Applied Research, Computer Simulation Technology In The Cement Precalciner

The thesis is about numerical simulation of the subtask of the study and application of a new cement's production process in plateau, which is based on an "863" project of Industrialization and Key Preparation Technology of Low Environmental Impact Cement.There are three major problems in cement industry of China: high consumption of energy and resource, heavy pollution of environment and backward cement technology, so it is important task how to improve on cement technology in China. Precalciner is key equipment of the system of precalcination in cement's production process, and its capability influences directly on the output of cement, the consumption of energy and resource, environment impact and so on. So the optimization design of precalciner is very important.Based on Fluent 6.1, one of software of Computational Fluid Dynamics, the thesis simulates fully a precalciner from a cement factory. Its object is to provide a new method for the design and reconstruction of precalciner in the later. In addition, the result of numerical simulation can also give many valuable monitoring parameters for operating precalciner. The study of the thesis has important theoretical meanings and application values.The major contents of the thesis include:(1) It briefly introduces the current state and the development of the cement industry in China. Based on analysis of the current state the fluid simulation abroad and at home, it explains the meaning of the numerical simulation of precalciner.(2) It presents in detail how to set up geometry mold of precalciner, operate grid and define boundary types and so on.(3) Based on the actual controlling parameter, it simulates the precalciner in detail, and compares these results with the real condition at the same time.(4) It gives three optimization designs for the problem of this precalciner exposing in this simulation, simulates them under the same condition and analysis these results further. These give valuable conclusion and useful advice for the design of precalciner.The major innovations in the thesis include:(1)The thesis acquires a breakthrough of settting up the exact geometry mold ofprecalciner, and increases the reliability of the numerical simulation.(2)The physical and chemistry properties of Al₂O₃, Fe₂O₃ and SiO₂ and so on are input to Fluent successfully in the thesis. This method avoids the disadvantage of approximate treatment and improves the precision of simulation.(3)The combustion of coal and decomposition of CaCO₃ are firstly simulated separately by the Eddy-dissipation model and the Eddy-dissipation-concept model through FLUENT in detail there. The results show the numerical simulation of precalciner is very feasible to a further research of its structure design.(4) It firstly try to settle down the problem of this precalciner exposing in this simulation with three optimization designs and go on a comparatively analyses there.