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

2020 ◽  
Vol 16 ◽  
pp. 100466
Author(s):  
Mirosław Żukowski
Keyword(s):  
Water Temperature ◽  
Experimental Determination ◽  
Cold Water ◽  
Water Storage ◽  
Storage Tanks ◽  
Solar Water ◽  
Cold Water Temperature

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.

System Modeling of Greenhouse Type Solar Water Heater

Solar Energy ◽  
2005 ◽  
Author(s):  
Yiping Wang ◽  
Wei Tian ◽  
Yonghui Liu ◽  
Zhiyong Yang ◽  
Li Zhu ◽  
...  
Keyword(s):  
Experimental Data ◽  
Water Temperature ◽  
Flat Plate ◽  
Air Temperature ◽  
Water Storage ◽  
Solar Water Heater ◽  
Storage Tanks ◽  
Water Heater ◽  
Solar Water ◽  
New System

A Greenhouse type solar water heater has been built to evaluate the thermal performance of the new system and to extend the application field of thermosyphon solar heating system. The system consists of flat plate absorbers, greenhouse, water storage tanks and connection pipes. The greenhouse has dimensions of 34.6m in length and 9.2m in width. Ten cylindrical tanks of 0.5m in diameter and 1.5m in length and the flat plate absorbers with total area of 138m2 are connected in parallel. The roof and south wall of the greenhouse are made from polycarbonate which has high light transmission and low heat transmission and other walls are from Sandwiched color steel plates which are thermally insulated from the ambient environment. The water storage tanks, the flat plate absorbers and the connection pipes, which need no other insulation because of greenhouse effect, are placed in the greenhouse. The experimental data includes solar radiation, wind speed, ambient temperature, greenhouse air temperature, storage water temperature, and absorber temperature et al. To investigate new system performance, it is necessary to develop mathematical model which is different from models of traditional thermosyphon solar water heater because the new system combines natural circulation system and greenhouse technology. The transient thermal model of greenhouse type solar water heater is derived, which is based on energy balance of the flat plate absorbers, the floor, the air in the greenhouse, the roof, and the storage tank. Greenhouse air temperature and storage water temperature are predicted and mass flow rate is calculated according to the balance between the frictional pressure drop and pressure due to density differences around the thermosyphon circuit. It shows that the experimental data fit well with the estimated values according to the new mathematical models.

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.

Performance of Rigid Porous Stratification Manifolds With Interpretation for Off-Design Operation

2013 ◽  
Author(s):  
Shuping Wang ◽  
Jane H. Davidson
Keyword(s):  
Performance Indicator ◽  
Water Storage ◽  
Operating Conditions ◽  
Hot Water ◽  
Storage Tanks ◽  
Solar Water ◽  
Inlet Flow Rate ◽  
Wide Range ◽  
Collector Efficiency ◽  
D Model

Thermal stratification of solar water storage tanks improves collector efficiency and provides higher quality energy to the user. A crucial aspect of maintaining stratification is preventing mixing in the tank, particularly during solar charging and hot water draws. An effective and simple approach to flow control is an internal stratification manifold. In this paper, the performance of the rigid porous manifold, which consists of a series of vertical hydraulic resistance elements placed within a perforated tube, is considered for charging operation. A 1-D model of the governing mass, momentum, and energy conservation equations is used to illustrate the procedure for designing a manifold and to explore its performance over a broad range of operating conditions expected in solar water storage tanks. A manifold performance indicator (MPI) is used to evaluate the effectiveness of the manifold relative to an inlet pipe positioned at the top of the tank. The rigid porous manifold improves the stratification in the tank over a wide range of operating conditions unless the inlet flow rate is significantly reduced from the design point.

A Coefficient to Characterize Mixing in Solar Water Storage Tanks

1994 ◽  
Vol 116 (2) ◽  
pp. 94-99 ◽  
Author(s):  
J. H. Davidson ◽  
D. A. Adams ◽  
J. A. Miller
Keyword(s):  
Water Storage ◽  
Fluid Mixing ◽  
Test Duration ◽  
Drop Tube ◽  
Storage Tanks ◽  
Vertical Temperature ◽  
Solar Water ◽  
Dimensionless Coefficient ◽  
The Moment ◽  
Limiting Values

A dimensionless coefficient is developed to characterize the level of mixing in solar water storage tanks. The MIX number, based on the height weighted energy, or moment of energy, in the tank, ranges from 0 to 1, with 0 representing a perfectly stratified (unmixed) tank and 1 representing a fully mixed tank. Limiting values are based on theoretical determinations of the maximum and minimum values of the moment of energy in a tank without mixing and a tank with complete mixing, respectively. Use of the new MIX number is illustrated by experimental data obtained in a 372-liter storage tank operated with both a conventional drop-tube inlet and a rigid, porous stratification manifold. The initial tank temperature profile, the temperature of the water entering the tank, and test duration are varied in three testing schemes. Fluid mixing is quantified by measured vertical temperature profiles and the dimensionless MIX number.

scholarly journals DESIGN OF TANDON AND AUTOMATIC FILLING TOOLS ON DISPENSERS WITH ULTRASONIC SENSORS

2019 ◽  
Vol 4 (1) ◽  
pp. 55-64
Author(s):  
Hafizt Azzari Aldaf ◽  
Indyah Hartami Santi ◽  
Yusniarsi Primasari
Keyword(s):  
Drinking Water ◽  
Water Level ◽  
Cold Water ◽  
Water Storage ◽  
Ultrasonic Sensor ◽  
Hot Water ◽  
Storage Tanks ◽  
Ultrasonic Sensors ◽  
Modern Era ◽  
Maximum Limit

Nowdays, The development of water dispensers has hot and cold water technology, but fills water into cold and hot water storage tanks by lifting and putting the gallons on top of the dispenser so that water can flow into hot and cold water storage tanks, this is assessed less efficient. The purpose of making this tool is to make it easier for users to install gallons without having to lift the gallon and put it on top of the reservoir, it can also facilitate the taking of drinking water without having to press or open the faucet first. Because in modern era, the need for tools that work automatically and efficiently are increasing. The results of this study indicate that automatic water and faucet filler devices in dispensers using ultrasonic sensors as a whole work well and are in accordance with the function specified. The function of the ultrasonic sensor is as a reader the maximum limit of water level in the reservoir, so that when the water is in its maximum state, the pump will stop filling the reservoir. And the ultrasonic sensor in front of the dispenser functions to read the glass, the sensor will detect and then be received by the microcontroller and continue to execute the relay and open the selenoid so that the water can come out.

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