【作者】 古新；

【导师】 董其伍； 刘敏珊；

【作者基本信息】 郑州大学 ， 化学工艺， 2006， 博士

【摘要】 高效节能过程装备的研究开发是当今工程节能的重要手段。换热器是化工、炼油、动力、食品、轻工、原子能、制药、航空及其他许多工业部门广泛使用的一种通用工艺设备。管壳式换热器由于结构可靠、技术成熟、适用面广，是目前国内外换热设备的主要结构形式。随着对换热器强化传热技术和现代设计研究方法的长足进步，管壳式换热器不断获得改进和发展。本文采用理论分析、数值模拟和实验研究相结合的方式，进行了管壳式换热器壳程强化传热研究，在以下几个方面开展了研究和创新性工作： 1、研究了三角形、菱形等异型截面折流杆对壳程流体的强化传热性能，发现了折流杆截面形状的变化对流体流动和传热性能的影响规律，为折流杆换热器的升级换代提供了更多可供选择的结构形式。 2、在深入研究管壳式换热器壳程结构特点及流体流动和传热规律的基础上，相对于壳程流体横向流、纵向流和螺旋流的流动状态，首次提出了壳程流体“斜向流”的概念。该流动状态的作用效果是，将壳程横向流换热器壳程主流区的横向流动分散为多股受迫倾斜流动，将其流动和传热死区予以分散并凭借特殊管束支撑结构予以部分消除，避免了流体因受横向阻挡产生的速度剧烈变化和动能损失，同时还有效利用了横向流对换热管更为强烈的冲刷作用引起强化传热效果；其总体上的纵向流动趋势，在一定程度上继承了壳程纵向流换热器抗振性能好、除垢防垢效果强、综合性能优等优点。这种流动状态，使得管壳式换热器将折流板换热器和折流杆换热器的各自独特性能相结合，兼备了横向流和纵向流换热器的双重优势。 3、在上述壳程流体“斜向流”状态理念的指导下，首次研制开发了新型高效节能管壳式换热器—帘式折流片换热器，改进和发展了换热器壳程的结构形式，实现了壳程流体的斜向流动。数值模拟和对比实验研究表明，帘式折流片换热器可明显减弱或消除壳程流体流动和传热死区，进一步有效利用传热面积，有助于降低壳程流体的压力损失；将换热器场协同原理引入到帘式折流片换热器的强化传热研究中，结果表明帘式折流片换热器具有良好的速度场和温度梯度场的协同性能，强化传热效果显著。研究和实验结果表明，帘式折流片换热器的研究具有较高的理论和工程应用价值。考察了结构和操作参数对帘式折流片换热器传热与流阻性能的影响，推导了其壳程传热系数准数关联式和流体阻力降准数关联式，为帘式折流片换热器的工程设计和推广应用提供了参考依据。更多还原

【Abstract】 The research and development of energy saving process equipments is an important method to save energy nowadays. The heat exchange is a kind of universal technologic equipment, which is widely used in many industries, such as chemical industry, oil refining, power generation, food industry, light industry, atomic energy installation, medicine manufacturing industry, aerospace industry and so on. Shell-and-tube heat exchanger has many advantages such as reliable structure, mature technique and wide applicability, so it is the mostly used structure in the internal and overseas applications of heat exchangers. The shell-and-tube heat exchanger gets continuous improvement and development with the great progress of the heat transfer enhancement technique and modern design and research method.The method which integrates theoretical analysis, numerical simulation and experiment is adopted to research the heat transfer enhancement technique for the shell-side of the shell-and-tube heat exchanger in the paper. The following main achievements and innovations are obtained.1. Heat transfer enhancement performances of rod baffles with abnormal profiles such as triangular one, rhombic one, are investigated. And influence laws of the profile shapes of rod baffles on fluid flow and heat transfer performance are discovered, which provides more optional structures for improving the rod baffle heat exchanger.2. Based on the deep research of structure characteristics of the shell-side of the shell-and-tube heat exchanger and laws of fluid flow and heat transfer, the concept of "sideling flow" in the shell-side is presented for the first time, which is relative to the flow states of the cross-flow, the longitudinal-flow and the helical-flow. The effect of this flow states is that it can disperse the cross-flow in the main flow region of the cross-flow heat exchanger into the sideling-flow compelled, and so that dead spaces of the flow and heat transfer are dispersed and partly eliminated by the special support structure for tube bundles. The great change of velocity and the kinetic energy loss of the fluid caused by the transverse obstruct is avoided, besides, the heat transfer enhancement caused by the much more strong scour effect of the cross-flow on tubes is utilized effectively. Because of the overall更多还原