Catalytic Combustion Technology Development for Gas Turbine Engine Applications

1998 ◽  
Vol 549 ◽  
Author(s):  
Robert N. Carter ◽  
Lance L. Smith ◽  
Hasan Karim ◽  
Marco Castaldi ◽  
Shah Etemad ◽  
...  
Keyword(s):  
Gas Turbine ◽  
Catalytic Combustion ◽  
Materials Science ◽  
Technology Development ◽  
Flame Temperature ◽  
Oxides Of Nitrogen ◽  
Nox Formation ◽  
Turbine Engine ◽  
Lean Premixed ◽  
Homogeneous Combustion

AbstractCatalytic combustion is one means of meeting increasingly strict emissions requirements for ground-based gas turbine engines for power generation. In conventional homogeneous combustion, high flame temperatures and incomplete combustion lead to emissions of oxides of nitrogen (NOx) and carbon monoxide (CO), and in lean premixed systems unburned hydrocarbons (UHC). However, catalyst-assisted reaction upstream of a lean premixed homogeneous combustion zone can increase the fuel/air mixture reactivity sufficiently to provide low CO/UHC emissions. Additionally, catalytic combustion extends the lean limit of combustion, thereby minimizing NOx formation by lowering the adiabatic flame temperature. An overview of this technology is presented including discussion of the many materials science and catalyst challenges that catalytic combustion poses ranging from the need for high temperature materials to catalyst performance and endurance. Results of ongoing development efforts at Precision Combustion, Inc. (PCI) are presented including modeling studies and experimental results from both bench-scale and combustor-scale studies.

Low Emissions Combustion for the Regenerative Gas Turbine: Part 1—Theoretical and Design Considerations

1974 ◽  
Vol 96 (1) ◽  
pp. 32-48 ◽  
Author(s):  
W. R. Wade ◽  
P. I. Shen ◽  
C. W. Owens ◽  
A. F. McLean
Keyword(s):  
Gas Turbine ◽  
Flame Temperature ◽  
Homogeneous System ◽  
Automotive Application ◽  
Inlet Temperature ◽  
Oxides Of Nitrogen ◽  
Turbine Engine ◽  
Homogeneous Combustion ◽  
Hc Emissions ◽  
Model Year

This first part, of a two part paper, reviews the NOx emission problem of the regenerative gas turbine engine for automotive application. It discusses the problem of fuel droplet burning, which causes heterogenous combustion with resulting high flame temperatures and high levels of oxides of nitrogen. The paper proposes means to achieve homogeneous combustion and shows that, even with this approach, flame temperatures need to be closely controlled to effect a compromise between NOx, CO, and HC emissions in order to meet the stringent numerical levels of emissions specified by the Federal standards for 1976 and subsequent model year automobiles. The paper shows that combustor inlet temperature of a homogeneous system has little effect, theoretically, on computed NOx emissions expressed as grams per mile, thereby strengthening the case for the regenerative turbine engine. A design concept for homogeneous combustion with controlled flame temperature is discussed.

A NOx Prediction Scheme for Lean-Premixed Gas Turbine Combustion Based on Detailed Chemical Kinetics

1996 ◽  
Vol 118 (4) ◽  
pp. 765-772 ◽  
Author(s):  
W. Polifke ◽  
K. Do¨bbeling ◽  
T. Sattelmayer ◽  
D. G. Nicol ◽  
P. C. Malte
Keyword(s):  
Flow Field ◽  
Gas Turbine ◽  
Concentration Field ◽  
Operating Conditions ◽  
Chemical Mechanism ◽  
Reacting Flow ◽  
Oxides Of Nitrogen ◽  
Detailed Chemical Kinetics ◽  
Nox Formation ◽  
Lean Premixed

The lean-premixed technique has proven very efficient in reducing the emissions of oxides of nitrogen (NOx) from gas turbine combustors. The numerical prediction of NOx levels in such combustors with multidimensional CFD codes has only met with limited success so far. This is to some extent due to the complexity of the NOx formation chemistry in lean-premixed combustion, i.e., all three known NOx formation routes (Zeldovich, nitrous, and prompt) can contribute significantly. Furthermore, NOx formation occurs almost exclusively in the flame zone, where radical concentrations significantly above equilibrium values are observed. A relatively large chemical mechanism is therefore required to predict radical concentrations and NOx formation rates under such conditions. These difficulties have prompted the development of a NOx postprocessing scheme, where rate and concentration information necessary to predict NOx formation is taken from one-dimensional combustion models with detailed chemistry and provided—via look-up tables—to the multidimensional CFD code. The look-up tables are prepared beforehand in accordance with the operating conditions and are based on CO concentrations, which are indicative of free radical chemistry. Once the reacting flow field has been computed with the main CFD code, the chemical source terms of the NO transport equation, i.e., local NO formation rates, are determined from the reacting flow field and the tabulated chemical data. Then the main code is turned on again to compute the NO concentration field. This NOx submodel has no adjustable parameters and converges very quickly. Good agreement with experiment has been observed and interesting conclusions concerning superequilibrium O-atom concentrations and fluctuations of temperature could be drawn.

scholarly journals A NOx Prediction Scheme for Lean-Premixed Gas Turbine Combustion Based on Detailed Chemical Kinetics

1995 ◽  
Author(s):  
Wolfgang Polifke ◽  
Klaus Döbbeling ◽  
Thomas Sattelmayer ◽  
David G. Nicol ◽  
Philip C. Malte
Keyword(s):  
Flow Field ◽  
Gas Turbine ◽  
Concentration Field ◽  
Operating Conditions ◽  
Chemical Mechanism ◽  
Reacting Flow ◽  
Oxides Of Nitrogen ◽  
Nox Formation ◽  
Processing Scheme ◽  
Lean Premixed

The lean-premixed technique has proven very efficient in reducing the emissions of oxides of nitrogen (NOx) from gas turbine combustors. The numerical prediction of NOx-levels in such combustors with multidimensional CFD codes has only met with limited success so far. This is at least to some extent due to the complexity of the NOx formation chemistry in lean-premixed combustion, i.e. all three known NOx formation routes (Zeldovich, nitrous and prompt) can contribute significantly. Furthermore, NOx formation occurs almost exclusively in the flame zone, where radical concentrations significantly above equilibrium values are observed. A relatively large chemical mechanism is therefore required to predict radical concentrations and NOx formation rates under such conditions. These difficulties have prompted the development of a NOx post-processing scheme, where rate and concentration information necessary to predict NOx formation is taken from one-dimensional combustion models with detailed chemistry and provided — via look-up tables — to the multi-dimensional CFD code. The look-up tables are prepared beforehand in accordance with the operating conditions and are based on CO concentrations, which are indicative of free radical chemistry. Once the reacting flow field has been computed with the main CFD code, the chemical source terms of the NO transport equation, i.e. local NO formation rates, are determined from the reacting flow field and the tabulated chemical data. Then the main code is turned on again to compute the NO concentration field. This NOx sub-model has no adjustable parameters and converges very quickly. Good agreement with experiment has been observed and interesting conclusions concerning superequilibrium O-atom concentrations and fluctuations of temperature could be drawn.

Numerical Investigation of the Pressure Effect on the NOx Formation in a Lean-Premixed Gas Turbine Combustor

2021 ◽  
Vol 35 (8) ◽  
pp. 6776-6784
Author(s):  
Truc Huu Nguyen ◽  
Jungkyu Park ◽  
Changhun Sin ◽  
Seungchai Jung ◽  
Shaun Kim
Keyword(s):  
Numerical Investigation ◽  
Gas Turbine ◽  
Pressure Effect ◽  
Gas Turbine Combustor ◽  
Nox Formation ◽  
Lean Premixed

Analysis of Water–Fuel Ratio Variation in a Gas Turbine With a Wet-Compressor System by Change in Fuel Composition

2017 ◽  
Vol 140 (5) ◽  
Author(s):  
Yonatan Cadavid ◽  
Andres Amell ◽  
Juan Alzate ◽  
Gerjan Bermejo ◽  
Gustavo A. Ebratt
Keyword(s):  
Gas Turbine ◽  
Burning Velocity ◽  
Thermal Power ◽  
Flame Temperature ◽  
Fuel Composition ◽  
Nox Formation ◽  
Gaseous Hydrocarbon ◽  
Power Generators ◽  
Fuel Ratio ◽  
Combustion Properties

The wet compressor (WC) has become a reliable way to reduce gas emissions and increase gas turbine efficiency. However, fuel source diversification in the short and medium terms presents a challenge for gas turbine operators to know how the WC will respond to changes in fuel composition. For this study, we assessed the operational data of two thermal power generators, with outputs of 610 MW and 300 MW, in Colombia. The purpose was to determine the maximum amount of water that can be added into a gas turbine with a WC system, as well as how the NOx/CO emissions vary due to changes in fuel composition. The combustion properties of different gaseous hydrocarbon mixtures at wet conditions did not vary significantly from each other—except for the laminar burning velocity. It was found that the fuel/air equivalence ratio in the turbine reduced with lower CH4 content in the fuel. Less water can be added to the turbine with leaner combustion; the water/fuel ratio was decreased over the range of 1.4–0.4 for the studied case. The limit is mainly due to a reduction in flame temperature and major risk of lean blowout (LBO) or dynamic instabilities. A hybrid reaction mechanism was created from GRI-MECH 3.0 and NGIII to model hydrocarbons up to C5 with NOx formation. The model was validated with experimental results published previously in literature. Finally, the effect of atmospheric water in the premixed combustion was analyzed and explained.

scholarly journals Development of Ceramic Gas Turbine Components for the CGT301 Engine

1996 ◽  
Author(s):  
Mitsuru Hattori ◽  
Tsutomu Yamamoto ◽  
Keiichiro Watanabe ◽  
Masaaki Masuda
Keyword(s):  
Gas Turbine ◽  
Technology Development ◽  
Turbine Blades ◽  
High Heat ◽  
Turbine Engine ◽  
Development Organization ◽  
All Ceramic ◽  
New Energy ◽  
Ceramic Components ◽  
Resistant Ceramic

NGK Insulators, Ltd. (NGK) has undertaken the research and development on the fabrication processes of high-heat-resistant ceramic components for the CGT301, which is a 300kW recuperative industrial ceramic gas turbine engine. This program is under the New Sunshine Project, funded by the Ministry of International Trade and Industry (MITI), and has been guided by the Agency of Industrial Science & Technology (AIST) since 1988. The New Energy and Industrial Technology Development Organization (NEDO) is the main contractor. The fabrication techniques for ceramic components, such as turbine blades, turbine nozzles, combustor liners, gas-path parts, and heat exchanger elements, for the 1,200°C engine were developed by 1993. Development for the 1,350°C engine has been underway since 1994. The baseline conditions for fabricating of all ceramic components have been established. This paper reports on the development of ceramic gas turbine components, and the improved accuracies of their shapes as well as improved reliability from the results of the interim appraisal conducted in 1994.

New Catalytic Combustion Technology for Very Low Emissions Gas Turbines

1994 ◽  
Author(s):  
R. A. Dalla Betta ◽  
J. C. Schlatter ◽  
S. G. Nickolas ◽  
D. K. Yee ◽  
T. Shoji
Keyword(s):  
Thermal Shock ◽  
Gas Turbine ◽  
High Temperatures ◽  
Gas Turbines ◽  
Catalytic Combustion ◽  
Combustion Process ◽  
Combustion System ◽  
Gas Turbine Combustors ◽  
Homogeneous Combustion ◽  
Combustion Technology

A catalytic combustion system has been developed which feeds full fuel and air to the catalyst but avoids exposure of the catalyst to the high temperatures responsible for deactivation and thermal shock fracture of the supporting substrate. The combustion process is initiated by the catalyst and is completed by homogeneous combustion in the post catalyst region where the highest temperatures are obtained. This has been demonstrated in subscale test rigs at pressures up to 14 atmospheres and temperatures above 1300°C (2370°F). At pressures and gas linear velocities typical of gas turbine combustors, the measured emissions from the catalytic combustion system are NOx < 1 ppm, CO < 2 ppm and UHC < 2 ppm, demonstrating the capability to achieve ultra low NOx and at the same time low CO and UHC.

scholarly journals Analysis of NOx Formation in a Hydrogen Fueled Gas Turbine Engine

2008 ◽  
Author(s):  
Peter Therkelsen ◽  
Tavis Werts ◽  
Vincent McDonell ◽  
Scott Samuelsen
Keyword(s):  
Natural Gas ◽  
Gas Turbine ◽  
Full Range ◽  
Gas Turbine Engine ◽  
System Level ◽  
Stable Operation ◽  
No Production ◽  
No Emission ◽  
Nox Formation ◽  
Turbine Engine

A commercially available natural gas fueled gas turbine engine was operated on hydrogen. Three sets of fuel injectors were developed to facilitate stable operation while generating differing levels of fuel/air premixing. One set was designed to produce near uniform mixing while the others have differing degrees of non-uniformity. The emissions performance of the engine over its full range of loads is characterized for each of the injector sets. In addition, the performance is also assessed for the set with near uniform mixing as operated on natural gas. The results show that improved mixing and lower equivalence ratio decreases NO emission levels as expected. However, even with nearly perfect premixing, it is found that the engine, when operated on hydrogen, produces a higher amount of NO than when operated with natural gas. Much of this attributed to the higher equivalence ratios that the engine operates on when firing hydrogen. However, even at the lowest equivalence ratios run at low power conditions, higher NO was observed. Analysis of the potential NO formation effects of residence time, kinetic pathways of NO production via NNH, and the kinetics of the dilute combustion strategy used are evaluated. While no one mechanism appears to explain the reasons for the higher NO, it is concluded that each may be contributing to the higher NO emissions observed with hydrogen. In the present configuration with the commercial control system operating normally, it is evident that system level effects are also contributing to the observed NO emission differences between hydrogen and natural gas.

NOx Emissions Modeling and Uncertainty From Exhaust-Gas-Diluted Flames

2015 ◽  
Vol 138 (5) ◽  
Author(s):  
Antonio C. A. Lipardi ◽  
Jeffrey M. Bergthorson ◽  
Gilles Bourque
Keyword(s):  
Nox Reduction ◽  
Flame Temperature ◽  
No Production ◽  
Exhaust Gas ◽  
Oxides Of Nitrogen ◽  
Nox Formation ◽  
Kinetic And Thermodynamic Parameters ◽  
Emissions Modeling ◽  
Combustion Processes ◽  
Gas Recirculation

Oxides of nitrogen (NOx) are pollutants emitted by combustion processes during power generation and transportation that are subject to increasingly stringent regulations due to their impact on human health and the environment. One NOx reduction technology being investigated for gas-turbine engines is exhaust-gas recirculation (EGR), either through external exhaust-gas recycling or staged combustion. In this study, the effects of different percentages of EGR on NOx production will be investigated for methane–air and propane–air flames at a selected adiabatic flame temperature of 1800 K. The variability and uncertainty of the results obtained by the gri-mech 3.0 (GRI), San-Diego 2005 (SD), and the CSE thermochemical mechanisms are assessed. It was found that key parameters associated with postflame NO emissions can vary up to 192% for peak CH values, 35% for thermal NO production rate, and 81% for flame speed, depending on the mechanism used for the simulation. A linear uncertainty analysis, including both kinetic and thermodynamic parameters, demonstrates that simulated postflame nitric oxide levels have uncertainties on the order of ±50–60%. The high variability of model predictions, and their relatively high associated uncertainties, motivates future experiments of NOx formation in exhaust-gas-diluted flames under engine-relevant conditions to improve and validate combustion and NOx design tools.

scholarly journals The Importance of the Nitrous Oxide Pathway to NOx in Lean-Premixed Combustion

1993 ◽  
Author(s):  
David G. Nicol ◽  
Robert C. Steele ◽  
Nick M. Marinov ◽  
Philip C. Malte
Keyword(s):  
Nitrous Oxide ◽  
Pressure Dependence ◽  
Porous Plate ◽  
Premixed Combustion ◽  
Nox Formation ◽  
Lean Premixed Combustion ◽  
Turbine Engine ◽  
Stirred Reactor ◽  
Primary Zone ◽  
Lean Premixed

This study addresses the importance of the different chemical pathways responsible for NOx formation in lean-premixed combustion, and especially the role of the nitrous oxide pathway relative to the traditional Zeldovich pathway. NOx formation is modeled and computed over a range of operating conditions for the lean-premixed primary zone of gas turbine engine combustors. The primary zone, of uniform fuel-air ratio, is modeled as a micro-mixed well-stirred reactor, representing the flame zone, followed by a series of plug flow reactors, representing the post-flame zone. The fuel is methane. The fuel-air equivalence ratio is varied from 0.5 to 0.7. The chemical reactor model permits study of the three pathways by which NOx forms, which are the Zeldovich, nitrous oxide, and prompt pathways. Modeling is also performed for the well-stirred reactor alone. Three recently published, complete chemical kinetic mechanisms for the C1-C2 hydrocarbon oxidation and the NOx formation are applied and compared. Verification of the model is based on the comparison of its NOx output to experimental results published for atmospheric pressure jet-stirred reactors and for a ten atmosphere porous-plate burner. Good agreement between the modeled results and the measurements is obtained for most of the jet-stirred reactor operating range. For the porous-plate burner, the model shows agreement to the NOx measurements within a factor of two, with close agreement occurring at the leanest and coolest cases examined. For lean-premixed combustion at gas turbine engine conditions, the nitrous oxide pathway is found to be important, though the Zeldovich pathway cannot be neglected. The prompt pathway, however, contributes small-to-negligible NOx. Whenever the NOx emission is in the 15 to 30ppmv (15% O2, dry) range, the nitrous oxide pathway is predicted to contribute 40 to 45% of the NOx for high pressure engines (30atm), and 20 to 35% of the NOx for intermediate pressure engines (10atm). For conditions producing NOx of less than 10ppmv (15% O2, dry), the nitrous oxide contribution increases steeply and approaches 100%. For lean-premixed combustion in the atmospheric pressure jet-stirred reactors, different behavior is found. All three pathways contribute; none can be dismissed. No universal behavior is found for the pressure dependence of the NOx. It does appear, however, that lean-premixed combustors operated in the vicinity of 10atm have a relatively weak pressure dependence, whereas combustors operated in the vicinity of 30atm have an approximately square root pressure dependence of the NOx.

Sign in / Sign up

Export Citation Format

Share Document