• 过程与工艺 •

### 带钢保护气氛循环喷射冷却热工过程的数值模拟

1. 1. 武汉科技大学钢铁冶金及资源利用省部共建教育部重点实验室，湖北 武汉 430081 2. 高温材料与炉衬技术国家地方联合工程研究中心，湖北 武汉 430081 3. 黄石山力兴冶薄板有限公司，湖北 黄石 435100 4. 黄石山力科技股份有限公司，湖北 黄石 435003
• 收稿日期:2018-09-11 修回日期:2018-12-29 出版日期:2019-08-22 发布日期:2019-08-15
• 通讯作者: 戴方钦 daifangqin@wust.edu.cn

### Numerical simulation on thermal process of recycling jet cooling in heat treatment of strip steel in protective hydrogen atmosphere

Ping'an CHEN1,2, Fangqin DAI1,2*, Yue GUO1,2, Luwei PAN1,2, Jiangjun KE3, Jiamou WU4, Yuansheng LEI3, Yuncheng LI4

1. 1. Key Lab for Ferrous Metallurgy and Resources Utilization of Ministry of Education, Wuhan University of Science and Technology, Wuhan, Hubei 430081, China 2. National?provincial Joint Engineering Research Center of High Temperature Materials and Lining Technology, Wuhan University of Science and Technology, Wuhan, Hubei 430081, China 3. Huangshi Sunny Xingye Strip Co., Ltd., Huangshi, Hubei 435100, China 4. Huangshi Sunny Technology Co., Ltd., Huangshi, Hubei 435003, China
• Received:2018-09-11 Revised:2018-12-29 Online:2019-08-22 Published:2019-08-15
• Contact: DAI Fang-qin daifangqin@wust.edu.cn

Abstract: A one-dimensional unsteady heat transfer model was established for the cyclic spray cooling heat transfer of strip steel protective atmosphere. The temperature field of strip steel was calculated by finite difference numerical calculation method. The comprehensive heat transfer coefficient required of the strip steel at different thicknesses, different initial temperatures and operating speeds were determined. The effects of structural parameters of the spray box and the parameters of the circulating cooling medium on strip steel outlet temperature were studied. The results showed that there was a maximum operating velocity for strip steel with different thicknesses on the premise of meeting the performance requirements and safety. For strip steel with thickness of more than 3 mm, the influence of the section temperature difference on the strip steel properties could not be ignored. The temperature of strip steel outlet increased with the increase of the ratio (H/D) of distance between strip and orifice (H) to orifice diameter (D), but increase rate gradually decreased as ?/D increased. There was an optimal range of the ratio (?n/D) of the orifice spacing (?n) to the orifice diameter (D) which was related to H. Therefore, when actually designing the spray box structure, it is necessary to consider not only the optimal value of D, but also the H. As the temperature of the cooling medium increased by 10℃, strip steel outlet temperature increased by about 3℃. When the volume percentage of hydrogen in the cooling medium and the flow rate of the cooling medium increased, the temperature of strip steel outlet decreased, however, the decrease rate gradually decreased as the volume percentage of hydrogen in the cooling medium and its flow rate increased. The industrial application results showed that the calculated value of the outlet temperature of strip steel was in good agreement with the measured value, and the error was about 3.4% which meant that the model met the application requirements.