南水北调中线天津段泵站输水方案水击等效管计算方法

Equivalent Method of Parallel Pipes for Water Hammer in Tianjin Project in Middel Route of South-to-North Water Transfers

通过研究了解水击条件下k条特性相同管道并联的等效计算模型,在特征线法的基础上,导出了用一条等效管代替并联管道的等效模型:等效管的直径和沿程阻力系数分别是实际管道直径和沿程阻力系数的k^(1/2)倍,等效管的长度和水击波速等于任一实际管道的水击波速和长度;等效泵的机组惯性时间常数、扬程、出口阀门特性与实际泵相同,等效泵的Suter变换流量、力矩特性与实际泵相同,但等效泵的流量等于并联各泵流量之和。

An analysis model for water hammer is investigated, in which k pipes with the same characters connected in parallel are replaced by an equivalent pipe. Based on the characteristic method, the relationships between the equivalent pipe and the parallel pipes are; the diameter and Darcy friction factor of the equivalent pipe equal times of those of any of the parallel pipes respectively, while the length and wave speed of the former are the same as those of the latter; moreover, the machine time constant, head and valve characteristics as well as the pump flow and torque characteristics with respect to Suter functions of the equivalent pump are the same as those of any of the parallel pumps, but the flow of the former should equal the sum of all parallel pumps.