Recent Developments in Application of 'Bursts and Background Estimates'Concepts for Leakage Management

ABSTRACT During the UK 'national leakage control initiative', which was carried out in 1991–94, Welsh Water formulated a conceptual model of leakage management which was intended for international application.
This paper explains how the concepts of 'bursts and background estimates'(BABE) have been calibrated and extended to cover financial/economic analysis and pressure management, using specialist software for practical application and following the methodologies in the recent water industry 'Managing Leakage'reports. Examples of applications of BABE software and concepts, in the UK and internationally, are also described.     

Leakage Control in a Universally Metered Distribution System: Pinetown Water's Experience

As a result of water losses reaching a high point of 16% in 1973, combined with a relatively high and increasing retail tariff, the Pinetown Regional Water Services Corporation embarked upon a programme to reduce losses to an acceptable level of about 10%. The programme involved: (i) the establishment of district metering throughout the distribution system; (ii) the replacement of certain retail meters; and (iii) the metering of new fire connections (other than those serving sprinkler installations). Further steps were taken to improve the situation and included: (a) the monitoring of minimum night flows, (b) regular sounding of distribution mains; (c) the establishment of a full-time waste detection gang; and (d) with improved control valves becoming available, more effective pressure control of the system. The Corporation's computer was called upon to determine: (i) the monthly losses from each of the hundred or so districts; (ii) the life history, in graphical form, of retail meters under review; and (iii) a record of expenditure on leakage control. The paper describes the development of the methods used in leakage control, costing less than half a cent per cubic metre of water purchased, and outlines the practical experience gained in reducing losses from 16% to less than 5% over a period of 14 years.     

A Methodology for Surveying Domestic Water Consumption

This paper describes the experimental design and engineering of the largest contemporary survey of domestic water consumption in the UK. Results are presented for the first full year of data collection and are discussed in terms of explanatory variables, reliability and usefulness. Significant findings include (a) the range of per capita consumption, (b) relationships to explanatory variables, (c) components of consumption including legitimate night flows, and (d) the contributions of specific domestic appliances.     

Estimation of the benefits yielded by pressure management in water distribution systems

The occurrence of water losses in Water Distribution Systems is inevitable. Knowing that most of the real losses take place in distribution mains and in service connections, the methodology proposed in this paper is based on several leakage-assessment approaches from literature and on water distribution network modeling. This allows assessment of the benefits that can be achieved by pressure management in Water Distribution Systems, particularly in terms of water production reduction. Moreover, this approach can be useful for cost benefit analysis to help establish the level after which there is no more economic interest in reducing water losses (Economic Level of Leakage). Finally, the results from hypothetical case studies are presented and discussed, assuming the installation of Pressure Reducing Valves at District Metered Areas entry points.     

远传监控系统在DMA漏损控制工作中的应用

城市供水管网漏失长期以来是供水企业关注的重点,直接关系到企业的经营成本和经济效益。近年来城市发展迅速,供水管网新旧结合,分布复杂,给供水管网漏损控制管理工作带来很大不便,造成城市管网漏损率偏高。针对上述问题,主要介绍了郑州自来水投资控股有限公司借助远传监控系统在DMA漏损控制方面的一些应用,并探讨了DMA漏损控制的有效方法。     

Estimating Pipe Reticulation Losses in a Municipal Water-Supply System

Domestic water consumption in the city of Dunedin, New Zealand, is unmetered. Recently, the Council's Water Department adopted sampling methods to estimate domestic water consumption and system losses, consistent with the recent reports on managing leakage produced by the UK water industry. This paper describes the exercise (which is ongoing), including the treatment of practical issues which arise in applying the methodology. System losses were estimated to increase substantially over the initial two years of the study, leading to the investigation of an assignable cause. The data reflect the effects of the corrective action, lending considerable support to the validity of the method.     

水平衡测试法用于城乡统筹供水管网漏损控制

介绍了水平衡测试法的特点、原理及应用条件,重点分析了其在城乡统筹地区供水管网漏损控制中的实用性和优越性.以上海市自来水奉贤有限公司供水管网系统为例,总结了水平衡测试应用于管网漏损控制的方法和经验,并对其经济效益进行了分析,为城乡统筹地区供水管网的漏损控制提供了参考.     

区域供水管网漏损现状的实验研究

在分析城市供水管网漏损现状的基础上,采用区域装表法在特定区域进行实验,获得大量实验数据。通过实验数据分析,得出小区供水管网区域漏损资料,并对供水管网漏损的原因及控制措施做了分析,提出了用现代技术手段提高供水管网管理水平的必要性及重要性。     

A Realistic Basis for an International Comparison of Real Losses from Public Water-Supply Systems

The paper considers the subject of physical (real) losses from pressurised systems which are used for public water supply. To date, attempted comparisons of leakage management performance between water undertakings world-wide have been severely compromised because there have been no standard methods of defining and calculating real losses. Performance indicators, which have been traditionally used for comparisons, have been too simplistic. Limitations of existing performance indicators are identified in the paper by reference to key factors which should be incorporated in objective comparisons of real losses.
The paper describes an improved methodology which was developed by an International Water Association Task Force, based upon logical concepts using local key parameters, calibrated using auditable assumptions, and tested against twenty-seven diverse sets of data from twenty countries.     

供水管道漏损预测模型研究

根据某市供水管网漏损数据的大量统计,应用多元线性回归分析理论,通过供水管道漏损原因相关分析,对供水管道投入使用后产生漏损的初妈中时间进行了科学预测,建立了供水管道漏损预测模型,该方法为改变供水行业被动式的漏损管理模式,对管道漏损做到早预防、早解决提供了一个新的思路。     

天然气产销差的成因与控制方法

产销差问题已经成为制约燃气行业效益提高的重要问题。文章以天然气产销差的现状为出发点,结合实际工作,分析了产销差的成因,对天然气产销差的控制方法进行了探讨。同时对加强计量技术工作提出了一些方法和设想。     

Water losses investigation and evaluation in water distribution system – the case of SA city in China

Faced with the severe leakage and chaotic water management situation in developing countries, this research is committed to provide an appropriate and practical water audit calculation method for most water companies so as to guide their leakage control management. It prepares a recommended basic standard terminology for calculation of real and apparent losses, which can be consistent with practice in China. Due to more detailed subdivision of unmetered water along with water component analysis, the water consumption of SA city can be calculated more accurately. The proportion of water loss in SA is 18.02%, while unbilled authorized consumption contributes no more than 1% to the total water consumption. Meanwhile, the “Neighbourhood Metering Area (NMA)” project in SA city also suggests that metering inaccuracies and leakage on service connections up to the point of customer metering can be prioritized for active leakage control in China.     

北京昌平区城市夜景照明工程智能化控制系统的设计与实施

本文简述北京昌平区夜景无线照明工程智能控制系统的系统原理,提出了工程设计和实施中的主要问题和解决方案,供业内人士参考。     

城市供水管网漏损预测模型及检漏方法的研究

介绍了多元线性回归模型、灰色预测模型、漏损检测周期的优化数字模型等几种供水管网漏损预测模型，并对供水管网漏损的检漏方法进行了阐述，从而为消除其对管道基础、公共设施造成的危害提供了保证。     

供水企业产销差控制工作的策略与实践

产销差控制是国内外供水企业普遍重视的工作之一。以佛山市水业集团有限公司旗下A供水分公司2012年产销差控制的实践工作为例,对该公司产销差控制工作进行了总结与分析。分析表明,A公司产销差控制工作取得了一定成效,但仍存在一些问题需要进一步研究与探讨。     

基于一个控制网的多个互不平行异型建筑的施工测量

只要与拟建建构筑物的主要轴线发生平行或垂直关系,即可用一个不规则矩形测量控制网中包含多个矩形或不规则四边形测量控制网,同时控制多个互不平行（或垂直）的异型建筑。此设置不仅操作简便易行,测量精度高,而且比设置多个互不关联的矩形测量控制网成本低、闭合简便。     

郑州水司的供水管网漏水检测实践

管网漏水是整个供水行业普遍面临的问题。对漏水检测方法、检测技术流程进行了简单介绍。郑州水司的漏水检测实践证明，主动开展供水管网漏水检测是降低管网漏损的有效途径。     

燃气管道泄漏原因分析、预防及控制

燃气管道一旦发生泄漏,后果不堪设想,目前天然气管道日益增多,必须防忠于未然。造成管道泄漏的管材、工程质量、外力、阀门以及凝水缸等问题,应该在新建管网、天然气转换时采取措施,以预防和控制事故发生。     

浅谈地下室化学灌浆补漏与内防水施工

针对工程建设中经常出现的地下室渗水、漏水等质量通病，介绍了对高层建筑地下室大面积漏水进行全面技术处理的施工方法，并对其施工效果作了分析，达到了治漏与防水综合治理的效果。     

先张梁冬期施工的技术控制

结合大运高速公路祁临段道路工程板梁冬期施工,介绍了冬期施工中的主要施工方法及各项工程质量控制参数,并对预应力筋应力损失原因、预应力损失组成及减少应力损失的方法作了探讨,以积累先张梁冬期施工经验。