Full range nuclear power plant steam generator level control system
AssigneeWestinghouse Electric Corp.
InventorJacques M. Geets
Life of this patent
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Abstract
A full range steam generator level control system and method is provided by a weighted linear combination of a pair of inputs from a low power and a high power controller to actuate feedwater regulation valves.
Claims17
In a method of controlling feedwater level in a steam generator of a pressurized water reactor nuclear power plant, said steam generator having secondary loop feedwater lines, said method including the steps of outputting a first signal from a first three-mode controller to control feedwater flow through the secondary loop feedwater lines at reactor power levels below a predetermined percentage, and outputting a second signal from a second three-mode controller to control feedwater flow through the secondary loop feedwater lines at reactor power levels above the predetermined percentage, the improvement in combination therewith comprising:
- receiving the first and second signals at a transition controller means;
- generating a first feedwater temperature-dependent function;
- operating on the first input signal with said first temperature-dependent function to produce a third signal;
- generating a second feedwater temperature-dependent function;
- operating on the second input signal with said second temperature-dependent function to produce a fourth signal;
- and
- adding said third and fourth signals resulting from said operating steps to control the feedwater flow through the secondary loop feedwater lines throughout an entire range of reactor load.
A nuclear steam supply system, comprising:
- reactor means having a full range of power for generating a source of heat;
- secondary loop means including feedwater lines providing a source of water;
- steam generator means coupled to said reactor means and said secondary loop means for generating steam through the vaporization of said source of water by said source of heat;
- and
- control means for controlling the flow of water in said feedwater lines throughout the full range of said reactor means said control means comprising:
- first three-mode controller means for producing a first signal to control feedwater flow at reactor power levels below a predetermined percentage;
- second three-mode controller means for producing a second signal to control feedwater flow at reactor power levels above said predetermined percentage;
- and
- transition controller means receiving said first and second signals for transferring control of feedwater flow between said first and second three-mode controller means.
A control subsystem for a nuclear steam supply system, said nuclear steam supply system including a pressurized water reactor supplying a source of heat to a steam generator having a level of feedwater maintained by secondary loop feedwater lines, the flow through which is regulated by a feedwater regulating valve, said control subsystem comprising:
- a low power controller outputting a first signal;
- a high power controller outputting a second signal;
- transition controller means receiving said first and second signals for producing a third signal indicative of a weighted linear combination of said first and second signals, said third signal being fed to the feedwater regulating valve for regulation of the feedwater flow through the secondary loop feedwater lines.
Dependencies are inferred from the claim text.