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Mitsubishi Hitachi Power Systems America – Energy and Environment, Ltd.

Mitsubishi Hitachi Power Systems America – Energy and Environment, Ltd. has been a steam turbine supplier since 1933 and has since accumulated significant experience in the design of STG sets for both thermal and nuclear power plants.

Steam Turbines

Our steam turbines can be found in nuclear plants, large coal fired plants, combined cycle plants, integrated gasification combined cycle plants, cogeneration and district heating plants, industrial plants, petrochemical plants and in small power generation applications. The installed STG capacity is over 116 GW worldwide, supplied by a total of more than 1600 units. Since 1990 we have supplied a total of 27 large supercritical STG sets with a combined output of approximately 20 GW. In addition, in the same period we have supplied over 100 subcritical STG sets with a combined capacity of approximately 30 GW. This includes five turbine generator sets for nuclear power plant applications and 46 turbine generator sets for combined cycle applications, with a unit capacity ranging from approximately 40 MW to 360 MW.

From 1960 to 1973 Hitachi was a licensee of General Electric’s large steam turbine technology. Limitations on technology disclosure and market access remained in place until 1989. After the expiration of the licensing agreement in 1973 we have continuously and autonomously improved our steam turbine design and today, 37 years later, Hitachi’s steam turbine design has distinct and significant differences from the original General Electric design. Hence, although some of the general structural features of our design may still appear similar to General Electric’s design the turbine and generator technologies and operating experiences have diverged significantly.

We offer ongoing, full-service client support. We design new steam turbines, perform maintenance, plan facility upgrades, and continually stay abreast of customer need and requests.

Major Milestones in our steam turbine development

1933 First Hitachi steam turbine manufactured
1971 First Hitachi supercritical steam turbine in commercial operation
1972 First large steam turbine in commercial operation in North America
1972 First Hitachi Nuclear Turbine in commercial operation

Advanced Turbine Technology

Over the last two decades we has been focused on the large, sub and supercritical steam turbine technology applied in coal fired power plants, such as the Isogo Unit 2, a state-of-the-art 600 MW turbine generator set with main steam pressures and temperatures of 3,700 psig and 1,112 ºF (600 ºC), respectively, and with a reheat steam temperature of 1,148 ºF (620 ºC). Isogo Unit 2 has been in operation since 2009.

In Japan alone, we operate ten major research laboratories with a research and development staff of 8,000 highly trained professionals. As a result, we continuously develop and brings new products and services to market, such as the world’s largest mono block turbine rotors that were conceived and first produced by Hitachi.

Technology Improvements

Strength and Reliability Enhancements
Strength and reliability improvements are those design changes that extend the life of the turbine through stronger, more robust components, such as our centerline-supported diaphragms, advanced Electron Beam Welded (EBW) diaphragms, advanced steel rotor design, erosion prevention for last stage blades, and Continuous Cover Blades.

Efficiency Enhancements
Efficiency enhancements are those design changes that result in an overall turbine performance improvement, such as increased number of turbine stages; optimized degree of reaction stage versus impulse stage; balanced, highly loaded and advanced laminar blade profiles; controlled and advanced vortex lean nozzles; Continuous Cover Blades with multiple fin seals; Elliptical Packings; and Diffuser Type Exhaust Hoods.

Operation and Maintenance Enhancements
Operation and Maintenance (O&M) Enhancements are those design changes that result in longer intervals between scheduled maintenance outages or in shorter outage times. Such design improvements include our advanced hydraulic bolt tightening technology and topless alignment. The strength and durability enhancements stated above also have a positive impact on the O&M intervals.

In spring of 2007, we commissioned a new steam turbine testing facility for steam loading tests. The facility consists of a simplified small scale power plant that includes steam generator, turbine, cooling towers and balance of plant equipment. Moreover, the facility includes an inverter motor to drive the turbine shaft during low load simulations, and flash tanks to simulate feedwater heater flashbacks. The facility was designed to perform turbine scale model testing at actual internal steam flow conditions and stress distributions. Among others, flow field simulations, centrifugal stress simulations, feed-water heater flash-back simulations, low load operation simulations, and load rejection simulations can be performed.