【作者】 肖蕾；

【导师】 冀春俊；

【作者基本信息】 大连理工大学 ， 动力机械及工程， 2005， 硕士

【摘要】 离心式压缩机由于单级压比高,工艺性能好在航天、能源、化工及冶金等部门发挥着及其重要的作用。本文所研究的离心压缩机小流量模型级是沈阳鼓风机有限公司某多级离心压缩机后面段的一小流量级。此小流量模型级的原始设计采用的是意大利新比隆公司七十年代的离心压缩机制造技术,由于技术老化,此小流量模型级级效率比现今国际同类产品低十个百分点,在激烈的国际市场竞争中,如此大的差距必然使我国的压缩机产品处于劣势。 为了提高国际市场的竞争能力,本文利用计算流体力学的手段对离心压缩机小流量模型级内部流动情况进行数值模拟,对数值计算的结果进行分析,找出其效率低的原因,并进行相应的优化,达到显著提高其效率的目的,进而提高产品的性能,创造更高的经济效益和社会效益。本文主要工作包括:1、利用NUMECA等软件建立起完整的离心压缩机小流量模型级内部流动数值分析平台,对多级离心压缩机小流量模型级原结构内部流场进行数值模拟,得到了模型级初始的性能参数以及各通流元件(包括叶轮、扩压器、弯道及回流器)内部三维流场的完全信息。2、对模型级各通流元件内部流场进行详细的分析,针对流动中存在的问题找出影响原模型级性能因素,提出叶轮等通流元件结构参数的多种优化方案。3、根据流场分析的结果,对模型级各通流元件进行多次多方案的结构优化,结构优化工作的最终结果使多级离心压缩机小流量模型级整级性能得到明显的改善,级多变效率提高6.6个百分点,达到预期的结构优化要求。 本文建立的数值分析平台是离心式压缩机小流量模型级的内部流场分析的一个实用的工具。在实际工程设计中利用此平台可以有效的改善机器的性能。更多还原

【Abstract】 Centrifugal compressors are widely used in aeronautics, power and energy, chemical metallurgy-and many other industries for higher stage -pressure ratio and superiors manufacturing technique. The model stage studied in this thesis was designed by Nuovo Pignone in the 70s last century. The efficiency of such a model stage is usually 10% lower than the modern state-of-art products in current market and thus at a very disadvantage position in the competitive market, as the design method is out-of-date now.Based on the CFD software NUMECA, a numerical analytic system for the centrifugal model stage was developed and the detailed flow field with the main flow features inside the through-flow passages were obtained and studied. Main problems affecting the efficiency of the stage were analyzed carefully. Various approaches for the modification of the stage geometry, including the impeller, the diffuser, the curved duct and the return channel were explored numerically. The final results indicate that the stage efficiency has been increased by 6.6% with a satisfactory improvement of the flow structure inside the stage. Vaned diffuser can improve the efficiency of the model stage effectively, although may affect the off-design performance slightly.The analytic system developed in this thesis is a powerful tool in the analysis of the flow inside the centrifugal model stage. It can be used in engineering design process to improve the performance of the machine significantly.更多还原