COAL-FIRED BOILER SYSTEM DETECTING SENSING ERROR IN UNBURNED CARBON CONCENTRATION SENSOR

摘要

A coal-fired boiler system is disclosed. A coal-fired boiler system according to the present invention comprises: a coal-fired boiler for burning coal being input; a refined ash production unit for refining ash produced from the coal-fired boiler; a refined ash discharge pipe for discharging refined ash produced from the refined ash production unit; a refined ash storage unit connected to the refined ash discharge pipe; a branch valve installed between the refined ash discharge pipe and refined ash storage unit and for selectively supplying the refined ash to the refined ash storage unit; a first branch pipe branching from the refined ash discharge pipe and for receiving the supply of refined ash; a second branch pipe which is different from the first branch pipe, branches from the refined ash discharge pipe and is for receiving the supply of refined ash; a first selection valve installed on the first branch pipe and for blocking or opening such that the refined ash is selectively supplied to the first branch pipe; a second selection valve installed on the second branch pipe and for blocking or opening such that the refined ash is selectively supplied to the second branch pipe; a first unburned carbon concentration sensor installed on the first branch pipe downstream from the first selection valve and for measuring the unburned carbon concentration of refined ash; a second unburned carbon concentration sensor installed on the second branch pipe downstream from the second selection valve and for measuring the unburned carbon concentration of refined ash; and a control unit which receives a sensing signal of the first unburned carbon concentration sensor and determines a sensing error in the sensing signal of the first unburned carbon concentration sensor and, if the first unburned carbon concentration sensor is determined to be erroneous, blocks the supply of refined ash to the first branch pipe by blocking the first selection valve, and selectively controls the branch valve on the basis of a sensing signal of the second unburned carbon concentration sensor.