Soot aerosol generating device and working method thereof

Abstract

The invention relates to a soot aerosol generating device and a working method thereof. The device comprises a soot aerosol generating system and a gas supply system. The soot aerosol generating system comprises an oxidizing gas laminar flow cavity, a combustion cavity and a cooling and uniform mixing cavity; the oxidizing gas laminar flow cavity is provided with an oxidizing gas inlet and a fuel gas conveying pipe; a laminar flow plate is arranged at the lower end of the oxidizing gas laminar flow cavity; a plurality of laminar flow holes are formed in the laminar flow plate; the gas outlet end of the fuel gas conveying pipe penetrates through the oxidation gas laminar flow cavity and then extends into the combustion cavity, and a bluff body combustion head is installed at the gas outlet end of the fuel gas conveying pipe. Based on the diffusion flame combustion process of the organic fuel under different combustion conditions, soot aerosols with different particle sizes and different concentrations can be generated in a wide range, and the generated soot aerosols are stable in physicochemical property and can be used in multiple fields such as instrument test calibration and combustion characteristic research.

Description

Technical Field

[0001] The invention relates to the technical field of atmospheric aerosol monitoring, and in particular to a carbon smoke aerosol generating device and a working method thereof. Background Art

[0002] Particle pollution in the air affects the health of billions of people around the world. A review of European data from 2000 to 2012 showed that soot particles emitted by motor vehicles are one of the main causes of particulate pollution, with 20% of PM coming from road transport. Therefore, issues such as the climate effects and health impacts of soot particles in the air have always been one of the international research hotspots.

[0003] Since the soot particles directly from motor vehicle exhaust have the disadvantages of unstable and uncontrollable particle size distribution, concentration and chemical composition, researchers have developed other schemes to produce stable and controllable soot particles for soot particle property research, instrument calibration, etc. Although the existing soot particle generation scheme has a considerable improvement in the properties of motor vehicle exhaust particles directly, there are still some shortcomings. The particles generated by the graphite generator based on spark discharge or laser ablation have a large difference in structure from the soot particles generated by motor vehicle exhaust. U.S. Patent Document US20150283533 A1 discloses a CAST burner based on the quenching principle, which generates particles with slightly poor repeatability and contains more volatile impurities on the surface. Chinese Patent Document CN 115069178 A discloses a carbon particle generation device with controllable concentration and particle size, which is also based on the quenching principle of the upright flame, but the entire device has a complex structure and cannot generate soot particles with larger particle sizes. Chinese patent document CN 112999989 B discloses a black carbon aerosol generator, which is bulky, poorly portable, and has poor adjustability of the particle size of the generated soot particles. Chinese patent CN 103983738 B discloses a low-pressure environment combustion device, which is only for optical research of soot particles and cannot sample and analyze the generated soot particles.

[0004] In view of the above problems, it is necessary to realize a carbon smoke aerosol generating device and a working method thereof. Summary of the invention

[0005] In order to solve the deficiencies in the prior art, an object of the present invention is to provide a carbon smoke aerosol generating device and a working method thereof.

[0006] To achieve the above object, the present invention adopts the following technical solutions:

[0007] A carbon smoke aerosol generating device comprises a carbon smoke aerosol generating system.

[0008] The carbon smoke aerosol generating system comprises an oxidizing gas laminar flow chamber, a combustion chamber and a cooling and mixing chamber which are arranged in sequence and connected; the oxidizing gas laminar flow chamber is provided with an oxidizing gas inlet and a fuel gas delivery pipe; a laminar flow plate is provided at the lower end of the oxidizing gas laminar flow chamber; a plurality of laminar flow holes are provided on the laminar flow plate; the gas outlet end of the fuel gas delivery pipe extends into the combustion chamber after passing through the oxidizing gas laminar flow chamber, and a blunt body burner head is installed at the gas outlet end of the fuel gas delivery pipe.

[0009] The blunt body burner head comprises a burner head main body; the burner head main body is provided with a first through hole and a plurality of second through holes evenly distributed along the periphery of the first through hole; the first through hole is provided in the middle position of the burner head main body and is coaxially arranged with the burner head; the second through hole is arranged at an angle.

[0010] Furthermore, the oxidizing gas laminar flow chamber includes an oxidizing gas laminar flow chamber body and an oxidizing gas laminar flow chamber end cover installed at the upper end opening of the oxidizing gas laminar flow chamber body; a fuel gas inlet is installed on the oxidizing gas laminar flow chamber end cover; the inlet end of the fuel gas delivery pipe is installed on the oxidizing gas laminar flow chamber end cover and is connected to the fuel gas inlet.

[0011] Furthermore, the device also includes a gas supply system; the gas supply system includes an oxidizing gas supply source and a fuel gas supply source; the oxidizing gas supply source is connected to the oxidizing gas inlet; the fuel gas supply source is connected to the fuel gas inlet.

[0012] Furthermore, the gas supply system also includes an oxidizing gas flow control unit and a fuel gas flow control unit; the oxidizing gas flow control unit is arranged on the pipeline between the oxidizing gas inlet and the oxidizing gas supply source; the fuel gas flow control unit is arranged on the pipeline between the fuel gas inlet and the fuel gas supply source.

[0013] Furthermore, the combustion chamber adopts a quartz tube; the upper and lower ends of the combustion chamber are respectively provided with a first protective cover and a second protective cover.

[0014] Furthermore, the oxidizing gas laminar flow chamber is installed on the first protective cover; the combustion chamber and the cooling and mixing chamber are both installed on the second protective cover; a channel is provided on the second protective cover; the channel is used to connect the combustion chamber and the cooling and mixing chamber; a sampling port is provided on the cooling and mixing chamber.

[0015] Furthermore, a plurality of support rods are arranged between the first protective cover and the second protective cover.

[0016] Furthermore, a sheath flow exhaust port is provided on the second protective cover.

[0017] Furthermore, the second protective cover is installed on a tray, and a supporting foot pad is provided between the tray and the second protective cover.

[0018] The present invention also includes a working method of the above-mentioned carbon smoke aerosol generating device, the method comprising the following steps:

[0019] S1. Remove the structural components consisting of the fuel gas inlet, the oxidizing gas inlet, the oxidizing gas laminar flow cavity end cover, the oxidizing gas laminar flow cavity, the fuel gas delivery pipe and the blunt body burner head from the first protective sleeve;

[0020] S2, adjusting and setting the fuel gas flow control unit and the oxidizing gas flow control unit to target fuel gas flow and target oxidizing gas flow, and introducing the fuel gas and oxidizing gas into the two gas paths respectively;

[0021] S3, hold the structural part, bring the outlet of the blunt-body burner head close to the ignition source for ignition;

[0022] S4, after the ignition is completed, the structural component is reset so that the structural component is installed on the first protective cover;

[0023] S5, the fuel gas and the oxidizing gas meet at the outlet of the blunt body burner after passing through the fuel gas delivery pipe and the oxidizing gas laminar flow cavity respectively and undergo diffusion combustion, generating soot particles, and the combustion flame presents an inverted structure;

[0024] S6. The soot particles are carried into the cooling and mixing chamber under the action of the laminar oxidizing gas. The volatile substances and water vapor on the surface of the soot particles are cooled and stabilized in the cooling and mixing chamber, so that the particle size and concentration of the soot particles remain stable.

[0025] S7. After cooling and stabilization, the soot particles are discharged from the sampling port for sampling and analysis.

[0026] Furthermore, the soot particles in the combustion flame are generated in a vertical distribution, and the vertical distribution includes hydrocarbon molecules polymerized at the root of the combustion flame to form polycyclic aromatic hydrocarbons, soot monomer particles in the middle of the combustion flame, and soot aggregate particles at the tip of the combustion flame;

[0027] Due to the inverted flame structure, the generated soot particles move from the flame root to the flame tip under the interaction of the downward airflow force and the upward thermal buoyancy, and form a particle stagnation plane at the flame tip, causing the soot particles to further aggregate and grow.

[0028] The method further includes:

[0029] By adjusting the composition of the fuel gas, the composition of the oxidant gas and the ratio of the fuel gas to the oxidant gas, flame combustion under different equivalence ratios can be achieved, thereby adjusting the particle size and concentration of the generated soot particles.

[0030] Compared with the prior art, the advantages of the present invention are:

[0031] (1) The present invention is based on the diffusion flame combustion process of organic fuel under different combustion conditions, and can generate carbon soot aerosols of different particle sizes and concentrations in a wide range. The generated carbon soot aerosols have stable physical and chemical properties and can be used in multiple fields such as instrument testing and calibration, combustion characteristics research, etc.

[0032] (2) The carbon particle generating device described in the present invention can accurately control the flow supply of fuel gas and oxidizing gas through a flow control unit, thereby avoiding the problem of unstable carbon soot aerosol generation caused by flow fluctuations; and the composition and ratio of the fuel gas and oxidizing gas can be adjusted arbitrarily, so as to meet the generation of carbon soot aerosols with different physical and chemical properties such as particle size and concentration.

[0033] (3) The carbon particle generating device of the present invention adopts an inverted combustion structure. The generated carbon soot particles slowly move from the flame root to the flame tip and are discharged from the flame under the interaction of the downward airflow force and the upward thermal buoyancy force, thereby effectively preventing the problem of flame flickering caused by the same-direction thermal buoyancy and airflow force, thereby greatly improving the flame stability and carbon soot particle generation stability. The present invention adopts a diffusion flame combustion method, and the fuel gas and the oxidizing gas are supplied separately, which is highly safe and the flame state is easy to observe.

[0034] (4) The carbon particle generating device described in the present invention has a combustion head with a blunt body structure, so that part of the high-temperature airflow generates a reflux motion when the flame burns, thereby serving as a self-compensating continuous ignition source to stabilize the flame combustion, thereby preventing the flame from flickering and improving the stability of particle generation; by adopting a laminar flow plate, the oxidizing gas flows downward in a laminar flow state, thereby ensuring the high stability of the flame; by designing a cooling and mixing chamber, the volatile substances and water vapor on the surface of the soot particles can be cooled and stabilized in the cooling and mixing chamber, so that the particle size and concentration of the soot particles can remain stable during sampling and analysis; by setting a sheath flow exhaust port, excess laminar oxidizing gas can be discharged, and the flame asymmetry caused by the change in the airflow state at the bottom of the quartz tube combustion chamber can be effectively prevented. The carbon particle generating device described in the present invention has simple ignition operation, high success rate, and the entire device is small in size and portable. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 It is a structural schematic diagram of the carbon particle generating device in the present invention;

[0036] Figure 2 It is an axonometric view of the carbon smoke aerosol generating device of the present invention;

[0037] Figure 3 It is an axonometric cross-sectional view of the blunt body burner head of the present invention;

[0038] Figure 4 The figure is a combustion flame morphology diagram of the soot aerosol generating device of the present invention under a certain combustion condition;

[0039] Figure 5 The particle size distribution diagram of soot particles generated by the soot aerosol generating device of the present invention under certain combustion conditions;

[0040] Figure 6 The average result and error band diagram of 8 particle size spectrum measurement results of soot particles generated by the soot aerosol generating device of the present invention under the same combustion conditions;

[0041] Figure 7 This is a comparison diagram of electron microscope photos of soot particles generated by the soot aerosol generating device of the present invention and soot particles emitted from motor vehicle exhaust.

[0042] in:

[0043] 1-1, fuel gas supply source; 1-2, oxidizing gas supply source; 1-3, fuel gas flow control unit; 1-4, oxidizing gas flow control unit; 1-5, fuel gas inlet; 1-6, oxidizing gas inlet; 1-7, oxidizing gas laminar flow chamber end cover; 1-8, oxidizing gas laminar flow chamber; 1-9, fuel gas delivery pipe; 1-10, porous laminar flow net; 1-11, first protective cover; 1-12, quartz tube combustion chamber; 1-13, blunt body combustion head; 1-14, support rod; 1-15, second protective cover; 1-16, sheath flow exhaust port; 1-17, support foot pad; 1-18, tray; 1-19, cooling and mixing chamber; 1-20, sampling port; 2-1, first through hole; 2-2, second through hole. DETAILED DESCRIPTION

[0044] The present invention will be further described below in conjunction with the accompanying drawings:

[0045] like Figure 1 and Figure 2 A carbon soot aerosol generating device is shown, comprising a gas supply system and a carbon soot aerosol generating system.

[0046] like Figure 1 and Figure 2As shown, the carbon soot aerosol generating system includes an oxidizing gas laminar flow chamber 1-8, a combustion chamber and a cooling and mixing chamber 1-19 which are arranged in sequence and connected. The oxidizing gas laminar flow chamber 1-8 is provided with an oxidizing gas inlet 1-6 and a fuel gas delivery pipe 1-9. The carbon soot aerosol generated by the system is discharged from the sampling port 1-20 at the end of the cooling and mixing chamber 1-19, and the laminar flow plate provided at the bottom end of the oxidizing gas laminar flow chamber 1-8 is a porous laminar flow net 1-10. A laminar flow plate is provided at the lower end of the oxidizing gas laminar flow chamber 1-8; a plurality of laminar flow holes are provided on the laminar flow plate, and the dense hole design makes the oxidizing gas entering the quartz tube combustion chamber 1-12 present a laminar flow state, thereby preventing the generation of turbulence in the quartz tube combustion chamber 1-12, thereby keeping the flame highly stable.

[0047] The present invention is based on an inverted flame combustion chamber design. Through the inverted flame design, the flickering instability problem in the combustion process of the traditional forward combustion flame is solved. The design of the blunt body burner head 1-13, the oxidizing gas laminar flow chamber 1-8, and the sheath flow exhaust port 1-16 effectively improves the stability of the combustion flame. Combined with the design of the cooling and mixing chamber 1-19, the problem of changes in particle size and surface properties caused by rapid condensation of OC and water vapor on the surface of the generated soot particles is solved, and the particle size and concentration stability of the generated particles are effectively improved.

[0048] In some embodiments, the gas outlet end of the fuel gas delivery pipe 1-9 passes through the oxidizing gas laminar flow chamber 1-8 and then extends into the combustion chamber, and a blunt body burner head 1-13 is installed at the gas outlet end of the fuel gas delivery pipe 1-9. Through the design of the blunt body burner head 1-13, part of the high-temperature airflow generates reflux movement during flame combustion, thereby serving as a self-compensating continuous ignition source to stabilize flame combustion, thereby preventing flame flickering and improving particle generation stability.

[0049] In some embodiments, the oxidizing gas laminar flow chamber 1-8 includes an oxidizing gas laminar flow chamber body and an oxidizing gas laminar flow chamber end cover 1-7 installed at the upper end opening of the oxidizing gas laminar flow chamber body; a fuel gas inlet 1-5 is installed on the oxidizing gas laminar flow chamber end cover 1-7; an inlet end of the fuel gas delivery pipe 1-9 is installed on the oxidizing gas laminar flow chamber end cover 1-7 and is communicated with the fuel gas inlet 1-5.

[0050] In some embodiments, the combustion chamber adopts a quartz tube; the upper and lower ends of the combustion chamber are respectively provided with a first protective cover 1-11 and a second protective cover 1-15. The oxidation gas laminar flow chamber end cover 1-7 and the oxidation gas laminar flow chamber body are connected and fixed to each other by screws to form an oxidation gas laminar flow chamber 1-8, and the oxidation gas laminar flow chamber 1-8 is detachably mounted on the upper end of the first protective cover 1-11 by long screws. The combustion chamber made of a quartz tube is clamped between the first protective cover 1-11 and the second protective cover 1-15, and is supported and connected by three support rods 1-14. The design of the combustion chamber made of quartz material facilitates the observation of the flame combustion state; the design of the protective cover and the support rod 1-14 plays the role of sealing the quartz tube combustion chamber 1-12 and connecting and supporting the first protective cover 1-11 and the second protective cover 1-15.

[0051] In some embodiments, the oxidizing gas laminar flow chamber 1-8 is installed on the first protective cover 1-11; the combustion chamber and the cooling and mixing chamber 1-19 are both installed on the second protective cover 1-15; a channel is provided on the second protective cover 1-15; the channel is used to connect the combustion chamber and the cooling and mixing chamber 1-19; and a sampling port 1-20 is provided on the cooling and mixing chamber 1-19. The cooling and mixing chamber 1-19 is used to cool and stabilize the volatile OC and water vapor on the surface of the generated soot particles, prevent the particle size and surface properties from changing under unstable conditions, and improve the stability of the generated particles.

[0052] In some embodiments, a sheath flow exhaust port 1-16 is provided on the second protective cover 1-15. Through the design of the sheath flow exhaust port 1-16, excess laminar oxidizing gas can be discharged, and the occurrence of flame asymmetry caused by changes in the airflow state at the bottom of the quartz tube combustion chamber 1-12 can be effectively prevented.

[0053] In some embodiments, the second protective cover 1-15 is mounted on a tray 1-18, and a support pad 1-17 is provided between the tray 1-18 and the second protective cover 1-15. The tray 1-18 and the support pad 1-17 are used for heat insulation and support of upper components such as the combustion chamber.

[0054] like Figure 1 and Figure 2As shown, the gas supply system includes an oxidizing gas supply source 1-2 and a fuel gas supply source 1-1; the oxidizing gas supply source 1-2 is connected to the oxidizing gas inlet 1-6; the fuel gas supply source 1-1 is connected to the fuel gas inlet 1-5. The gas supply system also includes an oxidizing gas flow control unit 1-4 and a fuel gas flow control unit 1-3; the oxidizing gas flow control unit 1-4 is arranged on the pipeline between the oxidizing gas inlet 1-6 and the oxidizing gas supply source 1-2; the fuel gas flow control unit 1-3 is arranged on the pipeline between the fuel gas inlet 1-5 and the fuel gas supply source 1-1.

[0055] The fuel gas supply source 1-1 can be a pure combustible gas such as propane, ethylene, etc., or a mixture of a combustible gas and a non-combustible gas such as nitrogen; the oxidizing gas supply source 1-2 can be clean air or a mixture of oxygen and nitrogen in a certain ratio. By adjusting the ratio of combustible gas to non-combustible gas in the fuel gas and the ratio of clean air or oxygen to nitrogen in the oxidizing gas, the particle size and concentration of the generated soot particles can be regulated.

[0056] like Figure 3 As shown, the blunt body burner head 1-13 includes a burner head body; the burner head body is provided with a first through hole 2-1 and a plurality of second through holes 2-2 evenly distributed along the outer periphery of the first through hole 2-1; the first through hole 2-1 is provided in the middle of the burner head body and is coaxially arranged with the burner head; the second through hole 2-2 is inclined. Specifically, there is an axial first through hole 2-1 at the outlet center of the blunt body burner head 1-13, and 6 second through holes 2-2 having a certain angle with the first through hole 2-1 are evenly arranged around the first through hole 2-1. Through this structural design, a low-pressure area is formed at the blunt body outlet, which causes the high-temperature airflow at the flame tip to produce a reflux motion, thereby serving as a continuous ignition source to ignite the fuel gas and prevent the flame flickering phenomenon caused by the unstable temperature in the flame.

[0057] The working method of the above-mentioned carbon smoke aerosol generating device is:

[0058] S1. Place the carbon smoke aerosol generator on a horizontal tabletop and away from flammable materials. Loosen and remove the three fixing screws connecting the oxidation gas laminar flow chamber 1-8 and the first protective cover 1-11. Remove the structural parts consisting of the fuel gas inlet 1-5, the oxidation gas inlet 1-6, the oxidation gas laminar flow chamber end cover 1-7, the oxidation gas laminar flow chamber 1-8, the fuel gas delivery pipe 1-9 and the blunt body burner head 1-13.

[0059] S2. Adjust and set the fuel gas flow control unit 1-3 and the oxidizing gas flow control unit 1-4 to target fuel gas flow and oxidizing gas flow, and introduce the fuel gas and oxidizing gas into the gas channels respectively.

[0060] S3. Hold the structural part and bring the outlet of the blunt-body burner head 1-13 close to the ignition source for ignition.

[0061] S4. After the ignition is completed, the structural parts are reset, and three fixing screws connecting the oxidation gas laminar flow cavity 1-8 and the first protective cover 1-11 are installed and tightened.

[0062] S5, the fuel gas and the oxidizing gas meet at the outlet of the blunt body burner head 1-13 after passing through the fuel gas delivery pipe 1-9 and the oxidizing gas laminar flow cavity 1-8 respectively and diffuse combustion occurs, and the combustion flame presents an inverted structure.

[0063] At this time, the soot particles in the flame have a vertical distribution characteristic, which is specifically manifested as the polymerization of hydrocarbon molecules at the root of the flame to form polycyclic aromatic hydrocarbons, to the soot monomer particles in the middle of the flame, and then to the soot aggregate particles at the tip of the flame. Due to the inverted flame structure, the generated soot particles slowly move from the root of the flame to the tip of the flame under the interaction of the downward airflow force and the upward thermal buoyancy, and form a particle stagnation plane at the tip of the flame, which promotes the further aggregation and growth of the soot particles.

[0064] The flame stability is observed through the quartz tube combustion chamber 1-12. The laminar oxidizing gas in the quartz tube combustion chamber 1-12 keeps the flame highly stable. The design of the blunt body burner head 1-13 allows part of the high-temperature airflow to produce reflux movement during flame combustion, thereby serving as a self-compensating continuous ignition source to stabilize flame combustion, thereby preventing flame flickering and improving particle generation stability. The sheath flow exhaust port 1-16 is designed to discharge excess laminar oxidizing gas and effectively prevent flame asymmetry caused by changes in the airflow state at the bottom of the quartz tube combustion chamber 1-12;

[0065] S6. The generated soot particles are carried into the cooling and mixing chamber 1-19 under the action of the laminar oxidizing gas. The volatile substances and water vapor on the surface of the soot particles are cooled and stabilized in the cooling and mixing chamber 1-19, so that the particle size and concentration of the soot particles remain stable.

[0066] S7. After cooling and stabilization, the soot particles are discharged from sampling ports 1-20 for sampling and analysis.

[0067] like Figure 4 As shown, the combustion flame morphology photos of the above-mentioned carbon soot aerosol generating device under certain combustion conditions were recorded. The specific combustion conditions are: ethylene is selected as the fuel gas, clean air is used as the oxidizing gas, the ethylene flow rate is set to 130mL / min, and the clean air flow rate is set to 8000mL / min.

[0068] like Figure 5As shown, the particle size distribution of soot particles generated by the above-mentioned soot aerosol generating device under several combustion conditions was measured. Here, an optional combustion condition is given: a mixed gas of ethylene and nitrogen is selected as the fuel gas, clean air is used as the oxidizing gas, the flow rate of ethylene is set in the range of 80-170mL / min, the flow rate of nitrogen is set in the range of 80-170mL / min, and the flow rate of clean air is set in the range of 8000-15000mL / min. Within this flow rate range, by adjusting different ratios of ethylene, nitrogen and clean air, a soot aerosol with a peak particle size of 61.5-310.6nm can be generated, and the distribution presents an approximately normal distribution.

[0069] like Figure 6 As shown, the particle size spectrum of the soot particles generated by the above-mentioned soot aerosol generator when it is continuously running under the same combustion conditions is measured 8 times, and the mean and error of all measurement results are calculated, with an interval of 15 minutes between each measurement. The specific combustion conditions are: ethylene is selected as the fuel gas, clean air is used as the oxidizing gas, the flow rate of ethylene is set to 140mL / min, and the flow rate of clean air is set to 10000mL / min. The results show that the relative standard deviation of the particle size of the soot aerosol generated by the soot aerosol generator in Example 1 is ≤3.21%, and the relative standard deviation of the concentration is ≤0.91%, indicating that the generator has excellent soot aerosol generation stability under long-term operation.

[0070] like Figure 7 As shown, the electron microscope photos of the soot particles generated by the soot aerosol generating device are compared with the soot particles emitted from the exhaust gas of a motor vehicle. The left picture is a TEM photo of the soot particles emitted from the exhaust gas of a motor vehicle, and the right picture is a SEM photo of the soot particles generated by the soot aerosol generating device. The results show that the soot particles generated by the soot aerosol generating device of the present invention have the same polymer structure as the soot particles emitted from the exhaust gas of a motor vehicle.

[0071] Generally speaking, the method of generating soot particles by an inverted flame combustion structure proposed in the present invention is a brand-new soot particle generation scheme, which is different from the existing domestic and foreign schemes listed in the background technology. Although some detailed designs are common technical features, these designs are all for the service of the overall generation scheme, in order to achieve a better scheme effect, rather than a simple technical patchwork. The working method of the soot aerosol generating device described in the present invention provides a detailed description of the soot particle generation process and principle, which is also the innovation of the present invention. The present invention proposes an inverted flame combustion structure, combined with the design of a blunt body burner head 1-13, an oxidizing gas laminar flow chamber 1-8, a sheath flow exhaust port 1-16, and a cooling mixing chamber 1-19. Compared with the traditional soot particle generation method, the particle size and concentration stability of the generated soot particles are greatly improved, which plays an important role in the calibration of equipment such as the particle number concentration and particle mass concentration of motor vehicle exhaust.

[0072] The above-described embodiments are merely descriptions of preferred implementations of the present invention and are not intended to limit the scope of the present invention. Without departing from the design spirit of the present invention, various modifications and improvements made to the technical solutions of the present invention by ordinary technicians in this field should all fall within the scope of protection determined by the claims of the present invention.

Claims

1. A carbon smoke aerosol generating device, characterized in that: The device includes a soot aerosol generating system; The carbon smoke aerosol generating system comprises an oxidizing gas laminar flow chamber (1-8), a combustion chamber (1-12) and a cooling and mixing chamber (1-19) which are arranged in sequence and are connected; the oxidizing gas laminar flow chamber (1-8) is provided with an oxidizing gas inlet (1-6) and a fuel gas delivery pipe (1-9); a laminar flow plate is provided at the lower end of the oxidizing gas laminar flow chamber (1-8); a plurality of laminar flow holes are provided on the laminar flow plate; the gas outlet end of the fuel gas delivery pipe (1-9) passes through the oxidizing gas laminar flow chamber (1-8) and then extends into the combustion chamber (1-12), and a blunt body combustion head (1-13) is installed at the gas outlet end of the fuel gas delivery pipe (1-9); The blunt body burner head (1-13) comprises a burner head body; the burner head body is provided with a first through hole (2-1) and a plurality of second through holes (2-2) evenly distributed along the periphery of the first through hole (2-1); the first through hole (2-1) is provided in the middle of the burner head body and is coaxially arranged with the burner head body; the second through hole (2-2) is arranged obliquely.

2. The carbon smoke aerosol generating device according to claim 1, characterized in that: The oxidizing gas laminar flow chamber (1-8) comprises an oxidizing gas laminar flow chamber body and an oxidizing gas laminar flow chamber end cover (1-7) installed at the upper end opening of the oxidizing gas laminar flow chamber body; The oxidation gas laminar flow cavity end cover (1-7) is provided with a fuel gas inlet (1-5); The air inlet end of the fuel gas delivery pipe (1-9) is mounted on the oxidation gas laminar flow cavity end cover (1-7) and communicates with the fuel gas air inlet port (1-5).

3. The carbon smoke aerosol generating device according to claim 1, characterized in that: The device also includes a gas supply system; The gas supply system comprises an oxidizing gas supply source (1-2) and a fuel gas supply source (1-1); the oxidizing gas supply source (1-2) is connected to the oxidizing gas inlet (1-6); the fuel gas supply source (1-1) is connected to the fuel gas inlet (1-5); The gas supply system further comprises an oxidizing gas flow control unit (1-4) and a fuel gas flow control unit (1-3); the oxidizing gas flow control unit (1-4) is arranged on a pipeline between the oxidizing gas inlet (1-6) and the oxidizing gas supply source (1-2); and the fuel gas flow control unit (1-3) is arranged on a pipeline between the fuel gas inlet (1-5) and the fuel gas supply source (1-1).

4. The carbon smoke aerosol generating device according to claim 1, characterized in that: The combustion chamber (1-12) adopts a quartz tube; A first protective sleeve (1-11) and a second protective sleeve (1-15) are respectively provided at the upper and lower ends of the combustion chamber (1-12).

5. The carbon smoke aerosol generating device according to claim 4, characterized in that: The oxidizing gas laminar flow chamber (1-8) is installed on the first protective cover (1-11); The combustion chamber (1-12) and the cooling and mixing chamber (1-19) are both installed on the second protective sleeve (1-15); The second protective sleeve (1-15) is provided with a channel; the channel is used to connect the combustion chamber (1-12) and the cooling and mixing chamber (1-19); The cooling and mixing chamber (1-19) is provided with a sampling port (1-20).

6. The carbon smoke aerosol generating device according to claim 4, characterized in that: A plurality of support rods (1-14) are arranged between the first protective cover (1-11) and the second protective cover (1-15).

7. The carbon smoke aerosol generating device according to claim 4, characterized in that: The second protective sleeve (1-15) is provided with a sheath flow exhaust port (1-16).

8. The carbon smoke aerosol generating device according to claim 1, characterized in that: The second protective cover (1-15) is installed on the tray (1-18), and a supporting foot pad (1-17) is provided between the tray (1-18) and the second protective cover (1-15).

9. The working method of the carbon smoke aerosol generating device according to any one of claims 4 to 8, characterized in that: The method comprises the following steps: S1. Remove the structural components consisting of the fuel gas inlet (1-5), the oxidizing gas inlet (1-6), the oxidizing gas laminar flow cavity end cover (1-7), the oxidizing gas laminar flow cavity (1-8), the fuel gas delivery pipe (1-9) and the blunt body burner head (1-13) from the first protective sleeve (1-11); S2, adjusting and setting the fuel gas flow control unit (1-3) and the oxidizing gas flow control unit (1-4) to target fuel gas flow and target oxidizing gas flow, and respectively introducing the fuel gas and oxidizing gas into the two gas paths; S3, holding the structural member, bringing the outlet of the blunt body burner head (1-13) close to the ignition source for ignition; S4, after the ignition is completed, the structural component is reset so that the structural component is installed on the first protective cover (1-11); S5, the fuel gas and the oxidizing gas respectively pass through the fuel gas delivery pipe (1-9) and the oxidizing gas laminar flow cavity (1-8), meet at the outlet of the blunt body burner head (1-13) and undergo diffusion combustion, generating soot particles, and the combustion flame presents an inverted structure; S6, the soot particles are carried into the cooling and mixing chamber (1-19) under the action of the laminar oxidizing gas, and the volatile substances and water vapor on the surface of the soot particles are cooled and stabilized in the cooling and mixing chamber (1-19), so that the particle size and concentration of the soot particles remain stable; S7. The cooled and stabilized soot particles are discharged from the sampling port (1-20) for sampling and analysis.

10. The working method of the carbon smoke aerosol generating device according to claim 9, characterized in that: The soot particles in the combustion flame are generated in a vertical distribution, and the vertical distribution includes hydrocarbon molecules at the root of the combustion flame polymerizing to form polycyclic aromatic hydrocarbons, soot monomer particles in the middle of the combustion flame, and soot aggregate particles at the tip of the combustion flame; Due to the inverted flame structure, the generated soot particles move from the flame root to the flame tip under the interaction of the downward airflow force and the upward thermal buoyancy, and form a particle stagnation plane at the flame tip, causing the soot particles to further aggregate and grow; The method further includes: By adjusting the composition of the fuel gas, the composition of the oxidant gas and the ratio of the fuel gas to the oxidant gas, flame combustion under different equivalence ratios can be achieved, thereby adjusting the particle size and concentration of the generated soot particles.

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