摘要:

Experimental results are described which identify the dependence of soot production on fuel molecular structure in strongly backmixed combustion. This type of aerodynamic process simulates that occurring within the primary zone of many continuous combustion devices (e.g. the gas turbine) where fuel-air ratio conditions are sufficiently rich to form appreciable quantities of soot. Results to be presented are gaseous combustion product distributions, incipient soot limits, and soot production. These parameters have been developed for a variety of hydrocarbons which represent constituents of practical fuels—normal and cyclic paraffins, olefins, single-ring aromatics, and double-ring aromatics. Substantial differences in sooting behavior between the aromatic and aliphatic hydrocarbons have been found and important observations regarding the presence of unburned hydrocarbons at and near the soot limit have been made.

ISSN:0010-2202    

DOI:10.1080/00102208008946922

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

摘要:

In this experiment the scheme of linked vertical wells forin-situcoal gasification was used with an 18.3-m well spacing. The experiment took 100 days for air-flow testing, reverse-combustion linking, forward-combustion gasification, and postburn steam flow. Air was used for gasification except for a 2-day test with oxygen and steam flow. Reverse-combustion linking took 14 days at 1.6 m/day and used 0.40 Mgmol of air per meter of link. At least two linkage paths were formed. The detected links stayed below the 3 m level in the 7.6 m coal seam; however, the product flow from the forward-burn gasification probably followed the coal-overburden interface, rather than the reverse-burn links at the 3-m level. Forward-burn gasification took 58 days and produced a total of 232 Mgmol (194 Mscf) of gas with an average heating value of 96 kJ/gmol (108 Btu/scf(. During the oxygen-steam test, the heating value averaged 235 kJ/gmol (265 Btu/scf). The coal recovery was 1310 m3 (1950 ton). Gasification was terminated because of decreasing product quality, not because the burn had reached the production well. Product quality decreased as a result of increasing heat loss to inert materials underground.

ISSN:0010-2202    

DOI:10.1080/00102208008946923

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

摘要:

An experimental study on the nonsteady ignition process of magnesium and 50-50 magnesium-aluminum alloy was made by using the stagnation region of an impinging hot air stream. The study has revealed that the ignition of magnesium was caused to occur through a four-stage surface oxidation process and finally through a homogeneous exothermic reaction in the gaseous phase. The ignition mechanism of the magnesium-aluminum alloy was essentially identical with that of magnesium, although the observed ignition behavior was more complicated. The difference could be explained in terms of the aluminum ingredient contained in the oxide film formed on the sample surface.

ISSN:0010-2202    

DOI:10.1080/00102208008946924

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

摘要:

The transient processes of evaporation, ignition, and combustion of a fuel droplet in a hot, reactive fuel-oxidizer environment simulating the spray interior are studied numerically, with emphasis on the relative importance of diffusional burning in the droplet vicinity and premixed burning in the ambience. It is shown that for a fuel-lean environment diffusional burning is generally possible and is initiated rapidly, whereas for a fuel-rich environment only premixed burning is possible. For a sufficiently reactive environment one of the reactants is rapidly depleted such that during most of the droplet lifetime the environment is really non-reactive. The present numerical study yields much physical insight useful for further analytical modeling efforts. A new transient process, involving the need to build up the fuel vapor concentration in the droplet vicinity from an initial state of low concentration, has also been identified to be important during droplet combustion and warrants further study.

ISSN:0010-2202    

DOI:10.1080/00102208008946925

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

摘要:

The ignition of a liquid fuel under high intensity radiation was studied experimentally to obtain a fundamental understanding of the ignition mechanism and to aid in the selection of design improvements to minimize hazards of unwanted fires. The experiments were conducted using a CW CO2laser with incident fluxes from 1000 to 5000 W/cm2andn-decane as the flammable liquid. The study of the effect of the container size showed 6 cm diameter by 5 cm depth sufficiently large to prevent container size effects on ignition. High speed photographs of ignition events showed the motion of decane prior to ignition and the onset of the ignition in the gas phase. The effect on ignition of the incident angle of the laser beam with respect to the decane surface was studied from 90° to 30°. On reducing the incident angle, the ignition delay time becomes longer and the minimum incident flux for ignition increases significantly. The proposed autoignition mechanism of decane by a CO2laser is the absorption of the incident laser beam energy by the vapor plume.

ISSN:0010-2202    

DOI:10.1080/00102208008946926

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

摘要:

Kinetics of cellulose pyrolysis in nitrogen and steam at five different heating rates are presented. A single rate equation for each pyrolysis medium is discussed which provides a good engineering fit to the weight loss curves. The presence of steam in the pyrolysis medium was found to have no measurable affect on cellulose pyrolysis kinetics. The activation energy, pre-exponential factor and reaction order for nitrogen and 1 steam pyrolysis of cellulose are: 36.6 kcal/mol, 6.06 × 109sec-1, 0.46 and 34.2 kcal/mol, 1.67 / 109 sec-1, 0.51 respectively. Apparent differences in the data derived using steam rather than nitrogen as a pyrolysis medium are shown to be artifacts of heat transfer phenomenon within the TGA instrumentation used to measure rate of weight loss. Heat transfer effects observed here may explain the large discrepancies in previously reported studies of cellulose pyrolysis kinetics. Kinetic data given for steam pyrolysis are believed to be more accurate due to the more accurate measurement of sample temperature in the reactor system used for the steam experiments.

ISSN:0010-2202    

DOI:10.1080/00102208008946927

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

ISSN:0010-2202    

DOI:10.1080/00102208008946928

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

摘要:

Nitric oxide and hydrogen cyanide concentration distributions established in an unseeded, laminar, atmospheric methane-air diffusion flame have been analyzed in order to gain insight into the role nitrogen-containing species play in influencing NO formation in such flames. The experimental data indicate that HCN and NO formation are strongly dependent on the local stoichiometry within the flame region. Cyanide formation occurs only within the fuel-rich luminous flame core, presumably via reaction between hydrocarbon radicals and molecular nitrogen or nitric oxide. The cyanide species are subsequently partially converted to nitric oxide on the fuel-lean side of the primary reaction zone, contributing 15-30 percent of the total nitric oxide production by the flame. The nitric oxide concentration profiles peak on the fuel-lean side of the flame in the zone where the thermal production of NO by the extended Zeldovich mechanism occurs.

ISSN:0010-2202    

DOI:10.1080/00102208008946929

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

ISSN:0010-2202    

DOI:10.1080/00102208008946930

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor

ISSN:0010-2202    

DOI:10.1080/00102208008946931

出版商:Taylor & Francis Group    

年代:1980

数据来源: Taylor