Experimental analysis of the optical loss of a dusty Fresnel lens with a novel solar flux test system

The effect of dust deposition on a point-focus Fresnel lens is experimentally analyzed using a novel outdoor solar flux test system. The solar flux maps of the concentration region of the Fresnel lens are obtained. A detailed mathematical heat transfer model of the thermocouple is developed to calculate the solar flux density at a given spot temperature. The solar flux intensity and shape, spot temperature, dust deposition density, and imaging distance are analyzed. The flux spot exhibits an ellipsoidal Gaussian distribution. As the dust density increases from 0 g/m(2) to 5 g/m(2), the peak flux exhibits a decrease of 57.4%, and the spot temperature decreases from 307 degrees C to 98.1 degrees C. An average optical loss of 16.69% is obtained for each 1 g/m(2) increase in the dust density. Error sources and estimates of the system are analyzed. The experimental measurements are in good agreement with the theoretical values. The deviation is within 8.33%, and the maximum deviation is 18.39 kW/m(2).