DEVOLATILIZATION TEMPERATURE HISTORIES FOR COAL PARTICLES SUBJECTED TO COMBUSTION LEVEL HEAT FLUXES

Historically Black College and University and Other Minority Institutions

Ramanathan Sampath ; Esmail R. Monazam ; Daniel J. Maloney1 2 3

Others  :  http://www.netl.doe.gov/publications/proceedings/99/99hbcu/sampath.pdf
PID  :  25512

来源: CEUR

【 摘 要 】

Devolatilization is an important initial step in virtually all commercial fossil fuel applications such as combustion, gasification, and liquefaction. Characterization of the temperature history of pulverized coalparticles under high heating rates, representative of coal combustors, is critical to the understanding ofdevolatilization.To this end, 28 single coal particles were caught in an electrodynamic balance and their volume, externalsurface area, mass, and density were measured. The same single particles were then heated bidirectionallywith a pulsed (10 ms pulse width) Nd:YAG laser beams of equal intensity with heating rates (104-107 K/s)representative of coal combustors. The temporal power variation in the laser pulse was monitored for usein the heat transfer analysis by an ultra-fast fiber optic uv light transmitter included in the beam path andcoupled to a silicon photodiode. Transient surface temperatures of the particles were measured using asingle-color pyrometer. Dynamics of volatile evolution and particle swelling were recorded using well established time-resolved high-speed cinematography. Presently, heat transfer analysis for the devolatilization time-scales, and temperature histories is in progress. In this paper, details of the experimental activities conducted are presented. Also, the modeling activities on-going are briefly discussed.