sCO2 Waste Heat Recovery System for Aircraft Engines

Resumo

© 2022, American Institute of Aeronautics and Astronautics Inc.. All rights reserved.Waste heat recovery is a key pathway to achieving reduced emissions and improved system efficiency. Waste heat can potentially be converted to electric power by several methods. One of the most effective methods is based on using a supercritical CO2 waste heat recovery power system. The sCO2 power system has advantages because of component compactness, which is an important consideration for aircraft integration. The present work focuses on implementing the supercritical CO2 power system into both current and next-generation aircraft engines that may use different fuels, such as hydrogen, ammonia, or sustainable aviation fuel (SAF). The first part of the work is focused on detailed optimization of the sCO2 waste heat system for a real aircraft engine with two sCO2 cycle configurations. The second part of the work is focused on detailed design of the heat exchangers, including weight and pressure drop calculation. The simulation was done using an in-house computer program for gas turbine performance and for the sCO2 cycle. The results show the potential utilization of waste heat in different operational regimes: idling on the ground, cruise, landing, and takeoff. One engine (nominal thrust of 9kN) with two different waste recovery units are investigated. The results demonstrated that the waste heat unit could generate an additional 100-200 kW for the 9-kN-engine (under cruise operation), which may reduce fuel consumption, even if the sCO2 system weight is around 800 lbm / 364 kg.