凝汽器设置局部强化传热“急冷区”的数值模拟研究

Numerical Study of Locally Enhancing Heat Transfer “Quench Area” in Condenser

在凝汽器的空冷区内设置"急冷区"对提升其换热效率具有重要意义。通过软件建立数值模型,研究设置单排型、多排相邻型和多排不相邻型3种分布型式的"急冷区"对于空冷区换热效果的影响。计算结果表明,各种型式的"急冷区"都可以提高空冷区整体真空度和换热系数。通过对比发现,多排相邻型中,三排相邻型"急冷区"对空冷区真空度和换热系数提升效果更佳;多排不相邻型中,两排不相邻型"急冷区"能更好地提高空冷区换热效果。在所有型式中,三排相邻型"急冷区"的设置对空冷区的强化换热效果最佳。凝汽器强化传热工程改造中,综合经济性与换热效果,最佳方案为在空冷区的中后段设置两排不相邻"急冷区"。

It is of great significance to set up a"quench area"in the air cooling zone of condenser to improve its heat transfer efficiency.In this paper,a software was used to investigate the heat transfer effect of air cooling zone with three distribution types of"quench area",namely single row type,multi-row adjacent type and multi-row non-adjacent type.The results show that the existence of"quench area"can improve the vacuum and heat transfer coefficient of the air cooling zone.Through comparison,the setting of three-row adjacent"quench area"in the multi-row adjacent type brings the better heat transfer performance;the setting of two-row non-adjacent"quench area"in the multi-row non-adjacent type brings the better heat transfer performance.In all types,three-row adjacent"quench area"brings the best heat transfer performance in the air cooling zone.In the retrofit of enhanced heat transfer project of condenser,the best scheme is to set two rows of non adjacent"quench area"in the middle and rear section of its air cooling zone,considering the economy and heat transfer effect.