Impact of sCO2 Waste Heat Recovery System Air Cooler Integration on Aircraft Engine Thrust Performance

Abstract

Abstract The aviation industry has established a goal to reduce net carbon emissions by 50 % relative to 2005 levels by 2050. Carbon emissions can be reduced through direct or indirect methods. Direct approaches include alternative fuels, while indirect approaches can include waste heat recovery (WHR) from engine exhaust using a supercritical CO2 (sCO2) Brayton power cycle. Power cycle component design, particularly the heat sink heat exchanger (i.e., Cooler), are strongly influenced by changes in engine operating conditions. The present work focuses on integration of a sCO2 power system into an aircraft propulsion system and evaluation of its performance. The first part addresses the operation of the WHR unit under different operating conditions for an aircraft engine with a nominal thrust of 30 kN. The second part addresses the impacts of operating the sCO2 cycle near the critical point, Cooler heat addition and pressure drop in the engine bypass flow path, and Cooler design under different engine operating conditions. Analysis results show that the sCO2 WHR system can generate approximately 492 kW of electrical power with a cycle efficiency between 24 % and 28 % across different aircraft operating regimes.