Comparative study of various supermarket refrigerating systems in European climate context

Due to the enormous carbon footprint of food retail stores the interest in natural working fluids, such as propane (R290) and CO₂ (R744), has recently intensified in the commercial refrigeration sector. In this theoretical investigationthe performance of various technologies employing low-global warming potential (GWP) refrigerants was compared in an average-size supermarket located in different European cities. It was found that a R744 multi-ejector enhanced parallel compression systemconsumed from 24.6% in Athens (Greece) to 37.1% in Oslo (Norway) less electricity compared to a R404A direct expansion refrigerating solution (baseline). Also, the results obtained suggested that CO₂/R1234ze(E) indirect arrangements perform slightly better than CO₂/R290 indirect units. In particular, the former offered, at best, energy savings by 6.9% (in Athens) over the selected baseline. Finally, it was revealed that thesolution outfitted with the multi-ejector block featuresbetween 36.8% and 50.3% in heating mode and between 3.1% and 18% in air conditioning (AC) mode lower total power input than separated hydrofluorocarbon (HFC) units over the selected range of outdoor temperatures. It could be concluded that highly efficient as well as climate friendly technologies are readily available for the European food retail industry.