The Numerical Simulation Study Of The Flow Field With The Firing Zone Of The Roller Kiln

The quality of the product and the heat consumption are directly affected by the design and the operation level of the ceramic kilns. In order to accomplish the target of optimum quality, high quantity and low heat consumption, it is meaningful actually and theoretically to carry out the numerical simulation study of fluid process in ceramic kilns. However, It is very difficult to research on ceramic kiln with experiments of various factors. But with the development of computer technology, the numerical simulation method based on CFD (computational fluid dynamics) makes it possible. It can simulate actual and visual conditions with low cost, fast speed and high efficiency.In this paper, commercial CFD software FLUENT is used to study the flow field of the firing zone with roller kiln. Numerical simulation can save cost and over come the restriction during actual measure. Therefore, the study contents are as follows:(1) FLUENT is systematically studied, including the basis theory, solving methods of equations, basic functions and using methods. As process of studying, the fluid problem is researched and through analysis, the problems which can be solved by FLUENT are recognized and mastered. Meanwhile, many experiences of generating calculation mesh, choice of turbulent flow models, tactics of solving the turbulent flow movement difference equations numerically and the like have been accumulated. Basic theories and algorithms of CFD have also been better understood and grasped.(2) The kiln structure of firing zone with roller kiln is studied and three-dimensional model is established. Base on this, the fluid space is studied and the space model is established. Combining the structure and requirement for mesh by numerical solve, mesh generation scheme is decided and high quality mesh structure is generated.(3) By analyzing the FLUENT software and actual conditions, the three-dimensional fluid space of firing zone with the roller kiln is deeply studied. The boundary conditions of inlets and outlets are respectively set as pressure inlet, pressure outlet, and those of the residual parts are set as solid wall according to the boundary conditions of numerical solution to incompressible turbulent flow.(4) By overall analysis of the turbulent models that are commonly used in engineering to numerically solve incompressible turbulent flow, k-e model is chosen to close the turbulent flow movement difference equations group, and in order to numerically solve the difference equations group, the difference scheme andalgorithm are also specified. A suit of concrete measure of improving the solution instability and speeding convergence has been made by studying the numerical solution process.(5) Through numerical simulation, structure of the flow field, distribution feature and the impact to the kiln are studied. Considering factors of different inlet velocities and fluid speed of the flue gas, the distribution condition is revealed, the design of ceramic kiln is also guided.