New nanofluids, based on clay minerals, as promising heat carriers for energetics

Abstract

ABSTRACTIn an automated installation powered by direct current (DC), the boiling curves and heat-transfer-coefficient (HTC) dependencies on the superheat values (ΔT) under free convection conditions for the water nanodispersions of clay minerals – illite, montmorillonite, palygorskite and genetic mixtures of the latter two – were obtained. The effects of some factors on pool boiling heat transfer were also studied.A significant influence of the shape and anisotropy of nanoparticles (NPs) on the heat-transfer parameters of nanofluids (NFs) was detected. A significant critical heat flux (CHF) enhancement (up to 200–300%) at boiling of the nanofluids studied was established, which is due to nanoparticle deposition on the heater surface during nanofluid boiling. The structure of the nanomaterials deposited is important in the enhancement of heat transfer at boiling of nanofluids and in avoiding boiling crises.The present study showed the effectiveness of clay-mineral nanofluids for extra emergency cooling of overheated surfaces of powerful equipment in the event of the sudden onset of a boiling crisis.