核电厂连通管式水位计测量值偏大的影响因素分析

Influencing factor analysis of measurement deviation for communicating pipe level gauge of a nuclear power plant

国内某核电厂汽水分离再热器系统的连通管式水位计测量值偏大严重,导致测量失效,影响机组运行。针对此问题,参考汽包水位模型建立合理的简化模型,应用流体力学相关理论,对影响偏差的因素进行了分析。通过简化流体流动损失的表达式,得到了水侧连通管流体流动损失与汽侧连通管流体流动损失的相对关系,确定了不同工况下影响测量偏差的主要因素。根据分析结果,提出改进措施,该核电厂采取改进措施后,测量偏差大的问题得到解决。基于分析结果和实践检验,针对核电厂连通管式水位计的测量偏差问题,提出了具有普遍适用性的处理原则,并在国内某EPR核电得到应用。

A reasonable simplified model was established by refering to the drum water level model, the factors affecting the deviation were analyzed by using hydrodynamics theory. By simplifying the expression of fluid flow loss, the relative relationship between the flow loss of water-side communicating pipe and that of steam-side communicating pipe was obtained, and the main factors affecting the measurement deviation under different conditions were determined. Based on the analysis results and practical tests, the improvement was taken, and the problems were solved.