The effect of BNNB concentration in carrier fluids on nanofluid thermal conductivity was investigated by introducing BNNBs into ethylene glycol-water and propylene glycol-water mixtures at 010 wt%. The PG/W nanofluids are prepared with acid treated ND particles. This paper reviews and summarizes the experimental values of the physical and thermal properties, including an appropriate focus on the thermal conductivity enhancement, of nanodiamond-nanofluid systems found in the literature as well as different techniques for thermal conductivity measurement. Theoretical approach is used to identify the heat transfer benefits of the prepared propylene glycol/water based ND nanofluids in laminar and turbulent flow conditions using the thermal properties. The stability, thermophysical properties and rheological characteristics of N-CQDs nanofluids were investigated. 0000088462 00000 n The findings suggest that BNNBs have great potential for use as thermally conductive nanoparticles in nanofluids for various heat transfer applications. There are different methods to purify the UDD powders. The stable PG/W mixture based ND nanofluids were prepared by dispersing ND acid treated, The nanodiamond (ND) particles were produced using commercially available ultra-dispersed diamond (UDD) powders. 0000002101 00000 n 2016 Elsevier B.V. All rights reserved. 108-65-6) Dipropylene Glycol Methyl Ether (DPM; CAS No. Kole and Dey [29] prepared 50:50% PG/W based Al2O3 nanofluids and observed nanofluids obey Newtonian behaviour in the measured temperature range from 10C to 50C. Yeganeh et al. to access the full features of the site or access our, Joint School of Nanoscience and Nanoengineering, North Carolina A&T State University, Greensboro, NC 27401, USA, Joint School of Nanoscience and Nanoengineering, University of North Carolina at Greensboro, Greensboro, NC 27401, USA. Thereby, nanofluids have proven to be useful in applications, especially electronic cooling, where increasing thermal properties and avoiding electrical conductivity are vital. Joint School of Nanoscience and Nanoengineering, North Carolina A&T State University, Greensboro, NC 27401, USA Please enable JavaScript The study also investigated the dispersion stability of BNNBs in different solvents using Hansen Solubility Parameters, revealing that propylene glycol mixtures demonstrated better long-term stability compared to ethylene glycol mixtures. 115-123, International Communications in Heat and Mass Transfer, Volume 76, 2016, pp. 40-48, Applied Thermal Engineering, Volume 90, 2015, pp. A shell and helically coil heat exchanger (SCHE) is used to experimentally investigate the performance of 60% water and 40% ethylene glycol mixture based Fe3O4 nanofluid as a coolant. Under constant heat flux conditions, ZnOPG nanofluids exhibited linear increase in heat removal rates with increasing nanoparticle concentration. Naik and Sundar [28] prepared 30:70% PG/W based CuO nanofluid and estimated thermal conductivity and viscosity experimentally. Nanodiamond (ND) nanoparticles of primary particle size of 510nm can be produced in large quantity by using commercially available ultra-dispersed diamond (UDD) powders. However, conjugate heat transfer and measurement uncertainties were significant. The thermal entropy generation is decreased by 31.78% and the frictional entropy generation is raised by 22.50% over the basic fluid data at 1.0% and Reynolds number of 1454.4. The propylene glycol/water mixtures at different weight ratios were used as base fluids for the preparation of stable ND nanofluids. [27] model and Mouromtseff number [31] is used to study the heat transfer benefits of PG/W based ND nanofluids in laminar and turbulent flow conditions. The fluid is colorless (water white). The low freezing point of water (below 0C) may be achieved by adding different ratios of ethylene glycol or propylene glycol, so that the EG/W or PG/W fluid can operate up to 50C without any difficult [22]. In addition, it was found that the proposed models could capture the physically expected trends with variation of temperature, size of nanoparticles, and volume fraction. Thermophysical, rheological and electrical properties of The stable ND nanofluids were prepared by considering 60:40% water+ethylene glycol (weight percentage) mixture as base fluid and the experiments were performed at particle loadings ranging from 0.2% to 1.0% and the Reynolds number ranging from 900 to 4800, respectively. k5fX.TX#HksQ} >6!"vg8{!SP/(b8#_"hr 1q"I}\gxu'Gxq`j^vGF`i R7`md\qM._8>)pbE.x%6s&Eg)c^mDO1 }rZ~&\!=[aHM3]qIvT=nD{vf!oSAc0T]z4J0({(YxkyCWboRycfP'{ug04tTS[eun-8'$Q)^U/+jkaIB@^%BX# Future research should focus on enhancing the dispersion stability of BNNB nanofluids and exploring the influence of BNNB morphology on the thermal conductivity and other thermophysical properties of nanofluids. The hybrid nanofluid presents intermediate values between those of the mono nanofluids for all the properties except dynamic viscosity. The commercially available ultra-dispersed diamond (UDD) powders of an average size of 0.12.0m have been used by Dolmatov [2] for the preparation of ND nanofluids, but he faced serious agglomeration problem with UDD powders in the base fluid. Our results indicate that the surfactant-free, ZnOPG nanofluids behave like liquid coolants but with improved thermal conductivity and specific heat and hence suitable for energy management. Table 8-3-1 - Properties of mixture Water/Glycol - CERN Branson et al. conductivity Namburu et al. In this work, mono B4C and TiB2 and hybrid TiB2:B4C nanoadditives are used for the first time to design nanofluids based on propylene glycol:water 20:80wt%. Copyright 2023 Elsevier B.V. or its licensors or contributors. If you are an author contributing to an RSC publication, you do not need to request permission The GMDH model showed a better performance compared to GEP, and could predict all data with an average absolute relative error of 2.27% in training and 2.44% in testing data set. New thermal conductivity and viscosity correlations were proposed by including the effects of volume concentrations and temperatures. The other chemicals such as sulfuric acid (H2SO4), nitric acid (HNO3), sodium chloride (NaCl), sucrose (C12H22O11) and propylene glycol (C3H8O2) were purchased from Sigma-Aldrich Chemicals, USA. The thermal conductivity and viscosity of ND nanofluids were estimated experimentally at different particle concentrations and temperatures. 107-98-2) Propylene Glycol Methyl Ether Acetate (PMA; CAS No. 0 The statistical and graphical results showed that the proposed models are more precise and reliable than the existing ones in literature. The relative electrical conductivity of -SiC NFs and model predictions determined at 298.15 K are compared as illustrated in Fig. Water-Glycol mixture measurement | Baker Hughes Effects of heatlight source on the thermal efficiency of - Springer Further to cme's statement, the injection pump for the feed can be alarmed to allow the user know that there may be a system leak. See the follo It has been shown that water is the best solar energy absorbance among four fluids including water, ethylene glycol, propylene glycol, Zeta potential is a measure of the electric potential difference between the surface of a particle and the surrounding fluid. Electrical Conductivity and Dielectric Properties [27] prepared PG based Al2O3 nanofluids and estimated viscosity experimentally and proposed viscosity model. Webviscosity, a relatively high specific heat and thermal conductivity, as well as good mixing with water and alcohols cause the ethylene glycol to be widely used in practice [13]. 0000003035 00000 n The purchased ultradispersed diamond (UDD) nanoparticles were treated with strong acid solution to make it into almost single nano-diamond (ND) particles. Xie et al. One of the authors (L.S.S.) Here, we perform electrical characterizations of propylene glycol-based ZnO nanofluids with volume fractions as high as 7%, measuring up to a 100-fold increase in electrical conductivity over the base fluid. Results show, at 1.0vol% and the Reynolds number of 2702, the heat transfer coefficient and Nusselt number is increased by 36.05%, and 27.47%, respectively, over the base fluid. 180 0 obj <> endobj FPx[[cu/Ajl22jw+x{5DD93o9$C y6q`xTu/~:'KY'Nf700zGRb9 cyI/ dk'Cw JO|i%H_o]*2?h1tz{]uhD5:h;)[.2sQvW |ZHcv7Qcr9]Ee5c w?a%2b5XATC3{d^Tzt h-!T`EH|}'EPj:]vRFl_/ uoDG0x5zUK;EI[".WzVkE=*j\2U]O sh`5 The synthesized environmentally friendly N-doped carbon quantum dots nanoparticles (N-CQDs) had a uniform particle size distribution, with particle sizes concentrated between 2 and 2.5nm. Effects of working temperature on thermo-physical properties and forced convection heat transfer of TiO 2 nanofluids in waterEthylene glycol mixture. electrical Webconductivity. of Propylene Glycol [15] observed thermal conductivity enhancement of 12% at 0.9vol.% of nanodiamond (ND)-poly (glycidol) polymer brush/EG nanofluids, similarly observed thermal conductivity enhancement of 11% at 1.0vol.% of ND.oleic acid/mineral oil nanofluids. The heat transfer capability of these single phase heat transfer fluids is limited because of its poor thermal conductivity. [27] analysis.knfkbf=1+Cknfbf=1+Cwhere, is the volume concentration, Ck and C are the thermal conductivity and viscosity enhancement coefficients. Annual production of propylene glycol in The results show that the contact area between the blade and granite is not following a straight line, and the time required for stone sawing is only one half of the full sawing cycle. 0000125049 00000 n 0000088822 00000 n Similarly, at 1.0vol% and Reynolds number of 2702, the thermal entropy generation is dropped by 38.12%, frictional entropy generation is raised by 12.86%, exergy efficiency is enhanced by 36.48% and thermal performance factor is augmented by 1.2094 times over the base fluid. This study investigates theoretically and experimentally the electrical and thermal conductivities of 50/50 water-ethylene glycol based TiO 2 nanofluids with nanoparticle concentrations in the range of 0.05-0.5 vol%. FROZKHQ KHDWHGLQWKH+9HOHFWULFILHOG Copyright Clearance Center request page. The density, isobaric heat capacity, and thermal conductivity of the nanofluids are determined by the oscillating U-tube, differential scanning calorimetry, and transient hot wire methods, respectively. Engineering and Operating Guide for Dowfrost and Dowfrost HD Nanodiamondwater nanofluids were prepared and estimated the thermal conductivity, viscosity and also estimated their potential use in heat transfer applications. [34], in which the nanofluids prepared in pure PG have lower thermal conductivity enhancement than that of. The ultra-sonication technique was employed for preparing the mixture and results showed that the stability and thermal conductivity enhancements of Al2O3H2O nanofluids are highly dependent on sonication time and the energy supplied to the fluid for its preparation. On the other hand preparation of propylene glycol/water (PG/W) based nanofluids and estimation of thermal properties is also important before use in heat transfer equipments, because these PG/W fluids are also used as engine coolants for automobile radiators. Conductivity Accurate estimation of thermal conductivity (TC) of nanofluids is essential in thermophysical studies of nanofluids. Investigation on the Electrical Conductivity of The eccentric hinge guide mechanism facilitates the formation of both matrix tails on the segments and a group of more new micro cutting edges, which improve diamond stability as well as self-sharpening. Experiments were performed to study the transient heat transfer characteristics of probe-ultrasonicated, surfactant-free, ZnOpropylene glycol (ZnOPG) nanofluids under constant heat flux and constant bath temperature conditions. Electrical conductivity measurements of nanofluids and - PubMed The peak near 1630cm1 represents the OH bending of physically adsorbed water and the hydrogen, Since the literature does not report for the thermal conductivity ratios of 20:80%, 40:60% and 60:40% PG/W nanofluids, in Fig. The thermal performance of the internal heat transfer fluid was an important factor affecting the heat transfer efficiency of the exchanger system. 0000033853 00000 n The NTU of SCHE is improved only by 2% over that of the base fluid at the flow rate of 6 lit/min because of the limited improvement of the overall heat transfer coefficient. Results showed that ND nanofluids achieved higher heat transfer coefficients than the base fluid. Download : Download high-res image (216KB)Download : Download full-size image. The authors would like to acknowledge the Portuguese Science and Technology Foundation (FCT) for the funding of the present research work through the grant no: PTDC/EME-MFE/105031/2008 (ACMS) and UID/EMS/00481/2013 (TEMA/DEM). They also observed the formation of carboxyl groups on the surface of ND particles based on the FTIR analysis. The sensitivity analysis illustrated that temperature has the highest effect on the relative TC followed by base fluid TC and particle volume fraction. Liquids - Thermal Conductivities - Engineering ToolBox The results of proposed models were compared to 23 well-known theoretical and empirical models. Due to the different particle sizes and shapes of nanoparticles, the proposed model can better predict the thermal conductivity and viscosity of N-CQDs nanofluids compared with other empirical models. The purchased UDD powders treated with strong acid treatment, dry salt and dry sucrose to make them into single ND-crystals. The X-ray powder diffraction (XRD), transmission electron microscope (TEM) and Raman spectra was also performed on acid treated ND particles. 0000073108 00000 n Forget about conductivity, it is directly related to temperature and is used in domestic/process water systems (water treatment) where you don't ha Because dissolved salts and other inorganic chemicals conduct electrical current, conductivity increases as salinity increases. There have been numerous investigations of nanodiamond-nanofluid systems with many suggesting that considerable property enhancements, e.g., increased thermal conductivity, might be possible. Nanofluids offer many opportunities to enhance the efficiency of thermal systems by improving the thermal properties of the host fluids. WebThermal conductivities for some common liquids at temperature 300 K (26.8 oC, 80.3 oF): 1 W/(m K) = 1 W/(m oC) = 0.85984 kcal/(h m oC) = 0.5779 Btu/(ft h oF) = 0.048 Btu/(in h 11 is presented the percentage thermal conductivity enhancement [(knfkbf)/kbf100] for these ratios along with the data with the data of Palabiyik et al. Joint School of Nanoscience and Nanoengineering, University of North Carolina at Greensboro, Greensboro, NC 27401, USA. You do not have JavaScript enabled. Since water is seen as the golden standard in thermal conductivity, higher concentrations of ethylene glycol in a water solution will cause heat to pass through it slower, therefore, the lower the amount of ethylene glycol in the mixture, the more efficient it is at conducting heat. 0000003207 00000 n These values are significantly larger than that of the marble frame saw. Complex Coolant Fluid for PEM Fuel After cycling at 25 and 80 C, LiGe alloy was formed at the Li/LAGP interface as investigated by synchrotron high energy X-ray Diffraction (HEXRD) spectra (Figure 3b ). BNNBs are allotrope composites composed of boron nitride nanotube cores with walls decorated with attached hexagonal boron nitride crystals, creating a jagged morphology that facilitates the formation of a connected network and contributes to the enhancement of thermal conductivity in nanofluids. 0000086285 00000 n The preparation of ND based nanofluids and their thermal properties are given below. Appl. However, those results have not been collectively compared or discussed. WebConductivity is a measure of the ability of water to pass an electrical current. The inadequacy of the widely used VogelTammannFulcher or WilliamsLandelFerry equations to describe the temperature variation of the vacuum The Raman, TEM and XRD analysis was also performed on acid treated nanodiamond particles. PROPYLENE GLYCOL PPG WebMaintains low electrical conductivity Uses proprietary non-ionic corrosion inhibitor formulation with years of research Can be used with Formulation: Propylene Glycol, An investigation has been undertaken into the stone processing machines. WebPropylene Glycol Methyl Ether (PM; CAS No. Substance and % by volume in mixture: Minimal working temperature [o C] Conductivity is also affected by temperature: the warmer the water, the higher the conductivity. WebPGI is a distilled product with a purity specification of minimum 99.5% and is available from The Dow Chemical Company in drum, IBC and bulk quantities. The earlier works reveal the preparation, estimation of thermal conductivity and viscosity of water, ethylene glycol, mineral oil and midel oil based ND nanofluids. 0000113197 00000 n 8 . In addition, the models for estimating the viscosity and thermal conductivity of N-CQDs nanofluids are proposed, respectively. This study recommends that the volume concentration of Fe3O4/60:40%W+EG nanofluid should not exceed volume concentration of 1.0% because the added benefit of working with concentrations higher than 1.0vol% may not outweigh the added cost and complexities of the nanofluid. A binary mixture of propylene glycol and water at 20:80 mass ratio offers protection against freezing up to 265.98 K [13], making it suitable as a heat transfer fluid The dataset includes 13 different nanofluids with temperature from 30.00 to 149.15C, particle size from 5.00 to 150.00nm, particle thermal conductivity from 1.20 to 1000.00W/mk, particle volume fractions from 0.01 to11.22%, and base fluid thermal conductivity from 0.11 to 0.69W/mk. 209 0 obj<>stream Interactions between spherical and sheet-like nanoparticles explain this behaviour. The thermal conductivity of 0.1vol% of N-CQDs nanofluid increased by 43.21% at 50C compared to the base fluid. An estimation of the optimal supplied energy and time for sonication was suggested, while temperature and volumetric concentration effects on thermal conductivity are evaluated by measurements. 0000003320 00000 n WebBNNBs exhibit high thermal conductivity due to efficient phonon transfer and they are electrical insulators owing to their wide bandgap. Experimental research was done on the heat transfer, entropy generation, and exergy efficiency of ethylene glycol (EG) based nanodiamond (ND) nanofluids flowing in a circular tube. The results showed that BNNBs enhanced thermal conductivity of carrier fluids up to 45%, and the enhancement was proportional to the concentration of BNNBs in the carrier fluid. and diagrams provided correct acknowledgement is given. [14,15] for mono nanofluids based on the same base fluid, propylene glycol:water 20:80 wt%. The hot fluid volume flow rate was fixed to 1 lit/min, whereas, the cold fluid (nanofluid) volume flow rate was varied from 2 to 6 lit/min. New thermal conductivity and viscosity correlations have been developed based on the experimental data. Based on the results, the thermal conductivity enhancements are 18.8%, 16.8% and 14.1% at 1.0 vol.% of 20:80%, 40:60% and 60:40% PG/W based nanofluids. xref The theoretical models of Maxwell and Einstein have failed to estimate the thermal conductivity and viscosity of nanofluids as a function of temperature. The effect of various factors on the thermal-physical properties of diamond nanofluids is also reviewed, and the stability and viscosity of diamond nanofluids are tabulated and compared. The X-ray powder diffraction (XRD), transmission, C, respectively compared to their respective base fluids. The results are beneficial for the design and operation of micro-channel absorber plates. The exergy analysis and heat transfer characteristics pertaining to the heat exchanger were also investigated. 0000088556 00000 n Propylene glycol Absolute deviations lower than 1.5% were obtained between the experimental and predicted data using the aforementioned nanopowder thermal conductivities, as can be observed in Fig. Hybrid nanofluids aim to further improve the characteristics of mono nanofluids. The UDD powders can be treated with strong acids such as HNO3, mixture of H2SO4/HNO3, K2Cr2O7 in H2SO4, KOH/KNO3 to remove the carbon impurities [3], [4]. The B4C mono nanofluid shows the highest improvements of thermal conductivity (6.0%) and electrical conductivity (70 times higher), but also the highest viscosity increases (5154%). Drazen, you seem to have drifted from the original question. The problem is glycol in the condensate which could be fatal to the boiler. We need The frictional exergy destruction is found to contribute together with heat transfer exergy destruction to the total entropy of the SCHE system. 0000000016 00000 n Check with Union Carbide or Dow as they manufacture glycols. I understand they do have a web site. <50C [21]. The UDD powders contains large quantity of carbon impurities, which can be removed using strong acid treatment, dry salt and dry sucrose to make UDD powders into single ND particles. WebElectrical Conductivity ( S/cm) 55% Propylene Glycol + 45% DI Water + 0.1% Benzotriazole + 0.05% Nanoparticles (Mix# 2) 55% Propylene Glycol + 45% DI Water + 0.1% Benzotriazole + 0.025% Nanoparticles (Mix# 2) Electrical Conductivity vs. Time for the Coolant Formulations in a 1 L Dynamic Test Loop at 70oC 11 In the heat exchanger, the hot fluid passes through the shell side and the cold fluid (nanofluid) passes through the helical coil side. The starting product, MICRONAL 5428 X, which contains about 43% microencapsulated paraffin with a transformation temperature of 28 1000W/mK and Young's modulus, high electrical resistivity, attractive optical characteristics, and excellent chemical stability and biocompatibility. Scaling effects such as viscous dissipation and entrance effects had insignificant impact on the measured average Nusselt number. Properties for Dowfrost (Propylene Glycol) Electrical conductivity for 50% at 25 deg C = 2,060 micromhos/cm and 249 micromhos/cm for 50% at 0 deg C. Looks E-mail: The electrical conductivity of glycol mixtures within the range of These plates are to be used in a proposed compact (thin and light-weight) solar thermal flat plate collector (FPC). Vajjha and Das [24] also prepared 60:40% (weight ratio) of EG/W based Al2O3, CuO and ZnO nanofluids and measured thermal conductivity up to 10.0vol.%. Common uses: antifreeze/heat transfer fluid. The viscosity of N-CQDs nanofluid behaves as a Newtonian fluid. The overall heat transfer coefficient and nanofluid-side heat transfer coefficient under constant bath temperature condition were found to increase with increasing nanoparticle volume concentration. The thermal conductivity and viscosity of ND nanofluids were estimated experimentally at different particle concentrations and temperatures. 34590-94-8 isomeric mixture and 20324-32-7 major isomer) PM and PMA were reviewed at SIAM 11 and DPM was reviewed at SIAM 12. WebDOWFROSTfluid is a formulation of 95.5 percent propylene glycol, dipotassium phosphate and water. Based on the results, the thermal conductivity enhancements are 18.8%, 16.8% and 14.1% at 1.0vol.% of 20:80%, 40:60% and 60:40% PG/W based nanofluids. They obtained increases of 10.4% and 9.9% for 0.5 vol% concentration of Fe3O4 [14] and 1 vol% concentration of nanodiamonds [15] at 293.15 K, respectively. Propylene Glycol Ethers