PRESSURE CONTROLLER OF DRIVING STEAM OF TURBINE DRIVING FEED WATER PUMP

摘要

PURPOSE:To improve a response characteristic of a pressure regulating valve, by switching a pressure adjustment meter to a pressure detector and controlling pressure through a signal from a signal generator when a driving steam source of a feed water pump driving turbine (FPT) is selected to an auxiliary steam side at negative pressure drop. CONSTITUTION:Extracted steam from the half way of a main turbine 1 flows in through a check valve 2 and control valve 3 and is fed to a feed water pump driving turbine 4, and a feed water pump 5 is driven by its output. In this device, at low extraction pressure of the turbine, auxiliary steam is supplied to the turbine 4 from an auxiliary header 6 through a pressure regulating valve 7. This valve 7 is controlled by a pressure adjustment meter 12 in accordance with an output of a pressure detector 8, here a pressure monitor 10 monitoring driving steam pressure is provided to close a contact 11 when the driving steam pressure is decreased to a preset pressure. Then a signal of a signal generator 13 is fed to the meter 12 to rapidly open the valve 7 and hold the driving steam pressure to the preset pressure.