Library Subscription: Guest

ISSN Online: 2377-424X

ISBN Print: 978-1-56700-474-8

ISBN Online: 978-1-56700-473-1

International Heat Transfer Conference 16
August, 10-15, 2018, Beijing, China

NUMERICAL STUDIES OF COAL PARTICLE HEAT TRANSFER AND IGNITION MODE OF TWO INTERACTING COAL PARTICLES

Get access (open in a dialog) DOI: 10.1615/IHTC16.cat.023167
pages 1557-1564

Abstract

The interaction between two coal particles in heat transfer and combustion process is very important for coal ignition and subsequent burning. To gain fundamental and quantitative understanding of the interactions in pulverized coal ignition time and combustion process, a two-dimensional mathematical model was developed to simulate the combustion characteristics of two interacting coal particles arranged in the upstream-downstream configuration in a hot laminar flow. The model took into account coal particle heating, coal devolatilization, volatile burning, and the heterogeneous particle surface reactions by using the commercial software FLUENT and its UDF based on coal devolatilization and char reaction models. Two ignition time criteria are applied to coal particle and homogeneous ignition time. The effects of gas velocity on the coal ignition time were numerically investigated at different particle separation distances. The results show that gas velocity has a significant effect on the coal particle heating and burning processes, the interactions between the two coal particles also have a great effect on their ignition time and burning process and are strongly dependent on the separation distance. The inlet gas velocity has a little influence on the upstream particle ignition time, but it has a great influence on the ignition time of the downstream particle. Increasing the particle spacing, the ignition time decreases first and then increases, especially for the homogeneous ignition time.