Kazuhiko Kawaike

Conceptual Design of the Cooling System for 1700°C-Class, Hydrogen-Fueled Combustion Gas Turbines

The effects of three types of cooling systems on the calculated operating performances of a hydrogen-fueled thermal power plant with a 1,700°C-class gas turbine were studied with the goal of attaining a thermal efficiency of greater than 60 percent. 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 system which 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 and uses 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 with V-shaped staggered turbulence promoter ribs which intensify the internal cooling.

Conceptual Design of the Cooling System for 1700°C-Class Hydrogen-Fueled Combustion Gas Turbines

The effects of three types of cooling systems on the calculated operating performances of a hydrogen-fueled thermal power plant with a 1,700°C-class gas turbine were studied with the goal of attaining a thermal efficiency of greater than 60%. 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 system which 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 and uses 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 with V-shaped staggered turbulence promoter ribs which intensify the internal cooling.Copyright

Development of a New 25MW High Efficiency Heavy-Duty Gas Turbine H-25

A new 25MW class gas turbine H-25 has been developed to meet both 50 Hz and 60 Hz power generation needs with high reliability and efficient performance utilizing advanced high temperature gas turbine technologies. Because of its superior performance, over 32% in simple cycle efficiency, the H-25 gas turbine enables significant reduction of fuel consumption compared with previous 25MH class turbines. The H-25 also achieves higher thermal efficiency in a combined cycle power plant and a cogeneration plant with a waste heat recovery boiler. The first unit entered commercial operation at the end of November 1988 after full load factory test instrumented with more than 800 pieces of instrumentation.This paper describes the design features and the latest technological refinements in each component of the H-25 gas turbine. Also presented are the component test programs and the results of full load factory test and field test on the first unit.Copyright