Project: Super Best Supermarket / Denmark

Planning / Implementation / Main components

Güntner AG & Co. KG

Refrigerant

Carbon dioxide (CO₂)

System start-up

October 2005

At its Copenhagen branch, the Danish supermarket chain Super Best uses a carbon dioxide refrigeration system which operates at three different temperature levels. The cold rooms were fitted with evaporators by the company Güntner.

Demands

The new building, which has a volume of approximately 65,000 m³, was to be fitted with an economic, environmentally friendly system to maintain a temperature of -28°C in the deep-freeze warehouse, and of -10°C in the adjacent automatic picking hall.Refrigeration was to be delivered without the use of F-gases, as Danish law has restricted the use of fluorinated gases in newly installed refrigeration systems to a maximum charge of 10 kg since 2007.

Solution

With an evaporation temperature of -28°C the carbon dioxide keeps the air in the freezer cabinets and deep-freeze chambers at -20°C. For above-freezing refrigeration in the cabinets and the cold rooms, the system supplies the evaporators with carbon dioxide at -10°C. The heat is dissipated using a condenser, supplied by Güntner, which acts as a gas cooler when ambient temperatures are high or when the system is operated in supercritical mode.

Type of facility

Cascade system

Refrigerant

CO₂

Secondary refrigerant:

CO₂

Refrigerating capacity

150 kW

Refrigerating temperature

Deep-freeze chambers/cabinets: -28ºC
Cold rooms/cabinets: -10ºC

Main components:

Evaporators, CO₂ gas cooler/ condenser, 13 compressors, plate heat exchanger

Special features / Comments:

Its quiet design makes the gas cooler a good choice even for locations with very strict noise protection requirements, e.g. in spa towns, hospitals or nursing homes.