Dramatically enhanced thermal properties for TiO2-based nanofluids for being used as heat transfer fluids in concentrating solar power plants

Abstract The paper presents an analysis of the properties of TiO2-based nanofluids such as their physical stability and heat transfer performance. The nanofluids were prepared with a eutectic mixture of diphenyl oxide and biphenyl with the addition of TiO2 nanoparticles and 1-octadecanethiol (ODT), used as a surfactant. The nanofluids were tested to determine their thermal and physical properties, such as stability, density, viscosity. The introduction of TiO2 nanoparticles accompanied with equal quantity of ODT was seen to sharply enhance the properties of the system in terms of heat transfer in concentrating solar power (CSP) plants. In particular, the system became stable after 3–5 days, and the settlement rate depended on the nanoparticle concentration. There was a slight increase in density and viscosity of no more than 0.12% and 4.85%, respectively. The thermal properties improved significantly, up to 52.7% for the isobaric specific heat and up to 25.8% for the thermal conductivity. The dimensionless Figure of Merit parameter (FoM), which is based on the Dittus-Boelter correlation, was used as a criterion for evaluating efficiency. At all the temperatures tested the nanofluid with 2.5·10−4 wt% (volume fraction of 2.44%) of TiO2 performed best, increasing the efficiency by up to 35.4% with regard to the pure heat transfer fluid (HTF) used in CSP plants. Thus, nanofluids based on TiO2 nanoparticles seem to be a promising alternative to HTFs in CSP plants.

[1]  Josua P. Meyer,et al.  Thermodynamic optimisation of the performance of a parabolic trough receiver using synthetic oil–Al2O3 nanofluid , 2015 .

[2]  J. L. Legido,et al.  Specific heat of metal oxide nanofluids at high concentrations for heat transfer , 2015 .

[3]  T. Teng,et al.  Enhanced heat dissipation of a radiator using oxide nano-coolant , 2014 .

[4]  A. Mwesigye,et al.  Thermal and Thermodynamic Performance of a Parabolic Trough Receiver with Syltherm800-Al2O3 Nanofluid as the Heat Transfer Fluid , 2015 .

[5]  J. J. Gallardo,et al.  Ag-based nanofluidic system to enhance heat transfer fluids for concentrating solar power: Nano-level insights , 2017 .

[6]  J. J. Gallardo,et al.  Preparation of Au nanoparticles in a non-polar medium: obtaining high-efficiency nanofluids for concentrating solar power. An experimental and theoretical perspective , 2017 .

[7]  P. Estellé,et al.  The influence of ash content on thermophysical properties of ethylene glycol based graphite/diamonds mixture nanofluids , 2017 .

[8]  J. J. Gallardo,et al.  On the enhancement of heat transfer fluid for concentrating solar power using Cu and Ni nanofluids: An experimental and molecular dynamics study , 2016 .

[9]  K. S. Rajan,et al.  Heat transfer performance and transport properties of ZnO-ethylene glycol and ZnO-ethylene glycol-water nanofluid coolants , 2014 .

[10]  Tiantian Kong,et al.  CuS/Cu2S nanofluids: Synthesis and thermal conductivity , 2010 .

[11]  D. Das,et al.  Numerical study of fluid dynamic and heat transfer performance of Al2O3 and CuO nanofluids in the flat tubes of a radiator , 2010 .

[12]  Haisheng Chen,et al.  Predicting the thermal conductivity of nanofluids based on suspension viscosity , 2008, 2008 4th International Conference on Information and Automation for Sustainability.

[13]  Javier Muñoz-Antón,et al.  Dual Loop line-focusing solar power plants with supercritical Brayton power cycles , 2017 .

[14]  C. A. N. Castro,et al.  Conduction and convection heat transfer characteristics of ethylene glycol based nanofluids – A review , 2016 .

[15]  Sanjay Mathur,et al.  Use of metallic nanoparticles to improve the thermophysical properties of organic heat transfer fluids used in concentrated solar power , 2014 .

[16]  R. Martinez-Cuenca,et al.  Increment of specific heat capacity of solar salt with SiO2 nanoparticles , 2014, Nanoscale Research Letters.

[17]  Stephen U. S. Choi.  NANOFLUIDS: FROM VISION TO REALITY THROUGH RESEARCH , 2009 .

[18]  M. Chandrasekar,et al.  Mechanisms proposed through experimental investigations on thermophysical properties and forced convective heat transfer characteristics of various nanofluids – A review , 2012 .

[19]  J. Eastman,et al.  Measuring Thermal Conductivity of Fluids Containing Oxide Nanoparticles , 1999 .

[20]  Dae-Hwang Yoo,et al.  Study of thermal conductivity of nanofluids for the application of heat transfer fluids , 2007 .

[21]  Gianpiero Colangelo,et al.  Experimental test of an innovative high concentration nanofluid solar collector , 2015 .

[22]  N. Mousavi,et al.  Effective heat capacity of ferrofluids – Analytical approach , 2014 .

[23]  Liu Yang,et al.  A comprehensive review on heat transfer characteristics of TiO2 nanofluids , 2017 .

[24]  Debjyoti Banerjee,et al.  Enhanced Specific Heat Capacity of Nanomaterials Synthesized by Dispersing Silica Nanoparticles in Eutectic Mixtures , 2013 .

[25]  S. Kim,et al.  Surface wettability change during pool boiling of nanofluids and its effect on critical heat flux , 2007 .

[26]  D. A. G. Bruggeman.  Berechnung verschiedener physikalischer Konstanten von heterogenen Substanzen. II. Dielektrizitätskonstanten und Leitfähigkeiten von Vielkristallen der nichtregulären Systeme , 1936 .

[27]  Soteris A. Kalogirou,et al.  Solar thermal collectors and applications , 2004 .

[28]  A. S. Shirani,et al.  Experimental investigation of TiO2/Water nanofluid effects on heat transfer characteristics of a vertical annulus with non-uniform heat flux in non-radiation environment , 2014 .

[29]  Haisheng Chen,et al.  Stability of nanofluids in quiescent and shear flow fields , 2011, Nanoscale research letters.

[30]  Valan Arasu Amirtham,et al.  A review on preparation, characterization, properties and applications of nanofluids , 2016 .

[31]  Umberto Desideri,et al.  Comparative analysis of concentrating solar power and photovoltaic technologies: Technical and environmental evaluations , 2013 .

[32]  B. Wang,et al.  A fractal model for predicting the effective thermal conductivity of liquid with suspension of nanoparticles , 2003 .

[33]  D. Banerjee,et al.  Specific heat of nanofluids synthesized by dispersing alumina nanoparticles in alkali salt eutectic , 2014 .

[34]  J. Maxwell.  A Treatise on Electricity and Magnetism , 1873, Nature.

[35]  Wenhua Yu,et al.  Review and Comparison of Nanofluid Thermal Conductivity and Heat Transfer Enhancements , 2008 .

[36]  D. Wen,et al.  Investigating the collector efficiency of silver nanofluids based direct absorption solar collectors , 2016 .

[37]  U. S. Hareesh,et al.  Synthesis and characterization of cerium oxide based nanofluids: An efficient coolant in heat transport applications , 2014 .

[38]  J. Koo,et al.  A new thermal conductivity model for nanofluids , 2004 .

[39]  Tiantian Kong,et al.  Synthesis and thermal conductivity of Cu2O nanofluids , 2009 .

[40]  J. C. Gomez,et al.  Nanofluid heat capacities , 2011 .

[41]  Duygu Melek Cakici,et al.  Thermal design and analysis of a shell and tube heat exchanger integrating a geothermal based organic Rankine cycle and parabolic trough solar collectors , 2017 .

[42]  Gianpiero Colangelo,et al.  A new solution for reduced sedimentation flat panel solar thermal collector using nanofluids , 2013 .

[43]  P. Estellé,et al.  Thermophysical and dielectric profiles of ethylene glycol based titanium nitride (TiN–EG) nanofluids with various size of particles , 2017 .

[44]  Eduardo Zarza,et al.  Parabolic-trough solar collectors and their applications , 2010 .

[45]  O. K. Crosser,et al.  Thermal Conductivity of Heterogeneous Two-Component Systems , 1962 .

[46]  Gianpiero Colangelo,et al.  Results of experimental investigations on the heat conductivity of nanofluids based on diathermic oil for high temperature applications , 2012 .

[47]  Sarit K. Das,et al.  Thermal conductivities of naked and monolayer protected metal nanoparticle based nanofluids: Manifestation of anomalous enhancement and chemical effects , 2003 .

[48]  Simon Tung,et al.  A review on development of nanofluid preparation and characterization , 2009 .

[49]  V. Zare,et al.  Parabolic trough solar collectors integrated with a Kalina cycle for high temperature applications: Energy, exergy and economic analyses , 2017 .

[50]  Rob J. Vandebriel,et al.  Risk assessment of titanium dioxide nanoparticles via oral exposure, including toxicokinetic considerations , 2016 .

[51]  Haisheng Chen,et al.  Rheological behaviour of ethylene glycol based titania nanofluids , 2007 .

[52]  C. Zou,et al.  Experimental investigation on stability and thermal conductivity of diathermic oil based TiO2 nanofluids , 2017 .