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A review on boiling heat transfer enhancement with nanofluids.

Barber J, Brutin D, Tadrist L - Nanoscale Res Lett (2011)

Bottom Line: This article covers recent advances in the last decade by researchers in both pool boiling and convective boiling applications, with nanofluids as the working fluid.Conflicting data have been presented in the literature on the effect that nanofluids have on the boiling heat-transfer coefficient; however, almost all researchers have noted an enhancement in the critical heat flux during nanofluid boiling.Several researchers have observed nanoparticle deposition at the heater surface, which they have related back to the critical heat flux enhancement.

View Article: PubMed Central - HTML - PubMed

Affiliation: Aix-Marseille Université (UI, UII)-CNRS Laboratoire IUSTI, UMR 6595, 5 Rue Enrico Fermi, Marseille, 13453, France. barber@polytech.univ-mrs.fr.

ABSTRACT
There has been increasing interest of late in nanofluid boiling and its use in heat transfer enhancement. This article covers recent advances in the last decade by researchers in both pool boiling and convective boiling applications, with nanofluids as the working fluid. The available data in the literature is reviewed in terms of enhancements, and degradations in the nucleate boiling heat transfer and critical heat flux. Conflicting data have been presented in the literature on the effect that nanofluids have on the boiling heat-transfer coefficient; however, almost all researchers have noted an enhancement in the critical heat flux during nanofluid boiling. Several researchers have observed nanoparticle deposition at the heater surface, which they have related back to the critical heat flux enhancement.

No MeSH data available.


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Mechanism of nanoparticle deposition during the boiling process (micro-layer evaporation) [15].
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Figure 4: Mechanism of nanoparticle deposition during the boiling process (micro-layer evaporation) [15].

Mentions: Further nanoparticle deposition was observed by Bang and Chang [30], who also measured a CHF enhancement of 50%, with alumina-water nanofluids on a stainless steel plate. They determined that the nanoparticle deposition on the heater after boiling was a porous layer that led to increased surface wettability. However, they also noted a deterioration in the BHT coefficient, which could have been an unfortunate result of the nanoparticle-fouled surface. Das et al. [13] also observed nanoparticle deposition on the heater surface after boiling. They too noted an increase in wall superheat with increasing nanoparticle concentration, and again degradation in the BHT with the alumina-water nanofluid that they investigated. Kwark et al. [15] postulated that the decrease in the BHT coefficient with increased nanoparticle concentration, which they observed, can be attributed to the corresponding thicker coating created, which offers increased thermal resistance. CHF, on the other hand, is not dictated by the thickness of the nanoparticle coating, but by the increased wettability that the nanoparticle deposit provides at the heater surface [36]. They concluded that there is an optimal nanofluid concentration, at which point the CHF enhancement is at a maximum, and without any degradation of the BHT coefficient. They found the optimal concentration to be about 0.025 g/l, and this is also consistent with data found in other studies [4]. They also demonstrated how the nanofluid boiling performance shows transient-like behaviour dependent on both heat flux and experiment duration, that is prolonging the nanofluid experiments adversely affects the BHT coefficient. Kwark et al. [15] also investigated possible mechanisms behind the deposition and adhesion of nanoparticles to the heater surface during boiling of nanofluids. Figure 4 illustrates the mechanism as proposed by Kwark et al. [15], where it is the boiling itself that appears to be the mechanism responsible for the nanoparticle coating formation. This is also consistent with Kim et al. [36], who postulated that nanoparticles are deposited on the heater surface during nanofluid boiling, hence creating a nanoparticle coating. They assumed that the nanoparticle coating was formed by nucleated vapour bubbles growing at the heater surface and the evaporating liquid that is left behind, inducing a concentrated micro-layer of nanoparticles at the bubble base.


A review on boiling heat transfer enhancement with nanofluids.

Barber J, Brutin D, Tadrist L - Nanoscale Res Lett (2011)

Mechanism of nanoparticle deposition during the boiling process (micro-layer evaporation) [15].
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3211345&req=5

Figure 4: Mechanism of nanoparticle deposition during the boiling process (micro-layer evaporation) [15].
Mentions: Further nanoparticle deposition was observed by Bang and Chang [30], who also measured a CHF enhancement of 50%, with alumina-water nanofluids on a stainless steel plate. They determined that the nanoparticle deposition on the heater after boiling was a porous layer that led to increased surface wettability. However, they also noted a deterioration in the BHT coefficient, which could have been an unfortunate result of the nanoparticle-fouled surface. Das et al. [13] also observed nanoparticle deposition on the heater surface after boiling. They too noted an increase in wall superheat with increasing nanoparticle concentration, and again degradation in the BHT with the alumina-water nanofluid that they investigated. Kwark et al. [15] postulated that the decrease in the BHT coefficient with increased nanoparticle concentration, which they observed, can be attributed to the corresponding thicker coating created, which offers increased thermal resistance. CHF, on the other hand, is not dictated by the thickness of the nanoparticle coating, but by the increased wettability that the nanoparticle deposit provides at the heater surface [36]. They concluded that there is an optimal nanofluid concentration, at which point the CHF enhancement is at a maximum, and without any degradation of the BHT coefficient. They found the optimal concentration to be about 0.025 g/l, and this is also consistent with data found in other studies [4]. They also demonstrated how the nanofluid boiling performance shows transient-like behaviour dependent on both heat flux and experiment duration, that is prolonging the nanofluid experiments adversely affects the BHT coefficient. Kwark et al. [15] also investigated possible mechanisms behind the deposition and adhesion of nanoparticles to the heater surface during boiling of nanofluids. Figure 4 illustrates the mechanism as proposed by Kwark et al. [15], where it is the boiling itself that appears to be the mechanism responsible for the nanoparticle coating formation. This is also consistent with Kim et al. [36], who postulated that nanoparticles are deposited on the heater surface during nanofluid boiling, hence creating a nanoparticle coating. They assumed that the nanoparticle coating was formed by nucleated vapour bubbles growing at the heater surface and the evaporating liquid that is left behind, inducing a concentrated micro-layer of nanoparticles at the bubble base.

Bottom Line: This article covers recent advances in the last decade by researchers in both pool boiling and convective boiling applications, with nanofluids as the working fluid.Conflicting data have been presented in the literature on the effect that nanofluids have on the boiling heat-transfer coefficient; however, almost all researchers have noted an enhancement in the critical heat flux during nanofluid boiling.Several researchers have observed nanoparticle deposition at the heater surface, which they have related back to the critical heat flux enhancement.

View Article: PubMed Central - HTML - PubMed

Affiliation: Aix-Marseille Université (UI, UII)-CNRS Laboratoire IUSTI, UMR 6595, 5 Rue Enrico Fermi, Marseille, 13453, France. barber@polytech.univ-mrs.fr.

ABSTRACT
There has been increasing interest of late in nanofluid boiling and its use in heat transfer enhancement. This article covers recent advances in the last decade by researchers in both pool boiling and convective boiling applications, with nanofluids as the working fluid. The available data in the literature is reviewed in terms of enhancements, and degradations in the nucleate boiling heat transfer and critical heat flux. Conflicting data have been presented in the literature on the effect that nanofluids have on the boiling heat-transfer coefficient; however, almost all researchers have noted an enhancement in the critical heat flux during nanofluid boiling. Several researchers have observed nanoparticle deposition at the heater surface, which they have related back to the critical heat flux enhancement.

No MeSH data available.


Related in: MedlinePlus