A kind of steam turbine, water film active purging type steam turbine static blade and its purging control method

Abstract

The invention discloses a steam turbine, a water film active purging type steam turbine stator blade and a purging control method thereof. The water film active purging type steam turbine stator bladecomprises a blade body, wherein a cavity is formed in the blade body; a plurality of suction surface through holes are formed in the suction surface of the blade body; a plurality of pressure surfacethrough holes are formed in the pressure surface of the blade body; the suction surface through holes and the pressure surface through holes communicate with the cavity; and the cavity is provided with an air inlet for communicating with an external purging air source. The water film active purging type steam turbine stator blade adopts the active purging manner for dehumidification to ensure that the pressure in the cavity is higher than the pressure of the outer surface basin of the blade, so that water film series flow generated due to pressure difference of the pressure surface and the suction surface is avoided. The water film active purging type steam turbine stator blade mainly adopts the active purging manner for dehumidification, can purge liquid drops with smaller shapes and ishigher in dehumidification efficiency.

Description

technical field [0001] The invention belongs to the technical field of steam turbine static vane dehumidification, in particular to a steam turbine, a water film active purging type steam turbine stationary vane and a purging control method thereof. Background technique [0002] Water erosion is a phenomenon that easily occurs on the moving blades of the wet steam stage of the steam turbine. Specifically, after the steam expands and does work, if it crosses the saturation line, water droplets will condense and precipitate to increase the humidity in the stage, and the excessive internal humidity of the steam turbine will cause the blades to be damaged by liquid. Drop impact damage. Water erosion will seriously reduce the flow efficiency of the blade, and at the same time weaken the blade matrix, generate crack sources, endanger the reliability of the blade, and even cause accidents such as fracture. The measures adopted to reduce or prevent water erosion include: moving bla...

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Problems solved by technology

[0003] Among them, the existing dehumidification structure principle of the stationary vane is: open a dehumidification tank on the surface of the stationary vane, and use the flow field pressure difference to passively pump the water film; the technical solution based on the above principle has the following problems: the passive suction is due to the pressure surface and There is a pressure difference on the suction surface, which will cause water film to flow in series, and the dehumidification efficiency is low; some of the liquid droplets impacting the final rotor blade may have a small shape at the stationary blade, making it difficult to passively suction and dehumidify

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