CFD study of hydrogen combustion effects on the heat-up characteristics of steel samples using a low-swirl burner: A comparative analysis with methane

By substituting natural gas (NG) with hydrogen (H2), the production of greenhouse gases can be avoided in high-temperature processes such as reheating furnaces. However, researchers are lagging behind in analyzing the effects of H2 flue gas on the products introduced and publishing their findings. This study represents the first published investigation of heating process effects in both air-fuel setups in a semi-industrial furnace equipped with a low swirl burner. The research combined experimental trials with theoretical calculations and 3D computational fluid dynamics (CFD) simulations for the transient heat-up of the samples introduced inside the lab furnace. In addition to a RANS model of the entire domain, a numerically more efficient method was used to model the turbulent flow field in the area of the samples, which reduced the calculation time by 90%. It was found that for comparable furnace and sample temperatures of 1060 degrees C, hydrogen combustion required a lower fuel input of 70 kW compared to 94 kW for methane. In terms of the heating behavior, H2 caused an enhanced convective heat transfer, which led to a 13% faster heating process compared to CH4. Overall, the combustion of H2 can both reduce emissions and increase efficiency through lower fuel input and faster heat-up times.