Uneven longitudinal pitch effect on tube bank heat transfer in cross flow
Uneven longitudinal pitch effect on tube bank heat transfer in cross flow
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DOI：
10.1016/j.applthermaleng.2012.10.031
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发表时间：
2013-03
影响因子：
6.4
通讯作者：
Dongkyun Lee;Joon Ahn;Seungwon Shin
中科院分区：
文献类型：
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作者：
Dongkyun Lee;Joon Ahn;Seungwon Shin
为了在余热锅炉系统中实现蒸汽发生的最佳运行，可以针对每个单独的排独立地控制管束的纵向节距。为了实现均匀的传热率为每排的管组，我们进行了一个完整的数值研究，包括一个变化的纵向间距的在线管组的几何形状。通过管束的整体传热进行了比较，现有的相关性，它显示出良好的协议在雷诺数范围内的500-2000。有人发现，横向间距效应可以包括在最小横截面处的最大雷诺数的形式，在传统的传热公式。增加均匀分布的圆柱体的纵向空间增强了整体热传递。获得了作为每个方向上间距比的函数的适当关系。最后，通过考虑纵向间距不均匀的附加效应，得到了每排单个努塞尔数的一般相关性。该关联式可以预测目标余热锅炉系统各排温度的变化，并与实验结果相一致。
For the optimal operation of steam generation in the HRSG system, the longitudinal pitch distance of the tube banks can be controlled independently for each individual row. To achieve a uniform heat transfer rate for each row of the tube bank, we conducted a full numerical study that includes a variation of the longitudinal pitch for the in-line tube bank geometry. The overall heat transfer across the tube bundles was compared to the existing correlation; it showed good agreement within a Reynolds number range of 500–2000. It was found that the transverse pitch effect can be included in the form of the maximum Reynolds number at the minimum cross section, as in conventional heat transfer formulation. Increasing the longitudinal space for uniformly distributed cylinders enhances the overall heat transfer. An appropriate relationship was obtained as a function of the pitch ratio in each direction. Finally, a general correlation of the individual Nusselt number for each row was obtained by considering the additional effect from uneven longitudinal pitch distances. The proposed correlation could predict the temperature variation across each row of the target HRSG system and was in agreement with the experimental results.