M701G Series

Gas Turbines

Standalone Gas Turbine Output

330 MW class
Combined Cycle Output

500 MW class / 1,000 MW class
Combined Cycle Efficiency

More than 59%

High-performance large-capacity gas turbines for 50Hz power generation

In February 1997, the first unit of the 1,500°C Class M501G Series gas turbines came into commercial operation. This series features the use of steam for cooling combustors. Developed as a model with a similar design, the M701G Series for 50 Hz power generation began commercial operation at the middle of 1999.

Features
Specifications
Layout
Delivery Records

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 40 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

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.

The inlet guide vanes and variable stationary vanes at the first three stages are controlled to ensure stable operation 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.

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.

Configuration

		M701G
Compressor	Number of Stages	14
Combustor	Number of Cans	20
Combustor	Cooling Method	Steam Cooled
Turbine	Number of Stages	4
Rotor	Number of Rotors	1
Output Shaft		Cold End
Rated Speed		3,000 rpm
Gas Turbine	Approx. L × W × H	14.4 × 6.2 × 6.7 m
Gas Turbine	Approx. Weight	490 ton

Simple Cycle Performance

		M701G
Frequency		50 Hz
ISO Base Rating		334 MW
Efficiency		39.5 %LHV
LHV Heat Rate		9,110 kJ/kWh
LHV Heat Rate		8,630 Btu/kWh
Exhaust Flow		755 kg/s
Exhaust Flow		1,664 lb/s
Exhaust Temperature		587 °C
Exhaust Temperature		1,089 °F
Exhaust Emission	NOx	25 ppm@15%O₂
Exhaust Emission	CO	10 ppm@15%O₂
Turn Down Load		60 %
Ramp Rate		22 MW/min
Starting Time		30 minutes