mostafa siminar

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Helwan University

Faculty of Engineering

Mechanical Power Eng. Dep. Mattaria-Cairo

1

PERFORMANCE EVALUATION OF A RESIDENTIAL

AIR-CONDITIONER WORKING WITH OZONE-FRIENDLY REFRIGERANTS

Submit ted by

Eng. Mostafa Hassanain Mahmod

In Partial Fulfillment of the Requirement for Degree of Master

of Science in Mechanical Engineering

Supervised by

Prof. Dr. Mohamed Fatouh Ahmed

Dr. Essam Mahrous Elgendy

Mechanical Power Engineering Department

Faculty of Engineering (Mattaria)

Helwan University


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2

Helwan University

Faculty of Engineering

Mechanical Power Eng. Dep. Mattaria-Cairo

PERFORMANCE EVALUATION OF A RESIDENTIALAIR-CONDITIONER WORKING WITH OZONE-FRIENDLY REFRIGERANTS

Examining committee:

Mechanical Power Engineering

Department

Faculty of Engineering, Cairo

University

Pro. Dr. Adel Khalil Hassan


Department

Faculty of Engineering,

Mattaria, Helwan University

Pro. Dr. Abdel Hamid Basheer Helali


Department

Faculty of Engineering,

Mattaria, Helwan University

Pro. Dr. Mohamed Fatouh Ahmed


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Table of contents

1. Introduction

2. Literature Survey

3. Objective of Present Work

4. Test rig Description

5. Experimental Results

6. Conclusions and Recommendations

3


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Introduction

4


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Introduction

5

Environmental Challenges.

Ozone Depletion (The Montreal Protocol)

Substance) Base Level Production/Consumption Rate Control

First Group

HCFC

substances

Average

Consumpti

on Rate in

2009-2010

Freezing production/consumption

levels (1st January, 2013)

10% reduction (1st January ,2015)

35% reduction (1st January , 2020)

67.5% reduction (1st January ,2025)

100% reduction (1st January, 2030) with a

possible exemptions for necessary uses.

Table (2.1): Timetable for phasing out use of HCFCs for (UNIDO, 2009)


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6

Introduction

Global Climate Change (Kyoto Protocol)

Fig.1 Global warming of HFC mixtures (Dupont,2009)


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7

Introduction

Refrigerant Selection Criteria.

Fig.2 Mechanisms and some refrigerant options to substitute R22 in medium

and low temperature applications. (Llopis et al., 2012)


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8

Introduction

100 200 300 400 500

Specific enthalby (kJ/kg)

1

10

100

Pressure(bar)

R-22

R-438A

T=40C

T=-25C

T=5C

Fig. 3 Pressure -enthalpy diagram of

the R-22 and R-438A

Fig.4 Pressure -enthalpy diagram of the R-22

and its drop-in R-422A.


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Literature Survey

9


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Literature survey

10

Authors YearInvestigation

TypeWorking fluids

Investigation

in

Elgendy E., Hassanain

M, Fatouh M 2014 Experimental R22,R438A

Assessment of R-

438A as a retrofit

refrigerant for R-22in direct expansion

water chiller

R. Llopis a,*, E. Torrella

b, R. Cabello a, D.

Sanchez a

2012 TheoreticalR22,R417B,R422D,

R404

HCFC-22

replacement with

drop-in and retrofit

HFC refrigerants in a

two-stagerefrigeration plant

for low Temperature


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Literature survey

11

Authors YearInvestigation

TypeWorking fluids Investigation in

R. Llopis,

Cabello,Snchez

, Torrella,

Patio. Snchez

2011 Experimental R22,R422A,R417B

Experimental evaluation of

HCFC-22 replacement by

the drop-in fluids HFC-

422A

and HFC-417B for low

temperature refrigerationapplications

Bukola Olalekan

Bolaji2011 Experimental R22,R404A,R507

Performance investigation

of ozone-friendly R404A

and R507 refrigerants as

alternatives to R22 in a

window air-conditioner

J.U. Ahamed

,R. Saidur, H.H.

Masjuki

2011Review

A review on exergy

analysis of vapor

compression

refrigeration system


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12

Literature survey

Authors Year InvestigationType

Working fluids Investigatedparameters

Vincenzo La

Rocca,

Giuseppe

Panno

2011 Experimental R417A, R422A ,R422D

Experimental performance

evaluation of a vapour

compression refrigerating

plant when replacing R22

with alternative

refrigerants

E. Torrella a, R.

Cabellob,, D.

Slnchezb, J.A.

Larumbea, R.

Llopisb

2010 ExperimentalR417A, R422A ,R422D

On-site study of HCFC-22

substitution for HFC non-

azeotropic blends

(R417A, R422D) on a water

chiller of a centralized

HVAC system

Ki-Jung Park,

Yun-Bo Shim,Dongsoo Jung

2009 Experimental R432A

Experimental performance

of R432A to replace R22 in

residential

air-conditioners and heat

pumps


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The literature survey revealed that many investigations were carried out on

air conditioner working with R22 alternatives but.

13

Literature survey

Concluding Remarks

Less research was conducted on an air conditioner running with R-422A

No investigation was carried for R-438A to evaluate its performance at

various operating conditions.


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15

Objective of Present Work

Flow rate through the condenser

Operating parameters

Inlet water temperature to the evaporator.

Inlet water temperature to the condenser.


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Test Rig

16


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PC unit

17

Test rig description

Plate 2 Hot water circuit.Plate 1 Primary working fluid circuit.


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18

Sightglass Receiver

Filter

drier

Evaporator

Expansion

Condenser

device

Compressor

p 3,t 3

ValveBall valveGate valve

T Temperaturep Pr es su reF Flow rate

Measured parameters

Chilled water

Hot water

Refrigerant

V 12

Condensing unit

DrainV 13

Hot water tank

Cooling coil

V 11 V 10t8

t9

F 2

Hot waterpu m p

t7

F 1

V 7V 6t6

V 9

V 8

Chilled water

pu m p

Drain

Chilled water

tank

Electric heater

Condensing unitCooling coil

Electric heater

V 1

p 5,t 5

p4

,t4

V 5

V 4

p 1,t 1p 2,t 2

V 3

V 2

Fig.5 A schematic diagram of the experimental apparatus.


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19


Ranges of operating parameters during the

experimental work

10 to 20 CInlet water temperature to the evaporator.

25 to 35CInlet water temperature to the condenser.

360kg/h to 556.9kg/hFlow rate through the condenser

358.2kg/hFlow rate through the evaporeator


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20


Instrumentation

Temperature at various locations in both primary and secondary

working fluids

Pressure at four locations in the primary working fluid circuit

Flow rate of secondary working fluids.

Input current and voltage supplied to the compressor.


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21

Data Reduction

EquationsParameter

)8T9(Twccwc= mcon,actQActual heating load

Qeva,act = mwe cwe (T6 T7)Actual cooling capacity

mr = Qeva,act / (h5 h1)Calculated ref. mass flow rate

Pelec = I V cos ()Actual compressor power

COPact,c = Qeva,act / PelecActual coefficient of

performance


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Experimental

Results

22


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Experimental result

23

Test Rig Validations

0

0.5

1

1.5

2

2.5

3

COP

PR

Present model

Fatouh et al. (2010)

Fig.6 Test rig validation using R-22 with Fatouh et al. (2010)


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24

Experimental result

Effect of Evaporator Water Inlet Temperature

Effect of Condenser Water Inlet Temperature

10 15 20Evaporator water inlet temperature (C )

1

6

11

16

21

26

Condenserandevaporatorpressures(bar)

pcon

peva

Twci=25.4 0.9 C

Twci=29.9 1.1 C

Twci=34.9 0.9 C


1

6

11

16

21

26

Condenserandevapora

torpressures(bar)

pcon

peva

Twci=24.9 0.5 C

Twci=30.7 0.8 C

Twci=34.8 1.5 C

Fig.8 Variation of operating pressures with evaporator water inlet

temperature at different condenser water inlet temperature for R-

422A.

Fig.7 Variation of operating pressures with evaporator

water inlet temperature at different condenser water inlet

temperature for R-438A


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25

Experimental result


1

2

3

4

5

Pressureratio

30

60

90

120

150

Ref

rigerantmassflowrate(kg/h)

PR

ref.

Twci=25.4 0.9 C

Twci=29.9 1.1 CTwci=34.9 0.9 C

Fig.9 Variation of pressure ratio and refrigerant mass

flow rate with evaporator water inlet temperature at

different condenser water inlet temperature for R-438A


1

2

3

4

5

Pressureratio

20

65

110

155

200

Refrigerantmassflowrate(kg/h)

PR

ref.

Twci=24.9 0.5 C

Twci=30.7 0.8 CTwci=34.8 1.5 C

Fig.10 Variation of pressure ratio and refrigerant mass

flow rate with evaporator water inlet temperature at

different condenser water inlet temperature for


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26

Experimental result

10 15 20Evaporator water inlet temperature ( C )

1

2

3

4

5

Coolingcapac

ityandcompressorpower(kW)

Qeva

Pcomp

Twci=25.4 0.9 C

Twci=29.9 1.1 C

Twci=34.9 0.9 C

Fig.11 Variation of actual cooling capacity and the

power input to the compressor with evaporator waterinlet temperature at different condenser water inlet

temperature for R-438A.


0

1

2

3

4

Coolingcapacityandcompressorpower(kW)

Qeva

Pcomp

Twci=24.9 0.5 CTwci=30.7 0.8 C

Twci=34.8 1.5 C

Fig.12 Variation of actual cooling capacity and the

power input to the compressor with evaporator water

inlet temperature at different condenser water inlet



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27

Experimental result


0

5

10

15

20

25

Evaporatoerwateroutlettemperature(C)

0

0.7

1.4

2.1

2.8

Coefficientofperformance

Tweo

COP

Twci=25.4 0.9 C

Twci=29.9 1.1 C

Twci=34.9 0.9 C

Fig.13 Variation of actual coefficient of performance andexit temperatures of evaporator with evaporator water

inlet temperature at different condenser water inlet



0

6

12

18

24

30

Evaporatoerwateroutlettemperature(C)

0

0.5

1

1.5

2


Tweo

COP

Twci=24.9 0.5 CTwci=30.7 0.8 C

Twci=34.8 1.5 C

Fig.14 Variation of actual coefficient of performance and exittemperatures of evaporator with evaporator water inlet

temperature at different condenser water inlet



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28

Experimental result

Effect of Condenser Water Mass Flow Rate

10 15 20

Evaporator water inlet temperature (C )

0

9

18

27

36

Evaporatoerwaterout

lettemperature(C)

0

0.55

1.1

1.65

2.2


Tweo

COP

wc=363.6kg/h

wc=406.8kg/h

wc=542.5kg/h

Fig.15 Variation of actual coefficient of performance and

exit temperatures of evaporator with evaporator water

inlet temperature at different condenser water flow rate

for R-438A

10 15 20

Evaporator water inlet temperature (C )

0

9

18

27

36

Evaporatoerwaterout

lettemperature(C)

0

0.55

1.1

1.65

2.2


Tweo

COP

wc=367.2kg/h

wc=406.8kg/h

wc=558kg/h

Fig.18 Variation of actual coefficient of performance and

exit temperatures of evaporator with evaporator water

inlet temperature at different condenser water flow rate

for R-422A.


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29

Experimental result

Comparison among Investigated Refrigerants

5 10 15 20 25Evaporator water inlet temperature (C )

0

5

10

15

20

25

Condenserandevapo

ratorpressures(bar)

pconpeva

R-22

R-438A

R-422A


1

1.75

2.5

3.25

4

Pressur

eratio

30

55

80

105

130

Refrigerantmassflowrate(kg/h)

PR

ref.

R-22

R-438A

R-422A

Fig.20 Comparison of variation of pressure ratio and

refrigerant mass flow rate with evaporator water inlet

temperature.

Fig.19 Comparison of variation of operating pressures with

evaporator water inlet temperature.


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30

Experimental result


0

1

2

3

4

Coolingcapacityandcompressorpower(kW)

Qeva

Pcomp

R-22

R-438A

R-422A


0

9

18

27

36

Evaporatoerw

ateroutlettemperature(C)

0

0.7

1.4

2.1

2.8


Tweo

COP

R-22

R-438A

R-422A

Fig.22 Comparison of variation of actual coefficient ofperformance and exit temperatures of evaporator

with evaporator water inlet temperature.

Fig.21 Comparison of variation of actual coolingcapacity and the power input to the compressor with

evaporator water inlet temperature.


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31

Experimental result

8 12 16 20 24Evaporator water inlet temperature (C )

75

80

85

90

95

100

Compressordichargetemperature(C)

R-22R-438A

R-422A

Fig. 23 Comparison of variation of compressor discharge temperature with evaporator water inlet temperature.


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Conclusions

32


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Conclusions

33

The relative condenser pressure of R-438A and R-422A to R-22 is

106.8% and129%, respectively.

The refrigerant mass flow rate of R-438A and R-422A is higher than

that of R-22 by 8% and 27.5% respectively.

The Pressure ratio of R-438A and R-422A increase by 8.9% and 18%

respectively.

The compressor electric power of R-438A decreases by 1.7% about

R-22, while R-422A increases by16.4%.

Actual cooling capacity of R-438A decreases by 8.6% and R-422A by

21.6%.


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34

Conclusions

The reported results of present work confirm that R-438A is the best

drop-in refrigerant for R-22 in the old water cooled chiller.

COP of R-438A and R-422A decrease by 9.3% and 32.8%

respectively.


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Recommendations

Predict the performance characteristics of the Heat pump system working

with R-438A .

Predict the performance characteristics of the R438A as a drop-in to R-22

in low back pressure applications.

35


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Present work publications

36

Elgendy E., Hassanain M., Fatouh M., Assessment of R-438A as a

retrofit refrigerant for R-22 in direct expansion water chiller,

International Journal of Refrigeration 2014, In press.

Elgendy E., Hassanain M, Fatouh M, International Journal of

Refrigeration 2014, In reviw.


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Thank you

mostafa siminar

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