【作者】 石文梅；

【导师】 段振亚；

【作者基本信息】 青岛科技大学 ， 化工过程机械， 2011， 硕士

【摘要】 粉尘污染是我国大气环境污染的重要组成部分,也是中国城市大气污染的重点问题之一。对于露天堆料场粉尘防治问题,防风网抑尘工程技术是比较有效的、适合我国国情的二次扬尘防治技术与装置。本文主要以蝶形网和拦沙网为研究对象,依托风洞实验装置研究不同参数对蝶形网和拦沙网后庇护区内流场特性的影响,为防风网的结构优化设计提供可靠的实验数据。还对本课题组在工程中采用的两种钢构架进行了受力特性分析及结果校核。研究结果对防风网抑尘工程装置的优化设计和安全操作具有重要意义。首先,对防风网在现场测试、数值模拟及实验研究方面的国内外现状及进展进行了综述,并对几个代表性的防风网抑尘工程进行了简要介绍。其次,建立了风洞实验平台,进行了不同工况下不同参数对平面网、蝶形网和拦沙网后庇护区内流场特性影响的实验研究。得出了如下的结论:①不同形式的防风网具有不同的最优开孔率。平面网的最佳开孔率为26.4%,减风率为68.44%;蝶形网的最佳开孔率为27.3%,减风率为63.39%;拦沙网的开孔率为27.1%时庇护效果最好,减风率为63.01%。②具有相似开孔率时,蝶形网和拦沙网的庇护效果略低于平面网,但其强度远远大于平面网,适合在工程建设中推广使用。③风速为3m/s时,不同孔径的蝶形网对尾流区的庇护效果最好;风速为5、7.5、10m/s时其庇护效果依次降低。④开孔率分别为26.4%和27.3%的平面网和蝶形网均在底部间隙为0.15倍网高时减风率最大,分别为68.81%和66.84%,且分别高于在相同条件下平面网无间隙时的减风率68.44%与蝶形网无间隙时的减风率63.39%。最后,采用有限元分析软件对直立平行式支撑钢构架和直立斜支撑钢构架进行力学分析,并对计算结果进行了校核,结果表明两种钢构架均满足强度、刚度和稳定性要求。直立斜支撑钢构架与直立平行式支撑钢构架的综合比较表明前者的结构形式较为合理。更多还原

【Abstract】 Dust pollution contributes to a great portion of as well as one of main causes to air pollution in China. As for the method to control dust in a large open stock piles, the porous fences technology is comparatively effective, and is the control technology and device of dust re-entrainment which is suitable for China.The paper mainly studies on butterfly and sand-interception porous fences, to research the influence of setting different parameters to the characteristics of flow field in the sheltering place behind butterfly and sand-interception porous fences by wind tunnel experiment device, and to provide reliable experiment data for optimal design of porous fence’s structure. What is more, the paper makes force analysis and results verification for two kinds of steel framework applied to projects by the project group. The results of the study are significant to optimize the design and guarantee safety operation for the dust control engineering equipment of porous fences.Firstly, generally review the current state and development of porous fences with consideration of on-site test, numerical simulation and experimental research at home and abroad. And briefly introduce several representative dust control engineering of porous fences.Secondly, establish a wind tunnel experiment platform, conduct experimental study on the influence of setting different parameters to the characteristics of flow field in the sheltering place behind planar,butterfly and sand-interception porous fences in different working conditions. And the conclusions are as follows:①Different types of porous fences have different optimal porosity. The best porosity is 26.4% for planar porous fences, with wind reduction rate 68.44%; Butterfly porous fences for 27.3%, with wind reduction rate 63.39%; the shelter will be most effective as the porosity of sand-interception porous fences is 27.1%, with wind reduction rate 63.01%.②As three types of porous fences have similar porosity, butterfly and sand-interception porous fences’shelter effect is a little lower than planar porous fences’, but their intensity is much larger than planar porous fences’, which are suitable to be used in engineering construction and promotion.③As the wind speed is 3m/s, butterfly porous fences with different hole diameters will have the best shelter effect to wake zone; the shelter effect will be reduced sequentially with the wind speed of 5, 7.5 and 10m/s.④Planar and butterfly porous fences, with porosity of 26.4% and 27.3%, will have the biggest wind reduction rate of 68.81% and 66.84% respectively as their bottom gap is 0.15H. Under the same condition, they are respectively higher than wind reduction rates of 68.44% and 63.39%of planar and butterfly porous fences as both of them have no bottom gap.Finally, make force analysis for both upright-parallel and upright-oblique supporting steel framework by finite element analysis software, as well as have results verification. The conclusions show that both two kinds of steel framework meet the requirements of intensity, rigidity and stability. After the comparison is made between two kinds of steel framework, the structure of upright-oblique supporting steel framework is more reasonable.更多还原