comparative study of new ecological gases · 0 2151 13,5 43,03 4 1,205 34811,964 : r442a (m tª) 0...

2017

JOSE LUIS URIBE-ECHEBARRIA

JAVIER MARTINEZ DE ILARDUYA

ANARTZ ITURRIOTZ

LEIRE LONBIDE INTXAUSTI

FRINSA S.L.

March 2017

COMPARATIVE STUDY OF NEW ECOLOGICAL GASES

March 2017

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1. INTRODUCTION

The purpose of the study is to provide a tool for both installers and maintainers,

as designers and distributors of refrigerant gases, to be able to choose the most

appropriate refrigerant to their needs, due to the large number of new gases

that have appeared in the market. It should be mentioned that this work has

been done within the TKgune program of the Basque Government.

TKgune is a Network of Innovation, Technology Transfer and Competitive

Enterprise development for the implementation and improvement of technology,

developing a specialized offer, including advanced training and technical value -

added services in the field of R + D + I, for the development of innovation

dynamics and continuous improvement of the key processes and products of

SMEs, to help them access to emerging markets and high added value.

In TKgune Vocational Training centres in collaboration with the Basque

Government are involved. TKgune is divided into five strategic environments, which include the following technology areas: Automation, Energy, Automotive, Manufacturing and Creative Industries. Through the network of centres and faculty of Vocational Training in the

ENERGY environment in which the Integrated Centre of Vocational Training of

Construction and Energy Efficiency of Vitoria-Gasteiz, Eraiken CIFP

Construcción LHII., we offer the possibility of assistance in the implementation

and / or improvement of new work processes. The company will thus have

personalized tutoring of our professionals, such as the possibility of using our

network of centres as a test bench, prior to the implementation of the production

process.

On the initiative of the FRINSA SL company, the ERAIKEN centre has carried

out this project, which consists of analysing how the new refrigerant gases,

including the new organic refrigerants, to replace those currently used in

traditional Air conditioning, conservation and freezing.

As we know, we cannot talk about an ideal gas that fits in all kinds of

installations. Therefore, it is necessary to study each case, the conditions of

application, considering that we should achieve maximum energy efficiency,

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complying with environmental regulations, without harming the performance of

the facility and being economically viable.

This scenario forces planners and installers, above all, not to mention

conservative-repairers, to take into consideration a new generation of

refrigerant gases or refrigerators that are not yet sufficiently tested.

Because of this new scenario, a study has been carried out to clarify the

characteristics and consequences of using these new refrigerants in both new

installations and installations that are in operation.

The study has consisted in checking both the behaviour and the characteristics

determined by the manufacturers of new refrigerants, considering that some

refrigerants are in force until 2020.

To this end, two refrigeration chambers of identical construction characteristics

were installed and both were in identical environmental conditions and their

properties and characteristics were verified.

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2. CHARACTERISTICS OF THE INSTALLATION

1. Illustration. REFRIGERATOR SCHEME

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2. Illustration. REFRIGERATOR HOUSING PLANT

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3. Illustration. SITE OF THE COMMERCIAL REFRIGERATOR

4. Illustration. INSTALLATION AND EQUIPMENTS

6. Illustration. INSTALLATION DATA SHEET 5. Illustration. CHECKING AND ADJUSTING THE INSTALLATION

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The refrigerant gases checked in this project have been tested in medium (-5 / 0

° C) and low temperature (-25 / -20 ° C) and there have been as follows:

OPERATING TEMPERATURE

REFERENCE REFRIGERANT

ALTERNATIVE REFRIGERANT

MEDIUM

TEMPERATURE R 404 A

R 407 F

R 438 A

R 442 A

R 434 A

R 422 D

MEDIUM

TEMPERATURE R 134 A

R 450 A

R 1234 YF

R 1234 ZE

R 513 A

R 434 A

R 422 D

LOW

TEMPERATURE R 404 A

R 449 A

R 448 A

R 442 A

R 453 A

R 434 A

R 452 A

1. Table. TESTED REFRIGERANTS

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The following table shows the data corresponding to the refrigerants used for

the study.

In the data table enclosed, you can see the values corresponding to refrigerant

charges, GWP, prices, taxes of each refrigerant ..., which will allow us to select

the proper refrigerant in each of the situations.

PHYSICAL/ENVIRONMENTAL PROPERTIES

REFRIGERANTS ODP GWP Price €/kg Tax/kg Glide (ºC)

Gas charge (Kgs)

TEWI (Kgs CO2)

R134A 0 1300 6,06 26 0 1,3 18857,961

R450A 0 547 16,11 10,94 0,79 1,73 19398,011

R1234ze 0 7 29,33 0 0 0,89 17880,629

R1234yf 0 4 155,56 0 0 1 17934,869

R422D 0 2623 13,79 52,46 4,5 1,3 26555,847

R434A (M Tª) 0 3131 15,01 62,62 1,5 1,52 28378,535

R513A 0 572 24,8 11,44 0 1,005 17666,265

R404A (M Tª) 0 3784 7,69 75,68 0,7 1,5 39212,729

R407F 0 1705 8,61 34,1 6,4 1,2 33581,666

R438A 0 2151 13,5 43,03 4 1,205 34811,964

R442A (M Tª) 0 1793 9,94 35,86 4,6 1,2 35453,577

R404A (L Tª) 0 3784 7,69 75,68 0,7 1,5 31572,9

R442A (L Tª) 0 1793 9,94 35,86 4,6 1,2 27531,033

R448A 0 1300 17,24 26 6 1,25 24158,583

R449A 0 1307 16,25 26,15 6 1,02 22613,79

R434A (L Tª) 0 3131 15,01 62,62 1,5 1,52 29304,84

R452A 0 2067 23,90 41,34 3 1,12 23434,583

R453A 0 1664 13,835 33,28 4,2 1,13 23598,714

2. Table. CHARACTERISTICS OF THE REFRIGERANTS. GWP: AR3 IPCC VERSION III

NOTE: all data about prices and tax are referred to the Spanish market.

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3. METODOLOGY

The test methodology consisted in verifying the behaviour of the installation in

identical operating conditions (same thermal load and varying the refrigerant

gases.

0

5

10

15

20

25

10,8612,15

11,4212,31 12,27

14,02 13,47

19,9120,53 20,70 21,02

15,08 15,5814,58

13,88 14,2413,23

13,88

ENERGY CONSUMPTION Kwh/day

7. Illustration. DAILY ENERGY CONSUMPTION (KWh/day)

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DATA ACHIEVED

Suction Temperature

Discharge Temperature

High Side Refrigerant Out Temperature

Ambient Temperature

Cool room Temperature

Discharge Pressure

Suction Pressure

Compressor consumption

Energy consumption

Leaks and glide testing

Refrigerant measured charge by weight

MESURING DEVICES

• T, P probes

• Data logger: CLIMACHECK

• Energy counter: CIRCUTOR MOD. AR 6

• Data logger: AKM (Danfoss) CONCLUSIONS

The output of this study is to describe in detail the function of different

refrigerants by determining their advantages and disadvantages.

• COP.

• Cooling Capacity.

• Discharge Temperature.

• Glide tests.

• Expansion valve adjustments in comparison to R-404A and R134A.

• Real refrigerant charge (kg).

• Electric consumption (kWh).

• TEWI.

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4. PROCESS TO BE FOLLOWED

PHASES DESCRIPTION COMMENTS

Prepare fridge freezers and installation

• Make installation inert

• Prove out the pressure at 28 bar

• Make vacuum in the installation until 760 mmHg

Charge the refrigerant gas

Process to be carried out until stabilization

• Weigh the refrigerant gas

• Charge the refrigerant (in liquid phase) through the suction valve by means of a pressure gauge

• Start (ON/OFF) both of the fridge freezers simultaneously from vacuum condition until stable condition

• If necessary, recharge the refrigerant gas

• Load up to full viewfinder

• Check and write down data

Follow the procedure until the installation stabilizes

After 3 hours

Defrost process

• Defrost with electrical resistance

• Check and take data

Carry out the procedure every 3-4 hours

Cause leaks

• The installation should be kept on balance until leaks are provoked

• The induced leaks would be done as

Keep the procedure this way and under this condition for 1 day

Each leak procedure

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percentage of weight (20%)

means 3 hours

Recharge refrigerant gas

• Fill the installation by weight (20%). Recharge the gas and start up the system until it stabilizes. Then observe the performance of the system

Record the grams of gas recharged

Cause leaks

• Provoke again a 20% leak

• Fill the installation by weight (20%).

• Recharge the gas and start up the system until it stabilizes (until reaching Evap. T). Then observe the performance of the system

• Recharge with the same weight extracted

• Follow the same procedure until the system does not work

Keep functioning during 30 minutes

Keep functioning during 3 hours

CONCLUSION • Refrigerant variation Do not consider the leaks

Restart the procedure

• Make the installation inert blowing nitrogen

• Make vacuum in the installation

• Adjust the fridge freezers to initial condition

Clean the system

Fill the installation with a new oil before starting again e

3. Table. DEVELOPMENT OF THE PROCESS

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5. CONCLUSIONS

1. DATA AND OUTPUTS OF THE REFRIGERANTS TESTED IN THE FIRST ROOM IN MEDIUM TEMPERATURE

In the data table enclosed, you can see, among others, the values corresponding to Refrigeration Capacities, COP, Tª of discharge of each of the refrigerants, that will help to select the most appropriate option in each one of the installations.

On the other hand, and about the part of the test corresponding to the study of the possible variations in the properties of the refrigerants that are mixtures, when carrying out successive leaks, in these behaviours have not been detected very significant changes.

The following diagram shows the properties of the different gases checked in 1st

room. The fluorinated gases that have been tested in this room are R 134 A and its substitutes.

R134 AAvg.T (ºC) = 0,55

Suction Dens. (Kg/m3) = 9,44Net Refrig Cap. (Kw) = 2,06

Valv.Open. (%) = 36,53Charge (gr) = 1300

Liq. Dens.25ºC 1206 Kg/m3

R450 AAvg T (ºC) = 0,74



Liq. Dens.25ºC 1175,1 Kg/m3

R513 AAvg. T (ºC) = 1,14


Valv.Open. (%) = 50.69Charge (gr) = 1010

Liq. Dens.25ºC 1185,5 Kg/m3

R1234 zeAvg. T (ºC) = 3.62


Valv.Open. (%) = 39.98Charge (gr) = 890

Liq. Dens.25ºC 1293 Kg/m3R1234 yf

Avg. T (ºC) = 0.85Suction Dens. (Kg/m3) = 12,50

Net Refrig Cap. (Kw) =1.91Valv.Open. (%) = 65.10

Charge (gr) = 1000Liq. Dens.25ºC 1092 Kg/m3

R422 DAvg.T (ºC) = 1,06

Suction Dens. (Kg/m3) = 15,40Net Refrig Cap. (Kw) =2,25



R434 AAvg.T (ºC) = 1,56




1. Illustration. REFRIGERANTS PROPERTIES, 1ST ROOM

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In the following table, there are characteristics of refrigerants for this first group in comparison to the reference of this group which is the R134 A.

C O M P A R A T I V E R134A Medium Temperature Heat addition 1000w

M T R134A R450A R1234ze R1234yf R513A R422D R434A

Room T (ºC) 0,55 0,74 3,62 0,85 1,14 1,06 1,56 LP(Bar) 0,84 0,71 0,53 1,06 1,11 2,03 2,05 Ev T (ºC) -12,05 -10,43 -8,87 -11,89 -11,33 -14,06 -13,99 Suction T (ºC) 4,73 4,75 7,32 3,54 4,77 2,85 1,43 Superheat (ºC) 16,78 14,96 16,19 15,44 16,05 15,62 14,04 HP (Bar) 8,32 7,79 6,89 8,03 8,51 14,64 13,75 Conden. T (ºC) 36,85 39,43 41,15 35,36 35,53 38,98 36,82 EntEV T (ºC) 35,20 37,61 38,04 34,25 32,93 37,09 31,82 Sub-cool(ºC) 1,66 1,50 3,11 1,10 2,60 0,66 3,60 Discharge T (ºC) 67,30 66,52 63,11 57,56 57,08 66,13 60,18 Isoent Perform 71,48 65,24 70,21 63,10 77,37 65,98 69,44 Elec. Power (Kw) 0,67 0,63 0,59 0,70 0,72 0,98 0,98 COP 3,06 2,72 2,98 2,72 3,48 2,29 2,67 Cool. Cap (Kw) 2,06 1,72 1,75 1,91 2,49 2,25 2,62 Cool. Cap (%) 100,00 83,50 84,95 92,72 120,87 109,22 127,18 Comp. Ratio 5,07 5,14 5,16 4,38 4,51 5,16 4,84 Exp V. (%) 36,53 41,81 39,98 65,10 50,69 60,24 63,13 Suc. Dens. (Kg/m3) 9,44 7,50 7,50 12,50 11,10 15,40 16,50 Liq. Dens at 25ºC (Kg/m3) 1206,00 1175,10 1293,00 1092,00 1185,50 1150,00 1096,00 Refr.Charge (Kg) 1,30 1,73 0,89 1,00 1,01 1,30 1,52

Reference value Lower value Higher value

4. Table. REFRIGERANTS CHARACTERÍSTICS, 1ST ROOM

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The following graphs show the behaviour of an operating cycle of the gases tested in 1st room.

In the "drop in" operation that has been used in this test, we observe the order, from highest to lowest, of refrigerants that more easily exceed the thermal load of the heater (1000 W) and in addition to the other loads (transmission for refrigeration panels, defrosting, evaporator fans ...).

For R1234ze, to operate the expansion valve satisfactorily, an alternative orifice has been chosen and in addition to it the superheat has been modified.

9. Illustration. REFRIGERANTS BEHAVIOUR, 1ST ROOM

-505

R134A

-505

R450A

-505

R513A

-505

R1234yf

-505

R422D

-505

R434A

-5

0

5

R1234ze

-5

0

5

R1234ze with regulation

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The following graphs correspond to the results obtained of the gases tested in 1st room. The test conditions that have been established for these gases are the next ones:

O

Test conditions: Heater thermal load: 1000w Heating cycle: 50´(ON)-10´(OFF) Ambient Temperature: 25-27ºC

0,00

5,00

10,00

15,00

LP(Bar) HP(Bar)

0,84

8,32

0,71

7,79

0,53

6,89

1,06

8,03

2,03

14,64

2,05

13,75

1,11

8,51

HIGH AND LOW PRESSURE FOR R134A AND ALTERNATIVE GASES

R134AR450AR1234zeR1234yfR422DR434AR513A

0,00

50,00

100,00

150,00

Cap Frig(%)

100,0083,50 84,95 92,72

109,22127,18 120,87

COOLING CAPACITY (KW) FOR R134 A AND ALTERNATIVE GASES


0,0020,0040,0060,0080,00

V.Exp %

36,53 41,81 39,9855,00 60,24 63,13

50,69

EXP. VALVE OPENING (%) FOR R134A AND ALTERNATIVE GASES


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3. Illustration REFRIGERANTS PROPERTIES IN MEDIUM TEMPERATURE, 1ST ROOM

0,0010,0020,0030,0040,0050,0060,0070,00

TªCond(ºC) Tª Desc.(ºC)

36,85

67,30

39,43

66,52

41,15

63,11

35,36

57,56

38,98

66,13

36,82

60,18

35,53

57,08

CONDENSING AND DISCHARGE TEMPERATURE FOR R134A AND ALTERNATIVE GASES


0,00

0,20

0,40

0,60

0,80

1,00

P.Elec

0,67 0,63 0,59 0,70

0,98 0,98

0,72

ELECTRIC POWER (KW) FOR R134A AND ITS ALTERNATIVE GASES


0,000,501,001,502,002,503,003,50

COP

3,062,72 2,98

2,722,29

2,67

3,48

COP FOR R134 A AND ALTERNATIVE GASES

R134AR450AR1234zeR422DR434AR513AR513A

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2. DATA AND OUTPUTS OF THE REFRIGERANTS TESTED IN THE SECOND CAMERA IN MEDIUM TEMPERATURE

The following diagram shows the properties of the different gases checked in 2nd room. The gases that have been tested in this room are R 404A and its alternative gases.

R404 AAvg.T (ºC) = 1,06




R407 FAvg.T (ºC) = 1,47



Liq. Dens.25ºC 1117 Kg/m3 R438 AAvg.T (ºC) = 4,74




R442 AAvg.T (ºC) = 1,75

Suction Dens. (Kg/m3) = 10,00Net Refrig Cap. (Kw) = 3.33



R434 AAvg.T (ºC) = 2,24




R422 DAvg.T (ºC) = 4,2




11. Illustration. THERMODYNAMIC PROPERTIES OF THE GASES, 2ND ROOM

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The characteristics corresponding to this second group of refrigerants appeared in comparison to the reference that is the R404 A in the following table.

C O M P A R A T I V E R 404A Medium Temperature

Heat addition 2000w

M T R404A R407F R438A R442A R422D R434A

Room T (ºC) 1,06 1,47 4,74 1,75 4,2 2,24

LP(Bar) 2,53 2,14 2,03 2,23 2,14 2,46

Ev T (ºC) -15,73 -15,99 -12,54 -15,57 -14 -13

Suction T (ºC) -1,13 3,19 5,75 3,55 2,08 -4,85

Superheat (ºC) 14,38 17,01 16,46 16,82 15,98 9,01

HP (Bar) 15,00 15,26 13,98 15,43 13,08 14,46

Conden. T (ºC) 34,71 35,58 38,13 35,70 34,6 36,72

EntEV T (ºC) 33,76 33,10 36,07 32,80 32,6 33,81

Sub-cool(ºC) 0,78 0,19 0,00 0,49 1,11 0,97

Discharge T (ºC) 64,64 77,32 70,76 74,53 59,34 56,75

Isoent Perform 64,99 77,68 73,96 80,25 77,98 79,23

Elec. Power (Kw) 1,10 1,07 1,00 1,10 0,96 1,06

COP 2,40 2,90 2,82 3,02 2,89 2,94

Cool. Cap (Kw) 2,63 3,12 2,82 3,33 2,76 3,24

Cool. Cap (%) 100,00 118,63 107,22 126,62 104,9 123,2

Comp. Ratio 4,53 5,18 4,94 5,09 4,48 4,47

Exp V. (%) 68,30 41,40 52,67 43,28 67,12 75,5

Suc. Dens. (Kg/m3) 18,20 12,00 12,50 10,00 23,1 16,8

Liq. Dens at 25ºC (Kg/m3)

1048,00 1117,00 1140,00 1108,00 1095 1080

Refr.Charge (Kg) 1,50 1,20 1,21 1,20 1,52 1,3


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The following graph show the behaviour of an operating cycle (ON-OFF thermal load) of the refrigerant gases tested in 2nd room.

For R442A, R422D and to operate the expansion valve satisfactorily, an alternative orifice has been chosen and in addition to it the superheat has been modified.

12 Illustration. REFRIGERANTS BEHAVIOUR, 2ND ROOM

-5

0

5

R442A WITH REGULATION

-5

0

5R404 A

-5

0

5

R422DWITH REGULATION

-5

0

5

R434A WITH REGULATION

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The following graphs show the results about characteristics of the refrigerant gases tested in room 2. The test conditions that have been established for these gases are the following:


0,00

5,00

10,00

15,00

20,00

LP(Bar) HP(Bar)

2,53

15,00

2,14

15,26

2,03

13,98

2,23

15,43

2,14

13,08

2,46

14,46

HIGH AND LOW PRESSURE FOR R404A ND ALTERNATIVE GASES

R404AR407FR438AR442AR422DR434A

0,00

50,00

100,00

150,00

Cap Frig(%)

100,00118,63 107,22

126,62104,90

123,20

COOLING CAPACITY (KW) FOR R404 A AND ALTERNATIVE GASES


0,0020,0040,0060,0080,00

V.Exp %

68,30

41,4052,67

43,28

67,12 75,50

OPENING VALVE (%) FOR R404 A AND ALTERNATIVE GASES


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0,85

0,90

0,95

1,00

1,05

1,10

P.Elec

1,101,07

1,00

1,10

0,96

1,06

ELECTRIC POWER (KW) FOR R404A AND ALTERNATIVE GASES

R404A

R407F

R438A

R442A

R422D

R434A

0,0010,0020,0030,0040,0050,0060,0070,0080,00

TªCond(ºC) TªDesc. (ºC)

34,71

64,64

35,58

77,32

38,13

70,76

35,70

74,53

34,60

59,34

36,72

56,75

CONDENSING AND DISCHARGE TEMPERATURE FOR R404A AND ALTERNATIVE GASES

R404A

R407F

R438A

R442A

R422D

R434A

0,000,501,001,502,002,503,003,50

COP

2,402,90 2,82 3,02 2,89 2,94

COP FOR R 404A AND ALTERNATIVE GASES

R404A

R407F

R438A

R442A

R422D

R434A

13. Illustration. REFRIGERANTS PROPERTIES IN MEDIUM TEMPERATURE, 2ND ROOM

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3. DATA AND OUTPUTS OF THE REFRIGERANTS TESTED IN THE FIRST AND SECOND ROOM IN LOW TEMPERATURE

The next graph shows the physical properties of the gases tested in both chambers at low temperature. The fluorinated gases observed have been R404 A and its alternative gases for low temperature.

R404 AAvg.T (ºC) = -19,38

Suction Dens. (Kg/m3) = 8,33Apert.Válv. (%) = 23,61

Charge (gr) = 1500


R449 AAvg.T (ºC) = -18,66

Suction Dens. (Kg/m3) = 5,00Valv.Open. (%) = 16,45


R448 AAvg.T (ºC) = -18,24


Charge (gr) = 1250Liq. Dens.25ºC 1092.3 Kg/m3

R434 AAvg.T (ºC) = -19,30


Charge (gr) = 1520Liq. Dens.25ºC 1108 Kg/m3R442 A

Avg.T (ºC) = -19,00Suction Dens. (Kg/m3) = 6,25



R452 AAvg.T (ºC) = -19,69


Charge (gr) = 1120Liq. Dens.25ºC 1148,8 Kg/m3

R453 AAvg.T (ºC) = -18,90



14. Illustration. THERMODYNAMIC PROPERTIES OF THE GASES AT LOW TEMPERATURE

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Experimental Comparison of Low Temperature Refrigerants. R404A vs alternative refrigerants.

C O M P A R A T I V E R404A Low Temperature

Heat Addition 500w

L.T. R404A R434A R442A R448A R449A R452A R453A

Room T (ºC) -19,38 -19,30 -19,00 -18,24 -18,66 -19,69 -18,90

LP(Bar) 0,97 0,76 0,62 0,58 0,50 0,69 0,79

Ev T (ºC) -30,80 -30,97 -32,08 -31,91 -33,31 -33,20 -24,55

Suction T (ºC) -4,40 -7,32 -5,52 -1,74 -2,24 -5,66 -20,21

Superheat (ºC) 26,15 22,79 24,26 28,51 29,47 28,03 2,05

HP (Bar) 13,97 12,67 13,80 13,94 12,37 12,49 11,35

Conden. T (ºC) 32,07 30,58 31,70 33,16 29,38 32,77 31,48

EntEV T (ºC) 29,84 28,86 28,78 27,31 25,02 26,67 28,03

Sub-cool(ºC) 2,04 0,99 0,44 3,38 -0,27 -0,59 0,61

Discharge T (ºC) 67,68 59,71 66,64 63,13 60,84 57,87 56,35

Isoent Perform 82,00 83,70 80,00

Elec. Power (Kw) 0,83 0,72 0,74 0,69 0,66 0,71 0,77

COP 2,23 2,30 2,66

Cool. Cap (Kw) 1,85 1,66 2,05

Cool. Cap (%) 100,00 89,73 110,81

Comp. Ratio 7,60 7,77 9,14 9,46 8,91 7,98 6,90

Exp V. (%) 23,61 28,22 16,42 16,38 16,45 25,62 26,32

Suc. Dens. (Kg/m3) 8,33 7,70 6,25 4,50 5,00 9,09 7,14

Liq. Dens at 25ºC (Kg/m3) 1048,00 1108,00 1096,00 1092,30 1139,00 1148,80 1136,00

Refr.Charge (Kg) 1,50 1,52 1,20 1,25 1,02 1,12 1,13


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The following graphs show the performance of a normal operating cycle

(thermal load heater ON-OFF) of refrigerant gases tested in both rooms at low

temperature (Tª≈ - 20 ºC).

Operation behaviour of the tested gases that reach a temperature of -25ºC in a

cycle with orifice adjustment and regulation in the expansion valve.

15. Illustration. THE BEHAVIOUR OF THE REFRIGERANTS AT LOW TEMPERATURE

-27-25-23-21

R404ATª Set -25ºC

-27-25-23-21

R452A Tª Set -25ºC

-27-25-23-21

R453ATª Set -25ºC

-27-25-23-21

R442ATª set -25ºC

-25

-20

-15

R448A

-25

-20

-15

R449A

-25

-20

-15

R442A

-25

-20

-15

R448AWITH REGULATION

-25

-20

-15

R442AWITH REGULATION

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The following graphs correspond to the results obtained from the refrigerants

tested in the two rooms under low temperature conditions. The test conditions

established for these gases are the following:


0,00

5,00

10,00

15,00

LP(Bar) HP(Bar)

0,97

13,97

0,76

12,67

0,62

13,80

0,58

13,94

0,50

12,37

0,79

11,35

0,69

12,49

HIGH AND LOW PRESSURE FOR R404A AND ALTERNATIVE GASES R404A

R434AR442AR448AR449AR453AR452A

0,00

20,00

40,00

60,00

80,00

TªCond(ºC) Tª Desc.(ºC)

32,07

67,68

30,58

59,71

31,70

66,64

33,16

63,13

29,38

60,84

31,48

56,35

32,77

57,87

CONDENSING AND DICHARGE TEMPERATURE FOR R404A AND ALTERNATIVE GASES

R404AR434AR442AR448AR449AR453AR452A

0,00

5,00

10,00

15,00

20,00

25,00

30,00

V.Exp %

23,6128,22

16,42 16,38 16,45

26,32 25,62

EXP.VALV.OPENING (%) FOR R404A AND ALTERNATIVE GASES


March 2017

26

NOTE: The last two graphs, do not show values of all refrigerants since some

values are out of range.

16. Illustration. REFRIGERANTS PROPERTIES IN LOW TEMPERATURE

0,00

0,50

1,00

P.Elec

0,830,72 0,74 0,69 0,66 0,77 0,71

ELECTRIC POWER FOR R404A AND ALTERTENATIVE GASES AT LOW TEMPERATURE

R404A

R434A

R442A

R448A

R449A

R453A

R452A

2,002,102,202,302,402,502,602,70

COP

2,232,30

2,66

COP FOR R404A AND ALTERNATIVE GASES AT LOW TEMPERATURE

R404A

R434A

R442A

R448A

R449A

R453A

0,00

20,00

40,00

60,00

80,00

100,00

120,00

Cap Frig(%)

100,0089,73

110,81

COOLING CAPACITY FOR R404A AND ALTERNATIVE GASES AT LOW TEMPERATURE


March 2017

27

6. SUMMARY

Summarizing, the most extraordinary notes that have been observed after

conducting the study are:

Cycle graphs have been performed in a general way for all the gases in

each group, varying only the programming of the specific parameters of

each one, without varying orifice nor values of superheating. In cases

where adjustments have been made, it is indicated in the title of the

graph. These cycle graphs show the capacity of the installation to

overcome the thermal charge in each case.

The tables that are attached, which indicate the values reached by each

of the refrigerants tested, provide us with useful information to make a

preliminary and approximate estimate of the performance of the

installation. Specifically connecting the flow of refrigerant, specific

refrigeration production and / or valve opening.

As another complement for aiding the installer, when choosing between

a refrigerant or another, in addition to the cooling performance, the one

referring to the prices and taxes of each of them is attached, to provide

another Criteria, in this case economic and environmental.

The successive leaks and refills of refrigerant did not imply relevant

changes of operation in the different tests carried out

In relation to the configuration of the expansion system, the parameters

of other refrigerants (R22, R407A) have been tested in some of the tests

to check if there are any more stable improvements or operations, not

producing this improvement in any of the cases.

Medium Temperature: Generally, no special settings of the expansion

system have been needed once the electronic control for each type of

refrigerant has been configured.

March 2017

28

Low Temperature: In this case, a specific adjustment of the expansion

system in terms of orifice size and superheat values, in relation to the

configuration of the reference refrigerant, is required in all the alternative

gases. To carry out any retrofit, at least should be adjusted the elements

(expansion valve ...) and in the most adverse cases, some of the

elements of the installation must be changed. In Low Temperature, under

the conditions established, not all the gases tested reach -25ºC.

Likewise, there have been situations with very low superheat. With the

R453A the superheat was very low, even with risk of liquid entering the

suction of the compressor. In this case, the size of the orifice (smaller)

and the superheat (greater) were established, eliminating the problem

described above and achieving a correct operation. Although with the

R452 A. the situation was the opposite one.

Another test carried out in Low Temperature was the change of the

values called Ctes. Of Antoine, which are different and unique for each

gas and adjusting them with them the electronic control of expansion

valve can operate according to the specific characteristics of each

refrigerant.

For further information and / or doubts or any other question send an email to the following email address:

JOSE LUIS URIBE-ECHEBARRIA: [email protected]

LEIRE LONBIDE: [email protected]

mailto:[email protected]

mailto:[email protected]

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