Pressure exchanger is a device used to recover energy from high pressure working fluid in systems like Reverse Osmosis water desalination. The pressure exchanger enables the high-pressure fluid to transfer portion of its energy to the low-pressure fluid by transferring the fluid pressure. This working concept can be applied to systems where there is a significant pressure variation of the working fluid along the system. Trans critical CO2 refrigeration system is a good example for significant pressure variation during the flow path. The high-pressure CO2 exiting the condenser can be recovered by the low-pressure CO2 upstream of the compressor using a pressure exchanger to increase the system overall efficiency. The proposed research is to numerically simulate a prototype pressure exchanger for trans critical CO2 refrigeration system. The focus of this study is to understand the thermo-fluid behavior of the system when CO2 is used as the working fluid. Contour plots of velocity and pressure are presented for qualitative analysis.