【作者】 丁磊；

【导师】 刘人怀；

【作者基本信息】 暨南大学 ， 工程力学， 2007， 硕士

【摘要】 焦炭塔作为石油化学工业的关键设备，其操作条件苛刻，一旦发生失效将导致严重的后果，造成人员伤亡和巨大的经济损失。确保其长周期、安全、稳定的运行，具有很大实际意义和经济价值，一直是石化科研努力奋斗的目标。塔体变形情况与材质有关，从研究材质的角度出发，对长岭炼油化工总厂运行三十多年的焦炭塔塔体母材20g钢的室温拉伸试验和金相试验，研究塔体材质的物理性质是否发生较大改变；并通过对塔体热应力微分方程的推导、求解，以及塔体受到动态温度场、内压、自重等载荷作用下的有限元计算分析，进一步研究塔体发生鼓胀变形的原因。分析结果表明，塔体材质20g钢已发生一定程度的老化；物理性质(尤其是杨氏模量和屈服强度)的改变，冷焦阶段产生的较大应力，以及焊缝金属与塔体母材结构与材料的不连续导致焊趾附近的应力集中，而引起的塑性变形积累是造成塔体鼓胀变形的原因。更多还原

【Abstract】 Coke drum is the key equipment of delayed coking device in petrochemical industry. Due to the severe service conditions, once occurring failure will result in the serous consequence such as personal casualty and tremendous economic losses. It has practical meaning and economic value to prolong the service life of coke drum and its safe and stable operation in a longer period. Base on the mechanical property ,this article regards coke tower of delayed coking workshop of Changling Refining and Chemical Works as the research object,and accomplished of following content: Based on the analysis and the experimental studies of mechanics performance of low carbon steel 20g, especially the change of mechanical property such as the modulus of elasticity and yield strength, and the corresponding relationship between the degree of pearlite spheroidization and the material mechanics performance. This article also presents theoretical formulas of deflections internal stresses and thermal stresses in cylindrical shells subjected to axial-symmetrical temperature distributions. The transient heat transfer between the drum wail and cooling water rising up with steady rate was simulated numerically using FEM, and the time history of the stress and strain fields were also acquired with direct coupling method. The calculation results indicate that along with the decrease of modulus of elasticity and yield strength, the loin-drum deformation is unavoidable in coke drum operation,which is the result of the development of material degradation, the decreasing of the modulus of elasticity and yield strength, and the difference in intensity and stiffness welding seam and low carbon steel 20g. As the accumulation of plastic deformation, and under the effect of so great heat stress, the local yield is produced in the heat affected zone of welds and then developed and accumulated, leading to the loin-drum deformation of the coke drum.更多还原