Boiler controlling device and boiler controlling method

Abstract

The invention provides a boiler control device capable of keeping oxygen concentration at an outlet of an economizer at a set value. In this boiler control device comprising a ventilating device provided with a plurality of forced draft fans 52 for supplying the combustion air to a boiler, a plurality of vanes 54 for adjusting a flow rate of the combustion air and a plurality of air flow rate detectors 55 for detecting the flow rate of the combustion air, an inverter 64 for converting the AC power source voltage into the AC voltage of a specific frequency and supplying the same to a motor driving the forced draft fans, breakers 62, 63, 65, 66 for supplying any one of the output of the inverter and the concord current power source AC power source voltage to the motor, and a boiler automatic control device 59 for adjusting an opening of the vane and a rotating frequency of the motor on the basis of the air flow rate command supplied from the external and the detection output of the air flow rate detector, and keeping the oxygen concentration at the outlet of the economizer to a predetermined value. The boiler automatic control device 59 applies the bias to the opening command of the vane for a specific time in the failure of the switching operation of the motor driving source from an inverter side to an AC power source voltage side by switching the breakers.

Description

technical field [0001] The invention relates to a boiler control device and a boiler control method, in particular to a boiler control device and a boiler control method capable of maintaining the oxygen concentration at the outlet of a coal economizer at a set value. Background technique [0002] For example, in Patent Document 1, a ventilator with two systems respectively having a commercial power supply and an inverter power supply is disclosed. When the above-mentioned inverter power supply cannot operate, the power supply can be switched from the inverter power supply to the commercial power supply. Boiler controls to keep the ventilator running. Furthermore, in order to compensate for the reduction in the ventilation rate due to the decrease in the driving speed of the fan at the time of the switching, and to maintain the stability of combustion, there is disclosed a technique of providing an open bias command to the damper that limits the ventilation rate. [0003] [...

AI Technical Summary

Problems solved by technology

[0005] In this return operation, the air supply to the boiler may be insufficient, or the fuel supply may be excessive, and the possibility that the oxygen concentration at the outlet of the economizer decreases may increase.

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