蒸汽发生器管板疲劳分析中若干影响因素的分析

Analysis on Several Influencing Factors in Fatigue Analysis of Steam Generator Tube Sheet

蒸汽发生器是压水堆核电厂的关键核设备,研究核安全级设备的疲劳特性是保障核电安全的关键所在。蒸汽发生器的管板为排布有密集深孔的大型锻件,其制造难度高,生产周期长。在设备运行期间经历复杂而全面的载荷,针对蒸汽发生器管板,根据ASME B&PV Code III-1-NB要求和规定,进行疲劳分析的多种对比计算。以考察管板组合体应力分布对瞬态条件、材料不连续、孔板应力修正方法和孔桥超差的敏感性,最终确定合理的分析方法,为今后蒸汽发生器结构应力分析提供方法参考,而且更重要的,为处理管板制造过程中经常发生的孔桥超差不符合项提供评定的数据依据和计算的方法。

The Steam Generator is the key equipment of the PWR nuclear power plant,the fatigue behavior study on the nuclear safety grade equipment is pivotal for nuclear safety.We focus on the steam generator tube sheet in this paper,which is a complicated structure and undergoes a variety of load.Some comparative fatigue analysis are performed to find out different influencing factors,including different disposals of reactor coolant system design transients,different treatment of material discontinuity,different stress multipliers for equivalent plate stress,different size of tube hole ligament.The appropriate fatigue method is obtained via the above comparative analyses.Even more importantly,the data basis for assessment is available when a tube hole ligament NRC(Non Conformance Report)is happened during the manufacture of the tube sheet.