Co-firing hydrogen with natural gas for 9 MW Siemens Energy dry low emissions combustor: Part I - high pressure rig test

To validate 30% H2 capability for the 9 MW SGT-300-2S engine, high-pressure rig testing was conducted. The Dry Low Emissions combustor was initially operated with natural gas to establish a baseline. Subsequently, it was fuelled with a 30% H2 blend under various ambient temperatures. To evaluate operational margins, tests were extended to 35% and 40% H2. Finally, the combustion system's robustness was rigorously tested under various of overfiring conditions. The impact of H2 concentration on combustor performance was investigated, focusing on factors such as burner metal temperature, NOx and CO emissions, combustion dynamics, and combustor wall temperatures. Test results indicate that burner metal temperatures and NOx emissions increase with increasing H2 concentration. The turbine entry temperature at which CO emissions begin to rise is lowered with increasing H2 content. This suggests that adding H2 to the fuel can lower the emissions turndown temperature for controlling CO emissions, thereby improving the engine's part load thermal efficiency. Combustion dynamic pressure amplitudes remained low for H2 concentrations up to 40%. Combustor wall temperatures for H2 operation up to 40% were comparable to those for natural gas. Test results demonstrate that the combustion system can safely operate with up to 40% H2 in the fuel. The effect of pilot split on combustion was investigated for natural gas and the fuel blends with 30% and 40% H2. A key finding is that different fuel compositions may require different pilot split and turndown control temperature for optimal operation.