CFD analysis of steam superheater, transient state

Abstract

Nowadays, industry requirements referring to the optimization, not only demand better efficiency ordurability but also the lower total cost of the project. Maximum temperatures, allowablestress and economics determine materials used during the engineering process. Moreover, different materials in different parts of superheater can be used. Regarding the steady–state, calculations can be derived without major difficulties but transient–state is a much more complex issue, where Computational Fluid Dynamics can be applied. CFD as an engineering tool, that gives a better understanding of the problem, is more and more popular during the optimization process. Appropriate knowledge about heat transfer, fluid dynamics, finite element method is required to find the solution to the given question. The paper presents a CFD analysis of the transient-state of the steam boiler superheater when attemperator is running. Temperature distribution of the steam, flue gas and maximum wall temperature were determined.

Performance degradation analysis of a medium pressure superheater due to tube deactivation

“…Superheater tubes are reported to be the most common malfunctioning component in boilers. Approximately 40% of forced boiler shutdowns are caused by damages in superheater tubes [11]. High operating temperature is the main reason for frequent failures of the steam superheater due to creep as well as formation of heavy clinkers on the tube surfaces, leading to localised tube overheating and concentrated flue gas flow over a specific zone of the tube bundle [12].…”