Effect of nanoparticle shapes on heat transfer characteristics and thermodynamic performance of a shell and tube heat exchanger / Miqdad Khairulmaini
The use of nanofluids as working fluids have resulted in increased performance for various applications involving heat transfer in today’s industrial sector. Many studies on nanofluids have been conducted for shell and tube heat exchanger performance based on spherical shaped nanoparticles. The o...
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Format: | Thesis |
Published: |
2012
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Online Access: | http://studentsrepo.um.edu.my/8140/4/MEng_Research_Project_Report_2012.pdf http://studentsrepo.um.edu.my/8140/ |
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Summary: | The use of nanofluids as working fluids have resulted in increased performance
for various applications involving heat transfer in today’s industrial sector. Many
studies on nanofluids have been conducted for shell and tube heat exchanger
performance based on spherical shaped nanoparticles. The objective of this research
project is to study the effects of different nanoparticle shapes for nanofluids in terms of
heat transfer characteristics (i.e. heat transfer coefficient, and overall transfer
coefficient), and also determine the thermodynamic performance for a shell and tube
heat exchanger used in a waste heat recovery industry (i.e. heat transfer rate, and
entropy generation). The effect of four types of nanoparticle shapes were studied (i.e.
platelets, blades, cylinders, and bricks) for this research project. The results showed an
increase in both heat transfer characteristics and thermodynamic performance for all
nanoparticle shapes when compared to conventional basefluid. From the results
obtained, it was established that EG/H2O-AlOOH nanofluid containing cylinder shaped
nanoparticles was the best performing nanofluid with an increase of 3.9% for heat
transfer coefficient (h), 1.9% for overall heat transfer coefficient (Uo), and 1.3% for heat
transfer rate (q). Although increase in entropy generation minimization for EG/H2OAlOOH
nanofluid containing cylinder shaped nanoparticle was lowest (1.48%)
compared to the remaining EG/H2O-AlOOH nanofluids containing the remaining
nanoparticle shapes, the percentage difference was less 0.5%. Two comparison studies
were conducted with respect to EG/H2O-AlOOH nanofluid containing the best
performing nanoparticle shape. The first comparison study was between EG/H2OAlOOH
nanofluid containing cylinder shaped nanoparticles and EG/H2O-AlOOH
containing spherical shaped nanoparticles. While the second comparison study was
between EG/H2O-AlOOH nanofluid containing cylinder shaped nanoparticles with and without considering the size factor of the nanoparticle shape. Comparison between
EG/H2O-AlOOH nanofluid containing cylinder shaped nanoparticle and EG/H2OAlOOH
nanofluid containing conventional shaped nanoparticle showed an increase in
heat transfer characteristics (2.4% for heat transfer coefficient, h and 1.14% for overall
heat transfer coefficient, Uo) and thermodynamic performance (0.88% for heat transfer
rate, q) for the former nanofluid. While comparison between EG/H2O-AlOOH
nanofluid containing cylinder shaped nanoparticles with and without considering the
size factor, heat transfer characteristics and thermodynamic performance were slightly
lower (0.88% for heat transfer coefficient, h, 0.40% for overall heat transfer coefficient,
Uo, and 0.30% for heat transfer rate, q). The reason behind this was that if size factor
was not taken into consideration, the thermal resistance between nanoparticles and
basefluid was neglected, resulting in the increase in theoretical performance. Overall,
this study clearly showed the effect of different nanoparticle shapes in terms of heat
transfer characteristics and thermodynamic performance.
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