大型冷却塔风致响应的干扰效应

Interference effect of wind-induced response on large hyperbolic cooling tower

为了研究渡桥电厂冷却塔的群塔干扰效应,采用呈倒品字型布置的3个冷却塔进行简化分析.变化塔间距和风向角,进行180个工况的风洞试验.基于试验结果进行风致响应的计算和干扰效应分析,将干扰计算结果作为渡桥电厂塔群干扰的参考.研究表明:在单塔情况下,冷却塔横风向底部剪力系数的平均值几乎为零,极大值较大;冷却塔壳体在风荷载作用下拉应力主要出现在迎风面的中下部;在三塔情况下环向薄膜应力的干扰系数均小于1,子午向薄膜应力极大值的干扰系数基本上均大于1,最大值达1.57.

The interference effect between three cooling towers that are arranged in reverse triangle was analyzed as a simplified model in order to investigate the grouping effect of wind loadings acting on Ferrybridge cooling towers.For three towers condition,180 wind tunnel tests with respect to tower distance and wind azimuth were conducted.The wind induced responses based on the test results were calculated and the interference effect for 180 test conditions was analyzed.Then the referenced interference values for the Ferrybridge cooling towers were given.Results showed that the mean value of base shear coefficient in the crosswind direction was nearly zero,whereas the peak value was large under the isolated tower condition.The tensile stresses on the tower shell under wind loading were mainly located on the middle and lower parts of the shell.For the three towers condition,the interference factors of the latitudinal membrane stress were all less than 1,whereas the interference factors of the peak meridian membrane stress were mostly bigger than 1 with the biggest value reaching 1.57.