混流式水轮机导水机构损伤三维数值模拟分析

摘要

为了分析和预测混流式机组导水机构在运行中出现的损伤，结合华能瑞丽江一级水电站机组的设计参数及运行实例，利用CFD软件，采用雷诺时均Navier-Stokes控制方程、S-A湍流模型和SIMPLC算法，对额定运行工况下的混流式机组导水机构进行三维数值模拟，分析导水机构内部流速场、压力场分布情况。数值模拟结果显示，蜗壳引水区流态良好，活动导叶区流态紊乱，出口边存在较大尺度脱流现象，压力分布不均匀，背水面偏心小圆面处出现负压区，存在空化现象，能量损失较为严重。水电站导水机构实际运行情况与数值模拟结果基本吻合，证明了数值模拟方法的有效性。根据导水机构损伤情况提出了相应的修复建议。%Fransic turbine units play a dominant role in hydropower development,and it is still under research in China. Accordinf to the hydro-power station of Ruili River in Myanmar,Fransic turbines of which the installed capacity reach 60MW had been researched. Based on the Reyn-olds-averafed Navier-Stokes equations,the S-A turbulence model and SIMPLEC alforithm,the three-dimensional distributor of Fransic turbine was numerically simulated by CFD software. Flow distribution,pressure field and velocity field which inside the distributor under the rated conditions had been analyzed. The results show that the flow pattern of volute is steady,the pressure distribution is well-distributed,and the loss of water head is small. But in fuide vanes area,the flow pattern disorderrs and nefative pressure exists in the local position. Flow separation,cavitation and vor-ticity led to more enerfy loss. The numerical simulation results and practical operation have been compared and the numerical simulation results afree with the practical operation results,which indicates the accuracy of numerical simulation. Repair suffestions are put forward based on damafe situation of distributor.