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

Ishii, Katsunori  ; Ono, Masato ; Noguchi, Hiroki  ; Shimizu, Atsushi ; Nomoto, Yasunobu ; Sato, Hiroyuki ; Sakaba, Nariaki 

Hydrogen production using nuclear heat offers a stable and large-scale method for generating carbon-free hydrogen. High temperature gas-cooled reactors are notable for their inherent safety and ability to supply heat. Japan Atomic Energy Agency owes the HTTR (High Temperature Engineering Test Reactor), which successfully ran at a coolant outlet temperature of 950C. To demonstrate hydrogen production using HTTR heat, JAEA launched a heat application test project. Prior to this, a mock-up test using a single-tube steam reformer heated by electric-powered helium gas was conducted to validate the design and control system. In this study, a 3D CFD model of the reformer was developed and validated using mock-up test data to support scale-up to multi-tube systems. ANSYS Fluent was used to analyze flow, temperature, and hydrogen yield. The Yagi-Wakao correlation was applied to estimate heat transfer, improving temperature prediction and achieving hydrogen yield accuracy within 2%.