基于直接自由曲面变形方法的液环泵壳体优化研究

发布时间：2018-10-17 21:02

【摘要】：液环泵因为具有构造简单、等温压缩、使用维修便利、适合应用于抽吸和压缩易燃易爆气体,被普遍应用于化工、煤矿、制药、石化、发电、饮食以及废气的回收等行业范围中。由于其广泛的使用性能,研究者们对其做了深入细致的分析研究,通过研究了解得知,对液环泵性能产生影响的结构参数有很多,如叶轮、壳体型线、吸气口的形状大小、排气口的位置形状及喷射器等,这些都可能严重影响液环泵的性能。但是这些年,国内外研究者大多只是对液环泵的内部流动数值计算以及喷射器的影响,做了大量的研究,可是就壳体型线对液环泵性能的影响,这方面的分析研究还不是很充分。因此,本文的主要工作是通过优化液环泵的壳体型线,以达到优化液环泵性能的目的。提出一种新的液环泵壳体型线的变形控制方法,结合响应面方法,进行液环泵壳体型线的优化研究。主要工作内容和成果如下:1.提出了一种新的液环泵壳体型线的变形控制方法——基于直接自由曲面变形的液环泵壳体型线的变形控制方法,根据试验设计要求,结合直接自由曲面变形方法的数学原理,构建有效的变形函数,从而实现对壳体型线直接的、精确的参数化变形控制。2.根据响应面分析法。在控制变量空间上,对壳体型线进行试验设计,并结合直接自由曲面变形方法进行壳体型线的变形控制。得到了液环泵壳体型线与其进口真空度和效率之间的关系,实现了对液环泵进口真空度及效率的优化。算例结果表明:壳体型线对液环泵水力性能有较大的影响,在一定范围内可实现泵效率及进口真空度提高,具有较大吸气区面积扩散比的壳体型线所对应的液环泵具有较高的进口真空度,在试验设计变量空间,泵的效率随其进口真空度的增大近似呈线性下降趋势。3.根据提出的直接自由曲面变形控制方法,编写了基于直接自由曲面变形方法的液环泵壳体型线的变形控制计算程序,该方法可以比较理想的实现对物体的形状变形。并编写了液环泵壳体型线的响应面优化分析程序,可以快速便捷实现对液环泵壳体型线的优化。4.对液环泵壳体优化结果表明液环泵的进口真空度在吸气区始端随着叶轮与壳体内壁间距的增大而减小,在吸气区末端随着叶轮与壳体内壁间距的增大而增大,进口真空度随着吸气区始端与末端间流道面积比值的增大而增大。效率的变化规律与之相反。
[Abstract]:Because of its simple structure, isothermal compression, convenient operation and maintenance, the liquid ring pump is suitable for suction and compression of flammable and explosive gases, and is widely used in chemical, coal, pharmaceutical, petrochemical, power generation, Food and waste gas recovery and other industries in the scope. Because of its extensive performance, the researchers have made a thorough and detailed analysis and study of it. Through the study, we know that there are many structural parameters that affect the performance of the liquid ring pump, such as the shape of the impeller, the shell line, and the suction port. The position and shape of the vent and ejector, which may seriously affect the performance of the liquid ring pump. However, in recent years, most researchers at home and abroad have done a lot of research on the numerical calculation of the internal flow of the liquid ring pump and the influence of the ejector, but on the influence of the shell line on the performance of the liquid ring pump, Analytical research in this area is not sufficient. Therefore, the main work of this paper is to optimize the performance of the liquid ring pump by optimizing the shell shape line of the liquid ring pump. A new deformation control method for the shape line of the liquid ring pump shell is proposed. The optimization of the shape line of the liquid ring pump shell is studied by combining the response surface method. The main contents and results are as follows: 1. A new deformation control method for the shape line of the liquid ring pump shell is presented, which is based on the deformation of the direct free surface. According to the requirements of the experimental design and the mathematical principle of the deformation method of the direct free surface, the deformation control method of the liquid ring pump shell shape line based on the deformation of the direct free surface is proposed. The effective deformation function is constructed to realize the direct and accurate parameterized deformation control of the shell profile. 2. According to response surface analysis. In the control variable space, the shell profile is tested and designed, and the deformation control of the shell profile is carried out with the method of direct free-form surface deformation. The relationship between the shape line of the liquid ring pump shell and its inlet vacuum degree and efficiency is obtained, and the inlet vacuum degree and efficiency of the liquid ring pump are optimized. The calculation results show that the shell line has a great influence on the hydraulic performance of the liquid ring pump, and the pump efficiency and inlet vacuum can be improved within a certain range. The liquid ring pump corresponding to the shell shape line with larger area diffusion ratio of suction area has higher inlet vacuum. In the experimental design variable space, the efficiency of the pump approximately decreases linearly with the increase of the inlet vacuum. 3. According to the direct free surface deformation control method, the deformation control calculation program of the liquid ring pump shell shape line based on the direct free surface deformation method is compiled. This method can realize the shape deformation of the object perfectly. The response surface optimization analysis program of the liquid ring pump shell shape line is compiled, which can quickly and conveniently realize the optimization of the liquid ring pump shell shape line. 4. The results of shell optimization show that the inlet vacuum of the liquid ring pump decreases with the increase of the distance between the impeller and the inner wall of the shell in the suction zone, and increases with the increase of the distance between the impeller and the inner wall of the shell at the end of the suction zone. The inlet vacuum increases with the increase of the flow channel area ratio between the beginning and the end of the suction zone. The law of change of efficiency is opposite to it.
【学位授予单位】：兰州理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TB752

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