scholarly journals Reduction of NOx Emission from Gas TURBINE COMBUSTOR Applying Fuel-Staged Combustion

2008 ◽  
Vol 2 (1) ◽  
pp. 61
Author(s):  
Mohammad Nazri ◽  
Mohd. Jaafar
Keyword(s):  
Carbon Monoxide ◽  
Gas Turbine ◽  
Main Stage ◽  
Nox Emissions ◽  
Fuel Injector ◽  
Gas Turbine Combustor ◽  
Inside Diameter ◽  
Fuel Staging ◽  
In Series ◽  
The Rich

A two-stage lean/lean gas turbine combustor was developed with low NOx characteristics in each stage using a small radial swirler of 40-mm outlet diameter in the pilot stage. Both flame tubes were arranged in series with the smaller combustor (76 mm inside diameter) as the pilot stage and the larger combustor (140 mm inside diameter) as the main stage. The pilot stage was fuelled via vane passage fuel injector, while the main stage was fuelled around the wall of the exit plane of the pilot stage, using wall fuel injectors. Low NOx emissions were obtained when using fuel staging for methane fuel, as low as 6 ppm. A NO. reduction of more than 40 % was obtained at equivalence ratio of near 0.7, when using fuel staging compared to the non-fuel-staging test. Tests were conducted using methane as fuel. This was achieved at very small increase in carbon monoxide emissions especially near the rich region and with almost no increase at all in the unburned hydrocarbon emissions at the same equivalence ratio.Keywords: NOx emissions, fuel staging, carbon monoxide, swirler.

Experimental Assessment of the Emissions Benefits of a Ceramic Gas Turbine Combustor

1996 ◽  
Author(s):  
K. O. Smith ◽  
A. Fahme
Keyword(s):  
Natural Gas ◽  
Gas Turbine ◽  
Flow Distribution ◽  
Operating Conditions ◽  
Nox Emissions ◽  
Fuel Injector ◽  
Gas Turbine Combustor ◽  
Experimental Assessment ◽  
Industrial Gas Turbine ◽  
Combustor Liner

Three subscale, cylindrical combustors were rig tested on natural gas at typical industrial gas turbine operating conditions. The intent of the testing was to determine the effect of combustor liner cooling on NOx and CO emissions. In order of decreasing liner cooling, a metal louvre-cooled combustor, a metal effusion-cooled combustor, and a backside-cooled ceramic (CFCC) combustor were evaluated. The three combustors were tested using the same lean-premixed fuel injector. Testing showed that reduced liner cooling produced lower CO emissions as reaction quenching near the liner wall was reduced. A reduction in CO emissions allows a reoptimization of the combustor air flow distribution to yield lower NOx emissions.

Kinetics Modeling on NOx Emissions of a Syngas Turbine Combustor Using RQL Combustion Method

2019 ◽  
Author(s):  
Haoyang Liu ◽  
Wenkai Qian ◽  
Min Zhu ◽  
Suhui Li
Keyword(s):  
Gas Turbine ◽  
Residence Time ◽  
Air Flow ◽  
Nox Reduction ◽  
Outlet Temperature ◽  
Nox Emissions ◽  
Gas Turbine Combustor ◽  
Kinetics Modeling ◽  
The Rich ◽  
Nox Control

Abstract To avoid flashback issues of the high-H2 syngas fuel, current syngas turbines usually use non-premixed combustors, which have high NOx emissions. A promising solution to this dilemma is RQL (rich-burn, quick-mix, lean-burn) combustion, which not only reduces NOx emissions, but also mitigates flashback. This paper presents a kinetics modeling study on NOx emissions of a syngas-fueled gas turbine combustor using RQL architecture. The combustor was simulated with a chemical reactor network model in CHEMKIN-PRO software. The combustion and NOx formation reactions were modeled using a detailed kinetics mechanism that was developed for syngas. Impacts of combustor design/operating parameters on NOx emissions were systematically investigated, including combustor outlet temperature, rich/lean air flow split and residence time split. The mixing effects in both the rich-burn zone and the quick-mix zone were also investigated. Results show that for an RQL combustor, the NOx emissions initially decrease and then increase with combustor outlet temperature. The leading parameters for NOx control are temperature-dependent. At typical modern gas turbine combustor operating temperatures (e.g., < 1890 K), the air flow split is the most effective parameter for NOx control, followed by the mixing at the rich-burn zone. However, as the combustor outlet temperature increases, the impacts of air flow split and mixing in the rich-burn zone on NOx reduction become less pronounced, whereas both the residence time split and the mixing in the quick-mix zone become important.

Development of a Small-Scale Catalytic Gas Turbine Combustor

1982 ◽  
Vol 104 (1) ◽  
pp. 52-57 ◽  
Author(s):  
S. J. Anderson ◽  
M. A. Friedman ◽  
W. V. Krill ◽  
J. P. Kesselring
Keyword(s):  
Steady State ◽  
Gas Turbine ◽  
Gas Turbines ◽  
Combustion Efficiency ◽  
Small Scale ◽  
Time Interval ◽  
Nox Emissions ◽  
Fuel Injector ◽  
Gas Turbine Combustor ◽  
Opposed Jet

Catalytically supported thermal combustion can provide low NOx emissions with gaseous and distillate fuels while maintaining high combustion efficiency. For stationary gas turbines, catalytic combustion may be the only emerging technology that can cost effectively meet recent federal regulations for NOx emissions. Under EPA sponsorship, a small-scale, catalytic gas turbine combustor was developed to evaluate transient and steady state combustor performance. The combustor consisted of a multiple air-atomizing fuel injector, an opposed jet igniter, and a graded-cell monolithic reactor. System startup, including opposed jet ignition and catalyst stabilization, was achieved in 250 seconds. This time interval is comparable to conventional gas turbines. Steady state operation was performed at 0.505 MPa (5 atmospheres) pressure and 15.3 m/s (50 ft/s) reference velocities. Thermal NOx emissions were measured below 10 ppmv, while fuel NOx conversion ranged from 75 to 95 percent. At catalyst bed temperatures greater than 1422K (2100°F), total CO and UHC emissions were less than 50 ppmv indicating combustion efficiency greater than 99.9 percent. Compared with conventional gas turbine combustors, the catalytic reactor operates only within a relatively narrow range of fuel/air ratios. As a result, modified combustor air distribution or fuel staging will be required to achieve the wide turndown required in large stationary systems.

Kinetics Modeling on NOx Emissions of a Syngas Turbine Combustor Using Rich-Burn, Quick-Mix, Lean-Burn Combustion Method

2020 ◽  
Vol 142 (2) ◽  
Author(s):  
Haoyang Liu ◽  
Wenkai Qian ◽  
Min Zhu ◽  
Suhui Li
Keyword(s):  
Gas Turbine ◽  
Residence Time ◽  
Air Flow ◽  
Outlet Temperature ◽  
Nox Emissions ◽  
Gas Turbine Combustor ◽  
Lean Burn ◽  
Kinetics Modeling ◽  
The Rich ◽  
Nox Control

Abstract To avoid flashback issues of the high-H2 syngas fuel, current syngas turbines usually use nonpremixed combustors, which have high NOx emissions. A promising solution to this dilemma is rich-burn, quick-mix, lean-burn (RQL) combustion, which not only reduces NOx emissions but also mitigates flashback. This paper presents a kinetics modeling study on NOx emissions of a syngas–fueled gas turbine combustor using RQL architecture. The combustor was simulated with a chemical reactor network (CRN) model in chemkin-pro software. The combustion and NOx formation reactions were modeled using a detailed kinetics mechanism that was developed for syngas. Impacts of combustor design/operating parameters on NOx emissions were systematically investigated, including combustor outlet temperature, rich/lean air flow split, and residence time split. The mixing effects in both the rich-burn zone and the quick-mix zone were also investigated. Results show that for an RQL combustor, the NOx emissions initially decrease and then increase with combustor outlet temperature. The leading parameters for NOx control are temperature-dependent. At typical modern gas turbine combustor operating temperatures (e.g., &lt;1890 K), the air flow split is the most effective parameter for NOx control, followed by the mixing at the rich-burn zone. However, as the combustor outlet temperature increases, the impacts of air flow split and mixing in the rich-burn zone on NOx reduction become less pronounced, whereas both the residence time split and the mixing in the quick-mix zone become important.

scholarly journals The GE Rich-Quench-Lean Gas Turbine Combustor

1998 ◽  
Vol 120 (3) ◽  
pp. 502-508 ◽  
Author(s):  
A. S. Feitelberg ◽  
M. A. Lacey
Keyword(s):  
Natural Gas ◽  
Gas Turbine ◽  
Coal Gasification ◽  
Perforated Plate ◽  
Combined Cycle ◽  
Development Effort ◽  
Nox Emissions ◽  
Gas Turbine Combustor ◽  
Chemical Kinetic Model ◽  
The Rich

The General Electric Company has developed and successfully tested a full-scale, F-class (2550°F combustor exit temperature), rich-quench-lean (RQL) gas turbine combustor, designated RQL2, for low heating value (LHV) fuel and integrated gasification combined cycle applications. Although the primary objective of this effort was to develop an RQL combustor with lower conversion of fuel bound nitrogen to NOx than a conventional gas turbine combustor, the RQL2 design can be readily adapted to natural gas and liquid fuel combustion. RQL2 is the culmination of a 5 year research and development effort that began with natural gas tests of a 2” diameter perforated plate combustor and included LHV fuel tests of RQL1, a reduced scale (6” diameter) gas turbine combustor. The RQL2 combustor includes a 14” diameter converging rich stage liner, an impingement cooled 7” diameter radially-stratified-quench stage, and a backward facing step at the entrance to a 10” diameter film cooled lean stage. The rich stage combustor liner has a novel double-walled structure with narrow circumferential cooling channels to maintain metal wall temperatures within design limits. Provisions were made to allow independent control of the air supplied to the rich and quench/lean stages. RQL2 has been fired for almost 100 hours with LHV fuel supplied by a pilot scale coal gasification and high temperature desulfurization system. At the optimum rich stage equivalence ration NOx emissions were about 50 ppmv (on a dry, 15 percent O2 basis), more than a factor of 3 lower than expected from a conventional diffusion flame combustor burning the same fuel. With 4600 ppmv NH3 in the LHV fuel, this corresponds to a conversion of NH3 to NOx of about 5 percent. As conditions were shifted away from the optimum, RQL2 NOx emissions gradually increased until they were comparable to a standard combustor. A chemical kinetic model of RQL2, constructed from a series of ideal chemical reactors, matched the measured NOx emissions fairly well. The CO emissions were between 5 and 30 ppmv (on a dry, 15 percent O2 basis) under all conditions.

Experimental Evaluation of Fuel Injection Configurations for a Lean-Premixed Low NOx Gas Turbine Combustor

1987 ◽  
Author(s):  
Kenneth O. Smith ◽  
F. R. Kurzynske ◽  
Leonard C. Angello
Keyword(s):  
Gas Turbine ◽  
Experimental Evaluation ◽  
Fuel Injection ◽  
Nox Emissions ◽  
Fuel Injector ◽  
Gas Turbine Combustor ◽  
Program Goal ◽  
Preliminary Step ◽  
Gas Fuel ◽  
Design And Testing

The design and testing of three natural gas fuel injector configurations for a low emissions gas turbine combustor are described. The injectors provided varying degrees of fuel/air premixing and permitted an assessment of the degree of premixing necessary to achieve NOx emissions below the program goal of 10 ppm. The work described represents a preliminary step in an effort to develop production-level gas turbine combustor hardware with ultra-low NOx capabilities.

The aerodynamic challenges of aeroengine gas-turbine combustion systems

2014 ◽  
Vol 118 (1204) ◽  
pp. 557-599 ◽  
Author(s):  
J. J. McGuirk
Keyword(s):  
Gas Turbine ◽  
Combustion Efficiency ◽  
Great Success ◽  
Fuel Injector ◽  
Gas Turbine Combustor ◽  
Lean Burn ◽  
Combustion Systems ◽  
The Rich ◽  
Acoustic Instabilities

Abstract The components of an aeroengine gas-turbine combustor have to perform multiple tasks – control of external and internal air distribution, fuel injector feed, fuel/air atomisation, evaporation, and mixing, flame stabilisation, wall cooling, etc. The ‘rich-burn’ concept has achieved great success in optimising combustion efficiency, combustor life, and operational stability over the whole engine cycle. This paper first illustrates the crucial role of aerodynamic processes in achieving these performance goals. Next, the extra aerodynamic challenges of the ‘lean-burn’ injectors required to meet the ever more stringent NO x emissions regulations are introduced, demonstrating that a new multi-disciplinary and ‘whole system’ approach is required. For example, high swirl causes complex unsteady injector aerodynamics; the threat of thermo-acoustic instabilities means both aerodynamic and aeroacoustic characteristics of injectors and other air admission features must be considered; and high injector mass flow means potentially strong compressor/combustor and combustor/turbine coupling. The paper illustrates how research at Loughborough University, based on complementary use of advanced experimental and computational methods, and applied to both isolated sub-components and fully annular combustion systems, has improved understanding and identified novel ideas for combustion system design.

scholarly journals The GE Rich-Quench-Lean Gas Turbine Combustor

1997 ◽  
Author(s):  
Alan S. Feitelberg ◽  
Michael A. Lacey
Keyword(s):  
Natural Gas ◽  
Gas Turbine ◽  
Coal Gasification ◽  
Perforated Plate ◽  
Combined Cycle ◽  
Development Effort ◽  
Nox Emissions ◽  
Gas Turbine Combustor ◽  
Chemical Kinetic Model ◽  
The Rich

The General Electric Company has developed and successfully tested a full-scale, ‘F’ class (2550°F combustor exit temperature), rich-quench-lean (RQL) gas turbine combustor, designated RQL2, for low heating value (LHV) fuel and integrated gasification combined cycle applications. Although the primary objective of this effort was to develop an RQL combustor with lower conversion of fuel bound nitrogen to NOx than a conventional gas turbine combustor, the RQL2 design can be readily adapted to natural gas and liquid fuel combustion. RQL2 is the culmination of a 5 year research and development effort that began with natural gas tests of a 2″ diameter perforated plate combustor and included LHV fuel tests of RQL1, a reduced scale (6″ diameter) gas turbine combustor. The RQL2 combustor includes a 14″ diameter converging rich stage liner, an impingement cooled 7″ diameter radially-stratified-quench stage, and a backward facing step at the entrance to a 10″ diameter film cooled lean stage. The rich stage combustor liner has a novel double-walled structure with narrow circumferential cooling channels to maintain metal wall temperatures within design limits. Provisions were made to allow independent control of the air supplied to the rich and quench/lean stages. RQL2 has been fired for almost 100 hours with LHV fuel supplied by a pilot scale coal gasification and high temperature desulfurization system. At the optimum rich stage equivalence ratio NOx emissions were about 50 ppmv (on a dry, 15% O2 basis), more than a factor of 3 lower than expected from a conventional diffusion flame combustor burning the same fuel. With 4600 ppmv NH3 in the LHV fuel, this corresponds to a conversion of NH3 to NOx of about 5%. As conditions were shifted away from the optimum, RQL2 NOx emissions gradually increased until they were comparable to a standard combustor. A chemical kinetic model of RQL2, constructed from a series of ideal chemical reactors, matched the measured NOx emissions fairly well. The CO emissions were between 5 and 30 ppmv (on a dry, 15% O2 basis) under all conditions.

Experimental Evaluation of a Liquid-Fueled, Lean-Premixed Gas Turbine Combustor

1989 ◽  
Author(s):  
K. O. Smith ◽  
L. H. Cowell
Keyword(s):  
Gas Turbine ◽  
Experimental Evaluation ◽  
Operating Conditions ◽  
Nox Emissions ◽  
Test Results ◽  
Fuel Injector ◽  
Gas Turbine Combustor ◽  
Lean Premixed

Rig testing of a lean-premixed, liquid-fueled corabustor was conducted to establish the feasibility of achieving ultra-low NOx emissions at typical gas turbine operating conditions. Two different filming fuel injector concepts were evaluated. The majority of combustor testing was conducted using No. 2 diesel. The test results showed 12 and 20 ppm NOx at 6 and 9 atm, respectively. Corresponding CO levels were 50 ppm in both cases.

Combustion Characteristics of Small Size Gas Turbine Combustor Fueled by Biomass Gas Employing Flameless Combustion

2007 ◽  
Author(s):  
Masato Hiramatsu ◽  
Yoshifumi Nakashima ◽  
Sadamasa Adachi ◽  
Yudai Yamasaki ◽  
Shigehiko Kaneko
Keyword(s):  
Gas Turbine ◽  
Combustion Efficiency ◽  
Combustion Characteristics ◽  
Operating Conditions ◽  
Nox Emissions ◽  
Gas Turbine Combustor ◽  
Flameless Combustion ◽  
Engine Exhaust ◽  
Micro Gas Turbine

One approach to achieving 99% combustion efficiency (C.E.) and 10 ppmV or lower NOx (at 15%O2) in a micro gas turbine (MGT) combustor fueled by biomass gas at a variety of operating conditions is with the use of flameless combustion (FLC). This paper compares experimentally obtained results and CHEMKIN analysis conducted for the developed combustor. As a result, increase the number of stage of FLC combustion enlarges the MGT operation range with low-NOx emissions and high-C.E. The composition of fuel has a small effect on the characteristics of ignition in FLC. In addition, NOx in the engine exhaust is reduced by higher levels of CO2 in the fuel.

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