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International Journal of Mechanical & Mechatronics Engineering IJMME-IJENS Vol:19 No:05 1
193205-8484-IJMME-IJENS © October 2019 IJENS I J E N S
Thermal Performance of Corrugated Solar Air Heater
Integrated with Nanoparticles to Enhanced the
Phase Change Material (PCM)
Ali Mohammed Hayder1,2, Azwan Bin Sapit1, Qahtan Adnan Abed2, Mohammed Saad Abbas1,2 , Bassam Abed
Saheb2 , Nawfel Muhammed Baqer Mohsin3 1Faculty of Mechanical and Manufacturing Engineering, University Tun Hussein Onn Malaysia, Batu Pahat, Johor, Malaysia.,
([email protected] ) 2Al-Furat Al-Awsat Technical University, Al Najaf, Iraq([email protected])
3Al-Furat Al-Awsat Technical University, Al Najaf, Iraq([email protected])
Abstract-- The purpose of this study is to design, fabricate and evaluate the performance of SAH with integrated
nanoparticles enhanced phase change material (PCM)
absorber storage system ,the central problem of the solar
energy is that it is an intermittent source, due to it dependence
on the period of solar radiation. Consequently, thermal energy
storage is considered a perfect option to solve this issue Three
different of the SAH configurations have been designed and
studied; without thermal storage, with thermal storage using
paraffin wax as a PCM and with thermal storage using Al2O3-
paraffin wax. All configurations are fabricated and tested
under the climatic conditions of middle Iraq according to
ASHRAE standard tests at different air mass flow rates. The
two steps method is used to prepare the mixture of
nanoparticles with PCM and ultrasonic device is used to
suspend the nanoparticles in the PCM. The experimental
results show that improvement in the efficiency of the SAH
integrated with storage compared to SAH without storage.
Moreover, the discharging time of heat stored took 5.5, 5, 4.5
and 4 hours at the air mass flow rate 0.03, 0.04, 0.05 and 0.06
kg/s, respectively. The experimental results also show that
increment in the thermal conductivity of PCM with the
dispersion 1wt. % Al2O3 which led to raise the outlet air
temperature and thermal efficiency of the SAH compared to
SAH with pure PCM. Index Term-- Corrugated solar air heater, Nanoparticles,
thermal efficiency, air mass flow rate, phase change material
(PCM).
1. INTRODUCTION In some case, solar energy has occupied graded prime
position in the renewable energy research field, caused
from an inexhaustible energy source [1, 2]. A
thermal energy storage unit works to enhance
the conservation of energy and hence, improve
the performance of the solar heating system [3]. The most
important components in the solar heat systems are thermal
solar collector and thermal energy storage system [4]. The
improvement of mechanism technical methods of the
thermal energy storage systems is essential to taking
advantage of solar radiation falling on the ground for
generating thermal energy effectively [5]. It is
necessary to determine a thermal energy storage method and
a material used for thermal energy storage systems. Using
thermal storage materials in solar energy systems not only
reduces the mismatch between request and supply of energy,
but also improves the performance and reliability of solar
energy systems as well [6]. Therefore, using the thermal
storage materials in solar energy systems is appropriate in cities where there is a significant difference in temperature
between day and night such as desert cities [7]. The
development of heat energy storage systems, the thermal
performance of storage materials is enhanced by mixing it
with nanoparticle to increase the thermal conductivity for
storage materials [8, 9]. The thermo-physical properties of
the storage materials are affected after being mixed with
nanoparticles and leads to enhancement of the heat transfer
characteristics of the storage materials [10]. The use of high
thermal conductivity nanoparticles in increasing thermal
conductivity of thermal storage materials is a simpler thermal conductivity enhancement method than thermal
storage materials integration into porous material [11].
Therefore, the thermal conductivity and heat transfer
characteristics of the thermal storage materials are important
factors to develop thermal performance of the solar energy
systems.
The solar energy systems integrated with a thermal energy
storage unit has been a subject of interest for scientists and
researchers in the past decades. Numerical and experimental
studies have been reported in order to increase the output
temperature of the solar energy heater, increase the thermal
conductivity of the material used for thermal
energy storage, and reduce the thermal losses of the heating
solar systems. The thermal storage in solar energy system
gives rise to a high thermal efficiency of the system, which
may be exploited in many applications such as space heating
of buildings, drying agricultural crops and heating of water
in homes. One of the most significant things to emerge from
this study is the investigation of the effect of using latent
thermal energy storage materials. Many types of research have shown that when solar energy is stored in the form of
latent heat by using PCMs, it gives a good performance.
This is due to the fact that the PCMs provide suitable
temperature rates during the melting and freezing processes
[12]. Consequently, using PCMs is a more effective way to
mailto:[email protected]:[email protected]:[email protected]
International Journal of Mechanical & Mechatronics Engineering IJMME-IJENS Vol:19 No:05 2
193205-8484-IJMME-IJENS © October 2019 IJENS I J E N S
meet the request of energy and balance between request and
supply of energy and is the most common storage types in
heating solar systems [13]. An experimental study have
been carried out by Khadraoui et al. [14] to improve the performance of SAH by using a paraffin wax as a PCM. The
PCM is filled in rectangular container as a thermal storage
unit. The experimental tests were conducted on two solar air
collector (with and without PCM). They found that the PCM
increases the outlet air temperature from 3 °C to 7 °C
compared with a SAH without PCM during the night. Also,
the daily efficiency of collector reached 33 % and 17 % with
and without PCM, respectively.
Felinski and Sekret [15] presented the optimized design of
evacuated tube collector with paraffin wax as a PCM. The
experimental tests conducted to study the impact of paraffin wax on the thermal performance of the evacuated tube
collector. They found that the total quantity of useful heat
for evacuated tube collector integrated with PCM increases
by 45 % - 79 % compared with a solar air collector without
PCM. Also, the heat losses for evacuated tube collector
integrated with PCM decreased by 31 % - 32 % compared to
without PCM.
Shalaby et al. [16] evaluated the performance of the
corrugated absorber solar collector with and without paraffin wax. The collector is tested with and without the
paraffin wax by using different water masses. The hourly
production of the system with and without the PCM
depending on the temperature difference between water and
glass cover. They observed that the daylight productivity
decreases by 7.4 % whereas, overnight productivity
increases by 72.7 % when the PCM is used. Kabeel et al.
[17] performed an experimental investigation of the finned
absorber plate solar air collector with paraffin wax as a PCM. The suggested finned solar air collector was
fabricated and tested under the climate condition of Tanta
city Egypt. The authors found that the daily efficiency of
finned solar air collector with PCM was increased by 10.8
% - 13.6 % compared to a finned solar air collector without
PCM. Also, the finned solar air collector with PCM
continues to four hours after sunset to be the outlet air
temperature 8.6 °C higher than ambient temperature. Rabha
and Muthukumar [18] provided a detailed analysis of energy
and exergy of novel double pass solar air collector dryer
integrated with the paraffin wax as a PCM. The dryer was
operated for ten hours every day from 8 AM. to 6 PM. to dry 20 kg of red chili. They found that the values of energy
and exergy efficiency for thermal storage unit are between
43.6 % - 49.8 % and 18.3 % - 20.5 %, respectively while,
the average exergy efficiency of the drying chamber is 52.2
% and the overall efficiency of the drying system is 10.8 %.
An experimental study was conducted by Arfaoui et al. [19]
to evaluate the performance of solar air collector integrated
with AC27 as a PCM under climate condition of Tunisia.
They found that the outlet air temperature is almost constant
which is 27 °C at nights during the discharge period and the
daily energy efficiency amounted to about 47 %.
Wang et al. [20] developed a novel experimental
investigation for the flat micro heat pipe arrays collectors
integrated with a lauric acid as a PCM. The results showed
that the high air flow rate achieves high thermal collector
efficiency and low charging and discharging period which
lead to improved heat transfer, whilst the air flow rate of 60 m3/h achieves a constant outlet temperature during the
discharge period. Hamed et al. [21] presented a Numerical
analysis of a solar water collector with and without PCM.
They found that the maximum outlet water temperatures
obtained from the collector with and without PCM are 62.52
°C and 64.10 °C, respectively. In addition, the final melting
period for PCM is shorter than the freezing period because
of the rise heat transfer coefficient during melting period.
Miqdam et al. [22] conducted an experimental study of the
novel solar air collector consists of vertical and horizontal
parts. The vertical part consists of five pipes filled with
paraffin wax as a PCM while, the horizontal part is filled with the black colored iron chip. Two tests were conducted
at the natural and forced convection of the air movement.
The authors found that the efficiencies in natural and forced
convection were close. However, the use of PCM extends
the work time of the collector for 14 hours during the day.
Although PCMs have been widely used on the thermal
energy storage in many applications. On the other hand, the
low thermal conductivity of the PCMs leads to low heat
transfer rate [23] as well as increases the melting and
solidification time [24]. The heat transfer rate is an
important factor in evaluating the performance of thermal
energy storage system, and the enhancement of thermal
conductivity is considered as an effective method to
improve thermal energy storage system [25]. The high
thermal conductivity is an important property of materials
used for thermal energy storage. Therefore, various types of
metals such as nanoparticles are added to enhance the
thermal conductivity of thermal energy storage materials
[26]. The addition of nanoparticles to latent thermal energy
storage materials leads to improving the thermal
conductivity and achieves a good thermal performance of
energy storage systems. However, nanoparticles can't be
added excessively to thermal energy storage materials
because this increases their dynamic viscosity [27]. The
enhancement of materials properties used for latent thermal
energy storage by nanotechnology gives us a great
opportunity to be used in various industrial and engineering
applications such as; communication engineering systems,
fields of electronic industries, boilers for power plants and
building heating systems etc. [28]. The heat transfer
properties of the thermal energy storage materials after the
addition of nanoparticles could be affected by several
parameters; type of thermal energy storage material,
nanoparticles concentration, nanoparticles shape,
nanoparticles size, and method of preparation. The
nanoparticles concentration is considered the major
International Journal of Mechanical & Mechatronics Engineering IJMME-IJENS Vol:19 No:05 3
193205-8484-IJMME-IJENS © October 2019 IJENS I J E N S
parameter that has the most influence and it has a direct
relationship in enhancement of the thermal conductivity
[29]. There is a large volume of recent studies focusing on
how to enhance the thermal conductivity of the latent
thermal energy storage material. Therefore, Table 1 presents
the summary of the previous studies for the latent thermal
energy storage materials with nanoparticles of the solar
system
TABLE I
Summary of the previous studies for the latent thermal energy storage materials with nanoparticles of the solar system
Author Year Type of nanoparticles
Size of nanoparticles
Type of PCM
wt. % Result
Shaikhc et al.
[30]
2008 SWCNTs,
MWCNTs,
CNFs
1 nm
10 nm 100 nm
Paraffin
wax
0.1-1 The various types of nanoparticle are
additives to paraffin wax leads to
improve the latent energy of wax.
The maximum improvement in
SWCNTs nanoparticle at the mass fraction 1 % which reached 13 %.
Mahmud et
al. [31]
2009 Al2O3 80 μm Paraffin
wax
5 The performance of collector
enhanced by adding the Al2O3 to paraffin wax. The flow rate affects
the discharging time so that at the
flow rate of 0.19 kg/s took a
discharge time 3.5 h, while at the
flow rate of 0.05 kg/s took a
discharge time of 8 h.
Alkilani et al.
[32]
2011 Al2O3 70 μm Paraffin
wax
5 By adding nanoparticles to wax gives
a better storage efficiency from the
pure wax. Accordingly, the storage
efficiency attained the maximum
value 71.9 % for pure wax and 77.18 % when the wax-nanoparticles at the
mass flow rate of 0.05 kg/s.
Guo and
Wang [33]
2012 Al2O3 50 nm Paraffin
wax
1, 5, 10 The thermal energy storage rate of
paraffin wax-nanoparticles is better
than conventional pure paraffin wax
due to an increase in the thermal
conductivity and melting rate.
Hence, it will lead to an
improvement in the efficiency of
heat transfer.
Teng and Chieh Yu
[34]
2012 Al2O3, TiO2,
SiO2, ZnO
20-30 nm Paraffin wax
1.2, 3 By adding TiO2 nanoparticles to PCM gives a better performance than
the other nanoparticles in the
improvement of the heat conduction.
In addition, TiO2 decreases the start
of melting temperature and increases
the start of freezing temperature of
PCM.
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Dhaidan et al.
(a) [35]
2013 CuO 9 nm Paraffin
wax
1, 3, 5 The addition of CuO nanoparticles to
paraffin wax leads to enhancing the
thermal conductivity of paraffin wax
and increasing the heat transfer rate
which leads to decreasing the charging time. Also, the increasing
concentration of nanoparticles results
in increasing viscosity,
agglomeration and precipitation of
the composite.
Dhaidan et al.
(b) [36]
2013 CuO 9 nm Paraffin
wax
1, 3, 5 The addition of the CuO
nanoparticles with paraffin wax
resulted in improvement of melting
characteristics as well as an increase
in both the thermal conductivity and
natural convection. Therefore, the
properties of compound decreased by increasing the concentration
nanoparticles due to increase
viscosity, agglomeration and
precipitation.
Pise et al.
[37]
2013 Al2O3 20 nm Paraffin
wax
1, 3, 5 The suspend of nanoparticles with
paraffin increases the heat transfer
rate, thermal energy charging rate
and heat release rate compared with
the pure paraffin.
Wang et al.
[38]
2014 TiO2 20 nm Paraffin
wax
0.3, 0.5,
0.7, 0.9,
1, 3, 5, 7
The difference in mass fraction of
TiO2 nanoparticles leads to
difference in latent thermal capacity
and phase change temperature. They
found that the mass fraction 1 wt. %
or less which results in latent thermal
capacity increases and decreases the
phase change temperature. The mass
fraction of 3wt. % or more results in the latent thermal capacity decreases
and increases the phase change
temperature.
Chaichan and
Kazem [39] 2015 Al2O3 45 μm Paraffin
wax 1 The results proved that the addition
of Al2O3 nanoparticles to paraffin
wax increases productivity and time
of distillation as well as improving
thermal conductivity.
Baydaa J.
Nabhan [40]
2015 TiO2 10 nm Paraffin
wax
1, 3, 5 The phase change temperature varies
depending on mass fraction for TiO2
nanoparticles, at the mass fraction
5wt. % the thermal conductivity
increases by around 10 % with
increasing temperature 15 ⁰C.
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Chaichan et
al. [41]
2015 Al2O3,
TiO2
30-60 nm
20-50 nm
Paraffin
wax
1, 2, 3, 4,
5
The thermal conductivity of wax
increased by addition the
nanoparticles so that the increase was
found 65 % and 40 % at mass
fraction 5 % for Al2O3 and TiO2, respectively.
Nourani et al.
[42]
2016 Al2O3 10-20 nm Paraffin
wax
2.5, 5,
7.5, 10
The best improvement of thermal
conductivity was the mass fraction
10wt. % by 13 %, and increasing the
melting rate by 27 %.
Arya et al. [43]
2016 Al2O3 80 lm Paraffin wax
1.3, 4, 5 Based on the results, the low thermal conductivity for the paraffin wax
could be increased by adding various
types of nanoparticles with various
types of mass fractions.
Singh et al.
[44]
2017 Al2O3, CuO 40-50 nm Myo-
inositol
1.2, 3 It was found that the myo-inositol
with nanoparticles could be used for high temperature applications from
160 ⁰C to 260 ⁰C. They found also that the Al2O3 is more suitable for
this applications due to an increase in
melting temperature.
Mohamed et
al. [45]
2017 α-Al2O3 2-4 nm Paraffin
wax
0.5, 1, 2 The α-Al2O3 nanoparticles additive
to paraffin wax leads to enhancement
in the latent heat and thermal
conductivity by 2 % with the highest
effect at 50 ⁰C. Chaichan et
al. [46]
2017 Al2O3 30-60 nm Paraffin
wax
1.2, 3 Adding the Al2O3 nanoparticles with
paraffin wax leads to change in many properties of the wax paraffin such
as the color and thermal
conductivity. The thermal
conductivity of paraffin wax was
enhanced by 18 %, 21 %, and 30 %
at the mass fraction 1 %, 2 % and 3
%, respectively.
Tarish and
Alwan [47]
2017 CuO 70 μm Paraffin wax
10 The thermal storage rate of the CuO nanoparticles with paraffin wax is
increased by 30.7 % compared with
pure paraffin.
Saeed et al.
[48]
2017 Fe3O4 16.6-30.1 nm Paraffin
wax
1, 5, 10 Enhancement of the activation
energy and latent heat for the paraffin wax after addition of Fe3O4
nanoparticles compared with
pure paraffin. But the range of
melting temperature stay the same
and unaffected.
Qian et al.
[49]
2018 Na2SiO3 - Paraffin
wax
5 The thermal conductivity increasing
by 60 % when adding Na2SiO3
nanoparticles to paraffin wax as well
as enhancement of the thermal
storage efficiency and release.
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Purohit et al.
[50]
2018 CuO 5-17 nm Paraffin
wax
1, 2, 3, 4,
5
Increasing the concentration of CuO
nanoparticles increases both the
latent heat and melting temperature
even for mass fraction of 2 %. On the
other hand, the latent heat and melting temperature were decreased
at the mass fraction higher than 2 %.
Shalaby et al.
[51]
2018 α-Al2O3 71.5 nm Paraffin
wax
3 The using of α-Al2O3 nanoparticles
with a mass fraction 3% increasing
the thermal conductivity by 18.6 %,
and also increasing the thermal
effusively by 28.2 %.
NOMENCLATURE
TI Solar irradiance on the tilt surface (W/m2)
convh Convection heat transfer coefficient (W/m2 K)
radh Radiation heat transfer coefficient (W/m2 K)
condh Conduction heat transfer coefficient (W/m2 K)
outT Output temperature (°C)
inT Inlet temperature (°C)
ambT Ambient temperature (°C)
pT Absorber plate surface temperature (°C)
gT Glass cover surface temperature (°C)
skyT Sky temperature (°C)
mT Mean temperature (°C)
PCMT PCM Temperature (°C)`
k Thermal conductivity (W/m K)
LU Overall heat loss coefficient (kJ/kg K)
tU Top heat loss coefficient (kJ/kg K)
bU Bottom heat loss coefficient (kJ/kg K)
eU Edges heat loss coefficient (kJ/kg K)
S (W) The Absorbed Solar Irradiance by a Collector
PC Coefficient heat capacity (kJ/kg K)
uQ Useful energy of collector (W)
airm Air mass flow rate (kg/s) .g w Glass Wool
cA Cross section area of collector (m2)
l Absorber to glass cover distance (m)
HD Hydraulic diameter of the air flow channel (m)
chH Depth of air flow channel (m)
cW Width of air flow channel (m)
cL Length of the Collector (m)
eR Reynolds number (Dimensionless)
rP Prandtl number (Dimensionless)
aR Rayleigh number (Dimensionless)
uN Nusselt number (Dimensionless) Greek Symbols
Density (kg/m3) Stephan constant (W/m2 K) Transmittance (Dimensionless) Absorptance (Dimensionless) Emissivity (Dimensionless) Kinetic viscosity (m2 /s) Dynamic Viscosity (kg/m s)
th Thermal efficiency (%)
Volumetric coefficient of expansion (1/ K)
II. MATERIALS AND METHODS
Thermal Energy Storage Material (PCM)
Phase change material storage is preferable to sensible
material storage in low temperature applications because of
its isothermal storing mechanism and high storage density.
Paraffin wax is commonly used as a PCM in most thermal energy storage systems because to it melts at
fixed temperatures, unreactive, inexpensive and available.
The PCM used in the current experiences is Iraqi paraffin
wax. It was purchased from the Al-Dora Factory in
Baghdad-Iraq. The paraffin wax was placed inside the
containers of the novel designed collector, each container
was filled with 80 % due to the expansion of paraffin wax
size when melts. Each container has 0.515 kg paraffin wax
and the total paraffin wax of the collector is 8.76 kg as Table 2 indicates the thermo-physical properties of paraffin
wax used in the experiments. Paraffin wax absorbs the
excessive thermal energy during the charging period in
International Journal of Mechanical & Mechatronics Engineering IJMME-IJENS Vol:19 No:05 7
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daytime and releases the absorbed thermal energy later
during the discharging period in night-time. The thermal
energy storage could be dimensioned in a way that the
storage temperature is kept in a specified temperature level
while the excess external thermal energy is stored at the
same time. TABLE II
Thermo-physical properties of paraffin wax
Property Value
Latent Heat 176 KJ/kg
Thermal Conductivity 0.21 W/m K
Specific Heat Capacity 2.871 KJ/kg K
Melting Temperature 60 ºC
Freezing Temperature 55 ºC
Liquid Density 770 kg/ m3
Solid Density 850 kg/ m3
Dynamic viscosity 0.03499 KJ/m.s
Alumina (Al2O3) Nanoparticles
Although the paraffin wax have been widely used for the
thermal energy storage in applications of solar systems, but
the low thermal conductivity for the paraffin wax generates
high thermal resistance for a heat transfer between the
surface and wax. This high thermal resistance may not melt
the entire depth of the PCM. To overcome this problem and
give the best condition for the PCM, paraffin wax was
mixed with nanoparticles. Alumina Al2O3 nanoparticles are
thermodynamically stable particles over a wide temperature
range as well as it has a high thermal conductivity [52], so it
is used as thermal conductivity enhancer. In general, Al2O3
nanoparticles have several interesting properties, for
example high solidity, high stability, high insulation, and
transparency [53]. They have been widely used in many
applications such as catalysts, sensors, semiconductors,
capacitors, batteries, fire retard, surface protective coating,
composite materials, pharmaceutical industry and
biomedical field [54]. The thermo-physical properties of
Al2O3 nanoparticles are presented in Table III.
TABLE III
Thermo-physical properties of Al2O3 nanoparticles
Property Value
Color White
Morphology Spherical
Purity 99 % (trace metals basis)
Average Particle Size (APS)
40 nm
SSA 60 m2 /g
Thermal Conductivity 40 W/m K
Specific Heat Capacity 765 J/kg K
Density 3970 kg/m3
Thermal Diffusivity 1.31×10-5 m2/s
Preparation of Mixture (Nanoparticles with PCM)
The mass fraction ( ) of nanoparticles was calculated by the following equation:
(1)
The two steps method are used to prepare the mixture of
Al2O3 nanoparticles and paraffin wax with mass fraction by
1wt. %. Paraffin wax is melted at 60 ℃ and the dispersion of nanoparticles is done directly in flask with capacity of
1000 ml that could be closed by a PVC cap. The ultrasonic
water bath used Elmasonic P180H type with tank and its
capacity is of 18 liters. The flask was fixed to the stainless
steel basket inside the ultrasonic water path. The tank of the
ultrasonic device is filled with distilled water above the
level of mixture in the flask about 3 cm as shown in Figure
1. Then, the degas mode is switched on to remove the air
from the mixture. After that, the flask is closed by the cap
and oscillated continuously for 2 hours in the ultrasonic path
water with working frequency of 37 kHz and power
efficiency of 100 % at 70 ℃, until Al2O3 nanoparticles are uniformly suspended in paraffin wax as shown in figure 2.
Fig. 1. Suspension of nanoparticles in PCM
by ultrasonic water bath (Elmasonic P180H)
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Fig. 2. View of the (a) pure paraffin wax, (b) Al2O3 nanoparticle suspended
in paraffin wax with concentration 1wt. %
Thermo-physical properties of Mixture
The uniform distribution of nanoparticles in the paraffin
wax affects the thermo-physical properties of the mixture
such as thermal conductivity, density, specific heat capacity
and viscosity. In this section the thermo-physical properties
of mixture were determined to define the heat transfer
coefficient of the mixture.
a. Thermal Conductivity of Mixture
Suspension of nanoparticles in PCM with a low mass
fraction is to give stability to the mixture for a longer period
of time more than the mixture with a high mass fraction. The thermal conductivity of the mixture depends on the
thermal conductivities of constituents, the concentration of
nanoparticles and dispersed nanoparticles in PCM. In the
current study, Maxwell’s equation is adopted evaluating the
effective thermal conductivity of mixture, as given by this
equation [55].
2 2 ( )
2 ( )
np PCM np PCM
mix PCM
np PCM np PCM
k k k kk k
k k k k
(2)
b. Density of Mixture
The density of the mixture is affected by the concentration
ratio of nanoparticles and type of base fluid (PCM) while
the shape and size of nanoparticles do not affect the density
of the mixture. The density equation of the mixture can be written as following [56].
(1 ) mix PCM np (3)
c. Specific Heat Capacity of Mixture
The specific heat capacity of the mixture depends on the
concentration ratio of nanoparticles, the density of the
mixture and the heat capacity of mixture components. The
specific heat capacity equation is given by the following
[56].
(1 )( ) ( )
mix
p PCM p np
p
mix
C CC
(4)
d. Viscosity of Mixture
The viscosity is considered as an important property of
fluids thermal applications and it describes the internal
resistance of fluids to flow. The heat transfer coefficient
depends mainly by viscosity and it is also important in
thermal conductivity in thermal systems. The viscosity of
the mixture depends on the viscosity of base fluid (PCM)
and concentration ratio of nanoparticles. The shape and size
of nanoparticles affect the viscosity of the mixture. In this
study, Brinkman equation [57] to compute the viscosity of
the mixture was adopted. It is an equation used to calculate the viscosity of the mixture containing suspensions of small
spherical particles as following.
2.5(1 )
PCMmix
(5)
Field Emission Scanning Electron Microscopy (FESEM)
The Field Emission Ecanning Electron Microscope
(FESEM) was conducted for a sample of Al2O3 nanoparticles with paraffin wax. FESEM device is a
microscope that works by electrons instead of light, these
electrons are liberated by a field emission source. Figure 3
shows image of FESEM for the sample of Al2O3
nanoparticles suspension with paraffin wax. The figure
indicates that the mixture of Al2O3 nanoparticles with
paraffin wax has non porous structure. Also, the figure
shows that there is an acceptable dispersion of Al2O3
nanoparticles in paraffin wax.
Fig. 3. FESEM image of 1wt. % Al2O3 nanoparticles with paraffin
wax
a b
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Experimental Setup
The experimental tests were conducted in the current study
on three configurations of the single pass solar air heater.
The first configuration represents a solar air heater without
storage (SAHWOS), the second configuration represents a
solar air heater with paraffin wax as PCM (SAHWP) and the third configuration represents a solar air heater with
nanoparticles and PCM (SAHWNP) as shown in Figure 4.
The experimental prototypes of the solar air collector were
fabricated using locally available materials and tested under
actual outdoor operating weather conditions. The
experimental tests were conducted in the Technical College
Najaf, Al-Furat Al-Awsat Technical University located in
the center of Iraq 31°57 N and 44°15 E [58]. The dimensions and specifications of the Solar Air Heaters
(SAH) configurations are summarized in Table 4. The air
temperatures were measured in the experimental tests
by using K-type thermocouples which were distributed in
different places of the SAH. Furthermore, all the K-
type thermocouples were fitted in a data logger, and all the
data was registered automatically.
Fig. 4. Photographic view of the experimental setup of the SAH
TABLE IV
Dimensions and specifications of the solar air heaters
Parameters Measurement
Thickness of plywood used
for the fabrication
16 mm
Thickness of
transparent glass
4 mm
Thickness of glass-wool 20 m
Distance between glazing
and absorber plate
10 mm
Length of the air flow
channel
1.8 m
Width of the air flow channel
0.7 m
Height of the air flow 0.07 m
channel
Area of transparent glass 1.8 × 70 m2
Cross sectional area of
SAHWOS
3.6 × 0.7 m2
Cross sectional area of
SAHWS
2.75 × 0.7 m2
Distance after the axial fan 0.3 m
Distance before the axial fan 0.3 m
Capacity of axial fan 50 W
Collector tilt angle 42º
Air flow rates 0.03, 0.04, 0.05,
0.05 kg/s
Thickness of absorber plate 0.8 mm
Type of absorber plate Aluminum
4. Thermal Analysis of the SAH
In this round, the thermal analysis of the SAH were
presented. The experimental useful energy from the SAH
can be calculated by the following equation [59]:
( )u air P out inQ m C T T (6)
The thermal efficiency is considered the primary indicator
to evaluate the performance of a solar air collector. In
general, thermal efficiency for a solar collector is defined as
the ratio of the obtained useful thermal energy to the overall
absorbed thermal energy. Consequently, the thermal
efficiency equation of the solar collector is written as follows:
( )
.
air p out in
th
T c
m C T T
I A
(7)
The difference between thermal heat losses energy and the
absorber solar irradiance was identified by using the Hottel-
Whillier equation.
[ ( )]u c R L out inQ A F S U T T (8)
Where to determine how to absorb energy ( )RF is used,
while the method of loss energy is determined by R LF U ,
RF is defined as the removal factor and given by the
following equation.
1 expp c L
R
c L p
mC A U FF
A U mC
(9)
Where F is collector efficiency factor, can be calculated by the following equation:
International Journal of Mechanical & Mechatronics Engineering IJMME-IJENS Vol:19 No:05 10
193205-8484-IJMME-IJENS © October 2019 IJENS I J E N S
1
1
( )
( ) ( )
1
1 1
L
conv p air
conv p air rad p b
UF
hh h
(10)
Therefore, the steady state efficiency of the
collector is given by the following equation, known as
Hottel-Whillier–Bliss equation.
( )( ) out inth R R L
T
T TF F U
I
(11)
The convection and radiation heat transfer
coefficient between the transparent glass cover and
the ambient is given by the following equations.
0.6
( ) 0.4
8.6 (w )
( )
vconv g amb w
c
h hL
(12)
2 2
( )
( ) (T )( )
( )
g sky
rad g sky g g amb g amb
g amb
T Th T T T
T T
(13)
1.50.0552sky ambT T (14)
The convection and radiation heat transfer
coefficient between the absorber plate surface and the transparent glass cover is given by the following equations.
( )
( )
u p g air
conv p g
N kh
l
(15)
0.2917
( ) 0.1673 ( cos )u p g aN R (16)
3
2
g. . ra p g
PR T T l
(17)
1
mT (18)
2
p g
m
T TT
(19)
2 2
( ) 1 11
p g p g
rad p g
p g
T T T Th
(20)
The convection heat transfer coefficient between the
corrugated absorber plate surface and air flow channel is
given by the following equation.
( )
( )
.u p air airconv p air
D
N kh
H
(21)
4 2
2
c chD ch
c
W HH H
W
(22)
0.76
( ) 0.0743 ( )u p air eN R (23)
air De
v HR
(24)
The overall heat losses from the system can be calculated by
the following equation:
1
( ) ( ) ( )
1 1
( ) ( )t
conv p g rad p g w rad g sky
Uh h h h
(25)
.
.
g w
b
g w
kU
t (26)
.
.
g w c c
e
g w c
k p HU
t A (27)
III. RESULTS AND DISCUSSION
Thermal Performance Test of the SAH
The thermal performance tests of the solar heater was
performed according to ASHRAE [60] standard. In this work, four thermal efficiency curves were established at
different air mass flow rates. The efficiency curve equation
for each air mass flow rate was obtained to calculate SAH
characteristic parameters. The equation (11) mentioned in
above indicates that if efficiency th is plotted against Tout – Tin / IT, it well be resulted in a straight line where the slope
is equal to FRUL and the y-intercept is equal to FR(τα).
Figure 5 to Figure 7 illustrate the typical efficiency curves
for SAHWOS, SAHWP and SAHWNP collectors,
respectively, at different air mass flow rates. It is clearly
seen that the efficiency increases considerably as the air
mass flow rate increases. From these figures it is also
observed that the slope of the efficiency curves decreases with the increase of air mass flow rate which means a
decrease in the heat loss coefficient with the increase of the
air mass flow rates. This result is due to the lower plate
temperature with increased air mass flow rate resulting in
lower heat loss coefficient. It can also be seen from the
International Journal of Mechanical & Mechatronics Engineering IJMME-IJENS Vol:19 No:05 11
193205-8484-IJMME-IJENS © October 2019 IJENS I J E N S
curves that the loss coefficient is higher in the SAHWOS
collector, followed by SAHWP collector and least in
SAHWNP collector for the same air mass flow rates.
Fig. 5. Efficiency curve for SAHWOS at different air mass flow rates
Fig. 6. Efficiency curve for SAHWP at different air mass flow rates
Fig. 7. Efficiency curve for SAHWNP at different air mass flow rates
The incidence angle modifier of the collector is important to
predict efficiency during a day of normal collector
efficiency [60]. The incidence angle modifier for flat plate
collectors was explained in detail in Ref. [61], whilst the
incidence angle modifier for corrugated plate collectors is
not yet determined. The incidence angle sensitivity of corrugated plate collectors is different from the flat plate
collectors because of shading between aspects of the
corrugated plate. This may lead to the incidence angle
modifier of corrugated plate collectors is a lower than flat
plate collectors. Furthermore, the solar air collector with a
single glass cover is insensitive for incidence angle modifier
as stated by Hill et al. [62].
The incidence angle modifier for corrugated solar air
collectors was investigated by the method of ASHRAE
standard. Three pairs separate from efficiency values of the
solar collector about solar noon at early and late in the time
of day have been selected, when the incidence angles of
beam radiation are almost 30 , 45 and 60 . It was observed that the average incidence angle of both data
values was the same, as well as the efficiency value for the
incidence angle, is equal to the average of those two values.
Figure 8 shows the variation between incidence angle modifier Kατ and the incidence angle. Therefore, the
relationship between incidence angle modifier Kατ and the
collector efficiency is given by the following equation.
,( )R e nK
F
(28)
Fig. 8.Variation incidence angle modifier Kατ
Experimental Performance Results of The SAH
Figure 9 to Figure 12 presents the hourly solar irradiance
and the performance of SAHWOS collector for different air
mass flow rates in the entire daytime. It is clearly seen from
the figures that the solar irradiance increases from 8:00
(Tout
-Tin)/I
T(
oC.m
2/W)
Eff
icie
ncy
(%)
0 0.01 0.02 0.03 0.04 0.050
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
Air mass flow rate = 0.03 kg/s
Air mass flow rate = 0.04 kg/s
Air mass flow rate = 0.05 kg/s
Air mass flow rate = 0.06 kg/s
(Tout
-Tin)/I
T(
oC.m
2/W)
Eff
icie
ncy
(%)
0 0.01 0.02 0.03 0.04 0.050
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
Air mass flow rate = 0.03 kg/s
Air mass flow rate = 0.04 kg/s
Air mass flow rate = 0.05 kg/s
Air mass flow rate = 0.06 kg/s
(Tout
-Tin)/I
T(
oC.m
2/W)
Eff
icie
ncy
(%)
0 0.01 0.02 0.03 0.04 0.050
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
Air mass flow rate = 0.03 kg/s
Air mass flow rate = 0.04 kg/s
Air mass flow rate = 0.05 kg/s
Air mass flow rate = 0.06 kg/s
Incidence Angle (degrees)
In
cid
en
tA
ng
leM
od
ifie
r
0 10 20 30 40 50 60 700
0.2
0.4
0.6
0.8
1
1.2
International Journal of Mechanical & Mechatronics Engineering IJMME-IJENS Vol:19 No:05 12
193205-8484-IJMME-IJENS © October 2019 IJENS I J E N S
A.M. to 12:30 P.M. Then, the sun irradiation begins
declining toward the end of the day at 6:00 P.M. From the
temperature measurements it can be seen that the
temperature of air at the outlet of the collector in the
beginning increased at a slower rate, because of the low
irradiation rate. After that, the increase in outlet temperature
is at a faster rate which is due to the increase in the
insolation rate. After 12:00 P.M., the increase in
temperature is slightly reduced, and this increase continues
until 1:00 P.M. The little irradiation in the increase of
temperature is due to the increase in the average air
temperature of the collector. After 2:00 P.M. there is a clear
linear drop in outlet air temperature even 6:00 P.M. at all
cases, which is in direct proportion to the reduction in the
solar irradiance.
Fig. 9. Hourly solar irradiance and mean temperature of (Tamb, Tout,
Tg and Tp) for the SAHWOS at m = 0.03 kg/s Fig. 10. Hourly solar irradiance and mean temperature of (Tamb, Tout,
Tg and Tp) for the SAHWOS at m = 0.04 kg/s
Fig. 11. Hourly solar irradiance and mean temperature of (Tamb, Tout,
Tg and Tp) for the SAHWOS at m = 0.05 kg/s Fig. 12. Hourly solar irradiance and mean temperature of (Tamb, Tout,
Tg and Tp) for the SAHWOS at m = 0.06 kg/s
Time of Day (Hrs)
So
lar
Irra
dia
nce
(W/m
2)
Tem
pera
ture
(oC
)
7 8 9 10 11 12 13 14 15 16 17 18 190
100
200
300
400
500
600
700
800
900
0
10
20
30
40
50
60
70
80
90
100
110
120
130
140
150Solar irradiance
Ambient temperature
Outlet temperature
Glass temperature
Plate temperature
Time of Day (Hrs)
So
lar
Irra
dia
nce
(W/m
2)
Tem
pera
ture
(oC
)
7 8 9 10 11 12 13 14 15 16 17 18 190
100
200
300
400
500
600
700
800
900
0
10
20
30
40
50
60
70
80
90
100
110
120
130
140
150Solar irradiance
Ambient temperature
Outlet temperature
Glass temperature
Plate temperature
Time of Day (Hrs)
so
lar
Irra
dia
nce
(W/m
2)
Tem
pera
ture
(oC
)
7 8 9 10 11 12 13 14 15 16 17 18 190
100
200
300
400
500
600
700
800
900
0
10
20
30
40
50
60
70
80
90
100
110
120
130
140
150Solar irradiance
Ambient temperature
Outlet temperature
Glass temperature
Plate temperature
Time of Day (Hrs)
So
lar
Irra
dia
nce
(W/m
2)
Tem
pera
ture
(oC
)
7 8 9 10 11 12 13 14 15 16 17 18 190
100
200
300
400
500
600
700
800
900
0
10
20
30
40
50
60
70
80
90
100
110
120
130
140
150Solar irradiance
Ambient temperature
Outlet temperature
Glass temperature
Plate temperature
International Journal of Mechanical & Mechatronics Engineering IJMME-IJENS Vol:19 No:05 13
193205-8484-IJMME-IJENS © October 2019 IJENS I J E N S
Fig. 13. Hourly solar irradiance and mean temperature of (Tamb, Tout,
Tg, Tp and Tpcm) for the SAHWP at m = 0.03 kg/s Fig. 14. Hourly solar irradiance and mean temperature of (Tamb, Tout,
Tg, Tp and Tpcm) for the SAHWP at m = 0.04 kg/s
Fig. 15. Hourly solar irradiance and mean temperature of (Tamb, Tout,
Tg, Tp and Tpcm) for the SAHWP at m = 0.05 kg/s Fig. 16. Hourly solar irradiance and mean temperature of (Tamb, Tout,
Tg, Tp and Tpcm) for the SAHWP at m = 0.06 kg/s
Fig. 17. Hourly solar irradiance and mean temperature of (Tamb, Tout,
Tg, Tp and Tpcm) for the SAHWNP at m = 0.03 kg/s Fig. 18. Hourly solar irradiance and mean temperature of (Tamb, Tout,
Tg, Tp and Tpcm) for the SAHWNP at m = 0.04 kg/s
Time of Day (Hrs)
So
lar
Irra
dia
nce
(W/m
2)
Tem
pera
ture
(oC
)
8 10 12 14 16 18 20 22 240
100
200
300
400
500
600
700
800
900
10
20
30
40
50
60
70
80
90
100
110
Solar irradiance
Ambient temperature
Outlet temperature
Glass temperature
Plate temperature
PCM temperature
Time of Day (Hrs)
So
lar
Irra
dia
nce
(W/m
2)
Tem
pera
ture
(oC
)
8 10 12 14 16 18 20 220
100
200
300
400
500
600
700
800
900
10
20
30
40
50
60
70
80
90
100
110
Solar irradiance
Ambient temperature
Outlet temperature
Glass temperature
Plate temperature
PCM temperature
Time of Day (Hrs)
So
lar
Irra
dia
nce
(W/m
2)
Tem
per
atu
re(o
C)
8 10 12 14 16 18 20 220
100
200
300
400
500
600
700
800
900
10
20
30
40
50
60
70
80
90
100
110Solar irradiance
Ambient temperature
Outlet temperature
Glass temperature
Plate temperature
PCM temperature
Time of Day (Hrs)
So
lar
Irra
dia
nce
(W/m
2)
Tem
per
atu
re(o
C)
8 10 12 14 16 18 200
100
200
300
400
500
600
700
800
900
10
20
30
40
50
60
70
80
90
100
110Solar irradiance
Ambient temperature
Outlet temperature
Glass temperature
Plate temperature
PCM temperature
Time of Dat (Hrs)
So
lar
Irra
dia
nce
(W/m
2)
Tem
pera
ture
(oC
)
7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 230
100
200
300
400
500
600
700
800
900
10
20
30
40
50
60
70
80
90
100
110
120
Solar irradiance
Ambient temperature
Outlet temperature
Glass temperature
Plate temperature
PCM temperature
Time of Day (Hrs)
So
lar
Irra
dia
nce
(W/m
2)
Tem
pera
ture
(oC
)
7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 220
100
200
300
400
500
600
700
800
900
10
20
30
40
50
60
70
80
90
100
110
120
Solar irradiance
Ambient temperature
Outlet temperature
Glass temperature
Plate temperature
PCM temperature
Melting
Solidification
Liquid
International Journal of Mechanical & Mechatronics Engineering IJMME-IJENS Vol:19 No:05 14
193205-8484-IJMME-IJENS © October 2019 IJENS I J E N S
Fig. 19. Hourly solar irradiance and mean temperature of (Tamb, Tout,
Tg, Tp and Tpcm) for the SAHWNP at m = 0.05 kg/s Fig. 20. Hourly solar irradiance and mean temperature of (Tamb, Tout,
Tg, Tp and Tpcm) for the SAHWNP at m = 0.06 kg/s Figure 13 to Figure 16 presents the effect of using paraffin
wax on the performance of the SAH. These Figures illustrates
the variation of outlet air temperatures, plate temperature,
glass temperature and PCM temperature. Hourly variations of
measured solar irradiance intensity and ambient temperature
are also shown during the day. Measured data for all cases
explain that the maximum temperatures are obtained about
1:00 P.M. The move of the peaks location for different
temperatures versus time curves compared to solar irradiance
curve are due to the heat stored on the PCM during charging period. In all cases, it was observed that the absorber plate
surface temperature exhibited the highest temperature from
1:00 P.M. until 3:00 P.M. After this time, the PCM
temperature will be the highest. From these figures, it was
clearly seen that the heating rate of PCM during the solid
sensible heating is slow and increases at a higher rate beyond
60 °C. After that, the PCM has changed its phase completely
into liquid. Hence, the experiment is continued until the exit
air temperature is equal to the ambient temperature. It can be
seen that the absorber plate surface temperature in general
increases with the increasing intensity of solar irradiance that
leads to melt the paraffin wax.
Figure 17 to Figure 20 illustrate the variation of the outlet air
temperatures, plate temperature, glass temperature and PCM
temperature. Hourly variations of measured solar irradiance
intensity and ambient temperature are also shown during the
day for the SAHWNP. Measured data for all cases explains
that the maximum temperatures are obtained at about 1:00
P.M. which is the same with SAHWP. In all results, it was
observed that the temperature difference between absorber
plate surface and PCM is small compared to the case of
SAHWP due to the effect of nanoparticles (Alumina). The
effect of nanoparticles was to increase the thermal conductivity and thermal diffusivity. It was also found that the
maximum temperatures of PCM vary with different values of
air mass flow rate.
Figure 21, 22 and 23 shows the variation of the thermal
efficiency of SAHWOS, SAHWP and SAHWNP
respectively, at different air mass flow rates. The thermal
efficiency increases with the day time due to increasing solar
irradiance which leads to increase in the air flow temperature.
Furthermore, the thermal efficiency increases with the
increasing of the air mass flow rate until the value of 0.06
kg/s. Moreover, the use of PCM leads to increasing the
thermal efficiencies as the time increases to obtain their peak
values about 2:00 P.M. and decrease slowly at about 5:00 P.M. Then, the thermal efficiencies increase sharply due to the
large heat supply from the PCM during discharging process.
Fig. 21. A instantaneous thermal efficiency versus time of day at different air
mass flow rates for SAHWOS
Time of Day (Hrs)
So
lar
Irra
dia
nce
(W/m
2)
Tem
pera
ture
(oC
)
7 8 9 10 11 12 13 14 15 16 17 18 19 20 210
100
200
300
400
500
600
700
800
900
10
20
30
40
50
60
70
80
90
100
110
Solar irradiance
Ambient temperature
Outlet temperature
Glass temperature
Plate temperature
PCM temperature
Time of Day (Hrs)
So
lar
Irra
dia
nce
(W/m
2)
Tem
pera
ture
(oC
)
7 8 9 10 11 12 13 14 15 16 17 18 19 200
100
200
300
400
500
600
700
800
900
10
20
30
40
50
60
70
80
90
100
110
Solar irradiance
Ambient temperature
Outlet temperature
Glass temperature
Plate temperature
PCM temperature
Time of Day (Hrs)
Insta
nta
neo
us
Th
erm
al
Eff
icie
ncy
(%)
7 8 9 10 11 12 13 14 15 16 17 18 190
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
Air mass flow rates = 0.03 kg/s
Air mass flow rates = 0.04 kg/s
Air mass flow rates = 0.05 kg/s
Air mass flow rates = 0.06kg/s
International Journal of Mechanical & Mechatronics Engineering IJMME-IJENS Vol:19 No:05 15
193205-8484-IJMME-IJENS © October 2019 IJENS I J E N S
Fig. 22. A instantaneous thermal efficiency versus time of day at different air
mass flow rates for SAHWP
Fig. 23. A instantaneous thermal efficiency versus time of day at different air
mass flow rates for SAHWNP
Finally, the results of the all configurations in current
experiments can be summarized in Table 5 which represents a
comparison of different configuration in terms of Tin, Tout, T
and th.
TABLE V
Change of (Tin, Tout, T and th) for different configuration of the SAH at different air mass flow rates and solar irradiance of 800 W/m2
Configuration
m
(kg/s)
Tin
(C)
Tout
(C)
T
(C)
th
(%)
SAHWOS
0.03 28.9 57.2 28.3 44
0.04 29.7 55.5 25.8 53
0.05 28.4 53.3 24.9 60
0.06 30.3 50.5 20.2 66
SAHWP
0.03 28.9 52.5 23.6 41
0.04 29.7 50.5 20.8 49
0.05 28.4 46.8 18.4 56
0.06 30.3 44.4 14.1 60
SAHWNP
0.03 28.9 55.1 26.2 43
0.04 29.7 53.0 23.3 52
0.05 28.4 49.9 21.5 59
0.06 30.3 47.4 17.1 64
IV. CONCLUSIONS
The main aim of this paper is to present the actual SAH
collector's experimental performance and efficiency results for
various design configurations of SAH. In thermal
performance, those parameters such as; plate temperature,
glass temperature, inlet and outlet air temperature, ambient
temperature, solar irradiance, thermal efficiency and air mass
flow rate have been investigated thoroughly.
The air mass flow rate is an important and factor influential on results of SAH temperatures. Increment in air mass flow rate
will result to more and more air volume which entering the air
flow channel. It has been noted from the results the outlet air
temperature decreased because of the increase in air velocity
inside a flow channel.
It is clearly there is enhancement in performance of SAH with
thermal storage by using paraffin wax compared to SAH
without storage. Furthermore, the discharging of heat is
possible for duration of 5.5 , 5, 4.5, and 4 hours at the air mass
flow rates of 0.03, 0.04, 0.05 and 0.06 kg/s, respectively.
There is also an increase in the thermal conductivity of
paraffin wax with the dispersion of 1wt. % alumina nanoparticles which led to raise the outlet air temperature and
increased the thermal efficiency of the SAH compared with
pure paraffin wax.
REFERENCES [1] N. Panwar, S. Kaushik, S. Kothari, “Role of renewable energy
sources in environmental protection : A review,” Renew. Sustain.
Energy Rev., vol. 15, no. 3, pp. 1513–1524, (2011).
[2] M. Abbas, A. Bin Sapit, H. Balla, A. M. Haider, and A. Al-shamani,
“A Review Study on the Effect of Glass Envelope, Working Fluid
and Geometry Contributions for the Receiver on Performance of
Parabolic Trough Collector (PTC),” vol. 13, no. 20, pp. 8199–
8210,( 2018).
[3] A. Kumar , K. Shukla, “A Review on Thermal Energy Storage Unit
for Solar Thermal Power Plant Application,” Energy Procedia, vol.
74, pp. 462–469,( 2015).
Time of Day (Hrs)
Insta
nta
neo
us
Eff
icie
ncy
(%)
7 8 9 10 11 12 13 14 15 16 17 180
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
Air mass flow rate = 0.03 kg/s
Air mass flow rate = 0.04 kg/s
Air mass flow rate = 0.05 kg/s
Air mass flow rate = 0.06 kg/s
Time of Day (Hrs)
Eff
icie
ncy
(%)
7 8 9 10 11 12 13 14 15 16 17 180
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1
Air mass flow rate = 0.03 kg/s
Air mass flow rate = 0.04 kg/s
Air mass flow rate = 0.05 kg/s
Air mass flow rate = 0.06 kg/s
International Journal of Mechanical & Mechatronics Engineering IJMME-IJENS Vol:19 No:05 16
193205-8484-IJMME-IJENS © October 2019 IJENS I J E N S
[4] I. Sarbu, “A Comprehensive Review of Thermal Energy Storage,”
Jan. (2018).
[5] Q. Zhang, H. Yu, Q. Zhang, Z. Zhang, C. Shao, D. Yang, “A solar
automatic tracking system that generates power for lighting
greenhouses,” Energies, vol. 8, no. 7, pp. 7367–7380, (2015).
[6] A. Arasu, A. Sasmito, “Numerical Performance Study of Paraffin
Wax Dispersed with Alumina in A Concentric Pipe Latent Heat
Storage System,” pp. 1–17, (2012).
[7] A. Benato, A. Stoppato, A. Mirandola, “State-of-the-art and future
development of sensible heat thermal electricity storage systems,”
vol. 35, no. 1, (2017).
[8] S. Palm, G. Roy, C. Nguyen, “Heat transfer enhancement with the
use of nanofluids in radial flow cooling systems considering
temperature-dependent properties,” vol. 26, pp. 2209–2218,( 2006).
[9] N. Sohrabi, N. Massoumi, A. Behzadmehr, S. Sarvari, “Numerical
Study of Laminar Mixed Convection of a Nanofluid in a Horizontal
Tube using Two Phase Mixture Model with Variables Physical
Properties,” pp. 50–58, (2008).
[10] M. Kedzierski, R. Brignoli, K. Quine, J. Brown, “Viscosity ,
density , thermal conductivity of aluminum oxide and zinc oxide
nanolubricants Viscosité , densité et conductivité thermique de
nanolubrifiants d ’ oxyde d ’ aluminium et d ’ oxyde de zinc,” Int. J.
Refrig., vol. 74, pp. 1–9, (2017).
[11] A. Mallow, “Stable Paraffin Composites for Latent heat Thermal
Storage Systems,” Thesis Degree Master Sci. Georg. W. Woodruff
Sch. Mech. Eng., no. December, (2015).
[12] A. Olimat, A. Al-salaymeh, A. Al-maaitah, “Studying the Stability
of Melting and Solidification Behavior of Phase Change Material,”
vol. 4, no. 3, pp. 192–198, (2017).
[13] M. Karthik, A. Faik, B. Aguanno, “Solar Energy Materials and
Solar Cells Graphite foam as interpenetrating matrices for phase
change para ffi n wax : A candidate composite for low temperature
thermal energy storage,” Sol. Energy Mater. Sol. Cells, vol. 172, no.
April, pp. 324–334, (2017).
[14] A. El Khadraoui, S. Bouadila, S. Kooli, A. Guizani, A. Farhat,
“Solar air heater with phase change material : An energy analysis
and a comparative study,” Appl. Therm. Eng., vol. 107, pp. 1057–
1064, (2016).
[15] R. Sekret, “Experimental study of evacuated tube collector / storage
system containing paraf fi n as a PCM,” vol. 114, pp. 1063–1072,
(2016).
[16] S. Shalaby, E. El-bialy, and A. El-sebaii, “An experimental
investigation of a v-corrugated absorber single-basin solar still using
PCM,” DES, vol. 398, pp. 247–255, (2016).
[17] A. Kabeel, A. Khalil, S. Shalaby, M. Zayed, “Improvement of
thermal performance of the finned plate solar air heater by using
latent heat thermal storage,” Appl. Therm. Eng., vol. 123, pp. 546–
553, (2017).
[18] D. Rabha, P. Muthukumar, “Performance studies on a forced
convection solar dryer integrated with a paraffin wax – based latent
heat storage system,” Sol. Energy, vol. 149, pp. 214–226, (2017).
[19] N. Arfaoui, S. Bouadila, A. Guizani, “A highly efficient solution of
off-sunshine solar air heating using two packed beds of latent
storage energy,” Sol. Energy, vol. 155, pp. 1243–1253, (2017).
[20] T. Wang, Y. Diao, T. Zhu, Y. Zhao, J. Liu, X. Wei, “Thermal
performance of solar air collection-storage system with phase
change material based on flat micro-heat pipe arrays,” Energy
Convers. Manag., vol. 142, pp. 230–243, (2017).
[21] M. Hamed, A. Fallah, A. Ben Brahim, “ScienceDirect Numerical
analysis of an integrated storage solar heater,” Int. J. Hydrogen
Energy, vol. 42, no. 13, pp. 8721–8732, 2016.
[22] A. Ali, K. Abass, “Experimental Study on Solar Air Heating,” vol.
14, no. 1, pp. 1–9, (2018).
[23] Y. Lin, Y. Jia, G. Alva, and G. Fang, “Review on thermal
conductivity enhancement , thermal properties and applications of
phase change materials in thermal energy storage,” Renew. Sustain.
Energy Rev., vol. 82, no. Oct. 2017, pp. 2730–2742,( 2018).
[24] Y. Deng, J. Li, H. Nian, “Solar Energy Materials and Solar Cells
Polyethylene glycol-enwrapped silicon carbide nanowires
network/expanded vermiculite composite phase change materials :
Form- stabilization , thermal energy storage behavior and thermal
conductivity enhancement,” Sol. Energy Mater. Sol. Cells, vol. 174,
no. August 2017, pp. 283–291, (2018).
[25] G. Alva, Y. Lin, G. Fang, “An overview of thermal energy storage
systems,” Energy, vol. 144, pp. 341–378, (2018).
[26] R. Tchinda , “A review of the mathematical models for predicting
solar air heaters systems,” vol. 13, pp. 1734–1759, (2009).
[27] C. Kaviarasu D. Prakash, “Review on Phase Change Materials with
Nanoparticle in Engineering Applications,” vol. 9, no. 4, pp. 26–36,
(2016).
[28] M. Jamalabadi, “Effects of Brownian Motion on Freezing of PCM
Containing Nanoparticles,” vol. 20, no. 5, pp. 1533–1541, (2016).
[29] M. Tawfik, “Experimental Studies of Nanofluid Thermal
Conductivity Enhancement and Applications : A Review *,” vol. 75,
no. August, pp. 1239–1253, (2017).
[30] S. Shaikh, K. Hallinan, “Carbon Nanoadditives to Enhance Latent
Energy Storage of Phase Change Materials,”J.Eng.Elc, pp. 74–77,
(2008.)
[31] A. Mahmud, K. Sopian, M. Sohif, A. Graisa, “Using a Paraffin
Wax-Aluminum Compound As a,” vol. 4, no. December 2009, pp.
74–77, (2009).
[32] M. Alkilani, K. Sopian, S. Mat, and S. Ehsan, “Fabrication and
Experimental Investigation of PCM Capsules Integrated in Solar Air
Heater Institute of Solar Energy Research , Faculty of Engineering
,” vol. 7, no. 6, pp. 542–546, (2011).
[33] C. Guo, “Numerical investigation of Nanoparticle-enhanced High
Temperature Phase Change Material for Solar Energy Storage,” vol.
515, pp. 961–964, (2012).
[34] T. Teng and C. Yu, “Characteristics of phase-change materials
containing oxide nano-additives for thermal storage,” Nanoscale
Res. Lett., vol. 7, no. 1, p. 1, (2012).
[35] N. Dhaidan, J. Khodadadi, T. Al-hattab, S. Al-mashat,
“Experimental and numerical investigation of melting of phase
change material / nanoparticle suspensions in a square container
subjected to a constant heat flux,” Int. J. Heat Mass Transf., vol. 66,
pp. 672–683, (2013).
[36] N. Dhaidan, J. Khodadadi, T. Al-hattab, S. Al-mashat,
“Experimental and numerical study of constrained melting of n -
octadecane with CuO nanoparticle dispersions in a horizontal
cylindrical capsule subjected to a constant heat flux,” HEAT MASS
Transf., vol. 67, pp. 523–534, (2013).
[37] A. Pise, A. Waghmare, V. Talandage, “Heat Transfer Enhancement
by Using Nanomaterial in Phase Change Material for Latent Heat
Thermal Energy Storage System,” vol. 2, no. 2, pp. 52–57, (2013).
[38] J. Wang, H. Xie, Z. Guo, L. Guan, Y. Li, “Improved thermal
properties of paraf fi n wax by the addition of TiO 2 nanoparticles,”
vol. 73, pp. 1541–1547, (2014).
[39] M. Chaichan, H. Kazem, “Using Aluminium Powder with PCM (
Paraffin Wax ) to Enhance Single Slope Solar Water Distiller
Productivity in Baghdad – Iraq Winter Weathers,” vol. 5, no. 1, pp.
251–257, (2015).
[40] B. Nabhan, “Using Nanoparticles for Enhance Thermal
Conductivity of Latent Heat Thermal Energy Storage,” vol. 21, no.
6, pp. 37–51,( 2015).
[41] M. Chaichan, S. H. Kamel, “Thermal Conductivity Enhancement by
Using Nano-Material in Phase Change Material for Latent Heat
Thermal Energy Storage Systems,” vol. 5, no. 6, pp. 48–55, (2015).
[42] M. Nourani, N. Hamdami, J. Keramat, and A. Moheb, “Thermal
behavior of paraf fi n-nano-Al2O3 stabilized by sodium stearoyl
lactylate as a stable phase change material with high thermal
conductivity,” Renew. Energy, vol. 88, pp. 474–482, (2016).
[43] G. Arya and A. Lanjewar, “To Increase The Thermal Conductivity
Of Paraffin Wax Using Nano Particles,” pp. 2978–2982,( 2016).
[44] D. Singh, S. Suresh, H. Singh, B. Rose, S. Tassou, N.
Anantharaman, “Myo-inositol based nano-PCM for solar thermal
energy storage,” Appl. Therm. Eng., vol. 110, pp. 564–572, (2017.)
[45] N. Mohamed, F. Soliman, H. El, Y. Moustfa, “Thermal conductivity
enhancement of treated petroleum waxes, as phase change material ,
by α nano alumina : Energy storage,” Renew. Sustain. Energy Rev.,
vol. 70, no. Oct. 2015, pp. 1052–1058, (2017).
[46] M. Chaichan, R. Hussein, A. Jawad, “Thermal Conductivity
Enhancement of Iraqi Origin Paraffin Wax by Nano-Alumina,” vol.
13, no. 3, pp. 83–90, 2017.
[47] A. Tarish, N. Alwan, “Experimental Study of Paraffin Wax-Copper
International Journal of Mechanical & Mechatronics Engineering IJMME-IJENS Vol:19 No:05 17
193205-8484-IJMME-IJENS © October 2019 IJENS I J E N S
Nanoparticles Thermal Storage Material,” vol. 3, no. 3, pp. 11–17,
(2017).
[48] F. Saeed, “Nanomagnetite Enhanced Paraffin for Thermal Energy
Storage Applications,” vol. 12, no. 2, pp. 273–280, (2017).
[49] Z. Qian, H. Shen, X. Fang, L. Fan, N. Zhao, J. Xu, “Phase change
materials of paraffin in h-BN porous scaffolds with enhanced
thermal conductivity and form stability,” Energy Build., vol. 158,
pp. 1184–1188, (2018).
[50] K. Purohit, M. Dhonde, K. Sahu, V. Murty, “ISSN NO : 2394-8442
Latent heat enhancement using CuO nanoparticles in paraffin for
thermal energy storage applications,” vol. 5, no. 2, pp. 798–806,(
2018).
[51] S. Shalaby, H. Abosheiash, S. Assar, A. Kabeel, “Improvement of
Thermal Properties of Paraffin Wax as Latent Heat Storage Material
with Direct Solar Desalination Systems by Using Aluminum Oxide
Nanoparticles,” no. June, pp. 28–35, (2018).
[52] A. Mukherjee, M. Prathna, N. Chandrasekaran, “Antimicrobial
activity of aluminium oxide nanoparticles for potential clinical
applications,” pp. 245–251, (2011).
[53] A. Khazaei, S. Nazari, G. Karimi, and E. Ghaderi, “Synthesis and
Characterization of γ -Alumina Porous Nanoparticles from Sodium
Aluminate Liquor with Two Different Surfactants,” vol. 12, no. 4,
pp. 207–214, (2016).
[54] V. Piriyawong, V. Thongpool, P. Asanithi, P. Limsuwan,
“Preparation and Characterization of Alumina Nanoparticles in
Deionized Water Using Laser Ablation Technique,” vol. 2012,(
2012).
[55] W. Yu, S. Choi, “The role of interfacial layers in the enhanced
thermal conductivity of nanofluids : A renovated Maxwell model,”
pp. 167–168, (2003).
[56] L. Garch, J. Zhong, “Thermal Conductivity Enhancement for Phase
Change Storage Media,” vol. 23, pp. 91–100, (1996).
[57] H. C. Brinkman, “The Viscosity of Concentrated Suspensions and
Solutions,” vol. 571, pp. 1–2, (1952).
[58] Y. Al-Douri, F. M. Abed, “Solar energy status in Iraq: Abundant or
not - Steps forward,” J. Renew. Sustain. Energy, vol. 8, no. 2,
(2016).
[59] J. Duffie, W. Beckman, Solar Engineering of Thermal Processes.,
Fourth Edi., vol. 116. University of Wisconsin-Madison, (2013).
[60] ASHRAE. STANDARD 93–86, “Methods of testing to determine
the thermal performance of solar collectors,” p. 45, (1986).
[61] W. J. Apley, “No TitleSYSTEMS ANALYSIS OF SOLAR
THERt~AL POWER SYSTEMS,” 1978.
[62] D. E. J, J. E. Hill, “Testing of Pebble- Bed and Phase-Change
Thermal Energy Storage Devices According to ASHRAE Standard
94-77,” no. May, (1979).