Development of the three-dimensional CFD model of heat exchanger type steam reformer for hydrogen production

A helium-heated multi-tube steam reformer is required for large-scale hydrogen production utilizing high temperature gas-cooled reactors (HTGRs). However, scale-up of the reformer causes axial and radial temperature distributions, which affect reaction rates and hydrogen production performance. In this study, a three-dimensional thermal-fluid and reaction analysis model of a single tube of a helium-heated steam reformer was developed by ANSYS Fluent and was validated using the experimental data from a mock-up test. Comparison of the Yagi–Wakao correlation and Kunii–Suzuki correlation showed that the Yagi–Wakao correlation provided better agreement with the measured temperature and hydrogen production rates. Under certain operating conditions, most of the calculated internal temperatures in the steam reformer agreed with measurements within ±5%. The validated model incorporating the Yagi–Wakao correlation can serve as a basis for future scale-up studies of HTGR-based hydrogen production systems.