电除尘器巨型灰库受力特性的研究

发布时间：2019-01-22 10:15

【摘要】：我国现有的火电厂除灰系统,大多数都采用上世纪80年代从国外引进的“正压浓相气力除灰系统”,即先将粉尘暂时储存在除尘器下部的小灰斗里,再由设在除尘器下的浓相气力输送装置输送到厂内灰库中进行储存,然后用汽车将积灰外运,耗能占地较大,近年来,为节能省地出现一种器——库合一的新型除尘器,这种除尘器中灰库体积巨大,盛灰量大,受力复杂,是影响除尘器运行安全的重要因素。本文首先以某器——库合一型除尘器为背景,根据电除尘器巨型灰库的受力特点,构建了受力较为合理的巨型灰库的结构体系,将巨型灰库简化成空间杆系模型,使用大型有限元分析软件Midas/GEN,分别按正压、负压参与组合的两种工况,对巨型灰库进行静力计算,分析了底梁、柱、水平圈梁及管撑等主要受力构件的受力特点;然后在空间杆系模型的基础上考虑板和肋条的作用,建立梁板协同工作模型,并与空间杆系模型的计算结果进行了对比分析,对梁板协同工作进行研究;最后考虑温度、支座失效的因素,研究了这两种因素对巨型灰库结构的变形和构件内力的影响。根据以上研究,得出结论如下:(1)负压对结构受力较正压更为有利,底座大梁结构的布置形式合理。(2)框架与围护结构的协同工作有利于结构受力,板对结构的影响不可忽略,并建议进行类似结构设计时采用协同工作模型进行分析计算。(3)应该在围护壁板应力较大的部位,进行补强和加固,以免弱化梁板协同工作的效果。(4)在除尘器运行时,各支座均能正常工作的情况下,温度荷载不会对结构产生明显的影响。(5)任何一个支座失效,都会对巨型灰库及除尘器主钢结构的安全构成威胁。
[Abstract]:In most of the existing ash removal systems of thermal power plants in China, the "barotropic dense phase ash removal system" introduced from abroad in the 1980s means that dust is stored temporarily in the small ash hopper in the lower part of the dust collector. Then transported by the dense phase pneumatic conveying device under the dust collector to the ash storehouse in the plant for storage, and then transported the ash deposit out of the factory by car, which consumed a large area of energy. In recent years, in order to save energy and save land, a new type of dust precipitator with a combination of storage and storage has emerged in order to save energy and save land. In this kind of dust collector, the volume of ash storage is huge, the ash content is large, and the force is complex, which is an important factor affecting the safety of the dust collector operation. In this paper, the structure system of the mega ash storehouse with reasonable force is constructed according to the mechanical characteristics of the mega ash storehouse of the electric precipitator based on the background of an integrative precipitator, and the mega ash storehouse is simplified into a spatial bar system model. By using the finite element analysis software Midas/GEN, according to the two working conditions of positive pressure and negative pressure respectively, the static calculation of the huge ash storehouse is carried out, and the stress characteristics of the main load-bearing members such as bottom beam, column, horizontal ring beam and pipe brace are analyzed. On the basis of the spatial bar system model, considering the action of plate and rib, the beam-plate cooperative work model is established, and the calculation results of the spatial bar system model are compared and analyzed, and the beam-plate cooperative work is studied. Finally, considering the factors of temperature and bearing failure, the influence of these two factors on the deformation and internal force of the structure is studied. According to the above study, the conclusions are as follows: (1) the negative pressure is more favorable to the structure than the positive pressure, and the layout of the base beam structure is reasonable. (2) the cooperative work between the frame and the enclosure structure is beneficial to the structure stress. The influence of the plate on the structure should not be ignored, and it is suggested that the cooperative work model should be used in the design of similar structures. (3) reinforcement and reinforcement should be carried out in the areas where the stress of the retaining panels is high. In order to avoid weakening the effect of beam and plate cooperative work. (4) when the dust collector is in operation, the temperature load will not have a significant effect on the structure when all the supports can work normally. (5) any of the supports fail, It will pose a threat to the safety of the huge ash storage and the main steel structure of dust collector.
【学位授予单位】：兰州交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM621.73

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