Advanced Technologies and Future Perspectives of CO ₂ Refrigeration Systems Development for Supermarket Applications

The Kigali Amendment to the Montreal Protocol officially calls for a global phase-down of conventional hydrofluorocarbon refrigerants to reduce the climate impact of the refrigeration, heating, ventilation and air-conditioning industry. Several Asian countries, such as China, Japan and Singapore, have ratified the Kigali Amendment. Among the various options, CO ₂ is recognized as a viable solution to replace conventional refrigerants, especially in supermarket applications. However, current CO ₂ refrigeration systems suffer from significant throttling loss due to their high operating pressure which makes CO ₂ systems less efficient as compared to conventional systems. This paper introduces different CO ₂ refrigeration systems for supermarkets as well as the latest technology development to improve energy efficiency and the global refrigeration market landscape. Supermarket CO ₂ refrigeration systems have already been widely adopted in Europe and several Asian countries, but China has been slow in adopting this technology despite having a tremendous and potentially expanding refrigeration market. A summary of the constraining factors and corresponding proposition of future development strategies is provided with a focus on China which can be also applied to other Asian countries.