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针对高频等离子体化学气相沉积法制备纳米WOx粉体过程中传热和产物颗粒长大过程进行了阐述,建立了高频等离子反应器内温度场二维轴对称模型以及产物颗粒长大动力学模型。采用有限差分法和C语言对温度场模型中涉及到的偏微分方程进行了编程求解,得到了模型的数值解。计算结果表明热辐射对温度分布有着重要的影响;颗粒粒径主要由长大区温度,浓度以及停留时间来决定。在实验工艺条件下,求解颗粒长大动力学模型,得到纳米WOx最终粒径在20～60nm范围,且与实验结果对比可知:模型数值解与实验值相接近。
The process of heat transfer and product particle growth during the preparation of nano-WOx powder by high-frequency plasma chemical vapor deposition was described. The two-dimensional axisymmetric model of temperature field in high frequency plasma reactor and the particle growth kinetics model. Finite difference method and C language were used to solve the partial differential equation involved in the temperature field model. The numerical solution of the model was obtained. The calculation results show that the thermal radiation has an important influence on the temperature distribution; the particle size is mainly determined by the temperature, concentration and residence time in the growing area. Under the experimental conditions, the kinetic model of particle growth was solved to obtain the final particle size of WOx in the range of 20 ~ 60 nm. Compared with the experimental results, it can be seen that the numerical solution of the model is close to the experimental value.