Optimal Location Of Valves Research Articles

Optimal Segmentation Approach for Reducing Water Outage Damage Considering Urbanization in Water Distribution Systems

Damage due to abnormal conditions in water distribution systems is attributable to direct causes, such as facility deterioration, as well as indirect causes, including inadequate management, natural disasters, and negligence of a manager. Such damage can be prevented from being spread by closing a shut-off valve to isolate the incident area, although additional damage may occur in the area isolated by the control valve due to water outage, thus requiring a structural solution. Therefore, this study proposed an optimal segment division technique that minimizes the damage due to water outage occurring in the isolated area by installing a shut-off valve at an appropriate location through an optimal valve location determination model designed based on various urban development scenarios. The proposed technique was applied to a benchmark network and J-city network in Korea for performance verification. This technique can be used to select the number of installable valves and find the optimal valve locations according to the urban development scenario.

Optimal Location of Valves to Improve Equity in Intermittent Water Distribution Systems

This paper proposes a methodology to increase the level of water distribution equity in intermittent water distribution networks (WDNs) with users equipped with private tanks. The methodology makes it possible to identify optimal valve locations and settings to improve the distribution of water among users by rearranging the flow circulation in the network. Two optimization schemes based on the use of NSGA II were developed. The first scheme aims at maximizing the global distribution equity of a WDN through installation of valves fully closed. The second scheme looks also at the levels of supply of the individual nodes of a WDN and includes optimization of both locations and settings of control valves. The two optimization schemes are applied to the case study of a WDN in northern Italy considering a scenario of water shortage. The EPA’s Storm Water Management Model software was used for the pressure-driven simulation of an intermittent WDN. Results of the application of the two optimization schemes highlight the potential for an increase in the global equity of the WDN by installation of a few valves. However, some nodes of the WDN were penalized by the new flow circulation as obtained by solutions provided by the first scheme. In fact, these nodes unacceptably worsen their condition compared to the no-valve scenario. Conversely, solutions obtained with the second scheme allowed demand satisfaction levels to not worsen compared to the no-valve scenario for all nodes.

Improving Water Distribution Systems Robustness through Optimal Valve Installation

This study proposes a framework for improving the robustness of water distribution systems using the optimal valve installation approach with regard to system reinforcement. To improve the robustness in valve design, this study introduces critical segment selection technique and optimal valve location determination within the concept of segment. Using the segment finding algorithm, the segment and the unintentional isolation can be identified. To select the critical segment, a multicriteria decision technique is applied by considering the hydraulic, social and economic effect. Finally, the optimal valve locations and the number of additional valves is determined by pipe failure analysis through the trade-off relationship with the number of additional valves and the maximum damage under pipe failure situations. To verify the proposed technique, the real-world water distribution systems are applied and compared with the original design.

Minimizing Excess Pressures by Optimal Valve Location and Opening Determination in Water Distribution Networks

Water leakage, which could be defined as supplied, treated, transmitted and finally lost volume of a water source; needs to be minimized in a water distribution network (WDN). This paper presents a heuristic optimization model to minimize excess nodal pressures in a water distribution network by determining the location and setting of control valves. The optimization technique is based on Genetic Algorithms (GA) which could be defined as a search heuristic that imitates the process of natural selection. The eventual optimization objective is to find optimal setting of control valves to decrease excess pressures and water leakage proportionally. The main body of the methodology is divided into sub-sections. These sections allocate the operative valves considering both Steady State (SS) and Extended Period Simulation (EPS) cases consecutively. The setting of operative valves are then determined in the final step by employing Throttle Control Valves (TCVs) into the network. The developed model has been applied on a case study network that has 89 nodes and considerable excess pressure decrements are handled.

Multiobjective Optimization of Pipe Replacements and Control Valve Installations for Leakage Attenuation in Water Distribution Networks

This paper shows how pipe replacements and control valve installations can be optimized in water distribution networks to reduce leakage, under minimum nodal pressure constraints. To this end, a hybrid multiobjective algorithm, which has pipe diameters and valve positions and settings as decisional variables, was set up. The algorithm also enables identification of the isolation valves that have to be closed in order to improve effectiveness of the control valves installed. The algorithm is initially applied to the optimal valve location problem, where it explores the trade-off between the number of installed control valves and the daily leakage volume. In this context, the analysis of the results proves the new algorithm more effective than a multiobjective genetic algorithm widely adopted in the scientific literature. Furthermore, it shows that if some isolation valves identified ad hoc are closed in the network, the installation of control valves determines larger leakage volume reductions. In a second application of the algorithm, pipe replacements and control valve installations are simultaneously performed. In this case, a Pareto front of trade-off solutions between installation costs and daily leakage volume is obtained. For the choice of the final solution within the front, an economic criterion based on the long-term convenience analysis is also illustrated.

Knowledge-Based Optimization Model for Control Valve Locations in Water Distribution Networks

This paper presents a knowledge-based optimization model for minimizing leakage in water distribution systems through the most effective location and setting of control valves. The optimization model is based on the use of a genetic algorithm (GA), which is known for its robustness for handling the optimization of water distributions networks. Knowledge of the water distribution system has been incorporated into the optimization model to reduce the search space and to enhance the model efficiency in finding the optimal solutions. A single optimization model to search for both the optimal location of valves and their settings has been used. These two improvements over other models have enhanced the efficiency of the model and improved the search for the optimum solution. The model has been used to test leakage minimization in a benchmark water network studied by other researchers and has proven to be very efficient and robust.

A Stochastic Programming Approach for the Strategic Valve Locations Problem in a Water Distribution System

Water distribution networks are important systems that provide citizens with an essential public service which is crucial for the normal development of most basic activities of life. We address a challenging problem in the design of the isolation system for water distribution networks concerning the optimal location of valves in a water network.The aim of an isolation valve system is to separate a portion of the water distribution network for maintenance, pipe breaks or protection against contaminants. Despite many water distribution network problems have been extensively investigated in the literature, the presence of uncertainty in the data has often been neglected.We address this shortcoming presenting a stochastic programming approach for the strategic valve locations problem in water distribution networks by considering different failure scenarios. Numerical results on case studies taken from the literature are presented.

다구치 방법과 근사최적설계를 이용한 자동차 연료탱크의 연료 넘침 방지 시스템 설계

자동차 연료탱크는 크게 본체와 본체에 조립되는 부품들로 구성되어 있다. 본체에는 차량 주행시에 연료탱크에서 발생되는 증발가스를 배출하고, 연료가 외부로 유출되는 것을 방지하기 위한 여러 밸브들이 조립되어 있다. 하지만 이러한 밸브들은 연료 넘침에 주된 원인으로 알려져 있음에도 불구하고 현재 증발가스의 배출과 기구적인 위치만 고려하여 설계되고 있다. 따라서 본 연구에서는 밸브들의 기존기능을 유지하면서 연료 넘침을 최소화 시키기 위해 근사최적설계를 적용하였고, 다구치방법을 통해 실제 실험에서 근사최적설계의 유용성을 보였다. 결과적으로 최적화된 밸브 위치를 통해 개발기간과 비용을 절감하였고, 연료 넘침 최소화를 통해 자동차의 신뢰성을 향상시켰다.

The valve location problem: Minimizing environmental damage of a spill in long oil pipelines

A shutoff valve is a control device that blocks oil flow in a pipeline in order to reduce the oil escape. This paper addresses the valve location problem where, given a pipeline network and a number of valves for installation, the task is to find a valve location that minimizes the maximum environmental damage of an oil spill. We present the first complete framework for fast computing of an optimal valve location in a general oil pipeline network. To achieve this, we formalize the problem and explain how to quantify environmental damages. Next, we present two fast algorithms optimally solving the valve location problem on linear pipeline segments. Further, we show how to extend the algorithms to solve the problem on a general pipeline network. We conclude with a computational study showing that solutions provided by our framework can reduce the adverse effects of a spill by up to 37% compared to the currently used solutions.

Optimal Location of Control Valves in Pipe Networks by Genetic Algorithm

This paper addresses the problem of appropriate location of control valves in a water supply pipe network and their settings via genetic algorithm (GA) to obtain maximum leakage reduction for given nodal demands and reservoir levels. Embedded in this optimization is the problem of determination of optimal control-valve settings in terms of minimization of system leakage for a given location of valves. It is shown through an example water distribution network that the optimally located valves are much more effective at producing maximum leakage reduction in the network. On the basis of multiple simulations of demand patterns, it was found that the expected value of leakage in a network provided with optimally placed control valves is practically independent of total demand. A study of the effect of varying demands on the optimal location of valves indicated distinct combinations of valve-locations for the different spatial patterns of nodal demands and for different total demands.