摘 要：为进一步优化冷风稀释器的结构，提高混合、传热性能，利用有限元分析软件Workbench建立冷风稀释器流场的数值分析模型，研究“突缩-突扩”缩口直径、烟气入口与主管夹角、烟气与空气入口速比等设计参数对设备性能的影响。研究表明： 减小缩口直径、增大烟气入口与主管夹角有利于提高混合气体流速、增强流场湍动状态从而改善混合传热效果；保持合适的烟气与空气入口速比，在增强流动的同时、可以控制流场死区，保证良好的混合传热状态；在烟气与空气入口速比约为0.31时，流场内的混合传热效果达到最佳。

Abstract:In order to further optimize the structure of a cold air dilutor and enhance the mixing and heat transfer performance,a finite element analytic software Workbench was utilized to establish a numerical analytic model for flow fields in cold air dilutors and study the influence of such design parameters as the diameter of the throat of an “abrupt convergingdiverging section”,angle included between the flue gas inlet and the main pipe and ratio of the flue gas and air speed at the inlets on the performance of equipment items.It has been found that to reduce the diameter of the throat and increase the angle included between the flue gas inlet and the main pipe will be instrumental to enhancing the flow speed of the mixed gas,intensify the turbulent flow in the flow field and improve the hybrid heat transfer result.To maintain a proper ratio of the flue gas and air speed at the inlets can promote the flow and at the same time control the dead zone in the flow field and secure a good hybrid heat transfer state.When the ratio of the flue gas and air speed at the inlets is around 0.31,the hybrid heat transfer result in the flow field will achieve the optimum.

TF805