scholarly journals An Analysis Model for Domestic Hot Water Distribution Systems

2011 ◽  
Author(s):  
Jeff Maguire ◽  
Xia Fang ◽  
Moncef Krarti
Keyword(s):  
Distribution System ◽  
Distribution Systems ◽  
Water Distribution ◽  
Water Distribution System ◽  
Water Distribution Systems ◽  
Simulation Software ◽  
Hot Water ◽  
Water Heater ◽  
Domestic Hot Water ◽  
Study Results

A thermal model was developed to estimate the energy losses from prototypical domestic hot water (DHW) distribution systems for homes. The developed model, using the TRNSYS simulation software, allows researchers and designers to better evaluate the performance of hot water distribution systems in homes. Modeling results were compared with past experimental study results and showed good agreement. The model was also compared with existing domestic hot water distribution system modeling software HWSIM for verification. The developed model has several capabilities that are not available in HWSIM, including the ability to integrate any new or existing types of water heater systems, the ability to handle several simultaneous draws to different end uses, and the ability to handle unique annual draw profiles instead of weekly draw profiles. It also allows for draw profiles and ambient conditions to be considered using any time resolution. To demonstrate the abilities of this new model, a series of sensitivity analyses were performed using a benchmark domestic hot water distribution system. The effects of adding insulation to the domestic hot water distribution system of homes with a gas water heater and a solar water heater were also examined.

Resistance of Legionella to disinfection in hot water distribution systems

2005 ◽  
Vol 52 (8) ◽  
pp. 15-28 ◽  
Author(s):  
S. Saby ◽  
A. Vidal ◽  
H. Suty
Keyword(s):  
Distribution System ◽  
Distribution Systems ◽  
Water Distribution ◽  
Water Distribution System ◽  
Water Distribution Systems ◽  
Distribution Networks ◽  
Hot Water ◽  
Chemical Treatments ◽  
Alarm Systems ◽  
Treatment Shock

The efficiency of various disinfection treatments against Legionella was tested on a hot water distribution system (HWDS) pilot unit. The results demonstrated clearly that most Legionella in the networks were fixed in the biofilm at the surface of the pipe (more than 98% for each loop). Chemical treatments (continuous chlorination, hyperchlorination, hydrogen peroxide and peracetic acid mixing) commonly used for the eradication of Legionella in hot water distribution networks appeared to be inadequate for eradicating the bacteria in the biofilm. Unfortunately, the biofilm contained most of the pathogens in an HWDS whereas legislation is only restricted to the Legionella concentration in the water phase. Thermal treatment appeared to be efficient to disinfect most of the biofilm but seemed to promote the biofilm re-growth as well. It was then concluded that the best solution to prevent Legionella contamination in hot water distribution systems would be to have perfect control of the temperature in the networks (temperature > 55°C at all points). Nevertheless, in many cases it is difficult to have such control, so during the time necessary to modify networks, the best solution to control Legionella proliferation appears to be to apply a treatment shock (thermal or chlorination as a function of pipe characteristics). These treatments must be followed by a continuous chlorination that is totally controlled and equipped with alarm systems. This study demonstrates that biofilm sampling devices must be installed in hot water distribution systems to anticipate Legionella contamination and correctly determine the efficiency of the treatments.

Risk Assessment Modeling for Water Distribution Systems in Mega Cities

2013 ◽  
Vol 353-356 ◽  
pp. 2957-2960
Author(s):  
Jia Sun ◽  
Guo Ping Yu
Keyword(s):  
Risk Assessment ◽  
Land Subsidence ◽  
Distribution System ◽  
Distribution Systems ◽  
Water Distribution ◽  
Water Distribution System ◽  
Water Distribution Systems ◽  
Assessment Model ◽  
Strategic Decision ◽  
Mega Cities

In study of a series of damages to water distribution systems caused by urban land subsidence, risk assessment modeling is necessary for risk management especially in Mega-cities. First of all, the Catastrophe Theory was employed to analyze the Catastrophe mechanism, and a function catastrophe simulation model was established accordingly to get the vulnerability index of water distribution system. Secondly, risk entropy model was used to analyze the risk of pipe network suffering the land subsidence with the disorder and uncertainty features according to risk theory. Finally, to get the risk index the water distribution system of Guangzhou city was taken to the risk assessment model utilizing the level of land subsidence identified by the dimensional analytical method. The results showed that the risk of land subsidence under the city water distribution system security upgrade is feasible to provide a risk assessment of the strategic decision-making model.

scholarly journals THE ANALYSIS OF WATER SPEED INFLUENCE IN HOT-WATER DISTRIBUTION SYSTEM ON THE AMOUNT OF HEAT LOSS

2021 ◽  
Vol 2021 (1) ◽  
pp. 23-28
Author(s):  
Peter Kapalo ◽  
◽  
Khrystyna Kozak ◽  
Khrystyna Myroniuk ◽  
◽  
...  
Keyword(s):  
Energy Consumption ◽  
Heat Loss ◽  
Distribution System ◽  
Distribution Systems ◽  
Water Distribution ◽  
Water Distribution System ◽  
Ventilation System ◽  
Hot Water ◽  
Graphical Form ◽  
Hot Water Supply System

One of the main tasks around the world is to reduce energy consumption with constant consumer comfort. The hot water supply system uses a significant part of thermal energy and requires no less attention than the heating or ventilation system. The amount of heat loss from hot water distribution systems is of great importance for the energy consumption of buildings. In winter, part of this heat is used for space heating, in summer they are unused and is considered as lost heat. For this reason, this paper considers the influence of water velocity in the pipe, pipe size, and water temperature on the total heat losses in the insulated hot-water distribution system. The data are presented in tabular and graphical form. A graph of the dependence of the amount of heat loss on the temperature and velocity of hot water is obtained.

scholarly journals Analisis Sistem Distribusi Air Bersih di Perumahan Ciomas Permai Kabupaten Bogor Jawa Barat

2021 ◽  
Vol 6 (2) ◽  
pp. 107-120
Author(s):  
Kiki Rizky Fauziah ◽  
Nora Pandjaitan ◽  
Titiek Ujianti Karunia
Keyword(s):  
Data Analysis ◽  
Distribution System ◽  
Distribution Systems ◽  
Water Distribution ◽  
Water Distribution System ◽  
Water Distribution Systems ◽  
Secondary Data ◽  
Clean Water ◽  
Customer Requirements

Water distribution systems are often problematic in terms of quantity, pressure, continuity and quality. The research aimed to analyze water distribution system of PDAM Tirta Kahuripan Kabupaten Bogor in Ciomas Permai Residence. The research was conducted by collecting primary and secondary data. Analysis of clean water distribution system was carried out using the EPANET 2.0. Ciomas Permai Residence was located in zone 6 of PDAM Tirta Kahuripan servive areas. The result showed that the quality of the distributed water was in accordance with the applicable standard and continuous for 24 hours even though there were significant discharge differences during peak hours. Based on the measurement on Sunday and Monday, the minimum discharge were 14.4 l/sec and 13.8 l/sec respectively, higher than customer requirements of 7.34 l/sec, The water distribution pressure ranged from 0.7 - 1.35 bar. The result of clean water distribution simulation using EPANET 2.0 showed that the velocity of water and headloss were not accordance with the applicable standards.

A New Energy Optimization Strategy for Pumping Operation in Water Distribution Systems

2012 ◽  
Author(s):  
Dhafar Al-Ani ◽  
Saeid Habibi
Keyword(s):  
Distribution System ◽  
Energy Cost ◽  
Distribution Systems ◽  
Water Distribution ◽  
Water Distribution System ◽  
Water Distribution Systems ◽  
Energy Optimization ◽  
Operating Conditions ◽  
Optimization Strategy ◽  
Multi Objective

As time goes on, more and more operating-modes based on changing demand profiles will be compiled to enrich the range of feasible solutions for a water distribution system. This implies the conservation of energy consumed by a water pumping station and improves the ability for energy optimization. Another important goal was improving safety, reliability, and maintenance cost. In this paper, three important goals were addressed: cost-effectives, safety, and self-sustainability operations of water distribution systems. In this work, the objective functions to optimize were total electrical energy cost, maintenance costs, and reservoir water level variation while preserving the service provided to water clients. To accomplish these goals, an effective Energy Optimization Strategy (EOS) that manages trade-off among operational cost, system safety, and reliability was proposed. Moreover, the EOS aims at improving the operating conditions (i.e., pumping schedule) of an existing network system (i.e., with given capacities of tanks) and without physical changes in the infrastructure of the distribution systems. The new strategy consisted of a new Parallel Multi-objective Particle Swarm optimization with Adaptive Search-space Boundaries (P-MOPSO-ASB) and a modified EPANET. This has several advantages: obtaining a Pareto-front with solutions that are quantitatively equally good and providing the decision maker with the opportunity to qualitatively compare the solutions before their implementation into practice. The multi-objective optimization approach developed in this paper follows modern applications that combine an optimization algorithm with a network simulation model by using full hydraulic simulations and distributed demand models. The proposed EOS was successfully applied to a rural water distribution system, namely Saskatoon West. The results showed that a potential for considerable cost reductions in total energy cost was achieved (approximately % 7.5). Furthermore, the safety and the reliability of the system are preserved by using the new optimal pump schedules.

Energy Analysis of Hot Water Distribution System - Interrupted Operation

2013 ◽  
Vol 437 ◽  
pp. 1062-1065 ◽  
Author(s):  
Peter Kapalo ◽  
Ladislav Böszörmenyi
Keyword(s):  
Distribution System ◽  
Distribution Systems ◽  
Water Distribution ◽  
Energy Analysis ◽  
Water Distribution System ◽  
Energy Requirement ◽  
Hot Water ◽  
Energy Price ◽  
Actual Increase

At an actual increase energy price it is has impact cut-down energy requirement for preparation and distribution of hot water (HW). In the paper are presented results of exploration, where been evaluation effect interrupted operations distribution systems HW flat building. From presented analyses result - relative more savings heat is for long interrupted distribution systems and for little the number of flat in building.

scholarly journals Forensic Engineering Analysis Of The Negative Effect Of Hot Water Distribution Systems On Heater Operation

2002 ◽  
Vol 19 (1) ◽  
Author(s):  
Edward W. Saltzberg
Keyword(s):  
Distribution Systems ◽  
Water Distribution ◽  
Water Distribution Systems ◽  
Hot Water ◽  
Engineering Analysis ◽  
Water Heater ◽  
Water Heaters ◽  
Negative Effect ◽  
Forensic Engineering ◽  
Construction Defects

Our Office Had Two Condominium Litigation Cases That Had A Number Of Construction Defects. One Was A Luxury Complex And One Was A Moderately Priced Project. However, There Were Two Common Allegations In Both Cases. These Allegations Were That The Occupants Complained That They Did Not Have Sufficient Hot Water And That The Water Heater Was Not Able To Provide A Sufficient Quantity Of Hot Water. We Prepared Calculations On Both Of The Water Heater Systems To Determine If They Were Undersized. The Calculations Determined That The Water Heater Assembly Of Both Installations Were Liberally Sized And Should Have Been Able To Maintain Design Temperature All The Time, Even At Peak Use. To Ensure That The Water Heaters Were Both Operating Correctly, We Had The Water Heater Manufacturer Come Out And Service The Heaters On Both Systems. Both Systems Were Operating Properly.

scholarly journals Reliability analysis of water distribution systems

2004 ◽  
Vol 6 (4) ◽  
pp. 281-294 ◽  
Author(s):  
Avi Ostfeld
Keyword(s):  
Reliability Analysis ◽  
Distribution System ◽  
Distribution Systems ◽  
Water Distribution ◽  
Water Distribution System ◽  
Water Distribution Systems ◽  
Nonlinear Behavior ◽  
Conflicting Objectives ◽  
The Many ◽  
Acceptable Reliability

Reliability is an integral part of all decisions regarding water distribution system layout, design, operation and maintenance. Providing reliability for water distribution systems is complicated due to the many factors that affect reliability, the inherent nonlinear behavior of the system and its consumers, and due to the different conflicting objectives facing a water distribution system utility. Although the reliability of water distribution systems has received considerable attention over the last two decades, there is still no common, acceptable, reliability measure or reliability assessment methodology. This paper describes the classification and reliability analysis methodologies of water distribution systems and compares two previously published algorithms for reliability evaluation of water distribution systems: a tailor-made ‘lumped supply–lumped demand’ approach used most commonly in regional water distribution systems and a general stochastic (Monte Carlo) framework suitable for any generic network.

Investigation into biofilms in a local drinking water distribution system

Biofilms ◽  
2005 ◽  
Vol 2 (1) ◽  
pp. 19-25 ◽  
Author(s):  
J. Y. Hu ◽  
B. Yu ◽  
Y. Y. Feng ◽  
X. L. Tan ◽  
S. L. Ong ◽  
...  
Keyword(s):  
Distribution System ◽  
Distribution Systems ◽  
Water Distribution ◽  
Water Distribution System ◽  
Water Distribution Systems ◽  
Plate Count ◽  
Residual Chlorine ◽  
Biofilm Growth ◽  
Water Plant ◽  
Biofilm Development

Biofilm growth within a water distribution system could lead to operational problems such as pipe corrosion, water quality deterioration and other undesirable impacts in water distribution systems. With the high ambient temperatures experienced in Singapore, the operating environment in water distribution systems is expected to be more conducive to biofilm development. We have recently conducted a survey on biofilms potentially present in a local water distribution system.The survey results indicated that residual chlorine (±standard deviation) decreased from 1.49±0.61 mg/l (water plant outlets) to 0.82±0.21 mg/l (block pipes) or 0.18±0.06 mg/l (unit pipes), respectively. Consumed chlorine, instead of residual chlorine, was found to be correlated with biofilm bacterial population. Assimilable organic carbon (AOC) level was 160±66 μg acetate C/l, and AOC:PO4-P:NO3-N was about 8:13:1. Carbon source seemed to be the limiting nutrient for bacterial growth. The concentration of iron increased from <0.04 mg/l (water plant outlets) to 0.22±0.10 mg/l (all sites). All samples showed negative results in a coliform test. The average heterotrophic plate count (HPC) for the suspended bacteria was 20 colony-forming units (c.f.u.)/ml (2 days, 35 °C) or 290 c.f.u./ml (8 days, 35 °C). The average HPC for the biofilm bacteria was 6500 c.f.u./cm2 (2 days, 35 °C) or 29000 c.f.u./cm2 (8 days, 35 °C). High HPC values in samples B2a, B2b and B3a (representing biofilm samples at site 2 from block/unit pipes and biofilm samples at site 3 from block pipes, respectively) illustrated that the relevant sample sites had a higher probaboility of biofilm growth.

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