Rationalization Study Of Heat Exchanger Types And Heat Transfer Enhancement Technologies Based On Knowledge Engineering

Heat exchangers are the process equipment for exchanging the heat. Heat exchangers are widely used in many fields such as chemical, petro-chemical, nuclear and food industries, etc. Although there are standards for design of heat exchangers, selections of types and materials are still versatile. In addition, with the applications of larger and larger heat exchangers, light-weight design of heat exchangers has attracted more and more attention. In this thesis, heat exchangers were selected for the study of the reasonable selection of heat exchanger types, materials, heat transfer enhancement technologies, energy efficiency evaluation methods and light-weight design. The work can be summerized as forllows.(1) Based on the theories of knowledge engineering and ideas of collection, storage, management and employment of data, the technical route for developing the Rational Selection Software of Heat Exchangers Types and Heat Transfer Enhancement Technologies was proposed. Heat exchanger types, materials, heat transfer enhancement technologies and energy efficiency evaluation methods were summarized through data collection methods such as literature review, patents, documents and expert verification. Meantime, corresponding characteristic parameters were also defined and the data bases were built up with Excel.(2) Visual Studio was applied for data management. Selection programmes of heat exchanger types, materials, heat transfer enhancement technologies and energy efficiency evaluation methods were established and the interfaces of The Rational Selection Software of Heat Exchanger Types and Heat Transfer Enhancement Technologies were designed. The software has the functions of heat exchanger types, materials, heat transfer enhancement technologies and energy efficiency evaluation methods, reflecting the application of knowledge engineering in the design of heat exchangers.(3) Heat exchangers are special equipment. There are two design methods, namely design-by-rules and design-by-analysis. In this thesis, the tubesheet of a U-tube heat exchanger was designed based on those methods and the results were compared.(4) The light-weight design on a U-tube heat exchanger was performed. By applying the ANSYS code, the finite element model for the heat exchanger was established and the strength was analyzed. The stress distribution at the heat exchanger was investigated. By applying finite element method and based on the design-by-analysis code, the thickness of the tubesheet was minimized, so as to achieve the purpose of light-weight design and cost reduction.(5) Basing on VB and ANSYS software, an analysis and calculation software of heat exchanger tubesheets with specific structures has been developed. The interactive interface of this software was designed and ANSYS could be called automatically in the background to generate the analysis model. This software could shorten the computation period of strength calculation and light-weight design of heat exchangers.