微波加热化学反应所产生的部分特殊现象至今仍没有得到合理解释,非热效应成为一个悬而未决的热点问题.同时,缺少一种真正意义上对微波化学反应器设计的指导理论.因而急需一种微波加热过程中的数值模拟方法来定量研究这些问题.本文利用黄卡玛等提出的经验公式计算得到任意温度和反应时刻的丙酮碘化反应过程中混合溶液的等效介电系数,联合求解了化学反应方程、Maxwell方程和热传导方程,得到反应过程中的电磁场与温度分布.计算结果与实验结果吻合较好,验证了这种数值方法的合理性.为微波加热化学反应的数值模拟提供了一种有效的新方法,并为进一步解释部分特殊现象和进行非热效应的相关机理研究提供可能.
Up to now, there is no reasonable explanation for some special effects in microwave heating on chemical reaction, consequently, the non-thermal effect is an uncertain problem pending solution. At the same time, there are no rigorous and effective methods to guide the design of microwave-assisted chemical reactor. It is necessary to develop numerical methods to simulate the interaction between microwave and chemical reaction. In this paper, the empirical formula of effective permittivity proposed by Huang et al was used to calculate effective permittivity in acetone iodation at any temperature and time of the reaction, and the kinetic equation, Maxwell' s equation, and heat transport equation were solved for the distribution of electromagnetic field and temperature in the reaction process. At last, the calculated results were compared with the measured results to verify this calculation. This method offers high potential application to the explanation of some specific phenomena in the microwave heating for chemical reactions and guides the design of microwave-assisted chemical reactor.