CFD analysis of the combustion in the BERL burner fueled with a hydrogen-natural gas mixture

Abstract

The regulatory restrictions, currently acting, impose a significant reduction of the Greenhouse Gas (GHG) emissions. After the coal-to-gas transition of the last decades, the fossil fuel-to-renewables switching is the current perspective. However, the variability of energy production related to Renewable Energy Sources requires the fundamental contribution of thermal power plants in order to guaranty the grid stability. Moving toward a low-carbon society, the industry is looking at a reduction of high carbon content fuels, pointing to Natural Gas (NG) and more recently to hydrogen-NG mixtures. In this scenario, a preliminary study of the BERL swirled stabilized burner is carried out in order to understand the impact of blending natural gas with hydrogen on the flame morphology and CO emissions. Preliminary 3D CFD simulations have been run with the purpose to assess the best combination of combustion model (Non Premixed and Partially Premixed Falmelets), turbulence model (Realizable k ɛ and the Reynolds Stress equation model) and chemical kinetic mechanism (GriMech3.0, GriMech 1.2 and Frassoldati). The numerical results of the BERL burner fueled with natural gas have been compared with experimental data in terms of flow patterns, radial temperature profiles, O2, CO and CO2 concentrations. Finally, a 30% hydrogen in natural gas mixture has been considered, keeping fixed the thermal power output of the burner and the global equivalence ratio.

Mathematical investigation of syngas fired burner with various configurations in the BERL combustor

“…A mixture of natural gas and hydrogen at various concentrations are oxidized in BERl burner. 25 The mixture compared with pure natural gas to maintain the same power and the global equivalence ratio. Furthermore, a numerical investigations study implemented on BERL to substitute natural gas with syngas fuel.…”

Analysis of the partially premixed combustion in a labscale swirl-stabilized burner fueled by a methane-hydrogen mixture

“…Nevertheless, there are still several challenging technical issues that must be addressed such as the potential flashback and autoignition due to the significantly higher flame speeds and shorter autoignition times [7][8][9]. Several research groups are working both on experimental and numerical activities concerning the premixed combustion of natural gas enriched with hydrogen [10]. Furthermore, an excessive lean combustion can cause the occurrence of dangerous thermoacoustic instabilities [11][12][13][14][15].…”

Numerical study of the lean premixed PRECCINSTA burner with hydrogen enrichment

“…Green hydrogen combustion can represent a viable solution to reach the decarbonization of power generation industry since it is a carbon-free energy vector for combustion and energy-storing. Many researchers are currently studying the e↵ect of hydrogen addition in natural gas-fuelled turbine with the aim of reaching 100% hydrogen combustion until 2030 [3].…”