为研究管束内的换热规律与管间距的关系，通过分析不同物理模型的流场、换热系数，验证了针对横掠管束充分发展段采用周期性边界条件和对称性边界条件的合理性。采用FLUENT 软件，对一定雷诺数范围内、不同的管间距横掠顺排管束周期性充分发展段模型的流动换热进行数值模拟。结果表明：密集排列管束的换热效果明显要比稀疏排列的管束大，且对于纵向管间距Sn/d=1.25的管束，当横向管间距取Sp/d=2.0左右时，管束间的换热达到最强，可以为提高换热器换热能力提供工程实际参考。最后将数值模拟结果与已有的经验公式以及实验结果进行比较，验证数值模拟方法的正确性。

In order to study the relationship between heat transfer law and tube spacing,the rationality of using periodic boundary conditions and symmetrical boundary conditions for the full development section of the crossing tube bundle was verified by analyzing the flow field and heat transfer coefficient of different physical models.Numerical simulation of flow and heat transfer in a certain Reynolds number range with different tube spacing across the periodically fully developed section of parallel tube bundles is carried out by using FLUENT software.The results show that the heat transfer effect of densely arranged tube bundles is evidently larger than that of sparsely arranged tube bundles,and for the longitudinal tube spacing Sn/d=1.25 tube bundles,when the transverse tube spacing is about Sp/d=2.0,the heat transfer between tube bundles reaches the strongest,which can provide practical reference for improving the heat transfer capacity of heat exchangers.Finally,the numerical simulation results are compared with previous empirical formulas and experimental results to ensure the accuracy of the numerical simulation method.

TK124

国家自然科学基金重点课题（51736007）；国家自然科学基金（51476103）