OPERATING METHOD FOR POWER GENERATING PLANT BY RECOVERING OF BLAST FURNACE GAS ENERGY WHILE BLAST FURNACE CONDITIONS ARE UNSTABLE

摘要

PURPOSE:To continue operation without stopping a gas turbine power generating plant while blast furnace conditions are unstable by closing and locking a protective relay of protector only during that time and changing over constant power factor operation or constant excitation operation to automatic voltage-regulated operation. CONSTITUTION:A power generating plant by recovering of blast furnace gas energy is juxtaposed with a gas turbine power generating plant 7 for recovering of the pressure energy of blast furnace gases and a septum valve device 4 in a blast furnace waste gas system, and generates electric power by controlling the furnace top pressure of a blast furnace 1 by said plant 7 and the device 4. When outputs increase abruptly in unstable conditions such as generation of slips in the blast furnace, a turbine generator 10G is controlled to constant power factor operation or constant excitation operation. When the quantity of the blast furnace gases produced and the furnace top pressure decrease, a protective interlock device 15 is closed and locked for a specified time limit to change over the generator 10G to automatic voltage-regulated operation, whereby the operation is continued.