Dual cycle gas turbine engine system

Claim 1

A dual cycle gas turbine engine system comprising: a high pressure ratio turbine engine section having a two-spool compressor, a fueled high pressure combustor, a first high pressure turbine stage for driving the second compressor spool, a second high pressure turbine stage for driving the first compressor spool and a third high pressure turbine stage for powering a load via an axially centered output shaft, said high pressure ratio engine section having an air intake at one end and an exhaust passage at its other end, said exhaust passage terminating at a first tailpipe; a heat exchanger concentrically mounted in the exhaust passage of said high pressure ratio turbine engine section, said heat exchanger having first and second passage means, said first passage means serving to communicate spent products of combustion from the final turbine stage of said high pressure ratio turbine engine section to said first tailpipe; and a moderate pressure ratio turbine engine section having a moderate pressure compressor, a fueled moderate pressure combustor and moderate pressure turbine stages and including an axially centered output shaft for powering a load, said moderate pressure ratio turbine engine section having an air intake at one end and a second tailpipe at its other end, said moderate pressure ratio turbine engine section including passages for ducting air from said moderate pressure compressor through said secondary passage means of said heat exchanger to said moderate pressure combustor whereby the heat energy to the moderate pressure ratio engine section is increased because of the heat energy absorbed from the spent products of combustion being exhausted from said high pressure ratio turbine engine section.