B. Brunone University of Perugia C. Chiesa Metropolitana Milanese M. Ferrante - University of Perugia

Transcription

1 MM TEA leakagesummit-2013.com/ B. Brunone University of Perugia C. Chiesa Metropolitana Milanese M. Ferrante - University of Perugia

2 Outline MM pipe system What do we know about leak detection in transmission mains? Transient test-based methods for pipe diagnosis - the single pipe case: numerical, laboratory, and field tests; wavelet analysis Complex pipe systems Conclusions Brunone et al. Global Leakage Summit, London 2013

3 METROPOLITANA MILANESE

4 GENERAL STRUCTURE OF WATER SYSTEM DOWNSTREAM UPSTREAM Raw water supply from 500 deep wells widespread all over Milan municipal area (182 km 2 ) grouped in 30 clusters serving each one a treatment, storage and pumping facility. Over 230 M 3 of water distributed throughout the network. Raw water transport through 100 km of mains to the 30 treatment, storage and pumping facilities. Raw water treatment of 70% of the total supplied volume (activated carbon filters, stripping towers, reversal osmosis). Storage at ground level of m3 of treated water for daily balance of the gap between average supply ( m3/day) and demand peak ( m3/s). Pumping of treated water in the water distribution network through 30 pumping stations equipped with 3 to 5 single speed or variable speed pumps. Treated water distribution through km network made of steel (for trunk mains), cast iron (past years), ductile iron (recent years) trunk and distribution mains ranging from 1200 to 100 mm diameter. Potable water delivery to residents (plus commuters) through collective customer points, typically story-building / condos or public buildings and small to medium BUSINESSES.

5 OPERATIONS MAINTENANCE DEVELOPMENT OPERATIONS Supply system daily operations (wells, pumps, some controlling valves) at San Siro Control Room (to be visited) and SCADA maintenance and development. Raw water and treated water quality control sampled times a year at wells, treatment facilities, reservoirs, distribution network, customer points (upon request). MAINTENANCE Upstream supply system facilities emergency and planned maintenance (wells, wells power lines, row water transport mains, treatment plants, reservoirs, pumps, power equipment, buildings). Downstream supply system network emergency repair and planned maintenance (trunk mains, distribution mains, valves and hydrants, customer connections and meters). DEVELOPMENT Computer modelling of the water supply system for hydraulic and energetic efficiency / performance improvement and mathematical and pilot testing of new structural configurations (e.g. districts). Design and construction / revamping / replacement of facilities and networks (MM Engineering).

6 CORPORATE AND OPERATIONS INFORMATION SYSTEMS CORPORATE ERP: accounting and finance, cost control, HR management, Document Management System Enterprise Asset Management System (planned boy) OPERATIONS Customer Management and Billing System Water Supply Geographical Information System Water Supply Computer Modelling System Water Supply System SCADA

7 COMPUTER MODELLING AND SCADA COMPUTER MODELLING State-of-the-art software InfoWorks WS by Innovyze ( Functionalities: Network hydraulics analysis, water quality analysis (pollutant diffusion, age), energy optimization, leakage estimation. Planned integration with SCADA system for real-time modelling and system behaviour forecasting (state-of-the-art).

8 COMPUTER MODELLING AND SCADA SCADA SUBSYSTEMS Wells remote control Remote operations Remote supervision Automation 27 pressure & 7 capacity points monitored 26 analogical samplings/1-10 sec. and 260/290 on/off substation level over point of measurements

9 MAIN ISSUES / CRITICALITIES OF MILAN WATER SUPPLY OPERATIONS Huge energy consumption and bill (0,4 kwh/m3, 0,07 / m3, /year, raising): Supply system kept pressurized as a whole electricity fed pumping systems widespread all over the served area MM planning to move to district operated model (IWA) High energy consumption due to unbalanced pressurization of the distribution network from the higher north-west area to the lower south-east area (altitude gap is 40 m, pressure gap is 25 m). physical losses of water distribution network and customer connections.

10 MAIN ISSUES / CRITICALITIES OF MILAN WATER SUPPLY OPERATIONS Physical losses (13,4% in 2011): Root causes: age of pipes (65 years average), environment stress (traffic, frequent maintenance of other underground networks, stray current), operational stress (high pressure, water hammers). slow and poor leakages detection pipes repair maintenance process leaves much to be desired Asset management (predictive / preventive maintenance): Pipes bursts repaired when fault detected No predictive / preventive maintenance required: DSS connected to network of flow, Pressure and noise sensors enabling early detection of leakages Pressure transients and service (pressure) monitoring and optimization Water quality: Quality issues chemical pollution of ground water released by agricultural and industrial activities (nitrates, metals, hydrocarbons, pesticides, etc.). Nitrates are the very serious issue.

11 OBJECTIVES RELEVANT TO MILAN WATER SUPPLY SYSTEM OPERATIONS BASED UPON THE ABOVE PAIN POINTS : MM PRIORITIES FOR ICEWATER : INTEGRATE IWA METHODOLOGY AND BEST PRACTICES INTO ICeWater. (methods, calculation tools, performance indicators, etc.) to optimise water supply system management. R&D OF A DUAL (Districted and Centralized) SSD: monitoring and continuous improvement of water supply management at overall and district level. manage and optimise key parameters: pressure, flows, physical losses optimization / minimization, energy optimisation, demand forecasting, switch from a demand driven to a production driven system, operational scenarios, etc. Develop an Enterprise Asset Management System integrating IT operations systems (GIS, AMR, SCADA, Modelling etc.). EXPECTED BUSINESS BENEFITS: Energy consumption & losses reduction system operation, reliability and security improvements, water quality, customer service and demand management.

12 MILAN WATER UTILITY MAIN CONTRIBUTION TO THE PROJECT Operational expertise inject pragmatism; system design and development in keeping with real life operational needs. Knowledge of water utilities business drivers and state of the art of technology and processes: water consumption; tariffs and customer needs, network maintenance data requirements, remote control system management, operational best practices to ensure likely, robust, consistent DSS development. Definition of use case scenarios and user and system requirements.. Supply historical data (production, consumption, maintenance, tariffs, etc..). Support the definition of functional and technical system specifications consistent with water utility organizations, processes, activities and resources. Set up and operation of Pilot area system validation and testing in real life water utility operations: Contact point to end users.

13 REASONS FOR CHOOSING THE PILOT SITES Southern part of Milan water distribution system characterised by high level of pressure. Creating a pilot Pressure Management Zone (PMZ) isolated from the rest of the system and fed by a dedicated pumping facility already existing inside the area: Optimise pressure in the system Reduce energy consumption Reduce and control level of real losses Measure the benefits in terms of energy saved, volume of real losses, etc. Advantages of the PMZ, first simulated numerically through computer model sessions (InfoWorks WS; LEAKS modeling software). then gradually validated on-site

14 What Do We Know About Real Losses On Transmission Mains? TRANSMISSION MAINS are defined as larger diameter pipelines (reasonable assumption: 300 mm and larger for plastic or concrete mains, and 600 mm and larger for metallic mains) with few service connections per km of main, insufficient numbers of accessible fittings for effective use of historically available external leak detection technologies, such as acoustic listening devices and conventional leak noise correlators. Brunone et al. Global Leakage Summit, London 2013

15 What Do We Know About Real Losses On Transmission Mains? The cost of detection, location, and repair of TM leaks is significantly greater than in distribution mains, often by an order of magnitude or more. In fact, TMs tend to be buried more deeply, and in less accessible locations than distribution lines, often making it impractical to detect sound rising to the surface. They also tend to have few appurtenances, and do not transmit broad bands of sound for long distances in the way that many distribution mains do. This makes historical approaches to leak detection on TMs ineffective and leads utilities to simply exclude TMs from leak detection programs. Brunone et al.

16 What Do We Know About Real Losses On Transmission Mains? Acoustic leak detection - two main approaches: detecting the sound of leaks at greater distances in TMs (TMs correlators), finding a way to bring the acoustic sensor to the sound (inline methods). Brunone et al. Global Leakage Summit, London 2013

17 What Do We Know About Real Losses On Transmission Mains? Inline methods involve inserting a sensor into the pipeline, which traverses a run of the pipeline, collecting acoustic data as it travels. Unique challenges: eliminating other noise sources (acoustic noise inside the pipe and electrical noise in the cable), costs and risks involved in deploying and retrieving the sensors in this challenging environment. Brunone et al. Global Leakage Summit, London 2013

18 What Do We Know About Real Losses On Transmission Mains? Transmission main correlators (Canada NRC): certain acoustic signals travel extremely long distances before dissipating. Research findings have brought new correlators to the market in the past decade specifically for large diameter transmission mains. This technology has since been improved, and is now capable of consistently finding most transmission main leaks at extremely long sensor spacings (generally 1 to 2 km). Brunone et al. Global Leakage Summit, London 2013

19 What Do We Know About Real Losses On Transmission Mains? Inline technologies tend to be more expensive, and also to require significant preparatory work (adding and modifying taps), as well as much more support during the surveys (modulating flows and closing side outlets to ensure the devices travel the desired path). TM correlator services are less expensive, and can often be employed with no preparatory work and minimal support during the surveys. They are generally appropriate as part of nonrevenue water reduction programs aiming to reduce water loss at minimal cost, or where inline technologies are not feasible due to the complexity of piping or risk involved. Brunone et al. Global Leakage Summit, London 2013

20 What Do We Know About Real Losses On Transmission Mains? Inline technologies and TM correlator services are primarily offered as commercial services, as they require a great deal of specific expertise to employ successfully. Brunone et al. Global Leakage Summit, London 2013

21 Why we need more reliable techniques NEEDS To reduce duration and costs of field tests To reduce the effects of tests on the system functioning Real time monitoring of the system

22 Literature review shows that less attention has been devoted to transmission mains with respect to distribution networks $ $& In September 2012 a research project with the University of Perugia about transient test-based techniques for pipe system diagnosis

23 Towards transient test-based techniques 1 st step: Numerical experiments (early nineties)

24 Transient in an intact pipe Supply reservoir Manoeuver valve

25 Transient in a pipe with a leak Supply reservoir Manoeuver valve leak

26 Towards transient test-based techniques 2 nd step: Laboratory experiments (early 2000)

27 Water Engineering Laboratory, University of Perugia, I (WEL) Brunone et al. Global Leakage Summit, London 2013

28 Single pipe with a leak d = 14.9 mm d = 9.9 mm transect A-A orifice A A CA L L LP = m L = m; D = 93.3 mm Brunone et al. Global Leakage Summit, London 2013 V

29 Real leaks Illegal branch in Zambia (Mfula, 2007) draught water in Zambia (Chulu, 2007) Small leak in Perugia pipe system Brunone et al. Global Leakage Summit, London 2013