转炉炉口段汽化烟道热应力研究

Thermal Stress Analysis of Nozzle Section of Converter's Vaporizing Cooling Flue

针对转炉汽化烟道尤其是炉口段烟道使用寿命不理想的问题,基于Ansys Workbench仿真平台,研究其热应力。采用Fluent多相流混合物模型,通过用户自定义编程实现对流动沸腾的模拟,对烟道体与冷却工质组成的流固耦合传热系统进行整场求解,考虑温度对冷却工质和烟道材料物性参数的影响,得到烟道的温度场分布;考虑温度对烟道材料物性参数和力学性能的影响,在Static Structure模块中,将温度场结果作为体载荷施加到烟道上进行热应力计算。结果表明:烟道背烟侧热应力较高,尤其是烟道底部背烟侧水冷壁管;隔板的应力不高,但超过屈服极限,导致其发生塑性变形,故隔板是烟道的薄弱部位。

For the question that converter＇s vaporizing cooling flue＇s life is far from ideal,especially the nozzle section,taking Ansys Workbench as simulation platform to analyze its thermal stress.Using Fluent multiphase mixture model,the flow boiling was simulated with User-Defined Function （UDF）,and the fluid-solid coupling heat transfer system comprising of the flue and cooling medium was solved.Considering the influence of the temperature on physical parameters of cooling medium and flue,the temperature distribution of the flue was attained.Then combining the influence of the temperature for physical parameter mechanical property of 20G steel and taking the temperature results as body load,the thermal stress was calculated.The results show that the thermal stress of the non-gas-side flue is high,especially the tube of the non-gas-side of the bottom part.The weak part lies at flat steel of flue as its thermal stress exceeds the yield stress and has plastic deformation,though stress is not high.