| 摘要 |
PURPOSE:To keep an instruction output as long as possible by a method wherein wheather or not the metering of a steam control valve is possible is judged in reference to a quantitative relation between the load of a turbine and the requirement of load from a central power supplying station. CONSTITUTION:When a water level is rised in more than two units of high-pressure feed water heater 6, 8 and 10 at a low pressure side in the same system, the steam extraction for the high pressure feed water heater 8 and 10 is terminated. At this time, wheather or not the metering of a steam contol valve 24 for turbine inlet steam is judged in response to the load in the turbine and the instruction requiring value sent from the central power supplying station, and if it is possible to have a metering of the control valve, the control valve 24 is metered and in turn if not the steam extraction for the high pressure feed water heater 6 at the highest pressure side is terminated. In case of terminating of the steam extraction for the high pressure feed water heater, a distribution of the pressure for each of the stages is disturbed and in particular the load at the highest pressure stage shows an excessive disturbance of the pressure distribution. Thus, even the steam extraction for the high pressure feed water heater at the highest pressure side is terminated, resulting in decreasing the limited load and keeping the rated load as much as possible. |
