Gas Turbine Combustor Liner Wall Heat Load Characterization for Different Gaseous Fuels

摘要

The knowledge of detailed distribution of heat load on swirl stabilized combustor liner wall is imperative in the development of liner-specific cooling arrangements, aimed towards maintaining uniform liner wall temperatures for reduced thermal stress levels. Heat transfer and fluid flow experiments have been conducted on a swirl stabilized lean premixed combustor to understand the behavior of Methane-, Propane-, and Butane-based flames. These fuels were compared at different equivalence ratios for a matching adiabatic flame temperature of Methane at 0.65 equivalence ratio. Above experiments were carried out a fixed Reynolds number (based on the combustor diameter) of 12000, where the pre-heated air temperature was approximately 373K. Combustor liner in this setup was made from 4 mm thick quartz tube. An infrared camera was used to record the inner and outer temperatures of liner wall, and two-dimensional heat conduction model was used to find the wall heat flux at a quasi-steady state condition. Flow field in the combustor was measured through Particle Image Velocimetry. The variation of peak heat flux on the liner wall, position of peak heat flux and heat transfer, and position of impingement of flame on the liner have been presented in this study. For all three gaseous fuels studied, the major swirl stabilized flame features such as corner recirculation zone, central recirculation zone and shear layers have been observed to be similar. Liner wall and exhaust temperature for Butane was highest among the fuel tested in this study which was expected as the heat released from combustion of Butane is higher than that of Methane and Propane.