Comparative study on the performances of solar air collectors with trapezoidal corrugated and flat absorber plates

Abstract

Thermal performance of the solar air collectors which are mostly used for space heating and drying is generally low. Therefore there are different studies aimed at increasing the thermal performance of the solar air collectors. One of the technics used for this purpose is making changes in surface geometry of the absorber plate. In this research, the thermal performance of two solar air collectors constructed with trapezoidal corrugated and flat absorber plate is investigated experimentally under weather conditions of Konya/Turkey. The experiments were conducted for three different air mass flow rates of 0.022, 0.033 and 0.044 kg/s. The results obtained are compared to the ones of solar air collector with flat absorber plate. It has been observed that difference between inlet and outlet air temperatures of the solar air collectors increases as the mass flow rate decreases. For the air mass flow rate of 0.022 kg/s, the maximum temperature rise in solar air collector with trapezoidal corrugated plate is 9 degrees C compared to the flat plate solar air collector. It has been shown that thermal performance of the solar air collectors rises with the increase in mass flow rates. It is determined that the average daily thermal efficiency of the solar air collector with trapezoidal absorber plate is 63% for 0.044 kg/s.