Ejector for the world: simplified ejector-supported CO2 refrigeration systems for all climates

The novel configuration presented in this work simplifies the layout of ejector-supported booster systems while maintaining all the benefits of an ejector implementation. The basic version of the solution is based on: i) MT and LT compressor suction groups, ii) flooded MT evaporation with increased evaporation temperature, and iii) ejector utilization throughout the year. The ejector is actively operated as a high-pressure-control device at elevated ambient temperatures ('summer mode'). With lower ambient temperatures the ejector is operated passively, and the high-pressure control is performed by individual metering devices upstream of the different evaporators ('winter mode'). The feasibility tests performed in the laboratory proved that energy-wise this novel system configuration outperforms traditional and parallel compression supported booster systems under any condition. The pressure lift measured with active ejector is sufficient for liquid refrigerant distribution to the evaporators, while the pressure drop recorded in passive mode is negligible for practical applications.