Preliminary study on the feasibility assessment of CO2 booster refrigeration systems for supermarket application in China: An energetic, economic, and environmental analysis

The cold chain industry related to people's livelihood in China is developing rapidly today. The energy efficiency level and environmentally-friendly characteristics of cold chain equipment need to be enhanced and improved urgently. The CO2 booster refrigeration systems (BRS) are widely used and developed in European supermarkets due to outstanding environmental benefits. The two objectives of this paper are to reveal the energy efficiency level of six CO2 BRS solutions under five typical Chinese climate conditions, as well as to objectively evaluate the application feasibility in Chinese supermarkets to inform manufacturers. Comprehensive analyses consist of energy efficiency, economy, and environment are conducted. The results show that the CO2 BRS assisted with flooded evaporation and parallel compression has the best performance. For most cities, its annual energy efficiency ratio improved by 3.9 similar to 23.2%, the payback period is averaging less than 5.5 years, and the total equivalent warming impact reduced by 11.9 similar to 52.9% compared to the reference systems. The CO2 BRS solutions are proved to be good alternatives and recommended for use in northern China, while it is not suitable for hot climate cities, such as Guangzhou, and further modifications are required. For the reference systems, the R134a/CO2 cascade refrigeration system can be considered a short-term transition solution in southern China, considering its relatively decent performance.