温度变化对水电站地下厂房机墩组合中风罩应力的影响

Impact of Temperature Variation on Wind Cowling Stress of Turbine Pier for Underground Powerhouse of Hydropower Station

风罩作为地下厂房机墩组合中的重要构筑物,在电站运行期受力特性及其复杂。主要研究温度荷载对风罩应力的影响特征,为结构体型优化及配筋设计提供依据。采用有限元数值模拟方法进行分析,模型选取了机墩根部至发电机层楼板的范围,考虑最不利情况下的运行状态。结果表明,对风罩这种薄壁结构,温度荷载是决定其应力的最主要因素,而且温度荷载不仅对应力的大小起决定因素,对应力的分布形式也有影响,应采取有效措施尽量减小风罩的内外温差,在结构和配筋设计时重视温度荷载的严重影响。

The wind cowling is an important component of generator pier structure in underground hydropower house and its mechanical characteristics is complicated during power station operation. This paper studies the impact of temper- ature loading on the stress of wind cowling, which provides basis for structural shape optimization and reinforcement de- sign. FEM b^tsed on numerical simulation is used to analyze the stress state caused by temperature loading and the model is chosen to the range of turbine pier bottom and generator floor. The results show that temperature loading is the main factor for influencing wind cowling stress values and its distribution. Therefore, it should take effective measures to re- duce tht, temperature difference between inside and outside wind cowling and pay attention to the serious impact of tem- perature loading in structure and reinforcement design.