GE new aeroderivative

September 15 2011 - TI Staff

The latest LM6000 from GE has been released and is being showcased as the aeroderivative element of its recently released FlexEfficiency program. GE unveiled the machine at its Aero plant in Houston, Texas, during the week of the Turbomachinery Symposium.

Known as the GE FlexAero 6000-PH, it is a 50 MW gas turbine with a new Dry Low Emission (DLE) combustor known as DLE 2.0 which allows the unit to meet low emissions standards without the need for water.

“The GE FlexAero 6000-PH provides flexibility, efficiency and speed while addressing water concerns,” said Steve Bolze, CEO of GE Power and water.

With over 1000 LM6000s shipped and more than 21 million operating hours to date, it can go from zero to full power in less than 10 minutes. A 5-minute fast start option is also avaialble.  GE promises that once the hardware is onsite, the plant can be up and running within 70 days and can achieve 99% reliability.  Efficiency wise, it can reach 42% simple cycle and 55% when operated as part of a combined cycle facility.

Corey Nelson, GE’s General Manager for its LM6000 and LM2500 product lines, discussed the technical changes to the LM6000. This, he said, is the third generation of the machine.  Earlier generations were based on the CF6-80C2 aircraft engine whereas this one is based on the CF6-80E1 engine. As a result, it can function at higher temperatures – about 60°F hotter – and can spin about 10% faster.

“That makes the LM6000-PH able to pull about 25% more power and have 18% more exhaust in the same footprint as previous generations,” said Nelson. 

He feels confident that this unit will sell well as customers seem to be keen on buying 50 MW blocks of power. With good reliability and efficiency, he said, the machine can deal with whatever the market throws at the user i.e. ramping up or down rapidly or coping well with different operating modes. 

“50 MW is a popular block of power MW for many applications,” said Nelson.

In actuality, the LM6000-PH has an output of 48 MW at ISO conditions. When a Sprint unit is added, it adds about 4 MW. Hence the company uses 50 MW as an average output amount.

The Sprint system for the LM6000-PC/PD injected water into the High Pressure (HP) and Low Pressure (LP) combustor. With the LM6000 PH, however, water only needs to be injected into the LP combustor to provide the same amount of power augmentation. 

GE’s DLE 2.0 combustor differs from the previous generation in several respects. Instead of three rows of premixers, the company now prefers two rows of larger premixers as a means of achieving the same emissions level of 15 ppm NOx.

“This is a simpler design with fewer fuel valves that provides improved operability,” said Nelson.

Billion Dollar Year
Bolze announced that the company had achieved more than $1 billion in turbine orders in North America since the end of last year. This includes large frame turbines as well as aeroderivatives.

“Several factors are driving strong interest in gas,” said Bolze. “The recent increase in production has helped to ensure reliable supply and a consistent price structure, making natural gas an economically viable, dependable option for power generation needs.

Darryl Wilson, GE’s Vice President of Power and Water Aero Products, explained the ramp up rate of 50 MW per minute. Once the engine is turned on, it takes a few minutes to get ready then one minute to reach full power. 

On the water side, no water is required in general to run the turbine. However, if a Sprint system is employed, it now consumes 55 gpm less than the previous generation.

“This provides a typical savings of 26 million gallons of water per year,” said Wilson.