Power station unit multi-steam-source shaft seal steam/gas supply system and control method

Abstract

The invention discloses a power station unit multi-steam-source shaft seal steam / gas supply system and a control method thereof. The power station unit multi-steam-source shaft seal steam / gas supply system comprises a high-pressure cylinder, a medium-pressure cylinder, a low-pressure cylinder, a shaft seal cooler, a hydrophobic air heat exchanger, a desuperheater (A), a desuperheater (B) and a rotor connected with a cylinder body accessory; the steam inlet side of the high-pressure cylinder and the steam inlet side of the medium-pressure cylinder share a first branch shaft seal to supply steam, and residual steam enters a shaft seal steam return main pipe through a steam return pipeline manual valve after a shaft seal cavity is sealed; the steam exhaust sides of the high-pressure cylinder and the medium-pressure cylinder share a second branch shaft seal to supply steam, the desuperheater is arranged on a second branch steam supply pipeline, and a measuring point for measuring the temperature of the steam is arranged behind the desuperheater and in front of a shaft seal body; and all shaft seal return steam of the high-pressure cylinder, the medium-pressure cylinder and the low-pressure cylinder is gathered and then enters the shaft seal cooler. The system has the advantages of multi-source steam supply, parameter matching, flexible control mode, reliable protection logic and automatic tracking under accident conditions.

Description

technical field [0001] The invention relates to the technical field of transformation of steam turbine shaft seal systems, in particular to a multi-steam source shaft seal steam / gas supply system of a power station unit and a control method thereof. Background technique [0002] The steam turbine shaft seal system is an important part of the steam turbine. At the part where the steam turbine passes through the outer cylinder, some measures must be taken to prevent external air from leaking in or steam from leaking out of the cylinder. In the high-pressure section of the steam turbine, the function of the shaft seal system is to prevent the steam from leaking out, so as to ensure the high efficiency of the steam turbine. In the low-pressure area of ​​the steam turbine, the function of the shaft seal system is to prevent outside air from entering the inside of the steam turbine, so as to ensure that the steam turbine has as high a vacuum as possible and high efficiency of the ...

AI Technical Summary

Problems solved by technology

The study found that when the rotor is idling to near the critical speed after the turbine trips, improper control of the steam supply temperature of the shaft seal will aggravate the vibration of the entire shaft system, and even further cause the risk of the large shaft locking

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