9 N. ACHAICHIA HONEYWELL

Evolution des Fluides Frigorigènes et leurs futurs.
Nacer Achaichia - Honeywell
Nacer.achaichia@honeywell.com

Résumé.
L’industrie de la réfrigération a subi d'importants changements afin de répondre
aux différentes réglementations. Le Protocole de Montréal prévoit l'élimination
progressive des substances appauvrissant l'ozone. En conséquence, divers
fluides de remplacement ont été proposés et utilisés. Certains de ces fluides ont
malheureusement un index d’effet de serre (GWP) plus important que celui des
fluides frigorigènes substitués. Le protocole de Kyoto a également mis en
lumière la question du réchauffement climatique. Fluides frigorigènes comme les
HFC sont de nouveau sous contrôle en raison de leurs propriétés radiatives et
présentent généralement des GWP élevés. Il est évident que le GWP est utilisé,
entre autres, par les décideurs politiques comme un critère de sélection des
fluides frigorigènes en vue de réglementer leur utilisation.
Honeywell a lancé un vaste programme de recherche pour identifier la quatrième
génération qui intègre les propriétés environnemental souhaitées tel que un
faible GWP, tout en évitant les problèmes de toxicité, de stabilité et de
compatibilité et en conservant les caractéristiques de hautes performances
associées aux fluides frigorigènes fluorés.
Une nouvelle plate-forme à ultra-faible GWP basée sur les Hydrofluoroléfines
(HFO).
Parmi les molécules découvertes par Honeywell, HFO-1234yf a émergé comme
un nouveau réfrigérant à faible réchauffement global (GWP = 4) qui est
essentiellement une solution de remplacement pour la plupart des systèmes
actuellement conçu pour le R134a et a été choisi comme réfrigérant de choix
pour une solution durable et globale pour la climatisation automobile.
Une autre molécule à faible GWP HFO1234ze (E) a été identifiée et est
actuellement commercialisé par Honeywell. Cette molécule présente des
propriétés chimiques proches de celles du R-134a, est très efficace en énergie
avec un GWP de seulement 6.
Les formulations du HFO-1234yf et du HFO-1234ze permettent d’envisager de
remplacer le R-134a dans d’autres types d’application telle la réfrigération
commerciale et industrielle. En plus de ces deux fluides frigorigènes, des
mélanges à base de HFO, ont été développés pour couvrir les besoins de la
réfrigération et de la climatisation. Ces mélanges formant la gamme des HFO ont
des propriétés plus proches de celles des fluides frigorigènes de hautes
pressions, comme le R-404A, R-407C et R-410A.
Pour le court terme et afin de trouver une réponse aux besoins pressant pour
remplacer le R22 et le R404A, un nouveau fluide frigorigène, Performax-LT, sera
présenté.

Evolution des Fluides
Frigorigènes et leurs futurs.
Nacer Achaichia
Nacer.achaichia@honeywell.com

Refrigerants Technology Progress

Introduction
 Two very low GWP molecules have been developed:
 HFO-1234yf as a near drop-in replacement for R-134a
in auto a/c system.
This molecule is a Hydro-Fluoro-Olefin (HFO) that
has a very short atmospheric life of only 11 days (as
compared to 12 years for HFC-134a) and an
extremely low GWP of only 4 vs. 1430 for R-134a.
 HFO-1234ze, is currently replacing R-134a for onecomponent foam applications.
This molecule also has a very short atmospheric
lifetime with a GWP of 6.
 This presentation will discuss applications of these two
molecules as components of higher pressure refrigerant
blends in stationary AC&R systems.
Viable LGWP Candidates exist for Stationary AC&R

Overview of Fluorocarbon Refrigerants

Volumetric Capacity

Mildly Flammable “2L”
Refrigerants

Non-Flammable Refrigerants

R410A

L41
N40

L40

PERFORMAX-LT

N20

R22

R404A

L20
1234yf

N13

R134a

1234ze

0
0
GWP<150 - Ultra Low GWP →

500

GWP<500 - Low GWP →

1000
←Reduced
GWP→

1500

2000

2500

GWP

3000

3500

4000

LGWP Molecules
GWP

Tb (C)

Tc (C)

PEL, ppm

LFL-UFL
vol%, 23C

Base: 134a

1410

-26

101

1000

-

1234ze(E)

6

-19

110

1000*

-

1234yf

4

-30

94

500

6.2-12.3

Isobutane

~5

-12

135

800

1.8-8.5

CO2

1

-78

31

4000

-

Ammonia

~1

132

50

15-28

(extrapolated)

-33

1234yf
1234ze(E)

* Company preliminary values

Pressure – Temperature Relationship
1800

Vapour Pressure (kPa)

1600
1400

R134a
1200
1000
800

1234ze
Isobutane
1234yf

600
400

Atmospheric Pressure

200
0
-30 -25 -20 -15 -10 -5

0

5

10 15 20 25 30 35 40 45 50 55 60

Temperature (Deg. C)

Toxicological Properties
• Both HFO-1234yf and HFO-1234ze have been extensively studied.
– Acute, sub-chronic, and chronic effects evaluated
– These molecules are judged safe to use based on these
evaluations.
• Results are comparable to HFC-134a
• ASHRAE std 34 has classified HFO-1234yf as low toxicity or class A.
• Would expect the same classification of HFO-1234ze.

HFO-1234ze & HFO-1234yf have low Toxicity

HFO-1234yf Flammability Properties
Flammability is evaluated by ‘Chance of Flame occurring’ and ‘Effect of Flame occurring’
• Chance of Flame occurring -> Lower Flame Limit, Minimum Ignition Energy
Minimum Ignition Energy, mJ

10000

HFO-1234yf

1000

g
in ity
s
ea abil
r
c
1243zf
In mm
a
Fl

Ammonia

100

10

1 Iso-Butane

R-32

> 5000 times
more energy
to ignite!

Methane
R-152a

0.1 Propane

Gasoline

Acetylene

0.01
0

25

50

75

100

125

150

175

200

225

250

275

300

325

350

Lower Flame Limit, g/m3

Difficult to ignite HFO-1234yf due to high Minimum Ignition Energy

HFO-1234yf Flammability Properties
Flammability is evaluated by ‘Chance of Flame occurring’ and ‘Effect of Flame occurring’
•Effect of Flame occurring -> Burning Velocity, Heat of Combustion
Heat of Combustion, MJ/kg

60
methane
butane

50
gasoline

propane

40

ing
s
rea ct
c
In
pa
Im

30
Ammonia

20

ASHRAE Class 3

10

ASHRAE Class 2

R152a

HFO-1234yf
Class 2L
R32 (proposed)

R134a

0
0

5

10

15

20

25

30

35

40

45

50

Burning Velocity, cm/s

HFO-1234yf will be classified in Class 2L (Low Burning Velocity)

Refrigerant Stability
Thermal Stability:
 Sealed tube tests using 1234ze and 1234yf with lower viscosity (ISO 10 and ISO 7).
 Test Conditions: 2-week duration; 2 temperatures (175C and 200C); 2 moisture
levels (<50 ppm and 1000 ppm).
 Both 1234yf and 1234ze show excellent stability: Clear color and very low TAN
numbers.
1234ze 2-week Tests
1000 ppm Moisture @ 200°C

1234yf 2-week Tests
1000 ppm Moisture @ 200°C

Honeywell’s Reduced/Lowest GWP Options
N Series
L Series
Current Product

Reduced GWP Option
( A1)

Lowest GWP Option
(A2L)

R-404A
GWP=3922

HFO Blend – GWP~1300 (retrofit) N-40
HFO Blend – GWP~1000 (new equip) N-20

HFO Blend GWP~200-300 L-40

HCFC-22
GWP=1810

HFO Blend – GWP ~1000 N-20

HFO Blend GWP <150 L-20

HFC-134a
GWP=1430

HFO Blend – GWP ~600 N-13

HFO-1234yf GWP = 4 L-YF
HFO-1234ze GWP = 6 L-ZE

R-410A
GWP=2088

HFO-Blend GWP <500 L-41

Low and Reduced GWP R-404A Replacements
Honeywell has developed refrigerant replacements for R-404A with significantly lower GWP
 Currently available refrigerant - Performax LT Refrigerant
 GWP reduction of over 50% relative to R-404A and ~15% lower than R-407A.
 Performance is superior to both R-404A and R-407A.
 In addition we have two developmental refrigerants, N-40 and N-20
 N-40 can be used in existing R-404A equipment with little or no modifications
 GWP reduction of over 65% as compared to R-404A with superior performance.
 N-20 is intended for new equipment.
 GWP reduction of over 75% (GWP lower than1000) as compared to R-404A
 Improved efficiency, somewhat lower capacity
 A low GWP refrigerant (<300) is also under development
 L-40 offers superior performance with a >90% reduction in GWP.

Refrigeration System Test Apparatus

 2.2 kW semi-hermetic condensing unit with evaporator for walk-in freezer/cooler.
 Simulated long connecting lines as found in typical supermarket facilities, taking into
account suction pressure drop effects.
 Operating Conditions:
 Low temperature:
 -26C and -18C Box
 24C and 35C Ambient Temperature
 Medium Temperature
 2C and 10C Box
 24C and 35C Ambient Temperature

Refrigeration System Test Results
Retrofit & New Equipment
Appl.

New Equipment

Parameter
R407A

Performax LT

N-40

N-20

L-40

Capacity
Efficiency

94%
107%

102%
109%

99%
108%

83%
105%

99%
110%

Comments

Needs to close TXV (2.5
turns)

Needs to close TXV (2.5
turns)

Capacity
Efficiency

92%
99%

103%
105%

Comments

Needs to close TXV (3.75
turns)

Low
Temperature

Medium
Temperature

Reasonable drop-in at Needs new TXV. Controlled
17.7ºC. Needs to close
superheat using an EEV
TXV(1.25 turns) for all range.

102%
105%

86%
101%

Maintains small superheat as Maintains small superheat as
drop-in. Closed TXV (2.25
drop-in. Closed TXV (1.6
Needs new TXV. Controlled
turns) to match R404A
turns) to match R404A
superheat using an EEV
superheat.
superheat.

Needs new TXV. Controlled
superheat using an EEV

101%
104%
Needs new TXV. Controlled
superheat using an EEV

Reduced GWP Options:
 Currently available refrigerant - Performax LT Refrigerant
 GWP reduction of over 50% relative to R-404A. GWP ~15% lower than R-407A. Performance is superior
to both R-404A and R-407A.
 We have two developmental refrigerants, N-40 and N-20
 N-40 can be used in existing R-404A equipment with little or no modifications
 GWP reduction of over 65% as compared to R-404A. Superior Performance
 N-20 is intended for new equipment.
 GWP reduction of over 75% (GWP lower than1000) as compared to R-404A. Improved efficiency,
slightly lower capacity
Low GWP Options:
 L-40 is the best match from performance point of view
 GWP reduction of over 90% relative to R-404A with superior performance.
 L-20 testing is underway.

Experimental Evaluation of Heat Pumps
 Test Systems
 R-22 13 SEER (3.8 Seasonal COP) 3-Ton (10.5kW) Split-type Heat Pump
 R-410A 13 SEER 3-Ton Split-type Heat Pump (smaller size for same perf.)
 Tests Conditions according to AHRI Std 210
 All tests performed under drop-in conditions using original equipment.
 An Electronic Expansion Valve used for R410A tests.
 Used charge closer heating mode (H1) optimum to avoid overcharge.
Operating Conditions (Cooling Mode)
Test Condition
AHRI Std. A
AHRI Std. B
AHRI Std. C
AHRI Std. MOC

Indoor Ambient
DB(ºC)
WB(ºC)
26.7
19
26.7
19
26.7
14
26.7
19

Outdoor Ambient
DB(ºC)
WB(ºC)
35
24
27.8
18
27.8
46.1
24

Operating Conditions (Heating Mode)
Test Condition
AHRI Std. H1
AHRI Std. H2
AHRI Std. H3

Indoor Ambient
DB(ºC)
WB(ºC)
21.1
15.6
21.1
15.6
21.1
15.6

Outdoor Ambient
DB(ºC)
WB(ºC)
8.3
6.1
1.7
0.6
-8.3
-9.4

R410A Heat Pump: Cooling Mode Results
Cooling Mode
Refrigerant

R410A

L-41

Cap.

EER

mass
flow

Tcd

Tev

% of
R410A
100%
100%
100%
100%
92%
93%
95%
94%

% of
R410A
100%
100%
100%
100%
100%
101%
104%
104%

% of
R410A
100%
100%
100%
100%
68%
69%
75%
67%

% of
R410A
100%
100%
100%
100%
103%
103%
104%
103%

% of
R410A
100%
100%
100%
100%
105%
106%
114%
105%

AHRI-Std

A
B
C
MOC(46)
A
B
C
MOC(46)

Tdisch

°C
77
67
71
94
88
76
77
108

Pd/Ps
% of
R410A
100%
100%
100%
100%
100%
99%
96%
102%

R410A Heat Pump: Heating Mode Results

Heating Mode
Refrigerant

R410A

L-41

Cap.

EER

mass
flow

Tcd

Tev

Tdisch

Pd/Ps

% of
R410A

% of
R410A

% of
R410A

% of
R410A

% of
R410A

°C

% of
R410A

100%
100%
100%
100%
91%
93%
84%
84%

100%
100%
100%
100%
102%
102%
95%
95%

100%
100%
100%
100%
71%
74%
69%
68%

100%
100%
100%
100%
101%
102%
97%
99%

100%
100%
100%
100%
108%
119%
120%
115%

79
80
76
90
84
85
83
98

100%
100%
100%
100%
96%
95%
99%
97%

AHRI-Std

H1 (8.3/21)
H2 (1.6/21max)
H2(1.6/21 avg)
H3 (-8.3/21)
H1 (8.3/21)
H2 (1.6/21max)
H2(1.6/21 avg)
H3 (-8.3/21)

R22 Heat Pump: Cooling Mode Results

Cooling Mode
Refrigerant

R22
L-20
N-20

AHRI-Std
A
B
C
A
B
C
A
B
C

Cap.

Eff

mass
flow

Tcd

Tev

Tdisch

Pd/Ps

% of R22

% of R22

% of R22

% of R22

% of R22

°C

% of R22

100%
100%
100%
94%
95%
95%
91%
94%
94%

100%
100%
100%
93%
95%
94%
95%
99%
98%

100%
100%
100%
107%
107%
109%
107%
106%
109%

100%
100%
100%
103%
104%
105%
100%
100%
101%

100%
100%
100%
103%
103%
107%
100%
99%
103%

81
70
73
68
59
60
65
57
58

100%
100%
100%
107%
107%
106%
106%
105%
103%

R22 Heat Pump: Heating Mode Results
Heating Mode
Refrigerant

R22

L-20

N-20

AHRI-Std

Cap.

Eff

mass
flow

Tcd

Tev

Tdisch

Pd/Ps

% of R22

% of R22

% of R22

% of R22

% of R22

°C

% of R22

H0 (16.6/21)
H1 (8.3/21)
H2 (1.6/21max)
H2(1.6/21 avg)
H3 (-8.3/21)
H1 (8.3/21)
H2 (1.6/21max)
H2(1.6/21 avg)
H3 (-8.3/21)

100%
100%
100%
100%
100%
100%
100%
97%
101%

100%
100%
100%
100%
100%
92%
90%
89%
89%

100%
100%
100%
100%
100%
106%
104%
104%
107%

100%
100%
100%
100%
100%
111%
115%
112%
117%

100%
100%
100%
100%
100%
104%
105%
105%
125%

83
80
80
80
87
72
73
71
77

100%
100%
100%
100%
100%
118%
126%
122%
125%

H1 (8.3/21)

96%

95%

105%

103%

92%

68

116%

Comments on Heat Pump Results
 R410A-like Refrigerant - L-41 shows potential to replace R410A
 Capacity and efficiency close to that of R-410A
 Slightly higher efficiency but slightly lower capacity
 These differences should be reduced with minor system changes.
 GWP of this blend offer considerable reduction from R-410A(>75%).
 R22-like Refrigerants (L-20 and N-20)
 5% to 6% lower capacities and efficiencies in cooling mode.
 Heating mode: similar capacity with lower efficiency.
 The use of optimum charge for cooling mode affected results in heating
mode (higher condensing temperatures).
 Significantly lower discharge temperature.
 GWP of mildly flammable blend (L-20) is less than 150 while the nonflammable blend (N-20) is less than 1000.
 Results show trade-off between GWP (direct effect) and efficiency.
 Higher GWP refrigerant outperformed the lower GWP refrigerant despite
the physically smaller R-410A heat pump.
 An LCCP analysis shown on the next slide shows that the higher GWP
refrigerant is a better environmental choice

GWP Impact on LCCP – Heat Pumps

•
•
•

An evaluation was conducted on the contribution of the direct impact of refrigerant GWP
on overall system contribution to global warming.
– LGWP refrigerants with GWPs of 500 and 150 are compared to R-410A
Results show minimal gain when reducing GWP below 500.
Any decrease in efficiency would more than offset any reduction in direct impact
Analysis based on paper presented at Earth Technology Forum “Performance and
Environmental Characteristics of R-22 Alternatives in Heat Pumps” and heat pump
results.
40,000

Assumptions:
•
5% annual leak rate
•
15 year life
•
15% end-of-life loss
•
Southern EU climate
used.
•
Units are reversible
(heat/cool)
•
No efficiency loss
relative to R-410A for
LGWP-500 but 8%
lower COP for LGWP150

35,000

34,000

33,100 Total

0.5%

31,600
5.8% Direct

1.2%

30,000

LCCP (kg CO2 eq.)

•

25,000
Direct
Indirect

20,000

15,000

10,000

5,000

Baseline 410A

LGWP-500

LGWP-150

Conclusions
•

•

•

Recently developed low global warming molecules may have potential
applications in systems that currently employ medium pressure refrigerants
and there is a need for this transition.
– Such as small commercial refrigeration systems and chillers.
– Unlike CO2, comparable performance to existing refrigerants can be
achieved in applications investigated to date without significant
hardware modification.
Preliminary evaluations of higher pressure blends show promise however
there are trade offs in performance, flammability, and GWP that need to be
made.
This initial work is encouraging but further work is needed to more fully
explore these applications.
– This would include additional performance evaluations as well as
conducting flammability risk assessments where appropriate.

Thank you!
Questions?
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