Computational Investigation of Using Emulsified Fuels in Heavy Duty Gas Turbines

Gas turbines operating on liquid fuels may produce higher NOx and soot emissions and may suffer from reduced combustion part durability, as compared to gas turbines operating on gaseous fuels. With some fuels, like diesel (aka light distillate), the NOx emissions increase is related to the liquid fuel spray atomization process, which plays a vital role in the combustion process. A promising technology for enhancing fuel atomization in a combustor is water-fuel emulsion technology. Injecting a water-fuel emulsion into a gas turbine combustor may lead to favorable effects. Since fuel atomization should be enhanced, combustion should occur at lower local equivalence ratio values, thus reducing the creation of NOx and soot emissions. Moreover, the presence of water in the combustion mixture decreases the average temperature of the combusting mixture due to the high latent heat of vaporization of water, which in turn should reduce NOx. In this study, a numerical investigation is conducted to quantify the impact of the water-fuel emulsion technology on gas turbine combustors operating on diesel fuel. The objective is to determine if NOx and soot emissions are improved, and if flame structure changes when the emulsion technology is utilized at different water to fuel ratios.