Retrofit Kits For GE Aeroderivatives To Enhance Reliability, Increase Output, Reduce Emissions
--ANAHEIM, CA -- Users of GE Marine & Industrial Engines'
(M&I) aeroderivative gas turbines can enhance
maintainability and reliability, increase power output and
reduce emissions by applying GE's retrofit kits on existing
LM units.Many of the retrofits offered can be tailored to specific
customer needs and can be performed on-site to maximize
availability while reducing maintenance costs. The kits are
intended to help users:
- increase revenue by improving power output and
increasing availability and reliability.
- reduce operating costs by increasing engine
efficiency, enhancing parts life and reducing operating
and maintenance costs
The popular LM2500 aeroderivative gas turbine is used to
illustrate the types of retrofit packages offered by M&I:
Maintainability/Reliability
LM2500: PE/PH Stage 1 high-pressure turbine nozzle with
thermal barrier coating -- a thermal barrier coating is
applied to the stage 1 high-pressure turbine nozzle of the
LM2500 to enhance part life and repair. This enhancement
can be incorporated as a set of individual nozzle segments
or a modular assembly.Condition monitoring -- a variety of condition monitoring
devices are available for the LM2500 to provide on-line
remote monitoring of compressor performance to evaluate
overall gas turbine performance. For example, a
high-pressure compressor can be monitored with a variable
stator vane position transducer and signal conditioner, as
well as a T3 temperature sensor. Condition monitoring
devices can be installed on-site during routine maintenance.
Power Output/Efficiency Enhancement
Upgrade from PC to PE model -- the key factor in this
upgrade is the replacement of the two-shank bladed
high-pressure turbine with the improved technology based on
single-shank blades. This enhanced air-cooled design uses
special cored turbine blade castings and permits the
turbine blade to operate at both lower temperatures and
stress levels than the LM2500PC.Upgrade to PE steam model -- steam injection can be used in
the standard LM2500PE model to enhance power output,
improve thermal efficiency and suppress NOx . With the
upgrade to the steam model, steam is injected into the
compressor discharge port to increase power from 23.2
megawatts to 25 megawatts (ISO conditions).
Upgrade to PE STIGĂ´ (Steam Injected Gas turbine) system --
the highest rating configuration for the LM2500PE uses the
STIG system to enhance power output and suppress emissions.
For the STIG upgrade, steam is injected into both
combustor and compressor discharge pressure manifolds.
Since the STIG system is capable of changing the steam
injection rate rapidly, this type of configuration is ideal
for cogeneration applications with varying process demands.
In this case, the power increases from 23.2 megawatts to
28 megawatts, a 21% greater output.
Upgrade from PE to PH STIG -- the PE configuration can be
upgraded to the PH STIG model. This gas turbine is
identical to the standard steam-injected LM2500PE STIG, but
includes internal hardware modifications which increase
high-pressure flow function by 2.2% and decrease
low-pressure turbine flow function by 5%. These
enhancements permit the injection of increased rates of
steam to further improve power output and thermal
efficiency.
Emissions Reduction
Dry Low Emissions (DLE) system -- the DLE design provides
very uniform mixture of fuel and air, a primary requirement
in achieving low NOx levels. The DLE retrofit kit for the
LM2500 is designed to meet emissions levels of 25 ppm NOx ,
25 ppm CO and 5 ppm UHC. This system does not affect power
output.
Wet Low Emissions system -- users of an LM2500 without
water or steam injection systems can choose from several
wet retrofit options for existing units. Choices include
gas/water, gas/steam, dual fuel/steam. Wet technology
systems for the LM2500 are designed to achieve NOx levels
as low as 15 ppm, depending on the type of fuel and the
volume of water or steam injected.
Retrofits can be performed by M&I, its OEMs or its
authorized depots. M&I is currently developing other
retrofit kits to meet end users' needs.
Retrofit Orders
To date, M&I and its OEMs have secured the following orders
for its retrofit kits:
PEMEX/LM2500 uprate -- MTU Maintenance GmbH will install
an uprate retrofit kit on an LM2500 compressor drive gas
turbine owned by PEMEX, Mexico. This project marks the
first sale of this type of retrofit kit for a compressor
drive unit. The unit will be uprated from an LM2500PC to
an LM2500PE model, and the unit's output will be enhanced
to 31,200 shaft horsepower (shp) at ISO conditions from the
present 27,500 shp rating.
TBG Cogen/LM2500 emissions reduction -- two LM2500s at the
TBG Cogen plant in Hicksville, NY, recently were
retrofitted with new emissions reduction systems. This
project, which was completed during a routine maintenance
in April 1995, marked the first application of steam
injection for NOx reduction on dual fuel LM2500s. The
systems enable the gas turbines to meet New York state
mandated RACT (reasonable available control technology)
emissions requirement.