| 摘要 |
PROBLEM TO BE SOLVED: To provide a control method for a once-through waste heat recovery boiler, not lowering the boiler efficiency by always keeping the vapor temperature to a normal value to secure maximum evaporation amount. SOLUTION: When the vapor temperature at an outlet of a superheater 8 is larger or smaller than its target value, a preset value of degree of superheat of outlet vapor of an evaporator 6 is increased or decreased, when an opening of a governor valve 22 of a superheater temperature reducing device 9 is larger than a preset value, the target value of degree of superheat of outlet vapor of the evaporator 6 is decreased, and when the degree of superheat of vapor at the outlet of the evaporator 6 is larger or smaller than the target value, the water supply amount to a fuel economiser 5 is increased or decreased. Instead of the opening of the governor valve 22 of the temperature reducing device 9, a difference in vapor temperature before and after the temperature reducing device 9 or a filling water flow to the temperature reducing device 9 may be used to obtain the similar effect. COPYRIGHT: (C)2008,JPO&INPIT
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