不同工况下非对称导流环对排汽缸气动性能的影响

The Influence of Asymmetric Flow Guide on the Aerodynamic Performanceof Exhaust Cylinder Under Different Working Conditions

以某公司制造的带有非对称导流环的低压排汽缸为主要研究对象,采用标准k-ε模型,对不同蒸汽流量和不同入射角下排汽缸内流场和气动性能进行数值模拟。结果表明:只考虑入口蒸汽沿轴向的流动时,额定流量下排汽缸的气动性能随着蒸汽质量流量的增加而升高,排汽缸最大静压恢复系数达到0.3,当蒸汽质量流量大于100%THA时,气动性能降低明显;考虑蒸汽入射角的影响时,排汽缸气动性能在最大入射角小于20°时变化较为平缓;角度继续增大后,排汽缸气动性能迅速恶化。非对称导流环表面的压力分布受蒸汽入射角影响显著。

The flow field and aerodynamic performance of a low-pressure exhaust cylinder with asymmetric flow guide manufactured by a company were numerically simulated by using the standard k-εmodel.The results show that:when the axial flow of the inlet steam is considered only,the aerodynamic performance of the exhaust cylinder under the rated flow rate increases with the increase of the steam mass flow rate.The maximum static pressure recovery coefficient of the exhaust cylinder reaches 0.3.When the steam mass flow rate is greater than 100%THA,the aerodynamic performance decreases significantly.Considering the influence of steam incidence angle,the aerodynamic performance of exhaust cylinder changes gently when the maximum incidence angle is less than 20°.After the angle continues to increase,the exhaust cylinder's aerodynamic performance deteriorates rapidly.The pressure distribution on the surface of the asymmetric guide ring is significantly affected by the vapor incident angle.