空冷岛两风道地下进风数值分析  

Numerical Analysis of Air Cooling Island with Two-Duct Underground Ventilation

作　　者：周兰欣[1] 王喆[1] 王晓斐[1] 杨新健[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6期127-132,共6页Electric Power Construction

摘　　要：直接空冷凝汽器在高空中受环境风的影响,容易出现热风回流和倒灌等问题,影响机组的安全与经济运行,为此提出了空冷岛地下进风方式.以某600 MW直接空冷机组为例,建立空冷岛地下进风的物理模型,利用Fluent软件,采用Simple算法和标准k-ε模型,对采用两风道地下进风布置方式的空冷岛周围空气流场和温度场进行数值模拟;计算了地上、地下进风的空冷岛通风量,分析了在主导风向下风速对直接空冷凝汽器换热效率及压力的影响.计算结果表明：在有环境风的条件下,空冷岛地下进风方式的凝汽器工作性能优于地上进风,在任何风速下都没有出现热风回流和倒灌;在同等条件下,当环境风速大于4 m/s时,地下进风的通风量较地上进风大,换热效率较地上进风高,当风速超过8 m/s后,凝汽器压力比地上进风低7～11 kPa.Due to the influence of environmental wind on direct air-cooling condenser arrangeo laugh in me sky, me not air recirculation and intrusion phenomenon easily occurred, which would affect the security and economics of the unit. Therefore, this paper proposed underground ventilation mode for air cooling island. The physical model of air cooling island with underground ventilation in a 600 MW direct air-cooling unit was established. The air flow filed and temperature filed of air cooling island with two-duct underground ventilation was numerically simulated with using Simple algorithm and standard k-e model in Fluent. Then, the ventilation rate of air cooling condenser with underground ventilation or overground ventilation was calculated, and the impact of wind speed on the heat transfer efficiency and pressure of condenser under dominant wind direction was analyzed. The calculation results show that, under the influence of environment wind, the condenser performance of air cooling island with underground ventilation is better than that with overground ventilation, and there is not hot air recirculation and intrusion phenomenon in any wind speed. When environmental wind speed is over 4 rn/ s, under the same conditions, the ventilation rate of air cooling island with underground ventilation is greater than that with overground ventilation, and the heat transfer efficiency is higher. When environmental wind speed exceeds 8 m/s, the condenser pressure of air cooling island with underground ventilation is about 7 - 11 kPa lower than that with overground ventilation.

关 键 词：空冷岛 地下进风 数值计算 通风量 换热效率 

分 类 号：TK264[动力工程及工程热物理—动力机械及工程]