排水管网费用函数概述

排水管网费用函数在应用计算机对排水管道系统设计、运行和管理中具有非常重要的作用 ,根据费用函数可以对新建、改扩建排水工程进行技术经济分析 ,以期达到优化设计和控制费用的目的。应用遗传算法对排水管道单价模型进行了回归分析。     

水力模型于西安城区排水管网管理中的应用

在对城市排水管网综合管理研究的基础上,对水力模型在西安老城区排水管网运行管理过程中的微观应用模式进行了探讨和案例分析。案例分析表明,利用监测数据与模型的紧密集成使用的方法,可提高模型预测的可靠性和城市排水管网管理的科学性与高效性。     

基于F-ANP的武汉市黄孝河流域排水管网运行效能评估

为了研究武汉市黄孝河流域排水管网面临的风险,提出了基于F-ANP方法的武汉市黄孝河流域排水管网运行效能评估模型.首先,该模型在现有的研究和规范标准的基础上,考虑到影响排水管网安全受多因素影响,这些因素又存在相互关联的关系.分析排水管网运行效能的影响因素并进行风险识别,构建排水管网运行效能评估模型;然后,用三角模糊数表示两两比较矩阵,结合三角模糊数理论解决由于专家主观不确定性造成的结果不准确,算出因素相互间的影响权重;最后进行效能评估,结合武汉市黄孝河流域排水管网项目实例,验证所构建模型的可靠性和有效性,为武汉市排水管网之后的运行维护管理提供了新的研究思路.     

镇江市主城区排水管网计算机建模方法

为了预防道路积水等城市型水灾害，基于暴雨雨水管理模型（SWMM）平台建立了镇江市主城区排水管网计算机模拟模型。结合建模实践，对排水管网计算机实用建模方法进行了探讨，可分为汇水子区域划分、参数获取、模拟情境设计、灵敏度分析及模型预校准等步骤，为后续的模型微观校准提供了有利条件。该方法对现阶段建模数据不完备地区的排水管网建模具有借鉴意义。     

监测技术在排水管网运行管理中的应用及分析

针对排水管网溢流造成的城市污染问题,对监测技术在城市排水管网运行管理过程中的应用模式进行了探讨和案例分析,对监测数据的分析方法和监测数据支持下的模型动态模拟技术进行了研究。案例分析表明,通过对监测数据的分析和模拟可全面掌握整个排水管网系统内各个管道的水力负荷和水质状况,利用监测数据与模型的紧密集成使用的方法,可提高模型预测的可靠性和城市排水管网管理的科学性与高效性。     

水力模型用于排水系统的设计优化

在传统的城市排水管网设计和管理中,一般采用恒定流水力学理论计算管网的汇流过程,无法反映真实水流的突涨突落的非恒定流特点,因此在上海市虹南排水系统的规划设计中,应用城市排水系统水力模型模拟技术详细分析了雨水排水系统的水力学特征,诊断了管网瓶颈,优化了其管网布局、调度方式和工程方案,为提高虹南雨水排水系统的规划、设计、管理、运行技术水平发挥了重要作用。     

排水管网维护新技术的应用

文章主要表述了管道运行情况评估、非开挖性修复、流量的测量及水力模型新技术的应用,该技术的推广应用能够提高排水管网管理水平以及维护效率,加强排水管网运行的安全性。     

城市排水管网检测技术现状及发展趋势

排水管网病害的检测是解决排水管网病害的有效手段,也是管网运行管理的关键。文章对排水管网检测技术的现状进行了研究,并对传统排水管网检测技术和排水管网在线监测技术的技术特点及应用分别进行了总结,最后分析了城市排水管网检测技术的发展趋势。     

信息化建设在排水管网管理中的作用

分析了国内排水管网管理中存在的问题,叙述了排水管网地理信息系统、液位在线监测、水力模型等在排水管网管理中的作用。     

城市排水管网数值模拟分析技术研究进展

结合当前排水管网模拟技术的应用现状，介绍了排水模型在管网现状评估、溢流分析以及规划设计方面的应用。以北京市北小河流域为例，介绍了模型的构建流程，评估了现状条件和未来规划期内污水管网、雨水管网和污水厂的排放负荷，为今后排水改造规划制定提供了指导和依据，并结合北小河流域的管理要求开发了相应的业务子系统。     

基于SWMM模型的截流倍数环境效应分析

由于对改造建设的重视程度、时序安排、经济条件、改造难度等许多主观和客观因素的限制,许多城市老城区的合流制排水系统保留至今。采用SWMM水力水质模型,对城市合流区的污染物削减情况进行模拟评价,以期为合流制排水系统的截流倍数取值及建设方向提供参考。结果表明,当截流倍数n≥2时,合流制排水系统即可达到分流制排水系统的污染物截流效果;但只有当截流倍数n≥5时,合流制排水系统才能达到分流制排水系统的污染物削减效果。城市合流区需尽快进行合改分建设,或加大末端处理设施的建设。     

城市污水管道实际健康度评价模型及应用研究

根据现状管道破坏数据及其对环境影响的后果建立了城市污水管道实际健康度评价指标体系,基于属性理论提出了城市污水管道实际健康度属性综合评价模型,并运用此模型对四川岳池城东新区城市污水管道的实际健康度进行了综合评价.评价结果表明,运用城市污水管道属性综合评价模型得到的实际健康度,可以客观地反映城市污水管道实际整体健康状况,可为确定管道维护顺序和维护方案提供理论依据.     

城市污水管道预报健康度评价模型及其应用研究

根据现状管道破坏的可能性及其环境影响后果等因素,建立了城市污水管道预报健康度评价指标体系,基于灰色系统理论提出了城市污水管道预报健康度灰色关联综合评价模型,并运用此模型对四川岳池城东新区城市污水管道的预报健康度进行了综合评价.结果表明:运用灰色关联综合评价模型计算得到的预报健康度可为确定污水管道检测的优先次序提供依据,健康度较低的管道应优先被检测;在灰色关联评价法中,将模的大小与夹角的大小结合起来,可以较全面地反映污水管道与虚拟最健康管道的接近程度;采用多时段管道评价矩阵可避免评价模型的奇异性.     

基于GIS的昆明主城区排水系统诊断研究

昆明主城区地处滇池流域北岸滨湖上游区域,污染负荷比重大,占流域污染负荷总量的约80%,目前昆明主城区二环路内区域为合流制排水系统,二环路外为分流制排水系统,在雨季雨、污合流污水溢流污染问题严重.在昆明市地下管线探测工作的基础上,对排水管网数据进行空间信息和属性信息处理,建立污染源与排水系统的拓扑关系,构建排水片区--子排水片区--排水单元结构网络.统计分析结果表明,昆明主城区的现状污水收集率约为81%;污水处理厂处理能力有限,在雨季大量合流污水不经处理而直接溢流排入河道,并汇入滇池.通过对典型排水区域船房河排水片区--第一污水处理厂纳污区域进行排水系统详查和污水产生--收集--处理全过程分析,确定依托沟渠主干的排水系统地下水渗入量约占系统收集总水量的35%,此截流式合流制与不完全分流制相结合的典型排水片区旱季污水收集率约为60%,在雨季典型降雨条件下,合流污水溢流率约为90%.此研究成果为昆明主城区排水系统的改造和污水处理厂的规划建设提供了一定依据,也为全面开展排水系统诊断工作奠定了基础.     

Quantifying costs and lengths of urban drainage systems with a simple static sewer infrastructure model

A generic model is introduced that is capable of quantitatively representing the combined sewer infrastructure of a settlement. It consists of a catchment area module, which calculates the length and size distribution of the needed sewer pipes on the basis of rain, housing densities and area size. These results are fed into the sewer construction costs module in order to estimate the combined sewer costs of the entire catchment area.

The model could be successfully fitted to existing Swiss sewer systems, indicating that it can emulate their principal characteristics. It could also identify fundamental differences in sewer designs in cities with historic roots. The results confirm that there are economies of scale for combined sewer systems in Switzerland. The modelling approach proved to be an effective tool for understanding the factors underlying the cost structure for water network infrastructures.     

Multi-objective evolutionary optimization for greywater reuse in municipal sewer systems

Sustainable design and implementation of greywater reuse (GWR) has to achieve an optimum compromise between costs and potable water demand reduction. Studies show that GWR is an efficient tool for reducing potable water demand. This study presents a multi-objective optimization model for estimating the optimal distribution of different types of GWR homes in an existing municipal sewer system. Six types of GWR homes were examined. The model constrains the momentary wastewater (WW) velocity in the sewer pipes (which is responsible for solids movement). The objective functions in the optimization model are the total WW flow at the outlet of the neighborhoods sewer system and the cost of the on-site GWR treatment system. The optimization routing was achieved by an evolutionary multi-objective optimization coupled with hydrodynamic simulations of a representative sewer system of a neighborhood located at the coast of Israel. The two non-dominated best solutions selected were the ones having either the smallest WW flow discharged at the outlet of the neighborhood sewer system or the lowest daily cost. In both solutions most of the GWR types chosen were the types resulting with the smallest water usage. This lead to only a small difference between the two best solutions, regarding the diurnal patterns of the WW flows at the outlet of the neighborhood sewer system. However, in the upstream link a substantial difference was depicted between the diurnal patterns. This difference occurred since to the upstream links only few homes, implementing the same type of GWR, discharge their WW, and in each solution a different type of GWR was implemented in these upstream homes. To the best of our knowledge this is the first multi-objective optimization model aimed at quantitatively trading off the cost of local/onsite GW spatially distributed reuse treatments, and the total amount of WW flow discharged into the municipal sewer system under unsteady flow conditions.     

Reliability-based layout design of sewage collection systems in flat areas

The sewer layout in flat areas significantly influences the final design which is desired to be optimized for the construction and operational costs. This study introduces a model for designing the layout of sewer networks considering their reliability. A reliability criterion is introduced and optimized using a simple simulated annealing scheme. The best layout with the maximum reliability represents an optimum sewer layout in which clogging in a sewer has the least effect on its upstream lines. A case study is solved using the proposed model. Then, for the obtained layout, the sewer specifications are designed using a dynamic programming model. The reliability somehow reflects the operational costs that can be taken into account in the system design by the proposed model. Furthermore, it is concluded that the network's reliability and construction cost are in conflict with each other such that more reliable layouts lead to more expensive designs.     

Grey-box modelling of pollutant loads from a sewer system

Using a compact measuring unit with on-line meters for UV absorption and turbidity, it is possible to determine concentrations of organic load (chemical oxygen demand (COD) and suspended solids (SS)) anywhere in a sewer system. When measurements of the flow are available as well, the pollutant mass flow at the measuring point can be calculated.The measured data are used to estimate different models describing the load of pollutants in the sewer. A comparison of the models shows that a grey-box model is most informative and best in terms measured by the multiple correlation coefficient. The grey-box model is a state-space model, where the state represents the actual amount of deposition in the sewer, and the output from the model is the pollutant mass flow to the wastewater treatment plant (WWTP). The model is formulated by means of stochastic differential equations. Harmonic functions are used to describe the dry weather diurnal load profiles. It is found that the accumulation of deposits in the sewer depends on previous rain events and flows.By means of on-line use of the grey-box models, it is possible to predict the amount of pollutants in a first flush at any time, and hence from the capacity of the plant to decide if and when the available detention basin is to be used for storage of wastewater. The mass flow models comprise an important improvement of the integrated control of sewer and WWTP including control of equalisation basins in the sewer system. Further improvements are expected by the introduction of an additive model where dry weather situations and storm situations are modelled separately before addition to the resulting model.     

自贡市截污管道工程设计

自贡市城市污水处理工程是国债支持的四川省城建环保工程重大项目，通过对其中最重要的子项工程——截污干管工程设计、建设经验的总结，介绍了管道结构形式的选型与城市景观的协调、截污干管穿越障碍物与因地制宜的设计、对附属构筑物采用的特殊处理形式等方面的经验，其对丘陵河谷城市的截污管道设计、建设具有很强的参考价值。     

Calibration of hydrodynamic model-driven sewer maintenance

Sewer performance is typically assessed using hydrodynamic models assuming the absence of in-sewer defects. As a consequence, hydraulic performance calculated by models is likely to be overestimated, while the real hydraulic performance of the sewer system remains unknown. This article introduces the concept of ‘hydraulic fingerprinting’ based on model calibration to identify in-sewer defects affecting hydraulic performance. Model calibration enables detection of changes in hydraulic properties of the sewer system. Each model calibration results in a set of model parameter values, their uncertainties and residuals. The model parameter values also incorporate the antecedent condition of the catchment of the event calibrated and are therefore less suitable to identify in-sewer defects. The residuals on the other hand, and more specifically their absolute values, statistical properties and the correlation between residuals at different monitoring locations are suitable as indicators of the occurrence of in-sewer defects. This allows the application of ‘hydraulic fingerprinting’ based on model calibration, where the ‘fingerprint’ is defined by the model parameters and the residuals. The concept of ‘fingerprinting’ is demonstrated for the combined sewer system ‘Tuindorp’ (Utrecht, the Netherlands). The results show that ‘hydraulic fingerprinting’ can be a powerful tool for directing sewer asset management actions.