摘要
针对超高压聚乙烯管式反应器超温分解时热冲击造成的安全性问题,建立厚壁圆筒有限元模型,采用直接耦合的方法,模拟分析了自增强处理后的厚壁圆筒承受波动内压同时经历热冲击后的温度、应力的分布情况,并对比了内压、热冲击、内压和热冲击耦合作用这3种载荷对自增强残余应力的影响。计算结果表明,热冲击后圆筒内壁温度梯度大,应力变化幅度大,外壁的温度梯度小,应力变化幅度小;等效应力最大值出现在内壁;内压单独作用后,残余应力分布基本不变,热冲击后的残余应力在内壁附近发生较大的变化。
In order to study the security problems of thermal shock caused by high temperature decomposition of ultrahigh pressure polyethylene tubular reactors,the finite model of thick cylinder was established.The direct coupling method was employed,and the temperature,stress and plastic deformation of an autofrettaged thick cylinder under fluctuating internal pressure and thermal shock were analyzed.The influences of internal pressure loading,thermal shock and internal pressure combined with thermal shock on residual stress of an autofrettaged thick cylinder were discussed.The conclusion suggests that the inner surface of cylinder was subjected to a sharp temperature gradient and large stress variation amplitude.There are small temperature and stress gradients in the outer surface of cylinder.The maximum equivalent stress appears on the inner wall.The residual stress is almost constant after the pressure loading and changed a lot near inner wall after thermal shock.Thermal shock has a great influence on the stress and strain near the inner wall.The results provide a certain basis for the safety of the ultrahigh pressure reactor.
出处
《石油化工设备》
CAS
2016年第4期6-11,共6页
Petro-Chemical Equipment
关键词
厚壁圆筒
热冲击
残余应力
有限元
自增强
thick cylinder
thermal shock
resistant stress
finite element
autofrettage