纵翅片结构形式对管换热器性能的影响

Influences of heat exchanger with different types of longitudinal louver fin on heat recovery performances

提出了一种可改善换热效率的百叶窗式纵翅片换热管的结构模型,对其进行简化,采用Fluent软件对换热管烟气侧流动与传热过程进行数值模拟,对比了两种百叶窗纵翅片与普通纵翅片的换热效率与压降,结果发现:百叶窗式纵翅片传热效果比普通纵翅片高130%以上。模拟了6组不同流体入口速度下传热与压降的变化情况,分析了百叶窗翅片间距与倾斜角度对传热与压降的影响,结果表明:入口速度越大,进出口温差越小,压降越大;翅片间距越大,进出口温差和压降都越小;翅片倾斜角度越大,换热效果相差不大,压降越大。搭建了简易实验平台对模拟结果进行验证。

Longitudinal finned tube heat exchanger is a new type of tube heat exchanger used in flue gas heat recovery. In order to improve the heat transfer efficiency,the structural model of a new type of longitudinal louvered fin tubes was proposed and simplified. Using Fluent Software,the process of flow and heat transfer in gas phase was simulated for the longitudinal louver fined heat exchangers,and the transfer efficiency and pressure drop of two types of longitudinal louver fin and the common type exchanger were compared. The results showed that the heat transfer efficiency of longitudinal louvered fin heat transfer were over 130% higher than that of the common type. This paper simulates the changes of transfer and pressure drop at six different inlet velocities,and analyzed the influences of heat transfer and pressure drop caused by the difference of spacing and inclination angles on longitudinal louver fin. The results showed that at higher inlet velocities, the range of temperature was smaller,and the pressure drop was bigger. At bigger spacing the range of temperature and pressure drop were both smaller. Bigger inclination angles resulted in bigger pressure drop,but had little impact on heat exchange effects.