Title:
CONTROL DEVICE
Document Type and Number:
Japanese Patent JPS54138970
Kind Code:
A
Abstract:
PURPOSE:To eliminate influences on a plant of a time delay from a detection of occurence of an unusual condition to a lock of an operating end of the plant by constituting a control device therefor such that an output of a recording controller is continually stored in a memory so that, upon occurrence of an unusual condition, the signal stored in the memory is output to a regulation valve. CONSTITUTION:Outputs of a main steam flow signal generator 22 and a feed water flow signal generator 23 are each applied to an evolutor 24 which extracts the square root thereof. Either a signal of the sum total of outputs of the evolutors 24 and an output of a pile water level signal generator 21, or the output of the water level signal generator 21 is selected by a control mode change-over switch 27 to be applied to a recording controller 28. A control signal output from the recording controller 28 is applied by way of a lock mode relay contact 29 to a feed water regulation valve as an opening demand signal thereof. The opening demand signal is continually stored in an analogue memory 30, and when an unusual condition is detected, the change-over switch 29 is changed over to connect the analogue memory 30 so that the regulation valve opening demand signal which was stored in the analogue memory 30 directly before the unusual condition occured is supplied, thereby enabling a safe running of the plant to be attained.
More Like This:
Inventors:
NAGAHAMA MINAO
Application Number:
JP4658278A
Publication Date:
October 27, 1979
Filing Date:
April 21, 1978
Export Citation:
Assignee:
HITACHI LTD
International Classes:
G05B9/02; G05B9/00; (IPC1-7): G05B9/00