Very few studies have been reported on the fundamental mechanism analysis the augmentation of heat and mass transfer for the convection and condensation processes in the slit finned tube heat exchanger under dehumidifying conditions. By developing a 3D numerical model for the condensation of the slit finned tube heat exchanger under dehumidifying conditions, the heat and mass transfer characteristics were investigated under different the geometrical and operational parameters. The models neglecting convective mass flux or neglecting the water vapor loss can greatly enlarge the deviations of numerical results with respect to experimental data. The synergy angles are smaller in the windward and leeward sides of slits where the velocity field has a better synergy with both temperature field and the mass field. The slits on the fin not only increase the disturbance of fluid but continuously destroy the developments of thermal and mass concentration boundary layers, greatly enhancing the heat and mass transfer. The latent heat transfer is significantly greater than the sensible heat transfer, which accounts for 71.7% of the total heat transfer rate when inlet velocity is 1 m·s⁻¹ and volume fraction of water vapor is 15%. The increases in the inlet velocity, and the volume fraction of water vapor can enhance the heat and mass transfer coefficient of wet flue gas. Whereas, the increase in inlet velocity can reduce the difference of synergy for the velocity field and the temperature or mass concentration gradient field of different fin tubes.

中文翻译：

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湿烟气狭缝翅片管换热器传热传质数值研究

关于除湿条件下狭缝翅片管换热器中对流和冷凝过程的传热和传质增强的基本机理分析的研究很少。通过建立除湿条件下狭缝翅片管换热器冷凝的3D数值模型，研究了不同几何参数和运行参数下的传热传质特性。忽略对流质量通量或忽略水汽损失的模型会大大扩大数值结果与实验数据的偏差。狭缝迎风面和背风面的协同角较小，速度场与温度场和质量场的协同作用较好。翅片上的狭缝不仅增加了流体的扰动，而且不断破坏热质浓集边界层的发展，大大增强了热质传递。潜热传热明显大于显热传热，在入口速度为1 m·s时占总传热率的71.7%^-1，水蒸气的体积分数为 15%。入口风速和水蒸气体积分数的增加可以提高湿烟气的传热传质系数。而入口速度的增加可以减小不同翅片管的速度场与温度或质量浓度梯度场的协同差异。