地铁车站下沉式冷却塔工作环境研究及优化

Working Environment Study and Optimization of Metro Station Sunken Cooling Tower

采用MRF(多重参考系模型)法模拟不同的布置方式对下沉式冷却塔工作环境的影响。模拟结果表明:随着下沉深度增大、塔进风口间距减小,以及塔进风口与下沉坑墙壁间距减小,冷却塔出风热羽流越易受环境风速及冷却塔进口负压影响,回流率越高。影响回流率的因素由大到小依次:下沉深度,塔进风口间距,塔进风口与下沉坑墙壁间距。考虑土建成本和电机噪声影响,建议适当减小下沉坑尺寸、增加下沉深度;并对由此带来的较高回流率提出了两种改善方案:在风筒上安装70cm具有消声功能的渐缩导风管或直导风管。模拟结果表明,渐缩管对出风热羽流的改善效果优于直管段。

The influence of different arrangements on the external flow field of the sunken cooling tower by MRF(multiple reference system mode)is simulated.The results show that with the increasing of the sinking depth,the distance between the inlets of cooling tower will decrease,same is the distance between the cooling tower inlet and the pouring pit;then the hot plume of cooling tower is impacted easily by the ambient wind speed and the inlet negative pressure of cooling tower,and the recirculation rate will be higher.Meanwhile,the important factors that influence the recirculation rate in the order from big to small are the sinking depth,the distance between the cooling towers'inlets and the distance between the inlet and the pouring pit.Considering the civil construction cost and motor noise,it is suggested that the sinking size of the pit should be reduced and the sinking depth be increased properly.Two recirculation rate improvement schemes are proposed:the installation of 70 cm reducing pipe and that of 70 cm straight pipe with muffling functions on the air-duct.Simulation results indicate that the effect of the reducing pipe is better than that of the straight pipe for cooling tower's hot plume.