The invention belongs to the technical field of combustors, and particularly relates to a front and back wall opposed firing
coal-fired boiler
system for mixed
combustion of
ammonia gas, a
combustion area and a
burnout area are sequentially arranged in a boiler from bottom to top, the
combustion area comprises pulverized
coal combustion areas and
ammonia gas combustion areas which are alternately arranged, and the bottommost layer is the pulverized
coal combustion area; the pulverized coal combustion area is a main combustion area, and pulverized coal combustors are arranged on the front wall and the rear wall of the boiler. The
ammonia gas combustion area is a high-temperature micro-aerobic area, ammonia guns are arranged on the front wall and the rear wall of the boiler, and
ammonia gas sprayed into the
ammonia gas combustion area through the ammonia guns is cracked into
nitrogen gas and
hydrogen gas under the high-temperature anoxic condition; the
burnout area is a reduction area, and
burnout air nozzles are arranged on the front wall and the rear wall of the boiler. Compared with the prior art, the invention solves the problem of low ammonia blending combustion ratio in the prior art. According to the scheme, the front wall and the rear wall for mixed combustion of the
ammonia gas are arranged oppositely, so that the combustion reaction is effectively promoted,
NOx emission increase caused by ammonia-doped combustion of the pulverized coal is controlled, and large-proportion mixed combustion of the ammonia gas can be reliably realized.