This work presents a computational investigation of hydrodynamics, coal combustion and NOx emissions in a tangentially fired pulverized coal boiler at different loads (630, 440 and 300 MW; relative loads of 100%, 70% and 48%) to clarify the effect of load change on the furnace processes. A computational fluids dynamics model was established; the flow field, temperature profile, species concentration and NOx emissions were predicted numerically; and the influence of burner tilt angles was evaluated. Simulation results indicate that a decrease in boiler load decreases the gas velocity, attenuates the airflow rotations, and increases the tangent circle size. The high-temperature zone and flame moved toward the side walls. Such behaviors impair air–fuel mixing, heat transfer and steady combustion in the furnace. In terms of species concentrations, a decrease in boiler load increased the O₂ content, decreased the CO content, and decreased the char burnout rates only slightly. A change in boiler load from 630 to 440 and 300 MW increased the NOx emissions from 202 to 234 and 247 mg/m³, respectively. Burner tilt angles are important in coal combustion and NOx emissions. A burner angle of –15° favors heat transfer and low NOx emissions (<185 mg/m³) for the current tangentially fired boiler.

这项工作对不同负载（630、440 和 300 MW；相对负载为 100%、70% 和 48%）的切向燃烧煤粉锅炉中的流体动力学、煤燃烧和 NOx 排放进行了计算研究，以阐明负载的影响改变熔炉工艺。建立了计算流体动力学模型；对流场、温度分布、物种浓度和氮氧化物排放进行了数值预测；并评估了燃烧器倾斜角度的影响。仿真结果表明，锅炉负荷的降低会降低气体速度、减弱气流旋转并增加切圆尺寸。高温区和火焰向侧壁移动。这种行为会损害空气-燃料的混合、传热和炉内的稳定燃烧。在物种浓度方面，₂含量，降低了 CO 含量，并且仅略微降低了烧焦率。锅炉负荷从 630 到 440 和 300 MW 的变化分别使 NOx 排放量从 202 增加到 234 和 247 mg/m ³。燃烧器倾斜角在煤燃烧和 NOx 排放中很重要。–15° 的燃烧器角度有利于当前切向燃烧锅炉的热传递和低 NOx 排放 (<185 mg/m ³ )。