Greencold has installed a new CO2-based cooling plant at a food-processing firm in the United Kingdom. The plant, which has a cooling capacity of 180 kW, comprises six identical cooling chambers for low-temperature blast chilling of meat down to -20° C.
For the end user, the choice of CO2 was motivated by price and the desire for future-proof technology, according to Greencold.
The customer initially considered an ammonia-based pumped recirculation system. But this was subsequently ruled out due to price, space, delivery time and specific site safety considerations.
Another option would have been to use a direct expansion system with HFC R407F, but the end user ruled this out amid the HFC phasedown, rising refrigerant prices and the mass of the refrigerant required.
A pumped system with CO2 was also considered, but again this was ruled out due to the significantly higher cost of including the required low-pressure station vessel and skid. Space was also lacking for such a system.
The system chosen is a direct expansion system with approximately 300 kg of CO2. The freezer suction line pressure is typically around 15 bar and the average freezer liquid line pressure is approximately 25 bar.