基于加权最小二乘法的供水管网节点流量校核
2016-07-11范江杜坤周明徐冰峰龙天渝
范江 杜坤 周明 徐冰峰 龙天渝



摘要:管网水力模型是实现供水系统现代化管理的重要工具,要使水力模型能比较准确地反映管网真实运行状态,达到预期使用目的,其中的参数需要校核。将管网节点流量校核作为优化问题,采用加权最小二乘法逐步迭代求解,与已有研究相比,采用矩阵分析法推导供水管网雅克比矩阵解析式,引入水量分配矩阵聚合节点流量,将欠定问题转化为超定,提高了校核的计算效率和结果的可靠性。采用简单管网阐明了雅克比矩阵的计算、节点流量的聚合及梯度向量的构造,利用实际管网验证了方法的实用性。
关键词:供水管网;节点流量校核;加权最小二乘法;雅克比矩阵;解析式
中图分类号:TU 991.32
文献标志码:A 文章编号:1674-4764(2016)03-0073-07
Abstract:Hydraulic model of water distribution systems (WDSs) is an essential tool to realize modernization management of WDSs. To make the model capable of reflecting the systems behavior with reasonable accuracy and achieving intended purposes, the parameters in it should be calibrated. The nodal demand calibration of WDS models is formulated as a nonlinear optimization problem, which is then solved iteratively using weighted least squares method. Comparing to previous studies, the proposed method deduces the analytical solution of Jacobian matrix of WDSs based on matrix analysis method, and translates the under-determined problem to over-determined by aggregating the nodal demand using demand allocation matrix, such that the computational efficiency and the reliability of calibration results were improved. A simple network is used to illustrate the computation of Jacobian matrix, the construction of gradient vectors and the aggregation of nodal demand. The practicability of the method is further validated by a real network.
Keywords:water distribution system; nodal demand calibration; weighted least squares algorithm; jacobian matrix; analytical solution
管网水力模型不仅能用于指导供水调度、优化运营管理,还是开展其他相关研究的基础,如管网水质模拟、突发性水质污染事件预警与定位等。随着社会经济发展,各地自来水厂开始投入大量人力与财力构建或完善管网水力模型。管网水力模型校核,或称管网参数校正,是指通过调整模型中预先设置的水力参数,使模型计算值与监测值匹配的过程,其目的在于使构建的水力模型能比较准确地反映管网的真实运行状态,达到预期使用目的。在构建的管网水力模型中,由于节点流量随时间不断发生变化,为时间“常变量”,需要进行实时校核[1]。
针对管网节点流量校核,吴学伟等[2]尝试以节点水压为已知量计算节点流量,并采用实验室管网进行验证,结果表明,对实验室小型管网状态估计精度较高,但对于实际大型管网的工况分析有待进一步研究。……
