Abstract:

China formally accepted the Kigali Amendment to the Montreal Protocol on September 15th,2021.For the frozen and refrigeration equipment in supermarkets,CO₂ is a reliable substitute for regular synthetic refrigerants.However,high-pressure operation of CO₂ refrigeration systems leads to huge throttling losses,resulting in low energy efficiency of the system.The configurations of the CO₂ refrigeration systems applied in supermarkets are introduced,and the latest technology to improve the energy efficiency and their status quo at home and abroad are summarized.At present,only a few demonstration supermarkets in China are using CO₂ refrigeration equipment.According to the actual energy consumption of CO₂ refrigeration equipment,the life cycle climate performance（LCCP） is calculated.Compared with the carbon emission of the existing equipment taking refrigerant R404A,the carbon emission reduction realized by the equipment taking new technology is predicted.Analyzing the factors restricting the CO₂ technology promotion in China,it is suggested that the energy efficiency of the refrigeration system can be enhanced by taking climatic conditions,differences between peak electricity price and off-peak electricity price and the site condition around the supermarket into consideration.It is recommended that the exorbitant price of the equipment should be lower by policy subsidies,and the acceptance of CO₂ refrigeration system on the market can be improved by promoting the of alternative refrigerants,the goals of carbon peaking and carbon neutrality and awareness of energy conservation and emission reduction.The suggestion will provide a reference for the optimization design and low-carbon and efficient operation of the refrigeration equipment.

Key words: natural refrigerant CO₂, supermarket, frozen and refrigeration, efficiency enhancement technology, carbon emission, LCCP, carbon peaking and carbon neutrality