LOW-NITROGEN OXIDE STRAIGHT-THROUGH PULVERIZED COAL COMBUSTION APPARATUS APPLICABLE TO LEAN COAL-FIRED BOILER

摘要

A low-nitrogen oxide straight-through pulverized coal combustion apparatus applicable to a lean coal-fired boiler comprises main combustor groups that are disposed in corner-tangential combustion manner at the four corners of a furnace of the lean coal-fired boiler, cooperate with a water-cooling wall anti-high temperature anti-corrosion system of the furnace, and are of the same structure with the system, each main combustor group comprising pulverized coal combustors and secondary air nozzles (AA, AB, BC, CC, DD, DE, EF, FF1, and FF2) that are disposed at a spacing. The upper portion of each main combustor group is provided with a corresponding over fire air separation group. A layer of a prechamber reverse-flow combustor is disposed every n layers of pulverized coal combustors, a jet flow rotation direction of the main combustor group is the anticlockwise direction, a jet flow rotation direction at the secondary air nozzle closely neighboring to the upper portion of the prechamber reverse-flow combustor is the clockwise direction, and the diameter of the imaginary tangential circle is greater than that of the main combustor. The over fire air separation group is formed by an upper group and a lower group, the jet flow of the lower group is a large imaginary tangential circle, and the upper group is in an opposed firing manner. The combustion apparatus can implement stable combustion and minimize the discharge of oxynitride.