Staged Premix EV Combustion in Alstom’s GT24 Gas Turbine Engine

2012 ◽  
Author(s):  
Daniel Guyot ◽  
Thiemo Meeuwissen ◽  
Dieter Rebhan
Keyword(s):  
Gas Turbine ◽  
Distribution System ◽  
Fuel Oil ◽  
Operational Flexibility ◽  
Nox Formation ◽  
Diffusion Type ◽  
Fuel Gas ◽  
Start Up ◽  
Reduce Emissions ◽  
Ev Burner

Reducing gas turbine emissions and increasing their operational flexibility are key targets in today’s gas turbine market. In order to further reduce emissions and increase the operational flexibility of its GT24, Alstom has introduced an internally staged premix system into the GT24’s EV combustor. This system features a rich premix mode for GT start-up and a lean premix mode for GT loading and baseload operation. The fuel gas is injected through two premix stages, one injecting fuel into the burner air slots and one injecting fuel into the centre of the burner cone. Both premix stages are in continuous operation throughout the entire operating range, i.e. from ignition to baseload, thus eliminating the previously used pilot operation during start-up with its diffusion-type flame and high levels of NOx formation. The staged EV combustion concept is today a standard on the current GT26 and GT24. The EV burners of the GT26 are identical to the GT24 and fully retrofittable into existing GT24 engines. Furthermore, engines operating only on fuel gas (i.e. no fuel oil operation) no longer require a nitrogen purge and blocking air system so that this system can be disconnected from the GT. Only minor changes to the existing GT24 EV combustor and fuel distribution system are required. This paper presents validation results for the staged EV burner obtained in a single burner test rig at full engine pressure, and in a GT24 field engine, which had been upgraded with the staged EV burner technology in order to reduce emissions and extend the combustor’s operational behavior.

Development and Design of Alstom’s Staged Fuel Gas Injection EV Burner for NOx Reduction

2007 ◽  
Author(s):  
Martin Zajadatz ◽  
Rudolf Lachner ◽  
Stefano Bernero ◽  
Christian Motz ◽  
Peter Flohr
Keyword(s):  
Gas Turbine ◽  
Distribution System ◽  
Nox Reduction ◽  
Gas Injection ◽  
Hole Injection ◽  
Test Facility ◽  
Fuel Gas ◽  
Turbine Engine ◽  
Operating Range ◽  
Ev Burner

Alstom’s combustion development on the EV burner concept has taken another step forward with the introduction of a staged premix system, which allows even lower NOx values also at lower part load values compared to the pilot/premix EV burner. The development target was achieved by introducing one fuel stage over the conventional EV fuel lance, while other fuel stage is realized with a gas hole injection pattern over the EV air slots, similar to the conventional EV burner system. Due to this no major design modifications for the EV burner system were required, and the new system is fully retrofittable to the existing GT26 gas turbine engines including the existing fuel distribution system. The final design is a result of a step-by-step development. In a first step, variants defined in a feasibility study by CFD calculations indicated that a staged fuel gas injection over the fuel lance could substitute a part of the conventional premix gas injection. The water tunnel tests results performed with the LIF measurement technique demonstrated the improved mixing properties of the staged EV burner in the burner flow field. With a single burner test facility under atmospheric pressure conditions the broad operating range of the staged EV burner system could be confirmed. The single burner tests allowed investigation of the low NOx operating range for the burner system also with respect to flame generated instabilities. Finally the burner system was validated with gas turbine engine tests at the Alstom GT Test Power Plant in Birr, Switzerland, which demonstrated the excellent combustion performance of the staged EV burner system derived by the development procedure.

Experimental Study of a 200 kW Partial Oxidation Gas Turbine (POGT) for Co-Production of Power and Hydrogen-Enriched Fuel Gas

2009 ◽  
Author(s):  
Joseph Rabovitser ◽  
Stan Wohadlo ◽  
John M. Pratapas ◽  
Serguei Nester ◽  
Mehmet Tartan ◽  
...  
Keyword(s):  
Experimental Study ◽  
Gas Turbine ◽  
Partial Oxidation ◽  
Synthesis Gas ◽  
Combustion Products ◽  
Working Fluid ◽  
Fuel Gas ◽  
Lean Combustion ◽  
Start Up ◽  
Oxidation Reactor

Paper presents the results from development and successful testing of a 200 kW POGT prototype. There are two major design features that distinguish POGT from a conventional gas turbine: a POGT utilizes a partial oxidation reactor (POR) in place of a conventional combustor which leads to a much smaller compressor requirement versus comparably rated conventional gas turbine. From a thermodynamic perspective, the working fluid provided by the POR has higher specific heat than lean combustion products enabling the POGT expander to extract more energy per unit mass of fluid. The POGT exhaust is actually a secondary fuel gas that can be combusted in different bottoming cycles or used as synthesis gas for hydrogen or other chemicals production. Conversion steps for modifying a 200 kW radial turbine to POGT duty are described including: utilization of the existing (unmodified) expander; replacement of the combustor with a POR unit; introduction of steam for cooling of the internal turbine structure; and installation of a bypass air port for bleeding excess air from the compressor discharge because of 45% reduction in combustion air requirements. The engine controls that were re-configured for start-up and operation are reviewed including automation of POGT start-up and loading during light-off at lean condition, transition from lean to rich combustion during acceleration, speed control and stabilization under rich operation. Changes were implemented in microprocessor-based controllers. The fully-integrated POGT unit was installed and operated in a dedicated test cell at GTI equipped with extensive process instrumentation and data acquisition systems. Results from a parametric experimental study of POGT operation for co-production of power and H2-enriched synthesis gas are provided.

On Key Features of the AEV Burner Engine Implementation for Operational Flexibility

2013 ◽  
Author(s):  
Mirko R. Bothien ◽  
Douglas A. Pennell ◽  
Martin Zajadatz ◽  
Klaus Döbbeling
Keyword(s):  
Low Frequency ◽  
Operational Flexibility ◽  
Fuel Gas ◽  
Thermoacoustic Instabilities ◽  
Fuel Flow ◽  
Control Schemes ◽  
The One ◽  
Cooling Air ◽  
Operating Window ◽  
Ev Burner

Modern gas turbine combustors have to fulfill two major requirements. On the one hand they have to provide reliable operation with low emissions; on the other operational flexibility is of utmost importance. Alstom’s new AEV (Advanced EnVironmental) burner — an evolution of the proven EV burner technology — is one key feature to fulfill both on engine level. It can be operated on fuel gas and oil. In order to achieve low NOx emissions, modern combustors are operated in lean-premixed mode which is prone to thermoacoustic instabilities. This is accounted for by the implementation of multi-volume dampers. These dampers feature high damping performance in a broad low-frequency range thus widely enlarging the operating window. During transient operation, especially when switching from gaseous to liquid fuel and vice versa, the specific switching procedure with sophisticated fuel flow control schemes allows for a very smooth transmission. Another very important aspect is the optimization of leakage and cooling air into the combustion chamber. In order to validate the reduction of both, multiple thermal paint applications for fuel gas and oil operation in the full scale engine were performed at different engine loads up to baseload. In this paper, the AEV burner, broadband acoustic dampers, optimized cooling and leakage schemes, as well as innovative fuel switchover and operation concepts are described. It is shown that the combination of all of them makes the GT13E2 outstanding in fuel and operational flexibility featuring low emissions over the whole operating window.

Recent Experimental Results on Gasification and Combustion of Low BTU Gas for Gas Turbines

1974 ◽  
Author(s):  
W. B. Crouch ◽  
W. G. Schlinger ◽  
R. D. Klapatch ◽  
G. E. Vitti
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Electrical Power ◽  
Combined Cycle ◽  
Experimental Results ◽  
Fuel Oil ◽  
Cooperative Research ◽  
Fuel Gas ◽  
Gasification Process ◽  
Cycle System

A proposed system is presented for low pollution power generation by means of a combined cycle gas turbine system using low Btu fuel gas produced from high sulfur residual oil and solid fuel. Experimental results and conclusions are presented from a cooperative research program involving Texaco Inc. and Turbo Power and Marine Systems, Inc. whereby high sulfur crude oil residue was partially oxidized with air to produce a 100 to 150 Btu/scf sulfur-free fuel gas for use in a turbine combustor. An FT4 gas turbine combustion chamber test demonstrated that low Btu gas can be efficiently burned with a large reduction in NOx emissions. Gas turbine modifications required to burn low Btu gas are described and projected NOx emission compared to No. 2 fuel oil and natural gas are shown for an FT4 gas turbine. Integration of the gas turbine combined cycle system to a low Btu gasification process is described. The system provides an efficient method of generating electrical power from high sulfur liquid fuels while minimizing emission of air and water pollutants.

Test Results of 40MW-Class Advanced Humid Air Turbine and Exhaust Gas Water Recovery System

2014 ◽  
Author(s):  
Takuya Takeda ◽  
Hidefumi Araki ◽  
Yasushi Iwai ◽  
Tetsuro Morisaki ◽  
Kazuhiko Sato
Keyword(s):  
Gas Turbine ◽  
Test Facility ◽  
Nox Emissions ◽  
Exhaust Gas ◽  
Water Recovery ◽  
Test Results ◽  
Operational Flexibility ◽  
Start Up ◽  
Air Turbine ◽  
Recovery System

Operational flexibility, such as faster start-up time or faster load change rate, and higher thermal efficiency, have become more and more important for recent thermal power systems. The advanced humid air turbine (AHAT) system has been studied to improve operational flexibility and thermal efficiency of gas turbine power generation systems. A 40MW-class AHAT test facility was built and the rated output was achieved. Through operations at the facility, it has been verified for the first time that the key components of the medium-class gas turbines, such as an axial compressor and multi-can combustor, can be applied to the AHAT system. The cold start-up time from ignition to rated power was about 60 min, which is approximately one-third that of a conventional gas turbine combined cycle (GTCC) plant. NOx emissions were 24ppm (at 16% O2) when the humidity of combustion air was approximately a half that of present commercial AHAT plants, and NOx emissions in a future commercial AHAT system were thought to be less than 10ppm. A water recovery system which recovers water from a part of the exhaust gas of the 40MW-class test facility was built and test operations were made from June 2013. In this paper, water recovery test results as well as the 40MW-class gas turbine test results are shown.

Development and Implementation of the Advanced Environmental Burner for the Alstom GT13E2

2013 ◽  
Vol 135 (6) ◽  
Author(s):  
Martin Zajadatz ◽  
Douglas Pennell ◽  
Stefano Bernero ◽  
Bettina Paikert ◽  
Raffaele Zoli ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Public Awareness ◽  
Gas Composition ◽  
Combustion System ◽  
Operational Flexibility ◽  
Ambient Conditions ◽  
Additional Advantage ◽  
Energy Demands ◽  
Ev Burner

Increasing public awareness and more stringent legislation on pollutants drive gas turbine manufacturers to develop combustion systems with low NOx emissions. In combination with this demand, the gas turbines have to provide a broad range of operational flexibility to cover variations in gas composition and ambient conditions along with varying daily and seasonal energy demands and load profiles. This paper describes the development and implementation of the Alstom AEV (advanced environmental) burner, an evolution of the envorinmental (EV) burner. A continuous fuel supply to two fuel stages at any engine load simplifies the operation and provides a fast and reliable response of the combustion system during transient operation of the gas turbine. Increased turndown with low emissions is an additional advantage of the combustion system upgrade.

Low NOx Lean Premix Reheat Combustion in Alstom GT24 Gas Turbines

2015 ◽  
Vol 138 (5) ◽  
Author(s):  
Daniel Guyot ◽  
Gabrielle Tea ◽  
Christoph Appel
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Fuel Injection ◽  
Test Facility ◽  
Inlet Temperature ◽  
Combustion System ◽  
Operational Flexibility ◽  
Nox Formation ◽  
Term Operation ◽  
Fuel Flexibility

Reducing gas turbine emissions and increasing their operational flexibility are key targets in today's gas turbine market. In order to further reduce emissions and increase the operational flexibility of its GT24 (60 Hz) and GT26 (50 Hz), Alstom has introduced an improved sequential environmental (SEV) burner and fuel lance into its GT24 and GT26 upgrades 2011 sequential reheat combustion system. Sequential combustion is a key differentiator of Alstom GT24/GT26 engines in the F-class gas turbine market. The inlet temperature for the SEV combustor is around 1000 °C and reaction of the fuel/oxidant mixture is initiated through auto-ignition. The recent development of the Alstom sequential combustion system is a perfect example of evolutionary design optimizations and technology transfer between Alstom GT24 and GT26 engines. Better overall performance is achieved through improved SEV burner aerodynamics and fuel injection, while keeping the main features of the sequential burner technology. The improved SEV burner/lance concept has been optimized toward rapid fuel/oxidant mixing for low emissions, improved fuel flexibility with regard to highly reactive fuels (higher C2+ and hydrogen content), and to sustain a wide operation window. The burner front panel features an improved cooling concept based on near-wall cooling as well as integrated acoustics damping devices designed to reduce combustion pulsations, thus extending the SEV combustor's operation window even further. After having been validated extensively in Alstom's high pressure (HP) sector rig test facility, the improved GT24 SEV burner has been retrofitted into a commercial GT24 field engine for full engine validation during long-term operation. This paper presents the obtained HP sector rig and engine validation results for the GT24 (2011) SEV burner/lance hardware with a focus on reduced NOx and CO emissions and improved operational behavior of the SEV combustor. The HP tests demonstrated robust SEV burner/lance operation with up to 50% lower NOx formation and a more than 70 K higher SEV burner inlet temperature compared to the GT24 (2006) hardware. For the GT24 engine with retrofitted upgrade 2011 SEV burner/lance, all validation targets were achieved including an extremely robust operation behavior, up to 40% lower GT NOx emissions, significantly lower CO emissions at partload and baseload, a very broad operation window (up to 100 K width in SEV combustor inlet temperature), and all measured SEV burner/lance temperatures in the expected range. Sector rig and engine validation results have confirmed the expected SEV burner fuel flexibility (up to 18 vol. % C2+ and up to 5 vol. % hydrogen as standard).

Experimental and Analytical Study on the Operation Characteristics of the AHAT System

2012 ◽  
Vol 134 (5) ◽  
Author(s):  
Hidefumi Araki ◽  
Tomomi Koganezawa ◽  
Chihiro Myouren ◽  
Shinichi Higuchi ◽  
Toru Takahashi ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Ambient Temperature ◽  
Gas Turbine ◽  
Thermal Efficiency ◽  
Pilot Plant ◽  
Temperature Effects ◽  
Operational Flexibility ◽  
Start Up ◽  
Air Turbine ◽  
Load Characteristics

Operational flexibility, such as faster start-up time or faster load change rate, and higher thermal efficiency, have become more and more important for recent thermal power systems. The advanced humid air turbine (AHAT) system has been studied to improve operational flexibility and thermal efficiency of the gas turbine power generation system. Advanced humid air turbine is an original system which substitutes the water atomization cooling (WAC) system for the intercooler system of the HAT cycle. A 3 MW pilot plant, which is composed of a gas turbine, a humidification tower, a recuperator and a water recovery system, was built in 2006 to verify feasibility of the AHAT system.In this paper, ambient temperature effects, part-load characteristics and start-up characteristics of the AHAT system were studied both experimentally and analytically. Also, change in heat transfer characteristics of the recuperator of the 3 MW pilot plant was evaluated from Nov. 2006 to Feb. 2010. Ambient temperature effects and part-load characteristics of the 3 MW pilot plant were compared with heat and material balance calculation results. Then, these characteristics of the AHAT and the combined cycle (CC) systems were compared assuming they were composed of mid-sized industrial gas turbines.The measured cold start-up time of the 3 MW AHAT pilot plant was about 60 min, which was dominated by the heat capacities of the plant equipment. The gas turbine was operated a total of 34 times during this period (Nov. 2006 to Feb. 2010), but no interannual changes were observed in pressure drops, temperature effectiveness, and the overall heat transfer coefficient of the recuperator.

Operational Flexibility of GE’s F-Class Gas Turbines With the DLN2.6+ Combustion System

2018 ◽  
Author(s):  
William D. York ◽  
Derrick W. Simons ◽  
Yongqiang Fu
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Combined Cycle ◽  
Nox Emissions ◽  
Combustion System ◽  
Operational Flexibility ◽  
Start Up ◽  
Wide Range ◽  
Combined Cycle Plant ◽  
Base Load

F-class gas turbines comprise a major part of the heavy-duty gas turbine power generation fleet worldwide, despite increasing penetration of H/J class turbines. F-class gas turbines see a wide range of applications, including simple cycle peaking operation, base load combined cycle, demand following in simple or combined cycle, and cogeneration. Because of the different applications, local power market dynamics, and varied emissions regulations by region or jurisdiction, there is a need for operational flexibility of the gas turbine and the combustion system. In 2015, GE introduced a DLN2.6+ combustion system for new and existing 7F gas turbines. Approximately 50 are now in operation on 7F.04 and 7F.05 turbines, combining for nearly 150,000 fired hours. The system has been demonstrated to deliver 5 ppm NOx emissions @ 15% O2, and it exhibits a wide window of operation without significant thermoacoustic instabilities, owing the capability to premixed pilot flames on the main swirl fuel-air premixers, low system residence time, and air path improvements. Based on the success on the 7F, this combustion system is being applied to the 6F.03 in 2018. This paper highlights the flexibility of the 7F and 6F.03 DLN2.6+ combustion system and the enabling technology features. The advanced OpFlex* AutoTune control system tightly controls NOx emissions, adjusts fuel splits to stay clear of instabilities, and gives operators the ability to prioritize emissions or peak load output. Because of the low-NOx capability of the system, it is often being pushed to higher combustor exit temperatures, 35°C or more above the original target. The gas turbine is still meeting 9 or 15 ppm NOx emissions while delivering nearly 12% additional output in some cases. Single-can rig test and engine field test results show a relatively gentle NOx increase over the large range of combustor exit temperature because of the careful control of the premixed pilot fuel split. The four fuel legs are staged in several modes during startup and shutdown to provide robust operation with fast loading capability and low starting emissions, which are shown with engine data. The performance of a turndown-only fueling mode is highlighted with engine measurements of CO at low load. In this mode, the center premixer is not fueled, trading the NOx headroom for a CO emissions benefit that improves turndown. The combustion system has also demonstrated wide-Wobbe capability in emissions compliance. 7F.04 engine NOx and dynamics data are presented with the target heated gas fuel and also with cold fuel, producing a 24% increase in Modified Wobbe Index. The ability to run unheated fuel at base load may reduce the start-up time for a combined cycle plant. Lastly, there is a discussion of a new OpFlex* Variable Load Path digital solution in development that will allow operators to customize the start-up of a combined cycle plant.

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