CFD技术在管束传热问题教学中的应用

Application of CFD Technology in Tutoring of Heat Transfer of Tube Banks

管束传热问题在工业生产过程(化工、能源等)中广泛存在,例如列管式换热器、中空纤维膜组件等热质传递组件中存在流体横掠或交错掠过管束表面的对流换热现象。因此,在能源动力类专业核心课程《传热学》教学过程中,把这一类问题列为对流传热的代表性问题。在讲述这一现象的过程中,目前就是简单地列举经验关联式,学生普遍反映概念抽象,理解困难。通过实验来讲解又存在周期长,实验测量的参数少等问题。计算流体力学(CFD)能够较直观地将管束间流场、温度场展现给学生,让学生对这一问题有清晰的认识。本文主要利用CFD技术研究了流体交错流过规则排布管束和不规则排布管束的对流传热问题,直观地揭示了管道排布对传热性能的影响。

The phenomena of heat transfer of tube banks widely exist in industry process, including chemical engineering and energy production process. They are basic elements at tube-shell heat exchangers and hollow fiber membrane contactors. Thus, it is a key problem in the text book of heat transfer, which is the center course for major of energy and power engineering. In teaching process, teachers just write out many correlations, but students usually reflected that it was had to understand the concepts. Through experiment to demonstrate the concept is an option. However, it takes long time and the measured parameters are few. CFD technology directly demonstrates the flow and temperature field. Students will feel straightforward to understand the phenomena. In this paper, CFD technology is utilized to study the heat transfer of cross flow over tube banks with uniform and random patterns. It directly demonstrates the effect of distribution patterns of tube bank on its heat transfer features.