Experimental performance evaluation of an impinging jet with fins type solar air heater.

Abstract

The current experimental investigation aimed to evaluate performance of a non-cross flow type solar air heater (SAH). The design comprises of an array of continuous longitudinal fins which extends the bottom of absorber surface and alongside to it a jet plate with inline holes has also been encapsulated. The experiments were performed in natural outdoor conditions for a specified range of flow and geometrical parameters, namely, {[Formula: see text], 5700≤ Re ≤ 11700,0.046 ≤ Dj/Dh ≤ 0.076, andX/Dh, w/Dh = 0.23, 0.46}, respectively. The key indices such as temperature rise parameter (TRP) and collector thermal efficiency are chosen to analyze the performance characteristics of collector. The influence of the above listed parameters on these constraints has been investigated in details. As a function of the entire range of geometrical parameters, an increase in the air flow rate degrades the value of TRP. At the same situation, collector thermal efficiency was found to increase. The peak values of TRP were obtained between 12:00 and 01:00 pm. The rise in air temperature corresponding to hourly deviation of solar intensity has been interpreted at different fin spacing ratios. Furthermore, a parametric optimization approach is employed to identify the optimum values of fin and jet plate parameters yielding maximum collector thermal efficiency. The obtained data have been worked out to plot the design curves for fin and jet parameters. The experimental results were validated with similar literature. The comparative analysis reports a maximum enhancement in TRP of 20.5 % at Dj/Dh = 0.076. The percentage improvement in collector thermal efficiency of 16.4% at w/Dh = 0.23 and 9.8% at Dj/Dh = 0.076 has also been noted with reference to compared works.