叶片式空化射流清洗器的结构参数设计及数值仿真研究

发布时间：2018-01-19 07:24

本文关键词： 管道清洗正交试验结构优化流场数值仿真空化射流　出处：《大连海事大学》2017年硕士论文　论文类型：学位论文

【摘要】：随着工业化的发展,管道结垢现象一直是影响管道输送能力、使用周期的一个重大问题,迫切需要研究一种能适宜复杂管路系统的清洗方式。本文以单、双折弯叶片式空化射流清洗器为研究对象,采用理论分析、数值计算和试验研究相结合的方法研究空化清洗过程,分析清洗器的清洗机理、优化清洗器结构参数及空化模型,通过试验检测空化溃灭的强弱指导实际工程清洗作业。对单、双折弯清洗器进行了流场数值仿真及正交试验参数优化。分析单折弯清洗器流场的速度、压力及含气量的流场特性分布,研究发现单折弯清洗器的叶片数对空化影响较大,其次是叶片厚度,叶片折弯角度影响较小;双折弯清洗器的下折弯角对空化的影响较大,其次是上下叶片的高度比,叶片数影响较小。以清洗器的空化长度为优化目标研究单、双折弯清洗器清洗效果和清洗机理,正交试验参数影响结果和流场仿真结果一致。经过优化单、双折弯清洗器的空化长度分别提高了 163%、180%,双折弯清洗器的空化长度比单折弯清洗器提高了 67%。改进了空化射流清洗试验装置,通过高速相机法、亚甲基蓝分光光度计法及应力应变法对空化强度进行了测试。高速摄像机法捕捉到双折弯清洗器具有更好的空化效果。双折弯清洗器消耗的亚甲基蓝比单折弯多14%,也间接验证了双折弯空化清洗器具有更好的空化效果。应力应变测试结果表明在清洗器空化位置处应变数值最大,证明在该位置附近产生空化并伴随空泡的溃灭。入口压力越大,空化现象越明显,应变值越高。
[Abstract]:With the development of industrialization, the phenomenon of pipe scaling has been a major problem affecting the pipeline transportation capacity and service cycle. It is urgent to study a cleaning method suitable for complex pipeline system. The double bent vane cavitation jet cleaner was used to study the cavitation cleaning process and the cleaning mechanism was analyzed by the methods of theoretical analysis, numerical calculation and experimental study. The structural parameters and cavitation model of the cleaner are optimized, and the strength of cavitation collapse is tested to guide the actual engineering cleaning operation. The flow field numerical simulation and orthogonal test parameter optimization of double bending cleaner are carried out. The velocity, pressure and flow field characteristic distribution of single bending cleaner are analyzed. It was found that the number of blades of the single bending cleaner had a greater effect on cavitation, followed by blade thickness and less influence on the bending angle of the blade. The lower bending angle of double bending cleaner has a great influence on cavitation, followed by the ratio of upper and lower blade height and the number of blades. The cleaning effect and cleaning mechanism of double bending cleaner are consistent with the results of flow field simulation. The cavitation length of double bending cleaner is increased by 163% and 180% respectively after the optimization of single and double bending cleaner. The cavitation length of double bending cleaner is 67 higher than that of single bending cleaner. The cavitation jet cleaning test device is improved by high speed camera method. The intensity of cavitation was tested by methylene blue spectrophotometer and stress-strain method. The double bending cleaning apparatus captured by high-speed camera method had better cavitation effect. The methylene blue consumed by double bending cleaner was more than that by single bending. 14%. The double bending cavitation cleaning apparatus has better cavitation effect. The results of stress-strain test show that the strain value is the largest at the cavitation position of the washer. It is proved that cavitation occurs near this position and accompanied by the collapse of cavitation. The higher the inlet pressure, the more obvious the cavitation phenomenon is, and the higher the strain value is.
【学位授予单位】：大连海事大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TH122

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