管翅式换热器数值设计方法及其应用研究

The optimization design of the heat exchanger is one of the effective measures to reduce high temperature energy consumption and emission. Due to a very wide range of applications of the tube bank fin heat exchanger, its optimization design has received serious attention. Because of the complex fin geometrical parameters, the traditional study on the optimization design of this type of exchanger is mainly by experiment. How to shorten the optimization design period and reduce the funding requirements are the severe challenges encountered in the design of this type of exchanger. Along with the improvement of numerical methods and the development of computer power, using numerical method to design this type of exchanger has become increasingly possible. To realize this object, this project aims at the present research situation and its existing key problems of the numerical design of this type of exchanger, and combines the numerical simulation, theoretical analysis and experimental test as the research method to carry out the studies with the main contents as: (1) seeking for the general principles of selecting a basic heat transfer unit as an computational domain and how to locate an effective symmetric surfaces; (2) studying on the high-efficient numerical method to obtain the accurate flow and temperature fields of the heat transfer unit, such as using an grid system which is accessible to use symmetric surfaces and calculate the heat transferred from or to the interested surfaces, and some effective measures to improve the efficiency of computing the conjugated heat transfer; (3) studying on how to define the characteristic temperature in the definition of tube-side and fin-side heat transfer coefficient and then seeking for its physical meaning; (4) exploreing the numerical method to determine the log-mean temperature difference correction factor of the heat transfer unit and its theoretical basis; (5) testing the proposal numerical design method by comparing the existing experimental data with the numerical results of the correaponding models. And then such a tube bank fin heat exchanger will be designed, and the sample will be manufactured and its performance will be tested by experiment. Finally the experimental results will be compared with the numerical design performance indexes to assess the accuracy and effectiveness of the numerical design method. By exploring and researching the above mentioned problems, this project will not only establish the fundamentals of numerical design of the tube bank fin heat exchanger and the correspnding numerical method which can expand the application of numerical methods in industrial design, but also promote a deeper understanding and description of the heat transfer process in the heat exchanger. The results of this project will have a paramount scientific significance for contributing to the contents of the heat transfer and its numerical method, as well as a high value of industrial applications.

换热器的优化设计是减少高品位能量消耗和排放的有效措施之一。管翅式换热器的翅片结构复杂，传统优化设计多以实验为依据，如何缩短优化设计周期和减少经费投入面临严峻挑战。本项目针对该类换热器数值设计的研究现状及存在的关键问题，采用数值模拟、理论分析和实验测试相结合的研究方法重点开展：选择基本传热单元的原则；快速获得准确传热单元流场和温度场的数值方法；两侧表面传热系数定义式中特征温度的定义方法及其物理意义；传热单元温差修正系数的方法及其理论依据；考核数值方法后设计一换热器，加工样品并进行性能实验，与数值设计的指标对比来考核数值设计方法的准确性和有效性等研究工作。通过这些探索和研究，不但可建立管翅式换热器的数值设计原理、数值方法，拓展数值方法在工业设计中的应用，还可增进对换热器中进行的传热过程更深刻的理解和描述。项目研究结果对丰富传热学及其数值方法内容具有重要的科学意义，同时还具有很高的工业应用价值。

强化型翅片几何形状比较复杂，获得其能用于管翅式换热器设计的关键数据非常困难，以传统实验获取设计依据在设计周期和经费投入方面面临严峻挑战，数值方法成为设计该类换热器的主流方法。本项目针对该类换热器数值设计的研究现状及存在的关键问题，以建立管翅式换热器的数值设计原理及数值方法为目标，通过深入细致研究获得的主要学术进展是：明晰了管翅式换热器典型传热单元的选择原则及其数值处理方法；获得了物理意义明确、实施简单的肋侧气流出口边界条件的处理方法；完善了管翅式换热器传热单元全耦合传热模型的计算方法；获得了传热单元中沿流动方向两端的温度边界条件的确定方法及依据；提出了肋侧表面传热系数定义中合适的特征温度；确定了全耦合与非耦合设计方法选择的判据。并应用构建的数值方法对多种强化翅片进行了深入研究，建立了间断环面槽和曲面涡产生器翅片的核心关联式，揭示了翅片侧间断环面槽和曲面涡产生器强化传热机理，拓展了数值方法在工业设计中的应用。项目累计在国内外发表论文14篇，已被SCI收录5篇，EI收录5篇；培养硕士研究生4名。