The Effect of Heterogeneous Natural Gas-Hydrogen Input Into F-Class Gas Turbine Combustor As a Combustion Optimization Method

Abstract The global push to combat climate change by transitioning to clean power generation is accelerating. One promising avenue involves utilizing low-carbon fuels like hydrogen and ammonia in place of conventional fossil fuels such as coal and natural gas, particularly in gas turbine-based combined cycle power plants. While hydrogen co-firing technology shows potential, its widespread adoption faces challenges like infrastructure readiness and cost. To address this, optimizing existing gas turbine engines for hydrogen compatibility becomes crucial. In our study, we propose a novel approach: varying hydrogen content between different nozzle groups in gas turbine combustors. Through experiments using the full-scale combustor of a commercialized F-class gas turbine model, we investigated the impact of heterogeneity or variations in hydrogen concentrations at the center and outer nozzles on combustion dynamics and emissions, comparing with the cases of the homogeneous natural gas only fuel and natural gas-hydrogen mixtures. Hydrogen co-firing increased NOx emission while decreasing CO2 emissions. The peak amplitudes of combustion dynamic pressure, especially in the frequency domain of 125∼245Hz, were linearly proportional to the co-firing ratio, with 41.2% increase observed for 30% co-firing ratio. To ensure stable gas turbine operation, the co-firing ratio should be limited. Our findings revealed a significant correlation between NOx emissions and combustion stability, and varying levels of heterogeneity. Moreover, under higher heterogeneity conditions with intensive hydrogen input into the center nozzle, improved hydrogen co-firing performance was observed, reducing the peak amplitude of the frequency domain limiting co-firing by 22% for 25% co-firing ratio. This potentially extended the critical hydrogen co-firing ratio. Thus, implementing heterogeneous natural gas-hydrogen inputs emerges as a promising method to enhance combustion stability and enable effective hydrogen co-firing, offering a pathway towards cleaner energy generation.