Heat transfer performance and transport properties of ZnO–ethylene glycol and ZnO–ethylene glycol–water nanofluid coolants

Metal-based microchannel heat exchangers (MHEs) offer potential solutions to applications demanding high heat flux removal, such as cooling of high-performance microelectronic and energy-efficient lighting modules. Efficient fabrication of metal-based MHEs and quantitative flow and heat transfer measurements on them are critical for establishing the economic and technical feasibility of such devices. Adopting metal-based MHEs in many applications demands quantification of flow and heat transfer performance with application-relevant coolants, e.g. ethylene glycol (EG)/water mixtures rather than pure water. As a first step in this direction, we report here fabrication and assembly of all-Cu MHE prototypes, as well as results of flow and heat transfer testing using pure EG and pure water as the fluid medium. Results of heat transfer testing indicate sensitivity of overall heat transfer performance to entrance length effects, which in the case of pure EG, is significantly influenced by its physical properties under the testing condition.

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Hybrid nano-coolants in automotive heat transfer – an updated report

Maejo International Journal of Energy and Environmental Communication ◽

10.54279/mijeec.v2i3.245040 ◽

2021 ◽

Vol 2 (3) ◽

pp. 43-57

Author(s):

Madderla Sandhya ◽

D. Ramasamy ◽

K. Sudhakar ◽

K. Kadirgama ◽

W.S.W. Harun

Keyword(s):

Heat Transfer ◽

Ethylene Glycol ◽

Heat Transfer Performance ◽

Freezing Point ◽

Weather Conditions ◽

Hybrid Nanoparticles ◽

Transfer Performance ◽

The Past ◽

Different Types ◽

Efficient Heat Transfer

Nano coolants have been attracting various researchers for efficient heat transfer agents. The efficacy of nanofluids as nano coolants is reviewed in the present study. The addition of nanoparticles to existing coolant fluids can enhance their heat transfer performance. Conventionally water and ethylene glycol are used as engine radiator coolants. The addition of ethylene glycol is needed to increase the boiling point of the water and decrease the freezing point. The convention also seems to be a crucial factor for heat exchanger performance. This is a requirement for vehicles that are being used under harsh weather conditions. Different types of nanoparticles used as nano coolants SiO2, TiO2, Al2O3, Cu/CuO, G/GO, CNT, and Hybrid nanoparticles, were extensively illustrated. Finally, nanofluids applications in the past decade were included. As many researchers have shown, they can be used to enhance radiator performance as well. In this review paper, studies of heat transfer performance of various Nanofluids as nano coolants conducted by researchers are studied. Finally, a conclusion is presented.

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Comments on: “Toward improved heat transfer performance of annular heat exchangers with water/ethylene glycol based nanofluids containing graphene nanoplatelets, Journal of Thermal Analysis and Calorimetry 126.3 (2016): 1427–1436”

Journal of Thermal Analysis and Calorimetry ◽

10.1007/s10973-018-7240-9 ◽

2018 ◽

Vol 134 (2) ◽

pp. 853-855 ◽

Cited By ~ 1

Author(s):

Abdullah A. A. A. Alrashed ◽

Naghmeh Mahmoodian ◽

Asterios Pantokratoras

Keyword(s):

Heat Transfer ◽

Thermal Analysis ◽

Ethylene Glycol ◽

Heat Exchangers ◽

Heat Transfer Performance ◽

Graphene Nanoplatelets ◽

Transfer Performance ◽

And Calorimetry

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Numerical Investigation of the Single Phase Forced Convection Heat Transfer Characteristics of Nanofluid Flowing in Circular and Noncircular Tubes

Volume 8B: Heat Transfer and Thermal Engineering ◽

10.1115/imece2015-50007 ◽

2015 ◽

Author(s):

Nurullah Kayaci ◽

Mahdi Tabatabaei Malazi ◽

Ahmet Selim Dalkiliç ◽

Somchai Wongwises

Keyword(s):

Heat Transfer ◽

Thermal Conductivity ◽

Numerical Model ◽

Ethylene Glycol ◽

Forced Convection ◽

Single Phase ◽

Heat Transfer Performance ◽

Transfer Performance ◽

Heat Transfer Characteristics ◽

Time Required

Thermal conductivity is an important parameter that expresses the heat transfer performance of a heat transfer fluid. Due to their low thermal conductivity, conventional heat transfer fluids (e.g. water, oil, ethylene glycol mixtures) restrict the enhancement of performance and compactness in heat exchangers used in the electronic, automotive, and aerospace industries. Nanofluids are functional liquid suspensions including particles that are smaller than 100 nm. These smaller sized particles allowed forming uniform and stable suspensions. The most well-known nanoparticles are Al2O3, CuO, TiO2, each of which is used, together with the base fluids of water and ethylene glycol, in the experimental work of many researchers. Across the range of particle sizes and types of base fluids, the enhancement of thermal conductivity has been achieved under all experimental conditions with these nanoparticles. The nanofluids provide higher heat transfer enhancement than existing techniques. With some improved properties, they have extensive potential application for concentrating heat transfer performance in a variety of systems. Forced convection flows of nanofluids containing of water with TiO2 and AI2O3 nanoparticles in circular and noncircular tubes with constant wall temperature are investigated numerically in this paper. A single-phase numerical model having three-dimensional equations is solved with either constant heat flux or temperature dependent properties to determine the hydrodynamics and thermal behaviors of the nanofluid flow by means of a CFD program for the water flow in circular and noncircular tubes. An intensive literature review on the determination of the physical properties (k, μ, ρ, Cp) of nanofluids is given in the paper. The software package ANSYS Fluent was employed in the numerical study. Investigated tubes were plotted in the SolidWorks program and were imported to ANSYS Geometry. After the investigated tubes were imported to ANSYS Geometry, they were forwarded for meshing in the ANSYS Meshing program. The mesh influences the accuracy, convergence, and speed of the solution. Furthermore, the time required to create a mesh model often represents a significant portion of the time required to acquire results from the solutions; this means that the better and more automated the meshing tools, the better the solution. The numerical model is validated by means of a CFD program to compare the experimental smooth tube data as a case study and it is also solved in the CFD program for noncircular tubes as a simulation study. Velocity, temperature and pressure distributions are shown in the paper. Morever, the values of experimental and numerical are compared with each other in terms of convective heat transfer coefficients and pressure drops. Besides this, the effects of the presence of nanofluids and noncircular tubes on the heat transfer characteristics are investigated in detail.

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