Influence of Process Parameters on the Mechanical Properties of the Reformer Tube

Considering the non-linear characteristics of the reformer tube material with temperature changes and the influence of the fluid inside and outside the tube, we suggest to establish a thermal-fluid-solid coupling model and calculation method for the reformer tube of the hydrogen production reformer. The multi field coupling theory is used to analyze and study the stress distribution of the fluid in the reformer tube under different process conditions, different inlet temperature and different inlet flow rate.We found that under hot operating conditions, as the fluid inlet temperature in the tube increasing, the maximum equivalent stress of the overall reformer tube structure gradually decreased. As the flow rate gradually increasing, the maximum equivalent stress of the reformer tube decreased gradually and then increased. In this paper, all the technological parameters come from the actual production conditions, so the research results provide a certain reference for safe production.

Failure Analysis of Hot Clamp Induced Cracking on Hydrogen Reformer Outlet Pigtail Tubes

Failure analysis of the hot clamped outlet pigtail tubes connected with hydrogen reformer tube in refineries has been carried out. In this paper, hot clamp induced cracking on Incoloy 800HT outlet pigtail tube of a reformer unit is studied by microscopic observation and mechanical properties testing. Metallurgical evaluation and chemical composition analysis have been performed on both hot clamped cracking tube and no cracking one. Results indicated that the most important parameter affecting the high temperature brittleness of pigtails are the Ni/Cr value, surface grain size and impurity atoms grain boundary segregation.