外热式回转窑传热过程计算流体力学模拟与强化

Computational Fluid Dynamics Simulation and Intensification of Heat Transfer in Indirectly Heated Pyrolysis Rotary Kiln

基于工业数据,建立了典型无折流板外热式回转窑加热过程的计算流体动力学(CFD)模型,并对窑内温度云图和速度流线图进行了分析,发现热流主体沿中心对称面流动,而内筒的左右两端附近区域流经的热流较少,并且存在热流滞留区。在此基础上,提出了通过添加折流板强化湍流以促进传热的方案,并对改进后的设备结构重新进行了模拟分析,比较了改进前后的换热效果。结果表明:改进后的回转窑整体受热得到强化,传热热流量提升了11.4%。

In this study,the CFD model of the heating process in a typical unbaffled indirectly heated rotary kiln was established based on industrial data,and the temperature contour and velocity streamline were analyzed inside the equipment.It was found that the most heat flowed along the central symmetry plane in the classical unbaffled rotary kiln,and less heat flows through the areas near the left and right ends of the inner cylinder.Based on the heat transfer simulation of the classic rotary kiln,a scheme for enhancing the turbulence by adding baffles to promote heat transfer was proposed.The improved equipment structure was re-simulated numerically,and the heat exchange efficiencies of the classic unbaffled rotary kiln and the modified baffled rotary kiln are compared.The results showed that the heat process of improved rotary kiln was enhanced and the heat transfer heat flow increased by 11.4%.