摘要
螺纹槽管作为一种有效的强化传热元件被广泛使用。以试验为基础,首先对螺纹槽管单管的换热特性及流动阻力特性进行了研究,得出了换热特性及流动阻力特性的无量纲关系式,然后以现在电厂空气预热器上最常用规格的螺纹槽管制作试验管束,管内为高温空气,管外为低温空气横向冲刷管束,改变错列管束的横向管节距及纵向管节距,从而得到各个管束的努谢尔特数以及欧拉数与各个因素的无量纲关系式,通过分析可得到横向管节距及纵向管节距对换热特性及流动阻力特性的影响趋势。根据结论,得到较合理的管束的横向管节距(S1=66 mm)和纵向管节距(S2=48 mm),为螺纹槽管在空气预热器中的应用提供设计依据,以达到最佳的换热特性和阻力特性的综合效果。
As a kind of effective intensified heat transfer elements,spirally fluted tubes are widely used.On the basis of experiments,the heat exchange performance and flow resistance characteristics of a single spirally fluted pipe were first studied and a non-dimensional relationship of heat-exchange and flow-resistance characteristics was ascertained.Thereafter,a test tube bundle was made by use of the spirally fluted tubes of the most common specifications currently used on air preheaters of power plants.High temperature air flows inside the tubes,and low temperature air outside the tubes transversely sweeps across the tube bundle. By changing the transverse and longitudinal tube pitch of the staggered tube bundles,a non-dimensional relationship between the Nusselt number and Euler number of each tube bundle on the one hand and various other factors on the other can be obtained.Through an analysis,the tendency of influence exercised by the above-cited transverse and longitudinal tube pitch on the heat-exchange and flow-resistance characteristics can also be revealed.On the basis of the conclusions made from the foregoing,a comparatively rational transverse tube pitch(S_1=66 mm) and longitudinal tube pitch(S_2=48 mm) of the tube bundles may be determined,providing a design basis for the use of spirally fluted tubes in air preheaters and attaining a combined benefit of optimum heat-exchange and flow-resistance characteristics.
出处
《热能动力工程》
CAS
CSCD
北大核心
2006年第4期358-361,共4页
Journal of Engineering for Thermal Energy and Power
关键词
螺纹槽管
错列管束
努谢尔特数
欧拉数
spirally fluted tube,staggered tube bundle,Nusselt number,Euler number
