高炉冷却壁非稳态传热热态实验分析

Thermal Trial Analysis on Unsteady Heat Transfer for Blast Furnace Cooling Stave

冷却壁安全工作是保证高炉长寿的基础。通过设计并建造冷却壁热态实验炉,研究了高炉铸铁冷却壁热面无渣皮和有渣皮时的非稳态传热过程,考察了不同炉气温度条件下冷却壁热电偶温度的变化规律。回归得到了炉气在升温阶段、稳定阶段、降温阶段时冷却壁热电偶温度随时间的变化关系式。计算得出了冷却壁热面在有无渣皮条件下的平均热流强度,回归得出了炉气平均对流换热系数随炉温的变化关系。结果表明,冷却壁热面在有渣皮时热电偶温度的变化速率显著低于无渣皮时的变化速率,冷却壁破损的主要原因是冷却壁温度的反复变化和渣皮的频繁脱落而产生的热应力。

BF campaign is of great significance for efficient, sustainable development of iron and steel enterprises. Smooth operation and the service life of the cooling stave is one of the fundamental factors affecting the life of a blast fur-nace, and therefore subject to focus on the stave efficient longevity research. Through design and construction of hot test furnace for cooling stave, unsteady state heat transfer of blast furnace cooling stave was studied under condition of with or without slag crust and changing rules of thermocouple temperature under different furnace temperatures were also ana-lyzed. Changing rules of thermocouple temperature at heating stage, steady stage and cooling stage were obtained by re-gression method. Average heat flux intensity without slag crust was calculated and through regression method convective heat transfer coefficient was obtained. It was concluded that the changing rate of thermocouple temperature which embed-ded in the cooling stave under condition of with slag crust is significantly lower than without slag crust. The damage of cooling stave is mainly due to thermal stress produced by repeatedly change of temperature and frequently production and separation of slag crust, which shows the actions that are being executed and the results that are extending the cooling stave service lives.