| 摘要 |
PURPOSE:To prevent a steam turbine from deteriorating due to a rise in the degree of vacuum in a condenser, by automatically setting an upper limit of opening degree of a steam governing valve to prevent the inflow rate of the turbine from increasing in association with a rise in the degree of vacuum in the condensor. CONSTITUTION:A signal from a condensor vacuum detector 40 for detecting the vacuum 41 of a condensor is delivered to a device 42 for computing and setting an opening degree upper limit value for a governing valve 31, and the value computed by the device 42 is delivered as a load limiter correction set value 43 to a low value priority function section 42 together with a load limiter reference set value 21 previously set by the operator. The section 42 selects smaller one of them and delivers the same to a load limiter 20 which delivers a governing value opening degree setting signal 22 to a low value priority function section 23 together with a governing valve opening degree setting signal 29 which is obtained by adding a predetermined gain to the deviation 27 between a load setting signal 24 and a rotational speed signal 25. Further, smaller one of them is selected as an upper limit value 30 of the governing valve opening degree for adjusting the governing valve 31.
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