GE LM2500+: Packing A More Powerful Punch

Market demand for more powerful machines led GE Marine & Industrial Engines' (M&IE) to expand its aeroderivative product line, resulting in the recent introduction of the LM2500+ gas turbine.

With a design based on the popular LM2500, the new LM2500+ is designed to provide lower installed and life-cycle costs than its predecessor, while providing up to a 25 percent increase in power output.

Combined with minimal changes to the gas turbine package design, the LM2500+ will also provide a reduction in the dollars-per-kilowatt.

The LM2500+ will be initially offered at 37,000 shaft horse power (shp) and 27.6 MW, with a simple cycle thermal efficiency of more than 37 percent. It is expected that the engine will achieve standards for reliability in excess of 99.6 percent, and availability above 96.5 percent.

Once enough experience has been accumulated on the new gas turbine to ensure it maintains high reliability standards, it will be uprated to its design rating of39,000 shp, 29 MW and a thermal efficiency of 38 percent. Shipment of the first production engine is scheduled for the first quarter of 1996.

Marketing The LM2500+ The two-shaft LM2500+ is aimed at the industrial and commercial marine markets for various power generation applications in the 50- and 60-Hz markets, pipeline compression and mechanical drive, and fast ferry commercial marine use.

Emissions controls available from introduction of the LM2500+ will include water or steam injection using a standard combustor or the LM2500 Dry Low Emissions (DLE) combustion system.

Performance By Design The new LM2500+ incorporates several enhanced design elements, including: • Compressor Rotor: The current LM2500has a 16-stage compressor.

The LM2500+ will have a 0-stage added to increase compressor airflow by approximately 20 percent.

This wide chord bladed disk forward of stage 1 will be based on aircraft engine technology. M&IE's re-design of stage 1 blades CF6- 80C2 to wide chord configuration will eliminate the mid-span dampers.

A CF6-80C2/LM6000 rotor airfoil design will also be added to stages 2 and 3. CF6-80C2/LM6000 stages will be incorporated into the compressor to improve compressor efficiency. Additional changes to the compressor include a new inlet guide vane assembly.

• High Pressure Turbine Rotor & Stator: These components will be redesigned to reduce maintenance costs, and will include new materials for improved oxidation life. Stage 1 and 2 contours will be optimized for higher flows.

• Power Turbine: Aerodynamically coupled with and driven by the exhaust gas from the gas generator, the LM2500+ power turbine will be redesigned for the higher power output.

The Stage 1 and 6 blades are optimized for aerodynamic efficiency.

The power turbine rotor has been strengthened for the higher torque and potential energy of the LM2500+.

The changes make the LM2500+ 13.5 in. (34.3 cm) longer than the 21.4-ft. (6.52-m) LM2500. The weight, in any configuration, is not expected to increase more than 800 lbs.

Operating on natural gas at the design point rating, the LM2500+'s expected hot section repair and overhaul intervals are 25,000 and 50,000 hours, respectively.

M&IE has produced more than 1,300 LM2500 marine and industrial gas turbines to date.

For m o r e i n f o r m a t i o n on GE Circle 11 on R e a d e r Service C a rD

Other stories from September 1994 issue


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