烟道孔对钢烟囱的影响分析

THE IMPACT ANALYSIS OF FLUE HOLE IN THE CHIMNEY

烟道孔是烟囱的重要组成部分,在设计中多数按经验公式计算或按构造处理,不能正确反映对整体烟囱的影响。以高50m,直径为4.4m的实际钢烟囱为例,用数值分析方法研究烟道孔对其静、动力特性,温度应力及地震响应的影响。研究表明,烟道孔周围不仅受力复杂,而且对整个烟囱的受力和变形有较大的影响;开孔引起应力集中,使风载和自重作用下的最大应力增加了近2倍,温度应力增加80%;开孔使烟囱的基频减小10%,地震应力响应增加了2倍多。

Flue hole is an important component part of the chimney, in its design, most are according to experience formula calculation or structure treatment. So it is unable to correctIy reflect the influence to the whole chimney. With a high 50 m, 4.4 m diameter of the actual steel chimney for example,the flue hole static and dynamic characteristics, temperature stress and the influence of earthquake response were studied by numerical analysis method. Research showed that the areas around the flue hole was not only loading complexly, but also having large influence on the stress and deformation of the entire chimney. Because the hole arouses the stress concentration, leading to the maximum stress of under the action of wind load and dead weight increasing almost 2 times,and the temperature stress increasing by 80%. Because of the hole that the fundamental frequency of the chimney was reduced by 10%, leading to the seismic stress response increasing more than twice.