Development of Surface-Stabilized Fuel Injectors With Sub-Three PPM NOx Emissions

2002 ◽  
Author(s):  
Christopher K. Weakley ◽  
Steven J. Greenberg ◽  
Robert M. Kendall ◽  
Neil K. McDougald ◽  
Leonel O. Arellano
Keyword(s):  
Porous Metal ◽  
Operating Conditions ◽  
Stable Operation ◽  
Nox Emissions ◽  
Single Digit ◽  
Turbine Engine ◽  
Fuel Injectors ◽  
Developed Surface ◽  
Low Nox Emission ◽  
Full Pressure

ALZETA Corporation has developed surface-stabilized fuel injectors for use with lean premixed combustors which provide extended turndown and ultra-low NOx emission performance. These injectors use a patented technique to form interacting radiant and blue-flame zones immediately above a selectively-perforated porous metal surface. This allows stable operation at low reaction temperatures. This technology is a successful extension of ALZETA’s line of proven Pyromat™ SB metal fiber burners. A proof-of-concept injector in a full-pressure test rig at NETL in Morgantown, West Virginia achieved sub-3 ppm NOx emissions with concurrent single-digit CO emissions, both corrected to 15% O2. Operating conditions ranged between inlet pressures of 182.4 kPa (1.8 atm) and 1236.2 kPa (12.2 atm), inlet temperatures between 86° C (186° F) and 455° C (850° F) and calculated adiabatic flame temperatures between 1466° C (2670° F) and 1593° C (2900° F). Testing with prototype fuel injectors in test rigs at Solar Turbines last year yielded similar results. In May of 2001, a Solar Saturn 1 MW gas-turbine engine was operated to 95% load with a surface-stabilized injector. Programs are moving forward to adapt these injectors to the Solar Turbines Taurus 60 and Titan 130 engines. Engine tests are scheduled to begin in 2003.

Surface-Stabilized Fuel Injectors With Sub-Three ppm NOx Emissions for a 5.5 MW Gas Turbine Engine

2003 ◽  
Author(s):  
Steven J. Greenberg ◽  
Neil K. McDougald ◽  
Christopher K. Weakley ◽  
Robert M. Kendall ◽  
Leonel O. Arellano
Keyword(s):  
Porous Metal ◽  
Stable Operation ◽  
Nox Emissions ◽  
Turbine Engine ◽  
Fuel Injectors ◽  
Engine Simulation ◽  
Developed Surface ◽  
Low Nox Emission ◽  
Combustor Liner ◽  
Blue Flame

ALZETA Corporation has developed surface-stabilized fuel injectors for use with lean premixed combustors which provide extended turndown and ultra-low NOx emission performance. These injectors use a patented technique to form interacting radiant and blue-flame zones immediately above a selectively-perforated porous metal surface. This allows stable operation at low reaction temperatures. A previous ASME paper (IJPGC2002-26088) described the development of this technology from the proof-of-concept stage to prototype testing. In 2002 development of these fuel injectors for the 5.5 MW turbine accelerated. Additional single-injector rig tests were performed which also demonstrated ultra-low emissions of NOX and CO at pressures up to 1.68 MPa (16.6 atm) and inlet temperatures up to 670 °K (750 °F). A pressurized multi injector ‘sector rig’ test was conducted in which two injectors were operated simultaneously in the same geometric configuration as that expected in the engine combustor liner. The multi-injector package was operated with various combinations of fired and unfired injectors, which resulted in low emissions performance and no adverse affects due to injector proximity. To date sub-3 ppm NOx emissions with sub-10 ppm CO emissions have been obtained over an operating range of 0.18 to 1.68 MPa (1.8 to 16.6 atm), inlet temperatures from 340 to 670 °K (186 to 750 °F), and adiabatic flame temperatures from 1740 to 1840 °K (2670 to 2850 °F). A full scale multi-injector engine simulation is scheduled for the beginning of 2003, with engine tests beginning later that year.

Surface-Stabilized Fuel Injectors With Sub-Three PPM NOx Emissions for a 5.5 MW Gas Turbine Engine

2005 ◽  
Vol 127 (2) ◽  
pp. 276-285 ◽  
Author(s):  
Steven J. Greenberg ◽  
Neil K. McDougald ◽  
Christopher K. Weakley ◽  
Robert M. Kendall ◽  
Leonel O. Arellano
Keyword(s):  
Porous Metal ◽  
Stable Operation ◽  
Nox Emissions ◽  
Proof Of Concept ◽  
Turbine Engine ◽  
Fuel Injectors ◽  
Engine Simulation ◽  
Developed Surface ◽  
Combustor Liner ◽  
Blue Flame

ALZETA Corporation has developed surface-stabilized fuel injectors for use with lean premixed combustors which provide extended turndown and ultralow NOx emission performance. These injectors use a patented technique to form interacting radiant and blue-flame zones immediately above a selectively perforated porous metal surface. This allows stable operation at low reaction temperatures. A previous ASME paper (IJPGC2002-26088) described the development of this technology from the proof-of-concept stage to prototype testing. In 2002 development of these fuel injectors for the 5.5 MW turbine accelerated. Additional single-injector rig tests were performed which also demonstrated ultralow emissions of NOx and CO at pressures up to 1.68 MPa (16.6 atm) and inlet temperatures up to 670°K (750°F). A pressurized multi-injector “sector rig” test was conducted in which two injectors were operated simultaneously in the same geometric configuration as that expected in the engine combustor liner. The multi-injector package was operated with various combinations of fired and unfired injectors, which resulted in low emissions performance and no adverse affects due to injector proximity. To date sub-3 ppm NOx emissions with sub-10 ppm CO emissions have been obtained over an operating range of 0.18–1.68 MPa (1.8–16.6 atm), inlet temperatures from 340 to 670K (186–750°F), and adiabatic flame temperatures from 1740 to 1840K (2670–2850°F). A full scale multi-injector engine simulation is scheduled for the beginning of 2003, with engine tests beginning later that year.

Development and Demonstration of Engine-Ready Surface-Stabilized Combustion System

2006 ◽  
Author(s):  
Leonel O. Arellano ◽  
Arun K. Bhattacharya ◽  
Kenneth O. Smith ◽  
Steven J. Greenberg ◽  
Neil K. McDougald
Keyword(s):  
Porous Metal ◽  
Full Scale ◽  
Low Flow ◽  
Screening Tests ◽  
Stable Operation ◽  
Combustion System ◽  
Nox Formation ◽  
Single Digit ◽  
Fuel Injectors ◽  
Developed Surface

Alzeta Corporation has developed surface-stabilized fuel injectors for use in lean-premixed low-emissions combustion systems. These injectors use a patented technique to form interacting high-flow and low-flow flame zones immediately above a selectively-perforated porous metal surface. This allows stable operation at low reaction temperatures conducive for preventing high NOx formation. Solar Turbines and Alzeta had previously worked together to evaluate single-injector and full-scale proof-of-concept test hardware. This paper presents results of a combustion system developed for evaluation on an engine. The next-generation hardware has evolved to include a pilot to handle low engine speeds, and flow circuits have been adjusted to meet low-pressure drop requirements. Screening tests of the full-scale system have been completed at simulated engine conditions in a full-scale rig. Single-digit NOx and CO emissions have been achieved without encountering combustion-driven instabilities. The combustion system demonstrated adequate power turndown with the assistance of the pilot module, and studies to predict the service life of burners have been initiated.

Full-Scale Demonstration of Surface-Stabilized Fuel Injectors for Sub-Three ppm NOx Emissions

2004 ◽  
Author(s):  
Steven J. Greenberg ◽  
Neil K. McDougald ◽  
Leonel O. Arellano
Keyword(s):  
Pressure Ratio ◽  
Full Scale ◽  
Low Flow ◽  
Stable Operation ◽  
Inlet Temperature ◽  
Nox Emissions ◽  
Fuel Injectors ◽  
Air Inlet ◽  
Radial Profiles ◽  
Developed Surface

ALZETA Corporation has developed surface-stabilized fuel injectors for use with lean premixed combustors which provide extended turndown and ultra-low NOx emission performance. These injectors use a patented technique to form interacting high-flow and low-flow flame zones immediately above a selectively-perforated porous metal surface. This allows stable operation at low reaction temperatures. This technology has been given the product name nanoSTAR™. Previous work involved the development of nanoSTAR technology from the proof-of-concept stage to prototype testing. Rig testing of single injectors and of two injectors simulating a sector of an annular combustion liner have been completed for pressure ratios up to 17 and combustion air inlet temperatures up to 700 K (800°F). This paper presents results from the first ever full-scale demonstration of surface-stabilized fuel injectors. An annular combustion liner, fitted with twelve nanoSTAR injectors was successfully tested up to a pressure ratio of 12 and combustion air inlet temperature of 700 K (800°F). NOx emissions were 2 ppm with CO emissions of 3 ppm both corrected to 15% O2. The combustion system exhibited excellent temperature uniformity around the annular combustor outlet with a maximum pattern factor of 0.16 and engine-appropriate radial profiles.

Evaluation of Fuel Preparation Systems for Lean Premixing-Prevaporizing Combustors

1986 ◽  
Vol 108 (2) ◽  
pp. 391-395
Author(s):  
W. J. Dodds ◽  
E. E. Ekstedt
Keyword(s):  
System Design ◽  
Large Scale ◽  
Fuel Injection ◽  
Operating Conditions ◽  
Turbine Engine ◽  
Fuel Injectors ◽  
Design Concepts ◽  
Mixture Preparation ◽  
Design Variables ◽  
System Length

A series of tests was conducted to provide data for the design of premixing-prevaporizing fuel-air mixture preparation systems for aircraft gas turbine engine combustors. Fifteen configurations of four different fuel-air mixture preparation system design concepts were evaluated to determine fuel-air mixture uniformity at the system exit over a range of conditions representative of cruise operation for a modern commercial turbofan engine. Operating conditions, including pressure, temperature, fuel-air ratio, and velocity had no clear effect on mixture uniformity in systems which used low-pressure fuel injectors. However, performance of systems using pressure atomizing fuel nozzles and large-scale mixing devices was shown to be sensitive to operating conditions. Variations in system design variables were also evaluated and correlated. Mixture uniformity improved with increased system length, pressure drop, and number of fuel injection points per unit area. A premixing system compatible with the combustor envelope of a typical combustion system and capable of providing mixture nonuniformity (standard deviation/mean) below 15% over a typical range of cruise operating conditions was demonstrated.

Effect of Fuel System Impedance Mismatch on Combustion Dynamics

2005 ◽  
Author(s):  
Geo A. Richards ◽  
Edward H. Robey
Keyword(s):  
Dynamic Response ◽  
Operating Conditions ◽  
Combustion Stability ◽  
Stable Operation ◽  
Fuel System ◽  
Fuel Injector ◽  
Pressure Oscillations ◽  
Impedance Mismatch ◽  
Combustion Dynamics ◽  
Fuel Injectors

Combustion dynamics are a challenging problem in the design and operation of premixed gas turbine combustors. In premixed combustors, pressure oscillations created by the flame dynamic response can lead to damaging pressure oscillations. These dynamics are typically controlled by designing the combustor to achieve stable operation for planned conditions, but dynamics may still occur with minor changes in ambient operating conditions, or fuel composition. In these situations, pilot flames, or adjustment to fuel flow splits can be used to stabilize the combustor, but often with a compromise in emissions performance. As an alternative to purely passive design changes, prior studies have demonstrated that adjustment to the fuel system impedance can be used to stabilize combustion. Prior studies have considered just the response of individual fuel injector and combustor. However, in practical combustion systems, multiple fuel injectors are used. In this situation, individual injector impedance can be modified to produce a different dynamic response from individual flames. The resulting impedance mismatch prevents all injectors from strongly coupling to the same acoustic mode. In principle, this mismatch should reduce the amplitude of dynamics, and may expand the operating margin for stable combustion conditions. In this paper, a 30 kW laboratory combustor with two premixed fuel injectors is used to study the effect of impedance mismatch on combustion stability. The two fuel injectors are equipped with variable geometry resonators that allow a survey of dynamic stability while changing the impedance of the individual fuel systems. Results demonstrate that a wide variation in dynamic response can be achieved by combining different impedence fuel injectors. A baseline 7% RMS pressure oscillation was reduced to less than 3% by mismatching the fuel impedance.

Effect of Fuel System Impedance Mismatch on Combustion Dynamics

2008 ◽  
Vol 130 (1) ◽  
Author(s):  
Geo A. Richards ◽  
Edward H. Robey
Keyword(s):  
Dynamic Response ◽  
Operating Conditions ◽  
Combustion Stability ◽  
Stable Operation ◽  
Base Line ◽  
Fuel System ◽  
Fuel Injector ◽  
Impedance Mismatch ◽  
Combustion Dynamics ◽  
Fuel Injectors

Combustion dynamics are a challenging problem in the design and operation of premixed gas turbine combustors. In premixed combustors, pressure oscillations created by the flame dynamic response can lead to damage. These dynamics are typically controlled by designing the combustor to achieve a stable operation for planned conditions, but dynamics may still occur with minor changes in ambient operating conditions or fuel composition. In these situations, pilot flames or adjustment to fuel flow splits can be used to stabilize the combustor, but often with a compromise in emission performance. As an alternative to purely passive design changes, prior studies have demonstrated that adjustment to the fuel system impedance can be used to stabilize combustion. Prior studies have considered just the response of an individual fuel injector and combustor. However, in practical combustion systems, multiple fuel injectors are used. In this situation, individual injector impedance can be modified to produce a different dynamic response from individual flames. The resulting impedance mismatch prevents all injectors from strongly coupling to the same acoustic mode. In principle, this mismatch should reduce the amplitude of dynamics and may expand the operating margin for stable combustion conditions. In this paper, a 30kW laboratory combustor with two premixed fuel injectors is used to study the effect of impedance mismatch on combustion stability. The two fuel injectors are equipped with variable geometry resonators that allow a survey of dynamic stability while changing the impedance of the individual fuel systems. Results demonstrate that a wide variation in dynamic response can be achieved by combining different impedance fuel injectors. A base line 7% rms pressure oscillation was reduced to less than 3% by mismatching the fuel impedance.

Combustion Dynamics Diagnostics and Mitigation on a Prototype Gas Turbine Combustor

2012 ◽  
Author(s):  
Bassam S. Mohammad ◽  
Preetham Balasubramanyam ◽  
Keith McManus ◽  
Jeffrey Ruszczyk ◽  
Ahmed M. Elkady ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Flame Temperature ◽  
Operating Conditions ◽  
Published Data ◽  
Stable Operation ◽  
Nox Emissions ◽  
Gas Turbine Combustor ◽  
Combustion Dynamics ◽  
The Impact ◽  
Intermittent Mode

Combustion dynamics have detrimental effects on hardware durability as well as combustor performance and emissions. This paper presents a detailed study on the impact of combustion dynamics on NOx and CO emissions generated from a prototype gas turbine combustor operating at a pressure of 180 psia (12.2 bars) with a pre-heat temperature of 720 F (655.3 K) (E-class machine operating conditions). Two unstable modes are discussed. The first is an intermittent mode, at 750 Hz, that emerges at flame temperatures near 2900°F (1866.5 K), resulting in high NOx and CO emissions. With increasing fuel flow, NOx and CO emissions continue to increase until the flame temperature reaches approximately 3250°F (2061 K), at which point the second acoustic mode begins to dominate. Flame images indicate that the intermittent mode is associated with flame motion which induces the high NOx and CO emissions. The second mode is also a 750 Hz, but of constant amplitude (no intermittency). Operation in this second 750 Hz mode results in significantly reduced NOx and CO emissions. At pressures higher than 180 psia (12.2 bars), the intermittent mode intensifies, leading to flashback at flame temperatures above 2850°F (1839 K). In order to mitigate the intermittent mode, a second configuration of the combustor included an exit area restriction. The exit area restriction eliminated the intermittent mode, resulting in stable operation and low emissions over a temperature range of 2700–3200°F (1755–2033 K). A comparison of the NOx emissions, as function of flame temperature, with previous published data for perfectly premixed indicates that, while the low amplitude 750 Hz oscillations have little effect, the intermittent mode significantly increases emissions. Mode shape analysis shows that the 750 Hz instability corresponds to the 1/4 wave axial mode. In the current research a ceramic liner is used while the previous published data was collected with a quartz liner. Typically, quartz is avoided due to reductions in effective flame temperature by radiation losses. Experiments showed that NOx emissions were not affected by the combustor liner type. This agreement between the quartz and ceramic liners data indicates limited effect from the radiation heat losses on NOx emissions.

Development of a Fuel Air Premixer for Aero-Derivative Dry Low Emissions Combustors

1994 ◽  
Author(s):  
Narendra D. Joshi ◽  
Michael J. Epstein ◽  
Susan Durlak ◽  
Steven Marakovits ◽  
Paul E. Sabla
Keyword(s):  
Gas Turbine ◽  
Operating Conditions ◽  
Experimental Program ◽  
Design Parameters ◽  
Turbine Engines ◽  
Nox Emissions ◽  
Gas Turbine Engines ◽  
Single Digit ◽  
Test Conditions ◽  
Industrial Gas Turbine

An experimental program was conducted to develop premixer concepts for use in GE’s aero-derivative Marine and Industrial gas turbine engines such as the LM 1600, 2500 and 6000. These engines operate typically at pressure ratios up to 30:1. Extensive tests in 1 and 2 cup test combustors were carried out to evaluate the Double Annular Counter-Rotating Swirler (DACRS) premixers at test conditions representative of the above mentioned engines. These tests also help establish combustor design parameters. Single digit NOx emissions were measured at engine operating conditions with the DACRS II and III premixers. Premixer interactions and their effects on Lean Blow Out were also studied.

Intelligent Operation of Siemens (SGT-300) DLE Gas Turbine Combustion System Over an Extended Fuel Range With Low Emissions

2011 ◽  
Author(s):  
Ghenadie Bulat ◽  
Kexin Liu ◽  
Gavin Brickwood ◽  
Victoria Sanderson ◽  
Brian Igoe
Keyword(s):  
Natural Gas ◽  
Gas Turbine ◽  
Intelligent Control ◽  
Control Algorithm ◽  
Landfill Gas ◽  
Stable Operation ◽  
Nox Emissions ◽  
Single Digit ◽  
Engine Operation ◽  
Wobbe Index

The use of an innovative, intelligent control algorithm applied to the Siemens SGT-300 DLE engine is described. The algorithm ensures stable operation and minimises emissions over a wide variation in fuel composition. The Siemens 8MW class SGT-300 gas turbine has been in operation at the University of New Hampshire (USA) since 2006. As well as operating on natural gas or diesel, the engine also operates on a gas processed from a landfill. These gases have a variable Wobbe Index (WI) covering the range 29.7 to 49 MJ/m3. No modifications have been required to the standard DLE combustion hardware. Introduction of the intelligent control algorithm has been instrumental in achieving this tri-fuel capability. Accumulation of more than 10 000 hours running on non-standard fuel has been achieved. The intelligent control algorithm exploits knowledge of the stable operating window through continual modification of the fuel schedule to avoid both lean blow out and high metal temperatures. Operationally, this results in a reduction in the NOx emissions, through controlling the unmixedness, and higher engine reliability, through the response of the algorithm to flame stability. Combining these advantages the control algorithm can deliver reliable engine operation on variable composition fuels when using standard combustion hardware achieving single digit NOx emissions not only on natural gas but also on processed landfill gas. This paper describes the control algorithm and presents results of the development from high pressure combustion rig and engine development test to field operation with both natural gas and processed landfill gas.

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