SUMMARY
Solar energy is sufficient source of energy for a solar-rich country like Pakistan to meet its energy needs. The Solar thermal technologies such like evacuated tube, flat plate, and compound parabolic trough collectors is being used all around the world. However, the type ofitheiworkingifluidihaveiaisignificantimpact onitheiperformanceiofithese collectors. The use of high thermal conductivity nanofluids to increase the performance of solar collectors is very smart technology. The purpose of this research is to improves the thermal performance analysis and characterization ofinon-metallicinanofluidsisuchiasiwater-basedimulti-wall carbon nanotubes (Water/MWCNT) with 3000W/mK thermal conductivity are employed in compound parabolic solar collectors (CPC). In this present work several test are perform to determine stability and thermal conductivity of the nanofluid using a thermal analyzer and UV-Vis spectroscopy, respectively. Water/MWCNT nanofluid have thermal conductivity is 37.2% better than water at 0.075% volumetric concentration according to test results. The prepared nanofluids are then used in CPC for extensive investigation, with nanoparticle concentrations (0.025, 0.05, 0.075%) at (0.02, 0.015 kg/s) flow rates. In the experimental investigation, a maximum temperature difference of 10.52°C was achieved with a 0.075% volumetric concentration at 0.015 kg/s flow rate. 19.36% thermal efficiency enhancement with volumetric concentration of 0.075% is record as compare to water at i0.015 kg/s flow rate.