Experimental determination of thermal conductivity of CNTs-H2O based nanofluids

Solar thermal collectors are being widely used for water heating applications in domestic, commercial, and industrial sectors. The main drawback of these collectors is their low thermal efficiency. The thermal efficiency of these collectors can be significantly increased by enhancing the heat transfer fluid's thermal properties. This problem can be overcome by homogeneous mixing of nanoparticles in the base fluid such as water. The fluids with nanoparticles have better heat transfer efficiency and thermo-physical properties as compared to monofluid (water). In this study, the percent rise in thermal conductivity of the nanofluids is measured through experimentation by dissolving carbon nanotubes (CNTs) as nanoparticles in different concentrations (v/v %) inside the base fluid. The nanofluids are characterized by using the computer controlled thermal conductivity of liquids and gases unit, (TCLGC) by varying the CNTs sample composition from 0.01-0.05 v/v %. The results show that the inclusion of CNTs as nanoparticles significantly improves the thermal conductivity of nanofluids. Moreover, when CNTs are used at 0.05 v/v% inside a 100 ml sample solution, the highest increase in thermal conductivity is observed as 72%.