Effects of working temperature on thermo-physical properties and forced convection heat transfer of TiO 2 nanofluids in waterEthylene glycol mixture. 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. WebDOWFROSTfluid is a formulation of 95.5 percent propylene glycol, dipotassium phosphate and water. New thermal conductivity and viscosity correlations have been developed based on the experimental data. WebPropylene Glycol Methyl Ether (PM; CAS No. 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. 0000086902 00000 n The Prasher et al. Prasher et al. The fluid is colorless (water white). Conductivity The frictional exergy destruction is found to contribute together with heat transfer exergy destruction to the total entropy of the SCHE system. [34], in which the nanofluids prepared in pure PG have lower thermal conductivity enhancement than that of. However, the penalty in friction factor and pressure drop is 17.28% and 14.24% under the same Reynolds number and 1.0vol% nanofluid over the base fluid. 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. They also observed the formation of carboxyl groups on the surface of ND particles based on the FTIR analysis. 0000102258 00000 n The formation of carboxyl (COOH) groups on the surface of nanodiamond was analyzed by FTIR. The thermal conductivity results here reported can be compared with those previously published by Sundar et al. From the Prasher et al. The inadequacy of the widely used VogelTammannFulcher or WilliamsLandelFerry equations to describe the temperature variation of the vacuum Webconductivity. Thermal conductivity of nanoparticle-fluid mixture. 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. model and the Mouromtseff number were used to study the heat transfer capability of ND nanofluid under laminar and turbulent flow conditions. 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. These plates are to be used in a proposed compact (thin and light-weight) solar thermal flat plate collector (FPC). WebConductivity is a measure of the ability of water to pass an electrical current. Naik and Sundar [28] prepared 30:70% PG/W based CuO nanofluid and estimated thermal conductivity and viscosity experimentally. The earlier works reveals the preparation, estimation of thermal conductivity and viscosity of PG/W mixture based Al2O3, CuO, and Fe3O4 nanofluids. The present findings are consistent with those of Palabiyik et al. 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 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. of nanofluid, the exergy efficiency is 22.97%, while for ethylene glycol, it is 6.78%. There have been numerous investigations of nanodiamond-nanofluid systems with many suggesting that considerable property enhancements, e.g., increased thermal conductivity, might be possible. We use cookies to help provide and enhance our service and tailor content and ads. 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. MEG (Mono Ethylene Glycol) or C2H6O2. Diamond circular saws and diamond wire saws present some technological limits, and the marble frame saw cannot process granite by now. The thermal conductivity of 0.1vol% of N-CQDs nanofluid increased by 43.21% at 50C compared to 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%. The viscosity of N-CQDs nanofluid behaves as a Newtonian fluid. <]>> 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. Progress and Perspectives of Lithium Aluminum Germanium Due to its exceptional thermal, mechanical and electrical properties, diamond has attracted attention for use as a nanoparticle in fluids. [27] analysis if the value of C/Ck<4 then the nanofluid is heat transfer beneficial fluid. WebBNNBs exhibit high thermal conductivity due to efficient phonon transfer and they are electrical insulators owing to their wide bandgap. 0000086285 00000 n Conjugate heat transfer was found to reduce the Nusselt number which agrees with the literature, this also resulted in a Peclet number dependent Nusselt number. For 1.0% vol. The stability, thermophysical properties and rheological characteristics of N-CQDs nanofluids were investigated. These values are significantly larger than that of the marble frame saw. 181-190, International Journal of Heat and Mass Transfer, Volume 129, 2019, pp. , DOI: 10.1039/D2NR06332H. However, those results have not been collectively compared or discussed. The X-ray powder diffraction (XRD), transmission electron microscope (TEM) and Raman spectra was also performed on acid treated ND particles. 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 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. Increasing the concentration of the nanofluid beyond 1.0vol% shows a little improvement in the effectiveness of the heat exchanger. Xu X, Choi SUS. 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. 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. 11 is presented the percentage thermal conductivity enhancement [(knfkbf)/kbf100] for these ratios along with the data with the data of Palabiyik et al. 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. Joint School of Nanoscience and Nanoengineering, North Carolina A&T State University, Greensboro, NC 27401, USA 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. Annual production of propylene glycol in It is hygroscopic, meaning that it readily absorbs water from the surrounding environment. The results of proposed models were compared to 23 well-known theoretical and empirical models. would like to thank FCT for his post-doctoral research grant: SFRH/BPD/79104/2011. 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. The propylene glycol/water mixtures at different weight ratios were used as base fluids for the preparation of stable ND nanofluids. 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. The functional groups on the treated UDD powders were analyzed by FTIR. If you are an author contributing to an RSC publication, you do not need to request permission 0000113197 00000 n The statistical and graphical results showed that the proposed models are more precise and reliable than the existing ones in literature. The proportion of micro-fractured and good diamonds in the new frame saw machine are 45% and 25%, respectively, and the productivity of the new machine is between 6 and 15m2/h. Islam, R.; Shabani, B. 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 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. 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. Table 8-3-1 - Properties of mixture Water/Glycol - CERN Water-Glycol mixture measurement | Baker Hughes 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]. 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. How about a secondary heat exchanger, i.e primary steam/water heats intermediate water. Intemediate water is pumped to a secondary heat exchanger w 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. The starting product, MICRONAL 5428 X, which contains about 43% microencapsulated paraffin with a transformation temperature of 28 The preparation of ND based nanofluids and their thermal properties are given below. 0000088822 00000 n The specific heat capacity decreases with increasing nanofluid loading. 499-508, Energy Conversion and Management, Volume 96, 2015, pp. 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. Among all the carbon materials ND particles creates great interest because of their superior hardness, thermal conductivity, i.e. All were assigned as low priority for further work. Forget about conductivity, it is directly related to temperature and is used in domestic/process water systems (water treatment) where you don't ha A sawing test and a simulation were carried out to analyze the sawing trajectory, the surface topography of the segments and the percentage of worn diamond particles. 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. Electrical and Thermal Conductivities of 50/50 Water 2016 Elsevier B.V. All rights reserved. [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. 2 shows the IR spectra of UDD powders, acid treated, salt and sucrose milled samples. jralston1@ncat.edu, b It was observed that the position of the thermocouples can result in an under-estimation of the Nusselt number. In addition, both cutting efficiency and slab flatness were recorded. [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. 0000047379 00000 n 0000133274 00000 n Hybrid nanofluids aim to further improve the characteristics of mono nanofluids. 245-255, Applied Thermal Engineering, Volume 91, 2015, pp. trailer Interactions between spherical and sheet-like nanoparticles explain this behaviour. The thermal conductivity and viscosity of ND nanofluids were investigated experimentally, whereas the density and specific heat were estimated theoretically. 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. 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. 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). The relative electrical conductivity of -SiC NFs and model predictions determined at 298.15 K are compared as illustrated in Fig. In this particular system we are using an expansion tank with a bladder, so we don't have a make-up pump. [27] analysis.knfkbf=1+Cknfbf=1+Cwhere, is the volume concentration, Ck and C are the thermal conductivity and viscosity enhancement coefficients.

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