Experimental and Numerical Analysis of an Ignition Sequence in a Multiple-Injectors Burner

2013 ◽  
Author(s):  
M. Cordier ◽  
A. Vandel ◽  
B. Renou ◽  
G. Cabot ◽  
M. A. Boukhalfa ◽  
...  
Keyword(s):  
Combustion Chamber ◽  
Gas Turbine ◽  
Fuel Injection ◽  
Ignition Time ◽  
Ignition Process ◽  
Eddy Simulation ◽  
Ignition Time Delay ◽  
Crucial Information ◽  
Set Up ◽  
The Cost

The design of a gas turbine combustion chamber integrates multiple contradicting objectives. Among all the parameters available to the engineers, the number of fuel injection systems and their spacing are crucial information which need to be fixed early on in the design phase. Indeed, such choices not only impact the cost and size of the combustor but they also affect the operability of the future engine. One key objective behind these parameters is the ignition time delay needed for the whole combustion chamber to successfully light. To gather knowledge in the ignition process that takes place in real gas turbine engines, current research orient towards the development of experimental facilities that complement high fidelity unsteady numerical simulations. In this context, a multi-injectors experimental set-up located at CORIA (France) is used to validate Large Eddy Simulation (LES) tools developed by CERFACS, IFP-EN and CORIA (France). Preliminary validations against experimental data show that for a given inter-injector distance, LES stationary and ignition transient predictions are very promising and recover the main features found in the experiment. Exit mean and root mean square velocity profiles of the steady flow are in good agreement with measurements obtained for all injectors at multiple axial locations. The simulation of the ignition transient phase well captures global events such as the propagation of the flame front from one injector to its neighbors and the related mechanisms. Improvement is however still needed to recover the proper ignition time of the whole burner.

Modeling and Exergy and Exergoeconomic Optimization of a Gas Turbine Power Plant Using a Genetic Algorithm

2010 ◽  
Author(s):  
Soheil Fouladi ◽  
Hamid Saffari
Keyword(s):  
Genetic Algorithm ◽  
Power Plant ◽  
Combustion Chamber ◽  
Gas Turbine ◽  
Exergy Efficiency ◽  
Design Parameters ◽  
Working Fluid ◽  
Exergy Destruction ◽  
The Cost ◽  
Gas Turbine Power Plant

In this paper, the thermodynamic modelling of a gas turbine power plant in Iran is performed. Also, a computer code has been developed based on Matlab software. Moreover, both exergy and exergoeconomic analysis of this power plant have been conducted. To have a good insight into this study, the effects of key parameters such as compressor pressure ratio, gas turbine inlet temperature (TIT), compressor and turbine isentropic efficiency on the total exergy destruction, total exergy efficiency as well as total cost of exergy destruction have been performed. The modelling results have been compared with an actual running power plant located in Yazd city, Iran. The results of developed code have shown reasonable agreement between the simulation code results and experimental data obtained from power plant. The exergy analysis revealed that the combustion chamber is the must exergy destructor in comparison with other components. Also, its exergy efficiency is less than other components. This is due to the high temperature difference between working fluid and burner temperature. In addition, it was found that by the increase of TIT, the exergy destruction of this component can be reduced. On the other hand, the cost of exergy destruction is high for the combustion chamber. The effects of design parameters on exergy efficiency have shown that increase in the air compressor ratio and TIT, increases the total exergy efficiency of the cycle. Furthermore, the results have revealed that by the increase of TIT by 350°C, the cost of exergy destruction is decreased about 22%. Therefore, TIT is the best option to improve the cycle losses. In addition, an optimization using a genetic algorithm has been conducted to find the optimal solution of the plant.

Exergoeconomic analysis and performance assessment of selected gas turbine power plants

2015 ◽  
Vol 12 (3) ◽  
pp. 283-300 ◽  
Author(s):  
S.O. Oyedepo ◽  
R.O. Fagbenle ◽  
S.S. Adefila ◽  
Md. Mahbub Alam
Keyword(s):  
Combustion Chamber ◽  
Gas Turbine ◽  
Power Plants ◽  
Exergy Analysis ◽  
Unit Cost ◽  
Exergy Destruction ◽  
Improvement Potential ◽  
And Performance ◽  
Exergoeconomic Analysis ◽  
The Cost

In this study, exergoeconomic analysis and performance evaluation of selected gas turbine power plants in Nigeria were carried out. The study was conducted using operating data obtained from the power plants to determine the exergy efficiency, exergy destruction, unit cost of electricity and cost of exergy destruction of the major components of a gas turbine engine in the selected power plants. The results of exergy analysis confirmed that the combustion chamber is the most exergy destructive component compared to other cycle components as expected. The total efficiency defects and overall exergetic efficiency of the selected power plants vary from 38.64 to 69.33% and 15.66 to 30.72% respectively. The exergy analysis further shows that the exergy improvement potential of the selected plants varies from 54.04 MW to 159.88 MW. The component with the highest exergy improvement potential is the combustion chamber and its value varies from 30.21 MW to 88.86 MW. The results of exergoeconomic analysis show that the combustion chamber has the greatest cost of exergy destruction compared to other components. Increasing the gas turbine inlet temperature (GTIT), both the exergy destruction and the cost of exergy destruction of this component were found to decrease. The results of this study revealed that an increase in the GTIT of about 200 K can lead to a reduction of about 29% in the cost of exergy destruction. From exergy costing analysis, the unit cost of electricity produced in the selected power plants varies from cents 1.99 /kWh (N3.16 /kWh) to cents 5.65 /kWh (N8.98 /kWh).

Improvement of Gas Turbine Injection Systems by Combined Experimental/Numerical Approach

2002 ◽  
Author(s):  
G. Riccio ◽  
P. Adami ◽  
F. Martelli ◽  
D. Cecchini ◽  
L. Carrai
Keyword(s):  
Combustion Chamber ◽  
Gas Turbine ◽  
Fuel Injection ◽  
Numerical Approach ◽  
Combustion Stability ◽  
Pollutant Emissions ◽  
Injection System ◽  
Flame Stability ◽  
Fuel Injection System ◽  
Joint Application

An aerodynamic study for the premixing device of an industrial turbine gas combustor is discussed. The present work is based on a joint application of numerical CFD and experimental investigation tools in order to verify and optimize the combustor gaseous fuel injection system. The objective is the retrofit of an old generation gas turbine combustion chamber that is carried out considering new targets of NOx emission keeping the same CO and combustion stability performances. CFD has been used to compare different premixing duct configurations for improved mixing features. Experimental test has been carried out in order to assess the pollutant emissions, flame stability and pattern factor characteristics of the full combustion chamber retrofitted with the modified injection system.

Further Studies of Alternative Jet Fuels

2009 ◽  
Author(s):  
Christopher J. Mordaunt ◽  
Seong-Young Lee ◽  
Vickey B. Kalaskar ◽  
Amy Mensch ◽  
Robert J. Santoro ◽  
...  
Keyword(s):  
Heat Release ◽  
Combustion Chamber ◽  
Gas Turbine ◽  
Fuel Injection ◽  
Combustion Instability ◽  
Combustion Efficiency ◽  
Liquid Fuels ◽  
Pollutant Emission ◽  
Fischer Tropsch ◽  
Mixing Processes

Future gas turbine technology may require that liquid fuels play an additional role as a coolant over a wide range of combustion-chamber operating conditions. Additionally, in order to satisfy greater efficiency and performance goals, gas turbine operating temperatures and pressures are steadily increasing. Given the desire to reduce dependence on foreign fuels and that current hydrocarbon fuels, such as JP-8, are prone to thermal or catalytic decomposition at such elevated conditions, there is great interest in utilizing alternatively-derived liquid fuels. The successful development of a versatile, multiple-use fuel must achieve the desired operational characteristics of high combustion efficiency, excellent combustion stability, acceptable pollutant emission levels, and compatibility with current engine seals. Combustion instability represents a critical area of concern for future gas turbine engines that may burn alternative fuels. Combustion instability is characterized by large, unsteady combustion-chamber pressure oscillations which occur at the characteristic frequencies associated with the acoustic modes of the combustor. The occurrence of combustion-driven instabilities is closely tied to the details of the injection and fuel-air mixing processes, the heat release characteristics, and the degree to which heat release rate couples with the acoustics of the combustor. Additionally, the efficiency and emissions characteristics are also largely determined by the fuel injection, atomization, and mixing processes associated with combustion. As fuel properties and composition vary, effects on combustion efficiency and emissions, especially the formation of nitrogen oxides (NOx) and soot, can be expected. Therefore, changes in these processes attributed to differing fuel properties can have a dramatic affect on the combustion characteristics and require careful consideration through a well-coordinated combustion research program. The current study investigates whether a coal-based aviation fuel, JP-900, which has the required thermal stability attributes, also satisfies the engine combustion requirements. Additionally, a Fischer-Tropsch fuel and a volumetric 50/50 blend of JP-8 and the Fischer-Tropsch fuel are studied. Previous studies of coal-based fuels have shown that soot production can be a significant problem due to the higher aromatic content than found in conventional fuels. However, improvements in the fuel refinement processes have helped reduce this problem. Experiments included in this current research effort involve studying the combustion instability patterns, the pollutant emission levels, and sooting propensity of coal-based and Fischer-Tropsch fuels as compared to JP-8. The experimental setup consists of an optically-accessible model gas turbine dump combustor, with provisions for laser extinction measurements, which utilizes a Delavan hollow-cone pressure atomizer for fuel injection.

Analysis of the Fuel Injection in Gas Turbine Premixing Systems by Experimental Correlations and Numerical Simulations

2006 ◽  
Author(s):  
G. Riccio ◽  
L. Schoepflin ◽  
P. Adami ◽  
F. Martelli
Keyword(s):  
Combustion Chamber ◽  
Gas Turbine ◽  
Fuel Injection ◽  
Cross Flow ◽  
Navier Stokes ◽  
Air Stream ◽  
Fuel Jet ◽  
Fuel Mixing ◽  
Gas Turbine Combustion ◽  
The Cross

This paper presents the aerodynamic study of two premixing systems for gas turbine combustion chamber based on detailed CFD 3-D simulations. The work was carried out with the aim to describe the aerodynamic and the mixing process in two different premixing system schemes, typical for DLE gas turbine combustion chamber. Results from different numerical tools (CFD 3-D and 0/1-D) for the estimation of the fuel jet pathway were compared. Both the premixer configurations analysed are related to the cross-flow injection scheme. The first one considers the fuel injection orthogonal to a low swirled air stream while the second one considers the fuel injection directly from hole rows drilled on the suction and pressure side of the swirler blades. The aerodynamic analysis of the premixing devices was focused on the fuel injection in terms of the jets pathway and air/fuel mixing in steady-state conditions. The aerodynamic investigations were performed by CFD 3-D “full Navier-Stokes” codes. Calculations were repeated, on the same mesh, by an in-house developed code (HybFlow) and by commercial codes also. Some previous experimental results were exploited to tune and validate the calculations. Results of the simulation were post-processed in order to allow a quantitative evaluation of the air/fuel mixing. Moreover the calculations were used to verify the accuracy of 0/1-D models, taken from the literature, for the estimation of the maximum penetration and the trajectory for the cross-flow of gaseous fuel jet, considering typical working conditions for gas turbine premixing system. Finally, preliminary considerations related to the fuel injection schemes and to the influence of the main injection conditions on the mixing were carried out.

scholarly journals Generation of Realistic Boundary Conditions at the Combustion Chamber/Turbine Interface Using Large-Eddy Simulation

Energies ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 8206
Author(s):  
Benjamin Martin ◽  
Florent Duchaine ◽  
Laurent Gicquel ◽  
Nicolas Odier
Keyword(s):  
Large Eddy Simulation ◽  
Boundary Conditions ◽  
Combustion Chamber ◽  
Important Criterion ◽  
Design Phase ◽  
Eddy Simulation ◽  
Large Eddy ◽  
The Cost ◽  
The Impact ◽  
Realistic Boundary Conditions

Numerical simulation of multiple components in turbomachinery applications is very CPU-demanding but remains necessary in the majority of cases to capture the proper coupling and a reliable flow prediction. During a design phase, the cost of simulation is, however, an important criterion which often defines the numerical methods to be used. In this context, the use of realistic boundary conditions capable of accurately reproducing the coupling between components is of great interest. With this in mind, this paper presents a method able to generate more realistic boundary conditions for isolated turbine large-eddy simulation (LES) while exploiting an available integrated combustion chamber/turbine LES. The unsteady boundary conditions to be used at the inflow of the isolated turbine LES are built from the modal decomposition of the database recorded at the interface between the two components of the integrated LES simulation. Given the reference LES database, the reconstructed field boundary conditions can then be compared to standard boundary conditions in the case of isolated turbine configuration flow predictions to illustrate the impact. The results demonstrate the capacity of this type of conditions to reproduce the coupling between the combustion chamber and the turbine when standard conditions cannot. The aerothermal predictions of the blade are, in particular, very satisfactory, which constitutes an important criterion for the adoption of such a method during a design phase.

Parametric Study to Optimize Air/Fuel Mixing for Lean, Premix Combustion Systems

2002 ◽  
Author(s):  
Ibrahim Yimer ◽  
Ian Campbell
Keyword(s):  
Gas Turbine ◽  
Fuel Injection ◽  
Fuel Mixture ◽  
Statistical Technique ◽  
Gas Temperature ◽  
Physical Processes ◽  
Mixture Preparation ◽  
Premix Combustion ◽  
Planar Laser ◽  
Set Up

New designs of gas turbine combustors for power generation applications have to meet ever-tightening emission standards (mainly NOx, CO and UHC) while operating at high combustor pressures. This requires a detailed understanding of the physical processes involved. The air-fuel mixture preparation is a critical step in most advanced gas turbine combustion strategies to achieve lower emissions. It has long been established that the level of unmixedness between the fuel and air is strongly tied with NOx levels. The present paper applies the statistical technique of Design Of Experiments (DOE) to a generic mixer set-up that includes an axial swirler, with fuel injected at discrete locations and transverse to the flow. The objective is to identify influential design and operating parameters that will provide rapid and enhanced mixing. The parameters tested include Swirl strength as measured by the Swirl number, Swirl type (Constant angle vs. Free vortex), number and momentum of fuel injection sites and gas temperature. Planar Laser Induced Fluorescence of acetone (PLIF) was used to quantify mixing at various planar locations in the mixing section. Commercial CFD software is used to model the flow field and predict the spatial mixing at selected conditions. Comparisons are made with experimental measurements with the aim to validate the CFD code and also on comparing the model results with the measurements.

Study of a Gas Turbine Combustion Chamber: Influence of the Mixing on the Flame Dynamics

2004 ◽  
Author(s):  
Christophe Duwig ◽  
Laszlo Fuchs
Keyword(s):  
Flow Field ◽  
Combustion Chamber ◽  
Gas Turbine ◽  
New Technologies ◽  
Mean Flow ◽  
Flamelet Model ◽  
Demand Growth ◽  
Eddy Simulation ◽  
Flame Dynamics ◽  
Gas Turbine Combustion

The new challenge of the Gas Turbine industry is to develop new technologies for meeting electricity demand growth and reducing harmful emissions. Thus a better understanding of the combustion phenomenon and an improvement in simulation capabilities are needed. Large Eddy Simulation tools brought the hope of meeting these two conditions and enabling the design of safe and clean burners. In the present paper, the influence of the unsteady mixing on the flame in a Lean Premixed Pre-vaporized combustor have been investigated. A premixed combustion flamelet model has been extended to non-uniform fuel/air mixtures cases. Extra terms in the equations, their effects and the modeling issues are discussed. Additionally, the effects of mixing on the flow field in an industrial gas turbine combustion chamber have been investigated. The mean flow field has been found to be weakly sensitive to the mixing effects. It is deduced that the modeling of the mixing and the combustion can be decoupled in the RANS framework. Regarding the flame dynamics, all runs show similar characteristic frequencies. However, different details of models lead to differences in the temperature fluctuations. This suggests that a rigorous modeling of the thermo-acoustic sources (e.g. heat-release fluctuations) requires accurate modeling of the mixing/combustion coupling, for handling accurately the dynamics of the flame.

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