Performance Study of Solar Air Heater Having Absorber Plate with Half-Perforated Baffles

Abstract

The paper presents a detailed mathematical model for performance prediction of a smooth duct solar air heater validated against the experimental results. Experimental study on a solar air heater having absorber plate with half-perforated baffles on the air flow side shows thermal efficiency enhancement of 28%-45% over that of the smooth duct solar air heater, which is attributed to the heat transfer enhancement (of the order of 180%-235%) due to the perforated baffles attached to the absorber plate and reduction in the mean temperature of the absorber plate by 20• C-25• C as compared to the temperature of absorber plate of smooth duct air heater. Using the mathematical model, the performance plot for the baffled duct air heater has been presented, and the effect of the variation of ambient parameters on the predicted thermal efficiency has been studied.

Performance evaluation of solar air heater equipped with louvered fins

“…They investigated the effects of recycled ratio and mass flow rate on the power consumption and heat collection. Further, Maheshwari et al [9] carried out a study of heat transfer and thermal efficiency in such an absorber plate with half perforated baffles. A significant improvement in thermal efficiency was obtained in an experimental study carried out on solar air heater having absorber plate with half perforated baffles.…”

Performance Study of Solar Air Heater with Baffled Duct

“…3); increasing with the flow rate because an increase in the flow velocity results in the increase in the heat transfer coefficient. The mean temperature of the baffled absorber plate over the ambient temperature (T p -T a ) has been found to be lower by [4][5][6][7][8][9][10][11][12][13][14] o C as compared to the smooth duct air heater. Thus, both the increase in the heat collection rate due to the enhancement in the heat transfer coefficient and decrease in the heat loss from the collector due to the lower working temperature of the absorber plate lead to an increase in the thermal efficiency of the collector.…”

“…An experimental test facility, as reported in an earlier publication [6], has been designed and fabricated as per ASHRAE Standard 93-77 [7] for the testing of solar collectors, which works in an open loop mode. It consists of two parallel ducts (each 300 mm in width) with entrance, test and exit sections, a blower, control valves, and provision for temperature, flow and pressure drop measurements.…”

“…From the analysis of uncertainties in the recording of various experimental data [8] the uncertainties (odds of 20:1) in the values of various parameters have been estimated as [6] Mass flow rate per unit area of absorber plate, G = ±1.6% Heat collection rate, Q = ±3.8% Thermal efficiency, η = ±4.9% Pumping power, P = ±4.3 %.…”

Energy and Exergy Analysis of a Flat-Plate Solar Air Heater Artificially Roughened and Coated with a Novel Solar Selective Coating

“…(W/m 2 . • C) as mentioned in [35,36]. Despite 11 October being the day with the highest incident solar radiation, the thermal efficiency was lower than on 31 October since on 11 October, the (T p -T a ) was the highest; also, the wind heat transfer coefficient that dramatically increased the amount of lost energy by radiation and convection consequently decreased the thermal efficiency.…”