ISSN:0263-0257    

DOI:10.1080/02630259108970625

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

ISSN:0263-0257    

DOI:10.1080/02630259108970626

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

The paper describes a step-by-step approach to the implementation of procedures for ensuring efficient operation of the Loch Lomond Water Supply Scheme. The implementation involved the installation of a Telemetry and Telecontrol system to allow real-time operational control of the full scheme to be exercised from the Board's Headquarters at Balmore. On site Pump Efficiency Determination was carried out which enabled technical appraisals to be made and rational decisions taken on which pumps required to be used to produce water at minimal cost. The energy costs were further reduced by a computer based scheduling program which used the results of the Pump Efficiency Tests.

ISSN:0263-0257    

DOI:10.1080/02630259108970627

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

The Syndicat des Eaux d'lle de France and the Compagnie Generale des Eaux, contractual operators of a network comprising 144 municipalities in the suburbs of Paris, have undertaken to automate the Mery-sur-Oise plant (design capacity 270 000m3/day) by 1993. The system will include the related booster stations and reservoirs. This project, bringing round-the-clock shift work to an end, requires an automatic pilot system for pumping stations as a first step. The originality of the program that we have engineered, resides in the consumption forecasting module. It will function on a real-time basis using a data base enriched daily by the real consumption figures of the previous day. Owing to its capabilities, the network can operate automatically, taking into account energy consumption constraints and the safety of supply to consumers.

ISSN:0263-0257    

DOI:10.1080/02630259108970628

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

The paper discusses the prospect of implementing a software package for the optimal scheduling of large-scale water supply and distribution networks. The time distribution function methodology is considered to be a suitable candidate for the solver implementation. However, since the existing methodology enables optimization of middle size networks, a concept of spatial decomposition is introduced and investigated. The resulting optimization problems are convex and soluble by the existing numerical methods of mathematical programming. Effective measures are proposed to reduce computational complexity of the approach. Finally software technologies to be used for the implementation are presented along with a relational data model for the problem.

ISSN:0263-0257    

DOI:10.1080/02630259108970629

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

The rehabilitation of water supply distribution systems is generally triggered by complaints of discoloured water. The solution to such problems has predominantly rested with scraping and relining; a technique which has. historically, cost less than half the price of mains renewal. More recently, the introduction of MDPE together with accompanying novel mains and service laying techniques has reduced the cost of renewal and together with environmental pressures for reducing leakage, calls for greater consideration to renew in preference to reline. The paper considers these and other benefits and compares UK performance with that of certain continental companies but concludes that relining remains the most economic solution in most cases-for the time being.

ISSN:0263-0257    

DOI:10.1080/02630259108970630

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

This paper introduces a system designed to improve the accuracy of short term water demand forecasts by combining a proven mathematical prediction model with a knowledge base of information relating to non-cyclic abnormal demand occurrences. In part one of the paper, a prototype system is described that comprises a mathematical prediction module and a simplified knowledge base of FORTRAN rules. The results derived from the testing of the prototype show that the methodology is capable of providing significant improvements in prediction accuracy when the normal cyclic demand pattern is disrupted. Part two of the paper describes the steps taken towards implementing the elements that make up a full combined forecasting system in the light of the knowledge gained from building and testing the prototype.

ISSN:0263-0257    

DOI:10.1080/02630259108970631

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

The water industry is heavily regulated, and is in a monopolistic situation, so it is restricted in the charges it can levy, while it has to meet the full demands of its customers. Therefore the economist's approach to optimization, based on the assumption that volume is the sole determinant of cost and revenue changes, cannot be used. Thus an alternative approach is required. The aim of strategic optimization at North West Water Ltd is to produce an operating procedure for the major sources, to meet a declared demand, while maintaining a specified minimum storage volume, at minimum cost.

ISSN:0263-0257    

DOI:10.1080/02630259108970632

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

The water industry has undergone radical change in the late 1980s and changes continue apace. We have been, and will continue to be, under increasing pressure to reduce costs and increase service within a framework where regulations are becoming tighter and demanding more information to achieve and substantiate performance. The major challenge will lie with the leaders of the industry. They have to achieve the right attitude, management technique and technical excellence to meet the requirements of change and to create adaptable organizations that can manage the challenges of change in a positive and proactive way. Cultural change has started but has a long way to go. We must overcome the traditional attitude of many water suppliers, which has typically been one of the ‘professional stewardship’ of a resource in which they supply water in the way they believe to be best. This must change and is changing to a more commercially minded management which is ‘customer centred’ rather than ‘product centred’. We must realize that our organizations manage a complex asset base which has to work towards strictly defined objectives of service quality, operational efficiency and regulatory requirements, all of which, as time goes on, are influenced more and more by substantial external forces.

ISSN:0263-0257    

DOI:10.1080/02630259108970633

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor

摘要:

The observability problem in water systems consists in determining whether the available set of measurements provides sufficient information for the computation of the full system state (this latter operation is called state estimation): given a set of network measurements including some flow, head, consumption and/or resistance values, is it possible to derive all the other hydraulic unknowns of the network? This question is crucial especially for water systems, where the pipe resistances and the consumptions at the nodes are often roughly estimated. One may thus want to use all available measurements for calibrating or estimating these parameters. The aim of this contribution is to determine which variables are structurally observable from the available measurements in a systematic way. This is achieved using a graph-theoretic approach. We split the variables into three classes: the redundant variables, the variables which can be estimated without redundancy (they will be called calculable) and finally the unobservable variables. This provides some insight in where to add new measurements for improving the observability of the system. This classification is also used to formulate a well conditioned least square problem and to compute the values of redundant and calculable variables. We then show how to use optimization techniques for solving this least square problem, with a special emphasis put on the choice of the weighting coefficients, depending on what kind of result is expected (calibration, leak detection, …). Finally, we present results obtained for calibration and leak detection on a real life network, and we give an idea of how to extend these results obtained in the static case to the case when the dynamical behaviour of the system is taken into account (measurements being available at every time).

ISSN:0263-0257    

DOI:10.1080/02630259108970634

出版商:Taylor & Francis Group    

年代:1991

数据来源: Taylor