An experimental system for analyzing combustion of aluminum powder at different concentrations

Abstract

The application discloses an experimental system for analyzing combustion of aluminum powder with different concentrations, and belongs to the field of aluminum powder combustion experiments.The application comprises a multi-element diffusion flat flame burner, an aerosol generator and an optical diagnosis system.The multi-element diffusion flat flame burner and the aerosol generator are placed in a high-pressure bin, and gas paths are connected.The high-pressure bin is closed, combustion gas is introduced from the lower part of the burner, oxidizing gas is introduced from the upper part of the burner, mixing is carried out in a capillary, and the capillary mouth is reached.The multi-element diffusion flat flame burner simulates the high-temperature gas phase environment and component atmosphere in a real combustion device through gas distribution, carries out particle ignition and combustion characteristic test through central supply of aerosol, and has good optical visualization conditions.The aerosol generator is used to generate relatively uniform monodisperse aluminum powder aerosol from a powder generator without using a vibration device.The optical diagnosis system obtains temperature information of combustion through various means, carries out comparison, and increases accuracy of experimental data.

Description

TECHNICAL FIELD

[0001] The application relates to an experimental system for analyzing aluminum powder combustion at different number concentrations, and relates to an experimental system using a jet impact type aerosol generator and a multi-element diffusion flat flame burner, and belongs to the field of aluminum powder combustion experiments. BACKGROUND

[0002] Solid rocket engines have many advantages such as simple structure, large thrust density, high technical maturity, convenient storage and maintenance, and are one of the most widely used rocket propulsion systems at present. In order to improve the specific impulse of the solid rocket engine, metal powder is usually added to the solid propellant to improve the energy level, and the addition of 10-20% of aluminum powder by mass fraction can produce more than 30% of heat, and the aluminum powder combustion process and its products have a relatively complex influence on the solid engine.

[0003] On the other hand, a new type of powder rocket engine directly using aluminum powder particles as fuel has the advantages of relatively simple structure, adjustable thrust, multiple start-ups, and wide environmental temperature applicability, and can be used in the fields of supersonic missiles, space propulsion and underwater propulsion.

[0004] The experimental system for studying the ignition and combustion of aluminum particles mainly includes a single particle laser ignition system and a monodisperse aerosol flat flame combustion system. The aluminum particle combustion characteristic parameters include important information such as ignition temperature, ignition delay time, combustion time, particle surface temperature, geometric structure of gas phase flame and condensed phase products. However, in general experimental devices, the environmental temperature of aluminum powder combustion is not controllable, and the temperature field distribution is not uniform, which affects the accuracy of the experimental results. SUMMARY

[0005] The purpose of the present application is to provide an experimental system for analyzing aluminum powder combustion at different number concentrations. The multi-element diffusion flat flame burner simulates the high-temperature gas phase environment and component atmosphere in the real combustion device by gas distribution, carries out particle ignition and combustion characteristic test by central gas aerosol supply, and has good optical visualization conditions. The aerosol generator is used to generate relatively uniform monodisperse aluminum powder aerosol without using a vibration device. The optical diagnosis system obtains temperature information of combustion by multiple means, compares and increases the accuracy of experimental data.

[0006] The purpose of the present application is achieved by the following technical solutions.

[0007] The application discloses an experimental system for analyzing aluminum powder combustion at different number concentrations, which comprises a multi-element diffusion flat flame burner, an aerosol generator and an optical diagnosis system.

[0008] The multi-element diffusion flat flame burner body structure is divided into a lower part of the burner and an upper part of the burner. The lower part of the burner is supplied with fuel gas through the gas inlets around the periphery, and the upper part of the burner is supplied with oxidizing gas through the gas inlets around the periphery. The upper part of the burner is provided with a large number of capillary tubes for forming a diffusion flame array. The fuel gas and the oxidizing gas reach the vicinity of each capillary tube outlet through the capillary tubes and are ignited to form tiny methane diffusion flames. Hundreds of small flames form an approximately planar diffusion flame array, and a high-temperature zone with uniform temperature and controllable gas phase components is formed in the flame after zone. The number and position of the large number of capillary tubes are determined according to the requirements and constraints of the diffusion flame array.

[0009] The aerosol generator comprises an aerosol generating device, a flat capacitor, an air flow cover, a metal bolt, and a high-voltage direct current power supply. The aerosol generating device is mainly used to disperse aluminum particles in a gas environment and spray them out with a predetermined gas. The upper plate of the flat capacitor is used as the upper end cover of the air flow cover, and the lower plate is fixed inside the air flow cover through the metal bolt penetrating the bottom surface of the air flow cover, so that the internal space of the flat capacitor is enclosed in the air flow cover. The bottom of the air flow cover is provided with an air inlet hole for the gas to enter the inside of the aerosol generator. The gas entering the air flow cover is sprayed out through the nozzle of the upper plate of the flat capacitor, forming a gas passage through the internal space of the flat capacitor. The negative electrode of the high-voltage direct current power supply is connected to the upper plate of the flat capacitor, and the positive electrode is connected to the metal bolt fixing the lower plate. By applying high-voltage electricity to charge the capacitor, a directional electric field is formed between the plates, and the particles on the lower plate are charged. The charged particles are affected by the electric field force and move away from the lower plate and towards the upper plate. When the particles contact the upper plate, the charge disappears and returns to the lower plate under the action of gravity. The particles continue to move repeatedly during charging and discharging, thereby forming a stable aerosol between the plates of the flat capacitor. The particle number density in the aerosol is adjusted by adjusting the strength of the direct current power supply and the distance between the plates, and theoretically a single particle can be transported one by one. The particles carried by the airflow between the plates are sprayed out of the nozzle of the upper plate, forming an aerosol jet, and the aluminum particles are transported into the burner.

[0010] The optical diagnostic system comprises a high-speed microscopic photography system, an emission spectrum system, and a colorimetric temperature measurement system. The high-speed microscopic photography system is used for online observation of the agglomeration and ignition process of the aluminum particles on the propellant combustion surface. The emission spectrum system is used for measuring wide spectrum data. The colorimetric temperature measurement system measures temperature information by colorimetry.

[0011] Further, the high-speed microscopic photographing system comprises a high-speed camera and a long-focus return type microscope lens, and a spatial resolution of 10 μm is achieved by the combination of the high-speed camera and the long-focus return type microscope lens; the high-speed camera can reach a frame rate of 10000 at a resolution of 600*800 pixels, and the exposure time can be as low as 10 μs. Therefore, the high-speed microscopic photographing system is used for online observation of the agglomeration of aluminum particle on the propellant combustion surface and the ignition process. The high-speed camera can be matched with a common microscope lens or even an industrial-grade microscope lens. When the magnification is set to 1:1, the resolution of the high-speed camera can approach 10-20 μm, and the micro flame structure observation of a larger single particle or particle group can be satisfied.

[0012] The emission spectrum system mainly comprises a portable fiber-optic spectrometer. A fiber-optic probe is connected to a collimator installed on a fixing base. The recording interval of the spectrometer is 0.25 nm, the actual resolution is 0.4 nm, wide spectrum data can be quickly collected in the wavelength range of 200-1100 nm, and the collection frequency can reach 100 Hz.

[0013] The colorimetric temperature measurement system adopts a colorimetric method to measure temperature information. The colorimetric method is a colorimetric method based on a single color digital camera, and has convenience and economy. The digital camera adopts three channels of RGB to record color information. After the equipment is individually calibrated, the temperature information is obtained based on the camera calibration data and the measured emission coefficient variation law with temperature according to the formula:

[0014]

[0015] The integral ratio of radiation intensity at different temperatures is calculated, and a contrast curve or table is established. After the colorimetric data of the measured object are obtained, the curve or table is searched and linear interpolation is performed to obtain the temperature information.

[0016] The working method of the experimental system for analyzing combustion of aluminum powder with different number concentrations disclosed in the application is as follows: a multi-element flat flame burner and an aerosol generator are placed in a high-pressure bin, and various gas paths are connected, a high-speed camera, a spectrometer and a digital camera are placed; the high-pressure bin is closed, combustion gas is introduced from the lower part of the burner, oxidizing gas is introduced from the upper part of the burner, mixing is carried out in a capillary, and the mixed gas reaches the capillary port; a laser igniter is started, the capillary port is ignited, and an approximately planar diffusion flame array is formed; the aerosol generator is started, aluminum particles are dispersed in the gas environment, safety gas is introduced, the aluminum powder is carried out by the safety gas to form a particle density stable particle carrying gas flow, and the aluminum particles are transported into the burner; the flow of the combustion gas is gradually reduced, the flow of the oxidizing gas is changed, the flow of the aluminum particles is changed by changing the flow of the safety gas, until the flow of the combustion gas is 0, the aluminum particle combustion flame is stable, the flow of the oxidizing gas and the flow of the safety gas at this time are recorded, the real-time flame state is recorded through the quartz observation window by using the high-speed camera, the spectrum data are recorded by using the spectrometer, and the real-time picture is taken by using the digital camera. Since the fuel gas and the oxidizing gas introduced into the burner in the radial direction and the gas-solid mixed fuel introduced into the burner in the axial direction are all introduced into the burner in the form of a jet, the generation of turbulence and backflow is reduced. The particle number density in the aerosol generator is adjusted by adjusting the intensity of the direct current voltage and the distance between the plates, and single particles are sequentially transported. Through the experiment in the high-pressure bin, the high-pressure gas phase environment in the real combustion device is simulated in real time. By using the multi-element diffusion burner, the high-temperature gas phase environment and the component atmosphere in the real combustion device are simulated. The temperature information of the combustion is obtained by using a high-speed microscopic photography system, an emission spectrum system and a colorimetric temperature measurement system, comparison is carried out, and the accuracy of the experimental data is increased.

[0017] Advantages:

[0018] 1. The experimental system for analyzing combustion of aluminum powder with different number concentrations disclosed in the application controls the aluminum particle concentration by using an aerosol powder feeder, the charged particles continuously and repeatedly move in the process of charging and discharging, so that a stable aerosol can be formed in the capacitor plate. The particle number density in the aerosol can be adjusted by adjusting the intensity of the direct current voltage and the distance between the plates, and single particles are sequentially transported. While controlling the aluminum particle concentration, a relatively uniform monodisperse aluminum powder aerosol can also be generated, and a particle density stable particle carrying gas flow is formed. After being introduced into the burner, the problem of flameout caused by too small particle density can be avoided, and the problem of deposition and slagging caused by too large particle density can also be avoided. In the subsequent processing of experimental data, the problem of uneven distribution in space caused by the fluctuation of the aluminum particle density can also be reduced.

[0019] 2, The experimental system for analyzing the combustion of aluminum powder with different number concentrations disclosed in the application simulates a high-temperature complex oxidizing environment by using a flat flame burner, a large number of capillary tubes are added to the upper part of the burner to form an approximate planar diffusion flame array, compared with the flat flame premixed burner, the multi-element diffusion burner does not have tempering risk and has wider temperature and component adjustment capability. The flat flame burner simulates the high-temperature gas phase environment and component atmosphere in the real combustion device by gas distribution, cooperates with the central supply aerosol generator to perform particle ignition and combustion characteristic test, and has good optical visualization conditions. The adjustment range and optical diagnosis environment of the burner are fully utilized to control the temperature of aluminum particle combustion, which is convenient for analyzing the influence of a wide range of temperature on aluminum particle combustion and reducing the error caused by large temperature fluctuation on experimental data.

[0020] 3, The experimental system for analyzing the combustion of aluminum powder with different number concentrations disclosed in the application, the axial fuel jet can carry solid-phase fuel particles by using the safe gas jet, and the stable injection of aluminum particles can be realized by adjustment. By changing the flow rate and flow velocity of the axial jet, the powder flow can be controlled. By changing the flow rate and velocity of the radial inflow and the axial jet, the residence time of the particles in the combustion chamber can be controlled. The mutual impact of the radial inflow and the solid-phase fuel particles carried by the safe gas jet is beneficial to the full mixing of the fuel and the oxidizer, which can effectively improve the combustion efficiency of the fuel (especially the combustion efficiency of the solid-phase fuel particles with high melting point and difficult ignition and combustion), and further form a high-temperature multiphase combustion gas with high combustion efficiency.

[0021] 4, The experimental system for analyzing the combustion of aluminum powder with different number concentrations disclosed in the application, based on the spectral temperature measurement and colorimetric temperature measurement of the portable device, the high-speed microscopic camera system can observe the microstructure of the aluminum particle (group) combustion process online, can clearly analyze the distribution characteristics of the aluminum particle (group) and the combustion flame structure, and is convenient for monitoring and analyzing the combustion mode of the aluminum particle group formed in the high-temperature oxidizing atmosphere. BRIEF DESCRIPTION OF DRAWINGS

[0022] Figure 1 It is a device schematic diagram of the experimental system for analyzing the combustion of aluminum powder with different number concentrations.

[0023] Among them: 1-high voltage power supply, 2-aluminum powder, 3-aerosol powder feeder, 4-high pressure bin, 5-multi-element flat flame burner, 6-spectrometer, 7-high-speed camera, 8-digital camera, 9-laser igniter, 10-quartz observation window. DETAILED DESCRIPTION

[0024] In order to better illustrate the purpose and advantages of the present application, the content of the application will be further described below in combination with the drawings and examples.

[0025] As Figure 1As shown in the embodiment, the experimental system for analyzing the combustion of aluminum powder with different concentrations comprises a high-voltage power supply 1, an aerosol powder feeder 3, a high-pressure bin 4, a multi-element flat flame burner 5, a spectrometer 6, a high-speed camera 7, a digital camera 8, and a laser igniter 9.

[0026] The working method of the experimental system for analyzing the combustion of aluminum powder with different concentrations comprises the following steps: placing the multi-element flat flame burner 5 and the aerosol generator 3 in the high-pressure bin 4, connecting the gas pipeline of the aerosol generator 3, connecting the two gas pipelines of the multi-element flat flame burner 5, and connecting the aerosol generator 3 and the high-voltage power supply 1. Placing the high-speed camera 7, the spectrometer 6, and the digital camera 8. Sealing the high-pressure bin and checking whether the gas pipelines are well sealed. First, the combustion gas is introduced into the multi-element flat flame burner 5 I, the oxidizing gas is introduced into the multi-element flat flame burner 5 II, and the mixture is mixed in the capillary tube and reaches the capillary tube opening. Starting the laser igniter 9 to ignite at the capillary tube opening to form an approximately planar diffusion flame array. Turning on the high-voltage power supply 1 and starting the aerosol generator 3 to disperse aluminum particles in the gas environment. The safe gas is introduced to carry the aluminum powder to form a particle density stable particle carrying gas flow, and the aluminum particles are transported into the multi-element flat flame burner 5. Gradually reducing the flow rate of the combustion gas, changing the flow rate of the oxidizing gas, and changing the flow rate of the aluminum particles by changing the flow rate of the safe gas until the flow rate of the combustion gas is 0, the aluminum particle combustion flame is stable, the flow rate of the oxidizing gas and the flow rate of the safe gas are recorded at this time, the real-time flame state is recorded by the high-speed camera 7 through the quartz observation window 10, the spectral data are recorded by the spectrometer 6, and the real-time pictures are taken by the digital camera 8. Since the fuel gas and the oxidizing gas introduced into the burner in the radial direction and the gas-solid mixed fuel introduced into the burner in the axial direction are all introduced into the multi-element flat flame burner 5 in the form of jets, the generation of turbulence and backflow can be effectively reduced. The particle number density in the aerosol generator 3 can be adjusted by adjusting the intensity of the direct current voltage and the distance between the electrodes, and theoretically, single particles can be transported one by one. Through the experiment in the high-pressure bin 4, the high-pressure gas phase environment in the real combustion device is simulated in real time. By using the multi-element diffusion burner 5, the high-temperature gas phase environment and the component atmosphere in the real combustion device are simulated. It has good visualization conditions and can use various optical diagnosis methods.

[0027] Step 1: Introduce safe gas for a period of time to clean the high-pressure bin, and discharge the waste gas of the last experiment. Placing the multi-element flat flame burner 5 and the aerosol generator 3 in the high-pressure bin 4, connecting the gas pipeline of the aerosol generator 3, connecting the two gas pipelines of the multi-element flat flame burner 5, and connecting the aerosol generator 3 and the high-voltage power supply 1. Placing the high-speed camera 7 and connecting it with the computer, the spectrometer 6 and the computer, and the digital camera 8. Sealing the high-pressure bin and checking whether the gas pipelines are well sealed.

[0028] Step 2: Connect the flow meters of combustion gas, oxidizer gas, and safety gas to the pipeline, and adjust to the closed position. Open the corresponding gas cylinders of combustion gas, oxidizer gas, and safety gas, and open the pressure reducing valves at the outlets of each cylinder to set the downstream pressure to 2 MPa. Introduce safety gas to increase the pressure of high-pressure chamber 4 to 3 MPa as indicated by the pressure digital display.

[0029] Step 3: Open the valve control position of the oxidizer gas flow meter and adjust the flow to 22.3 L / min to introduce oxidizer gas from multi-element flat flame burner 5 II. Open the valve control position of the combustion gas flow meter and adjust the flow to 4.5 L / min to introduce combustion gas from multi-element flat flame burner 5 I, mix in the capillary tube, and reach the capillary tube outlet. Start the laser igniter 9 to ignite at the capillary tube outlet to form an approximately planar array of diffusion flames. Turn on the high-voltage power supply 1 to start the aerosol generator 3 to disperse aluminum particles in the gas environment. Open the flow meter of safety gas and adjust the flow to 0.25 L / min to introduce safety gas, which carries 45 μm aluminum powder to form a stable particle-laden gas stream, and transports the aluminum particles to the multi-element flat flame burner 5. Gradually change the flow of combustion gas, the flow of oxidizer gas, and the flow of aluminum particles by changing the flow of safety gas, and observe the aluminum particle combustion flame under different operating conditions.

[0030] Step 4: Use Nikon D300s digital camera and high-speed microscopic photography system to record the combustion of aluminum particles. The high-speed microscopic photography system includes a Phantom VEO 410E high-speed camera and a Questar long-focus fold-back microscope lens, which can achieve a spatial resolution of 10 μm. The high-speed camera can achieve a frame rate of 10000 at a resolution of 600*800 pixels, and the exposure time can be as low as 10 μs. The high-speed camera is used to take pictures at a frame rate of 2000 fps and an exposure time of 0.5 ms, and the particle volume number density is estimated to be about 30-40 cm -3 According to the known exposure time image, the particle velocity can be estimated by the ratio of trace length to exposure time, and the velocity of 45 μm aluminum particles is calculated to be 3-4 m / s.

[0031] Step 5: Use Ocean Optic's HR4000CG-UV-NIR fiber optic spectrometer to collect single-point spectra of burning particles. The wavelength resolution is 0.25 nm, and the spatial resolution of the collimator is 5 mm. Fitting the detected spectrum to the Planck law in the logarithmic formula can obtain the particle surface temperature.

[0032] Step 6: Colorimetric thermometry using a Nikon D300s digital camera, which can perform two-dimensional temperature measurement based on the colorimetric thermometry of the digital camera, but since the traditional camera is not designed for scientific detection, it needs to be calibrated.

[0033] Step 7: Close the aerosol generator 3, gradually reduce the flow of the safety gas until 0, and place the safety gas flow meter in the closed file. Gradually reduce the flow of the fuel gas until 0, and the flame is extinguished. Gradually reduce the flow of the oxidizing gas until 0, and place the fuel gas and oxidizing gas flow meters in the closed file. Close the gas cylinders, depressurize the high-pressure chamber 4, and vent the entire pipeline. When the pressure of the high-pressure chamber 4 is 0, open the high-pressure chamber 4, remove the multi-element flat flame burner 5 and the aerosol generator 3, and the experiment is complete.

[0034] In this embodiment, the fuel gas introduced into the burner 5 I from the bottom of the high-pressure chamber 4 is methane, the oxidizing gas introduced into the burner 5 II from the bottom of the high-pressure chamber 4 is oxygen, and the gas introduced into the aerosol generator 3 from the bottom of the high-pressure chamber 4 is nitrogen.

[0035] The above description further details the purpose, method, device scheme and advantages of the present application. It should be understood that the above description is only a specific implementation process of the present application, which is used to explain the present application and does not limit the protection scope of the present application. Any modification, equivalent replacement, improvement, etc. within the spirit and principles of the present application should be included in the protection scope of the present application.

Claims

1. An experimental system for analyzing the combustion of aluminum powder with different number concentrations, characterized in that: This includes a multi-element diffusion flat flame burner, an aerosol generator, and an optical diagnostic system; The main structure of the multi-element diffusion flat flame burner is divided into two parts: the lower part of the burner and the upper part of the burner. The lower part of the burner is supplied with fuel gas through the gas flow inlets around the perimeter, while the upper part of the burner is supplied with oxidizing gas through the gas flow inlets around the perimeter. The upper part of the burner is equipped with a large number of capillaries for forming a diffusion flame array. The fuel gas and oxidizing gas reach the vicinity of the outlet of each capillary tube through the capillary tubes and are ignited to form a tiny methane diffusion flame. Hundreds of small flames form a near-planar diffusion flame array, creating a high-temperature zone with relatively uniform temperature and controllable gas phase composition in the back flame zone. The aerosol generator includes an aerosol generating device, a parallel-plate capacitor, an airflow hood, metal bolts, and a high-voltage DC power supply. The aerosol generating device is mainly used to disperse aluminum particles in a gaseous environment and to carry them out by a predetermined gas. The upper plate of the parallel-plate capacitor serves as the upper end cover of the airflow hood, and the lower plate is fixed inside the airflow hood by metal bolts penetrating the bottom surface of the airflow hood, thus sealing the internal space of the parallel-plate capacitor within the airflow hood. An air inlet is provided at the bottom of the airflow hood for gas to enter the aerosol generator. The gas entering the airflow hood is ejected through a nozzle on the upper plate of the parallel-plate capacitor, forming a gas passage through the internal space of the parallel-plate capacitor. The negative terminal of the high-voltage DC power supply is connected to the upper plate of the parallel-plate capacitor... The upper plate is connected, and the positive electrode is connected to the metal bolt that fixes the lower plate. High voltage is applied to charge the parallel plate capacitor, forming a directional electric field between the plates, which simultaneously charges the particles on the lower plate. The charged particles are driven away from the lower plate by the electric field and move to the upper plate. When the particles come into contact with the upper plate, their charge disappears and they return to the lower plate under the influence of gravity. The particles continue to move repeatedly during the charging and discharging process, forming a stable aerosol between the plates of the parallel plate capacitor. The particle number density in the aerosol is adjusted by regulating the intensity of the DC power supply and the distance between the plates. The airflow between the plates carries the particles out through the nozzle on the upper plate, forming an aerosol jet that delivers the aluminum particles into the burner. The optical diagnostic system includes a high-speed microscopic imaging system, an emission spectroscopy system, and a colorimetric temperature measurement system. The high-speed microscopic imaging system is used for online observation of the agglomeration and ignition process of aluminum particles on the propellant combustion surface. The emission spectroscopy system is used to measure broadband data. The colorimetric temperature measurement system uses colorimetry to measure temperature information. The high-speed microscopy system includes a high-speed camera and a long-focal-length telescope lens. The combination of the high-speed camera and the long-focal-length telescope lens achieves a spatial resolution of 10 μm. The high-speed camera can achieve a frame rate of 10,000 at a resolution of 600*800 pixels, and the exposure time can be as low as 10 μs. The emission spectroscopy system consists of a portable fiber optic spectrometer; the fiber optic probe is connected to a collimator mounted on a fixed base; the spectrometer has a recording interval of 0.25 nm and an actual resolution of 0.4 nm, and can quickly acquire broadband data in the wavelength range of 200–1100 nm, with an acquisition frequency of up to 100 Hz. The colorimetric temperature measurement system uses a colorimetric method to measure temperature information. This colorimetric method is based on a single color digital camera. The digital camera records color information using RGB three channels. After individual calibration of the device, based on the camera calibration data and the measured emissivity variation with temperature, the system uses the following formula: Calculate the integral ratio of radiation intensity at different temperatures and establish a reference curve or table; after obtaining the colorimetric data of the object being measured, find the curve or table and perform linear interpolation to obtain the temperature information; A multi-stage flat-flame burner and an aerosol generator were placed in a high-pressure chamber, connected to various gas paths, and equipped with a high-speed camera, spectrometer, and digital camera. The high-pressure chamber was sealed, and combustion gas was introduced from the bottom of the burner while oxidizing gas was introduced from the top. The mixture was passed through a capillary tube and reached the capillary opening. A laser igniter was activated, igniting the mixture at the capillary opening to form a near-planar diffusion flame array. The aerosol generator was then activated, dispersing aluminum particles in the gaseous environment. A safety gas was introduced, carrying aluminum powder and forming a stable particle-carrying gas flow that transported the aluminum particles to the burner. The flow rates of the combustion gas, oxidizing gas, and safety gas were gradually decreased to alter the flow rate of the aluminum particles until the combustion gas flow rate reached zero, at which point the aluminum particle combustion flame stabilized. The flow rates of the oxidizing gas and safety gas at this point were recorded. The flow rate was monitored by observing the flame in real time through a quartz window using a high-speed camera, recording spectral data using a spectrometer, and capturing real-time images using a digital camera. Since the fuel gas and oxidizing gas introduced radially into the burner, along with the gas-solid mixture introduced axially, were all jet-introduced, turbulence and backflow were reduced. The particle number density in the aerosol generator was adjusted by regulating the DC voltage intensity and the distance between the plates, enabling sequential delivery of single particles. Experiments in a high-pressure chamber simulated the high-pressure gas phase environment of a real combustion device in real time. A multi-element diffusion burner was used to simulate the high-temperature gas phase environment and component atmosphere of a real combustion device. Combustion temperature information was obtained and compared using a high-speed microscopic imaging system, an emission spectroscopy system, and a colorimetric temperature measurement system to increase the accuracy of the experimental data.

2. The experimental system for analyzing the combustion of aluminum powder with different number concentrations as described in claim 1, characterized in that: When the magnification ratio is set to 1:1, the resolution of the high-speed camera is 10–20 μm.

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