开洞口煤仓风致积雪数值模拟及雪荷载不利分区研究

风雪共同作用下开洞口煤仓网壳表面雪压不均匀分布,对网壳结构安全性极为不利,且我国《建筑结构荷载规范》和《火力发电厂圆形贮煤仓施工技术规范》并未明确规定此种结构的雪荷载,故模拟研究了此种更接近实际煤仓选型的结构表面积雪侵蚀和沉积量的变化情况。运用FLUENT计算流体力学软件,基于Euler-Euler的方法,分析了不同风向角、积雪厚度和吹雪时间对开洞口煤仓表面积雪侵蚀量和沉积量的影响,结果表明,风向角和积雪厚度对煤仓表面积雪变化量影响较大,随风向角和积雪厚度增大,煤仓中心部位垂直来流风方向的积雪侵蚀量显著增大。将数值模拟所得结果与规范进行对比,发现此类结构并不适用于我国规范给出的屋面积雪分布系数,故提供煤仓表面最不利积雪分布系数分区图,为煤仓表面雪荷载设计提供依据。

Numerical simulation of snow drifting and research on snow unfavorable area of opening round coal bunker

Under the joint action of wind and snow,the snow pressure on the surface of a coal bunker with an opening is irregularly distributed,which may be extremely harmful to the structure’s safety.And the《Load code for the design of building structures》and the《Technical specification for construction of circular coal bunker of thermal power plants》do not clearly specifify the snow load of this kind of structures.For this reason,we simulated the variation of snow erosion and deposition amount on surface of such a bunker,which is close to the actual type.Using computational fluid dynamics software FLUENT,based on Euler-Euler’s method,the effects of different wind direction angles,snow thickness and snow blowing time on the snow erosion amount and deposition amount on the surface of the spherical reticulated shell with an opening were analyzed.The results showed that the wind angle and the snow thickness have a great influence on the snow surface area of the coal bunker.With the increase of the wind direction angle and snow thickness,the amount of snow erosion in the vertical flow direction in the center of the coal bunker increases significantly.Compared the numerical simulation results with China’s specifications,it is founded that this structure does not fellow the snow distribution coefficient by the China’s specifications,so provide the partition map of the most unfavorable snow distribution coefficient on the surface of the coal bunker.This study provides a reference on snow load design of coal bunker surface in the future.