Presentazione di Bachir Bella (Emerson Climate Technologies) al XVI Convegno Europeo il 12 giugno 2015 - 1a sessione

1. Latest Technologies in Refrigeration and Air Conditioning - XVI European Conference Milano, 12th - 13th June 2015
Low GWP Refrigerants and their
Effects on Scroll Compressors
Bachir Bella

2. Latest Technologies in Refrigeration and Air Conditioning - XVI European Conference Milano, 12th - 13th June 2015
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• Most of the test evidences are generated on Scroll
• Volumetric efficiency curves with pressure ratio are
different for scroll and other compression technologies
– Implication on Capacity
– Implication on COP
• Scroll has different limits parameters
– (e.g. Unloading)
Why Scroll

3. Latest Technologies in Refrigeration and Air Conditioning - XVI European Conference Milano, 12th - 13th June 2015
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Selected Refrigerant Evaluation
Criteria
Evaluation criteria Significance
GWP (PRG) Direct GWP - highest focus of F-gas Regulation
Efficiency (COP) Indirect GWP - Run-time energy costs (TEWI)
Volumetric Capacity Compressor size - retrofit for existing installations
Discharge Temperature,
Pressure,…
Application limitations - need for injection, impact on
efficiency and retrofit suitability
Safety Flammability class – EN378 A1, A2,A3
Pressure - PED : category I, II, III, IV
Materials (Lubricants) Reliability (FMEA) and Compatibilty
System impact cost, skill, … Considering system complexity (high pressures,
flammability,..), skill in system design, operation and
servicing, system cost impact

4. Latest Technologies in Refrigeration and Air Conditioning - XVI European Conference Milano, 12th - 13th June 2015
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Refrigerants Landscape
R-410A
Like
Capacity
R404A &
R407/22
Like
R134a
Like
GWP Level
400-675
< 1500
~600
150 -
300
HFO1234yf
HFO1234ze
R410A
R407C/F/A
0 500 1000 1500 2000
Pressure
Or
R32 – L41
DR5A - ARM71A
R134a
CO2
R404A
R290
NH3
A1 – Non Flammable
A2L – Mildly Flammable
A3 – Flammable
B2L – Toxic, Mildly Flam.
Qualitative Chart –
Not To Scale
(3922)
DR7 - DR3
L40 - L20
HDR110,... R448A, R449A,..
R513A, R450A
- Developed
- Under Qualification
- In Development

5. Latest Technologies in Refrigeration and Air Conditioning - XVI European Conference Milano, 12th - 13th June 2015
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Refrigerants Landscape
Refrigeration Focus
R-410A
Like
Capacity
R404A &
R407/22
Like
R134a
Like
GWP Level
400-675
< 1500
~600
150 -
300
HFO1234yf
HFO1234ze
R410A
R407C/F/A
0 500 1000 1500 2000
Pressure
Or
R32 – L41
DR5A - ARM71A
R134a
CO2
R404A
R290
NH3
A1 – Non Flammable
A2L – Mildly Flammable
A3 – Flammable
B2L – Toxic, Mildly Flam.
Qualitative Chart –
Not To Scale
(3922)
DR7 – DR3
L40- L20
HDR110,...
R448A, R449A,..
R513A, R450A
High GWP
Low GWP

6. Latest Technologies in Refrigeration and Air Conditioning - XVI European Conference Milano, 12th - 13th June 2015
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R404A R448A R407A
0
1
2
3
4
5
6
7
8
9
10
WeightedEER
EER LT w/ VI
-6% 3%
Baseline
R404A R448A R407A
0
5000
10000
15000
20000
25000
30000
35000
40000
45000
50000
Capacity(BTU/hr)
Capacity MT (-6.6/49°C)
R448A vs. R404A
Medium and Low Temperatures Performances
6
R404A R448A R407A
0
5000
10000
15000
20000
25000
30000
35000
40000
45000
50000
Capacity(BTU/hr)
Capacity LT w/ VI (-31.6/41°C)
-1% - 4%
- 18%
- 22%
Baseline
Baseline
R404A R448A R407A
0
2
4
6
8
10
12
14
16
18
WeightedEER
EER MT
Baseline
-1% -2%
Model ZB45: 17 m3/h
65°F RG
Model ZF18

7. Latest Technologies in Refrigeration and Air Conditioning - XVI European Conference Milano, 12th - 13th June 2015
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R448A vs. R449A
Operating Envelopes
 Good potential for R448A and R449A in MT applications
 The high discharge temperature in LT requires further wet/liquid injection
with consequence on cost and/or performances
0
20
40
60
-45 -35 -25 -15 -5 5
CondensingTemp.(°C)
Evaporating Temp. (°C)
Low Temperature
0
20
40
60
-30 -20 -10 0 10
CondensingTemp.(°C)
Evaporating Temp. (°C)
Medium Temperature
ZF ModelZB Model

8. Latest Technologies in Refrigeration and Air Conditioning - XVI European Conference Milano, 12th - 13th June 2015
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Refrigerants Landscape
Refrigeration Focus (Low GWP)
R-410A
Like
Capacity
R404A &
R407/22
Like
R134a
Like
GWP Level
400-675
< 1500
~600
150 -
300
HFO1234yf
HFO1234ze
R410A
R407C/F/A
0 500 1000 1500 2000
Pressure
Or
R32 – L41
DR5A - ARM71A
R134a
CO2
R404A
R290
NH3
A1 – Non Flammable
A2L – Mildly Flammable
A3 – Flammable
B2L – Toxic, Mildly Flam.
Qualitative Chart –
Not To Scale
(3922)
DR7 – DR3
L40- L20
HDR110,...
R448A, R449A,..
R513A, R450A
Low GWP

9. Latest Technologies in Refrigeration and Air Conditioning - XVI European Conference Milano, 12th - 13th June 2015
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HFO & Blends (R32/R1234/…)
Performances & Properties
44%
57%
96% 100%
90%
107%
86%
1.25
1.10
1.15
1.08 1.09
1.06
0.94
20%
40%
60%
80%
100%
120%
140%
R1234ze
R1234yf
HFO1
HFO2
HFO3
HFO4
R290
PropertiesVs.R404A(%)
Volumetric Cooling capacity COP Pressure ratio
-10/45°C

10. Latest Technologies in Refrigeration and Air Conditioning - XVI European Conference Milano, 12th - 13th June 2015
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A Drop-in Experiment on a R404A
Scroll Compressor with DR7 and L40
• L40 & DR7 equal or better efficiency
• DR7 and L40 discharge temperatures are
+21 K and +38 K at LT
• Additional cooling (EVI or LI) is required
Med. Temp.Low Temp. Med. Temp.Low Temp.
0.92
1
0.94
0.975
0.95
1.04
0.79
0.85
0.82
0.86
0.83
0.95
0.7
0.75
0.8
0.85
0.9
0.95
1
1.05
1.1
-31.7/21.1 °C -31.7/40.6 °C -17.8/21.1 °C -17.8/37.8 °C -6.7/21.1 °C -6.7/48.9 °C
DR7, L40 Relative Capacity vs. R404A (Dew Point Based)
Actual compressor Tests - 6HpScroll
11 K Superheat, 0 k Subcool
DR-7 L-40
1.04
1.11
1.01
1.07
1.00
1.1
1.03
1.1
1.02
1.07
1.00
1.13
0.7
0.75
0.8
0.85
0.9
0.95
1
1.05
1.1
1.15
1.2
-31.7/21.1 °C -31.7/40.6 °C -17.8/21.1 °C -17.8/37.8 °C -6.7/21.1 °C -6.7/48.9 °C
DR7, L40 Relative COP vs. R404A (Dew Point Based)
Actual compressor Tests - 6HpScroll
11 K Superheat, 0 k Subcool
DR-7 L-40
17 m3/h Scroll compressor
Capacity
COP
21
16
13
38
26
22
0
10
20
30
40
50
-25/41 C -18/38 C -6.7/49 C
DischargeTemp.vsR404A(K)
Operating Conditions
HFOs Discharge Temperaure
DR7 Increase L40 Increase
(*) Blends Performance are referred to the Dew Point

11. Latest Technologies in Refrigeration and Air Conditioning - XVI European Conference Milano, 12th - 13th June 2015
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Most Critical Design Parameter for
CO2 is Pressure
• Most challenging feature is the high pressure for the Enclosure and sliding surfaces
• Enclosures designed at least for 3 times the max allowed pressures
– 270/420 bar for Medium Temperature
– 100/150 bar for booster and cascade LT application
• Sliding surfaces are highly stressed when used for transcritical application (reliability)
0
20
40
60
80
100
120
140
-60 -40 -20 0 20 40 60 80 100 120
MaxworkingPresures(bar) Temperature ( C)
R404A
Cycle
Optimization
LS-MediumT.
HS-MediumT.
R744
R134a
HSLowT.
System
Charge
CO2
R404A
R134a
LSLowT.
Criteria How R744 meet criteria?
Capacity
Cooling
Significantly higher volumetric capacity
4 to 5 times R404A
Efficiency Varies, depending on system type and
ambient temperature
Operating
Conditions
Operating and Standstill pressures
significantly higher
Safety high pressures and associated hazards
present challenges, Low toxicity
Suitability
as a retrofit
Not suitable because of higher pressure

12. Latest Technologies in Refrigeration and Air Conditioning - XVI European Conference Milano, 12th - 13th June 2015
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Propane R290 and
Propene R1270
78 83 9698 104 105102 109 130110 117 119
-50
-40
-30
-20
-10
0
10
20
30
40
50
60
70
80
90
100
110
120
130
140
DischargeTemperaturevs.R404A
R290 R1270 Discharge Temp.
30 C 45 C 60 C
Condensing Temp. ( C)
R290andR1270PerformancesvsR-404A(%) Evaporating Temp. : -10 CEvaporating Temp. : -10 C
COP
COP COP
Cap. Cap. Cap.

13. Latest Technologies in Refrigeration and Air Conditioning - XVI European Conference Milano, 12th - 13th June 2015
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R1234yf vs. R134a
Scroll Compressor Performances
102%
96%
102%
95%
104%
92%
109%
96%
-13 K -27 K
-30
-25
-20
-15
-10
-5
080%
85%
90%
95%
100%
105%
110%
115%
Volumetric
Efficiency
Cooling
capacity
Isentropic
Efficiency
COP Difference in
Discharge
Temp.
R1234yfvs.R134aDischargeTemp.(K)
PerformanceR1234yfvs.R134a(%)
-10/45 °C -15/60 °C
Model : ZH26

14. Latest Technologies in Refrigeration and Air Conditioning - XVI European Conference Milano, 12th - 13th June 2015
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Consequence of Flammability
• Flammability needs compliance with European Directives 94/9/EC and
99/9/EC so called ATEX
• Directives set the requirement for devices operating the explosive atmosphere
• Directive 94/9/EC is not harmonized with the standard EN378, does not
differentiate between flammability class as classified by EN378 (A2/A3) or
ASHRAE34 (A2L, A2, A3)
• Directive 94/4/EC impacts the electrical components of the compressor
Atmosphere Occurancy Zone Impact for the compressor
Explosive Permanent 0 Not applicable for most of refrigeration application
Occasionally 1
Accidentally 2 Assessment and mitigate the risk according to EN60079
Non Explosive Accidentally No zone Safe Ambient around the compressor (w/ or w/o ventilation)

15. Latest Technologies in Refrigeration and Air Conditioning - XVI European Conference Milano, 12th - 13th June 2015
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• PED directive 97/3/EC classifies the equipment in
accordance to the exposure risk, hence PED is more
restrictive for flammable
• All pressure bearing parts shall comply with PED (shell,
fittings, sight glass, Fusite)
• Scroll compressor housing belongs to higher PED
category by using flammable refrigerant
Consequence of Flammability
PED Category I II III
Pressure x Volume
(bar.liter)
Non flammable 50 - 200 200 -1000 1000 - 3000
Flammable 25 - 50 50 - 200 200 - 1000
Quality System approval Internal NB NB
Design Review Internal Internal NB
Welding process approval Internal NB NB
Weld Inspection Non destructive Test - - NB
NB: Notified body

16. Latest Technologies in Refrigeration and Air Conditioning - XVI European Conference Milano, 12th - 13th June 2015
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• Good potential with R448A/R449A for MT applications
• Potential shortfalls when replacing R404A in LT applications
– Efficiency shortfall will have a negative impact on global emissions
• HFO blends with GWP below 300 are promising candidates
– High discharge temperature most probably requires liquid/wet injection for LT
• CO2’s most challenging criteria is the high pressure for MT
• R290 shows good Performances, but high flammability is still a limiting factor
• Refrigerants with GWP below 300 are flammable except CO2
– Affects of electrical and the main pressure bearing parts
• Industry is investing in development qualification of many refrigerants
– Only few likely to be relevant in 15 years
Conclusion

17. Latest Technologies in Refrigeration and Air Conditioning - XVI European Conference Milano, 12th - 13th June 2015
Grazie per la Vostra
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