基于小波分析的气力提升系统流型辨识研究

发布时间：2018-09-07 18:06

【摘要】：作为特殊类型泵,气力提升泵主要被用在传统泵不能发挥作用的场合。如抽取粒状、块状固体颗粒和腐蚀性液体等。因对气力提升系统流场结构方面的研究不够完善,气力提升泵存在应用性能偏低的问题,为改善此问题,本文以气力提升泵提升管内气液两相流和气液固三相流做研究对象,对流型的特征、转变机理、以及基于小波分析提取各流型的特征进行流型辨识研究,结果表明:研究了提升管内气液两相流流型的特征和转换机理,得出随着进气量的增大,管内流型的转变顺序分别为:泡状流、弹状流、泡沫流、环状流。对气-液-固三相流流型的特征及转换机理进行了分析,研究表明,聚泡流最有利于固体颗粒的提升,随着进气量的增大,气液固三相流流型的转变顺序为:弹旋流、旋涡流、波浪流、聚泡流、环柱流。基于小波分析对流型特征值提取的方法,能有效对流型进行识别。在气液两相流流型中,主要通过四种流型在1子频带上,及在2、3、4、7四个子频带中的能量分布差异,可很好对四种流型进行识别。在气液固三相流中,五种流型能量差异最主要表现在1、2子频带中,以及根据3、4、5、6、7、8子频带中能量的不同分布,也实现了对五种流型的辩识。通过对气液两相流和气液固三相流的流型信号实例进行辨识,结果整体辨识率分别达到91.4%、88.1%,达到识别效果。研究成果,丰富了气力提升系统的流场结构理论,对其在工程中应用有重要意义。
[Abstract]:As a special type of pump, pneumatic lift pump is mainly used in the situation where the traditional pump can not play its role. Such as the extraction of granular, massive solid particles and corrosive liquids and so on. Because the research on flow field structure of pneumatic lift system is not perfect, the application performance of pneumatic lift pump is low. In order to improve this problem, this paper takes gas-liquid two-phase flow and gas-liquid-solid three-phase flow in lift pipe of pneumatic lift pump as the research object. The characteristics of convection type, transformation mechanism, and flow pattern identification based on wavelet analysis are studied. The results show that the characteristics and conversion mechanism of gas-liquid two-phase flow pattern in riser are studied, and the results show that with the increase of air intake, The flow patterns in the tube are in the following order: bubbly flow, slug flow, foam flow and annular flow. The characteristics and conversion mechanism of gas-liquid-solid three-phase flow pattern are analyzed. The results show that the bubbling flow is the most favorable for the lifting of solid particles. With the increase of air intake, the transformation sequence of gas-liquid-solid three-phase flow pattern is as follows: elastic swirl and vortex flow. Wave current, bubble current, annular current. The method of extracting convection eigenvalue based on wavelet analysis can effectively identify convection type. In the gas-liquid two-phase flow pattern, the four flow patterns can be well identified by the difference of energy distribution between four flow patterns in one sub-band and four sub-bands in 2 ~ 3 ~ 3 ~ 4 ~ 4 ~ (7) subbands. In the gas-liquid-solid three-phase flow, the energy differences of the five flow patterns are mainly manifested in the 1 / 2 sub-band, and according to the different distribution of energy in the 3 / 4 / 5 / 6 / 6 / 7 / 8 sub-band, the identification of the five flow patterns is also realized. Through the identification of flow pattern signals of gas-liquid two-phase flow and gas-liquid-solid three-phase flow, the result shows that the overall identification rate is 91.4 and 88.1, respectively, and the recognition effect is achieved. The research results enrich the flow field structure theory of pneumatic lift system, and have important significance for its application in engineering.
【学位授予单位】：湖南工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：O359

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