A Decoupled Numerical Study of Thermal Fluid Field In The Slab Reheating Furnace

• Main Authors: Pai-Yu Hsiao, 蕭百佑
• Other Authors: Mei-Jiau Huang
• Format: Others
• Language: zh-TW
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/37062464261981967295

碩士 === 國立臺灣大學 === 機械工程學研究所 === 96 === In this paper, we aim at the walking beam type slab reheating furnace of China Steel Corporation, and we use computational fluid dynamic software, Star-CD, to build a three-dimensional aerothermal model. The study employs the high-Reynolds- number k-ε turbulence model based on Favre-averaged governing equations. The pre-assumed PDF model associated with the fast chemistry assumption and a single diffusivity is used to account for turbulent combustion. The absorption coefficient of the gases mixture is calculated by WSGGM (weighted-sum-of-gray-gases model). The discrete ordinates method is adopted to calculate the radiactive heat transfer. Here we use the decoupled method to simulate the reheating furnace. It means we assume the surface temperature of the slab first, and then we exploit the assumed temperature to get gas temperature and heat flux of the slab. We use heat flux of the slab to get the surface temperature of the slab after the slab model is established. We should iterate the case until the calculating surface temperature of the slab converges to the assumed one. Finally, we use the convergent results to discuss the skid mark of slab caused by the radiative shielding by the beams. Keywords：Reheating furnace, Decoupled method, Radiative shielding, Skid mark.