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为探究冷却塔群塔布置对整体风荷载和风致响应的不同干扰机理,通过刚体模型单塔和群塔风洞试验和结构动力响应计算,以风压环向分布模式对阻力系数C_D和子午向拉力F_T的不同影响为基础,对两者的干扰机理分别进行了分析。群塔布置下,目标塔表面风压的干扰效应主要表现为:前塔的遮挡效应(Ⅰ),主要使迎风区风压均值下降;侧边塔和侧后塔的吸力效应(Ⅱ),主要使背风区吸力均值增加;前塔和侧前塔的尾流涡激效应(Ⅲ),主要使迎风区和侧风区的脉动风压增加。这三种效应对C_D和F_T的影响并不相同:C_D主要受迎风区和背风区风压影响,所以效应Ⅰ和效应Ⅱ分别使C_D均值减小和增加,效应Ⅲ则使C_D根方差明显增加;F_T主要受迎风区和侧风区风压影响,所以效应Ⅰ和效应Ⅲ分别使F_T减小和增加,背风区风压的变化对F_T几乎没有影响。与单塔相比,各种群塔组合下F_T增加的主要原因是脉动风压的急剧增加。在工程常用塔间距范围内,干扰效应对风向的敏感性明显大于对塔间距的敏感性,群塔双排布置时的不利风向范围明显大于单排布置。渡桥电厂的群塔双排布置形式和事故当天风向恰使后排塔的风致响应有所增加。
In order to explore the different disturbing mechanism of cooling tower group tower layout on the overall wind load and wind response, through the rigid-body model single tower and group tower wind tunnel test and structural dynamic response calculation, the wind pressure distribution model is used to analyze the drag coefficients C_D and meridional Rally F_T different effects based on the interference mechanism of the two were analyzed. The disturbance effect of the wind pressure on the surface of the target tower is mainly as follows: the obstruction effect of the front tower (Ⅰ) mainly decreases the mean value of the wind pressure in the windward area; (2) the suction effect of the side and rear towers So that the mean value of suction in the leeward zone increases. The wake vortex effect in the front tower and the side tower (Ⅲ) increases the fluctuating wind pressure in the windward and crosswind areas. The effects of these three effects on C_D and F_T are not the same: C_D is mainly influenced by the wind pressure in the windward and leeward regions, so effects I and II reduce and increase the C_D mean, respectively. Effect III increases the variance of C_D significantly ; F_T is mainly affected by the wind pressure in the windward and crosswind areas, so effects I and III reduce and increase F_T, respectively, whereas changes in the leeward wind pressure have almost no effect on F_T. Compared with single tower, the main reason for the increase of F_T under various group and tower combinations is the sharp increase of fluctuating wind pressure. In the range of commonly used tower pitches, the sensitivity of the interference effect to the wind direction is obviously greater than the sensitivity to the tower spacing. The range of unfavorable wind direction when the double-row arrangement of group towers is obviously larger than that of the single-row arrangement. Dushuqiao power plant group towers double-row layout and wind direction on the day just to make the back row of the wind tower response has increased.