溪洛渡电站东电机组补气阀技术改造方案研究

Study on technological transformation of air-admission valve of hydro-generating unit made by Dongfang Electric Machinery Co.,ltd in Xiluodu Hydropower Station

溪洛渡水电站东电机组采用主轴中心自然补气装置,补气阀安装于发电机顶部,安装高程低于尾水位,若补气阀出现漏水现象,量小会影响到机组绝缘效果,量大则会导致水淹机组,严重威胁到机组安全,为此,必须对不能完全关闭的补气阀实施技术改造。通过更换阀盘与减振器,使补气阀实现了缓开缓关,由于补气量充足,保证了机组安全、稳定运行,且再无漏水现象出现;在补气阀回装过程中,由于传统的盘车定位方法工序复杂、费时费力,因此提出了无销钉定位的回装补气阀方法。实践证明,该方法简单、可靠,可以显著地缩短检修工期。

Natural air admission device is employed in the turbine shaft of the generating-unit made by Dongfang Electric Machinery Co.,Ltd in Xiluodu Hydropower Station and the air-admission valve is installed on the top of the generator at an elevation lower than the tail water level.If water leakage occurs to the valve,insulation of the generating unit may be impaired by a small amount of leakage and the whole unit may even be submerged and endangered when the leakage reaches a certain amount.Therefore it is highly necessary to transform the air-admission valve which cannot be closed tightly.By replacing the original valve disc and vibration damper,the valve can be opened and closed slowly and sufficient air can be admitted to the shaft,which ensures the safe and stable operation of the unit as well as prevents it from water leakage.According to the re-installation of the valve,a positioning method without pins is proposed because the traditional positioning method through turning gear is complicated and time-consuming.The practice proves that the proposed method is reliable and handy to significantly shorten the overhaul duration.