scholarly journals Graphene Nanoplatelets Suspended in Different Basefluids Based Solar Collector: An Experimental and Analytical Study

Processes ◽  
2021 ◽  
Vol 9 (2) ◽  
pp. 302
Author(s):  
Omer Alawi ◽  
Haslinda Kamar ◽  
Abdul Mallah ◽  
Hussein Mohammed ◽  
Mohd Sabrudin ◽  
...  
Keyword(s):  
Mass Flow ◽  
Solar Collector ◽  
Graphene Nanoplatelets ◽  
Operating Conditions ◽  
Working Fluid ◽  
Scanning Calorimetry ◽  
Maximum Enhancement ◽  
Mass Flow Rates ◽  
Electron Microscopes ◽  
Flat Plate Solar Collector

A flat plate solar collector (FPSC) was analytically studied, with functionalized graphene nanoplatelets (f-GNPs) as its working fluid. Four samples (wt % nanofluids) were prepared in different base fluids such as ethylene glycol (EG), distilled water (DW):EG (70:30), and DW:EG (50:50). Experimental results (via DW) were used to verify the effectiveness of the analytical model. Some of the operating conditions were taken into account in this research, including temperatures, power, and mass flow rates. Experimental techniques were used to elucidate the modified nanofluids’ physicochemical properties, such as its particle sizes, stability, and morphology, involving electron microscopes (EMs), UV–VIS, and X-ray techniques. Differential scanning calorimetry (DSC) and thermogravimetric analysis (TGA) were applied to test the thermal analysis. The findings confirmed that the use of f-GNPs nanofluids enhanced the performance of the FPSC relative to the use of base fluids for all testing conditions. The maximum enhancement of the collector’s effectiveness at a mass flow rate of 1.5 kg min−1 and a weight concentration of 0.1 wt %, increased to 12.69%, 12.60%, and 12.62% in the case of EG, DW:EG (70:30), and DW:EG (50:50), respectively. The results also confirmed an improvement in both the heat gain (FR(τα)) and heat loss (FRUL) coefficients for the f-GNPs nanofluid.

scholarly journals Effect of the Number of Nozzles of Swirl Flow Generator Utilized in Flat Plate Solar Collector: An Entropic Analysis

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Yan Cao ◽  
Hamdi Ayed ◽  
Tuqa Abdulrazzaq ◽  
Taza Gul ◽  
Abdul Bariq ◽  
...  
Keyword(s):  
Flat Plate ◽  
Mass Flow ◽  
Solar Collector ◽  
Swirl Flow ◽  
Injection Angle ◽  
Swirl Generator ◽  
Flow Generator ◽  
Mass Flow Rates ◽  
Flat Plate Solar Collector ◽  
Heat Transfer Improvement

The numerical model of the pipes of a flat plate solar collector (FPSC) with several nozzles has been investigated in the present study. Indeed, the effect of the number of nozzles of the swirl generator on the entropic characteristics has been evaluated. The nozzles were applied for improving the performance of FPSC. For evaluating the proposed system based on the entropy concept, the effect of injection angle and mass flow rate has been considered. The selected injection angles were 30°, 45°, 60°, and 90°. Also, the total mass flow rates entered from all of the nozzles were 0.2 kg/s, 1 kg/s, and 2 kg/s. The effect of said variables on frictional and thermal entropy generations was analyzed; then, the overall energetic-entropic performance of the system was predicted using several dimensionless parameters including NE, NS, Nu ∗ , and heat transfer improvement (HTI). Moreover, Witte-Shamsundar efficiency ( η W − S ) was applied to pinpoint the efficiency of the system. The highest value of HTI and η W − S was 1.7 and 0.9 that achieved by “single-nozzle; A90-D50-N12.5-M0.2” and “quad-nozzle; A30-D50-N12.5-M2,” respectively.

scholarly journals Performance Evaluation of Flat Plate and Vacuum Tube Solar Collectors by Applying a MWCNT/Fe3O4 Binary Nanofluid

Energies ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1715
Author(s):  
Minjung Lee ◽  
Yunchan Shin ◽  
Honghyun Cho
Keyword(s):  
Flat Plate ◽  
Solar Collector ◽  
High Performance ◽  
Operating Conditions ◽  
Working Fluid ◽  
Efficiency Improvement ◽  
Solar Collectors ◽  
Vacuum Tube ◽  
Flat Plate Solar Collector ◽  
Wide Operating

This study experimentally investigated the performance characteristics of water and MWCNT/Fe3O4 binary nanofluid as a working fluid in a flat plate and vacuum tube solar collectors. As a result, the highest efficiency was 80.3% when 0.005 vol.% MWCNT/0.01 vol.% Fe3O4 binary nanofluid was applied to the flat plate solar collector, which was a 17.6% increase in efficiency, compared to that when water was used. In the case of the vacuum tube solar collector, the highest efficiency was 79.8%, which was 24.9% higher than when water was applied. Besides, when the mass flux of MWCNT/Fe3O4 binary nanofluid was changed from 420 to 598 kg/s·m2, the maximum efficiencies of the flat plate and vacuum tube solar collectors were increased by 7.8% and 8.3%, respectively. When the MWCNT/Fe3O4 binary nanofluid was applied to the vacuum tube solar collector, the efficiency improvement was much more significant, and the high performance could be maintained for wide operating conditions, compared with the flat plate solar collector.

EFFECTS OF A MIXTURE OF CuO AND Al2O3 NANOPARTICLES ON THE THERMAL EFFICIENCY OF A FLAT PLATE SOLAR COLLECTOR AT DIFFERENT MASS FLOW RATES

2019 ◽  
Vol 50 (10) ◽  
pp. 945-965 ◽  
Author(s):  
Zahra Ouderji Hajabdollahi ◽  
Mohsen Mirzaei ◽  
Kyung Chun Kim
Keyword(s):  
Flat Plate ◽  
Mass Flow ◽  
Thermal Efficiency ◽  
Solar Collector ◽  
Al2o3 Nanoparticles ◽  
Flow Rates ◽  
Mass Flow Rates ◽  
Flat Plate Solar Collector

scholarly journals AN EXPERIMENTAL INVESTIGATION OF THE EFFECT OF MASS FLOW RATES ON THE PERFORMANCE OF FLAT-PLATE SOLAR WATER HEATING SYSTEM USING CuO/WATER NANOFLUID

2017 ◽  
Vol 13 (8) ◽  
pp. 6376-6380
Author(s):  
P.Michael Joseph Stalin ◽  
T.V. Arjunan ◽  
N. Sadanandam
Keyword(s):  
Flat Plate ◽  
Mass Flow ◽  
Flow Rate ◽  
Solar Collector ◽  
Volume Fraction ◽  
Average Particle Size ◽  
Average Particle ◽  
Flow Rates ◽  
Mass Flow Rates ◽  
Flat Plate Solar Collector

One of the effective ways of increasing the efficiency of flat plate solar collector is to utilize nanofluids which are having high thermal conductivity. In the present study, an attempt is made to investigate the effect of mass flow rates on the performance of flat plate solar collector using CuO/water nanofluid. The experimental set up consists of flat plate solar collector; storage tank and ladder type heat exchanger. The instantaneous efficiency of solar collector is calculated by taking lower volume fraction of 0.01% with average particle size of 30 nm and varying the flow rate from 1 lpm to 3 lpm, as per ASHRAE standard, with and without Triton X-100 surfactant. The experimental results reveal that utilizing the nanofluid with mass flow rate at 1.5 lpm increases the collector efficiency by 19.7%. 

Numerical Analysis of the Flow Inside a Centrifugal Compressor’s Vaneless Diffuser and Volute

2001 ◽  
Author(s):  
Hooman Rezaei ◽  
Abraham Engeda ◽  
Paul Haley
Keyword(s):  
Experimental Data ◽  
Numerical Analysis ◽  
Mass Flow ◽  
Operating Conditions ◽  
Vaneless Diffuser ◽  
Flow Angle ◽  
Flow Rates ◽  
Mass Flow Rates ◽  
Minimum Medium ◽  
Good Agreement

Abstract The objective of this work was to perform numerical analysis of the flow inside a modified single stage CVHF 1280 Trane centrifugal compressor’s vaneless diffuser and volute. Gambit was utilized to read the casing geometry and generating the vaneless diffuser. An unstructured mesh was generated for the path from vaneless diffuser inlet to conic diffuser outlet. At the same time a meanline analysis was performed corresponding to speeds and mass flow rates of the experimental data in order to obtain the absolute velocity and flow angle leaving the impeller for those operating conditions. These values and experimental data were used as inlet and outlet boundary conditions for the simulations. Simulations were performed in Fluent 5.0 for three speeds of 2000, 3000 and 3497 RPM and mass flow rates of minimum, medium and maximum. Results are in good agreement with the experimental ones and present the flow structures inside the vaneless diffuser and volute.

Transient Considerations of Flat-Plate Solar Collectors

1974 ◽  
Vol 96 (2) ◽  
pp. 109-113 ◽  
Author(s):  
S. A. Klein ◽  
J. A. Duffie ◽  
W. A. Beckman
Keyword(s):  
Flat Plate ◽  
Solar Collector ◽  
Meteorological Data ◽  
Weather Conditions ◽  
Operating Conditions ◽  
Transfer Coefficients ◽  
Heat Transfer Coefficients ◽  
Thermal Capacitance ◽  
Flat Plate Solar Collector ◽  
Capacitance Effects

The effects of thermal capacitance in the modeling of the performance of a flat plate solar collector have often been neglected because of the computation involved. But because the solar collector is inherently exposed to continuously variable weather conditions, capacitance effects may be significant. To investigate these effects, three different models of flat-plate collectors have been investigated. The first, a quasi-steady-state model, simulates the performance of a collector of zero capacitance. The second model accounts for capacitance effects by assuming that a single value of thermal capacitance can be determined for the collector as a unit. The third model divides the collector into many isothermal segments, or nodes. For all three models the heat transfer coefficients are calculated as a function of operating conditions. The results show that, when hourly meteorological data are used, the zero-capacitance model is adequate.

Numerical Investigation of the Effects of Environmental Parameters and Geometry on Energy Absorption for an Open-type Water-cooled Flat-plate Solar Collector

2000 ◽  
Vol 122 (2) ◽  
pp. 56-62 ◽  
Author(s):  
B. Song ◽  
H. Inaba ◽  
A. Horibe
Keyword(s):  
Heat Flux ◽  
Flat Plate ◽  
Energy Absorption ◽  
Tilt Angle ◽  
Solar Collector ◽  
Water Film ◽  
Operating Conditions ◽  
Open Type ◽  
Type Water ◽  
Flat Plate Solar Collector

A two-dimensional mathematical model was developed for predicting the performance of an open-type water-cooled flat-plate solar collector, and solved numerically through an implicit finite difference method. The effects of various environmental and geometric conditions on energy absorption for the collector were investigated. The results predict that there is an optimum length and tilt angle for the absorbing plate for which the collector could obtain the highest solar energy absorptance. The latent heat flux of water evaporation can be 3 to 15 times larger than the sensible heat flux under normal operating conditions. The wind speed and the inlet water temperature have a large influence on the energy absorption of the collector. The effects of the solar incident flux, the atmospheric humidity and temperature, the absorbing plate tilt angle and length, and the water film thickness on the temperature rise of the water film and/or the absorptance of the collector are clarified. The open-type flat-plate collector is suitable to operate at lower inlet water temperatures and in regions where the local latitude is in the range of 20°N-40°N, and the weather is humid and hot with low winds. [S0199-6231(00)00202-1]

Impact of drying temperatures and air mass flow rates on the dryingperformance of a Parabolic Trough Solar Collector (PTSC) used fordehydration of apricots

2013 ◽  
Vol 25 (6) ◽  
pp. 418 ◽  
Author(s):  
M Hanifbr ◽  
M Rahmanbr ◽  
M Khanbr ◽  
M Aamirbr ◽  
M Ramzanbr ◽  
...  
Keyword(s):  
Mass Flow ◽  
Solar Collector ◽  
Parabolic Trough ◽  
Flow Rates ◽  
Air Mass ◽  
Mass Flow Rates ◽  
Parabolic Trough Solar Collector

Investigating the Effect of Al2O3/Water Nanofluid on the Efficiency of a Thermosyphon Flat-Plate Solar Collector

2016 ◽  
Author(s):  
Mohamed Nabeel A. Negm ◽  
Ahmed A. Abdel-Rehim ◽  
Ahmed A. A. Attia
Keyword(s):  
Flat Plate ◽  
Solar Collector ◽  
Fossil Fuels ◽  
Energy Conversion Efficiency ◽  
High Energy ◽  
Green Energy ◽  
Working Fluid ◽  
Steady Increase ◽  
Solar Collectors ◽  
Flat Plate Solar Collector

The world is still dependent on fossil fuels as a continuous and stable energy source, but rising concerns for depletion of these fuels and the steady increase in demand for clean “green” energy have led to the rapid growth of the renewable energy field. As one of the most available energy sources with high energy conversion efficiency, solar energy is the most prominent of these energies as it also has the least effect on the environment. Flat plate collectors are the most common solar collectors, while their efficiency is limited by their absorber’s effectiveness in energy absorption and the transfer of this energy to the working fluid. The efficiency of flat plate solar collectors can be increased by using nanofluids as the working fluid. Nanofluids are a relatively recent development which can greatly enhance the thermophysical properties of working fluids. In the present study, the effect of using Al2O3/Water nanofluid as the working fluid on the efficiency of a thermosyphon flat-plate solar collector was experimentally investigated. The results of this experiment show an increase in efficiency when using nanofluids as the working fluid compared to distilled water. It was found that Al2O3/water nanofluids are a viable enhancement for the efficiency of flat-plate solar collectors.

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