翅片管束通道流动中涡动力学特性及其对传热的影响

Finned tube heat exchangers are widely used in various engineering applications, thus the amount of their energy consumption is very large during operation process, in which the predominant portion of the energy consumption is in the air flow channel of finned tube bundles. As the heat transfer and pressure drop performances of finned tube heat exchangers are mainly determined by the vortex dynamics characteristics involved in the channel of finned tube bundles, it is very important to investigate the vortex dynamics characteristics and their effects on heat transfer and pressure drop performances in the channel of finned tube bundles so as to achieve the optimal design of this type of exchanger. In contrast, the study of vortex dynamics characteristics of finned tube bundles in cross flow is rarely reported up to now. In order to reveal the relationship between heat transfer and vortex dynamics characteristics and explore the heat transfer enhancement means by taking the advantage of the vortex dynamics characteristics, the target of the project intends to carry out the following investigations by using theoretical analysis, numerical simulation and experimental combined method including the critical inflow condition and the critical structure conditions of the channel of finned tube bundles that occurs an oscillating vortices system, the relationship between the characteristics of oscillating vortices system and flow conditions as well as structure conditions of the channel of finned tube bundles, the relationship between the characteristics of oscillating vortices system and fin geometry shape, the influence regulations of the features of oscillating vortices system on heat transfer from the finned tube, the methods of controlling the oscillating vortices system for heat transfer enhancement of the finned tube heat exchanger. The results of this project not only can enlarge the findings and understanding the characteristics of vortex dynamics experienced in the channel of finned tube bundles, but also can supply theoretical basis and fundamental data for designing low energy consumption finned tube heat exchangers. Thus, the results of this project have a paramount academic significance and a high value of industrial applications.

翅片管换热器应用广泛，其运行耗能基数巨大，且气流流经翅片管束通道的能耗占绝大部分。由于翅片管束通道中涡动力学特性决定着翅片管换热器的传热及流动阻力特性，因而获得翅片管束通道中涡动力学特性及其对传热特性的影响规律对优化设计高效换热器非常重要。然而目前鲜见翅片管束通道中涡动力学的研究报道。为了揭示翅片管束通道中涡动力学特性及其与传热的关系，寻求利用涡动力学特性强化传热的方法，项目采用理论分析、数值模拟和实验相结合的方法开展翅片管束通道流动中出现振荡涡系的流动条件及管束结构条件、振荡涡系特性与流动条件及管束结构条件的关系、振荡涡系特性与翅片形状的关系、振荡涡系特性对通道表面传热特性的影响规律、控制振荡涡系强化通道表面传热的方法等研究。项目研究结果不仅可增进对翅片管束通道中涡动力学特性的认识和理解，还可为设计低能耗管翅换热器提供理论依据及基础数据，具有重要的学术意义和很高的应用价值。

决定翅片管换热器产品质量主要是翅片侧和管侧表面传热系数及工质流经换热器时的阻力系数。涡动力学特性又决定着翅片管换热器的关键功能特性：传热及流动阻力特性。项目以优化设计翅片管换热器提供奠定理论依据为目标，采用数值模拟和试验相结合的方法对翅片管束通道中的涡动力学特性及其对传热特性的影响进行了深入细致的研究。以不同几何形貌的涡强化翅片管换热器换热单元为研究对象，考察连续翅片管束通道中的涡特性及传热特性。采用实验和数值模拟方法研究了不同形貌曲面涡产生器连续翅片管束通道内流动及对流传热特性研究；数值研究了间断环面槽翅片、金字塔型翅片、三角形波纹翅片、百叶窗翅片、条缝翅片及其与涡产生器组合式翅片管束通道内涡结构和对流换热特性及其关系。以非连续平直环翅、螺旋环翅管束通道为研究对象，研究了环翅宽度、翅片间距、管间距比等参数对涡动力学特征参数和传热性能参数的影响。为实现管内涡强度的调控，研究了内插涡产生器圆管中涡特性及其对流换热强度的关系。项目发展了复杂计算区域交叉区域分裂/耦合数值方法；建立了不同几何形貌的曲面涡产生器连续翅片、金字塔型翅片、间断环面槽翅片、三角形波纹翅片、百叶窗翅片、条缝翅片及其涡强化组合式翅片管束通道中相关二次流强度与对流传热核心关联式；获得环翅管束通道的传热特性关联式及涡动力学特性对传热关系影响规律。.通过项目的实施，不仅增进对翅片管束通道中涡动力学特性的认识和理解，也为设计低能耗管翅式换热器提供理论依据及基础数据，具有重要的学术意义和很高的应用价值。目前已在国内外刊物上发表期刊论文4篇，国际会议论文4篇，国内会议论文5篇，其中，SCI检索论文2篇；培养硕士研究生7名；授权日本发明专利1项；授权中国实用专利4项，申请中国发明专利1项；获甘肃省科技进步奖一等奖1项。