An apparatus for quantitatively detecting the entire process of a single-particle solid fuel combustion flame and its operation method

Abstract

The present invention discloses a device for quantitatively detecting the whole process of a single-particle solid fuel combustion flame and its operation method, which includes a combustion chamber, an air intake device, a pulverized coal particle loading device, an observation and measurement device, and a tail gas treatment device. The air intake device is located on the left side of the combustion chamber. On the outside, there are two right-angle air inlet pipes, and on the inside, there are two horizontal pipes. The first horizontal pipe is used to place a thermocouple, and the second horizontal pipe is used to place a high-temperature resistant ultra-fine metal wire mesh loaded with pulverized coal particles; the pulverized coal particle loading device includes a high-temperature resistant ultra-fine metal wire mesh and a three-dimensional electric displacement platform; the observation and measurement device is located on the right side of the transparent combustion chamber; the tail gas treatment device is located on the right side of the combustion chamber. The construction of the single-particle pulverized coal ignition combustion - flame online detection system of the present invention can obtain the ignition time, burnout time and flame dynamic drift characteristics of single-particle pulverized coal, which play a crucial role in the stable operation of combustion in boilers and the efficient utilization of coal.

Description

Technical Field

[0001] The present invention belongs to an energy detection device and its usage method, and particularly relates to a full-process quantitative detection device for the combustion flame of single-particle solid fuel and its operation method. Background Art

[0002] The ignition characteristics of pulverized coal particles play a crucial role in the stable operation of combustion in boilers and the efficient utilization of coal. Usually, the ignition and combustion process of pulverized coal can be divided into two stages, namely the volatilization reaction stage of volatile matter and the oxidation reaction stage of residual coke. However, due to various physical and chemical factors such as combustion reactions, mass, momentum, and energy transfer, the ignition and combustion reaction process of pulverized coal is very complex. A large number of studies have shown that the ignition modes of pulverized coal particles can be divided into three types: homogeneous ignition, heterogeneous ignition, and combined ignition. For different ignition modes, their detailed combustion processes, including the morphological changes of pulverized coal particles, the distribution of each component, the temperature distribution, the flame drift characteristics, etc., are all different. Therefore, a detailed study of the ignition process of single pulverized coal particles, especially particles with a micron-level fineness, is of great significance for the distinction of pulverized coal ignition modes, the establishment of ignition models, and the guidance of industrial practical applications.

[0003] Existing pulverized coal combustion devices and observation methods cannot achieve continuous measurement during the combustion process of single pulverized coal particles, especially particles with a micron-level fineness. They can only roughly determine a few parameters such as the ignition time, combustion intensity, and burnout time of solid fuels such as pulverized coal, and are powerless to obtain characteristics such as the ignition and combustion process of volatile matter, the burnout time of volatile matter, the ignition and combustion process of coke, and the dynamic drift of the flame during the entire combustion process.

[0004] Therefore, it is necessary to design a full-process quantitative detection device for the combustion flame of single-particle solid fuel to study the ignition time, burnout time, and flame dynamic drift characteristics of single particles, even particles with a micron-level fineness. Summary of the Invention

[0005] Object of the Invention: The object of the present invention is to provide a full-process quantitative detection device for the combustion flame of single-particle solid fuel.

[0006] Another object of the present invention is to provide an operation method for the full-process quantitative detection device of the combustion flame of single-particle solid fuel.

[0007] Technical Solution: The full-process quantitative detection device for the combustion flame of single-particle solid fuel includes a combustion chamber, an air intake device, a pulverized coal particle loading device, an observation and measurement device, and a tail gas treatment device;

[0008] The combustion chamber is placed inside a high-temperature electric furnace;

[0009] The intake device is located on the left side of the combustion chamber and is of a multi-tube cold trap structure. On the outside are two right-angled intake pipes. The first intake pipe 2a is used to introduce oxygen, and the second intake pipe 2b is used to introduce nitrogen or carbon dioxide or other gases. The intake volume is controlled by a mass flow meter. On the inside are two horizontal pipes. The first horizontal pipe 3a is used to place a thermocouple, and the thermocouple is connected to a temperature controller. The second horizontal pipe 3b is used to place an ultra-fine nickel wire mesh or other high-temperature-resistant ultra-fine metal mesh loaded with coal powder particles. The first intake pipe 2a is connected to an oxygen gas cylinder, and the second intake pipe 2b is connected to a nitrogen gas cylinder; one end of the ultra-fine nickel wire mesh or other high-temperature-resistant ultra-fine metal mesh is connected to a high-temperature-resistant quartz tube;

[0010] The coal powder particle loading device includes an ultra-fine nickel wire mesh or a high-temperature-resistant ultra-fine metal mesh and a three-dimensional electric displacement platform;

[0011] The observation and measurement device is located on the right side of the transparent combustion chamber and includes a CCD camera equipped with a visible light filter and a long focal length lens. After collecting image data, it is sent to a computer for processing;

[0012] The tail gas treatment device is located on the right side of the combustion chamber and includes a cooling duct and filter cotton nested outside the quartz tube of the combustion chamber or other high-temperature-resistant transparent tubes.

[0013] Furthermore, the combustion chamber is made of high-temperature-resistant quartz glass material or other high-temperature-resistant transparent materials.

[0014] Furthermore, the inner diameter of the combustion chamber is 40 - 50 mm, and the length is 40 - 50 mm.

[0015] Furthermore, the diameter of the metal wire of the ultra-fine nickel wire mesh or other high-temperature-resistant ultra-fine metal mesh can be selected according to the different particle sizes of the coal powder particles to be loaded, and the mesh aperture is controlled by weaving; the ultra-fine nickel wire mesh or other high-temperature-resistant ultra-fine metal mesh is used to dip coal powder soaked in a volatile substance that does not react with coal powder at room temperature, such as alcohol or acetone. After the volatile substances such as alcohol or acetone that are not likely to react with coal powder volatilize, the coal powder particles are loaded on the ultra-fine nickel wire mesh or other high-temperature-resistant ultra-fine metal mesh.

[0016] Furthermore, the three-dimensional electric displacement platform in the coal powder particle loading device is composed of an electric displacement device and a high-temperature-resistant quartz tube. One end of the high-temperature-resistant quartz tube is connected to the ultra-fine nickel wire mesh or other high-temperature-resistant ultra-fine metal mesh loaded with coal powder particles, and the other end is connected to the electric displacement device, which is used to move the position of the ultra-fine nickel wire mesh or other high-temperature-resistant ultra-fine metal mesh loaded with coal powder particles so that it can be accurately placed at a set position in the furnace for combustion reaction.

[0017] Furthermore, the observation and measurement device is used to capture images of the ignition and combustion processes of pulverized coal particles loaded on an ultra-fine nickel wire mesh or other high-temperature-resistant ultra-fine metal wire meshes in the combustion chamber. After the images are collected, they are sent to a computer and processed and calculated by image processing software to obtain the time of each stage of pulverized coal particle combustion and the combustion process.

[0018] The operation method of the single-particle solid fuel combustion flame full-process quantitative detection device includes the following steps:

[0019] (1) First, design and process the ultra-fine nickel wire mesh or other high-temperature-resistant ultra-fine metal wire meshes in the pulverized coal particle loading device. After the metal wires are woven into a mesh, place the ultra-fine nickel wire mesh or other high-temperature-resistant ultra-fine metal wire meshes in the combustion chamber for high-temperature calcination to form an oxide layer on the mesh surface to prevent it from affecting the subsequent combustion of pulverized coal particles;

[0020] (2) Immerse the pulverized coal in a volatile substance that does not easily react with the pulverized coal at room temperature and stir it. Use the prepared ultra-fine nickel wire mesh or other high-temperature-resistant ultra-fine metal wire meshes to dip the pulverized coal soaked in volatile substances such as alcohol or acetone. After the volatile substances such as alcohol or acetone have volatilized, the pulverized coal particles are loaded on the ultra-fine nickel wire mesh or other high-temperature-resistant ultra-fine metal wire meshes; the concentration ratio of the pulverized coal to the volatile substance that does not easily react with the pulverized coal is determined according to the particle size (d m ) of the pulverized coal particles and the pore size (D s ) of the ultra-fine nickel wire mesh or other high-temperature-resistant ultra-fine metal wire meshes to ensure that after the pulverized coal particles are loaded on the ultra-fine nickel wire mesh or other high-temperature-resistant ultra-fine metal wire meshes, the distance between any two particles is large enough so that they do not affect each other during combustion;

[0021] (3) After the pulverized coal is loaded on the ultra-fine nickel wire mesh or other high-temperature-resistant ultra-fine metal wire meshes, observe it under a microscope with a magnification of 40 times or more. When the ratio of the distance (D) between the pulverized coal particles to the diameter (d m ) of the pulverized coal particles is greater than 30 (D:d m >30), it can be judged as a single-particle loading mode. At this time, the combustion of pulverized coal particles does not affect each other. When the pulverized coal is loaded in the single-particle loading mode, number the pulverized coal particles under the microscope and record their specific positions;

[0022] (4) Rapidly heat the combustion chamber with an electric furnace. When the temperature controller shows that the temperature in the furnace reaches above 1000 °C or other temperatures required by the experiment, start to introduce the required oxygen or other gases. After the temperature stabilizes, send the ultra-fine nickel wire mesh or other high-temperature-resistant ultra-fine metal wire meshes loaded with pulverized coal particles into the combustion chamber for experiments through a three-dimensional electric displacement platform;

[0023] (5) A CCD camera is used to observe and measure the images of pulverized coal particle combustion process. During the experiment, the CCD camera is placed on the right side of the combustion chamber to receive the image information of combustion particles, and after collection, it is sent to a computer for processing and analysis. The brightness index L - time t curve, combustion time T, peak brightness index L are obtained through calculation. m , average brightness index L av , and bright light area S.

[0024] Among them, the combustion time T represents the time required for the brightness index L of a single pulverized coal particle to increase from 5% of the peak brightness to the peak brightness and then decrease to 5% of the peak brightness. The peak brightness L m is the maximum brightness index during the combustion process, representing the most intense volatile combustion. The average brightness index L av is the average value of the brightness index L at each moment during the combustion time T. The higher the average brightness, the more intense the combustion. The bright light area S is the area in the flame image captured through the filter lens that reaches more than 80% of the highest brightness. Through the bright light area, the volatile combustion stage and char particle combustion stage during the combustion process of pulverized coal particles can be judged.

[0025] The effect indicators are as follows:

[0026] Peak brightness index L m : L m = L(t) max

[0027] Average brightness index L av :

[0028] Bright light area S: When S > 2d m , the combustion is defined as volatile combustion; when S < 2d m , it is defined as char particle combustion.

[0029] (6) After combustion, the ultra - fine nickel wire mesh or other high - temperature - resistant ultra - fine metal wire meshes loaded with coal ash are placed under a microscope with a magnification of 40 times or more for observation, and compared with the numbered positions of the pulverized coal particles before the test. If coal ash residue can be determined at the numbered position before the experiment, the numbered position can be taken as an effective observation point, and the combustion images obtained by the high - speed camera at this observation point are analyzed and processed.

[0030] (7) The tail gas generated by the experiment is filtered through a filter cotton and then discharged into the air.

[0031] Further, ultra - fine nickel wires or other high - temperature - resistant ultra - fine metal wires with corresponding diameters are selected according to the diameter of the pulverized coal particles. Specifically, the diameter (d s ) of the selected ultra - fine nickel wire or other high - temperature - resistant ultra - fine metal wire is the diameter (d m1.5 to 3 times that of [[ID=]], ensuring that the pulverized coal particles can be loaded onto the wire and are clearly distinguishable under a microscope. When weaving an ultra-fine nickel wire mesh or other ultra-fine high-temperature-resistant metal wire meshes, the distance between two wires is determined according to the diameter of the pulverized coal particles. Specifically, the distance between two wires (D s ) of the selected ultra-fine nickel wire mesh or other ultra-fine high-temperature-resistant metal wire meshes is 30 - 50 times the diameter of the pulverized coal particles (d m ), ensuring that the pulverized coal particles do not affect each other during combustion.

[0032] Furthermore, the volatile substances that are not likely to react with pulverized coal at room temperature are alcohol or acetone.

[0033] Single-particle pulverized coal realizes suspended loading through an ultra-fine nickel wire mesh or an ultra-fine high-temperature-resistant metal wire mesh. The ultra-fine nickel wire mesh or the ultra-fine high-temperature-resistant metal wire mesh is used to dip the pulverized coal soaked in volatile substances such as alcohol or acetone that are not likely to react with pulverized coal. After the volatile substances such as alcohol or acetone that are not likely to react with pulverized coal volatilize, the single-particle pulverized coal is loaded onto the ultra-fine nickel wire mesh or the ultra-fine high-temperature-resistant metal wire mesh. Rapid heating is achieved through a high-temperature electric furnace, so that the temperature in the combustion chamber rises above 1000 °C or the required experimental temperature within 2 hours. A CCD camera equipped with a visible light filter and a long focal length lens is used to capture the ignition and combustion process images of the pulverized coal particles loaded on the ultra-fine nickel wire mesh or other ultra-fine high-temperature-resistant metal wire meshes in the combustion chamber. After the image acquisition, it is sent to a computer for processing and calculation to obtain the time of each stage of the pulverized coal particle combustion and the specific combustion process.

[0034] Beneficial effects: Compared with the prior art, the present invention has the following advantages:

[0035] The present invention provides a device for quantitatively detecting the whole process of a single-particle solid fuel combustion flame and its operation method. The operation principle is clear. By constructing a single-particle pulverized coal ignition and combustion - flame on-line detection system, the ignition time, burnout time and flame dynamic drift characteristics of a single-particle pulverized coal can be obtained, which play a crucial role in the stable operation of combustion in boilers and the efficient utilization of coal. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 is a schematic structural diagram of the device of the present invention;

[0037] Figure 2 is a detailed view of the ultra-fine nickel wire mesh or other ultra-fine high-temperature-resistant metal wire meshes loaded with pulverized coal particles;

[0038] Figure 3 is a dynamic change diagram of the single-particle pulverized coal loaded combustion flame;

[0039] Figure 4 is an attached drawing of the embodiment;

[0040] Among them: electric furnace 1, first intake pipe 2a, second intake pipe 2b, first horizontal pipe 3a, second horizontal pipe 3b, thermocouple 4, three-dimensional electric displacement platform 5, temperature controller 6, high-temperature resistant quartz tube 7, ultra-fine nickel wire mesh 8, combustion chamber 9, visible light filter 10, CCD camera 11, cooling duct 13, filter cotton 14, computer 15, mass flowmeter 16, oxygen gas cylinder 17, nitrogen gas cylinder 18. Specific implementation manner

[0041] As Figure 1 shown, the single-particle solid fuel combustion flame full-process quantitative detection device of this embodiment includes a transparent combustion chamber, an intake device, a pulverized coal particle loading device, an observation and measurement device, and an exhaust gas treatment device.

[0042] The combustion chamber 9 is placed inside the high-temperature electric furnace 1; the intake device is located on the left side of the combustion chamber 9 and is a multi-tube cold trap structure. The outer side has two right-angle intake pipes. The first intake pipe 2a is used to introduce oxygen, and the second intake pipe 2b is used to introduce nitrogen or carbon dioxide or other gases. The intake volume is controlled by the mass flowmeter 16. The inner side has two horizontal pipes. The first horizontal pipe 3a is used to place the thermocouple 4, and the thermocouple 4 is connected to the temperature controller 6. The second horizontal pipe 3b is used to place the ultra-fine nickel wire mesh 8 loaded with pulverized coal particles or other high-temperature resistant ultra-fine metal wire meshes. The first intake pipe 2a is connected to the oxygen gas cylinder 17, and the second intake pipe 2b is connected to the nitrogen gas cylinder 18; one end of the ultra-fine nickel wire mesh 8 or other high-temperature resistant ultra-fine metal wire meshes is connected to the high-temperature resistant quartz tube 7; the pulverized coal particle loading device includes the ultra-fine nickel wire mesh 8 or the high-temperature resistant ultra-fine metal wire mesh and the three-dimensional electric displacement platform 5; the observation and measurement device is located on the right side of the transparent combustion chamber 9 and includes a CCD camera 11 provided with a visible light filter 10 and a telephoto lens. After collecting the image data, it is sent to the computer 15 for processing; the exhaust gas treatment device is located on the right side of the combustion chamber 9 and includes a cooling duct 13 and a filter cotton 14 nested outside the quartz tube of the combustion chamber or other high-temperature resistant transparent tubes.

[0043] A small-sized transparent observation chamber with an inner diameter of 40 - 50 mm and a length of 40 - 50 mm is made of high-temperature-resistant quartz glass or other high-temperature-resistant transparent materials. A multi-tube cold trap structure is installed on the left side of the combustion chamber 9. The two outer right-angled tubes are intake pipes. Oxygen is introduced through the first intake pipe 2a, and nitrogen, carbon dioxide or other gases are introduced through the second intake pipe 2b. The intake volume is controlled by a mass flowmeter 16. There are two horizontal tubes inside. The first horizontal tube 3a is used to place a thermocouple, and the second horizontal tube 3b is used to place an ultra-fine nickel wire mesh 8 carrying pulverized coal particles or other high-temperature-resistant ultra-fine metal wire meshes. The combustion chamber 9 is rapidly heated by a high-temperature electric furnace 1, so that the temperature of the combustion chamber 9 rises above 1000 °C within 2 hours. Single-particle pulverized coal is suspended and loaded through the ultra-fine nickel wire mesh 8 or other high-temperature-resistant ultra-fine metal wire meshes. The ultra-fine nickel wire mesh 8 or other high-temperature-resistant ultra-fine metal wire meshes are dipped in pulverized coal soaked in volatile substances that are not likely to react with pulverized coal at room temperature, such as alcohol or acetone. After the volatile substances that are not likely to react with pulverized coal at room temperature, such as alcohol or acetone, volatilize, the pulverized coal particles are loaded on the ultra-fine nickel wire mesh 8 or other high-temperature-resistant metal wire meshes. The three-dimensional electric displacement platform 5 moves the position of the ultra-fine nickel wire mesh 8 carrying the pulverized coal particles or other high-temperature-resistant ultra-fine metal wire meshes through an electric displacement device, so that it is accurately placed at a set position in the furnace for combustion reaction. The cooling duct 13 is arranged on the right side of the combustion chamber 9, and the tail gas is filtered through the internal filter cotton 14.

[0044] A CCD camera 11 is provided on the right side of the combustion chamber 9. A visible light filter 10 and a telephoto lens are arranged in front of the camera, which are used to photograph the ignition and combustion process images of the pulverized coal particles loaded on the ultra-fine nickel wire mesh 8 or other high-temperature-resistant ultra-fine metal wire meshes in the combustion chamber 9. After the images are collected, they are sent to a computer and the time of each stage of the pulverized coal particle combustion and the specific combustion process are obtained through processing and calculation.

[0045] The operation method of the single-particle solid fuel combustion flame full-process quantitative detection device includes the following steps:

[0046] (1) First, design and process the ultra-fine nickel wire mesh 8 or other high-temperature-resistant ultra-fine metal wire meshes in the pulverized coal particle loading device. Select ultra-fine nickel wires 8 or other high-temperature-resistant ultra-fine metal wires with corresponding diameters according to the diameter of the pulverized coal particles. Specifically, the diameter (d s ) of the selected ultra-fine nickel wire 8 or other high-temperature-resistant ultra-fine metal wire is 1.5 - 3 times the diameter (d m ) of the pulverized coal particles, ensuring that the pulverized coal particles can be loaded on the wire and are clearly distinguishable under a microscope. When weaving the ultra-fine nickel wire mesh 8 or other high-temperature-resistant ultra-fine metal wire mesh, the distance between the two wires is determined according to the diameter of the pulverized coal particles. Specifically, the distance (D s ) between the two wires of the selected ultra-fine nickel wire mesh 8 or other high-temperature-resistant ultra-fine metal wire mesh is the diameter (d m) 30 to 50 times that, ensuring that the pulverized coal particles do not affect each other during combustion. After the metal wire is woven into a mesh, the ultra-fine nickel wire mesh 8 or other high-temperature resistant ultra-fine metal wire meshes 8 are placed in the combustion chamber 9 for high-temperature calcination to form an oxide layer on the surface of the mesh to prevent it from affecting the subsequent combustion of the pulverized coal particles.

[0047] (2) Soak the pulverized coal in a volatile substance such as alcohol or acetone that does not easily react with the pulverized coal at room temperature, stir it, and use the prepared ultra-fine nickel wire mesh 8 or other high-temperature resistant ultra-fine metal wire meshes 8 to dip the pulverized coal soaked in the volatile substance such as alcohol or acetone. After the volatile substances such as alcohol or acetone have volatilized, the pulverized coal particles are loaded onto the ultra-fine nickel wire mesh 8 or other high-temperature resistant ultra-fine metal wire meshes 8; the concentration ratio of the pulverized coal to the volatile substance such as alcohol or acetone that does not easily react with the pulverized coal at room temperature is determined according to the particle size (d m ) of the pulverized coal particles and the pore size (D s ) of the ultra-fine nickel wire mesh 8 or other high-temperature resistant ultra-fine metal wire meshes 8, ensuring that after the pulverized coal particles are loaded onto the ultra-fine nickel wire mesh 8 or other high-temperature resistant ultra-fine metal wire meshes 8, the distance between any two particles is large enough so that they do not affect each other during combustion.

[0048] (3) After the pulverized coal is loaded onto the ultra-fine nickel wire mesh 8 or other high-temperature resistant ultra-fine metal wire meshes 8, observe it under a microscope with a magnification of more than 40 times. When the ratio of the distance (D) between the pulverized coal particles to the diameter (d m ) of the pulverized coal particles is greater than 30 (D:d m >30), it can be judged as a single-particle loading mode, and at this time, the combustion of the pulverized coal particles does not affect each other. When the pulverized coal loading is in the single-particle loading mode, number the pulverized coal particles under the microscope and record their specific positions.

[0049] (4) Use the electric furnace 1 to quickly heat the combustion chamber 9. When the temperature controller 6 shows that the temperature in the furnace reaches above 1000 °C, start to introduce the required oxygen and other gases. After the temperature stabilizes, send the ultra-fine nickel wire mesh 8 or other high-temperature resistant ultra-fine metal wire meshes 8 loaded with pulverized coal particles into the combustion chamber 9 through the three-dimensional electric displacement platform 5 for experiments.

[0050] (5) Use a CCD camera 11 to observe and measure the images of the pulverized coal particle combustion process. During the experiment, place the high-speed CCD camera 11 on the right side of the combustion chamber 9 to receive the image information of the combustion particles, and collect and send it to the computer 15 for processing and analysis. Through calculation, obtain the brightness index L - time t curve, combustion time (T), peak brightness index (L m ), average brightness index (L av ), bright area (S), etc.

[0051] Among them, the combustion time (T) represents the time required for the brightness index L of a single pulverized coal particle to increase from 5% of the peak brightness to the peak brightness and then decrease to 5% of the peak brightness. The peak brightness (L m ) is the maximum brightness index during the combustion process, representing the most intense combustion of volatile matter. The average brightness index (L av ) is the average value of the brightness index L at each moment during the combustion time (T). The higher the average brightness, the more intense the combustion. The bright light area (S) is the area in the flame image captured by the CCD camera 11 through the visible filter 10 that reaches more than 80% of the highest brightness. The combustion stage of volatile matter and the combustion stage of carbon particles during the combustion process of pulverized coal particles can be judged through the bright light area.

[0052] The effect indicators are as follows:

[0053] Peak brightness index L m : L m = L(t) max

[0054] Average brightness index L av :

[0055] Bright light area S: When S > 2d m When, the combustion is defined as the combustion of volatile matter; when S < 2d m When, it is defined as the combustion of carbon particles.

[0056] (6) After the combustion is completed, the ultrafine nickel wire mesh 8 loaded with coal ash or other high-temperature-resistant ultrafine metal wire meshes are placed under a microscope with a magnification of 40 times or more for observation, and compared with the numbered positions of the pulverized coal particles before the test. If coal ash residues can be determined at the numbered positions before the experiment, the numbered positions can be taken as effective observation points. Analyze and process the combustion images obtained by the high-speed camera 11 at this observation point.

[0057] (7) The tail gas generated by the experiment is filtered and treated by the filter cotton 14 and then discharged into the air.

[0058] The following are specific embodiments

[0059] (1) First, select the pulverized coal particle diameter (d m ) to be 70 μm. Therefore, select ultrafine nickel wire with a diameter (d s ) of 150 μm as the material for the design and processing of the ultrafine nickel wire mesh 8 to ensure that the pulverized coal particles can be loaded on the wire and are clearly distinguishable under the microscope. The specific processing scheme is that the distance between the two selected ultrafine nickel wires (D s)Weave it with a diameter of 3 mm to ensure that the pulverized coal particles do not affect each other during combustion. After weaving the ultra-fine nickel wire mesh 8, place it in the combustion chamber 9 and calcine it at a high temperature of 1000 °C for 10 minutes to form an oxide layer on the surface of the wire mesh to prevent it from affecting the subsequent combustion of pulverized coal particles.

[0060] (2) Put the selected pulverized coal with a diameter (d m ) of 70 μm into alcohol, soak and stir it, and its concentration is 0.1 g / 100 ml. Dip the alcohol-soaked pulverized coal with the prepared ultra-fine nickel wire mesh 8. After the alcohol volatilizes, the pulverized coal particles are loaded on the ultra-fine nickel wire mesh 8. Ensure that after the pulverized coal particles are loaded on the ultra-fine nickel wire mesh 8, the distance (D) between any two pulverized coal particles is large enough so that they do not affect each other during combustion.

[0061] (3) After the pulverized coal is loaded on the ultra-fine nickel wire mesh 8, place it under a microscope with a magnification of more than 40 times for observation. When the ratio of the distance (D) between pulverized coal particles to the diameter (d m ) of the pulverized coal particles is greater than 30 (D:d m >30), it can be judged as a single-particle loading mode. At this time, the combustion of pulverized coal particles does not affect each other. When the pulverized coal loading is in the single-particle loading mode, number the pulverized coal particles under the microscope and record their specific positions.

[0062] (4) Use the electric furnace 1 to quickly heat the combustion chamber 9. When the temperature controller 6 shows that the temperature in the furnace reaches above 1000 °C, start to introduce the required oxygen and other gases. After the temperature stabilizes, send the ultra-fine nickel wire mesh 8 loaded with pulverized coal particles into the combustion chamber 9 through the three-dimensional electric displacement platform 5 for experiments.

[0063] (5) Use a high-speed camera 11 to observe and measure the images of the combustion process of pulverized coal particles. During the experiment, place the high-speed camera 11 on the right side of the combustion chamber 9 to receive the image information of the combustion particles, and collect and send it to the computer 15 for processing and analysis. Through calculation, obtain the brightness index L-time t curve, combustion time (T), peak brightness index (L m ), average brightness index (L av ), bright light area (S), etc.

[0064] Among them, the combustion time (T) represents the process in which the brightness index L of a single-particle pulverized coal increases from 5% of the peak brightness to the peak brightness and then drops to 5% of the peak brightness. The peak brightness (L m ) is the maximum brightness index during the combustion process, representing the most intense combustion of volatile matter. The average brightness index (L av) is the average value of the brightness index L at each moment within the combustion time (T). The higher the average brightness, the more intense the combustion. The bright light area (S) is the area in the flame image captured by the high-speed camera 11 through the visible filter 10 that reaches more than 80% of the maximum brightness. The volatile combustion stage and the char particle combustion stage during the combustion process of the pulverized coal particles can be judged through the bright light area.

[0065] The effect indicators are as follows:

[0066] Peak brightness index L m : L m = L(t) max

[0067] Average brightness index L av :

[0068] Bright light area S: When S > 2d m , the combustion is defined as volatile combustion; when S < 2d m it is defined as char particle combustion.

[0069] (6) After the combustion ends, place the ultrafine nickel wire mesh 8 loaded with coal ash under a microscope with a magnification of 40 times or more for observation, and compare it with the position of the pulverized coal particle number before the test. If coal ash residue can be determined at the position of the number before the experiment, that position of the number can be taken as an effective observation point. Analyze and process the combustion image obtained by the high-speed camera 11 at this observation point.

[0070] (7) The tail gas generated by the experiment is filtered by the filter cotton 14 and then discharged into the air.

Claims

1. A device for quantitatively detecting the whole process of a single-particle solid fuel combustion flame, characterized in that: it includes a combustion chamber (9), an air intake device, a pulverized coal particle loading device, an observation and measurement device, and a tail gas treatment device; the combustion chamber (9) is placed inside a high-temperature electric furnace (1); the air intake device is located on the left side of the combustion chamber (9) and is a multi-tube cold trap structure. On the outside are two right-angled intake pipes. The first intake pipe (2a) is used to introduce oxygen, and the second intake pipe (2b) is used to introduce nitrogen. The intake air volume is controlled by a mass flowmeter (16). On the inside are two horizontal pipes. The first horizontal pipe (3a) is used to place a thermocouple (4), and the thermocouple (4) is connected to a temperature controller (6). The second horizontal pipe (3b) is used to place a high-temperature resistant ultra-fine metal wire mesh loaded with pulverized coal particles. The first intake pipe (2a) is connected to an oxygen gas cylinder (17), and the second intake pipe (2b) is connected to a nitrogen gas cylinder (18); one end of the high-temperature resistant ultra-fine metal wire mesh is connected to a high-temperature resistant quartz tube (7); The pulverized coal particle loading device includes a high-temperature resistant ultra-fine metal wire mesh and a three-dimensional electric displacement platform (5); the high-temperature resistant ultra-fine metal wire mesh can select the wire diameter according to the different particle sizes of the pulverized coal particles to be loaded, and control the mesh aperture through weaving; the high-temperature resistant ultra-fine metal wire mesh is used to dip the pulverized coal soaked in a volatile substance that does not react with the pulverized coal at room temperature, such as alcohol or acetone. After the volatile substance that is not easily reactive with the pulverized coal volatilizes, the pulverized coal particles are loaded on the high-temperature resistant ultra-fine metal wire mesh; the high-temperature resistant ultra-fine metal wire with a corresponding diameter is selected according to the particle size of the pulverized coal particles. Specifically, the diameter (d s ) of the selected high-temperature resistant ultra-fine metal wire is 1.5 to 3 times the diameter (d m ) of the pulverized coal particles, ensuring that the pulverized coal particles can be loaded on the wire and are clearly distinguishable under a microscope; when weaving the high-temperature resistant ultra-fine metal wire mesh, the distance between two wires is determined according to the particle size of the pulverized coal particles. Specifically, the distance (D s ) between two wires of the selected high-temperature resistant ultra-fine metal wire mesh is 30 to 50 times the diameter (d m ) of the pulverized coal particles, ensuring that the pulverized coal particles do not affect each other during combustion; the observation and measurement device is located on the right side of the transparent combustion chamber (9) and includes a CCD camera (11) provided with a visible light filter (10) and a long focal length lens. After collecting image data, it is sent to a computer (15) for processing; the tail gas treatment device is located on the right side of the combustion chamber (9) and includes a cooling duct (13) nested outside the quartz tube of the combustion chamber or other high-temperature resistant transparent tubes and filter cotton (14).

2. The device for quantitatively detecting the whole process of a single-particle solid fuel combustion flame according to claim 1, characterized in that: the combustion chamber (9) is made of high-temperature resistant quartz glass material or other high-temperature resistant transparent materials.

3. The device for quantitatively detecting the whole process of a single-particle solid fuel combustion flame according to claim 1, characterized in that, the inner diameter of the combustion chamber is 40 - 50 mm, and the length is 40 - 50 mm.

4. The device for quantitatively detecting the whole process of a single-particle solid fuel combustion flame according to claim 1, characterized in that: in the pulverized coal particle loading device, the three-dimensional electric displacement platform (5) is composed of an electric displacement device and a high-temperature resistant quartz tube (7). One end of the high-temperature resistant quartz tube (7) is connected to the high-temperature resistant ultra-fine metal wire mesh loaded with pulverized coal particles, and the other end is connected to the electric displacement device, which is used to move the position of the high-temperature resistant ultra-fine metal wire mesh loaded with pulverized coal particles so that it can be accurately placed at a set position in the furnace for combustion reaction.

5. The device for quantitatively detecting the whole process of a single-particle solid fuel combustion flame according to claim 1, characterized in that: the observation and measurement device is used to photograph the ignition and combustion process images of the pulverized coal particles loaded on the high-temperature resistant ultra-fine metal wire mesh in the combustion chamber. After the image is collected, it is sent to a computer (15) and processed and calculated through image processing software to obtain the time of each stage of the pulverized coal particle combustion and the combustion process.

6. The operation method of the device for quantitatively detecting the whole process of a single-particle solid fuel combustion flame according to any one of claims 1 - 5, characterized in that: it includes the following steps: (1)Firstly, design and process the high-temperature resistant ultra-fine metal wire mesh in the pulverized coal particle loading device. After the metal wires are woven into a mesh, place the high-temperature resistant ultra-fine metal wire mesh in the combustion chamber for high-temperature calcination to form an oxide layer on the surface of the mesh, preventing it from affecting the subsequent combustion of pulverized coal particles; (2) Immerse the pulverized coal in a volatile substance that does not easily react with the pulverized coal at room temperature and stir. Dip the pulverized coal soaked in the volatile substance such as alcohol or acetone with the prepared high-temperature resistant ultra-fine metal wire mesh. After the volatile substance such as alcohol or acetone volatilizes, the pulverized coal particles are loaded on the high-temperature resistant ultra-fine metal wire mesh; the concentration ratio of the pulverized coal to the volatile substance that does not easily react with the pulverized coal is based on the particle size of the pulverized coal particles (d m ), and the pore size of the high-temperature resistant ultra-fine metal wire mesh (D s ), to ensure that after the pulverized coal particles are loaded on the high-temperature resistant ultra-fine metal wire mesh, the distance between any two particles is large enough so that they do not affect each other during combustion; (3) After the pulverized coal is loaded onto the high-temperature resistant ultra-fine metal wire mesh, it is placed under a microscope with a magnification of 40 times or more for observation. When the ratio of the distance (D) between pulverized coal particles to the diameter (d m ) is greater than 30 (D:d m > 30), it can be judged as the single-particle loading mode. At this time, the combustion of pulverized coal particles does not affect each other. When the pulverized coal loading is in the single-particle loading mode, the pulverized coal particles are numbered under the microscope and their specific positions are recorded; (4)Use an electric furnace (1) to quickly heat the combustion chamber (9). When the temperature controller (6) shows that the temperature in the furnace reaches above 1000 °C or other temperatures required by the experiment, start introducing the required oxygen or other gases. After the temperature stabilizes, send the high-temperature resistant ultra-fine metal wire mesh loaded with pulverized coal particles into the combustion chamber for the experiment through the three-dimensional electric displacement platform (5); (5) A CCD camera (11) is used to observe and measure the images of the pulverized coal particle combustion process. During the experiment, the CCD camera (11) is placed on the right side of the combustion chamber (9) to receive the image information of the combustion particles, and after collection, it is sent to the computer (15) for processing and analysis. Through calculation, the brightness index L - time t curve, combustion time T, peak brightness index L m , average brightness index L av , bright light area S Among them, the combustion time T represents the time required for the brightness index L of a single pulverized coal particle to increase from 5% of the peak brightness to the peak brightness and then decrease to 5% of the peak brightness. The peak brightness L m is the maximum brightness index during the combustion process, representing the most intense volatile combustion. The average brightness index L av is the average value of the brightness index L at each moment within the combustion time T. The higher the average brightness, the more intense the combustion. The bright light area S is the area in the flame image captured through the filter lens that reaches more than 80% of the highest brightness. Through the bright light area, the volatile combustion stage and char particle combustion stage during the combustion process of the pulverized coal particle can be judged. The effect indicators are as follows: Peak brightness index L m : L m = L(t) max； Average brightness index L av : L av = ; Bright area S: When S > 2d m , the combustion is defined as volatile combustion; when S < 2d m , it is defined as char particle combustion (6)After combustion, place the high-temperature resistant ultra-fine metal wire mesh loaded with coal ash under a microscope with a magnification of 40 times or more for observation, and compare it with the position numbers of the pulverized coal particles before the test. If coal ash residues can be determined at the position numbers before the experiment, the position at this number can be taken as an effective observation point, and the combustion images obtained by the high-speed camera at this observation point are analyzed and processed; (7)The tail gas generated by the experiment is filtered through a filter cotton and then discharged into the air.

7. The operation method of the single-particle solid fuel combustion flame full-process quantitative detection device according to claim 6, characterized in that: The high-temperature resistant ultra-fine metal wire mesh is an ultra-fine nickel wire mesh (8).

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