초록 ▼

A turbine control system for changing two speed governing operations of a steam turbine from a throttle governing operation to a nozzle governing operation and vise versa by controlling steam control valves comprises function generators grouped according to the two speed governing operations and ope

A turbine control system for changing two speed governing operations of a steam turbine from a throttle governing operation to a nozzle governing operation and vise versa by controlling steam control valves comprises function generators grouped according to the two speed governing operations and operated by a main control flow-rate request signal to produce function outputs which are applied to respective low-value gate circuits, means for comparing the sum of the outputs of the gate circuits and the main control flowrate request signal, and means for varying the main control flowrate request signal with the aid of the difference between the signals thus compared in such a manner that while one of the outputs of the gate circuits decreases, the other output increases to supplement the decrease, whereby the steam control valves are gradually operated with the output of the turbine being kept unchanged during the operating mode changing operation.

대표청구항 ▼

A turbine control system for changing two speed governing operations of a steam turbine from a throttle governing operation to a nozzle governing operation and vice versa by controlling a plurality of steam control valves on the basis of a main control flow-rate request signal, which system comprise

A turbine control system for changing two speed governing operations of a steam turbine from a throttle governing operation to a nozzle governing operation and vice versa by controlling a plurality of steam control valves on the basis of a main control flow-rate request signal, which system comprises: a. a first group of function generators for said throttle governing operation provided respectively for said steam control valves and a second group of function generators for said nozzle governing operation provided respectively for said steam control valves, each function generator producing a function output signal in response to a main control flow-rate request signal applied thereto, b. a low-value preference circuit provided for each steam control valve for selectively passing the lower of the function output signals applied thereto, said lower function output signal thus passed being utilized to control an opening degree of said steam control valve, c. first means for obtaining a difference signal between said main control flow-rate request signal and the sum of said function output signals thus passed, and d. second means for increasing, according to said difference signal, a bias applied to one of said two groups of function generators which operates for one of said two governing operations which is not a speed governing operation intended to effect, and for decreasing a bias applied to the other group of function generators which operates for said speed governing operation intended to effect, whereby during the speed governing operation changing period of said turbine, the output of said turbine is kept unchanged and no thermal shock is caused to said turbine.