Recirculation Effects in Gas Turbine Combustors

1975 ◽  
Vol 97 (4) ◽  
pp. 527-530 ◽  
Author(s):  
R. Kollrack ◽  
L. D. Aceto
Keyword(s):  
Thermal Effect ◽  
Gas Turbine ◽  
Residence Time ◽  
General Result ◽  
Bluff Body ◽  
Combustion Products ◽  
Inlet Temperature ◽  
Gas Turbine Combustors ◽  
End Products ◽  
Temperature Levels

An evaluation of the effects caused by recirculation of hot final combustion products into unburned or partially burned fuel/air mixtures indicates that the thermal effect predominates the combustion activity. Dilution and the introduction of active radicals produce lesser results. Internal recirculation, such as produced by swirl or bluff body stabilization, differs from external recirculation by the temperature levels of the recirculant and its composition. The net effect of recirculation is to simulate a longer residence time and/or an effective higher inlet temperature. As a general result, the end products are closer to equilibrium, specifically the CO levels are lower and the NO levels higher.

A Critical Review of NOx Correlations for Gas Turbine Combustors

1975 ◽  
Author(s):  
D. A. Sullivan ◽  
P. A. Mas
Keyword(s):  
Experimental Data ◽  
Data Base ◽  
Gas Turbine ◽  
Critical Review ◽  
Inlet Temperature ◽  
Nox Emissions ◽  
Empirical Correlations ◽  
Gas Turbine Combustors ◽  
Semi Empirical ◽  
Adequate Data

The effect of inlet temperature, pressure, air flowrate and fuel-to-air ratio on NOx emissions from gas turbine combustors has received considerable attention in recent years. A number of semi-empirical and empirical correlations relating these variables to NOx emissions have appeared in the literature. They differ both in fundamental assumptions and in their predictions. In the present work, these simple NOx correlations are compared to each other and to experimental data. A review of existing experimental data shows that an adequate data base does not exist to evaluate properly the various NOx correlations. Recommendations are proposed to resolve this problem in the future.

Valveless-Gas-Turbine Combustors With Pressure Gain

1958 ◽  
Author(s):  
Carroll D. Porter
Keyword(s):  
Steady Flow ◽  
Gas Turbine ◽  
Total Pressure ◽  
High Efficiency ◽  
Combustion Products ◽  
Efficiency Gain ◽  
Developmental Problems ◽  
Gas Turbine Combustors ◽  
Turbine Inlet ◽  
Gas Turbine Compressor

A valveless combustor has been developed which has been tested at one to three atmospheres of pressure. It discharged combustion products at practical turbine-inlet temperatures and at a total pressure above that of the inlet. Developmental problems encountered and results are discussed. The smooth combustor cycle, a phased system of combustor tubes and pulsation traps, achieves steady flow at the inlet and outlet of the combustor system to preserve the high efficiency of today’s turbines and compressors. The combustor will soon be tested on a gas-turbine compressor to verify efficiency gain estimates.

scholarly journals Dependence of Soot Production on Fuel Blend Characteristics and Combustion Conditions

1979 ◽  
Author(s):  
W. S. Blazowski
Keyword(s):  
Gas Turbine ◽  
Hydrogen Content ◽  
Soot Formation ◽  
Combustion Products ◽  
Small Scale ◽  
Inlet Temperature ◽  
Fuel Blend ◽  
Fuel Blends ◽  
Energy Demands ◽  
Petroleum Resources

Liquid synthetic fuels derived from non-petroleum resources will play a major role in meeting future national energy demands. In the case of gas turbine applications, it is known that the different properties of these fuels can rusult in substantially altered combustion performance. Most importantly, decreased fuel hydrogen content resulting from an increased aromatic content has been observed to result in increased exhaust smoke and particulates as well as greater flame luminosity. This paper contributes empirical information and insight which allows the greater soot formation tendencies of low hydrogen content fuels to be better understood. A small scale laboratory device which simulates the strongly backmixed conditions present in the primary zone of a gas turbine combustor is utilized. The Jet Stirred Combustor provides for very rapid mixing between a premixture of vaporized fuel and air and the combustion products within a 5.08-cm-dia hemispherical reactor. Results to be presented are gaseous combustion product distributions, incipient soot limits, and soot production (mg) for a variety of fuels. The influences of combustor inlet temperature and reactor mass loading have been evaluated and the sooting characteristics of fuel blends have been studied. These results have been analyzed to develop useful correlation which are in general agreement with existing mechanistic concepts of the soot formation process.

scholarly journals Development of a Low Btu Gas Fuel Cooled Combustor for 3000°F Gas Turbine Operation

1983 ◽  
Author(s):  
T. R. Koblish ◽  
R. Schaefer
Keyword(s):  
Gas Turbine ◽  
Coal Gasification ◽  
Combustion Efficiency ◽  
Combined Cycle ◽  
Department Of Energy ◽  
Combustion Stability ◽  
Inlet Temperature ◽  
Cycle System ◽  
Gas Fuel ◽  
Temperature Levels

The attraction of a coal gasification combined cycle system to utility operation lies in its higher efficiencies (pile-to-busbar) relative to competing power generating systems. In order to achieve these higher efficiencies the coal gasification combined cycle combustor/turbine section must provide reliable operation with low or medium Btu gaseous coal derived fuel at turbine inlet temperature levels above 2600°F. Utilization of low Btu gas (LBG) fuel for attainment of temperature levels up to 3000°F in a gas turbine combustor environment presents several unique design and development problems. Because of the extremely high stoichiometric ratios required to attain 3000°F, the management of combustor cooling as well as internal air and low Btu gas fuel flow mixing patterns is considered critical for high combustion efficiency and stability. Equally important is the requirement for long term combustor durability. A unique combustor design concept has been developed to utilize the available heat sink capability of the LBG fuel to adequately cool the combustor walls for long service life. Under a U.S. Department of Energy contract, an LBG fuel cooled combustor was designed for operation with 150 Btu/SCF fuel for use in development of a turbine capable of operating at 3000°F. This paper describes the background combustor technology and test program results with 150 Btu/SCF fuel regarding the combustion stability, efficiency, emissions and burner wall temperature levels for operation up to 3000°F exit gas temperatures and 6 atmospheres.

Dependence of Soot Production on Fuel Blend Characteristics and Combustion Conditions

1980 ◽  
Vol 102 (2) ◽  
pp. 403-408 ◽  
Author(s):  
W. S. Blazowski
Keyword(s):  
Gas Turbine ◽  
Hydrogen Content ◽  
Soot Formation ◽  
Combustion Products ◽  
Small Scale ◽  
Inlet Temperature ◽  
Fuel Blend ◽  
Fuel Blends ◽  
Energy Demands ◽  
Primary Zone

Liquid synthetic fuels derived from nonpetroleum resources will play a major role in meeting future national energy demands. In the case of gas turbine applications, it is known that the different properties of these fuels can result in substantially altered combustion performance. Most importantly, decreased fuel hydrogen content resulting from an increased aromatic content has been observed to result in increased exhaust smoke and particulates as well as greater flame luminosity. This paper contributes empirical information and insight which allows the greater soot formation tendencies of low hydrogen content fuels to be better understood. A small scale laboratory device which simulates the strongly backmixed conditions present in the primary zone of a gas turbine combustor is utilized. The Jet Stirred Combustor provides for very rapid mixing between a premixture of vaporized fuel and air and the combustion products within a 5.08 cm dia hemispherical reactor. Results to be presented are gaseous combustion product distributions, incipient soot limits, and soot production (mg/l) for a variety of fuels. The influences of combustor inlet temperature and reactor mass loading have been evaluated and the sooting characteristics of fuel blends have been studied. These results have been analyzed to develop useful correlations which are in general agreement with existing mechanistic concepts of the soot formation process.

Modelling Flame-Generated Noise in a Partially Premixed, Bluff Body Stabilized Model Combustor

2012 ◽  
Author(s):  
Saverio Tufano ◽  
Phil Stopford ◽  
J. C. Roman Casado ◽  
J. B. W. Kok
Keyword(s):  
Gas Turbine ◽  
Bluff Body ◽  
Cfd Simulation ◽  
Experimental Results ◽  
Combustion Model ◽  
Acoustic Oscillations ◽  
Gas Turbine Combustors ◽  
Resonance Frequencies ◽  
Partially Premixed ◽  
Good Agreement

Numerical simulation using Computational Fluid Dynamics (CFD) has become increasingly important as a tool to predict the potential occurrence of combustion instabilities in gas turbine combustors operating in lean premixed mode. Within the EU-funded Marie Curie project, LIMOUSINE (Limit cycles of thermo-acoustic oscillations in gas turbine combustors), a model test burner has been built in order to have reproducible experimental results for model validation. The burner consists of a Rijke tube of rectangular section having a flame-stabilizing wedge at about 1/4 of its length. Fuel and air supplies were carefully designed to give closed end acoustic inlet boundary conditions while the atmospheric outlet representing an acoustically open end. A transient CFD simulation of the turbulent, partially premixed, bluff body stabilized combusting flow has been carried out for the LIMOUSINE burner using ANSYS CFX commercial software. A 2-D section has been modelled by means of the scale resolving turbulence model, Scale-Adaptive Simulation (SAS), and a two-step Eddy Dissipation combustion model. Experiments were performed on the LIMOUSINE model burner to measure the dynamic variation of pressure and temperature. Results were obtained for several cases with power input ranging from 40 to 60 kW and air factors between 1.2 and 1.8. The CFD results are found to be in good agreement with experiments: the flame is predicted to stabilise on the bluff body in the fluid recirculation zone; resonance frequencies are found to change depending on power and air excess ratio and have a good agreement with experimental results and analytical values; pressure oscillations are consistent with pipe acoustic modes.

Analysis of Radiation-Convection Coupled Effects on the Turbine Vane With Different Gas Compositions

2020 ◽  
Author(s):  
Peng Sun ◽  
Xueying Li ◽  
Jing Ren ◽  
Hongde Jiang
Keyword(s):  
Heat Transfer ◽  
Gas Turbine ◽  
Combustion Products ◽  
Heat Transfer Analysis ◽  
Working Fluid ◽  
Inlet Temperature ◽  
Heat Transfer Characteristics ◽  
Cfd Simulations ◽  
Transfer Characteristics ◽  
Development Direction

Abstract To reduce the emission of greenhouse gases, especially carbon dioxide, the combustion of hydrogen and oxy-fuel is a development direction for the gas turbine systems. Because the fuels are different from the traditional gas turbine which uses natural gas as fuel, the compositions of the working fluid are different, which can lead to differences in heat transfer characteristics. Furth more, in order to get higher overall efficacy, the turbine inlet temperature is becoming higher and higher. The radiation becomes an important factor then must be considered seriously. To study the influence of different gas compositions on heat transfer characteristics, three gas compositions, representing the combustion products of IGCC system, hydrogen turbine system, and the oxy-fuel turbine system, respectively, is chosen in this paper. Based on a real turbine first stage vane, the influence of radiation and gas compositions are both researched using CFD simulations. The results show that different gas compositions can lead to different heat transfer characteristics on the vane. The radiation effect can be dealt with as an independent factor in the turbine heat transfer analysis.

Prediction of NO and CO Distribution in Gas Turbine Combustors

1987 ◽  
Author(s):  
Shinichi Kajita ◽  
Ryuichi Matumoto
Keyword(s):  
Gas Turbine ◽  
Chemical Reaction ◽  
Chemical Species ◽  
Combustion Products ◽  
Reaction Rates ◽  
Quantitative Agreement ◽  
Reaction Model ◽  
Experimental Program ◽  
Gas Turbine Combustors ◽  
Break Up

An experimental and numerical investigation was conducted to assess the validity of a prediction procedure of NO and CO formed in gas turbine combustors. A premixed gas turbine combustor burning propane was used in the experimental program, and the flow, temperature and pollutants fields were measured. The prediction procedure solves the governing conservation equations of mass, momentum, energy and chemical species simultaneously by means of finite difference solution algorithm. Two main mathematical models were employed in the procedure to represent the turbulent nature of the flow and the chemical reaction rates. For the turbulence model, the two-equation k-ε model was applied. The chemical reaction model assumed a two step reaction, and the effect of turbulence on reaction rates is taken into account by employing the modified eddy-break-up model which considers the dissipation rate of eddy and the concentrations of fuel and combustion products. The reaction rate is considered to be the smaller of the two expressions given by the Arrhenius equation and the modified eddy-break-up model. For NO formation, the extended Zeldovich mecanism was assumed. The prediction results were compared with those obtained from the corresponding expreiment. The prediction results showed the correct overall features, but a quantitative agreement was not obtained for NO and CO concentrations.

Application of CFD-Based Analysis Technique for Design and Optimization of Gas Turbine Combustors

2004 ◽  
Author(s):  
I. G. Koutsenko ◽  
S. F. Onegin ◽  
A. M. Sipatov
Keyword(s):  
Nitric Oxide ◽  
Combustion Chamber ◽  
Gas Turbine ◽  
Combustion Products ◽  
Combustion Chambers ◽  
Design And Optimization ◽  
Gas Turbine Combustors ◽  
Analysis Technique ◽  
Nitric Oxide Emissions ◽  
Operational Development

The design and operational development of gas turbine combustors is a complex process, involving a great volume of design and experimental work. The application of computational fluid dynamics (CFD) methods allows to lower the volume of experimental works on operational development of combustors and to make changes to the design of combustion chambers on early design stages. In this paper the application of commercial CFD package CFX-TASCflow for calculation of flow structure and analysis of nitric oxide formation process in the combustion chamber of the PS-90A gas turbine and its modifications is considered. The results of the analysis show, that the basic determinative criterion of a nitric oxide emission level is the residence time of a combustion products in high-temperature zones. With help of this criterion, an optimization of the PS-90A combustion chamber was performed. A design of an optimized combustion chamber allows to achieve a low level of nitric oxide emissions.

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