Battle Of Background Leakage Assessment Research Articles

Special Issue on the Battle of Background Leakage Assessment for Water Networks

Special Issue on the Battle of Background Leakage Assessment for Water Networks

Comparing Optimization Techniques with an Engineering Judgment Approach to WDN Design

AbstractThe design of water distribution networks (WDNs) is a complex nonlinear problem that has been solved using optimization techniques attempting to find near-globally optimal solutions. This paper demonstrates that relying on engineering judgment, with very limited use of optimization, can generate reasonable quality approximations of the Pareto front of multiobjective WDN design problems without intensive computational requirements. First the results of the implementation of a previous implementation of the engineering judgment approach to the Battle of Background Leakage Assessment for Water Networks (BBLAWN) design competition is summarized. Additionally, a simplified version of the BBLAWN problem is solved using both the engineering judgment approach and a multiobjective optimization algorithm and the corresponding Pareto fronts are compared. Relative to other BBLAWN solutions, the engineering judgment solution produced a high-quality result with a very small computational budget and was able to ...

Combining Engineering Judgment and an Optimization Model to Increase Hydraulic and Energy Efficiency in Water Distribution Networks

AbstractThis paper presents a methodology for optimizing the operations of water distribution networks. The methodology combines the use of best management practices with a pseudogenetic algorithm, and has been applied to solve the problem of the battle of background leakage assessment for water networks. This problem involves more than 70,000 decision variables. To reduce this number, the problem was divided into three steps. First, a preliminary analysis was performed to define criteria for the replacement of pipes and pumps with a definition of potential subareas. Then, an optimization model was used to determine the pump schedule and pipe replacement. Finally, fine adjustments were performed including pump replacement, control pressure valve usage, and valve-setting definition. The main conclusion derived from this work is that a proper combination of optimization techniques and manual adjustments based on the use of engineering judgment is suitable to solve generic problems in water supply networks.

Decreasing Leakage and Operational Cost for BBLAWN

AbstractThe solution approach proposed in this paper is on the basis of trial-and-error methodology, using heuristic methods with simulation at the battle of background leakage assessment for water networks (BBLAWN). To achieve the optimal solution, customized researched tools were developed for water distribution system (WDS) optimization. These include subroutines for: optimization of water tanks levels to switch pumps on and off; estimation of the influence of the pressure-reducing valves (PRVs) on leakages, to make a decision whether there is a justification for adding a PRV to a pipe or not; calculation of leakages under different conditions; and replacing old pipes with new ones. For design decisions, commercially available tools were also used, carrying out comparison of various network structures (parallel pipe alternatives). The final result included the installation of 80 PRVs, the replacement of 370 pipes, and the change of 2 pump elements; the pumping schedule, on the basis of water tank level...

Decomposition Approach for Background Leakage Assessment: BBLAWN Instance

AbstractThis paper summarizes an approach for the assessment and control of background leakage on water distribution networks. The methodology was developed for the battle of background leakage assessment for water networks (BBLAWN) held at the Water Distribution System Analysis Conference 2014 in Bari, Italy. The problem instance posed for the conference considers an aging water network with high levels of background leakage. A range of operational and design changes including new valves, pipes, pumps, tanks, and controls are available to reduce the expenditure needed to operate the system. Constraints are imposed on nodal pressures and tank levels to meet service level requirements. The solution methodology proposed in this paper decomposes the problem according to the type of intervention, considering each type separately. An initial diagnosis of the network informs the manner and order of evaluating the various interventions. Custom implementations of network simulation, heuristic algorithms, and opti...

Optimal Management of Water Distribution Networks with Simulated Annealing: The C-Town Problem

AbstractSustainability is a major issue for water companies, who have to provide high quality services at achievable costs. In this context, water loss control and energy efficiency are two great challenges water companies have to face. Water loss represents both higher service cost (real losses) and loss of revenue (apparent losses), while the energy bill from treatment plants and pumping stations represents a significant part of the service cost. The Battle of Background Leakage Assessment for Water Networks (BBLAWN) was a competition dedicated to this subject: water distribution network (WDN) optimal management. Teams/individuals from academia, consulting firms, and utilities were invited to propose methodologies for solving the C-Town WDN problem: minimize operational and capital costs and background leakages. This paper presents one of the methodologies proposed at BBLAWN. The methodology proposed here to solve the C-Town WDN problem comprises two optimization models: a least-cost design model to ide...

Hybrid Evolutionary Optimization/Heuristic Technique for Water System Expansion and Operation

AbstractThis paper presents a methodological solution to The Battle of Background Leakage Assessment for Water Networks (BBLAWN) competition. The methodology employs two constrained multiple-objective optimization problems and is implemented in the context of a software application for the generic hydraulic optimization and benchmarking of water distribution system (WDS) problems. The objectives are the combined infrastructure and operational costs and system-wide leakage, both to be minimized. In order to accelerate the evaluation of potential solutions, a distributed computing approach permits multiple EPANET solutions to be evaluated in parallel. A pressure-driven demand extension to EPANET assists the optimization in accurately ranking near-feasible solutions and to dynamically allocate leakage demand to nodes. Pressure-reducing valves (PRVs) have been located in two ways: a priori, with respect to the optimization analysis, and a posteriori after the infrastructure optimization to reduce excess press...

Redesigning Water Distribution Networks Using a Guided Evolutionary Approach

AbstractThe paper describes and discusses the application of a guided evolutionary approach for the optimization of water distribution networks. Initially developed for the Battle of the Water Networks II (BWN-II), the approach was adapted and improved for competing in the Battle of Background Leakage Assessment for Water Networks (BBLAWN). The proposed evolutionary approach operates in an exclusively discrete solution space and is intended to require as little engineering judgment and time as possible while attaining acceptable and informative results that are useful for decision making. Its main features are custom crossover and mutation operators specific for water distribution network optimization tasks. A simple postprocessing greedy algorithm to locally refine pipe replacements is introduced as a means of complementing the evolutionary approach.

Operational and Tactical Management of Water and Energy Resources in Pressurized Systems: Competition at WDSA 2014

AbstractOptimal management of water and energy resources worldwide is a basis for environmental and socioeconomic sustainability in urban areas, which has become even more relevant with the advent of the smart and water sensitive city paradigm. In water distribution networks (WDNs) water resource management is concerned with increased efficiency, which is primarily related to the reduction of leakages, whereas energy management refers to optimal pump, valve, and source scheduling strategies considering the hydraulic system requirements. These management goals require planning of asset renewal and improvement works in the short time (operational) and medium time (tactical) horizons, considering the financial sustainability of relevant actions. The battle of background leakage assessment for water networks (BBLAWN) was designed as a competition held at the 16th Water Distribution Systems Analysis Conference, in Bari (Italy) in 2014 (WDSA), to address the aforementioned management goals. The teams taking par...

Successive Linear Programming Approach Applied to BBLAWN

AbstractThe battle of background leakage assessment for water networks (BBLAWN) challenge was approached using successive linear programming. A linear representation was solved successively for the nonlinear constraints of headloss, leakage, pump energy consumption, and pipe sizing. The optimization model returned minimal cost pump scheduling and pipe sizing while minimizing leakage and maintaining minimum service pressures to the consumers. Pressure reducing valves, pump, and water tank sizing were performed manually and their effect was examined using the optimization model. Parallel pipes were added along the main supply pipes from the pumping stations to the water tanks, to allow for minimum service pressures. Pressure reducing valves were added to pipes branching from the main supply pipes to lower excess pressures to the secondary supply pipes.

Battle of Background Leakage Assessment for Water Networks (BBLAWN) at WDSA Conference 2014

Abstract The Battle of Background Leakage Assessment for Water Networks (BBLAWN) is the fifth in a series of “Battle Competitions” dating back to the Battle of the Water Networks (BWN) in 1985 and, more recently, the Battle of the Water Sensor Networks (BWSN) in 2006; the Battle of the Water Calibration Networks (BWCN) in 2010 and the Battle of the Water Networks Design (BWN-II) in 2012. The BBLAWN asks for a design methodology for reducing water losses due to background leakages in a real water distribution system. The results have been presented at a special session of the 16th Water Distribution Systems Analysis Conference, held in Bari, Italy in July 2014, where 14 teams from academia, research centers and companies presented their solutions to the problem in hand.

Guided Evolutionary Approaches for Redesigning Water Distribution Networks

The paper describes water distribution network optimization procedures proposed for the Battle of Background Leakage Assessment for Water Networks (BBLAWN) competition. The tested optimization methodologies build upon research carried out in the earlier Battle of the Water Networks II (BWN-II), hosted in the Water Distribution System Analysis 2012 (WDSA 2012) conference. Two approaches were evaluated: a single-objective genetic algorithm and a multi-objective genetic algorithm, both taking advantage of a guided mutation scheme. Computations have been carried out in a Java version of EPANET aiming at increased computational efficiency, greater platform portability, and improved flexibility regarding optimization software.

A Simulation-Optimization Approach for Reducing Background Leakage in Water Systems

Abstract This paper forms an entry to the battle of background leakage assessment for water networks (BBLAWN). The proposed method- ology for this problem is a sequential assessment of intervention types. In an initial stage, a diagnosis of the network is performed through simulating its hydraulic behaviour with no infrastructure or operational modifications. An optimization technique is de- veloped to recommended improvements of a particular type, such as pipes to replace. These techniques are applied sequentially to yield a list of suggested improvements for the network. Our approach requires a hydraulic model that simulates background leakage, custom implementations of heuristic algorithms and optimization solvers.

WDS Leakage Management through Pressure Control and Pipes Rehabilitation Using an Optimization Approach

Leakage management through pressure control is a common practice in many water utilities to reduce water loss. The current Battle of Background Leakage Assessment for Water Networks (BBLAWN), is an attempt to combine WDS rehabilitation planning with pressure control management to achieve a better leakage ratio and lower WDS capital and operational costs. The aim of the current paper is to present the optimization results that pertain to the C-Town network as part of the BBLAWN competition. Results indicate that the selected solution is a feasible solution in regards to the battle constraint and reduces the leakage rate by 80 percent.

BBLAWN: A Combined Use of Best Management Practices and an Optimization Model Based on a Pseudo-Genetic Algorithm

Abstract The paper presents a solution to the problem of the Battle of Background Leakage Assessment for Water Networks (BBLAWN) using a methodology that combines the use of Best Management Practices (BMPs) and an optimization model based on a Pseudo-Genetic Algorithm (PGA) as described in [1] . In a first stage, an analysis of marginal costs of pipes whose replacement would be potentially recommended was performed. Next, a network topological analysis to study the pipes that could potentially be closed in order to facilitate pressure control was done. Furthermore, a methodology for studying branched areas was also developed, determining possible location for pressure reducing valves (PRV). A significant reduction in the number of decision variables was obtained and a specific optimization model was developed.

Sequential Multi-objective Evolutionary Algorithm for a Real-world Water Distribution System Design

Abstract This paper presents a methodology based on a three-stage multi-objective optimization model for solving the problem of Battle of Background Leakage Assessment for Water Networks (BBLAWN) at WDSA2014 conference. At the first stage, the optimal design of pipeline rehabilitation, pump scheduling and tank sizing is formulated and solved on the skeletonized network by a optimizing (1) the costs of pipes, pumps and tank upgrading and (2) the cost of water losses and energy. Three optimal solutions are used for a second optimisation step on the full network (i.e. not skeletonised). The third optimisation step is then performed starting from second stage optimal solutions considering the three objectives of the original problem.

A Comparison of Population-based Optimization Techniques for Water Distribution System Expansion and Operation

Abstract This paper presents a water distribution system expansion and operation methodology employing population-based optimization algorithms applied to the Battle of Background Leakage Assessment for Water Networks competition. The problem is formulated as constrained single and multiple-objective optimization problems and implemented in a generic hydraulic optimization and benchmarking software application (Acquamark). To accelerate the evaluation of potential solutions, a distributed computing approach is employed, where necessary, to permit multiple solutions to be executed and evaluated in parallel. A pressure-driven demand extension to the EPANET hydraulic model is also employed to assist the optimization techniques in accurately ranking near-feasible solutions and to dynamically allocate leakage demand to the end nodes of each pipe.

Battle of Background Leakage Assessment for Water Networks Using Successive Linear Programing

Abstract This research attempts to solve the BBLAWN challenge. The examined town consists of several pressure zones with significant elevation differences, causing accesses water pressure and pipe leakage. The challenge of optimally resizing the water system, to meet future water demands and minimize leakage, was solved using a successive linear programming, minimum cost, optimal operation model that includes head loss constraints, leakage control, pipe diameter selection and pressure reducing valves. A combination of an optimization model and practical engineering experience was used in the positioning of the pressure reducing valves and sizing of pump stations and water tanks.

Battle of Background Leakage Assessment for Water Networks (BBLAWN): An Incremental Savings Approach

Abstract The design problem is solved considering the methodology used by [1] in the previous WDSA Battle competition. In particular, engineering judgment defines the entire solution process such that no optimization algorithm was utilized beyond a simple root-finding algorithm for determining some PRV settings. Then the problem is formulated as a bi-objective optimization problem that maximizes the operational savings and minimizes the total capital costs - both relative to the baseline solution. Finally, the design is modified to remove previously selected decision variables with low incremental operational savings per unit of capital cost expenditures and then fine-tuned to ensure pressure and tank level constraints are exceeded by a comfortable margin (at least 5%).