A Turbocharged Turbogenerator

Turbocharging generally implies the attainment of higher power through increased piston engine air inlet charge density. Turbocharging has too been visualized for gas turbines in the form of an exterior or integrated low pressure compressor and turbine spool module boosting a high pressure power producing spool.This “turbocharged” cycle has been previously developed for both simple and intercooled recuperative cycles (ICR) gas turbine versions, the latter of which are recognized as one of the most thermally efficient Brayton cycles.The two spool ICR flowpath with a separate power turbine has been extensively pursued for vehicular and marine applications accompanied with commercialized versions of large turbofans with low pressure (LP) spool power, yet the application of a two spool ICR counterpart with power extraction from the HP spool has been sporadic.This paper focuses upon the thermodynamic performance and transient operating characteristics of non-concentric two spool non-recuperated Brayton cycles. A hypothetical “turbocharged” adaptation of an existing conventional single shaft 150kW turbogenerator simple cycle gas turbine is chosen as an example with which to portray the concept advantage of increased specific power yet inherent characteristic of diminished hot day performance.Copyright © 2012 by ASME