A numerical simulation of pulverized coal combustion employing a tabulated-devolatilization-process model (TDP model)

摘要

A new coal devolatilization model employing a tabulated-devolatilization-process model (TDP model) is developed, and its validity is investigated by performing a numerical simulation of a pulverized coal combustion field formed by an industrial low-NO_x burner in a 100 kg-coal/h test furnace. The predicted characteristics of the pulverized coal combustion field obtained from the simulation employing the TDP model are compared with those employing the conventional devolatiiization model, those employing the two competing reaction rate model, and the experiments. The results show that drastic differences in the gas flow patterns and coal particle behavior appear between simulations. In particular, the recir-culation flow behavior is strongly affected by the difference in the coal devolatilization model because of the difference in the volatile matter evolution rate. The TDP model captures the observed behavior of the coal particles in the experiment better than the other models. Although it is considered that by adjusting the devolatilization parameters the prediction similar to the TDP model is also possible by the other models, appropriate devolatilization parameters are automatically set to particles depending on the particle heating rate without trial-error method by employing the TDP model.