A simulation tool for mass transfer inside compressed air vessel for water networks pressurisation

2019 ◽  
Author(s):  
Andrea Volpi ◽  
Eleonora Bottani
Keyword(s):  
Mass Transfer ◽  
Water Distribution ◽  
Water Distribution Network ◽  
Analytical Models ◽  
Model Parameters ◽  
Cyclic Loading And Unloading ◽  
Level Measurement ◽  
Controlling System ◽  
Mass Transfer Phenomenon ◽  
Reliable Solution

Feeding a water distribution network with the correct pressure is a fundamental requirement for its proper operation; to this end, a simple and reliable solution commonly adopted in small and medium industrial plants is the adoption of a pressure vessel. For small systems, a membrane seals the system water from the gas compartment, anyway, as the size of the vessel increases, the adoption of sealing diaphragm or bladder is no longer feasible, and thus there is a direct contact between air and water. The high pressure of the vessel, combined with the cyclic loading and unloading phases, which replace the water inside the tank, leads to a considerable mass transfer phenomenon of air inside water. The loss of air mass cannot be monitored and detected by simply controlling system pressures; to this extent, water level measurement and reference analytical models are required. Since there is a lack in scientific literature of these models, the present study presents a model for mass transfer estimate in the systems described, starting from a real pilot plant. The main results of the model implementation in a spreadsheet, in terms of the trend of the key model parameters in time, are also reported and discussed.

scholarly journals Development of Nonlinear Analytical Models for the Study of Heat/Mass Transfer Properties in the Drying of Porous Type Fabric

2012 ◽  
Vol 326-328 ◽  
pp. 593-598
Author(s):  
Ralph W.L. Ip ◽  
Elvis Iok Cheong Wan
Keyword(s):  
Heat Transfer ◽  
Mass Transfer ◽  
Moisture Diffusion ◽  
Analytical Models ◽  
Model Parameters ◽  
Drying Process ◽  
Drying Characteristics ◽  
Experimental Findings ◽  
Transfer Properties ◽  
Describe Heat Transfer

Designing a drying process for porous type fabrics using traditional linear heat transfer models may be inefficiency because the drying characteristics in the process are usually nonlinear. Using nonlinear approaches to describe the heat/mass flow could be better for many industrial application cases. The paper as presented here is a study for an analytical model using differential form nonlinear equations to describe heat transfer and moisture diffusion process using air as the processing medium. Experimental findings were used to evaluate the performance of the studied model. Relationships between the model parameters and fabric physical properties were determined for further used in the design of drying equipment.

A GIS-based water distribution model for Zhengzhou city, China

2011 ◽  
Vol 11 (4) ◽  
pp. 497-503 ◽  
Author(s):  
Hou Yu-Kun ◽  
Zhao Chun-Hui ◽  
Huang Yu-Chung
Keyword(s):  
Water Supply ◽  
Distribution System ◽  
Water Distribution ◽  
Distribution Network ◽  
Water Distribution Network ◽  
Hydraulic Model ◽  
Distribution Model ◽  
Roughness Coefficient ◽  
Model Parameters ◽  
Pipe Roughness

Many water companies in China are developing GIS as a computer-based tool, for mapping and analyzing objects and events that happen on a water distribution network. However, only a few companies have taken a further step to develop a hydraulic model based on GIS, and Zhengzhou Water Supply Corporation is one of them. The WaterGEMS V8 XM from Bentley is used to develop the hydraulic model for the water distribution network in Zhengzhou city, which has a population of over 3 million. During establishment of the model, some of the data extracted from GIS are missing, abnormal, and redundant and require careful screening, searching, and judging. Model calibration is performed after a sensitivity analysis. Peaking factor and pipe roughness coefficient are key model parameters to calibrate. In calibrating peaking factors, the distribution system is divided into 5 operation districts with different types of water usage. To calibrate pipe roughness coefficients, the system was divided into 4 water supply districts with different attributes of pipelines. Finally, a case study of pipe layout evaluation it shows the hydraulic model to be a powerful tool for water supply management.

EFFICIENT CHLORINATION SCHEDULE FOR A WATER DISTRIBUTION NETWORK WITH MULTIPLE PUMPING STATIONS

2017 ◽  
Vol 16 (5) ◽  
pp. 1071-1079 ◽  
Author(s):  
Andrei-Mugur Georgescu ◽  
Sanda-Carmen Georgescu ◽  
Remus Alexandru Madularea ◽  
Diana Maria Bucur ◽  
Georgiana Dunca
Keyword(s):  
Water Distribution ◽  
Distribution Network ◽  
Water Distribution Network ◽  
Pumping Stations

A study on appropriate investment of pipeline rehabilitation for water distribution network

2005 ◽  
Vol 5 (2) ◽  
pp. 31-38
Author(s):  
A. Asakura ◽  
A. Koizumi ◽  
O. Odanagi ◽  
H. Watanabe ◽  
T. Inakazu
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Water Supply ◽  
Water Distribution ◽  
Ad Hoc ◽  
Distribution Network ◽  
Water Distribution Network ◽  
Distribution Networks ◽  
Optimal Basis ◽  
Model Case

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.

Whole life costing: application to water distribution network

2003 ◽  
Vol 3 (1-2) ◽  
pp. 87-93 ◽  
Author(s):  
M. Engelhardt ◽  
D. Savic ◽  
P. Skipworth ◽  
A. Cashman ◽  
A. Saul ◽  
...  
Keyword(s):  
Network Management ◽  
Asset Management ◽  
Water Distribution ◽  
Distribution Network ◽  
Operating Cost ◽  
Water Distribution Network ◽  
Activity Based Costing ◽  
Operational Strategies ◽  
Long Term Impact ◽  
Whole Life Costing

There is an increasing pressure from the economic regulator in England and Wales for water companies to ensure that their capital maintenance decisions reflect an understanding of the long-term impact on their operational costs and risks. This implies that decisions must not only reflect the costs borne now but the likely costs in the future, and how these might be optimised. It is noteworthy that within the construction and transport industries, asset management decisions which have been driven in this direction utilise a whole life costing (WLC) methodology. This paper addresses the implications of transferring the concept of WLC to service-based assets such as water systems. A WLC approach to distribution network management aims to achieve the lowest network provision and operating cost when all costs are considered to achieve standards enforced by regulation. Cognisance is to be taken of all relevant costs - direct and indirect, private and societal - in order to balance the needs of the service supplier, the customer, society and the environment in a sustainable manner. A WLC analysis thus attempts to develop a cost profile over the life of the asset. Accounting for the costs over this period is achieved through a combination of activity based costing (ABC) and a life cycle assessment (LCA) used to identify potential social and environmental costs. This process means that each of these identified costs must be linked to some physical parameter that itself varies over time due to changing demands on the system, the different operational strategies available to the operator and natural deterioration of the fabric of the system. The links established between the cost and activities of the operator provide the basis for the development of a WLC decision tool (WiLCO) for application to water distribution network management.

Assessment of Lisbon drinking water distribution network biofilm colonization and associated hazards

2008 ◽  
Vol 8 (4) ◽  
pp. 421-426
Author(s):  
J. Menaia ◽  
M. Benoliel ◽  
A. Lopes ◽  
C. Neto ◽  
E. Ferreira ◽  
...  
Keyword(s):  
Drinking Water ◽  
Distribution System ◽  
Water Distribution ◽  
Water Distribution System ◽  
Water Distribution Network ◽  
Storage Tanks ◽  
Water Pipe ◽  
Cultural Methods ◽  
Drinking Water Distribution ◽  
And Storage

Concerns arise from the possible occurrence of pathogens in drinking water pipe biofilms and storage tank sediments. In these studies, biofilm samples from pipes and sediments from storage tanks of the Lisbon drinking water distribution system were analyzed. Protein determinations and heterotrophic counts on pipe biofilm samples were used to assess the Lisbon network sessile colonization intensity and distribution. Indicator and pathogenic microorganisms were analyzed in pipe biofilm samples, as well as in storage tanks biofilm and sediments, by using cultural methods and PCR, to assess risks. Results have shown that the Lisbon network sessile colonization is relatively weak in intensity. In addition, no meaningful hazards were apparent for both the network biofilm and the storage tanks biofilm and sediments.

Nitrite and Nitrate Levels in Groundwater, Water Distribution Network, Bottled Water and Juices in Iran : A systematic Review

2020 ◽  
Vol 21 ◽  
Author(s):  
Maasoumeh Marhamati ◽  
Asma Afshari ◽  
Behzad Kiani ◽  
Behrooz Jannat ◽  
Mohammad Hashemi
Keyword(s):  
Drinking Water ◽  
Water Distribution ◽  
Scientific Information ◽  
Distribution Network ◽  
Water Distribution Network ◽  
The Body ◽  
International Standards ◽  
Nitrogen Fertilizers ◽  
Nitrate Content ◽  
Nitrate And Nitrite

Background: Nitrate and nitrite can get into the body through the consumption of contaminated water either directly or indirectly. The accumulation of these compounds in the body, in the long run, leads to health problems, for example, digestive disorders, cancers, and even death threats in children. The aim of this review is to investigate nitrate and nitrite pollution levels in drinking water and fruit juices in Iran. Methods: In this review data were collected through searching the Scientific Information Database, Science-Direct, Scopus, PubMed, Google Scholar, and Magiran databases using the keywords Nitrate, Nitrite, Drinking water, Drinking Water Resources, Juice and Iran. Finally, the location of the studies was geocoded through the Google My Maps (https://www.google.com/mymaps) software. Results: Studies clearly indicated that the juices are safe in terms of nitrate. Nitrate and nitrite values were less than the national and international standards in all samples of bottled drinking water except for a few of the studies. The results of the reviewed studies also indicated that the nitrate content was higher than that written on the label in 96% of the samples, and nitrite was not labeled in 80% of them. The nitrate quantity was higher than the permissible limit, in the water distribution network of Bushehr, Gilan and Mazandaran Provinces. Talesh, Ardabil, Hashtgerd, Divandareh, and Kerman cities had high nitrate levels in more than 50% of wells. Conclusion: Using nitrogen fertilizers and lack of a wastewater treatment system were the main reasons for the presence of nitrate and nitrite.

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