The document discusses technologies for replacing HCFC refrigerants with lower global warming potential and more energy efficient alternatives in the refrigeration and air conditioning sector. It focuses on carbon dioxide (CO2) as a replacement refrigerant, describing its use in industrial applications. The technologies discussed include CO2 cascade systems, transcritical CO2 systems, compressors, safety valves, and the current and future market trends for CO2 refrigerants in Brazil.

1. Tecnologías de Reemplazo para HCFC de
Bajo Potencial de Calentamiento Global y
Eficientes Energéticamente en el Sector de
Refrigeración y Aire Acondicionado
Soluciones para
Aplicaciones Industriales con
CO2 como Remplazo
Leonilton Tomaz Cleto - Yawatz Engenharia
Bogotá – Colombia – 22/04/2010

2. The peak of utilizing
CO2 as refrigerant
Reinvention of CO2-
refrigeration technology
(G. Lorentzen)
1850 1920 ----------1930 1960 1993

4. CO2 Thermodynamic Process
Transcritical Cycle
Sub-critical Cycle

5. +35ºC
R-744/R-717 – Cascade System
Compressor
R717
R-717
Pressure
R717
R-744/R-717 – Cascade HX
-12ºC +35oC (13.5 bar)
-8ºC
Compressor -12oC (2.7 bar)
R-744
Enthalpy
-40ºC
Liquid Sep.
R-744
Pressure
-8oC (28.0 bar)
R-744
-40oC (10 bar)
-40ºC
Evaporator – R-744 Enthalpy
By Finn Broesby Olsen & Niels P Vestergaard – Danfoss AS - 2004

6. +35ºC R-744/R-717 – Cascade System
R-744 Hot Gas Defrost
Compressor
R717
R-717
Pressure
R717
R-744/R-717 – Cascade HX
-12ºC +35oC (13.5 bar)
-8ºC
Compressor -12oC (2.7 bar)
R-744
Enthalpy
-40ºC
Liquid Sep.
R-744
+8 oC (43 bar)
Pressure
Compressor -8oC (28.0 bar)
R-744 for Defrost
-40oC (10 bar)
-40ºC
Evaporator – R-744 Enthalpy
By Finn Broesby Olsen & Niels P Vestergaard – Danfoss AS - 2004

7. +35ºC
R-744/R-717 Cascade System
Pumped CO2 as Secundary Fluid
Compressor
R717 R-717
R-717/R-744 – Trocador “Cascata”
-14ºC
R717
-10ºC
Compressor
R-744
+35ºC (13.5 bar)
-10ºC Sep. Líquido -14ºC (2.5 bar)
Sep. Líquido
CO2 Enthalpy
Evaporador – R-744 -10ºC
-40ºC R-744
Sep. Líquido
-10ºC (26.4 bar)
CO2 -40ºC (10 bar)
Enthalpy
-40ºC
Evaporador – R-744

8. R-744 x R-717 – Compressor Displacement
R-744 R-22
HPC104S
Compressors: Vs x 7-10
HPC106S
3 x SAB202SF
By John Ritmann – York Refrigeration - 2004

9. R-744 x R-717 – Compressor Displacement
R-22
R-744
By John Ritmann – York Refrigeration - 2004

10. R-744/R-717 – Cascade System
No se puede mostrar la imagen. Puede que su equipo no tenga suficiente memoria para abrir la imagen o que ésta esté dañada. Reinicie el equipo y , a continuación, abra el archiv o de nuev o. Si sigue apareciendo la x roja, puede que tenga que borrar la imagen e insertarla de nuev o.
By John Ritmann – York Refrigeration - 2004

11. R-744/R-717 – Cascade System
By John Ritmann – York Refrigeration - 2004

12. R-717 – PHE Chillers

13. R-744 Compressors
Transcritical Cycle
Transcritical CO2 for Industrial Refrigeration - By Yoshikawa – Mayekawa Co.
Danfoss IR Consensus - 30/11/2004

14. R-744 Compressors
Transcritical Cycle
Transcritical CO2 for Industrial Refrigeration - By Yoshikawa – Mayekawa Co.
Danfoss IR Consensus - 30/11/2004

15. Design Pressure
By Finn Broesby Olsen & Niels P Vestergaard – Danfoss AS - 2004

16. Optimized COP
By L. Tomaz Cleto – Yawatz Engenharia - 2007

17. COP Comparison of Refrigeration Systems

18. COP – R-744/R-717 Cascata x R-717 “Booster”
By L. Tomaz Cleto – Yawatz Engenharia - 2007

19. Data for comparison of
pipe cross section areas
Common calculation data:
Capacity 250 kW
Temperature Drop in Dry Suction 0.8 K
Line: ∆T
Temperature Drop in Wet return 0.8 K
Line: ∆T
Circulating Rate (Liquid Pump) 3
Velocity in Liquid Line 0.8 m/s
Equivalent Pipe Length 50 m
Evaporating Temperature -40 oC
Condensing Temperature -15 oC
By Finn Broesby Olsen & Niels P Vestergaard – Danfoss AS - 2004

20. Comparison of pipe cross
section area
Dry suction / Liquid lines
By Finn Broesby Olsen & Niels P Vestergaard – Danfoss AS - 2004

21. Comparison of pipe cross
section area
Wet return / Pumped Liquid lines
By Finn Broesby Olsen & Niels P Vestergaard – Danfoss AS - 2004

22. Comparison of pipe cross
section area
Dry suction / Liquid lines
Index
5%
95%
Liquid
Suction
4%
96%
CO2= 30%
70%
R-134a R-717 R-744
By Finn Broesby Olsen & Niels P Vestergaard – Danfoss AS - 2004

23. Comparison of
pressure and subcooling
produced in liquid risers
Refrigerante R-134a R-717 R-744
Pressure produced in
liquid riser ”∆p” bar 0.418 0.213 0.329
Subcooling produced in
liquid riser ”∆ t ” K 14.91 5.21 0.88
CO2 reciever
H=3m ∆p ∆t
By Finn Broesby Olsen & Niels P Vestergaard – Danfoss AS - 2004

24. Safety Valves
CO2 expansion - phase changes +31 oC
31.0ºC
Supercritical
Vapor - 50 bar
Liquid Vapor - 35 bar
Liquid - 20 bar
Pressure (bar abs)
Sólido -Liquido
Liquido - Vapor
50% solid CO2 at 0% solid CO2 at the
Sólido the triple point triple point
-56.6 oC
5.2 bar
3% solid CO2 at the
Solid - Vapor triple point
Vapor
-78.4 oC
Enthalpy
By Finn Broesby Olsen & Niels P Vestergaard – Danfoss AS - 2004

25. Safety Valves

26. CO2 Expansion – Trapped Liquid
Relative liquid volume
Volume Change
Temperature
By Finn Broesby Olsen & Niels P Vestergaard – Danfoss AS - 2004

27. R-744/R-717 – Cascade System
No se puede mostrar la imagen. Puede que su equipo no tenga suficiente memoria para abrir la imagen o que ésta esté dañada. Reinicie el equipo y , a continuación, abra el archiv o de nuev o. Si sigue apareciendo la x roja, puede que tenga que borrar la imagen e insertarla de nuev o.
By John Ritmann – York Refrigeration - 2004

28. Water Solubility
Water Solubility – Vapour Phase
Water Content (ppm)/
CO2 +
kg of Refrigerant
CO2 + Water
Ice
CO2 +
Water Vapour
Temperature
By Finn Broesby Olsen & Niels P Vestergaard – Danfoss AS - 2004

29. R-744 (CO2) as REFRIGERANT
Primary Refrigerant – (Sub-Critical Cycle):
Low Temperatures – Cascade System (-30ºC to -55ºC)
Higher COP for temperature lower than -35ºC
Lower Compressor Displacement
Small refrigerant lines
Low Toxicity ( ASHRAE Standard 34 - Class - A1 – TLV = 5000 ppm > HFCs)
No flammable
High Pressure(40 - 60 bar)
New Technologies (Some conceptions from “Freon” Systems)
Higher Water Solubility

30. R-744 (CO2) as REFRIGERANT
Secondary Refrigerant:
IntermediateTemperatures (-20.0ºC to 0.0ºC)
Two-phase Flow
High Heat Transfer Coefficient
Very Small Refrigerant Lines

31. Industrial Refrigeration Market
Industrial Refrigeration – EU
JCI-York – DK (Sabroe/ Frick)
GEA-Grasso
Danfoss
Alfa-Laval
Star Refrigeration
FMC - Frigoscandia
Mayekawa (Japan)
IIR-IIF
USA to support CO2 solutions

32. Market Trend
Industrial Refrigeration in Brasil
Food Industry
R-717, Ammonia and NH3
PHE Chillers – Reduced Refrigerant Charge
Secondary Fluids (-15.0ºC a 0.0ºC)
R-744 - ??? – Great Future!
Legislation/ Safety NBR 16069:2010

33. Market Trend
Industrial Refrigeration in Brasil
Process Industry/ Industrial Air Conditioning
R-22 – Almost “Naturally” Phased Out
R-717 Plants
HCs – (R-1270) – Classified Area
R717 – PHE Chillers – Reduced Refrigerant Charge
HFCs – Chilled Water Systems

34. Natural Refrigerants in Brasil (2010)
More than 80% of the food industry using R-717 plants.
Hundreds of R717 PHE Chillers:
Mainly for Process and Food Industry.
Very few in air conditioning for office buildings.
4 Supermarkets using PHE chillers and secondary fluids (LT/ MT/ AC).
Few plants using HCs (Chemical Industry).
1 R-744/R-717 cascade system for food industry.
1 R-744/R-404A cascade system for supermarket.
2-3 new projects using R-744 cascade system for distribution
centers.