scholarly journals Improved Hydraulic Simulation of Valve Layout Effects on Post-Earthquake Restoration of a Water Distribution Network

2020 ◽  
Vol 12 (8) ◽  
pp. 3492
Author(s):  
Jeongwook Choi ◽  
Doosun Kang

To restore water pipes damaged by earthquakes, it is common to block the water flow by closing the associated shut-off valves. In this process, water supply suspension in the area connected to the isolated pipes is inevitable, which decreases the serviceability of the water distribution network (WDN). In this study, we identified the impact of valve layout (i.e., number and location) on system serviceability during a seismic damage restoration process. By conducting a pressure-driven-analysis (PDA) using EPANET 3.0, a more realistic hydraulic analysis could be carried out under the seismically damaged condition. Furthermore, by considering the valve-controlled segment in the hydraulic simulation, a more realistic water suspension area was determined, and efficient seismic damage restoration strategies were identified. The developed model was implemented on a WDN to demonstrate the effect of valve layout on the post-earthquake restoration process. Finally, effective restoration strategies were suggested for the application network.

Water ◽  
2021 ◽  
Vol 13 (16) ◽  
pp. 2141
Author(s):  
Stavroula Tsitsifli ◽  
Vasilis Kanakoudis

Disinfection is one of the most important water treatment processes as it inactivates pathogens providing safe drinking water to the consumers. A fresh-water distribution network is a complex system where constant monitoring of several parameters and related managerial decisions take place in order for the network to operate in the most efficient way. However, there are cases where some of the decisions made to improve the network’s performance level, such as reduction of water losses, may have negative impacts on other significant operational processes such as the disinfection. In particular, the division of a water distribution network into district metered areas (DMAs) and the application of various pressure management measures may impact the effectiveness of the water chlorination process. Two operational measures are assessed in this paper: (a) the use of inline chlorination boosters to achieve more efficient chlorination; and (b) how the DMAs formation impacts the chlorination process. To achieve this, the water distribution network of a Greek town is chosen as a case study where several scenarios are being thoroughly analyzed. The assessment process utilizes the network’s hydraulic simulation model, which is set up in Watergems V8i software, forming the baseline to develop the network’s water quality model. The results proved that inline chlorination boosters ensure a more efficient disinfection, especially at the most remote parts/nodes of the network, compared to conventional chlorination processes (e.g., at the water tanks), achieving 100% safe water volume and consuming almost 50% less chlorine mass. DMAs’ formation results in increased water age values up to 8.27%, especially at the remote parts/nodes of the network and require more time to achieve the necessary minimum effective chlorine concentration of 0.2 mg/L. However, DMAs formation and pressure management measures do not threaten the chlorination’s efficiency. It is important to include water age and residual chlorine as criteria when optimizing water pressure and the division of DMAs.


2020 ◽  
Vol 2 (1) ◽  
pp. 18 ◽  
Author(s):  
Marco Amos Bonora ◽  
Fabio Caldarola ◽  
Mario Maiolo ◽  
Joao Muranho ◽  
Joaquim Sousa

A new set of local performance indices has recently been introduced within a mathematical framework specifically designed to promote a local–global analysis of water networks. Successively, some local indices were also set up and implemented on WaterNetGen to better exploit their potential. In this paper, after a very brief overview of tools and main notations, Santarém’s (Portugal) water distribution network (WDN) is examined, applying to it the mentioned set of local indices, as a new real case study. The paper also focuses on the Hypotesis required to assess these indices in a pressure driven analysis (PDA) approach, analyzing and discussing the results obtained from such a simulation.


Water ◽  
2020 ◽  
Vol 12 (5) ◽  
pp. 1323 ◽  
Author(s):  
Menelaos Patelis ◽  
Vasilis Kanakoudis ◽  
Anastasia Kravvari

In this paper, the effects of pressure regulation in a water distribution network (WDN) are being examined. Quality is hammered the most when pressure is reduced in a WDN and this occurs due to the increase in the age of water flowing inside the network pipes (water age is actually the total time the water remains inside the pipes before reaching the customer’s tap). Kos town WDN is used as the case study network. Kos town is the capital of the homonymous Greek island, among the most famous and popular of the Greek islands. The specific WDN is quite typical but very interesting, as it is extended along the seafront. The network’s hydraulic simulation model was developed through the WaterCad V8i software. As Kos experiences too high-water demand peaks and lows during summer and winter time, respectively, its WDN has already been thoroughly studied, in order to regulate the pressure and reduce its annual water loss rates. Nevertheless, these scenarios have never been examined regarding the impact on water quality. In the current study, the division of the WDN in District Metered Areas (DMAs) and the use of a Pressure Reducing Valve (PRV) in the entering node of each DMA are being evaluated in terms of water age. Additionally, a swift optimization process takes place to produce different DMAs’ borders, based on the criteria of minimum nodal water age, instead of optimal pressure. Different scenarios were tested on the calibrated and validated hydraulic model of Kos town WDN.


2007 ◽  
Vol 9 (1) ◽  
pp. 51-64 ◽  
Author(s):  
Elad Salomons ◽  
Alexander Goryashko ◽  
Uri Shamir ◽  
Zhengfu Rao ◽  
Stefano Alvisi

Haifa-A is the first of two case studies relating to the POWADIMA research project. It comprises about 20% of the city's water-distribution network and serves a population of some 60,000 from two sources. The hydraulic simulation model of the network has 126 pipes, 112 nodes, 9 storage tanks, 1 operating valve and 17 pumps in 5 discrete pumping stations. The complex energy tariff structure changes with hours of the day and days of the year. For a dynamically rolling operational horizon of 24 h ahead, the real-time, near-optimal control strategy is calculated by a software package that combines a genetic algorithm (GA) optimizer with an artificial neural network (ANN) predictor, the latter having replaced a conventional hydraulic simulation model to achieve the computational efficiency required for real-time use. This paper describes the Haifa-A hydraulic network, the ANN predictor, the GA optimizer and the demand- forecasting model that were used. Thereafter, it presents and analyses the results obtained for a full (simulated) year of operation in which an energy cost saving of some 25% was achieved in comparison to the corresponding cost of current practice. Conclusions are drawn regarding the achievement of aims and future prospects.


2007 ◽  
Vol 9 (1) ◽  
pp. 15-24 ◽  
Author(s):  
Zhengfu Rao ◽  
Fernando Alvarruiz

As part of the POWADIMA research project, this paper describes the technique used to predict the consequences of different control settings on the performance of the water-distribution network, in the context of real-time, near-optimal control. Since the use of a complex hydraulic simulation model is somewhat impractical for real-time operations as a result of the computational burden it imposes, the approach adopted has been to capture its domain knowledge in a far more efficient form by means of an artificial neural network (ANN). The way this is achieved is to run the hydraulic simulation model off-line, with a large number of different combinations of initial tank-storage levels, demands, pump and valve settings, to predict future tank-storage water levels, hydrostatic pressures and flow rates at critical points throughout the network. These input/output data sets are used to train an ANN, which is then verified using testing sets. Thereafter, the ANN is employed in preference to the hydraulic simulation model within the optimization process. For experimental purposes, this technique was initially applied to a small, hypothetical water-distribution network, using EPANET as the hydraulic simulation package. The application to two real networks is described in subsequent papers of this series.


2017 ◽  
Vol 18 (1) ◽  
pp. 183-192 ◽  
Author(s):  
Rojacques Mompremier ◽  
Óscar Arturo Fuentes Mariles ◽  
Kebreab Ghebremichael ◽  
Ana Elisa Silva Martínez ◽  
José Elías Becerril Bravo

Abstract The objective of this study was to evaluate the factors that affect the formation and diffusion of disinfection by-products, especially trihalomethanes (THM), in a laboratory-scale water distribution network constructed with three different pipe materials. Sampling locations were chosen on the basis of residence time, pipe material and mixing zone. Water samples were collected and analyzed for temperature, pH, total organic carbon, turbidity, free chlorine and THM. Experiments were carried out where two different flow directions at cross junctions were studied. It was observed that for incoming flow at 90° with varying flow rate, mixing was shown to be incomplete where inflows tend to bifurcate rather than mix completely. For two incoming flows in opposing direction (180°), solute mixing has shown to be perfect due to the collision of the fluid streams. The results demonstrated how THM concentration can greatly vary in the same water distribution network due to the impact of pipe material, residence time and the outcome of mixing at cross junctions.


2021 ◽  
Vol 83 (6) ◽  
pp. 193-201
Author(s):  
Rosiah Rohani ◽  
Siti Aishah Basiron ◽  
Nurul Suraya Rosli ◽  
Izzati Izni Yusoff ◽  
Nadiah Khairul Zaman ◽  
...  

Drinking water quality monitoring is compulsory in order to ensure that it does not pose any harm to the public health. Water fluoridation is aimed to provide sufficient amount of fluoride in the drinking water for the consumer dental health benefit. In this study, EPANET software was used to model the water distribution network from a specific water treatment plant and later to simulate the hydraulic and water quality analysis for the system. From the simulation and modeling of the water distribution network, the hydraulic simulation and water quality behavior for fluoride concentration of each nodes and links in the drinking water distribution network were found to change over time following the drinking water distribution segment. From the hydraulic simulation, especially for head and flow at a particular point in time, it consists of simultaneous solution of flow equivalence for every junction and headloss relationship in every link of network as a result of hydraulic balancing. In the water distribution network, every pipe in a network made up a single segment, where the water quality was proportional to its initial quality set at the starting node. In conclusion, the hydraulic status of the physical and non-physical components of the water distribution network found to have a significant impact on the fluoride content of drinking water.


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