不同四塔组合形式对特大型冷却塔局部风压干扰效应影响研究

Influences of different four-tower combination forms on super-large cooling towers' local wind pressure interference effect

局部风压过大是引起冷却塔局部损伤和破坏的重要因素之一,塔群干扰会显著改变冷却塔局部风压分布模式。以在建世界最高冷却塔(220 m)为工程背景,分别对单体、双塔和5种典型四塔组合方案共353种工况进行测压试验。系统讨论了四塔组合冷却塔群风压干扰因子的分布特性,提炼出组合形式对冷却塔平均和脉动风压分布模式的影响规律,基于数理统计和HHT(希尔伯特—黄)方法对风压信号进行了分解和时频分析。结果表明,不同四塔组合方案均为中间塔受干扰效应影响最大,塔群效应对平均风压的影响主要集中于最小负压区和背风区。固定塔间距下,典型四塔组合形式中对局部风压静力干扰最小的布置形式是菱形方案,对局部风压动力干扰最小的是斜L形方案。

Excessive large local wind pressure is one of important factors causing a cooling tower’s local damage and destruction,and the interference effect of tower groups can significantly change cooling tower’s local wind pressure distribution pattern. Taking the world’s highest cooling tower（ 220 m） now being built as the engineering background,the wind tunnel tests for a single tower,two towers and five typical four-tower combinations were conducted. The distribution features of four-tower combinations’ wind pressure interference factor were discussed. Influence laws of fourtower combinations on distribution modes of cooling towers’ mean wind pressure and fluctuating one were analyzed. Wind pressure signals were decomposed and analyzed in time-frequency domain based on the mathematical statistics and HilbertHuang transformation（ HHT）. The results showed that the interference effect of four-tower combinations on the middle tower is the maximum; the influence of four-tower combination effect on mean wind pressure mainly focuses on the minimum negative pressure area and leeward zone; in 5 typical four-tower combinations,the diamond scheme has the smallest static interference on local wind pressure,and the oblique L-shaped scheme has the smallest dynamic interference on local wind pressure.