Investigation of Thermal Performance of Evacuated Tube with Parabolic Trough Collector with and without Porous Media

Abstract In this paper a new model has demonstrated that it operates in moderate performance scale to generate hot water. its early stage, the preliminary model, which built with double pass water tube inside evacuated tube, was investigated experimentally. The tested room under different operation conditions terms of solar radiation 300, 400, 500 and 600 W/m 2 mass flow rates 0.00305 0.0083kg/s. first case, there problem because air gap surrounding so second two filling medium proposed modify model. mediums cases include porous media (stainless steel wire mesh Aluminum fiber metallic). results show maximum efficiency without 62.4% at 0.0083 kg/s heat flux , but after applied, reached 79.4% 99.997% porosity metallic same flow.