具有特殊地形条件的长距离供水工程水锤防护

在长距离供水工程中输水管道一般按地形走势布置。针对一些地形条件特殊的供水工程，本文提出了一种空气罐与出口溢流池联合设置的水锤防护方案，并建立了出口溢流池的数学模型。在空气罐体型一定时，给出了出口溢流池截面积的理论计算公式，有效地减小了在溢流池体型初期选取过程中的盲目性和工作量。结合某长距离输水工程，对比分析了空气罐和出口溢流池联合防护与单纯的空气罐防护对水锤的影响。结果表明空气罐与出口溢流池联合防护方案在前陡后缓的长距离供水工程中能够取得良好的水锤防护效果，且溢流池的溢流水位越高，其对负压的防护效果越好。

Water hammer protection of long-distance water supply projects with special terrain conditions

In a long-distance water supply project, generally the pipeline is arranged according to topography. In view of certain special topographic conditions, this paper presents a water hammer protection scheme of combining an air vessel with an outlet overflow tank, and develops a mathematical model of the overflow tank. For the air vessel of fixed shapes and sizes, we derive a theoretical formula for calculating the cross-sectional area of the tank, which can effectively reduce the blindness and labor cost in the initial selection of the tank parameters. In a case study of a real long-distance water supply project, we compare the water hammer protection performance of the combination scheme with that of no overflow tank. The results show that the combination scheme is better for long-distance water supply projects pipelines with a steep slope in front and a mild slope behind, and that it achieves a better protective effect against negative pressure if a higher overflow threshold level in the tank is adopted.