Patent ID: 7396228

Claim:
A fuel gas calorie control method which is applied to a fuel gas production system for mixing a first heat increasing gas with a blast furnace gas discharged from a blast furnace of an iron mill to form a first mixed gas, further mixing a second heat increasing gas with the first mixed gas to form a second mixed gas, and supplying the second mixed gas, as a fuel gas, to blast furnace gas fired gas turbine equipment, and which exercises control such that calories of the second mixed gas become set calories required by the blast furnace gas fired gas turbine equipment, the fuel gas calorie control method comprising: predicting calories of the first mixed gas by calculations based on a mixed flow rate of the blast furnace gas measured by blast furnace gas flow rate measuring means, a mixed flow rate of the first heat increasing gas measured by first heat increasing gas flow rate measuring means, preset blast furnace gas calories, and preset first heat increasing gas calories; calculating a flow rate ratio of a mixed flow rate of the second mixed gas to a gas turbine consumed fuel gas flow rate based on the predicted calories, the set calories, and preset second heat increasing gas calories; calculating a mixed flow rate required value of the second heat increasing gas based on the flow rate ratio and a gas turbine fuel gas requirement signal corresponding to the gas turbine consumed fuel gas flow rate; and controlling an opening of a flow control valve for the second heat increasing gas provided in the fuel gas production system, based on the mixed flow rate required value of the second heat increasing gas, to control a mixed flow rate of the second heat increasing gas.