초록 ▼

A combined cycle power plant includes gas and steam turbines, gas turbine afterburners, steam generators, and a digital/analog control system. A megawatt load control system varies a fuel control signal to govern a detected power output according to a reference value, the fuel control signal determi

A combined cycle power plant includes gas and steam turbines, gas turbine afterburners, steam generators, and a digital/analog control system. A megawatt load control system varies a fuel control signal to govern a detected power output according to a reference value, the fuel control signal determining the flow rate of fuel to a gas turbine. An afterburner is connected to heat the exhaust gas from the gas turbine. Both the gas turbine and the afterburner are adapted to use gas and liquid fuels. During gas turbine fuel transfer, the gas and liquid fuel flows are controlled in response to the fuel control signal to compensate power output disturbances that typically result from various nonlinearities of fuel system elements. Afterburner fuel transfer is initiated upon completion of gas turbine transfer. During afterburner transfer, the output signals of a temperature controller that otherwise determine the positions of the afterburner fuel control valves are interrupted, and a burner supervisor generates such signals to transfer afterburner fuel flow at a desired flow rate. Upon completion of transfer the burner supervisor returns control of the fuel valve positions to the controller, which resumes control bumplessly.

대표청구항 ▼

A coordinated fuel transfer system for an afterburner in a combined cycle power plant, said afterburner being adapted to use first and second fuels to heat the exhaust gas of a gas turbine which is rotatably coupled to drive an electric generator, said system comprising, first means to control a flo

A coordinated fuel transfer system for an afterburner in a combined cycle power plant, said afterburner being adapted to use first and second fuels to heat the exhaust gas of a gas turbine which is rotatably coupled to drive an electric generator, said system comprising, first means to control a flow of the first fuel to the afterburner in accordance with an input fuel to the afterburner in accordance with an input signal to said first means, second means to control a flow of the second fuel to the afterburner in accordance with an input signal to said second means, means to generate first and second selection signals, the first selection signal being generated when the desired afterburner fuel is the first fuel, and the second selection signal being generated when the desired afterburner fuel is the second fuel, means to detect a power plant temperature that is related to a flow of the first or the second fuel to the afterburner and to generate a signal representative of the detected temperature, means to generate a signal representative of a desired value of the temperature that is detected by said temperature detecting means, a controller to generate first and second fuel demand signals associated with the respective first and second fuels, said controller being responsive to a difference between the desired and detected temperature signals to vary the fuel demand signals associated with the fuel flowing to the afterburner to reduce such difference, and means to transmit the generated first and second fuel demand signals to the respective inputs of said first and second control means, said transmitting means being responsive to the first and second selection signals to interrupt such transmission upon generation of one of the first and second selection signals, and following such interruption to generate input signals to said first and second control means for controlling the flows of the first and second fuels to ignite the desired fuel from the existing fuel, and following such ignition to terminate the flow of the existing fuel and to restore the generated first and second fuel demand signals to the inputs of said first and second control means.