摘 要：针对某660 MW超临界墙式切圆燃烧直流煤粉锅炉在30%负荷下无法长时间稳定燃烧的问题，选取多种富氧配风方式对其进行低负荷下富氧燃烧改造的数值模拟研究，对比分析该电厂30%负荷下空气工况及改造后3种富氧配风工况下炉内速度场、温度场和氧浓度场等各项模拟参数。结果表明：在30%负荷下，通过开启不同层一、二次风喷口及在中间层通入富氧二次风的配风方式，使得煤粉燃烧特性得到明显改善，煤粉在炉内停留时间增加，燃烧器浓、淡侧煤粉气流都能及时地着火燃烧，主燃烧器区温度维持在1 750 K以上，较初始工况提高了近200 K，为锅炉低负荷稳定燃烧提供了有利条件，工况三是该墙式切圆锅炉低负荷下较为理想的运行工况。

Abstract: The paper is aimed at the problem that a 660 MW supercritical wall tangentially fired once through pulverized coal boiler cannot burn stably for a long time at 30% load.A variety of oxygen enriched air distribution methods were used to carry out the boiler oxygen enriched combustion transformation under low load.The velocity field,temperature field and oxygen concentration field of 30% load with air and three kinds of oxygen enriched air conditions were compared and analyzed.The results showed that by opening the primary and secondary air nozzles and adding oxygen enriched secondary air,the ignition characteristics of pulverized coal are improved evidently,and the residence time of pulverized coal in the furnace is increased.The rich and lean pulverized coal gas flow can be ignited and burned in time and the main burner temperature can be maintained above 1 750 K,nearly 200 K higher compared to the initial working condition.

TK16

吉林省教育厅“十三五”科学技术研究项目(201680)