially the flue gas balance in upper flue duct of the furnace

but in the event of unsuitable opening degree for the air damper

it is easily to result in shortage of oxygen and local high temperature on wall surface in the furnace

thereby leading to problems of slagging and high-temperature corrosion. In case of overlarge SOFA

the carbon content in fly ash and solid uncombustible loss may be increased

and the boiler efficiency may be decreased

therefore

the SOFA should be carefully adjusted.