A carbon particle generating device and method with controllable concentration and particle size

Abstract

A carbon particle generating device and method with controllable concentration and particle size according to the present invention includes a carbon particle generating device, a particle dilution and mixing device, a buffer and shunt device, a bipolar corona charging device, a particle size classification device, and a Faraday cup electrometer connected in sequence. The carbon particle generating device includes a nitrogen inlet, an oxygen inlet, a fuel gas inlet, an anti-backfire chamber, a capillary nozzle, an oxygen buffer chamber, a combustion chamber, and a cooling chamber. The fuel gas inlet is connected to a flow meter, a solenoid valve, and a fuel gas source in sequence and is internally connected to the anti-backfire chamber. The present invention effectively improves the safety of equipment use. An annular nozzle is provided at the mixing point of oxygen and fuel gas, allowing oxygen to be ejected from the annular nozzle to evenly wrap the fuel gas ejected from the central nozzle, making the mixing more sufficient and improving the combustion efficiency. Coupled with the real-time monitoring of the temperature in the combustion chamber, a carbon particle generating environment with controllable particle size and concentration can be provided for other instruments to measure.

Description

Technical Field

[0001] The present invention relates to the technical field of atmospheric aerosol monitoring, and particularly to a carbon particle generation device and method with controllable concentration and particle size. Background Art

[0002] Currently, in the context of the "dual-carbon" goal, reducing carbon emissions has become a consensus. However, most of the carbon related to our life and production currently comes from fossil fuels such as coal and oil, and these fuels will bring carbon emissions during the combustion process. Therefore, accurate monitoring of carbon emissions and the development of carbon emission monitoring equipment are crucial for the realization of the "dual-carbon" goal. Among them, the monitoring of carbon particles is a key part of the realization of the "dual-carbon" goal. For this reason, the development of a carbon particle emission device is of great significance for the research of black carbon aerosols, the calibration and testing of carbon particle monitoring equipment, the testing of soot sensors and smoke alarms, and the testing of the filtration performance of filter materials. However, for the simulation of soot particle emissions, existing technologies have proposed some combustion schemes to generate carbon particles, but there is a lack of technical solutions for the stable generation of carbon particle concentration and particle size. Moreover, the existing commercial instrument, the scanning electrical mobility particle sizer, although it can measure particle size and concentration values, its design can only meet the measurement of ambient air and cannot meet the measurement of high-concentration soot particles (high-concentration soot particles are likely to contaminate the particle size classification and particle counting units in the scanning electrical mobility particle sizer). Therefore, it is necessary to design a soot particle generation device that can control particle size and concentration and can be monitored to ensure the stability of carbon particles during the measurement period. Summary of the Invention

[0003] A carbon particle generation device and method with controllable concentration and particle size proposed by the present invention can overcome the deficiencies of the prior art. By using real-time monitoring, it can provide a carbon particle generation environment with controllable particle size and concentration for other instruments to measure.

[0004] To achieve the above object, the present invention adopts the following technical solutions:

[0005] A carbon particle generation device with controllable concentration and particle size includes a carbon particle generation device, a particle dilution and mixing device, a buffer and shunt device, a bipolar corona charging device, a particle size classification device, and a Faraday cup electrometer. The gas outlet of the soot particle generation device is connected to the gas inlet to be diluted of the particle dilution and mixing device through a steel pipe; the gas outlet of the particle dilution and mixing device is connected to the total flow inlet of the buffer and shunt device through a steel pipe; the second outlet of the buffer and shunt device is connected to the gas inlet of the sampling device in the bipolar corona charging device through a steel pipe; the gas outlet of the bipolar corona charging device is connected to the gas inlet of the particle size classification device through a steel pipe; the gas outlet of the particle size classification device is connected to the gas inlet of the Faraday cup electrometer through a steel pipe;

[0006] The carbon particle generating device includes a nitrogen inlet, an oxygen inlet, a fuel gas inlet, an anti-backfire chamber, a capillary nozzle, an oxygen buffer chamber, a combustion chamber, and a cooling chamber; the fuel gas inlet is sequentially connected to a flowmeter, a solenoid valve, and a fuel gas source, and is internally connected to the anti-backfire chamber;

[0007] A spring and a cushion block are provided in the anti-backfire chamber, and the other end is connected to the combustion chamber through a capillary nozzle; the oxygen inlet is sequentially connected to a flowmeter, a solenoid valve, and an oxygen source, and directly leads to the oxygen buffer chamber. There is an annular slit between the oxygen buffer chamber and the combustion chamber, and the annular slit wraps the capillary nozzle; heating wires and temperature probes are provided on the side wall of the combustion chamber, and the front end of the heating wire extends to the outlet of the capillary nozzle; the nitrogen inlet is sequentially connected to a flowmeter, a solenoid valve, and a nitrogen source, and directly leads to the cooling chamber; a round hole is provided between the combustion chamber and the cooling chamber.

[0008] Further, the particle dilution mixer includes a gas to be diluted inlet, a compressed air inlet, a compressed air buffer chamber, and a dilution mixing chamber; the compressed air inlet is sequentially connected to a flowmeter, a solenoid valve, and a compressed air source, and the compressed air passes through the compressed air buffer chamber and then enters the dilution mixing chamber; a slit is provided between the buffer chamber and the dilution mixing chamber.

[0009] Further, the buffer diverter includes a total flow inlet, a buffer chamber, a first outlet, a second outlet, and a third outlet; the total flow inlet admits the gas to be diverted, and after being buffered in the buffer chamber, it evenly flows out from the three outlets; the first outlet is connected to the device to be measured, the second outlet is connected to the bipolar corona charging device, and the third outlet is connected to the high-efficiency filter.

[0010] Further, the bipolar corona charging device includes a cyclone cutter, a charger housing, a first steel pipe, a second steel pipe, a charging area, a positive and negative discharge area, a metal mesh, a positive discharge needle, a negative discharge needle, an insulating mounting seat, a positive high-voltage source, and a negative high-voltage source; the cyclone cutter includes a sample introduction device, a sampling device, and a collector. A conical tube is provided in the sample introduction device, and a sample gas inlet is provided on the side wall. The sampling device is coaxially arranged with the sample introduction device; the first steel pipe is installed at the outlet of the sampling device of the cutter, and the first steel pipe is coaxially arranged with the second steel pipe, and the middle interval is the charging area; positive and negative discharge areas are provided on both sides of the charging area, and discharge needles are provided in the discharge area. Among them, the positive discharge needle is connected to the positive high-voltage source, and the negative discharge needle is connected to the negative high-voltage source; insulating mounting seats are provided between the discharge needles and the charger housing.

[0011] Further, the particle size grading device includes a metal housing, an air inlet, an air outlet, a high-voltage electrode plate, a high-voltage source, a filter, and a circulation pump; the filter and the circulation pump provide laminar sheath gas for the particle size grading device; the high-voltage source provides high voltage for the high-voltage electrode plate.

[0012] Further, the Faraday cup electrometer includes a sintered filter element, a honeycomb housing, an insulating gasket, a measurement circuit, a metal housing, and a suction pump; the sintered filter element is installed in the honeycomb housing and is arranged inside the metal housing through the insulating gasket; a spring probe is provided on the measurement circuit, and the spring probe abuts against the bottom of the honeycomb housing.

[0013] Further, the data measured by the flowmeter is directly fed back to the host computer; the solenoid valve, the positive high-voltage source, the negative high-voltage source, and the high-voltage source are all controlled by the host computer.

[0014] Further, the honeycomb housing adopts a multi-layer honeycomb structure; the sintered filter element is a copper powder sintered multi-layer filter element with a mesh number greater than 200 meshes.

[0015] Further, the temperature probe is a thermocouple obtained by brazing a nickel-chromium alloy wire and a copper-nickel alloy wire together; the heating wire and the discharge needle are both made of tungsten; the surface of the high-voltage electrode plate is gold-plated.

[0016] On the other hand, the present invention also discloses a method for using a carbon particle generating device with controllable concentration and particle size, which includes the following steps:

[0017] S1. First, heat the heating wire. After the temperature reaches the required value, the host computer opens the solenoid valves of nitrogen, oxygen, and fuel gas; the fuel gas lifts the spacer under pressure and is sprayed into the combustion chamber through the capillary nozzle; oxygen is introduced into the oxygen buffer chamber and then enters the combustion chamber through the annular slit; the combustion gas is mixed with oxygen and burns at the high temperature of the heating wire to generate high-temperature carbon particles; the high-temperature carbon particles are mixed with nitrogen in the cooling chamber to reduce the temperature of the carbon particles, and then flow out from the outlet.

[0018] S2. Compressed air passes through the buffer chamber and then evenly enters the dilution mixing chamber through the slit, and is fully mixed with the carbon particles generated by the carbon particle generating device to achieve the purpose of dilution.

[0019] S3. The diluted aerosol enters the total flow inlet of the buffer and shunt device, and after buffering, it is respectively extracted from the first outlet and the second outlet, and the excess gas is discharged from the third outlet through the high-efficiency filter to prevent fluctuations in the concentration of the generated carbon particles caused by unstable air pressure.

[0020] S4. The aerosol extracted from the second outlet will enter the bipolar corona charging device. In the cyclone cutter sampling device, due to the conical design, the aerosol gas will spiral upward. Among them, the large particle carbon particles are trapped by the collector under the action of inertia, and the small particle size carbon particles are drawn away through the sampling device with the air flow; a high-voltage electric field is formed between the positive discharge needle and the negative discharge needle and the grounded metal mesh to ionize the air to generate a large number of positive and negative ions, which collide with the passing small particle size carbon particles in the charging area to make the carbon particles fully charged.

[0021] S5. In the particle size classification device, the filter and the circulation pump provide a circulating laminar sheath gas. The charged carbon particles will flow into the particle size classification device along with the gas flow. A uniform high-voltage electric field will be formed between the high-voltage electrode plate and the metal shell. The charged carbon particles will deflect in the electric field, and some will flow out from the air outlet. By adjusting the corresponding high voltage, the corresponding monodisperse carbon particles can be obtained.

[0022] S6. The screened monodisperse carbon particles will enter the Faraday cup electrometer and be collected by the sintered filter element. The charge carried by the carbon particles will be transmitted to the filter element, and the measurement circuit will measure the corresponding current value through the honeycomb shell and the spring probe, and upload the measured result to the upper computer.

[0023] S7. The upper computer inversely calculates the concentration from the current value measured by the Faraday cup electrometer, and the concentration of this particle size can be obtained corresponding to the high-voltage value of the particle size classification device; by adjusting the high-voltage value of the particle size classification device, the soot particle size spectrum generated by the carbon particle generating device can be measured; then, by adjusting each solenoid valve, the particle size and concentration of the generated soot particles can be controlled in real time. After adjusting each solenoid valve to meet the requirements of the soot particle size and concentration, the soot particle size and concentration are monitored in real time.

[0024] As can be seen from the above technical solutions, for the carbon particle generating device with controllable concentration and particle size of the present invention, compared with the prior art, the present invention has the following advantages:

[0025] (1) The carbon particle generating device in the present invention is provided with an anti-backfire device, effectively improving the safety of equipment use; an annular nozzle is arranged at the mixing place of oxygen and fuel gas, so that oxygen sprays out from the annular nozzle, evenly wrapping the fuel gas sprayed out from the central nozzle, making the mixing more sufficient, improving the combustion efficiency, and cooperating with the real-time monitoring of the temperature in the combustion chamber to provide a carbon particle generating environment with controllable particle size and concentration for other instruments to measure.

[0026] (2) The present invention adopts a particulate matter charging method without a radiation source and X-rays, and adopts a bipolar corona charging method (which is safer for device operators without radiation). Compared with the traditional radiation source charging, X-ray charging or unipolar charging, improper use of the first two charging methods will cause harm to device operators, and there will be an obvious multi-charging phenomenon in the unipolar charging method. In the bipolar corona charging device of the present invention, not only the harm that may be caused by improper use is reduced, but also the occurrence of the multi-charging phenomenon is alleviated, so that the charging distribution of particulate matter obeys the Boltzmann distribution, and the charging efficiency of nano-scale carbon particles can be improved.

[0027] (3) The Faraday cup electrometer in the present invention adopts a multi-layer honeycomb and sintered multi-layer filter element structure, which can improve the measurement efficiency of nano-scale carbon particles. Description of the Drawings

[0028] Figure 1It is a schematic structural diagram of the present invention;

[0029] Figure 2 It is a schematic structural diagram of the carbon particle generating device;

[0030] Figure 3 It is a schematic diagram of the particle dilution and mixing device;

[0031] Figure 4 It is a schematic structural diagram of the buffer and shunt device;

[0032] Figure 5 It is a schematic structural diagram of the bipolar corona charging device;

[0033] Figure 6 It is a schematic structural diagram of the particle size classification device;

[0034] Figure 7 It is a schematic structural diagram of the Faraday cup electrometer. Specific embodiments

[0035] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention.

[0036] As Figure 1 shown, a carbon particle generating device with controllable concentration and particle size includes a carbon particle generating device, a particle dilution and mixing device, a buffer and shunt device, a bipolar corona charging device, a particle size classification device, a Faraday cup electrometer, a compressed air source, a nitrogen source, a fuel gas source, an oxygen source, solenoid valves, flow meters, high-efficiency filters, and a host computer;

[0037] Among them, the gas outlet of the soot particle generating device is connected to the gas inlet to be diluted of the particle dilution and mixing device through a steel pipe; the gas outlet of the particle dilution and mixing device is connected to the total flow inlet of the buffer and shunt device through a steel pipe; the second outlet of the buffer and shunt device is connected to the gas inlet of the sampling device in the bipolar corona charging device through a steel pipe; the gas outlet of the bipolar corona charging device is connected to the gas inlet of the particle size classification device through a steel pipe; the gas outlet of the particle size classification device is connected to the gas inlet of the Faraday cup electrometer through a steel pipe.

[0038] As Figure 2The carbon particle generating device shown includes a nitrogen inlet, an oxygen inlet, a fuel gas inlet, a spring, a spacer, a flashback prevention chamber, a capillary nozzle, an oxygen buffer chamber, a combustion chamber, a heating wire, a temperature probe, and a cooling chamber; the fuel gas inlet is sequentially connected to a flow meter, a solenoid valve, and a fuel gas source, and is internally connected to the flashback prevention chamber; a spring and a spacer are provided in the flashback prevention chamber, and the other end is connected to the combustion chamber through a capillary nozzle; the oxygen inlet is sequentially connected to a flow meter, a solenoid valve, and an oxygen source, and directly leads to the oxygen buffer chamber. There is an annular slit between the oxygen buffer chamber and the combustion chamber, and the annular slit wraps the capillary nozzle; the side wall of the combustion chamber is provided with a heating wire and a temperature probe. To improve the combustion efficiency, ignition is set after the fuel gas and oxygen are fully mixed, so the front end of the heating wire extends to 10 mm from the outlet of the capillary nozzle; the nitrogen inlet is sequentially connected to a flow meter, a solenoid valve, and a nitrogen source, and directly leads to the cooling chamber; a circular hole with a diameter of 3 mm is provided between the combustion chamber and the cooling chamber, which is much smaller than the inner diameter of the cooling chamber to ensure that the cooling gas will not flow back into the combustion chamber.

[0039] As Figure 3 The particle dilution mixer shown includes a gas to be diluted inlet, a compressed air inlet, a compressed air buffer chamber, and a dilution mixing chamber; the compressed air inlet is sequentially connected to a flow meter, a solenoid valve, and a compressed air source, and the compressed air passes through the compressed air buffer chamber and then enters the dilution mixing chamber; a slit is provided between the buffer chamber and the dilution mixing chamber, so that the dilution gas uniformly blows into the dilution mixing chamber from all around the slit to prevent the generated carbon particles from being swept to the side wall of the dilution mixing chamber only when blowing in from one side, causing unnecessary losses.

[0040] As Figure 4 The buffer diverter shown includes a total flow inlet, a buffer chamber, a first outlet, a second outlet, and a third outlet; the total flow inlet leads to the gas to be diverted, and after being buffered in the buffer chamber, it uniformly flows out from the three outlets; the first outlet is connected to the device to be measured, the second outlet is connected to a bipolar corona charging device, and the third outlet is connected to a high-efficiency filter.

[0041] As Figure 5 The bipolar corona charging device shown includes a cyclone cutter, a charger housing, a first steel pipe, a second steel pipe, a charging area, a positive and negative discharge area, a metal mesh, a positive discharge needle, a negative discharge needle, an insulating mounting seat, a positive high-voltage source, and a negative high-voltage source; the cyclone cutter includes a sampling device, a sampling device, and a collector. A conical tube is provided in the sampling device, and a sample gas inlet is provided on the side wall. The sampling device is coaxially arranged with the sampling device; the first steel pipe is installed at the outlet of the sampling device of the cutter, and the first steel pipe and the second steel pipe are coaxially arranged, with a 10 mm interval in the middle as the charging area; positive and negative discharge areas are provided on both sides of the charging area, and discharge needles are provided in the discharge area. Among them, the positive discharge needle is connected to the positive high-voltage source, and the negative discharge needle is connected to the negative high-voltage source; an insulating mounting seat is provided between the discharge needle and the charger housing.

[0042] As Figure 6 shown, the particle size classification device includes a metal shell, an air inlet, an air outlet, a high-voltage electrode plate, a high-voltage source, a filter, and a circulation pump; the filter and the circulation pump provide laminar sheath gas for the particle size classification device; the high-voltage source provides high voltage for the high-voltage electrode plate.

[0043] As Figure 7 shown, the Faraday cup electrometer includes a sintered filter element, a honeycomb shell, an insulating gasket, a measurement circuit, a metal shell, and a vacuum pump; the sintered filter element is installed in the honeycomb shell and is arranged inside the metal shell through the insulating gasket; a spring probe is provided on the measurement circuit, and the spring probe abuts against the bottom of the honeycomb shell.

[0044] Specifically, the data measured by the flow meter is directly fed back to the host computer; the solenoid valve, the positive high-voltage source, the negative high-voltage source, and the high-voltage source are all controlled by the host computer.

[0045] The temperature probe is a thermocouple in which a nickel-chromium alloy wire and a copper-nickel alloy wire are brazed together; the heating wire and the discharge needle are both made of tungsten; the surface of the high-voltage electrode plate is gold-plated.

[0046] The honeycomb shell adopts a multi-layer honeycomb structure; the metal mesh is made of copper and has a mesh number of 30; the sintered filter element is a copper powder sintered multi-layer filter element with a mesh number greater than 200.

[0047] All the devices are connected by 316 stainless steel pipes.

[0048] The above-mentioned carbon particle generating device with controllable concentration and particle size, the usage method of the device includes the following steps:

[0049] (1) First, heat the heating wire. After the temperature reaches the requirement, the host computer opens the solenoid valves of nitrogen, oxygen, and fuel gas; the fuel gas lifts the spacer under pressure and is sprayed into the combustion chamber through the capillary nozzle; oxygen is introduced into the oxygen buffer chamber and then enters the combustion chamber through the annular slit; the combustion gas and oxygen are mixed and burned at the high temperature of the heating wire to generate high-temperature carbon particles; the high-temperature carbon particles are mixed with nitrogen in the cooling chamber to reduce the temperature of the carbon particles, and then flow out from the outlet;

[0050] (2) Compressed air passes through the buffer chamber and then evenly enters the dilution mixing chamber through the slit, and is fully mixed with the carbon particles generated by the carbon particle generating device to achieve the purpose of dilution;

[0051] (3) The diluted aerosol enters the total flow inlet of the buffer and shunt device, and after buffering, it is respectively extracted from the first outlet and the second outlet, and the excess gas is discharged from the third outlet through the high-efficiency filter to prevent the concentration of the generated carbon particles from fluctuating due to unstable air pressure;

[0052] (4) The aerosol extracted from the second outlet will be introduced into a bipolar corona charging device. In the cyclone cutter sampling device, due to the conical design, the aerosol gas will spiral upward. Among them, large particle carbon particles are trapped by the collector under the action of inertia, and small particle size carbon particles are drawn away with the air flow through the sampling device; a high-voltage electric field will be formed between the positive discharge needle and the negative discharge needle and the grounded metal mesh to ionize the air to generate a large number of positive and negative ions, which will collide with the small particle size carbon particles passing through in the charging area to fully charge the carbon particles;

[0053] (5) In the particle size classification device, the filter and the circulation pump provide a circulating laminar sheath gas. The charged carbon particles will be introduced into the particle size classification device with the air flow. Among them, a uniform high-voltage electric field will be formed between the high-voltage electrode plate and the metal shell, and the charged carbon particles will deflect in the electric field, and some will flow out from the air outlet. By adjusting the corresponding high voltage, the corresponding monodisperse carbon particles can be obtained.

[0054] (6) The sieved monodisperse carbon particles will enter the Faraday cup electrometer and be collected by the sintered filter element. The charge carried by the carbon particles will be transmitted to the filter element, and the measurement circuit will measure the corresponding current value through the honeycomb shell and the spring probe, and upload the measured result to the upper computer.

[0055] (7) The upper computer will invert the current value measured by the Faraday cup electrometer into concentration, and the concentration of this particle size can be obtained corresponding to the high voltage value of the particle size classification device; by adjusting the high voltage value of the particle size classification device, the soot particle size spectrum generated by the carbon particle generating device can be measured; and then by adjusting each solenoid valve, the particle size and concentration of the generated soot particles can be controlled in real time. After adjusting each solenoid valve to meet the requirements of the soot particle size and concentration, the soot particle size and concentration can be monitored in real time. For example: If it is necessary to obtain carbon particle sources with specified concentrations of 50 nm and 100 nm respectively, first, monodisperse charged carbon particles of 50 nm are screened out in the particle size classification device, and their concentration is measured by the Faraday cup electrometer and the upper computer; if the concentration does not meet the requirements, the upper computer will control the solenoid valve to increase (decrease) the intake of fuel gas and oxygen, and decrease (increase) the intake of compressed air to control the concentration of 50 nm soot particles; if a carbon particle source with a specified concentration of 100 nm is also required, the same method is used. First, monodisperse charged carbon particles of 100 nm are screened out in the particle size classification device, and their concentration is measured by the Faraday cup electrometer and the upper computer; if the concentration does not meet the requirements, the upper computer will control the solenoid valve to increase (decrease) the intake of fuel gas and oxygen, and decrease (increase) the intake of compressed air to control the concentration of 100 nm soot particles. Thus, a carbon particle generating device with controllable concentration and particle size that can be monitored in real time and can provide a carbon particle generating environment with controllable particle size and concentration is realized.

[0056] Generally speaking, the carbon particle generating device of the embodiment of the present invention is provided with an anti-backfire device, which effectively improves the safety of equipment use; an annular nozzle is arranged at the mixing place of oxygen and fuel gas, so that oxygen is ejected from the annular nozzle to evenly wrap the fuel gas ejected from the central nozzle, making the mixing more sufficient, improving the combustion efficiency, and cooperating with the real-time monitoring of the temperature in the combustion chamber to provide a carbon particle generating environment with controllable particle size and concentration for other instruments to measure; the bipolar corona charging device adopts a bipolar charging method. Traditionally, a radiation source charging, X-ray charging or unipolar charging is generally adopted. The improper use of the first two charging methods will cause harm to the device operator, and there will be an obvious multiple charging phenomenon in the unipolar charging method. In the bipolar corona charging device of the present invention, not only the harm that may be caused by improper use is reduced, but also the occurrence of the multiple charging phenomenon is alleviated.

[0057] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some of the technical features; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A carbon particle generating device with controllable concentration and particle size, comprising a carbon particle generating device, a particle dilution and mixing device, a buffer and shunt device, a bipolar corona charging device, a particle size classification device, and a Faraday cup electrometer, characterized in that: The gas outlet of the soot particle generating device is connected to the gas inlet to be diluted of the particle dilution and mixing device through a steel pipe; the gas outlet of the particle dilution and mixing device is connected to the total flow inlet of the buffer and shunt device through a steel pipe; the second outlet of the buffer and shunt device is connected to the gas inlet of the sampling device in the bipolar corona charging device through a steel pipe; the gas outlet of the bipolar corona charging device is connected to the gas inlet of the particle size classification device through a steel pipe; the gas outlet of the particle size classification device is connected to the gas inlet of the Faraday cup electrometer through a steel pipe; The carbon particle generating device includes a nitrogen inlet, an oxygen inlet, a fuel gas inlet, an anti-backfire chamber, a capillary nozzle, an oxygen buffer chamber, a combustion chamber, and a cooling chamber; the fuel gas inlet is sequentially connected to a flow meter, a solenoid valve, and a fuel gas source, and is internally connected to the anti-backfire chamber; A spring and a cushion block are provided in the anti-backfire chamber, and the other end is connected to the combustion chamber through a capillary nozzle; the oxygen inlet is sequentially connected to a flow meter, a solenoid valve, and an oxygen source, and directly leads to the oxygen buffer chamber. There is an annular slit between the oxygen buffer chamber and the combustion chamber, and the annular slit wraps the capillary nozzle; heating wires and temperature probes are provided on the side wall of the combustion chamber, and the front end of the heating wire extends to the outlet of the capillary nozzle; the nitrogen inlet is sequentially connected to a flow meter, a solenoid valve, and a nitrogen source, and directly leads to the cooling chamber; a round hole is provided between the combustion chamber and the cooling chamber.

2. The carbon particle generating device with controllable concentration and particle size according to claim 1, characterized in that: The particle diluter mixer includes a gas inlet to be diluted, a compressed air inlet, a compressed air buffer chamber, and a dilution and mixing chamber; the compressed air inlet is sequentially connected to a flow meter, a solenoid valve, and a compressed air source, and the compressed air passes through the compressed air buffer chamber and then enters the dilution and mixing chamber; a slit is provided between the buffer chamber and the dilution and mixing chamber.

3. The carbon particle generating device with controllable concentration and particle size according to claim 1, wherein: The buffer and shunt device includes a total flow inlet, a buffer chamber, a first outlet, a second outlet, and a third outlet; the total flow inlet introduces the gas to be shunted, and after being buffered in the buffer chamber, it evenly flows out from the three outlets; the first outlet is connected to the device to be measured, the second outlet is connected to the bipolar corona charging device, and the third outlet is connected to a high-efficiency filter.

4. The carbon particle generating device with controllable concentration and particle size according to claim 1, characterized in that: The bipolar corona charging device includes a cyclone cutter, a charger housing, a first steel pipe, a second steel pipe, a charging area, a positive and negative discharge area, a metal mesh, a positive discharge needle, a negative discharge needle, an insulating mounting seat, a positive high-voltage source, and a negative high-voltage source; the cyclone cutter includes a sampling device, a sampling device, and a collector. A conical tube is provided in the sampling device, and a sample gas inlet is provided on the side wall. The sampling device is coaxially arranged with the sampling device; the first steel pipe is installed at the outlet of the cutter sampling device, and the first steel pipe is coaxially arranged with the second steel pipe, and the middle interval is the charging area; positive and negative discharge areas are provided on both sides of the charging area, and discharge needles are provided in the discharge area. Among them, the positive discharge needle is connected to the positive high-voltage source, and the negative discharge needle is connected to the negative high-voltage source; an insulating mounting seat is provided between the discharge needle and the charger housing.

5. The concentration and particle size controllable carbon particle generating device according to claim 1, characterized in that: The particle size classification device includes a metal shell, an air inlet, an air outlet, a high-voltage electrode plate, a high-voltage source, a filter and a circulation pump; the filter and the circulation pump provide laminar sheath gas for the particle size classification device; the high-voltage source provides high voltage for the high-voltage electrode plate.

6. The concentration and particle size controllable carbon particle generating device according to claim 1, characterized in that: The Faraday cup electrometer includes a sintered filter element, a honeycomb shell, an insulating gasket, a measurement circuit, a metal shell and a suction pump; the sintered filter element is installed in the honeycomb shell and is arranged in the metal shell through the insulating gasket; a spring probe is arranged on the measurement circuit, and the spring probe abuts against the bottom of the honeycomb shell.

7. The concentration and particle size controllable carbon particle generating device according to claim 1, characterized in that: The data measured by the flowmeter is directly fed back to the upper computer; the solenoid valve, the positive high-voltage source, the negative high-voltage source and the high-voltage source are all controlled by the upper computer.

8. The concentration and particle size controllable carbon particle generating device according to claim 6, characterized in that: The honeycomb shell adopts a multi-layer honeycomb structure; the sintered filter element is a copper powder sintered multi-layer filter element with a mesh number greater than 200 meshes.

9. The concentration and particle size controllable carbon particle generating device according to claim 5, characterized in that: The temperature probe is a thermocouple obtained by brazing a nickel-chromium alloy wire and a copper-nickel alloy wire together; the heating wire and the discharge needle are both made of tungsten; the surface of the high-voltage electrode plate is gold-plated.

10. A carbon particle generating device with controllable concentration and particle size according to any one of claims 1 to 9, characterized in that: The usage method of this device includes the following steps: S1. First, heat the heating wire. After the temperature reaches the requirement, the upper computer opens the solenoid valves of nitrogen, oxygen and fuel gas; the fuel gas lifts the cushion block under the action of pressure and is sprayed into the combustion chamber through the capillary nozzle; oxygen is introduced into the oxygen buffer chamber and then enters the combustion chamber through the annular slit; the combustion gas is mixed with oxygen and burns at the high temperature of the heating wire to generate high-temperature carbon particles; the high-temperature carbon particles are mixed with nitrogen in the cooling chamber to reduce the temperature of the carbon particles, and then flow out from the outlet; S2. Compressed air passes through the buffer chamber and then evenly enters the dilution mixing chamber through the slit, and is fully mixed with the carbon particles generated by the carbon particle generating device to achieve the purpose of dilution; S3. The diluted aerosol enters the total flow inlet of the buffer and shunt device, and after buffering, it is respectively extracted from the first outlet and the second outlet, and the excess gas is discharged from the third outlet through the high-efficiency filter to prevent the concentration of the generated carbon particles from fluctuating due to unstable air pressure; S4. The aerosol extracted from the second outlet will enter the bipolar corona charging device. In the cyclone cutter sampling device, due to the conical design, the aerosol gas will spiral upward. Among them, the large particle carbon particles are trapped by the collector under the action of inertia, and the small particle size carbon particles are drawn away through the sampling device along with the air flow; a high-voltage electric field is formed between the positive discharge needle and the negative discharge needle and the grounded metal mesh to ionize the air to generate a large number of positive and negative ions, which collide with the passing small particle size carbon particles in the charging area to make the carbon particles fully charged; S5. The filter and the circulation pump in the particle size grading device provide a circulating laminar sheath gas. The charged carbon particles will flow into the particle size grading device along with the gas flow. A uniform high-voltage electric field will be formed between the high-voltage electrode plate and the metal shell. The charged carbon particles will deflect in the electric field, and some will flow out from the air outlet. By adjusting the corresponding high voltage, the corresponding monodisperse carbon particles can be obtained; S6. The sieved monodisperse carbon particles will enter the Faraday cup electrometer and be collected by the sintered filter element. The charge carried by the carbon particles will be transmitted to the filter element. The measurement circuit will measure the corresponding current value through the honeycomb shell and the spring probe, and upload the measured result to the upper computer; S7. The upper computer inverses the current value measured by the Faraday cup electrometer into concentration, and the concentration of this particle size can be obtained corresponding to the high-voltage value of the particle size grading device; the soot particle size spectrum generated by the soot particle generating device is measured by adjusting the high-voltage value of the particle size grading device; then, by adjusting each solenoid valve, the particle size and concentration of the generated soot particles are controlled in real time. After adjusting each solenoid valve to meet the requirements of the soot particle size and concentration, the soot particle size and concentration are monitored in real time.

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