Thermal performance analysis of fin-and-tube heat exchanger circuit in supercritical hydrogen refrigeration cycle system

A circuit arrangement model for air-to-refrigerant fin-and-tube heat exchanger with supercritical hydrogen as the refrigerant is developed. The mass, momentum and energy balance equations in the circuit arrangement model are solved by the effectiveness-NTC method. The effects of gravity force, flow state and inhibit heat conduction on the heat transfer in the supercritical hydrogen refrigerant heat exchanger are investigated. Results show that the flow arrangement placed at a location where the fluid flows from the high place to the low one can achieve a better heat heat transfer performance. The form of counter-flow has a better heat transfer performance compared to that of parallel-flow. The heat transfer performance in the six-in-three-out arrangement is the better compared to that of three-in-three-out arrangement. Thus, the structure of the six-in-three-out with counter-flow from high to low one is recommend to achieve a better heat transfer performance in the supercritical hydrogen refrigerant heat exchanger.