Heat Transfer and Energy Storage Performance of Methane Reforming with Carbon Dioxide in Semi-cavity Reactor

The heat transfer and energy storage performance of methane reforming with carbon dioxide in a semi-cavity reactor catalyzed by Ni/Al2O3 are numerically investigated. The concentrated solar energy flux is calculated by Gaussian distribution model, and the heat losses of radiation and convection in semi-cavity reactor are reduced by considering the angle factor. The simulated methane conversion and thermochemical storage efficiency have good agreements with previous experimental data. The simulation results indicate that the higher operating temperature promotes the methane reforming reaction, so the methane conversion obviously increases with the operating temperature. As DNI (direct normal irradiation) increases, the methane conversion increases, while the thermochemical storage efficiency first increases and then decreases. Compared with tubular reactor, the methane conversion of semi-cavity reactor increases for 13.2%, and the thermochemical storage efficiency get an increase of 12.9%. When the inlet velocity rises, the fluid temperature decreases with heat loss increasing, the methane conversion remarkably decreases with the residence time decreasing, and the thermochemical storage efficiency has a maximum.