压力容器水位测点信号扰动问题研究

Study on Signal Perturbation Issues of Water Level Measurement Points of Pressure Vessels

反应堆压力容器水位测量结果反映堆芯装水量的变化,用于监测堆芯是否裸露失水,为事故后工况下的一回路热工水力状态提供重要信息。某核电厂热态功能试验期间,一回路首次充水过程及半环路液位运行工况下,出现堆芯上部水位低报警信号频繁跳变问题,干扰机组操纵员对于一回路水位状态的判断。通过对压力容器水位测量原理进行深入研究,并根据水位探测器组件所处热工环境,对水位信号扰动问题作传热分析,确定该问题的根本原因。制定了优化水位测量系统加热电流函数的试验方案。结合实测数据进行分析,论证了优化加热电流方法的可行性,并给出解决方案。鉴于水位测量技术成熟,在仪控领域应用较广,该研究成果可为液位监测系统异常问题的处理提供借鉴。

The reactor pressure vessel water level measurement results reflect the change of core water charge,which is used to monitor whether the core is exposed to water loss and provide important information for the thermal hydraulic status of the one-loop under post-accident conditions.During the thermal function test of a nuclear power plant,the first filling process of the one-loop and the half-circuit level operation,there is a problem that the alarm signal of low water level in the upper part of the core frequently jumped,which disturbs the judgment of the unit operator on the water level status of the one-loop.Through an in-depth study of the pressure vessel water level measurement principle and heat transfer analysis of the water level signal disturbance problem according to the thermal environment in which the water level detector assembly is located,the root cause of the problem is determined.A test program is developed to optimize the heating current function of the water level measurement system.Combined with the measured data for analysis,the feasibility of the optimized heating current method is demonstrated,and a solution is given.Given that the water level measurement technology is mature and widely used in the field of instrumentation and control,the research results can provide reference for the treatment of abnormal problems in the level monitoring system.