Comparative analysis of various CO2 configurations in supermarket refrigeration systems
Our paper presents an analysis of various CO2 transcritical and cascade/secondary loop refrigeration systems that are becoming popular in supermarket applications with the objective of optimizing the operating parameters of these systems. In addition, the performance of selected CO2-based refrigeration systems is compared to the baseline R404A multiplex direct expansion system using bin analyses in the eight climate zones of the United States. Moreover, for the refrigeration systems investigated, it was found that the Transcritical Booster System with Bypass Compressor (TBS-BC) had the lowest energy consumption for ambient temperatures (Tamb) less than 8 °C, and for higher ambient temperatures the R404A direct expansion system was found to have the lowest energy consumption. Finally, the TBS-BC performs equivalent to or better than the R404A direct expansion system in the northern two-thirds of the US. For the southern portion of the US, the R404A multiplex DX system performs better than CO2 systems.