物流园区供水管网漏损控制管理

小区DMA管理是供水企业漏损控制管理的重要一环,按照将水量平衡管理思路应用于小区漏损控制管理中,通过漏损分析、综合运用优化水表口径、在线监控夜间最小流量、竞争性探漏等方法,有效地将盐田港保税区物流园南区对照表的夜间最小流量从7m~3/h降低到0.5m~3/h。     

供水管网水量整体计量误差分析方法研究

提出了一种基于独立计量区域(District metering area,DMA)小区总表记录值反演区域居民用水强度分布规律的方法,并结合水表检定得出的区域水表误差特性,计算区域居民用水计量误差。在HZ水务集团CX分公司辖区内通过分层抽样选取了466块水表进行检定,统计得出该考核区内DN20户表的计量误差在最小流量Q1处为0.55%,分界流量Q2处为1.15%,常用流量Q3处为1.02%。在辖区内随机抽取的16个DMA小区中,通过其考核表的记录值计算出区域内居民用水90%的水量服从参数μ=1.8,σ=0.5的对数正态分布,10%的水量服从参数μ=1.7,σ=0.4的对数正态分布,该区域居民用水整体计量误差为1.31%。     

基于线性回归法预测南方居民夜间合法用水量研究

DMA小区内无收益水量类型较多,分析困难,对其类型准确分离的关键是确定居民夜间合法用水量。以南方某市8个居民小区17 000余户智能水表实时远传数据为基础样本,采用统计学方法对居民夜间合法用水量进行了研究。户均夜间合法用水量Y与户均日用水量X之间存在较好的线性相关性,其回归方程为Y=7.876 X+0.446(R~2=0.760)。并在6个新安装的智能小区加以验证,整体准确性较高。采用年度平均值实时估计夜间合法用水量时,其误差范围宽度与用户夜间合法用水总量的年度平均值存在显著的线性关系。应用线性回归方程,同时考虑误差范围,可计算得到未装智能远传水表的DMA小区居民夜间合法用水量,从而为小区漏损控制奠定基础。     

区域夜间最小流量的灰色DGM(1,1)动态预测

针对一个实际独立计量区域(DMA),根据数据采集与监控系统(SCADA)的数据,采用趋势图和灰色关联度分析了DMA入水口的流量特征。然后基于灰色理论建立4个夜间最小流量的灰色模型,对比分析4个模型的模拟和预测精度,确定离散灰色DGM(1,1)模型是此DMA的夜间最小流量的最佳预测模型。灰色DGM(1,1)新陈代谢模型具有很好的动态预测精度,应用灰色DGM(1,1)新陈代谢区间预测方法分析了此DMA区域的夜间最小流量的阈值,从而为DMA的漏失状况起到预警作用。     

DMA不可避免漏失量计算值与实测值对比分析

构建独立计量区域（DM A ）是一种经济有效的控制供水管网漏损的方法,近年来受到国内外供水企业的广泛关注。利用IWA提出的不可避免漏失水量计算公式计算独立计量区域中不可避免漏失水量,与采用最小夜间流量法实测出的该DM A不可避免漏失水量进行对比分析。并利用SPSS软件对不可避免漏失水量经验公式影响因素进行验证,可为进一步提出适合我国独立计量区域不可避免漏失量计算方法提供依据。     

供水管网独立计量区域管理数据库系统开发

独立计量区域(DMA)技术在城市供水系统漏损控制和管网优化运营管理中的应用取得了较快发展。但是,随着管网监测时间增加,数据量增大,采用人工手动逐项查询、计算、分析漏损情况等的方式很难迅速、及时、准确地了解DMA运行状况,并无法及时利用相关信息数据指导管理。开发设计DMA管理数据库系统可以用来对数据进行合理的对比分析和评价。数据库系统的总体设计和功能设计实现了图形浏览、编辑、查询、数据分析、评价分析、可视性分析等功能,并可用于DMA的预警。     

基于独立计量区的夜间最小流量的研究进展

夜间最小流量是评估独立计量区实际漏损水平的重要指标,流量数值的变化有助于管理者及时发现新增漏点,开展主动探测,降低泄漏损失和产销差等经济损失。在指出夜间最小流量构成的基础上,重点回顾了夜间最小流量的发生时间、基准值确定方法和夜间最小流量的应用,并对基准值的确定方法的优缺点进行了对比分析。研究发现各地夜间最小流量出现的时间存在差异,基准值的确定方法受客观条件限制,通用性较差,相对而言,采用统计学确定夜间合法用水量进而得到夜间最小流量基准值的方法应用性较强。     

基于水表误差曲线重建的供水系统表观漏损量估算方法及应用

在分类用户用水模式分析的基础上,考虑选取5个特征流量进行水表误差曲线重建,对水表误差值进行修正,建立了基于水表误差曲线重建的表观漏损量估算方法.利用该方法对苏州市研究区域内新建小区、老旧小区、工业、商业、学校和医院等6类用户的水表误差进行修正,各水表的误差修正值分别为-0.25％、-4.1％、-4.59％、-2.03％、-5.74％、-0.34％,据此计算得到各类用户的表观漏损水量分别为7.41万m3、103.42万m3、292.50万m3、28.29万m3、167.83万m3、2.82万m3.与传统方法相比,建立的方法考虑到用户用水模式对水表误差曲线的影响,对表观漏损水量估算更为准确,能为用水行为类似的苏南地区的表观漏损水量估算提供参考.     

供水管网漏损控制管理的应用

供水管网漏损控制管理在供水企业中日益得到重视和加强,以某市供水管网独立计量区域(DMA)为例,提出管网更新改造投入较多,回报期较长时,可采取精细化压力控制策略来降低漏损,如控制管理复杂的小区,可采用固定输出压力控制法,再采用精细化调压,并提出了精细化的分区管理模式来解决管网漏损问题,以降低漏损率、减少爆管事故、延长资产使用寿命。     

应用KS聚类算法处理DMA分区流量数据

通过应用具备实时监控功能的智能水表,水司获得了大量管网流量数据.目前,数据挖掘技术可实现对这些数据的信息利用最大化和合理分析.针对聚类算法中经典的K-means、自主映射(SOM)和模糊C均值(FCM)存在的聚类效果不理想问题,采用基于DMA分区水量曲线距离和形状的KS聚类算法处理流量数据提高聚类效果.通过对X市43个DMA分区预处理的流量数据的聚类分析,KS聚类算法的聚类效果优于K-means、SOM和FCM聚类算法,且可利用对KS聚类结果的分析,指导水司检测漏损、偷水的异常情况.     

Apparent Losses Analysis in District Metered Areas of Water Distribution Systems

As one of the most important component of Non-Revenue Water (NRW), apparent loss exists in all kinds of water distribution system but hardly can be assessed due to its complexity and invisibility. Aimed to analyze the different component of apparent loss on the basis of the characteristic of flow meters in district metered areas (DMA), an effective methodology to calculate the three primary parts of NRW is presented in this paper. In particular, the real loss assessment can be carried out by Minimum Night Flow (MNF) analysis; while the unauthorized consumption can be identified by consuming variation curve; finally, the metering error is calculated by the genetic algorithm with the integrated model based on IWA water balance audit. Application of this method in water distribution network of a steel-making enterprise improves its significance in controlling NRW of DMA.     

Implementation of Hydraulic Modelling for Water-Loss Reduction Through Pressure Management

This study was conducted in the Konyaalti Water Distribution Network in Antalya, Turkey. The study area was divided into 18 district metered areas (DMAs) for better management of water losses. Water levels in reservoirs, flow rates, and water pressures were monitored on-line by the SCADA data system. A hydraulic model was calibrated and verified for each DMA using data provided by SCADA. The model results revealed that a number of DMAs exhibited high pressures, greater than 3.5 bars, and high minimum night flow (MNF) throughout the year. Also, the Infrastructure Leakage Index (ILI) for the study area was greater than 20, indicating high water losses. As a result of these findings, a pressure reducing valve (PRV) was installed at DMA No. 2 as an example and set at 3.0 bars resulting in considerable reduction in water losses. The optimum pressure level for setting the PRV was chosen using the hydraulic model. The same model was used to predict water savings due to pressure reduction. The predicted water savings were verified using long periods of flow rates and water pressure profiles. The predicted and measured water savings showed good agreement. The study concluded that hydraulic modelling is essential for applying appropriate pressure management strategies.     

Calibration Model for Water Distribution Network Using Pressures Estimated by Artificial Neural Networks

The success of hydraulic simulation models of water distribution networks is associated with the ability of these models to represent real systems accurately. To achieve this, the calibration phase is essential. Current calibration methods are based on minimizing the error between measured and simulated values of pressure and flow. This minimization is based on a search of parameter values to be calibrated, including pipe roughness, nodal demand, and leakage flow. The resulting hydraulic problem contains several variables. In addition, a limited set of known monitored pressure and flow values creates an indeterminate problem with more variables than equations. Seeking to address the lack of monitored data for the calibration of Water Distribution Networks (WDNs), this paper uses a meta-model based on an Artificial Neural Network (ANN) to estimate pressure on all nodes of a network. The calibration of pipe roughness applies a metaheuristic search method called Particle Swarm Optimization (PSO) to minimize the objective function represented by the difference between simulated and forecasted pressure values. The proposed method is evaluated at steady state and over an extended period for a real District Metering Area (DMA), named Campos do Conde II, and the hypothetical network named C-town, which is used as a benchmark for calibration studies.     

流量实时监测代表垂线法应用探讨

代表垂线法具有提升水文监测技术手段和防汛测报的快速反应能力,提高通航河道监测效率,简化测验方法等特点。通过从流速仪精测法实测流量中筛选出代表垂线,对实测垂线平均流速与实际断面平均流速进行横向比较,经过误差分析,确定垂线的平均断面流速和实测断面平均流速之间相关关系。经数据检验后,结果满足《水文资料整编规范》标准要求。代表垂线法可以提高流量测验效率,缩短在中高水期间通航河道流量监测时间,实现流量实时监测,为防汛救灾指挥部门提供及时、准确的水情信息。     

Leakage Detection Using Smart Water System: Combination of Water Balance and Automated Minimum Night Flow

This paper presents a methodology for the application of the Smart Water technology to detect water leakage. This methodology consists in the use of the traditional water balance method together with the minimum night flow approach. This procedure has been applied to a large-scale pilot project conducted at the Scientific Campus of the University of Lille, which is the size of a small town. The water network of the campus is monitored by a set of sensors that record and transmit, in real-time, the hydraulic parameters of the water system. Analysis of real-time data has allowed the verification of water balance and the estimation of water losses level in the network. The paper presents an improvement of the application of the minimum night flow method, which is based on the determination of flow thresholds. A leak alarm is generated if the night flow exceeds the thresholds. This data analysis methodology provides the capability to detect the pipe bursts quickly, thereby reducing the runtime of leakage. The application of the improved method allowed the detection of 25 unreported leaks and decreased the Non-Revenue Water (NRW) level by 36%.     

南水北调中线工程流量监测站点 倒挂数据清洗模型及应用

以南水北调中线工程为研究对象,针对调度运行中出现监测站点流量倒挂的数据异常现象,基于水量动态 平衡原理及区间流量最长序列法,构建流量监测站点倒挂数据清洗模型。以中线工程白河至黄金河河段为例,基 于模型清洗后的流量数据作为上边界条件,构建水动力模型进行验证。结果表明：清洗模型消除了流量监测数据 中存在的倒挂现象,提高了流量监测数据的质量,并发现节制闸流量监测设备存在的监测数据偏差及闸门调控的 干扰是造成该现象的主要原因;水动力数值模拟的闸前水位平均绝对误差减少 0.075?7?m,均方根误差减小 0.089?5 m,清洗后的流量数据在数据空间的逻辑性、一致性等方面优于实测流量数据。     

Water Saving and Energy Reduction through Pressure Management in Urban Water Distribution Networks

Water shortages and climate change are worldwide issues. Reduction in water leakage in distribution networks as well as the associated energy saving and environmental impacts have recently received increased attention by scientists and water industries. Pressure management has been proposed as a cost-effective approach for reduction in water leakage. This study conducted a real-world water pressure regulation experiment to establish the pressure-leakage relationship in a district metering area (DMA) of the water distribution network in Beijing, China. Results showed that flow into the DMA was sensitive to inlet water pressure. A 5.6 m reduction in inlet pressure (from 38.8 m to 33.2 m) led to an 83 % reduction (12.1 l/s) in minimal night flow, which is a good approximator of leakage. These reductions resulted in 62,633 m³ of water saved every year for every km pipe, as well as associated savings of 1.1?×?10⁶ MJ of energy and 68 t of CO₂ equivalent greenhouse gas emissions. The results of this study provide decision makers with advice for reducing leakage in water distribution networks with associated energy and environmental benefits.     

青藏高原羌塘内流区降水时空特征

利用8套卫星反演与模式模拟的降水资料及地面实测降水数据,分析了羌塘内流区2001—2015年的降水时空分布特征,评估了卫星反演与模式模拟降水资料在羌塘内流区的适用性。结果表明:GSMaP_Gauge降水资料在羌塘内流区表现出更好的适用性,其月数据与地面实测降水数据的相关系数达到0.95,相对误差、平均绝对误差和均方根误差最低;羌塘内流区降水空间格局整体上呈现自东南向西北、由南向北逐渐减少的分布规律;2001—2015年,内流区年降水量总体呈现增加趋势,GSMaP_Gauge年降水量更接近于内流区真实情况;年降水主要集中在夏季,占全年降水的59%以上。     

一种基于Google Earth影像的河道地形数据提取方法

为解决无实测资料地区的河道地形数据获取问题,提出了一种基于Google Earth影像提取河道地形数据的方法,利用该方法提取了鉴江流域的河道地形数据并将其应用于水动力模型的构建。结果表明:利用该方法提取的河道地形数据所构建的水动力模型,其模拟过程与实际过程基本一致,其中模拟的最大、最小流量与实测对应的最大、最小流量的相对误差分别为14.3%和7.8%,流量模拟的整体相对误差为13.2%;模拟的最高、最低水位与实测对应的最高、最低水位的相对误差分别为5.5%和3.9%,水位模拟的整体相对误差为5.2%;基于Google Earth影像提取河道地形数据是解决无河道地形资料地区的一种便捷且行之有效的方法。     

An Integrated Model to Evaluate Losses in Water Distribution Systems

To evaluate non revenue water (NRW) and losses in water distribution networks a methodology is developed by applying “annual water balance” and “minimum night flow” analyses. In this approach the main NRW components such as leakage from reported and un-reported bursts and background leakage, with real or estimated data, enabling assessment of indices of leakage performance are evaluated. Also, a novel procedure is introduced in this paper that can determine the nodal and pipe leakage by using a hydraulic simulation model. Recognising the pressure dependency of leakage the total consumption is divided into two parts, one pressure dependent and the other independent of local pressure, and the hydraulic behaviour of the network is analyzed. A computer code is developed to evaluate all components of water losses based on the proposed methodology. For better representation of the results and management of the system, the outputs are exported to a GIS model. Using the capabilities of this GIS model, the network map and attribute data are linked and factors affecting network leakage are identified. In addition, the effects of pressure reduction are investigated. The model is illustrated by a real case study. The results show that the suggested model has overcome the shortcomings of the existing methodologies by accounting for the leakage and other NRW components in water distribution networks more realistically.