Design performance of CO2 refrigeration systems for ice production in snow making generators at ambient temperatures above 0 °C.

Paper published in poster form during the conference. Flake ice systems (sub-critical and trans-critical) with a production capacity of 50 and 100 tons day-1 was modelled in EES, to investigate the thermodynamic performance at different ambient temperatures. Optimization of trans-critical system was made with respect to pressure in gas-cooler and type of heat exchanger. Flake ice machine was modelled in COMSOL for design optimization. The increasing of flake ice machine capacity can be achieved by varying boiling temperature and ice thickness. The 200 pipes were sufficient to provide to provide effective freezing. One stage sub-critical system showed the best COP at low ambient temperatures. Two stage trans-critical can be preferable, when there is a demand in hot tap-water production or heating. The trans-critical two stage system was more energy demanding, when producing ice (up to 33.65 kWh m-3). Application of coaxial gas-cooler was beneficial due to increasing of total COP of the system and heat recovery.