Commercial refrigeration KEY APPLICATIONS FOR NATURAL REFRIGERANTS IN JAPAN
CO2 UEI STORAGE EQUIPPED SYSTEM VERSUS STANDARD DIRECT EXPANSION CO2 SYSTEM Advantages of brine-ice storage refrigerator during nighttime over a standard direct expansion refrigerator during daytime lie in three key points: •
Energy efficiency (kWh): At least 9% energy efficiency improvements can be measured, increased to 10.2% when using the improved ice generator (indicated in Fig. 2). Real air temperature measured throughout the year is used in this case study. •
Average COP of DX refrigerator during the year (daytime 10:00am – 10:00pm), with average evaporating temperature of -10°C: 2.55
•
① Refrigerator for thermal storage ② Continuous operating refrigerator ③ Reduction of refrigeration electric and cooling capacity
Average COP of brine-ice storage refrigerator during the year (nighttime 10:00pm – 10:00am), with evaporating temperature of CO2 UEI at -10 – -15°C: 2.78
• Fig.1 Operation of direct expansion refrigerators and thermal storage refrigerators
Reduced electric power consumption (kW): As a result of increased COP, the electricity consumption is decreased by 30% when using the brine-ice storage refrigerator compared to a standard direct expansion refrigerator.
CO2 evaporating
•
temperature for
Reduced cooling capacity (△kW): The cooling capacity of the a refrigerator is reduced by 35% with CO2 UEI storage system.
brine-ice thermal storage operation
In addition, changing an existing HFC and HCFC-based display case to brine can be done
shows gradual
easily and at low cost and without the need to replace the case with a new equipment for
decline with
secondary coolant system.
increasing of ice production and decreasing of brine temperature in ice storage tank. Fig.2 Temperature profiles
STATE OF THE INDUSTRY — GUIDE TO NATURAL REFRIGERANTS IN JAPAN 2016
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