混凝土安全壳的LOCA温度场分布与温度内力分析

ANALYSES ON TEMPERATURE FIELD DISTRIBUTION AND INTERNAL FORCE OF CONCRETE CONTAINMENT VESSEL AFTER LOCA

在混凝土安全壳的结构设计中,LOCA事故下的温度效应是不容忽视的问题。由于其温度变化具有较强的瞬时特征,温度场在壳壁内的分布也具有显著的不均匀性,导致其内力计算较为复杂。而我国现行的安全壳设计规范并没有对LOCA温度效应的计算与设计提出具体的方法。该文基于传热学分析方法计算得到了LOCA事故下不同时刻安全壳壳壁内的温度场分布,可作为安全壳进行温度内力分析的基础;基于弹性力学理论,忽略结构底端的约束效应,提出了安全壳结构在LOCA温度作用下的内力简化分析方法;采用有限元软件ANSYS对安全壳结构在LOCA各时刻温度场作用下的应力、位移、内力等进行了详细分析,并与理论分析结果进行了比较,结果表明两者在一定范围内吻合得较好。

The stress due to thermal loads after LOCA is indispensable in the design of concrete containment vessel（CCV）.As the temperature variation is instantaneous,and the temperature field distribution is non-uniform,the internal force calculation is very complicated.Detailed calculation method and design approach have not been proposed in current CCV design code in China.In this paper,based on heat transfer theory,temperature field distribution in CCV walls at different time after LOCA has been calculated,which could provide the basis for temperature-induced internal force analysis;on the basis of shell mechanics,a simplified calculation method of the internal force due to thermal loads after LOCA in CCV structure has been proposed.According to finite element analysis with ANSYS,a detailed analysis of stress,displacement,and internal force of CCV due to thermal loads in each time after LOCA has been performed.A comparison between the theoretical result and the finite element result demonstrates the accuracy of the proposed method.