Soot Yield Measurement System and Measurement Method Based on Extinction Method of Spectrometer

Abstract

The present invention provides a measurement system and method for soot yield based on the extinction method using a spectrometer. The system receives the laser signals emitted by a He-Ne laser before and after passing through the combustion flame of aviation kerosene through the spectrometer, and then measures the soot yield during the combustion process of aviation kerosene in real time according to the change of the laser signals. By receiving the change of the laser signals of the He-Ne laser before and after passing through the flame through the spectrometer, the present invention measures the soot yield during the combustion process of hydrocarbon fuels based on the extinction method, and has the characteristics of simple structure, safety and strong practicability. It can function to detect and measure in real time the change of the soot yield during the combustion process of different aviation kerosenes such as Jet series, JP series, RP series, and JP7.

Description

Technical Field

[0001] The present invention relates to a technology in the field of aviation fuel, specifically a measurement system and method for soot yield based on the extinction method using a spectrometer, which is used for measuring the soot yield during the combustion process of hydrocarbon fuels. The experimental device for measuring the soot yield based on the spectrometer and using the extinction method is used to study the change of the soot yield during the combustion process of hydrocarbon fuels. Background Art

[0002] Hydrocarbon fuels such as Jet series, JP series, RP series, and JP7 and other different aviation kerosene often emit a large amount of soot during use. This phenomenon is attributed to the relatively large molecular weight of the heavy oil itself, resulting in difficulty in achieving complete combustion during the combustion process. Especially in cases where the engine is overloaded, the fuel atomization in some cylinders is poor, or the air supply to the cylinders is insufficient, the phenomenon of generating a large amount of black soot is more serious. The generation of soot not only reduces the energy utilization rate, but also forms carbon deposits that block the engine and cause serious air pollution. Therefore, effective measurement means are needed to detect the change of soot during the combustion process, so as to serve the search for strategies to inhibit soot generation during the effective combustion process, thereby solving the problem of generating a large amount of soot during the combustion process of heavy oil. However, the existing measurement system for soot yield based on the extinction method cannot accurately detect and measure the change of soot yield during the combustion process in real time and has a complex structure. Summary of the Invention

[0003] The purpose of the present invention is to propose a measurement system and method for soot yield based on the extinction method using a spectrometer to solve the problem that the soot yield during the combustion process of different aviation kerosene such as Jet series, JP series, RP series, and JP7 cannot be effectively measured. By receiving the change of the laser signal of the He-Ne laser before and after passing through the aviation kerosene combustion flame through the spectrometer, the soot yield during the combustion process of hydrocarbon fuels based on the extinction method is measured. It has the characteristics of simple structure, safety, and strong practicability, and has the function of being able to detect and measure the change of soot yield during the combustion process of hydrocarbon fuels in real time.

[0004] The invention purpose of the present invention is achieved through the following technical solutions:

[0005] A measurement system for soot yield based on the extinction method using a spectrometer, which receives the laser signals of the He-Ne laser emitted before and after passing through the aviation kerosene combustion flame through the spectrometer, and then measures the soot yield during the combustion process of aviation kerosene in real time according to the change of the laser signals.

[0006] As a further technical solution, the system further includes a diaphragm, a plane mirror, an optical fiber holder, an optical fiber, a spectrometer, a photomultiplier tube, a high-voltage power supply, a photon counter, and a control module. The laser emitted by the He-Ne laser passes through the diaphragm and then through the flame, and then the optical path is changed by the plane mirror and reaches the optical fiber holder. After that, it enters the spectrometer through the optical fiber. The laser signal received by the spectrometer is converted into a corresponding voltage signal by the photomultiplier tube. This voltage signal is transmitted to the photon counter, and the photon counter transmits the obtained data to the control module. The high-voltage power supply provides power for the system.

[0007] As a further technical solution, the aviation kerosene combustion flame is generated by a burner.

[0008] A method for measuring the soot yield based on the extinction method of a spectrometer, the method comprising the steps of:

[0009] (1) Diaphragm adjustment and instrument startup;

[0010] (2) Set the receiving wavelength to 632.8 nm through the control module, and then measure the initial incident light intensity I0 of the He-Ne laser without flame;

[0011] (3) Measure the transmitted light intensity I of the He-Ne laser passing through the fuel flame;

[0012] (4) Calculate the soot yield SY, where, [c] is the molar concentration of soot, [c0] is the molar concentration of carbon in the fuel, ρc is the soot concentration, λ is the laser wavelength, μc is the molar mass of carbon, L is the optical path, and m is the complex refractive index of soot.

[0013] Compared with the prior art, in the present invention, the laser emitted by the He-Ne laser passes through the diaphragm and then through the flame, and then the optical path is changed by the plane mirror and reaches the optical fiber holder and enters the spectrometer through the optical fiber. The spectrometer receives the laser signals of the He-Ne laser before and after passing through the flame, thereby measuring the change in the soot yield during the combustion process of hydrocarbon fuels based on the extinction method, realizing real-time detection and measurement of the soot yield during the combustion process of hydrocarbon fuels, having the characteristics of simple structure, safety, and strong practicability, and having the function of being able to detect and measure the change in the soot yield during the combustion process of hydrocarbon fuels in real time. Description of the Drawings

[0014] Figure 1 It is a schematic structural diagram of a soot yield measurement system based on the extinction method of a spectrometer.

[0015] Description of reference numerals: a-1 is a He-Ne laser, a-2 is a diaphragm, a-3 is a mirror, a-4 is an optical fiber holder, a-5 is an optical fiber, b is a burner, c-1 is a spectrometer, c-2 is a photomultiplier tube, c-3 is a high-voltage power supply, c-4 is a photon counter, and c-5 is a control module. Detailed implementation mode

[0016] The present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0017] Embodiment

[0018] As Figure 1 As shown, this embodiment provides a soot yield measurement system based on a spectrometer. By receiving the change of the He-Ne laser signal before and after passing through the flame by the spectrometer, the real-time measurement of the soot yield during the combustion of hydrocarbon fuels such as Jet series, JP series, RP series, and JP7 is realized. The soot yield measurement system based on the spectrometer includes: a He-Ne laser (a-1), a diaphragm (a-2), a plane mirror (a-3), an optical fiber holder (a-4), an optical fiber (a-5), a burner (b), a spectrometer (c-1), a photomultiplier tube (c-2), a high-voltage power supply (c-3), a photon counter (c-4), and a control module (c-5). The laser emitted by the He-Ne laser passes through the flame after being adjusted by the diaphragm, and then the optical path is changed by the plane mirror and enters the spectrometer through the optical fiber fixed by the optical fiber holder. The spectrometer receives the optical signal, forms a corresponding voltage signal by the photomultiplier tube, and then this signal is transmitted to the photon counter. The photon counter transmits the obtained data to the control module for calculation. In addition, the spectrometer receives the He-Ne laser signal (632.8 nm) to measure the soot yield during the combustion process.

[0019] The measurement method of the soot yield measurement system based on the spectrometer is specifically as follows:

[0020] Step 1: Diaphragm adjustment and instrument startup

[0021] Start the He-Ne laser (a-1) and adjust the spot size of the laser by adjusting the aperture size of the diaphragm (a-2). Adjust the angle of the plane mirror (a-3) to ensure that the laser can be completely injected into the optical fiber of the optical fiber holder; transmit the laser to the spectrometer through the optical fiber, and start the spectrometer (c-1), the photomultiplier tube (c-2), the high-voltage power supply (c-3), the photon counter (c-4), and the control module.

[0022] Step 2: Set the reception wavelength to 632.8 nm through the control module, and then measure the initial incident light intensity (I0) of the He-Ne laser (a-1) without flame.

[0023] Step 3: Turn on the burner (b) (the fuel to be measured, such as different aviation kerosene like Jet series, JP series, RP series, JP7, etc.) to form the flame to be measured;

[0024] Step 4: Measure the transmitted light intensity (I) of the He-Ne laser (a-1) passing through the hydrocarbon fuel flame through the control module (632.8 nm);

[0025] Step 5: Calculate the soot yield of the hydrocarbon fuel;

[0026] The evaluation of the soot yield is carried out according to the following formula: The light with a wavelength of 632.8 nm emitted by the He-Ne laser enters the soot particle cloud generated by fuel combustion through the diaphragm, and after being reflected by the plane mirror, it enters the spectral measurement system (set to receive the wavelength of 632.8 nm) to record data.

[0027] When the laser passes through the particle cloud, according to the Lambert-Beer law

[0028]

[0029] In the formula, I0 is the incident light intensity, I is the transmitted light intensity, L is the optical path (cm), and K ext is the extinction coefficient. The soot particles generated by pyrolysis are collected. The soot particles are approximately spherical. According to the Mie scattering theory, the soot volume fraction can be obtained as

[0030]

[0031] where λ is the laser wavelength and m is the complex refractive index of the soot. It is a function of the incident light wavelength. When λ = 632.8 nm, E(m) takes 0.30. From the soot volume fraction, the molar concentration of the generated soot can be obtained

[0032]

[0033] In the formula, ρc is the soot concentration, generally 1.86 g·cm -3 . μc is the molar mass of carbon, 12 g·mol -1 . Then the soot yield (soot yield, SY) can be expressed as

[0034]

[0035] Using the above system solves the problem of accurately detecting and measuring the change of soot yield in the combustion process by the extinction method soot yield measurement system. The present invention has the characteristics of simple structure, safety and strong practicability, and has the function of being able to detect and measure the change of soot yield in the combustion process of hydrocarbon fuels in real time.

[0036] Compared with the existing system, the present invention uniquely solves the problem of accurately detecting and measuring the change in soot yield during the combustion process by using a spectrometer-based extinction method to measure the soot yield of hydrocarbon fuels.

[0037] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. It should be noted that any modifications, equivalent replacements, and improvements made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims

1. A soot yield measurement system based on an extinction method using a spectrometer, characterized in that, The system receives the laser signals before and after passing through the combustion flame of aviation kerosene emitted by a He-Ne laser through a spectrometer, and then measures the soot yield in the combustion process of aviation kerosene in real time according to the change of the laser signals. The system also includes a diaphragm, a plane mirror, an optical fiber holder, an optical fiber, a spectrometer, a photomultiplier tube, a high-voltage power supply instrument, a photon counter and a control module. The laser emitted by the He-Ne laser passes through the diaphragm and then through the flame, and then the optical path is changed by the plane mirror and reaches the optical fiber holder, and then enters the spectrometer through the optical fiber. The laser signal received by the spectrometer is converted into a corresponding voltage signal by the photomultiplier tube, and this voltage signal is transmitted to the photon counter. The photon counter transmits the obtained data to the control module, and the high-voltage power supply instrument provides power for the system.

2. The soot yield measurement system based on an extinction method using a spectrometer according to claim 1, wherein The combustion flame of aviation kerosene is generated by a burner.

3. A measurement method based on the measurement system described in claim 1, characterized in that, The method includes the steps: (1) Diaphragm adjustment and instrument startup; (2) Set the receiving wavelength to 632.8 nm through the control module, and then measure the initial incident light intensity I0 of the He-Ne laser without flame; (3) Measure the transmitted light intensity I of the He-Ne laser passing through the fuel flame; (4) Calculate the soot yield SY, where, [c] is the molar concentration of soot, [c0] is the molar concentration of carbon in the fuel, ρc is the soot concentration, λ is the laser wavelength, μc is the molar mass of carbon, L is the optical path length, and m is the complex refractive index of soot.

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