Minimum Pumping Energy of Tree-Shaped Water Supply Networks for Probabilistic Demands in Built Environment

Author(s):  
L. T. Wong ◽  
K. W. Mui ◽  
C. T. Cheung

Minimization of pumping energy is a major concern for designing sustainable water supply in buildings. Modular designs of tree-shaped water supply piping system, such as 2 by N array include water cisterns of water closet in public toilets, washbasin taps in schools are commonly found in building complexes. Potable water demands in water systems serving built environment are unsteady, random and intermittent. However, the existing statistical Hunter-based probabilistic approaches to pipe sizing, however, do not consider the minimization of pumping energy for water distribution through proper selection of pipe radii. This paper demonstrates a pipe sizing method with probabilistic demands for optimizing pipe friction energy loss constrained by the fixed pipeline volume. A mathematical model for pumping energy optimization in infinite tree-shape water supply piping networks for probabilistic demands is proposed. Compared with the Hunter’s based probabilistic approach in sizing an 8-section tree-shape water supply network for demand of probabilities 0.1 and 0.2, the proposed method offers reduction potentials of pipe friction energy loss of 12% and 43% respectively. With piping systems of pipe radius ratios, the optimal tree-shape networks are also determined.


2019 ◽  
Vol 3 (2) ◽  
pp. 118-124
Author(s):  
Alfian Hamsi ◽  
Tulus Burhanuddin Sitorus

Pump is mechanical device to increase the pressure energy of a fluid. Generaly pumps are used to lift the water from low level to high level. These are of two types,namely reciprocating pumps and centrifugal pumps. On centrifugal pumps the centrifugal force or variation of pressure due to rotation is responsible for their operation or working. The program of community services as implementation of sciences and technology intended to introduced and give skill training about water supply units to the community at Desa Sempa jaya ,Kabupaten Deli-Karo. In this area the people have a problem about availibity of water for  agricultute, when mountain Sinabung gets eruption the leave of plantation are covered with dust and damaged to citrus plants,in dry season orange plants lack of water even though the success of the harvest is very dependent on water. The program was carried out by designing, fabricating and erecting the unit of water supply,consist of deepwell pump,piping system, valve,tee,bent,tower tank and panel control. The result of this community services  showed that the capacity of pumps are 6 liter/menit,head are 50-70 meter,power 2 HP,speed 1500 rpm.capacity of tower tank 5400 liter, the pump may supply the water to tower tank until full about 2 hours,and the farmer may use the water from the tower tank by gravitation about 3 days.



Energies ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 6221
Author(s):  
Jedrzej Bylka ◽  
Tomasz Mróz

The water supply system is one of the most important elements in a city. Currently, many cities struggle with a water deficit problem. Water is a commonly available resource and constitutes the majority of land cover; however, its quality, in many cases, makes it impossible to use as drinking water. To treat and distribute water, it is necessary to supply a certain amount of energy to the system. An important goal of water utility operators is to assess the energy efficiency of the processes and components. Energy assessments are usually limited to the calculation of energy dissipation (sometimes called “energy loss”). From a physical point of view, the formulation of “energy loss” is incorrect; energy in water transport systems is not consumed but only transformed (dissipated) into other, less usable forms. In the water supply process, the quality of energy—exergy (ability to convert into another form)—is consumed; hence, a new evaluation approach is needed. The motivation for this study was the fact that there are no tools for exergy evaluation of water distribution systems. A model of the exergy balances for a water distribution system was proposed, which was tested for the selected case studies of a water supply system and a water treatment station. The tool developed allows us to identify the places with the highest exergy destructions. In the analysed case studies, the highest exergy destruction results from excess pressure (3939 kWh in a water supply system and 1082 kWh in a water treatment plant). The exergy analysis is more accurate for assessing the system compared to the commonly used energy-based methods. The result can be used for assessing and planning water supply system modernisation.



2020 ◽  
Vol 4 (1) ◽  
pp. 91
Author(s):  
Lucas Nyuydine Wirba ◽  
Amawa Sani Gur ◽  
Victor Konfor Ntoban ◽  
Bruno Lainjo Baye ◽  
Emmanuel Nkembo Ngang ◽  
...  

City governments, the world over, are grappling with the problem of sustaining water supply to their rapidly growing population. The need to meet up with this exigency has been emphasized in Sustainable Development Goal (SDG) 6 (Ensure availability and sustainable management of water and sanitation for all) and SDG 11 (Make cities and human settlements inclusive, safe, resilient, and sustainable). While a series of demand and supply-side approaches to water management have been employed, the extent to which water management practices could guarantee (un)sustainability still require clarity, especially in the context of cities in Sub-Saharan Africa (SSA). Taking the case of the Bamenda Metropolis of Cameroon, we contribute to address this lacunae, by identifying household level water management practices in Bamenda, and discussing the implications it has for sustainable water supply (availability, affordability). To obtain relevant data for this study, a random sample of 120 households, within 8 neighborhoods of Bamenda, was conducted. Furthermore, we employed descriptive and inferential statistical methods to test the relationship between household socio-economic characteristics and water management (consumption, rationing, preservation). The results  reveal the following: In terms of regularity, approximately 63% of the households have irregular water supply, and consume less than 50 litres of water per day. The key water source is pipe borne water (65%), supplied by CAMWATER and Community Water Systems. One of the main water management practice at household level is rainwater harvesting (41.7%), while sustainability is compromised by the weak management systems from supply side, and limited knowledge and resources at the demand side (household level). There is a need for policy (re)orientation to regulate household water distribution, consumption and affordability. Further studies are required to ground this assertion.



Water ◽  
2019 ◽  
Vol 11 (6) ◽  
pp. 1297 ◽  
Author(s):  
Irene Fernández García ◽  
Daniele Novara ◽  
Aonghus Mc Nabola

Pressure Reducing Valves (PRV) have been widely used as a device to control pressure at nodes in water distribution networks and thus reduce leakages. However, an energy dissipation takes place during PRV operation. Thus, micro-hydropower turbines and, more precisely, Pump As Turbines (PAT) could be used as both leakage control and energy generating devices, thus contributing to a more sustainable water supply network. Studies providing clear guidelines for the determination of the most cost-effective device (PRV or PAT) analysing a wide database and considering all the costs involved, the water saving and the eventual power generation, have not been carried out to date. A model to determine the most cost-effective device has been developed, taking into account the Net Present Value (NPV). The model has been applied to two case studies: A database with 156 PRVs sites located in the UK; and a rural water supply network in Ireland with three PRVs. The application of the model showed that although the investment cost associated to the PRV installation is lower in the majority of cases, the NPV over the lifespan of the PAT is higher than the NPV associated with the PRV operation. Furthermore, the ratio between the NPV and the water saved over the lifespan of the PAT/PRV also offered higher values (from 6% to 29%) for the PAT installation, making PATs a more cost-effective and more sustainable means of pressure control in water distribution networks. Finally, the development of less expensive turbines and/or PATs adapted to work under different flow-head conditions will tip the balance toward the installation of these devices even further.



2020 ◽  
Vol 12 (21) ◽  
pp. 8978
Author(s):  
Eun Joo Park

Although it is completely surrounded by the Mediterranean Sea, the island of Cyprus has long suffered from water problems arising from irregular rainfall, leading to sustained political conflict conditions for a long period. Water scarcity is likely to become a major issue, thus a range of options for water catchments should be examined and trialed. This article explores the connection between ownership of water and water management in a divided territory to gain an understanding of how politics are involved in water conflict. By investigating the water situation in Cyprus, this study aims to evaluate the strategies that can ensure the sustainability of new water networks for domestic and irrigation needs. This understanding can be used to minimize the gap between water supply and demand to provide water stressed countries with sufficient, safe, and reliable water for their domestic and irrigation needs. The research proposes a reinterpretation of the extraterritorial conditions of contemporary Cyprus and a plan to realign the island’s water system through the creation of a new post-national territory. Thus, the study presents a vision for a sustainable water supply. In addition, the study discusses strategies and actions for water distribution networks with consideration of political and social issues to provide a potential new vision for future urbanization.



Author(s):  
Kegong Diao

Abstract This paper shares a vision that sustainable water supply requires resilient water infrastructures which are presumably in the centralized control and decentralized execution (CCDE) mode with multiscale resilience. The CCDE should be planned based on the multiscale structure of water infrastructures, in which the systems are divided into a number of hierarchically organized subsystems. The CCDE allows independent execution of all subsystems under normal situations yet coordination of subsystems at different scales to mitigate any disturbances during failure events, i.e. the multiscale resilience. This vision is discussed in detail for water distribution systems (WDSs). Specifically, the conceptual design of the multiscale CCDE is described, and progress on understanding the multiscale structures in WDSs is summarized based on the literature review. Furthermore, a few theories consistent with the multiscale CCDE concept are discussed which include the decomposition theorems, fractal theory, control theories, and complex network theory. The next step in the vision will be to identify the optimal multiscale structure for the CCDE based on the best trade-off of different goals of WDS analysis and management. This process needs supports from not only innovative modelling tools and extensive datasets and theories but also inspiring exemplar systems, e.g. natural systems.



2020 ◽  
Vol 21 (2) ◽  
pp. 227-235
Author(s):  
Muhammad Rizki Apritama ◽  
I Wayan Koko Suryawan ◽  
Yosef Adicita

ABSTRACTThe clean water supply system network on Lengkang Kecil Island was developed in 2019. A small portion of the community's freshwater comes from harvesting rainwater and dug wells, which are only obtained during the rainy season. The primary source of clean water used by the community comes from underwater pipelines with a daily discharge of 0.86 l/sec. The water supply of the Lengkang Kecil Island community is 74.3 m3/day, with 146 House Connections (HCs) and to serve public facilities such as elementary schools, primary health centers, and mosques. Hydraulic evaluation of clean water distribution using EPANET 2.0 software on flow velocity shows the lowest rate of 0.29 m/s and the highest of 1.21 m/s. The lowest pressure value in the distribution system is 6.94-6.96 m and headloss units in the range 0.08-0.25 m/km. These three criteria are still within the distribution network design criteria (feasible). A carbon footprint can be calculated from each activity from the analysis of the evaluation of clean water distribution networks. The most massive emissions came from pumping activities with 131 kg CO2-eq, followed by emissions from wastewater 62.5 kgCO2-eq. Further research is needed to determine the quality of wastewater and the design for a centralized wastewater treatment plant (IPALT) to improve Lengkang Kecil Island residents' living standards.Keywords: Lengkang Kecil Island, water, EPANET, carbon footprintABSTRAKJaringan sistem penyediaan air bersih pada Pulau Lengkang Kecil dimulai pada tahun 2019. Sebagian kecil air bersih yang digunakan masyarakat berasal dari pemanenan air hujan dan sumur gali yang hanya didapat pada musim hujan. Sumber air bersih utama yang digunakan masyarakat berasal dari pengaliran perpipaan bawah laut dengan debit harian 0,86 l/detik. Kebutuhan air masyarakat Pulau Lengkang Kecil adalah 74,3 m3/hari dengan 146 Sambungan Rumah (SR) serta untuk melayani fasilitas umum seperti sekolah dasar (SD), puskesmas, dan masjid. Evaluasi hidrolis distribusi air bersih dengan menggunakan software EPANET 2.0 terhadap kriteria kecepatan aliran menunjukkan nilai terendah 0,29 m/s dan tertinggi 1,21 m/s. Nilai sisa tekan dalam sistem distribusi adalah 6,94–6,96 m dan unit headloss pada kisaran 0,08–0,25 m/km. Ketiga kriteria ini masih berada dalam kriteria desain jaringan distribusi (layak). Dari analisis evaluasi jaringan distribusi air bersih, dapat dihitung jejak karbon yang dihasilkan dari setiap kegiatannya. Emisi terbesar berasal dari kegiatan pemompaan dengan nilai 131 kgCO2-eq, diikuti dengan emisi yang berasal dari air limbah dengan nilai 62,5 kgCO2-eq. Penelitian lanjutan diperlukan untuk mengetahui kualitas dari air limbah dan desain untuk instalasi pengolahan air limbah terpusat (IPALT) untuk meningkatkan taraf hidup penduduk Pulau Lengkang Kecil.Kata kunci: Pulau Lengkang Kecil, air, EPANET, jejak karbon



Author(s):  
E. Rozhnov ◽  
E. Siksina

С целью упорядочения и анализа информации о системе распределения воды и стоков г. Новокузнецка и исключения многократного дублирования данных в разных информационных средах было принято решение о внедрении разработки компании ИВЦ Поток Информационно-графической системы ГидроГраф из линейки продуктов под торговой маркой CityComТМ. В настоящее время система ГидроГраф активно используется многими подразделениями ООО Водоканал . Планирование производственной программы на сегодняшний день уже невозможно без системы ГидроГраф . С ее помощью осуществляется выдача технических заданий, подготовка отключений, составление планов производства работ, заключение договоров с новыми абонентами, оптимизация системы водоснабжения и водоотведения. Появление полноценной, выверенной и постоянно актуализируемой базы данных позволило оперативно и в удобной форме решать множество задач. При этом обеспечивается повышение эффективности и точности планирования ремонтов, сокращение издержек и в целом рациональная эксплуатация системы водоснабжения и водоотведения г. Новокузнецка.To provide for sorting and analyzing the data on the water distribution and sewer network system in Novokuznetsk and to avoid multiple data duplication in various IT environments, it was decided to introduce the product of Potok data processing center HydroGraph Information and Graphic System from the product line under CityComTM trademark. Currently, HydroGraph system has been in active use by many divisions of Vodokanal, LLC. Planning an operational program today is no longer possible without HydroGraph system. The system provides for issuing the performance specifications, preparing for shutdowns, compiling work execution plans, signing contracts with new customers, and upgrading the water supply and wastewater disposal systems. The development of a meaningful, verified and continuously updated database made it possible to quickly and conveniently solve many problems. Therein it ensures improved efficiency and accuracy of repair planning, cost reduction and generally rational operation of the water supply and wastewater disposal system in Novokuznetsk.



2005 ◽  
Vol 5 (2) ◽  
pp. 31-38
Author(s):  
A. Asakura ◽  
A. Koizumi ◽  
O. Odanagi ◽  
H. Watanabe ◽  
T. Inakazu

In Japan most of the water distribution networks were constructed during the 1960s to 1970s. Since these pipelines were used for a long period, pipeline rehabilitation is necessary to maintain water supply. Although investment for pipeline rehabilitation has to be planned in terms of cost-effectiveness, no standard method has been established because pipelines were replaced on emergency and ad hoc basis in the past. In this paper, a method to determine the maintenance of the water supply on an optimal basis with a fixed budget for a water distribution network is proposed. Firstly, a method to quantify the benefits of pipeline rehabilitation is examined. Secondly, two models using Integer Programming and Monte Carlo simulation to maximize the benefits of pipeline rehabilitation with limited budget were considered, and they are applied to a model case and a case study. Based on these studies, it is concluded that the Monte Carlo simulation model to calculate the appropriate investment for the pipeline rehabilitation planning is both convenient and practical.



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