scholarly journals Optimal Location of Energy Dissipation Box in Long Distance and High Drop Gravitational Water Supply System

Water ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 461
Author(s):  
Weixiang Ni ◽  
Jian Zhang ◽  
Sheng Chen
Keyword(s):  
Energy Dissipation ◽  
Water Supply ◽  
Water Level ◽  
Pressure Head ◽  
Optimal Location ◽  
Water Supply Systems ◽  
Protective Effects ◽  
Long Distance ◽  
Optimal Position ◽  
Gravitational Flow

In the long-distance and high-drop gravitational water supply systems, the water level difference between the upstream and downstream is large. Thus, it is necessary to ensure energy dissipation and pressure head reduction to reduce the pipeline pressure head. The energy dissipation box is a new type of energy dissipation and pressure head reduction device, which is widely used in the gravitational flow transition systems. At present, there is still a dearth of systematic knowledge about the performance of energy dissipation boxes. In this paper, a relationship between the location of the energy dissipation box and the pressure head amplitude is established, a theoretical optimal location equation of the energy dissipation box is derived, and numerical simulations using an engineering example are carried out for verification. The protective effects of an energy dissipation box placed at the theoretical optimal location and an upstream location are compared. The results indicate that for the same valve action time, the optimal position allows effectively reducing the total volume of energy dissipation box. The oscillation amplitudes of the water level in the box and the pressure head behind the box are markedly reduced. Under the condition that the water level oscillation of the energy dissipation box is almost the same, the optimal location offers better pressure head reduction protection performance than the upstream location.

scholarly journals Evaluation of Current Issues in Water Supply Systems and Implications for Sustainable Urban Water Management in Limbe, South West Region of Cameroon

2020 ◽  
pp. 52-74
Author(s):  
Baba Adamu ◽  
Ndi Humphrey N. ◽  
Balgah Sounders N.
Keyword(s):  
Water Management ◽  
Water Supply ◽  
Urban Growth ◽  
Primary Data ◽  
Water Supply Systems ◽  
Urban Water ◽  
Urban Water Management ◽  
Long Distance ◽  
Sustainable Urban Water Management ◽  
Supply Systems

Water supply system has played a significant role in the growth, development and wellbeing of cities. Until now, meeting the need of city residents in terms of availability, reliability, and access to a good quality water supply is a major challenge facing many denizens of the 21st Century due to unprecedented urban growth and urbanization rates. This study is out to examine the current issues and challenges to water supply systems in Limbe. The study adopted the mix method approach which involves triangulation of quantitative and qualitative methods of data collection. Primary data were obtained from field observations, interviews and the administration of 383 questionnaires to households and stakeholders. Secondary data were obtained from relevant official documents, published and unpublished sources relevant to water supply systems. Satellite imageries and ArcGIS were used to describe the pattern of growth in built-up areas between 1986 and 2019. Data from the questionnaire were entered using Epi Data Version 3.1, analysed using the Statistical Package for Social Science Standard version 21.0 and Microsoft Excel and presented in the form of tables, figures, plates and maps. Findings revealed that, although the water supply accessibility by utilities has improved significantly, the reliability, distribution, flow frequency, supply, price and quality are still low. The inaccessibility and unreliability in the water supply have turned most households to alternative sources with poor quality. Unsustain urbanization and urban growth are occurring through infills in city remaining open spaces and ‘out spill’ and expansion at the outskirt without a concurrent increase, upgrading or extension of water supply infrastructural systems resulting to congestion, conflict over allocation, long-distance trekking to source water, deterioration of basic social services, pollution, inaccessibility amongst to ensure efficient water supply systems and sustainable urban water management. The paper, therefore, calls for the rehabilitation and renovation of dilapidated water supply structures, extension and upgrading basic services, limit urbanization and urban growth, encourage the construction and use of alternative water sources, community participation amongst others for sustainable urban water supply management.

Optimum use of gravity springs in water supply systems

2008 ◽  
Vol 8 (3) ◽  
pp. 313-318
Author(s):  
K. Tothova ◽  
I. Mrnco
Keyword(s):  
Water Resources ◽  
Water Supply ◽  
Water Supply Systems ◽  
Long Distance ◽  
Variable Yield ◽  
Service Areas ◽  
Potable Water Supply ◽  
Quality Water ◽  
Local Water ◽  
Supply Systems

The potable water supply concept reflects relationships between distribution of available water resources that determine hydrogeological attributes of the region, and distribution of water service areas. The distribution of the water resources is often uneven, which is one of reasons of development of extensive long distance water supply systems. The long distance water supply systems connect deficit areas with surplus water resources areas. For example, the yield of large capacity wells in Danube region near Bratislava is several times higher than the real demand in this region. In this case, water from the wells is transferred by multiple pumping over a long distance (tens or hundreds of kilometres) to the areas with shortage of sources. The Little Carpathians foothills, where local water sources (springs) do not give a sufficient yield all year long. Most of these springs offer high-quality water, but fluctuating yields of the sources and do not guarantee continuous water supply. The sources are important for its quality and yield as well as for their elevation. The elevation potential allows gravity water supply without a need for pumping. However, the water supply systems do not even use average yields of the springs. The balance capacity of the springs is technically designed for minimum yields. Therefore, several reasonable questions arise: Is it efficient to pump and transport water over a long distance even in the time of maximum yields of the gravity springs? How can we determine efficiency rate of use of such yield in its extreme status? The answers can be found in the analysis of the necessary technical measures and investments, and calculation of operating costs of a system dependent on variable yield of gravity springs.

scholarly journals Assessment of inline technique-based water hammer control strategy in water supply systems

2019 ◽  
Vol 68 (7) ◽  
pp. 562-572 ◽  
Author(s):  
Ridha Ben Iffa ◽  
Ali Triki
Keyword(s):  
Water Supply ◽  
Plastic Material ◽  
Pressure Head ◽  
Oscillation Period ◽  
Water Hammer ◽  
Steel Pipe ◽  
Water Supply Systems ◽  
Wave Oscillation ◽  
Supply Systems ◽  
Short Section

Abstract This article discusses and compares the effectiveness of the compound and dual technique-based inline strategy used to upgrade existing steel pipe-based water supply systems. Basically, these techniques are based on splitting the single inline short section, used in the conventional technique, into a couple of two sub-short sections made of two distinct plastic material types: high- and low-density polyethylene (HDPE) and (LDPE). The 1D unconventional water hammer solver based on the method of characteristics was used for numerical computations. Results evidenced that the specific setup of the compound technique based on (HDPE-LDPE) sub-short sections (where the former sub-short section is attached to the hydraulic parts, while the latter is attached to the main steel pipe) is the most prominent configuration providing an acceptable trade-off between attenuation of pressure head surge, and limitation of excessive wave oscillation period spreading. Furthermore, this compound technique setup allowed more important pressure head peak (or crest) attenuation as compared with the dual technique based on (LDPE-LDPE) sub-short sections; while inducing about similar values of wave oscillation period spreading.

scholarly journals Optimal volume selection of air vessels in long-distance water supply systems

2021 ◽  
Author(s):  
Lin Shi ◽  
Jian Zhang ◽  
Xiao-dong Yu ◽  
Xing-tao Wang ◽  
Xu-yun Chen ◽  
...  
Keyword(s):  
Water Supply ◽  
Design Guidelines ◽  
Water Supply Systems ◽  
Calculation Error ◽  
Small Range ◽  
Long Distance ◽  
Effective Measure ◽  
Vessel Volume ◽  
Analytical Formulas ◽  
Supply Systems

Abstract The use of air vessels is an effective measure to control water hammers, and its volume selection has a certain blindness. This paper aims to reveal the surge wave characteristics and provide design guidelines for air vessels in long-distance water supply systems. First, the analytical formulas of water-level oscillations in the air vessel are derived based on the Krylov–Bogoliubov–Mitropolsky method. Then, an optimization model is constructed for selecting the optimal volume of the air vessels. Finally, the validation of the analytical formulas and the optimization of the model are conducted through two actual projects. The results show that the calculation error of the analytical formulas can be controlled within a very small range, and the process of selecting air vessel volume can be simplified with the provided model. In addition, increasing the air chamber height within its range can reduce the volume of air vessels with the same protection requirements. The optimization analysis results of the air vessel can provide guidance and reference for the design of actual projects.

scholarly journals Transient nature of riverbank filtered drinking water supply systems - a new challenge of natural radioactivity assessment

2020 ◽  
Author(s):  
Katalin Csondor ◽  
Petra Baják ◽  
Bálint Izsák ◽  
Márta Vargha ◽  
Heinz Surbeck ◽  
...  
Keyword(s):  
Drinking Water ◽  
Water Supply ◽  
Water Level ◽  
Natural Radioactivity ◽  
Drinking Water Supply ◽  
Water Supply Systems ◽  
Gross Alpha ◽  
River Bank ◽  
Transient Nature ◽  
Activity Concentrations

<p>In Hungary the drinking water supply is mainly based on groundwater from aquifers characterized by different lithology. Riverbank filtered systems represent 40 % of drinking water supply. According to the EURATOM drinking water directive, there are recent regulations in Hungary regarding the natural radioactivity of drinking waters. Based on this, if gross alpha or gross beta radiation exceeds the limit, nuclide-specific measurements are required to be performed by the relevant waterworks. Since the mobility of uranium and radium is strongly influenced by the geochemical conditions, knowledge on the geochemical parameters of water is required. Therefore hydrogeology has a crucial role in revealing the origin of elevated activity concentrations. This research presents a case study in Hungary where the drinking water supply is provided by bank filtered and karst wells. The main aim of this study is to determine which radionuclides may cause the elevated radioactivity and explain their occurrence using hydrogeological approach, considering also the temporal variation of groundwater/surface water ratio. In most of the wells of the research area the gross alpha values are above the screening level, 0.1 Bq L<sup>-1</sup>. The study revealed the correlation between the river water level fluctuation and the uranium content of the wells. Among the investigated radionuclides, the uranium activity concentrations responded the most to the water level changes of the river and showed systematically higher values during low water conditions. In addition the karst wells showed low activity concentrations. This suggests, that uranium is transported by the groundwater component, and possibly sourced from the fluviatile sediments. The results of this study highlighted the transient nature of river bank filtered systems, which should be taken into account in the monitoring and water supply strategy. Nevertheless, the study emphasizes the importance of considering the dynamics of groundwater and associated geochemical environment in addition to geological factors, when investigating the radioactivity of groundwater or other potential contaminants.</p><p>This study was supported by the ÚNKP-19-3 New National Excellence Program of the Ministry of Human Capacities. This study is part of a project that has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 810980.</p>

ELECTRICITY LOAD PREDICTION FOR WATER SUPPLY SYSTEMS

2008 ◽  
Vol 7 (4) ◽  
pp. 453-458
Author(s):  
Mihai Gavrilas ◽  
Gilda Gavrilas ◽  
Ovidiu Ivanov
Keyword(s):  
Water Supply ◽  
Water Supply Systems ◽  
Load Prediction ◽  
Electricity Load ◽  
Supply Systems
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