Cracking Failure Analysis of Inlet Manifold in Hydrogen Reformer Furnace and Prevention

摘要

A study of cracking failure of three-way T junctions between inlet manifold and branch pipes in large-scale hydrogen reformer furnaces in terms of pipe material, operation medium, properties of cracking zone material, and vertical displacements of inlet manifold and branch pipes is presented. The results revealed that cracking failures of three-way T junctions can be attributed to the stress concentration, which was caused by incongruous vertical deformations of inlet manifold and branch pipes, as well as variations in horizontal deformation heights of branch pipes. The incongruous displacements of inlet manifold and branch pipes were significantly mitigated by optimization design of the suspension device of the inlet pipe using the finite element method. The vertical displacement differences between inlet manifold and branch pipes and the east-west vertical displacement differences between the five branch pipes were reduced by 48 and 91.5%, respectively. Bending of three-way T junctions was relieved and torsions were eliminated, resulting in mitigation of stress concentration. As a result, the maximum equivalence stress was reduced by 40%, satisfying strength requirements. In this way, cracking failures of inlet manifold in hydrogen reformer furnace were prevented and stable hydrogen production was guaranteed.