| 摘要 |
PURPOSE:To prevent a turbine from any reduction in efficiency when it makes mixed pressure operation without reduction in pressure of boosted main steam by controlling a process steam pressure by means of a mixed pressure extraction regulator valve and another mixed pressure throttle valve. CONSTITUTION:When a process steam becomes short, a pressure detector 9 outputs a detected pressure below a set value and a controller 25 controls an extraction stopper valve 21 and an extraction control valve 6' to be opened and closed, respectively so that the amount of process steam equivalent to the shortage is sent via a valve 21 to a factory by a turbine 5 and the remaining main steam is sent to the low pressure side of the turbine so as to perform bleeding operation. On the other hand, when process steam becomes excess, the pressure detector 9 outputs the detected pressure over the set value. The controller 25 opens a valve 6' while a controller 26 opens a mixed steam throttle valve 22. Main steam which flows into the turbine 5 via a main steam valve 3 turns a turbine blade and the excess process steam on the factory side is let into the turbin 5 via a valve 22, whereby performing mixed pressure operation and avoiding a throttle loss of the valve 6'. |
