| 摘要 |
PROBLEM TO BE SOLVED: To provide a main steam temperature control method for waste treatment facility, in which safe operation is continued as no main steam temperature becomes high even when boiler incoming heat quantity is largely changed, by exerting a control performance resistant to disturbance. SOLUTION: Main steam generated in a boiler 1 disposed in a waste treatment facility is heated by a primary superheater 2, temperature-adjusted by a desuperheater 3, and successively reheated by a secondary superheater 5 to supply main steam of a predetermined temperature to a using destination. The spray injection of the desuperheater 3 is adjusted by PID control using a variable gain in which the main steam temperature on the outlet side of the primary superheater 2 and the steam flow rate on the outlet side of the secondary superheater 5, and the boiler incoming heat quantity are added, and a proportional zone is changed according to the addition result and a temperature deviation between the outlet-side main steam temperature of the secondary superheater 5 and a temperature set value to perform feedback control of the main steam temperature. When the main steam temperature becomes a regulated temperature or higher, switching from the PID control to an emergency water injection logic is made to increase the spray water injection quantity of the desuperheater 3. COPYRIGHT: (C)2007,JPO&INPIT
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