空冷岛加装挡风墙的数值模拟  

Numerical Simulation of Air Cooling Island with Windbreak

作　　者：周兰欣[1] 王晓斐[1] 王喆[1] 吴瑞康[1] 

机构地区：[1]电站设备状态监测与控制教育部重点实验室(华北电力大学),河北省保定市071003

出　　处：《电力建设》2014年第5期88-93,共6页Electric Power Construction

摘　　要：在大风情况下,空冷凝汽器换热效率由于热风回流和"倒灌"现象的共同作用而降低。为了改善环境风对空冷凝汽器的影响,提出了在空冷岛背风侧(主导风向下)加装挡风墙的方案。以某600 MW直接空冷机组为例,利用计算流体动力学(computational fluid dynamics,CFD)软件对空冷岛外部流场进行数值模拟,分析主导风向、主导风向相反风向情况下,不同风速时挡风墙对空冷凝汽器换热效率的影响。结果表明:在主导风向下,加装挡风墙使空冷单元空气流量大幅度增加,空冷凝汽器换热效率提高;在主导风向相反风向下,加装挡风墙造成空冷岛背风侧出现热风回流,空冷凝汽器换热效率降低,在背风侧水平挡板边缘处竖直加装一定高度的挡风墙可以改善热风回流现象。Under the condition of strong wind,the combination of hot air recirculation and ＇ intrusion＇ phenomenon results in the reduction of heat transfer efficiency of air cooling condenser.In order to improve the impact of environmental wind on air cooling condenser,this paper proposed the scheme that installed the windbreak on the leeward side of air cooling island（in the dominant wind direction）.Taking a 600 MW direct air cooling unit as an example,the external flow field of air cooling island was numerically simulated with using CFD（computational fluid dynamics） software.The impact of windbreak on heat transfer efficiency of air cooling condenser with different wind speed in the dominant wind direction or the opposite direction was analyzed.The calculation results show that,in the dominant wind direction,the air flow of air cooling unit with windbreak significantly increases,and the heat transfer efficiency of air cooling condenser is improved;in the opposite direction,the installation of windbreak make the hot air recirculation occur on the leeward side of air cooling island and the heat transfer efficiency of air cooling condenser decrease,and the windbreak with certain height installed at horizontal baffle edges on leeward sid can improve the phenomenon of hot air recirculation.

关 键 词：空冷岛 热风回流 倒灌 挡风墙 数值模拟 

分 类 号：TK264.11[动力工程及工程热物理—动力机械及工程]