scholarly journals Natural and mixed convection in a vertical water-flow chamber in the presence of solar radiation

2021 ◽  
pp. 101073
Author(s):  
M. Rashevski ◽  
S. Slavtchev ◽  
M. Stoyanova
Keyword(s):  
Solar Radiation ◽  
Mixed Convection ◽  
Water Flow ◽  
Flow Chamber

scholarly journals Monitoring the performances of a maximum power point tracking photovoltaic (MPPT PV) pumping system driven by a brushless direct current (BLDC) motor

2019 ◽  
Vol 8 (2) ◽  
pp. 193
Author(s):  
Ba Abdellahi ◽  
Mohamed El Mamy Mohamed Mahmoud ◽  
Ne Ould Dah ◽  
Amadou Diakité ◽  
Aroudam El Hassen ◽  
...  
Keyword(s):  
Solar Radiation ◽  
Water Flow ◽  
Bldc Motor ◽  
Maximum Power Point ◽  
Pumping System ◽  
Point Tracking ◽  
Power Point Tracking ◽  
Dc Power ◽  
Power Point ◽  
The Relationship

Nowadays, water pumping systems powered by solar-cell generators are one of the most important applications. It’s a promising alternative to conventional electricity and diesel based pumping systems, especially for applications like community water supplies and irrigation. This study presents a monitored standalone photovoltaic solar direct pumping system using the Maximum Power Point Tracking (MPPT) algorithm to optimize the solar photovoltaic conversion efficiency. It was done at ISET-Rosso in Mauritania. The experimental setup based on Lorentz PS1200C-SJ8-5 pumping system consists of four photovoltaic (PV) panels, inverter PS1200, BLDC motor, centrifugal pump and a storage tank. The system has been monitored, in order to determine the relationship between: the DC power produced by the PV generator and the solar radiation; the water flow and the DC power and by then the relationship between the water flow and the solar radiation. The effect of ambient temperature and solar radiation on the PV panels was also done under Matlab/Simulink environment and compared to the experimental results. ©2019. CBIORE-IJRED. All rights reserved

scholarly journals Evaluation of Thermal Comfort and Energy Consumption of Water Flow Glazing as a Radiant Heating and Cooling System: A Case Study of an Office Space

2020 ◽  
Vol 12 (18) ◽  
pp. 7596
Author(s):  
Belen Moreno Santamaria ◽  
Fernando del Ama Gonzalo ◽  
Benito Lauret Aguirregabiria ◽  
Juan A. Hernandez Ramos
Keyword(s):  
Energy Consumption ◽  
Solar Radiation ◽  
Energy Management ◽  
Water Flow ◽  
Cooling System ◽  
Air Cooling ◽  
Radiant Heating ◽  
Large Glass ◽  
Heating And Cooling ◽  
Office Space

Large glass areas, even high-performance glazing with Low-E coating, could lead to discomfort if exposed to solar radiation due to radiant asymmetry. In addition, air-to-air cooling systems affect the thermal environment indoors. Water-Flow Glazing (WFG) is a disruptive technology that enables architects and engineers to design transparent and translucent facades with new features, such as energy management. Water modifies the thermal behavior of glass envelopes, the spectral distribution of solar radiation, the non-uniform nature of radiation absorption, and the diffusion of heat by conduction across the glass pane. The main goal of this article was to assess energy consumption and comfort conditions in office spaces with a large glass area by using WFG as a radiant heating and cooling system. This article evaluates the design and operation of an energy management system coupled with WFG throughout a year in an actual office space. Temperature, relative humidity, and solar radiation sensors were connected to a control unit that actuated the different devices to keep comfortable conditions with minimum energy consumption. The results in summer conditions revealed that if the mean radiant temperature ranged from 19.3 to 23 °C, it helped reduce the operative temperature to comfortable levels when the indoor air temperature was between 25 and 27.5 °C. The Predicted Mean Vote in summer conditions was between 0 and −0.5 in working hours, within the recommended values of ASHRAE-55 standard.

scholarly journals Observations on the Glaciers of the Ruwenzori

1963 ◽  
Vol 4 (35) ◽  
pp. 581-616 ◽  
Author(s):  
J. B. Whittow ◽  
A. Shepherd ◽  
J. E. Goldthorpe ◽  
P. H. Temple
Keyword(s):  
Solar Radiation ◽  
Water Flow ◽  
Mountain Range ◽  
Flow Rates ◽  
Makerere University ◽  
Glacier Melt ◽  
Melt Water ◽  
History Of ◽  
Radiation Measurements ◽  
Apparent Acceleration

Abstract The glaciological work of six expeditions from Makerere University College to the Ruwenzori between December 1957 and July 1961 is described and some results are given. The history of glaciological research in the Ruwenzori mountain range is outlined and the present ice distribution is described. A variety of evidence is presented to illustrate the pattern of change over the last 50 years, and all the glaciers examined are shown to have been drastically reduced in size, with an apparent acceleration in melting since the 1940’s. Six glaciers are known to have disappeared completely, whilst several others have split into smaller units. A detailed survey of the Speke Glacier on Mount Speke was made, and calculations show that if the present trends continue all the ice below 4,573 in. on Mount Speke can he expected to disappear within the next 40 years. The Elena and Savoia Glaciers on Mount Stanley and the Moore Glacier on Mount Baker are described, and recessional rates for each glacier are calculated. Measurements of the ice movement of the Elena Glacier demonstrate that it is still a fairly active glacier, although the Moore Glacier is thought to be completely stagnant. Other scientific measurements of glaciological significance include subglacial temperatures for the Elena Glacier, melt-water flow rates from the Speke Glacier and solar radiation measurements for several stations near the Ruwenzori ice margins.

scholarly journals Experiment study of water based photovoltaic-thermal (PV/T) collector

2019 ◽  
Vol 9 (1) ◽  
pp. 118
Author(s):  
Nur Farhana Mohd Razali ◽  
Ahmad Fudholi ◽  
Mohd Hafidz Ruslan ◽  
Kamaruzzaman Sopian
Keyword(s):  
Solar Radiation ◽  
Water Flow ◽  
Electrical Energy ◽  
Energy Output ◽  
Photovoltaic Panel ◽  
Pv Panel ◽  
Increase With Increase ◽  
Output Increase ◽  
Energy And Exergy ◽  
Water Based

<span lang="EN-US">Solar radiation can be converted to the electrical energy and thermal energy by photovoltaic panel and solar collector. In this experiment, PV/T collector was designed, fabricated and tested its performance. The experiment conducted on PV/T collector with water flow at mass flow rate 0.012 kg/s to 0.0255 kg/s. The water flow with the stainless stell absorber help the PV/T collector in increasing the convection of thermal heat transfer. The power output increase with increase of radiation. The efficiency of PVT varies with different intensity of radiation which stated in this experiment for 750 W/m<sup>2</sup> and 900 W/m<sup>2</sup>. The analysis of energy and exergy are excuted and results show energy output for water based PV/T collector are 346 W for solar radiation 700 W/m<sup>2</sup> and 457 W for solar radiation 900 W/m<sup>2</sup>.  Meanwhile the total exergy output compared to the PV panel without stainless stell absorber, which the exergy increased by 22.48% for 700 W/m<sup>2</sup> and 20.87% for 900 W/m<sup>2</sup>.</span>

scholarly journals Observations on the Glaciers of the Ruwenzori

1963 ◽  
Vol 4 (35) ◽  
pp. 581-616 ◽  
Author(s):  
J. B. Whittow ◽  
A. Shepherd ◽  
J. E. Goldthorpe ◽  
P. H. Temple
Keyword(s):  
Solar Radiation ◽  
Water Flow ◽  
Mountain Range ◽  
Flow Rates ◽  
Makerere University ◽  
Glacier Melt ◽  
Melt Water ◽  
History Of ◽  
Radiation Measurements ◽  
Apparent Acceleration

AbstractThe glaciological work of six expeditions from Makerere University College to the Ruwenzori between December 1957 and July 1961 is described and some results are given.The history of glaciological research in the Ruwenzori mountain range is outlined and the present ice distribution is described. A variety of evidence is presented to illustrate the pattern of change over the last 50 years, and all the glaciers examined are shown to have been drastically reduced in size, with an apparent acceleration in melting since the 1940’s. Six glaciers are known to have disappeared completely, whilst several others have split into smaller units.A detailed survey of the Speke Glacier on Mount Speke was made, and calculations show that if the present trends continue all the ice below 4,573 in. on Mount Speke can he expected to disappear within the next 40 years.The Elena and Savoia Glaciers on Mount Stanley and the Moore Glacier on Mount Baker are described, and recessional rates for each glacier are calculated. Measurements of the ice movement of the Elena Glacier demonstrate that it is still a fairly active glacier, although the Moore Glacier is thought to be completely stagnant. Other scientific measurements of glaciological significance include subglacial temperatures for the Elena Glacier, melt-water flow rates from the Speke Glacier and solar radiation measurements for several stations near the Ruwenzori ice margins.

scholarly journals SPECIFICS OF THE FLOW OF SUPERCRITICAL WATER UNDER CONDITIONS OF MIXED CONVECTION

2018 ◽  
Vol 40 (3) ◽  
pp. 12-19
Author(s):  
N.М Fialko ◽  
V.A. Nosovskyi ◽  
Ju.V. Sherenkovskiy ◽  
N.O. Meranova ◽  
I.G. Sharaevskyi ◽  
...  
Keyword(s):  
Mixed Convection ◽  
Water Flow ◽  
Supercritical Water ◽  
Convection Zone ◽  
Numerical Solutions ◽  
Tube Wall ◽  
Turbulent Transport ◽  
Cfd Modeling ◽  
Tube Length ◽  
Buoyancy Forces

A study of the specifics of supercritical water flow under conditions of mixed convection was made on the basis of CFD modeling. The results of comparison of the numerical solutions obtained in the presence and absence of the buoyancy forces are given. It is shown that the influence of Archimedean forces on the flow structure is localized in the central region of tube length. The data of computer modeling of supercritical water flow pattern with the variation of heat flux q on the tube wall are obtained. The dependence of the localization of mixed convection zone from the value of q is established. The change of the local Richardson number in the context of the effect of the localization of buoyancy forces action is analyzed. For the conditions under consideration, the dependence of turbulent transfer intensity on the effect of Archimedean forces is investigated. It is shown that this action causes oppression of turbulent transport, which is most significantly manifested near the wall of the tube.

Solar Radiation Assisted Mixed Convection Flow Along a Vertical Plate

2014 ◽  
Vol 31 (1) ◽  
pp. N1-N8
Author(s):  
S. Siddiqa ◽  
M. A. Hossain
Keyword(s):  
Solar Radiation ◽  
Mixed Convection ◽  
Vertical Plate ◽  
Gaussian Elimination ◽  
Computation Time ◽  
Convection Flow ◽  
Convection Boundary Layer ◽  
Coupled Equations ◽  
Layer Flow ◽  
Stream Function Formulation

ABSTRACTSolar radiation assisted mixed convection boundary layer flow of Newtonian fluid along a non- reflecting, non-absorbing and ideally transparent semi-infinite vertical plate is studied here. Beer's law is used to express the solar radiation term. It is convenient to transform the non-linear dimensionless parabolic partial differential equations into (i) primitive variable formulation (PVF) and (ii) stream function formulation (SFF) before applying the numerical schemes. Coupled equations thus obtained from PVF are integrated numerically through implicit finite difference method together with the Gaussian elimination technique whereas block tridiagonal Keller-box technique is adopted to simulate the system of equations obtained from SFF. Numerical results from these two methods are also compared graphically in order to test the validation of the two schemes. However, due to less computation time and accuracy numeric results of shear stress, local Nusselt number coefficient, velocity and temperature profiles are obtained via SFF. It is found that velocity as well as temperature of the non-absorbing fluid enhances owing to the increase in solar radiation parameter.

scholarly journals PERFORMANCE ENHANCEMENT OF SOLAR STILL BY USING REFLECTORS-JUTE CLOTH-IMPROVED GLASS ANGLE

2019 ◽  
Vol 16 (1) ◽  
pp. 1 ◽  
Author(s):  
Bibhuti Sahoo ◽  
Chandana Subudhi
Keyword(s):  
Solar Radiation ◽  
Water Flow ◽  
Performance Enhancement ◽  
Water Productivity ◽  
Additional Cost ◽  
Solar Still ◽  
Flow Properties ◽  
Jute Cloth ◽  
And Performance

This paper is aimed to improve the productivity of an existing conventional single slope solar still with modifications. In this study, the conventional solar still is modified by using reflectors, jute cloth and improved glass angle. The modified still productivity and performance are investigated experimentally and compared to that of conventional solar still.  The results demonstrated that solar still performance is improved with the 10o glass angle due to better water flow properties and higher solar radiation fall on the still. The results reveal that, with all combined modifications, the water productivity and efficiency of modified solar still  increase by 72.18% and 41.51% respectively more than the conventional one. This implies that modified solar still could be adopted for higher water productivity at a lower additional cost.

Sign in / Sign up

Export Citation Format

Share Document