核级石墨密封垫片应力补偿机理研究

Study on Stress Compensation Mechanism of Nuclear Graphite Gasket

以核级石墨密封垫片为研究对象,对垫片的压缩回弹性能以及密封性能进行试验研究,并采用ANSYS有限元软件对法兰连接进行仿真模拟,分析垫片在常温及高温工况下的应力分布规律,研究垫片的应力补偿机理。研究结果表明,预紧时石墨环和金属外环同时承受螺栓预紧力作用,金属外环承受多余载荷并在内压升高过程中将载荷释放以起到应力补偿作用,维持垫片应力在一定承载范围内基本不变;高温工况下,压力在一定范围波动,垫片即可维持一稳定的应力状态,从而确认了垫片应力补偿机理的有效性。

Taking the nuclear graphite gasket as the research object,the performance of gasket compression resilience and sealing properties were studied by experiments and the finite element software ANSYS was used to simulate the flange connection. The stress distribution law of gasket at normal temperature and high temperature conditions were analyzed,and the stress compensation mechanism was studied. The results showed that： In the case of preloading,the bolt preloading force was undertaken by the graphite ring and the outer ring of the metal. The excess load was undertaken by the outer ring of the metal and the load is released in the process of internal pressure rise to compensate stress and the gasket stress is basically unchanged in a certain range of load bearing. Under the condition of high temperature,the pressure fluctuate in a certain range,and the gasket is maintained a steady state of stress. The effectiveness of the gasket stress compensation mechanism is confirmed.