NH3/CO2 cascade predicts big savings

USA: The installation of an ammonia/CO2 cascade refrigeration system at a food manufacturing facility in Irvine, California, is expected to provide energy savings of 20-50%.

The refrigeration system has been installed at Imuraya USA Inc, the US subsidiary of the Japanese Imuraya Group, a leading manufacturer of Japanese-style confectioneries.

The NewTon refrigeration system installation is a joint development of Canadian company CIMCO Refrigeration Inc, US electricity supplier Southern California Edison (SCE) and Japanese compressor manufacturer Mayekawa, best known for its Mycom compressors. The system uses ammonia and CO2 to achieve a higher level of efficiency and energy savings than current HFC refrigeration systems.

Mayekawa will monitor the refrigeration system in real time for the operator. SCE will gather and analyse the performance data on both the NewTon and the existing refrigeration system which can alternate operation at the Imuraya USA plant, which manufactures desserts for Japanese restaurants.

Using CO2 as the secondary refrigerant reduces the amount of ammonia refrigerant used to around 1/6 the amount of a conventional ammonia system. With a minimised ammonia charge and automatic control, the NewTon has a new screw compressor, semi-hermetic IPM motor, flooded evaporator, and double economiser.

Around 500 NewTons have already been successfully installed in Japan and Mayekawa’s existing research is said to show that ice arenas achieved an average of 50% reduction in energy, compared to conventional HFC refrigeration systems. Cold storage facilities are said to have shown an average energy reduction of 27.8%, and freezers at processing plants an average reduction of 20% of electricity consumption, using this system.

Jose Mergulhao, CIMCO vice president of US operations, oversaw the installation, which was completed in late June. “Reducing the carbon footprint and decreasing overall energy consumption is of significant value to commercial and industrial consumers and to the surrounding electric grid, especially during times of peak demand and warm, summer days,” he said.

The team expects to complete its research on the novel refrigeration system by the end of 2016 and will issue its first update in early 2017.