Self-adjusting method for blade tip clearance of semi-open type magnetic suspension impeller

Abstract

The invention discloses a self-adjusting method for a blade tip clearance of a semi-open type magnetic suspension impeller. The method comprises the following steps that a, firstly, an optimal clearance delta between a semi-open type impeller blade tip and an impeller cover is calculated when the overall efficiency is highest; b, the blade tip molded line Sa of the semi-open type impeller is equally divided into N-1 sections (N is larger than or equal to 20); c, the maximum offset delta1 delta2... deltaN-1 deltaN of each end point of the segmented blade tip molded line Sa in the direction of the impeller cover are calculated under the operation condition; and d, the blade tip molded line Sa serves as the reference, all the end points deviate (delta + delta 1, delta + delta 2... delta + delta N-1 and delta + delta N) in the direction of the impeller cover, all the points are connected through splines to form a curve Sc, and the curve Sc is the inner surface contour machining curve of an impeller cover base body. The method has the beneficial effects that on the premise of guaranteeing the safety of the blade tip clearance of the impeller, and the clearance between the blade tip and the impeller cover is always in the optimal clearance delta by utilizing the deformation generated by the impeller under the operation condition.

Description

technical field [0001] The invention belongs to the technical field of impellers, and in particular relates to a method for self-adjusting the tip clearance of a semi-open magnetic levitation impeller. Background technique [0002] Blowers are widely used in high-energy industries such as metallurgy, building materials, chemicals, and municipal administration, and play a vital role in the development of the national economy. Blowers consume a lot of energy. For example, the energy consumption of aeration blowers in sewage treatment plants accounts for 50%-60% of the total energy consumption of sewage treatment plants. It can be seen that improving the operation efficiency of blowers will bring considerable economic benefits. [0003] The overall efficiency of the semi-open impeller blower can be divided into the efficiency of the impeller and the efficiency of stationary components such as diffuser and volute; when the efficiency of stationary components such as diffuser and...

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Problems solved by technology

[0003] The overall efficiency of the semi-open impeller blower can be divided into the efficiency of the impeller and the efficiency of stationary components such as diffuser and volute; when the efficiency of stationary components such as diffuser and volute is constant, improving the efficiency of the impeller will inevitably increase the efficiency Lifting, semi-open impeller tip clearance has a significant impact on impeller efficiency. Scholar He Yi has obtained through CFD calculations and a large number of actual tests that every 1% increase in tip clearance ratio will result in a drop of more than 0.5% in stage efficiency, and the step ratio The higher the value, the greater the drop in efficiency

Controlling the tip clearance of the impeller is a common topic of research by scholars. For example, patent number: CN105201904A, a method for controlling the tip clearance of a semi-open impeller. Although this method can achieve the effect of controlling the tip clearance, the operation is relatively cumbersome

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