The invention discloses a W-firing boiler advanced denitration
combustion method. The method comprises the following steps: fire
coal is sent to a
hearth through primary air in the primary air nozzles of a plurality of main combustors on boiler arches of a front wall and a rear wall and is combusted, secondary air and under-arch secondary air are respectively introduced through secondary air nozzles and under-arch secondary air nozzles,
exhaust gas wind is introduced through
exhaust gas wind nozzles on the front wall and the rear wall, one or two
layers of over-fire air are introduced through over-fire air nozzles, the excess air coefficient range of a main
combustion area is 0.7-1.05, and the fire
coal undergoes
low oxygen combustion; the excess air coefficient range of an over-fire area is 1.05-1.3, and
oxygen rich combustion is carried out; and one or more
layers of an amino reduction inhibitor are injected to the
hearth under the uppermost over-fire
air layer to reduce
nitrogen oxides in
flue gas and inhibit generation of new
nitrogen oxides. The W-firing boiler advanced denitration combustion method has the advantages of substantial reduction of the
nitrogen oxide discharge value of the outlet of the
hearth, realization of ultralow
discharge, no strict temperature window or catalyst, great reduction of the denitration cost, and prevention of
high temperature corrosion of water screens in the boiler.