Retrofit and Analysis on Deep Air Staging Low NOx Combustion System of a 600 MW Tangentially-fired Boiler

To study the effect of deep air staging low NOx combustion technology on the pollutant emission, economy and safety of a power plant boiler, based on the deep air staging low NOx combustion retrofit practice for a 600 MW tangentially-fired boiler, the influence of the retrofit on the NOx emission, boiler efficiency, steam temperature and metallic wall temperature was analyzed. Results show that after retrofit, the NOx emission is greatly reduced and the boiler thermal efficiency is increased; however, the boiler steam temperature is increased simultaneously, which leads to the rise of desuperheating water consumption, and to the rise of metallic wall temperature caused by the moving up of heat load, where the tubes of superheater and reheater are easy to be overheated, especially in the load range of 300~600 MW.