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Book Ammonia and Hydrogen for Green Energy Transition

Download or read book Ammonia and Hydrogen for Green Energy Transition written by Sudarshan Kumar and published by Springer Nature. This book was released on with total page 399 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Detailed Modeling and Laser induced Fluorescence Imaging of Nitric Oxide in a NH i seeded Non premixed Methane

Download or read book Detailed Modeling and Laser induced Fluorescence Imaging of Nitric Oxide in a NH i seeded Non premixed Methane written by and published by . This book was released on 2001 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this paper we study the formation of NO in laminar, nitrogen diluted methane diffusion flames that are seeded with ammonia in the fuel stream. We have performed numerical simulations with detailed chemistry as well as laser-induced fluorescence imaging measurements for a range of ammonia injection rates. For comparison with the experimental data, synthetic LIF images are calculated based on the numerical data accounting for temperature and fluorescence quenching effects. We demonstrate good agreement between measurements and computations. The LIF corrections inferred from the simulation are then used to calculate absolute NO mole fractions from the measured signal. The NO formation in both doped and undoped flames occurs in the flame sheet. In the undoped flame, four different mechanisms including thermal and prompt NO appear to contribute to NO formation. As the NH3 seeding level increases, fuel-NO becomes the dominant mechanism and N2 shifts from being a net reactant to being a net product. Nitric oxide in the undoped flame as well as in the core region of the doped flames are underpredicted by the model; we attribute this mainly to inaccuracies in the NO recycling chemistry on the fuel-rich side of the flame sheet.

Book Measurements and Modeling of Nitric Oxide Formation in Counterflow Premixed Ch4 O2 N2 Flames

Download or read book Measurements and Modeling of Nitric Oxide Formation in Counterflow Premixed Ch4 O2 N2 Flames written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-06-27 with total page 286 pages. Available in PDF, EPUB and Kindle. Book excerpt: Laser-induced fluorescence (LIF) measurements of NO concentration in a variety of CH4/O2/N2 flames are used to evaluate the chemical kinetics of NO formation. The analysis begins with previous measurements in flat, laminar, premixed CH4/O2/N2 flames stabilized on a water-cooled McKenna burner at pressures ranging from 1 to 14.6 atm, equivalence ratios from 0.5 to 1.6, and volumetric nitrogen/oxygen dilution ratios of 2.2, 3.1 and 3.76. These measured results are compared to predictions to determine the capabilities and limitations of the comprehensive kinetic mechanism developed by the Gas Research Institute (GRI), version 2.11. The model is shown to predict well the qualitative trends of NO formation in lean-premixed flames, while quantitatively underpredicting NO concentration by 30-50%. For rich flames, the model is unable to even qualitatively match the experimental results. These flames were found to be limited by low temperatures and an inability to separate the flame from the burner surface. In response to these limitations, a counterflow burner was designed for use in opposed premixed flame studies. A new LIF calibration technique was developed and applied to obtain quantitative measurements of NO concentration in laminar, counterflow premixed, CH4/O2/N2 flames at pressures ranging from 1 to 5.1 atm, equivalence ratios of 0.6 to 1.5, and an N2/O2 dilution ratio of 3.76. The counterflow premixed flame measurements are combined with measurements in burner-stabilized premixed flames and counterflow diffusion flames to build a comprehensive database for analysis of the GRI kinetic mechanism. Pathways, quantitative reaction path and sensitivity analyses are applied to the GRI mechanism for these flame conditions. The prompt NO mechanism is found to severely underpredict the amount of NO formed in rich premixed and nitrogen-diluted diffusion flames. This underprediction is traced to uncertainties in the CH kinetics as well as in the nitrogen oxidation chemistry. S

Book Nitric Oxide Formation and Modelling Uncertainty from Exhaust gas diluted Methane Flames

Download or read book Nitric Oxide Formation and Modelling Uncertainty from Exhaust gas diluted Methane Flames written by Antonio Lipardi and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: "Nitrogen oxides (NOx) are pollutants emitted by various combustion processes that are subject to increasingly-stringent regulations due to their impact on human health and the environment. Exhaust gas recirculation (EGR) has been shown to reduce NOx emissions by decreasing the oxygen concentration and, for a given heat release, reducing peak flame temperatures. Previous simulated combustion results (at a constant burning temperature) have demonstrated that EGR dilution may generate an NO minimization range governed by an increase in the prompt NO formation and a decrease in the thermal NO rate. However, this range is not predicted by all combustion models, thereby necessitating its experimental validation.This thesis conveys the constant burning temperature effects of EGR on NOx formation and the modelling performance of three thermochemical mechanisms (Gri-Mech 3.0, San-Diego 2005, and Combustion Science and Engineering). Using NO planar laser-induced fluorescence (NO-PLIF) and particle tracking velocimetry (PTV), constant burning temperature (1850K and 2000K) measurements of nitric oxide (NO-PLIF), temperature (NO-PLIF), and flame reactivity (PTV) were performed on methane-air flames with (and without) EGR dilution using a counterflow apparatus. These results confirmed the existence of the EGR-induced NO minimization range. However, this interesting engine design constraint was obscured by the high level of variability (factor of approx. 4) and uncertainty (up to 99%) found in the simulated NO profiles. A reduced set of reactions that may serve as a basis for the optimization process of the investigated NO submodels is also presented." --

Book Ammonia Conversion and NOx Formation in Laminar Coflowing Nonpremixed Methane air Flames

Download or read book Ammonia Conversion and NOx Formation in Laminar Coflowing Nonpremixed Methane air Flames written by and published by . This book was released on 2002 with total page 5 pages. Available in PDF, EPUB and Kindle. Book excerpt: This paper reports on a combined experimental and modeling investigation of NOx formation in nitrogen-diluted laminar methane diffusion flames seeded with ammonia. The methane-ammonia mixture is a surrogate for biomass fuels which contain significant fuel-bound nitrogen. The experiments use flue-gas sampling to measure the concentration of stable species in the exhaust gas, including NO, O2, CO, and CO2. The computations evolve a two-dimensional low Mach number model using a solution-adaptive projection algorithm to capture fine-scale features of the flame. The model includes detailed thermodynamics and chemical kinetics, differential diffusion, buoyancy, and radiative losses. The model shows good agreement with the measurements over the full range of experimental NH3 seeding amounts. As more NH3 is added, a greater percentage is converted to N2 rather than to NO. The simulation results are further analyzed to trace the changes in NO formation mechanisms with increasing amounts of ammonia in the fuel.

Book Laser based Diagnostics and Modeling of Nitric Oxide and Its Precursor Ammonia in Low Specific Energy Gas Flames

Download or read book Laser based Diagnostics and Modeling of Nitric Oxide and Its Precursor Ammonia in Low Specific Energy Gas Flames written by Denise Charlston Goch and published by . This book was released on 2000 with total page 796 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Chemical Kinetic Models for Combustion of Hydrocarbons and Formation of Nitric Oxide

Download or read book Chemical Kinetic Models for Combustion of Hydrocarbons and Formation of Nitric Oxide written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-08-13 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt: The formation of nitrogen oxides NOx during combustion of methane, propane, and a jet fuel, JP-4, was investigated in a jet stirred combustor. The results of the experiments were interpreted using reaction models in which the nitric oxide (NO) forming reactions were coupled to the appropriate hydrocarbon combustion reaction mechanisms. Comparison between the experimental data and the model predictions reveals that the CH + N2 reaction process has a significant effect on NO formation especially in stoichiometric and fuel rich mixtures. Reaction models were assembled that predicted nitric oxide levels that were in reasonable agreement with the jet stirred combustor data and with data obtained from a high pressure (5.9 atm (0.6 MPa)), prevaporized, premixed, flame tube type combustor. The results also suggested that the behavior of hydrocarbon mixtures, like JP-4, may not be significantly different from that of pure hydrocarbons. Application of the propane combustion and nitric oxide formation model to the analysis of NOx emission data reported for various aircraft gas turbines showed the contribution of the various nitric oxide forming processes to the total NOx formed. Jachimowski, C. J. and Wilson, C. H. Langley Research Center NASA-TP-1794, L-14106 RTOP 506-52-33-01...

Book The Formation of Nitric Oxide in Diffusion Flames

Download or read book The Formation of Nitric Oxide in Diffusion Flames written by A. D. Tuteja and published by . This book was released on 1972 with total page 500 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Nitric Oxide Formation in a Lean Premixed Prevaporized Jet A Air Flame Tube

Download or read book Nitric Oxide Formation in a Lean Premixed Prevaporized Jet A Air Flame Tube written by National Aeronautics and Space Adm Nasa and published by Independently Published. This book was released on 2018-12-31 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt: An experimental and analytical study was performed on a lean, premixed-prevaporized Jet A/air flame tube. The NO(x) emissions were measured in a flame tube apparatus at inlet temperatures ranging from 755 to 866 K (900 to 1100 F), pressures from 10 to 15 atm, and equivalence ratios from 0.37 to 0.62. The data were then used in regressing an equation to predict the NO(x) production levels in combustors of similar design. Through an evaluation of parameters it was found that NO(x) is dependent on adiabatic flame temperature and combustion residence time, yet independent of pressure and inlet air temperature for the range of conditions studied. This equation was then applied to experimental data that were obtained from the literature, and a good correlation was achieved. Lee, Chi-Ming and Bianco, Jean and Deur, John M. and Ghorashi, Bahman Glenn Research Center NASA-TM-105722, E-7121, NAS 1.15:105722 RTOP 537-01-11...

Book Fundamental Limits of NO Formation in Fuel rich Premixed Methane air Flames

Download or read book Fundamental Limits of NO Formation in Fuel rich Premixed Methane air Flames written by and published by . This book was released on 2007 with total page 157 pages. Available in PDF, EPUB and Kindle. Book excerpt: