Abstract:

An experimental study is carried out on an affordable cost air heater with a constant volumetric air flow of 0.015 kg/s m2, under sunlight in a coastal area. It is a single pass solar air heater with glazing and corrugated sheet metal absorber locally manufactured and destined for red algae Gelidium sesquipedale drying. The heater is continuously maintained towards the sun in order to increase the absorbed energy. Solar irradiance, inlet and outlet air temperature of the solar heater, as well as the average temperature at the absorber surface are measured. Special care is taken to airflow measurements. The effect of collector tilt angle on its thermal and effective performances is characterized. For a tilt angle of 60° and under an average irradiance of 811 W/m² during 9 hours of exposure, 3 kWh/m2 are harvested, with an efficiency of 41.2% and a temperature rise of 22 °C. The corresponding specific power is 337 W/m², which is about 14.7 times the power of the used draft fan. The outlet air temperature is in the range of 34 to 58°C which significantly reduces the drying time of red algae Gelidium sesquipedale compared to the traditional drying process at approximately 28°C.<

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