关键词: 主轴中心补气系统, 补气阀, 减振器, 技术改造, 溪洛渡电站

Abstract:

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.

Key words: air-admission system of the turbine shaft, air-admission valve, vibration damper, technological transformation, Xiluodu Hydropower Station