NHR200-Ⅱ燃料组件定位格架简化建模方法研究  

Simplified Modelling Method for Spacer Grid of NHR200-Ⅱ Fuel Assembly

作　　者：王淅铖 王鼎渠[1,2] 蒋跃元[1,2] 李松阳[1,2] Wang Xicheng;Wang Dingqu;Jiang Yueyuan;Li Songyang(Institute of Nuclear and New Energy Technology,Tsinghua University,Beijing,100084,China;Key Laboratory of Advanced Reactor Engineering and Safety,Ministry of Education of China,Tsinghua University,Beijing,100084,China)

机构地区：[1]清华大学核能与新能技术研究院,北京100084 [2]清华大学先进反应堆工程与安全教育部重点实验室,北京100084

出　　处：《核动力工程》2021年第4期105-111,共7页Nuclear Power Engineering

摘　　要：提出了一种基于NHR200-Ⅱ供热堆燃料组件定位格架的简化模型。简化建模方法包括2方面:将定位格架上的内刚凸及三弯弹簧用非线性连接器代替;使用梁单元代替实际燃料棒。结合前期关于NHR200-Ⅱ定位格架的研究成果,确定了非线性连接器的刚度,并通过有限元软件建立了燃料组件简化前后的1×2局部子模型,分析了其固有频率与碰撞特性,证明了简化建模方法的有效性。随后,该简化方法被应用于全尺寸的9×9定位格架模型,研究了格架夹持能力对动力学特性的影响,结果表明,该简化方法可以有效地模拟不同夹紧程度下格架的地震谱响应。综上,从有限元建模角度来看,本文提出的基于NHR200-Ⅱ燃料组件定位格架的方法是有效的。A simplified modelling method for the spacer grid of NHR200-Ⅱ fuel assembly is proposed to increase the computational efficiency in the dynamic analysis. It includes the replacement of the grid inside the dimples and three-arc springs with the non-linear connectors, and the replacement of the fuel rods with beam elements. The stiffness of connectors was derived from previous experiments of NHR200-Ⅱ spacer grid. Natural frequency analysis and impact simulation were performed by a 1×2 sub-model of the fuel assembly to verify this method. Then, this simplified method was applied to a full-scale 9×9 spacer grid model, to study the effects of the grid clamping ability on its dynamic characteristics. The results suggest that this simplified approach can give a reasonable response when induced by a seismic load at different clamping levels. In conclusion, from the modelling point of view, the proposed simplified method for NHR200-Ⅱ spacer grid is effective.

关 键 词：低温供热堆 燃料组件 定位格架 简化建模 动力学分析 

分 类 号：TL327[核科学技术—核技术及应用]