离心压气机内流分析及扩压器的优化设计

发布时间：2018-04-07 16:34

本文选题：离心压气机　切入点：数值模拟　出处：《华中科技大学》2011年硕士论文

【摘要】：离心压气机由于其具有高压力、运行范围广宽、结构简单、易于维护等特点，被广泛应用于石油化工、航空航天、能源动力等行业，并发挥着重要作用。随着我国能源问题的日益严峻，因此提高离心压气机的研究和设计水平，来提高其效率和增加其运行工况范围已显得格外重要。由于叶轮机械内部流动的复杂性，通过实验手段来完成设计优化所需的时间周期较长，随着计算流体动力学的发展，运用CFD软件进行数值模拟能有效的缩短设计研发周期，并能节省大量的试验费用，现已在得到了很广泛的应用。本文首先运用CFD软件对Krain叶轮进行数值模拟，计算其在不同转速下的性能特性，通过与文献中给出的实验数据进行对比分析，验证计算方法的可行性，经验证，该计算方法可以应用于本文的计算工作。以某离心压气机模型级为基础，分析其在不同工况下的内部流动分布情况。以原始翼型扩压器为基础，通过改型设计几款不同翼型的扩压器，分析其内部流动特性和外部性能曲线，，为扩压器翼型的选取工作提供一定的参考意见。对楔形扩压器采取切削尾缘和缩短弦长的办法进行优化，分析其内流和外部流动特性曲线，来研究不同楔形扩压器对压气机性能的影响。最后，通过改变原始翼型扩压器的叶片进口半径来改变无叶扩压段长度，分析其内流和外部流动特性曲线，研究无叶扩压段长度对级性能和级内部流动情况的影响，为无叶扩压段的选择和离心压气机叶轮和扩压器间的干涉问题研究提供一定的参考依据。
[Abstract]:Centrifugal compressor is widely used in petrochemical, aerospace, energy power and other industries because of its high pressure, wide range of operation, simple structure, easy maintenance and other characteristics, and plays an important role.With the increasingly serious energy problems in China, it is very important to improve the research and design level of centrifugal compressor, to improve its efficiency and to increase its operating range.Due to the complexity of internal flow in impeller machinery, the time period needed to complete design optimization by experimental means is longer. With the development of computational fluid dynamics, numerical simulation with CFD software can effectively shorten the design research and development cycle.And can save a large number of test costs, has been widely used.In this paper, the numerical simulation of Krain impeller is carried out by using CFD software, and the performance characteristics of Krain impeller under different rotational speeds are calculated. The feasibility of the calculation method is verified by comparing and analyzing the experimental data given in the literature.This method can be applied to the calculation work in this paper.Based on the model stage of a centrifugal compressor, the internal flow distribution under different working conditions is analyzed.Based on the original airfoil diffuser, several diffusers with different airfoils are designed, and their internal flow characteristics and external performance curves are analyzed, which provides some references for the selection of diffuser airfoils.In order to study the influence of different wedge diffuser on compressor performance, the cutting tail edge and chord length of wedge diffuser are optimized, and the internal flow and external flow characteristic curves are analyzed to study the influence of different wedge diffuser on compressor performance.Finally, by changing the inlet radius of the blade of the original airfoil diffuser, the length of the vaneless diffuser section is changed, and the internal and external flow characteristic curves are analyzed, and the influence of the length of the vaneless diffuser section on the stage performance and internal flow is studied.Some references are provided for the selection of vaneless diffuser section and the study of interference between impeller and diffuser of centrifugal compressor.
【学位授予单位】：华中科技大学
【学位级别】：硕士
【学位授予年份】：2011
【分类号】：TH452

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