The heat transfer applications of prepared ND nanofluids in a fully developed laminar flow (Reynolds number, Re<2300) can be evaluated based on the Prasher et al. 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. 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. [27] prepared PG based Al2O3 nanofluids and estimated viscosity experimentally and proposed viscosity model. The thermal conductivity and viscosity of ND nanofluids were estimated experimentally at different particle concentrations and temperatures. 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 X-ray powder diffraction (XRD), transmission electron microscope (TEM) and Raman spectra was also performed on acid treated ND particles. It was observed that the position of the thermocouples can result in an under-estimation of the Nusselt number.
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. The carbon impurities present in the UDD powders have been removed using mixture of H2SO4 and HNO3 [5], [6], [7], [8], [9]. Appl. [27] analysis.knfkbf=1+Cknfbf=1+Cwhere, is the volume concentration, Ck and C are the thermal conductivity and viscosity enhancement coefficients. The present work shows an innovative frame saw machine to cut granite, the eccentric hinge guide mechanism is introduced into the machine. The acid treated ND particles were characterized by XRD, TEM, FTIR and XPS. The functional groups on the treated UDD powders were analyzed by FTIR. Prediction of electrical conductivity of TiO 2 water and ethylene glycol-based nanofluids for cooling application in low temperature PEM fuel cells. 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]. These values are significantly larger than that of the marble frame saw. [16] prepared 20% of water and 50% of engine oil based ND nanofluids and obtained thermal conductivity enhancement of 25% at 1.0wt.% Taha-Tijerina et al. p^h72n*
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:qz*jn88H1 Z'2P?[-ik,2T0!L A. O. Maselugbo, B. L. Sadiku and J. R. Alston,
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. For 1.0% vol. 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. Substance and % by volume in mixture: Minimal working temperature [o C] The thermal conductivity of 0.1vol% of N-CQDs nanofluid increased by 43.21% at 50C compared to the base fluid. The formation of carboxyl (COOH) groups on the surface of ND particles was analyzed by FTIR spectrum. 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]. 107-98-2) Propylene Glycol Methyl Ether Acetate (PMA; CAS No. New thermal conductivity and viscosity correlations have been developed based on the experimental data. E-mail:
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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. Chemical treatment was used to make ND nanoparticles with an average size of 5.42nm. Forget about conductivity, it is directly related to temperature and is used in domestic/process water systems (water treatment) where you don't ha 0000002868 00000 n
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You do not have JavaScript enabled. WebIn this study the electrical conductivity of aluminum oxide (Al2O3), silicon dioxide (SiO2) and zinc oxide (ZnO) nanoparticles dispersed in propylene glycol and water mixture 0000047379 00000 n
2 shows the IR spectra of UDD powders, acid treated, salt and sucrose milled samples. 0000086285 00000 n
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. PGI is a colorless, water soluble, hygroscopic liquid with a characteristic glycol odor, medium viscosity, low vapor [34] for Al2O3/PG and TiO2/PG nanofluids. , DOI: 10.1039/D2NR06332H. The earlier works reveals the preparation, estimation of thermal conductivity and viscosity of PG/W mixture based Al2O3, CuO, and Fe3O4 nanofluids. The values of Ck and C for all the volume concentrations and, The purchased UDD powders were successfully treated using strong acids, dry powders of salt and sucrose to remove carbon impurities. Conductivity is also affected by temperature: the warmer the water, the higher the conductivity. The thermal conductivity and viscosity of ND nanofluids were investigated experimentally, whereas the density and specific heat were estimated theoretically. The Raman, XRD and TEM analysis are also used on UDD and ND-acid treated nanoparticles. To create stable nanofluids, the ND nanoparticles are ultrasonically agitated with EG for 4h. At a constant heat flux of q=9099W/m2, experiments were carried out in a laminar flow with Reynolds numbers ranging from 264.4 to 2194.4. jralston1@ncat.edu, b
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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. All were assigned as low priority for further work. Under constant heat flux conditions, ZnOPG nanofluids exhibited linear increase in heat removal rates with increasing nanoparticle concentration. 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.
DOWFROSTfluid has an operating 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. [30] also prepared 20:80%, 40:60% PG/W based Fe3O4 nanofluids and estimated thermal conductivity and viscosity experimentally. 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. The thermal conductivity of single phase heat transfer fluids may be enhanced by dispersing small quantity of solid particles. 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. We use cookies to help provide and enhance our service and tailor content and ads. The results are beneficial for the design and operation of micro-channel absorber plates. The main advantages of this measurement technique are short measurement times, easy sample preparation and high accuracy. Because dissolved salts and other inorganic chemicals conduct electrical current, conductivity increases as salinity increases. The starting product, MICRONAL 5428 X, which contains about 43% microencapsulated paraffin with a transformation temperature of 28 The as-obtained LAGP thin film also possessed a high ionic conductivity of 2 10 5 S cm 1 at 25 C and a low electronic conductivity value of 1.1 10 9 S cm 1. 40-48, Applied Thermal Engineering, Volume 90, 2015, pp. How about a secondary heat exchanger, i.e primary steam/water heats intermediate water. Intemediate water is pumped to a secondary heat exchanger w Forced convection experiments were performed on an instrumented metal plate with micro-channels. 0000003207 00000 n
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 present findings are consistent with those of Palabiyik et al. 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
Prasher et al. 0
Sundar et al. The Raman, TEM and XRD analysis was also performed on acid treated nanodiamond particles. 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. 5. in a third-party publication (excluding your thesis/dissertation for which permission is not required)
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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. 0000113197 00000 n
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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. 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 [17] prepared mineral oil based ND nanofluids and obtained thermal conductivity enhancement of 70% at 0.1wt.%. 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 The earlier works reveals the preparation, estimation of thermal conductivity and viscosity of EG/W mixture based Al2O3, CuO, ZnO and Fe3O4 nanofluids. The two-step approach was used to create ND nanofluids with volume concentrations ranging from 0.2% to 1.0%. 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.%. Yeganeh et al. 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. 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]. [27] analysis if the value of C/Ck<4 then the nanofluid is heat transfer beneficial fluid. An investigation has been undertaken into the stone processing machines. 0000088822 00000 n
Joint School of Nanoscience and Nanoengineering, North Carolina A&T State University, Greensboro, NC 27401, USA
It is hygroscopic, meaning that it readily absorbs water from the surrounding environment. Check with Union Carbide or Dow as they manufacture glycols. I understand they do have a web site. This study investigates theoretically and experimentally the electrical and thermal conductivities of 50/50 water-ethylene glycol based TiO 2 nanofluids with 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. <50C [21]. The exergy analysis and heat transfer characteristics pertaining to the heat exchanger were also investigated. 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 In this particular system we are using an expansion tank with a bladder, so we don't have a make-up pump. Therefore, there is no literature on the thermal properties of PG/W mixture based ND nanofluids. To request permission to reproduce material from this article, please go to the
If you want to reproduce the whole article
The formation of carboxyl (COOH) groups on the surface of nanodiamond was analyzed by FTIR. Nanodiamond (ND) nanoparticles of primary particle size of 510nm can be produced in large quantity by using commercially available ultra-dispersed diamond (UDD) powders. WebMaintains low electrical conductivity Uses proprietary non-ionic corrosion inhibitor formulation with years of research Can be used with Formulation: Propylene Glycol,
Scaling effects such as viscous dissipation and entrance effects had insignificant impact on the measured average Nusselt number. The Prasher et al. 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. 0000060250 00000 n
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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. [12] also used acid mixtures of perchloric acid, nitric acid and hydrochloric acid (based on the procedure of Jang and Xu [13]) for the removal of carbon impurities from the UDD powders and prepared stable ND nanofluids in the base fluid of 55:45% ethylene glycol/water mixture and observed thermal conductivity enhancement of 18% at 2.0vol.%. The different weight ratios of propylene glycol/water mixtures are used as base. 499-508, Energy Conversion and Management, Volume 96, 2015, pp. The sensitivity analysis illustrated that temperature has the highest effect on the relative TC followed by base fluid TC and particle volume fraction. 0000017674 00000 n
[25], [26] also prepared 20:80%, 40:60% and 60:40% EG/W based Fe3O4 nanofluids and measured both thermal conductivity and viscosity experimentally. 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. *
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115-123, International Communications in Heat and Mass Transfer, Volume 76, 2016, pp. 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. In addition, the models for estimating the viscosity and thermal conductivity of N-CQDs nanofluids are proposed, respectively. For 1.0% and a Reynolds number of 1454.4, the thermal performance factor is increased by 1.194-times above the basic fluid. 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 Increasing the concentration of the nanofluid beyond 1.0vol% shows a little improvement in the effectiveness of the heat exchanger. 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 The preparation and properties of hybrid nanofluids containing diamond nanoparticles are analyzed and discussed in detail, and a list of potential uses for these enhanced heat transfer fluids in industrial and commercial applications is provided and deliberated. 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.
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