摘要: Previous work has shown that replacing shaft-driven mechanical generators with more efficient high temperature fuel cells integrated directly into the hot section of a turbine engine can significantly extend the range and enduranc... 展开 Previous work has shown that replacing shaft-driven mechanical generators with more efficient high temperature fuel cells integrated directly into the hot section of a turbine engine can significantly extend the range and endurance of uncrewed aerial vehicles and civil transport aircraft with large electrical loads. One advantage of this hybridization is that fuel not consumed in the fuel cell is burned in the combustor to produce propulsive power enabling the use of smaller/lighter fuel cells. However, the impacts of introducing this hydrogen-containing and thus highly reactive secondary fuel stream into the combustor are unknown. An initial paper showed that the residual heating value in the fuel cell exhaust is significant accounting for 20% of the overall heat release when 30% of the total system power was provided by the fuel cell. It also showed that the composition of the fuel cell exhaust was most influenced by the utilization. This follow-on paper investigates the impacts of fuel cell exhaust on the fundamental parameters of flame temperature and ignition delay time in the combustor due to varying SOFC fuel utilization and SOFC electric power fractions. The results show that ignition is enhanced by up to two orders of magnitude when the fuel cell operates at higher fuel utilizations due to the higher initial temperatures of the exhaust mixtures, even while the adiabatic flame temperature is reduced. The relatively large changes in the magnitudes of these fundamental combustion characteristics suggest that a) combustors in turbine/fuel cell hybrids may need to be designed differently to accomodate these variations and b) that introducing fuel cell exhaust could be used to reduce NOx emissions by enabling stable combustor operation at lower overall equivalence ratios. 收起