High temperature transient analysis for nitride bonded silicon
carbide ceramics in over 700 megawatt coal fired boilers
was completed to identify the source of failure due to thermal gradient
self-stressing. The analysis attempted to design a lower cost solution
to replace conventional steel designs. The project involved a retro fit
design limitation of the proposed ceramic part, and included fixed constraints
based on the established flow characteristics of the burner. A proprietary
finite element thermal-structural analysis was completed which
included details of the air flow and coal particle system, effects on thermal
loading due to the coal ash debris, effects of heat conduction, heat convection
and thermal radiation from the flame front. The novel aspects of the analysis
showed the competition between the heat conduction and convection effects
that caused a severe self-stressing structural loading of the ceramic part.
A new conceptual design using organic shapes was rendered
and recommended to the client.