Proceeding Paper
Design of an Indoor Setup for Experimental Investigation of
Thermosiphoning Heat Transfer Using Water and Nanofluid for
Application in Compound Parabolic Solar Collectors †
Muhammad Taimoor Jahangir * , Muzaffar Ali * , Ozair Ghufran Bhatti, Muhammad Arbaz, Muhammad Irfan
and Muhammad Hassan Haider
Department of Mechanical Engineering, Faculty of Mechanical & Aeronautical Engineering, University of
Engineering and Technology Taxila, Punjab 47050, Pakistan
* Correspondence: taimoorjahanger@gmail.com (M.T.J.); muzaffar.ali@uettaxila.edu.pk (M.A.)
† Presented at the 2nd International Conference on Advances in Mechanical Engineering (ICAME-22), Islamabad,
Pakistan, 25 August 2022.
Abstract: The world is moving towards renewable energy sources because of fossil fuel depletion
and its adverse environmental impacts. To study the thermosiphoning process using water and
nanofluids at different angles of receiver tubes, an indoor experimental setup was designed. The
maximum flow rate achieved at a 35◦ angle was 6.30 mL/s and the maximum outlet temperature
achieved was 82.8 ◦ C at a 45◦ angle using water. The flow rate achieved using Al2 O3 nanofluid was
8.20 mL/s. The results show that the time to achieve the thermosiphoning was greatly reduced with
an enhanced flow rate of 30.1% using nanofluids as compared with water.
Citation: Jahangir, M.T.; Ali, M.;
Keywords: thermosiphoning; nanofluids; heat transfer; receiver tube; boundary conditions;
Boussinesq approximation
Bhatti, O.G.; Arbaz, M.; Irfan, M.;
Haider, M.H. Design of an Indoor
Setup for Experimental Investigation
of Thermosiphoning Heat Transfer
1. Introduction
Using Water and Nanofluid for
In recent decades, many advancements have been made in the field of solar energy
technology. Parabolic collectors are the type of solar collectors used to concentrate sun
rays on an absorber tube [1]. The acceptance angle of the compound parabolic collector
determines the maximum number of sun rays to be concentrated [2].The concentrated light
is used to heat the liquid flowing through it. The circulation of fluid in the tubes takes place
using an active system that requires a continuous power source. However, thermosiphoning
is a passive system used to circulate the fluid using natural convection [3]. The main aim
of this research is to design an indoor setup to investigate the use of thermosiphoning for
the purpose of pumpless water flow in a compound parabolic collector. The numerical
results use the Boussinesq approximation method for incompressible fluids [4]. Boussinesq
approximation suggests that the variation in all of the fluid properties other than density is
ignored. The work accomplished in this research is the design and fabrication of an indoor
setup for experimental thermosiphoning results. Using the experimental results, the flow
rate, volume accumulated, and temperatures were calculated. The use of thermosiphoning
in solar water heaters using the flat plate solar collectors has already been implemented
and is a mature technology [5]. However, thermosiphoning has not yet been accomplished
in compound parabolic solar collectors. There is a considerable research gap in achieving
thermosiphoning in the case of compound parabolic collectors. This research paper is
a contribution to achieving passive fluid flow in a compound parabolic solar collector
through the principle of thermosiphoning. This study also focuses on using Al2 O3 -based
nanofluids with enhanced thermal properties as working fluids. This research has not been
carried out previously and very little literature reviews are available on it.
Application in Compound Parabolic
Solar Collectors. Eng. Proc. 2022, 23,
12. https://doi.org/10.3390/
engproc2022023012
Academic Editors: Mahabat Khan, M.
Javed Hyder and Manzar Masud
Published: 20 September 2022
Publisher’s Note: MDPI stays neutral
with regard to jurisdictional claims in
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Copyright: © 2022 by the authors.
Licensee MDPI, Basel, Switzerland.
This article is an open access article
distributed under the terms and
conditions of the Creative Commons
Attribution (CC BY) license (https://
creativecommons.org/licenses/by/
4.0/).
Eng. Proc. 2022, 23, 12. https://doi.org/10.3390/engproc2022023012
https://www.mdpi.com/journal/engproc
Eng.Proc.
Proc.2022,
2022,23,
23,12
12
Eng.
of55
22 of
Eng. Proc. 2022, 23, 12
working fluids.
fluids. This
This research
research has
has not
not been
been carried
carried out
out previously
previously and
and very
very little
little literature
literature 2 of 5
working
reviews
are
available
on
it.
reviews are available on it.
2. Methodology
Methodology
2.
2. Methodology
2.1. Simulation
Simulation Analysis
Analysis
2.1.
2.1. Simulation Analysis
Complete setup
setup and
and analysis
analysis was
was carried out
out using
using ANSYS
ANSYS 2021
2021 R2.
R2. This
This is
is the
the free
free
Complete
Complete setup
and analysiscarried
was carried
out using ANSYS
2021 R2.
This is the
convection heat
heat transfer
transfer phenomena,
phenomena, where
where the
the motion
motion of
of fluids
fluids is
is caused
caused by the buoybuoyconvection
free convection
heat transfer phenomena,
where the
motion
of fluidsbyis the
caused by the
ancy
forces
arising
from
variation
in
the
density
of
fluid
with
the
temperature.
This
is
why
ancy forces
arising
from
variation
the density
of fluid
withofthe
temperature.
This is why
buoyancy
forces
arising
frominvariation
in the
density
fluid
with the temperature.
This
we
used
the
Boussinesq
method,
which
is
a
density-based
solver
used
to
achieve
thermowe used
the Boussinesq
which
is a density-based
solver used tosolver
achieve
thermois why
we used themethod,
Boussinesq
method,
which is a density-based
used
to achieve
siphoning. The
The geometry,
geometry, meshing,
meshing, and
and boundary
boundary conditions are
are shown
shown in
in Figure 1.
1.
siphoning.
thermosiphoning.
The geometry,
meshing, andconditions
boundary conditions
areFigure
shown in Figure 1.
(a)
(a)
(b)
(b)
(c)
(c)
Figure 1.
1. (a)
(a) Ansys
Ansys model,
model, (b)
(b) meshing,
meshing, and
and (c) boundary
boundary conditions.
conditions.
Figure
Figure
1. (a) Ansys
model,
(b) meshing,(c)and
(c) boundary conditions.
2.2. Indoor
Indoor
Experimentation
2.2. Indoor
Experimentation
2.2.
Experimentation
The
experimentation
involved
achieving
thermosiphoning
usingusing
waterwater
in an
anin
indoor
The experimentation
involved
achieving
thermosiphoning
an indoor
The experimentation
involved
achieving
thermosiphoning
using
water
in
indoor
designed
setup.
The
heater
was
made
using
an
induction
coil
that
heats
the
pipe
placed
designed
setup.
The
heater
was
made
using
an
induction
coil
that
heats
the
pipe
placed
designed setup. The heater was made using an induction coil that heats the pipe placed
inside
of
it.
The
whole
setup
of
the
indoor
system
consists
of
a
heater,
copper
pipe,
water
of it.whole
The whole
the indoor
system
consists
of a heater,
copper
insideinside
of it. The
setupsetup
of theof
indoor
system
consists
of a heater,
copper
pipe, pipe,
waterwater
tank,tank,
and K-type
K-type
thermocouple.
The schematic
schematic
diagram
and indoor
indoor
setupsetup
diagram
are are
and K-type
thermocouple.
The schematic
diagram
and indoor
diagram
tank,
and
thermocouple.
The
diagram
and
setup
diagram
are
shown
in
Figure
2.
shown
in Figure
2.
shown
in Figure
2.
(a)
(a)
(b)
(b)
Figure
2. (a)
(a) Schematic
Schematic
diagram
of the
theof
indoor
setupsetup
and (b)
(b)
indoor
experimental
setup.setup.
Figure
2.
(a) Schematic
diagram
the indoor
and
(b) indoor
experimental
Figure
2.
diagram
of
indoor
setup
and
indoor
experimental
setup.
Readings
at different
angles
of inclination.
The copper
pipe
is inside
Readings
were were
takentaken
at different
different
angles
of inclination.
inclination.
The copper
copper
pipe is
is inside
inside
the the
Readings
were
taken
at
angles
of
The
pipe
the
heating
source
to
gain
maximum
heat
flux
through
the
heater.
The
heater
is
made
heating source
source to
to gain
gain maximum
maximum heat
heat flux
flux through
through the
the heater.
heater. The
The heater
heater is
is made
made in
in aa in a
heating
way
that
maximum
heat
flux
reaches
the
copper
tube.
The
K-type
thermocouple
is
used to
way that
that maximum
maximum heat
heat flux
flux reaches
reaches the
the copper
copper tube.
tube. The
The K-type
K-type thermocouple
thermocouple is
is used
used
way
measure
temperature
at
inlet
and
outlet
copper
pipe.
to measure
measure
thethe
temperature
at the
thethe
inlet
and
outlet
of of
thethe
copper
pipe.
to
the
temperature
at
inlet
and
outlet
of
the
copper
pipe.
3. Results
and Discussion
3. Results
Results
and Discussion
Discussion
3.
and
The theoretical
results
are from
the
simulation
of the
pipe
ANSYS
setup
2021 R2.
The theoretical
results
are from
the simulation
simulation
of the
the
pipe
onon
thethe
ANSYS
setup
2021
The
results
of
pipe
on
the
ANSYS
setup
The theoretical
energy model
was are
usedfrom
withthe
a viscous laminar
type
of fluid.
The
gravity
and 2021
buoyancy
R2. The
The energy
energy model
model was
was used
used with
with aa viscous
viscous laminar
laminar type
type of
of fluid.
fluid. The
The gravity
gravity and
R2.
effect was also
added into
the simulation.
The Boussinesq
approximation
method and
was used
for defining the values of density, specific heat capacity (Cp ), thermal conductivity, and
viscosity of the fluid with the change in the temperature of the fluid. The simulation results
for temperature and velocity are shown in Figure 3.
Eng. Proc. 2022, 23, 12
3 of 5
buoyancy effect was also added into the simulation. The Boussinesq approximation
method was used for defining the values of density, specific heat capacity (Cp), thermal
conductivity, and viscosity of the fluid with the change in the temperature of the fluid.
The simulation results for temperature and velocity are shown in Figure 3.
Eng. Proc. 2022, 23, 12
(a)
3 of 5
(b)
Figure 3. (a) Temperature distribution diagram and (b) velocity distribution diagram.
Figure 3. (a) Temperature distribution diagram and (b) velocity distribution diagram.
The temperature and velocity distribution diagrams show that the outlet temperature
The temperature and velocity distribution diagrams show that the outlet temperature
obtained was 379 K, whereas the inlet temperature was 300 K. At the start of the thermoobtained
wasthe
379whirling
K, whereas
the inlet
At the start
thermosisiphoning,
phenomena
of temperature
fluid occurred,was
then300
theK.
continuous
flowofofthe
fluid
phoning,
the whirling
phenomena
fluid occurred,
thenabout
the continuous
fluid was
was obtained.
The maximum
outletofvelocity
obtained was
0.011 m/s. Asflow
theseofnuobtained.
maximum
velocity obtained
m/s.the
Asincrease
these numerical
merical The
results
are close outlet
to the experimental
results,was
this about
shows 0.011
that, with
in
the flux
thethe
outlet
temperature results,
and velocity
also with
increase.
the experiresults
are value,
close to
experimental
this contours
shows that,
theIn
increase
in the flux
mental
cases of receiver
tubes atcontours
differentalso
angles
with water
as working
fluid setup,
value,
the setup,
outletthree
temperature
and velocity
increase.
In the
experimental
arecases
studied.
The parameters
observed
during
the experimentation
were flowfluid
rate, are
inletstudied.
three
of receiver
tubes at
different
angles
with water as working
temperature,
and
outlet
temperature.
All
of
the
parameters
are
shown
in
Table
1
below.
The parameters observed during the experimentation were flow rate, inlet temperature,
andTable
outlet
temperature. All of the parameters are shown in Table 1 below.
1. Indoor setup specifications and the experimental results.
Receiverresults.
Tube Angles
Table 1. Indoor setup specifications and the experimental
35°
40°
45°
Receiver Tube21
Angles
Receiver tube length (in)
21
21
Tube diameter (in)
0.63
0.63
0.63
◦
◦
35
40
45◦
Flow rate achieved (mL/s)
6.30
5.92
4.97
Receiver tube length (in)
21
21
21
Inlet temperature (°C)
28.5
27
28
Tube diameter (in)
0.63
0.63
0.63
Outlet temperature (°C)
76.1
74.9
80.8
Flow rate achieved (mL/s)
6.30
5.92
4.97
◦
Inlet temperature ( C)
28.5
27
28
The results
that the(◦thermosiphoning
starts76.1
at different temperatures
for all
Outletshow
temperature
C)
74.9
80.8
inclination angles. At a 35° angle of the receiver tube, the thermosiphoning starts at a temperature of 54.5 °C, while thermosiphoning start at a slightly higher temperature of 57 °C
atThe
an angle
of 40°.
Thethat
longest
and temperaturestarts
to achieve
thermosiphoning
took for all
results
show
the time
thermosiphoning
at different
temperatures
◦
place
at
45°,
which
was
60
°C.
This
is
because
a
larger
temperature
difference
is
required
inclination angles. At a 35 angle of the receiver tube, the thermosiphoning starts at a
to cause theofbuoyancy
four cases use a tube
of 0.63higher
in and length
of
temperature
54.5 ◦ C,effect.
whileThe
thermosiphoning
startdiameter
at a slightly
temperature
of
◦21 in. The results of the
◦ thermosiphoning are shown in Figure 4.
57 C at an angle of 40 . The longest time and temperature to achieve thermosiphoning took
place at 45◦ , which was 60 ◦ C. This is because a larger temperature difference is required to
4 of 5of 21 in.
cause the buoyancy effect. The four cases use a tube diameter of 0.63 in and length
The results of the thermosiphoning are shown in Figure 4.
Eng. Proc. 2022, 23, 12
(a)
(b)
(c)
Figure 4. (a) Time vs. accumulated volume, (b) time vs. outlet temperature, and (c) volume accu-
Figure
4. (a) Time vs. accumulated volume, (b) time vs. outlet temperature, and (c) volume accumulated.
mulated.
The water-based Al2O3 nanofluid with a 0.05% concentration of nanoparticles shows
an increased flow rate of 8.2 mL/s at a 35° angle of the receiver tube. The graphs in Figure
5 show that the thermosiphoning took less time and a lower temperature to achieve thermosiphoning as compared with water. The comparison of the numerical and simulation
Eng. Proc. 2022, 23, 12
(a)
(b)
(c)
4 of 5
Figure 4. (a) Time vs. accumulated volume, (b) time vs. outlet temperature, and (c) volume accumulated.
Thewater-based
water-basedAl
Al2O
nanofluidwith
witha a0.05%
0.05%concentration
concentrationofofnanoparticles
nanoparticlesshows
shows
2O
The
33
nanofluid
◦ angle of the receiver tube. The graphs in
an
increased
flow
rate
of
8.2
mL/s
at
a
35
an increased flow rate of 8.2 mL/s at a 35° angle of the receiver tube. The graphs in Figure
5 show
the thermosiphoning
took
less
time
and atemperature
lower temperature
to achieve
5Figure
show that
the that
thermosiphoning
took less
time
and
a lower
to achieve
therthermosiphoning as compared with water. The comparison of the numerical and simulation
mosiphoning as compared with water. The comparison of the numerical and simulation
results is also shown in Figure 5 for the case of water as working fluid.
results is also shown in Figure 5 for the case of water as working fluid.
(a)
(b)
Figure
Figure5.5.(a)
(a)Volume
Volumeaccumulated
accumulatedwith
withtime
timeand
and(b)
(b)temperature
temperatureatatoutlet.
outlet.
The
Themaximum
maximumflow
flowrate
rateof
of6.30
6.30mL/s
mL/swith
withwater
waterwas
wasachieved
achievedatata areceiver
receivertube
tubeangle
angle
35◦The
. Thesimulation
simulation
results
show
a flow
rate
mL/s.
simulation
shows
ofof35°.
results
show
a flow
rate
of of
5.85.8
mL/s.
TheThe
simulation
shows
that that
an
an
outlet
temperature
of
379
K
was
achieved.
The
temperature
at
which
thermosiphoning
outlet temperature of 379 K was achieved. The temperature at which thermosiphoning
beginsvaried
variedbetween
between10
10min
minand
and12
12min
mindepending
dependingon
onthe
theangle
angleofofthe
thetube.
tube.The
Theresults
results
begins
obtainedusing
usingwater-based
water-based
show
thermosiphoning
obtained
AlAl
2O23O
nanofluid
show
thatthat
the the
thermosiphoning
timetime
was was
re3 nanofluid
◦ angle. The flow rate achieved was also enhanced by 30% with
reduced
to just
8 min
a 35angle.
duced
to just
8 min
at aat35°
The flow rate achieved was also enhanced by 30% with
nanofluids.This
Thisdifference
differenceinintime
timewas
wasachieved
achievedasasaaresult
resultofofthe
theenhanced
enhancedheat
heattransfer
transfer
nanofluids.
capacity
of
nanofluids.
The
results
show
that
water
and
nanofluids
can
be
employed
capacity of nanofluids. The results show that water and nanofluids can be employed inin
compoundparabolic
parabolic collectors
collectors for a pumpless
rate
requirements
are
compound
pumplesswater
waterflow
flowififthe
theflow
flow
rate
requirements
very
small.
are very small.
AuthorContributions:
Contributions: Conceptualization,
Conceptualization, M.T.J.
methodology,
M.T.J.
and
Author
M.T.J. and
andM.A.
M.A.(Muzaffar
(MuzaffarAli);
Ali);
methodology,
M.T.J.
M.I.;
software,
M.T.J.
and
O.G.B.;
validation,
M.T.J.
and
O.G.B.;
formal
analysis,
M.T.J.
and
M.H.H.;
and M.I.; software, M.T.J. and O.G.B.; validation, M.T.J. and O.G.B.; formal analysis, M.T.J. and
investigation,
M.T.J. and
M.I.;and
dataM.I.;
curation,
M.A. (Muzaffar
Ali); writing—original
draft preparation,
M.H.H.;
investigation,
M.T.J.
data curation,
M.A. (Muzaffar
Ali); writing—original
draft
M.T.J.;
writing—review
and
editing,
M.T.J.
and
M.H.H.;
supervision,
M.A.
(Muzaffar
project
preparation, M.T.J.; writing—review and editing, M.T.J. and M.H.H.; supervision, M.A.Ali);
(Muzaffar
administration,
M.A. (Muhammad
Arbaz). All authors
have
and agreed
to the
published
Ali);
project administration,
M.A. (Muhammad
Arbaz).
Allread
authors
have read
and
agreed version
to the
of the manuscript.
published
version of the manuscript.
Funding:This
Thisresearch
researchreceived
receivedno
noexternal
externalfunding.
funding.
Funding:
InstitutionalReview
ReviewBoard
BoardStatement:
Statement:Not
Notapplicable.
applicable.
Institutional
InformedConsent
ConsentStatement:
Statement:Not
Notapplicable.
applicable.
Informed
Data Availability Statement: Not applicable.
Conflicts of Interest: The authors declare no conflict of interest.
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