GE lowers emissions with LM2500 upgrade
GE undertook this LM2500 DLE gas turbine retrofit at the Helmond power station owned by Essent Energie (formerly PNEM Energy Systems). The Dutch utility operates this distributed power, district heating plant in Helmond, just east of Eindhoven in the Netherlands.
To date, GE Aeroderivative and Package Services (GEAPS) has contracted for or performed DLE conversions on an additional eight LM2500s. DLE conversion kits also are available for standard combustor LM1600 and LM6000 gas turbines.
Project Background
After 10 years in service, the Helmond unit reached 50,000 fired hours and was scheduled for a major gas turbine overhaul. This is when Essent Energie opted for a DLE retrofit to meet increasingly stringent emissions regulations.
The existing unit was removed from service on August 10, 1999 during the low consumption season. The customer allowed two months to complete the engine exchange and package upgrade project. The upgraded package and new LM2500 DLE gas turbine successfully resumed service on October 15.
Retrofit Benefits
Existing owners of LM2500 aeroderivative gas turbines with standard combustion systems can improve unit efficiency and reduce life cycle costs by performing a DLE package modification and engine exchange. Other benefits include:
- Improved NOx emissions on gas fuel without catalyst
- Elimination of combustor erosion common with water injection
- Elimination of need for water/steam injection
- No water treatment and support equipment required
- Lower CO at lower NOx (25 ppm at 60% to 100% power)
- Reduced cost if upgrade is performed during scheduled outage to avoid lease engine removal and installation.
Retrofit Description
Following a typical LM2500 DLE retrofit, the unit will yield 25 ppm NOx and 25 ppm CO on gas fuel without steam or water injection for emissions control. The low NOx and CO are achieved by incorporating lean pre-mix combustion and by close control of the combustion flame temperature.
Flame temperature is controlled using two basic principles: Staged combustion, with sections of the combustor turned off at low power; and by maintaining the proper fuel/air ratio
using bleed air from the compressor.
GEAPS will make these basic hardware changes during the retrofit to meet the current LM2500 DLE model design (see Figure for cross section of major DLE retrofit component changes):
- Compressor rear frame, combustor case, and stage 1 high-pressure turbine nozzle
- Combustor, fuel nozzles (premixers), and fuel system (manifolds, etc.)
- Package changes to control system and module
The retrofit can be done in conjunction with any scheduled event including a hot section repair or overhaul. The engine exchange requires a few days during the package conversion defined below and eliminates the need for a lease engine.
The package upgrade is done on site and takes approximately three to four weeks (will vary by OEM/package). This requires site shutdown for package and control modifications. Once the engine is re-installed, it will take about one week for start-up and DLE checkout. Following the retrofit, all major interfaces will be compatible with lease DLE engines. DLE manuals will be applicable and provided with upgrade, and the exchange engine will be covered by GE's 12-month warranty.
GE Power Systems (http://www.gepower.com) is one of the world's leading suppliers of power generation technology, energy services and management systems with 2000 revenues of $15 billion. The business has the largest installed base of power generation equipment in the global energy industry.
For additional information contact:
Kimberly Minter, GE Power System, tel: (713) 803-0316, fax: (713) 803-0390, email: kimberly.minter@ps.ge.com
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