多载荷作用下内压对烟风道安全性的影响

为研究大型圆形烟风道的加固肋设计选型规律,采用有限元数值计算的方法,在不同积灰厚度、不同加固肋型号、不同加固肋数量时,分析内压对电厂烟风道的强度和屈曲安全性的影响。结果表明,圆形烟风道的应力主要为主支座与道体接触区域,自重力是道体产生应力的主要原因。对于大直径烟风道,负压时道体应力大于零压和正压时的应力。直径越大,应力会随负压的增大而快速增大,负压管段不宜采用大直径管道。积灰厚度对道体应力的影响较小,积灰越多道体越不容易发生屈曲,考虑积灰的设计中应当校核无积灰时的屈曲安全系数。

Influence of internal pressure on the safety of exhaust duct under multiple loads

To study the stiffener design discipline of large scale circular exhaust duct, finite element method was used to analyze the impacts on the strength, flexibility and buckling security from internal pressure load under different ash thickness, different number and specification stiffeners. The results indicated that the main stress on the circular duct lied on the contact zone of duct and support, the self-weight was the main factor of stress. For the large diameter duct, the stress under negative press was much higher than the condition of zero pressure and positive pressure. And for the large diameter duct, the stress may rapidly increase while the negative pressure rising, and the large diameter should not be used on negative duct. The ash thickness had smaller impact on the stress of duct, the buckling may less happen while the duct was thicker. The buckling factor of non-dusty condition should be checked on the design of considering dusty thickness.