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. The X-ray powder diffraction (XRD), transmission, C, respectively compared to their respective base fluids. 0000088822 00000 n The strong acid treatment on UDD powders, the carboxyl groups are formed on the surface of ND particles, which can be clearly observed in the IR spectra (red line). Effects of working temperature on thermo-physical properties and forced convection heat transfer of TiO 2 nanofluids in waterEthylene glycol mixture. Additionally, surface tension and electrical conductivity are investigated. PGI is a colorless, water soluble, hygroscopic liquid with a characteristic glycol odor, medium viscosity, low vapor Web9.9 Liquid Water Interfacial Tension: Not pertinent 9.10 Vapor (Gas) Specific Gravity: Not pertinent 9.11 Ratio of Specific Heats of Vapor (Gas): 1.073 9.12 Latent Heat of Vaporization: 306 Btu/lb = 170 cal/g = 7.12 X 105J/kg 9.13 Heat of Combustion: 10,310 Btu/lb = 5,728 cal/g = 239.8 X 105J/kg 9.14 Heat of Decomposition: Not pertinent 0000002868 00000 n Glycol soutions are fed (topped-off) buy a pumped glycol feeder available by JL wingert, armstrong, etc Heat exchanger tubes are .035" wall I've ne 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. Measuring glycol concentrations by electrical conductivity is not recommended, especially in process systems, heat exchangers, etc. The quality of In this study, more than 3200 data of thermal conductivity of nanofluids were collected from literature to develop simple-to-use and accurate correlations for predicting relative thermal conductivity of nanofluids. Jee and Lee [11] used strong acids of H2SO4 and HNO3 in the molar ratio of 3:1 for the purification of UDD powders and observed the removal of carbon impurities. The carbon impurities present in the UDD powders is removed with strong acid treatment, dry salt and dry sucrose to make them into single ND crystals. Xie et al. Among all the carbon materials ND particles creates great interest because of their superior hardness, thermal conductivity, i.e. 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. [20] obtained thermal conductivity enhancement of 17.23% for ND/EG nanofluid at 1.0vol.% at a temperature of 30C. These plates are to be used in a proposed compact (thin and light-weight) solar thermal flat plate collector (FPC). Thus, the new prototype machine is suitable for sawing granite. <]>> 0000089466 00000 n [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 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. An investigation has been undertaken into the stone processing machines. Prediction of electrical conductivity of TiO 2 water and ethylene glycol-based nanofluids for cooling application in low temperature PEM fuel cells. [18] observed thermal conductivity enhancements of 7.2% and 9.8% for water based ND nanofluids at 3.0vol.% at temperatures of 30C and 50C, respectively. The electrical conductivity of glycol mixtures within the range of 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. Forget about conductivity, it is directly related to temperature and is used in domestic/process water systems (water treatment) where you don't ha 180 0 obj <> endobj Because dissolved salts and other inorganic chemicals conduct electrical current, conductivity increases as salinity increases. 0000086902 00000 n 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. [14] also used strong acids of H2SO4 and HNO3 in the molar ratio of 3:1 for the purification of UDD powders and prepared 20:80%, 40:60% and 60:40% ethylene glycol/water mixture based ND nanofluids and estimated both thermal conductivity and viscosity experimentally. 0 Results showed that ND nanofluids achieved higher heat transfer coefficients than 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%. One of the authors (L.S.S.) of nanofluid, the exergy efficiency is 22.97%, while for ethylene glycol, it is 6.78%. Increasing the concentration of the nanofluid beyond 1.0vol% shows a little improvement in the effectiveness of the heat exchanger. Using propylene glycol (PG) without any dispersants as a salt-free medium, we measure the electrical conductivities of 20, 40, and 60 nm diameter ZnO nanoparticle dispersions up to 7% volume fraction, applying Ohshima's model to determine the limiting ionic conductance of the system. Nanofluid preparation and characterization Nanofluid preparation The results showed that the Turbiscan stability index of N-CQDs nanofluid was about 1.5 and the T value fluctuated within 0.5%, showing excellent stability. 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. All were assigned as low priority for further work. Nanodiamond (ND) nanoparticles of primary particle size of 510nm can be produced in large quantity by using commercially available ultra-dispersed diamond (UDD) powders. The main advantages of this measurement technique are short measurement times, easy sample preparation and high accuracy. About 26% increase in coolant side heat transfer coefficient was obtained with 2vol.% ZnOPG nanofluid under constant bath temperature condition which could be attributed to thermal conductivity enhancement as well as improved natural convection due to viscosity reduction. Therefore, there is no literature on the thermal properties of PG/W mixture based ND nanofluids. For 1.0% vol. 0000087804 00000 n provided correct acknowledgement is given. 0000002832 00000 n trailer Joint School of Nanoscience and Nanoengineering, North Carolina A&T State University, Greensboro, NC 27401, USA Energy . This study investigates theoretically and experimentally the electrical and thermal conductivities of 50/50 water-ethylene glycol based TiO 2 nanofluids with Nanoscale, 2023, Advance Article The X-ray powder diffraction (XRD), transmission electron microscope (TEM) and Raman spectra was also performed on acid treated ND particles. 5. Naik and Sundar [28] prepared 30:70% PG/W based CuO nanofluid and estimated thermal conductivity and viscosity experimentally. 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%). 499-508, Energy Conversion and Management, Volume 96, 2015, pp. Namburu et al. The article presents the results of detailed studies of the thermal conductivity of the water slurry of microencapsulated PCM (mPCM) and slurry based on waterpropylene glycol solutions. We use cookies to help provide and enhance our service and tailor content and ads. 0000087536 00000 n The earlier works reveal the preparation, estimation of thermal conductivity and viscosity of water, ethylene glycol, mineral oil and midel oil based ND nanofluids. Chemical treatment was used to make ND nanoparticles with an average size of 5.42nm. 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 results are beneficial for the design and operation of micro-channel absorber plates. The ultra-dispersed diamond (UDD) powders were purchased from International Technology Centre, USA (http://www.itc-inc.org) with the following specifications: 98% purity, 510nm particle core size, cubic shape, grey color, 300400m2/g specific surface area. The fluid is colorless (water white). The purchased UDD powders treated with strong acid treatment, dry salt and dry sucrose to make them into single ND-crystals. 0000003320 00000 n The present work focused on the preparation of different weight ratio of PG/W (20:80%, 40:60% and 60:40%) mixture based ND nanofluids and the estimation of thermal conductivity and viscosity experimentally at different particle concentrations and temperatures. ScienceDirect is a registered trademark of Elsevier B.V. ScienceDirect is a registered trademark of Elsevier B.V. 2023, Thermal Science and Engineering Progress, 2023, International Journal of Thermal Sciences, 2022, International Communications in Heat and Mass Transfer, Diamond and Related Materials, Volume 69, 2016, pp. Based on the above methods the acid treatment method is more effective compared to other salt and sucrose methods. The present findings are consistent with those of Palabiyik et al. This study investigates the potential of composite allotrope boron nitride nanobarbs (BNNBs) as nanoparticles for enhancing the thermal conductivity of nanofluids based on mixtures of ethylene glycol and propylene glycol with water. [27] prepared PG based Al2O3 nanofluids and estimated viscosity experimentally and proposed viscosity model. 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.%. WebMaintains low electrical conductivity Uses proprietary non-ionic corrosion inhibitor formulation with years of research Can be used with Formulation: Propylene Glycol, The single phase heat transfer fluids such as water (W), ethylene glycol (EG), propylene glycol (PG) and engine oil (EO) are primarily used in may industrial applications, among others, power, chemical and food industries. [17] prepared mineral oil based ND nanofluids and obtained thermal conductivity enhancement of 70% at 0.1wt.%. This study reports a nanofluid that achieves long-term stability without any additives. 0000000016 00000 n Similarly, the viscosity enhancements are 1.55-times, 1.50-times and 1.66-times for the same 1.0vol.% of 20:80%, 40:60% and 60:40% PG/W based nanofluids at a temperature of 60C, respectively compared to their respective base fluids. 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. Diamond circular saws and diamond wire saws present some technological limits, and the marble frame saw cannot process granite by now. %PDF-1.6 % E-mail: 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 The optimized method for purifying the UDD powders is established. Different weight or mass ratios of ethylene glycol/water (EG/W) or propylene glycol/water (PG/W) fluids are commonly used as engine coolants for automobile radiators and also used as coolant for electronic equipments, heating industrial and residential buildings in the cold countries of the world such as Alaska, Canada, Northern Europe and Russia, because of its low freezing point i.e. 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# The instrument is based on transient plane source (TPS) technique and is widely used for thermal conductivity measurement. WebLearn about the chemical and physical properties of Ethylene Glycol/water mixtures, on our blog. New thermal conductivity and viscosity correlations have been developed based on the experimental data. The specific heat capacity decreases with increasing nanofluid loading. 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. DOWFROSTfluid has an operating The carbon impurities present in the UDD powders have been removed using mixture of H2SO4 and HNO3 [5], [6], [7], [8], [9]. Ghazvini et al. The exergy analysis and heat transfer characteristics pertaining to the heat exchanger were also investigated. WebPropylene glycol is a colourless liquid that is relatively viscous, has no odour, and tastes slightly sweet. Sundar et al. Yu et al. At 1.0vol%, the thermal conductivity enhancements of 12.7% and 22.8%, at 1.0vol%, the viscosity enhancements of 1.57-times and 1.8-times were observed at temperatures of 293K and 333K compared to water data. 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. There are different methods to purify the UDD powders. The purification of UDD powders is important for achieving good stable nanofluids. The theoretical models of Maxwell and Einstein have failed to estimate the thermal conductivity and viscosity of nanofluids as a function of temperature. 209 0 obj<>stream 0000073108 00000 n [27] analysis if the value of C/Ck<4 then the nanofluid is heat transfer beneficial fluid. 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. 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]. 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]. 0000073219 00000 n How about a secondary heat exchanger, i.e primary steam/water heats intermediate water. Intemediate water is pumped to a secondary heat exchanger w The starting product, MICRONAL 5428 X, which contains about 43% microencapsulated paraffin with a transformation temperature of 28 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. 0000113197 00000 n If you are an author contributing to an RSC publication, you do not need to request permission Appl. Hybrid nanofluids aim to further improve the characteristics of mono nanofluids. 0000125049 00000 n The acid treated ND particles were characterized by XRD, TEM, FTIR and XPS. 0000088556 00000 n 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. The exergy efficiency of the SCHE can be increased by 21% using 1.0vol% of nanofluid, but the improvement becomes modest as the volume concentration is increased further. 0000002101 00000 n 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. 40-48, Applied Thermal Engineering, Volume 90, 2015, pp. The different weight ratios of propylene glycol/water mixtures are used as base. [19] obtained viscosity enhancement of 80% for midel oil based ND nanofluids at 3.0wt.%. 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 statistical and graphical results showed that the proposed models are more precise and reliable than the existing ones in literature. [14,15] for mono nanofluids based on the same base fluid, propylene glycol:water 20:80 wt%. The formation of carboxyl (COOH) groups on the surface of ND particles was analyzed by FTIR spectrum. 115-123, International Communications in Heat and Mass Transfer, Volume 76, 2016, pp. 0000002234 00000 n [34], in which the nanofluids prepared in pure PG have lower thermal conductivity enhancement than that of. 2 shows the IR spectra of UDD powders, acid treated, salt and sucrose milled samples. 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. Prasher et al.