Research Progress of Hydrogen/Ammonia Gas Turbine Combustion Chambers

Ammonia/hydrogen mixed fuel is important for the deep decarbonization of gas turbines. However, the combustion characteristics of the mixed fuel are at two opposite extremes: the highly reactive hydrogen is easily flashback; the less reactive ammonia has poor flame stability and high fuel nitrogen oxide emissions. In this paper, the basic combustion chemistry of the ammonia-hydrogen mixture is systematically reviewed, and three kinds of combustion technology, the swirl-stabilized combustion, the micro-mixing combustion and the staged combustion, are evaluated, with attention focused on the flame stabilization, the flashback prevention and the organization of low nitrogen oxide combustion. The swirl stabilization is able to anchor the ammonia flame by forming a strong recirculation zone. The micro-mixing combustion provides an effective physical barrier to prevent the flashback, and is suitable for high hydrogen mixing ratio. The staged rich-lean combustion is able to achieve significant nitrogen oxide reduction of decoupling the fuel nitrogen conversion in the rich stage from the combustion in the lean stage, and as low as 54 10-6 (54 ppm, 15% O2) under the optimum conditions. This work gives the theoretical basis of the development of zero-carbon burner, and supports the development of the cleaner gas turbine combustion technologies.