Experimental investigation of solar compound parabolic collector using Al2O3/H2O nanofluid in a subtropical climate

Abstract

Different solar concentrator technologies are used for low medium range temperature applications. In this paper, a non-tracking compound parabolic collector with a nanofluid is experimentally analyzed under real climate conditions of a typical sub-tropical climate Taxila, Pakistan. The collector used for the experimentation has concentration ratio of 4.17, collector area of 0.828 m2 and half acceptance angle of 24?. The heat transfer fluid used for the study is water based nanofluid with particles of Al2O3. The investigation is carried out at three different volumetric concentrations (0.025%, 0.05%, and 0.075%) of nanofluids at flowrates of 0.01 kg/s, 0.02 kg/s, 0.05 kg/s, and 0.07 kg/s are compared with base fluid (water). Comparison of system thermal efficiency, solar heat gain, and temperature difference is presented for different selected days in real climate conditions during months of March to May. It is observed that performance of the compound parabolic collector is improved by 8%, 11%, 14%, and 19%, respectively, at considered flow rates compared to water.