Multiphase models of slag layer built-up in solid fuel gasification and combustion

A steady-state model has been developed to describe the flow and heat transfer characteristics of slag. The model incorporates two submodels for particle capture and wall burning; takes into consideration the temperature and composition dependent properties of slag, the contribution of momentum of captured particles and the possibility of slag resolidification. The model predicts the local thickness of molten and solid slag layers as well as the average slag velocity. Moreover, it is capable of predicting heat losses and the inner as well as outer wall temperatures, taking into account the influence of molten and resolidified slag layers coating the combustor or reactor wall. An equally important issue is the interaction of the particles colliding with the slag layer. High inertia particles tend to rebound whereas slower particles are trapped in the slag layer. Since only trapped particles are relevant to the slag layer built-up, a particle capture criterion for colliding particles is introduced. Particles with combustibles may be captured by the slag layer while they continue to bum at a different rate. To take this into account, a wall burning submodel is proposed to predict a correction factor for both solid and porous char combustion models.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Mechanical Engineering.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2010

Author dc:creator

• Yong, Sze Zheng

Advisor dc:contributor.advisor

• Ahmed F. Ghoniem.

• Mechanical Engineering.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/61928

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/61928