| Heat exchanger is widely used in oil refining, chemical engineering, chemical fertilizer, power, nuclear power, metallurgy, environmental protection, light industry etc, which all are basic industries and mainstays in our country. Shell-and-tube heat exchanger is the main form in the domestic heat exchangers at present, whose structure is reliable, technology is mature, application scope is broad. Its main function is to complete heat exchange in the process needed and reuse remaining heat, and its quality plays an important role in the investment in industrial process, power consumption and safe economic operation etc. As a new energy-saving equipment, the Tubular Heat Exchanger with Longitudinal Flow of the Shellside fluid(THELFSF) has many remarkable advantages. It betters anti-vibration and anti-smudge performances, enhances heat transfer efficiency, and reduces the shell side pressure loss, also prolongs service lifetime, reduces the weight and saves materials, etc.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 for national economy by means of top and new technology. The technology of CAD beginning in the fifties of 20th,through the formation in 50 to 60,the development in 70 and the spring up in 80,it is now developing ahead, called the next generation of CAD system or the fourth CAD system, whose relevant technologies are being studied. The third CAD system began in the middle of 1980,whith the feature-based modeling and preference restriction in modeling method. The character of which is expressing the product information by feature, setting up the same information model of the product, thus helping the integration of CAD\CAPP\CAM.The subject of this dissertation roots in "The Research and Application of CAD/CAE/CAPP/VM of Important Process Equipment and the Network Technology", which is one of magnitude science and technology projects of Henan province. The feature-based modeling system of new type heat exchanger is one of the key technology of it. The traditional geometrical modeling, wire frame modeling, curvedsurface modeling and solid modeling only depict the geometrical data of part, hard to express the tolerance, precision, roughness and heat treatment,etc. The traditional modeling method can't realize the integration of CAD\CAPP\CAM, which require to express the product from every phrase in the whole life time of product in order to express it comprehensive and other application systems can extract the information wanted. Based above analysis, this dissertation study and develop the feature-based modeling system of new type heat exchanger.Based on summary and analysis of CAD technology, feature technology, computer graphics, development environment and database technology, this dissertation has made researches and practice with the emphasis on the following several aspects:1, This dissertation has discussed and studied the relevant theory and technology of developing feature-based modeling system of New Type Heat Exchanger, including feature technology, parameter technology, object-oriented technology, database technology and practice the above theory and technology in the application of feature-based modeling system of New Type Heat Exchanger. 2, On the basis of the analysis on the part of New Type Heat Exchanger, the commonness of the same kind of part is extracted and the UDF library is set up. Part information model can be realized with the help of UDF library, adding features needed.3 , Because the nongeometrical information and the geometrical information can be separated, this dissertation extract geometrical feature from the information model of the part. On the bases of dimension driving theory, the New Type Heat Exchanger parts library is set up and it is visited, queried and changed easily by UG developed tools. In order to manage the geometrical data expediently and form series of part, this dissertation apply ODBC database visiting technology to add,... |
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