To contribute to the development of a hydrogen society, Kawasaki Heavy Industries (KHI) is investigating the use of hydrogen fuel in gas turbine combustors. The KHI gas turbine combustor uses lean premixed combustion to achieve low emissions. However, this approach may lead to flashback phenomena, which can cause thermal damage to the combustors. Consequently, it is crucial to design combustors that prevent flashbacks and predict these occurrences through numerical analysis. This study presents a numerical combustion analysis aimed at evaluating flashback phenomena in the combustor under investigation. The analysis employs the large eddy simulation (LES) approach and finite-rate chemistry models to accurately assess the impact of turbulence on flame structure and flashback, particularly in scenarios with high hydrogen concentrations. As a further study, this reaction model applies to the detailed actual combustor flow to get a design direction for the flashback avoidance.

In many gas turbine (GT) power generation facilities, GTCC is adopted from the viewpoint of high efficiency, and a duct burner for reheating is installed in order to expand the operating range of the exhaust heat recovery boiler included in the cycle. In order to build a decarbonized society, it is necessary to develop not only hydrogen combustion GT but also hydrogen combustion duct burner technology. Combustion stability and NOx formation characteristics of hydrogen and LPG in high temperature and low oxygen concentration atmosphere simulating GT exhaust gas were evaluated. It was verified that low CO and high NOx reduction characteristics were obtained in LPG combustion by applying gas nozzles with improved flame retention. It was also confirmed that the NOx reduction characteristics in LPG and hydrogen combustion were improved in low temperature and low oxygen concentration condition.