Modeling the thermal analysis of the uncovered solar collectors using perforated absorbent plate

Abstract

Abstract Uncovered solar collectors using perforated absorbent plates are a variety of reception collectors that are used for solar heating of air for consumption in air conditioning systems and dryers. The thermal performance of these collectors is subject to various factors including diameter and step holes, air suction velocity and solar radiation. Using modeling, a proper evaluation of the effect of each of these parameters on the thermal performance of the collector can be obtained. In this paper, by using heat transfer and energy balance modeling in different components of the sample collector, the effect of each of these parameters is estimated by using the preheatment of building air, thermal efficiency and output temperature of the collector according to the parameters of solar radiation, air suction velocity, diameter and step of the holes of the absorbent plate. Also, the efficiency of heat exchange of perforated plates is estimated for air suction velocity, diameter and step of holes. The results show that increasing the suction rate of air and solar radiation increases the thermal efficiency of the collector. Also, efficiency of the heat exchange (εHX), which decreases with increasing suction speed, is due to the decrease in the output temperature of the collector because of the increase in the amount of inlet air to it, increasing the suction rate from 60 m/h to 160 m/h reduces the efficiency of the heat exchange by 30%.