METHOD AND APPARATUS FOR PREVENTING TRIP IN LOW LOAD OPERATION OF COAL FIRED BOILER

摘要

PROBLEM TO BE SOLVED: To drive an operation with high safety stably at the time of extremely low load by opening an auxiliary fuel supply valve of a second fuel system for auxiliary combustion if a measured value of a coal mill body exceeds a target set value or a coal feeder is tripped at the time of low load operation of a pulverized coal fired boiler. ;SOLUTION: If a coal feeder 3 is tripped n a first fuel system at the time of low load operation of a coal fired boiler, a signal 14 is transmitted or if a measured value of a pulverized coal feeder 5 (mill vibration, mill current or bearing temperature) exceeds a set value, a signal 15 is transmitted to an auxiliary fuel supply controller 16. When either the signal 14 or 15 is transmitted, the controller 16 transmits an open signal to an auxiliary fuel supply valve 17 of a second fuel system. Thus, auxiliary fuel 18 is injected from a combustion burner 7 into a boiler furnace 8 via an auxiliary fuel supply tube 19, and auxiliary combustion is conducted. Thus, stable combustion of the burner 7 is ensured. Even if the feeder 5 is stopped in emergency, a boiler trip can be avoided.;COPYRIGHT: (C)1998,JPO