Improving the cooling performance of automobile radiator with ethylene glycol water based TiO2 nanofluids

AbstractAdvances in nano-lubricant additives are vital to the pursuit of energy efficiency and sustainable development. Carbon dots (CDs) have been widely investigated in the domain of lubricant additives owing to their extraordinary tribological properties, in particular, their friction-reducing and anti-wear properties. Metal-doped CDs are a new type of CDs, and their friction-reducing and anti-wear properties are attracting increasing attention. Therefore, a series of CDs doped with various divalent metal ions have been successfully synthesized via one-pot pyrolysis. The tribological properties of the synthesized CDs as water-based lubricant additives are in the following order: Zn-CDs > Cu-CDs ≫ Mg-CDs > Fe-CDs > U-CDs. Specifically, adding 1.0 wt% of Zn-CDs into water-based lubricant results in 62.5% friction and 81.8% wear reduction. Meanwhile, the load-carrying capacity of the water-based lubricant increases from 120 N to at least 500 N. Zn-CDs as an additive have long service life. Additionally, anion-tuned Zn-CDs fabricated via anion exchange exhibit promise as lubricant additives for poly(ethylene glycol). Based on the results of wear scar surface analyses, it is discovered that tribochemical films, primarily composed of iron oxides, nitrides, metal carbonates, zinc oxides, zinc carbonates, organic compounds, and embedded carbon cores, formed on the rubbing surfaces with a thickness of approximately 270 nm when Zn-CDs are used as additives. This film combined with the “ball-bearing” and third-particle effects of Zn-CDs contributed to excellent lubrication performance.

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Thermal conductivity of an ethylene glycol/water-based nanofluid with copper-titanium dioxide nanoparticles: An experimental approach

International Communications in Heat and Mass Transfer ◽

10.1016/j.icheatmasstransfer.2017.10.005 ◽

2018 ◽

Vol 90 ◽

pp. 23-28 ◽

Cited By ~ 35

Author(s):

Kin Yuen Leong ◽

Idayu Razali ◽

K.Z. Ku Ahmad ◽

Hwai Chyuan Ong ◽

M.J. Ghazali ◽

...

Keyword(s):

Thermal Conductivity ◽

Titanium Dioxide ◽

Ethylene Glycol ◽

Experimental Approach ◽

Titanium Dioxide Nanoparticles ◽

Water Based

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Heat transfer studies in compact heat exchanger using ZnO and TiO2 nanofluids in ethylene glycol/water

Chemical Industry and Chemical Engineering Quarterly ◽

10.2298/ciceq170720003m ◽

2018 ◽

Vol 24 (4) ◽

pp. 309-318

Author(s):

Srinivasan Manikandan ◽

Rajoo Baskar

Keyword(s):

Heat Transfer ◽

Nusselt Number ◽

Ethylene Glycol ◽

Volume Fraction ◽

Inlet Temperature ◽

Percentage Increase ◽

Cold Side ◽

Volume Fractions ◽

Experimental Values ◽

Tio2 Nanofluids

This paper reports an experimental study on the heat transfer characteristics of a nanofluid consisting of ZnO/water/ethylene glycol (EG) and TiO2/water/ /ethylene glycol. In this study, the base fluids of ethylene glycol (EG):water (W) with volume fractions of 30:70, 40:60, and 50:50 were prepared, and 0.2 to 1.0 volume fractions of ZnO and TiO2 nanofluids were used as a cold side fluid. The prime objective of this study is to identify the effects of nanofluid concentration and three different hot fluid inlet temperatures viz., 55, 65 and 75?C C on the heat transfer enhancement of cold side fluid. The results are compared with base fluids and the percentage increase of the Nusselt number because of nanoparticle addition is noted both experimentally and theoretically. The results showed that at the hot fluid inlet temperature of 75?C, the increase in the Nusselt number is maximum with volume concentrations of 0.6 and 0.8% for ZnO and TiO2 nanofluids, respectively. The corresponding maximum Nusselt number enhancements are about 11.5 and 21.4%, respectively, for the base fluid volume fraction of 30:70 (EG:W). There is good agreement between the results calculated from experimental values and the correlation.

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Experimental investigation of heat transfer coefficient and friction factor of ethylene glycol water based TiO2 nanofluid in double pipe heat exchanger with and without helical coil inserts

International Communications in Heat and Mass Transfer ◽

10.1016/j.icheatmasstransfer.2013.11.002 ◽

2014 ◽

Vol 50 ◽

pp. 68-76 ◽

Cited By ~ 85

Author(s):

M. Chandra Sekhara Reddy ◽

Veeredhi Vasudeva Rao

Keyword(s):

Heat Transfer ◽

Experimental Investigation ◽

Heat Transfer Coefficient ◽

Heat Exchanger ◽

Ethylene Glycol ◽

Transfer Coefficient ◽

Helical Coil ◽

Water Based ◽

Double Pipe ◽

Pipe Heat

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Experimental investigation on viscosity of water-based Al2O3 and TiO2 nanofluids

Rheologica Acta ◽

10.1007/s00397-015-0838-y ◽

2015 ◽

Vol 54 (5) ◽

pp. 411-422 ◽

Cited By ~ 29

Author(s):

Mariam Jarahnejad ◽

Ehsan B. Haghighi ◽

Mohsin Saleemi ◽

Nader Nikkam ◽

Rahmatollah Khodabandeh ◽

...

Keyword(s):

Experimental Investigation ◽

Water Based ◽

Tio2 Nanofluids

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A Parameter for Selection of Nano-Dispersoids in Nanofluids for Thermal Applications

Materials Science Forum ◽

10.4028/www.scientific.net/msf.736.223 ◽

2012 ◽

Vol 736 ◽

pp. 223-228

Author(s):

M.M. Ghosh ◽

S. Ghosh ◽

S.K. Pabi

Keyword(s):

Heat Transfer ◽

Thermal Conductivity ◽

Elastic Modulus ◽

Heat Source ◽

Ethylene Glycol ◽

Preliminary Identification ◽

Water Based ◽

Selection Of ◽

Poissons Ratio

A model reported by the present investigators has earlier shown that the extent of heat pick up by a nanoparticle during its collision with the heat source in a given nanofluid would depend on the thermal conductivity (kp, unit W/m.K), density (ρ, unit kg/m3), elastic modulus (E, unit GPa) and Poissons ratio (μ) of the nanoparticle and heat source. Considering the expression for collision period and thermal conductivity of nanoparticle, a factor χ =kp(ρ/E)0.4 is proposed here and examined for the preliminary identification of the potential of a dispersoid in enhancing the thermal conductivity of a nanofluid. The χ-factor for Ag, Cu, CuO, Al2O3 and SiO2 are 2960, 2247, 116, 14.1 and 5.5, respectively. The higher χ-factor of CuO compared to that of Al2O3 can explain why water and ethylene glycol (EG) based CuO-nanofluid is reported to show higher enhancement in the thermal conductivity, when compared to similar Al2O3-nanofluid. The χ for SiO2 is much smaller than that for Ag, which also corroborates well with the marginal enhancement in thermal conductivity of water based nanofluid containing SiO2 nanoparticles. Therefore, a high value of χ of the nanodispersoid can serve as a parameter for the design of nanofluids for heat transfer applications.

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