The condensation heat transfer characteristics of steam with the non-condensable gases (NCGs) in the tubes bundle channel are quite different from those in the simple geometry structure, such as the single tube and flat plate. In the present work, to evaluate the thermal characteristics of steam condensation with NCGs in the vertical tubes bundle channel, the numerical model of steam condensation was established based on the CFD code ANSYS FLUENT, which combined the gas component transport equations and the diffusion balance model. And several conditions with different thermal parameters were simulated, the simulation results are in good agreement with the experimental data. The condensation heat transfer in a hexagonal 7-tubes bundle channel with various tube pitches (from 1.5d to 5d) is investigated. The results indicate that the distribution of typical thermal parameters, such as velocity, air mass fraction, temperature and density, is quite different from that in the single tube due to the cross and mixture in each condensation tube boundary layer. As the condensation length increases, the air mass fraction rises, the gas flow rate decreases and the sub-cooling decreases, resulting in a lower natural convection intensity. When the tube pitch is less than 4d, the condensation heat transfer capacity in the tubes bundle channel is weakened obviously, and the heat transfer coefficient with the tube pitch 1.5d is only about 32% of that in a single tube. The air mass fraction and pressure have a significant positive effect on the heat transfer coefficient, and the wall sub-cooling has a significant negative effect on that.

管束通道内含不凝气体（NCGs）的蒸汽的冷凝传热特性与单管、平板等简单几何结构的蒸汽冷凝传热特性有很大不同。在目前的工作中，为了评价垂直管束通道内含NCGs的蒸汽冷凝热特性，基于CFD程序ANSYS FLUENT，结合气体组分输运方程和扩散平衡模型，建立了蒸汽冷凝的数值模型。 . 并对几种不同热参数的工况进行了仿真，仿真结果与实验数据吻合较好。研究了具有不同管距（从 1.5d 到 5d）的六边形 7 管束通道中的冷凝传热。结果表明，由于每个冷凝管边界层的交叉和混合，典型的热参数，如速度、空气质量分数、温度和密度的分布与单管中的分布有很大不同。随着冷凝长度的增加，空气质量分数升高，气体流速降低，过冷度降低，导致自然对流强度降低。当管距小于4d时，管束通道内的冷凝传热能力明显减弱，管距为1.5d时的传热系数仅为单管的32%左右。空气质量分数和压力对传热系数有显着的正向影响，壁面过冷对传热系数有显着的负向影响。