METHOD FOR REDUCING NITROGEN OXIDE EMISSIONS IN A BUBBLING FLUIDIZED BED BOILER AND BUBBLING FLUIDIZED BED BOILER

摘要

The invention relates to a meth- od for reducing nitrogen oxide emissions in a bubbling fluidized bed boiler. The method comprises supplying nitrogen oxide reductant in the boiler furnace at a cer- tain injection level where the tempera- ture in the furnace is such as to enable the nitrogen oxide reductant to reduce nitrogen oxide concentration in the flue gas. Combustion air for volatile matter is supplied into the first combustion zone (I) along with the fuel supply such that part of the combustion air for vola- tile matter is supplied as mixed with the fuel supply and part of the combustion air for volatile matter is supplied as surrounding at least part of the fuel supply. The velocity at which the combus- tion air for volatile matter is supplied is 10 to 25 m/s. The invention further relates to a bubbling fluidized bed and to ause thereof.