Influence of Flow Path Configuration on the Performance of Hybrid Turbine - Solid Oxide Fuel Cell Systems for Aircraft Propulsion and Power

摘要

This work investigates the use of gas turbine (GT) engine integrated solid oxide fuel cells (SOFCs) to reduce fuel burn in aircraft with large electrical loads. The concept offers several advantages: the GT absorbs many SOFC balance of plant functions (supplying fuel, air, and heat to the SOFC) thereby reducing the quantity of system components; the GT supplies fuel and pressurized air that significantly increases SOFC performance; heat and unreacted fuel from the SOFC are recaptured by the GT offsetting system-level losses. The resulting system can supply more electrical power more efficiently than comparable engine-generator systems. A sensitivity analysis identifies important design parameters and translates uncertainties in model parameters into uncertainties in overall performance. Fuel burn reductions of 15-20% are possible on 35 kN rated engines at the 200 kW electric power level. GT-SOFCs are able to provide more electric power (factors ≥3 in some cases) than generator-based systems before encountering turbine inlet temperature limits. Aerodynamic drag effects of engine-airframe integration are the most important limiter of the combined propulsion/generation concept. However, up to 100-200 kW can be produced in high bypass ratio, high pressure ratio turbofans with minimal drag penalty.