Patent Number: 040615332
Section: claims

1. In a control system for a nuclear power producing unit comprising a pressurized water reactor, a once-through steam generator provided with feedwater supply means, a turbine-generator supplied with steam from the steam generator and means maintaining a flow of pressurized water through the reactor and steam generator, the combination comprising; means generating a feed forward control signal proportional to the desired power output of the power producing unit, a second means for adjusting the reactor heat release, a third means for adjusting the rate of flow of feedwater to the steam generator, said second and third means solely responsive to and operated in parallel from said feed forward control signal whereby the reactor heat release and the rate of flow of feedwater to the steam generator are each maintained in a discrete functional relationship to said feed forward control signal. 2. In a control system as set forth in claim 1 further including a fourth means for adjusting the rate of flow of steam from the steam generator to the turbine, said fourth means solely responsive to and operated in parallel with said second and third means from said feed forward control signal. 3. In a control system as set forth in claim 1 further including a function generator responsive to said feed forward signal and producing a modified feed forward signal, said second means responsive to said modified feed forward signal. 4. In a control system as set forth in claim 1 further including means modifying the response of said second means to said feed forward signal in proportion to the time integral of the difference between the desired and actual power output of the power producing unit. 5. In a control system as set forth in claim 2 wherein the nuclear power producing unit has a plurality of critical parameters, further including means modifying the discrete response of said second, third and fourth means in proportion to changes in the magnitudes of said plurality of parameters. 6. In a control system as set forth in claim 1 further including means modifying the response of said third means to said feed forward signal in proportion to the time integral of the deviation in the average of the temperatures of the said pressurized water entering and leaving the reactor from set point. 7. In a control system as set forth in claim 6 further including means modifying the response of said third means in accordance with the average of the temperatures of the said pressurized water entering and leaving the reactor from set point in proportion to the difference between the desired and actual power output of the power producing unit. 8. In a control system as set forth in claim 1 further including means modifying the response of said third means to said feed forward signal in functional relationship to changes in the rate of said pressurized water flow through the steam generator. 9. In a control system as set forth in claim 1 further including means modifying the response of said third means to said feed forward control signal in proportion to changes in the temperature of the feedwater entering the steam generator. 10. In a control system as set forth in claim 1 wherein the nuclear power producing unit includes a second once-through steam generator provided with feedwater supply means and supplying steam to the turbine-generator and means maintaining said pressurized water flow through the reactor and said second steam generator, the combination further comprising; means for maintaining the total rate of feedwater flow to said generators in a discreet functional relationship to said feed forward signal. 11. In a control system as set forth in claim 10 further including means for adjusting the relative rates of feedwater flow to the steam generators in accordance with the difference in the average temperatures of the said pressurized water entering and leaving said first named steam generator and said second steam generator. 12. In a control system as set forth in claim 11 further including means adjusting the relative rates of feedwater flow to the steam generators in accordance with the time integral of the difference in said average temperatures. 13. In a control system as set forth in claim 10 further including means for adjusting the relative rates of feedwater flow to the steam generators in accordance with changes in the relative rates of said pressurized water flow through the steam generators. 14. The combination as set forth in claim 10 further including means for adjusting the relative rates of feedwater flow to the steam generators in proportion to the difference in temperatures of the feedwater supplied the steam generators. 15. The combination as set forth in claim 10 further including means for adjusting the relative rates of feedwater flow to the steam generators in accordance with the algebraic sum of the difference in the average of the temperatures of the said pressurized water entering and leaving the steam generators, the relative rates of said pressurized water flow through the steam generators and the difference in temperature of the feedwater supplied the steam generators.