Mitsubishi Heavy Industries Technical Review Vol. 49 No. 1 (March 2012)
18Test Results of the World’s Firsto
1,600 C J-series Gas Turbine

SATOSHI HADA*1

KEIZO TSUKAGOSHI*2

JUNICHIRO MASADA*3EISAKU ITO*4

Gas-turbine combined-cycle (GTCC) power generation is expected to be a market successbecause it is the cleanest and the most efficient thermal power generating system that complements
renewable energy sources. Mitsubishi Heavy Industries, Ltd. (MHI) has developed the world’s firsto1,600 C J-series gas turbine by utilizing components and technology from the national projectoaimed at developing 1,700 C -class gas turbine. Long-term reliability testing of the M501J gasturbine continues, following testing at the demonstration combined-cycle power plant (T-point) at
our Takasago Machinery Works from February to June 2011. The commercial version of theM501J gas turbine has already been shipped to Kansai Electric Power Company’s Himeji No. 2power station and will enter operational use in October 2013. This report describes the features ofthe M501J gas turbine and the test results of M501J gas turbine at T-point.

|1. Introduction
Gas-turbine combined-cycle (GTCC) power generation is the cleanest and most efficient
power generating system of all the fossil-fuel-burning approaches. It has the following social andeconomic impacts: (1) The long-term world market for GTCC power generation is expected togrow. (2) A great demand exists for GTCC power generation in developing countries because
GTCC systems can be constructed quickly and provide a stable source of electricity. (3) The needexists in developed countries for highly efficient power generation for further enhancement of
economic efficiency and environmental adaptability. (4) The superior load-absorbing capability of
GTCC power generation is in increasing demand because of the growth of renewable energysources.
oMitsubishi Heavy Industries, Ltd. (MHI) developed the M701D 1,150 C-class large-capacity
gas turbine in the 1980s and demonstrated high plant thermal efficiency and reliability with aliquid-natural-gas-burning combined-cycle generation plant at Tohoku Electric Power Company’s
East Niigata Thermal Power Station 3. This led to the development of the M501F gas turbine withoa turbine inlet temperature of 1,350 C in 1989 and the M501G gas turbine with a turbine inletotemperature of 1,500 C and steam-cooled combustor in 1997, each with improved efficiency andoreliability. Starting in 2004, MHI participated in the national 1,700 C -class gas turbine component
technology development project, concentrating on developing new technologies required for higher
turbine inlet temperatures and efficiency. We have developed the M501J gas turbine, the firstoturbine in the world with a turbine inlet temperature of 1,600 C capable of a combined-cycle
power-generating gross thermal efficiency of 61.5% under ISO normal low heat value (LHV)
conditions (Figure 1). We are also developing the M701J for 50 Hz.
This report describes the features of the M501J gas turbine and the results of its first
verification test conducted at the T-point facility in our Takasago Machinery Works starting inFebruary 2011.

*1

Gas Turbine Engineering Department, Power Systems*3

General Manager, Gas Turbine Engineering Department, Power Systems*2

Chief Engineer, Power Systems*4

Deputy General Manager, Takasago Research & Development Center, Technology & Innovation Headquarters

Mitsubishi Heavy Industries Technical Review Vol. 49 No. 1 (March 2012)
19Figure 1

MHI gas turbine (60-Hz machine) efficiency and output|2. M501J gas turbine features
oThe M501J gas turbine was designed with a turbine inlet temperature of 1,600 C byoo
integrating the proven component technologies used in the 1,400 C F-series and the 1,500 C Gand H-series turbines. The M501J also benefited from the development of key technologies for theonational 1,700 C -class gas turbine project (Figure 2). Adoption of the higher inlet temperature andlatest component technology means that the combined-cycle gross thermal efficiency, which issignificantly better than that of conventional machines, will be 61.5% on a LHV basis (Figure3,Table 1). Therefore, a power plant with a natural-gas-burning J-series combined-cycle plant can
reduce carbon dioxide emissions by approximately 60% compared to a conventional coal-burningthermal power plant.

Figure 2

M501J gas turbine concept

Figure 3

M501J gas turbine features

Table 1 J-series gas turbine performance
Series
Turbine inlet temperature
Rotating speed
Gas turbine output (gross)
Combined-cycle output (gross)
Combined-cycle efficiency(gross，LHV，ISO base)Compressor/pressure ratio
Combustor
Turbine

2.1

M501G
o
1,500 C3,600 rpm
267 MW
399 MW

M501Jo1,600 C3,600 rpm
327 MW
470 MW

58% or higher

61.5% or higher

17 stages/20
16 cans

15 stages/23
16 cans
Row 1 to row 4 blades, air cooled;
Row 1 to row 3 vanes and blades, air cooling;Row 1 to row 3 vanes, air cooled;
Row 4 vane and blade, uncooled
Row 4 vane, uncooled

Overall design

The design of the M501J gas turbine is based on these proven F- and G-series features: The compressor shaft end drive connected to the generator reduces the thermal expansion andeliminates 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 the torque pin in the compressor rotor and adisc with curvic coupling in the turbine rotor to ensure reliable torque transmission.Mitsubishi Heavy Industries Technical Review Vol. 49 No. 1 (March 2012)20

2.2Compressor

The M501J compressor was designed as an axial flow type with a pressure ratio of 23; it wasbased on the technology used in the H-series compressor, which had a pressure ratio of 25.
Three-dimensional (3D) advanced design techniques were used to improve the performance andreduce the shockwave loss in the initial stages and frictional loss in the intermediate and finalstages. This concept was evaluated by 3D computational fluid dynamics (CFD) software andverified using the full-scale high-speed research compressor (Figure 4). Figure 5 shows anexample of 3D CFD analysis results. In addition, bleeding was used in the low-, middle-, andhigh-pressure stages during compressor start-up. Rotating stall on start-up was suppressed, and thepartial-load performance of the combined cycle was improved, by controlling the inlet guide vane(IGV) and three-stage variable stator vanes.

2.3Combustor

The M501J combustor was based on the proven steam cooling system used in G-series gasooturbines. Although the turbine inlet temperature was increased by 100 C from 1,500 C in theoG-series to 1,600 C, the emission density of nitrogen oxide (NOx) was suppressed to the samelevel as that of the G-series through the use of low-NOx technologies, such as reducing the local
flame temperature in the combustion area by improving the combustion nozzle (Figure 6) for morehomogeneous mixing of fuel and air. Air flow tests, atmospheric-pressure combustion tests, andhigh-pressure combustion tests were conducted to verify the performance and reliability, and theresults were applied to the detailed design of the combustor.

Figure 5 Air flow near the compressor endwall(advanced 3D design result)
Figure 4 High-speed research
compressor

Figure 62.4

Improved combustion nozzle region

Turbine

The M501J turbine is an axial-flow, four-stage, high-load, high-performance turbine. To
improve its performance, a 3D endwall contouring was used to control the secondary flow
generated at the endwall, the design of which considered the flow field interference and horseshoe
vortex from the blade leading edge. This was in addition to the complete 3D design used in theG-series turbine. The metal temperature was maintained at the level of a conventional machineoousing the technology developed in the national 1,700 C -class gas turbine project. The 100 C
temperature increase was half offset by high-performance cooling technology and half by anadvanced thermal barrier coating (TBC, Figure 7).

Figure 7

oComponent technologies for a turbine inlet temperature of 1,600 C

Mitsubishi Heavy Industries Technical Review Vol. 49 No. 1 (March 2012)21

Row 1 to row 4 rotating blades and row 1 to row 3 stationary vanes are air-cooled. The row 4blades in the G-series turbine were not cooled, but those in the J-series turbine were cooled to copewith the higher inlet temperature. MGA1400 (Mitsubishi Gas Turbine Alloy) used for the rotatingblades, while the vanes were made of MGA2400. The row 1 to 3 blades were made of DS(directional solidified) superalloy. MGA1400 and MGA2400 were also used in the F-series andG-series gas turbines.
The cooling structure was improved for the F-series and again for the G-series turbine, andthe J-series uses high-performance film cooling and advanced TBC developed in the nationalproject, as shown in Figure 8. The film cooling effectiveness of high-performance film cooling
was tested after selecting the optimum film shape in a flat plate component test, in a large-scale
low-speed rotational test, and in a medium-pressure cascade test (Figure 9 and 10).
High-performance film cooling and advanced TBC were applied to the M501G turbine blades at
T-point, its effectiveness was tested by a special measurement, and then long-term testing of theactual machine took place. The design of the J-series turbine blade was based on these test results,
and the final verification was done using the first M501J gas turbine after conducting thehigh-pressure high-temperature cascade test.

Figure 8 Turbine cooling structure improvement

Figure 10 Result of film
efficiency measurements with low
speed rotating testfacility

Figure 9Low speed Rotating test facility overview|3. Verification test results at the T-point demonstration power plant
In developing the M501J turbine, each component was tested in the basic design stage, andthe results were reflected in the detailed design. Commercial models were produced only after theentire turbine had been tested in T-point.
Figure 11 shows a photograph of the T-point at the MHI Takasago Machinery Works.
T-point was equipped with a M501G gas turbine, a steam turbine, and a heat recovery steam
generator boiler. T-point plant has logged more than 2,300 start and stop cycles and 39,253 total
operating hours and made a huge contribution to improving the performance and reliability of theM501G gas turbine.
Work to convert the M501G turbine to M501J started in October 2010, and operating tests ofthe first M501J gas turbine started in February 2011. The tests proceeded as scheduled with thefirst spin-up on February 2nd and the first ignition on February 7th; the inlet temperature reachedo1,600 C on the seventh start-up. Various tests were then conducted until the end of April when theMitsubishi Heavy Industries Technical Review Vol. 49 No. 1 (March 2012)22

turbine was disassembled and each part inspected. Long-term reliability operational testing started
in July 2011, resulting in 58 start-up tests and 3,540 hours of operation by the end of December
2011 (Figure 12). The special measurement and the test results of each component are described inthe sections that follow.

Figure 11
MHI
Takasago
Machinery Works
T-Point demonstration
combined-cycle power-plant

3.1

Figure 12

M501J test operational record at T-point

Special measurement outline

The M501J turbine at T-point was equipped with at least 2,300 special measuring sensors,
including approximately 100 rotating parts monitors in addition to the more usual monitoring
devices.

3.2

Compressor

The natural frequency, vibration stress of blades and vanes, and pressure fluctuation weremeasured to determine the starting characteristics and the blade/vane reliability in the compressor.
Desirable characteristics, such as the extinction of rotating stall at approximately 60% of therotating speed, were confirmed (Figure 13). Compressor efficiency and inlet air flow weremeasured at each IGV angle to show that the design performance was achievable.

Figure 13

3.3

Compressor starting characteristics

Combustor

The metal temperature, vibration stress, and stress fluctuation were measured in theocombustor. During operation with a turbine inlet temperature of 1,600 C, the metal temperature of
the combustion liner was less than the maximum allowable temperature (Figure 14). Thecombustion pressure fluctuation and vibration stress were confirmed to be within the allowable
range.

3.4Turbine

The metal temperature was measured by installing thermocouples on turbine blades andvanes. The metal temperature of rotating blades was measured using a telemetry system. Theotemperature was verified to be lower than the allowable metal temperature at the 1,600 C inlet
temperature. Figure 15 shows the distribution of the metal temperature on the turbine row 1 vane.
The temperature distributions of the row 1 blade surface and platform were measured with apyrometer. Figure 16 shows a typical temperature measurement of the moving blade platform.
Detuning to the natural frequency was verified across the operational range, and the vibrationstress was verified to be lower than the maximum allowable stress.

Mitsubishi Heavy Industries Technical Review Vol. 49 No. 1 (March 2012)23

3.5

Disassembly inspection result

The gas turbine was disassembled in June 2011, and the soundness of each part wasconfirmed as shown in figure 17. Long-term operational reliability testing then began, and theturbine and combustor were inspected in October 2011.

Figure 14 Metal temperature of combustion lineroat a turbine inlet temperature of 1,600 C

Figure 16 Temperature distribution
on platform in the turbine row 1
blade obtained using a pyrometer

Figure 17

Figure 15 Metal temperature measurementof the row 1 vane

Disassembly inspection result|4. Conclusion
GTCC power generation is the cleanest and most efficient approach to power generation
using combustion of fossil fuels and has many favorable social and economic aspects. MHI hasodeveloped the world’s first 1,600 C J-series gas turbine using technologies developed during theoJapanese national 1,700 C -class Ultra-high Temperature Component Technology Development
project. The first M501J gas turbine has now completed the trial operation. MHI will contribute tothe reduction of carbon dioxide emissions and help stabilize electric power generation with theJ-series GTCC power generation system, which has a gross thermal efficiency of 61.5% (LHVbasis).

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Heavy Industries Technical Review Vol. 47 No. 1 (2010) pp. 19-25
Ito. E. et al., Development of Key Technologies for an Ultra-high-temperature Gas Turbine, Mitsubishi
Heavy Industries Technical Review Vol. 48 No. 3 (2011) pp. 1-8
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1600degree C J class gas turbine, IGTC, IGTC2011-0189