Auto-ignition and upper explosion limit of rich propane-air mixtures at elevated pressures.
ABSTRACT The auto-ignition limits of propane-air mixtures at elevated pressures up to 15 bar and for concentrations from 10 mol% up to 70 mol% are investigated. The experiments are performed in a closed spherical vessel with a volume of 8 dm3. The auto-ignition temperatures decrease from 300 degrees C to 250 degrees C when increasing the pressure from 1 bar to 14.5 bar. It is shown that the fuel concentration most sensitive to auto-ignition depends on initial pressure. A second series of experiments investigates the upper flammability limit of propane-air mixtures at initial temperatures up to 250 degrees C and pressures up to 30 bar near the auto-ignition area. Finally the propane auto-oxidation is modelled using several detailed kinetic reaction mechanisms and these numerical calculations are compared with the experimental results.
- European Urology Supplements - EUR UROL SUPPL. 01/2011; 10(9):652-653.
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ABSTRACT: The lower and upper flammability limits of a fuel are key tools for predicting fire, assessing the possibility of explosion, and designing protection systems. Knowledge about the risks involved with the explosion of both gaseous and vaporized liquid fuel mixtures with air is very important to guarantee safety in industrial, domestic, and aeronautical applications. Currently, most countries use various standard experimental tests, which lead to different experimental values for these limits. A comprehensive literature review of the flammability limits of combustible mixtures is developed here in order to organize the theoretical and practical knowledge of the subject. The main focus of this paper is the review of the flammability data of ethanol-air mixtures available in the literature. In addition, the description of methodology for experiments to find the upper and lower limits of flammability of ethanol for aeronautical applications is discussed. A heated spherical 20L vessel was used. The mixtures were ignited with electrode rods placed in the center of the vessel, and the spark gap was 6.4mm. LFL and the UFL were determined for ethanol (hydrated ethanol 96% °INPM) as functions of temperature for atmospheric pressure to compare results with data published in the scientific literature.Journal of hazardous materials 09/2012; · 4.14 Impact Factor
Conference Paper: Subband coding with modified multipulse LPC for high quality audio[Show abstract] [Hide abstract]
ABSTRACT: A modified multipulse excitation linear predictive coding (MMPLPC) structure combined with a subband (SB) technique is proposed to encode audio signals of 15-kHz bandwidth. The bit allocation is dynamically adapted according to both the signal power in different subbands and a perceptual hearing model. Informal listening tests showed that high fidelity audio coding can be achieved at bit rates of less than 86 kbit/s by SB-MMPLPC.< >Acoustics, Speech, and Signal Processing, 1993. ICASSP-93., 1993 IEEE International Conference on; 05/1993