DEVICE FOR NOZZLE STEAM DISTRIBUTION IN HIGH-PRESSURE CYLINDER OF STEAM TURBINE Russian patent published in 2003 - IPC

FIELD: turbines. SUBSTANCE: device is designed for delivering steam into regulating stage of high-pressure cylinder of steam turbine with nozzle steam distribution. Proposed device contains regulating valves connected with their servos, nozzle boxes with nozzle cascade. Box of each regulating valve is connected with group of nozzle boxes in which nozzles of cascades are in central symmetry relative to axis of high-pressure cylinder rotor. As a result, device provides central symmetrical supply of steam, relative to axis of high-pressure cylinder rotor, into regulating stage of steam turbine at all modes of operation, including operation at break of rod of servo of any regulating valve. Device provides balanced steam flow acting onto turbine rotor which decreases sagging of rotor of high-pressure cylinder and vibration of rotor and bearings of turbine, with resulting higher reliability of turbine in operation. Decrease of rotor sagging permits use of turbine blading with smaller radial clearances, thus increasing economy of turbine. To increase additionally economy of turbine owing to provision of larger number of modes of operation at nominal pressure ion nozzle boxes by correspondingly changing preset sequence of opening of regulating valves, all servos in nozzle steam distribution device, except for servo of regulating valve the last to open, are provided, each, with additional device for its closing at any load on turbine, and groups of nozzle boxes of each regulating valve differ in number of nozzles relative to each other. EFFECT: improved reliability, increased economy of turbine. 2 cl, 2 dwg