The Study Of Optimal Design For A Swirl-Spray Cement Pre-Calciner

With the development of cement industry, the national policy emphasizes the technique of the new dry cement production. pre-calciner is the core of the technique, its reform and optimal design are regarded. For the swirl-spray pre-calciner, this thesis presents a new optimal design method using numerical simulation technique.Firstly, this thesis introduce the physicochemical modeling of an in-line swirl-spray pre-calciner, including the model of turbulence, the motion model of particle, the combustion model of coal particle, the decompose model of raw materials and models of heat transfer between gas and particle, then simulates a swirl-spray pre-calciner that has been putted into production using these models. Through the analysis result of the difference between the modeling results and the measured results, we can consider that these models are correct and rational.Based on the 3-D numerical simulation of the swirl-spray pre-calciner, borrows ideas from the traditional optimal design method, this thesis resolve three key problems: the orthogonal analysis of orthogonal table can determine the contribution significance of the optimized variables and guide the direction of optimal design; artificial neural network can build the object function in optimization model, genetic algorithms can figure out the best value of the optimized variables as the optimization algorithm in optimization model. Then optimization model presents a new optimal design method. Then using this optimization model, this thesis optimize a specific non-linear function, through the difference between the optimized results and the actual maximal value that calculated by algebraic method, it can consider that this optimal design model is reliable.Then using the platform, this thesis optimized structural parameters of a specific swirl-spray pre-calciner, the analysis of the optimized result proves that the optimal design is rational.Based on the physicochemical model and optimal design model, this thesis developed an optimal design platform for swirl-spray pre-calciner using mixed coding of Visual C++, FORTRAN and OpenGL. This platform implements many functions, for example, it can display vector field, scalar field by using three visualization method: nephogram, contour and vector line; it can design orthogonal table and make orthogonal analysis, it can set parameters of artificial neural network and implements visualization of the train process, it also can set parameters of genetic algorithms and implements visualization of the evolution process; after the evolution process, it provide the final optimized result.Finally, the thesis summarized the studies and puts forward problems for further studies.