The Australian copper industry has developed a new range of tubes to handle large scale refrigeration.
The addition of transcritical CO2 refrigerant systems for large scale refrigeration applications, initially for freezers in retail food outlets, requires tubes of higher strength than previously available in the market.
The previous range of tubes catered for pressure ratings of up to 40 Bar (4,100 kPa) but transcritical CO2 refrigerant operate at around 120 Bar (12,000 kPa) in the liquid phase and 60 Bar (6,000 kPa) in the gas phase. CO2 refrigerant also operates at a far higher temperature (150°C) compared to the current range of refrigerants that run at around 65°C.
Local manufacturer MM Kembla is producing a range of thicker wall copper tube for the 60 Bar application. It is also supplying a 120 Bar Copper-Iron alloy tube for the 120 Bar application along with suitable pressure rated fittings as part of its Kembla ECO XS range for CO2 refrigerant systems.
The use of transcritical CO2 refrigerant systems is currently a limited market but with the push for environmentally friendly, low GWP and efficient cooling systems it will undoubtedly increase.
With the change in refrigerant usage, it’s important installers select the appropriate pressure rated copper tube to suit the refrigerant and operating parameters of your equipment and installation.
This means we are now not talking about pressure increases of several hundred kPa that occurred when R410A refrigerants were introduced, but up to 9,000 kPa pressure increases.