scholarly journals Qualification of Hydraulic Analysis Models for Optimal Design of Water Distribution Systems

2021 ◽  
Vol 11 (17) ◽  
pp. 8152
Author(s):  
Young Hwan Choi
Keyword(s):  
Optimal Design ◽  
Negative Pressure ◽  
Distribution Systems ◽  
Water Distribution ◽  
Water Distribution Systems ◽  
Real Life ◽  
Operating Conditions ◽  
Design Model ◽  
Hydraulic Analysis ◽  
Design Characteristics

The hydraulic analysis of water distribution systems (WDSs) is divided into two approaches, namely, a demand-driven analysis (DDA) and a pressure-driven analysis (PDA). In DDA, the basic assumption is that the nodal demand is fully supplied irrespective of the nodal pressure, which is mainly suitable for normal operating conditions. However, in abnormal conditions, such as pipe failures or unexpected increases in demand, the DDA approach may cause unrealistic results, such as negative pressure. However, despite these realistic hydraulic analysis approaches for WDSs being emphasized in the design process, this consideration was lacking in the design aspect. Therefore, in this study, the designs by the DDA-based design model and PDA-based design model are compared, and their design characteristics are analyzed to identify the efficiency of the WDSs design under abnormal system conditions. The developed PDA model was applied to three networks (a well-known benchmark system and a real-life WDN), and the results showed that the proposed model is superior to other reported models when dealing with negative pressure under abnormal conditions. In addition, the optimal design of WDN considered PDA is presented, and the optimal construction cost is decreased to increase the percentage of PDA.

scholarly journals Modeling Bacterial Regrowth and Trihalomethane Formation in Water Distribution Systems

Water ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 463
Author(s):  
Gopinathan R. Abhijith ◽  
Leonid Kadinski ◽  
Avi Ostfeld
Keyword(s):  
Distribution Systems ◽  
Water Distribution ◽  
Mechanistic Model ◽  
Water Distribution Systems ◽  
Sensitivity Study ◽  
Operating Conditions ◽  
Growth Rate Constant ◽  
Model Parameters ◽  
Bacterial Regrowth ◽  
The Impact

The formation of bacterial regrowth and disinfection by-products is ubiquitous in chlorinated water distribution systems (WDSs) operated with organic loads. A generic, easy-to-use mechanistic model describing the fundamental processes governing the interrelationship between chlorine, total organic carbon (TOC), and bacteria to analyze the spatiotemporal water quality variations in WDSs was developed using EPANET-MSX. The representation of multispecies reactions was simplified to minimize the interdependent model parameters. The physicochemical/biological processes that cannot be experimentally determined were neglected. The effects of source water characteristics and water residence time on controlling bacterial regrowth and Trihalomethane (THM) formation in two well-tested systems under chlorinated and non-chlorinated conditions were analyzed by applying the model. The results established that a 100% increase in the free chlorine concentration and a 50% reduction in the TOC at the source effectuated a 5.87 log scale decrement in the bacteriological activity at the expense of a 60% increase in THM formation. The sensitivity study showed the impact of the operating conditions and the network characteristics in determining parameter sensitivities to model outputs. The maximum specific growth rate constant for bulk phase bacteria was found to be the most sensitive parameter to the predicted bacterial regrowth.

Optimal Design of Water Distribution Systems Using an NLP Method

1997 ◽  
Vol 123 (4) ◽  
pp. 381-388 ◽  
Author(s):  
K. Vasant Kumar Varma ◽  
Shankar Narasimhan ◽  
S. Murty Bhallamudi
Keyword(s):  
Optimal Design ◽  
Distribution Systems ◽  
Water Distribution ◽  
Water Distribution Systems

Evolutionary Computation for Single and Multiobjective Water Distribution Systems Optimal Design

2010 ◽  
pp. 332-345
Author(s):  
Avi Ostfeld
Keyword(s):  
Genetic Algorithm ◽  
Optimal Design ◽  
Distribution Systems ◽  
Water Distribution ◽  
Water Distribution Systems ◽  
Future Research ◽  
Research Directions ◽  
Fixed Set ◽  
Gradient Type ◽  
Future Research Directions

Water distribution systems least cost pipe sizing/design is probably the most explored problem in water distribution systems optimization. Attracted numerous studies over the last four decades, two main approaches were employed: decomposition in which an “inner” linear programming problem is solved for a fixed set of flows/heads, while the flows/heads are altered at an “outer” problem using a gradient or a sub-gradient type technique; and the utilization of an evolutionary optimization algorithm (e.g., a genetic algorithm). In reality, however, from a broader perspective the design problem is inherently of a multiobjective nature incorporating competing objectives such as minimizing cost versus maximizing reliability. This chapter reviews some of the literature on single and multiobjective optimal design of water distribution systems and suggests a few future research directions in this area.

Coping with future change: Optimal design of flexible water distribution systems

2020 ◽  
Vol 61 ◽  
pp. 102306
Author(s):  
Seneshaw Tsegaye ◽  
Kristopher C. Gallagher ◽  
Thomas M. Missimer
Keyword(s):  
Optimal Design ◽  
Distribution Systems ◽  
Water Distribution ◽  
Water Distribution Systems ◽  
Future Change

scholarly journals Development of Multi-Objective Optimal Redundant Design Approach for Multiple Pipe Failure in Water Distribution System

Water ◽  
2019 ◽  
Vol 11 (3) ◽  
pp. 553 ◽  
Author(s):  
Young Choi ◽  
Joong Kim
Keyword(s):  
Optimal Design ◽  
Distribution System ◽  
Distribution Systems ◽  
Water Distribution ◽  
Search Algorithm ◽  
Harmony Search ◽  
Water Distribution Systems ◽  
Design Approach ◽  
Pipe Failure ◽  
Multi Objective

This study proposes a multi-objective optimal design approach for water distribution systems, considering mechanical system redundancy under multiple pipe failure. Mechanical redundancy is applied to the system’s hydraulic ability, based on the pressure deficit between the pressure requirements under abnormal conditions. The developed design approach shows the relationships between multiple pipe failure states and system redundancy, for different numbers of pipe-failure conditions (e.g., first, second, third, …, tenth). Furthermore, to consider extreme demand modeling, the threshold of the demand quantity is investigated simultaneously with multiple pipe failure modeling. The design performance is evaluated using the mechanical redundancy deficit under extreme demand conditions. To verify the proposed design approach, an expanded version of the well-known benchmark network is used, configured as an ideal grid-shape, and the multi-objective harmony search algorithm is used as the optimal design approach, considering construction cost and system mechanical redundancy. This optimal design technique could be used to propose a standard for pipe failure, based on factors such as the number of broken pipes, during failure condition analysis for redundancy-based designs of water distribution systems.

scholarly journals Optimal Design of Water Distribution Systems with Pressure Driven Demands

2014 ◽  
Vol 89 ◽  
pp. 839-847 ◽  
Author(s):  
D. Páez ◽  
J. Saldarriaga ◽  
L. López ◽  
C. Salcedo
Keyword(s):  
Optimal Design ◽  
Distribution Systems ◽  
Water Distribution ◽  
Water Distribution Systems ◽  
Pressure Driven

Uncertainty quantification of pressure-driven analysis for water distribution network modeling

2015 ◽  
Vol 16 (3) ◽  
pp. 599-610 ◽  
Author(s):  
Ho Min Lee ◽  
Do Guen Yoo ◽  
Doosun Kang ◽  
Hwandon Jun ◽  
Joong Hoon Kim
Keyword(s):  
Negative Pressure ◽  
Water Distribution ◽  
Real Life ◽  
Water Distribution Network ◽  
Distribution Networks ◽  
Operating Conditions ◽  
Service Reliability ◽  
High Degree ◽  
Pressure Driven Analysis ◽  
Pressure Driven

The hydraulic analysis of water distribution networks (WDNs) is divided into two approaches: namely, a demand-driven analysis (DDA) and a pressure-driven analysis (PDA). In the DDA, the basic assumption is that the nodal demand is fully supplied irrespective of the nodal pressure, which is mainly suitable for normal operating conditions. However, in abnormal conditions, such as pipe failures or unexpected increase in demand, the DDA approach may cause unrealistic results, such as negative pressure. To address the shortcomings of DDA, PDA has been considered in a number of studies. For PDA, however, the head-outflow relation (HOR) should be given, which is known to contain a high degree of uncertainty. Here, the DDA-based simulator, EPANET2 was modified to develop a PDA model simulating pressure deficient conditions and a Monte Carlo simulation (MCS) was performed to consider the quantitative uncertainty in HOR. The developed PDA model was applied to two networks (a well-known benchmark system and a real-life WDN) and the results showed that the proposed model is superior to other reported models when dealing with negative pressure under abnormal conditions. In addition, the MCS-based sensitivity analysis presents the ranges of pressure and available discharge, quantifying service reliability of water networks.

Sign in / Sign up

Export Citation Format

Share Document