AN IMPROVEMENT IN CHEMICAL KINETIC COMPUTATION WITH STEEP TEMPERATUREDISTRIBUTION

In numerical computation of coal combustion and gasification severe pr oblems can arise owing to large temperature gradients occurring in som e regions. This is because the reaction rate is strongly dependent on temperature due to the Arrhenius law. Thus, a conventional step-wise d istribution of temperature will lead to great errors in the computatio nal results of the reaction rates. A numerical and analytical modifica tion technique to compute the chemical reaction rates in the computati on cell is proposed here. The reaction rates computed from the analyti cally derived modification formula coincides excellently with the resu lts from precise numerical integration. A criterion is also suggested to judge where this modification is necessary, and effects of cell tem perature, activation energy, reaction order and temperature gradient a re treated. Principally, the method proposed here applies equally well to any chemical reaction systems.