Technical and Environmental Evaluation of CO2-based Booster Refrigeration Systems

Abstract

The present study deals with the performance evaluation of four CO2 booster refrigeration system configurations: a conventional, a parallel compressor, an ejector-based, and an NH3/CO2 cascade configuration, under the ambient conditions of the city of Bucaramanga, Colombia. Applying detailed energy and exergy analyses, as well as an evaluation of environmental impact through Total Equivalent Warming Impact (TEWI), it was identified that the ejector-based configuration as the most energy-efficient, exhibiting a 13.2% reduction in annual power consumption compared to the conventional system. The cascade configuration demonstrated the lowest exergy destruction above 26°C, highlighting its potential under higher ambient temperatures. Furthermore, the ejector-based configuration consistently achieved the highest 2nd law efficiency across the temperature range set. The environmental impact analysis showed the ejector-based configuration also had the lowest TEWI, with a 14.36% reduction. The results underscore the importance of selecting appropriate refrigeration configurations based on local climate conditions.

Keywords

• Refrigeration
• Carbon dioxide
• Ammonia
• natural refrigerants
• booster refrigeration systems
• energy and exergy analysis