ANALYSIS OF THE COMBUSTION PROCESS OF LOW-CALORIFIC GASEOUS FUELS IN EXPERIMENTAL COMBUSTION CHAMBER OF GAS TURBINE

This paper presents the combustion process of gaseous fuels in turbine combustion chamber. Authors investigated fuels with significant amount of inert gases like nitrogen and carbon dioxide. For selected fuels, experimental studies in an experimental silo combustion chamber were performed. During the experiment the effect of molar fraction of nitrogen and excess air ratio on the temperature and gas composition inside and in the outlet channel of the combustion chamber were analyzed. At the same time the numerical calculation were performed with using Cantera and Ansys FLUENT software. Basic parameters like adiabatic flame temperature and laminar flame speed and process of the flow with combustion in simplified geometrical model of combustion chamber were calculated. Results from CFD calculation were compared qualitatively with the experimental result. The CFD part was supplemented with a calculation with carbon dioxide used as inert gas. Research on utilization of fuels like biogases, nitrogen-rich natural gases and their mixtures is very important, especially in countries where energy production is based on coal and lignite. The use of these kind of fuels in high-performance combined cycle allow to significantly reduce emission of toxic compound into the atmosphere.