Heat Transfer Enhancement in Air-Heating Flat-Plate Solar Collectors

1984 ◽  
Vol 106 (3) ◽  
pp. 358-363 ◽  
Author(s):  
Ye-Di Liu ◽  
L. A. Diaz ◽  
N. V. Suryanarayana
Keyword(s):  
Flat Plate ◽  
Friction Factor ◽  
Heated Plate ◽  
Plate Temperature ◽  
Air Heating ◽  
Pin Fins ◽  
Mass Flow Rates ◽  
Significant Temperature ◽  
Extended Surfaces ◽  
Flat Plate Solar Collector

The efficiency of an air-heating flat-plate solar collector can be increased by reducing the absorber plate temperature by providing it with extended surfaces. An experimental study was conducted to determine the temperature depression and the increase in friction factor, by providing a uniformly heated plate with pin fins. Data were obtained with three spacings of the fins for five mass flow rates of air and two values of heat flux. Significant temperature depressions can be obtained leading to increase in efficiency but these are acompanied by increases in friction factor. Employing different length scales and the concept of pumping power factor, it is shown that the data can be correlated by j = 1.018 Re−0.49 and Nu = 1.03 F0.19.

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.

Temperature Variation in the Absorber Plate of an Air Heating Flat Plate Solar Collector

1981 ◽  
Vol 103 (2) ◽  
pp. 153-157 ◽  
Author(s):  
L. A. Diaz ◽  
N. V. Suryanarayana
Keyword(s):  
Flat Plate ◽  
Temperature Variation ◽  
Solar Collector ◽  
Entrance Region ◽  
Low Flow ◽  
Absorber Plate ◽  
Plate Temperature ◽  
Thermal Entrance Region ◽  
Flat Plate Solar Collector ◽  
Thermal Entrance

A flat plate solar collector is modelled as a rectangular channel of high width to gap ratio with air entering the collector with a fully developed turbulent velocity profile. One plate of the collector is subjected to a uniform heat flux with the other plate heavily insulated. Experimental values of friction factor and heated plate temperature in the thermal entrance region are presented and compared with analytical predictions. It is shown that there will be significant plate temperature variation in the thermal entrance region particularly at low flow rates. It is also shown that neglecting conduction effects in the absorber plate will not lead to any significant errors in estimating absorber plate temperature variation. Tabulated values of dimensionless plate temperature for different values of the dimensionless distance from the leading edge for several Reynolds number are presented.

scholarly journals Experimental and Theoretical Analysis of Energy Efficiency in a Flat Plate Solar Collector Using Monolayer Graphene Nanofluids

2021 ◽  
Vol 13 (10) ◽  
pp. 5416
Author(s):  
Omer A. Alawi ◽  
Haslinda Mohamed Kamar ◽  
Abdul Rahman Mallah ◽  
Hussein A. Mohammed ◽  
Mohd Aizad Sazrul Sabrudin ◽  
...  
Keyword(s):  
Flat Plate ◽  
Solar Collector ◽  
Morphological Properties ◽  
Monolayer Graphene ◽  
Distilled Water ◽  
Maximum Increase ◽  
Mass Flow Rates ◽  
Temperature Parameter ◽  
Collector Efficiency ◽  
Flat Plate Solar Collector

Flat-plate solar collectors are one of the cleanest and most efficient heating systems available. Studies on the presence of covalently functionalized graphene (Gr) suspended in distilled water as operating fluids inside an indoor flat-plate solar collector (FPSC) were experimentally and theoretically performed. These examinations were conducted under different testing conditions namely 0.025%-wt., 0.05%-wt., 0.075%-wt., and 0.1%-wt., 0.5, 1, and 1.5 kg/min, 30, 40, and 50 °C, and 500, 750, and 1000 W/m2. Various techniques were used to characterize the functionalized nanofluids’ stability and morphological properties namely UV/Vis spectrophotometry, EDX analysis with a Scanning Electron Microscope (SEM), zeta potential, and nanoparticle size. The results showed that the collected heat improved as the percentage of GrNPs and the fluid mass flow rates increased, although it decreased as the reduced temperature coefficient increased, whereas the maximum increase in collector efficiency at higher concentration was 13% and 12.5% compared with distilled water at 0.025 kg/s. Finally, a new correlation was developed for the base fluid and nanofluids’ thermal efficiency as a function of dropped temperature parameter and weight concentration with 2.758% and 4.232% maximum deviations.

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%. 

Performance analysis of domestic solar air heating system using V-shaped baffles – An experimental study

2021 ◽  
pp. 095440892110162
Author(s):  
Vijayakumar Rajendran ◽  
Harichandran Ramasubbu ◽  
Karthick Alagar ◽  
Vignesh Kumar Ramalingam
Keyword(s):  
Experimental Study ◽  
Performance Improvement ◽  
Mass Flow ◽  
Thermal Efficiency ◽  
Heating System ◽  
Solar Air Heater ◽  
Absorber Plate ◽  
Air Heating ◽  
Mass Flow Rates ◽  
Carbon Dioxide Mitigation

An experimental study has been carried out to enhance a solar air heater’s performance by integrating artificial roughness through baffles on the absorber plate. In this paper, the thermal and energy matrices analysis of a Solar Air Heater (SAH) roughened with V up perforated baffles have been investigated. The effect of various mass flow rates on the SAH was analyzed with and without baffles. Experimental outputs like outlet air temperature, useful energy (heat) gain and thermal efficiency were evaluated to confirm the performance improvement. The baffled absorber plate SAH was found to give the maximum thermal efficiency and useful energy gain of 89.3% and 1321.37 W at a mass flow rate of 0.0346 kg/s, 13% and 12% higher than SAH without baffle. This result showed that the V up-shaped ribs in flow arrangement provide better thermal performance than smooth plate SAH for the parameter investigated. Energy matrices analysis and carbon dioxide mitigation of the SAH system were also analyzed.

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