Aluminum nitride nanoparticles (AlNs) have been found to be a good additive for enhancing the thermal conductivity of traditional heat exchange fluids.At a volume fraction of 0.1,the thermal conductivity enhancement ratios are 38.71% and 40.2%,respectively,for ethylene glycol and propylene glycol as the base fluids.Temperature does not have much influence on the enhanced thermal conductivity ratios of the nanofluids,though a volume fraction of 5.0% appears to signify a critical concentration for rheology:for<5.0 vol% for Newtonian behavior,and for >5.0 vol% for obvious shear-shinning behavior,for both ethylene glycol and propylene glycol. Aluminum nitride nanoparticles (AlNs) have been found to be a good additive for enhancing the thermal conductivity of traditional heat exchange fluids. At a volume fraction of 0.1, the thermal conductivity enhancement ratios are 38.71% and 40.2%, respectively, for ethylene glycol and Temperatures do not have much influence on the enhanced thermal conductivity ratios of the nanofluids, though a volume fraction of 5.0% appears to signify a critical concentration for rheology: for <5.0 vol% for Newtonian behavior, and for > 5.0 vol% for obvious shear-shinning behavior, for both ethylene glycol and propylene glycol.