Method and apparatus for detecting the presence of flame in the exhaust path of a gas turbine engine

A method of determining the state of the fuel nozzle of a gas turbine comprising the steps of:

• receiving radiant energy from the exhaust path of a gas turbine;
• transferring the radiant energy to at least one sensor capable of detecting radiant energy;
• determining an average of a baseline intensity of a normal background intensity of the radiant energy of a gas turbine known to be operating efficiently with clean fuel nozzles;
• producing an electrical signal from the at least one sensor relative to the radiant energy;
• comparing the electrical signal to the average of the baseline intensity;
• indicating when radiant energy having an intensity greater than the baseline intensity has been received from the exhaust path.

A method of determining the state of the fuel nozzle of a gas turbine, comprising the steps of:

• receiving radiant energy from the exhaust path of a gas turbine;
• transferring the radiant energy to at least one sensor capable of detecting radiant energy produced from a flame present in the exhaust;
• determining the average of the baseline intensity of the normal background intensity of the radiant energy of a gas turbine known to be operating efficiently with clean fuel nozzles;
• producing a signal from the at least one sensors when the radiant energy in the 200 nm to 800 nm range has been received from the exhaust path;
• comparing the signal of the sensor to the average of the known baseline intensity;
• and
• signaling the presence of flame when the signal produced has a relative intensity greater than that of the average baseline intensity.

A method of detecting the presence of flame in the exhaust of a turbine engine, comprising the steps of:

• gathering a light energy by a view port attached to the exhaust plenum of a turbine engine;
• transmitting said light energy by a fiber optic cable into a spectrometer through a fixed aperture;
• striking light energy against a collimating mirror in the spectrometer;
• directing said light energy from the collimating mirror at a diffraction grating;
• refracting the light energy into wavelengths by the grating;
• directing the refracted light toward a focusing mirror;
• reflecting the refracted light to strike onto a focusing mirror;
• focusing the refracted light onto a detector array comprising a plurality of detectors;
• concentrating the refracted light in front of the detector array with a lens onto an individual detector;
• responding to an individual wavelength of light that strikes a detector element (pixel) with an electrical signal;
• feeding said signal into a microprocessor;
• interpreting a signal strength and information relative to the intensity of the individual wavelengths of light as received by said detector array, and
• providing information to an end user of the gas turbine.

A method of determining the presence of flame in the exhaust of a gas turbine, comprising the steps of:

• collecting spectral energy from the exhaust portion of a gas turbine;
• transmitting said spectral energy to a sensor;
• producing an electrical signal corresponding to the intensity and presence of a flame in the exhaust;
• storing the electrical signal in a storage device;
• providing a computer processor to evaluate the electrical signal;
• and
• performing with the computer processor operations, further comprising the steps of:
• establishing a threshold level
• T
• i
• =
• 1
• α
• ⁢
• ∑
• n
• =
• i
• +
• 1
• α
• +
• i
• ⁢
• X
• n
• 2
• +
• NT
• ⁢
• ❘
• i
• =
• 0
• ∞
• wherein α=running average interval, n=discrete sample
• number, NT=noise threshold;
• determining a sample intensity value
• SI
• i
• =
• 1
• α
• ⁢
• ∑
• n
• =
• i
• +
• 1
• α
• +
• i
• ⁢
• X
• n
• 2
• ⁢
• ❘
• i
• =
• 0
• ∞
• wherein α=running average interval, n=discrete sample number;
• freezing the threshold level until the sample intensity value gets below the threshold level;
• establishing an ending point of the flash interval
• B
• =
• SI
• i
• >
• T
• i
• ⁢
• ❘
• i
• =
• 0
• ∞
• ;
• establishing a total integrated intensity value
• E
• =
• SI
• i
• <
• T
• frozen
• ⁢
• ❘
• i
• =
• 0
• ∞
• ;
• establishing a total time captured for the flash interval
• I
• =
• ∑
• B
• E
• ⁢
• SI
• i
• -
• T
• frozen
• ⁢
• ❘
• i
• =
• 0
• ∞
• ⁢
• ⁢
• C
• =
• ∑
• B
• E
• ⁢
• i
• ⁢
• ❘
• i
• =
• 0
• ∞
• ;
• and
• establishing a peak intensity value
• P
• =
• SI
• i
• ⁢
• max
• ⁢
• ❘
• i
• =
• 0
• ∞
• ;
• wherein the results of operations T1, SI1, B, E, I, C and P produced are stored in a memory device.