温差载荷对氨合成塔中心管断裂破坏的影响分析

Analysis of the Influences of Temperature Difference Load on the Central Tube Failure Damage of an Ammonia Converter

通过建立分析简化的力学模型,分析计算中心管失稳的温差条件和温差载荷导致中心管失稳大变形条件及可能性,说明当内筒与中心管的温差达到250℃左右,在中心管轴向会产生很高的压缩力,使中心管筛条失稳弯曲,在局部产生塑性大变形。若筛条大变形处在较长时间内保持很高的应力水平时会有裂纹,裂纹的扩展引起筛条断裂,最终导致中心管的破坏。

The condition of unstable big deformation of the central tube induced with the unstable temperature difference condition and temperature difference load of the central tube and its possibility were analyzed and calculated with the foundation of simplified mechanic model. It indicates that a very high compression force was generated at the axial direction of the central tube, and this made the grizzly bars of the central tube unstable and deformative, and a plastic big deformation would occur somewhere when the temperature difference between inner cylinder and the central tube rose up to 250℃. Some cracks would occur when a high stress level was kept at the location of big deformation of the grizzly bars for a long time, the diffusion of the cracks would induce the failure of the grizzly bars, and make the central tube damaged.