Выбор высоты лопаток рабочего колеса центробежного компрессора при первичном проектировании

Abstract

In the preliminary designing of industrial centrifugal compressors using the universal modeling method, the relative blade heights at the exit of the impeller of a centrifugal compressor are determined only by the dimensionless compressor performance parameter— a conditional flow rate in the design mode. The second main design parameter, the theoretical head factor, is not taken into account. This rule is formulated on the basis that the relative height of the blades has relatively little effect on the slowing down the flow on the suction side of the blades, where separation can occur. The article considers another negative aspect of the large blade height. Increasing the height of the blades reduces their exit angle at a given theoretical head coefficient. The rotation of the flow by the blades decreases (which helps to reduce losses), but their length increases. With a larger area of the blades, friction losses increase. The computational research was carried out on the example of impellers with a moderate flow rate = 0.0518 in the theoretical head coefficient range = 0.475–0.70. Mathematical models of the Universal Modeling Method and calculations of an inviscid quasi-three-dimensional flow were selected as a tool for research. The results show that the existing primary design methodology can be refined.