【作者】 周懿；

【导师】 童水光； 钟崴；

【作者基本信息】 浙江大学 ， 化工过程机械， 2011， 博士

【摘要】 机械系统的方案设计直接决定着产品的功能、质量及成本,是产品设计的关键。当前,计算机辅助设计(CAD)技术在一般机械系统的设计信息表达、结构性能分析以及产品数据管理等方面的研究和应用日趋成熟,但对于方案设计环节的支撑还相对较为薄弱。鉴于机械系统的计算机辅助方案设计往往依赖于特定领域的专业知识,并可能需要依据设计问题的特点采用专用的设计模型和具体的智能化设计方法,其研发工作多为针对特定范围、特殊类别机械系统的专用型系统。本文研究针对锅炉、汽轮机、压缩机等具有过程系统特征的特定机械系统,提出将这些在功能原理上与过程系统相似,通过多个或多级部件的相互配合、协作,共同完成对进出系统的物料变换或能量转换的机械系统归类为“过程型机械系统”(以下简称“PMS”),进而结合机械系统和过程系统的设计理论和方法,研究PMS计算机辅助方案设计的共性问题和技术,具体包括功能原理分析,设计模型、设计过程和方法研究等,旨在研发PMS计算机辅助方案设计系统以提高PMS方案设计的质量与效率。论文的主要内容如下：◆提出了PMS的分类,定义了“过程部件”、“总体布置”等关键概念。其中“过程部件”泛指实现对进出物料或能量的进行特定变换处理的机械部件,多级过程部件按照特定的逻辑组合构成PMS的“总体布置”。对PMS的主要特征进行了分析,提出从单元级和系统级的物料变换逻辑两个层次来理解PMS的功能原理,前者表现为过程部件对于进出物料的分支数、类型以及相关属性的变换,后者主要描述在特定总体布置逻辑下,由PMS所有过程部件共同配合将输入系统的物料逐级累积变换为输出系统的物料。(?)以PMS的概念和特征认知为基础,借鉴机械工程和过程系统工程的相关理论,提出将PMS的方案设计分为总体布置设计与过程部件设计两个层次,通过总体布置设计解决系统层面的部件配合问题,而通过过程部件设计探索满足特定物料变换任务的部件具体结构。结合“功能-行为-结构”FBS设计模型理论,提出分别采用系统级和单元级的“功能-行为-结构-知识”四元组描述PMS的总体布置设计模型和过程部件设计模型。其中,“结构”对应于PMS中任一过程部件以及部件组合形成的PMS总体布置,“功能”表达结构的物料变换需求,“行为”描述特定结构所实现的详细物料变换内容,“知识”统括设计过程所使用的规则、经验、方法等。(?)物料变换逻辑的描述和表达是构建PMS方案设计模型的关键。将PMS系统中任意位置处的过程部件和物料分别抽象为“广义过程部件”和“广义物料”两类对象,部件级的物料变换逻辑由一个广义过程部件和输入输出该部件的广义物料集合组成,进而再通过同一广义物料对于相连广义过程部件的流出和流入逻辑使得各广义过程部件相互衔接形成系统级的物料变换逻辑。对于上述变换逻辑的形式化表达问题,在技术上提出了一种基于ID关联的描述方法,采用ID来唯一标识所对应的过程部件和物料,通过记录相关联对象的ID来建立对象之间的连接关系。(?)提出将PMS系统方案设计活动分解为方案创建、方案分析、方案评价和方案调整四项子活动,分别在总体布置设计和过程部件设计两个层面上,研究了基于四项子活动而实现PMS方案设计的过程。归纳了支持PMS系统的方案设计过程的主要智能CAD方法,并阐述了这些方法在PMS系统设计过程中的运用。(?)基于本文研究提出的PMS系统计算机辅助方案设计理论框架,具体针对锅炉计算机辅助方案设计问题,采用面向对象技术设计了系统的软件模型,研发了锅炉方案设计系统的原型,并给出了系统的具体应用描述。本文针对PMS这一特殊类别的机械系统开展计算机辅助方案设计技术的研究工作,奠定了该领域进一步技术研究及系统开发的基础,填补了过程系统与机械系统学科交叉领域的研究空白,并对其它类别系统的计算机辅助方案设计研究具有借鉴意义。更多还原

【Abstract】 Mechanical system conceptual design determined many key factors of target products including function, quality, and costs, which was the key node in the products design process. Currently, CAD technology was becoming mature for regular mechanical system in the design information expression, structure performance analysis and data management, et cetera. But it was still weak in the node of supporting conceptual design. Considering mechanical system conceptual CAD technology usually relied on professional knowledge for special field, specialized design model and intelligent design methodology might needed according to the characteristic of the target design, which resulted in research of specific design systems for mechical system of particular range and special classification.This paper focused on specialized mechical systems which with process system characteristic, e.g. Boiler, steam turbine, compressor etc. Process-form Mechanical System (PMS for short) was proposed to classify these mechanical systems whose function principle was similar to process systems. The function principle of PMS could be described as converting material and energy that flowed in and out of PMS by interworking of several parts. Further, combining the design theory and methods of mechanical system and process system, we could develop the generally applicable CAD technology for PMS including function principle analysis, design model, and design process and methods, in order to improve design efficiency and quality by developing CAD technology for PMS.The main content of the paper were listed as follows:(?) The paper proposed the classified concept of PMS, and defined key concepts such as“”and "general layout". Process part refered to mechanical parts which made specialized deal with material and energy that flowed in and out. Several process parts consisted of general layout for PMS according to special logic. The main characteristic of PMS was analyzed, and it was proposed to acknowledge the function principle of PMS with material conversion of unit and system level. The former was performanced as converting the brance number, type and properties of material that flowed in and out. The later mainly described the performance of all the process parts working together under specialized logic of general layout, to convert material that flowed in and out of PMS step by step.(?) Based on the acknowledgement of concet and characteristic of PMS, the conceptual design of PMS was devided into two levels, general layout design and process part design, by drawing on relevant theories of mechanics engineering and process systems engineering. By the general layout design process, the interworking problem of system level was solved, and the process part design helped to get the detailed part structure that satisfied specific material conversion target. Combining the Function-Behavior-Structure (FBS) model, the general layout design model and the process part design model of PMS were expressed by four components (function, behavior, structure and knowledge) which were constructed by system level and unit level. The structure refered to both of any process part in PMS and the general layout consisted of several parts.The function expressed the material conversion requirement, while behavior was described by details of material conversion that was achieved by specific structure. Knowledge involved the rules, experience and methods used in the process of PMS design.(?) The desription and expression for material conversion was most important for the conceptual design model of PMS. Abstracting any process part and material of PMS respectively as "General Process Part"(GPP) and "General Material"(GM), the material conversion logic of unit level could be described by one GPP and GM with in-out GPP. Further more, the material conversion logic of system level was composed by many GM and GPP with some logical relations. An ID linked description method was proposed for the expression of the conversion logic mentioned above, which used ID to mark the corresponding object uniquely, and built up the relationships between each other by record the ID of object relatively.(?) The PMS scheme design activities was decomposed into four sub activities including scheme creation, scheme analysis, scheme evaluation and scheme adjustment. PMS design process was realized by the four sub activities in the two design levels containing general layout design and process part design. The main intelligent CAD methods which supported the PMS design process were generalized and the application of these methods in the PMS design process was expounded.(?) Based on the PMS conceptual CAD theoretical frame stated previously, the software model for boiler conceptual CAD was proposed with object-oriented technology. The system prototype was developed, and the application details were given.This paper developed the generally applicable CAD technology for PMS, which established the basis for further research and application of this fied. It filled up the research gap of interdisciplinary areas with process systems and mechanical systems, and was of reference value for the computer-aided conceptual design technology development of the other systems.更多还原