International Journal of Ambient Energy

ISSN: 0143-0750 (Print) 2162-8246 (Online) Journal homepage: http://www.tandfonline.com/loi/taen20

Performance Study of a domestic refrigerator

using CuO/AL2O3-R22 a nano- refrigerant as
working fluid

M. Anish, G. Senthil kumar, N. Beemkumar, B. Kanimozhi & T. Arunkumar

To cite this article: M. Anish, G. Senthil kumar, N. Beemkumar, B. Kanimozhi & T. Arunkumar
(2018): Performance Study of a domestic refrigerator using CuO/AL2O3-R22 a nano- refrigerant as
working fluid, International Journal of Ambient Energy, DOI: 10.1080/01430750.2018.1451376

To link to this article: https://doi.org/10.1080/01430750.2018.1451376

Accepted author version posted online: 13

Mar 2018.

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Publisher: Taylor & Francis & Informa UK Limited, trading as Taylor & Francis Group
Journal: International Journal of Ambient Energy
DOI: 10.1080/01430750.2018.1451376

Performance Study of a domestic refrigerator using CuO/AL2O3-R22 a

nano- refrigerant as working fluid
M. Anish1,, G.Senthil kumar2,N.Beemkumar3,B.Kanimozhi4,,T.Arunkumar5
School of mechanical engineering, Sathyabama University, , Chennai, India 1,2,3,4
Abstract
In this work, an Performance study was investigated on the nano-refrigerant.
CuO/AL2O3-R22 a nano-refrigerants were used in a refrigerator without any remodelling
of a System. The refrigerator performance was then investigated using energy consumption
test and Enhancing Heat transfer rate. The heat transfer enhancement was investigated on
the surface of a refrigerator by using Al2O3/CuO nano-refrigerants The results indicate that
CuO-R22 a nano-refrigerants work normally and safely in the refrigerator and has better
power consumption and heat transfer rate. Thus, using CuO-R22 a nano-refrigerant in
domestic refrigerators is feasible for better heat transfer rate.
Keywords: Al2O3 Nanoparticles, Nano-Refrigerant, CuO , COP,
List of abbreviations
Symbol Description Unit

A Cross sectional m2
area
Cp Specific heat J/Kg k
D Diameter m
h Enthalpy KJ/Kg
hfg Latent heat of w/m k
vaporization
K Thermal w/m k
conductivity
m Mass flow rate Kg/s
T Temperature °C
v Velocity m/s

1.Introduction
Nano-refrigerant was contemplated on the basis of the perception of the Nanofluids, which
was prepared by weave the Nanoparticles and traditional refrigerant. There were three
main advantages followed for the Nanoparticle used in the refrigerator.
[1]For instance the thermal conductivities of CNT-R113 Nano-refrigerants and found that
the measured thermal conductivities of four kinds of 1.0 vol.% CNT-R113 Nano-
refrigerants increase 82%, 104%, 43% and 50%, respectively. [2]The experimental study
of boiling heat transfer characteristics of Al2O3 Nanoparticles dispersed in R22 refrigerant,
and found that Nanoparticles can enhance the heat transfer characteristic of the refrigerant,
and the bubble size diminish and move quickly near the heat transfer
surface. [3] Scrutinized the pool boiling heat transfer of the R11 refrigerant mixed with
Nanoparticles TiO2, and the results indicated that the heat transfer enhancement reached
20% at a particle loading of 0.01 g/L. [4]Reviewed the effect of carbon Nanotubes (CNTs)
on nucleate boiling heat transfer of halocarbon refrigerants of R123 and R134a. Test
results showed that CNTs increase nucleate boiling heat transfer coefficients for these
refrigerants. Especially, large enhancement up to 36.6% was observed at low heat fluxes.
[5] The heat transfer coefficient of CuO-R113 was preponderant than that of pure
refrigerant R113, and the maximum enhancement of heat transfer coefficient was 29.7%.
[6] Probed the migrated mass of nanoparticles in awe pool boiling process of twain nano-
refrigerant as a consequence nano-refrigerant–oil mixture, and found that the migrated
mass of nanoparticles and migration ratio in the nano-refrigerant were preponderant than
those in the nano-refrigerant–oil mixture.
Finally, nanoparticles dispersed in lubricant should decrease the friction coefficient and
wear rate. Lee et al. [7] Scrutinized the friction coefficient of the mineral oil mixed with
0.1 vol.% fullerene nanoparticles, and the results indicated that the friction coefficient
decreased by 90% in comparison with raw lubricant, which lead us to the conclusion that
nanoparticles can ameliorate the efficiency and fidelity of the compressor. Jwo et
al. [8] carried out the performance experiment of a domestic refrigerator using hydrocarbon
refrigerant and 0.1 wt.% Al2O3-mineral oil as working fluid, the results determined that the
power consumption was reduced by about 2.4%, and the coefficient of performance was
increased by 4.4%.
In the precedent work, the author has investigated the basic characteristics of the TiO2-
R134a nano-refrigerants, including the dispersion behavior [9], thermal conductivity and
flow boiling heat transfer [10,11]. The performance of a domestic refrigerator with
nanoparticles added was also investigated. In the former experiment, the nanoparticles
were added into the refrigeration system in two different ways. In unhindered the
nanoparticles were added to the refrigeration system by first adding them into the lubricant
to synthesize nanoparticle–lubricant mixture. Then, the mixtures were put into the
compressor as the lubricant [12]. In the other way nanoparticles and historic refrigerant
were mixed directly to make nano-refrigerant [13]. The results of both of the ways had
showed the better performance of the refrigerator with nanoparticles combined.Liu et al.
(2006) recycled the skill of chemical reduction test for coalescence of nano fluids
encompass Cu nano particles in water without using surfactant as the dispersant.
Thus the synthesized copper nano fluid shows improved thermal conductivity when
compared to pure fluids.Hindawi (2009) Effectuate an experimental debate on the
boiling heat transfer virtue of R22 refrigerant with Al2O3 nano particles and
found that the nano particles enhanced the refrigerant heat transfer characteristics with
shrunk bubble sizesSaterile M. S. et al. (2011) Testify that copper based Nano fluids
the increase in thermal conductivity was due to the formation of controlled
agglomeration.The Global Warming Potential (GWP) of currently used R134a is
high as 1300.The Ozone Depleting Potential (ODP) of R134a is also relatively
high. The Montreal and Kyoto Protocol of United Nations suggests minimizing of
Hydro Fluorocarbons (HFCs) to use as refrigerants. Researches show HFC 134a not
much miscible with lubricant oil in the compressor. European countries have already banned
R134a.
Blending of R134a with other HFC is a dispute. R-22 and R134a will be phased
out due to environmental issues. To overthrown the above problem, refrigerant R152a is
proposed in the instant study because R152a has Zero Ozone Depleting Potential and a
very less value of 120 as Global Warming Potential (GWP) when compared to other
refrigerants. Pure substance R152a bid excellent thermodynamic properties non toxic
and compatibility with the conventional oil in compressor. R152a dated already
approved for use in automobile applications as an alternative to R134a by US
Environmental Protection Agency.Isobutane (R600a) is more widely adopted in domestic
refrigerator because of its better environmental and energy performances. In this paper, a
new refrigerator test system was built up according to the National Standard of China.
Hence based on the literature review it is ostensibily clear that addition of
dissimilar nano additives in refrigeration system revamp the performance of the system.
However only limited investigation has been carried out with nano additives in
R152a refrigerant. Hence it is a worthwhile attempt to hybrid nano additives with
R152a refrigerant in refrigerant system and also it will be useful to study the influence
of surfactants on the performance of refrigeration system. The Global Warming
Potential (GWP) of currently used R134a is high as 1300.The Ozone Depleting
Potential (ODP) of R134a is also relatively high. The Montreal and Kyoto Protocol
of United Nations suggests minimizing of Hydro Fluorocarbons (HFCs) to use as
refrigerants. Researches show HFC 134a not much miscible with lubricant oil in the
compressor. European countries have already banned R134a.Blending of R134a with other
HFC is a problem. R-22 and R134a will be phased out due to environmental issues. To
overcome the above problem, refrigerant R152a is proposed in the present study
because R152a has Zero Ozone Depleting Potential and a very less value of 120 as
Global Warming Potential (GWP) when compared to other refrigerants. . Pure substance
R152a offers excellent thermodynamic properties non toxic and compatibility with
the conventional oil in compressor. [15]R152a has been already approved for use in
automobile applications as an alternative to R134a by US Environmental Protection
Agency. R-22 is much used as an substitue to the ozone-depleting CFC-11 and CFC-12,
because of its comparatively low ozone depletion potential of 0.077, among the lowest
for chlorine. Nevertheless, even this lower ozone depletion potential is no longer
considered as acceptable.

2. Experimental setup

The experimental subsist of a compressor, fan cooled condenser, expansion device

and an evaporator section. Capillary tube is recycled as an expansion device. The evaporator
is of serpentine coil type which is loaded with water. Service ports are provided at
the inlet of expansion device and compressor for charging the refrigerant. The mass flow
rate is measured with the help of flow meter fitted in the line between expansion
device and drier unit. The experimental setup was placed on a platform at a constant
temperature.

Fig: 1: Experimental setup

3 .Homogenizing Of Nano Particles in the Lubricant

Three lubricants bottles of Sanden SP-10 lubricant was taken 250 ml in each
beaker. The nano particles CuO of 0.05%v was taken and added to one of the beaker
containing the lubricant. The same procedure was followed for the rest of the two ZnO and
Al2O 3 samples. It is manually stirred first and then closed tightly with a cap and shaken
properly to get it mixed well.
4. Magnetic stirring
A magnetic stirrer or magnetic mixer is a device that exploit a rotating magnetic
field to cause a stir bar immersed in a liquid to spin very hastily, thus stirring it. The
rotating field may be conceive either by a rotating magnet or a set of stationary
electromagnets, placed beneath the vessel with the liquid. A stir bar is the magnetic bar
placed inward the liquid which implement the stirring action motion . The stir bar's
motion is driven by rotating magnet or assembly of electromagnets in the stirrer device,
beneath the vessel containing the liquid.
5. Experiment and calculation before nano fluid addtition
Initially, the experiment is carried out to find Coefficient of performance, power
consumed while operation with default configuration and only R22 as refrigerant. The
temperature measurements shown by thermocouples and energy meter reading which
denotes time taken for particular number of turns of disc. These observations are tabulated
and calculated using formula to find theoretical and actual COP and power consumption.
Experimental test rig is started and allowed to run for few minutes. All respective
readings are taken for corresponding meters and sensors and tabulated.
Readings: (Before adding nano-fluid)
Compressor suction pressure: 20 psi (1.4 bar)
Compressor delivery pressure: 180 psi (20 bar)
Temperature at junctions:
T1 = 27.5o C T3 = 28.7 o C
T2 = 60.5 o C T4 = -2.4 o C
Dry bulb Temperature of air:
Tin = 28 o C Tout = 26 o C
Wet bulb Temperature of air:
Tin = 22 o C Tout = 20 o C
Energy meter:
Time taken for 10 revolutions of disc = 107.2 s
Energy meter constant = 600
Velocity of air (V) = 3 m/s
Formula for calculation
COPth = (h1 –h4) / (h2 – h1) [vapour compression cycle]
COPact = Refrigeration Effect / input
Refrigeration effect = ma (H1- H2) kW
ma = AVp kg/s (Area of outlet, p - density)
Calculation (Before nano fluid additive)
From R22 P-h chart (pressure-enthalpy)
For P1 = 1.4 bar, T1 = 27.5o C  h1 = 428 kJ/kg
P2 = 20 bar, T2 = 60.5o C  h2 = 440 kJ/kg
h3 = h4 = 235 kJ/kg
COPth = (h1 –h4) / (h2 – h1) = 16.05
Refrigeration effect = ma (H1 –H2)
H1 = 64.5kJ/kg H2 = 57.5 kJ/kg (psychometric chart)
ma = (21 * 10-2) * 3 * 1.183 = 0.747 kg/s
RE = .747 * 8 = 5.32 kW
Input = no. of revolutions * 3600 / time * 600
 Input = 10 * 3600 / (107.2 * 600) = .559 kW
COPact = RE/input = 9.32
6. Nano refrigerant in to the system
In refrigeration system the Nano partices can be recycled because of its
increase in heat transfer capabilities to enhancing the performance of the refrigeration
system. The Nano particles can be added to the lubricant oil in the compressor. When the
refrigerant is disperse over the compressor it import the evidence of lubricant and nano
particles mixture (nano lubricant) in the system[16] . so that the other heat transfer
components will have nano lubricant- refrigerant mixture[17]. Hence the concentration of
nano additives of CuO in this work was taken in the order of 0.05%v.The lubricant oil
blended with the three nano additives was loaded in the compressor. The setup was
charged with 150 gm of the working fluid R152a and the performance tests were
conducted as per standards (Wong wises et al., 2005). Tests were conveyed with three
concentrations of the three nano additives in the system. The suction temperature, discharge
temperature, suctions and discharge pressures were noted. The power consumption was
calculated with the help of digital watt-hour meter. The performance parameters of
the system computed are refrigerating effect, compressor work input, co-efficient of
performance, volumetric cooling capacity and pressure ratio.
Readings (Using Nano Refrigerant)
Compressor suction pressure: 20 psi (1.4 bar)
Compressor delivery pressure: 180 psi (20 bar)
Temperature at junctions:
T1 = 31o C T3 = 26 o C
T2 = 54 o C T4 = -3.1 o C
Dry bulb Temperature of air:
Tin = 26 o C Tout = 23.6 o C
Wet bulb Temperature of air:
Tin = 19 o C Tout = 17.9 o C
Energy meter:
Time taken for 10 revolutions of disc = 125 s
Energy meter constant = 600
Velocity of air (V) = 3 m/s
From R22 P-h chart (pressure-enthalpy)
For P1 = 1.4 bar, T1 = 31o C  h1 = 428 kJ/kg
P2 = 20 bar, T2 = 54o C  h2 = 440 kJ/kg
h3 = h4 = 235 kJ/kg
COPth = 18.72
H1 = 52.5kJ/kg H2 =45.1kJ/kg (psychometric chart)
ma = (21 * 10-2) * 3 * 1.183 = 0.747 kg/s
 RE = .747 * 7.4 = 5.52 kW
Input = 10 * 3600 / (125 * 600) = .48 kW
COPact = RE/input = 11.51
7. Result
After calculating and analyzing the above output data, we can see that COP of
refrigeration system which is used Freon along with CuO (nano particle) additive is greater
than that of the one which used conventional refrigerant alone
Table .1 – comparison of COPs

Fig:2: P-h variation with nano Refrigerant addition

8. Discussion
from the above table we could evidently see that coefficient of performance of
refrigeration system which used nano refrigerant as working fluid is significantly higher
than that of ordinary refrigerant system. the addition of nano particles, 0.05% by volume,
has improved heat transfer properties of the refrigerant and reduced power consumption.
this in future may be adopted widely which would lead to less pollution by cfc gases, cost
incurred on power consumption and good performance.
fig 3.1 is a graph between quantities, relative cop and refrigerant involved in
vapour compression cycle. from that, it is evident that relative cop has increased from 0.58
to 0.62 when r22 with 0.05% concentration of nano-particles. this increased performance
also reduced overall compressor work done on the working fluid while compressing. nano
fluid, thus effectively increases heat transfer rate and performance characteristics.Increase
in evaporation temperature due to the increase in cooling capacity improves the cop
of the system with the reduction in power consumption of the compressor.
The addition of nano additives facilitates the improvement in cooling capacity.
this due to low specific volume at 0.05% cuo which reduces the size of the
compressor requirement.

Fig .3. – Performance chart

9. conclusion:
An experimental study was conducted in chapter 2 with the blend of R22 and
The mixture containing 0.05%vol of nano particles (copper oxide) in refrigerant shows
increased heat transfer rates.The nano refrigerant has further reduced consumer work done,
which led to reduction in power consumption. This can be seen in section 2.12, where time
taken for 10 revolutions of disc in energy meter varies positively from default conventional
refrigerant.The output conditioned air has temperature and humidity regulated perfectly,
which does not get altered for change of refrigerant. Only power consumption and heat
transfer rate has changed to desirable values.
10. scope for future work
The following are the important future research needs with respect to environment
friendly alternative refrigerants:
• Hydro carbon refrigerant will be considered as a long-term alternative for
halogenated refrigerants which are flammable.
• Hence development for new refrigeration system with low refrigerant inventory is
essential.
• Very limited pure alternatives are available. Therefore, the new refrigeration
system designs should accommodate the non-linear property variation of
environment friendly mixed refrigerants.
• Compatibility of the alternative refrigerants mixtures with lubricants and the
construction materials is required to be studied further.
• Inert nature of hydrocarbons with hydro fluorocarbon refrigerants needs further
investigation.
• An environmental property of new refrigerant mixtures also needs
further investigation.
11.References

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domestic refrigerator, International Journal of Engineering Science and Technology, vol. 3,
No. 8
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domestic refrigerator, International Journal of Energy, Vol. 35, pp 3793- 3798.
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behavior of nano fluids in rectangular micro channels using a mixture model,
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of carbon nanotube nanorefrigerants,Int J Therm Sci, 48 (2009), pp. 1108-1115

[8]X.M. Wu, P. Li, H. Li, et al.Investigation of pool boiling heat transfer of R11 with
TiO2 nano-particleJ Eng Thermophys, 28 (2008), pp. 124-126

[9]K.J. Park, D.S. JungBoiling heat transfer enhancement with carbon nanotubes for
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[10]H. Peng, G.L. Ding, W.T. Jiang, et al.Heat transfer characteristics of refrigerant-
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[12]K. Lee, Y.J. Hwang, S. Cheong, L. Kwon, S. Kim, J. LeePerformance evaluation of

nano-lubricants of fullerene nanoparticles in refrigeration mineral oilCurr Appl
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[13]C.S. Jwo, L.Y. Jeng, T.P. Teng, H. ChangEffects of nanolubricant on performance

of hydrocarbon refrigerant systemJ Vac Sci Technol B, 27 (2009), pp. 1473-1477

[14]S.S. Bi, J.T. Wu, L. ShiThe thermal conductivity of the nanoparticles TiO2 and
R134a mixturesJ Eng Thermophys, 29 (2008), pp. 205-207

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Fig: 1: Experimental setup

Table .1 – comparison of COPs

COP Theoretical COP Actual COP Relative

Only R22 as 16.05 9.32 0.58

refrigerant
R22 and CuO as 18.72 11.51 .62
nano-refrigerant
Fig:2: P-h variation with nano Refrigerant addition

Fig .3. – Performance chart

.