Publicou 12 edições por ano
ISSN Imprimir: 1044-5110
ISSN On-line: 1936-2684
Indexed in
INFLUENCE OF EMULSIONS AND STEAM INJECTION ON A DIESEL FUELED MODEL GAS TURBINE COMBUSTOR
RESUMO
The introduction of water into a combustion chamber can mitigate NOX emissions because water's high specific heat allows it to act as a heat sink to reduce system temperatures. This effort compared the relative effects on combustion performance when introducing water into the combustion air compared to injection with the fuel as a diesel fuel−water emulsion. In this study, a pressure simplex nozzle was used to inject the fuel or emulsion. For this study, fuel was injected in a non-premixed (i.e., lean direct injection) fashion and an axisymmetric model gas turbine combustor was used. To complement the combustion studies, an assessment of how mixing the fuel with water impacted atomization behavior was also conducted. Increasing the water to fuel mass ratio (W/F) did not significantly affect the stability of steam injection flames, but it did significantly decrease the stability of emulsion flames. For a given amount of water added, emulsions were more effective at reducing NOX than water introduced into the combustion air. Investigation of emulsion atomization properties showed little change in droplet size and spray angle with increasing W/F, but faster sheet breakup was observed for the cone spray produced by the simplex nozzle used. Dual-wavelength planar laser induced fluorescence (D-PLIF) showed that water tends to locate away from the spray centerline, resulting in a nonuniform radial profile of local W/F. However, it is also observed that an increase in the overall W/F ratio leads to a more uniform radial profile of local W/F. OH* chemiluminescence and flame imaging showed a decrease in the average chemiluminescent intensity and a bimodal trend inflame length behavior. The changes in these characteristics were more extreme for the emulsion reactions, which can most likely be attributed to the water in the emulsion cases evaporating within the reaction zone and the overall higher amount of water interacting with the reaction zone for these overall lean reactions.