Impact Study Of Temperature Field And Flow Field With Roller Height Changing Of Roller Kiln

Roller kiln is the core of the production of building ceramics enterprises. In order to guarantee the rate of qualified products, Experts and scholars have long researched roller kiln furnace structure, the heating capacity allocation, human control and many other factors.With the development of computer technology, the use of CFD software becomes a new research direction to simulate the kiln gas heat transfer process, the combustion process, the temperature field and velocity field distribution and so on.In this paper,we build up five roller kiln firing zone models which have different roller height by preprocessor of the software Fluent, Gambit. Models choose both structured grid and unstructured grid meshing kiln burner and the RNG k-ε turbulence model, and DO radiative heat transfer model for turbulent and radiative heat transfer calculation.the gas density, the specific heat and the divergence rate and other physical parameters are calculated baseing on mixed gas composition of producer gas, the composition and content. It is based on the references to determine the flue gas entrance velocity boundary condition of the burner entrance and the gas outlet pressure boundary conditions.For the numerical calculation method, we use the separation provided by the Fluent solver for solving, second order upwind scheme to discretize the equations, the SIMPLEC algorithm to accelerate convergence.Through computer simulation, we get the following conclusions:1.Through simulating the temperature field and flow distribution Along the kiln length, wide kiln, kiln high three-dimensional direction and carefur analysis,we find model A’s structure model is superior to other models.2. With the roll height increases, the heat consumption of unit product and kiln wall heat dissipation will be a corresponding increase; increasing the height of the kiln will easily lead to gas stratification will increase the temperature difference in the high direction of the kiln. Considered in terms of energy efficiency and reduce the temperature difference, the kiln height is the lower, the better.3.In the design of the furnace structure, reasonable roller height can not only ensure the smooth of burner jet, but also can adjust the size of the range of annular furnace gas area.It also affects the gas location and strength, to strengthen the vortex of the kiln gases, such a result will strengthen the level of kiln gases disorder, make the kiln temperature distribution of a more stable and uniform and conducive to full heat exchanger products.4.In the firing zone, the trend of the gas circulation flow of the kiln gas flow field distribution a great impact, so a reasonable height of the kiln to control the flue gas flow rate within a certain range, making it easier to control the furnace thermal system.