Experimental Investigation on the Effect of Partially Metal Foam Inside the Absorber of Parabolic Trough Solar Collector

In the present work the efficiency of a solar parabolic trough has been investigated experimentally. parabolic trough solar collectors constitute a proven source of thermal energy for industrial process heat and power generation. the impact of using the partially porous media in the absorber on the efficiency of ptc (parabolic trough collector) has been investigated. the porosity of copper foam is 0.9 and its pore density is 30 ppi (pores per inch). the experiments were performed for different volume flow rates from 0.5 to 1.5 l/min. and the ashrae 93 standard was used to test the solar collector’s performance. results illustrate that using metal foam in the absorber has a positive impact on the collector efficiency and increases the pressure drop in the absorber. when absorber is filled with metal foam, the overall loss coefficient ul decreases 45% and it causes to increase efficiency because less energy is lost.