Modelling adiabatic flame temperature for methane with an overview for advanced combustion process: flameless combustion

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Anis Imakhlaf ◽  
Abdelhadi Beghidja
Keyword(s):  
Flame Temperature ◽  
Combustion Process ◽  
Flameless Combustion ◽  
Environmental Aspect ◽  
Equivalent Ratio ◽  
Rich Mixture ◽  
The Third ◽  
Advanced Combustion ◽  
Mathematical Equations ◽  
Optimal Values

Abstract In this study, we have carried out to modeling by mathematical equations the environment of the combustion chamber under some conditions using the software MATLAB in order to make an adequate algorithm of resolution and get solution of the different equations that taken part in the phenomenon of combustion, so the first was to identifies the kind of the fuel to use in that model (taking Methane as fuel combustion) and minimizing the reduction of novice gas burned is in priority, for this, we want to establish the optimal values to take to preserve the environment, especially from CO2 and CO emissions, secondly, its nature according to the equivalent ratio (lean, stoichiometric or rich mixture), all variations of equivalent ratio, the third idea is to retrace the ways of a different product of the reaction and see their variations compared to the equivalent ratio, once traced, we can improvise which exact place in the reaction, a product will be finished either in the form of a gas or to decompose in order to bind to another and form another component. We also discussed the percentage of O2 and H2O emissions for an interesting viewpoint of the environmental aspect of hydrocarbon’s chemical reaction. Another additional part will be dedicated to the process of flameless combustion to write its mathematical equation, compare it with the so-called traditional one, and see the variations in the temperature according to the equivalent ratio.

Pyrolysis and Oxidative Pyrolysis of Polystyrene

1993 ◽  
Author(s):  
Ashwani K. Gupta ◽  
Eugene L. Keating
Keyword(s):  
Thermal Destruction ◽  
Pyrolysis Temperature ◽  
Flame Temperature ◽  
Combustion Process ◽  
Chemical Species ◽  
Advanced Combustion ◽  
Oxidative Pyrolysis ◽  
Product Gas ◽  
Different Temperatures ◽  
Gas Volume

Abstract Equilibrium thermochemical calculations of polystyrene are presented here under conditions of pyrolysis and oxidative pyrolysis. Oxidative pyrolysis is examined using both air and oxygen for varying moisture content in the polystyrene. The pyrolysis of polystyrene at different temperatures prior to its oxidative pyrolysis provided significantly different results. Product gas volume and flame temperature is significantly affected by the pyrolysis temperature, nature and amount of the oxidant and the amount of moisture in the waste. Results reveal significant effect of controlled combustion on the amount and nature of the chemical species formed. The results also reveal that advanced combustion process can significantly reduce the extent of post processing of gases required, and hence the size of the equipment, for achieving environmentally acceptable thermal destruction system of the solid wastes.

MODEL OF SOCIAL POTENTIAL OF CHILDHOOD IN THE RUSSIAN REGIONS: THE RESULTS OF EXPERIMENTS

2019 ◽  
pp. 152-162
Author(s):  
A.G. Filipova ◽  
A.V. Vysotskaya
Keyword(s):  
Third Wave ◽  
Russian Regions ◽  
The Third ◽  
Control Factors ◽  
Social Potential ◽  
System Input ◽  
Optimal Values ◽  
Fixed Ideal ◽  
And Control ◽  
Selection Of

The article presents the results of mathematical experiments with the system «Social potential of childhood in the Russian regions». In the structure of system divided into three subsystems – the «Reproduction of children in the region», «Children’s health» and «Education of children», for each defined its target factor (output parameter). The groups of infrastructure factors (education, health, culture and sport, transport), socio-economic, territorial-settlement, demographic and en-vironmental factors are designated as the factors that control the system (input parameters). The aim of the study is to build a model îf «Social potential of childhood in the Russian regions», as well as to conduct experiments to find the optimal ratio of the values of target and control factors. Three waves of experiments were conducted. The first wave is related to the analysis of the dynam-ics of indicators for 6 years. The second – with the selection of optimal values of control factors at fixed ideal values of target factors. The third wave allowed us to calculate the values of the target factors based on the selected optimal values of the control factors of the previous wave.

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.

scholarly journals RESEARCH OF INFLUENCE OF AIR TEMPERATURE ON THE LEVEL OF NITROGEN OXIDES IN SMOKE GASES OF BOILER PLANTS

2019 ◽  
Vol 9 (4) ◽  
pp. 27-32
Author(s):  
Olga A. BALANDINA ◽  
Svetlana M. PURING
Keyword(s):  
Mathematical Modeling ◽  
Nitric Oxide ◽  
Nitrogen Oxides ◽  
Flue Gas ◽  
Software Package ◽  
Flame Temperature ◽  
Combustion Process ◽  
Flue Gases ◽  
Oxidizing Agent ◽  
Mixture Formation

The analysis of the values of the concentrations of the formed nitrogen oxides and the temperatures of the jet plume under various conditions of mixture formation is carried out. The plots of the distribution of torch temperatures and concentrations of nitric oxide in the calculated area for oxidizer temperatures of 20, 60, 100, 150, and 200 ° C were obtained and analyzed. Mathematical modeling of the gaseous fuel combustion process was carried out using the FlowVision software package. An analysis of the results showed that a decrease in the temperature of the air supplied as an oxidizing agent leads to a significant decrease in the concentration of nitrogen oxides in flue gases, while not significantly affecting the change in the flame temperature. The research results can be used to solve the problems of optimizing boiler plants, in order to reduce harmful flue gas emissions. Further modeling is planned to determine the dependence of the influence of various factors on the degree of formation of nitrogen oxides in the flue gases of boiler plants.

scholarly journals Chemiluminescence analysis of the effect of butanol-diesel fuel blends on the spray-combustion process in an experimental common rail diesel engine

2015 ◽  
Vol 19 (6) ◽  
pp. 1943-1957
Author(s):  
Simona Merola ◽  
Luca Marchitto ◽  
Cinzia Tornatore ◽  
Gerardo Valentino
Keyword(s):  
Diesel Fuel ◽  
Flame Temperature ◽  
Combustion Process ◽  
Injection Pressure ◽  
Common Rail ◽  
Pilot Injection ◽  
Soot Emission ◽  
Compression Ignition Engine ◽  
Working Cycle ◽  
Main Injection

Combustion process was studied from the injection until the late combustion phase in an high swirl optically accessible combustion bowl connected to a single cylinder 2-stroke high pressure common rail compression ignition engine. Commercial diesel and blends of diesel and n-butanol (20%: BU20 and 40%: BU40) were used for the experiments. A pilot plus main injection strategy was investigated fixing the injection pressure and fuel mass injected per stroke. Two main injection timings and different pilot-main dwell times were explored achieving for any strategy a mixing controlled combustion. Advancing the main injection start, an increase in net engine working cycle (>40%) together with a strong smoke number decrease (>80%) and NOx concentration increase (@50%) were measured for all pilot injection timings. Compared to diesel fuel, butanol induced a decrease in soot emission and an increase in net engine working area when butanol ratio increased in the blend. A noticeable increase in NOx was detected at the exhaust for BU40 with a slight effect of the dwell-time. Spectroscopic investigations confirmed the delayed auto-ignition (~60 ms) of the pilot injection for BU40 compared to diesel. The spectral features for the different fuels were comparable at the start of combustion process, but they evolved in different ways. Broadband signal caused by soot emission, was lower for BU40 than diesel. Different balance of the bands at 309 and 282 nm, due to different OH transitions, were detected between the two fuels. The ratio of these intensities was used to follow flame temperature evolution.

scholarly journals A Thermodynamic Analysis of an Air-Cooled Proton Exchange Membrane Fuel Cell Operated in Different Climate Regions

Energies ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2611 ◽  
Author(s):  
Torsten Berning ◽  
Søren Knudsen Kær
Keyword(s):  
Fuel Cell ◽  
Thermodynamic Analysis ◽  
Operating Temperature ◽  
Flame Temperature ◽  
Combustion Process ◽  
Cell Voltage ◽  
Proton Exchange ◽  
Outlet Temperature ◽  
Flow Ratio ◽  
Ambient Conditions

A fundamental thermodynamic analysis of an air-cooled fuel cell, where the reactant air stream is also the coolant stream, is presented. The adiabatic cell temperature of such a fuel cell is calculated in a similar way as the adiabatic flame temperature in a combustion process. Diagrams that show the dependency of the cathode outlet temperature, the stoichiometric flow ratio and the operating cell voltage are developed. These diagrams can help fuel cell manufacturers to identify a suitable blower and a suitable operating regime for their fuel cell stacks. It is found that for standard conditions, reasonable cell temperatures are obtained for cathode stoichiometric flow ratios of ξ = 50 and higher, which is in very good agreement with manufacturer’s recommendations. Under very cold ambient conditions, the suggested stoichiometric flow ratio is only in the range of ξ = 20 in order to obtain a useful fuel cell operating temperature. The outside relative humidity only plays a role at ambient temperatures above 40 °C, and the predicted stoichiometric flow ratios should be above ξ = 70 in this region. From a thermodynamic perspective, it is suggested that the adiabatic outlet temperature is a suitable definition of the fuel cell operating temperature.

scholarly journals Influence of Eddy-Generation Mechanism on the Characteristic of On-Source Fire Whirl

2019 ◽  
Vol 9 (19) ◽  
pp. 3989 ◽  
Author(s):  
Cheng Wang ◽  
Anthony Chun Yin Yuen ◽  
Qing Nian Chan ◽  
Timothy Bo Yuan Chen ◽  
Qian Chen ◽  
...  
Keyword(s):  
Flame Structure ◽  
Flame Temperature ◽  
Combustion Process ◽  
Flame Height ◽  
Reacting Flow ◽  
Detailed Chemistry ◽  
Eddy Generation ◽  
Fire Whirl ◽  
Generation Mechanisms ◽  
The Impact

This paper numerically examines the characterisation of fire whirl formulated under various entrainment conditions in an enclosed configuration. The numerical framework, integrating large eddy simulation and detailed chemistry, is constructed to assess the whirling flame behaviours. The proposed model constraints the convoluted coupling effects, e.g., the interrelation between combustion, flow dynamics and radiative feedback, thus focuses on assessing the impact on flame structure and flow behaviour solely attribute to the eddy-generation mechanisms. The baseline model is validated well against the experimental data. The data of the comparison case, with the introduction of additional flow channelling slit, is subsequently generated for comparison. The result suggests that, with the intensified circulation, the generated fire whirl increased by 9.42 % in peak flame temperature, 84.38 % in visible flame height, 6.81 % in axial velocity, and 46.14 % in velocity dominant region. The fire whirl core radius of the comparison case was well constrained within all monitored heights, whereas that of the baseline tended to disperse at 0.5   m height-above-burner. This study demonstrates that amplified eddy generation via the additional flow channelling slit enhances the mixing of all reactant species and intensifies the combustion process, resulting in an elongated and converging whirling core of the reacting flow.

Preliminary Study of a Low Power Plasma Radical Jet Generator for Combustion Systems

2006 ◽  
Author(s):  
Woong-Sik Choi ◽  
Jaecheol Kim ◽  
Yedidia Neumeier ◽  
Jeff Jagoda
Keyword(s):  
Fast Moving ◽  
Combustion Process ◽  
Combustible Mixture ◽  
Total Power ◽  
Main Stream ◽  
Incomplete Combustion ◽  
Rich Mixture ◽  
Drastic Effect ◽  
Steady Combustion ◽  
Solid Walls

A novel radical jet generator (RJG) was developed, whose purpose it is to supply concentrated, relatively low temperature radicals that penetrate into a flammable stream of reactants and trigger or modify a combustion process. The RJG is driven by a plasma whose power is only a fraction of a percent of the total power released in the combustor. In this approach, the plasma induces an incomplete combustion process in a small duct carrying a rich mixture of fuel and air. Results obtained using the developed RJG show that a jet, which consists of partially burnt reactants, some products and is, apparently, rich in radicals produced by the incomplete combustion process triggers extremely steady combustion in a fast moving combustible mixture whose flow rate far exceeds that of the RJG. Importantly, the results show that the jet, rich with radicals, that emerges from the RJG cavity at a temperature well below traditional ignition can ignite a fast moving stream of combustible mixture. Moreover, when injected normal to the main flow, this jet ignites the main stream at a location relatively far from the entrance point of the jet. This makes it possible to keep the combustion process away from solid walls while at the same time eliminating the need for solid flame holders. This in turn, provides an augmenter with reduced I.R signature. Finally, the results show a drastic effect of the RJG upon the flame dynamics in general and combustion instabilities in particular. Flames which displayed large, periodic pressure oscillations became completely stable when the plasma in the RJG was turned on. This suggests a novel use of the RJG to inhibit instabilities in combustors.

Humid Air NOx Reduction Effect on Liquid Fuel Combustion

2004 ◽  
Vol 126 (1) ◽  
pp. 69-74 ◽  
Author(s):  
A. G. Chen ◽  
Daniel J. Maloney ◽  
William H. Day
Keyword(s):  
Liquid Fuel ◽  
Nox Reduction ◽  
Flame Temperature ◽  
Substantial Reduction ◽  
Combustion Process ◽  
Pollutant Emissions ◽  
Humid Air ◽  
Wide Range ◽  
Reduction Of Nox ◽  
Reduction Effect

An experimental investigation was carried out at DOE NETL on the humid air combustion process using liquid fuel to determine the effects of humidity on pollutant emissions and flame stability. Tests were conducted at pressures of up to 100 psia (690 kPa), and a typical inlet air temperature of 860°F (733 K). The emissions and RMS pressures were documented for a relatively wide range of flame temperature from 2440-3090°F (1610–1970 K) with and without added humidity. The results show more than 90% reduction of NOx through 10% humidity addition to the compressed air compared with the dry case at the same flame temperature. The substantial reduction of NOx is due to a shift in the chemical mechanisms and cannot be explained by flame temperature reduction due to added moisture since the comparison was made for the same flame temperature.

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