scholarly journals Experimental determination of cold water temperature at the inlet to solar water storage tanks

2019 ◽  
Vol 116 ◽  
pp. 00106 ◽  
Author(s):  
Miroslaw Zukowski
Keyword(s):  
Water Temperature ◽  
Cold Water ◽  
Tap Water ◽  
Water System ◽  
District Heating ◽  
Hot Water ◽  
Storage Tanks ◽  
Climate Conditions ◽  
Cold Water Temperature

In the present work, results of experimental research on the mains water temperature supplying the Solar Domestic Hot Water system in the period from 2016 to 2018 are shown. The test object is located in the Hotel for Research Assistants on Bialystok University of Technology campus in Poland. One of the elements that will guarantee the correct energy balance of a hot tap-water system is the exact determination of the cold water temperature. The aim of this study is estimation of the temperature of the mains water flowing into the district heating substation and the water feeding directly the heat storage tanks. The research results showed that the average value of the cold water was 14.09°C during the 3 years of measurements. Moreover, it was shown that this temperature increased by about 0.4°C as a result of heat exchange with the air inside the substation. In the article, the author proposed modifications of coefficients in a commonly used model developed by National Renewable Energy Laboratory for determining the temperature of mains water in energy simulations. The proposed changes allow for accurate modelling of the cold water temperature under the climate conditions of north-eastern Poland.

scholarly journals Application of Response Surface Methodology (RSM) for Optimization of Operating Parameters and Performance Evaluation of Cooling Tower Cold Water Temperature

2011 ◽  
Vol 2 (1) ◽  
pp. 39-50
Author(s):  
Ramkumar RAMAKRISHNAN ◽  
Ragupathy ARUMUGAM
Keyword(s):  
Response Surface Methodology ◽  
Water Temperature ◽  
Response Surface ◽  
Cold Water ◽  
Hot Water ◽  
Optimum Operating ◽  
Operating Parameters ◽  
Operating Variables ◽  
Cold Water Temperature ◽  
And Performance

Performance  of the coolig tower was analysed with various operating parameters and find the minimum cold water temperature. In this study, optimization of operating parameters was investigated. An experimental design was carried out based on central composite design(CCD) with response surface methodology(RSM). This paper presents optimum operating parameters and   the minimum cold water temperature using RSM method.  The RSM was used to evaluate the effects of operating variables and their interaction towards the attainment of their optimum conditions. Based on statistical analysis, water flow, air flow, hot water temperature and packing height were high significant on cold water temperature, with very low probability values(<0.0001). The optimum operating parameters predicted using  RSM method and confirmed through experiment. 

scholarly journals THE USE OF SOLAR ENERGY FOR PREPARING DOMESTIC HOT WATER IN A MULTI-STOREY BUILDING / SAULĖS ENERGIJOS PANAUDOJIMAS KARŠTAM VANDENIUI RUOŠTI DAUGIABUČIAME NAME

2012 ◽  
Vol 5 (4) ◽  
pp. 507-512 ◽  
Author(s):  
Giedrius Šiupšinskas ◽  
Solveiga Adomėnaitė
Keyword(s):  
Flat Plate ◽  
Water System ◽  
District Heating ◽  
Heating System ◽  
Hot Water ◽  
Solar Collectors ◽  
District Heating System ◽  
Climate Conditions ◽  
Domestic Hot Water ◽  
Life Project

The article analyses the possibilities of solar collectors used for a domestic hot water system and installed on the roofs of modernized multi-storey buildings under the existing climate conditions. A number of combinations of flat plate and vacuum solar collectors with accumulation tank systems of various sizes have been examined. Heat from the district heating system is used as an additional heat source for preparing domestic hot water. The paper compares calculation results of energy and economy regarding the combinations of flat plate and vacuum solar collectors and the size of the accumulation tank. The influence of variations in the main indicators on the final economic results has also been evaluated. Research has been supported applying EC FP7 CONCERTO program (‘‘Sustainable Zero Carbon ECO-Town Developments Improving Quality of Life across EU - ECO-Life’’ (ECO-Life Project) Contract No. TREN/FP7EN/239497/”ECOLIFE”). Santrauka Straipsnyje analizuojamos saulės kolektorių, skirtų karšto vandentiekio sistemai ant modernizuojamų daugiabučių namų stogų įrengti esamomis klimatinėmis sąlygomis galimybės. Nagrinėjamos įvairaus dydžio plokščiųjų ir vakuuminių saulės kolektorių su akumuliacinėmis talpyklomis sistemų kombinacijos. Kaip papildomas šilumos šaltinis karštam vandeniui pašildyti naudojama iš centralizuotų šilumos tinklų tiekiama šiluma. Lyginami plokščiųjų, vakuuminių saulės kolektorių ir akumuliacinio bako dydžio kombinacijų energinių ir ekonominių skaičiavimų rezultatai. Įvertinama kai kurių esminių rodiklių pokyčių įtaka galutiniams ekonominiams rodikliams.

A simple method for the eradication ofLegionella pneumophilafrom potable water systems

1997 ◽  
Vol 43 (12) ◽  
pp. 1189-1196 ◽  
Author(s):  
Carmen Moreno ◽  
Isabel de Blas ◽  
Francisca Miralles ◽  
David Apraiz ◽  
Vicente Catalan
Keyword(s):  
Legionella Pneumophila ◽  
Potable Water ◽  
Cold Water ◽  
Tap Water ◽  
Water System ◽  
Water Systems ◽  
Hot Water ◽  
Residual Chlorine ◽  
Water Heater ◽  
Simple Method

In this paper we describe a simple method, noncorrosive to pipes, for the eradication of Legionella pneumophila from potable water systems. This method is based on the systematic purging of the pipe networks with cold water containing 1 – 1.5 mg residual chlorine/L. In the hot water system, a new pipe bypassing the water heater was installed, whereas in the air conditioning system, the circuit is purged with water from the tap water system. The feasibility of this method was studied in two hotels in which the presence of Legionella was detected despite treatment of the water by the hyperchlorination method. The evolution of the presence of Legionella was studied by culture and polymerase chain reaction. Eighty samples from hotel A and sixty-seven samples from hotel B were analyzed during the time that the eradication method was applied. Our results showed that this method permitted the effective elimination of L. pneumophila after 5 months in hotel A and 7 months in hotel B.Key words: Legionella pneumophila, eradication.

Theoretical analysis of an improved adsorption desalination system under different operating conditions

2021 ◽  
pp. 095440892198947
Author(s):  
Amirhossein Amirfakhraei ◽  
Taleb Zarei ◽  
Jamshid Khorshidi
Keyword(s):  
Water Temperature ◽  
Cold Water ◽  
Internal Heat ◽  
Operating Conditions ◽  
Hot Water ◽  
Performance Ratio ◽  
Cold Water Temperature ◽  
Conventional Systems ◽  
Heat And Mass Recovery ◽  
Mass Recovery

This paper presents the development of an advanced adsorption desalination system (ADS) with heat and mass recovery. By means of internal heat and mass recovery, this adsorption desalination system (ADS), offers a significantly higher performance ratio compared to the conventional systems. After vapor desorption, the pressure difference in the hot bed is first transmitted to the cold bed using mass recovery. Then, the heat from the hot bed is transferred into the cold bed and, eventually, to the condenser and evaporator, by means of the cold water. Numerical simulations for this system are compared to a verified experimental model, and then developed to study the effect of the operating parameters. The level of SDWP or specific daily water production for this ADS was found to be 13.48 m^3/ton of silica gel/day at a hot water temperature of 92.5 (°C) and a cold water temperature of 30 (°C). Consequently, in these operating conditions, the SDWP of the advanced ADS was found to be 153% more than the conventional ADS. Also, at the same temperature conditions, the performance ratio of the ADS with heat and mass recovery was 35% higher than the ADS without heat and mass recovery.

scholarly journals Fluctuating temperature of the mains water throughout the year and its influence on the consumption of energy for the purposes of DHW preparation

2018 ◽  
Vol 44 ◽  
pp. 00017 ◽  
Author(s):  
Agnieszka Chmielewska
Keyword(s):  
Water Treatment ◽  
Water Temperature ◽  
Cold Water ◽  
Treatment Plant ◽  
Water Treatment Plant ◽  
Monthly Basis ◽  
New Model ◽  
Water Influence ◽  
Family Building ◽  
Cold Water Temperature

The article discusses the influence of the cold water temperature on the amount of energy consumed for the purposes of the DHW preparation in multi-family buildings. The article begins with a presentation of the DHW consumption readings from a multi-family building, recorded on a monthly basis during the period of 4 years. The readings constituted the base for calculating the demand for energy for the purposes of the DHW preparation. Subsequently, basing on the output water temperature readings from the water treatment plant, it was proved that the temperature of the mains water fluctuates throughout the year. The review of the available literature, as well as the measurements, confirmed that it is necessary to develop a new model of the cold water temperature that would take into account the type of intake in a water treatment plant. The final part of the article presents how the accepted assumptions about the temperature of the mains water influence the consumption of energy for the purposes of the DHW preparation.

scholarly journals Evaluation of Legionella spp. Colonization in Residential Buildings Having Solar Thermal System for Hot Water Production

2020 ◽  
Vol 17 (19) ◽  
pp. 7050
Author(s):  
Michele Totaro ◽  
Anna Laura Costa ◽  
Lorenzo Frendo ◽  
Sara Profeti ◽  
Beatrice Casini ◽  
...  
Keyword(s):  
Cold Water ◽  
Disease Risk ◽  
Residential Buildings ◽  
Water Systems ◽  
Hot Water ◽  
Solar Thermal ◽  
Water Production ◽  
Systems Maintenance ◽  
Legionnaires Disease ◽  
Cold Water Temperature

Despite an increase of literature data on Legionella spp. presence in private water systems, epidemiological reports assert a continuing high incidence of Legionnaires’ disease infection in Italy. In this study, we report a survey on Legionella spp. colonization in 58 buildings with solar thermal systems for hot water production (TB). In all buildings, Legionella spp. presence was enumerated in hot and cold water samples. Microbiological potability standards of cold water were also evaluated. Legionella spp. was detected in 40% of the buildings. Moreover, we detected correlations between the count of Legionella spp. and the presence of the optimal temperature for the microorganism growth (less than 40 °C). Our results showed that cold water was free from microbiological hazards, but Legionella spp., was detected when the mean cold water temperature was 19.1 ± 2.2 °C. This may considered close to the suboptimal value for the Legionella growth (more then 20 °C). In conclusion, we observed the presence of a Legionnaires’ disease risk and the need of some strategies aimed to reduce it, such as the application of training programs for all the workers involved in water systems maintenance.

Effect of heat flushing on the concentrations of Legionella pneumophila and other heterotrophic microbes in hot water systems of apartment buildings

1996 ◽  
Vol 42 (8) ◽  
pp. 811-818 ◽  
Author(s):  
Outi M. Zacheus ◽  
Pertti J. Martikainen
Keyword(s):  
Water Temperature ◽  
Legionella Pneumophila ◽  
Heterotrophic Bacteria ◽  
Water System ◽  
Water Systems ◽  
Hot Water ◽  
Circulating Water ◽  
Heterotrophic Microbes ◽  
Before And After ◽  
Circulating Water System

The decontamination of Legionella pneumophila and other heterotrophic microbes by heat flushing in four legionellae-positive hot water systems was studied. Before the decontamination procedure, the concentration of legionellae varied from 3.0 × 10−3 to 3.5 × 10−5 cfu/L and the hot water temperature from 43.6 to 51.5 °C. During the contamination the temperature was raised to 60–70 °C. All taps and showers were cleaned from sediments and flushed with hot water twice a day for several minutes. The decontamination lasted for 2–4 weeks. In a few weeks the heat-flushing method reduced the concentration of legionellae below the detection limit (50 cfu/L) in the hot circulating water system just before and after the heat exchanger. The high hot water temperature also decreased the viable counts of heterotrophic bacteria, fungi, and total microbial cells determined by the epifluorescent microscopy. However, the eradication of legionellae failed in a water system where the water temperature remained below 60 °C in some parts of the system. After the decontamination, the temperature of hot water was lowered to 55 °C. Thereafter, all the studied hot water systems were recolonized by legionellae within a few months, showing that the decontamination by heat flushing was temporary. Also, the contamination of other bacteria increased in a few months to the level before decontamination.Key words: legionellae, hot water system, decontamination, water temperature, heterotrophic bacteria.

The Solar Energy-Air Source Heat Pump Was Applied to the Hot Water System

2014 ◽  
Vol 587-589 ◽  
pp. 243-246
Author(s):  
Chu Ping Lu ◽  
Kai Ji
Keyword(s):  
Solar Energy ◽  
Heat Pump ◽  
Water System ◽  
Hot Water ◽  
Water Heater ◽  
Circulating Water ◽  
Air Source Heat Pump ◽  
Hot Water Supply ◽  
The City

This paper is as an example of the hot water supply of the hotel in the city,The design of the hot water system is the solar energy and the air source heat pump,includes:the selection calculation of the air source heat pump of the water heater , the selection and calculation of the solar collector,the determination of the thermal storage tank and the determination of the circulating water pump of heat collecting .

Sign in / Sign up

Export Citation Format

Share Document