先进核电厂自然对流RELAP5计算能力验证

摘要

第三代核电厂是国际上最新型的核电厂,设计上均加强非能动冷却机制的应用。非能动自然对流冷却技术在AP1000核电厂非能动堆芯冷却系统、非能动安全壳冷却系统以及ESBWR反应堆中均有应用。本文结合热工水力分析程序 RELAP5/MOD3��3,建立自然对流回路模型,利用流体力学推导自然对流计算,同时分别比较验证轻水、氦气以及水的两相流等多种流体的 RELAP5自然对流计算能力。结果分析显示自然对流能力随冷热源高度差以及流体冷热温差的增大而增大；通过与解析结果的比较发现,RELAP5能很好地模拟自然对流现象。在环路流体为单相水和两相水时,RELAP5模拟结果与解析结果基本一致,两种表征参数误差均能控制在5％左右；当环路流体为氦气时,RELAP5模拟误差稍大。%The third-generation nuclear power plant is the latest nuclear power plant, whose application of passive cooling system has been strengthened.Passive natural convection cooling has been typically applied in the passive core cooling system and the passive containment cooling system of AP1000 reactors,and in the ESBWR reactors.Using fluid dynamics formulas and the RELAP5 code, a simple model of natural circulation loop of nuclear reactor has been established to estimate the RELAP5 natural convection calculation capability of light-water,helium and two-phase flow.The results show that the capability of natural convection is strengthened with the increase of the thermal center difference between hot and cold sources and the increases of temperature difference between the hot and cold working fluid.RELAP5 could perform natural convection calculation very well when the fluid is single water or two-phase water,in which,the errors between RELAP5 and analytical results are below 5%.When circulation fluid is helium,the error is larger than the forgoing two kinds of fluid.