新型抗磨蚀密封结构的研究

Study on New-style Sealing Structure for Anti-abrasion and cavitation

本文探讨了螺旋密封的设计方法。首次将该密封形式应用于甘肃巴家嘴水电站２＃机Ａ４３０转轮下止漏环的设计中。试验结果表明抗磨蚀效果显著。巴家嘴水电站年均含沙量为１９０ｋｇ／ｍ３，最大含沙量为１２００ｋｇ／ｍ３。在水头Ｈ＝３２ｍ转轮出口相对流速Ｗ＝１７ｍ／ｓ条件下，原转轮在浑水期运行４５天后，转轮上下迷宫环密封全部磨平，效率下降到６５％［１］。而采用螺旋密封形式的Ａ４３０转轮下止漏环经过两年多运行检查未发现磨蚀（图１）。由此可见，这种从尖端技术领域发展来的密封形式将在水轮机密封领域有着广阔的应用前景。

The design method and test results of spiral seal on turbine runner are presented in this paper.it has been frist applied to the runner band seal of A430 runner that was operated on 2# hydraulic turbine of Bajiazui hydropower station Gan Su province.Test results show that the new structure has good effect on anti-abrasion and cavitation.The mean content of sand in water is about 190 kg/m3 and the maximum content is over 1200 kg/m3 in this hydropower station.The operation head is 32m,and the relative velocity of runner outlet is 17m/s.Under above case,the conventional labyrinth sealing structure was rubbed down in 45 days,efficiency is a drop of 65 percent.For A430runner with runner band seal of spiral seal,which has been operating over two years,there were not any evident abration and cavitation.So we can make a conclusion that the spiral seal structure developed from advanced technology field could be widely used on hydraulic turbine.