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 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.

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

LAVIN NDZ-S BRONZE

Alloy Digest ◽  
1965 ◽  
Vol 14 (5) ◽  
Keyword(s):  
Water Supply ◽  
Physical Properties ◽  
Tensile Properties ◽  
Base Alloy ◽  
High Strength ◽  
Water Supply Systems ◽  
Copper Base ◽  
Valve Stem ◽  
Copper Base Alloy ◽  
Supply Systems

Abstract LAVIN NDZ-S BRONZE is a copper-base alloy recommended as a high-strength dezincification and dealuminization resistant valve stem material in water supply systems. This datasheet provides information on composition, physical properties, hardness, and tensile properties. It also includes information on casting and machining. Filing Code: Cu-151. Producer or source: R. Lavin & Sons Inc..

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