Performance Evaluation of Nanofluid (Al2O3/H2O-C2H6O2) Based Parabolic Solar Collector Using Both Experimental and CFD Techniques

The present work evaluates the performance of solar collector using Al2O3-C2H6O2-H2O nanofluid as a working fluid through both experimental and CFD analysis. Ethylene-glycol water mixture (40:60 v/v) is used as base fluid, where alpha-Al2O3 nanoparticle of 20 nm average size is dispersed for the preparation of nanofluid of four different volumetric concentration (vol. conc.) of 0.05, 0.075, 0.1 and 0.125%. Three different volume flow rates of 30 LPH, 50 LPH and 80 LPH are used. CFD analysis is carried out through ANSYS FLUENT 14.5. From both experimental and CFD analysis, an improvement in overall efficiency of solar collector is reported when nanofluid is used as compared to water-ethylene glycol mixture. With 0.125% vol. conc. of nanofluid Al2O3-C2H6O2-H2O (DI) maximum overall efficiency of about 4.6, 7.9 and 14.8% is reported at 30 LPH, 50 LPH and 80 LPH, respectively from CFD results while from experimental results maximum overall efficiency of about 4.3, 7.5 and 13.8% is seen at 30 LPH, 50 LPH and 80 LPH, respectively. Also, with increasing volume flow rate of working fluid, corresponding improvement in the overall efficiency of solar collector takes place. Close agreement is also developed between experimental and CFD result.