Performance operation of liquid ejectors for a R744 integrated multi-ejector supermarket system using a hybrid ROM.

• A hybrid reduced-order model of a R744 liquid ejector is developed. • A satisfactory accuracy of a low-order model is obtained for wide range. • Motive nozzle and mass entrainment ratio maps are generated. • A liquid ejector performance maximisation at different climate zones is done. Performance maps were generated for designed liquid ejectors installed in a multi-ejector module in an R744 integrated supermarket system using a hybrid of the reduced-order model (ROM). Hybrid ROMs of the investigated liquid ejectors were developed based on experimental data and CFD results. The CFD model achieved satisfactory accuracy at motive nozzle pressures above 59 bar, and the hybrid ROM improved the mass flow rate prediction. Maps were generated for the motive nozzle mass flow rate and the mass entrainment ratio at different ambient conditions related to cold, moderate, and hot climate zones. The set of the pressure lift for ejector efficiency maximisation at different ambient conditions is presented for refrigeration and air-conditioning applications. The developed liquid ejectors hybrid ROMs can be used to optimise work of the R744 integrated supermarket system equipped with the vapour and liquid ejectors. [ABSTRACT FROM AUTHOR]