冷点和操作参数对变形焦炭塔应力影响分析

Analysis of the Influence of Cold Spot and Operating Parameters on the Stress of Deformed Coke Drum

焦炭塔在运行过程中要承受热机械载荷,因此其安全性和可靠性至关重要。在每个生产周期中,焦炭塔中温度波动所产生的热应力是造成结构故障的主要原因。以长期使用的碳钢焦炭塔为研究对象,通过内部激光扫描检测,将变形后的焦炭塔处理为有限元几何模型,对变形较大的两个区域施加冷点作用,将其与未变形的焦炭塔模型进行了比较,并运用动态坐标系法定量研究了冷却水温度和进水速度对变形和未变形焦炭塔应力的影响。结果表明,在冷点作用下,与未变形模型相比,A区和B区的最大应力增加了10.3%和12.8%,这些模型均产生不同程度的鼓胀,变形模型的鼓胀更为严重。相对于一个冷点,两个冷点轴向排列时,两个模型的等效应力均提高。对于变形模型和未变形模型,其等效应力均随着冷却水温度的增加而降低,随着进水速度的增加而增加,操作参数对于变形模型的影响更为显著。冷点和操作参数对变形焦炭塔应力有一定影响,在实际生产中必须予以考虑。

The coke drum is subjected to a combination of thermal-mechanical loads during its operation,so its safety and reliability are of paramount importance.Thermal stress generated by temperature fluctuations in the coke drum is the main cause of structural failure in each production cycle.The long-term serviced carbon steel coke drum was used as the research object.Firstly,the deformed coke drum was treated as a finite element geometric model by internal laser scanning detection.Secondly,the cold spots were applied to the two areas with large deformation,and compared with the undeformed coke drum model.Finally,the dynamic coordinate system method was used to quantitatively study the influence of cooling water temperature and water intake speed on the stress of deformed and undeformed coke drums.The results show that under the action of cold spot,compared with the undeformed models,the maximum stresses in areas A and B have increased by 10.3%and 12.8%.These models have different degrees of bulging,and the bulging of the deformed model was more serious.Compared with one cold spot,the equivalent stress of the two models increases when the two cold spots are arranged axially.For the deformed model and the undeformed model,their equivalent stress decreases with the increase of the cooling water temperature,and increases with the increase of the water intake speed.Furthermore,the operating parameters have a more significant effect on the deformed model.Additionally,the cold spot and operating parameters have a significant impact on the stress of the deformed coke drum and must be considered in practical production.