scholarly journals Promising Nanoparticle-Based Heat Transfer Fluids—Environmental and Techno-Economic Analysis Compared to Conventional Fluids

2021 ◽  
Vol 22 (17) ◽  
pp. 9201
Author(s):  
Natalia Czaplicka ◽  
Anna Grzegórska ◽  
Jan Wajs ◽  
Joanna Sobczak ◽  
Andrzej Rogala
Keyword(s):  
Heat Transfer ◽  
Cost Efficiency ◽  
Operating Conditions ◽  
Heat Transfer Fluid ◽  
The Novel ◽  
Cooling Systems ◽  
Correct Operation ◽  
Heat Transfer Fluids ◽  
The Subject ◽  
Materials Used

Providing optimal operating conditions is one of the major challenges for effective heating or cooling systems. Moreover, proper adjustment of the heat transfer fluid is also important from the viewpoint of the correct operation, maintenance, and cost efficiency of these systems. Therefore, in this paper, a detailed review of recent work on the subject of conventional and novel heat transfer fluid applications is presented. Particular attention is paid to the novel nanoparticle-based materials used as heat transfer fluids. In-depth comparison of environmental, technical, and economic characteristics is discussed. Thermophysical properties including thermal conductivity, specific heat, density, viscosity, and Prandtl number are compared. Furthermore, the possible benefits and limitations of various transfer fluids in the fields of application are taken into account.

scholarly journals Nanofluids for the Next Generation Thermal Management of Electronics: A Review

Symmetry ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1362
Author(s):  
Ana Moita ◽  
António Moreira ◽  
José Pereira
Keyword(s):  
Thermal Management ◽  
Interfacial Flows ◽  
The Novel ◽  
Cooling Systems ◽  
Fluid Mixtures ◽  
Heat Transfer Fluids ◽  
Technological Field ◽  
Thermal Management Of Electronics ◽  
Higher Power ◽  
The Subject

Nowadays, the thermal management of electronic components, devices and systems is one of the most important challenges of this technological field. The ever-increasing miniaturization also entails the pressing need for the dissipation of higher power energy under the form of heat per unit of surface area by the cooling systems. The current work briefly describes the use on those cooling systems of the novel heat transfer fluids named nanofluids. Although not intensively applied in our daily use of electronic devices and appliances, the nanofluids have merited an in-depth research and investigative focus, with several recently published papers on the subject. The development of this cooling approach should give a sustained foothold to go on to further studies and developments on continuous miniaturization, together with more energy-efficient cooling systems and devices. Indeed, the superior thermophysical properties of the nanofluids, which are highlighted in this review, make those innovative fluids very promising for the aforementioned purpose. Moreover, the present work intends to contribute to the knowledge of the nanofluids and its most prominent results from the typical nanoparticles/base fluid mixtures used and combined in technical and functional solutions, based on fluid-surface interfacial flows.

A Brief Review on Thermal Behaviour of PANI as Additive in Heat Transfer Fluid

2021 ◽  
Vol 02 (01) ◽  
Author(s):  
A.G.N. Sofiah ◽  
◽  
M. Samykano ◽  
S. Shahabuddin ◽  
K. Kadirgama ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Thermal Properties ◽  
Conducting Polymers ◽  
Volume Fraction ◽  
Corrosion Property ◽  
Environmental Stability ◽  
Heat Transfer Fluid ◽  
Thermal Engineering ◽  
Engineering System ◽  
Heat Transfer Fluids

Since a decade ago, investigation on nanofluids has grown significantly owing to its enhanced thermal properties compared to conventional heat transfer fluids. This engineered nanofluid has been widely used in the thermal engineering system to improve their energy consumption by improving the thermal efficiency of the system. The addition of nano-size particles as additives dispersed in the base fluids proved to significantly either improve or diminish the behaviour of the base fluids. The behaviour of the base fluid highly depends on the properties of the additives material, such as morphology, size, and volume fraction. Among the variety of nanoparticles studied, the conducting polymers have been subject of high interest due to its high environmental stability, good electrical conductivity, antimicrobial, anti-corrosion property and significantly cheap compared to other nanoparticles. As such, the main objective of the present review is to provide an overview of the work performed on thermal properties performance of conducting polymers based nanofluids.

Numerical Investigation of Heat Transfer, Fluid Flow and Formation of Emissions in Diesel Engines

2013 ◽  
Author(s):  
Müjdat Firat
Keyword(s):  
Heat Transfer ◽  
Fluid Flow ◽  
Combustion Engine ◽  
Operating Conditions ◽  
Heat Transfer Fluid ◽  
Nox Emissions ◽  
Combustion Pressure ◽  
Crank Angle ◽  
The Relationship ◽  
Hole Number

The present study has been performed on heat transfer, fluid flow and formation of emissions in a diesel engine by different engine parameters. The analysis aims at an investigation of flow field, heat transfer, combustion pressure and formation of emission by means of numerical simulation which is using as parameter; hole number of injector and crank angle. Numerical simulations are performed using the AVL-FIRE commercial software depending on the crank angle. This software is successfully used in internal combustion engine applications, and its validity has been accepted. In this paper, k-zeta-f is preferred as turbulence model and SIMPLE/PISO used as algorithms. Thus, results are presented with pressure traces, temperature curves and NOx and soot levels for engine operating conditions. In addition, the relationship between the spray behaviors and combustion characteristics including NOx emissions, soot emissions, combustion pressure and temperature were illustrated through this analysis.

scholarly journals Contribution to the Parametric Study of the Performance of A Parabolic Trough Collector

2021 ◽  
Vol 321 ◽  
pp. 02016
Author(s):  
Belkacem Bouali ◽  
Hanane-Maria Regue
Keyword(s):  
Heat Transfer ◽  
Mass Flow ◽  
Flow Rate ◽  
Optimal Operation ◽  
Heat Transfer Fluid ◽  
Parabolic Trough ◽  
Parabolic Trough Collector ◽  
Heat Transfer Fluids ◽  
Ansys Cfx ◽  
Different Seasons

This paper presents an analysis of the performance of a parabolic trough collector (PTC) according to some key operating parameters. The effects of the secondary reflector, the length and thickness of the absorber tube (receiver tube) and the flow rate of the heat transfer fluid (HTF) are investigated. The main objective is to determine an optimal operation, which improves the performance of a traditional PTC. The target variables are the temperature at the outlet of the tube, the amount of energy collected by the HTF and the efficiency of the system. The solar flux data concern the city of LAGHOUAT located in the south of Algeria. Four days in different seasons are considered. The optical analysis of the system is performed by using the open source SolTrace code. The output of this analysis is used as a boundary condition for the CFD solver. The conjugate heat transfer and the fluid flow through the absorber tube are simulated by using ANSYS-CFX solver. Water is considered as heat transfer fluids. The obtained results show that the use of a curved secondary reflector significantly improves the performance of the traditional PTC. As the thickness of the tube increases, the heat storage in the material increases, which increases the temperature at the exit of the tube and therefore the efficiency of the system. However, the length of the tube depends on the mass flow of the HTF and vice versa. To keep the efficiency constant by choosing another length, it is necessary to choose a mass flow rate proportional to the flow rate corresponding to the initial length.

scholarly journals Active magnetocaloric heat pipes provide enhanced specific power of caloric refrigeration

2020 ◽  
Vol 3 (1) ◽  
Author(s):  
Lena Maria Maier ◽  
Patrick Corhan ◽  
Alexander Barcza ◽  
Hugo A. Vieyra ◽  
Christian Vogel ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Heat Pipes ◽  
Heat Transfer Fluid ◽  
Specific Power ◽  
Cooling Power ◽  
Cycle Frequency ◽  
Cooling Systems ◽  
Cooling Unit ◽  
Order Of Magnitude ◽  
Almost All

Abstract Today almost all refrigeration systems are based on compressors, which often require harmful refrigerants and typically reach 50% of the Carnot efficiency. Caloric cooling systems do not need any detrimental fluids and are expected to reach 60–70% of the Carnot limit. Current caloric systems utilise the active magnetocaloric regeneration principle and are quite cost-intensive, as it is challenging to achieve large cycle frequencies and thus high specific cooling powers with this principle. In this work, we present an alternative solution where the heat transfer from the heat exchangers to the caloric material is predicated on condensation and evaporation of a heat transfer fluid. Using thermal diodes, a directed heat flow is generated. Thereby we were able to build a cooling unit achieving a specific cooling power of 12.5 W g−1 at a cycle frequency of 20 Hz, which is one order of magnitude larger than the state-of-the-art.

Geothermal Power Cycle Analysis for Commercial Applicability Using Sequestered Supercritical CO2 as a Heat Transfer or Working Fluid

2011 ◽  
Author(s):  
Brian Janke ◽  
Thomas Kuehn
Keyword(s):  
Heat Transfer ◽  
Binary System ◽  
Power Plants ◽  
Power Production ◽  
Operating Conditions ◽  
Heat Transfer Fluid ◽  
Working Fluid ◽  
Direct System ◽  
Geothermal Power ◽  
The Impact

Thermodynamic analysis has been conducted for geothermal power cycles using a portion of deep ground sequestered CO2 as the working fluid. This allows energy production from much shallower depths and in geologic areas with much lower temperature gradients than those of current geothermal systems. Two different system designs were analyzed for power production with varying reservoir parameters, including reservoir depth, temperature, and CO2 mass flow rate. The first design is a direct single-loop system with the CO2 run directly through the turbine. This system was found to provide higher system efficiency and power production, however design complications such as the need for high pressure turbines, two-phase flow through the turbine and the potential for water-CO2 brine mixtures, could require the use of numerous custom components, driving up the cost. The second design is a binary system using CO2 as the heat transfer fluid to supply thermal energy to an Organic Rankine Cycle (ORC). While this system was found to have slightly less power production and efficiency than the direct system, it significantly reduces the impact of design complications associated with the direct system. This in turn reduces the necessity for certain custom components, thereby reducing system cost. While performance of these two systems is largely dependent on location and operating conditions, the binary system is likely applicable to a larger number of sites and will be more cost effective when used in combination with current off-the-shelf ORC power plants.

Didactic platform for teaching of three-phase rectifier circuits in power electronics

2014 ◽  
Vol 51 (4) ◽  
pp. 279-291 ◽  
Author(s):  
Marcelo R. S. Brito ◽  
Fernando C. Melo ◽  
Luiz C. Freitas ◽  
João B. Vieira ◽  
Ernane A. A. Coelho ◽  
...  
Keyword(s):  
Power Electronics ◽  
Learning Process ◽  
Electrical Engineering ◽  
Operating Conditions ◽  
Laboratory Activities ◽  
Mixed Use ◽  
Three Phase ◽  
The Subject ◽  
Materials Used ◽  
Rectifier Circuits

With the aim of preventing an Electrical Engineering course from being predominantly theoretical, the didactic materials used in laboratory activities are essential to make the learning process easier and more stimulating for the student. In this context, this paper presents a didactic platform developed for teaching a.c.-d.c. converters in the subject of power electronics at the Federal University of Uberlândia (UFU), Brazil. The proposed platform consists of a three-phase controlled and/or uncontrolled rectifier. The IC TCA785 is used to control thyristor operation. In order to make teaching more dynamical, the didactic platform was designed to have various operating conditions, simulating, for example, breakdown components and mixed use of thyristors and diodes. A prototype of the proposed platform was built, evaluated experimentally in the laboratory and the results are shown in this paper.

scholarly journals Effects of fluoride salt addition to the physico-chemical properties of the MgCl2-NaCl-KCl heat transfer fluid : a molecular dynamics study

2021 ◽  
Author(s):  
Weiguang Zhou ◽  
Yanping Zhang ◽  
Mathieu Salanne
Keyword(s):  
Heat Transfer ◽  
Molecular Dynamics ◽  
Experimental Studies ◽  
Chemical Properties ◽  
Heat Transfer Fluid ◽  
Electricity Production ◽  
Fluoride Ions ◽  
Heat Transfer Fluids ◽  
Physico Chemical ◽  
Dynamics Simulations

Concentrated solar plants are promising solutions for electricity production. In these plants, the heat transfer fluid plays an important role, and finding systems with good thermal properties is very important. In this regard, molten salts, and more particularly molten chlorides, are currently investigated. Experimental studies of these melts are difficult and expensive, so complementing them with simulations would allow to test a wider range of compositions. In this work, we show that classical molecular dynamics simulations are suitable for predicting the properties of a ternary salt composed of MgCl2, KCl and NaCl by extensive comparisons with experimental data (and previous simulations) on the density, heat capacity, viscosity and thermal conductivity. We then study the effect of adding fluoride ions in the melt on these properties in order to investigate the suitability of mixed chlorides-fluorides for future heat transfer fluids studies.

Stability of Nanofluids

2013 ◽  
Vol 757 ◽  
pp. 139-149 ◽  
Author(s):  
Hema Setia ◽  
Ritu Gupta ◽  
R.K. Wanchoo
Keyword(s):  
Heat Transfer ◽  
Base Fluid ◽  
Thermal Characteristics ◽  
Solid Particles ◽  
Heat Transfer Fluid ◽  
Published Data ◽  
Heat Transfer Fluids ◽  
Fluid Systems ◽  
Agglomeration Of Nanoparticles ◽  
The Stability

It has long been established that a suspension of nanosized solid particles in liquids provide useful advantages in industrial heat transfer fluid systems. Numerous investigations on nanofluids show a significant enhancement in thermal conductivity over the base fluid in which these nanoparticles are dispersed. However, the stability of the suspension is critical in the development and application of these new kind of heat transfer fluids. Rather, high discrepancy in the published data for the same nanoparticles on the physical and thermal characteristics of nanofluids is primarily due to different methods adopted by different researchers to obtain stable nanofluids. Sedimentation and agglomeration of nanoparticles in nanofluids and their dispersion stability has not been well addressed in the literature. Hence, there is a need to establish a standard method of preparation of these nanofluids so as to obtain a unified data which can eventually be utilized for the application of nanofluids. This chapter focuses on the stability of nanofluids prepared via two step process. Different parameters that affect the stability of nanofluids have been discussed. Different techniques that have been used for the evaluation of the stability characteristics of nanofluids have been elucidated.

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