Combustion device for tangentially fired boiler and ultralow NOx combustion method employing same

The utility model discloses a combustion device for a tangentially fired boiler and an ultralow NOx combustion method employing same. A high-position burner, a low-position burner and a main burner are arranged on a hearth from top to bottom; the space between the low-position burner and the main burner is H2, the main burner comprises dense-dilute primary air pulverized coal burners and secondary air pulverized coal burners arranged at the upper parts and the lower parts of the dense-dilute primary air pulverized coal burners, wherein the secondary air pulverized coal burners correspond to secondary air nozzles, the dense-dilute primary air pulverized coal burners are bifurcated pipes, light-phase primary air nozzles and dense-phase primary air nozzles are arranged at the front ends of the bifurcated pipes respectively, and middle secondary air nozzles are arranged between the light-phase primary air nozzles and the dense-phase primary air nozzles; and the main burner comprises an upper group of burners and a lower group of burners, and the space between the upper group of burners and the lower group of burners is H1. The characteristic of divided layer blowing in the horizontal direction is reflected, mixing the secondary air is delayed, the purpose of supplying air on the same layer by grading is achieved, mixing O2 is delayed, the production of NOx is inhibited, and the efficiency of the boiler is ensured not to be reduced.