Numerical Study On Transient Aerodynamic Characteristics In The Semi-open Impeller Stage Of Large Centrifugal Compressor

With the rapid development of China’s industrialization, the centrifugal compressor, as the core equipment for the petrochemical, metallurgy, air separation, electric power, coal chemical industry and other equipments, changes to the large-capacity, high-efficiency, high-parameter, high reliability. Therefore, the study of the aerodynamic characteristics of a large centrifugal compressor stage is very important in practical significance.The centrifugal compressor design need to meet the requirements of aerodynamic performance, and good structural characteristics also need to be considered as an important factor. Only static mechanical property is not comprehensive for structural strength analysis. It should be considered the impact of aerodynamic loads on the strength of the structure. This paper focuses on the aerodynamic characteristics of large centrifugal compressor semi-open impeller stages under different designs and different operating conditions. It analyses the reason that may cause the structure problem from the view of aerodynamic, and affords the static pressure pulsation on blade surface as the basis of the structure analysis.The main objects of study for this article are HI semi-open impeller centrifugal compressor and H2semi-open impeller centrifugal compressor. This paper investigated the aerodynamic characteristics in the centrifugal compressor by using numerical simulation method. It investigates the internal flow law and the blade aerodynamic load under different modifications of centrifugal compressor; on the comparative analysis of the inner flow field under winter conditions and design conditions, it obtains that the variation of aerodynamic load at the blade leading edge, and its aerodynamic load increases under winter conditions. The PLM method is superior to the DSM method by the study of two different unsteady treatment methods on the interface of rotor and stator. The influence of the different clocking positions on the aerodynamic characteristics is obtained by the transient simulation of H2semi-open impeller centrifugal compressor. The studies show that the clocking effects may occur in the centrifugal compressor and the impact on the aerodynamic loading of impeller blade cannot be ignored. When the clocking position changes within a certain range, the aerodynamic load of the impeller has no obvious change, and clocking position should be considered to determine the installation of the stator blade in the design. Static analysis of the semi-open impeller is studied by using fluid-structure coupling method and finite element method. The stress distribution is predicted under aerodynamic loads, centrifugal force load and fluid-structure interaction. The results show that the maximum stress area of the blade is in accord with that of the fracture location, so it provides a numerical basis for the structure analysis.