초록 ▼

Values such as a pressure for supplying fuel gas to a gas turbine, a pressure in a combustor casing of the gas turbine, an output of a generator connected to the gas turbine, and a controlled output for a flow rate control valve are detected by sensors. The detected values are input into a control d

Values such as a pressure for supplying fuel gas to a gas turbine, a pressure in a combustor casing of the gas turbine, an output of a generator connected to the gas turbine, and a controlled output for a flow rate control valve are detected by sensors. The detected values are input into a control device. A differential pressure across the flow rate control valve and a target value of the differential pressure are also input into the control device. The control device performs a desired arithmetic operation based on these input values to output a lift instruction for a pressure control valve.

대표청구항 ▼

What is claimed is: 1. A gas turbine fuel control method of controlling a lift amount of a pressure control valve provided at a piping in which fuel for a gas turbine flows, by feeding back an actually obtained differential pressure across a flow rate control valve also provided at the piping to th

What is claimed is: 1. A gas turbine fuel control method of controlling a lift amount of a pressure control valve provided at a piping in which fuel for a gas turbine flows, by feeding back an actually obtained differential pressure across a flow rate control valve also provided at the piping to the pressure control valve and making the differential pressure follow a desired target value of the differential pressure, the gas turbine fuel control method comprising: expressing a conductance of the pressure control valve using a pressure used to supply fuel gas that is detected upstream of the pressure control valve at the piping, a pressure in a combustor casing of the gas turbine, an output of a generator connected to the gas turbine, and a controlled output for the flow rate control valve that is calculated based on a difference between an output target value of the generator and an actual output of the generator; obtaining an additional lift amount of the pressure control valve from a relationship between the conductance of the pressure control valve and lift; and adding the additional lift amount to the lift amount. 2. A gas turbine fuel control method of controlling a lift amount of a pressure control valve provided at a piping in which fuel for a gas turbine flows, by feeding back an actually obtained differential pressure across a flow rate control valve also provided at the piping to the pressure control valve and making the differential pressure follow a desired target value of the differential pressure, the gas turbine fuel control method comprising: obtaining a mass flow rate of inflow fuel to the gas turbine that is derived from a relationship with an output of a generator connected to the gas turbine; obtaining density of the fuel by multiplying a pressure for fuel gas supply detected upstream of the pressure control valve by a proportional constant for a relationship between the pressure of the fuel gas supply and the density of the fuel; obtaining the differential pressure across the flow rate control valve by multiplying a square of the mass flow rate by the density of the fuel to obtain a product, and dividing the product by a square of a conductance of the flow rate control valve which is obtained from a controlled output for the flow rate control valve using a function between the controlled output for the flow rate control valve and the conductance of the flow rate control valve, the controlled output being calculated based on a difference between an output target value of the generator and an actual output of the generator; obtaining a conductance of the pressure control valve by dividing a product between the mass flow rate and a square root of the fuel density, by a square root of a differential pressure across the pressure control valve, the square root of the differential pressure being expressed by subtracting a pressure in a combustor casing of the gas turbine from the pressure for the fuel gas supply to obtain a pressure and further subtracting the differential pressure from the obtained pressure; determining an additional lift amount of the pressure control valve using a function between the conductance of the pressure control valve and lift; and adding the additional lift amount to the lift amount. 3. The gas turbine fuel control method according to claim 2, wherein the mass flow rate of inflow fuel to the gas turbine is expressed by a first-order progress function of an output of the generator connected to the gas turbine, and the conductance of the flow rate control valve is expressed by a first-order lag function of the controlled output for the flow rate control valve.