scholarly journals Nanofluid as Advanced Cooling Technology. Success Stories

2021 ◽  
Author(s):  
Jesús Esarte ◽  
Roger R. Riehl ◽  
Simone Mancin ◽  
Jesús Mª Blanco ◽  
Maite Aresti ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Base Fluid ◽  
Vapor Compression ◽  
Enhanced Heat Transfer ◽  
Heat Transfer Fluids ◽  
Success Stories ◽  
Heat Transfer Capacity ◽  
Vapor Compression System ◽  
Cooling Technology ◽  
Transfer Properties

Nanofluids are defined as heat transfer fluids with enhanced heat transfer properties by the addition of nanoparticles. Nanofluid’s stability, nanoparticles’ type and their chemical compatibility with the base fluid are essential not only to increase the nanofluid’s thermophysical properties but also to ensure a long-lasting and thermal efficient use of the equipment in which it is used. Some of these aspects are discussed in this chapter. Likewise, the improvement in terms of the heat transfer capacity (thermal resistance) that the use of nanofluids has on the heat pipes-thermosyphons is shown. On the other hand, the improvement in energy efficiency that nanofluid causes in a vapor compression system is also presented.

Settling Characteristics of Alumina Nanoparticles in Ethanol-Water Mixtures

2013 ◽  
Vol 372 ◽  
pp. 143-148 ◽  
Author(s):  
Suhaib Umer Ilyas ◽  
Rajashekhar Pendyala ◽  
Narahari Marneni
Keyword(s):  
Heat Transfer ◽  
Base Fluid ◽  
Particle Diameter ◽  
Alumina Nanoparticles ◽  
Visualization Method ◽  
Nanoparticle Concentration ◽  
Enhanced Heat Transfer ◽  
Heat Transfer Fluids ◽  
Sedimentation Behavior ◽  
Settling Characteristics

Nanofluids are considered as promising heat transfer fluids due to enhanced heat transfer ability as compared to the base fluid alone. Knowledge of settling characteristics of nanofluids has great importance towards stability of nanosuspensions. Sedimentation behavior of Alumina nanoparticles due to gravity has been investigated using different proportions of ethanol-water binary mixtures. Nanoparticles of 40 nm and 50 nm are used in this investigation at 23°C. Sediment height with respect to time is measured by visualization method in batch sedimentation. The effect of sonication on the sedimentation behavior is also studied using ultrasonic agitator. The effect of particle diameter, nanoparticle concentration and ethanol-water proportion on sedimentation behavior of nanofluids has been investigated and discussed.

Structuring zeolite bodies for enhanced heat-transfer properties

2015 ◽  
Vol 208 ◽  
pp. 196-202 ◽  
Author(s):  
Lars Borchardt ◽  
Nina-Luisa Michels ◽  
Torsten Nowak ◽  
Sharon Mitchell ◽  
Javier Pérez-Ramírez
Keyword(s):  
Heat Transfer ◽  
Enhanced Heat Transfer ◽  
Transfer Properties

Heat Transfer Properties of Engine Oils

2005 ◽  
Author(s):  
Scott Wrenick ◽  
Paul Sutor ◽  
Harold Pangilinan ◽  
Ernest E. Schwarz
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Diesel Engine ◽  
Specific Heat ◽  
Mineral Oil ◽  
Engine Oil ◽  
Group V ◽  
Engine Oils ◽  
Heat Transfer Fluids ◽  
Transfer Properties

The thermal properties of engine oil are important traits affecting the ability of the oil to transfer heat from the engine. The larger the thermal conductivity and specific heat, the more efficiently the oil will transfer heat. In this work, we measured the thermal conductivity and specific heat of a conventional mineral oil-based diesel engine lubricant and a Group V-based LHR diesel engine lubricant as a function of temperature. We also measured the specific heat of ethylene glycol. The measured values are compared with manufacturers’ data for typical heat transfer fluids. The Group V-based engine oil had a higher thermal conductivity and slightly lower specific heat than the mineral oil-based engine oil. Both engine oils had values comparable to high-temperature heat transfer fluids.

Analysis of nanofluids as a means of thermal conductivity enhancement in heavy machineries

2014 ◽  
Vol 66 (2) ◽  
pp. 238-243 ◽  
Author(s):  
Ayush Jain ◽  
Imbesat Hassan Rizvi ◽  
Subrata Kumar Ghosh ◽  
P.S. Mukherjee
Keyword(s):  
Heat Transfer ◽  
Thermal Conductivity ◽  
Ethylene Glycol ◽  
Base Fluid ◽  
High Concentration ◽  
Content Type ◽  
Conductivity Enhancement ◽  
Heavy Machinery ◽  
Heat Transfer Fluids ◽  
Experimental Findings

Purpose – Nanofluids exhibit enhanced heat transfer characteristics and are expected to be the future heat transfer fluids particularly the lubricants and transmission fluids used in heavy machinery. For studying the heat transfer behaviour of the nanofluids, precise values of their thermal conductivity are required. For predicting the correct value of thermal conductivity of a nanofluid, mathematical models are necessary. In this paper, the effective thermal conductivity of various nanofluids has been reported by using both experimental and mathematical modelling. The paper aims to discuss these issues. Design/methodology/approach – Hamilton and Crosser equation was used for predicting the thermal conductivities of nanofluids, and the obtained values were compared with the experimental findings. Nanofluid studied in this paper are Al2O3 in base fluid water, Al2O3 in base fluid ethylene glycol, CuO in base fluid water, CuO in base fluid ethylene glycol, TiO2 in base fluid ethylene glycol. In addition, studies have been made on nanofluids with CuO and Al2O3 in base fluid SAE 30 particularly for heavy machinery applications. Findings – The study shows that increase in thermal conductivity of the nanofluid with particle concentration is in good agreement with that predicted by Hamilton and Crosser at typical lower concentrations. Research limitations/implications – It has been observed that deviation between experimental and theoretical results increases as the volume concentration of nanoparticles increases. Therefore, the mathematical model cannot be used for predicting thermal conductivity at high concentration values. Originality/value – Studies on nanoparticles with a standard mineral oil as base fluid have not been considered extensively as per the previous literatures available.

Two-Phase Heat Transfer Enhancement on Sintered Copper Microparticle Porous Structure Module Surface

2009 ◽  
Author(s):  
Calvin H. Li ◽  
Ting Li ◽  
Brian Kanney
Keyword(s):  
Heat Transfer ◽  
Porous Structure ◽  
Bubble Dynamics ◽  
Transfer Enhancement ◽  
Enhanced Heat Transfer ◽  
Two Phase ◽  
Sintered Copper ◽  
Theoretical Predictions ◽  
Heat Transfer Capacity ◽  
Two Phase Heat Transfer

An experimental study of the pool boiling two-phase heat transfer on a sintered Cu microparticle porous structure module surface is conducted. Enhanced heat transfer capacity of this module surface has been reported, and the boiling characteristics have been investigated. The bubble dynamics and nucleate size distribution have been compared to the theoretical predictions, and the speculated mechanisms have been discussed.

Pool Boiling of Mixtures for Electronics Thermal Management

2010 ◽  
Author(s):  
Aravind Sathyanarayana ◽  
Yogendra Joshi ◽  
Yunhyeok Im
Keyword(s):  
Heat Transfer ◽  
Thermal Management ◽  
Pool Boiling ◽  
Nanowire Arrays ◽  
Test Surface ◽  
Electronic Components ◽  
Fluid Mixtures ◽  
Heat Transfer Fluids ◽  
Transfer Properties ◽  
Latent Heat Of Vaporization

Electrical and chemical compatibility requirements of electronic components pose significant constraints on the choice of liquid coolants. These constraints have led to the use of fluoroinerts and Novec liquids as coolants, which are plagued by significantly lower thermal conductivity, specific heat, and latent heat of vaporization compared to water, and also a number of these chemicals have significant environmental impact. These factors necessitate the development of new heat transfer fluids with improved heat transfer properties and applicability. Mixture formulations provide an avenue for enhancing the properties of existing heat transfer fluids. These can be tuned for specific applications. Mixture formulations of Novec fluid (HFE 7200) with alcohols and ethers (HFE 7200 and methanol; HFE 7200 and ethoxybutane) are considered in this study. A 1 cm × 1 cm Silicon (Si) sample having copper nanowire arrays is used as the test surface for pool boiling. Experiments are done under saturated conditions and also at different sub-cooled conditions to investigate the thermal performance of these new fluid mixtures. Pool boiling heat transfer performance and the critical heat flux are measured for fluid mixtures and compared with the corresponding base fluid. From the pool boiling experiments, it was observed that adding methanol to pure HFE 7200 enhances the CHF of the resulting mixture and adding ethoxybutane to pure HFE 7200 reduces the incipience temperature for boiling.

scholarly journals Characterization of Biofluid-Based Coolant-Mix Produced From Emulsified Groundnut Oils

2019 ◽  
Vol 11 (3) ◽  
pp. 285-292
Author(s):  
T. A. Yusuf ◽  
O. Orihu ◽  
T. D. Ipilakyaa
Keyword(s):  
Heat Transfer ◽  
Specific Gravity ◽  
Base Fluid ◽  
Water Extract ◽  
Total Dissolved Solids ◽  
Deionized Water ◽  
Cutting Fluids ◽  
Heat Transfer Fluids ◽  
Engine Cooling

Coolants are generally heat transfer fluids used as cutting fluids for machining or engine cooling. They are generally mixture of various constituents and their chemistry is responsible for their performance, acceptability and shelf lives. With much known about the merit of agro-based materials, this study proposes the use of bio-waters in coolant-mix as a substitute for ordinary water commonly used as base fluids. Water extract from fermented ground maize (WEFGM) employed as bio-water was emulsified in bio-oils (groundnut oils) to form a complete bio-fluid based for the coolant to which other additives are added to form the test solutions. Replicate samples were formulated with similar standards using deionized WEFGM and deionized water for comparison at 5 and 10%vol of additives. Following various analytical tests, the developed coolant samples have concentration 2.33-2.58mg/L, total dissolved solids 31.2-73.2 g/L, pH 1.85-2.50, specific gravity 1.29-1.31 and viscosity 8.12-11.44 cSt. At both additive concentrations, the biofluid-based samples have proven better in terms of all these properties than water which is generally considered as the most suitable and being currently used as base fluid in most heat transfer applications.

Introduction

2020 ◽  
pp. 1-19
Keyword(s):  
Heat Transfer ◽  
Minimum Quantity Lubrication ◽  
Current Status ◽  
Exploratory Research ◽  
Heat Transfer Mechanism ◽  
Enhanced Heat Transfer ◽  
Minimum Quantity ◽  
Heat Transfer Capacity ◽  
Minimal Quantity ◽  
Scientific Significance

This chapter introduces the application background and characteristics of five kinds of grinding processing methods, briefly describes the enhanced heat transfer mechanism and tribological properties of nanofluids, and points out that nanofluids minimum quantity lubrication (NMQL) solves the technical bottleneck, namely minimum quantity lubrication (MQL) heat transfer capacity is insufficient and opening a new path for application of MQL to grinding process. The current status of exploratory research on the mechanism of minimum quantity lubrication grinding using nanofluids as cooling lubricants is analyzed. The research characteristics of the new green NMQL grinding technology are described, and the chapter puts forward some key problems such as the heat transfer enhancement process of NMQL, the anti-friction and anti-wear tribological mechanism of nanoparticles, and the controlled transport strategies of minimal quantity of lubricating droplets. It will be of great scientific significance and pragmatic value to perfecting NMQL grinding technical system.

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