Nanoscale, 2023, Advance Article 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. All were assigned as low priority for further work. 0000089466 00000 n conductivity 209 0 obj<>stream 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. Effects of heatlight source on the thermal efficiency of - Springer of Propylene Glycol Group method of data handling (GMDH) and gene expression programming (GEP) as two white-box powerful models were used for modeling. 499-508, Energy Conversion and Management, Volume 96, 2015, pp. 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 functional groups on the treated UDD powders were analyzed by FTIR. [23] first time prepared 60:40% (weight ratio) of EG/W based CuO nanofluids and observed viscosity enhancement of 4.5-times and 3.1-times at 6.12vol.% at temperatures of 35C to 50C. 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 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. in a third-party publication (excluding your thesis/dissertation for which permission is not required) Table 8-3-1 - Properties of mixture Water/Glycol - CERN This paper presents results of experimental investigation into dielectric properties of silicon oxide lignin (SiO 2-L) particles dispersed with various mass fractions in ethylene glycol (EG).Measurements were conducted at a controlled temperature, which was changed from 298.15 to 333.15 K with an accuracy of 0.5 and 0.2 K for dielectric and diagrams provided correct acknowledgement is given. Progress and Perspectives of Lithium Aluminum Germanium The thermal conductivity and viscosity of ND nanofluids were investigated experimentally, whereas the density and specific heat were estimated theoretically. If you are the author of this article, you do not need to request permission to reproduce figures Prasher et al. In this study, the thermal conductivity of graphene/propylene glycol nanofluids is tested using the Hot Disk TPS-500S thermal constants analyzer (Hot Disk AB, Gteborg, Sweden). An enhancement of thermal conductivity with respect to temperature and volumetric concentration is found, as expected. 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. New thermal conductivity and viscosity correlations have been developed based on the experimental data. Therefore, there is no literature on the thermal properties of PG/W mixture based ND nanofluids. would like to thank FCT for his post-doctoral research grant: SFRH/BPD/79104/2011. The X-ray powder diffraction (XRD), transmission, C, respectively compared to their respective base fluids. 0000133274 00000 n We are continuing our optimization to bring this level down by an order of magnitude (which is accepted by almost all the fuel cell manufacturers). It was observed that the position of the thermocouples can result in an under-estimation of the Nusselt number. PGI is a colorless, water soluble, hygroscopic liquid with a characteristic glycol odor, medium viscosity, low vapor 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. Sundar et al. PROPYLENE GLYCOL PPG WebBNNBs exhibit high thermal conductivity due to efficient phonon transfer and they are electrical insulators owing to their wide bandgap. 0000000016 00000 n 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. Prediction of electrical conductivity of TiO 2 water and ethylene glycol-based nanofluids for cooling application in low temperature PEM fuel cells. endstream endobj 181 0 obj<. From the Prasher et al. The results are beneficial for the design and operation of micro-channel absorber plates. 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%. 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 earlier works reveals the preparation, estimation of thermal conductivity and viscosity of EG/W mixture based Al2O3, CuO, ZnO and Fe3O4 nanofluids. 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. 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. 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). If you want to reproduce the whole article 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. 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. 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. Effects of working temperature on thermo-physical properties and forced convection heat transfer of TiO 2 nanofluids in waterEthylene glycol mixture. 0000086285 00000 n WebLearn about the chemical and physical properties of Ethylene Glycol/water mixtures, on our blog. Diamond circular saws and diamond wire saws present some technological limits, and the marble frame saw cannot process granite by now. 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.%. 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. 5. The local Nusselt number was observed to vary axially despite satisfying the criteria for neglecting entrance effects; this variation increased with the Graetz number. Electrical Conductivity and Dielectric Properties The two-step approach was used to create ND nanofluids with volume concentrations ranging from 0.2% to 1.0%. Comparisons with data from literature confirmed the validity and the suitability of the nanoflash technique applied to thermal conductivity evaluation. WebPropylene Glycol Methyl Ether (PM; CAS No. New friction factor and Nusselt number equations were created. It is hygroscopic, meaning that it readily absorbs water from the surrounding environment. The thermal conductivity results here reported can be compared with those previously published by Sundar et al. 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 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. In addition, the models for estimating the viscosity and thermal conductivity of N-CQDs nanofluids are proposed, respectively. Sundar et al. 11 is presented the percentage thermal conductivity enhancement [(knfkbf)/kbf100] for these ratios along with the data with the data of Palabiyik et al. The carbon based materials such as multi walled carbon nanotubes (MWCNT), single walled carbon nanotubes (SWCNT), graphene and nanodiamond (ND) materials contain high thermal conductivity compared to other materials. 0000060250 00000 n 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. They also observed the formation of carboxyl groups on the surface of ND particles based on the FTIR analysis. The present findings are consistent with those of Palabiyik et al. WebThere are two main types of water glycol mixtures used in heating/cooling systems that mix well in water at any concentration. 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 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%. [19] obtained viscosity enhancement of 80% for midel oil based ND nanofluids at 3.0wt.%. One of the authors (L.S.S.) please go to the Copyright Clearance Center request page. 0000142997 00000 n 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. Thermophysical, rheological and electrical properties of [17] prepared mineral oil based ND nanofluids and obtained thermal conductivity enhancement of 70% at 0.1wt.%. The main advantages of this measurement technique are short measurement times, easy sample preparation and high accuracy. These plates are to be used in a proposed compact (thin and light-weight) solar thermal flat plate collector (FPC). The findings suggest that BNNBs have great potential for use as thermally conductive nanoparticles in nanofluids for various heat transfer applications. 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 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. 0000017674 00000 n The viscosity of N-CQDs nanofluid behaves as a Newtonian fluid. Please enable JavaScript 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. The acid treated ND particles were characterized by XRD, TEM, FTIR and XPS. Correlations for the thermo-physical properties of the nanofluid were developed. 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]. Engineering and Operating Guide for Dowfrost and Dowfrost HD The formation of carboxyl (COOH) groups on the surface of ND particles was analyzed by FTIR spectrum. 180 0 obj <> endobj Branson et al. 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 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. There are different methods to purify the UDD powders. 1123-1135, Experimental thermal conductivity and viscosity of nanodiamond-based propylene glycol and water mixtures, https://doi.org/10.1016/j.diamond.2016.07.007, nm can be produced in large quantity by using commercially available ultra-dispersed diamond (UDD) powders. Thermal conductivity of nanoparticle-fluid mixture. Accurate estimation of thermal conductivity (TC) of nanofluids is essential in thermophysical studies of nanofluids. Xu X, Choi SUS. 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 different weight ratios of propylene glycol/water mixtures are used as base. Webconductivity. The results of proposed models were compared to 23 well-known theoretical and empirical models. jralston1@ncat.edu, b During the preparation of UDD powders, igniter is used in the detonation process which causes metal and carbon impurities and those are aggregates or attached to the outer surface of the ND particles. 0 BNNBs exhibit high thermal conductivity due to efficient phonon transfer and they are electrical insulators owing to their wide bandgap. The hybrid nanofluid presents intermediate values between those of the mono nanofluids for all the properties except dynamic viscosity. We use cookies to help provide and enhance our service and tailor content and ads. FROZKHQ KHDWHGLQWKH+9HOHFWULFILHOG At 1.0vol% of nanofluid and a Reynolds number of 1454.4 in comparison to the base fluid, the Nusselt number and heat transfer coefficient are boosted by 29.43%, 45.01%, and a friction factor penalty of 27.59%, respectively. 0000002234 00000 n trailer <]>> [25], [26] also prepared 20:80%, 40:60% and 60:40% EG/W based Fe3O4 nanofluids and measured both thermal conductivity and viscosity experimentally. 108-65-6) Dipropylene Glycol Methyl Ether (DPM; CAS No. The formation of carboxyl (COOH) groups on the surface of ND particles was analyzed by FTIR spectrum. By continuing you agree to the use of cookies. [27] analysis.knfkbf=1+Cknfbf=1+Cwhere, is the volume concentration, Ck and C are the thermal conductivity and viscosity enhancement coefficients. To request permission to reproduce material from this article, please go to the The fluid is colorless (water white). The theoretical models of Maxwell and Einstein have failed to estimate the thermal conductivity and viscosity of nanofluids as a function of temperature. The formation of carboxyl (COOH) groups on the surface of nanodiamond was analyzed by FTIR. Chemical co-precipitation was used for the synthesis of large quantity of Fe3O4 nanoparticles with an average particle size of 11.42nm. Annual production of propylene glycol in 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. I always eqip the system with a 2" hose connection with check valve so the contractor can use a pump to fill the system those glycol feeders [20] obtained thermal conductivity enhancement of 17.23% for ND/EG nanofluid at 1.0vol.% at a temperature of 30C. 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. 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. The thermal conductivity and viscosity of ND nanofluids were estimated experimentally at different particle concentrations and temperatures. The statistical and graphical results showed that the proposed models are more precise and reliable than the existing ones in literature. The carbon impurities present in the UDD powders have been removed using mixture of H2SO4 and HNO3 [5], [6], [7], [8], [9]. Because dissolved salts and other inorganic chemicals conduct electrical current, conductivity increases as salinity increases. The sensitivity analysis illustrated that temperature has the highest effect on the relative TC followed by base fluid TC and particle volume fraction. 245-255, Applied Thermal Engineering, Volume 91, 2015, pp. 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. 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. Prasher et al. Another method for removing the carbon impurities from the UDD powders is with dry salt or dry sucrose [10]. This study investigates theoretically and experimentally the electrical and thermal conductivities of 50/50 water-ethylene glycol based TiO 2 nanofluids with When compared to Propylene glycolwater (50:50) along with Propylene glycolwater (50:50) dispersed with 0.25% Graphene, it is clear from Fig. The preparation of ND based nanofluids and their thermal properties are given below. WebUsing the results for propylene glycol/water with corrosion inhibitor and nanoparticles, for over 3,000 hours of operation, the conductivity of the solution would have gone up to about 27 mS/cm-hr. 107-98-2) Propylene Glycol Methyl Ether Acetate (PMA; CAS No. Nanodiamondwater nanofluids were prepared and estimated the thermal conductivity, viscosity and also estimated their potential use in heat transfer applications. 8 . Forced convection experiments were performed on an instrumented metal plate with micro-channels. For reliability, Electrical conductivity of aqueous Propylene glycol (PG/W-30/70) is determined (30EG/70W) as a for three times and the same is compared with The thermodynamic, heat transfer and thermal performance factor were analyzed experimentally at different particle volume loadings of water+ethylene glycol mixture based nanodiamond (ND) nanofluids flow in a shell and helical coiled tube heat exchanger. 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 ). The relative electrical conductivity of -SiC NFs and model predictions determined at 298.15 K are compared as illustrated in Fig. , DOI: 10.1039/D2NR06332H. Liquids - Thermal Conductivities - Engineering ToolBox The thermal conductivity of single phase heat transfer fluids may be enhanced by dispersing small quantity of solid particles. The purchased UDD powders treated with strong acid treatment, dry salt and dry sucrose to make them into single ND-crystals. This paper investigates the significance of some micro scaling effects in micro-channel absorber plates. provided correct acknowledgement is given. DOWFROSTfluid has an operating In the heat exchanger, the hot fluid passes through the shell side and the cold fluid (nanofluid) passes through the helical coil side. Xie et al. 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 Wilson plot method is used to analyze the helical coil side heat transfer coefficients. 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 frictional exergy destruction is found to contribute together with heat transfer exergy destruction to the total entropy of the SCHE system.
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