The document discusses Alstom's GT11N EV-alpha burner, an innovative upgrade to reduce NOx emissions from gas turbines. It achieves NOx emissions below 10ppm at base load and reduces emissions at upper part loads by 40% without negatively impacting performance. The burner was successfully tested at a power plant in Taiwan and additional units were ordered after confirming reduced emissions and improved pulsation behavior. The EV-alpha burner can be retrofitted during standard inspections and improves compliance with emissions regulations.

1. TPW/BPROS/GT11-EVAB/eng/GAS/10.12/CH/7758 © ALSTOM 2012. All rights reserved. Information contained in this document is indicative only. No
representation or warranty is given or should be relied on that it is complete or correct or will apply to any particular project. This will depend on the technical and
commercial circumstances. It is provided without liability and is subject to change without notice. Reproduction, use or disclosure to third parties, without express
written authority, is strictly prohibited. Alstom contributes to the protection of the environment. This leaflet is printed on environmentally-friendly paper.
The EV-alpha burner is
an innovative upgrade
that combines a hardware
improvement with
operational optimisation
to reduce NOx emissions.
It meets the need for
lower cost compliance and
offers operational benefits
in an easy to implement
package.
Gas SERVICE Solutions
GT11N EV-Alpha Burner
Evolution for lower emissions
for EV combustion chamber
State-of-the-art combustion
technology
The need for operational flexibility and the challenge of complying with stricter emis-
sions regulations are top of the agenda of every power plant owner. Alstom’s ongo-
ing investment in burner technology has culminated in the new EV-alpha burner for
GT11Nx gas turbines with fuel gas.
Building on the proven features of Alstom’s standard EnVironmental (EV) burner, the
EV-alpha burner employs the latest state-of-the-art combustion technology and brings
nitrous oxide (NOx) performance down to single digit parts per million (ppm) under
base load conditions. All other parameters are unchanged or improved.
Key technology features
• NOx emissions at base load down to <10ppm
• NOx emissions at upper part load reduced by 40%
• Significant emissions reductions down to gas turbine relative loads of 30%
• Improved pulsation behaviour during steady-state and transient operations
• Dry operation (no water/steam injection needed)
• Dual fuel capability unaffected
Scope
• Complete EV-alpha burner set
• Improved operation concept
CUSTOMER BENEFITS
Emission reduction
Comply with emission
regulations to maximise
income due to increased
utilisation
Reliability
Enhanced combustion
reliability due to improved
pulsation behaviour
Convenient implementation
Fully-retrofittable – compatible
with all available Alstom
upgrade packages during
standard C-inspection
or slightly extended A-
or B-inspection

2. TPW/BPROS/GT11-EVAB/eng/GAS/10.12/CH/7758 © ALSTOM 2012. All rights reserved. Information contained in this document is indicative only. No
representation or warranty is given or should be relied on that it is complete or correct or will apply to any particular project. This will depend on the technical and
commercial circumstances. It is provided without liability and is subject to change without notice. Reproduction, use or disclosure to third parties, without express
written authority, is strictly prohibited. Alstom contributes to the protection of the environment. This leaflet is printed on environmentally-friendly paper.
For more information
please contact Alstom Power:
ALSTOM (Switzerland) Ltd.
Brown Boveri Strasse 7
5401 Baden
Switzerland
Visit us online: www.alstom.com
Gas SERVICE Solutions
GT11N EV-alpha burner
Enhanced combustion for lower emissions
The EV-alpha burner is an innovative replacement product based on the best available
technology and insights. The original Alstom EV burner already set a high performance
standard. But the new EV-alpha burner has improved the fuel gas mixing and produces
an even more stable flame. Pulsation is reduced in both steady and transient states,
which reduces the risk of flame out failures. Furthermore, the improved fuel gas mixing
further reduces the NOx levels without the need for water or steam injection.
Overall with the EV-alpha burner you reduce the NOx emissions at upper relative part-
and base load by 40% (down to 10ppm NOx at base load) without any negative impact
on the performance or the component lifetime. All other emissions, such as carbon
monoxide (CO) or unburned hydro carbon (UHC) are kept at the same level.
Reference
The EV-alpha burner implementation was successfully performed at Tung Hsiao
combined cycle power plant (6 x GT11N gas turbines, Taiwan), during a slightly
extended A-inspection. Sensors were installed temporarily in 6 burners to verify
the combustion characteristics while emissions of all gases were measured during
commercial operations over the full load range. Both oil and gas firing was also
verified.
The results confirmed the emissions reductions specifications and improvements of the
pulsation behaviour. Reference measurements after 8 months of operation at reduced
ambient temperature confirmed the excellent emission and pulsation behaviour.
Based on the excellent results, the customer ordered five additional EV-alpha sets for
the remaining gas turbines to further reduce total emissions at the plant. Three sets are
already implemented while the two remaining sets are scheduled for implementation
during the next C-inspection (status October 2012).
Application
The EV-alpha burner can be
implemented during a standard
C-inspection or slightly extended A- or
B-inspection and is retrofittable on any
GT11N with an EV combustion chamber.
NOx emissions reduced by 40% in upper part- and base load
Relative GT load [%]
On-site NOx emission measurements
(site conditions); single switched burner configuration
0
0
10
20
30
40
50
60
70
80
90
100
110
120
10 20 30 40 9050 60 70 80 100
NOx@15%O2[ppm]
GT11NM unit pre-emission measurements, standard EV-burners Site conditions:
27°C/81°F ambient, fuel gasNot measured, typical NOx range
GT11NM unit pre-emission measurements, EV-alpha burners
EV-alpha burner & standard compressor
EV standard burner & standard compressor
< 10ppm NOx
at 100% GT load
with EV-alpha
burners