复杂山地环境下四塔组合特大型冷却塔风致干扰效应研究

摘要

为系统研究复杂山地和周边建筑对超规范190 m高度限直特大型冷却塔四塔组合的风致干扰效应,以国内在建210 m高特大型冷却塔四塔组合为对象,基于计算流体动力学(CFD)方法对不同来流风向角下考虑复杂山地(高度接近冷却塔喉部标高且距离塔体很近)四塔组合冷却塔的周围流场进行了数值模拟,并将单个冷却塔的风压分布与规范及实测曲线进行对比验证了数值模拟的有效性.在此基础上,对比分析了考虑复杂山地和周边建筑干扰时冷却塔表面最大负压、基于最大负压的干扰因子和平均风压分布特性,同时通过对最不利工况下冷却塔周边速度和涡量变化进行分析提炼出山地和塔群之间的风致干扰机理.研究表明复杂山地对冷却塔群来流湍流和风压分布模式的影响显著,同时受到冷却塔和建筑物之间“夹道效应”的影响,此时最不利工况下冷却塔基于最大负压的干扰因子最大可达1.43,远大于没有复杂地形下工程常见多塔干扰因子.主要研究结论可为此类考虑复杂山地环境的特大型冷却塔的群塔干扰因子取值提供参考.%In order to systematically study the wind-induced interference effect of complex mountain environment and surrounding buildings on a super large cooling 4-tower group with the height over the 190 m limit of the national standard,a group of four 210 m high large cooling towers under domestic construction was taken as astudy object.The flow field around the cooling towers group near a complex mountain (the height close to the cooling tower throat elevation and the distance close to the tower body) under different angles of wind flow was simulated based on the computational fluid dynamics (CFD) method.The wind pressure distribution of single cooling tower was compared with those of the national standard and the tested curves to verify the effectiveness of the numerical simulation.Furthermore,maximum negative pressures,interference factors and average wind pressure distribution characteristics of cooling tower surfaces were contrastively analyzed considering interferences of complex mountain and surrounding buildings.Then the wind-induced interference mechanism between mountain and towers was deduced based on the analysis of velocity and vorticity changes around cooling towers under the most unfavorable conditions.The results showed that complex mountain has a significant influence on flow turbulence and wind pressure distribution patterns of the cooling towers group;influenced by the "way effect" between cooling towers and buildings,the interference factor under the worst condition is up to 1.43,it is significantly greater than the common interference factor without complex landform;main conclusions can provide a reference for choosing the interference factor of such a super large cooling towers group considering complex mountain environment.