GE's new machines aim for better performance5 September 2002
While GE may be battening down the hatches in the face of shrinking power generation demand projections, there seems to be no loss of nerve when it comes to launching new turbine technologies into the market.
In the past few months GE has introduced no less than three new gas turbine designs - the Frame 9FB, the Frame 6C, the Frame 5E - and a new steam turbine line, snappily dubbed HEAT.
Described by GE as "the world's most advanced air-cooled, 50-hertz gas turbine," the GE MS9001FB, to give it its full title, is the 50 Hz version of the FB.
The 60 Hz version, the Frame 7FB, was introduced by GE in 1999 and the first of these was installed at a Reliant Energy project in Hunterstown, PA, USA, where it is being tested and is scheduled to enter commercial service in 2003.
The Frame 9FB will "deliver new levels of fuel efficiency and output for large, air-cooled combined-cycle systems", says GE. The Frame 9FB configured with the new HEAT steam turbine in combined cycle operation is designed to produce 412 MWe and will achieve nominally 58 per cent net plant thermal efficiency. This compares with 391 MWe and 56.7 per cent for GE's existing 50 Hz F machine, the 9FA.
The 9FB is described by Mark Little, vice president of GE Energy Products, as "the latest evolutionary step for GE's F technology and is based on continuing advancements in turbine technology and materials." The F technology recently passed the milestone of 5 million hours of commercial service.
The Frame 9FB also benefits from what GE calls an "advanced technology flowback" from the company's steam-cooled H System. The first H, at Baglan Bay, Wales, UK, is due to be starting up in the near future. The H system is the world's first combined cycle plant with the capability of reaching 60 per cent thermal efficiency.
Like the 7FB, the new 9FB features an aerodynamically redesigned turbine section employing single crystal material on the first stage buckets, and other improved materials used in the H System. These advanced materials have also been used in GE aircraft engines since 1988, and are "well-proven in millions of hours of reliable service," according to GE.
These improvements have enabled F technology to advance from a 2400°F (1316°C) class to a more than 2500°F (1371°C) class firing temperature, with consequent increases in thermal efficiency, and reduced fuel costs. As fuel is the single largest expense in the long-term operation of a power plant, "improved life-cycle cost is the single most important benefit the new 9FB will bring to our customers," said Little.
The 9FB will be equipped with GE's advanced Dry Low NOx2+ combustion system and NOx emissions will be less than 25 ppm. The new machine also will feature GE's advanced Speedtronic Mark VI control system.
The Frame 9FB will be available for shipment in early 2004.
Meanwhile, with its new 40 MW class MS6001C gas turbine, GE says "it is bringing the high efficiency and performance of its large, advanced gas turbine technology" into this size segment of the market. This, says GE, is another case of "flowback", this time from F technology experience into the smaller machines.
The first two Frame 6C gas turbines are being purchased by Akenerji of Turkey, to be installed at the company's Kemalpasa-Izmir combined cycle power plant. These gas turbines are scheduled for delivery to the site in early 2004.
Akenerji is hoping the new machines will help to give it the competitive advantage in the deregulating Turkish energy market.
GE says the 6C builds on experience with its established Frame 6B technology, which has achieved over 40 million hours of commercial operation, as well as incorporating features from F technology gas turbines.
The company emphasises that the 6C is an evolutionary design, incorporating well-proven features.
The Frame 6C will offer simple cycle efficiency of 36.3 per cent, with an output of 42.3 MW. Optimised for heat recovery applications, the new machine will achieve 54.4 per cent efficiency and 126.7 MWe of output in a GE 206C (two gas turbines, two heat recovery steam generators, one steam turbine) configuration.
The 6C will achieve NOx emissions below 15 ppm when operating on natural gas.
Main applications envisaged for the Frame 6C are industrial cogeneration, process industries, municipalities (district heating), CHP, and mid-sized combined cycle projects.
The new gas turbine will be manufactured in GE's facilities in Europe, and will serve both the 50 Hz and 60 Hz markets worldwide.
Moving down the size range, the new two-shaft 30 MW Frame 5E gas turbine (MS5002E) is designed primarily for mechanical drive applications in the oil and gas industry (pipelines, natural gas reinjection and liquefaction) - a market that remains buoyant. But it will also will be available for power generation.
The 30 MW niche is an area of the market that has been receiving growing attention from gas turbine suppliers in recent times, most recently from Alstom, with the launch of its GT10C.
This new GE machine is designed for simple cycle efficiency of more than 36 per cent and 51 per cent in combined cycle.
The high efficiency is achieved, despite the relatively low firing temperature, through the use of advanced tools to define, design and optimise air foils, clearances and cooling flow distribution.
The Frame 5E will achieve NOx emissions levels of 25 ppm or less, using a dry low emissions combustion system derived from the GE Dry Low NOx (DLN) 2 system. The DLN 2 is a single-stage, dual mode combustor system that has been installed on GE's F technology gas turbines and operates with gaseous fuel. Future development will include liquid fuel capability.
Key components of the Frame 5E include:
• An 11-stage, high-pressure-ratio, axial flow compressor directly scaled up from the GE10 gas turbine compressor.
• An axial flow, two-stage reaction, high-pressure turbine with air-cooled nozzles and buckets, designed for high efficiency over a wide power range.
• A low-pressure turbine that is the same module used in the GE LM2500+ aeroderivative gas turbine.
This design enables the Frame 5E to offer aeroderivative-quality performance and low emissions, with heavy duty reliability and availability, says GE.
The expected introductory performance of the Frame 5E at ISO conditions is as follows:
LPT shaft speed 6100 rpm
Output (shaft) 30 MW
Simple cycle efficiency (shaft) 36.4 per cent
Combined cycle efficiency 51.1%
Combined cycle output 46.1 MW
Exhaust temperature 523 °C
Exhaust flow 96 kg/s
A comprehensive test programme, including full-scale testing of the axial compressor, a full-scale rotordynamic test and combustion system tests, has been completed.
A full-load prototype test will be performed to validate the overall system, including engine and auxiliaries.
The Frame 5E will be manufactured at the GE Oil & Gas gas turbine plant in Florence, Italy, and the first unit will be available for commercial operation in the first quarter of 2004.
The Frame 5E gas turbine is designed for both 50 and 60 Hz applications.
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