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.

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.

Phase-Change Nanofluids With Enhanced Thermophysical Properties

2009 ◽  
Author(s):  
Zenghu Han ◽  
Bao Yang ◽  
Yung Y. Liu
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Heat Capacity ◽  
Phase Change ◽  
Thermophysical Properties ◽  
Phase Change Materials ◽  
Effective Heat Capacity ◽  
Heat Transfer Fluids ◽  
Effective Heat ◽  
Indium Nanoparticles

The colloidal dispersion of solid nanoparticles (1–100nm) has been shown experimentally to be an effective way to enhance the thermal conductivity of heat transfer fluids. Moreover, large particles (micrometers to tens of micrometers) of phase-change materials have long been used to make slurries with improved thermal storage capacity. Here, a hybrid concept that uses nanoparticles made of phase-change materials is proposed to simultaneously enhance the effective thermal conductivity and the effective heat capacity of fluids. Water-in-perfluorohexane nanoemulsion fluids and indium-in-polyalphaolefin nanofluids are examples of fluids that have been successfully synthesized for experimental studies of their thermophysical properties (i.e., thermal conductivity, viscosity, and heat capacity) as functions of particle loading and temperature. The thermal conductivity of perfluorohexane was found to increase by up to 52% for nanoemulsion fluids containing 12 vol. % water nanodroplets with a hydrodynamic radius of ∼10 nm. Also observed in water-in-perfluorohexane nanoemulsion fluids was a remarkable improvement in effective heat capacity, about 126% for 12 vol. % water loading, due to the melting-freezing transitions of water nanodroplets to ice nanoparticles and vice versa. The increases in the thermal conductivity and dynamic viscosity of these nanoemulsion fluids were found to be highly nonlinear against water loading, indicating the important roles of the hydrodynamic interaction and the aggregation of nanodroplets. For indium-in-polyalphaolefin nanofluids, the thermal conductivity enhancement increases slightly with increasing temperature (i.e., about 10.7% at 30°C to 12.9% at 90°C) with a nanoparticle loading of 8 vol. %. The effective volumetric heat capacity can be increased by about 20% for the nanofluids containing 8 vol. % indium nanoparticles with an average diameter of 20 nm. Such types of phase-change nanoemulsions and nanofluids possess long-term stability and can be mass produced without using as-prepared nanoparticles. The observed melting-freezing phase transitions of nanoparticles of phase-change materials (i.e., water nanodroplets and indium nanoparticles) considerably augmented the effective heat capacity of the base fluids. The use of phase-change nanoparticles would thus provide a way to substantially enhance the thermal transport properties of conventional heat transfer fluids. Future development of these phase-change nanofluids is expected to open new opportunities for studies of thermal fluids.

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.

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.

Thermal Conductivity of Ionic Liquids and IoNanofluids and Their Feasibility as Heat Transfer Fluids

2018 ◽  
Vol 57 (18) ◽  
pp. 6516-6529 ◽  
Author(s):  
João M. P. França ◽  
Maria José V. Lourenço ◽  
S. M. Sohel Murshed ◽  
Agílio A. H. Pádua ◽  
Carlos A. Nieto de Castro
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Ionic Liquids ◽  
Heat Transfer Fluids

scholarly journals Thermophysical Properties of Nanoparticle-Enhanced Ionic Liquids (NEILs) Heat-Transfer Fluids

2013 ◽  
Vol 27 (6) ◽  
pp. 3385-3393 ◽  
Author(s):  
Elise B. Fox ◽  
Ann E. Visser ◽  
Nicholas J. Bridges ◽  
Jake W. Amoroso
Keyword(s):  
Heat Transfer ◽  
Ionic Liquids ◽  
Thermophysical Properties ◽  
Heat Transfer Fluids

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.

Thermal Conductivity Enhancement by Adding Nanoparticles to Ionic Liquids

2017 ◽  
Vol 261 ◽  
pp. 121-126 ◽  
Author(s):  
Alina Adriana Minea ◽  
Madalina Georgiana Moldoveanu ◽  
Oana Dodun
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Ionic Liquid ◽  
Ionic Liquids ◽  
Thermophysical Properties ◽  
Base Fluid ◽  
Thermal Conductivity Enhancement ◽  
Conductivity Enhancement ◽  
New Class ◽  
Enhanced Thermal Conductivity

Ionanofluids are a very new class of nanofluids having ionic liquids as the base fluid. Thermophysical properties of base ionic liquids (ILs) and nanoparticle enhanced ionic liquids (NEILs) are part of studying a new class of fluids for heat transfer. NEILs are formed by dispersing different volume fractions of nanoparticles in a base ionic liquid. In this article, only the thermal conductivity enhancement was considered for comparison of the different ionanofluids. NEILs show enhanced thermal conductivity compared to the base ILs. Maximum thermal conductivity enhancement was observed by adding 1 % MWCNT to [C4mim][(CF3SO2)2N] ionic liquid. However, if 0.05% MWCNT are added to [(C6)3PC14)][NTf2] no enhancement in thermal conductivity was noticed.

scholarly journals Thermal Conductivity Enhancement Phenomena in Ionic Liquid-Based Nanofluids (Ionanofluids)

2019 ◽  
Vol 72 (2) ◽  
pp. 21 ◽  
Author(s):  
Kamil Oster ◽  
Christopher Hardacre ◽  
Johan Jacquemin ◽  
Ana P. C. Ribeiro ◽  
Abdulaziz Elsinawi
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Ionic Liquids ◽  
Theoretical Calculations ◽  
Industrial Applications ◽  
Theoretical Modelling ◽  
Conductivity Enhancement ◽  
Heat Transfer Fluids ◽  
Transfer Unit ◽  
Dispersion Of Nanoparticles

The dispersion of nanoparticles into ionic liquids leads to enhancement of their thermal conductivity. Several papers report on various enhancement values, whereas the comparison between these values with those from theoretical calculations is not always performed. These thermal conductivity enhancements are desired due to their beneficial impact on heat transfer performance in processes requiring the utilisation of heat transfer fluids. Moreover, on the one hand, the theoretical modelling of these enhancements might lead to an easier, cheaper, and faster heat transfer unit design, which could be an enormous advantage in the design of novel industrial applications. On the other hand, it significantly impacts the enhancement mechanism. The aim of this work is to discuss the enhancement of thermal conductivity caused by the dispersion of nanoparticles in ionic liquids, including the analysis of their errors, followed by its theoretical modelling. Furthermore, a comparison between the data reported herein with those available in the literature is carried out following the reproducibility of the thermal conductivity statement. The ionic liquids studied were 1-butyl-3-methylimidazolium dicyanamide, 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide, 1-ethyl-3-methylimidazolium ethylsulfate, 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide, and 1-hexyl-3-methylimidazolium hexafluorophosphate, while carbon nanotubes, boron nitride, and graphite were selected as nanoparticles to be dispersed in the investigated ionic liquids to design novel heat transfer fluids.

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