Experimental and numerical study of an overlay composite absorber plate material for a solar air heater

2021 ◽  
Vol 63 (7) ◽  
pp. 681-686
Author(s):  
Duraisamy Jagadeesh ◽  
Ramasamy Venkatachalam ◽  
Gurusamy Nallakumarasamy

Abstract The research in this paper is a sequel of an earlier work by the author in which experimental and CFD results were compared for an absorber plate made of iron with and without fins for two flow rates. The research yielded a good comparative result between the experimental and computational process for an optimized flow rate and the effect of the fins. The objective of this paper is to verify the effect of the overlay composite absorber plate material on a solar air heater through experimental and computational fluid dynamics. The experimental setup consists of an absorber plate as an overlay composite of aluminum and copper for enhanced heat transfer. Experiments and CFD analysis were done in three configurations. In configuration one, only the aluminum absorber plate with fins was considered. In configuration two, the overlay composite was considered with copper on the top and aluminum at the bottom as fins, and in configuration three, the overlay composite was considered with aluminum at the top and copper at the bottom as fins. A transient 8 hours CFD analysis was carried out using these configurations. While validating the results it was found that the overlay absorber plate Cu-Al was capable of generating a high outlet temperature Max of 88 °C and capable of generating 83 °C air for 5 hours and had good thermal efficiency when compared to the other materials in the other two configuration. It was found that experimental and computational analysis were in very close agreement, and the margin of error between the experimental and computational processes was less than 8 %.

2020 ◽  
Vol 56 (1) ◽  
pp. 35-41
Author(s):  
Parag Jyoti Bezbaruah ◽  
Rajat Subhra Das ◽  
Bikash Kumar Sarkar

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Vipin B. Gawande ◽  
A. S. Dhoble ◽  
D. B. Zodpe

CFD analysis of 2-dimensional artificially roughened solar air heater duct with additional circular vortex generator, inserted in inlet section is carried out. Circular transverse ribs on the absorber plate are placed as usual. The analysis is done to investigate the effect of inserting additional vortex generator on the heat transfer and flow friction characteristics inside the solar air heater duct. This investigation covers relative roughness pitch in the range of 10 ≤P/e≤ 25 and relevant Reynolds numbers in the range of 3800 ≤ Re ≤ 18000. Relative roughness height (e/D) is kept constant as 0.03 for analysis. The turbulence created due to additional circular vortex generator increases the heat transfer rate and at the same time there is also increase in friction factor values. For combined arrangement of ribs and vortex generator, maximum Nusselt number is found to be 2.05 times that of the smooth duct. The enhancement in Nusselt number with ribs and additional vortex generator is found to be 1.06 times that of duct using ribs alone. The maximum increase in friction factor with ribs and circular vortex generator is found to be 2.91 times that of the smooth duct. Friction factor in a combined arrangement is 1.114 times that in a duct with ribs alone on the absorber plate. The augmentation in Thermal Enhancement Factor (TEF) with vortex generator in inlet section is found to be 1.06 times more than with circular ribs alone on the absorber plate.


2021 ◽  
Vol 25 (Spec. issue 2) ◽  
pp. 333-337
Author(s):  
Filiz Ozgen ◽  
Ayse Dayan

In this study, the energy analysis of a solar air heater with an absorber plate made of different obstacles was made. Absorber plate of the solar air heater was created with porous steel wool. Three different absorber plates were used for the experimental study. Complex plate (Type I) was used as the first type of absorber plate, less complex plate (Type II) as the second type absorber plate, and flat plate (Type III) the third type absorber plate. On these plates, which are manufactured as three different absorber plates, steel wools are placed in a complex and less complex way. One absorber plate was left empty. In the experiments, the mass-flow rate of the air passing through the air passage channels was taken as 0.05 kg/s and 0.025 kg/s, and the optimum flow rate was found as 0.05 kg/s. In order to make heater efficiency calculations, heater inlet temperature, outlet temperature, absorber plate temperature, ambient temperature and solar radiation values were measured. Efficiency values for different absorber plate were found between 23% and 74%.


2019 ◽  
Vol 142 (2) ◽  
Author(s):  
Digpal Kumar ◽  
B. Premachandran

Abstract In this paper, the details of a numerical study performed for the optimum fin arrangement in a solar air heater with a rectangular fin array attached to the bottom side of the absorber plate have been presented. Results have been presented for various fin sizes and spacing between the fins, while the heat transfer and fluid flow are directed by natural convection. An inclined rectangular channel similar to the dimensions of a typical solar air heater has been considered. Three different fin configurations, namely, continuous long fins for the whole length of the channel, in-line interrupted and staggered interrupted arrangements of fins, have been studied. The present analysis aims to identify the optimum configuration of the fin array for enhanced heat transfer. The spacing between the fins and the height of the fins are varied to obtain an optimum configuration. The numerical simulations are performed for heat flux (q″) ranging from 250 to 750 W/m2 on the absorber plate. The inclination angles of the channel (θ) have been maintained at 15 deg, 30 deg, and 45 deg from the horizontal plane. The results show that with the spacing between fins, S = 5.4 cm performs better in the case of longitudinal continuous fin arrangement. However, a fin spacing of 4.75 cm shows a higher heat transfer in the case of staggered fin configuration. In comparison with nine long uninterrupted fins, using the staggered arrangement with 15 × 10 fins saves up to 33% of fin material.


2019 ◽  
Vol 4 (1) ◽  
pp. 24-31
Author(s):  
Haider A. Gadir Elbasher ◽  
Babiker Karama Abdalla ◽  
Adil Ali Mohamed

This study done for designing  industrial solar air heater drying unit with tow part of experimental steps(selecting solar air hater  type and other par for controlling outlet temperature through mixing hot and ambient air through static mixture) ., The experiment done for 6 six days for each type using fabricated glass covered corrugated solar air heater with tow possibility of modifications  one of them with fixed absorber plate defined as type one and other one tested with removed absorber  plate which defined as type two  experiments done with full  accessory (air supply fans, temperature mea with same test study using device, fresh air motor controlling RPM and fabricated static mixture. The drying temperature range (45 C to 55 C).Before testing pilot unit calculation of predicted hot air temperature was done for validity of unit then the experiments has been made with pilot unit of solar air heater with fresh air steam and static condition, the result show that solar air heater type one is better for stable results for out let temperature and suitable for working. also the experiments show that, the presented value of temperature of hot mixed air of SAH type one have fitness with set point of controller 90% for day one and day two but for SAH type two the present value haven’t fitness with set point, the reading either high or low than the set temperature   , for the other part of study prove that mixing hot air from solar air heater and fresh ambient air is success and control system working properly for the propellant drying process.


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