基于流型结构构造的混合设备优化设计方法

An Approach to Mixing Equipment Optimization Based on Flow Pattern Construction

针对混合过程强化,提出一种基于流型结构构造的混合设备设计方法,即通过构造特定的流型结构达到强化混合的目的.该方法提出以混合过程的熵产作为目标函数,通过变分法构造拉格朗日乘子方程,最终得到熵产达到极值时的流型结构.模拟结果表明所构造的流型结构能有效强化混合过程.为了验证该方法的实用性,以烟气脱硝过程中的氨气/空气混合过程为例,利用该方法得到能够强化混合过程的特定流型结构.最后利用所得到的流型结构,借助多孔介质模型设计出具有内部结构的混合器.

In the present study,an approach tomixing equipment optimization based on flow pattern construction was proposed. Namely,the specific flow pattern was constructed to enhance the mixing process. To obtain the desired flow pattern,a Lagrange multiplier equation,with the entropy generation as the objective function and some global constraints,was constructed. The solution of the Lagrange equation represented the flow pattern extremizing the en-tropy generation subject to a given viscous dissipation rate. The simulation results revealed that the flow pattern con-structed by extremizing the entropy generation contributed to an improvement in mixing performance. In order to demonstrate the applicability of this approach,the mixing for a mixture of ammonia/air involved in the flue gas deni-tration process was studied by constructing the specific flow pattern in which the mixing performance was improved. Finally,according to the specific flow pattern,a mixer with internal structure was designed by employing the porous media model.