CFD simulation of a non-premixed gas turbine combustor fed with natural gas/hydrogen blends

The world energy demand increases year by year together with the greenhouse gases emissions. The state regulations are becoming stricter and stricter requiring pollutants reduction. In this context, hydrogen represents an effective alternative to traditional fuels such as natural gas. Its high reactivity extends the flammability limits and the flame speed and one of the main advantages is the lower emissions. Despite the advantageous properties, some issues arise in the field of flame stabilization and safety. In this thesis, a heavy-duty gas turbine is considered, the FIAT TG-20. It was designed to be used with natural gas, hence after a preliminary study on the Base Load conditions, the study focuses on blended mixtures with hydrogen, in order to evaluate the potentials of the existing geometry. 3D-CFD simulations are performed on its combustor to quantify the effect of hydrogen injection. Particular attention is spent on the outlet temperature prediction which represents one of the most important parameters when running a gas turbine. To estimate it and the fuel quantity to inject with low computational effort, a 0D model was developed on MATLAB. The present work provides a basis for future studies and design changes in combustor geometry.