Conceptual design of the cooling system for 1700℃-class, hydrogen-fueled combustion gas turbines

摘要

The effects of three types of cooling systems on the calculated operating performances of a hydrogen-fueled thermal power plant with a 1700℃-class gas turbine were studied with the goal of attaining a thermal efficiency of greater than 60percent. The combination of a closed-circuit water cooling system for the nozzle blades and a steam cooling system for the rotor blades was found to be the most efficient, since it eliminated the penalties of a conventional open-circuit cooling systemwhich ejects coolant into the main hot gas stream. Based on the results, the water cooled, first-stage nozzle blade and the steam cooled first-stage rotor blade were designed. The former features array of circular cooling holes close to the surface anduses a copper alloy taking advantage of recent coating technologies such as thermal barrier coatings (TBCs) and metal coatings to decrease the temperature and protect the blade core material. The later has cooling by serpentine cooling passages withV-shaped staggered turbulence promoter ribs which intensify the internal cooling.