Influence of cooling process on heat transfer of thin slab mold
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摘要: 为揭示高速连铸结晶器铸坯-铜壁-冷却水体系的传热机制,建立了FTSC结晶器内铸坯-铜壁-冷却水三维流-固-热耦合数值模型。分析了高拉速条件下结晶器冷却工艺对结晶器铜壁和冷却水温度分布的影响。结果表明:采用反向供水铜壁热面温度峰值比正向供水降低15 ℃,冷却水温度峰值降低14 ℃;提高冷却水速度可有效降低铜壁和冷却水温度;在保证冷却水不出现沸腾的条件下,增加供水压力对结晶器温度场变化没有影响;冷却水进水温度对铜壁整体和弯月面附近冷却水的温度影响较小。在结晶器下部低热流区,冷却水温度变化受进水温度的影响较为明显。冷却水道与铜壁热面间距对铜壁温度具有显著的影响,对于冷却水温度,冷却水道在距铜壁热面15 mm和25 mm处温度相差不大,距离热面为35 mm时冷却水温度明显降低。Abstract: To reveal heat transfer mechanism of the slab-copper wall-cooling water system in the high-speed continuous casting mold, a three-dimensional fluid-solid-thermal coupling numerical model of slab-copper wall-cooling water in a FTSC mold was established. The influence of mold cooling process on temperature distribution of the mold copper wall and cooling water under the condition of high drawing speed had been analyzed. The results show that the peak temperature on hot surface of the copper wall with reverse water supply is 15 ℃ lower than that of the forward water supply, and the peak cooling water temperature is lowered by 14 ℃. Increasing cooling water speed can effectively reduce temperatures on copper wall and of the cooling water. Under the conditions of the cooling water does not boil , increasing the water supply pressure does not affect the mold temperature field and the cooling water inlet temperature has little effect on the temperature of the copper wall and the cooling water near the meniscus. In the low heat flow area at the lower part of the mold, the temperature change of the cooling water is more obviously affected by the inlet water temperature. The distance between the cooling water channel and the hot surface of the copper wall has a significant effect on the copper wall temperature. The cooling water temperature in the water channel at a distance of 15 mm and 25 mm from hot surface of copper wall remains same, while it significantly reduces at the distance of 35 mm away from the hot surface.
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表 1 结晶器的工艺参数
Table 1. Technical parameters of mold
铜壁长度/mm 冷却水道直径/mm 冷却水速/(m·s−1) 冷却水进水温度/℃ 供水压力/MPa 拉坯速度/(m·min−1) 浇注温度/℃ 1200 14 8、10、12、14 20、25、30 1.4、1.6 、1.8 6 1550 表 2 不同大气压下水的沸点
Table 2. The boiling point of water under different atmospheres pressure
压力/MPa 水的沸点/℃ 1.4 194.1 1.6 200.4 1.8 206.1 表 3 铜的物性参数
Table 3. Physical parameters of copper
密度/ (kg·m−3) 热容/(J·kg−1·℃−1) 热导率/(W·m−1·℃−1) 8900 390 380 -
[1] 徐旺. 冷却工艺对连铸结晶器铜壁传热的影响[D]. 唐山: 华北理工大学, 2020.Xu Wang. The effect of the cooling process on the heat transfer of the copper wall of the continuous casting mold [D]. Tangshan: North China University of Technology, 2020. [2] Liu Qilong, Liu Guoping, Fan Mancang, et al. Heat transfer analysis and cooling structure optimization of thin slab continuous casting mold narrow copper plate[J]. Iron Steel Vanadium Titanium, 2017,38(6):134−141. (刘启龙, 刘国平, 范满仓, 等. 薄板坯连铸结晶器窄面铜板传热分析及冷却结构优化[J]. 钢铁钒钛, 2017,38(6):134−141. doi: 10.7513/j.issn.1004-7638.2017.06.024Liu Qilong, Liu Guoping, Fan Mancang, et al. Heat transfer analysis and cooling structure optimization of thin slab continuous casting mold narrow copper plate[J]. Iron Steel Vanadium Titanium, 2017, 38(6): 134-141. doi: 10.7513/j.issn.1004-7638.2017.06.024 [3] Zhou Jiayong, Peng Xianghe, Su Hezhou, et al. Temperature field analysis and structure optimization of slab continuous casting mold cooling copper plate[J]. China Metallurgy, 2006,16(3):27. (周家勇, 彭向和, 苏鹤州, 等. 板坯连铸结晶器冷却铜板的温度场分析及结构优化[J]. 中国冶金, 2006,16(3):27. doi: 10.3969/j.issn.1006-9356.2006.03.009Zhou Jiayong, Peng Xianghe, Su Hezhou, et al. Temperature field analysis and structure optimization of slab continuous casting mold cooling copper plate [J]. China Metallurgy, 2006, 16(3): 27. doi: 10.3969/j.issn.1006-9356.2006.03.009 [4] 刘振领. 薄板坯结晶器内钢液流场和温度场的数值模拟[D]. 石家庄: 河北科技大学, 2010.Liu Zhenling. Numerical simulation of the molten steel flow field and temperature field in thin slab mold [D]. Shijiazhuang: Hebei University of Science and Technology, 2010. [5] Hou Xiaoguang. Exploring the measurement of the temperature difference and water volume adjustment of mold cooling water in continuous steel casting[J]. China Manganese Industry, 2017,35(3):193. (侯小光. 探究连续铸钢中结晶器冷却水温差的测量和水量调节[J]. 中国锰业, 2017,35(3):193. doi: 10.14101/j.cnki.issn.1002-4336.2017.03.056Hou Xiaoguang. Exploring the measurement of the temperature difference and water volume adjustment of mold cooling water in continuous steel casting[J]. China Manganese Industry, 2017, 35(3): 193. doi: 10.14101/j.cnki.issn.1002-4336.2017.03.056 [6] 杨刚. 薄板坯连铸结晶器铜板三维传热及温度场分析[D]. 沈阳: 东北大学, 2006.Yang Gang. Three-dimensional heat transfer and temperature field analysis of thin slab continuous casting mold copper plate[D]. Shenyang: Northeastern University, 2006. [7] Wang Zepeng, Cai Zongying, Zhu Liguang, et al. Three-dimensional heat transfer simulation of billet continuous casting mold[J]. Foundry Technology, 2017,38(11):2753. (王泽鹏, 蔡宗英, 朱立光, 等. 方坯连铸结晶器三维传热模拟[J]. 铸造技术, 2017,38(11):2753. doi: 10.16410/j.issn1000-8365.2017.11.053Wang Zepeng, Cai Zongying, Zhu Liguang, et al. Three-dimensional heat transfer simulation of billet continuous casting mold [J]. Foundry Technology, 2017, 38 (11): 2753. doi: 10.16410/j.issn1000-8365.2017.11.053 [8] 谢鑫, 陈登福, 吕奎, 等. 不同拉速下结晶器水缝传热的数值模拟研究[C]//第十八届全国炼钢学术会议论文集. 西安: 中国金属学会, 2014.Xie Xin, Chen Dengfu, Lv Kui, et al. Mathematical simulation on the heat transfer in mould slots at different casing speeds [C]//Proceedings of the 18th National Steelmaking Academic Conference. Xi, an: Chinese Society of Metals, 2014. [9] Pei Hongbin, Zhang Hui, Xi Changsuo, et al. Study on the characteristics of the slab continuous casting and bonding of the blowout slab shell and the temperature change of the mold copper plate[J]. Iron Steel Vanadium Titanium, 2012,33(6):45−48. (裴红彬, 张慧, 席常锁, 等. 板坯连铸粘结漏钢坯壳特征及结晶器铜板温度变化研究[J]. 钢铁钒钛, 2012,33(6):45−48. doi: 10.7513/j.issn.1004-7638.2012.06.010Pei Hongbin, Zhang Hui, Xi Changsuo, et al. Study on the characteristics of the slab continuous casting and bonding of the blowout slab shell and the temperature change of the mold copper plate[J]. Iron Steel Vanadium Titanium, 2012, 33(6): 45-48. doi: 10.7513/j.issn.1004-7638.2012.06.010 [10] Han Zhiwei, Feng Ke, Wang Yong, et al. Finite element simulation of heat transfer slab continuous casting process[J]. Computer Aided Engineering, 2006,15(z1):435. (韩志伟, 冯科, 王勇, 等. 板坯连铸凝固传热过程的有限元模拟[J]. 计算机辅助工程, 2006,15(z1):435. doi: 10.3969/j.issn.1006-0871.2006.z1.137Han Zhiwei, Feng Ke, Wang Yong, et al. Finite element simulation of heat transfer slab continuous casting process[J]. Computer Aided Engineering, 2006, 15(z1): 435. doi: 10.3969/j.issn.1006-0871.2006.z1.137 [11] Lyu Peisheng, Wang Wanlin, Zhang Haihui. Mold simulator study on the initial solidification of molten steel near the corner of continuous casting mold[J]. Metallurgical and Materials Transactions B, 2017, 48:247-259. [12] Wang Dong. Analysis of heat conduction based on Fourier's law[J]. Science and Technology Innovation, 2019,22(13):45. (王栋. 基于傅里叶定律对热传导的分析[J]. 科学技术创新, 2019,22(13):45.Wang Dong. Analysis of heat conduction based on Fourier's law [J]. Science and Technology Innovation, 2019, 22(13): 45. [13] Yang Changlin, Gao Qi, Yao Chenggong, et al. Optimal design of copper plate sink for slab continuous casting mold[J]. China Metallurgy, 2021,31(3):10. (杨昌霖, 高琦, 姚成功, 等. 板坯连铸结晶器铜板水槽的优化设计[J]. 中国冶金, 2021,31(3):10. doi: 10.13228/j.boyuan.issn1006-9356.20200459Yang Changlin, Gao Qi, Yao Chenggong, et al. Optimal design of copper plate sink for slab continuous casting mold [J]. China Metallurgy, 2021, 31(3): 10. doi: 10.13228/j.boyuan.issn1006-9356.20200459 [14] Yuan Lintao, Zhang Hui, Shi Zhe, et al. Study on the heat transfer behavior of the wide-surface copper plate of the thin slab mold[J]. Iron Steel Vanadium Titanium, 2013,34(5):58−62. (袁林涛, 张慧, 施哲, 等. 薄板坯结晶器宽面铜板传热行为研究[J]. 钢铁钒钛, 2013,34(5):58−62. doi: 10.7513/j.issn.1004-7638.2013.05.012Yuan Lintao, Zhang Hui, Shi Zhe, et al. Study on the heat transfer behavior of the wide-surface copper plate of the thin slab mold[J]. Iron Steel Vanadium Titanium, 2013, 34(5): 58-62. doi: 10.7513/j.issn.1004-7638.2013.05.012