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

Abstract 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 inves-tigated 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 differ-ent 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 appli-cations. The developed liquid ejectors hybrid ROMs can be used to optimise work of the R744 integrated super-market system equipped with the vapour and liquid ejectors. Keywords: carbon dioxide, refrigeration system, liquid ejector, reduced-order model, CFD model