| 摘要 |
PROBLEM TO BE SOLVED: To provide a once-through boiler, capable of preventing a trouble such as overheating or carryover of a heat-transfer tube due to an imbalance between a combustion amount and a water level in the heat-transfer tube. SOLUTION: In the once-through boiler with a water level set at the middle of the heat-transfer tube, the combustion amount of the boiler is set in multiple stages, and the operation of the boiler is controlled so as to attain a combustion amount determined based on a steam pressure value. The once-through boiler is operated, even in a case such that when the combustion amount is increased from a state where combustion is performed, two-stage increase in combustion amount or more is needed, or increase in combustion amount is needed again in a short period of time after previous combustion amount increase, to increase the combustion amount by one stage by one stage, perform combustion amount retention for a predetermined time T1 at the one-stage increased combustion amount, and to further raise the combustion amount by one stage after performing the combustion amount retention for the predetermined time T1 at the one-stage increased combustion amount. COPYRIGHT: (C)2011,JPO&INPIT |
