Advanced heavy-duty developments
for the 50 Hz market

Mitsubishi Hitachi Power Systems has recently achieved two important milestones in the development of its heavy-duty gas turbines for the 50 Hz market. The first two M701J units are now in commercial operation, while a new upgraded M701F has been introduced and commissioned.

Kawasaki No. 2 Power station. The second 701J entered commercial operation in July of 2016.

Scaled design. The M701J was designed by direct scaling of the M501J

Mitsubishi Hitachi Power Systems (MHPS) has accumulated significant

operating experience with its J technology gas turbines since the first 60 Hz

M501J began commercial operation in June 2011. A total of 45 units have been

sold and more than 300 000 hours have been amassed on 21 operating machines.


Leveraging the experience from 19 M501J turbines, MHPS has now manufactured

two M701J machines for the 50 Hz market for a combined cycle plant

in Japan. The first unit started commercial operation by the end of 2015 and the

second one in June 2016.


At the same time, in a move to satisfy the continuing demand for F-technology in the 50 Hz market, MHPS has also introduced its latest 50 Hz F-technology upgrade. The M701F5, featuring 1500°C-class turbine inlet temperature (TIT), has also started commercial operation at another combined cycle plant in Japan.


J-series technology

MHPS’s 50 Hz portfolio includes several high efficiency large frame gas turbines.

Table 1 shows their combined cycle efficiency – from the F-Class introduced in

the 1990s, to the J-series with combined cycle efficiency in excess of 61.7% efficiency (LHV).


The M501J and the M701J are MHPS’s largest and most advanced gas

turbines. The J design is based on the successful application of steam-cooling

developed and tested in the G series. The higher performance was achieved by incorporating state-of-the-art technologies developed for the Japanese National

Project. These include advanced turbine cooling, improved turbine aerodynamics

and advanced thermal barrier coating (TBC).


The first 60 Hz J-technology engine has been in operation since June 2011

and has accumulated more than 25,000 AOH and over 200 starts as of May



Of the first 19 turbines in commercial operation, six units in single-shaft combined

cycle configuration are in operation in Japan, with the remaining units in

South Korea.

The design of the M501J gas turbine is based on the proven F- and G-series. Key features are:

  • The compressor shaft-end drive connected to the generator reduces the
  • Kawasaki No. 2 Power station. The second 701J entered commercial operation in July of 2016. thermal expansion and eliminates the need for a flexible coupling.
  • The rotor has a two-bearing structure to support the compressor and turbine ends.
  • An axial flow exhaust structure is used to optimize the combined cycle plant
  • layout.
  • The rotor structure has bolt-connected disks with torque pins in the compressor rotor and disks with curvic couplings in the turbine rotor to ensure reliable torque transmission.


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