Universal Devolatilization Process Model for Numerical Simulations of Coal Combustion

A universal devolatilization process (UDP) model, considering the effect of particle instantaneous heating rates and coal types, is developed for an accurate prediction of the devolatilization process in numerical simulations of coal combustion. This model is developed in the framework of a competing two-step model based on the fitting and correlation works from the database, which is constructed from the devolatilization process of 23 coal types under 40 heating rates predicted by the chemical percolation devolatilization (CPD) model. The kinetic parameters are determined in terms of coal types and instantaneous heating rates with the correlations obtained. The thorough validations of the UDP model, including the internal and external validations, are carried out through comparing the devolatilization process of the 23 selected coals and 10 other coals predicted by the UDP model and the CPD model. It is found that the UDP model can accurately predict the coal devolatilization process for a wide range of coal types and heating rates with a less computational cost, which will significantly improve the efficiency and accuracy of numerical simulations of coal combustion. The devolatilization components are not taken into account in the present study and will be investigated in future work.