Stress Analysis of Steam-Methane Reformer Tube

Reformer tubes are designed to last at least 100,000 hours (11.4 years) of operation, but
frequently, some of the tubes in the furnace fail prematurely. Most of the failures occur
due to the high temperature and pressure developed within the tubes. Thus, the use of
Finite Element Analysis (FEA) software to model, simulate and draw meaningful
conclusion from the actual process conditions of the reformer tubes can reveal important
information regarding the mechanical and thermal stress response. The main objective of
this project is to simulate the combined stress and temperature profiles developed within
the reformer tube. This project involves modeling the mechanical and thermal loadings
present in the tube as well as simulating the stress distribution across the tube's thickness
and length. FEA using ANSYS utilized to analyze stress and temperature profile of the
tube. Literature review of reformer tube has been performed and data needed has been
identified. Stresses have been computed using ANSYS and verified with theoretical
value. It has been seen that the temperature difference across the tube length resulted
from the non-unifonn heat transfer coefficient can be considerable causing high thermal
stresses. Maximum von mises stress equal to 142.61 MPa developed at the inner surface
of the entrance region. The stress then compared with the tensile strength of the tube and
it is showed that the tube is able to sustain the stress without fracture.