Investigation and Assessment of the Performance of Various Recuperative Cycles Based on the Intercooled Recuperation Concept

Abstract

This work is focused on investigations of Intercooled Recuperation configurations for aero engines. The investigated configurations were the Conventional Recuperation, where the recuperator was placed downstream the low-pressure turbine (LPT), the Alternative Recuperation, where the recuperator was mounted between the intermediate pressure turbine (IPT) and LPT, and the Staged Heat Recovery concept, in which two recuperators were mounted, one between IPT and LPT and the other downstream the LPT. These concepts were further assessed with the use of an additional combustor between IPT and LPT. All recuperator concepts that have been developed within the framework of various research projects by Aristotle University of Thessaloniki and MTU Aero engines AG were utilized, named as the NEWAC, CORN and STARTREC concepts. Additionally, a new recuperator design was introduced using a secondary fluid as heat transfer medium. The configurations thermodynamic assessment was focused on specific fuel consumption reduction, while the configurations effect on NOx emissions was also investigated. The results showed that the most promising recuperator concept, with respect to low TSFC values compared with a reference GTF engine of 2050 year technology level, is the recuperator with the secondary fluid heat transfer medium.