Design and research of a novel type of arc fin for heat transfer enhancement in hot water oil-displacement system

Abstract

Phase change thermal storage system utilizes solar energy to provide continuous heat and electricity for offshore platforms in the petroleum industry. However, the low thermal conductivity of the heat storage medium (phase change material) in the system limits the overall heat transfer efficiency. This study focuses on the design of a novel longitudinal arc fin to enhance heat transfer in the storage system. A comparison is made between the influence of the rectangular fin and the novel longitudinal arc fin structure, as well as the impact of the fin number on the heat storage performance of the heat storage unit. A numerical model is constructed and used to analyze the grid and time step in the numerical process. The resulting data is further validated through experimental comparison. The study also examines the impact of fin structure and fin number on the internal convection and temperature of this phase change heat storage unit, comparing thermal performance parameters such as heat storage time, heat storage rate, temperature response, and overall heat storage. Findings indicate that, under constant overall fin size, increasing fin number significantly enhances the internal temperature of this unit. Additionally, changing the shape of fins from rectangular to arc-shaped results in decreased heat storage performance. Specifically, when compared to the initial rectangular structure, the melting time of 8 arc fins and 10 arc fins decreased by 30.70% and 40.65%, the mean temperature response increased by 45.01% and 67.70%, and the mean rate of heat storage increased by 45.35% and 69.23%. Therefore, increasing the number of arc-shaped fins, while maintaining the same fin volume, substantially improves the heat storage properties of the unit.