Thus, the new prototype machine is suitable for sawing granite. 0000033853 00000 n 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 formation of carboxyl (COOH) groups on the surface of ND particles was analyzed by FTIR spectrum. 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. An investigation has been undertaken into the stone processing machines. The inadequacy of the widely used VogelTammannFulcher or WilliamsLandelFerry equations to describe the temperature variation of the vacuum Appl. 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 heat transfer capability of these single phase heat transfer fluids is limited because of its poor thermal conductivity. 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 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 present findings are consistent with those of Palabiyik 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). Thermal conductivity of nanoparticle-fluid mixture. Prasher et al. Islam, R.; Shabani, B. [14,15] for mono nanofluids based on the same base fluid, propylene glycol:water 20:80 wt%. 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. Joint School of Nanoscience and Nanoengineering, University of North Carolina at Greensboro, Greensboro, NC 27401, USA. BNNBs exhibit high thermal conductivity due to efficient phonon transfer and they are electrical insulators owing to their wide bandgap. and diagrams provided correct acknowledgement is given. Increasing the concentration of the nanofluid beyond 1.0vol% shows a little improvement in the effectiveness of the heat exchanger. 40-48, Applied Thermal Engineering, Volume 90, 2015, pp. The theoretical models of Maxwell and Einstein have failed to estimate the thermal conductivity and viscosity of nanofluids as a function of temperature. 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. 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. 0000073108 00000 n 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 thermal conductivity of single phase heat transfer fluids may be enhanced by dispersing small quantity of solid particles. 0000003320 00000 n 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 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. The relative electrical conductivity of -SiC NFs and model predictions determined at 298.15 K are compared as illustrated in Fig. 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%. Nanoscale, 2023, Advance Article New thermal conductivity and viscosity correlations have been developed based on the experimental data. Common uses: antifreeze/heat transfer fluid. Substance and % by volume in mixture: Minimal working temperature [o C] 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%. 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. 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%). 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 conductivity and viscosity of ND nanofluids were investigated experimentally, whereas the density and specific heat were estimated theoretically. Therefore, there is no literature on the thermal properties of PG/W mixture based ND nanofluids. E-mail: WebBNNBs exhibit high thermal conductivity due to efficient phonon transfer and they are electrical insulators owing to their wide bandgap. Webconductivity. Group method of data handling (GMDH) and gene expression programming (GEP) as two white-box powerful models were used for modeling. Effects of working temperature on thermo-physical properties and forced convection heat transfer of TiO 2 nanofluids in waterEthylene glycol mixture. 180 30 The Raman, TEM and XRD analysis was also performed on acid treated nanodiamond particles. Among all the carbon materials ND particles creates great interest because of their superior hardness, thermal conductivity, i.e. The results are beneficial for the design and operation of micro-channel absorber plates. The thermal conductivity of 0.1vol% of N-CQDs nanofluid increased by 43.21% at 50C compared to the base fluid. Measuring glycol concentrations by electrical conductivity is not recommended, especially in process systems, heat exchangers, etc. The quality of Interactions between spherical and sheet-like nanoparticles explain this behaviour. The propylene glycol/water mixtures at different weight ratios were used as base fluids for the preparation of stable ND nanofluids. [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. 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 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. 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. Sundar et al. [20] obtained thermal conductivity enhancement of 17.23% for ND/EG nanofluid at 1.0vol.% at a temperature of 30C. 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. 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. 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. 0000087804 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. Nanofluids offer many opportunities to enhance the efficiency of thermal systems by improving the thermal properties of the host fluids. 0000060250 00000 n 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. 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 The two-step approach was used to create ND nanofluids with volume concentrations ranging from 0.2% to 1.0%. 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 ). [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. New friction factor and Nusselt number equations were created. A. O. Maselugbo, B. L. Sadiku and J. R. Alston, 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. Ghazvini et al. 0000003207 00000 n Corresponding authors, a 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 fluid is colorless (water white). endstream endobj 181 0 obj<. Reynolds numbers were in the range 10100 and fluid inlet temperatures ranged from 5 to 40C. 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. 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. <]>> 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. 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. Correlations for the thermo-physical properties of the nanofluid were developed. 2 shows the IR spectra of UDD powders, acid treated, salt and sucrose milled samples. 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 DOWFROSTfluid has an operating 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. WebIn this work, mono B 4 C and TiB 2 and hybrid TiB 2:B 4 C nanoadditives are used for the first time to design nanofluids based on propylene glycol:water 20:80 wt%. 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. 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 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. 0000088462 00000 n This paper investigates the significance of some micro scaling effects in micro-channel absorber plates. The earlier works reveal the preparation, estimation of thermal conductivity and viscosity of water, ethylene glycol, mineral oil and midel oil based ND nanofluids. 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 stability, thermophysical properties and rheological characteristics of N-CQDs nanofluids were investigated. New thermal conductivity and viscosity correlations have been developed based on the experimental data. 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%. Nanodiamondwater nanofluids were prepared and estimated the thermal conductivity, viscosity and also estimated their potential use in heat transfer applications. The rheological behaviour is investigated through rotational rheometry. 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. 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 How about a secondary heat exchanger, i.e primary steam/water heats intermediate water. Intemediate water is pumped to a secondary heat exchanger w 0000088822 00000 n model and the Mouromtseff number were used to study the heat transfer capability of ND nanofluid under laminar and turbulent flow conditions. The exergy analysis and heat transfer characteristics pertaining to the heat exchanger were also investigated. The reason for the agglomeration of UDD powders in the base fluid is due to the presence of carbon impurities. 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). 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. 8 . [27] analysis.knfkbf=1+Cknfbf=1+Cwhere, is the volume concentration, Ck and C are the thermal conductivity and viscosity enhancement coefficients. [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 hybrid nanofluid presents intermediate values between those of the mono nanofluids for all the properties except dynamic viscosity. [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. In this particular system we are using an expansion tank with a bladder, so we don't have a make-up pump. 0000086902 00000 n 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. A detailed procedure is presented for the implementation and evaluation, by Nano-Flash Method, of thermal conductivity of nanofluids with water as base fluid and at different volume concentrations of Al2O3. Nanodiamond (ND) nanoparticles of primary particle size of 510nm can be produced in large quantity by using commercially available ultra-dispersed diamond (UDD) powders. Results showed that ND nanofluids achieved higher heat transfer coefficients than the base fluid. The viscosity of N-CQDs nanofluid behaves as a Newtonian fluid. 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. [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. 0000142997 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 The statistical and graphical results showed that the proposed models are more precise and reliable than the existing ones in literature. 0000002868 00000 n Namburu et al. 180 0 obj <> endobj The starting product, MICRONAL 5428 X, which contains about 43% microencapsulated paraffin with a transformation temperature of 28 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 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 preparation of ND based nanofluids and their thermal properties are given below. The electrical conductivity of glycol mixtures within the range of 0000047379 00000 n 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. 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. 11 is presented the percentage thermal conductivity enhancement [(knfkbf)/kbf100] for these ratios along with the data with the data of Palabiyik et al. 0000002234 00000 n 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. [34] for Al2O3/PG and TiO2/PG nanofluids. When compared to Propylene glycolwater (50:50) along with Propylene glycolwater (50:50) dispersed with 0.25% Graphene, it is clear from Fig. In the heat exchanger, the hot fluid passes through the shell side and the cold fluid (nanofluid) passes through the helical coil side. [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. 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. 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. 245-255, Applied Thermal Engineering, Volume 91, 2015, pp. An enhancement of 4.24% in heat transfer rate was observed with 2vol.% ZnOPG nanofluid. The PG/W nanofluids are prepared with acid treated ND particles. Forced convection experiments were performed on an instrumented metal plate with micro-channels. would like to thank FCT for his post-doctoral research grant: SFRH/BPD/79104/2011. 0000000918 00000 n Diamond circular saws and diamond wire saws present some technological limits, and the marble frame saw cannot process granite by now. 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. 0000087536 00000 n WebLearn about the chemical and physical properties of Ethylene Glycol/water mixtures, on our blog. The Raman, XRD and TEM analysis are also used on UDD and ND-acid treated nanoparticles. For 1.0% and a Reynolds number of 1454.4, the thermal performance factor is increased by 1.194-times above the basic fluid. We use cookies to help provide and enhance our service and tailor content and ads. [17] prepared mineral oil based ND nanofluids and obtained thermal conductivity enhancement of 70% at 0.1wt.%. Tyler et al. Yu 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. There have been numerous investigations of nanodiamond-nanofluid systems with many suggesting that considerable property enhancements, e.g., increased thermal conductivity, might be possible. 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. 0000133274 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. 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. 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. Additionally, surface tension and electrical conductivity are investigated. 115-123, International Communications in Heat and Mass Transfer, Volume 76, 2016, pp. 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). 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. 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. The frictional exergy destruction is found to contribute together with heat transfer exergy destruction to the total entropy of the SCHE system. Read more about how to correctly acknowledge RSC content. [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.%. 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, Portuguese Science and Technology Foundation, Investigations of thermal conductivity and viscosity of nanofluids, Viscosity of alumina nanoparticles dispersed in car engine coolant, Thermal conductivity of ethylene glycol and water mixture based Fe, Experimental determination of thermal conductivity of three nanofluids and development of new correlations, Numerical study of turbulent flow and heat transfer characteristics of nanofluids considering variable properties, Experimental investigation on the thermal transport properties of ethylene glycol based nanofluids containing low volume concentration diamond nanoparticles, Thermal transport properties of diamond-based nanofluids and nanocomposites, Volume fraction and temperature variations of the effective thermal conductivity of nanodiamond fluids in deionized water, Enhanced thermal properties of nanodiamond nanofluids, Increase of nanodiamond crystal size by selective oxidation, Experimental investigation of heat transfer and effectiveness of employing water and ethylene glycol mixture based Fe3O4 nanofluid in a shell and helical coil heat exchanger, Heat transfer and exergy efficiency analysis of 60% water and 40% ethylene glycol mixture diamond nanofluids flow through a shell and helical coil heat exchanger, Laminar convective heat transfer, entropy generation, and exergy efficiency studies on ethylene glycol based nanofluid containing nanodiamond nanoparticles, Experimental and modeling studies of N-doped carbon quantum dot nanofluids for heat transfer systems, Modeling thermal conductivity of nanofluids using advanced correlative approaches: Group method of data handling and gene expression programming, Thermophysical, rheological and electrical properties of mono and hybrid TiB2/B4C nanofluids based on a propylene glycol:water mixture, A new frame saw machine by diamond segmented blade for cutting granite, The significance of scaling effects in a solar absorber plate with micro-channels, Improved transient heat transfer performance of ZnOpropylene glycol nanofluids for energy management, Thermal conductivity and viscosity of water based nanodiamond (ND) nanofluids: An experimental study, Effect of temperature and sonication time on nanofluid thermal conductivity measurements by nano-flash method, Thermo-physical properties of diamond nanofluids: A review.