Hot wire ignition of hydrogen-oxygen mixtures

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National Library of Canada , Ottawa
SeriesCanadian theses = Thèses canadiennes
The Physical Object
FormatMicroform
Pagination2 microfiches : negative.
ID Numbers
Open LibraryOL15136356M
ISBN 100315871660
OCLC/WorldCa46533921

A thin wire served in our experiments both as a hot surface to ignite Hot wire ignition of hydrogen-oxygen mixtures book hydrogen-oxygen mixtures and as a resistance temperature sensor. Nichrome wires, which are non-catalytic [13], were used, since a catalytic ma- terial such as platinum can greatly reduce the ignition temperature of hydrogen [5].Cited by: The risk of accidental ignition of flammable mixtures by a hot surface is of particular importance for industry.

Accurate measurements and modeling of the minimum surface temperature for ignition. Ignition of hydrogen-oxygen-diluent mixtures adjacent to a hot, nonreactive surface, Combustion and Flame,75(2), pp. [8] Adler. EXPERIMENTAL STUDY OF HOT INERT GAS JET IGNITION OF HYDROGEN-OXYGEN MIXTURE Elhsnawi, M.

and Teodorczyk, A. Warsaw University of Technology, ITC, Nowowiejska 21/25, Warszawa, Poland ABSTRACT Experiments were performed to investigate the diffusion ignition process that occurs when hot inert gasFile Size: 78KB. Hot surface ignition is relevant in the context of industrial safety.

In the present work, two-dimensional simulations with detailed chemistry, and study of the reaction pathways of the buoyancy-driven flow and ignition of a stoichiometric hydrogen-air mixture by a rapidly heated surface (glowplug) are by: The ability of a resonance tube to produce ignition of hydrogen-oxygen mixtures was first demonstrated at room temperature by E.

Conrad and A. Pavli of Lewis, thereby confirming its potential as a passive igniter for hydrogen-oxygen rocket engines. The work reported herein was intended to lay the groundwork for the design and demon­. For hydrogen, the minimum ignition energy is low at mJ for mixtures with air (ISO, ), and even lower at mJ for mixtures with oxygen (Kuchta, ).

Hydrogen has a such a low minimum ignition energy that it is often difficult to determine the exact mechanism and cause of an ignition when it occurs.

Description Hot wire ignition of hydrogen-oxygen mixtures FB2

IGNITION PROCESSES IN HYDROGEN-OXYGEN MIXTURES 55 where a = 0 for infinite cube, a = 1 for infinite cylinder, a = 2 for sphere, r = radius, ns = number of species, Cpi = constant pressure spe­ cific heat capacity of species i, cp = constant pressure specific heat capacity of the mixture.

hi = specific enthalpy of species i, Vi = diffusion. Experimental investigation of the ignition of a stoichiometric hydrogen–oxygen mixture behind an incident shock wave in a shock tube at pressures p = – MPa and temperatures T = – K is carried out.

The existence of three limits of ignition typical of the ignition of hydrogen–oxygen mixtures in a spherical vessel is noted. [4] N.M. Laurendau, Thermal ignition of methane-air mixtures by hot surfaces:a critical examination, Combustion and Flame 46 () [5] R.K.

Kumar, Ignition of hydrogen-oxygen-diluent mixtures adjacient to a hot. Weak and strong ignition: Of interest to Hot wire ignition of hydrogen-oxygen mixtures book present investigation is the weak and strong igni-tion behavior of H 2/O 2-mixtures.

Weak ignition is a combustion phenomenon that is observed for certain operating conditions, and is associated with the non-uniform and distributed ignition of the mixture. This is in contrast to strong ignition. the ignition time delay of hydrogen-oxygen mixtures under detonation or near detonation conditions was effected.

The results of these investigations have been published in part.1* 2> 10> n The theoretical approach presented herein represents a more rigorous treatment of the pertinent reaction equations. The problem to be considered is that. The detonation characteristics of hydrogen-oxygen mixtures were com- puted for the experimental range of conditions by the use of the elementary theory of detonation.

This theory pos- tulates a planar discontinuity in pres- sure, temperature, and composition moving at sonic velocity relative to the. with air or an oxidizer, will self-heat to ignition without an external ignition source. The Autoignition Temperature for a monopropellant is the temperature at which it will self-heat to ignition in the absence of an oxidizer.

Minimum Spark Ignition Energy for gaseous hydrogen in. Explosion Characteristics of Hydrogen-Air and Hydrogen-Oxygen Mixtures at Elevated Pressures Schroeder, V.1 and Holtappels, K.1 1Bundesanstalt für Materialforschung und –pruefung (BAM), Unter den Eic Berlin, Germany ABSTRACT An essential problem for the operation of high pressure water electrolyzers and fuel cells is the.

When fluorine use at NASA Lewis was eliminated in the late 's, the hydrogen-oxygen torch ignitor described herein was designed to fill the gap. It was subsequently used as an ignition source on research rocket engines that ran at conventional oxygen/fuel (OIF) ratios using all possible combinations of liquid and gaseous hydrogen and oxygen.

The results of numerical modeling of the ignition process of hydrogen–oxygen mixtures diluted with argon at temperatures of – K within wide ranges of the initial gas parameters are presented. The time evolutions of the concentration of the electron-excited radical OH* and other components, as well as the strength of the radical total radiation on wavelengths about λ = nm.

@article{osti_, title = {Reaction limits in knallgas saturated with water vapor. Progress report}, author = {Adler, L B and Hobaica, E C and Luker, J A}, abstractNote = {The basic objective of this research investigation is to determine the reactive limits of stoichiometric hydrogen-oxygen mixtures (knallgas) saturated with water vapor.

Fig.

Details Hot wire ignition of hydrogen-oxygen mixtures FB2

Ignition source energy Vs compositition (Because of low minimum ignition source, low energy spark is required to initiate the ignition. A glow plug or resistance hot wire can initiate the combustion process[8]. As the requirement of low ignition energy hydrogen engines meet uncontrolled pre - ignition problems.

Spark ignition.

Download Hot wire ignition of hydrogen-oxygen mixtures EPUB

Background Occasionally it is necessary to make measurements in hydrogen/oxygen mixtures. The increased use of fuel cells and the use of hydrogen as a vehicle fuel have increased the frequency with which this requirement occurs.

The requirement occurs usually within process vessels since when the mixture is released the problem becomes a mixture of hydrogen/oxygen.

This paper addresses homogeneous ignition of hydrogen-oxygen mixtures when the initial conditions of temperature and pressure place the system below the crossover temperature associated with the second explosion limit.

A three-step reduced mechanism involving H 2, O 2, H 2O, H 2O 2 and HO 2. In the framework of research motivated by the Challenger disaster a team of researchers have pursued all possible mechanisms of igniting explosions of.

@article{osti_, title = {Hydrogen:air:steam flammability limits and combustion characteristics in the FITS (Fully Instrumented Test Site) vessel}, author = {Marshall, Jr, B W}, abstractNote = {For the past few years,the United States Nuclear Regulatory Commission has sponsored research at Sandia National Laboratories addressing the combustion characteristics and flammability limits of.

The ignition of a gas mixture containing 8 mole %H2 and 2 mole %O2 in argon was studied in a shock tube at °—°K. The observed ignition delays were longer than would be expected by extrapolation of data obtained by other workers at higher temperatures. The rapid increase in induction time with decreasing temperature can be accounted for quantitatively by an ignition mechanism.

it is the theory chapter, which explains some of the properties of ignition and the most important chain reactions in a hydrogen-oxygen system.

Further-more, it states reasons for why there exist explosion and flammability limits. Chapter 3 will deal with the simulation methods of the Pencil Code. Here a. Minimum Ignition Points Heated Element Wire 0 50 0 10 % Hydrogen in air • Extremely lean hydrogen mixtures (• Oxygen probe to detect an air leak in the vacuum system.

If oxygen. the ignition temperature for hydrogen-oxygen mixtures at atmospheric pressure, Anzilotti felt the knock must have originated from an auto-ignition of the end gas.

The effect of tetraethyllead on flame speed was not investigated. King did a long-term study on hydrogen fueled engines at the University of Toronto in the s [6,8,9]. Hydrogen safety covers the safe production, handling and use of hydrogen - particularly hydrogen gas fuel and liquid main concern in working with hydrogen is flammability.

Hydrogen possesses the NFPA 's highest rating of 4 on the flammability scale because it is flammable when mixed even in small amounts with ordinary air; ignition can occur at a volumetric ratio of hydrogen.

Micro Rocket Lab continued 6 inn cientiic nc Rights Resered 2. Explain the relative loudness of pure oxygen and pure hydrogen in the pop-test. Write a balanced chemical equation for the combustion reaction of hydrogen and oxygen to give water. The minimum excess energy that must be supplied in the form of a flame or other source of ignition is called the activation energy for the reaction.

Write the balanced chemical equation for the single-replacement reaction of zinc and hydrochloric acid to generate hydrogen gas. Methods of ignition include pyrotechnic, electrical (spark or hot wire), and chemical. Hypergolic propellants have the advantage of self igniting, reliably and with less chance of hard starts.

In the s, the Russians began to start engines with hypergolic fuel, then switch over to .This turned out to be rather easy to do —lots of things are soluble in N 2 O 4 — but at an unacceptable price. L. G. Cole, at JPL, intried such tilings as mono and di nitrobenzene, picric acid, and methyl nitrate, and discovered, upon examining his mixtures, that he had some 56 Ignition.An igniter.

It is a hard core surface gap spark plug with a power supply that matches.