导流装置对直接空冷单元流场特性影响的数值模拟

横向风会造成直接空冷凝汽器换热效果严重恶化,横向风对直接空冷凝汽器换热效果影响的问题亟待解决。在1000 MW直接空冷机组凝汽器的典型结构上,建立带有导流叶片装置的直接空冷凝汽器三维流动模型,利用CFD模拟不同速度的横向风条件下直接空冷单元A字型内部的空气流场。研究表明:在横向风条件下空冷单元A字型内部会产生回流区,随着风速增大,回流区域影响范围逐渐增大;加装外导流装置可以减小横向风的影响,增加风机进风量,提高空冷单元的换热效率。

Numerical Simulation on Influencing of Flow Guiding Device upon Flow Field of Direct Air Cooled Condenser

The cross wind caused a serious deterioration in heat transfer effect of direct air-cooled condenser(DACC),the problem of cross wind to DACC is to be solved urgently.Based on the typical structure of DACC with flow guiding device of 1000MW unit,the three-dimensional models for the flow are worked out.Through analysis based on Computational Fluid Mechanics(CFD),the impact rules of cross winds on internal air flow field of DACC are studied.The results show that: in the environmental wind conditions,recirculation zone are produced inside the DACC units;with the wind speed increased,recirculation zone increased;installing the flow guiding device can minimize the impact of cross winds,raise airflow rates and improve the efficiency of the condenser heat transfer.