Study on heat transfer and pressure drop characteristics in marine S-CO2 power cycle hybrid heat exchangers

The S-CO2 power cycle has the advantages of compact structure and high energy density, which can be used to recover the waste heat of ship exhaust, thus improving the energy efficiency of ships and reducing emissions. The hybrid heat exchangers with etched plates and fins can be used as the heat transfer device of S-CO2 and exhaust, its heat transfer and pressure drop characteristics have a great influence on S- CO2 power cycle performance. In this study, a CFD model of the hybrid heat exchangers was established. The effects of different exhaust inlet temperatures, inlet mass flow rates and inlet pressures on the heat transfer and the pressure drop characteristics were analyzed by Fluent. The results show that the inlet temperatures and inlet mass flow rates of exhaust have a great influence on the heat transfer characteristics of the hybrid heat exchanger. The inlet mass flow rates and inlet pressures of exhaust have a great influence on the pressure drop characteristics of the hybrid heat exchangers. In the design of the hybrid heat exchangers, the status of the exhaust need to be considered to ensure efficient operation of the heat exchangers. The study can provide guidance for the design of the hybrid heat exchangers.