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PERFORMANCE EVALUATION OF ALTERNATIVE
REFRIGERANTS
Madhu Sruthi Emani1, Ranendra Roy2, Bijan Kumar Mandal3
1,2,3Department of Mechanical Engineering,
Indian Institute of Engineering Science and Technology, Shibpur,(India)
ABSTRACT
The environmental problems of ozone depletion and global warming are of major concern in the world.
Refrigeration and air-conditioning have been identified as major causes for ozone layer depletion and global
warming. Thus, there is a great need to search for alternative refrigerants which can be used to replace the
conventional CFC and HFC refrigerants used in the refrigeration and air-conditioning systems .This paper
presents a detailed study on identifying various alternative refrigerants based on exergetic analysis of vapour
compression refrigeration system. The alternative ecofriendly refrigerants for different systems like domestic
refrigeration, air-conditioning and automobile air-conditioning have been proposed in this study.
Keywords: Alternative refrigerants, Exergetic analysis, Global warming, Ozone depletion, Vapour
compression refrigeration system.
I. INTRODUCTION
Refrigeration and Air-Conditioning now-a-days are more than just comfort. Today, with advancement in
technology and change in climatic conditions of the earth’s environment, refrigeration and air-conditioning have
become a necessity. In good old days, the main purpose of refrigeration was to produce ice, which was used for
cooling beverages, food preservation and refrigerated transport etc. Now we find various applications of
refrigeration and air conditioning in all fields like food processing, preservation and distribution, power plants,
vehicles and for commercial and residential comfort.
Refrigeration and air-conditioning have become very essential for mankind, without which the basic frame of
the society will be adversely affected. Despite their inherent advantages refrigeration and air-conditioning
contribute to the two major environmental problems: ozone layer depletion and global warming. Ozone
depletion is caused by releasing refrigerants into the atmosphere. Global warming is increasing at high rate by
emissions of carbon dioxide and methane resulting from hu man activity. Direct release of refrigerants accounts
for only about 2% of total equivalent carbon dioxide release and carbon dioxide released by production of power
to drive refrigerating systems is atleast ten times the direct effect of refrigerant emission. Therefore,
refrigeration and air-conditioning accounts for about 20% of observed global warming. According to the terms
of the Montreal Protocol, the manufacture, sale and use of chlorinated refrigerants were progressively phased
out. Thus, refrigerants with high global warming potential (GWP) such as R-12, were replaced by compounds of
lower GWP such as R-134a. The challenge now is to improve efficiency of systems, to reduce power
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consumption, to reduce leakage of refrigerants and to find ecofriendly refrigerants. The properties of few
refrigerants are shown in Table 1.
1.1. Exergy analysis of vapour compression refrigeration system
The vapour compression refrigeration systems release large amount of heat to the surroundings. The difference
in temperatures between the system and the surroundings, gives rise to irreversibility. The efficiency of the
vapour compression refrigeration system according to the first law of thermodynamics is usually measured in
terms of coefficient of performance (COP). From the first law analysis the sources of thermodynamic losses in a
thermodynamic cycle cannot be known. To identify and quantify the thermodynamic losses in a cycle second
law of thermodynamics is used. The term exergy is defined as the maximum amount of work which can be
produced by a system or a flow of matter or energy as it comes to equilibrium with a reference environment. A
system in complete equilibrium with its environment does not have any exergy. Thermodynamic value of
exergy can be used to assess and improve energy systems. The magnitude of exergy efficiency depends on the
states of both the system and the environment. The decrease in environmental impact of a process indicates the
increase of exergy efficiency.
The vapour compression refrigeration cycle with liquid vapour heat exchanger including superheating,
subcooling and pressure losses in evaporator and condenser is shown in Fig.1 (a) and (b).The first law, measures
performance of the refrigeration cycle in terms of coefficient of performance (COP), which is defined as the net
refrigeration effect produced per unit of work required.
Fig.1 (a) schematic diagram of a vapour compression cycle with liquid vapour heat exchanger; (b) pressure
enthalpy diagram of an actual vapour compression cycle with liquid vapour heat exchanger
Table 1.Properties of some refrigerants
Refrigerants
Replaces
Molecular wt
Critical
temp
(οC)
ASHARAE
Safety code
ODP
GWP
R12
-
120.93
112
A1
0.82
10600
R22
-
86.47
96.2
A1
0.034
1700
R502
R134a
R404A
R407C
R410A
R417A
R152a
R600a
-
R12
R502,R22
R22
R22
R22
R12,R134a
R12,R134a
111.64
102.03
97.6
86.2
72.58
106.75
66.05
58.12
80.7
101.1
72.1
87.3
72.5
89.9
113.3
134.7
A1
A2
A1
A1
A1
A1
A3
A3
0.221
0.000
0.000
0.000
0.000
0.000
0.000
0.000
4500
1300
3800
1700
2000
2200
120
20
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The second law of thermodynamics derives the concept of exergy, which always decreases due to
thermodynamic irreversibility In exergetic analysis the performance of a system is measured by exergetic
efficiency which is defined as the ratio of coefficient of performance of vapour compression cycle and the
coefficient of performance of reversible refrigerator operating between the same temperatures [1].
II. BACKGROUND WORK
Different researches contributed to the testing of new eco -friendly refrigerants which can rep lace the
conventional CFC and HCFC refrigerants. Also, good amount of numerical and experimental work has been
carried out on the exergetic analysis of alternative refrigerants.
Arora and Kaushik (2008) investigated an actual vapour compression refrigeration (VCR) cycle for exergy
analysis. A computational model had been developed for computing coefficient of performance (COP), exergy
destruction, exergetic efficiency and efficiency defects for R502, R404A and R507A. The investigation was
done for evaporator and condenser temperatures in the range of -50οC to 0οC and 40οC to 55οC, respectively.
The results indicated that COP and exergetic efficiency for R507A were better than that for R404A at condenser
temperatures between 40ºC and 55ºC. However, both refrigerants showed 4 – 17% lower value of COP and
exergetic efficiency in comparison to R502 for the condenser temperatures between 40οC and 55οC.
Reddy et al. (2012) dealt with the exergetic analysis of a vapour compression refrigeration system with selected
refrigerants. Effects of condenser temperature, evaporator temperature, sub-cooling of condenser outlet, super-
heating of evaporator out let and effectiveness of vapour liquid heat exchanger were computed. It was found that
R134a showed better performance in all respect, whereas R407C refrigerant has poor performance.
Fig.2 (a) Variation of cOP and (b) variation of exergitic efficiency with evaporator temperature.
Bolaji (2010) investigated the exergetic performance of a domestic refrigerator using two environment-friendly
refrigerants (R134a and R152a) and compared with the performance of the system when R12 was used. The
effect of evaporator temperature on the coefficient of performance (COP) and exergetic efficiency for R12,
R134a and R152a is shown in Fig. 2(a) and 2(b). The results depicted that the average COP of R152a was very
close to that of R12 with only 1.4% reduction, while 18.2% reduction was calculated for R134a in comparison
with that of R12. Exergetic efficiency decreases with increase in evaporator temperature. Average exergetic
efficiencies for R134a and R152a are 13.6% lower and 4.4% higher in comparison to that of R12, respectively.
They concluded that R152a performed better than R134a in terms of COP, exergetic efficiency and efficiency
defect as R12 substitute in domestic refrigeration system.
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Anand and Tyagi (2012) presented a detailed experimental analysis of 2TR (ton of refrigeration) vapour
compression refrigeration cycle for different percentage of refrigerant charge using exergy analysis. They
developed an experimental setup and evaluated performance on different operating conditions using a test rig
having R22 as working fluid. The coefficient of performance, exergy destruction, and exergetic efficiency for
variable quantity of refrigerant had been calculated. The investigation had been done by using 2TR window air
conditioner and the results indicated that the losses in the compressor are more pronounced, while the losses in
the condenser are less pronounced as compared to other components, i.e., evaporator and expansion device. The
total exergy destruction was highest when the system was 100% charged, whereas it was found to be least when
the system was 25% charged. It was observed that the total exergy destruction was comparable when the system
was 75 and 100% charged and least when the system was 25% charged because the evaporator temperature is
very close to the reference temperature. The average COP was highest when the system was 50% charged and
this is because of higher refrigerating effect and reduced compressor work. The exergy efficiency of the system
varied from 3.5 to 45.9% which was mainly due to the variation of evaporator temperature.
Bhatkar et al. (2013) experimentally studied the popular refrigerants and gave recommendations for alternatives
such as carbon dioxide, ammonia and hydrocarbons and new artificially created fluid, Hydro-Fluoro-Olefin
1234yf by DuPont and Honeywell which exhibit good thermo-physical and environmental properties and would
be commercialized in the near future. They reported that considering global warming R 134a should be phased
out and replaced by natural refrigerants such as ammonia, carbon dioxide and hydro carbons in vapour
compression refrigerat ion system for sustainable environment. HFO-1234yf was also found suitable for
refrigeration and air conditioning systems.
Khan et al. (2015) provided a detailed exergy analysis for theoretical vapour compression refrigeration cycle
using R12, R22 and R134A. They concluded that the COP and exergetic efficiency of R12 were better than that
of R22 and R134A. The EDR of R134A was higher than that of R22 and R12. This analysis was performed at
condenser temperature on 40ºC and evaporator temperatures ranges from -10ºC to -40ºC. For all refrigerants
R12, R22 and R134A COP and exergy efficiency increases with increase in degree of subcooling.
Pottker et al. (2015) presented a theoretical study about the effect of condenser subcooling on the performance
of vapour-compression systems. It was shown that, as condenser subcooling increases, the COP reaches a
maximum Refrigerants with large latent heat of vaporization tend to benefit less from condenser subcooling. For
an air conditioning system, results indicated that the R1234yf (8.4%) would benefit the most from condenser
subcooling in comparison to R410A (7.0%), R134a (5.9%) and R717 (2.7%) due to its smaller latent heat of
vaporization. The value of COP maximizing subcooling does not seem to be a strong function of
thermodynamic properties.
In a numerical study by Yang and Yeh (2015) on vapour-compression refrigeration systems using R22, R134a,
R410A, and R717 showed that low cooling water temperatures in the condenser significantly improved
performance, heat transfer, and exergy destruction and enlarges the optimal degree of subcooling for a vapour-
compression refrigeration system. The optimal degrees of subcooling for a vapour-compression refrigeration
system occurred between 2οC and 6°C for initial cost saving and from 4οC to 7οC for total exergy destruction for
R134a, R22, R410A, and R717.
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Yan et al. (2015) proposed a modified vapour-compression refrigeration cycle (MVRC) system which operates
with the zeotropic mixture R290/R600a for domestic refrigerator-freezers. In the MVRC system, a phase
separator was introduced to enhance the overall system performance. A theoretical energy and exergy analysis
on the performance of the MVRC was carried out by developing mathematical model, and then the results were
compared with that of the traditional vapour compression refrigeration cycle (TVRC) operating with the
refrigerant R600a and the zeotropicmixtureR290/ R600a, respectively. According to the simulation results of
these two cycles, the MVRC gave the most excellent performances in the COP (coefficient of performance), the
volumetric refrigeration capacity, the total exergy destruction and the exergetic efficiency under the same given
operating conditions.
Mohanraj et al. (2008) theoretically assessed the possibility of using R152a and hydrocarbon refrigerants (such
as R290, R1270, R600a, and R600) as alternatives to R134a in domestic refrigerators. The refrigerants were
assessed over wider range of condensing and evaporator temperatures. The results showed that pure
hydrocarbon refrigerants were not suitable to be used as alternatives to R134a due to their mismatch in
Volumetric Cooling Capacity. Whereas, R152a had approximately the same Volumetric Cooling Capacity with
about 9% higher coefficient of performance and lower values of operating pressure and compressor input power.
They also found that the discharge temperature of R152a was higher than that of R134a by about 14–26 K.
R152a is an energy-efficient and environment friendly alternative to phase out R134a in domestic refrigerators
as reported by them.
The exergetic performance of vapour compression refrigeration cycle with two-stage and intercooler using
refrigerants R507, R407c and R404a was analysed by Kilic (2012). The necessary thermodynamic values for
analyses were calculated by Solkane program. The coefficient of performance, exergetic efficiency and total
irreversibility rate of the system in the different operating conditions for these refrigerants were investigated.
The coefficient of performance, exergetic efficiency and total irreversibility rate for alternative refrigerants were
compared. The variation of exergetic efficiency with evaporator temperature is shown in Fig. 3(a). It was
observed that COP increased when evaporator temperature was increased for all refrigerants and Fig. 3(b) shows
that COP decreased when the condenser temperature increased. Obtained results depicted that COP and exergy
efficiency of the system using R407c were better than the other refrigerants. It was noticed that the system using
R507 refrigerant reaches the worst outcome in terms of total irreversibility rate. New ozone-friendly refrigerants
such as R507, R407c and R404a could be used to replace CFCs and HCFCs were reported by them.
Fig.3 (a) Variation of exergetic efficiency with evaporator temperature (b) variation of exergetic efficiency with
condenser temperature
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Ahmed et al. (2012) compared the energetic and exergetic performances of a domestic refrigerator using pure
butane and isobutane as refrigerants. The thermodynamic performances such as exergy destruction or losses,
exergy efficiency, and coefficient of performances (COP) were investigated. These parameters were measured at
varied operating conditions. They found that exergy loss and energy efficiencies of isobutane were found higher
than that of R-134a in all operating conditions. The analysis showed that the performances of butane and
isobutane as refrigerants were very near with HFC134a. It was also found that at higher evaporating
temperatures, the exergy losses were minimal. They highlighted that the maximum exergy loss occurred in the
compressor which was 69% of the whole losses in the system. Highest sustainability index was found for butane
compared to that of R134a and R600a, respectively.
Wu et al. (2009) reported a ternary blend R152a/R125/R32 with a mass ratio of 48/18/34 as a potential
alternative to R22. A co mputer code was developed with NIST REFPROP 7.0 for the comparative analysis of
thermo physical properties and refrigerant performance of this new mixture and of R22. A drop-in test of this
new mixture was performed in a domestic air-conditioner originally designed for R22. Both the calculation and
experimental results showed that this new mixture could be regarded as a most likely drop-in substitute for R22
in many applications safely.
Jung et al. (1999) investigated thermodynamic performance of supplementary refrigerant mixtures for CFC12
used in existing automobile air-conditioners was examined. A thermodynamic computer analysis of an
automobile air-conditioner was carried out for the initial screening of possible mixture candidates, and
refrigerant mixtures composed of HCFC22,HFC134a, HCFC142b, RE170 (dimethylether), HC290 (propane),
and HC600a (iso-butane) were proposed to supplement CFC12. They also manufactured a breadboard type
refrigeration test facility to verify the performance of the alternative refrigerant mixtures. Test results showed
that HFC134a/RE170mixture with zero ozone depletion potential is the best supplement to CFC12 as long term
candidate. On the other hand, HCFC22/HFC134a/RE170 and HCFC22/HFC134a/HCFC142b mixtures were
good only as short term supplementary alternatives since they contain HCFC22 as noted by them. They also
reported that hydrocarbon mixture of HC290/HC600a showed a good performance but its use in existing
automobile air-conditioners should be carefully considered due to its flammability.
Yataganbaba et al. (2012) investigated the exergy analysis on a two evaporator vapour compression
refrigeration system using R1234yf, R1234ze and R134a as refrigerants. A computer code was developed by
using Engineering Equation Solver to calculate exergy losses occurring in different system components, besides
the exergy efficiency of the refrigeration cycle. They concluded that R1234ze was the best among considered
refrigerants due to lower GWP and ODP values than R134a. The highest exergy efficiencies were obtained with
R1234ze and R134a. They concluded that HFO-1234yf could be a good alternative to HFC-134a as a
environmentally friendly refrigerant and could replace the conventional HFC-134a after having a slight
modification in the design even though the values of performance parameters for HFO-1234yf are smaller than
that of HFC-134a.
Soni and Gupta (2012) performed a theoretical study of a vapour compression refrigeration system with
refrigerants R-407C and R-410A. A computational model based on energy and exergy analysis was presented
for the investigation of the effects of evaporating temperatures, degree of subcooling, dead state temperatures
and effectiveness of the heat exchanger on the coefficient of performance, second law efficiency and exergy
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destruction ratio of the vapour compression refrigeration cycle. The COP and exergetic efficiency of R-407C are
better than that of R-410A. For both refrigerants i.e. R-407C and R-410A, COP and exergy efficiency improved
by sub cooling of high pressure condensed liquid refrigerant as shown in Fig. 4. The total increase in exergetic
efficiency for R-407C was 7.02% for 10℃ subcooling and for R-410A is 8.01% for 10℃.
A theoretical study by Dalkilic and Wongwises (2012) on a traditional vapour-compression refrigeration system
with refrigerant mixtures based on HFC134a, HFC152a, HFC32, HC290, HC1270, HC600, and HC600a for
various ratios was carried out and their results were compared with CFC12, CFC22, and HFC134a as possible
alternative replacements They found that all of the alternative refrigerants investigated in the analysis showed
slightly lower performance coefficient (COP) than CFC12, CFC22, and HFC134a for the condensation
temperature of 50 °C and evaporating temperatures ranging between − 30 °C and 10 °C. Re frigerant blends of
HC290/HC600a (40/ 60 by wt.%) instead of CFC12 and HC290/HC1270 (20/80 by wt.%) instead of CFC22
were found to be replacement refrigerants among other alternatives as reported by them.
Lugo et al. (2002) presented an easy-to-use and accurate method to calculate some of the thermo physical
properties of aqueous solutions which are used as secondary refrigerants. This method is based on the c orrection
of the ideal behaviour of aqueous solutions by excess functions. This method allows to determine the following
properties: freezing points, densities, heat capacities, thermal conductivities and dynamic viscosities. As an
illustration, it is applied to aqueous solutions of (i) ethyl alcohol, (ii) ammonia, (iii) sodium chloride, (iv)
ethylene glycol and (iii) propylene glycol. The approach involved, based on excess functions, is quite
straightforward since it generally requires only one interaction coefficient to account for non-ideal behaviour;
the model can be applied to other aqueous solutions as long as a database covering the whole domain
corresponding to the first eutectic point is available. If the approach involved here is applied to different
aqueous solutions, it will be possible to compare the properties of different secondary refrigerants in order to
choose the more convenient one for a given application.
Sieres et al. (2012) presented a hybrid formulation for the calculation of thermodynamic properties of pure
refrigerants and refrigerant mixtures. Explicit formulations were obtained to model so me properties that are used
0 1 2 3 4 5 6 7 8 9 10
0.100
0.105
0.110
0.115
0.120
Exergetic efficiency
Degree of subcooling (C)
R407c
R410a
Fig. 4.Effect of degree of subcooling on coefficient of
performance
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to predict other thermodynamic properties through differentiation, which assures a fast and stable calculation.
As an example the equations for R1234yf and R407C were presented in the paper. The source data for
regressing was obtained from REFPROP 9.0. The accuracy of the thermodynamic properties formulae was
satisfactory for applications in which computation speed and stability are preferred rather than accuracy. It was
shown that the deviations of the calculated thermal properties were always low and within the uncertainties of
the source data used for regression and accuracy evaluation. Each refrigerant and thermodynamic property is
treated in a similar way, so the method can be easily programmed and extended to other refrigerants.
Sozen et al. (2009) proposed a new approach (artificial neural network, A NN) to determine of thermodynamic
properties of an environmentally friendly alternative refrigerant (R407c) for both saturated liquid–vapour region
(wet vapour) and superheated vapour region. In this study, an ANN based methodology for the calculation of
thermodynamic properties of new ozone-friendly refrigerant R407c has been put forward. This work clearly
showed that, for the calculation of thermodynamic properties of refrigerant mixtures, the ANNs may be
employed. With the formulas obtained the user may use such results without a system running the relevant ANN
Software. In other words, they may be put in a spreadsheet application to provide useful results. With the
empirical formulae obtained from the ANN, the interval values have been calculated correctly.
III. OBSERVATIONS
The following observations were noted from this review on the exergetic analysis of the vapour compression
refrigeration system using alternative refrigerants.
i. R1234ze had both the low ODP and GWP and could be used to replace R134a.It was found that the values
of performance parameters for HFO-1234yf were smaller than that of HFC-134a, but the difference was
small, so it could be a good alternative to HFC-134a because of its environmentally friendly properties.
ii. The COP and exergetic efficiency of R-407C were found to be better than that of R-410A. For both
refrigerants i.e. R-407C and R-410A, COP and exergy efficiency improved by sub cooling of high pressure
condensed liquid refrigerant and the total increase in exergetic efficiency of 7.02% for R-407C and 8.01%
for R-410A for 10℃ subcooling was observed.
iii. The performances of butane and isobutane as refrigerants were found to be similar to HFC134a. . Highest
sustainability index was found for butane compared to that of R134a and R600a, respectively.
iv. Refrigerant blends of HC290/HC600a (40/ 60 by wt.%) instead of CFC12 and HC290/HC1270 (20/80 by
wt.%) instead of CFC22 were identified to be replacement refrigerants.
v. Various methods like hybrid formulation method, method based on correction of ideal behaviour of
aqueous solutions by excess function, Artificial Neural Network (ANN) used to determine the properties of
refrigerants for both saturated liquid-vapour region and superheated vapour region were discussed for
calculating the thermodynamic properties for different refrigerants.
IV. CONCLUSIONS
The following conclusions had been drawn at the end of this study.
i. R152a could be used to replace the conventional R12 refrigerant in domestic refrigeration systems.
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ii. HFC134a/RE170 mixture with zero ozone depletion potential could be the best long term supplement for
CFC12 used in automobile air-conditioners.
iii. HFO1234yf could be used as an alternative for the most used R134a and was found suitable for
refrigeration and air conditioning systems.
REFERENCES
[1] Akhilesh Arora and S.C. Kaushik, Theoretical analysis of a vapour compression refrigeration system with
R502, R404A and R507A, International Journal of Refrigeration, 31, 2008, 998-1
[2] V. Siva Reddy, N. L. Panwar and S. C. Kaushik, Exergetic analysis of a vapour compression refrigeration
system with R134a, R143a, R152a, R404A, R407C, R410A, R502 and R507A, Clean Technology
Environmental Policy, 14, 2012, 47–53.
[3] Bukola O. Bolaji, Exergetic performance of a domestic refrigerator using R12 and its alternative
refrigerants, Journal of Engineering Science and Technology, vol. 5, 2010, no. 4: 435 – 446.
[4] S. Anand and S. K. Tyagi, Exergy analysis and experimental study of a vapour compression refrigeration
cycle Journal of Thermal Analysis and Calorimetry, 110, 2012, 961–971.
[5] V. W. Bhatkar, V. M. Kriplani and G. K. Awari, Alternative refrigerants in vapour compression
refrigeration cycle for sustainable environment: a review of recent research International Journal of
Environmental Science and Technology, 10, 2013, 871–880.
[6] Md. Nawaz Khan, Md. Mamoon Khan, Mohd. Ashar and Aasim Zafar Khan, Energy and Exergy Analysis
of Vapour Compression Refrigeration System with R12, R22 and R134a, International Journal of
Emerging Technology and Advanced Engineering, issue 3 volume 5, 2015, ISSN 2250-2459.
[7] Gustavo Pottker and Pega Hrnjak, Effect of the condenser subcooling on the performance of vapour
compression systems International Journal of Refrigeration, 50, 2015, 156-164.
[8] Min-Hsiung Yang and Rong-HuaYeh, Performance and exergy destruction analyses of optimal subcooling
for vapor-compression refrigeration systems, International Journal of Heat and Mass Transfer, 87, 2015,
1-10.
[9] Gang Yan, Chengfeng Cui and Jianlin Yu, Energy and exergy analysis of zeotropic mixture R290/R600a
vapour-compression refrigeration cycle with separation condensation, International Journal of
Refrigeration, 53, 2015, 155-162.
[10] M. Mohanraj, S. Jayaraj and C. Muraleedharan, Comparative assessment of environment-friendly
alternatives to R134a in domestic refrigerators, Energy Efficiency, 1, 2008, 189–19.8.
[11] Bayram Kilic, Exergy analysis of vapour compression refrigeration cycle with two-stage and intercooler,
Heat Mass Transfer, Springer-Verlag, 48, 2012, 1207–1217.
[12] J. U. Ahamed, R. Saidur, H. H. Masjuki and M. A. Sattar, An analysis of energy, exergy, an d sustainable
development of a vapor compression refrigeration system using hydrocarbon, Interna tional Journal of
Green Energy, 9:7, 2012, 702-717.
241 | P a g e
[13] Jiangtao Wu, Yingjie Chu, Jing hu and Zhigang Liu, Performance of mixture refrigerant r152a/r125/r32 in
domestic air-conditioner, International Journal of Refrigeration, 32, 2009, 1059-1057.
[14] Dongsoo Jung, Bongjin Park and Hyunchul Lee, Evaluation of supplementary/ retro®t refrigerants for
automobile air-conditioners charged with CFC12, International Journal of Refrigeration,22, 1999, 558-568.
[15] Alptug Yataganbaba, Ali Kilicarslan and Irfan Kurtbas, Exergy analysis of R1234yf and R1234ze as
R134a replacements in a two evaporator vapour compression refrigeration system, International Journal of
Refrigeration, 60, 2012, 26-37.
[16] R.C. Gupta and Jyoti Soni, Exergy analysis of vapour compression refrigeration system with using R-407c
andRr-410a International Journal of Engineering Research & Technology, vol. 1 issue 7, 2012, issn: 2278-
0181.
[17] A.S. Dalkilic and S. Wongwises, A performance comparison of vapour-compression refrigeration system
using various alternative refrigerants, International Communicat ions in Heat and Mass Transfer, 37, 2012,
1340-1349.
[18] R. Lugo, Fournaison J.M. Chourot and J. Guilpart, An excess function method to model the thermophysical
properties of one-phase secondary refrigerants, International Journal of Refrigeration, 25, 2002, 916-923.
[19] Jaime Sieres, Fernando Varas and Jose Antonio Martinez-Suareza, Hybrid formulation for fast explicit
calculation of thermodynamic properties of refrigerants, International Journal of Refrigeration, 35, 2012,
1021-1034.
[20] Adnan Sozen, Erolarcaklioglu, Tayfun Menlik and Mehmet Ozalp, Determination of thermodynamic
properties of an alternative refrigerant(R407c) using artificial neural network, Expert Systems with
Applications, 36, 2009, 4346-4356.
