Metal-supported tubular solid oxide steam electrolyser cell: thermomechanical stress analysis

Development of a tubular solid oxide steam electrolyser (SOSE) cell requires thermomechanical stress analysis for sustainable structural design. Being the Finite Element (FE) approach the most effective way to design the multi-material and multi-layer tubular structure, in this study we develop a comprehensive framework to describe the spectrum of deformation and stress associated with different materials and layers of tubular SOSE cell, while considering the effect of porosity, temperature and boundary condition. The tubular cell comprised of metal support with multi-layer system, such as two interconnects, a cathode, a dense and double dense electrolyte, and an anode, with porosities varying between 0% to 40%, including uniform and uneven design porosities. The operating conditions considered were between 500°C to 1000°C under the 1 MPa internal uniform fluid load of the heated steam. The simulation reported to capture key structural behaviours, including various deformation paths. The research reveals two areas of increased deformation and stress concentration in cross-sections in proximity to fixed boundaries and accidental occurrence of individual cross-sections where shear stresses peak on the level of stresses near fixed boundaries. The worst-case deformation of a non-porous structure is estimated to be within 0.482 mm at boundaries of shorter thin layers at 1000 C. These studies address previous research lack regarding thermomechanical stresses in multi-material and multi-layer tubular structure.