【作者】 王冰；

【导师】 蒋家羚；

【作者基本信息】 浙江大学 ， 化工过程机械， 2007， 博士

【摘要】 可拆式螺旋板换热器(Detachable spiral heat exchanger,简称DSHE)作为一种典型的紧凑式换热器,具有结构简单、制造方便、传热效率高、阻力小、易于清洗检修等诸多优点,但其现有设计因缺少系统的理论指导,影响了其推广应用。本论文针对可拆式螺旋板换热器设计过程的一些关键问题展开研究,给出了其关键设计参数的计算方法,完成了倒锥平盖的理论建模、有限元分析和实验测试,模拟了无相变流体在螺旋通道内的流场、压力场、温度场的分布和性能影响因素,开发了适于可拆式螺旋板换热器设计、校核计算的CAD软件系统。根据可拆式螺旋板换热器的基本结构及其特点,以不等间距螺旋通道为基础,推导了螺旋体有或无外包壳以及两个长轴方向共四种组合情况下的螺旋板换热器的通用几何计算公式,并从结构与流动参数两方面对可拆式螺旋板换热器的设计进行了优化。依经典板壳理论建立了可拆式螺旋板换热器倒锥平盖的理论力学模型,并借助有限元方法,分析了倒锥平盖的变形与应力分布状态,考查了内外锥的位置和厚度、圆环筋的径向位置与高度、厚度等对倒锥平盖中心最大变形的影响。理论模型计算结果、有限元分析结果与实验测试结果吻合较好,满足工程计算的精度要求,从而验证了理论模型与有限元分析的正确性。建立了可拆式螺旋板换热器内部流动与传热的数学模型,模拟得到了其内部流场、压力场和温度场的分布情况,此外还根据数值模拟结果讨论了换热器内流体的流速、流向、流动状态以及换热器的结构参数如换热器高度、流道间距、接管形式等对换热器性能的影响,这些模拟结果对可拆式螺旋板换热器的优化设计以及运行参数的调试都具有重要的参考价值和指导意义。在系统介绍面向对象理论基础上,采用面向对象建模理论,在VC 6.0可视化开发环境下建立了可拆式螺旋板换热器CAD软件系统,该系统由设计、校核与绘图三个部分构成,能完成基本的传热计算、结构尺寸确定、螺旋流道内流体温度分布的模拟以及强度、刚度、稳定性校核等工作。实际使用证明该软件对可拆式螺旋板换热器的基本设计是有效和可靠的。更多还原

【Abstract】 As a typical compact heat exchanger, although detachable spiral heat exchanger (hereinafter referred to as DSHE) has many advantages: simple structure, convenient manufacturing, high thermal efficiency, low drag ,easy cleaning, etc, its application and dissemination is not satifactory because of the lack of systematic design theory. In this paper, some key problems arising during the design process of DSHE was researched and the special method for calculating important design parameters was also given. In addition, the theoretic model , finite element analysis and experiment test was done to the circular-shaped cover with a concentric ring and topsy-turvy cone, the distribution of flow, pressure and temperature of fluid without phase transition in spiral duct was simulated , and a set of CAD software system for the design and check of DSHE was developed.In accordance with the basic structure, features and applications of DSHE, several general geometric calculation equations for the DSHE with uneven spiral ducts is deduced and the some parameters about structure and flow of DSHE were also optimized in this paper.The theoretical mechanical modol of circular-shaped cover with a concentric ring and topsy-turvy cone was built on the basis of classical theory of plates and shells and its distributions of deformation and stress were also analyzed with the help of finite element method. At the same time, the influence from the location, height and thinckness of topsy-turvy cone and concentric ring on the maximum deformation of circular-shaped cover were researched. The results computed by theoretical mechanical modol and finite element method conformed well to practical datas and can satisfy accuracy request of engineering calculation,which proved the correctness of theoretical mechanical model.Based on the mathematical model about flow and heat transfer of DSHE, the distribution of flow, pressure and temperature of fluid without phase transition in spiral duct was simulated. In addition, the influences of flow rate, flow direction, flowage and structural parameters such as the height of heat exchanger and the spacing of flow duct on the heat transfer performance were discussed in this paper, which have good theory guidance and reference value to the optimum design and parameter testing.Furthermore, with the Object-Oriented programming theory, the computer aided design (CAD) software of DSHE was developed in Visual C++ 6.0 environment, which consists of three function parts of design, testing and plotting and can complete basic heating calculation, the simuluation of temperature distribution and the testing of strength, stiffness and stability. The actual service proves that this CAD software about DSHE is convenient, effective and reliable.更多还原