Energy Analysis and Parametric Study of Hydrogen and Electricity Co-Production System Coupled With a Very-High-Temperature Gas-Cooled Reactor

Hydrogen is an important clean alternative energy resource for the future, and nuclear hydrogen production can efficiently produce carbon-free hydrogen on a large scale. In this study, a hydrogen and electricity co-production system coupling iodine-sulfur cycle with a very-high-temperature gas-cooled reactor is proposed. The helium on the secondary side of the intermediate heat exchanger provides high-grade heat for the sulfuric acid decomposition reactor and hydroiodic acid decomposition reactor, and the steam extracted from the power generation circuit provides low-grade heat for other hydrogen production components. A supercritical steam generator is used and a reheating section is designed to improve power generation efficiency. The energy analysis reveals that as the hydrogen production rate increases, the power generation efficiency decreases, whereas the overall hydrogen and electricity efficiency increases. The power generation efficiency and overall hydrogen and electricity efficiency of the system are 38.2 % and 45.5 % at a hydrogen production rate of 161.73 mol/s. The parametric study shows that the power generation efficiency and overall hydrogen and electricity efficiency of the system increase with an increase in the main steam temperature or main steam pressure, and decrease with an increase in the reheated steam pressure. Among the three parameters, the main steam temperature markedly affects the performance of the system, followed by the reheated steam pressure and main steam pressure.