Hisato Arimura

The Operating Experience of the Next Generation M501G/M701G Gas Turbine

The combined cycle power plant is recognized as one of the best thermal power plant for its high efficiency and cleanliness. As the main component of the combined cycle power plant, the gas turbine is the key for improvement of the combined cycle power plant.The next generation G class gas turbine, with turbine inlet gas temperature in 1,500°C range has been developed by Mitsubishi Heavy Industries, Ltd. (MHI). Many advanced technologies; a high efficiency compressor, a steam cooled low NOx combustor, a high temperature and high efficiency turbine, etc., are employed to achieve high combined cycle performance. Actually, MHI has been accumulating the operating experiences of M501G (60Hz machine) a combined cycle verification plant in MHI Takasago, Japan, and achieving the high performance and reliability. Also, M701G (50Hz machine) has been accumulating the operating experience in Higashi Niigata Thermal Power Station of Tohoku Electric Power Co., Inc. in Japan.This paper describes the technical features of M501G/M701G, and up-to-date operating status of the combined cycle power plant in MHI Takasago, Japan.© 2001 ASME

Development of Air Cooled Combustor for Mitsubishi G Class Gas Turbine

Mitsubishi Heavy Industries (MHI) pioneered the introduction of steam cooling technology for gas turbines with the introduction of the M501G in 1997. To date, 62 Mitsubishi G units have been sold making this series the largest steam cooled fleet in the market. The turbine inlet temperature (TIT) for this gas turbine is 1500 deg. C. The original M501G has been upgraded for air cooling applications. This upgraded version is called as M501GAC (G Air Cooled). Several Dry Low NOx (DLN) and cooling technologies from existing F and G series were applied to the upgraded M501GAC. The new GAC combustor was installed in the in-house verification Combined Cycle Power Plant, called T-Point, and verification tests of the combustor were conducted from November 2008. The air cooled M501GAC combustor demonstrated less than 15ppm NOx operation, stable combustor dynamics at all load levels, and high combustor ignition reliability making it suitable for daily start and stop operation at T-Point. Long term verification test is currently under way.Copyright

Development of an Air Cooled G Class Gas Turbine (the M501GAC)

Mitsubishi Heavy Industries (MHI) G series gas turbine is the industry pioneer in introducing steam cooling technology for gas turbines. The first M501G unit started commercial operation in 1997 and to date, with 62 G units sold, MHI G fleet is the largest steam cooled fleet in the market. The existing commercial fleet includes 35 commercial units with more than 734,000 accumulated actual operating hours, and over 9,400 starts. Upgraded versions have been introduced in the 60 and 50Hz markets (M501G1 and M701G2 respectively). On a different arena, MHI is engaged since 2004 in a Japanese National Project for the development of 1,700°C (3092°F) class gas turbine. Several enhanced technologies developed through this Japanese National Project, including lower thermal conductivity TBC, are being retrofitted to the existing F and G series gas turbines. Retrofitting some of these technologies to the existing M501G1 together with the application of an F class air cooled combustion system will result in an upgraded air-cooled G class engine with increased power output and enhanced efficiency, while maintaining the same 1500°C (2732°F) Turbine Inlet Temperature (TIT). By using an open air cooling scheme, this upgraded machine represents a better match for highly cyclic applications with G class efficiency, while the highly reliable and durable steam cooled counterpart is still offered for more base-loaded applications. After performing various R&D tests, the verification process of the air cooled 60 Hz G gas turbine has moved to component testing in the in-house verification engine. The final verification test prior to commercial operation is scheduled for 2009. This article describes the design features and verification plan of the upgraded M501G gas turbine.Copyright

Update on Mitsubishi's Large Frame 50 and 60Hz G-Series Gas Turbine Upgrades

This paper reports progress on Mitsubishi’s first commercial introductions of the M501G1 and M701G2 gas turbines for 60Hz and 50Hz, respectively. The first fire of the 50 Hz gas turbine took place late 2006 at Tokyo Electric Power Company’s (TEPCO’s) Kawasaki Thermal Power Station in Japan, and the 60 Hz unit in January 2007 at Portland General Electric’s Port Westward power plant at Portland, Oregon in the USA. The M501G1 and M701G2 gas turbines are upgrades to Mitsubishi G-series technology that was first introduced a decade ago utilizing steam from the bottoming cycle to cool the combustion liner, instead of compressor discharge air. In the abovementioned upgrades steam-cooling application is now extended to cool the turbine blade-rings thereby enabling better blade tip clearance control particularly during start-up transient conditions. It additionally benefits performance and reliability. Upgrades were also made to the row 1 and 2 vanes and row 1 blades utilizing advances in design technology since the original introduction of the G-series in 1997. Long-term reliability verification testing of the M501G1 gas turbine has been continuing at the Mitsubishi’s T-Point combined cycle power plant located at Takasago, Japan, since May 2003. This paper provides an update of that upgraded gas turbine with over three years of operating experience.Copyright

501F/M701F Gas Turbine Uprating

The share of the gas turbine combined cycle plants tends to increase rapidly in the world of power generation. Under the circumstances, MHI is developing the several kinds of gas turbine to meet each customer’s needs.The ‘F’ series’ engine, which has a firing temperature of 1350–1400 degree C, is predominant in the current market, and the reliability improvement is constantly performed. As a result, the operational hours of 50,000, and the combined cycle efficiency of 55–57% (LHV) is achieved for F-series combined cycle.During the operating experience, any events occurred in field operation is solved. Also, countermeasure was implemented on every machine. Furthermore, robust design improvement is introduced, and commercial operation of the design achieved higher reliability and availability.In this paper, the operating experiences, design improvements and the F series gas turbine uprating program are introduced.© 2001 ASME