THERMAL EVALUATION AND MODELING OF A DOUBLE-PASS SOLAR COLLECTOR FOR AIR HEATING

SILVINA GONZÁLEZ; SILVANA FLORES LARSEN; ALEJANDRO HERNÁNDEZ

Lima

Conferencia; 28th International PLEA Conference - OPPORTUNITIES, LIMITS & NEEDS; 2012

PLEA y Pontificia Universidad Católica del Perú

This paper shows the experimental study of the thermal efficiency of a double-pass solar air heater that was designed and manufactured at INENCO, National University of Salta, and the theoretical thermal model developed to describe its thermal behavior. The solar collector has a useful collection area of 2 m2, and a channel size of 0.025m high. The edge and bottom surfaces are thermally insulated with a 0.05 m thick glass wool layer. The air flow is forced by a tangential fan installed in a 0.18m diameter pipe that is connected to the flow outlet. The collector was mounted with a slope of 34° facing north, in order to maximize the intensity of solar irradiance during winter. The experimental tests were performed during December, 2011. The results show a temperature rise of 35 °C with respect to the inlet air temperature, for a solar irradiance on the collector plane around 900 W/m2. An average daily efficiency of 34% was measured. A thermal model was developed in order to simulate the air temperature at the collector outlet under different outdoor climatic conditions. Experimental results and the predictions of the theoretical model were found to be in good agreement.