In the early 1980s, General Electric recognized an emerging market for gas turbines called cogeneration (co-gen).  The MS6001B (a.k.a. Frame 6B) was introduced at this time to meet the demand.  In co-gen applications, the 6B provides exhaust heat to a heat recovery steam generator (HRSG).  This allows steam generation for a “host” company located next door and a secondary “by product” called electricity.  Thus, its primary purpose was to deliver low-pressure steam next door for a completely different industrial purpose. In upstate New York, Frame 6B plants were installed next door to several paper mills, a Morton Salt plant, and even the Remington Fire Arms manufacturing plant.  The high-pressure steam (typically 900 F at 800 psig) generated by the HRSG was sent to a separate steam turbine in the co-gen facility, acting as a pressure reducing station.  After passing through several turbine stages, some steam flow was then sent to the “host” next door, typically at a pressure in the range of 200 psig.  The remaining steam flow continued through the low-pressure turbine stages to the condenser.  Both gas and steam turbine generators were connected to an electrical grid.  The 6B gas turbine was considered to be kind of a hybrid between two Frame Sizes: 5P and 7C.  The 17-stage compressor in the 6B was similar to that of the 5P; however, the turbine section was more like a 7C, with its three turbine stages. In the combustion area, the design of the 6B closely resembles its smaller predecessor the 5P, except that the ten combustions are “canted” to shorten the overall length and preclude the need for an intermediate bearing to support the rotor like that of the 7C turbine.  Also, the early 5P and 7C turbines utilized the familiar straight-through combustors, running in parallel with the rotor centerline.

  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.”

Fig. 15-1- Areal View of MS6001B with Upper Casings Removed and Rotor in Place (circa 1985)

  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.

Fig. 15-2- Factory View of MS6001B Rotor in Balance Machine (circa 1985)

  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. 15-3- Modern MS6001FA gas turbine (circa 2000)

  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.

Fig. 15-4- Modern MS6001FA axial-flow compressor and inlet guide vanes (circa 2002)

  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.

Fig. 15-5- Modern MS6001 gas turbine #1 bearing clearance checks

  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.

Fig. 15-6- Speedtronic™ Mark IV Control Panel

  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.

Fig. 15-7- MS7001E Colored Cross-sectional Rendering

  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.

Fig. 15-8- MS9001E Colored Rendition – Accessory Base and Turbine

  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

Fig. 15-9- Part of the GETSCO staff at TEPCO-Futsu (exhaust towers in background)

  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.

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