Available online at ScienceDirect. Procedia Engineering 70 (2014 )

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1 Available online at ScienceDirect Procedia Engineering 70 (2014 ) th International Conference on Computing and Control for the Water Industry, CCWI2013 ICT for efficient water resources management: the ICeWater energy management and control approach M. Fantozzi a, I. Popescu b *, T. Farnham c, F. Archetti d, P. Mogre e, E. Tsouchnika e, C. Chiesa f, A. Tsertou g, M. Castro Gama b, M. Bimpas g a Studio Marco Fantozzi, Via Forcella 29, Gussago, Italy - b UNESCO-IHE Inst. for Water Education, Westvest 7, 2611AX Delft, The Netherlands - c Toshiba Research Europe Ltd, 32 Queen Square, Bristol, BS1 4ND, UK - d Consorzio Milano Ricerche, via L. Cicognara 7, Milano, Italy - e Siemens AG, Corp. Technology, Otto-Hahn-Ring 6, München, Deutschland - f Metropolitana Milanese, Via del Vecchio Politecnico, 8, Milan, Italy - g Inst. of Comm. and Comp. Systems, 9, Iroon. Polytechniou Str., GR Zografou, Greece Abstract Improving water resource management is a critical issue and is becoming increasingly relevant due to the increase in population and ageing of infrastructures. In response to this, research and development activities on new solutions supporting a more rational management are currently performed in many technological areas. Present paper addresses the energy management problem from the modeling and control perspective, considering optimal pressure management and network sectorization. This is part of the solutions under development by the European Commission (EC) funded collaborative project ICeWater, which aims to develop a flexible architecture allowing different water decision support modules to work in an integrated manner. ICeWater focuses on using a service oriented approach to connect the different systems, enabling higher flexibility to the urban water utilities. Key areas of focus are improving energy efficiency of water networks highly dependent on energy, as well as reduction of water loss via innovative leak detection mechanisms. In this paper we present the initial architecture of the ICeWater system and rationale for its selection, focusing on energy management of the water distribution network, which enables significant reduction in the pressure and the associated pumping and leakage, and the control logic to practically implement the sectorisation of the water distribution network and achieve water loss and energy consumption reduction The The Authors. Published by by Elsevier Elsevier Ltd. Ltd. Open access under CC BY-NC-ND license. Selection and peer-review under under responsibility of the of the CCWI2013 CCWI2013 Committee. Committee Keywords: ICT, sensors network, decision support system, energy management, pressure management, leakage reduction * Corresponding author. Tel.: ; fax: address: i.popescu@unesco-ihe.org The Authors. Published by Elsevier Ltd. Open access under CC BY-NC-ND license. Selection and peer-review under responsibility of the CCWI2013 Committee doi: /j.proeng

2 634 M. Fantozzi et al. / Procedia Engineering 70 ( 2014 ) Introduction Ageing infrastructure, budget constraints, in-efficient operation and ensuring good water quality at all times are some of the significant challenges plaguing water utilities worldwide. These issues have prompted all the stakeholders i.e. the utilities, technology developers and integrator companies towards new innovations and operation strategies. However, currently a fragmented approach is employed where innovative products address different areas (e.g. sensors, monitoring, automation and control). These individual solutions typically do not collaborate and communicate with each other making it very difficult to comprehend and model the performance of the whole system, and hence, the global potential for optimization. In order to address these issues European Commission funded a three years project, ICT Solutions for Efficient Water Resources Management (ICeWater), with the goal to increase the stability of freshwater supply to citizens in urban areas by adjusting the water supply to the actual consumption, while minimizing energy consumption through smart-grid integration and water spillage through leak detection. ICeWater uses wireless sensor networks for water flow monitoring and provides a decision support system (DSS) for the water utilities so that supply and demand patterns can be matched in real-time. As an additional benefit, leakage can be predicted with statistical methods so that water network damages can be mended even before they occur (fix-before-break). ICeWater uses wireless sensors of various types to provide real-time monitoring of water supply and demand. Based on the sensor data, decision support systems that facilitate optimization of the water grid network operation (pumping schedules, pressure etc.) will be developed. The demand management and consumption information will be accessible online to the relevant actors in the water supply chain (including consumers) and will allows dynamic pricing schemes with nudge-pricing to motivate behavioral change in customers causing critical consumption patterns. Services for asset management, such as predicting deterioration, leakage detection and leakage localization functionalities, will reduce water waste. In order to achieve all the above goals new networking concepts (protocols, management of virtualized network resources) are required for better information flow, network resources management and sharing in a service oriented architecture (SOA). The information gathered with these services allows a better understanding of the consumers and to improve the effectiveness of the water resource management together with new metering and pricing schemes. The technologies developed in ICeWater are tested on two water distribution networks (WDN) case studies: in Milan (Italy) and Timisoara (Romania). In Timisoara the main problem is leakeage, while in Milan the WDN is supplied from 30 pumping stations (each fed by a number of pumping wells via transmission lines) and pressure is maintained in the whole system. Due to different topography and topology in the WDN, this approach leads to maintaining just above minimum pressures in some parts of the network, and higher pressures in other parts of the network. The main idea of this use case is that with optimal sectorization the network can be divided in separate pressure zones (sectors), where optimal pressure (above minimum) will be maintained and managed by supply from one or several pumping stations. The ICeWater DSS modules are underpinned and enabled by an innovative ICT platform systems and network management and application and data management middleware, featuring: Open and standard based architecture High performance, high availability Data security and safety Scalability Layered architecture with intelligent communication gateways Data models and data and transaction management tools and components.

3 M. Fantozzi et al. / Procedia Engineering 70 ( 2014 ) The ICeWater DSS 2.1. Architecture of the DSS The overall structure of the ICeWater system depicted in Figure 1 consists of three layers, starting from bottom (in field level) to the user level. Water-specific Solutions Decision Support Modules ICT-driven Services ICT solution Data Fusion & Aggregation Real-time Monitoring Water Energy... IC-Network Online Sensing and Monitoring In-Network Data Proceessing Intelligent Sensors Intelligent Water network components Actors & Sensors Fig. 1. ICeWater system layered architecture The three layers are as follows: - Layer 1: Sensors, data loggers, smart meters, other intelligent electric devices (IEDs) used to retrieve state information, alerts, any relevant physical parameter from the water supply infrastructure at all levels in this structure are also included parameters collected through existing SCADA and passed through to the ICeWater upper layers, - Layer 2: IT/IC layer, where all data gathered are cleaned, normalized, aggregated and stored in order to be made available to the upper decision support system (DSS) layer, - Layer 3: the DSS layer, consisting of different modules which provide either online or offline functionalities to the user Modules of the ICeWater DSS The DSS solution consists of five functional modules as shown in Figure 2 1. Water Loss Management (WLM) 2. Water Operation Support (WOS) 3. Water Supply System Planning (WSSP) 4. Water Demand Management (WDM) 5. Water Asset Management (WAM)

4 636 M. Fantozzi et al. / Procedia Engineering 70 ( 2014 ) The modules are underpinned by a water infrastructure information module (WI2M) a data repository storing all relevant water management and planning information and attributes. WLM and WOS are online modules that are used in the operation phase while WSSP, WDM and WAM are designed for the offline planning phase. The end users trigger the requested functionalities and display outputs from DSS via a user interface (customizable) layer. Figure 2. ICeWater DSS modules The following sections describe the preparatory actions as well as the concepts and methodology applied in the creation of the Abbiategrasso pressure management zone (PMZ), originally fully connected with WDN of Milan. 3. Preparatory actions for pressure and energy management in Abbiategrasso pilot of Milan The PMZ has been designed by means of network analysis tools in order to verify that demand is guaranteed at all demand conditions. The optimization methodology applied to the water system includes the use of both network analysis and leakage management models which allowed the calculation of leakage level and of the obtainable benefits (leakage reduction, bursts frequency reduction etc.) associated with introduction of pressure management, the identification of the PMZ boundaries, the definition of most appropriate pressure management modalities and the design of a real time pressure control system. Abbiategrasso area is located in the lower part of the city of Milan and is characterised by high pressure. The creation of the Abbiategrasso PMZ (including 116 km of mains and 1628 connections mainly high residential buildings) allows to reduce the pressure by around 20 meters, significantly reducing leakage, bursts frequency and energy consumption in the zone. In order to guarantee water supply even in case of local black out effecting the Abbiategrasso plant, Abbiategrasso PMZ in Milan will be connected to the Milan WDN by means of a pressure reducing valve (PRV) capable (in case of need/emergency) to feed the Abbiategrasso PMZ at the same level of pressure.

5 M. Fantozzi et al. / Procedia Engineering 70 ( 2014 ) Pressure and energy optimisation and control 4.1. Pressure management approach implemented in Milan Pressure Management, according to definition of the IWA Water Loss Specialist Group is: the practice of managing system pressures to the optimum levels of service ensuring sufficient and efficient supply to legitimate uses and consumers, while reducing unnecessary or excess pressures and eliminating transients and faulty level controls all of which cause the distribution system to leak unnecessarily. Water distribution system should be divided in Pressure Management Zones (PMZ) in order to optimize the benefits achievable by Pressure Management. Measuring pressure is needed to identify if there are surges, excess pressure, low pressure, head loss. Pressure, in this respect, should be measured at the inlet point of each PMZ (and distribution district) and at other two points inside the PMZ: at the Critical Point of the system to determine excess pressures and to calculate the benefit of pressure management at the Average Zone Point of the system to determine the pressure/flow characteristic and the relationship between maximum pressure and bursts frequency. Pressure measurements at the inlet point, at the Critical Point and at the Average Zone Point are shown in Fig.3. In addition it is important tocheck for the presence of surges by short-period pressure measurements (1/10 second time interval or less). The presence of Pressure Transients (PTs) in the network represents a real threat to the integrity of the water distribution system. The PTs in fact are responsible for very heavy shocks and stresses that generate breaks of mains, convections seals and instrumentations too. In a network affected by PTs, the repair of faults without the radical elimination of the cause is an expensive and sterile exercise that can go on forever without reaching an acceptable situation. The identification and elimination of PTs therefore represents a very important step for infrastructure protection and service reliability. The development of pressure transients is due to pumps and valves operation, air pockets that can form at high points and uncontrollable events such as power failures and other equipment failures. Fig.3. Pressure measurements at the inlet point, at the Critical Point and at the AZP 4.2. Pressure and energy optimization and control system In order to achieve/optimise the benefits achievable by Pressure Management, once the optimal solution for Water Distribution Sectorization has been identified and approved by the utility, the practical implementation of sectorization and pressure optimization requires the installation/closure of valves in the distribution system as well as the installation of a control system capable to control/manage pumps/prvs in newly created Pressure Management Zones (PMZ). In case of direct pumping, pressure optimisation can be achieved by Pump Control. Pump control monitors the network, develops a control model and tells the pump to provide just the right amount of pressure to meet the correct level of service at the critical point.

6 638 M. Fantozzi et al. / Procedia Engineering 70 ( 2014 ) If the pump is fitted with a variable frequency drive (VFD), the VFD varies the frequency that s driving the pump in order to regulate or vary the outlet of the pump. Therefore it is possible to command the manifold pressure and by installing a controller taking flow and pressure data from the inlet point and the pressure at the critical point(s), it is possible to control the VFD directly from the controller. This way the VFD can be fed with information (learned from historical data) about what manifold pressure we want in order to compensate for that flow related head loss in the network to achieve the optimal pressure and the lowest critical point pressure. In case of PLC (Programmable Logic Controller) controlling one or more VFD (as in large pumps installation) than the controller is linked to the PLC with the information that are needed to maintain the pressure constant at the critical point and providing that confidence that pressure remains above the minimum level of service. Pressure optimisation in case of direct pumping s shown in Figure 7. By doing it constantly, adjusting the pumps to the optimum level it is possible to minimise leakage level and bursts frequency in the zone as peak pressures are diminished. But because energy consumption by pumps is related to both the flow rate through it and the manifold pressure that is being delivered we are reducing the energy as well. In fact pump control can cut energy costs dramatically, and improve an entire water system. Because this solution optimises pressure at the pump, its benefits extend throughout a water company s network, including each water zone affected by that pump. Also, pump control allows water networks without PRVs to get the benefits of advanced pressure management. In case of gravity supply pressure optimisation can be achieved by installation of a Pressure Reducing Valve (PRV) modulating pressure at entry point to keep the pressure at the minimum level of service in the system at the critical point. In the case of Abbiategrasso PMZ in Milan, fed by direct pumping, pressure optimisation is achieved by pump control. But, in order to guarantee water supply, even in case of local black out effecting the Abbiategrasso plant, Abbiategrasso PMZ will be connected to the Milan WDN by means of a PRV capable (in case of need/emergency) to feed the PMZ at the same level of pressure. The control system is designed to manage in an integrated way both the pumps and the PRV in order to maintain a constant level of pressure at the critical point. Figure 4 shows the scheme for practical implementation of water distribution sectorization and pressure optimisation in Abbiategrasso PMZ in Milan. Fig. 4. Pressure Optimisation in Abbiategrasso PMZ in Milan

7 M. Fantozzi et al. / Procedia Engineering 70 ( 2014 ) The presence of Pressure Transients (PTs) in the network represents a real threat to the integrity of the water distribution system. The PTs in fact are responsible for very heavy shocks and stresses that generate breaks of mains, joints and instrumentations too. In a network affected by PTs, the repair of faults without the radical elimination of the cause is an expensive and sterile exercise that can go on forever without reaching an acceptable situation. The identification and elimination of PTs therefore represents a very important step for infrastructure protection and service reliability. In MM system some pressure sensors will also able to catch the water hammer by monitoring the transients through the pressure sensors that vary the sampling frequency (<1/10 sec) when the pressure exceeds a maximum value. With a frequency of (at least) 50 Hz the logger records in its local memory only the portion of the pressure trace concerning the captured PTs, and it records the events combined with date and time. In order to save energy, records are sent to the Operational Centre in CSV format files, only once a day. 5. ICeWater solutions for energy management in Milan water distribution network Energy consumption represents a key component of the budget of a water utility like MM as about 90% of that energy is consumed by pumping systems. In view of the above it is clear that developing and implementing solutions that can significantly drive down the cost of the energy used, is the right approach and important factor in modern water delivery systems. The DSS solution developed in ICeWater enables to save on energy costs by taking operational decisions which are both performance and cost oriented. Reduction of energy consumption in water system operation will be achieved by improving efficiency of the pumping system while guaranteeing the optimal level of service. This optimization activity includes: checking efficiency of pumps at wells and in the distribution system, analyzing pumping needs in relation to consumption patterns and periodical variations, identifying pumps which need replacement as their efficiency is actually too low, implement proportional pressure control to ensure constant tap pressure at the consumer as opposedto a constant pump discharge pressure, determine the optimal pump configuration to meet the utility s objectives for cost-efficiency, identifying pumps operation which optimises filling the storage tanks during periods of low tariffs and then exploits the capacity of the reservoirs at times of peak tariffs. 6. Conclusions This paper has provided details of the ICeWater energy management and control approach, which is being developed within the project, including the preparatory actions implemented by Metropolitana Milanese to allow the application of the DSS. Work is ongoing within the project to refine the architecture and prepare the necessary solutions for the trials to realise and verify the proposed approaches. This includes the integration of the various solution aspects that are required including intelligent sensors, communication infrastructure, middleware and decision support modules. The overall cost / benefit of the solutions will also be evaluated to determine the realisable impact of the proposed approaches to water distribution networks. Acknowledgements This work was supported by the European Union ICeWater project - ICT See References Herrera, A. (2011). Improving water network tesis management by efficient division into supply clusters. PhD Thesis, UPV.

8 640 M. Fantozzi et al. / Procedia Engineering 70 ( 2014 ) Lambert, A., Fantozzi, M., Thornton, J., & Kovac, J. (2012). Ongoing Developments in analysing, predicting and validating benefits of Pressure Management. Proceedings of IWA Special Conference 'Water Loss 2012'. Ferrara, Italy. Martinez, F. et al. (n.d.). Optimizing the operation of the Valencia WDN. Journal of Hydroinformatics, 9(1). Mays, L., & Ozger, S. (2004). Optimal location of isolation valves in water distribution system reliability optimization approach. Water Supply Systems Security. Wide Bay Water Corp. (2011). Framework for Targeting Leakage and Pressure Management. In Report for Water Services Association of Australia, in WSAA Asset Management Project PPS-3, Review of Leakage Reporting and Management Practices, Stage 3. Wide Bay Water Corporation and Water Loss Research & Analysis Ltd. ICeWater Deliverable D2.2 Use cases ;