【作者】 李杰；

【导师】 冀春俊；

【作者基本信息】 大连理工大学 ， 动力机械及工程， 2012， 硕士

【摘要】 离心压缩机作为一种工业装备,广泛应用于能源动力、石油化工等国民经济的各重要部门,但也消耗着大量的能源。因此,研究出高性能的离心压缩机以满足各行业发展需求,对我国工业发展水平及国民经济建设至关重要。某离心压缩机小流量模型级采用有叶扩压器可以显著提高模型级的效率,然而考虑到有叶扩压器可能对叶轮造成冲击,因此在有叶扩压器的使用问题上需要非常谨慎。以前的研究表明,离心叶轮与叶片扩压器间的径向间隙对级性能有重要的影响。然而离心压缩机在设计工况下运行时,叶轮与叶片扩压器间的相对运动所导致的非稳态流动对级性能影响一般不大；在非设计工况运行时,由于叶片扩压器的存在,变工况时离心压气机冲击损失较大,效率下降较多。本文在扩压器叶片前缘与叶轮轮缘的距离合适的基础上,在不同流量下对其进行非定常数值模拟研究,分析有叶扩压器叶轮叶片上的压力脉动。考虑到小流量下,叶轮内部可能会产生漩涡,甚至会更加恶劣,以至于机组无法正常运行。在一定程度上可能会影响到叶片扩压器对叶轮叶片的冲击力分析,对带无叶扩压器的离心叶轮进行变工况数值模拟,并对非定常计算结果进行对比,得到了一个比较满意的结果。更多还原

【Abstract】 Centrifugal compressors, large energy consumers, are widely used in energy power and petrochemical and other important sectors in national economy. Therefore, it is high time to develop high-performance centrifugal compressors to meet the development needs of industries, which is essential to the level of industrial development and economic construction in our country.The vane diffuser can significantly improve the efficiency of the model stage for centrifugal compressor small flow coefficient model. However, it is careful to use vane diffuser for taking into the impact of the diffuser to impeller. Studies have shown that the radial clearance between the centrifugal impeller and vane diffuser has played an important role in performance influence on centrifugal compressors. However, the unsteady flow of centrifugal compressors on design conditions caused by the interaction between the impeller and vane-diffuser would create a bad effect on performance. The efficiency of centrifugal compressors decreased for the impact of vane-diffuser on off-design conditions. Based on leading edge of the vane diffuser is closer to the impeller rim, unsteady numerical simulation is studied by changing the flow to observe the pressure fields on the impeller in this paper.Taking into account the bad flow in the internal impeller on small flow condition will affect the impeller blades, centrifugal compressor with the vaneless diffuser need to be simulated on different condition. A result is obtained by compare several plans.更多还原