两相流工况下板翅式换热器进料封头结构优化设计

Optimization Design of Feed Head Structure of Plate-fin Heat Exchanger under Two-phase Flow Condition

板翅式换热器具有结构紧凑、体积小、传热效率高等特点,广泛应用于石油化工、航空航天和低温工程领域。但此类换热器入口处物流分配的不均匀会加剧其内部温度场分布不均匀和纵向传热,导致换热器整体性能下降。基于过渡段和S弯设计,通过CFD数值模拟计算原始封头和改进型封头的出口流速分布,比较两种封头结构的物料进料分配特性。模拟结果显示,改进型封头相较于原始封头使入口空气流速的相对不均匀度、水流速的相对不均匀度明显降低,有效改善了换热器物料进料的分配不均匀度,从而提高了换热器的整体性能。

The plate-fin heat exchanger characterized with compact structure,small volume and high heat transfer efficiency has been widely used in petrochemical,aerospace and cryoengineering fields.The uneven distribution of logistics at the entrance of the heat exchanger,however,will aggravate the uneven distribution of internal temperature field and longitudinal heat transfer,leading to overall performance degradation of the heat exchanger.In regard to this,based on the transition section and S-bend design,the outlet velocity distribution of the original head and the improved head is calculated by CFD numerical simulation,and the material feed distribution characteristics of the two head structures are compared.The simulation results show that the relative inhomogeneity of inlet air velocity and water velocity of the improved head is reduced obviously in comparison with the original head,and the inhomogeneity of material feed distribution is effectively improved,which improves the overall performance of the heat exchanger.