Design of regenerators for heat transfer fluids with variable thermophysical properties

1965 ◽  
Vol 9 (1) ◽  
pp. 89-95 ◽  
Author(s):  
G. D. Rabinovich
Keyword(s):  
Heat Transfer ◽  
Thermophysical Properties ◽  
Heat Transfer Fluids

Use of metallic nanoparticles to improve the thermophysical properties of organic heat transfer fluids used in concentrated solar power

Solar Energy ◽  
2014 ◽  
Vol 105 ◽  
pp. 468-478 ◽  
Author(s):  
Dileep Singh ◽  
Elena V. Timofeeva ◽  
Michael R. Moravek ◽  
Sreeram Cingarapu ◽  
Wenhua Yu ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Thermophysical Properties ◽  
Metallic Nanoparticles ◽  
Solar Power ◽  
Concentrated Solar Power ◽  
Heat Transfer Fluids

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.

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

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.

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.

Thermophysical properties of (diphenyl ether+biphenyl) mixtures for their use as heat transfer fluids

2012 ◽  
Vol 50 ◽  
pp. 80-88 ◽  
Author(s):  
D. Cabaleiro ◽  
M.J. Pastoriza-Gallego ◽  
M.M. Piñeiro ◽  
J.L. Legido ◽  
L. Lugo
Keyword(s):  
Heat Transfer ◽  
Thermophysical Properties ◽  
Diphenyl Ether ◽  
Heat Transfer Fluids

scholarly journals Critical evaluation of nanofluids and ionanocolloids as heat transfer fluids

2021 ◽  
Vol 2116 (1) ◽  
pp. 012053
Author(s):  
Elaine Fabre ◽  
S M Sohel Murshed
Keyword(s):  
Heat Transfer ◽  
Thermophysical Properties ◽  
Base Fluid ◽  
Critical Evaluation ◽  
Heat Transfer Fluids

Abstract Nanofluids and ionanocolloids are potential heat transfer fluids with remarkable thermophysical properties. The main difference between these two types of fluids remains in the base fluid used, which significantly impacts their performances. In this work, an attempt of a critical evaluation of the most relevant characteristics of both fluids is presented and the main challenges of their application are discussed.

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