| 摘要 |
PURPOSE:To prevent overheating and provide continuous operation with extra- low load, in a power generating plane of turbine bypass system, by using the step pressure signal from a high pressure turbine as a signal to open and close a ventilator valve equipped on the line to lead the exhaust part of said high pressure turbine with the condenser. CONSTITUTION:When a high pressure turbine 2 is to be drafted from turbine bypass operation at the plant starting time, a control valve 9 is opened to send the draft to the turbine 2. At this time, the pressure downstream a low- temp. reheating check valve 12 is put in condition with a specified pressure, while the overstream pressure is held, before said control valve 9 is closed, in the vacuum condition approx, the same as inside a condenser 5 with the aid of a ventilator valve 13. If under this condition the control valve 9 is opened to introduce steam into the high pressure turbine 2, the exhaust part of the turbine 2 will get excessive high temp. if the valve 13 is in full closed condition. Thus the step pressure of the high pressure turbine 2 is sensed by a pressure sensor 20, and the closing timing of the ventilator valve 13 is delayed according to the outcome of the sensing so as to exhaust the steam to the condenser 5 from valve 13. |
