空冷凝汽器翅片管换热器阻力特性数值研究

Numerical Study on the Resistance Characteristics of Finned Tube Heat Exchangers in an Air-Cooled Steam Condenser

水资源的匮乏使节水性能显著的直接空冷式发电厂在缺水富煤地区得到了迅速推广。翅片管换热器作为空冷凝汽器的基本组成单元,其流动特性是决定空冷凝汽器运行性能的关键因素。应用计算流体力学(CFD)方法,对不同迎面风速下单排及双排翅片管换热器的阻力特性进行了数值模拟。计算结果表明:对于2种不同形式的翅片管换热器,空气侧流动阻力皆随着迎面风速的增加而升高;双排管的流动阻力略大于单排管,且随着迎面风速的增加,双排管管束相对于单排管管束的压力损失增幅呈上升趋势。通过比较不同数量网格模型的数值模拟结果,验证了网格无关性,证明了模拟结果可靠。研究结果对提高空冷凝汽器乃至空冷电厂的运行经济性都具有重要的参考价值。

Due to excellent water conservation, air-cooled steam condenser （ACSC） is extensively utilized in the places where water is shortage but fuel abound in fossil power plant. As the important component of the ACSC, the resistance characteristics of the finned tube exchangers play an important role in determining the ACSC performance. Computational Fluid Dynamics （CFD） is applied to simulate the resistance characteristics under different frontal velocity for two different forms of finned tube heat exchangers. The results show that flow resistance rises with the increasing frontal velocity for both the different forms offinned tube heat exchangers. Resistance of double row finned tube exchanger is little larger than that of the single row but the difference gradually rises with the increasing of the frontal velocity. The mesh independence is validated through simulating the numerical models with different mesh quantity , thus, proving the reliability of the simulation results. The results provides that important reference to improve the operation economy of the ACSC and even the air-cooled power plant.