International Research Journal of Engineering and Technology (IRJET)
e-ISSN: 2395 -0056
Volume: 04 Issue: 04 | Apr -2017
p-ISSN: 2395-0072
www.irjet.net
Analysis of Heat Transfer Enhancement of Heat Exchanger using Nanofluid Bharat B. Bhosle1, Prof.D.N.Hatkar2 1 ME
student, Department of Mechanical Engineering, MGM’s COE, Nanded, Maharashtra, India.
2 Professor,
Department of Mechanical Engineering, MGM’s COE, Nanded, Maharashtra, India. ---------------------------------------------------------------------***---------------------------------------------------------------------
Abstract - Now days to achieve high heat transfer rate,
different techniques have been used. One of the advanced techniques among them is suspension of nanoparticle in the base fluids as water, ethylene glycol, oil. In the present work Al2O3 nanoparticle of diameter size 50 nm is suspended in water. The present work has been carried out on double pipe heat exchanger for water to water and nanofluid to water heat transfer investigation with counter flow arrangement under turbulent flow condition. The computational fluid dynamic code is used to simulated different concentrations of nanofluid (0.01% to 0.19%) in ANSYS FLUENT 14 software. The overall heat transfer coefficients for all concentrations are measured as a function of hot and cold streams mass flow rates. Considering friction factor, one appropriate concentration (0.1%) is taken into account experimentally. The thermal performance parameter overall heat transfer coefficient is compared for nanofluids with water. The study is done at different mass flow rates and inlet fluid temperatures. It is observed that for high Reynolds number low concentration of nanofluid is useful. The work concludes that there is promising enhancement in heat transfer rate using nanofluid. Key Words: Nanofluid, overall heat transfer coefficient, mass flow rate, LMTD, CFD.
In last few years so many research have been done for enhancing the heat transfer rate like inserting baffles, twisted tapes, brushes, etc. This leads to increase in weight of heat exchangers and also cost of manufacturing. The world wide researchers are making hard efforts to find out suitable alternatives for heat exchangers with different geometry and varying parameters which effects on performance of heat exchanger. Now days nanofluid has became blessings for researchers. Nanofluid increases the heat transfer rate when suspended in base fluids water, ethylene glycol. With the fast track development of nanotechnology, particles of nanometer size are used for enhancing heat transfer rate are called nanofluids. At present condition many scientists have focused on Alumina (Al2O3) due to ease of preparation, availability, and manufacturing. Table below compares the thermal properties of water and Alumina. From literature survey it is observed that higher concentration leads to increase in the |
1.1 Materials selection Many different particle materials are used for nanofluid preparation. Al2O3, CuO, SiO2, ZnO nanoparticles are frequently used in nanofluid research. Base fluids mostly used in the preparation of nanofluids are the common working fluids of heat transfer applications such as, water, ethylene glycol and engine oil. From available materials we have selected water as base fluid and Al2O3 as nanoparticles because of availability and safe to use. Table-1: Thermal Properties of water and Alumina. [10] Sr.no.
Property
Water
(Al2O3)
1
C, J/kg K
4179
765
2
ρ, kg/m3
997.1
3970
3
k, W/m K
0.65
40
4
α, m2/s
1.45*10-7
1.31*10-5
2. Computational fluid dynamic procedure
1. INTRODUCTION
© 2017, IRJET
viscosity of the nanofluid leading to increase in friction factor. This thesis is focused on study of heat transfer rate enhancement at low concentration.
Impact Factor value: 5.181
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2.1 Geometry and computational fluid domain The schematic diagram of computational fluid domain is as shown in fig.1.
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