山地城市供水管网分区优化两步法

A two-step method for dividing districts and optimization of water distribution system in mountainous urban

摘要:

为解决山地城市供水管网能耗大、漏损严重、爆管频繁和压力分布不均等问题,建立了山地城市供水管网分区优化模型,提出针对已建成管网的分区优化方法.该法先对已建管网进行分区,然后采用NSGA-Ⅱ算法对各区进行管径组合方案优化.供水管网分区先以两个节点间的高差作为管段的特征值,以管段为单位,兼顾各区内部节点的连通性,依次对每根管段上的两个节点按照一个给定的区内最大允许高差值进行分区,使得每个分区内最高点同最低点的高差均在该值范围内.管径组合方案优化采用NSGA-Ⅱ算法进行求解,该算法以各管段管径逼近其经济管径的方向为遗传变异方向.通过编制计算程序,对某一山区管网进行分区优化设计. 结果表明,采用该法进行分区优化,既能有效地降低供水能耗,又能很好地保证管网内压力分布的均匀性.[JP]

Abstract:

To reduce the energy consumption and solve the problems of serious leakage, frequent bursting of pipes and uneven pressure distribution in water distribution system of mountainous urban, a model for dividing districts and optimization is built. Based on systematized study of water distribution system of mountainous urban, a two-step method is proposed for optimizing the built water distribution system. In the first step, the built network is districted by the algorithm proposed in this paper; in the second step, every sub-district is optimized by NSGA-Ⅱ. In district algorithm, the elevation difference value between two nodes is taken as the characteristic value of corresponding pipe in pipe network. Whether a node in a pipe is classified as one sub-district depends on that the characteristic values between the node and other nodes in this sub-district is within a given maximum allowable elevation difference. The optimization of pipe diameter in every sub-district is solved by NSGA-Ⅱ, which has been successfully used in many multi-objective cases. In the process of evolution, the direction of mutation is that the diameter of every pipe approximates its economic pipe diameter. A practical dividing district and optimization of water distribution system is made by concerned calculation programs. And the results show that the energy consumption is reduced greatly and the pressure distribution of water distribution system is more even by proposed method.