【摘要】 为了保证核电系统安全阀的可靠性,在充分考虑阀体与高温高压介质和外部环境间的热交换作用的基础上,建立阀体三维稳态热-结构耦合分析模型,并选择合适的网格密度,采用有限元多物理场方法对阀体进行热-结构耦合分析;在此基础上采用概率有限元分析模块,选择蒙特卡洛模拟方法对阀体进行可靠性分析。结果表明,在工作环境下安全阀阀体的结构可靠度满足要求,但是原阀体的结构可靠度裕量较大;灵敏度分析表明宽度尺寸L是影响阀体内部最大应力的主要参数,在保证一定可靠度前提下通过减小宽度尺寸L改进原阀体的结构设计。考虑到螺纹孔的深度和空间分布,尺寸参数L可减小到290mm,体积减小17.9%,有效提升安全阀技术水平。更多还原

【Abstract】 To ensure the reliability of the safety valve for nuclear power system,a three-dimensional model for steady thermal-structure coupling was developed by considering the heat exchange of valve body with internal medium and environment.Based on the model,the thermal-structure coupling effect of valve body was analyzed by employing the multi-physics field method of the ANSYS software with proper gridding density.Further,the structure reliability analysis of valve body was carried out by using the probabilistic design system of the ANSYS software and Monte-Carlo simulation method.The results show that the structure reliability of the valve body is enough under working circumstance,but the reliability allowance seems too high for reliable operation of the safety valve.Sensitivity of the random variables on maximum stress was also researched.It is shown that the width dimension L of the valve is the most significant variable on reliability and the reliability allowance of body structure can be adjusted by changing the parameter L.The example calculation for a real dimension of safety valve shows that,considering the effects of threaded holes,the valve can work with 100% reliability even though L reduces to 290mm,making the valve volume decrease by 17.9%.更多还原