共查询到18条相似文献,搜索用时 62 毫秒
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给水管网系统动态建模是自来水公司实现科学管理、提高效益、提高服务水平的重要手段.以天津市给水管网系统建模为例,详细地阐述了给水管网系统微观建模的理论与方法. 相似文献
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建立给水管网微观动态水力模型标准方法研究 总被引:2,自引:1,他引:1
阐述了水司建立给水管网微观动态水力模型的必要性 ,提出了一套适合我国国情的给水管网建模标准方法。这一方法将有助于我国给水管网建模工作走上正规化和科学化的道路。该方法已经成功地应用于上海市。 相似文献
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给水管网建模中建立计算机供水系统管网图形和在地形图上划定节点流量区域的方法 总被引:1,自引:0,他引:1
本文提出了给水管网建模过程中,建立计算机供水管网图形及在地形图上划定节点流量区域的方法,实践证明这一方法应用于大型的复杂的城市供水管网建模是成功的,具有较大的应用价值。 相似文献
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应用有限元,线性化处理及优化方法,编写管网平差计算的FORTRAN程序。该程序可用于环状网或树状网有单水源或多水源的各种情形,且不受管网是平面的或立体的及环数多少的限制。 相似文献
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通过对一个山区城市给水管网规划实例的分析,提出在山区给水中应充分利用高差自流供水,并按照地形高差对给水管网进行分区,加压供水的区块与重力流供水的区块管网应相互隔断,同时,对长期运行在高水压下的管网,宜设置减压措施。 相似文献
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通过对分形理论和给水管网特点的研究,建立了一种新的定量描述给水管网空间分布状态的评价指标--管网覆盖度和管网覆盖深度。采用盒计数法计算给水管网规划布置的分形维数,将给水管网的规划布置由定性分析改为定量分析,从而为给水管网的定线和布局做出合理的指导,使给水管网的平面布置更加科学可靠。 相似文献
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计算机辅助设计动态给水管网模型 总被引:2,自引:0,他引:2
运用计算机建立给水管网动态模型不但能完成静态的数据分析和系统设计 ,还可以实现对给水管网的动态分析和仿真 ,从而实时获取管网系统在不同供水需求以及极端用水条件下的状况。讨论了国内现有的管网模型和应用情况 ,并详细介绍了国外专业软件WaterCAD。 相似文献
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对城市庞大的供水管网进行普查是一项复杂的系统工程。通过对武汉市武昌区供水管网的普查工作 ,探索和总结了一套较有成效的工作方法和程序。 相似文献
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Sara Nazif Mohammad Karamouz Massoud Tabesh Ali Moridi 《Water Resources Management》2010,24(3):437-458
A technique for leakage reduction is pressure management, which considers the direct relationship between leakage and pressure.
To control the hydraulic pressure in a water distribution system, water levels in the storage tanks should be maintained as
much as the variations in the water demand allows. The problem is bounded by minimum and maximum allowable pressure at the
demand nodes. In this study, a Genetic Algorithm (GA) based optimization model is used to develop the optimal hourly water
level variations in a storage tank in different seasons in order to minimize the leakage level. Resiliency and failure indices
of the system have been considered as constraints in the optimization model to achieve the minimum required performance. In
the proposed model, the results of a water distribution simulation model are used to train an Artificial Neural Network (ANN)
model. Outputs of the ANN model as a hydraulic pressure function is then linked to a GA based optimization model to simulate
hydraulic pressure and leakage at each node of the water distribution network based on the water level in the storage tank,
water consumption and elevation of each node. The proposed model is applied for pressure management of a major pressure zone
with an integrated storage facility in the northwest part of Tehran Metropolitan area. The results show that network leakage
can be reduced more than 30% during a year when tank water level is optimized by the proposed model. 相似文献
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Water shortage is experienced in different parts of the world in different magnitude. In certain countries, water deficit
is a regular phenomenon and in some other countries it happens for a short duration, due to failure of any component in the
system. Shortage of water at source can be best tackled by distributing the available water equally among the consumers. This
paper deals with the design of water distribution network capable of equitable supply during shortage in addition to the satisfactory
performance under non-deficit condition. Performance of a typical water distribution network, with shortage of water at source
is illustrated in detail. Head dependent outflow analysis with extended period simulation, is used to determine the actual
supply from each node to consumers. Relationship between duration of supply and volume available at source as well as supply
from each node are established for understanding the behaviour of network under low supply situation. A term “inequity” which
is the maximum difference in supply demand ratio among different consumers is presented. This is based on the actual performance
of the network instead of surrogate measures, generally used for reliability. It is illustrated that the maximum “inequity”
in supply in a network during the entire duration of supply can be estimated with single analysis. Design of a water distribution
network, duly considering equity in addition to the cost minimization and minimum head requirement is presented. Genetic Algorithm
is used for solving this multi objective problem. The solution technique is illustrated using two benchmark problems, namely
two loop network and Hanoi network. Results show that considerable improvement in equitable supply can be achieved with additional
investment on pipes above the least cost solution. Hence it is better to design networks duly considering deficit condition
for better reliability. It is also illustrated that it will be difficult to improve equity beyond a limit for a given network,
through selection of different pipe diameters. 相似文献
16.
Ioan Sarbu 《Water Resources Management》2014,28(10):3143-3159
There are three methods for analysing the flow and pressure distribution in looped water supply networks (the loop method, the node method, the pipe method), accounting for the chosen unknown hydraulic parameters. For all of these methods, the nonlinear system of equations can be solved using iterative procedures (Hardy–Cross, Newton–Raphson, linear theory). In the cases of the extension or the rehabilitation of distribution networks, the unknown parameters are the hydraulic heads at nodes, and the nodal method for network analysis is preferred. In this paper, a generalised classic model is developed for the nodal analysis of complex looped systems with non-standard network components and the solvability of new problems, along with the determination of the pressure state in the system. In addition, this paper exhibits a different approach to this problem by using the variational formulation method for the development of a new analysis model based on unconditioned optimisation techniques. This model has the advantage of using a specialised optimisation algorithm, which directly minimises an objective multivariable function without constraints, implemented in a computer program. The two proposed models are compared with the classic Hardy–Cross method, and the results indicated a good performance of these models. Finally, a study is performed regarding the implications of the long-term operation of the pipe network on energy consumption using these models. The new models can serve as guidelines to supplement existing procedures of network analysis. 相似文献
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A methodology is presented for determining sustainability indices for pressure and water age in water distribution systems (WDSs). These sustainability indices are based upon performance criteria including reliability, resiliency, and vulnerability. Pressure and water age are determined for a WDS as a function of operation time using the U.S. Environmental Protection Agency EPANET model. The values of pressure and water age are used to determine reliability, resiliency, and vulnerability performance criteria, which are then combined into the nodal sustainability indices for water age and pressure. In addition, the sustainability index (SI) computations are performed for zones to define the SI for water age and SI for pressure. A combined SI calculation is performed to produce an overall sustainability score for the entire zone in the water distribution network. The proposed methodology can be used to monitor the sustainability of existing WDSs and to help define alternative solutions including changes in pump operation and modifications to WDS to increase the sustainability. 相似文献