基于流固耦合的压水堆主管道上充管嘴热疲劳研究

Thermal Fatigue Study of Charging Nozzle in Pressurized-water Reactor Based on Fluid-Solid Interaction Method

采用3-D全尺寸非稳态流固耦合数值分析方法,基于某二代压水堆核电机组实测瞬态工况参数,实现了对瞬态工况下主管道上充管嘴真实温度场和结构场的有效表征,获得了瞬态工况下的疲劳特性。对比基于理想设计工况的传统设计分析方法分析结果,得到结论:采用传统设计分析方法得到的热冲击应力响应更加严苛,疲劳分析结果具备较大的保守裕度,但该方法无法对管嘴不同部位的疲劳严重程度进行有效表征;基于实测瞬态参数的流固耦合计算方法在有效表征管嘴不同区域的疲劳状态的同时,亦有效降低传统设计疲劳分析中过度保守的裕度,为核电站热疲劳敏感区域在役检查工作和运行执照更新提供可靠依据。

Based on the real transient working parameters of a second generation pressurized-water reactor(PWR),the 3D full-scale transient computational fluid-solid interaction(FSI)numerical analysis method was employed to effectively characterize the real thermal field and the stress field of the charging nozzle in PWR,including calculating the thermal fatigue under the transient working condition.Compared with the analysis results caused by traditional design analysis based on ideal design transient working condition showed that,although the thermal shock response by traditional design analysis based on ideal design working condition is more severe and the fatigue analysis results is also more conservative,this method could not effectively characterize the fatigue severity of different parts of the nozzle.The FSI numerical analysis based on the real transient working parameter can effectively reflect the fatigue state in different parts of the nozzle and effectively reduce the excessive conservative margin in the traditional design fatigue analysis,and this provides a reliable basis for the in-service inspection and operation license renewal in the thermal fatigue sensitive areas of nuclear power plants.