Patent attributes
By using a combustion flue gas (18) from a power turbine (16), a high-pressure secondary compressed air (12C) is subjected to heat exchange in a first heat exchange unit (19A) of an exhaust heat recovery device (19), and by using resultant heat-exchanged flue gas (18A), a low-pressure primary compressed air (12A) is subjected to heat recovery in a second heat exchange unit (19B) of a saturator (31). Then, a primary compressed air (12B) that has been subjected to heat recovery in the second heat exchange unit (19B) is introduced into a secondary air compressor (22) to increase the pressure of the air, and then the high-pressure air is subjected to heat recovery in the first heat exchange unit (19A), producing a secondary compressed air (12D). The secondary compressed air (12D) is introduced into a combustor (14) and combusted using fuel.