OPERATION OF STEAM FLOW CONTROL VALVE OF STEAM TURBINE AND ITS DEVICE

摘要

PURPOSE:To permit the test of a steam flow control valve in an operating state with easy handling by controlling the steam flow control valve with the opening varied within the range equivalent to saturation flow rate of the curve of the opening of the steam flow control valve to steam flow rate. CONSTITUTION:The phenomenon that a steam flow control valve (V) is agglutinated to disable open-and-close operation occurs mainly in between a valve rod 10 and a valve rod guide 14 exposed to high-temperature steam. To dissolve such an agglutinated condition, configuration is so made that the valve rod 10 can be stroked without varying a steam flow passing through the valve (V) when test operation is performed to stroke the valve rod 10 during load run. That is, a cam shaft 5 rotated by the action of a cylinder 1 via a rack 6 and a pinion 3 is mounted with a cam 7, and via a lever 11 associated with this cam 7 the valve rod 10 is elevated up and down. The cam 7 is formed in the shape of varying the opening of the valve within the range equivalent to saturation flow rate of the curve of the opening of the steam flow control valve (V) to steam flow rate.