新型换热设备三维造型技术研究与应用

【作者】 钱亚东；

【导师】 董其伍； 刘敏珊；

【作者基本信息】 郑州大学 ， 化工过程机械， 2002， 硕士

【摘要】 CAD是20世纪最杰出的工程技术成果之一，是用高新技术改造传统产业、加快国民经济发展的一项关键新技术。而换热设备在民用、工业、国防等部门有着广泛的应用，开发高效换热设备对国民经济建设具有重要意义。新型高效节能换热设备系我校“热能工程中心”专利产品，为加快该成果的推广步伐，“中心”曾自主开发了HECAD软件系统(HECAD是集新型换热设备工艺、机械、零部件及总装图的一体化二维CAD系统)。目前二维CAD绘图软件的使用已相当普遍，但二维图形表示三维物体存在许多局限性。随着计算机三维图形学技术的发展，建立的实体模型能够更直观、全面地反映设计意图，并且在此基础上还可以进行装配、干涉检查、有限元分析、运动分析等高级计算机辅助设计工作。 本文研究课题来源于省重大科技攻关项目“重大过程装备智能化CAD／CAE集成技术的研究与开发”，三维造型是其关键技术之一，它是工程设计的重要环节，贯穿了工程设计的核心信息，而信息的完备性、抽象性和可操作性对于CIMS的信息集成具有决定性的影响。原有HECAD是基于二维的CAD系统，三维零部件及结构的表现采用不同方向投影视图表示，但对于复杂情况，如折流栅装置要清楚地描述是困难的；在制造及装配过程中，由于新型结构与传统挡板结构不同，常给制造装配带来不便，如能对动态装配过程进行三维模拟，不仅能够解决现有问题，而且还能为制定其它新型结构的装配顺序提供有效手段；此外，在研究开发高效节能换热设备，进行结构改进和优化时的有限元分析及设备内流场、温度场的数值模拟分析更是离不开三维建模。基于上述情况，本文研究开发了新型换热设备的三维造型系统。 郑州大学硕士学位论文 第11页 在对CAD技术、计算机图形学、三维造型方法、开发环境、数 据库技术等进行综述分析的基础上，本文着重对以下几方面内容作了 研究及实践： l）CAD三维造型技术经历了线框造型、曲面造型、实体造型、参数 化造型及变量化造型技术等五个阶段，不同阶段的技术在具体软 件产品中往往是并存的，而非排它的。参数化造型方法注重于几 何图形元素的邻域，使用约束来定义和修改几何模型，适合于己 完全特性化的设计问题。因为新型换热设备专用零部件己经规格 化、系列化，其它常用零部件更有相关手册、国标作为依据，所 以本文采用了参数化实体造型方法。 2）在开发环境及工具方面考虑到 AUt。CAD的简易性和国内的普及程 度，更重要的是考虑到与“中心”在国家九五项目中己完成的大 型软件系统HECAD的兼容性和继承性（HECAD是在AUt。CAD提供 的ADSRX开发工具和Visual VC什5．0的集成设计环境下开发完成 的入 本文选择AulOCAD。3DS MAX为平台，ObjCCtARX 2000 和Visual C，，－6刀为开发工具进行三维系统的开发。AutoCAD系统 在三维造型方面提供的实体（SOLID）具有体的特征，能够较全面 地反映形体的物理特性，利用实体造型技术不仅可以生成所需要 的零部件模型，而且还能够对形体进行剖切生成剖视图，以及进 行体积、重心和惯性矩等物性计算和分析。objectARX支持MFC 二 基本类库，而mC类库的强大功能给编程带来很大方便。 3）三维造型系统的数据相当复杂，涉及到工艺设计、机械强度、三 维几何参数等方面的内容，其数据类型包括图形、文件等不同形 式，因此，信息处理和管理一直是三维造型系统必需面对的难题。 在objectARX开发工具中，本文使用了作为内嵌的扩展工程数据 库管理系统（EDBMS具有强大的图形处理能力），同时又结合利 用了外部关系型数据库系统（Visual FoxPro）。 2 郑州大学硕士学位论文 第＊ 页 本文通过对三维造型关键技术的深入研究及具体实践，首次完成 了新型换热设备的三维造型系统： 1）该系统零部件三维实体造型包括筒体、管箱、封头、膨胀节、 管板、接管、斜截弯管、变径段、支座及折流栅装置等造型子 模块，在造型中用数据库技术首次实现了二维工程图与三维模 型的相关联。 2）该系统动态装配模拟不仅包括典型部件（如折流栅装置），还包 括了用于电力工业热力系统及化工、化肥、炼油热力系统的疏 水加热器、冷凝器、主热交换器等九种类型的换热设备的装配 模拟。更多还原

【Abstract】 CAD is one of the most prominent engineering technology productions in the 20th century , which is an new key technology in alternation of traditional industry and promotion of national economy by means of top and new technology. Heat exchangers are used widely in civil , industrial and national defence departments and so on. The developments of high efficiency heat exchangers have important meanings to construction of civil economy. The New Type High Efficient Heat Exchanger(NTHE) is the patent developed by the Thermal Energy Research Center of Zhengzhou University , in order to promote the popularization of the technology, HECAD software system which consists of process design, mechanical design, components design and assembly drawings design of NTHE has been completed by our Research Center. Now , 2D CAD drawing software is very prevalent , but which has many limits in exhibition of 3D objects. With the development of computer 3D graphics technology , designers can express their intensions more directly and thoroughly by 3D body models. Advanced CAD tasks such as checkage of assembly and interference, the analysis by FEM and analysis of movements etc. may be carried on based on 3D models.The subject of this dissertation roots in R&D of CAD/CAE intelligent integration technology of important process equipments which is one of magnitude science and technology projects of Henan province, 3D modeling technology is one of the key research parts of the project. It is an important sector of engineering design, impenetrating core information of engineering design. At the same time, the integrality, abstraction and maneuverability of information have decisive effect on information integration of CIMS. HECAD is a CAD system based on 2D, it expresses 3D components and constructions by projections of different directions, but it is difficult to distinctly exhibit some complicated situations such as deflection fence set. In the course of manufactory and assembly, the difference between new constructions and traditional baffle construction causes some trouble. If there is a 3D simulation of dynamic assembly course, the present problem is able to be solved, what’s more, an efficient method by which assembly order of new constructions can be set down will be gained accordingly. In addition, when we research and develop high efficiency and energy-saving heat exchanger, the analysis by FEMwhich aims at betterment and optimization of constructions needs solid models, the analysis of numeric simulation of fluid flow fields and temperature fields of the whole heat exchanger also needs 3D models. Therefore, this dissertation has researched and developed the 3D modeling system of NTHE.Based on summary and analysis of CAD technology, computer graphics, 3D modeling method, development environment and database technology, this dissertation has made researches and practice with the emphasis on the following several aspects:1) The development of 3D modeling technology of CAD experiences wire frame modeling, curved surface modeling, solid modeling, parameterized modeling and variable modeling. The technologies of different period are usually coexistent and not exclusive in concrete software products. Parameterized modeling pays attention to the neighborhood of geometry graphics element, defining and modifying geometric model through constraints, which is fit to the design field characterized completely. Because the special components of NTHE have been normalized , other common components can also be designed according as manual and GB, The 3D modeling system of NTHE adopts parameterized solid modeling.2) Considering widespread extent in our country and facility of AutoCAD , a prior reason is the compatibility and inheritance of between 3D modeling system and HECAD which is accomplished by means of ADSRX and Visual C++ 5.0 , this dissertation selected ObjectARX 2000 and Visual C++ 6.0 based on AutoCAD and 3DS MAX. The 3D solids produced by 3D modeling of AutoCAD system更多还原