State determining device, operation controlling device, gas turbine, and state determining method

Abstract

A state determining device determines a state of a gas turbine connected to an electric generator. The gas turbine includes a compressor that compresses intake air into compression air, a fuel supply device that supplies fuel, a combustor that mixes the compression air supplied from the compressor and the fuel supplied from the fuel supply device and combusts a resultant mixture to generate combustion gas, and a turbine that is rotated with the generated combustion gas.

1 . A state determining device that determines a state of a gas turbine connected to an electric generator, the gas turbine comprising a compressor that compresses intake air into compression air, a fuel supply device that supplies fuel, a combustor that mixes the compression air supplied from the compressor and the fuel supplied from the fuel supply device and combusts a resultant mixture to generate combustion gas, and a turbine that is rotated with the generated combustion gas, the state determining device comprising:
 an instruction-value detecting unit that detects a difference in an instruction value related to an output of the gas turbine;   an output detecting unit that detects a difference in an output of the electric generator; and   a determining unit that determines an operation of the gas turbine has departed from a predetermined relation when a difference between the difference in the instruction value and the difference in the output is equal to or larger than a threshold.   
     
     
         2 . The state determining device according to  claim 1 , wherein the instruction value is a fuel-flow instruction value of fuel to be supplied from the fuel supply device to the combustor. 
     
     
         3 . The state determining device according to  claim 1 , wherein
 the instruction-value detecting unit detects a difference between a detected instruction value and an instruction value detected at a last time, and   the output detecting unit detects a difference between a detected output and an output detected at a last time.   
     
     
         4 . An operation controlling device comprising:
 the state determining device according to  claim 1 ; and   a controlling device that controls the gas turbine on a basis of the instruction value and the output of the electric generator.   
     
     
         5 . The operation controlling device according to  claim 4 , wherein the controlling device changes a value of the detected output of the electric generator to a value with smaller fluctuation when the state determining device has determined that an operation of the gas turbine departs from a predetermined relation. 
     
     
         6 . The operation controlling device according to  claim 5 , wherein the controlling device uses a value at a last time as a value of the output of the electric generator when the state determining device has determined that an operation of the gas turbine departs from a predetermined relation. 
     
     
         7 . The operation controlling device according to  claim 4 , wherein the controlling device changes a calculated value to a value with smaller fluctuation on a basis of a value of the output of the electric generator when the state determining device has determined that an operation of the gas turbine departs from a predetermined relation. 
     
     
         8 . A gas turbine comprising:
 a compressor that compresses intake air into compression air;   a fuel supply device that supplies fuel;   a combustor that mixes the compression air supplied from the compressor and the fuel supplied from the fuel supply device and combusts a resultant mixture to generate combustion gas;   a turbine that is rotated with the generated combustion gas; and   the operation controlling device according to  claim 4 .   
     
     
         9 . A state determining method that determines a state of a gas turbine connected to an electric generator, the gas turbine comprising a compressor that compresses intake air into compression air, a fuel supply device that supplies fuel, a combustor that mixes the compression air supplied from the compressor and the fuel supplied from the fuel supply device and combusts a resultant mixture to generate combustion gas, and a turbine that is rotated with the generated combustion gas, the state determining method comprising steps of:
 detecting a difference in an instruction value related to an output of the gas turbine;   detecting a difference in an output of the electric generator; and   determining that an operation of the gas turbine has departed from a predetermined relation when a difference between the difference in the instruction value and the difference in the output is equal to or larger than a threshold.