scholarly journals Deterministic Model to Estimate the Energy Requirements of Pressurized Water Transport Systems

Water ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 345
Author(s):  
Enrique Cabrera ◽  
Roberto del Teso ◽  
Elena Gómez ◽  
Enrique Cabrera ◽  
Elvira Estruch-Juan
Keyword(s):  
Water Transport ◽  
Distribution Systems ◽  
Energy Intensity ◽  
Deterministic Model ◽  
Water Cycle ◽  
Operating Conditions ◽  
Transport Systems ◽  
Energy Requirements ◽  
Pressurized Water ◽  
Energy Needs

Energy intensity, Ie (kWh/m3) is the most popular indicator when characterizing the energy requirements of the water cycle, due to its direct and easy interpretation. In pressurized water transport systems, when referred to an appropriate physical framework (such as a single water transport pipeline), it assesses the efficiency of the process. However, in complex urban water transport networks, Ie only provides a basic notion of the energy needs of the system. The aim of this paper is to define a standard physical framework for assessing the energy intensity in water transport and distribution systems. To that purpose, an analytic expression that estimates Ie is proposed, based on system data and its operating conditions. The results allow for a realistic approximation of the energy needs of water transport. This energy assessment is completed with two context indicators: energy origin (C1) and topographic energy (θt), both essential when the energy efficiency of different systems is to be compared.

scholarly journals Labeling Water Transport Efficiencies

Water ◽  
2018 ◽  
Vol 10 (7) ◽  
pp. 935 ◽  
Author(s):  
Elena Gómez ◽  
Roberto del Teso ◽  
Enrique Cabrera ◽  
Enrique Cabrera ◽  
Javier Soriano
Keyword(s):  
Water Transport ◽  
Electricity Consumption ◽  
Transport Systems ◽  
Energy Costs ◽  
Pressurized Water ◽  
Current Trends ◽  
Relative Metrics ◽  
Energy Score ◽  
Current Water

Pressurized Water Transport Systems (PWTSs) are responsible for a large percentage of the electricity consumption around the world, and current trends suggest that this proportion will continue to increase in the future. Controlling PWTS is therefore fundamental, including improving efficiency when necessary or compulsory. To achieve this, metrics to objectively assess the efficiency of the different losses and of the whole system are needed. These metrics, based on economic criteria, will be stricter if environmental costs are added to current water and energy costs. To assess different improvement strategies, some relative metrics, applied to both operational and structural losses, are considered. At the end, taking into account their relevance, these metrics are combined in a global energy score (IS), this being the main contribution of this paper. Finally, to focus on the concepts and methodology, a simple case study is presented.

scholarly journals EVALUATION OF OPERATING CONDITIONS OF ELECTROMECHANICAL SYSTEMS USING ENERGY PERFORMANCE

2018 ◽  
pp. 82-91
Author(s):  
Igor Alexandrovich Menshikov
Keyword(s):  
Water Transport ◽  
Energy Performance ◽  
Electric Machines ◽  
Operating Conditions ◽  
Technical State ◽  
Transport Systems ◽  
Electromechanical Systems ◽  
Diagnostic Parameters ◽  
Operation Conditions ◽  
Selection Of

The article presents the results of evaluating technical state of electromechanical transport systems with ДК-211БМ traction electric engine. Resolution of the problem of increasing operation efficiency of land and water transport can be achieved in many respects by implementation of advanced tools of automation and control over diagnostic parameters of electromechanical systems. Reducing operating costs due to the application of energy-saving technologies in maintenance of electromechanical systems on land and water transport is one of the main requirements of the industrial scientific and technical program. Electromechanical transport systems comprise a large number of sensors and actuators located directly on production sites in operation conditions. In this regard, there appears a need to bring electromechanical systems in conformity with modern requirements of operational safety on the basis of scientifically substantiated design concepts, scientific achievements in the field of new materials, production, technologies and automation controlof technical conditions of transport systems. One of the essential tasks of building an adaptive automation control system of monitoring technical state of electromechanical systems is selection of diagnostic parameters. The selection of diagnostic parameters of control of technical state of traction electric machines is suggested to carry out using mathematical modeling of power indexes. With the help of a simulation model of electromechanical system of control over electrical DC machines type ДК-211БМ there were obtained diagnostic energy parameters of the city electromotive vehicles moving at different speeds. Application of the obtained diagnostic parameters helps to control the faults and failures in armature windings of dc electric machines of transport electromechanical systems.

scholarly journals A Numerical Investigation into the PAT Hydrodynamic Response to Impeller Rotational Speed Variation

2021 ◽  
Vol 13 (14) ◽  
pp. 7998
Author(s):  
Maxime Binama ◽  
Kan Kan ◽  
Hui-Xiang Chen ◽  
Yuan Zheng ◽  
Daqing Zhou ◽  
...  
Keyword(s):  
Rotational Speed ◽  
Distribution Systems ◽  
Water Distribution ◽  
Production Efficiency ◽  
Operating Conditions ◽  
Energy Regulation ◽  
Speed Increase ◽  
Energy Field ◽  
Long Run ◽  
Study Results

The utilization of pump as turbines (PATs) within water distribution systems for energy regulation and hydroelectricity generation purposes has increasingly attracted the energy field players’ attention. However, its power production efficiency still faces difficulties due to PAT’s lack of flow control ability in such dynamic systems. This has eventually led to the introduction of the so-called “variable operating strategy” or VOS, where the impeller rotational speed may be controlled to satisfy the system-required flow conditions. Taking from these grounds, this study numerically investigates PAT eventual flow structures formation mechanism, especially when subjected to varying impeller rotational speed. CFD-backed numerical simulations were conducted on PAT flow under four operating conditions (1.00 QBEP, 0.82 QBEP, 0.74 QBEP, and 0.55 QBEP), considering five impeller rotational speeds (110 rpm, 130 rpm, 150 rpm, 170 rpm, and 190 rpm). Study results have shown that both PAT’s flow and pressure fields deteriorate with the machine influx decrease, where the impeller rotational speed increase is found to alleviate PAT pressure pulsation levels under high-flow operating conditions, while it worsens them under part-load conditions. This study’s results add value to a thorough understanding of PAT flow dynamics, which, in a long run, contributes to the solution of the so-far existent technical issues.

scholarly journals Configurations, Power Topologies and Applications of Hybrid Distribution Transformers

Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1215
Author(s):  
Alvaro Carreno ◽  
Marcelo Perez ◽  
Carlos Baier ◽  
Alex Huang ◽  
Sanjay Rajendran ◽  
...  
Keyword(s):  
Distribution Systems ◽  
Power Converter ◽  
Operating Conditions ◽  
Distribution Transformer ◽  
Nonlinear Loads ◽  
Electric Vehicle Charging ◽  
Distribution Transformers ◽  
Alternative Systems ◽  
Charging Stations ◽  
Hybrid Distribution

Distribution systems are under constant stress due to their highly variable operating conditions, which jeopardize distribution transformers and lines, degrading the end-user service. Due to transformer regulation, variable loads can generate voltage profiles out of the acceptable bands recommended by grid codes, affecting the quality of service. At the same time, nonlinear loads, such as diode bridge rectifiers without power factor correction systems, generate nonlinear currents that affect the distribution transformer operation, reducing its lifetime. Variable loads can be commonly found at domiciliary levels due to the random operation of home appliances, but recently also due to electric vehicle charging stations, where the distribution transformer can cyclically vary between no-load, rated and overrated load. Thus, the distribution transformer can not safely operate under highly-dynamic and stressful conditions, requiring the support of alternative systems. Among the existing solutions, hybrid transformers, which are composed of a conventional transformer and a power converter, are an interesting alternative to cope with several power quality problems. This article is a review of the available literature about hybrid distribution transformers.

scholarly journals Modeling Bacterial Regrowth and Trihalomethane Formation in Water Distribution Systems

Water ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 463
Author(s):  
Gopinathan R. Abhijith ◽  
Leonid Kadinski ◽  
Avi Ostfeld
Keyword(s):  
Distribution Systems ◽  
Water Distribution ◽  
Mechanistic Model ◽  
Water Distribution Systems ◽  
Sensitivity Study ◽  
Operating Conditions ◽  
Growth Rate Constant ◽  
Model Parameters ◽  
Bacterial Regrowth ◽  
The Impact

The formation of bacterial regrowth and disinfection by-products is ubiquitous in chlorinated water distribution systems (WDSs) operated with organic loads. A generic, easy-to-use mechanistic model describing the fundamental processes governing the interrelationship between chlorine, total organic carbon (TOC), and bacteria to analyze the spatiotemporal water quality variations in WDSs was developed using EPANET-MSX. The representation of multispecies reactions was simplified to minimize the interdependent model parameters. The physicochemical/biological processes that cannot be experimentally determined were neglected. The effects of source water characteristics and water residence time on controlling bacterial regrowth and Trihalomethane (THM) formation in two well-tested systems under chlorinated and non-chlorinated conditions were analyzed by applying the model. The results established that a 100% increase in the free chlorine concentration and a 50% reduction in the TOC at the source effectuated a 5.87 log scale decrement in the bacteriological activity at the expense of a 60% increase in THM formation. The sensitivity study showed the impact of the operating conditions and the network characteristics in determining parameter sensitivities to model outputs. The maximum specific growth rate constant for bulk phase bacteria was found to be the most sensitive parameter to the predicted bacterial regrowth.

scholarly journals Sustainable Transport in the Danube Region

2021 ◽  
Vol 13 (12) ◽  
pp. 6797
Author(s):  
Peter Mako ◽  
Andrej Dávid ◽  
Patrik Böhm ◽  
Sorin Savu
Keyword(s):  
Water Transport ◽  
Fossil Fuels ◽  
Environmentally Friendly ◽  
Road Transport ◽  
Transport Systems ◽  
Main Question ◽  
Inland Water ◽  
Danube Region ◽  
Inland Water Transport

Sustainability of transport systems is a key issue in transport. The main question is whether high levels of road and railway transport in areas along navigable waterways is an effective solution for this issue. The Danube waterway is an example. Generally, it is not observed that traffic performance is not as high as on the Rhine. This paper deals with the revelation of the available capacity of this waterway based on approximation functions and their comparison with real transport performances. This methodology points to the level of use of waterways. The connection of this model with the production of fossil fuels creates a basis for a case study. The case study in this paper offers a possibility for a sustainable and environmentally friendly transition from road transport to inland water transport on the example of specific transport routes. The main contribution of this paper is a presentation of the application of sustainable models of use transport capacity to increase the share of environmentally friendly and sustainable inland water transport. The conclusion based on the case study and materials is that the available capacity of inland water transport on the Danube could support the transition of traffic performances to sustainable and environmentally friendly means of transport.

scholarly journals Theoretical Estimation of Energy Balance Components in Water Networks for Top-Down Approach

Water ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1011
Author(s):  
Surachai Lipiwattanakarn ◽  
Suparak Kaewsang ◽  
Natchapol Charuwimolkul ◽  
Jiramate Changklom ◽  
Adichai Pornprommin
Keyword(s):  
Energy Balance ◽  
Water Loss ◽  
Distribution Systems ◽  
Minimum Energy ◽  
Head Loss ◽  
Water Networks ◽  
Top Down ◽  
Pressurized Water ◽  
Simple Method ◽  
Energy Balance Approach

The energy balance calculation for pressurized water networks is an important step in assessing the energy efficiency of water distribution systems. However, the calculation generally requires mathematical modelling of the water networks to estimate three important energy components: outgoing energy through water loss (El), friction energy loss (Ef) and energy associated with water loss (EWL). Based on a theoretical energy balance analysis of simplified pipe networks, a simple method is proposed to estimate El, Ef and EWL with minimum data requirements: input energy, water loss (WL) and head loss between the source and the minimum energy point (ΔH). By inclusion of the head loss in water networks into the estimation, the percentages of El and EWL are lower and higher, respectively, than using only the percentage of WL. The percentage of Ef can be a function of the percentage of ΔH. By demonstrating our analysis with the simulation results from the mathematical models of 20 real water networks, the proposed method can be used to effectively estimate El, Ef and EWL as a top-down energy balance approach.

scholarly journals Simulation of the Westinghouse AP1000 Response to SBLOCA Using RELAP/SCDAPSIM

2014 ◽  
Vol 2014 ◽  
pp. 1-9 ◽  
Author(s):  
Ayah Elshahat ◽  
Timothy Abram ◽  
Judith Hohorst ◽  
Chris Allison
Keyword(s):  
Driving Forces ◽  
Natural Circulation ◽  
Safety System ◽  
Operating Conditions ◽  
Severe Accident ◽  
Passive Safety ◽  
System Component ◽  
Pressurized Water ◽  
Loss Of Coolant Accident ◽  
Accident Conditions

Great interest is given now to advanced nuclear reactors especially those using passive safety components. The Westinghouse AP1000 Advanced Passive pressurized water reactor (PWR) is an 1117 MWe PWR designed to achieve a high safety and performance record. The AP1000 safety system uses natural driving forces, such as pressurized gas, gravity flow, natural circulation flow, and convection. In this paper, the safety performance of the AP1000 during a small break loss of coolant accident (SBLOCA) is investigated. This was done by modelling the AP1000 and the passive safety systems employed using RELAP/SCDAPSIM code. RELAP/SCDAPSIM is designed to describe the overall reactor coolant system (RCS) thermal hydraulic response and core behaviour under normal operating conditions or under design basis or severe accident conditions. Passive safety components in the AP1000 showed a clear improvement in accident mitigation. It was found that RELAP/SCDAPSIM is capable of modelling a LOCA in an AP1000 and it enables the investigation of each safety system component response separately during the accident. The model is also capable of simulating natural circulation and other relevant phenomena. The results of the model were compared to that of the NOTRUMP code and found to be in a good agreement.

scholarly journals A Flexible Load Control Strategy for Distribution Network to Reduce the Line Losses and to Eliminate the Transmission Congestion

2017 ◽  
Vol 2017 ◽  
pp. 1-16 ◽  
Author(s):  
Beibei Wang ◽  
Xiaoqing Hu ◽  
Peifeng Shen ◽  
Wenlu Ji ◽  
Yang Cao ◽  
...  
Keyword(s):  
Power Distribution ◽  
Distribution Systems ◽  
Renewable Energy Sources ◽  
Distribution Network ◽  
Test System ◽  
Operating Conditions ◽  
Load Control ◽  
Transmission Congestion ◽  
Heavy Load ◽  
Flexible Load

There are many uncertain factors in the modern distribution network, including the access of renewable energy sources and the heavy load level. The existence of these factors has brought challenges to the stability of the power distribution network, as well as increasing the risk of exceeding transmission capacity of distribution lines. The appearance of flexible load control technology provides a new idea to solve the above problems. Air conditioners (ACs) account for a great proportion of all loads. In this paper, the model of dispatching AC loads in the regional power grid is constructed, and the direct load control (DLC) method is adopted to reduce the load of ACs. An improved tabu search technique is proposed to solve the problem of network dispatch in distribution systems in order to reduce the resistive line losses and to eliminate the transmission congestion in lines under normal operating conditions. The optimal node solution is obtained to find the best location and reduction capacity of ACs for load control. To demonstrate the validity and effectiveness of the proposed method, a test system is studied. The numerical results are also given in this article, which reveal that the proposed method is promising.

NITROGEN UTILIZATION IN CALORIC INSUFFICIENCY

PEDIATRICS ◽  
1953 ◽  
Vol 11 (5) ◽  
pp. 435-448
Author(s):  
WARREN M. COX ◽  
RUDOLPH C. ELLINGSON ◽  
A. J. MUELLER
Keyword(s):  
Protein Hydrolysate ◽  
Caloric Intake ◽  
Tissue Growth ◽  
Nitrogen Utilization ◽  
Energy Requirements ◽  
Protein Loss ◽  
Dietary Nitrogen ◽  
Energy Needs ◽  
New Protein ◽  
Normal Stock

To determine whether a portion of ingested protein can be used for tissue growth when insufficient calories were fed, isocaloric and suboptimal amounts of calories in the form of dextrose or as dextrose and protein hydrolysate (amigen®) were fed to protein-depleted, partially starved, scalded and normal stock rats together with adequate vitamins and minerals. It is concluded that: 1. The greater the need for protein, the greater is the utilization of ingested nitrogen for new protein synthesis under conditions of caloric limitation. Protein-depleted rats are able to build new protein tissue even when basal energy requirements are not completely supplied. 2. Protein depleted, partially starved, scalded and stock animals retain or gain more weight when fed adequate or suboptimal quantities of the hydrolysate-dextrose diet than when fed isocaloric quantities of the dextrose diet. 3. Stock animals with no pre-existing protein loss, and in good nutritive condition, do not utilize dietary nitrogen for tissue building when the caloric intake is suboptimal. 4. When the caloric intake is less than that required to meet the estimated basal energy needs, a diet supplying approximately 20% of the calories as protein supported better growth than those supplying more or less than this amount.

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