Increasing the performances of a CO_2 refrigeration system using cool thermal energy storage for subcooling: a supermarket application

摘要

The electricity consumption of a supermarket refrigerating plant situated in the south of France hasbeen measured during 8 months. A cool thermal energy storage (CTES) and a CO_2 subcooler wereadded to the full CO_2 refrigerating plant. The plant is described, as well as thecharge/discharge/subcooling schedule strategy. The objectives of the work were to quantify theenergy saving obtained thanks to the CTES and the subcooling. We obtained 23 kWh electricitysaving and 2 k€ financial saving, which represents 6% of the annual electricity bill dedicated tomedium temperature refrigeration production. The strategy depends on a lot of parameters(supermarket opening hours, outside temperature, electricity tariffs), and the tests showed it isimportant to review the control (schedule and set points).