2a sessione

1. Latest Technology in Refrigeration and Air Conditioning - XVII European Conference Milano, 9 - 10 June 2017
R744 REFRIGERATING
SYSTEMS WITH MULTI
EJECTORS
Dario Agostini
09th June 2017

2. Latest Technology in Refrigeration and Air Conditioning - XVII European Conference Milano, 9 - 10 June 2017
Who we are
• Founded in 1988
• 35 Employees
• 5 Offices in Europe
• International presence
• Certified ISO 9001

3. Latest Technology in Refrigeration and Air Conditioning - XVII European Conference Milano, 9 - 10 June 2017
CO2 development references

4. Latest Technology in Refrigeration and Air Conditioning - XVII European Conference Milano, 9 - 10 June 2017
Efficiency increase
Liquid ejector
Benchmark power consumption:
rack with parallel compression
6-10%

5. Latest Technology in Refrigeration and Air Conditioning - XVII European Conference Milano, 9 - 10 June 2017
Efficiency increase
Liquid ejector
Vapour ejector
6-10%
5-8%
Liquid ejector
Vapour ejector
Heat exchanger
6-10%
5-8%
4-7%
Liquid ejector
Vapour ejector
Heat exchanger
Efficiency increase
6-10%
5-8%
4-7%
15-25%
Liquid ejector 6-10%
Benchmark power consumption:
rack with parallel compression

6. Latest Technology in Refrigeration and Air Conditioning - XVII European Conference Milano, 9 - 10 June 2017
Ejector design criteria
Gas cooler
Pressure 50-100 bar
Motive mass flow
Receiver
Pressure ± 38 bar
Total mass flow
Suction line medium temperature compressor
Pressure ± 33 bar
Suction mass flow

7. Latest Technology in Refrigeration and Air Conditioning - XVII European Conference Milano, 9 - 10 June 2017
• Total sales area: 5’250 m2
• Total length of cabinets: 135 m
• Medium temperature cabinets
without glass doors
• Walk-in-cooler/freezer: 9
• Medium temperature capacity: 2 x 100 kW
• Low temperature capacity: 2 x 30 kW
• 2 identical racks
– Unique possibility for energy benchmarking
– Supported by Swiss federals for energy research
Migros Mythencenter, Switzerland
Source: Genossenschaft Migros Luzern

8. Latest Technology in Refrigeration and Air Conditioning - XVII European Conference Milano, 9 - 10 June 2017
Measurement data 2nd July 2015
Peak values
TA: +32°C
pH: 90 bara
high pressure [bara]
gas cooler outlet temperature [°C]
ambient temperature [°C]
medium pressure [bara]
liquid level suction accumulator [%]
MT suction pressure [°C]
LT suction pressure [°C]

9. Latest Technology in Refrigeration and Air Conditioning - XVII European Conference Milano, 9 - 10 June 2017
Operation hours parallel compressor
19.6%
80.4%
Standard Booster with Parallel-
Compression
HT compressor
MT compressor
39.8%
60.2%
Multi-Ejector System 2
HT compressor
MT compressor
Comparable booster-system with
parallel compression
Migros Ibach
Multi-Ejector-System
Increased operation hours
of parallel compressor
Suction pressure: +3°C
Swept volume: 13.9 m3/h
Suction pressure: ±0°C
Swept volume: 8.4 m3/h

10. Latest Technology in Refrigeration and Air Conditioning - XVII European Conference Milano, 9 - 10 June 2017
Energy consumption

11. Latest Technology in Refrigeration and Air Conditioning - XVII European Conference Milano, 9 - 10 June 2017
Energy consumption
1'000
1'500
2'000
2'500
3'000
3'500
4'000
4'500
Energyconsumption[kWh/a-m]
Monthly average of comparable markets
Monthly average of Ejector system Migros Ibach
2860 kWh/m-a
2190 kWh/m-a
-23%

12. Latest Technology in Refrigeration and Air Conditioning - XVII European Conference Milano, 9 - 10 June 2017
Carrefour Timişoara (Romania)
• Total sales area: 7’770 m2
• Total length of cabinets: 249 m
• Medium temperature cabinets
without glass doors
• Walk-in-cooler/freezer: 31 (800 m2)
• Medium temperature capacity: 310 kW
(125 kW + 185 kW)
• Low temperature capacity: 66 kW
(46 kW + 20 kW)
• 2 racks
• Commissioning: November 2015

13. Latest Technology in Refrigeration and Air Conditioning - XVII European Conference Milano, 9 - 10 June 2017
Measurement data 21st August 2016
Peaks values
TA: +34 °C
HP: 91 bara
High pressure [bar]
gas cooler outlet temperature [°C]
ambient temperature [°C]
medium pressure [bar]
MT suction pressure [°C]
LT suction pressure [°C]
0
5
10
15
20
25
30
35
40
45
50
55
60
65
70
75
80
85
90
95
100
-35
-25
-15
-5
5
15
25
35
08:01:00 10:01:00 12:01:00 14:01:00 16:01:00 18:01:00 20:01:00 Pressure[bar]
Temperature[°C]
Tgc (°C) T ambient (°C) MT To (°C) LT To (°C) High pressure (bar) Medium pressure (bar)

14. Latest Technology in Refrigeration and Air Conditioning - XVII European Conference Milano, 9 - 10 June 2017
Electrical consumption
Average (Timişoara excluded): 2941 kWh/(m*a)
- 30 %
2207 kWh/(m*a)
0
500
1000
1500
2000
2500
3000
3500
Vulcan Turgu Jiu Mega Mall Ploiesti Orhideea Timisoara
kWh/(m*a)
Full CO2 installation electrical consumption

15. Latest Technology in Refrigeration and Air Conditioning - XVII European Conference Milano, 9 - 10 June 2017
• Multi-Ejector-System at Migros Bulle in operation since summer 2013
• Multi-Ejector-System at Migros Ibach in operation since November 2014
• Implementation based on standard components  except ejectors
• T0 = -2°C in MT
• T0 = -26°C in LT
• Increased operation hours of parallel compressor at T0 = +3°C
• Efficiency increase of 15-25% compared to booster with parallel
compression
– high ambient temperature
– heat recovery operation
Ejectors summary

16. Latest Technology in Refrigeration and Air Conditioning - XVII European Conference Milano, 9 - 10 June 2017
Thank you
for your attention
d.agostini@frigoconsulting.com