Investigation on a Novel Type of Tubular Flame Burner with Multi-stage Partially-Premixing Features for Liquid-Fueled Gas Turbine

A new combustion system, which consists of an evaporator and a tubular flame burner with multi-stage inlets, has been developed to meet the growing concerns over the fuel flexibility and flame stability of gas turbines. In the evaporator, a flash-boiling atomization technology was adopted to enhance atomization, evaporation, and fuel-air mixing to provide the burner with the optimized fuel-rich mixture under various operating conditions with liquid fuels. In the new-type of tubular flame burner, a tangential multi-stage inlet structures were proposed to realize fast fuel/air mixing and thus clear combustion with features of excellent stability, uniform temperature profile, and non-flashback. As a practice, ethanol was selected as the liquid fuel to examine the performances of the evaporator and the multi-stage tubular flame burner. Results show that ethanol spray has been fully evaporated under a wide load range owing to the flash-boiling technology, and tubular flames can be established stably and without flashback, and specifically in a wide range of equivalence ratio from 0.23 to 4.6, which has been greatly expanded compared to those of the conventional tubular flame burners. The temperature near the burner outlet were found uniformly distributed in the radial direction across the burner central area, but became very low when approaching the burner cylinder wall, which is believed helpful for decreasing the heat loss to the burner liner and thus preventing it from ablation. These results imply that this new burner has great potentials in application to the advanced gas turbine.