Multi-ejector is an effective device for improving the operation and regulation of transcritical carbon dioxide (CO2) refrigeration systems. This paper presents a dynamic model of a transcritical CO2 refrigeration system. The air cooler and low-temperature evaporator models are established using the finite volume method and the flooded evaporator model is established by lumped parameter method. A gas-liquid separator and accumulator model is established according to the conservation of mass and energy. A two-phase ejector model is established based on the physical properties of CO2

considering the phenomena of internal transonic flow

phase change

and congestion. The model predictions had an error within 10% compared with experimental data reported in the literature. The transient response of the system was studied by adjusting the multi-ejector and speeds of the compressor as disturbance conditions. The results show that the developed dynamic model has characteristics similar to that of the experimental data

which provides high-precision simulation conditions for studying the performance and regulation features of a multi-ejector refrigeration system.