Fig. 15-1 below shows an elevation view of a turbine rotor installed in its lower-half casings. The rotor is resting on its journal bearings (fore and aft), with the three turbine stages on the left and the 17-stage compressor on the right. This is a factory view from above often referred to as “rotor on the half shell.”
In Fig. 15-2 below, the rotor is supported by temporary bearings in a balance machine, where it can be spun at a low speed (typically 200-300 rpm). Although the turbine blades (called buckets in GE parlance) are “moment weighted” for pre-balance, a dynamic test is required to assure that the amount of tolerable unbalance (measured in gram-inches) is met before the rotor is installed in the turbine casings.
A more modern gas turbine (MS6001FA shown in Fig. 15-3 below) is ready for transport from the factory in Greenville, SC. Notice that the combustors are not yet installed nor are many of the extraction cooling and sealing air pipes from the axial-flow compressor.
Fig. 15-4 below shows a Frame 6FA rotor in its lower half casing as viewed from the compressor inlet end. Lower half inlet guide vanes are shown in the bellmouth.
In Fig 15-5, a factory assembler checks radial clearances on the #1 bearing forward seal at the compressor end of a Frame 6B gas turbine.
The MS6001 gas turbine is no longer made at the Greenville, SC plant. They are, however, manufactured in Europe at one of GE’s affiliates. Also, spare parts are made abroad for existing turbines installations in the USA. Companies other than GE also offer replacement parts in competition with the OEM. With the advent of the Frame 6B in the early 1980s, GE also offered a computer-based control system called Speedtronic™ Mark IV. A photo of a typical panel and control functions is shown in Fig. 15-6. Crude by today’s standards, this was considered a “state of the art” control system in the early 1980s.
Also, in the early 1980s, General Electric recognized another emerging market for gas turbines: combined cycle (CC). They had applied gas turbines to CC in earlier years. However, the MS7001E (a.k.a. Frame 7E) was reapplied to generate power, as well as to provide exhaust flow to an HRSG to create steam for a steam turbine. Note: The CC plant differs from the Co-genin that steam in the former system is not sent outside the plant for some nearby industrial process.
The design of the 7E closely resembles predecessors (7B & C) of lesser power generating capacity. However, the 7B had longer combustors that ran parallel to the centerline similar to the one shown below in Fig 15-7.
Sometimes the steam and gas turbine shafts were co-linear, with the generator in the middle of the drive train (dual end drive). This configuration (gas turbine-generator-steam turbine) was known as Steam Turbine And Gas (STAG). See Fig. 15-8 below for the 9E turbine. One of the most famous combined-cycle (CC) installations was a plant located in Futsu, Chiba prefecture in Japan. Tokyo Electric Power Company (TEPCO) reclaimed approximately 4 square miles of land from Tokyo Bay and installed fourteen MS9001E combined-cycle power plants that eventually generated over 2,000 MW in 1998. At the time, it was the largest CC plant in the world. Might still be.
In 1983, I joined the installation team at TEPCO on assignment for the installation of the first seven STAG 109E power plants. A total of fourteen Frame 9E units were eventually installed over a five-year period. Start-up came in 1988, on schedule, of course. Note: The Japanese had a charming habit of changing their schedule so they were always precisely on time. It would be an embarrassment to be either ahead of (or behind) the published “planned” schedule in any Japanese business venture. Most Americans would have just shrugged and responded: “ No big deal?”
I served as the on-site service manager for General Electric Technical Services Company (GETSCO)and lead technical advisor for most of the first two years. My staff included:
- Alfred Shuman, senior gas turbine technical advisor (TA)
- Bill Romizer, senior steam turbine and generator TA.
- Tom Hamilton, senior TA for the HRSG boiler installations
- Dave Smith, senior start-up TA for the Speedtronic™ Mark II controls
The TEPCO project was enormous. We had a total of GE 15 technical advisors at the site and a grand total of twenty on the GE staff, including office help. The client had hundreds of employees, as was the norm for Japanese firms. Also, GE affiliate companies, Hitachi and Toshiba, each built one complete unit (gas and steam turbines and their respective generators) in their Japanese factories. General Electric built 12 complete plants. All HRSG were built in the USA. Mitsui provided the interface between the Americans and the Japanese. Then this is what happened: After nearly two years in Japan, I returned to the USA in the spring of 1985.
My first year back in the USA was spent “soul searching” and I eventually resigned from GE in 1986. I started my first company, I&SE Associates of Schenectady, Inc., on the Monday after my last day with GE. The letters I&SE were a takeoff on the original GE turbine service group that they changed in 1980 called: Installation & Service Engineering, hence then letters I&SE. Note: I’m sure some people at GE minded that I did this, but my company was such “small potatoes” that nobody called me on it. Heck, if GE didn’t want to call their service engineering by that name anymore, I figured I would. It served me well for a dozen years into the late 1990s.