CFD Based Coal Combustion and Erosion Modelling for A 660 MWE, Super-Critical Tangentially Fired Pulverized Coal Boiler

A CFD based numerical modelling of coal combustion is performed in conjunction with erosion modelling for two samples of blended coal to estimate combustion characteristics, particle and gas flow field and erosion due to ash particles for a large scale, tangentially fired 660 MWe supercritical pulverized coal boiler. The numerical simulation was performed on commercially available CFD code, STAR-CCM+. The Eularian approach is used to model gas phase and Lagrangian approach to model particulate phase. The particle track is obtained in terms of particle velocity and temperature.

The ash particle velocity and trajectories are utilized to predict erosion on boiler components. The coal combustion with coal moisture evaporation, coal devolatilization and char oxidation is considered incorporating eddy break-up model (EBU) for continuous phase. The ash particle track obtained from coal combustion modelling is used to model erosion on internal pressure parts of the boiler, using Oka erosion model.

The simulation results show the good agreement with the flow pattern, gas velocity, particle velocity, and temperature distribution with existing boiler. The predictions made for erosion have been found to be in good agreement with the erosion trend observed on existing boiler.