Surfactant-Based Cu–Water Nanofluid Spray for Heat Transfer Enhancement of High Temperature Steel Surface

Abstract

Spray cooling is critical in many industrial applications to extract large heat fluxes from metal parts, such as hypervapotron in nuclear fusion reactors, heat treatment of steel plates in run-out table, electronic parts, and many more. The objective of the present study is to enhance the heat dissipation in transition and nucleate boiling regimes using an airatomized water spray with water based copper nanofluid as a coolant. The nanoparticle used in this study is energetic metal Cu, which has been prepared by mechanical milling process.The nanofluid has been prepared by suspending 0.1 vol% Cu nanoparticles in water, with or without a dispersing agent (surfactant). The effect of type of dispersing agent on augmentation of boiling heat transfer has also been studied. The spray cooling experiments are conducted on a 6 mm thicker stainless steel plate of initial temperature above 900 o C. The transient surface heat flux and temperatures are estimated using commercial inverse heat conduction software named INTEMP. The experimental results illustrated that transition and nucleate boiling heat flux as well as critical heat flux increased significantly using nanofluid spray. A maximum ultrafast cooling rate of 267 o C/s is achieved using surfactant based nanofluid spray, which is 31.53 % and 59.88 % higher as compared to the nanofluid without any dispersant and pure water sprays respectively. Overall, the surfactant based copper nanofluid spray can serve as a better coolant on the run-out table of steel processing industry.A c c e p t e d M a n u s c r i p t N o t C o p y e d i t e d Downloaded From: http://heattransfer.asmedigitalcollection.asme.org/ on 02/18/2015 Terms of Use: http://asme.org/terms 2

Effect of Surfactants on Liquid–Solid Heat Transfer on High‐Temperature Wall

“…In all the experiments, ordinary tap water was used as the basic fluid, while the concentrations of SDS, CTAB, and Tween‐20 were 600, 240, and 56 ppm, respectively, which were optimized according to a previous report. [ 25 ] The thermophysical parameters of each coolant were obtained from the previous literature, and the corresponding values are presented in Table 1 . [ 3 ] The increase in thermal conductivity was helpful in improving the thermal convection efficiency of solid–liquid interface.…”

Heat transfer in jet impingement on a hot steel surface using surfactant based Cu–Al layered double hydroxide nanofluid

“…From the table, it can be observed that surface tension of the nanofluid is lowered by the presence of a dispersant. Among the surfactants used, Tween 20 displays the highest drop in surface tension due to its lesser hydrophobic interactions in the alkyl side chains [17]. Lowering of surface tension results in finer droplets and effective dispersion of nanoparticles, which augments the thermal conductivity of the nanofluid [20].…”

“…Table 1 describes the different surfactants used as additives. The types of coolants employed are mixtures of water/LDH/SDS surfactant, mixtures of water/LDH/CTAB surfactant, mixtures of water/LDH/Tween-20 surfactant and mixtures of water/LDH/PVP surfactant, at their respective optimized concentrations [17]. These additives have been used based on the literature available on heat transfer studies in the case of a steel plate [17,18].…”

“…The types of coolants employed are mixtures of water/LDH/SDS surfactant, mixtures of water/LDH/CTAB surfactant, mixtures of water/LDH/Tween-20 surfactant and mixtures of water/LDH/PVP surfactant, at their respective optimized concentrations [17]. These additives have been used based on the literature available on heat transfer studies in the case of a steel plate [17,18]. where M 2+ denotes a divalent cation, M 3+ a trivalent cation, A the interlayer anion with charge 'mÀ' and x and y the fraction constants [19].…”

Spray Cooling as a High-Efficient Thermal Management Solution: A Review

“…Bandaru et al [98,99] conducted a series of experiments on the effect of dispersant type on heat-transfer enhancement of air-atomized spray cooling. The dispersants used include SDS, CTAB, Tween 20, and polymer surfactant polyvinylpyrrolidone (PVP).…”