M501G/GAC Series
High-performance large-capacity gas turbines for 60 Hz power generation
Features
- Standalone Gas Turbine Output
- 280MW class
- Combined Cycle Output
- 430MW/860MW/1,280MW class
- Combined Cycle Efficiency
- More than 60%
- Actual Operating Hours
- Over 8.6 million hours
- The GAC Series adopts an air-cooled combustors instead of conventional steam-cooled combustors.
- Validated 50% hydrogen fuel blending (by volume) at an actual power plant in the US, contributing to the early achievement of carbon neutrality.
Product Details
Overall Design
The gas turbine unit is based on the basic structure adopted in the early 1970s that has accumulated a track record of at least 50 years. Its main features are as follows:
- A compressor shaft end drive reduces the effect of thermal expansion on alignment
- A rotor with simple single-shaft two-bearing support
- A rotor structure has bolt-connected discs with the torque pins in the compressor section and CURVIC couplings in the turbine section to ensure stable torque transmission
- An axial flow exhaust structure advantageous in combined cycle plant layouts
- Horizontally split casings that facilitate field removal of the blades with the rotor in place
Key Component Technologies
Compressor
Axial flow compressors designed with advanced airfoil design technologies are introduced. They feature large capacity, high efficiency and a high pressure ratio. Variable inlet guide vanes ensure operational stability at the start-up and enhanced performance at partial load in combined cycle operation.
Combustor
A premixing low NOx combustor is a steam-cooled type, composed of one pilot burner and eight main burners that surround it. The combustor has an air bypass mechanism that enables fuel-air ratio regulation in the combustion region.
Incorporating air-cooled combustors, the GAC series adds operational flexibility by eliminating any need for steam cooling from the bottoming cycle.
Turbine
Four-stage axial flow turbines in a three-dimensional aerodynamic design are adopted. The vanes at the first three stages are air-cooled. Among these, those at the first two stages adopt directionally solidified (DS) materials with thermal barrier coating (TBC). Despite the rise in temperature, application of advanced cooling technologies and the TBC helps to maintain the metal temperature of turbine blades at the level of conventional gas turbines.
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Long-term Validation - T-POINT 2 Proving Ground for Gas Turbine Advancements
Mitsubishi Power has a unique design and validation approach, unlike any other Original Equipment Manufacturer (OEM). The current verification process for the J-series technology takes place at our grid-connected T-Point 2 commercial combined cycle power plant located at Takasago Machinery Works 1 km2 campus 48 km west of Kobe, Japan. In one single location, we house the four key pillars of validation: research and development, design, manufacturing, and full-scale validation. These turbine designs undergo long-term operation of at least 8,000 hours of validation, equivalent to nearly one year of normal operation.
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Hydrogen Capability
Georgia Power and Mitsubishi Power have successfully completed a second trial blending hydrogen and natural gas fuels at both partial and full load on an M501GAC natural gas turbine at Georgia Power’s Plant McDonough-Atkinson in Smyrna, Georgia.
(Photo courtesy of Georgia Power)
Configuration
| M501GAC | ||
|---|---|---|
| Compressor | Number of Stages | 17 |
| Combustor | Number of Cans | 16 |
| Cooling Method | Air Cooled | |
| Turbine | Number of Stages | 4 |
| Rotor | Number of Rotors | 1 |
| Output Shaft | Cold End | |
| Rated Speed | 3,600 rpm | |
| Gas Turbine | Approx. L × W × H | 12.9 × 5.1 × 5.5 m |
| Approx. Weight | 295 ton | |
Simple Cycle Performance
| M501GAC | ||
|---|---|---|
| Frequency | 60 Hz | |
| ISO Base Rating | 283 MW | |
| Efficiency | 40.0 %LHV | |
| LHV Heat Rate | 9,000 kJ/kWh | |
| 8,531 Btu/kWh | ||
| Exhaust Flow | 618 kg/s | |
| 1,364 lb/s | ||
| Exhaust Temperature | 617 °C | |
| 1,143 °F | ||
| Exhaust Emission | NOx | 15ppm@15%O2 |
| CO | 9 ppm@15%O2 | |
| Turn Down Load | 50 % | |
| Ramp Rate | 18 MW/min | |
| Starting Time | 30 minutes | |
Combined Cycle Performance
| M501GAC | ||
|---|---|---|
| 1 on 1 | Plant Output | 427 MW |
| Plant Efficiency | 60.5 %LHV | |
| 2 on 1 | Plant Output | 856 MW |
| Plant Efficiency | 60.7 %LHV | |
Performance Correction Curves
Effects of Compressor Inlet Temperature on Gas Turbine Performance (Typical)
Effects of Barometric Pressure on Gas Turbine Performance (Typical)
Typical Plant Layout - 1 on 1 configuration, single-shaft
- Gas Turbines
- Steam Turbines
- Generators
- Inlet Air Filter
- Heat Recovery Steam Generator (HRSG)
- Electrical / Control Package
- Main Transformer
- Condenser
Typical Plant Layout - 2 on 1 configuration
- Gas Turbines
- GT Generator
- Steam Turbines
- ST Generator
- Inlet Air Filter
- Heat Recovery Steam Generator (HRSG)
- Electrical / Control Package
- GT Main Transformer
- ST Main Transformer
- Condenser
Representative Example
KEILCO Ilijan
| Country/Region | Philippines |
|---|---|
| Plant | Ilijan Power Plant |
| Plant specifications × Qty | Combined cycle × 4 |
| Year of operation | 2002 started |
Taiwan Power Company
| Country/Region | Taiwan |
|---|---|
| Plant | Datan Power Plant |
| Plant specifications × Qty | Combined cycle × 14 |
| Year of operation | 2008 started |
Chubu Electric Power Co., Inc.
| Country/Region | Japan |
|---|---|
| Plant | Shin-Nagoya Thermal Power Station Group 8 |
| Plant specifications × Qty | Combined cycle × 4 |
| Year of operation | 2008 started |
The Kansai Electric Power Co., Inc
| Country/Region | Japan |
|---|---|
| Plant | Sakaiko Power Station |
| Plant specifications × Qty | Combined cycle × 5 |
| Year of operation | 2009-2010 started |
Other Delivery Records
| Client / Plant | Country/Region | Year of starting operation | Plant specifications × Qty |
|---|---|---|---|
| EL PASO ELECTRIC COMPANY / Newman Genarationg Station | USA | 2023 | Combined cycle × 1 |
| Entergy Texas, Inc. / Montgomery County Power Station | USA | 2021 | Combined cycle × 2 |
| Entergy Louisiana, LLC / Lake Charles Power Station | USA | 2020 | Combined cycle × 2 |
| NTE Energy / Middletown Energy Center | USA | 2018 | Combined cycle × 1 |
| NTE Energy / Kings Mountain Energy Center | USA | 2018 | Combined cycle × 1 |
Related Case Studies / News
Lifecycle & Operation Support Services
Gas Turbines – ServicesComprehensive lifecycle services that support reliable gas turbine operation.
Long Term Service Agreement (LTSA)Predictable maintenance planning and long-term support to maintain stable plant performance.
TOMONI® – Intelligent SolutionsDigital solutions that enhance plant performance, flexibility, and operational efficiency.
Support of Operation and MaintenanceWe comprehensively repair aging plants and aim to extend the life of facilities and equipment.
TrainingSkill-development programs for plant operators and maintenance engineers.
Steam Turbines – ServicesService solutions for steam turbines used in GTCC combined-cycle plants.
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