| 摘要 |
PROBLEM TO BE SOLVED: To provide a once-through boiler stably and quickly making control of a water level in a separation water tank even if there is continuous vibration between the separation water tank and a steam generating tube. SOLUTION: The once-through boiler 200A is equipped with: a water gauge 35 detecting the water level in the separation water tank 15; and a water gauge 36 detecting a water level in a secondary steam generator 13. A water level control circuit 105A has: an adder 61 outputting a water level deviation signal S4 based on a water level signal S1 of the water gauge 35; an adder 64 outputting a water level deviation signal S6 based on a water level signal S2 of the water gauge 36, a proportional amplifier 65; an adder 66 adding a water level deviation signal S7 outputted therefrom and the water level deviation signal S4 to calculate a water level deviation signal S8A for water level control of the separation water tank 15; and a PI controller 62 computing a valve opening demand signal S9A of a flow regulating valve 21 based on the water level deviation signal S8A. A gain G1 of the proportional amplifier 65 is a ratio of respective horizontal free cross-sectional areas of the secondary steam generator 13 and the separation water tank 15. COPYRIGHT: (C)2011,JPO&INPIT |
