核电站MSR疏水闪蒸引起的非预期跳机风险分析研究

Analysis and Research on Unexpected Turbine Trip Risk Cause by Drain Water Flash of Steam Water Separation Reheater in Nuclear Power Plant

核电机组在甩负荷工况下,汽水分离再热器开关量高液位触点会因闪蒸而产生虚假信号,存在误触发跳机保护风险.通过深入分析闪蒸原理及跳机逻辑,挖掘潜在的机组非预期跳机风险,并结合设备布置结构、系统运行原理、关联调节阀控制以及跳机保护需求等,提出两种优化改进方案,并对比分析其优缺点,实现既能避免原有的误动风险,又防止引入新的拒动风险.通过高功率平台下的瞬态试验对优化方案进行验证,结果表明,通过本次优化可有效消除潜在的跳机风险,在保护设备本身安全稳定运行的同时,也提高了核电站汽轮发电机组整体运行安全,对其他核电机组瞬态过程中疏水闪蒸风险防范也有很好的借鉴意义.

The high level contactor of the steam water separation reheater has a false signal caused by drain water flash in load shedding condition of the unit.Through the deep analysis of the principle of drain water flash and the logic of turbine trip,the potential risk of unexpected turbine trip is discovered.Combined with the arrangement structure of equipment,the operating principle of the system,the control of the actuated valve and the original intention of the turbine trip protection logic ,two optimization schemes are proposed,and their advantages and disadvantages are compared and analyzed to avoid the additional refuse trip risk in preventing the misoperation risk.In the subsequent high power platform transient test,the assume of the optimization scheme is verified,and the final scheme selection is implemented and its effectiveness is verified.Through the above measures,the potential risks are eliminated,while the safety and stability of the equipment itself is safe and stable,and the overall operation safety of the nuclear power plant steam turbine generator set is also improved.