CFD SIMULATION OF COMBUSTION IN A HYDROGEN ENRICHED GAS TURBINE BURNER

In the context of both a continuously increasing energy demand and an ever more pressing worldwide necessity of reducing pollutants emissions due to climate requirements, hydrogen represents an interesting alternative to natural gas for heavy-duty gas turbines (HD-GT) power supply. Its high reactivity widens indeed the flammability limits and enhances flame propagation: this results in a more efficient combustion giving lower emissions of greenhouse gases. However, since pre-existing technologies designed for natural gas have shown a lack of adequacy to provide flame stabilisation and safe operating conditions, it comes the need for retrofitting of already existing geometries. From this perspective, CFD simulations pose a powerful analysis tool. The main objective of the present work is to produce insights in HD-GT combustion processes. Particularly, can-annular FIAT TG-20 combustor is studied by means of 3D-CFD simulations. First, model performances are assessed with 100% methane base-case. Then, hydrogen-enriched combustion is analysed with different numerical settings and boundary conditions. A deeper understanding of how hydrogen affects the combustion process is therefore achieved through results comparison. This newly acquired knowledge will represent the base for future design changes in TG-20 combustor geometry.