【摘要】 绕管式换热器壳侧的流动及传热特性对大型液化天然气/浮式液化天然气装备设计和优化具有重要意义。本文建立了两相流动沸腾数值模型以预测壳侧流型、压降及其传热效果。通过耦合VOF模型、相变传质模型和表面张力模型，探究了不同质流密度、干度等因素对壳侧流动传热特性的影响，并通过绕管式换热器流动换热实验平台进行了实验验证，证明了模拟所得规律与实验结果有良好的吻合性。结果表明：压降随干度的增加而增加；传热系数随干度的增加有所减小；壳侧制冷剂在不同干度下主要呈现柱状流、滴状流、气状流等流型。本研究为设计和优化绕管式换热器提供了理论基础。更多还原

【Abstract】 The flow and heat transfer characteristics on the shell side of the wound tube heat exchanger are of great significance to the design and optimization of LNG/FLNG systems. To solve this problem, a two-phase flow boiling numerical model was established to predict the pressure drop and heat transfer coefficient in the shell side. The VOF model, the phase-change mass transfer model and the surface tension model were added to study the influence of different factors such as mass flow density and dryness on the flow and heat transfer characteristics at the shell side, and the experimental verification was carried out through the flow and heat transfer experimental platform of the wound tube heat exchanger, which proved that the simulation rules were in good agreement with the experimental results. The results showed that the pressure drop increased with the increase of dryness; the heat transfer coefficient decreased with the increase of dryness; the shell side refrigerant mainly presented columnar flow, droplet flow, gaseous flow and other flow patterns under different dryness. This study provideed a theoretical basis for the design and optimization of the coiled tube heat exchanger.更多还原