Fuel Feed Distribution Ratio and Furnace Efficiency Analysis for a Walking-Beam Type Reheating Furnace

• Main Authors: Yi-PingLuo, 羅翊萍
• Other Authors: Jiin-Yuh Jang
• Format: Others
• Language: zh-TW
• Published: 2015
• Online Access: http://ndltd.ncl.edu.tw/handle/79792579057994898510

碩士 === 國立成功大學 === 機械工程學系 === 103 === Three-dimensional numerical simulation is performed to predict the heat transfer performance in a walking-beam type reheating furnace. The furnace uses a mixture of COG (coke oven gas) as a heat source to reheat the slabs. The fuel is injected into the furnace at four zones: preheating zone, first heating zone, second heating zone, and soaking zone. This numerical model considers turbulent reactive flow coupled with radiative heat transfer in the furnace; meanwhile, the conjugated conduction, convection, radiation heat transfers in the slabs. This study contains two topics(1) Examining six cases of different fuel feed ratio at the four zones under constant total fuel feed condition. (2) Estimating the fuel mass flow rate at each zone of the reheating furnace when the slab heating curve is given. The numerical predictions of the slab temperature and furnace gas deviations with the in-situ data are about 6.5% and 11%, respectively. In addition, this study examines six cases of different fuel feed ratio at the four heating zones under constant total fuel feed condition. It is found that decrease fuel mass flow rate in the preheating zonee can enhance heat efficiency, while increasing the fuel mass flow rate in the soaking zone can lead the slab temperature non-uniformity. When the slab heating curve is given, an initial iterative method is proposed to estimate the fuel flow rate at each zone of the reheating furnace in 2-D model. The maximum errors for the temperature of slabs between the 2-D and 3-D numerical are 6.0% and 6.9% for case1 and case2, respectively. The maximum temperature relative error of the slab between 3-D numerical simulation and the exact 3-D solution is 5.2%.