Comprehensive JP8 Mechanism for Vitiated Flows

2010 ◽  
Vol 4 (1) ◽  
Author(s):  
K.M. Hall ◽  
X. Fu ◽  
K. Brezinsky
Keyword(s):  
Combustion Process ◽  
Combustion Products ◽  
Chemical Kinetic ◽  
Fused Silica ◽  
Liquid Fuels ◽  
Outer Diameter ◽  
Jet Engines ◽  
Flat Flame ◽  
Major Species ◽  
Flame Burner

With the intent of optimizing the combustion process of complex hydrocarbon liquid fuels such as JP8 in internal combustion jet engines and their afterburners, simpler surrogate hydrocarbon compounds were used in a counterflow diffusion flat flame burner to validate the chemical kinetic modeling process. The combustion products sampled from the flame produced during the burning of the validation fuels methane and n-heptane were analyzed using a Varian CP3800 gas chromatograph. The effects of sampling with a 350 micron outer diameter (OD) fused-silica tube were compared to those of a 3.5 mm quartz probe in order to minimize sampling effect on the flame. Simulations of the sampled species were performed using the OPPDIF package of CHEMKIN with chemistry models provided by UIC. Concentrations of major species (e.g. CO, CH4, CO2, O2) were found to be well simulated with the models, with the best fit occurring for methane and n-heptane, and wider variation occurring with some species in all validation fuels.

scholarly journals Effects of Catalysts on Emissions of Pollutants from Combustion Processes of Liquid Fuels

2014 ◽  
Vol 13 (2) ◽  
pp. 5-17
Author(s):  
Agnieszka Bok ◽  
Joanna Guziałowska-Tic ◽  
Wilhelm Jan Tic
Keyword(s):  
Combustion Process ◽  
Combustion Products ◽  
Organometallic Complexes ◽  
Liquid Fuels ◽  
Motor Fuels ◽  
Harmful Emissions ◽  
Fuel Oils ◽  
Sulphur Oxides ◽  
Dynamic Growth ◽  
Combustion Processes

Abstract The dynamic growth of the use of non-renewable fuels for energy purposes results in demand for catalysts to improve their combustion process. The paper describes catalysts used mainly in the processes of combustion of motor fuels and fuel oils. These catalysts make it possible to raise the efficiency of oxidation processes simultanously reducing the emission of pollutants. The key to success is the selection of catalyst compounds that will reduce harmful emissions of combustion products into the atmosphere. Catalysts are introduced into the combustion zone in form of solutions miscible with fuel or with air supplied to the combustion process. The following compounds soluble in fuel are inclused in the composition of the described catalysts: organometallic complexes, manganese compounds, salts originated from organic acids, ferrocen and its derivatives and sodium chloride and magnesium chloride responsible for burning the soot (chlorides). The priority is to minimize emissions of volatile organic compounds, nitrogen oxides, sulphur oxides, and carbon monoxide, as well as particulate matter.

Characteristics of a Laminar Diffusion Flame in a Cross-Flow of Combustion Products

2005 ◽  
Author(s):  
M. A. Simon ◽  
B. D. Baird ◽  
S. R. Gollahalli
Keyword(s):  
Diffusion Flame ◽  
Equivalence Ratio ◽  
Cross Flow ◽  
Combustion Products ◽  
Flame Length ◽  
No Production ◽  
Flat Flame ◽  
Laminar Diffusion ◽  
Flame Burner ◽  
The Cross

This study was an investigation of the characteristics of a horizontal laminar diffusion flame established from a tubular burner in a buoyant vertical flow vitiated with combustion products created by a flat flame. The effects of varying flat flame equivalence ratio on these characteristics were studied. Applications of this study include exhaust gas recirculation (EGR), staged combustion in furnaces, and afterburners in jet engines. The fuel used for both the horizontal (cross-flow flame) and the flat flame in this study was propane. For a range of flat flame burner equivalence ratio (0.6 to 0.9), measurements of cross-flow flame length, and global emissions of NO were made. The mass flow rate of propane delivered to the cross-flow flame was held constant during these measurements. The flames were photographed with a digital camera. Profiles of combustion species concentrations and temperature were taken at 25% and 50% of the cross-flow flame length for flat flame burner equivalence ratios of 0.6 and 0.8, and for a non-combustion case (air flow only) in the flat flame. It was found that increasing the flat flame burner equivalence ratio caused an increase in the length of the cross-flow flame. The maximum temperature of the cross-flow flame decreased with increasing flat flame burner equivalence ratio. The introduction of the cross-flow flame increased the NO production in a flat flame with an equivalence ratio of 0.6, but did not significantly affect the NO production in a flat flame of an equivalence ratios of 0.7 or 0.8, and reduced it (by as much as 25%) in a flat flame of equivalence ratio of 0.9. This reduction of NO production and flame temperature and increase in flame length with increasing flat flame equivalence ratio was attributed to the reduction of oxygen available to the cross-flow flame. These results were supported with the in-flame combustion species concentration profiles.

Numerical study on the combustion characteristics in a porous-free flame burner for lean mixtures

2019 ◽  
Vol 234 (4) ◽  
pp. 935-945 ◽  
Author(s):  
Seyed Amin Ghorashi ◽  
Seyed Mohammad Hashemi ◽  
Seyed Abdolmehdi Hashemi ◽  
Mahdi Mollamahdi
Keyword(s):  
Porous Medium ◽  
Numerical Study ◽  
Combustion Process ◽  
Experimental Tests ◽  
Kinetic Mechanism ◽  
Chemical Kinetic ◽  
Numerical Results ◽  
Flame Stability ◽  
Porous Burner ◽  
Flame Burner

The present work implements a numerical simulation to investigate the combustion process in a porous-free flame burner. The non-equilibrium thermal condition is performed, and discretization and solving of the governing equations are conducted in a two-dimensional axisymmetric model. In order to simulate the combustion process, a reduced chemical kinetic mechanism of GRI 3.0, which includes 16 species and 41 reactions, is used. In order to prove the precision of the numerical method, some experimental tests are carried out and the numerical results are in a good agreement with the experimental measurements. The numerical results demonstrate that the porous-free flame burner has a higher flame stability compared to the conventional porous burner and the radiative efficiency of the porous-free flame burner is less than the porous burner. In addition, an increase in thermal conduction of the porous medium leads to an extension in the flame stability. In addition, the results show that with decreasing the pore density of porous medium, the flame stability is extended.

Temperature and species measurement in a quenching boundary layer on a flat-flame burner

2010 ◽  
Vol 49 (4) ◽  
pp. 783-795 ◽  
Author(s):  
Takayuki Fuyuto ◽  
Helmut Kronemayer ◽  
Burkhard Lewerich ◽  
Jan Brübach ◽  
Taketoshi Fujikawa ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Flat Flame ◽  
Flame Burner

SPECTRAL DIAGNOSTICS OF THE HYDROCARBON FUEL COMBUSTION PROCESS

2021 ◽  
pp. 12-17
Author(s):  
M. A. Vaganov
Keyword(s):  
Combustion Process ◽  
Hydrocarbon Fuel ◽  
Combustion Products ◽  
Combustible Mixture ◽  
Fuel Combustion ◽  
Propane Combustion ◽  
Gaseous Hydrocarbon ◽  
Spectral Bands ◽  
Air Supply ◽  
Spectral Diagnostics

It is proposed to use the methods of applied optical spectroscopy to solve the problem of control and diagnostics of gaseous hydrocarbon fuel combustion in this work. The results of an experimental study of spectroscopic informative parameters characterizing the propane combustion process are presented for three modes: combustion of pure propane without air supply, stoichiometric combustion and combustion with a change in the amount of supplied air relative to stoichiometric combustion. As a result of the experiment, it was found that the most intense bands in the emission spectrum of the flame arising from the combustion of propane correspond to the spectral bands of radicals of combustion products: OH, CH, and C2. While the intensities of various systems of bands in the flame spectrum depend significantly on the composition of the combustible mixture.

Chemical Kinetic Analysis of a Flameless Gas Turbine Combustor

2008 ◽  
Author(s):  
G. Arvind Rao ◽  
Yeshayahou Levy ◽  
Ephraim J. Gutmark
Keyword(s):  
Combustion Chamber ◽  
Kinetic Analysis ◽  
Gas Turbine ◽  
Flame Temperature ◽  
Plug Flow ◽  
Combustion Process ◽  
Chemical Reactor ◽  
Chemical Kinetic ◽  
Combustion Regime ◽  
Reactor Model

Flameless combustion (FC) is one of the most promising techniques of reducing harmful emissions from combustion systems. FC is a combustion phenomenon that takes place at low O2 concentration and high inlet reactant temperature. This unique combination results in a distributed combustion regime with a lower adiabatic flame temperature. The paper focuses on investigating the chemical kinetics of an prototype combustion chamber built at the university of Cincinnati with an aim of establishing flameless regime and demonstrating the applicability of FC to gas turbine engines. A Chemical reactor model (CRM) has been built for emulating the reactions within the combustor. The entire combustion chamber has been divided into appropriate number of Perfectly Stirred Reactors (PSRs) and Plug Flow Reactors (PFRs). The interconnections between these reactors and the residence times of these reactors are based on the PIV studies of the combustor flow field. The CRM model has then been used to predict the combustor emission profile for various equivalence ratios. The results obtained from CRM model show that the emission from the combustor are quite less at low equivalence ratios and have been found to be in reasonable agreement with experimental observations. The chemical kinetic analysis gives an insight on the role of vitiated combustion gases in suppressing the formation of pollutants within the combustion process.

Innovative Passive Flame Ameliorator for a Diffusion Flame Burner Using Chevrons

2015 ◽  
Vol 787 ◽  
pp. 732-735
Author(s):  
A. Alaguraja ◽  
S. Balaji ◽  
Inti Sandeep ◽  
M. Karthikeyan ◽  
S. Soma Sundaram
Keyword(s):  
Diffusion Flame ◽  
Acoustic Noise ◽  
Combustion Process ◽  
Ambient Air ◽  
Premixed Flame ◽  
Experimental Investigations ◽  
Exhaust Gas ◽  
Novel Approach ◽  
Flame Burner ◽  
Safety Considerations

Diffusion flame burners are mainly used in industries over premixed flame burners for safety considerations. But the combustion process in a diffusion flame is not complete and the flame is usually in bright yellow in colour in contrast to the premixed flame which gives a bluish flame. To improve the combustion process in a diffusion flame burner a novel approach, using chevrons has been carried out. The chevrons are found to reduce the aero-acoustic noise in the exhaust jets of aircraft engines by allowing better mixing of the exhaust gas with the ambient air. The similar concept is used here where the tips of the burners are cut in the form of chevrons. Experimental investigations are carried out on burners with three and four chevrons in addition to a standard burner using LPG as the fuel. The results indicate that with the introduction of chevrons the diffusion flame becomes more compact. The premixed region, in the diffusion flame, where the air and fuel is mixed well is found to increase by nearly 100 % with the usage of chevrons, indicating better mixing of fuel and air. The results also indicate that increasing the number of chevrons from three to four does not show much variation. Further experiments are to be carried out to determine the improved fuel consumption with the usage of chevrons.

scholarly journals Energy-saving biomass stove

2014 ◽  
Vol 6 (2) ◽  
pp. 115-119
Author(s):  
Tri Hoang
Keyword(s):  
Energy Saving ◽  
Rice Husk ◽  
Flue Gas ◽  
Particle Concentration ◽  
Combustion Process ◽  
Combustion Products ◽  
Raw Material ◽  
Gas Emission ◽  
Biomass Stove ◽  
Residual Oxygen

This paper introduces an energy-saving biomass stove. The principle of energy-saving biomass stove is gasification. It is a chemical process, transforms solid fuel into a gas mixture, called (CO + H2 + CH4) gas. Emission lines in the stove chimneys typically remain high temperatures around 90° to 120°C. The composition of the flue gas consists of combustion products of rice husk which are mainly CO2, CO, N2. A little volatile in the rice husk, which could not burn completely, residual oxygen and dust will fly in airflow. The amount of dust in the outlet gas is a combination of un-burnt amount of impurity and firewood, usually occupied impurity rate of 1 % by weight of dry husk. Outlet dust of rice husk furnace has a normal size from 500μm to 0.1 micron and a particle concentration ranges from 200-500 mg/m3. Gas emissions is created when using energy-saving stove and they will be used as the main raw material in combustion process Therefore the CO2 emission into the environment when using the stove will be reduced up to 95% of a commonly used stove. Bài báo giới thiệu một bếp tiết kiệm dùng năng lượng sinh khối. Bếp tiết kiệm năng lượng thực hiện nguyên lý khí hóa sinh khối. Đó là một quá trình hóa học, chuyển hóa các loại nhiên liệu dạng rắn thành một dạng hỗn hợp khí đốt, gọi là khí Gas (CO + H2 + CH4). Dòng khí thải ra ở ống khói của bếp thông thường có nhiệt độ vẫn còn cao khoảng 90° ~ 120°C. Thành phần của khói thải bao gồm các sản phẩm cháy của trấu, chủ yếu là các khí CO2, CO, N2, một ít các chất bốc trong trấu không kịp cháy hết, oxy dư và tro bụi bay theo dòng khí. Lượng bụi tro có trong khói thải chính là một phần của lượng không cháy hết và lượng tạp chất không cháy có trong củi, lượng tạp chất này thường chiếm tỷ lệ 1% trọng lượng trấu khô. Bụi trong khói thải lò đốt trấu thông thường có kích thước hạt từ 500μm tới 0,1μm, nồng độ dao động trong khoảng từ 200-500 mg/m3. Lượng khí thải được sinh ra khi sử dụng bếp tiết kiệm năng lượng, sẽ được dùng làm nguyên liệu đốt cháy chính của quá trình đó. Do đó lượng khí CO2 thải ra môi trường khi sử dụng bếp tiết kiệm sẽ được giảm xuống 95 % so với sử dụng bếp thường.

scholarly journals Q-Learning Neural Controller for Steam Generator Station in Micro Cogeneration Systems

Energies ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 5334
Author(s):  
Krzysztof Lalik ◽  
Mateusz Kozek ◽  
Szymon Podlasek ◽  
Rafał Figaj ◽  
Paweł Gut
Keyword(s):  
Numerical Model ◽  
Control Systems ◽  
Steam Generator ◽  
Full Range ◽  
Combustion Process ◽  
Liquid Fuels ◽  
Control Algorithms ◽  
Exhaust Gas ◽  
Gas Temperature ◽  
The Impact

This article presents the results of the optimization of steam generator control systems powered by mixtures of liquid fuels containing biofuels. The numerical model was based on the results of experimental research of steam generator operation in an open system. The numerical model is used to build control algorithms that improve performance, increase efficiency, reduce fuel consumption and increase safety in the full range of operation of the steam generator and the cogeneration system of which it is a component. In this research, the following parameters were monitored: temperature and pressure of the circulating medium, exhaust gas temperature, oxygen content in exhaust gas, percentage control of oil burner power. Two methods of controlling the steam generator were proposed: the classic one, using the PID regulator, and the advanced one, using artificial neural networks. The work shows how the model is adapted to the real system and the impact of the control algorithms on the efficiency of the combustion process. The example is considered for the implementation of advanced control systems in micro-, small- and medium-power cogeneration and trigeneration systems in order to improve their final efficiency and increase the profitability of implementation.

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