METHOD OF DETERMINING GAS FLOW TEMPERATURE IN COMBUSTION CHAMBER OF GAS TURBINE ENGINE WITH HYDROCARBON FUEL Russian patent published in 2020 - IPC G01J5/00 G01K13/02 

FIELD: measurement.

SUBSTANCE: invention relates to noncontact measurement of high gas flow temperatures, in particular to methods of measuring temperature of gas flow in combustion chamber and processing spectral data of optical monitoring means, and can be used for experimental studies of working process in combustion zone combustion chambers and improving operating reliability of modern aircraft and helicopter engines and power turbines. Disclosed is method of determining temperature of gas flow in combustion chamber of gas turbine engine with hydrocarbon fuel, which includes recording in the wavelength range from 400 to 800 nm of the spectrum of heat radiation of the stream of gases formed during combustion of hydrocarbon fuel, and the gas flow temperature is determined based on the temperature of soot particles present in the gas stream, which is calculated by approximating Planck's radiation law in Wien coordinates. To calculate temperature of soot particles from the detected spectrum, a region of thermal radiation of the gas stream is selected in the wavelength range from 600 to 800 nm, as per the calculated temperature of soot particles by Planck's formula, spectrum of thermal emission of soot particles is calculated. Calculated spectrum of thermal radiation of soot particles is subtracted from initial spectrum of heat radiation of gas flow, spectrum of chemoluminescence of radicals is calculated, chemiluminescence spectrum of radicals is subtracted from spectrum of heat radiation of gas flow obtained after subtraction of spectrum of thermal emission of soot particles calculated by Planck formula. Integral intensities of the series of electron-vibrational transitions are calculated, and on their basis two ratios of integral intensities of the series of electronic-oscillatory transitions are determined. According to the obtained ratios, and using expressions G (1,0) obtained using a calculation method, and G (-1.0) of ratios of integral intensities of emission bands of radicals from vibrational temperature of radicals, two values of oscillatory temperature of radicals are obtained. Obtained values of the oscillation temperature are compared to obtain the error of calculating the oscillatory temperature . Determining two new values of oscillatory temperature of radicals , calculating a value, on which it is necessary to correct temperature of soot particles using the calculated optimization function, and using the corrected temperature value of particles of soot, repeating said actions until until difference of values of vibrational temperatures of radicals becomes less than a predetermined error value, and temperature value of particles of soot T, at which this condition is met, is taken as reliable value of required temperature of gas flow.

EFFECT: technical result is increase of reliability and expansion of application area of method for determination of gas flow temperature in combustion chamber of gas turbine engine with hydrocarbon fuel based on spectrum of heat radiation of gas flow, due to the compensation calculation and spectral components corresponding to thermal radiation of the particles of soot and radicals in the composition of the total gas flow of the thermal radiation, measuring the vibrational temperature of the radicals in the visible band and determining the gas flow temperature based on the temperature of the soot particles corrected based on the vibrational temperatures of the radicals.

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