Heat transfer performance of water based nanofluids containing various types of metal oxide nanoparticles in an air-cooled microchannel heat exchanger

2017 ◽  
Author(s):  
Murat Parlak ◽  
Ozge Osturk ◽  
Umit N. Temel ◽  
Kerim Yapici
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Metal Oxide ◽  
Heat Transfer Performance ◽  
Metal Oxide Nanoparticles ◽  
Oxide Nanoparticles ◽  
Transfer Performance ◽  
Microchannel Heat Exchanger ◽  
Water Based

Investigation of the Effect of Cross Section on the Convective Heat Transfer Performance of Nanoemulsion in Microchannel Heat Exchanger

2021 ◽  
Author(s):  
Takele Gameda ◽  
M. Mehdi Kabir ◽  
Jiajun Xu
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Cross Section ◽  
Cross Sections ◽  
Heat Transfer Performance ◽  
Operating Conditions ◽  
Transfer Performance ◽  
Heat Transfer Characteristics ◽  
Microchannel Heat Exchanger ◽  
Transfer Characteristics

Abstract The present study aims to numerically investigate the effect of cross section on the heat transfer performance of single-phase flow of Ethanol/Polyalphaolefin nanoemulsion fluid with ethanol concentrations of 8 wt.% in a microchannel heat exchanger. While the exterior geometry of the microchannels’ solid structure remains the same, four different cross sections of channels including: circular, upward semi-circular, rectangular, and trapezoidal, are designed with keeping the channels’ wetted perimeters, mass flow rate, and Reynolds number constant for comparison purposes. In the present study, the hydrodynamic and heat transfer characteristics, including local Nusselt number, heat transfer coefficient, and velocity profile, were investigated under a uniform wall heat flux boundary conditions within the laminar flow regime. The channel models of different cross sections were developed by the COMSOL-Multiphysics for numerical analysis. The heat transfer characteristics were then compared for different cross sections under the same operating conditions, and the effect of aspect ratio for rectangular and trapezoidal cross sections were also studied.

Numerical simulation of the fluid flow and heat transfer characteristics of microchannel heat exchangers with different reentrant cavities

2019 ◽  
Vol 29 (11) ◽  
pp. 4334-4348
Author(s):  
Minqiang Pan ◽  
Hongqing Wang ◽  
Yujian Zhong ◽  
Tianyu Fang ◽  
Xineng Zhong
Keyword(s):  
Heat Transfer ◽  
Fluid Flow ◽  
Heat Exchanger ◽  
Pressure Drop ◽  
Heat Exchangers ◽  
Heat Transfer Performance ◽  
Transfer Performance ◽  
Content Type ◽  
Microchannel Heat Exchanger ◽  
Flow And Heat Transfer

Purpose With the increasing heat dissipation of electronic devices, the cooling demand of electronic products is increasing gradually. A water-cooled microchannel heat exchanger is an effective cooling technology for electronic equipment. The structure of a microchannel has great impact on the heat transfer performance of a microchannel heat exchanger. The purpose of this paper is to analyze and compare the fluid flow and heat transfer characteristic of a microchannel heat exchanger with different reentrant cavities. Design/methodology/approach The three-dimensional steady, laminar developing flow and conjugate heat transfer governing equations of a plate microchannel heat exchanger are solved using the finite volume method. Findings At the flow rate range studied in this paper, the microchannel heat exchangers with reentrant cavities present better heat transfer performance and smaller pressure drop. A microchannel heat exchanger with trapezoidal-shaped cavities has best heat transfer performance, and a microchannel heat exchanger with fan-shaped cavities has the smallest pressure drop. Research limitations/implications The fluid is incompressible and the inlet temperature is constant. Practical implications It is an effective way to enhance heat transfer and reduce pressure drop by adding cavities in microchannels and the data will be helpful as guidelines in the selection of reentrant cavities. Originality/value This paper provides the pressure drop and heat transfer performance analysis of microchannel heat exchangers with various reentrant cavities, which can provide reference for heat transfer augmentation of an existing microchannel heat exchanger in a thermal design.

Pressure Drop and Heat Transfer Performance of Microchannel Heat Exchanger With Circular Reentrant Cavities and Ribs

2020 ◽  
Vol 142 (4) ◽  
Author(s):  
Tingbo Hou ◽  
Yuanlong Chen
Keyword(s):  
Heat Transfer ◽  
Heat Exchanger ◽  
Pressure Drop ◽  
Heat Transfer Performance ◽  
Hot Water ◽  
Outlet Temperature ◽  
Transfer Performance ◽  
Microchannel Heat Exchanger ◽  
Outlet Pressure ◽  
Rib Arrangement

Abstract The rib arrangement has an important influence on the pressure drop and heat transfer performance of a microchannel heat exchanger (MHE) with circular reentrant cavities and ribs. In this study, four kinds of MHEs with circular reentrant cavity and ribs were designed, namely, circular reentrant cavities (circular), circular reentrant cavities and single-sided ribs (circular—single), circular reentrant cavities and odd-symmetric ribs (circular—odd), and circular reentrant cavities and double symmetric ribs (circular—double). The effect of the rib arrangement on the pressure drop and heat transfer performance of MHEs was numerically investigated by ansysfluent 15.0. The experimental platform was then designed and built for the subsequent experimental verification. The results showed that the pressure drop between the inlet and outlet of the MHE with circular reentrant cavities and ribs increased as the inlet flow increased. At the same inlet flowrate, the pressure drop between the inlet and outlet of the MHEs was largest for the circular reentrant cavities and double symmetric ribs, followed by the circular reentrant cavities and odd-symmetric ribs, circular reentrant cavities and single-sided ribs, and the circular reentrant cavities. The presence of the rib structure increased the inlet and outlet pressure drop of the MHE. The MHE with circular reentrant cavities and double symmetric ribs had the largest inlet and outlet pressure drop, followed by that with circular reentrant cavities and odd-symmetric ribs, that with circular reentrant cavities and single-sided ribs, and that with circular reentrant cavities, indicating that the latter exhibited the best pressure drop performance. At the same inlet flowrate, the MHE with circular reentrant cavities had the highest hot water outlet temperature and the MHE with circular reentrant cavities and double symmetric ribs had the lowest temperature, whereas the results were the opposite for the cold-water outlet temperature. This indicates that the heat transfer performance was best for the MHE with circular reentrant cavities and double symmetric ribs, followed by that with circular reentrant cavities and odd-symmetric ribs and that with circular reentrant cavities and single-sided ribs.

Heat Transfer Performance of Different Nanofluids Flows in a Helically Coiled Heat Exchanger

2013 ◽  
Vol 832 ◽  
pp. 160-165 ◽  
Author(s):  
Mohammad Alam Khairul ◽  
Rahman Saidur ◽  
Altab Hossain ◽  
Mohammad Abdul Alim ◽  
Islam Mohammed Mahbubul
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Heat Exchanger ◽  
Pressure Drop ◽  
Transfer Coefficient ◽  
Friction Factor ◽  
Heat Exchangers ◽  
Heat Transfer Performance ◽  
Volume Concentration ◽  
Transfer Performance

Helically coiled heat exchangers are globally used in various industrial applications for their high heat transfer performance and compact size. Nanofluids can provide excellent thermal performance of this type of heat exchangers. In the present study, the effect of different nanofluids on the heat transfer performance in a helically coiled heat exchanger is examined. Four different types of nanofluids CuO/water, Al2O3/water, SiO2/water, and ZnO/water with volume fractions 1 vol.% to 4 vol.% was used throughout this analysis and volume flow rate was remained constant at 3 LPM. Results show that the heat transfer coefficient is high for higher particle volume concentration of CuO/water, Al2O3/water and ZnO/water nanofluids, while the values of the friction factor and pressure drop significantly increase with the increase of nanoparticle volume concentration. On the contrary, low heat transfer coefficient was found in higher concentration of SiO2/water nanofluids. The highest enhancement of heat transfer coefficient and lowest friction factor occurred for CuO/water nanofluids among the four nanofluids. However, highest friction factor and lowest heat transfer coefficient were found for SiO2/water nanofluids. The results reveal that, CuO/water nanofluids indicate significant heat transfer performance for helically coiled heat exchanger systems though this nanofluids exhibits higher pressure drop.

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