旋流角度对燃料掺混特性影响研究

Study on the Effect of Swirl Angle on Fuel Mixing Characteristics

为了研究工业燃气轮机燃烧室旋流器旋流角度对燃料/空气混合均匀度以及NO;排放的影响,针对某型燃烧室的中心分级双级轴向旋流器,应用Fluent软件,选择Realizable k-ε和Species Transport模型,在燃气轮机的设计工况下对不同旋流角度回流区形态、甲烷的体积分数分布、温度场和污染物的排放进行了数值模拟。研究表明:随着内旋流角度从30°增加到50°,燃烧室内流场形成的回流区尺寸有减小的趋势,燃料的分布趋于均匀,主燃区最高温度从2 304 K降低到2 180 K, NO_(x)排放呈先增大后减少的趋势,旋流角度为50°时NO_(x)排放质量浓度为501.045 mg/m;。

In order to study the effect of swirl angle on fuel/air mixing uniformity and NOx emission in industrial gas turbine combustor, the Realizable k-ε,Species Transport models were selected by Fluent software for a centralstage two-stage axial swirler of a combustor.Under the design conditions of the gas turbine, the shape of the recirculation zone, volume fraction of methane, temperature field and pollution emission at different swirl angles were numerically simulated.The results show that with the increase of the internal swirl angle from 30°to 50°,the size of the recirculation zone formed by the flowfield in the combustor tends to decrease, and the fuel distribution tends to be uniform. The maximum temperature in the main combustion zone decreasd from 2 304 K to 2 180 K.The NO_(x)emission increasing at first and then decreasing, and the NO_(x) emission concentration was 501.045 mg/m;at 50° swirl angle.