Enhanced Thermal Performance of Ionic Liquid-Al2O3 Nanofluid as Heat Transfer Fluid for Solar Collector

2013 ◽  
Author(s):  
Titan C. Paul ◽  
A. K. M. M. Morshed ◽  
Elise B. Fox ◽  
Ann E. Visser ◽  
Nicholas J. Bridges ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Heat Capacity ◽  
Ionic Liquids ◽  
Thermal Performance ◽  
Thermophysical Properties ◽  
Heat Transfer Fluid ◽  
Al2o3 Nanoparticles ◽  
Diphenyl Oxide ◽  
Volume Percentage

Next generation Concentrating Solar Power (CSP) system requires high operating temperature and high heat storage capacity heat transfer fluid (HTF), which can significantly increase the overall system efficiency for power generation. In the last decade several research going on the efficacy of ionic liquids (ILs) as a HTF in CSP system. ILs possesses superior thermophysical properties compare to currently using HTF such as Therminol VP-1 (mixture of biphenyl and diphenyl oxide) and thermal oil. However, advanced thermophysical properties of ILs can be achieved by dispersing small volume percentage of nanoparticles forming nanofluids, which is called Nanoparticle Enhanced Ionic Liquids (NEILs). In the present study NEILs were prepared by dispersing 0.5% Al2O3 nanoparticles (spherical and whiskers) in N-butyl-N, N, N-trimetylammonium bis(trifluormethylsulfonyl)imide ([N4111][NTf2]) IL. Viscosity, heat capacity and thermal conductivity of NEILs were measured experimentally and compared with the existing theoretical models for liquid–solid suspensions. Additional, the convective heat transfer experiment was performed to investigate thermal performance. The thermal conductivity of NEILs enhanced by ∼5%, heat capacity enhanced by ∼20% compared to the base IL, which also gives 15% enhancement in heat transfer performance.

Natural Convection in Rectangular Cavity With Nanoparticle Enhanced Ionic Liquids (NEILs)

2012 ◽  
Author(s):  
Titan C. Paul ◽  
A. K. M. M. Morshed ◽  
Elise B. Fox ◽  
Ann E. Visser ◽  
Nicholas J. Bridges ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Heat Capacity ◽  
Ionic Liquid ◽  
Ionic Liquids ◽  
Natural Convection ◽  
Thermophysical Properties ◽  
Convection Heat Transfer ◽  
Natural Convection Heat Transfer ◽  
Convection Heat

A systematic natural convection heat transfer experiment has been carried out of nanoparticle enhanced ionic liquids (NEILs) in rectangular enclosures (lengthxwidthxheight, 50×50×50mm and 50×50×75mm) heated from below condition. In the present experiment NEIL was made of N-butyl-N-methylpyrrolidinium bis{(trifluoromethyl)sulfonyl} imide, ([C4mpyrr][NTf2]) ionic liquid with 0.5% (weight%) Al2O3 nanoparticles. In addition to characterize the natural convection behavior of NEIL, thermophysical properties such as thermal conductivity, heat capacity, and viscosity were also measured. The result shows that the thermal conductivity of NEIL enhanced ∼3% from the base ionic liquid (IL), heat capacity enhanced ∼12% over the measured temperature range. The natural convection experimental result shows consistent for two different enclosures based on the degrading natural convection heat transfer rate over the measured Rayleigh number range. Possible reasons of the degradation of natural convection heat transfer may be the relative change of the thermophysical properties of NEIL compare to the base ionic liquid.

scholarly journals Ionic liquid-based nanofluids (ionanofluids) for thermal applications: an experimental thermophysical characterization

2019 ◽  
Vol 91 (8) ◽  
pp. 1309-1340 ◽  
Author(s):  
Kamil Oster ◽  
Christopher Hardacre ◽  
Johan Jacquemin ◽  
Ana P. C. Ribeiro ◽  
Abdulaziz Elsinawi
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Heat Capacity ◽  
Ionic Liquids ◽  
Thermophysical Properties ◽  
New Technologies ◽  
Organic Liquids ◽  
Published Data ◽  
Thermal Exchange ◽  
Heat Transfer Fluids

Abstract Heat transfer fluids materials are manufactured for the purpose of transfer, distribution and storage of heat. Several of their important properties can be listed (for example flash point, thermal expansivity or technical safety). However, to assess the thermal exchange performance of these fluids, a prior knowledge of their heat capacity, density, viscosity and thermal conductivity is obligatory. The most popular heat transfer fluids are based on organic liquids, such as ethylene glycol. However, new technologies and development require more efficient materials. Ionanofluids, mixtures of ionic liquids and nanoparticles, were proposed as a viable replacement for those commonly used fluids due to the properties of ionic liquids (wide liquid range or low vapour pressure and flammability) combined with enhanced thermophysical properties of nanofluids caused by the dispersion of nanoparticles (mainly thermal conductivity and heat capacity). Very few authors reported the extensive analysis of those systems thermophysical properties and impact on the heat exchange efficiency. Moreover, the availability of published data is very limited. The aim of this work is to investigate ionanofluids based on the trihexyl(tetradecyl)phosphonium cation paired with the acetate, butanoate, hexanoate, octanoate or decanoate anion, mixed with carbon nanotubes, boron nitride, graphite or mesoporous carbon as nanoparticles with concentration up to 3 wt %. The density, heat capacity, thermal stability, thermal conductivity and viscosity of selected ionanofluids were determined experimentally as functions of the temperature (up to 363.15 K) and compared with theoretical tools to evaluate the predictive capability. Based on the experimental results, lubrication, heat storage potential and economic analysis were also discussed and compared to commercial heat transfer fluids.

scholarly journals Thermal Conductivity of Ionic Liquids and IoNanofluids. Can Molecular Theory Help?

Fluids ◽  
2021 ◽  
Vol 6 (3) ◽  
pp. 116
Author(s):  
Xavier Paredes ◽  
Maria José Lourenço ◽  
Carlos Nieto de Castro ◽  
William Wakeham
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Ionic Liquids ◽  
Imaging Techniques ◽  
Interfacial Area ◽  
Thermal Conductivity Enhancement ◽  
Molecular Theory ◽  
Estimation Methods ◽  
Diphenyl Oxide ◽  
Conductivity Enhancement

Ionic liquids have been suggested as new engineering fluids, specifically in the area of heat transfer, and as alternatives to current biphenyl and diphenyl oxide, alkylated aromatics and dimethyl polysiloxane oils, which degrade above 200 °C, posing some environmental problems. Addition of nanoparticles to produce stable dispersions/gels of ionic liquids has proved to increase the thermal conductivity of the base ionic liquid, potentially contributing to better efficiency of heat transfer fluids. It is the purpose of this paper to analyze the prediction and estimation of the thermal conductivity of ionic liquids and IoNanofluids as a function of temperature, using the molecular theory of Bridgman and estimation methods previously developed for the base fluid. In addition, we consider methods that emphasize the importance of the interfacial area IL-NM in modelling the thermal conductivity enhancement. Results obtained show that it is not currently possible to predict or estimate the thermal conductivity of ionic liquids with an uncertainty commensurate with the best experimental values. The models of Maxwell and Hamilton are not capable of estimating the thermal conductivity enhancement of IoNanofluids, and it is clear that the Murshed, Leong and Yang model is not practical, if no additional information, either using imaging techniques at nanoscale or molecular dynamics simulations, is available.

scholarly journals Improved Thermophysical Properties and Energy Efficiency of Aqueous Ionic Liquid/MXene Nanofluid in a Hybrid PV/T Solar System

Nanomaterials ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 1372 ◽  
Author(s):  
Likhan Das ◽  
Khairul Habib ◽  
R. Saidur ◽  
Navid Aslfattahi ◽  
Syed Mohd Yahya ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Ionic Liquid ◽  
Palm Oil ◽  
Thermophysical Properties ◽  
Conductivity Measurement ◽  
Optimum Concentration ◽  
Heat Transfer Fluid ◽  
Solar Pv ◽  
T System

In recent years, solar energy technologies have developed an emerging edge. The incessant research to develop a power source alternative to fossil fuel because of its scarcity and detrimental effects on the environment is the main driving force. In addition, nanofluids have gained immense interest as superior heat transfer fluid in solar technologies for the last decades. In this research, a binary solution of ionic liquid (IL) + water based ionanofluids is formulated successfully with two dimensional MXene (Ti3C2) nano additives at three distinct concentrations of 0.05, 0.10, and 0.20 wt % and the optimum concentration is used to check the performance of a hybrid solar PV/T system. The layered structure of MXene and high absorbance of prepared nanofluids have been perceived by SEM and UV–vis respectively. Rheometer and DSC are used to assess the viscosity and heat capacity respectively while transient hot wire technique is engaged for thermal conductivity measurement. A maximum improvement of 47% in thermal conductivity is observed for 0.20 wt % loading of MXene. Furthermore, the viscosity is found to rise insignificantly with addition of Ti3C2 by different concentrations. Conversely, viscosity decreases substantially as the temperature increases from 20 °C to 60 °C. However, based on their thermophysical properties, 0.20 wt % is found to be the optimum concentration. A comparative analysis in terms of heat transfer performance with three different nanofluids in PV/T system shows that, IL+ water/MXene ionanofluid exhibits highest thermal, electrical, and overall heat transfer efficiency compared to water/alumina, palm oil/MXene, and water alone. Maximum electrical efficiency and thermal efficiency are recorded as 13.95% and 81.15% respectively using IL + water/MXene, besides that, heat transfer coefficients are also noticed to increase by 12.6% and 2% when compared to water/alumina and palm oil/MXene respectively. In conclusion, it can be demonstrated that MXene dispersed ionanofluid might be great a prospect in the field of heat transfer applications since they can augment the heat transfer rate considerably which improves system efficiency.

scholarly journals Thermal Conductivity of Metastable Ionic Liquid [C2mim][CH3SO3]

Molecules ◽  
2020 ◽  
Vol 25 (18) ◽  
pp. 4290 ◽  
Author(s):  
Daniel Lozano-Martín ◽  
Salomé Inês Cardoso Vieira ◽  
Xavier Paredes ◽  
Maria José Vitoriano Lourenço ◽  
Carlos A. Nieto de Castro ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Ionic Liquid ◽  
Melting Point ◽  
Solid Phase ◽  
Freezing Point ◽  
Phase Region ◽  
Heat Transfer Fluid ◽  
Diphenyl Oxide ◽  
Conductivity Models

Ionic liquids have been suggested as new engineering fluids, namely in the area of heat transfer, as alternatives to current biphenyl and diphenyl oxide, alkylated aromatics and dimethyl polysiloxane oils, which degrade above 200 °C and pose some environmental problems. Recently, we have proposed 1-ethyl-3-methylimidazolium methanesulfonate, [C2mim][CH3SO3], as a new heat transfer fluid, because of its thermophysical and toxicological properties. However, there are some interesting points raised in this work, namely the possibility of the existence of liquid metastability below the melting point (303 K) or second order-disorder transitions (λ-type) before reaching the calorimetric freezing point. This paper analyses in more detail this zone of the phase diagram of the pure fluid, by reporting accurate thermal-conductivity measurements between 278 and 355 K with an estimated uncertainty of 2% at a 95% confidence level. A new value of the melting temperature is also reported, Tmelt = 307.8 ± 1 K. Results obtained support liquid metastability behaviour in the solid-phase region and permit the use of this ionic liquid at a heat transfer fluid at temperatures below its melting point. Thermal conductivity models based on Bridgman theory and estimation formulas were also used in this work, failing to predict the experimental data within its uncertainty.

MEASUREMENT OF THERMOPHYSICAL PROPERTIES OF FLEXIBLE THERMAL INSULATION

2021 ◽  
pp. 119-126
Author(s):  
A.V. Zuev ◽  
◽  
Yu.P. Zarichnyak ◽  
D.Ya. Barinov ◽  
L.L. Krasnov ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Heat Capacity ◽  
Thermal Insulation ◽  
Thermophysical Properties ◽  
Fibrous Material ◽  
Sewing Thread ◽  
Silica Fibers ◽  
Porous Fibrous Material ◽  
Highly Porous

The paper presents the results of measuring thermal conductivity and heat capacity of a flexible thermal insulation. Flexible thermal insulation is a highly porous fibrous material, a construction that includes felt, covered on all sides with fabric. The whole structure is stitched with a thread. The fibrous core, fabric and sewing thread are composed of silica fibers. Thermal conductivity was measured by the stationary method on flat samples. The heat capacity was determined using a NT-1000 calorimeter. The calculation of heat transfer was carried out for the conditions characteristic of those in effect when the spacecraft entered the orbit.

scholarly journals A Critical Review on the Development of Ionic Liquids-Based Nanofluids as Heat Transfer Fluids for Solar Thermal Energy

Processes ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 858
Author(s):  
Titan Paul ◽  
Amitav Tikadar ◽  
Rajib Mahmud ◽  
Azzam Salman ◽  
A. K. M. Monjur Morshed ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Ionic Liquids ◽  
Vapor Pressure ◽  
Thermal Performance ◽  
Thermal Energy ◽  
Thermophysical Properties ◽  
Solar Thermal ◽  
Potential Candidate ◽  
Solar Thermal Energy ◽  
Heat Transfer Fluids

In recent years, solar thermal energy (STE) has attracted energy researchers because of its higher efficacy compared to the photovoltaic solar cell. STE is one of the forms of solar energy whereby heat is transferred via a secondary medium called heat transfer fluids (HTFs). Therefore, the overall performance of STE depends on the thermophysical properties and thermal performance of the HTFs. Traditional HTFs suffer from low decomposition temperature, high melting point, and higher vapor pressure. To overcome these limitations, researchers have recently begun working on new HTFs for STE. Ionic liquids (ILs) are considered as a potential candidate for the next generation of HTFs because of their enhanced thermophysical properties, such as thermal stability at high temperature, insignificant vapor pressure, and high ionic conductivity. In addition, thermophysical properties and thermal performance of ILs can be further enhanced by dispersing nanoparticles, which is one of the emerging research interests to improve the efficiency of the solar thermal system. This paper summarizes the recent study of ILs-based nanofluids as HTFs. These summaries are divided into two sections (i) thermophysical properties studies, such as density, viscosity, thermal conductivity, and heat capacity, and (ii) thermal performance studies such as natural convection and forced convection. Synthesis of ILs-based nanofluids and thermophysical properties measurement techniques are also discussed. Based on these state-of-the-art summaries, we offer recommendations for potential future research direction for ILs-based nanofluids.

Fundamental Study on Laser Interactions With Nanoparticles-Reinforced Metals—Part I: Effect of Nanoparticles on Optical Reflectivity, Specific Heat, and Thermal Conductivity

2016 ◽  
Vol 138 (12) ◽  
Author(s):  
Chao Ma ◽  
Jingzhou Zhao ◽  
Chezheng Cao ◽  
Ting-Chiang Lin ◽  
Xiaochun Li
Keyword(s):  
Thermal Conductivity ◽  
Heat Capacity ◽  
Specific Heat ◽  
Thermophysical Properties ◽  
Room Temperature ◽  
Al2o3 Nanoparticles ◽  
Fundamental Study ◽  
Optical Reflectivity ◽  
Theoretical Results ◽  
Laser Interactions

It is of tremendous interest to apply laser to process nanoparticles-reinforced metals for widespread applications. However, little fundamental understanding has been obtained on the underlining physics of laser interactions with nanoparticles-reinforced metals. In this work, fundamental study was carried out to understand the effects of nanoparticles on the optical and thermophysical properties of the base metal, the corresponding heat transfer and melt pool flow processes, and the consequent surface property in laser melting. Part I presents both experimental and theoretical results on the effects of nanoparticles on the optical reflectivity, specific heat, and thermal conductivity. Electrocodeposition was used to produce nickel samples with nanoparticles. Using a power meter, the reflectivity of Ni/Al2O3 (1.8 vol. %) was measured to be 65.8% while pure Ni was at 67.4%, indicating that the Al2O3 nanoparticles did not change the reflectivity substantially. Differential scanning calorimetry was used to determine the heat capacity of the nanocomposites. The specific heat capacities of the Ni/Al2O3 (4.4 vol. %) and Ni/SiC (3.6 vol. %) at room temperature were 0.424 ± 0.013 J/g K and 0.423 ± 0.014 J/g K, respectively, close to that of pure Ni, 0.424 ± 0.008 J/g K. An experimental setup was developed to measure thermal conductivity based on the laser flash method. The thermal conductivities of these Ni/Al2O3 and Ni/SiC nanocomposites at room temperature were 84.1 ± 3.4 W/m K and 87.3 ± 3.4 W/m K, respectively, less than that of pure Ni, 91.7 ± 2.8 W/m K. Theoretical models based on the effective medium approximation theory were also used to predict the heat capacity and thermal conductivity of the nanoparticles-reinforced nickel. The theoretical results match well with the measurements. The knowledge of the optical and thermophysical properties of nanoparticles-reinforced metals would provide valuable insights to understand and control laser processing of metal matrix nanocomposites.

scholarly journals Thermal performance evaluation of hot oils and nanofluids by simulation of an indirect heating plant

2020 ◽  
pp. 23-23
Author(s):  
Lis Ostigard ◽  
Silvana Mattedi
Keyword(s):  
Heat Transfer ◽  
Thermal Performance ◽  
Volume Fraction ◽  
Heat Transfer Fluid ◽  
Diphenyl Oxide ◽  
Heat Transfer Fluids ◽  
Industrial Unit ◽  
Lower Heat ◽  
Fractionation Plant ◽  
Heating Plant

This paper aims to analyze the thermal performance of four different heat transfer fluids in a hot oil system located in a paraffin hydrotreatment and fractionation plant of a petroleum refinery. The software Petro-SIM? (KBC-Yokogawa) was employed to elaborate steady-state simulations intended to compare the heat transfer fluid currently used (eutectic of biphenyl and diphenyl oxide) and three fluids proposed as substitutes: paraffin oil (namely n-C13+) produced in the very industrial unit, a nanofluid of eutectic of biphenyl and diphenyl oxide and copper at a 6 % volume fraction, and a CuO/polydimethylsiloxane nanofluid at a 6 % volume fraction. The results showed that n-C13+ was the only heat transfer fluid that could replace the eutectic diphenyl oxide/ biphenyl in the system under analysis since it absorbed the heat duty of 13.79 Gcal/ h, which exceeded the thermal energy of 10.57 Gcal/ h absorbed by the heat transfer fluid currently used at the same operating parameters. The Cu/ eutectic of biphenyl and diphenyl oxide and CuO/polydimethylsiloxane nanofluids presented lower heat duty than the energy needed for the operation of the hot oil system, which was 8.31 Gcal/h and 8.51 Gcal/h, respectively.

Thermophysical Properties of Nanofluids

2020 ◽  
Vol 16 ◽  
Author(s):  
Reyhan Arslan ◽  
Veysel Ahmet Özdemir ◽  
Emel Akyol ◽  
Ahmet Selim Dalkilic ◽  
Somchai Wongwises
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Heat Capacity ◽  
Heat Exchanger ◽  
Surface Area ◽  
Thermophysical Properties ◽  
Heat Transfer Area ◽  
New Generation ◽  
Conductive Particles ◽  
Base Liquid

: Nanofluids, consist of base liquid and nano-sized conductive particles, are widely acclaimed as a new generation liquid for heat transfer applications. Since it possesses a variety of conductive particles, it can be efficiently utilized in the heat exchanger. These nano-sized conductive particles can increase the surface area, thus the heat transfer area, and change the thermophysical features of nanofluids. Density, thermal conductivity, viscosity, and heat capacity are crucial parameters and cannot be underestimated in heat transfer. These properties can be manipulated by the particle and base-liquid, and significantly influence the performance of nanofluids. For the last decade, several models, equations, and investigations were performed to examine the parameters that promote the properties. The review is necessary for terms of classifying the studies both compatible, and contradictory on the effects of density, thermal conductivity, viscosity, and heat capacity on the performance of nanofluids.

Sign in / Sign up

Export Citation Format

Share Document