a brief presentation of increasing efficiency of refrigerants using nanotechnology. its main objective is to reduce other pollution effects produced due to refrigerants.

1. “NANOTECHNOLOGY
IN REFRIGERATION”
PRESENTED BY :- SUBHENDU KUMAR PRADHAN
MECHANICAL II GROUP-II
ROLL NUMBER:- 125109
REDG. NUMBER:-1201287457

2. CONTENTS
 Introduction
 Refrigeration system
 Types of refrigeration system
 Refrigerants
 Nanotechnology
 Nanoair
 Nanofluids
 Synthesis of nanofluids
 Evaluation of properties of nanofluids
 Nanoadditives in R-152a refrigerant
 Effect of concentration of nanoadditives
 Influence of nanoadditives concentration on COP of the system
 Conclusions
 Scope for future work
 References

3. INTRODUCTION
The rapid industrialization has led to unprecedented growth, development and technological advancement
across the globe. Today global warming and ozone layer depletion on the one hand and spiraling oil prices on the
other hand have become main challenges.
In the face of imminent energy resource crunch there is need for developing thermal systems which are energy
efficient.
The most common refrigerant in current time is R132a in all the refrigeration systems like vapour compression
refrigeration system, domestic refrigerators and air conditioners. But the only problem with this type of
refrigerant is they need the large amount of electric power. Now for the time demand we need something new
that will be able to replace alternative refrigerant with some advanced thermo-physical properties like high heat
transfer, low power consumption in order to make the refrigeration process more effective and efficient so that
we will have a chance to save the environment.
The rapid advances in nanotechnology have lead to emerging of new generation heat transfer fluids called nanofluids.

4. REFRIGERATION SYSTEM
Cooling of an object and maintenance of its
temperature below that of surroundings.
 A refrigerator is a reversed heat engine or heat
pump which takes heat from cold body and deliver it
to a hot body.
Basic examples of refrigeration system in daily life
are:-

5. REFRIGERANTS
Refrigerants is heat carrying medium which during their cycle in refrigeration
system absorbs heat from low temperature system and deliver it to high
temperature system.
Examples:-
 Chloroflourocarbons.
Ammonia (R-717).
Sulfur dioxide.
Non halogenated hydrocarbons like propane (R-290).
Tetraflouroethane (R-134a).

6. DISADVANTAGES OF USE OF REFRIGERANTS
 The first major environmental impact that struck the refrigeration based industries is
Ozone Depletion Potential (ODP) due to manmade chemicals into the atmosphere.
 The second major environmental impact is GWP, which is due to the absorption of
infrared emissions from the earth, causing an increase in global earth surface
temperature.
 Green House gas (GHG) emissions from fossil fuel combustion for power generation
and emission of halogenated refrigerants from vapour compression based refrigeration
, air conditioning and heat pump systems contribute significantly to global warming.

7. NANOTECHNOLOGY
 It is science, engineering and technology conducted at the nanoscale which is about 1 to 100
nanometers. ( 1 nanometer = 10^-9 meters )
 The ideas and concept behind nanoscience and nanotechnology started with a talk entitled
“there’s plenty of room at the bottom” by physicist RICHARD FEYNMAN in 1959.
 He is called father of nanotechnology.
 Applications of nanotechnology:-
Nanomedicine.
Nanobiotechnology.
Green nanotechnology.
Industrial application of nanotechnology.
Potential application of carbon nanotubes.

8. WHY USE OF NANOPARTICLES?
 The basic concept of dispersing solid particles in fluids to enhance thermal conductivity can
be traced back to Maxwell in the 19th Century.
 Studies of thermal conductivity of suspensions have been confined to
mm- or mm-sized particles.
 The major challenge is the rapid settling of these particles in fluids.
 Nanoparticles stay suspended much longer than micro-particles and, if below a threshold
level and/or enhanced with surfactants/stabilizers, remain in suspension almost
indefinitely.
 Furthermore, the surface area per unit volume of nanoparticles is much larger (million
times) than that of microparticles (the number of surface atoms per unit of interior atoms
of nanoparticles, is very large).
 These properties can be utilized to develop stable suspensions with enhanced flow, heat-
transfer, and other characteristics.

9. nanoAir
 nanoAir is a break through application that addresses both heating and
cooling and refrigeration.
 This system is developed by DAIS ANALYTIC and dubbed nanoAir is
projected to reduce harmful emissions by over 50 percent from today’s
most efficient heating, cooling and refrigeration equipment.
 Nanotechnology used for HVACR unit without refrigerants gases.
Working of technology
 This system uses a polymer membrane that allows moisture but not air to
pass through it. A vacuum behind the membrane pulls water vapour from
the air and a second set membrane releases the water vapour outside.
The membrane’s high selectivity translates into reduced energy
consumption for dehumidification.

10. NANOFLUID
 Nanofluids are engineered colloids which consist of a base fluid with Nano sized particles (1-100
nm) suspended within them.
 Common base fluids include:-
• Water.
• Ethylene- or tri-ethylene-glycols and other coolants.
• Oil and other lubricants.
• Bio-fluids.
• Polymer solutions.
• Other common fluids.
 Nanoparticle materials include:-
• Oxide ceramics – Al2O3, CuO
• Metal carbides – SiC
• Nitrides – AlN, SiN
• Metals – Al, Cu
• Nonmetals – Graphite, carbon nanotubes
• Layered – Al + Al2O3, Cu + C
• PCM – S/S
• Functionalized nanoparticles

11. NANOPARTICLE MATERIALS
 The characterization of copper oxide nanoparticles were done by XRD for
structural determination and estimation of crystalline size using the instrument
PAnalytical X’Pert PRO diffractometer and the average size of the nanoparticle were
calculated using Debye-Scherrer equation and it was 50 nm and image for XRD is
shown in Figure.
X-ray diffractogram for the copper oxideSEM Micrograph (5000X) of CuO nanoparticles
Working formulae
The crystal size of the
particle is calculated
using the Debye-
Scherrer formula as
shown in equation
D = 0.89λ/βcosθ

12. ADVANTAGES OF NANO FLUIDS
High specific surface area and therefore more heat transfer surface between
particles and fluids.
High dispersion stability with predominant Brownian motion of particles.
 Reduced pumping power as compared to pure liquid to achieve equivalent heat
transfer intensification.
Reduced particle clogging as compared to conventional slurries, thus promoting
system miniaturization.
Adjustable properties, including thermal conductivity and surface wettability, by
varying particle concentrations to suit different applications.

13. SYNTHESIS OF NANOFLUID
 In two-step process for oxide nanoparticles (“Kool-Aid” method), nanoparticles are
produced by evaporation and inert-gas condensation processing, and then dispersed
(mixed, including mechanical agitation and sonification) in base fluid.
 A patented one-step process simultaneously makes and disperses nanoparticles
directly into base fluid; best for metallic nanofluids.
Schematic diagram of nanofluid production
system designed for direct
evaporation/condensation of metallic
vapor into low-vapor-pressure liquids.

14. EVALUATION OF THE PROPERTIES OF THE NANO FLUID.
 Density of nano fluid
 The base fluid is R134a refrigerant. The density of the nano fluid (R134a – Cuonano
particles) for different concentrations of Cuo particles is developed by Pak and cho.
It is given by Pnf=φPp+(1-φ)Pbf
 Isobaric specific heat of nano fluid
 Specific heat is the amount of heat required to raise the temperature of one gram of
nano fluids by one degree centigrade.
It is given by Cpnf =φCp +(1–φ)Cbf
 Thermal conductivity of nano fluid
 The equation for calculating thermal conductivity is given below; it is developed by Maxwell – Eucken.
It is given by
 Viscosity of nano fluid
 The equation for calculating the Viscosity of the nano fluid given by Einstein is given below:-
μnf = μbf (1 + 2.5φ )
[(1+2φ)(1-(kbf/kcuo))/(2(kbf/kcuo)+1)]
[(1-φ(1-(Kbf/kcuo))/((Kbf/kcuo+1)]
Knf=kbf

15. BROWNIAN MOTION OF NANOPARTICLES
 A new model that accounts for the Brownian motion of
nanoparticles in nanofluids captures the concentration
and temperature-dependent conductivity.
 In contrast, conventional theories with motionless
nanoparticles fail to predict this behaviour (horizontal
dashed line).
 The model predicts that water-based nanofluids
containing 6-nm Cu nanoparticles (curve with triangles)
are much more temperature sensitive than those
containing 38-nm Al2O3 particles, with an increase in
conductivity of nearly a factor of two at 325 K.
Temperature-dependent thermal
conductivities of nanofluids at a fixed
concentration of 1 vol.%, normalized to the
thermal conductivity of the base fluid.

16. ENHANCED NANOFLUID THERMAL
CONDUCTIVITY.
Thermal conductivity enhancement of
copper, copper oxide, and alumina
particles in ethylene glycol.
Appl. Phys. Lett. 78, 718, 2001.
Temperature-Dependent
Conductivity
Temperature dependence of thermal
conductivity enhancement for Al2O3-
in-water nanofluids
(*) J. Heat Transfer, 125, 567, 2003.
Significant Increase in
Critical Heat Flux
CHF enhancement for Al2O3-in-water
nanofluids
You et al., Appl. Phys. Lett., in press.

17. NANOADDITIVES IN R152A REFRIGERANT
Suspending nano sized particles (1-100 nm) in the conventional fluids possess
higher thermal conductivity than the base fluid.
This concept is being adopted in the work of suspending nanoparticles in the
refrigerantR152a. R152a refrigerant is a nature friendly used in refrigeration
system.
The addition of nanoparticles to the refrigerant results in the improvement of
thermophysical properties and heat transfer characteristics of the refrigerant
thereby the performance of the system could be improved to a large extent.

18. EFFECT OF CONCENTRATION OF NANOADDITIVES
Influence of nanoadditive concentration on vapour pressure.
Variation of vapour pressure with 0.05%
concentration of three
Nano additives.
Variation of vapour pressure with 0.1%
concentration of three
Nanoadditive.
Variation of vapour pressure with 0.15%
concentration of three
nano additives.

19.  INFLUENCE OF NANOADDITIVE CONCENTRATION ON PRESSURE
RATIO.
Variation of pressure ratio with 0.05%
concentration of nano additives.
Variation of pressure ratio with 0.1%
concentration of nano additives.
Variation of pressure ratio with
0.15% concentration of nano
additives.

20.  INFLUENCE OF NANOADDITIVE CONCENTRATION ON COMPRESSOR
INPUT POWER
Variation of compressor input
power with 0.05% concentration
of nanoadditive.
Variation of compressor input
power with 0.1% concentration of
nanoadditive
Variation of compressor input power
with 0.15% concentration of
Nanoadditive

21.  INFLUENCE OF NANOADDITIVE CONCENTRATION ON VOLUMETRIC
COOLING CAPACITY.
Variation of volumetric cooling
capacity with 0.05% concentration of
nano additives.
Variation of volumetric cooling capacity
with 0.1% concentration of
Nanoadditive.
Variation of volumetric cooling
capacity with 0.15% concentration of
nano additives.

22.  INFLUENCE OF NANOADDITIVE CONCENTRATION ON COP OF THE
SYSTEM.
Variation of COP with 0.05%
concentration of three
Nanoadditives.
Variation of COP with 0.1% concentration
of nanoadditives.
Variation of COP with 0.15%
concentration of
Nano additives.

23. CONCLUSIONS
 As a conclusion to this topic I would like to say that Nanotechnology is a brand
new technology that has just began, it is a revolutionary science that will change all what we
knew before.
 Nano refrigerant is an advanced mode of heat transfer in refrigeration system. It was shown
already by the researches that were held in the past.
 Now the new thing will be done by mixing different nano particles of the same size and shape
so that the effect can be studied out.
 Thermophysical properties, pressure drop, pumping power andheat transfer performance of
Al2O3/R-134a nanorefrigerants have been investigated.
 The motive is to increase the heat transfer and other thermo physical properties.

24. SCOPE FOR FUTURE WORK
 Future research is required to investigate the influence of the particle material. Its shape,
size, distribution, and concentration on refrigerant boiling performance.
 In the present study typical anionic and cationic surfactants were used improve the
performance of the refrigeration system. Other types of surfactants such as Zwitterionic
which contains a head with two oppositely charged groups positive and negative could be
tried out.
 The heat transfer results show that nano fluids have significant potential for improving the
flow boiling heat transfer of refrigerant/lubricant mixtures. However, It is unclear why a
large increase in heat transfer is observed with a insignificant increase in pressure.
Moreover, obvious challenges with particle circulation and unknown effects on the
compressor of an air conditioning or refrigeration system have not been addressed.

25. REFERENCES
• Er. R.K.Rajput, and S.K. Kataria and Sons, second edition(2012) a textbook of refrigeration and air-conditioning
• Abhishek Tiwari, and R.C. Gupta (2011) Experimental study of R404A and R134A in domestic refrigerator, International
Journal of Engineering Science and Technology, vol. 3 No. 8.
• A.Baskaran, P.Koshy Mathews ,( Sep 2012) A Performance comparison of vapour compression refrigeration.
• Bi S., Shi L. and Zhang L., (2008) Application of nanoparticles in domestic refrigerators. Applied Thermal Engineering, Vol. 28,
pp.1834-1843.
• D. Sendil Kumar, Dr. R. Elansezhian .,( Sep.-Oct. 2012) Experimental Study on Al2O3-R134a Nano Refrigerant in Refrigeration
System, InternationalJournal of Modern Engineering Research (IJMER) Vol. 2, Issue. 5, pp-3927- 3929.
• N. Subramani 1, M. J. Prakash, Experimental studies on a vapour compression system using nanorefrigerants, International
Journal of Engineering, Science and Technology,Vol. 3, No. 9, 2011, pp. 95-102.
• K. Leong, C. Yang, S. Murshed, A model for the thermal conductivity of nanofluids–the effect of interfacial layer, J. Nanopart.
Res. 8 (2) (2006) 245–254.
• T Coumaressin and K palaniradja, Performance analysis of a refrigeration system using nano fluid, International Journal of
Advanced Mechanical Engineering. ISSN 2250-3234 Volume 4, Number 4 (2014), pp. 459-470 .
• Ching-Song Jwo, Chen-Ching Ting, Wei-Ru Wang (2012) ,Efficiency analysis of home refrigerators by replacing hydrocarbon
refrigerators, International Journal of Measurement, Vol. 42, 697-701.