Thermal Performance of Loop Heat Pipes Using Nanofluids

Abstract

The loop heat pipe (LHP) is a passive two-phase heat transfer device that operates on a closed two-phase fluid-flow cycle, sustained by a capillary medium in the evaporator. The present study deals with the numerical investigations on the thermal performance of LHPs using nanofluids. LHPs are subjected to a heat load of 40–320 W in steps of 40 W. The numerical results are validated with experimental data available in the literature. Silica–water, alumina–water, and copper–water are the nanofluids considered in the present study. The nanoparticles are taken at a concentration of 2 wt%. The thermal performance of LHP with nanofluids is compared with that of deionised water (baseline case). The LHP using nanofluids yields lower evaporator temperature than the baseline case. LHP attained steady-state faster with the presence of nanoparticles due to enhanced thermal properties. Among the three nanofluids, silica–water nanofluid shows better heat transfer performance. The evaporator temperature of the LHP using silica nanoparticles reduced by 27% than the baseline case. Thus, loop heat pipes using nanofluids are highly promising in the thermal management of electronic devices.