Ignition mechanism of subbituminous coal combustion in the stretched-flow field
Journal
Fuel
Journal Volume
69
Journal Issue
6
Pages
696-701
Date Issued
1990
Author(s)
Abstract
The relationship between the ignition mechanism and the stretched-flow characteristics of subbituminous coal particles was experimentally studied. The results indicate that two ignition mechanisms exist, namely heterogeneous char ignition and homogeneous volatile ignition in the vicinity of the stagnation point, and that the determining factor is the global flow stretch rate. In general, the global Damkohler number decreases steadily with Reynolds number, in agreement with the scale analysis prediction. Moreover, the ignition delay time increases with the global flow stretch rate at low Damkohler number. However, when the Damkohler number is high, the reduction in the stretch rate increases the ignition delay time. © 1990.
Type
journal article