Title:
FEEDWATER-FUEL RATIO CONTROLLER FOR CONSTANT-PRESSURE ONCE-THROUGH BOILER
Document Type and Number:
Japanese Patent JP3150536
Kind Code:
B2
Abstract:
PURPOSE: To make the feedwater-fuel ratio control follow changes in behavior of a constant-pressure once-through boiler much quicker than ever and control the boiler always favorably in the full range from the start to the rated load.
CONSTITUTION: The inlet temperature at the water-cooled wall is measured and inputted to a primary-lag element 31 and a subtracter 32 to obtain a Twwi deviation signal, from which signal a rise or a fall in the inlet temperature at the water-cooled wall is detected and a Twwi precedence signal is obtained. To be more exact, an analog- switching unit 38 selects, when the inlet temperature at the water-cooled wall has increased, a constant value-setting unit 43 to lower the feedwater-fuel ratio and, when the inlet temperature at the water-cooled wall has decreased, a constant value-setting unit 42 to raise the feedwater-fuel ratio. The selected set value is multiplied by the output of a function generator 33 corresponding to the Twwi deviation and the product, by the output of a function generator 49 corresponding to the actual amount of electric generation; the result is the Twwi precedence signal. This Twwi precedence signal is processed in a manner of level adjustment and then added to a precedence signal based on the outlet temperature of the water-cooled wall; the sum is added to a feedwater-fuel ratio signal based on the steam temperature to make a good feedwater- fuel ratio signal.
Inventors:
Hideya Sonoda
Michio Oyamada
Michio Oyamada
Application Number:
JP15380094A
Publication Date:
March 26, 2001
Filing Date:
July 05, 1994
Export Citation:
Assignee:
MITSUBISHI HEAVY INDUSTRIES,LTD.
International Classes:
F22B35/00; (IPC1-7): F22B35/00
Domestic Patent References:
| JP6170304A |
Attorney, Agent or Firm:
Takehiko Suzue