供水系统运行状态实时模拟方法

建立了供水系统运行状态实时模拟模型,在已知给水管网拓扑结构的基础上,利用实测的系统总供水量和少量管网测压点数据,实时模拟管网所有节点水压.利用Rosen投影梯度法求解模拟模型,对某供水系统的模拟计算表明,该模型计算精度较高,速度较快,能满足供水系统实时模拟的需要.     

供水管网优化研究概述

简述供水管网的优化设计建模和优化算法,重点介绍了供水管网的多目标优化设计及遗传算法用于供水管网的最优化理论,并针对该方法用于供水管网优化设计的缺点,提出了模拟退火遗传算法求解给水管网管径优化解的计算思路。     

城市给水管网水力计算系统研究

通过研究给水管网系统特征,分析了给水管网水力平衡计算理论,建立了城市给水管网水力计算模型,利用牛顿迭代法求解模型的数值解,为得到最优结果,引入步长因子A对系统初值进行修正,最终得到符合实际工况的管网运行数据。     

谱聚类在给水管网分区优化中的应用

利用图划分技术和图论算法实现给水管网分区。根据给水管网分析,确定分区数量,建立权重邻接矩阵并计算图拉普拉斯矩阵及其特征向量,通过多路图划分对隐藏在特征向量中的聚类信息进行数据挖掘,采用遗传算法和K均值方法实现最佳节点聚类。利用PageRank和最短路径算法确定水表和阀门位置,最终实现给水管网优化分区。实际给水管网模型分区实例表明所提方法在给水管网分区的有效性。     

基于遗传算法的大型给水管网模型C值校核

针对给水管网模型建立过程中存在的偏差问题,通过收集管网运行中的实测数据及对管道合理分组,建立了给水管网的校核模型,运用遗传算法对不同管材、管径及铺设年代的管道的摩阻系数进行了校核.计算结果表明,该模型的模拟值与实测值基本吻合,可以达到预定的精度要求.     

运行工况实时模拟基础上的给水管网优化调度方法研究

利用实测的给水管网总供水量和少量测压点水压数据,实时模拟管网所有节点水压和节点流量.在此基础上对管网运行压力分布作出评判,再进行优化调度,确立了运行工况实时模拟基础上的管网优化调度模式.建立了运行工况实时模拟基础上的管网优化调度模型,采用顺路返回枚举算法求解优化调度模型.编制了给水管网优化调度计算程序,对示例管网进行了优化调度计算,得出了优化调度方案.优化调度计算稳定,计算速度较快,能满足给水管网实时优化调度的需要.     

基于NSGA-Ⅱ的给水管网压力监测点多目标优化布置

针对给水管网压力监测点优化布置过程中采用单目标函数得到的优化结果不能代表多方面综合因素的问题,以监测点压力监测范围及监测点覆盖节点需水量作为目标函数,管网水力连通性、管网节点压力相关性、管网节点水量影响条件作为约束条件建立多目标压力监测点优化布置数学模型,并利用Matlab平台通过非支配排序遗传算法(NSGA-Ⅱ)求解。将该模型应用于某园区实际管网中,并分析不同约束条件的参数取值对模型所得优化结果的影响程度,以提高监测点布设方案的代表性,同时也验证了NSGA-Ⅱ求解多目标给水管网压力监测点优化布置模型的有效性。     

基于kriging的给水管网节点压力插值研究

为了及时准确了解给水管网的运行状态,针对管网水力状态在时间和空间上的随机性,将地统计分析中的Kriging插值法应用于管网节点的压力预测.鉴于Kriging插值中距离的定义决定了插值的效果,为此,结合给水管网系统的特殊性,提出了节点压力计算中节点间相对距离的定义,形成了一种新的给水管网节点压力的宏观预测方法.并通过仿真对所提出的计算方法进行了验证,结果表明该方法的预测结果精度较高、方法可行.     

遗传算法在消火栓供水优化问题中的应用

基于现有市政给水管网和灭火作战指挥原则,构建了消火栓供水多目标优化模型。利用MATLAB编程实现遗传算法,同时调用EPANET软件对给水管网模型进行水力平差计算适应度,迭代进化求得优化模型的最优解,科学选取战时所需要的消火栓,使其既能快速出水,又能确保供水稳定不中断。以华南某行政区为例计算,结果表明,利用该方法选取消火栓,供水的可靠性和经济性可达到最佳。     

城市给水管网改扩建优化设计研究

以克拉玛依市给水管网改扩建工程为实例,针对改扩建优化设计为复杂的非线性规划问题,决策变量、离散变量及目标函数为多峰值函数的特点,采用基于整数编码的改进遗传算法对所建模型进行求解。将优化模型结果与传统设计的模型进行比较,说明该模型算法是可行的,减少了整个城市的管网建设投资和运行管理费用。     

供水管网状态估计研究进展

系统地总结了供水管网状态估计的研究内容，包括参数估计、校核评估、数据（样本）设计。20年来国内外学者根据优化和统计分析理论并结合现场试验，提出了系统的理论分析和数值方法，近年来管网不确定分析理论被引入到管网校核评估和管网率定的样本数据设计中。此外还介绍了国外供水管网状态估计的精度标准。指出虽然相关理论研究有了较大进展，但应用研究相当薄弱，大型管网模型成功率定的实例还鲜有报道，今后应加强实用研究。     

Early determination of toxicant concentration in water supply using MHE

In this paper, a novel application of state estimation in environmental engineering is presented. The objective is to use on-line estimation techniques including moving horizon estimator (MHE) and extended Kalman filer (EKF) for an early concentration estimation of toxic agent presented in water supply. These estimation techniques (MHE and EKF) can be integrated in an early warning system of several features including the ability of early detection and quantification of the presence of toxicants in the water supply system. The estimation is based on dynamic measurements generated by a real-time cell electronic sensor (RT-CES) and on existing cytotoxicity mathematical dynamic models.     

供水管网的多水质组分预测建模研究

现有的城市供水管网水质预测模型仅针对单一水质组分,不足以全面反映管网水的水质状况.为此,以天津市某高校的校园管网为研究对象,在结合水力分析的基础上,同时对余氯和浊度进行预测和模拟建模.在模型的求解上,经对多元回归、人工神经网络和支持向量机进行详细的分析后,选用了较为成熟的BP算法.结果表明,模型预测的相对误差平均为20%左右,能满足实际应用的要求.     

Water quality parameter estimation for water distribution systems

Wall decay coefficients vary between pipes and must be determined indirectly from field measured concentration data. A general calibration model for identifying these parameters is formulated here. The problem is solved using the shuffled frog leaping algorithm optimisation algorithm that is coupled with hydraulic and water quality simulation models using the EPANET Toolkit. The methodology is applied to two application networks to examine the robustness of the parameter estimation algorithm and to study the effects of the network flow conditions, data availability, model simplification, and measurement errors. To that end, different field conditions are considered, including a network with or without tanks, altering disinfectant injection policies, changing measurement locations, and varying the number of wall decay coefficients. Results from conditions with exact data show that the solution approach is robust and consistently finds the true parameter values. However, when the number of decay coefficients is increased, results suggest that the distribution and number of meter locations affects model parameter identifiability. It is also noted that the parameter sensitivity is relatively small and related to the velocities in the network. Finally, isolated tracer data can supplement information from normal operating conditions to improve decay coefficient calibration but, if sufficient data is available, the incremental improvement may not be significant. To confirm this result, model calibration must be extended to parameter and model prediction uncertainty.     

城市供水管网仿真模拟分析平台的开发与应用

针对人们对城市供水安全性要求日益提高、供水系统的规模不断扩大、复杂性随之提高等问题,对城市供水管网仿真建模与软件开发技术进行了系统研究．首先,对供水管网参数测试分析技术进行研究,较为准确地掌握了整个供水管网的用水量负荷、用户用水模式及变化规律、压力分布规律及主要供水管段的实际过流能力等状况,建立供水管网仿真模拟数据库．在此基础上,以供水管网科学合理运行、保障供水水质等为目标,结合供水管网在线监测技术,以某城市开放式区域供水管网为例,建立了该区域供水管网微观水力模型,并开发了城市供水管网仿真模拟分析平台．该平台具有良好的扩展性及实用性,目前正在某城市进行应用．     

住宅生活给水管网水力计算程序设计

根据住宅建筑给水管网的水流特点及其水头损失计算公式 ,确定了采用有限元法分析住宅建筑给水管网水力平衡计算的数学模型 ,将各个管段的单元矩阵方程集合为供水管网的整体矩阵方程 ,通过引入节点水压边界条件并求解管网整体矩阵方程——对称正定线性方程组 ,得出各项水力要素。给出了计算程序框图 ,编写了通用电算程序 ,经实例计算表明 ,能够快捷准确地完成住宅建筑给水管网的水力平衡计算 ,满足设计计算要求。     

State estimation for large-scale wastewater treatment plants

Many relevant process states in wastewater treatment are not measurable, or their measurements are subject to considerable uncertainty. This poses a serious problem for process monitoring and control. Model-based state estimation can provide estimates of the unknown states and increase the reliability of measurements. In this paper, an integrated approach is presented for the optimization-based sensor network design and the estimation problem. Using the ASM1 model in the reference scenario BSM1, a cost-optimal sensor network is designed and the prominent estimators EKF and MHE are evaluated. Very good estimation results for the system comprising 78 states are found requiring sensor networks of only moderate complexity.     

Inverse estimation of nonpoint sources of fecal coliform for establishing allowable load for Wye River, Maryland

An estimation of the nonpoint sources of fecal coliform (FC) has been formulated as an inverse parameter estimation problem, using FC observation data from the receiving waters. An inverse algorithm was integrated into the three-dimensional transport model, HEM-3D. The modified Gauss-Newton method was used for the optimal estimation of the loads. The approach is straightforward and requires less effort in modification of the existing hydrodynamic model. Model experiments were conducted to investigate the feasibility of load estimation in a tidal river. The parameter uncertainty and accuracy associated with load estimation are discussed using data sets with different sampling sizes. The inverse model was applied to the tidal Wye River, Maryland, USA, to estimate FC nonpoint sources and to develop an allowable load for the river to attain water quality standards. The model results suggest that the inverse modeling approach is suitable for estimating FC nonpoint sources. The inverse method not only provides an efficient approach to assess the contribution of nonpoint sources, but has the additional advantage of addressing the problems of the uncertainty and error associated with FC simulation in the estuary using hydrodynamic models.     

供水管网地震漏损蒙特卡洛模拟分析

为研究供水管网在不同地震烈度下的漏损情况和水力特性,基于管道地震破坏评估模型和概率分析方法,对不同地震烈度下管线的破坏概率和渗漏状态进行了计算分析,引入折减系数对管段抗震可靠度分析方法进行改进,并与传统计算方法比较,验证了其合理性。发展了Monte Carlo模拟技术在供水管网流分析方面的应用,并考虑带渗漏和爆管两种出流方式。编制程序对一大型管网进行了模拟分析,给出了震后带漏损情况下管网的漏失率和破坏情况,结果与实际地震灾害情况相符。     

基于遗传神经网络的公路工程造价估算分析

从影响公路造价的影响因素中提取特征因子为参数,用历史数据为依据,用遗传神经网络建立了公路造价快速估测模型,最后用实例验证了遗传神经网络模型在公路工程造价估测中的优良效果。