高效板坯连铸二冷区纯水喷嘴传热特性  

Heat transfer characteristics of pure water nozzle in the second cooling zone of high-efficiency slab continuous casting

作　　者：孙雄博 张朝晖[1] 高琦[2] 吕明[1] 邢相栋[1] 李嘉堃 徐荣军 SUN Xiongbo;ZHANG Zhaohui;GAO Qi;LÜMing;XING Xiangdong;LI Jiakun;XU Rongjun(School of Metallurgical Engineering,Xi’an University of Architecture and Technology,Xi’an 710055,Shaanxi,China;Steelmaking Division,China National Heavy Machinery Research Institute Co,Xi’an 710032,Shaanxi,China;Institute of Steelmaking Technology,Baosteel Central Research Institute,Shanghai 201900,China)

机构地区：[1]西安建筑科技大学冶金工程学院,陕西西安710055 [2]中国重型机械研究院股份公司炼钢事业部,陕西西安710032 [3]宝钢中央研究院炼钢技术研究所,上海201900

出　　处：《钢铁》2024年第11期112-121,共10页Iron and Steel

基　　金：陕西省自然科学基础研究计划联合基金资助项目(2021JLM-32);陕西省创新能力支撑计划资助项目(2023-CX-TD-53);中国机械工业集团有限公司青年科技基金资助项目(B2205471)。

摘　　要：二冷区喷嘴的冷却效果和均匀性对提高板坯连铸拉速、改善铸坯质量具有重要影响。利用喷嘴冷却检测系统研究了不同型号纯水喷嘴的水量体积分数分布、喷嘴压力流量曲线和喷嘴打击力分布曲线等冷态特性,发现喷嘴结构差异是导致喷嘴冷态特性变化的主要原因。喷嘴水量集中分布在射流中心-100~100 mm范围内,射流中心及附近喷嘴打击力强。在此基础上,搭建了铸坯传热高温测试试验平台,完成了IF钢高温传热试验的温度测量,选用传热反问题方法 Fortran反传热计算程序,获取表面温度随时间的冷却规律及换热系数随表面温度的变化关系。研究发现,纯水喷嘴冷却下铸坯表面温度冷却速率随时间先增大后减小,铸坯表面换热系数与表面温度下降速率有关,表面温度下降越快,换热系数越高,足辊宽边喷嘴和足辊窄边喷嘴所测最大换热系数最高达到3 277.7和3 630.4 W/(m^(2)·K);喷嘴水流量越大、打击力越强,铸坯降温速率越快。对比分析了喷嘴冷态性能和传热特性,足辊宽边喷嘴3/4PZ47090BG4与足辊窄边喷嘴3/4PZ32090×30BG4喷嘴可以满足板坯高拉速的冷却需求,为板坯高效连铸二冷喷嘴的合理选型提供了技术参考。The cooling effect and uniformity of nozzles in the second cold zone have an important impact on improving the pulling speed of slab continuous casting and the quality of casting slabs.The nozzle cooling detection system was used to study the percentage distribution of water in different models of pure water nozzles,nozzle pressure and flow curves and nozzle striking force distribution curves and other cold characteristics.It is found that the differences in the nozzle structure is the main reason for changes in the nozzle cold characteristics,the nozzle water is concentrated in the centre of the jet within the range of±100 mm,the jet centre and the vicinity of the nozzle striking force is strong.On this basis,a billet heat transfer high temperature test experimental platform was set up,the IF steel high temperature heat transfer experiments temperature measurement was completed,heat transfer inverse problem method Fortran inverse heat transfer calculation procedure was selected,the surface temperature cooling law with time and the relationship between heat transfer coefficient and the change of the surface temperature were obtained.The results are found that under pure water nozzle cooling the billet surface temperature cooling rate first increases and then decreases with change of time,billet surface heat transfer coefficient is related to the rate of surface temperature drop,the faster the surface temperature drop,the higher the heat transfer coefficient,the maximum heat transfer coefficient measured by the foot roll wide side nozzle and foot roll narrow side nozzle reaches 3277.7 and 3630.4 W/(m^(2)·K).The larger the flow of water from the nozzle,the stronger the striking force,the faster the rate of billet cooling.Comparative analysis of the nozzle cold state performance and heat transfer characteristics,foot roll wide side nozzle 3/4PZ47090BG4 and foot roll narrow side nozzle 3/4PZ32090×30BG4 nozzle can meet the cooling needs of the slab high pulling speed,for the slab of high-efficiency continuous casti

关 键 词：板坯高效连铸 二冷纯水喷嘴 冷态性能 换热系数 传热特性 

分 类 号：TF341.6[冶金工程—冶金机械及自动化]