螺旋缠绕管式气冷器耦合传热特性研究

Study on Conjugate Heat Transfer Characteristics of Spiral Wound Tube Gas Cooler

摘要: 本文建立螺旋缠绕管式气冷器三维共轭传热数值模型，研究超临界二氧化碳–水双侧操作参数对耦合流动换热特性的影响规律。结果表明：管侧入口段受入口效应与螺旋离心力耦合作用形成强二次流，局部努塞尔数显著高于充分发展段；S-CO₂工况接近拟临界区时，对流换热系数提升15%~20%；水侧流量增大1倍，整体传热系数提升约22%。研究揭示了拟临界物性与二次流协同强化换热机制，可为该类气冷器的工程设计与运行优化提供参考。

Abstract: A threedimensional conjugate heat transfer model is established for a spiral wound tube gas cooler to investigate the effects of operating parameters on both sides of supercritical carbon dioxide and water. Results show that strong secondary flow is formed in the tubeside inlet section under the combined effect of inlet disturbance and spiral centrifugal force, leading to significantly higher local Nusselt number than that in the fully developed region. When S-CO₂ operates near the pseudocritical region, the convective heat transfer coefficient increases by 15%~20%. Doubling the water-side flow rate improves the overall heat transfer coefficient by approximately 22%. The synergistic heat transfer enhancement mechanism of pseudo-critical thermophysical properties and secondary flow is revealed, which can provide a reference for the engineering design and operation optimization of such gas coolers.