Abstract: A CO2 cooling system includes a compression stage in which CO2 refrigerant is compressed; a cooling stage in which the CO2 refrigerant releases heat; a CO2 liquid receiver in which the CO2 refrigerant is accumulated in liquid and gaseous states; an evaporation stage in which the CO2 refrigerant, having released heat in the cooling stage, absorbs heat. The evaporation stage has first and second evaporation sectors; a first metering device for feeding CO2 refrigerant into the first evaporation sector at a first pressure; and a second metering device for feeding CO2 refrigerant into the second evaporation sector at a second pressure. The first metering device and the second metering device are operated independently from one another. A plurality of CO2 transfer lines connects the compression stage, the cooling stage, the CO2 liquid receiver and the evaporation stage. The CO2 refrigerant is circulable in a closed-loop circuit.

Abstract: A refrigeration system operable in cooling mode and defrosting mode is provided. The refrigeration system includes a defrost line connecting a first reservoir to an evaporation stage for conveying at least part of the flash gas from the first reservoir to the evaporation stage when the refrigeration system is operating in defrosting mode. The flash gas thereby releases heat in the evaporation stage for defrosting the evaporation stage. The refrigeration system can also include a discharge line connecting the evaporation stage to a second reservoir.

Abstract: A refrigeration system operable in cooling mode and defrosting mode is provided. The refrigeration system includes a defrost line connecting a first reservoir to an evaporation stage for conveying at least part of the flash gas from the first reservoir to the evaporation stage when the refrigeration system is operating in defrosting mode. The flash gas thereby releases heat in the evaporation stage for defrosting the evaporation stage. The refrigeration system can also include a discharge line connecting the evaporation stage to a second reservoir.

Abstract: A CO2 cooling system includes a compression stage in which CO2 refrigerant is compressed; a cooling stage in which the CO2 refrigerant releases heat; a CO2 liquid receiver in which the CO2 refrigerant is accumulated in liquid and gaseous states; an evaporation stage in which the CO2 refrigerant, having released heat in the cooling stage, absorbs heat. The evaporation stage has first and second evaporation sectors; a first metering device for feeding CO2 refrigerant into the first evaporation sector at a first pressure; and a second metering device for feeding CO2 refrigerant into the second evaporation sector at a second pressure. The first metering device and the second metering device are operated independently from one another. A plurality of CO2 transfer lines connects the compression stage, the cooling stage, the CO2 liquid receiver and the evaporation stage. The CO2 refrigerant is circulable in a closed-loop circuit.

Abstract: There is provided a CO2 cooling system which comprises: a compression stage in which CO2 refrigerant is compressed; a cooling stage in which the CO2 refrigerant releases heat; and an evaporation stage in which CO2 refrigerant, having released heat in the cooling stage, absorbs heat. The CO2 refrigerant exiting the evaporation stage is directed to at least one of the compression stage, before being directed to the cooling stage, and the cooling stage by at least one of gravity and natural convection. There is also provided a method for operating a CO2 cooling system.

Abstract: There is provided a CO2 cooling system which comprises: a compression stage in which CO2 refrigerant is compressed; a cooling stage in which the CO2 refrigerant releases heat; and an evaporation stage in which CO2 refrigerant, having released heat in the cooling stage, absorbs heat. The CO2 refrigerant exiting the evaporation stage is directed to at least one of the compression stage, before being directed to the cooling stage, and the cooling stage by at least one of gravity and natural convection. There is also provided a method for operating a CO2 cooling system.