沙角A电厂300MW机组密封油系统改造及效果分析

针对沙角A电厂300MW机组密封油系统存在的油箱油位控制不准、滤网堵塞及压差阀、平衡阀结构不合理、调整精度不高的问题,提出了密封油系统的改造方案:密封油箱补排油系统选用YKF-1型和YKF-2型补排油浮球阀各1台分别装于油箱两侧;空气侧、氢气侧密封油滤网分别改造为独立运行的高精度不锈钢材质双层滤网,并加装三通阀,二者互为备用,并可以在线解列清洗;主压差阀选用密封油自动控制的MYF-2型外部调整溢流式压差阀;汽轮机端、励磁机端平衡阀改造为YPF-1型配重式平衡阀,采用立式垂直安装。改造实施后经试验验证,改造效果良好,有效地解决了原系统中存在的诸多问题。

Sealing Oil System Transformation and Effect Analysis for 300 MW Units of Shajiao A Power Plant

Aiming at dealing with inaccurate control of oil level,filter plugging,unreasonable structure as well as low adjustment accuracy of both differential vacuum valve and balance valve in sealing oil system of 300 MW units in Shajiao A Power Plant,a transformation scheme for the sealing oil system was proposed： one YKF-1 and one YKF-2 oil-feeding/exhausting float valves were selected and installed on either side of the sealing oil tank respectively;the sealing oil filters on air side and hydrogen side were respectively transformed into independent,highly accurate stainless-steel double-layer filters with three-way valves,capable of mutual standby and on-line splitting for cleaning;MYF-2 externally adjusted overflow differential vacuum valve with automatic sealing oil control was chosen as main differential vacuum valve;the balance valves at turbine and exciter ends were converted to vertically installed YPF-1 counterweight balance valves.Transformation effect was fine according to test verification,effectively solving the problems of the original system.