流速对含高浓度不凝气的蒸汽冷凝特性的影响

Effect of Flow Velocity on Condensation Characteristics of Vapors Containing High Concentrations of Non-Condensable Gases

为探究流速对含高浓度不凝气的蒸汽冷凝性能的影响,搭建了可视化水–空气混合蒸汽实验系统,实验研究了不同流速下混合蒸汽在竖直表面上的凝结特性。研究表明,添加肋片与增大流速均可强化混合蒸汽凝结换热特性,且随着不凝气浓度增大,两者增强换热的效果越显著,在两者共同作用下,换热系数可提高239%。实际换热器设计中,应考虑阻力压降选择合适的流速与强化肋片。

To investigate the effect of flow velocity on the condensation characteristics of vapor containing high concentrations of noncondensable gas,an experimental system was built to visualize a water-air vapor mixture,and the condensation characteristics of the mixture on a vertical surface at different flow velocities were investigated.The study shows that both adding ribs and increasing the flow velocity can enhance the heat transfer characteristics of mixed vapor condensation,and as the concentration of non-condensable gas increases,the more significant the effect of both enhanced heat transfer,and under the combined effect of both,the heat transfer coefficient can be increased by 239%.In the actual heat exchanger design,the resistance pressure drop should be considered to select the appropriate flow velocity and strengthen the ribs.