A pulverized coal gasification-combustion technology has exhibited distinct advantages in terms of combustion stabilities and NO_x controlling, but the evolution of solid- and gas-phase N-containing species is not clear during combustion of high temperature gasified fuel. Based on the previous experimental data from a lab-scale atmospheric entrained-flow gasification and combustion system, this work aimed to grasp the combustion characteristics of partially gasified fuel and to develop a NO_x formation model adaptive for this condition. Meanwhile, the influences of secondary air nozzle position/number/velocity at burner and the position of tertiary air along the height of furnace on NO_x formation were numerically predicted. The experimental results could be well described by the developed NO_x formation model after considering the effect of H₂O_(g) onto NH₃ and HCN, but NO concentration within the main combustion zone was overestimated. Increasing the secondary air velocity to 36 m/s could effectively expand the size of high temperature flue gas backflow zone. When the number of secondary air nozzles changing from two to six, the position corresponding to the temperature peak was shortened by about 0.25 m towards the burner. Moreover, the burnout of gasified fuel was more completed and NO concentration at the outlet was decreased to 67.9 ppm.

论文链接：https://authors.elsevier.com/a/1lIqv3PkfmSQ6T