为保证大型天然气液化（LN G）用板翅式换热器冷箱安全、可靠运行，建立了大型LN G 冷箱内板翅式换热器的板翅结构热应力有限元分析数学物理模型，基于热弹性理论采用热-结构直接耦合方法分析了运行参数（流体温度、外载荷以及操作压力）对LN G 板翅结构等效热应力的影响规律，模拟结果表明：天然气和混合冷剂之间温差越大板翅结构承受最大等效热应力越大，混合冷剂和天然气温度越低其最大等效热应力越大；外载荷为压力时压力越大其最大等效热应力越小，外载荷为拉力时拉力越大其最大等效热应力越大；此外，天然气侧压力对热应力的影响大于混合冷剂侧压力对其影响，但均表现出增大趋势。上述研究成果将为大型LN G 冷箱内板翅式换热器结构以及运行参数设计和安全可靠运行提供重要参考依据。%In orderto ensure the safe and reliable operation of Plate-fin structure in plate-fin heatexchanger which was used to Liquefied Natural Gas(LNG)in a large-scale cold-box.AFinite ElementModel(FEM)based on thermalelastic theory was established to simulate influence of operation parameters for the maximum equivalent thermal stress in plate-fin structure. The result shows that the maximum equivalent thermal stress grows steadily with the temperature difference between Natural Gas (NG) and Mixture R efrigerant (MR) and with pull load, decreases with NG or MR temperature and with press load. Addition, the maximum equivalent thermal stress increase with NG or MR pressure, and the influence of NGpressure is greater obviously.These results would provide some constructive instructions in the design and safe operation for plate-fin heatexchanger in large-scale LNG cold box.
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