Structural Optimization And Performance Prediction Of Digital Valve For Desulfuration And Dedusting

The working condition of the valve for the desulfuration and dedusting process is poor because of high temperature, corrosive material from this process. Performances of high temperature resistance and corrosive resistance are required for the valve, as well as the seal performance. For the purpose of the accurate control of the desulfuration and dedusting process, the valve with perfect regulation characteristics is needed in the real-time monitoring and adjustment of the fluid in the pipeline. The research object in the thesis is a digital valve used for the desulfuration and dedusting process, consisting of the V-ball valve, the transmission mechanism and the stepper motor. This digital valve with perfect regulation characteristics can adjust the flow and other parameters in real time flow. The V-ball valve has the characteristics of equal percentage regulation, and the V-notch shear the fluid, especially for the media containing viscous substance or particulate against choking.The pulse signal from the controller can be transformed to the angular displacement by the stepper motor.The digital valve for the desulfuration and dedusting process is studied in the research, adopting knowledge related to computational fluid dynamics, theoretical mechanics, mathematical statistics and optimization of mechanical design. The numerical simulation and prediction of the flow field, the characteristics study, the orthogonal test and the structural optimization for this valve are carried out. First, the structural arrangement of the digital valve for the desulfuration and dedusting is accomplished. Design calculations and2-D drawings of every part of the valve and the transmission mechanism are accomplished. Second, the model of the flow path of is exported from the built3-D model of the valve. The three-dimensional flow filed simulation of the valve is carried out and prediction data is obtained after meshing the model of the flow path and applying boundary conditions to the model. Third, the ideal flow characteristics, the displacement characteristics, the static characteristics for the valve are researched, and curves related to those are drawn. Forth, performances of valve are studied trough the method of orthogonal test. Evaluation indexes of valve’s performances is determined and regression analysis is applied in the numerical evaluation for the ideal flow characteristics of the valve. Factors influencing valve’s performances and levels of factors are determined. Influences on the valve’s performances from every factor are evaluated by range analysis. Fifth, On the basis of the result of orthogonal test, the multi-objective optimization problem is converted into the single-object optimization problem in the optimization of the digital valve through synthetic weighted mark method and the structure of the digital valve is optimized to obtain optimal structural parameters, using complex method.In the study, the digital valve for the desulfuration and dedusting process is designed. In addition, the numerical simulation and prediction of the flow field, the characteristics study, the orthogonal test and the structural optimization for this valve are carried out for the purpose of the reference and ideas provided for the research and development of the digital valve used in the desulfuration and dedusting process.