核电厂两台机组耗氢量增加,排查发现供氢站围栏外东南角地面氢气浓度超过测氢仪的量程,初步判断供氢站至两台机组的埋地供氢管线存在泄漏情况。本文通过分析发现,引起缺陷的直接原因是供氢总管埋地法兰因法兰螺栓应力松弛、垫片预紧力下降导致法兰垫片无法密封,产生泄漏;根本原因是供氢总管埋地法兰未曾安排定期预维检查项目。切除埋地法兰,将法兰连接改为管道焊接形式,同时将氢气系统剩余 2 处法兰连接变更为直通管连接,从根本上消除漏氢隐患。并在供氢母管上增加一对隔离法兰和一个隔离阀,以实现供氢站与机组间实体隔离
通过试验方法研究感应加热器的影响参数,以期寻找不同加热螺栓的最优加热器参数;并对非中心处加热的工况进行分析研究,确认加热器的安装范围及对热紧螺栓的温度、轴向应力、伸长量的影响.将优化后的螺栓加热方法运用于现场检修工作并取得良好的效果.
国内某核电厂大修启机阶段汽轮机低—发对轮联箱处出现渗油,渗油量随汽轮机转速的提升而加剧.通过分析得出渗油的原因是低—发轴对轮联箱浮动油封出现变形,下半浮动油封局部间隙过大.修复方案是对浮动油封配合处内外环涂抹密封胶保证密封性能,同时增加对浮动油封的检查预维.该修复方案解决了渗油缺陷,保证了油封的基本功能,避免跑油风险.
秦山核电重水堆生产单元二回路疏水阀为 V 型球气动调节阀,其故障可能影响机组功率甚至引起汽机跳机,文章通过对其主要缺陷形式进行系统性分析,并制定出有针对性的维修策略,可以有效提高检修质量和设备可靠性。
This paper takes the control oil system of Qin No. 3 Plant as the research object, aiming at the characteristics of complex system and high oil quality requirements, by controlling the process parameters and making special tools, the online variable pressure flushing is realized. An innovative method is used to ultrasonically clean emergency trip system offline. After starting the engine, the chemical indicators are all qualified, the MPC is far less than the expected value, and the control valve on the oil engine has been maintained for 2 years without jamming, and the reliability of the equipment is significantly improved. Therefore, this good practice is summarized for the reference of peer power plants.
对某核电厂汽轮机高压缸中分面螺栓建立三维有限元模型,计算高频感应加热过程中螺栓内部温度分布、应力变化和伸长量规律,为优化高频感应加热器的参数和制定规范提供理论支持和参考.