scholarly journals Effects of Conditions of Absorber Plate in the Solar Air Heater on the Increasing Air Temperature at Outlet of Duct

2015 ◽  
Vol 17 (3) ◽  
pp. 485-490
Author(s):  
Ko Dong Guk
2014 ◽  
Vol 493 ◽  
pp. 86-92 ◽  
Author(s):  
Ekadewi A. Handoyo ◽  
Djatmiko Ichsani ◽  
Prabowo ◽  
S. Sutardi

A solar air heater (SAH) is a simple heater using solar radiation that is useful for drying or space heating. Unfortunately, heat transfer from the absorber plate to the air inside the solar air heater is low. Some researchers reported that obstacles are able to improve the heat transfer in a flat plate solar air collector and others found that a v-corrugated absorber plate gives better heat transfer than a flat plate. Yet, no work of combining these two findings is found.This paper describes the result of experimental study on a SAH with v-corrugated absorber plate and obstacles bent vertically started from 80oto 0owith interval 10oon its bottom plate. Experiments were conducted indoor at five different Reynolds numbers (1447 Re 7237) and three different radiation intensities (430, 573, and 716 W/m2).It is found that the obstacles improve SAH performance. Both the air temperature rise and efficiency increase with inserting obstacles bent at any angle vertically. Unfortunately, the air pressure drop is increasing, too. Obstacles bent vertically at smaller angle (means more straight) give higher air temperature rise and efficiency. However, the optimum angle is found 30o. The air temperature rise and efficiency will be 5.3% lower when the obstacles bent 30oinstead of 0o, but the pressure drop will be 17.2% lower.


2019 ◽  
Vol 142 (1) ◽  
Author(s):  
S. M. Shalaby ◽  
A. E. Kabeel ◽  
E. El-Bialy ◽  
M. K. Elfakharany

Abstract Low thermal conductivity is the main drawback of using paraffin wax as a latent heat thermal storage material in the solar air heater (SAH). In order to overcome this drawback, an absorber plate with extended surfaces through the paraffin wax was used. Two extended surface absorbers were used: a flat plate attached with downward fins and a V-corrugated plate. For the purpose of comparison, the SAH integrated with paraffin wax was tested using three proposed types of the absorber plate: flat, downward finned, and V-corrugated plates. The results showed superiority of the downward finned plate during the day. But the V-corrugated SAH remains the best choice for the applications in which the hot air is mostly needed during night as it is continuously operated for 7 h after sunset with the outlet air temperature of 8–11 °C more than the ambient air temperature.


2015 ◽  
Vol 138 (1) ◽  
Author(s):  
Satyender Singh ◽  
Prashant Dhiman

Thermal performance of a single-pass single-glass cover solar air heater consisting of semicircular absorber plate finned with rectangular longitudinal fins is investigated. The analysis is carried out for different hydraulic diameters, which were obtained by varying the diameter of the duct from 0.3–0.5 m. One to five numbers of fins are considered. Reynolds number ranges from 1600–4300. Analytical solutions for energy balance equations of different elements and duct flow of the solar air heater are presented; results are compared with finite-volume methodology based numerical solutions obtained from ansys fluent commercial software, and a fairly good agreement is achieved. Moreover, analysis is extended to check the effect of double-glass cover and the recycle of the exiting air. Results revealed that the use of double-glass cover and recycle operation improves the thermal performance of solar air heater.


Solar Energy ◽  
2021 ◽  
Vol 215 ◽  
pp. 416-433
Author(s):  
Shreyas P. Shetty ◽  
N. Madhwesh ◽  
K. Vasudeva Karanth

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 %.


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