COMPARISON OF THERMAL CONDUCTIVITY FOR HHT-24-CNF-BASED NANOFLUID USING DEIONIZED WATER AND ETHYLENE GLYCOL

2015 ◽  
Vol 77 (21) ◽  
Author(s):  
Syarifah Norfatin Syed Idrus ◽  
Nor Salihah Zaini ◽  
Imran Syakir Mohamad ◽  
Norli Abdullah ◽  
Mohd Haizal Mohd Husin
Keyword(s):  
Thermal Conductivity ◽  
Thermal Properties ◽  
Ethylene Glycol ◽  
Carbon Nanofibers ◽  
Deionized Water ◽  
Water Based

Carbon nanofibers (CNF) is one of potential nanoparticles that possess superior thermal conductivity. In this study, nanofluids with suspension of CNF in deionized water (DI water) and ethylene glycol (EG) are prepare. Thermal conductivity (TC) of the nanofluids are measured at 6°C, 25°C and 40°C using KD2 Pro Thermal Properties Analyser. The results show that, TC increases with increasing of temperature and CNF loading. Best TC is recorded by 36.7 % enhancement at 40 °C for EG based fluid with 0.9 wt% CNF loading. Meanwhile, for DI water based fluid, best TC enhancement (39.6 %) can be achieved with CNF loading of 0.7 wt% at 40°C. Overall, both based fluid show a promising enhancement in thermal conductivity. However, DI water based fluid show higher TC in comparison to EG based fluid due to the higher TC in standard DI water itself.

A model for thermal conductivity of carbon nanotubes with ethylene glycol/water based nanofluids

2017 ◽  
Vol 59 (02) ◽  
pp. 10-13
Author(s):  
Trong Tam Nguyen ◽  
◽  
Hung Thang Bui ◽  
Ngoc Minh Phan ◽  
◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Carbon Nanotubes ◽  
Ethylene Glycol ◽  
Water Based

Shape Dependent Thermal Conductivity of TiO2-Deionized Water and Ethylene Glycol Dispersion

2015 ◽  
Vol 15 (5) ◽  
pp. 3670-3676 ◽  
Author(s):  
Bhupender Pal ◽  
Soumya Suddha Mallick ◽  
Bonamali Pal
Keyword(s):  
Thermal Conductivity ◽  
Ethylene Glycol ◽  
Deionized Water

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

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.

Intertube Falling-Film Heat Transfer Behavior of Multiwall Carbon Nanotube Suspensions (MWCNT Nanofluids)

2011 ◽  
Author(s):  
Binglu Ruan ◽  
Anthony M. Jacobi
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Heat Transfer Coefficient ◽  
Ethylene Glycol ◽  
Multiwall Carbon Nanotube ◽  
Falling Film ◽  
Water Based ◽  
Film Heat Transfer ◽  
The Heat Transfer Coefficient ◽  
Multiwall Carbon

The thermal conductivity and viscosity of water-based and ethylene-glycol-based multiwall carbon nanotube (MWCNT) suspensions are measured for MWCNT volume concentrations up to 0.24%. The thermal conductivity is found to increase up to 8.6% and 9.3% for water-based and ethylene-glycol-based nanofluids, respectively. The viscosity of the nanofluids increases compared to that of their base fluids, with larger increases for the ethylene-glycol-based nanofluids. Intertube falling-film heat transfer characteristics of these nanofluids are measured and compared to data for the base fluids. The heat transfer coefficient of the water-based nanofluids decreases at low MWCNT concentrations but increases as the concentration increases. The heat transfer coefficient of the ethylene-glycol-based nanofluids decreases with an increase in MWCNT concentration, with a maximum deviation of 30%.

Development of an Organic Acid Antifreeze Coolant

2014 ◽  
Vol 716-717 ◽  
pp. 130-132
Author(s):  
Jin Mao Chen ◽  
Guan Jun Leng ◽  
Ru Juan Yi ◽  
Bo Gao
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Low Temperature ◽  
Ethylene Glycol ◽  
Organic Acid ◽  
Environmental Protection ◽  
Inorganic Phosphate ◽  
Storage Stability ◽  
Deionized Water ◽  
Simple Preparation

An organic acid antifreeze coolant was developed in this paper which consisted mainly of deionized water, organic acid, pyrrole compound, alkali and dye. Glycol, nitrite, chromate, inorganic phosphate and other harmful additives were not contained in this formulation. The coolant overcomes the disadvantages in environmental protection, heat transfer and cost of the current technology which uses the ethylene glycol as antifreeze. The coolant has good low temperature protection, thermal conductivity and corrosion protection performance. Further more, the coolant has the advantages of simple preparation, good storage stability and a promising prospects.

Stability and thermal conductivity of tri-hybrid nanofluids for high concentration in water-ethylene glycol (60:40)

2020 ◽  
Vol 10 ◽  
Author(s):  
Anwar Ilmar Ramadhan ◽  
Wan Hamzah Azmi ◽  
Rizalman Mamat
Keyword(s):  
Thermal Conductivity ◽  
Thermal Properties ◽  
Ethylene Glycol ◽  
Volume Ratio ◽  
Hybrid Nanofluid ◽  
High Concentration ◽  
Maximum Increase ◽  
Basic Fluid ◽  
Hybrid Nanofluids ◽  
Nanofluid Stability

Background: Research has been focused on improving the thermal properties of single nanofluid components for recent of years. Therefore, hybrid nanofluids or composites have been developed to improve heat transfer performance. Stability and thermal conductivity of the Al2O3-TiO2-SiO2 nanoparticles suspended in the fluid base of water (W) and ethylene glycol (EG) mixture with volume ratio of 60:40. Methods: Experiments were tri-hybrid nanofluid stability was investigated for volume concentration of 0.5 ~ 3.0%, and temperature conditions from 30 to 70 °C for thermal conductivity measurements using a KD2 Pro Thermal Properties Analyzer. The experimental results show that the tri-hybrid nanofluid stability analysis was performed using a stable UVVis method for up to 30 days after preparation with 10 hour sonication time. Results: Comparison of data concentration ratios with sedimentation for single, hybrid, and tri-hybrid nanofluids yielding a stable tri-hybrid nanofluid with 80-90% value. Evaluation of zeta potential for tri-hybrid nanofluids yielded 63.72 mV in excellent stability classification. Sedimentation of this visual observation is influenced by the gravity of the movement of particles in the tube after 30 days. Conclusion: The highest thermal conductivity for tri-hybrid nanofluids was obtained at 3.0% and a maximum increase of up to 27% higher than that of the basic fluid (EG/W). Tri-hybrid nanofluids with a concentration of 0.5% gave the lowest effective thermal conductivity of 13.4% at 70 °C.

scholarly journals Physical-Statistical Model of Thermal Conductivity of Nanofluids

2014 ◽  
Vol 2014 ◽  
pp. 1-6 ◽  
Author(s):  
B. Usowicz ◽  
J. B. Usowicz ◽  
L. B. Usowicz
Keyword(s):  
Thermal Conductivity ◽  
Ethylene Glycol ◽  
Statistical Model ◽  
Effective Thermal Conductivity ◽  
Multinomial Distribution ◽  
Water Based ◽  
Classical Models ◽  
Parallel Connections ◽  
Solid Liquid ◽  
Thermal Resistors

A physical-statistical model for predicting the effective thermal conductivity of nanofluids is proposed. The volumetric unit of nanofluids in the model consists of solid, liquid, and gas particles and is treated as a system made up of regular geometric figures, spheres, filling the volumetric unit by layers. The model assumes that connections between layers of the spheres and between neighbouring spheres in the layer are represented by serial and parallel connections of thermal resistors, respectively. This model is expressed in terms of thermal resistance of nanoparticles and fluids and the multinomial distribution of particles in the nanofluids. The results for predicted and measured effective thermal conductivity of several nanofluids (Al2O3/ethylene glycol-based and Al2O3/water-based; CuO/ethylene glycol-based and CuO/water-based; and TiO2/ethylene glycol-based) are presented. The physical-statistical model shows a reasonably good agreement with the experimental results and gives more accurate predictions for the effective thermal conductivity of nanofluids compared to existing classical models.

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