Fuel Flexibility Test Campaign on a 10 MW Class Gas Turbine Equipped With a Dry-Low-NOx Combustion System

2007 ◽  
Author(s):  
Stefano Cocchi ◽  
Michele Provenzale ◽  
Gianni Ceccherini
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Pressure Ratio ◽  
Flame Temperature ◽  
Nox Emission ◽  
Pollutant Emissions ◽  
Combustion System ◽  
Fuel Flow ◽  
Fuel Flexibility ◽  
Air Staging

An experimental test campaign, aimed to provide a preliminary assessment of the fuel flexibility of small power gas turbines equipped with Dry Low NOx (DLN) combustion systems, has been carried over a full-scale GE10 prototypical unit, located at the Nuovo-Pignone manufacturing site, in Florence. Such activity is a follow-up of a previous experimental campaign, performed on the same engine, but equipped with a diffusive combustion system. The engine is a single shaft, simple cycle gas turbine designed for power generation applications, rated for 11 MW electrical power and equipped with a DLN silos type combustor. One of the peculiar features of such combustion system is the presence of a device for primary combustion air staging, in order to control flame temperature. A variable composition gaseous fuel mixture has been obtained by mixing natural gas with CO2 up to about 30% vol. inerts concentration. Tests have been carried over without any modification of the default hardware configuration. Tests performed aimed to investigate both ignition limits and combustors’ performances, focusing on hot parts’ temperatures, pollutant emissions and combustion driven pressure oscillations. Results indicate that ignition is possible up to 20% vol. inerts concentration in the fuel, keeping the fuel flow during ignition at moderately low levels. Beyond 20% vol. inerts, ignition is still possible increasing fuel flow and adjusting primary air staging, but more tests are necessary to increase confidence in defining optimal and critical values. Speed ramps and load operation have been successfully tested up to 30% vol. inerts concentration. As far as speed ramps, the only issue evidenced has been risk of flameout, successfully abated by rescheduling combustion air staging. As far as load operation, the combustion system has proven to be almost insensitive to any inerts concentration tested (up to 30% vol.): the only parameter significantly affected by variation in CO2 concentration has been NOx emission. As a complementary activity, a simplified zero-dimensional model for predicting NOx emission has been developed, accounting for fuel dilution with CO2. The model is based on main turbine cycle and DLN combustion system controlling parameters (i.e., compressor pressure ratio, firing temperature, pilot fuel and primary air staging), and has been tuned achieving good agreement with data collected during the test campaign.

An Introduction to the Ansaldo GT36 Constant Pressure Sequential Combustor

2017 ◽  
Author(s):  
Douglas A. Pennell ◽  
Mirko R. Bothien ◽  
Andrea Ciani ◽  
Victor Granet ◽  
Ghislain Singla ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Constant Pressure ◽  
Energy Market ◽  
Combustion System ◽  
Turbine Engine ◽  
Beneficial Effects ◽  
Fuel Flexibility ◽  
Temperature Ranges ◽  
System Robustness

This paper introduces and presents validation of the Constant Pressure Sequential Combustion system (denoted CPSC), a second generation concept developed for and applied to the new Ansaldo GT36 H-class gas turbine combustors. It has evolved from the well-established sequential burner technology applied to all current GT26 and GT24 gas turbines, and contains all architectural improvements implemented since original inception of this engine frame in 1994, with beneficial effects on the operation turndown, fuel flexibility, on the overall system robustness, and featuring the required aspects to stay competitive in the present day energy market. The applied air and fuel management therefore facilitate emission and dynamics control at both the extremely high and low firing temperature ranges required for existing and future Ansaldo gas turbine engine classes.

Extending the Fuel Flexibility From Natural Gas to Low-LHV Fuel: Test Campaign on a Low-NOx Diffusion Flame Combustor

2008 ◽  
Author(s):  
Nicola Giannini ◽  
Alessandro Zucca ◽  
Christian Romano ◽  
Gianni Ceccherini
Keyword(s):  
Natural Gas ◽  
Diffusion Flame ◽  
Gas Turbines ◽  
Molar Fraction ◽  
Pollutant Emissions ◽  
Combustion System ◽  
Extensive Experience ◽  
Fuel Flexibility ◽  
Partial Load ◽  
Fuel Mixtures

Today’s Oil & Gas facility market requires enlarging machines’ fuel flexibility toward two main directions: on the one hand burning fuels with high percentages of Ethane, Butane and Propane, on the other hand burning very lean fuels with a high percentage of inerts. GE has extensive experience in burning a variety of gas fuels and blends in heavy-duty gas turbines. From a technical point of view, the tendency towards leaner fuel gases for feeding gas turbines, introduces potential risks related to combustion instability, on both combustion hardware and machines’ operability. GE Oil&Gas (Nuovo Pignone), has developed a new program aimed to extend the fuel flexibility of its Low-NOx diffusion flame combustor (Lean Head End, or LHE), which currently equips single and dual shaft 30 MW gas turbines, so that it can handle low-LHV fuels. A fuel flexibility test campaign was carried out at full and partial load conditions over an ambient and fuel range, in order to investigate both ignition limits and combustor performances, focusing on hot parts’ temperatures, pollutant emissions and combustion driven pressure oscillations. The pressurized tests were performed on a single combustion chamber, using a dedicated full-scale (full-pressure, full-temperature and full-flow) combustor test cell. Variable composition gaseous fuel mixtures, obtained by mixing natural gas with N2 from 0% up to about 50% vol., were tested. The experienced LHE combustion system up to now had been fed only with natural gas in multi can single gas combustion systems. Combustion system modifications and different burner configurations were considered to enlarge system capabilities, in order to accommodate operation on the previous mentioned range of fuel mixtures, including: nozzle orifice sizing and combustor liner modification. This paper aims to illustrate the upgraded technology and the results obtained. Reported data show combustion system’s performances, mainly in terms of pollutant emissions and operability. The performed test campaign demonstrated the system’s ability to operate at all required loads with diluted natural gases containing up to 50% vol. of N2. Results also indicate that ignition is possible with the same inerts concentration in the fuel, keeping the fuel flow at moderately low levels. As far as load operation, the combustion system proved to be almost insensitive to any tested inerts concentration, while a huge reduction of NOx emissions was observed increasing the molar fraction of N2 in the fuel gas, maintaining good flame stability.

Dry, Low Emissions for the ‘H’ Heavy-Duty Industrial Gas Turbines: Full-Scale Combustion System Rig Test Results

2003 ◽  
Author(s):  
Geoff Myers ◽  
Dan Tegel ◽  
Markus Feigl ◽  
Fred Setzer ◽  
William Bechtel ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Pressure Ratio ◽  
Combined Cycle ◽  
Full Scale ◽  
Combustion System ◽  
Heavy Duty ◽  
Test Program ◽  
Industrial Gas Turbines ◽  
Inlet Conditions

The lean, premixed DLN2.5H combustion system was designed to deliver low NOx emissions from 50% to 100% load in both the Frame 7H (60 Hz) and Frame 9H (50 Hz) heavy-duty industrial gas turbines. The H machines employ steam cooling in the gas turbine, a 23:1 pressure ratio, and are fired at 1440 C (2600 F) to deliver over-all thermal efficiency for the combined-cycle system near 60%. The DLN2.5H combustor is a modular can-type design, with 14 identical chambers used on the 9H machine, and 12 used on the smaller 7H. On a 9H combined-cycle power plant, both the gas turbine and steam turbine are fired using the 14-chamber DLN2.5H combustion system. An extensive full-scale, full-pressure rig test program developed the fuel-staged dry, low emissions combustion system over a period of more than five years. Rig testing required test stand inlet conditions of over 50 kg/s at 500 C and 28 bar, while firing at up to 1440 C, to simulate combustor operation at base load. The combustion test rig simulated gas path geometry from the discharge of the annular tri-passage diffuser through the can-type combustion liner and transition piece, to the inlet of the first stage turbine nozzle. The present paper describes the combustion system, and reports emissions performance and operability results over the gas turbine load and ambient temperature operating range, as measured during the rig test program.

scholarly journals Combustion of LCV Coal Derived Fuel Gas for High Temperature, Low Emissions Gas Turbines in the British Coal Topping Cycle

1991 ◽  
Author(s):  
G. J. Kelsall ◽  
M. A. Smith ◽  
H. Todd ◽  
M. J. Burrows
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Calorific Value ◽  
Pollutant Emissions ◽  
Inlet Temperature ◽  
Outlet Temperature ◽  
Combustion System ◽  
Fuel Gas ◽  
Gas Turbine Combustion ◽  
Topping Cycle

Advanced coal based power generation systems such as the British Coal Topping Cycle offer the potential for high efficiency electricity generation with minimum environmental impact. An important component of the Topping Cycle programme is the development of a gas turbine combustion system to burn low calorific value (3.5–4.0 MJ/m3 wet gross) coal derived fuel gas, at a turbine inlet temperature of 1260°C, with minimum pollutant emissions. The paper gives an overview of the British Coal approach to the provision of a gas turbine combustion system for the British Coal Topping Cycle, which includes both experimental and modelling aspects. The first phase of this programme is described, including the design and operation of a low-NOx turbine combustor, operating at an outlet temperature of 1360°C and burning a synthetic low calorific value (LCV) fuel gas, containing 0 to 1000 ppmv of ammonia. Test results up to a pressure of 8 bar are presented and the requirements for further combustor development outlined.

scholarly journals Conceptual Studies of a Fuel-Flexible Low-Swirl Combustion System for the Gas Turbine in Clean Coal Power Plants

2010 ◽  
Author(s):  
Kenneth O. Smith ◽  
Peter L. Therkelsen ◽  
David Littlejohn ◽  
Sy Ali ◽  
Robert K. Cheng
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Power Plants ◽  
Fuel Injection ◽  
Pollutant Emissions ◽  
Injection System ◽  
Combustion System ◽  
High Hydrogen ◽  
Swirl Combustion ◽  
Auto Ignition

This paper reports the results of preliminary analyses that show the feasibility of developing a fuel flexible (natural gas, syngas and high-hydrogen fuel) combustion system for IGCC gas turbines. Of particular interest is the use of Lawrence Berkeley National Laboratory’s DLN low swirl combustion technology as the basis for the IGCC turbine combustor. Conceptual designs of the combustion system and the requirements for the fuel handling and delivery circuits are discussed. The analyses show the feasibility of a multi-fuel, utility-sized, LSI-based, gas turbine engine. A conceptual design of the fuel injection system shows that dual parallel fuel circuits can provide range of gas turbine operation in a configuration consistent with low pollutant emissions. Additionally, several issues and challenges associated with the development of such a system, such as flashback and auto-ignition of the high-hydrogen fuels, are outlined.

Low NOx SEV Lean Premix Reheat Combustion in Alstom GT24 Gas Turbines

2015 ◽  
Author(s):  
Daniel Guyot ◽  
Gabrielle Tea ◽  
Christoph Appel
Keyword(s):  
High Pressure ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Fuel Injection ◽  
Test Facility ◽  
Inlet Temperature ◽  
Combustion System ◽  
Operational Flexibility ◽  
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 (60Hz) and GT26 (50Hz), Alstom has introduced an improved SEV burner and fuel lance into its GT24 upgrade 2011 and GT26 upgrade 2011 sequential reheat combustion system. Sequential combustion is a key differentiator of Alstom GT24 engines in the F-class gas turbine market. The inlet temperature for the GT24 SEV combustor is around 1000 degC 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 towards rapid fuel/oxidant mixing for low emissions, improved fuel flexibility with regards to highly reactive fuels (higher C2+ and hydrogen content), and to sustain a wide operation window. In addition, 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 the Alstom high pressure 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 high pressure 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 high pressure tests demonstrated robust SEV burner/lance operation with up to 50% lower NOX formation and a more than 70K 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 100K 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).

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).

scholarly journals The Role of Fuel Preparation in Low Emissions Combustion

1995 ◽  
Author(s):  
A. H. Lefebvre
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Fuel Injection ◽  
Flame Temperature ◽  
Pollutant Emissions ◽  
Alternative Methods ◽  
Nox Emissions ◽  
Oxides Of Nitrogen ◽  
Lean Burn ◽  
The Impact

The attainment of very low pollutant emissions, in particular oxides of nitrogen (NOx), from gas turbines is not only of considerable environmental concern but has also become an area of increasing competitiveness between the different engine manufacturers. For stationary engines, the attainment of ultra-low NOx has become the foremost marketing issue. This paper is devoted primarily to current and emerging technologies in the development of ultra-low emissions combustors for application to aircraft and stationary engines. Short descriptions of the basic design features of conventional gas turbine combustors and the methods of fuel injection now in widespread use are followed by a review of fuel spray characteristics and recent developments in the measurement and modeling of these characteristics. The main gas turbine generated pollutants and their mechanisms of formation are described, along with related environmental risks and various issues concerning emissions regulations and recently-enacted legislation for limiting the pollutant levels emitted by both aircraft and stationary engines. The impact of these emissions regulations on combustor and engine design are discussed first in relation to conventional combustors and then in the context of variable-geometry and staged combustors. Both these concepts are founded on emissions reduction by control of flame temperature. Basic approaches to the design of “dry” low NOx and ultra-low NOx combustors are reviewed. At the present time lean, premix, prevaporize, combustion appears to be the only technology available for achieving ultra-low NOx emissions from practical combustors. This concept is discussed in some detail, along with its inherent problems of autoignition, flashback, and acoustic resonance. Attention is also given to alternative methods of achieving ultra-low NOx emissions, notably the rich-bum, quick-quench, lean-burn and catalytic combustors. These concepts are now being actively developed, despite the formidable problems they present in terms of mixing and durability. The final section reviews the various correlations which are now being used to predict the exhaust gas concentrations of the main gaseous pollutant emissions from gas turbine engines. Comprehensive numerical methods have not yet completely displaced these semi-empirical correlations but are nevertheless providing useful insight into the interactions of swirling and recirculating flows with fuel sprays, as well as guidance to the combustion engineer during the design and development stages. Throughout the paper emphasis is placed on the important and sometimes pivotal role played by the fuel preparation process in the reduction of pollutant emissions from gas turbines.

Fuel Flexibility of a Multi-Staged Prototype Gas Turbine Burner

2017 ◽  
Author(s):  
Atanu Kundu ◽  
Jens Klingmann ◽  
Arman Ahamed Subash ◽  
Robert Collin
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Greenhouse Gas Emission ◽  
New Technology ◽  
Combustion Process ◽  
Physical Property ◽  
Combustion System ◽  
Low Carbon ◽  
Property Variation ◽  
Fuel Flexibility

Gas turbines are widely used power generation equipment and very important for its efficiency and flexible operability. With the increasing demand of low carbon or less greenhouse gas emission from gas turbine, usage of clean fuel (i.e. hydrogen) is highly recommended. Adaptation with various type of fuels without any operability issues are the primary focus of interest while design and development of a low NOx gas turbine combustion system. Due to chemical and physical property variation of different fuel, a common combustion system design is complex and require extensive testing. The present paper is focused on fuel flexibility of an industrial prototype burner, designed and manufactured by Siemens Industrial Turbomachinery AB, Sweden. In this work, a baseline case (Methane fuel) is compared with different custom fuel blends (mixture of methane with natural gas and hydrogen). The primary and secondary combustion characteristics were modified when hydrogen blended fuels were introduced. The Lean Blowout limit was extended for the primary and secondary flames. The secondary flame macro structure was captured using Planar Laser Induced Fluorescence and natural luminosity imaging; whereas primary flame location was characterized by the thermocouple readings. Operational stability map and emission (NOx and CO) capability of the burner was determined from the experiment. Numerical calculation using ANSYS FLUENT was performed to simulate the combustion process and compare the results with experiment. The experimental and simulation effort provided information about the flame macrostructure and operability (lean operability limit was extended by 100 K) of the new technology burner when the combustion system was exposed to different type of fuels.

Development of the New Ansaldo Energia Gas Turbine Technology Generation

2017 ◽  
Author(s):  
U. Ruedel ◽  
V. Stefanis ◽  
A. D. Ramaglia ◽  
S. Florjancic
Keyword(s):  
Gas Turbine ◽  
Gas Turbines ◽  
Power Plants ◽  
Experimental Testing ◽  
Axial Flow ◽  
Design Feature ◽  
Combined Cycle ◽  
Combustion System ◽  
Technology Generation ◽  
Fuel Flexibility

This paper provides an overview of the ongoing development activities for the Ansaldo Energia gas turbines AE64.3A, AE94.2, AE94.2K, AE94.3A, GT26 (2006), GT26 (2011), GT36-S6 and GT36-S5. The improvements significantly reduce the energy consumption in gas turbine combined cycle (GTCC) power plants and are directed towards improved operational and fuel flexibility, increased GT power output, GT efficiency and improved component lifetime. The collaborative development, validation and application of the constant pressure sequential combustion system (‘CPSC’) for the GT36 engine will be introduced. Based on the well-established sequential burner technology as installed since 1994 on all legacy GT26 gas turbines, the operation turndown, fuel flexibility and the overall system robustness is described. The development and engine validation of the first stage burner for Improved Durability and Turndown as well as the design of a Combustor Sequential Liner within a can combustion system is shown. The reconstruction and analysis of the acoustic transfer matrix of the flame in the sequential burner together with the applied air and fuel management facilitate emission and dynamics control at both, the extremely high and low firing temperature ranges. The axial flow turbine of the GT36 heavy duty gas turbine, which has evolved from the existing and proven GT26 design, consists of an optimized annulus flow path, higher lift airfoil profiles, optimized aerodynamic matching between the turbine stages and a new and improved cooling systems of the turbine vanes and blades. A major design feature of the turbine has been to control and reduce the aerodynamic losses, associated with the airfoil profiles, trailing edges, blade tips, end walls and coolant ejection. The advantages of these design changes to the overall gas turbine efficiency have been verified via extensive experimental testing.

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