锯齿型螺旋鳍片管束传热特性的研究

Investigation on Heat Transfer Characteristics of Serrated Spiral Finned Tube Bundles

在燃气蒸汽联合循环发电机组余热锅炉的热交换器中,常使用锯齿型螺旋鳍片管束进行强化传热。综合考虑锯齿型螺旋鳍片管的外径、鳍片净高、鳍片节距以及管排横纵节距等结构因素,在传热风洞实验台中,对5组不同结构参数的锯齿型螺旋鳍片管束进行传热实验,探究不同结构参数对锯齿型螺旋鳍片管束传热特性的影响,并将实验结果与现有文献数据进行比较,分析误差原因。根据实验结果,拟合出管径44.45 mm的锯齿型螺旋鳍片管束横向节距不同时的传热关联式,进一步拟合出适用于不同结构参数的锯齿型螺旋鳍片管束的传热总关联式。对于总拟合关联式,所有实验数据与传热关联式拟合值之间的误差在10%以内,最大误差为7.68%。将总关联式的拟合值与2篇已经发表的文献中的实验数据进行比较,传热准则数的最大误差值分别为5.73%与12.71%。该研究对余热锅炉中热交换器的设计具有一定的参考价值。

The serrated spiral finned tube bundles are often applied in the HRSG of gas-steam combined cycle units for the enhancement of heat transfer.In this paper,considering the structural factors of the tube bundles such as the outer diameter,the net height of fins,the pitch of fins,and the transverse and longitudinal pitches of the tube rows,5 samples of serrated spiral finned tube bundles with different structural parameters were performed by extensive heat transfer experiments in the wind tunnel to investigate the effect of diverse geometrical parameters on the heat transfer characteristics.The experimental results were compared with the data from the existing literatures and the error was analyzed.The correlation of the serrated spiral finned tube bundles with the diameter of 44.45 mm with different transverse pitches was fitted in accordance with the experimental results,then the comprehensive heat transfer correlation was fitted for serrated spiral finned tube bundles with different geometrical parameters.The comprehensive correlation can describe all the database with an error of 10%and the maximum error of 7.68%.The maximum errors of criterion number for heat transfer were 5.73%and 12.71%respectively compared with two existing literatures.The research can be referred in HRSG design.