摘要
针对炼油催化裂化(FCC)装置三旋中心筒多开孔接管补强圈附近出现多处开裂泄漏的失效问题,建立反映FCC三旋中心筒实际传热和力学状态的三维有限元模型,采用ANSYS依次进行温度场、热变形和热应力分析。根据实测温度数据,插值处理后建立内外热分析边界条件,采用三维等参元模拟稳态温度场,指出补强圈附近热应力集中的原因之一是因补强圈不能与壳体紧密贴合形成近似绝热的死空气间隙层。对旋风分离器支腿底板的自由滑动与固定约束、虾米弯管道原设计冷拉伸和改进冷拉伸的各种工况组合,分别进行热应力分析及其分类强度评定,发现原设计缺陷及安装与维护中的热补偿不当是导致开裂的主要原因,从而提出改进方案,实践证明效果很好。本方法可为高温容器多开孔接管的强度与热补偿设计提供有益参考。
Several cracking leakage failures occurred near the reinforcement circle of the central cylinder with multi-opening nozzles of FCC（fluid catalytic cracking） unit. The 3-D FE model reflecting its actual thermal and mechanical conditions is established. The temperature field, thermal deformation and stress are analyzed sequentially by using ANSYS. The dead air gap is formed between the reinforcement circle and shell because they cannot fit closely. The dead air gap is similar to thermal insulation blanket and it has significant impact on the local temperature distribution and thermal stress concentration. The thermal stress analysis and the strength assessment of the structures is made when they are under the combined working conditions. The drawbacks of the previous design and the improper thermal compensation are found, the improvement design is proposed and the good effects are obtained. The present approach pro- vides reference for the strength and thermal compensation design of vessels with multi-opening nozzles in high temperature.
出处
《压力容器》
2017年第6期38-46,共9页
Pressure Vessel Technology
