核一级三通管热疲劳研究

Study on the thermal fatigue of tee in the first loop of nuclear reactor

钠冷快堆在启动和停止过程中会产生大的热应力,多次循环之后容易产生热疲劳损伤,特别是在三通管连接区域。本文将研究不同角度对三通管热疲劳性能的影响。通过ANSYS计算不同角度三通管道的热应力,确定三通管道的热疲劳寿命和疲劳损伤系数。给出了疲劳许用强度与三通管角度的函数关系。结果表明,随着角度的减小疲劳强度降低。此结果对核一级管道设计中选取三通管道的角度具有一定的参考价值。

Background： Thermal stress will be occurred in the Sodium Cooled Fast Reactor when it starts or stops, after a number of cycles, thermal fatigue damages will be emerged, especially in the connection areas of tees. Purpose： To study the relations between the angles and the fatigue life in tees. Methods： The thermal fatigue life and fatigue damage coefficient of the tees of different angles are computed by the ANSYS software. Results： This paper gives a function charactering the relations between the fatigue allowable intensity and the tee angle. Conclusions： The fatigue strength is reducing with the decreasing of angle, which can provide certain valuable reference for designing tee nuclear reactor.