Natural refrigerants with high pressure compressors in industrial plants.

The starting point for the plant was to realize a freezing plant for bakery products requiring -35°C product temperatures for approx.3000kW to be realized in 2 phases. The choice was made to apply for a CO2/NH3 cascade which is a main trend for low temperature refrigeration in food industry where CO2 of -40°C, still at very usefull pressure of 10 bara, to obtain -35°C product temperature. The CO2 is natural and can be used direct in the freezers. CO2 can also be used for defrosting of the freezers with the high pressure compressors .The high stage of the cascade can be done with the natural refrigerant NH3 with limited charge only for the high temperature side in the NH3 machine room and condensors. The realization of the plant was done in 2011 for phase 1 followed by phase 2 in 2013.