中文摘要：

四角切圆的燃烧方式在大型燃煤火电厂锅炉中普遍使用，利用CFD计算方法对某锅炉四角切圆空气动力场进行数值模拟，重点分析在不同一二次风配比情况下的炉膛空气动力场和温度分布。同时，对总风量相同、一二次风配比不同、改变各燃烧器喷口风速这3种不同工况进行了模拟分析。结果表明：所建模型成功捕捉到了四角切圆空气动力场的整体特性，不同的风率和风速会产生火焰对冲或对炉膛产生贴壁冲刷，切圆直径过小或过大，火焰中心高度也会随之发生变化，合适的一二次风配比使空气动力场混合更加均匀，气流更加稳定。

英文摘要：

The tangentially fired combustion was widely used in large coal fired power plant. This paper presents a three-dimensional numerical simulation on aerodynamic field for a full-size tangentially fired boiler base on the compu- tational fluid dynamics method. Attention was focused on the influence of the ratio between the primary air and second air on the furnace velocity and temperature profiles. Four cases with different primary air and second air proportion within same air quantity were conducted and analyzed, depended on changing burner wind speed. Results showed that our model successfully captured the overall characteristics of the aerodynamic field for the tangentially fired, different wind ratios caused bi-direction flame or washing down furnace,tangential circle diameter smaller or larger and differ- ent flame center heights, the reasonable ratio between the primary air and second air made aerodynamic field well- mixed and airflow steadier. This work provides theoretical basis for combustion adjusting