Experimental study of the inclined solar film evaporator

摘要

The present study investigated the experimentation of an inclined solar film evaporator in the meteorological conditions of the town of Bizerte, in Tunisia. The experimental device used in this study has a parallelepiped form. It is primarily constituted by an inclined metal plane plate. A water film falls on the external face of this plate through a porous tissue. A glass cover, placed on a wooden frame put on the plate, is exposed to the solar radiation acting as a solar panel. An ascending air flow enters in the evaporator where it is in direct contact with the falling water film. This experimental device is designed and supplemented by a protocol of measurements to conduct this study. The thermocouples installed along the metal plate were connected to an automatic acquisition making it possible to read and store the measured temperatures values. The evaporated flow is measured by an electronic balance and a stopwatch. The humidity and the air velocities are measured using a digital multifunction device. The series of measurement are carried out in natural and forced convections. The profile of the liquid film temperature and the variation of the evaporated flow are measured for the two convection modes. To quantify the effectiveness of the solar evaporator, the thermal and mass yields are calculated. The results show that the evaporated flow is more significant in forced convection and that the thermal and mass yields of the solar evaporator are higher than 80%.