Numerical Simulation of Combustion Processes and Analysis of Temperature Field Non-Uniformity in GTE-65 Gas Turbine Combustor

2010 ◽  
Author(s):  
Dmitry Tarasov ◽  
Alexander Lebedev ◽  
Nikolay Simin ◽  
Viktor Grinevich
Keyword(s):  
Experimental Data ◽  
Temperature Field ◽  
Combustion Chamber ◽  
Gas Turbine ◽  
Control Algorithm ◽  
Field Conditions ◽  
Pollutant Emissions ◽  
Temperature Fields ◽  
Operation Conditions ◽  
Partial Load

Our company has tested annular combustion chamber, being one of main components of hot gas path for GTE-65 gas turbine in mid power class. In order to arrange gaseous fuel oxidation process a method of lean homogenized air-fuel mixture burning is realized in the combustor. The same type two-contour burner modules are installed on the combustor cap in two rows by 60 burners in a row (120 burners in all). To optimize control algorithm and confirm main performances a model compartment, representing 1/12 part (segment) of actual combustion chamber, was produced. The tests have been conducted with using GP “Ivchenko-Progress” and OJSC “Power Machines” test rigs on modes from ignition to full load. Stable firing mode and pollutant emissions have been determined and the liner temperature condition and temperature field unevenness have been checked. The combustor control algorithm was optimized. As a result of the conducted tests there were confirmed environmental requirements to the combustor NOx emissions (less than 25 ppm). Mathematical simulating machine was being used to predict the combustor operation performances at the gas turbine operating in field conditions. 3D numerical analysis was carried out to predict the temperature and NOx fields before the experiment preparation. In order to meet the numerical model with the test conditions after the experiment the boundary conditions were specified (fuel / air temperature and mass flow rate). Full and partial load calculations were performed for simulation and field operation conditions. The calculation results were compared with experimental data obtained in the course of bench test. Errors obtained by comparison with numerical and experimental data were as follows: • full model pressure drop: ∼ 3–4%; • ratio of peripheral and radial non-uniformities of temperature fields: ∼ 2%; • nitrogen oxides at various operation modes: maximum 25 ppm. The obtained results make it possible to go on the combustor testing in field conditions.

Numerical Investigation of an Inverted Brayton Cycle Micro Gas Turbine Based on Experimental Data

2018 ◽  
Author(s):  
Eleni Agelidou ◽  
Martin Henke ◽  
Thomas Monz ◽  
Manfred Aigner
Keyword(s):  
Experimental Data ◽  
Power Systems ◽  
Gas Turbine ◽  
Residential Buildings ◽  
Pollutant Emissions ◽  
Brayton Cycle ◽  
Single Family ◽  
Total Energy Consumption ◽  
Gas Treatment ◽  
Micro Gas Turbine

Residential buildings account for approximately one fifth of the total energy consumption and 12 % of the overall CO2 emissions in the OECD countries. Replacing conventional boilers by a co-generation of heat and power in decentralized plants on site promises a great benefit. Especially, micro gas turbine (MGT) based combined heat and power systems are particularly suitable due to their low pollutant emissions without exhaust gas treatment. Hence, the overall aim of this work is the development of a recuperated inverted MGT as heat and power supply for a single family house with 1 kWel. First, an inverted MGT on a Brayton cycle MGT was developed and experimentally characterized, in previous work by the authors. This approach allows exploiting the potential of using the same components for both cycles. As a next step, the applicability of the Brayton cycle components operated in inverted mode needs to be evaluated and the requirements for a component optimization need to be defined, both, by pursuing thermodynamic cycle simulations. This paper presents a parametrization and validation of in-house 1D steady state simulation tool for an inverted MGT, based on experimental data from the inverted Brayton cycle test rig. Moreover, a sensitivity analysis is conducted to estimate the influence of every major component on the overall system and to identify the necessary optimizations. Finally, the component requirements for an optimized inverted MGT with 1 kWel and 16 % of electrical efficiency are defined. This work demonstrates the high potential of an inverted MGT for a decentralized heat and power generation when optimizing the system components.

Simulation of Pollutant Emissions in a Small-Sized Combustion Chamber With a Gas Fuel for Various Regime Modes

2019 ◽  
Author(s):  
Nikita I. Gurakov ◽  
Ivan A. Zubrilin ◽  
Ivan V. Chechet ◽  
Vladislav M. Anisimov ◽  
Sergey S. Matveev ◽  
...  
Keyword(s):  
Experimental Data ◽  
Combustion Chamber ◽  
Equivalence Ratio ◽  
Stokes Equations ◽  
Three Dimensional ◽  
Combustion Products ◽  
Pollutant Emissions ◽  
Eddy Simulation ◽  
Flamelet Generated Manifold ◽  
Combustion Processes

Abstract The study shows the results of the emission simulation in a small-sized combustion chamber. The influence of temperature and equivalence ratio on CO and CxHy in the combustion chamber was investigated. Experiments and calculations were carried out for the following modes: temperature at the inlet of the combustion chamber Tinlet = 323 ... 523 K; equivalence ratio φ = 0.2 ... 0.33; normalized flow rate at the inlet of the combustion chamber λ = 0.1 ... 0.3. The simulation of combustion of natural gas was carried out. The studies were conducted using CFD software and experimental methods. Measurements of the combustion products composition were carried out by the method of sampling collection and subsequent chromatographic analysis. The flow and combustion processes were simulated in a three-dimensional steady formulation using the Reynolds-averaged Novier-Stokes equations (RANS) and in a transient formulation using the Large Eddy Simulation (LES) method. The combustion processes were simulated by Flamelet Generated Manifold model in conjunction with the probability density function method (PDF). In addition to the above methods, the method of the reactor network model (RNM) was used to simulate the emission. As a result, a comparison of the calculated and experimental data of concentrations values of combustion products and emissions indices averaged over the combustion chamber outlet was conducted. According to the results of the calculated-experimental study obtained: - the simulated concentrations values of the main combustion products such as CO2 and H2O qualitatively and quantitatively coincide with the experimental data (the discrepancy is less than 5%) for all three approaches — RANS, LES, RNM; - when modeling CO emissions, the discrepancy between the calculated emission indices obtained by the RANS and LES methods is greatly underestimated relative to the experimental data, whereas the values calculated by the RNM method deviate from the experiment by less than 10%; - mass concentration values of unburned hydrocarbons obtained by the RANS method are overestimated relative to the experimental values, while using the LES with RNM methods, the discrepancy does not exceed 10%.

Investigation of Flame Stabilization in a High-Pressure Multi-Jet Combustor by Laser Measurement Techniques

2014 ◽  
Author(s):  
Oliver Lammel ◽  
Tim Rödiger ◽  
Michael Stöhr ◽  
Holger Ax ◽  
Peter Kutne ◽  
...  
Keyword(s):  
High Pressure ◽  
Natural Gas ◽  
Combustion Chamber ◽  
Gas Turbine ◽  
Recirculation Zone ◽  
Flame Stabilization ◽  
Operating Conditions ◽  
Pollutant Emissions ◽  
Single Shot ◽  
Optical Access

In this contribution, comprehensive optical and laser based measurements in a generic multi-jet combustor at gas turbine relevant conditions are presented. The flame position and shape, flow field, temperatures and species concentrations of turbulent premixed natural gas and hydrogen flames were investigated in a high-pressure test rig with optical access. The needs of modern highly efficient gas turbine combustion systems, i.e., fuel flexibility, load flexibility with increased part load capability, and high turbine inlet temperatures, have to be addressed by novel or improved burner concepts. One promising design is the enhanced FLOX® burner, which can achieve low pollutant emissions in a very wide range of operating conditions. In principle, this kind of gas turbine combustor consists of several nozzles without swirl, which discharge axial high momentum jets through orifices arranged on a circle. The geometry provides a pronounced inner recirculation zone in the combustion chamber. Flame stabilization takes place in a shear layer around the jet flow, where fresh gas is mixed with hot exhaust gas. Flashback resistance is obtained through the absence of low velocity zones, which favors this concept for multi-fuel applications, e.g. fuels with medium to high hydrogen content. The understanding of flame stabilization mechanisms of jet flames for different fuels is the key to identify and control the main parameters in the design process of combustors based on an enhanced FLOX® burner concept. Both experimental analysis and numerical simulations can contribute and complement each other in this task. They need a detailed and relevant data base, with well-known boundary conditions. For this purpose, a high-pressure burner assembly was designed with a generic 3-nozzle combustor in a rectangular combustion chamber with optical access. The nozzles are linearly arranged in z direction to allow for jet-jet interaction of the middle jet. This line is off-centered in y direction to develop a distinct recirculation zone. This arrangement approximates a sector of a full FLOX® gas turbine burner. The experiments were conducted at a pressure of 8 bar with preheated and premixed natural gas/air and hydrogen/air flows and jet velocities of 120 m/s. For the visualization of the flame, OH* chemiluminescence imaging was performed. 1D laser Raman scattering was applied and evaluated on an average and single shot basis in order to simultaneously and quantitatively determine the major species concentrations, the mixture fraction and the temperature. Flow velocities were measured using particle image velocimetry at different section planes through the combustion chamber.

Study on Low-Carbon Catalytic Combustion Furnace of Natural Gas

2012 ◽  
Vol 268-270 ◽  
pp. 1006-1010 ◽  
Author(s):  
Si Yu Huang ◽  
Long Fei Yan ◽  
Shi Hong Zhang
Keyword(s):  
Temperature Field ◽  
Natural Gas ◽  
Catalytic Combustion ◽  
Pollutant Emissions ◽  
Temperature Fields ◽  
Low Carbon ◽  
Test Report

This article did a research about temperature fields inside the catalytic combustion furnace with Pd-based honeycomb monoliths of lean natural gas-air mixtures and discussed the feature of the temperature field. In addition, the near-zero pollutant emissions of catalytic combustion burner was proved by a test report provided by NIM. From a low-carbon prospective, the application prospect of catalytic combustion furnace was discussed.

scholarly journals Numerical Modeling of Gaseous Partially Premixed Low-Swirl Lifted Flame at Elevated Pressure

2020 ◽  
Author(s):  
Leonardo Langone ◽  
Julia Sedlmaier ◽  
Pier Carlo Nassini ◽  
Lorenzo Mazzei ◽  
Stefan Harth ◽  
...  
Keyword(s):  
Experimental Data ◽  
Flame Front ◽  
Gas Turbine ◽  
Nozzle Exit ◽  
Numerical Results ◽  
Pollutant Emissions ◽  
Lifted Flame ◽  
Lifted Flames ◽  
Partially Premixed ◽  
Lift Off

Abstract Lifted flames have been investigated in the past years for their benefits in terms of NOx emissions reduction for gas turbine applications. In a lifted flame, the flame front stabilized on a position that is significantly detached from the nozzle exit, improving the premixing process before the reaction zone. The distance between the flame front and the nozzle exit is called lift-off height and it represents the main parameter that characterize this type of flame. In the present work, a partially premixed lifted flame employing air-methane mixture is investigated through numerical simulation. Indeed, even if lifted jet flames have been widely studied in the literature, there are only a few examples of lifted partially premixed flames. Nevertheless, this kind of flames assumes an important role considering the current gas turbine applications, since their benefits in terms of stability and low pollutant emissions. This study has been performed with LES calculations using a commercial software suite and the numerical results are compared with experimental data coming from a dedicated campaign held at Karlsruher Institute für Technologie (KIT) on a novel low-swirl injector nozzle. Quenching effects due to strain, curvature and heat loss have been introduced into the combustion model thanks to a correction of the source term in the progress variable equation within the FGM model. The comparison between numerical results and experimental data have been performed in terms of lift-off height and OH* chemiluminescence maps, showing the capability to properly predict the overall flow and to catch flame lift-off even if with an underpredicted height. This points out promising capability of the numerical model in the representation of lifted flames, allowing further investigations of the flame structure otherwise not available from experimental techniques.

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.

CFD Analysis of an Annular Micro Gas Turbine Combustion Chamber Fuelled With Liquid Biofuels: Preliminary Results With Bioethanol

2013 ◽  
Author(s):  
Paolo Laranci ◽  
Gianni Bidini ◽  
Umberto Desideri ◽  
Francesco Fantozzi
Keyword(s):  
Natural Gas ◽  
Combustion Chamber ◽  
Gas Turbine ◽  
Internal Combustion Engines ◽  
Oxidation Mechanism ◽  
Biodiesel Production ◽  
Pollutant Emissions ◽  
Cfd Analysis ◽  
Micro Gas Turbine ◽  
Preliminary Results

Liquid biofuels, such as bioethanol, biodiesel and vegetal oils, can effectively be used in internal combustion engines blended with liquid fuels of fossil origin or in their substitution, allowing a reduction of CO2 and pollutant emissions in the atmosphere. This work is supported by a CFD analysis to study the feasibility of using these fuels derived from biomass in a 80 kWel micro gas turbine, originally designed for operation with natural gas. In this paper preliminary results about the behavior of bioethanol in the MGT combustion chamber are presented. The complete investigation however includes biodiesel and also glycerin, a byproduct of biodiesel production. To carry out the computational simulations, combustion models included in a commercial software and oxidation mechanism of ethanol taken from the literature were used. The geometry of the NG injector was modified to optimize the liquid inlet into the combustor. Simulation results in terms of temperatures, pressures, and emissions were compared with data available for natural gas combustion in the original combustion chamber.

scholarly journals THE INFLUENCE OF OPERATIONAL AND STRUCTURAL PARAMETERS ON THE UNEVENNESS OF THE TEMPERATURE FIELD AT THE OUTLET OF THE GAS TURBINE COMBUSTION CHAMBER

2020 ◽  
pp. 80-87
Author(s):  
Ali Sulaiman ◽  
◽  
Bilal Mingazov ◽  
Yury Aleksandrov ◽  
The Nguyen ◽  
...  
Keyword(s):  
Temperature Field ◽  
Combustion Chamber ◽  
Gas Flow ◽  
Structural Parameters ◽  
Temperature Fields ◽  
Mixing Process ◽  
Operational Parameters ◽  
Air Jets ◽  
Annular Jet ◽  
Secondary Air

Ensuring acceptable temperature field non-uniformity at the outlet of the combustion chamber is a very important requirement that determines the reliability and durability of the turbine. The formation of non-uniformity is determined by the nature of the interaction of the secondary air jets with the gas flow in the flame tube and depends on many factors, both structural and operational parameters. In this paper, we propose to evaluate the non-uniformity of the temperature fields at the outlet of the combustion chamber using a mixing coefficient that determines the quality of mixing jets of secondary air with a gas stream in the mixer. Based on the equation of turbulent diffusion during the flow of an annular jet into a limited space, an analytical dependence is obtained in the work that allows one to calculate the mixing process in the combustion chamber. The connection of the mixing process with the formation of temperature fields is established. Based on this, dependences are obtained for calculating the nonuniformity of temperature fields. Their satisfactory agreement with experimental data was shown. The found dependences allow one to analyze the influence of various parameters on the non-uniformity of temperature fields and accelerate the refinement of the combustion chamber by this parameter. The possibility of predicting the effect of various parameters on the unevenness of temperature fields is shown. The presence of the optimal value of the degree of opening of the mixer is confirmed, at which the minimum value of the unevenness of the temperature field at the outlet of the combustion chamber is achieved. Therefore, the analytical relationships found in the work allow optimizing the design of the mixer in the combustion chamber and the distribution of secondary air in it in order to reduce the unevenness of the temperature fields at the outlet of the combustion chamber.

CFD Simulation of a Microturbine Annular Combustion Chamber Fuelled With Methane and Biomass Pyrolysis Syngas: Preliminary Results

2009 ◽  
Author(s):  
Francesco Fantozzi ◽  
Paolo Laranci ◽  
Michele Bianchi ◽  
Andrea De Pascale ◽  
Michele Pinelli ◽  
...  
Keyword(s):  
Experimental Data ◽  
Natural Gas ◽  
Combustion Chamber ◽  
Gas Turbines ◽  
Cfd Simulation ◽  
Combustion Process ◽  
Calorific Value ◽  
Methane Combustion ◽  
Pollutant Emissions ◽  
Preliminary Results

Micro gas turbines could be profitably used, for distributed energy production, also exploiting low calorific value biomass-derived fuels, obtained by means of integrated pyrolysis and/or gasification processes. These synthesis gases show significant differences with respect to natural gas (in terms of composition, low calorific value, hydrogen content, tar and particulate matter content) that may turn into ignition problems, combustion instabilities, difficulties in emission control and fouling. CFD simulation of the combustion chamber is a key instrument to identify main criticalities arising when using these gases, in order to modify existing geometries and to develop new generation combustion chambers for use with low calorific value gases. This paper describes the numerical activity carried out to analyze the combustion process occurring inside an existing microturbine annular combustor. A CFD study of the combustion process performed with different computational codes is introduced and some preliminary results are reported in the paper. A comparison of results obtained with the different codes is provided, for the reference case of methane combustion. A first evaluation of the pollutant emissions and a comparison with the available experimental data is also provided in the paper, showing in particular a good matching of experimental data on NOx emissions at different load conditions. Moreover, the carried out investigation concerns the case of operation with a syngas fuel derived from pyrolysis of biomass and finally the case of syngas and natural gas co-firing. This combustion condition is simulated with a simple reduced chemical kinetic scheme, in order to assess only the key issues rising with this fuel in comparison with the case of methane combustion. The analysis shows that in case of syngas operation the combustor internal temperature hot spots are reduced and the primary zone flame tends to stabilize closer to the injector, with possible implications on the emission release.

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