Abstract
Evaluating ash slagging can alleviate the operational problems and improve the efficiency of coal-fired boilers. This paper presents methods to quantify the extent of slagging in a 500 MWe tangential firing boiler by determining the thermal resistance and relating it to ash properties. To determine the thermal resistance by slagging, the operational data of the boiler were extracted for six coal-blend cases and analyzed using a one-dimensional process model. Although the conventional slagging indices based on ash composition have generated conflicting results, new indices based on thermo-mechanical analysis (TMA) of the coal-blend samples provided reasonable agreement with the operational data. In particular, the second peak of the TMA associated with the growth rate was correlated with the thermal resistance of the superheaters, and the third peak representing the slag melting was inversely correlated with that of the furnace wall. It was also found from the numerical modeling of the slag flow on the furnace wall that the critical viscosity temperature at 25 Pa·s can be positively related with the thermal resistance, and consequently, with the slagging propensity of specific coal ashes.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
