Mechanism for active control over blade top gap and case shape of air compressor within full working condition range

Abstract

The invention relates to a mechanism for active control over the blade top gap and the case shape of an air compressor within the full working condition range. Under the condition that the working condition of the air compressor changes, the blade top gap size and the case shape of the air compressor are controlled in a closed-loop mode by monitoring the pneumatic performance and the blade top gap, and the mechanism aims to improve the pneumatic stability and structural stability of the air compressor within the full working condition range. According to the mechanism for active control over the blade top gap and the case shape of the air compressor within the full working condition range, a main structure comprises a blade top gap measurement system, a corrugated inner case, a worm gear and worm transmission mechanism, a stepping motor and an outer case, wherein the blade top gap measurement system is used for monitoring the blade top gap delta; the corrugated inner case is used for adjusting the size of the blade top gap and the case shape; the worm gear and worm transmission mechanism is used for stretching or compressing the corrugated inner case; the stepping motor is used for driving the worm gear and worm transmission mechanism; the outer case is used for isolated sealing of a flow channel of the air compressor and safety protection of a rotating piece; the diameter DINmin of the inner wall surface of a trough of the corrugated inner case, the blade top gap delta and the diameter DBTop of the blade top of an impeller meet the relational expression of DINmin=DBTop+2delta; the wave number NTop of the corrugated inner case within the range of the axial chord length C of the blade top ranges from 5 to 6; the ripple depth h of the corrugated inner case and the axial chord length C of the blade top meet the relational expression of h=A.c / 100, wherein A=10-50; and the ripple opening width w of the corrugated inner case and the axial chord length C of the blade top meet the relational expression of w=B.c / 100, wherein B=10-15. The mechanism is suitable for active adjustment of the blade top gap and the case shape of the air compressor within the full working condition range, and the pneumatic stability and the structural stability of the air compressor are improved.

Description

technical field [0001] The present invention relates to the design field of the main control mechanism for blade tip clearance and casing shape adjustment of turbomachinery, and is an active control mechanism for adjusting the blade tip clearance and casing shape under variable working conditions of a compressor, specifically It is an active control mechanism for the blade tip clearance and the shape of the casing of the compressor within the range of all working conditions. Background technique [0002] The compressor is the core component of the gas turbine engine, and its aerodynamic performance plays a vital role in the overall performance of the engine. The occurrence and development of the leakage flow in the clearance area of ​​the compressor blade tip will not only affect the aerodynamic loss of the compressor blade tip, but also affect the stall margin of the compressor, which will bring great challenges to the reliable operation of the compressor. By controlling t...

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Problems solved by technology

However, as the speed of the compressor changes, the tensile deformation of the compressor blade disc under the action of centrifugal force will change greatly. In order to ensure the safety of the compressor operation, it is necessary to optimize the design of the blade top under the condition of the highest speed of the compressor. As the compressor speed decreases, the tensile deformation of the blade disc decreases, and the blade tip clearance will increase accordingly, which will affect the aerodynamic loss of the compressor under low speed conditions; on the other hand, As a passive control measure, the traditional casing processing structure cannot adjust its structural form and relative position with changes in the working conditions of the compressor, and thus cannot adapt to the different requirements of the casing shape in the full range of compressor working conditions.

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