CN-121978071-A - Kerosene atomization gas-liquid two-phase concentration measurement method and system in coupling air inlet state

CN121978071ACN 121978071 ACN121978071 ACN 121978071ACN-121978071-A

Abstract

The invention discloses a kerosene atomization gas-liquid two-phase concentration measurement method and system in a coupling air inlet state, which comprises the steps of regulating and controlling a liquid-phase fluorescent camera to delay shooting a spray section to be measured relative to a gas-phase fluorescent camera, synchronously collecting a liquid-phase fluorescence original image and a gas-phase fluorescence original image when the oil injection pressure of an oil injector is reduced to a set pressure, carrying out image processing on the liquid-phase fluorescence original image and the gas-phase fluorescence original image, extracting contour information of liquid-phase fuel and gas-phase fuel, counting fluorescence intensity of each pixel in the contour information of the liquid-phase fuel and the gas-phase fuel, and obtaining gas-liquid two-phase concentration distribution of the spray section to be measured by establishing a linear relation between fluorescence intensity and fuel vapor concentration gas phase and between fluorescence intensity and droplet concentration.

Inventors

ZENG SHUAI
YU XILONG
ZHANG GUOPENG
SUN HAITAO
ZHANG SHAOHUA
WANG XINGGUI
PU SIYU
SUI CHENGMIN
XIE KUN
LI PENGYU

Assignees

中国航发四川燃气涡轮研究院
中国科学院力学研究所

Dates

Publication Date: 20260505
Application Date: 20260206

Claims (10)

1. The utility model provides a kerosene atomizing gas-liquid two-phase concentration measurement system under coupling inlet state which characterized in that includes: a fuel injector (1) for introducing a mixed liquid of a base fuel and a fluorescent tracer into an inlet of the fuel injector (1); The laser light source (2) comprises a gas phase laser light source (21) and a liquid phase laser light source (22), the gas phase laser light source (21) and the liquid phase laser light source (22) adjust the laser direction through the dichroic mirror (3), and the laser with the adjusted direction illuminates the spray section to be detected of the oil sprayer (1) through the optical path system (4); The image acquisition system (5) comprises a gas-phase fluorescence camera (51) and a liquid-phase fluorescence camera (52), an opening is formed in the direction opposite to the inlet of the oil sprayer (1), and a dichroic mirror (3) is arranged at the intersection position of the gas-phase fluorescence camera (51) and the liquid-phase fluorescence camera (52) so that the gas-phase fluorescence camera (51) can shoot and acquire gas-phase fluorescence signals, and the liquid-phase fluorescence camera (52) can shoot and acquire liquid-phase fluorescence signals; the time sequence controller (6) is in communication connection with the image acquisition system (5) and the laser light source (2), and the time sequence controller (6) is used for controlling the triggering time sequence of the laser light source (2) and the image acquisition system (5) so that a time point of receiving the liquid-phase fluorescence signal and a time point of receiving the gas-phase fluorescence signal have relative delay signals to separate the gas-phase fluorescence signal and the liquid-phase fluorescence signal; The data processing system (7) is used for processing the gas-phase fluorescence original image and the liquid-phase fluorescence original image acquired by the image acquisition system (5), counting the fluorescence intensity of each pixel in a spraying area of the gas-phase fluorescence original image and the liquid-phase fluorescence original image, and acquiring the gas-liquid two-phase concentration distribution of the spraying section to be detected based on the relationship between the fluorescence intensity and the concentration gas phase of the fuel vapor and the liquid phase of the liquid drop.
2. The system for measuring the concentration of the gas phase and the liquid phase of the kerosene atomization under the coupling air inlet state according to claim 1, wherein, The gas phase laser light source (21) and the liquid phase laser light source (22) are distributed in the vertical direction, the gas phase laser light source (21) and the liquid phase laser light source (22) enable laser to be transmitted towards the same horizontal direction through the dichroic mirror (3), and the gas phase laser light source (21) and the liquid phase laser light source (22) are arranged on the side face of a to-be-detected spraying path formed by mixed liquid of the base fuel oil and the fluorescent tracer; The gas phase laser light source (21) outputs 266nm laser light, and the liquid phase laser light source (22) outputs 532nm laser light; wherein the bicolor mirror (3) reflects the gas phase laser and transmits the liquid phase laser.
3. The system for measuring the concentration of the gas phase and the liquid phase of the kerosene atomization under the coupling air inlet state according to claim 2, wherein, The optical path system (4) comprises a first quartz cylindrical lens (41) for receiving the laser light source (2), and a second concave quartz lens (42) and a third quartz cylindrical lens (43) arranged between the first quartz cylindrical lens (41) and the oil injector (1); After laser emitted by the gas-phase laser light source (21) and the liquid-phase laser light source (22) sequentially pass through the first quartz cylindrical lens (41), the second concave quartz lens (42) and the third quartz cylindrical lens (43), a piece of laser is formed below a nozzle of the oil sprayer (1) so as to illuminate the spray section to be tested of the oil sprayer (1).
4. The system for measuring the concentration of the gas phase and the liquid phase of the kerosene atomization under the coupling air inlet state according to claim 1, wherein, The base fuel oil is n-undecane (C 11 H 24 ), and the fluorescent tracer is p-tetramethyl-p-phenylenediamine (TMPD) and naphthalene (Np); Para-tetramethyl-para-phenylenediamine (TMPD) naphthalene (Np) n-undecane (C 11 H 24 ) 1:9:90.
5. The system for measuring the concentration of two phases of kerosene atomization gas and liquid under the coupling air inlet state according to claim 4, wherein, The gas-phase fluorescence camera (51) and the liquid-phase fluorescence camera (52) are distributed in a non-coaxial way; The gas-phase fluorescence camera (51) is provided with a 300-400 nm band-pass filter, and the gas-phase fluorescence camera (51) is used for shooting the fluorescence of a tetramethyl p-phenylenediamine (TMPD) monomer; The liquid phase fluorescence camera (52) is configured with a 410-490 nm bandpass filter and a 532nm notch filter, and the liquid phase fluorescence camera (52) is used for capturing fluorescence of a tetramethyl-p-phenylenediamine (TMPD) -naphthalene (Np) compound and filtering 532nm laser.
6. The system for measuring the concentration of two phases of kerosene atomized gas and liquid under the coupling air inlet state according to claim 5 or 1, wherein, The gas-phase laser light source (21) and the liquid-phase laser light source (22) are simultaneously excited by the time schedule controller (6) to form laser pulses, and the liquid-phase fluorescence camera (52) is regulated and controlled by the time schedule controller (6) to have delay shooting of 20 nanoseconds relative to the gas-phase fluorescence camera (51).
7. A method for measuring the concentration of two phases of kerosene atomization gas and liquid in a coupled air inlet state, which is characterized by comprising the following steps based on the system for measuring the concentration of two phases of kerosene atomization gas and liquid in the coupled air inlet state according to any one of claims 1to 6: step 100, assembling a kerosene atomization gas-liquid two-phase concentration measurement system, and regulating and controlling the liquid-phase fluorescent camera to delay shooting of a spray section to be measured relative to the gas-phase fluorescent camera; step 200, synchronously collecting a liquid-phase fluorescence original image and a gas-phase fluorescence original image when the oil injection pressure of the oil injector is reduced to a set pressure; step 300, performing image processing on the liquid-phase fluorescence original image and the gas-phase fluorescence original image, and extracting contour information of liquid-phase fuel and gas-phase fuel; And 400, counting the fluorescence intensity of each pixel in the contour information of the liquid-phase fuel and the gas-phase fuel, and obtaining the gas-liquid two-phase concentration distribution of the spray section to be tested by establishing the linear relation between the fluorescence intensity and the gas phase of the fuel vapor concentration and between the fluorescence intensity and the droplet concentration.
8. The method for measuring the concentration of two phases of kerosene atomization gas and liquid under the coupling air inlet state according to claim 7, wherein, In the step 300, the implementation method for performing image processing on the liquid-phase fluorescence original image and the gas-phase fluorescence original image is as follows: subtracting the background of the liquid-phase fluorescence original image and the gas-phase fluorescence original image to subtract the background noise when no spraying exists; Performing geometric correction and filtering on the liquid-phase fluorescence original image and the gas-phase fluorescence original image with background noise subtracted, correcting camera view field distortion, and performing noise reduction treatment on the images to obtain a liquid-phase fluorescence noise-reduced image and a gas-phase fluorescence noise-reduced image; Automatically determining a threshold value by adopting a maximum inter-class variance method, and separating a spraying area of the liquid-phase fluorescence noise reduction image and a spraying area of the gas-phase fluorescence noise reduction image from a background; extracting contour information of the liquid-phase fuel oil and contour information of the gas-phase fuel oil by utilizing an edge detection algorithm; And counting the fluorescence intensity of each pixel of the contour information of the liquid-phase fuel and the contour information of the gas-phase fuel, and obtaining the gas-liquid two-phase concentration distribution of the spray section to be tested based on the relationship between the fluorescence intensity and the concentration gas phase of the fuel vapor and the liquid phase of the liquid drop.
9. The method for measuring the concentration of the gas phase and the liquid phase of the kerosene atomization under the coupling air inlet state according to claim 8, wherein, The linear relationship between the gas phase fluorescence intensity and the gas phase fuel density is: I v (i,j)=K v (i,j)×ρ v (i,j); Wherein I v (I, j) is the original fluorescence intensity value measured by the gas phase fluorescence camera at the pixel position (I, j); ρ v (i, j) is the local mass density of the gas phase fuel to be solved; K v (i, j) is a local calibration coefficient, reflects the fluorescence intensity generated by unit density, and is influenced by the following factors, namely the spatial distribution of the light intensity of the laser sheet, the spatial non-uniformity of the quantum efficiency and the optical transmittance of the camera, the local temperature/pressure and the fluorescence quantum yield; The calculation flow is that a fluorescence image I v cal (I, j) is acquired in a standard gas phase calibration experiment of an n-undecane steam cavity with known concentration; Knowing the calibration concentration ρ v cal , then: ; In actual measurement, the substitution formula is used for back-pushing: 。
10. The method for measuring the concentration of the gas phase and the liquid phase of the kerosene atomization under the coupling air inlet state according to claim 8, wherein, The liquid phase concentration is calibrated by adopting a mass conservation inversion method, and the specific mode is as follows: The instantaneous total oil injection mass m total is measured through a high-precision flow meter by restraining the axisymmetric assumption and mass conservation; Integrating the gas phase image, and calculating the total mass of the gas phase fuel oil by combining known K v (i, j) Wherein L is the thickness of the sheet light, and the total mass of the liquid phase is obtained ; Extracting a pixel region V_pixel occupied by liquid phase from the liquid phase fluorescence image, and converting the pixel region V_pixel into a space volume V; The average density is correlated with the average fluorescence intensity I l of the liquid phase image to obtain a proportionality coefficient K l =I l /ρ l , and finally, the liquid phase concentration of each pixel is ρ l (i,j)=I l (i,j)/K l .

Description

Kerosene atomization gas-liquid two-phase concentration measurement method and system in coupling air inlet state Technical Field The invention relates to the technical field of measurement of gas-liquid two-phase concentration of kerosene atomization, in particular to a method and a system for measuring gas-liquid two-phase concentration of kerosene atomization in a coupling air inlet state. Background Aero-engines and heavy duty gas turbines are used as the core power devices in the modern aviation and energy fields, and the performance, efficiency and emission level of the aero-engines and heavy duty gas turbines are directly related to national safety and economic pulse. The combustion chamber acts as the heart of the power plant, and the internal processes of fuel atomization, evaporation, mixing with air and final combustion and heat release are extremely complex multiphase, transient and turbulent physicochemical processes. The initial boundary condition of combustion is formed by the initial droplet size distribution, the spatial distribution and the concentration distribution of fuel vapor of the spray field formed by atomizing liquid fuel through the nozzle, so that the stability and the completeness of the subsequent combustion process and the generation level of pollutants (such as smoke dust and NOx) are fundamentally determined. Therefore, the realization of accurate measurement of the distribution of the fuel spray field, in particular the gas (fuel vapor), liquid (liquid droplets) two phases in the combustion chamber is a key premise for understanding the basic physical mechanism of combustion, verifying the numerical model and finally optimizing the design of the combustion chamber. However, achieving accurate measurements of spray fields under real engine operating conditions presents nearly severe technical challenges. Firstly, the real combustion chamber internal environment is in a high temperature (up to 2000K or more) and high pressure (several mpa) state, and in order to achieve flame stabilization and efficient combustion, a strong swirl field is usually organized, which makes the fuel spray in an extremely complex and unsteady "coupled-intake" aerodynamic environment. In this environment, the evaporation, breaking, collision of droplets, and the mutual coupling, transient changes of the oil and gas mixing process, require that the measurement technique must have extremely high temporal resolution (in the order of microseconds or even nanoseconds) and spatial resolution (in the order of micrometers) to "freeze" and resolve these transient fine structures. Second, the physical properties of the two-phase oil and gas mixing field present substantial difficulties. The liquid phase (liquid drop, liquid filament, liquid film) and the gas phase (fuel vapor) are mutually interwoven and coexist in space, and the Laser Induced Fluorescence (LIF) technology is gradually developed into a powerful tool for researching a spray field at present. Wherein planar laser induced fluorescence techniques enable two-dimensional concentration field measurements of specific components (e.g., fuel vapors). However, if only a single fluorescent tracer is used in the conventional LIF technology, because the fluorescence spectra of the gas phase (tetramethyl-p-phenylenediamine TMPD monomer) and the liquid phase (tetramethyl-p-phenylenediamine TMPD: naphthalene Np complex) have significant tail overlap, the fluorescence spectra of the gas phase and the liquid phase are not perfectly distributed in an orthogonal manner, but have tail phenomena on both sides of the respective main peaks, so that "spectral crosstalk" is caused, and the difference of fluorescence lives of the two is limited (especially, the life is shortened and approaches under the high-temperature and high-pressure environment), the single-dimensional means cannot be effectively decoupled, so that the crosstalk is serious. Disclosure of Invention The invention aims to provide a kerosene atomization gas-liquid two-phase concentration measuring method and system in a coupling air inlet state, which are used for solving the technical problems that in the prior art, fluorescence spectrums of a gas phase and a liquid phase are not ideally distributed in an orthogonal mode, tailing phenomena exist on two sides of respective main peaks, so that spectral crosstalk is caused, a single-dimensional means cannot be effectively decoupled, and crosstalk is serious. In order to solve the technical problems, the invention specifically provides the following technical scheme: A kerosene atomization gas-liquid two-phase concentration measuring system under a coupling air inlet state comprises: The fuel injector is used for guiding the mixed liquid of the base fuel and the fluorescent tracer into an inlet of the fuel injector; The laser light source comprises a gas phase laser light source and a liquid phase laser light source, the gas phase laser light source and