scholarly journals Development of a Coal-Fueled Gas Turbine Slagging Combustor

1989 ◽  
Author(s):  
L. H. Cowell ◽  
R. T. LeCren
Keyword(s):  
Gas Turbine ◽  
Computer Modelling ◽  
Combustion Process ◽  
Development Program ◽  
Water Mixture ◽  
Fuel Injector ◽  
Cross Sectional ◽  
Fuel Injectors ◽  
Primary Zone ◽  
Multiple Jets

A slagging combustor for a coal-fueled gas turbine engine is being developed. The work to date has been accomplished using a bench-scale combustor with one-tenth the heat input required for the full-scale gas turbine unit. The combustor features a fuel-rich slagging primary zone with hot refractory walls. Both single and multiple primary air/fuel injectors have been tested. Aerodynamic jet impaction on a target at one end of the primary zone removes much of the slag. The jet impaction is the result of the single air/fuel injector flow for multiple injectors, the intersection of the multiple jets forms a central jet. There is an additional particulate rejection impact separator between the primary and secondary zones to remove the slag that escapes the primary zone. Secondary air is introduced via multiple jets that rapidly mix with the incoming gas from the particulate removal device, resulting in a minimal formation of thermal NOx and the completion of the combustion process. Variables that have been evaluated include coal-water mixture properties such as top and mean particle size, viscosity, loading and ash fusion temperature, and primary zone parameters such as volume, cross-sectional area, loading, and equivalence ratio. Combustor performance was compared with single or multiple fuel injectors, relating the combustor performance to the spray characteristics of the two injector configurations. Modifications of the single injector were evaluated with the goal of attaining at least the same atomization performance as the smaller injectors used in the multiple injector configuration. Flow visualization, computer modelling, and cold-flow velocity traverses have been employed to aid the development program. The results of the subscale development are being used to design and develop the full-size combustor for integration with the engine.

The Civic: A Concept in Vortex Induced Combustion for the Solar Gemini 10 kW Gas Turbine

1981 ◽  
Vol 103 (1) ◽  
pp. 34-42 ◽  
Author(s):  
J. R. Shekleton
Keyword(s):  
Gas Turbine ◽  
Diffusion Flames ◽  
Reynolds Numbers ◽  
Flame Stabilization ◽  
Fuel Injector ◽  
Combustion Chambers ◽  
Turbine Generator ◽  
Fuel Injectors ◽  
Swirl Flame ◽  
Combustion Processes

The Radial Engine Division of Solar Turbines International, an Operating Group of International Harvester, under contract to the U.S. Army Mobility Equipment Research & Development Command, developed and qualified a 10 kW gas turbine generator set. The very small size of the gas turbine created problems and, in the combustor, novel solutions were necessary. Differing types of fuel injectors, combustion chambers, and flame stabilizing methods were investigated. The arrangement chosen had a rotating cup fuel injector, in a can combustor, with conventional swirl flame stabilization but was devoid of the usual jet stirred recirculation. The use of centrifugal force to control combustion conferred substantial benefit (Rayleigh Instability Criteria). Three types of combustion processes were identified: stratified and unstratified charge (diffusion flames) and pre-mix. Emphasis is placed on five nondimensional groups (Richardson, Bagnold, Damko¨hler, Mach, and Reynolds numbers) for the better control of these combustion processes.

scholarly journals Testing of a Full Scale, Low Emissions, Ceramic Gas Turbine Combustor

1997 ◽  
Author(s):  
K. Smith ◽  
A. Fahme
Keyword(s):  
Gas Turbine ◽  
Engine Performance ◽  
Combustion Efficiency ◽  
Full Scale ◽  
Significant Deterioration ◽  
Lean Premixed Combustion ◽  
Fuel Injectors ◽  
Primary Zone ◽  
Test Engine ◽  
Cooling Air

The design and development testing of a full scale, low emissions, ceramic combustor for a 5500 HP industrial gas turbine are described. The combustor was developed under a joint program conducted by the U.S. DOE and Solar Turbines. The ceramic combustor is designed to replace the production Centaur 50S SoLoNOx burner which uses lean-premixed combustion to limit NOx and CO to 25 and 50 ppm, respectively. Both the ceramic and production combustors are annular in shape and employ twelve premixing, natural gas fuel injectors. The ceramic combustor design effort involved the integration of two CFCC cylinders (76.2 cm [30 in.] and 35.56 cm [14 in.] diameters) into the combustor primary zone. The ceramic combustor was evaluated at Solar in full scale test rigs and a test engine. Performance of the combustor was excellent with high combustion efficiency and extremely low NOx and CO emissions. The hot walls of the ceramic combustor played a significant role in reducing CO emissions. This suggests that liner cooling air injected through the metal production liner contributes to CO emissions by reaction quenching at the liner walls. It appears that ceramics can serve to improve combustion efficiency near the combustor lean limit which, in turn, would allow further reductions in NOx emissions. Approximately 50 hours of operation have been accumulated using the ceramic combustor. No significant deterioration in the CFCC liners has been observed. A 4000 hour field test of the combustion system is planned to begin in 1997 as a durability assessment.

The ultra-high efficiency gas turbine engine, UHEGT, Part II: A numerical study on reducing the stator blade surface temperature by indexing fuel injectors and using film cooling

2020 ◽  
pp. 095765092097353
Author(s):  
Seyed M Ghoreyshi ◽  
Meinhard T Schobeiri
Keyword(s):  
Surface Temperature ◽  
Gas Turbine ◽  
Film Cooling ◽  
Total Pressure ◽  
High Efficiency ◽  
Combustion Process ◽  
Blade Surface ◽  
Turbine Engine ◽  
Fuel Injectors ◽  
Stator Blade

In the Ultra-High Efficiency Gas Turbine Engine, UHEGT (introduced in our previous studies) the combustion process is no longer contained in isolation between the compressor and turbine, rather distributed within the axial gaps before each stator row. This technology substantially increases the thermal efficiency of the engine cycle to above 45%, increases power output, and reduces turbine inlet temperature. Since the combustion process is brought into the turbine stages in UHEGT, the stator blades are exposed to high-temperature gases and can be overheated. To address this issue and reduce the temperature on the stator blade surface, two different approaches are investigated in this paper. The first is indexing (clocking) of the fuel injectors (cylindrical tubes extended from hub to shroud), in which the positions of the injectors are adjusted relative to each other and the stator blades. The second is film cooling, in which cooling holes are placed on the blade surface to bring down the temperature via coolant injection. Four configurations are designed and studied via computational fluid dynamics (CFD) to evaluate the effectiveness of the two approaches. Stator blade surface temperature (as the main objective function) along with other performance parameters such as temperature non-uniformity at rotor inlet, total pressure loss over the injectors, and total power production by rotor are evaluated for all configurations. The results show that indexing presents the most promising approach in reducing the stator blade surface temperature while producing the least amount of total pressure loss.

Experimental Evaluation of Sorbents for Sulfur Control in a Coal-Fueled Gas Turbine Slagging Combustor

1990 ◽  
Author(s):  
L. H. Cowell ◽  
C. S. Wen ◽  
R. T. LeCren
Keyword(s):  
Sulfur Dioxide ◽  
Gas Turbine ◽  
Hydrated Lime ◽  
Capture Efficiency ◽  
Water Mixture ◽  
Dolomitic Lime ◽  
Bench Scale ◽  
Primary Zone ◽  
Secondary Zone ◽  
Sulfur Capture

A slagging combustor has been used to evaluate three calcium-based sorbents for sulfur capture efficiency in order to assess their applicability for use in a coal-fueled gas turbine. Testing is completed in a bench-scale combustor with one-tenth the heat input needed for the full-scale gas turbine. The bench-scale rig is a two-staged combustor featuring a fuel rich primary zone and a fuel lean secondary zone. The combustor is operated at 6.5 bars with inlet air preheated to 600 K. Gas temperatures of 1840 K are generated in the primary zone and 1280 K in the secondary zone. Sorbents are fed in either the secondary zone or mixed with the coal water mixture and fed into the primary zone. Dry powdered sorbents are fed into the secondary zone by an auger into one of six secondary air inlet ports. The three sorbents tested in the secondary zone include dolomite, pressure hydrated dolomitic lime, and hydrated lime. Sorbents have been tested while burning coal water mixtures with coal sulfur loadings of 0.56 to 3.13 weight percent sulfur. Sorbents are injected into the secondary zone at varying flow rates such that the calcium/sulfur ratio varies from 0.5 to 10.0. Hydrated lime exhibits the highest sulfur dioxide reductions in the exhaust of 90%. Pressure hydrated dolomitic lime and dolomite reduce SO2 concentrations by 82% and 55%, respectively. Coal sulfur loading is found to have a small influence on sorbent sulfur capture efficiency. Pressure hydrated dolomitic lime ground with the coal during coal water mixture preparation and injected into the primary zone is found to lower the sulfur dioxide concentration by an insignificant amount.

The Effect of the Fuel Injector Internal Geometry Upon the Primary Zone Aerodynamics

1998 ◽  
Author(s):  
R. A. Hicks ◽  
M. Whiteman ◽  
C. W. Wilson
Keyword(s):  
Boundary Conditions ◽  
Fluid Dynamic ◽  
Radial Component ◽  
Fuel Injector ◽  
Air Blast ◽  
Fuel Injectors ◽  
Cfd Models ◽  
Primary Zone ◽  
Flow Through ◽  
Semi Empirical

One of the major aims of research in gas turbine combustor systems is the minimisation of non-desirable emissions. The primary method of reducing pollutants such as soot and NOx has been to run the combustion primary zone lean. Unfortunately, this causes problems when the combustor is run under idle and relight conditions as the primary zone air fuel ratio (AFR) can exceed the flammability limit. Altering this AFR directly affects the primary zone aerodynamics through changes in the spray profile. One method of determining the influence of changes in AFR upon the primary zone is to use Computational Fluid Dynamic (CFD) models. However, to model the flow through an air-blast fuel injector and accurately predict the resulting primary zone aerodynamics requires hundreds of thousands, if not millions, of cells. Therefore, with current computer capabilities simplifications need to be made. One simplification is to model the primary zone as a 2-D case. This reduces the number of cells to a computationally solvable level. However, by reducing the problem to 2-D the ability to accurately model air-blast fuel injectors is lost as they are intrinsically 3-D devices. Therefore, it is necessary to define boundary conditions for the fuel injector. Currently, due to difficulties in obtaining experimental measurements inside a air-blast fuel injector, these boundary conditions are often derived using semi-empirical methods. This paper presents and compares two such models; the model proposed by Crocker et al. in 1996 and one developed at DERA specifically for modelling air-blast fuel injectors. The work also highlights the importance of the often neglected radial component upon the primary zone aerodynamics.

Measurement of Smoke Particle Size and Distribution Within a Gas Turbine Combustor

2005 ◽  
Vol 127 (2) ◽  
pp. 286-294 ◽  
Author(s):  
K. D. Brundish ◽  
M. N. Miller ◽  
C. W. Wilson ◽  
M. Jefferies ◽  
M. Hilton ◽  
...  
Keyword(s):  
Particle Size ◽  
Gas Turbine ◽  
Fluid Dynamic ◽  
Combustion Process ◽  
Analytical Techniques ◽  
Number Concentration ◽  
Operating Conditions ◽  
Fuel Injector ◽  
Gas Turbine Combustor ◽  
Smoke Particle

The objective of the work described in this paper was to identify a method of making measurements of the smoke particle size distribution within the sector of a gas turbine combustor, using a scanning mobility particle sizing (SMPS) analyzer. As well as gaining a better understanding of the combustion process, the principal reasons for gathering these data was so that they could be used as validation for computational fluid dynamic and chemical kinetic models. Smoke mass and gaseous emission measurements were also made simultaneously. A “water cooled,” gas sampling probe was utilized to perform the measurements at realistic operating conditions within a generic gas turbine combustor sector. Such measurements had not been previously performed and consequently initial work was undertaken to gain confidence in the experimental configuration. During this investigation, a limited amount of data were acquired from three axial planes within the combustor. The total number of test points measured were 45. Plots of the data are presented in two-dimensional contour format at specific axial locations in addition to axial plots to show trends from the primary zone to the exit of the combustor. Contour plots of smoke particle size show that regions of high smoke number concentration once formed in zones close to the fuel injector persist in a similar spatial location further downstream. Axial trends indicate that the average smoke particle size and number concentration diminishes as a function of distance from the fuel injector. From a technical perspective, the analytical techniques used proved to be robust. As expected, making measurements close to the fuel injector proved to be difficult. This was because the quantity of smoke in the region was greater than 1000mg/m3. It was found necessary to dilute the sample prior to the determination of the particle number concentration using SMPS. The issues associated with SMPS dilution are discussed.

Experimental Evaluation of Sorbents for Sulfur Control in a Coal-Fueled Gas Turbine Slagging Combustor

1992 ◽  
Vol 114 (1) ◽  
pp. 152-158 ◽  
Author(s):  
L. H. Cowell ◽  
C. S. Wen ◽  
R. T. LeCren
Keyword(s):  
Sulfur Dioxide ◽  
Gas Turbine ◽  
Hydrated Lime ◽  
Capture Efficiency ◽  
Water Mixture ◽  
Dolomitic Lime ◽  
Bench Scale ◽  
Primary Zone ◽  
Secondary Zone ◽  
Sulfur Capture

A slagging combustor has been used to evaluate three calcium-based sorbents for sulfur capture efficiency in order to assess their applicability for use in a coal-fueled gas turbine. Testing is completed in a bench-scale combustor with one-tenth the heat input needed for the full-scale gas turbine. The bench-scale rig is a two-stage combustor featuring a fuel-rich primary zone and a fuel-lean secondary zone. The combustor is operated at 6.5 bars with inlet air preheated to 600 K. Gas temperatures of 1840 K are generated in the primary zone and 1280 K in the secondary zone. Sorbents are either fed into the secondary zone or mixed with the coal-water mixture and fed into the primary zone. Dry powdered sorbents are fed into the secondary zone by an auger into one of six secondary air inlet ports. The three sorbents tested in the secondary zone include dolomite, pressure-hydrated dolomitic lime, and hydrated lime. Sorbents have been tested while burning coal-water mixtures with coal sulfur loadings of 0.56 to 3.13 weight percent sulfur. Sorbents are injected into the secondary zone at varying flow rates such that the calcium/sulfur ratio varies from 0.5 to 10.0. Hydrated lime exhibits the highest sulfur dioxide reductions in the exhaust of 90 percent. Pressure-hydrated dolomitic lime and dolomite reduce SO2 concentrations by 82 and 55 percent, respectively. Coal sulfur loading is found to have a small influence on sorbent sulfur capture efficiency. Pressure-hydrated dolomitic lime ground with the coal during coal-water mixture preparation and injected into the primary zone is found to lower the sulfur dioxide concentration by an insignificant amount.

Measurement of Smoke Particle Size and Distribution Within a Gas Turbine Combustor

2003 ◽  
Author(s):  
K. D. Brundish ◽  
M. N. Miller ◽  
C. W. Wilson ◽  
M. Hilton ◽  
M. P. Johnson ◽  
...  
Keyword(s):  
Particle Size ◽  
Gas Turbine ◽  
Fluid Dynamic ◽  
Combustion Process ◽  
Analytical Techniques ◽  
Number Concentration ◽  
Operating Conditions ◽  
Fuel Injector ◽  
Gas Turbine Combustor ◽  
Smoke Particle

The objective of the work described in this paper was to identify a method of making measurements of the smoke particle size distribution within the sector of a gas turbine combustor, using a Scanning Mobility Particle Sizing (SMPS) analyser. As well as gaining a better understanding of the combustion process, the principal reasons for gathering these data was so that they could be used as validation for Computational Fluid Dynamic (CFD) and chemical kinetic models. Smoke mass and gaseous emission measurements were also made simultaneously. A “water cooled,” gas sampling probe was utilised to perform the measurements at realistic operating conditions within a generic gas turbine combustor sector. Such measurements had not been previously performed and consequently initial work was undertaken to gain confidence in the experimental configuration. During this investigation, a limited amount of data were acquired from three axial planes within the combustor. The total number of test points measured were 45. Plots of the data are presented in 2 dimensional contour format at specific axial locations in addition to axial plots to show trends from the primary zone to the exit of the combustor. Contour plots of smoke particle size show that regions of high smoke number concentration once formed in zones close to the fuel injector persist in a similar spatial location further downstream. Axial trends indicate that the average smoke particle size and number concentration diminishes as a function of distance from the fuel injector. From a technical perspective, the analytical techniques used proved to be robust. As expected, making measurements close to the fuel injector proved to be difficult. This was because the quantity of smoke in the region was greater than 1000 mg/m3. It was found necessary to dilute the sample prior to the determination of the particle number concentration using SMPS. The issues associated with SMPS dilution are discussed.

Coal Fueled Aero-Derivative Gas Turbine: Design Approach

1988 ◽  
Author(s):  
M. W. Horner ◽  
P. E. Sabla ◽  
S. G. Kimura
Keyword(s):  
Gas Turbine ◽  
High Efficiency ◽  
Development Program ◽  
Small Scale ◽  
Water Mixture ◽  
Coal Fuel ◽  
Cost Of Energy ◽  
Annular Combustor ◽  
Environmentally Sound ◽  
Turbine Design

The direct use of coal as a gas turbine fuel offers the opportunity to burn coal in an environmentally sound manner at a competitive cost of energy. A development program is underway to verify the feasibility of using coal water mixture to fuel an aero-derivative gas turbine. This paper presents the overall program approach, required gas turbine design modifications, and reports the results from small-scale combustor test facilities. The GE LM500 gas turbine was selected for this program because of its high efficiency and size, which is appropriate for transportation and cogeneration markets. The LM500 gas turbine power system design will be modified to accommodate coal fuel and any required emissions control devices. The design for the modified annular combustor is complete and preparations for coal fired tests of a 140 degree annular sector combustor are in progress. The combustor design and test development are being supported by a component test program with a One Nozzle Segment Combustor and a single can combustor LM500 Turbine Simulator. These test facilities are providing results on coal water mixture handling and fuel nozzle design, air staging requirements, component metal temperatures, combustor temperature performance, ash deposition rates, and emissions abatement for NOx, SOx, and particulates.

The Design and Model Simulation of a Micro Gas Turbine Combustor Supplied With Methane/Syngas Fuels

2016 ◽  
Author(s):  
Chi-Rong Liu ◽  
Hsin-Yi Shih
Keyword(s):  
High Temperature ◽  
Gas Turbine ◽  
Film Cooling ◽  
Fuel Injection ◽  
Model Simulation ◽  
Combustion Process ◽  
Micro Gas Turbine ◽  
Primary Zone ◽  
Exit Temperature ◽  
Laminar Flamelet

The design and model simulation of a can combustor has been made for future syngas (mainly H2/CO mixtures) combustion application in a micro gas turbine. In previous modeling studies with methane as the fuel, the analysis indicated the design of the combustor is quite satisfactory for the 60-kW gas turbine; however, the cooling may be the primary concerns as several hot spots were found at the combustor exit. When the combustor is fueled with methane/syngas mixtures, the flames would be pushed to the sides of the combustor with the same fuel injection strategy. In order to sustain the power load, the exit temperature became too high for the turbine blades, which deteriorated the cooling issue of the compact combustor. Therefore, the designs of the fuel injection are modified, and film cooling is employed. Consequently, the simulation of the modified combustor is conducted by the commercial CFD software Fluent. The computational model consists of the three-dimensional, compressible k-ε model for turbulent flows and PPDF (Presumed Probability Density Function) model for combustion process between methane/syngas and air invoking a laminar flamelet assumption. The flamelet is generated by detailed chemical kinetics from GRI 3.0. Thermal and prompt NOx mechanisms are adopted to predict the NO formation. At the designed operation conditions, the modeling results show that the high temperature flames are stabilized in the center of the primary zone where a recirculation zone is generated for methane combustion. The average exit temperature of the modified can combustor is 1293 K, which is close to the target temperature of 1200 K. Besides, the exit temperatures exhibit a more uniform distribution by coupling film cooling, resulting in a low pattern factor of 0.22. The NO emission is also low with the increased number of the dilution holes. Comparing to the results for the previous combustor, where the chemical equilibrium was assumed for the combustion process, the flame temperatures are predicted lower with laminar flamelet model. The combination of laminar flamelet and detailed chemistry produced more reasonable simulation results. When methane/syngas fuels are applied, the high temperature flames could also be stabilized in the core region of the primary zone by radially injecting the fuel inward instead of outward through the multiple fuel injectors. The cooling issues are also resolved through altering the air holes and the film cooling. The combustion characteristics were then investigated and discussed for future application of methane/syngas fuels in the micro gas turbine. Although further experimental testing is still needed to employ the syngas fuels for the micro gas turbine, the model simulation paves an important step to understand the combustion performance and the satisfactory design of the combustor.

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