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Motor Cooling
Published in Wei Tong, Mechanical Design and Manufacturing of Electric Motors, 2022
Due to the recent developments in nanotechnology, a new class of heat transfer fluid called nanofluid has attracted considerable attention from researchers and engineers. A nanofluid is a solid–liquid mixture produced by dispersing nanoparticles in a liquid (usually water, ethylene glycol, or minerals oil) to display enhanced heat transfer due to the combination of convection and conduction and additional energy transfer by particle dynamics and collision [11.93]. The studies of nanofluids with phase change have shown that the presence of nanoparticles in liquid can enhance critical heat flux (CHF) in boiling heat transfer. The mechanism of the CHF enhancement is attributed to the deposition of nanoparticles on the boiling surfaces with foamed porous layers [11.94].
Renewable Energy Sources and Water Management
Published in Barney L. Capehart, Wayne C. Turner, William J. Kennedy, Guide to Energy Management, 2020
Barney L. Capehart, Wayne C. Turner, William J. Kennedy
A need for temperatures of 250°F or higher usually requires a concentrating collector. The surface of a concentrating collector must be highly reflective, enabling concentration of the sun’s rays on the heat absorption device. The heat transfer fluid can be a liquid or gas. A concentrating collector is usually also a tracking collector in order to keep the sun’s rays focussed on a small surface. A typical design for a parabolic trough-type, tracking collector is shown in Figure 15-6. The collector can track in an east to west direction to follow the daily sun, in a north to south direction to follow the seasons, or both. Concentrating collectors that accurately track the sun’s position are more efficient than those that do not track the sun’s position as well.
Renewable Energy Sources and Water Management
Published in Barney L. Capehart, William J. Kennedy, Wayne C. Turner, Guide to Energy Management, 2020
Barney L. Capehart, William J. Kennedy, Wayne C. Turner
A need for temperatures of 120°C or higher usually requires a concentrating collector. The surface of a concentrating collector must be highly reflective, enabling concentration of the sun’s rays on the heat absorption device. The heat transfer fluid can be a liquid or gas. A concentrating collector is usually also a tracking collector in order to keep the sun’s rays focussed on a small surface. A typical design for a parabolic trough-type, tracking collector is shown in Figure 15-6. The collector can track in an east to west direction to follow the daily sun, in a north to south direction to follow the seasons, or both. Concentrating collectors that accurately track the sun’s position are more efficient than those that do not track the sun’s position as well.
Chebyshev spectral approach to an exponentially space-based heat generating single-phase nanofluid flowing on an elongated sheet with angled magnetic field
Published in Numerical Heat Transfer, Part B: Fundamentals, 2023
MD. Shamshuddin, T. M. Agbaje, K. K. Asogwa, G. Makanda
A revolutionary heat transfer fluid termed as “nanofluid” has emerged because of scientific and nanotechnology advancements. Nanofluids are made up of nonmetallic or metallic nanometer sized particles (less than 100 nanometer) dispersed in various traditional fluids. There has been an explosion of study and invention utilizing amazing uses of nanofluids in industries including electrical cooling, solar energy, power generation, water heaters, biomedical, among others, over the previous few decades. The idea of nanofluids was suggested by Choi [1] at the NAL (National Argon Laboratory). The effective thermal conductivity of nanotube-in-oil suspensions is measured and proposes the usual thermal behavior which testifies the highest thermal conductivity [2]. The nanofluid is a suitable coolant and its excellent thermal properties contribute to the high heat transfer of the radiator. Arora and Gupta [3] investigated the hydrothermal performance of nanofluids in flat tube automobile radiators. Murshed and de Castro [4] evaluated the studies and improvement of conduction and convection warmth switch traits of ethylene glycol-primarily based totally nanofluids. The results demonstrated that those nanofluids own significantly better thermal conductivity and convective warmth switch traits as compared to their base fluids that is ethylene glycol and its aqua mixture. Further relevant literature is found in Refs. [5–9].
Hybrid photovoltaic–thermal system for simultaneous generation of power and hot water utilising mobiltherm as heat transfer fluid
Published in International Journal of Sustainable Energy, 2021
Sudhansu Sekhar Das, Pramod Kumar, Sarbjot Singh Sandhu
The desired thermo-physical property of a heat transfer fluid includes high thermal conductivity, low viscosity and high heat capacity. Apart, it should also possess high boiling point, low melting point and low vapour pressure (Cordaro, Rubin, and Bradshaw 2013; Pacio and Wetzel 2013). Several thermal oils, namely Syltherm XLT, Marlotherm SH, Syltherm 800, Santotherm 59, Santotherm LT, Marlotherm X and Therminol D12, were concluded to be thermally stable up to higher temperatures (Ouagued, Khellaf, and Loukarfi 2013). Apparently too low and high temperatures can affect the thermal performance of any fluid. The fluid should be tested for its efficient operating range of temperatures prior to its application. The selection of any particular heat transfer fluid has to be in line with the objectives to be attained. Mobiltherm was adopted as the heat transfer fluid in this research as specific heat and thermal conductivity of the fluid are conducive for adequate heat transfer.
An Experimental Investigation on the Effect of Ferrofluids on the Efficiency of Novel Parabolic Trough Solar Collector Under Laminar Flow Conditions
Published in Heat Transfer Engineering, 2019
Mustafa Alsaady, Rong Fu, Yuying Yan, Zeyu Liu, Shenyi Wu, Rabah Boukhanouf
Lot of efforts have been made to investigate the enhancement of the convective heat transfer of nanofluids in comparison with conventional heat transfer fluids [15], [16]. Nanofluids are a mixture of nano-sized particles (1–100 nm) in a conventional heat transfer medium. Heat transfer can be enhanced by increasing the thermal properties of heat transfer fluid (nanofluids). Nanofluids with excellent thermo-physical properties are appropriate to enhance the efficiency of any thermal management systems by selecting base fluids with suitable nanoparticle materials, dispersion agents, nanoparticle sizes, and particle volume fraction [17], [18].