Arenas-Fernandez, A. , Rodriguez-deArriba, P. , Escamilla-Perejon, A. , GONZALEZ ALMENARA, RAFAEL, Sanchez, D. , ASME

No

Proceedings Of Asme Turbo Expo 2024: Turbomachinery Technical Conference And Exposition, Gt2024, Vol 5

Proceedings Paper

Científica

0

0

01/01/2024

001303796500036

The interest in using hydrogen for civil aircraft propulsion is well known and has already been explored by the aero industry extensively. In this context, Iron NPE is a 25 M(sic) project funded by the Government of Spain with the aim to develop an efficient, flexible and compact generator of non-propulsive energy running on hydrogen. Aiming to achieve very high efficiency by exploiting the favourable boundary conditions at flight altitude ambient temperature as low as -65 degrees C), micro combined cycle systems are explored as an alternative to the more standard solution based on PEM fuel cells. These systems deliver a stream of hot gases which is harvested by a bottoming Organic Rankine Cycle system downstream, to further enhance global performance. This paper presents a preliminary analysis to benchmark the generation of non propulsive energy based on fuel cells, explore the thermodynamic potential of stand-alone of micro gas turbines with small and large recuperators and assess the benefits of sacrificing micro gas turbine performance in order to enhance waste-heat-to-power recovery in a bottoming organic Rankine cycle. Key aspects of the independent systems involved as well as the integrated combined system are assessed. Eventually, it is revealed that the utilisation of combined systems with bottoming ORC units running on either propane or isobutane enable close to 50% conversion efficiency. Moreover, even if the efficiency attained by the system incorporating a bottoming isobutane ORC system is slightly higher, it seems that adopting a subcritical ORC unit running on propane allows for easier and more compact design of components at minimum performance drop.

hydrogen; MGT; fuel cell,emissions; aircraft; aviation; organic rankine cycle(ORC)