Modeling of Pulverized Coal Combustion in Cement Rotary Kiln
In this paper, based on analysis of the chemical and physical processes of clinker formation, a heat flux function was introduced to take account of the thermal effect of clinker formation. Combining the models of gas-solid flow, heat and mass transfer, and pulverized coal combustion, a set of mathematical models for a full-scale cement rotary kiln were established. In terms of commercial CFD code (FLUENT), the distributions of gas velocity, gas temperature, and gas components in a cement rotary kiln were obtained by numerical simulation of a 3000 t/d rotary kiln with a four-channel burner. The predicted results indicated that the improved model accounts for the thermal enthalpy of the clinker formation process and can give more insight (such as fluid flow, temperature, etc,) from within the cement rotary kiln, which is a benefit to better understanding of combustion behavior and an improvement of burner and rotary kiln technology.
Modeling of coal devolatilization and its effect on combustion calculations
Etude de la devolatilisation du charbon a partir de 3 modeles: une reaction globale simple, deux reactions competitives, et des reactions paralleles multiples. Comparaison de ces trois cinetiques pour des vitesses de chauffe de 10 4 , 10 5 et 10 6 K/s et des temperatures finales de 1273 et 1773 K. Les resultats calcules a partir des modeles 2 et 3 correspondent assez bien aux resultats experimentaux
The Determination of Physicochemical Characteristics of Biodiesel and Its Blending Oils
The viscosity,combustion heat,sulfur content,carbon residue,ash,flash point,moisture and cetane value of biodiesel and its blending oils with diesel were determined.The influence of temperature on the viscosity was studied,and the physicochemical characteristics of biodiesel and its blending oils were compared with diesel.The results indicated that biodiesel and its blending oils had some superior performances and good application prospect.