Experimental Studies on the Influence of Spatial Orientation of a Passive Air Solar Collector on Its Efficiency

Abstract

The solar collector is used to convert solar energy into thermal energy. First, the internal energy of the absorber increases, which is reflected in the increase in its temperature. This energy is transferred to the working fluid in direct contact with the absorber. Depending on the type of fluid, liquid or air solar collectors are distinguished. When the flow of the working medium takes place naturally, without the support of pumps or fans, the solar collector is treated as a passive device. The gravitational movement of air in the inner space of an air solar collector depends on its construction and its spatial orientation in relation to both the source of radiation and the direction of the force of gravity. This paper describes the results of laboratory experimental tests of a prototype passive air solar collector, including: the influence of radiation intensity and the deflection of the solar collector from the vertical on the increase in the temperature of the air flowing through the collector, the mass flow rate of the air and the efficiency of the device. The tests were carried out using an air solar collector with the dimensions 2080 × 1040 × 180 (height × width × thickness) and radiation intensity in the range of I = 0 ÷ 550 W/m2. It was found that the vertical arrangement of the collector does not ensure maximum efficiency of the device.