Abstract: A method for decreasing nitrogen oxides of a pulverized coal boiler using burners of internal combustion type including during the operation of the boiler, ignition sources in the burners of internal combustion type mounted on side walls of the boiler are always in a working state, and igniting the pulverized coal in the burners in advance; decreasing secondary air amount in a primary combustion zone of the boiler so that the primary combustion zone is in a relatively strong reducing atmosphere and an oxygen-deficient condition for inhibiting generation of NOx is created; and supplying remaining air from an upper part of a furnace of the boiler in a form of over-fire air, so that a deep air staging is carried out in the total furnace. Thus, the NOx generation of combustion can be effectively controlled on the premise of not decreasing efficiency of the boiler.

Abstract: A pulverized coal burner and a pulverized coal boiler. The coal burner comprises a primary air cylinder (111) and a pulverized coal concentration device (112). The coal concentration device (112) makes the concentration of the coal flow gradually decrease from inside to outside along the radial direction, with respect to an axis (100) of the primary air cylinder (111). The coal burner further comprises a coal separating cylinder (113) and a coal guiding cylinder (114) located downstream of the device (112), the rear end of the cylinder (113) is connected with the front end of the coal guiding cylinder (114). The outlet of the cylinder (114) has a conical expansion portion (1141). The coal burner further comprises a divergent nozzle (115) connected with the rear end of the primary air cylinder (111) and whose cross-sectional area gradually increases along the flow direction of the coal flow.

Abstract: A pulverized coal burner and a pulverized coal boiler. The coal burner comprises a primary air cylinder (111) and a pulverized coal concentration device (112). The coal concentration device (112) makes the concentration of the coal flow gradually decrease from inside to outside along the radial direction, with respect to an axis (100) of the primary air cylinder (111). The coal burner further comprises a coal separating cylinder (113) and a coal guiding cylinder (114) located downstream of the device (112), the rear end of the cylinder (113) is connected with the front end of the coal guiding cylinder (114). The outlet of the cylinder (114) has a conical expansion portion (1141). The coal burner further comprises a divergent nozzle (115) connected with the rear end of the primary air cylinder (111) and whose cross-sectional area gradually increases along the flow direction of the coal flow.

Abstract: A method for decreasing nitrogen oxides of a pulverized coal boiler using burners (2) of internal combustion type comprising: designing or changing all or part of burners of the pulverized coal boiler as internal combustion type burners (2), in which the ignition sources may be plasma generators (1) or ignition devices such as small oil guns etc., and the power thereof can be adjusted for controlling the ignition intensity in the burners (2). The burners (2) are interiorly divided into several stage combustion chambers (5) and are provided with pulverized coal concentrators (4) which do deep fuel staging in the burners (2).

Abstract: A plasma ignition burner. The plasma ignition burner has at least two stages of burner barrels and a plasma generator for igniting the pulverized coal in a first stage burner barrel of the at least two stages of burner barrels. The burning flame of the former stage burner barrel ignites the pulverized coal in the next stage burner barrel, or further burns with the supplemented air in the next stage burner barrel. The axial direction of said plasma generator is parallel to the direction along which the pulverized-coal-contained air flow enters into the first stage burner barrel and at the same time, parallel to the axis of the burner barrels.