| Contact flexible seal is a new-style technology to solve air leakage of rotary air preheater. The rotary air preheater is an important equipment in the machines of modern power plant boiler, and has important function in increasing the efficiency of boiler. The high air leakage rate of rotary air preheater is a hot potato, has a vital disadvantage and has directly effect on the security and economy of boiler set. If contact flexible seal was applied to rotary air preheater, it would achieve zero clearance sealing and would decrease the air leakage of rotary air preheater. Contact flexible seal could increase the efficiency of boiler set and decrease energy wastage. So contact flexible seal has important significance and beautiful prospect. The thesis analyzed contact flexible seal through the mechanical experimentation method and the finite element method, and finished optimization design, reliability design, fatigue life analysis of contact flexible seal by high ANSYS module. Mostly contents consist of:(1)The thesis analyzed the mechanism of the rotary air preheater leakage, and showed that air leakage was in direct proportion to leaking area, so that it could control air leakage by reducing leaking area. Through the comparison of several seal technologies, new-style contact flexible seal technology is a available method and has characteristics of convenient setting, zero clearance and adapting to temperature distortion.(2)Structural parameters of contact flexible seal are wave thickness, wave number, wave interval, wave depth, initial length, total length and head-on angle. Stiffness is the main performance parameter of contact flexible seal. Contact flexible seal with different structural parameters was studied through the mechanical experimentation method and the finite element method based on basic mechanical model. The results are to get the maximal load for contact flexible seal with different structural parameters, load-displacement relation with different structural parameters and relation of different structural parameters and stiffness. Wave thickness, wave number, wave depth and total length are the main structural parameters to influence stiffness, and wave thickness is the main factor of stiffness.(3)This thesis introduced the theory of optimization design of Finite Element Method. Using ANSYS Parametric Design Language (APDL), the contact flexible seal was parameterized created, and it’s structures, load and stiffness were optimized through ANSYS Design Optimization. The optimization results showed that the optimum structures were achieved and the rigidity of the optimum structures was68%less than that of the initial structures.(4)Reliability is the main performance parameter of contact flexible seal. This thesis introduced the method of reliability analysis based on ANSYS. Using ANSYS Probabilistic Design System (PDS) and the combination of finite element method and the theory of probabilistic design, the contact flexible seal was analyzed. The results showed that the contact flexible seal was reliable, and wave thickness, wave number and wave depth were the main factors of contact flexible seal.(5)Fatigue life is the main performance parameter of contact flexible seal. This thesis introduced the method of fatigue life analysis based on ANSYS. Using ANSYS FATIGUE module and the combination of finite element method and the theory of fatigue life analysis, the contact flexible seal was analyzed. The results showed the fatigue life of contact flexible seal were eight years. |
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