scholarly journals Operating experience and ways to improve the performance of the service water supply system at the Novovoronezh NPP II (Units 1 and 2)

2020 ◽  
Vol 6 (4) ◽  
pp. 253-260
Author(s):  
Vladimir P. Povarov ◽  
Dmitry B. Statsura ◽  
Dmitry Ye. Usachev
Keyword(s):  
Distribution System ◽  
Water Distribution ◽  
Cooling Tower ◽  
Water Distribution System ◽  
Cooling System ◽  
Cooling Water ◽  
Operating Experience ◽  
Supply System ◽  
Summer Period ◽  
Service Water

The operating experience of Novovoronezh NPP II-1 shows that, in the summer period, the temperature of the cooling water exceeds the design value: this indicates the insufficient performance of the service water supply system. The main factor that has a negative impact on the performance of this system is the formation of carbonate deposits on the cooling tower filler. At Novovoronezh NPP II-1, the cooling tower water distribution system was cleaned from carbonate deposits by the method of combined vibration and aerohydraulic impact. The tested method of cleaning the filler cannot be considered optimal, since the main stage that determines the entire cleaning duration is the assembly/disassembly of the cooling tower filler. It is necessary to continue research on the choice of a strategy for controlling the carbonate deposition rate, taking into account the revealed influence of the design features of the main cooling water pipelines and pipelines of the cooling tower water distribution system on the mechanism of deposit formation in the peripheral spraying area. As compensating measures to ensure the required temperature regime of the turbine plant equipment at Novovoronezh NPP II-1, it is practiced during the summer period to put the standby heat exchangers of the lubrication system and the standby pump of the nonessential services cooling water system into parallel operation. This solution is fraught with the risk of an unplanned decrease in the electrical load if this equipment is turned off in the event of a malfunction. To increase the operating stability of Novovoronezh NPP II-1 and -2 in the summer period, it is proposed to carry out a number of measures aimed at mitigating the negative consequences caused by the elevated service water temperature. Equipment upgrade options are evaluated, e.g., by installing an additional pump for the turbine building services cooling system and (or) laying an additional pipeline to supply part of the makeup water from the Don River directly to the suction pipelines of the pumps of the turbine building services cooling system.

scholarly journals Exergy Evaluation of a Water Distribution System

Energies ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 6221
Author(s):  
Jedrzej Bylka ◽  
Tomasz Mróz
Keyword(s):  
Water Treatment ◽  
Energy Loss ◽  
Water Supply ◽  
Case Studies ◽  
Distribution System ◽  
Distribution Systems ◽  
Water Distribution ◽  
Water Distribution System ◽  
Supply System ◽  
Water Supply System

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.

scholarly journals Promoting equitable water distribution system from Melamchi Water Supply Project in Kathmandu Valley

2020 ◽  
Vol 20 (8) ◽  
pp. 2964-2970
Author(s):  
D. P. Ayadi ◽  
A. Rai ◽  
A. Pandey
Keyword(s):  
Water Supply ◽  
Distribution System ◽  
Water Distribution ◽  
Water Distribution System ◽  
Water Distribution Network ◽  
Supply System ◽  
Kathmandu Valley ◽  
Drinking Water Resources ◽  
Key Issues

Abstract The effective and efficient supply of drinking water resources are key to its long-term use and access. In recent decades, the population of Kathmandu Valley has exploded owing to several factors. The water supply system here has also undergone remarkable changes and efforts have been made to enhance its equitable distribution. The major effort, of course, is the Melamchi Water Supply Project (MWSP). As the project approaches completion of its first phase, we would like to point out several key issues for the water distribution system here and express our opinions on promoting equitable water distribution. For this we conducted a thorough literature review and found that improvement in the water distribution network and water tariff in the valley, along with promotion of alternative mitigation options, are the focal issues for promoting an equitable water distribution system in Kathmandu Valley.

scholarly journals Design and Analysis of Rural Water Supply System Using Loop 4.0 and Water Gems V8i for Nava Shihora Zone 1

2019 ◽  
Vol 9 (1) ◽  
pp. 2258-2266
Keyword(s):  
Water Supply ◽  
Distribution System ◽  
Water Distribution ◽  
Water Distribution System ◽  
Extended Period ◽  
Supply System ◽  
Water Supply System ◽  
Residual Chlorine ◽  
Residual Pressure ◽  
Rural Water

The study presents the hydraulic design and analysis of Rural Water Distribution System (WDS) for Nava shihora region of zone 1 of the state of Gujarat, India. Water supply distribution system is designed for this study for population estimated for future 30 years. LOOP 4.0 and Water Gems v8i software have been used and the results are compared to determine the economical size of pipes for water distribution system. The economical size of pipes of water supply distribution system is designed by considering the constraints; residual pressure at each node, velocity of flow in pipe, head loos in pipes, material of pipes, elevated service reservoir level, peak factor and available commercial pipe diameters. Further water distribution system has been analyzed for extended period simulation (EPS) for the present population scenario for intermittent water supply using Water Gems v8i. Further water supply system is analyzed the residual chlorine concentration at nodes and in the pipe links and also the total cost of water supply system of rural region is estimated.

scholarly journals Optimization of a Water Distribution System in Kenya

2019 ◽  
Vol 9 (1) ◽  
pp. 1334-1337
Keyword(s):  
Distribution System ◽  
Water Distribution ◽  
Water Distribution System ◽  
Supply System ◽  
Chlorine Concentration ◽  
Quality Analysis ◽  
Residual Chlorine ◽  
Study Results ◽  
Minimum Requirements ◽  
Feasible Solutions

Supplying water in significant quality and quantity is still a challenge for developing countries. Juja water distribution system located in Kenya faces low-pressure and inadequate residual chlorine concentration challenges and requires capacity boosting to meet the minimum requirements of a water supply system. For optimizing the existing Juja distribution network, the current study proposes some feasible solutions. The solutions comprise of network repairs, recommissioning of an existing tank coupled with a system of chlorine booster points, an addition of a booster pump and, changes in diameters of some pipes. The analysis was carried out using Epanet 3.0 hydraulic model. The hydraulic capacity of the upgraded network met the minimum requirements of a distribution system. Pressures in the distribution system ranged between 16.91 m to 63.63 m at user points after optimization with acceptable maximum headloss of 18.24 m/km and velocity of 2.25 m/s. The hydraulic behavior of the network satisfied general guidelines. The water quality analysis showed reasonable residual chlorine concentration, with 95% of the supply area ranging between 0.40 and 0.60 mg/l after upgrade by the model. These study results were recommended and shared with the Juja water company, which is currently undertaking a review process of the supply system.

Temperature Analysis of the Water Supply System of a Dairy Company by Means of a Simulation Model

2015 ◽  
Vol 11 (6) ◽  
pp. 731-745 ◽  
Author(s):  
Davide Marchini ◽  
Marta Rinaldi ◽  
Roberto Montanari ◽  
Eleonora Bottani ◽  
Federico Solari
Keyword(s):  
Thermal Properties ◽  
Water Supply ◽  
Simulation Model ◽  
Distribution System ◽  
Water Distribution ◽  
Water Distribution System ◽  
Supply System ◽  
Temperature Analysis ◽  
Food Engineering ◽  
Parmigiano Reggiano

Abstract This paper builds upon the study by Marchini et al. (2014, International Journal of Food Engineering, pp. 557–571) and represents the second part of a research project whose general aim was to analyse and optimize, through simulation, the water distribution system of a dairy company. In the first paper, the authors focused on finding opportunities for recycling water in the distribution system of the targeted company, i.e. a dairy company located near Parma (Italy) and manufacturing Parmigiano Reggiano cheese and butter. In this work, we go ahead by analysing the thermal properties (such as, primarily, the temperature) of the water used inside the distribution system and of that discharged. To this purpose, we add the relevant thermal equations to the MS ExcelTM simulation model developed in the first study. The resulting model is able to derive the temperature trend of water inside all the tanks of the distribution system. Situations where the temperature of the water used for rinsing is higher than the maximum allowed value of approx. 25°C are also highlighted and suggestions for improvement are proposed.

scholarly journals Rapid Testing and Interventions to Control Legionella Proliferation following a Legionnaires’ Disease Outbreak Associated with Cooling Towers

2021 ◽  
Vol 9 (3) ◽  
pp. 615
Author(s):  
Charlotte Young ◽  
Duncan Smith ◽  
Tim Wafer ◽  
Brian Crook
Keyword(s):  
Distribution System ◽  
Water Distribution ◽  
Cooling Tower ◽  
Quantitative Polymerase Chain Reaction ◽  
Cooling Water ◽  
Analytical Techniques ◽  
Remedial Action ◽  
Sampling Locations ◽  
Routine Monitoring ◽  
History Of

Most literature to date on the use of rapid Legionella tests have compared different sampling and analytical techniques, with few studies on real-world experiences using such methods. Rapid tests offer a significantly shorter feedback loop on the effectiveness of the controls. This study involved a complex of five factories, three of which had a history of Legionella contamination in their cooling water distribution system. Multiple sampling locations were utilised to take monthly water samples over 39 months to analyse for Legionella by both culture and quantitative polymerase chain reaction (qPCR). Routine monitoring gave no positive Legionella results by culture (n = 330); however, samples were frequently (68%) positive by qPCR for Legionella spp. (n = 1564). Legionella spp. qPCR assay was thus found to be a good indicator of cooling tower system health and suitable as a routine monitoring tool. An in-house qPCR limit of 5000 genomic units (GU)/L Legionella spp. was established to trigger investigation and remedial action. This approach facilitated swift remedial action to prevent Legionella proliferation to levels that may represent a public health risk. Cooling tower operators may have to set their own action levels for their own systems; however, in this study, 5000 GU/L was deemed appropriate and pragmatic.

scholarly journals Risk management of water distribution system in Armenia

2019 ◽  
Vol 97 ◽  
pp. 05020
Author(s):  
Artur Khachatryan ◽  
Emil Khachatryan
Keyword(s):  
Risk Management ◽  
Water Supply ◽  
Distribution System ◽  
Water Distribution ◽  
Water Distribution System ◽  
Risk Estimation ◽  
Supply System ◽  
Water Supply System ◽  
Risk Level ◽  
Risk Magnitude

Risks in the water distribution system in the Armenian village of Noratus, have been assessed and treated following a risk management study based on the ISO 31 000:2009 standards, but extended for a strategic and long term level of analysis. The main goal is to ensure the safety of the whole water supply system. The brief description of the region as well as the current condition of the water supply system is given in order to clarify system features. The risk management here presented approach is now implemented in the Noratus network. Simulation have been performed using the AWARE-P software platform with the purpose of identifying critical components in the network and the asset probability of structural failure, as inputs for risk quantification. Then the risk magnitude is evaluated with the introduction of risk matrix. The phases of risk estimation and treatment are also carried out to propose the solutions for risk level reduction.

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