Tar self-cleaning type coke oven gas burner and using method thereof

Abstract

The invention discloses a tar self-cleaning type coke oven gas burner. The burner comprises a shell and an inner container, the inner container is arranged in the shell, and an interlayer cavity is formed between the inner container and the shell. Wherein an inner space defined by the inner container is a coke oven gas channel. An inner space defined by the interlayer cavity is a combustion-supporting air channel. And a porous medium layer is arranged in the coke oven gas channel. The combustor further comprises a decoking oxygen pipeline. And the decoking oxygen pipeline extends into the shell from the outside and penetrates through the combustion-supporting air channel to be connected with the porous medium layer. By adopting the coke oven gas burner disclosed by the invention, off-line or on-line tar cleaning can be carried out without stopping gas, so that the problems of process product quality reduction, energy waste, operation danger and the like in the prior art are avoided, and continuous and stable supply of high-quality coke oven gas is ensured; and normal operation of the coke oven gas burner and the industrial furnace is maintained.

Description

Technical Field

[0001] The invention relates to the cleaning and removal of tar in coke oven gas, in particular to a tar self-cleaning coke oven gas burner and a use method thereof, belonging to the technical field of coke oven gas purification treatment. Background Art

[0002] Coke oven gas is an important by-product gas of steel mills. It has a large volume and high calorific value. It is second only to natural gas in my country's gas fuels. However, coke oven gas contains a lot of tar and naphthalene. In the long-term operation process, these tar and naphthalene will accumulate and block the pipeline and burner, causing the coke oven gas supply pipeline in the burner to be interrupted, making the combustion unstable and often unable to ignite. In addition, the coal tar entering the combustion system will also cause the gas nozzle to be blocked and coked, resulting in the entire combustion device being unable to produce normally, increasing the maintenance workload of operators, wasting energy and increasing labor intensity.

[0003] In the prior art, the cleaning of burners generally adopts offline solutions or online solutions. The offline solution means that after the burner is blocked, resulting in unstable combustion or flameout, the burner is removed from the combustion chamber for cleaning. The online solution means that the burner remains installed on the industrial furnace for cleaning. However, in order to ensure safety, whether it is an offline solution or an online solution, the coke oven gas in the burner and its pipeline needs to be purged and cleaned. Before the pipeline and the burner are separated, the purge gas is introduced from the main pipe, and the corresponding burner gas supply is stopped at this time. This will cause several problems:

[0004] (1) Stopping the gas supply will cause fluctuations in production conditions, affect the temperature and pressure fields in the furnace, and lead to a decline in production quality or even process shutdown. For example, after a burner of a belt roasting machine for oxidation pellets stops, the flue gas temperature near the burner drops rapidly, resulting in a decline in the roasting quality of the pellets in the corresponding area. For industrial furnaces such as rotary kilns that roast oxidation pellets with only one burner, stopping the gas supply to the burner means that the equipment will be shut down.

[0005] (2) After the new or cleaned burner is reinstalled into the combustion chamber and industrial furnace, it is necessary to carry out a purge and ignition procedure for explosion-proof safety purposes, which requires the use of nitrogen and fuel gas, which will lead to material and energy waste;

[0006] (3) The online cleaning method is through high-temperature gas purging, and the tar cleaning effect is limited;

[0007] (4) The offline cleaning and dismantling process wastes manpower. When the burner is removed, there may be local positive pressure in the furnace, causing high-temperature gas to spray out from the burner installation hole, posing an operational hazard.

[0008] (5) The burner removed by the offline solution is cooled quickly, and the tar hardens quickly at room temperature and firmly adheres to the inner wall of the coke gas channel of the burner, making it very difficult to clean and failing to achieve the expected effect;

[0009] (6) Shortening the life of the burner: When the burner is working, the ambient temperature reaches 1200℃ or even higher, and the temperature of the burner components itself will exceed 600℃ or higher. After being removed and exposed to normal temperature air, the material quickly cools from high temperature to normal temperature, and the burner steel has cracked or peeled off, affecting the life of the equipment. Summary of the invention

[0010] In view of the problems existing in the above-mentioned prior art, the present invention transforms the existing coke oven gas burner and proposes a tar self-cleaning coke oven gas burner and a method for using the same. In the scheme of the present invention, the coke oven gas burner adds a porous medium layer in the coke oven gas channel, and connects a decoking oxygen pipeline to the porous medium layer. The coke oven gas removes tar through the porous medium layer, and then ignites and burns with the combustion air. The tar captured by the porous medium reacts with the oxygen input through the decoking oxygen pipeline to undergo an oxidation reaction, thereby achieving the technical effect of tar cleaning. With the coke oven gas burner described in the present invention, it is no longer necessary to stop the gas for offline or online cleaning to clean the tar in the coke oven gas, thereby avoiding the problems of reduced process quality, energy waste, and operational dangers in the prior art, thereby ensuring a continuous and stable supply of high-quality coke oven gas and maintaining the normal operation of the coke oven gas burner and the industrial furnace.

[0011] Moreover, after effectively removing a large amount of tar from the coke oven gas, the present invention oxidizes this part of the tar to release heat, thereby fully utilizing the chemical heat of the combustible substances in the coke oven gas, releasing the chemical heat of the tar that was originally unusable and allowing it to enter the combustion chamber along with the coke oven gas, effectively increasing the calorific value of the coke oven gas and turning waste into treasure.

[0012] According to a first embodiment of the present invention, a tar self-cleaning coke oven gas burner is provided.

[0013] A tar self-cleaning coke oven gas burner, the burner comprises a shell and an inner shell. The inner shell is arranged in the shell, and an interlayer chamber is provided between the inner shell and the shell. The inner space enclosed by the inner shell is a coke oven gas channel. The inner space enclosed by the interlayer chamber is a combustion-supporting air channel. A porous medium layer is provided in the coke oven gas channel. The burner also comprises a decoking oxygen pipeline. The decoking oxygen pipeline extends into the shell from the outside, passes through the combustion-supporting air channel and is connected to the porous medium layer.

[0014] In the present invention, m decoking oxygen pipelines are connected to the porous medium layer, and the value of m ranges from 1 to 10, preferably from 2 to 6.

[0015] Preferably, m decoking oxygen pipes are evenly distributed around the periphery of the porous medium layer.

[0016] In the present invention, the decoking oxygen pipeline is arranged perpendicular to the axial direction of the inner container. Preferably, the inner container is arranged coaxially with the shell.

[0017] In the present invention, according to the direction of the coke oven gas, the upstream end and the downstream end of the coke oven gas channel are respectively provided with a coke oven gas inlet and a coke oven gas outlet. The upstream end and the downstream end of the combustion air channel are respectively provided with a combustion air inlet and a combustion air outlet. Among them, the shell is an equal-diameter cylindrical structure. The inner liner includes an air intake section, a decoking section, and an air outlet section which are arranged in sequence. The diameters of the air intake section, the decoking section, and the air outlet section are the same or different. The porous medium layer is arranged in the decoking section, and the diameter of the porous medium layer is equal to the diameter of the decoking section.

[0018] Preferably, the diameter of the decoking section is smaller than the diameters of the air inlet section and the air outlet section.

[0019] In the present invention, a first pressure monitoring point and a second pressure monitoring point are also provided in the coke oven gas channel, wherein the first pressure monitoring point is located upstream of the porous medium layer, and the second pressure monitoring point is located downstream of the porous medium layer.

[0020] In the present invention, the pore size of the porous medium in the porous medium layer is 0.001-5 mm, preferably 0.05-2 mm.

[0021] According to a second embodiment of the present invention, a method for using a tar self-cleaning coke oven gas burner is provided.

[0022] A method for using the tar self-cleaning coke oven gas burner described in the first embodiment, the method comprising the following steps:

[0023] 1) The coke oven gas and the combustion-supporting air are transported to the coke oven gas channel and the combustion-supporting air channel respectively. At the same time, the oxygen is transported to the decoking oxygen pipeline.

[0024] 2) In the coke oven gas channel, the coke oven gas first passes through the porous medium layer, and the porous medium captures the tar in the coke oven gas. Then, the coke oven gas without tar is discharged from the coke oven gas channel and ignites and burns with the combustion air discharged from the combustion air channel.

[0025] 3) Oxygen enters the porous medium layer through the decoking oxygen pipeline. The oxygen entering the porous medium area undergoes an oxidation reaction with the tar captured by the porous medium. The heat released by the reaction is discharged together with the coke oven gas after the tar is removed.

[0026] In the present invention, in step 2), the flow rate of the coke oven gas in the porous medium layer is greater than the flame propagation speed of the coke oven gas, preferably greater than the flame propagation speed of hydrogen.

[0027] In the present invention, in step 2), the porous medium is a foam metal material and / or a powder metallurgy material. Preferably, the pore size of the porous medium is 0.001-5 mm, preferably 0.05-2 mm.

[0028] In the present invention, the volume flow rate q1 of the coke oven gas in the coke oven gas channel is detected. The cross section of the porous medium layer is set to be circular, and the diameter of the cross section is d0. The superficial velocity v of the coke oven gas in the porous medium layer is calculated based on this. sup Specifically:

[0029]

[0030] Assume the flow rate of coke oven gas in the porous medium layer is v fuel , and the superficial velocity v of coke oven gas in the porous medium layer sup The velocity v of coke oven gas in the porous medium layer fuel Satisfies the following formula:

[0031] v sup =ε·v fuel ……(2).

[0032] Where: ε is the porosity of the porous medium.

[0033] Since the flow rate of coke oven gas in the porous medium layer is greater than the flame propagation speed of hydrogen, we have:

[0034] v fuel >S L ……(3).

[0035] Where: S L is the flame propagation speed of hydrogen.

[0036] Combining formulas (1)-(3), the cross-sectional diameter d0 of the porous medium layer is calculated. That is,

[0037]

[0038] In the present invention, the tar content m in the coke oven gas is determined tar , tar oxidation reaction rate w, combined with the volume flow rate q1 of coke oven gas in the coke oven gas channel and the cross-sectional diameter d0 of the porous medium layer, the length L of the porous medium layer in the axial direction of the coke oven gas channel is calculated. Specifically:

[0039] L>q1·m tar / (1 / 4×π·d02 ) / w……(5).

[0040] In the present invention, in step 3), by measuring the tar content m in the coke oven gas tar , the volume flow rate q1 of the coke oven gas in the coke oven gas channel, and the decoking oxygen flow rate q2 that needs to be input into the porous medium layer. Specifically:

[0041] q2=k·j·q1·m tar / ρ1……(6).

[0042] Where: k is the oxygen excess coefficient, and the value range of k is 1.02-1.1. j is the average molecular weight of tar molecules that consume oxygen when completely oxidized, and the value range of j is 15-30. ρ1 is the oxygen density.

[0043] Preferably, step 3) further comprises a sub-step of adjusting the flow rate of oxygen entering the porous medium layer for decoking, specifically comprising:

[0044] ① Input the initial decoking oxygen flow rate q2 into the porous medium layer.

[0045] ② Set the threshold of the pressure difference between the upstream end and the downstream end of the porous medium layer in the coke oven gas channel, denoted as Δp.

[0046]

[0047] Where: μ is the dynamic viscosity of coke oven gas, and the value range of μ is 5.4-5.8 Pa·s. sup is the superficial velocity of coke oven gas in the porous medium layer. ε is the porosity of the porous medium. ρ is the density of coke oven gas. Dp is the equivalent diameter of the porous medium. L is the length of the porous medium layer.

[0048] ③ The first pressure monitoring point monitors the pressure p1 at the upstream end of the porous medium layer in real time, and the second pressure monitoring point monitors the pressure p2 at the downstream end of the porous medium layer in real time.

[0049] ④ When Z1×Δp<p1-p2≤Z2×Δp, the decoking oxygen flow rate entering the porous medium layer is kept unchanged.

[0050] When p1-p2>Z2×Δp, it is determined that the decoking oxygen flow rate input into the porous medium layer is insufficient, and the decoking oxygen flow rate input into the porous medium layer is adjusted to increase.

[0051] When p1-p2≤Z1×Δp, it is determined that the decoking oxygen flow rate input into the porous medium layer is excessive, and the decoking oxygen flow rate entering the porous medium layer is adjusted to be reduced.

[0052] Among them, Z1 and Z2 are adjustment coefficients, the value range of Z1 is 1-1.05, and the value range of Z2 is 1.08-1.15.

[0053] In view of the problems of reduced process quality, energy waste, and dangerous operation caused by the need to stop gas during the cleaning process of the existing coke oven gas burner, the present invention transforms the existing coke oven gas burner and proposes a coke oven gas burner with tar self-cleaning function. The main structure of the coke oven gas burner still includes a coke oven gas channel and a combustion air channel, wherein the core component of the tar self-cleaning is to add a porous medium layer in the coke oven gas channel, and connect a decoking oxygen pipeline to the porous medium layer. The coke oven gas removes tar through the porous medium layer, and then ignites and burns with the combustion air. The tar captured by the porous medium undergoes an oxidation reaction with the oxygen input through the decoking oxygen pipeline, thereby achieving the technical effect of tar cleaning. The coke oven gas burner described in the present invention can effectively remove a large amount of tar in the coke oven gas and prevent the tar from clogging the burner. The tar cleaning no longer requires stopping the gas for offline or online cleaning, thus avoiding the problems of process quality decline, energy waste, operational hazards, etc. in the prior art, thereby ensuring a continuous and stable supply of high-quality coke oven gas and maintaining the normal operation of the coke oven gas burner and the industrial furnace.

[0054] In addition, after the present invention effectively removes a large amount of tar from the coke oven gas, the tar is oxidized to release heat, thereby making full use of the chemical heat of the combustible substances in the coke oven gas, converting the chemical energy of the tar that was originally unusable into thermal energy, increasing the calorific value of the coke oven gas, and turning waste into treasure. The present application uses pure oxygen to oxidize the tar removed from the coke oven gas. The oxidizing property of pure oxygen is particularly strong. Generally speaking, the higher the degree of oxidation, the easier it is for the oxidation reaction to occur, and the faster the oxidation reaction rate. Under the condition of 200-300°C, the tar will undergo a rapid oxidation reaction. Under the initial condition of pure oxygen at room temperature, the tar begins to undergo an oxidative exothermic reaction, and the oxidation reaction continues to release heat. The heat storage and heat transfer of the porous medium maintain the temperature required for the subsequent reaction of tar and oxygen.

[0055] In the present invention, one or more decoking oxygen pipelines are connected to the porous medium layer. When there are multiple decoking oxygen pipelines, it is preferred that the multiple decoking oxygen pipelines are evenly distributed along the periphery of the porous medium layer. Such an arrangement can inject decoking oxygen into the porous medium from multiple directions of the burner, thereby improving the uniformity of oxygen distribution in the porous medium layer, thereby improving the tar cleaning effect. Preferably, the decoking oxygen pipeline is arranged perpendicular to the axial direction of the inner liner to promote oxygen to enter the porous medium layer, which is conducive to further improving the dispersion and uniformity of oxygen in the porous medium layer.

[0056] The present invention transforms the traditional coke oven gas burner, and the main structure of the coke oven gas burner is still the coke oven gas channel and the combustion-supporting air channel, wherein the coke oven gas channel and the combustion-supporting air channel are coaxially arranged (that is, the inner tank and the shell are coaxially arranged). According to the direction of the coke oven gas, the upstream end and the downstream end of the coke oven gas channel are respectively provided with a coke oven gas inlet and a coke oven gas outlet, and the upstream end and the downstream end of the combustion-supporting air channel are respectively provided with a combustion-supporting air inlet and a combustion-supporting air outlet. The coke oven gas outlet and the combustion-supporting air outlet are designed according to the original burner, and the outlet size, swirl angle, etc. do not change.

[0057] In the present invention, the shell can be set to an equal-diameter cylindrical structure, and the inner liner arranged inside the shell includes an air inlet section, a decoking section and an air outlet section arranged in sequence, wherein the diameters of the air inlet section, the decoking section and the air outlet section are the same or different. The porous medium layer added in the present invention is arranged in the decoking section. In order to avoid the situation where part of the coke oven gas may not pass through the porous medium layer and the tar is not removed when passing through the coke oven gas channel, the diameter of the porous medium layer (i.e., the cross-sectional diameter) is set to be equal to the diameter of the decoking section. When the diameters of the air inlet section, the decoking section and the air outlet section of the inner liner are the same, the inner liner is also an equal-diameter cylindrical structure. In order to avoid waste of materials and energy, and taking into account the pressure problem in the coke oven gas channel, etc., the present invention preferably sets the diameter of the decoking section to be smaller than the diameters of the air inlet section and the air outlet section. Figure 3 As shown, the core components of tar self-cleaning are the porous medium layer and decoking oxygen pipeline shown in the figure. The cross-sectional diameter of the porous medium layer is d0, and the combustion air channel is the same as that of the traditional burner, with a size of d2 (i.e., the cross-sectional size of the shell), and the combustion air is sent into the combustion chamber at a certain speed and angle (i.e., the combustion air outlet); the size of the coke oven gas is d1 (i.e., the size of the air inlet section) before entering the decoking section, and changes in diameter (increases or decreases) to d0 after entering the decoking section, and changes in diameter to the combustion required size d3 (i.e., the size of the air outlet section) after passing through the decoking section, and then the clean coke oven gas is sent into the combustion chamber.

[0058] Preferably, the present invention also sets a first pressure monitoring point and a second pressure monitoring point in the coke oven gas channel, located upstream and downstream of the porous medium layer, respectively, for real-time monitoring of the upstream and downstream pressures of the porous medium layer to ensure the tar cleaning effect, thereby ensuring a continuous and stable supply of high-quality coke oven gas, maintaining the normal operation of the burner and the industrial furnace, and improving the safety of the system.

[0059] When the coke oven gas burner of the present invention is in operation, the coke oven gas and combustion-supporting air are input into the coke oven gas burner according to the design and production parameters of the industrial furnace, and flame combustion is formed in the combustion chamber after passing through the burner. At the same time, decoking oxygen is injected into the porous medium layer from multiple directions of the burner through the decoking oxygen pipeline. The original combustion-supporting air channel still passes through the same flow of combustion-supporting air for gas combustion. A porous medium layer is added to the original coke oven gas channel, and the coke oven gas flows to the coke oven gas outlet after passing through the porous medium, and then ignites and burns with the combustion-supporting air. In this process, the tar in the coke oven gas will be captured by the porous medium, and then undergo an oxidation reaction with the decoking oxygen passed into the porous medium area, thereby achieving the technical effect of tar cleaning.

[0060] Based on the above-mentioned tar self-cleaning coke oven gas burner, the present invention also proposes a method for using the coke oven gas burner, which also includes a description of the input parameters of decoking oxygen, the design parameters of the porous medium layer structure, etc. The method for using the coke oven gas burner of the present invention specifically includes the following steps:

[0061] 1) The coke oven gas and the combustion-supporting air are transported to the coke oven gas channel and the combustion-supporting air channel respectively. At the same time, the oxygen is transported to the decoking oxygen pipeline.

[0062] 2) In the coke oven gas channel, the coke oven gas first passes through the porous medium layer, and the porous medium captures the tar in the coke oven gas; then, the coke oven gas without tar is discharged from the coke oven gas channel and ignites and burns with the combustion air discharged from the combustion air channel.

[0063] 3) Oxygen enters the porous medium layer through the decoking oxygen pipeline. The oxygen entering the porous medium area undergoes an oxidation reaction with the tar captured by the porous medium. The heat released by the reaction is discharged together with the coke oven gas after the tar is removed.

[0064] In the above steps, in order to ensure that oxygen reacts with tar instead of coke oven gas, the gas velocity of coke oven gas, i.e. the flow velocity of coke oven gas in the porous medium layer, v fuel >S, S is the flame propagation speed of coke oven gas, which is affected by gas temperature, fuel molecular composition, pressure, and surrounding heat dissipation conditions. Among the components of coke oven gas, H2 has the largest flame propagation speed and the widest flame propagation volume fraction limit under the same conditions, and H2 accounts for about 60%. Therefore, in order to prevent the ignition and combustion of coke oven gas in porous media, it is sufficient to ensure that its flow rate is greater than the flame propagation speed of H2.

[0065] The flame propagation speed of H2 is S L =f(p,T,T ∞ ,w H2 ). In the present invention, S LThe value range is about 0.25-0.4m / s. As mentioned above, the flow rate of coke oven gas in the porous medium layer should satisfy v fuel >S L .

[0066] The industrial furnace requires a single burner coke oven gas volume flow rate, that is, the volume flow rate of coke oven gas in the coke oven gas channel is q1, then the superficial velocity of coke oven gas in the porous medium layer is v sup for:

[0067] v sup =q1 / A.

[0068] A is the area of ​​the cross section of the porous medium layer. Assuming the cross section is circular and the diameter is d0, then

[0069] A=0.25π·d0 2 .

[0070] The superficial velocity v of coke oven gas in the porous medium layer sup The velocity v of coke oven gas in the porous medium layer fuel Satisfies the following formula:

[0071] v sup =ε·v fue l.

[0072] ε is the porosity of the porous medium, and the value range of ε in the present invention is 0.85-0.95.

[0073] Therefore, the diameter of the cross section of the coke oven gas flowing through the porous medium layer should satisfy:

[0074]

[0075] In the present invention, the pore size d of the porous medium po The value range is 0.001-5mm, and the porous medium is preferably a foam metal material and a powder metallurgy material, and the pore size range is preferably 0.05-2mm, so that most of the tar in the coke oven gas can be attached to the surface of the porous medium and captured by the porous medium, while not adding a large flow resistance to the system. The captured tar undergoes an oxidation reaction under the action of decoking oxygen to generate CO2, H2O, or is incompletely oxidized to generate small molecular alkanes, alkenes or alkynes.

[0076] To ensure that the tar is completely oxidized, the length L of the porous medium layer in the axial direction of the coke oven gas channel should satisfy:

[0077] L>q1·m tar / (1 / 4×π·d0 2 ) / w.

[0078] q1 is the volume flow rate of coke oven gas in the coke oven gas channel, m tar The tar content in coke oven gas is generally 0.02-0.05g / m 3 w is the tar oxidation reaction rate, which is related to the tar component and oxygen component concentration Α O2 , porous medium porosity ε, porous medium thermal conductivity k1, porous medium specific heat capacity c p The tar components are based on the average carbon content per molecule M. C , hydrogen content M H , oxygen content M O measure.

[0079] The tar oxidation reaction rate needs to be determined experimentally, and its correlation with other factors is as follows:

[0080] w=f(M C , M H , M O , gas component concentration Α O2 ,ε,k1,c p ).

[0081] Generally speaking, M C 、M H , Α O2 , k1, c p The larger, or M O The smaller ε is, the greater the tar oxidation reaction rate w is.

[0082] In order to ensure complete removal of tar, the decoking oxygen flow rate q2 input into the porous medium of the present invention should satisfy:

[0083] q2=k·j·q1·m tar / ρ1.

[0084] ρ1 is the oxygen density, ρ1=1.429kg / m 3 ; k is the oxygen excess coefficient, and its value range is 1.02-1.1; j is the average molecular weight of tar molecules that consume oxygen when completely oxidized, which can achieve the complete oxidation reaction of tar attached to the porous medium without affecting the proportion of the combustible components of the coke oven gas itself (usually H2 accounts for 50-60% of the volume, CH4 accounts for 20-30% of the volume, and CO accounts for 5-10% of the volume):

[0085] Tar+j O2→a CO2+b H2O;

[0086] j=M C +1 / 2M H -1 / 2M O , j is generally 15-30.

[0087] The oxidation process of tar is an exothermic reaction, and the heat released by the combustion of unit mass of tar is f tar , then the coke oven gas burner of the present invention can add heat to the coke oven gas:

[0088] Q=f tar q1m tar .

[0089] Further preferably, Figure 4 As shown, after calculating the decoking oxygen flow rate input into the porous medium, the present invention can also adjust the decoking oxygen flow rate entering the porous medium layer in real time as needed, specifically:

[0090] ① Input the initial decoking oxygen flow rate q2 into the porous medium layer.

[0091] ② Set the threshold of the pressure difference between the upstream end and the downstream end of the porous medium layer in the coke oven gas channel, denoted as Δp.

[0092] Under normal operating conditions, there is no tar blockage in the porous medium layer, that is, the entire area of ​​the porous medium layer is connected, and there is a pressure difference between the upstream and downstream of the porous medium layer. When tar blockage occurs in the porous medium layer, the pressure difference between the upstream and downstream of the porous medium layer detected will be greater than the pressure difference under normal operating conditions. The threshold of the above pressure difference is the pressure difference between the upstream and downstream of the porous medium layer under normal operating conditions.

[0093] The pressure difference threshold Δp is calculated by Ergen's formula:

[0094]

[0095] Where: μ is the dynamic viscosity of coke oven gas, and the value range of μ is 5.4-5.8 Pa·s; v sup is the superficial velocity of coke oven gas in the porous medium layer; ε is the porosity of the porous medium; ρ is the density of coke oven gas, and the value range of ρ is 0.4-0.8 kg / m 3 ; Dp is the equivalent diameter of the porous medium, here Dp = d po , which is the same value as the pore size of the porous medium mentioned above; L is the length of the porous medium layer.

[0096] ④ When Z1×Δp<p1-p2≤Z2×Δp, it means that the pressure difference between the upstream and downstream of the porous medium layer is within the pressure difference range under normal working conditions. At this time, no adjustment is required, and the decoking oxygen flow rate entering the porous medium layer can be kept unchanged.

[0097] When p1-p2>Z2×Δp, it means that tar is accumulated in the porous medium layer, resulting in an increase in the pressure difference between the upstream and downstream of the porous medium layer. That is, it is judged that the decoking oxygen flow input into the porous medium layer is insufficient, and tar should not be allowed to continue to accumulate. Therefore, the operation of increasing the oxygen supplement amount is performed to adjust and increase the decoking oxygen flow entering the porous medium layer.

[0098] When p1-p2≤Z1×Δp, it means that there is little or no tar accumulation in the porous medium layer. In order to save oxygen and prevent a large amount of reaction between oxygen and the combustible components in the coke oven gas, it is judged that the decoking oxygen flow rate input into the porous medium layer is excessive. Therefore, the operation of reducing the oxygen supplement amount is performed to adjust and reduce the decoking oxygen flow rate entering the porous medium layer.

[0099] Through adjustment, the pressure difference between the upstream and downstream of the porous medium layer is finally controlled to Z1×Δp<p1-p2≤Z2×Δp. Among them, Z1 and Z2 are adjustment coefficients used to control the boundaries of the above adjustment action. The value range of Z1 is 1-1.05, and the value range of Z2 is 1.08-1.15.

[0100] In the present application, the shell of the coke oven gas burner can be set as an equal-diameter cylindrical structure, wherein the diameter of the shell is 0.01-10m, preferably 0.05-8m, preferably 0.1-5m, more preferably 0.15-3m, and further preferably 0.2-2m.

[0101] Compared with the prior art, the present invention has the following beneficial technical effects:

[0102] 1. By adopting the coke oven gas burner of the present invention, it is no longer necessary to stop the gas for offline or online cleaning to clean the tar in the coke oven gas, thus avoiding the problems of reduced process quality, energy waste, and operational hazards in the prior art, thereby ensuring a continuous and stable supply of high-quality coke oven gas and maintaining the normal operation of the coke oven gas burner and the industrial furnace.

[0103] 2. After effectively removing a large amount of tar from the coke oven gas, the present invention oxidizes this part of the tar to release heat, thereby fully utilizing the chemical heat of the combustible substances in the coke oven gas, releasing the chemical heat of the tar that was originally unusable and allowing it to enter the combustion chamber along with the coke oven gas, effectively increasing the calorific value of the coke oven gas and turning waste into treasure.

[0104] 3. The present invention uses high-purity decoking oxygen to ensure that the tar is completely cleaned, thereby ensuring the combustion effect of the coke oven gas and extending the service life of the burner.

[0105] 4. The present invention specifically defines the input parameters of decoking oxygen, the design parameters of the porous medium layer structure, etc., and also realizes real-time on-demand adjustment of the input decoking oxygen flow rate based on pressure detection, thereby ensuring that the oxygen in the porous medium layer undergoes an oxidation reaction with tar rather than with coke oven gas, and also ensuring that the tar is completely oxidized, increasing the calorific value of the coke oven gas, preventing tar from clogging the burner, and maintaining high-quality, safe and stable operation of the system.

[0106] 4. The present invention is a transformation of the traditional burner, has a simple structure, no moving parts, and good equipment operation stability. BRIEF DESCRIPTION OF THE DRAWINGS

[0107] Figure 1 This is a structural schematic diagram of a tar self-cleaning coke oven gas burner of the present invention;

[0108] Figure 2 for Figure 1 Cross-section view at the middle AA position;

[0109] Figure 3 It is a schematic diagram of the dimensions of the coke oven gas burner in the present invention;

[0110] Figure 4 This is a control flow chart of the decoking oxygen flow rate in the present invention.

[0111] Reference numerals:

[0112] 1: Shell; 2: Inner liner; 3: Coke oven gas channel; 4: Combustion air channel; 5: Porous medium layer; 6: Decoking oxygen pipeline; 701: First pressure monitoring point; 702: Second pressure monitoring point. DETAILED DESCRIPTION

[0113] The technical solution of the present invention is illustrated below by way of example, and the scope of protection requested by the present invention includes but is not limited to the following embodiments.

[0114] According to a first embodiment of the present invention, a tar self-cleaning coke oven gas burner is provided.

[0115] A tar self-cleaning coke oven gas burner, the burner comprises a shell 1 and an inner liner 2. The inner liner 2 is arranged in the shell 1, and an interlayer chamber is provided between the inner liner 2 and the shell 1. The inner space enclosed by the inner liner 2 is a coke oven gas channel 3. The inner space enclosed by the interlayer chamber is a combustion-supporting air channel 4. A porous medium layer 5 is provided in the coke oven gas channel 3. The burner also comprises a decoking oxygen pipeline 6. The decoking oxygen pipeline 6 extends into the shell 1 from the outside, passes through the combustion-supporting air channel 4 and is connected to the porous medium layer 5.

[0116] In the present invention, m decoking oxygen pipelines 6 are connected to the porous medium layer 5. The value range of m is 1-10, preferably 2-6.

[0117] Preferably, m decoking oxygen pipes 6 are evenly distributed around the outer circumference of the porous medium layer 5 .

[0118] In the present invention, the decoking oxygen pipeline 6 is arranged perpendicular to the axial direction of the inner container 2. Preferably, the inner container 2 and the shell 1 are arranged coaxially.

[0119] In the present invention, according to the direction of the coke oven gas, the upstream end and the downstream end of the coke oven gas channel 3 are respectively provided with a coke oven gas inlet and a coke oven gas outlet. The upstream end and the downstream end of the combustion air channel 4 are respectively provided with a combustion air inlet and a combustion air outlet. Among them, the shell 1 is an equal-diameter cylindrical structure. The inner liner 2 includes an air intake section, a decoking section, and an air outlet section arranged in sequence. The diameters of the air intake section, the decoking section, and the air outlet section are the same or different. The porous medium layer 5 is arranged in the decoking section, and the diameter of the porous medium layer 5 is equal to the diameter of the decoking section.

[0120] Preferably, the diameter of the decoking section is smaller than the diameters of the air inlet section and the air outlet section.

[0121] In the present invention, a first pressure monitoring point 701 and a second pressure monitoring point 702 are further provided in the coke oven gas channel 3 , wherein the first pressure monitoring point 701 is located upstream of the porous medium layer 5 , and the second pressure monitoring point 702 is located downstream of the porous medium layer 5 .

[0122] In the present invention, the pore size of the porous medium in the porous medium layer 5 is 0.001-5 mm, preferably 0.05-2 mm.

[0123] Example 1

[0124] like Figure 1 As shown, a tar self-cleaning coke oven gas burner includes a shell 1 and an inner liner 2. The inner liner 2 is arranged in the shell 1, and an interlayer chamber is provided between the inner liner 2 and the shell 1. Among them, the internal space surrounded by the inner liner 2 is a coke oven gas channel 3. The internal space surrounded by the interlayer chamber is a combustion-supporting air channel 4. A porous medium layer 5 is provided in the coke oven gas channel 3. The burner also includes a decoking oxygen pipeline 6. The decoking oxygen pipeline 6 extends into the shell 1 from the outside, and passes through the combustion-supporting air channel 4 to be connected with the porous medium layer 5.

[0125] Example 2

[0126] like Figure 2 As shown, Example 1 is repeated, except that four decoking oxygen pipelines 6 are connected to the porous medium layer 5 .

[0127] Example 3

[0128] Example 1 is repeated, except that two decoking oxygen pipelines 6 are connected to the porous medium layer 5 .

[0129] Example 4

[0130] Example 1 is repeated, except that six decoking oxygen pipes 6 are connected to the porous medium layer 5 .

[0131] Example 5

[0132] Example 2 is repeated, except that the four decoking oxygen pipes 6 are evenly distributed around the periphery of the porous medium layer 5 .

[0133] Example 6

[0134] Example 5 is repeated, except that the decoking oxygen pipeline 6 is arranged perpendicular to the axial direction of the inner container 2.

[0135] Example 7

[0136] Repeat Example 6, except that the inner liner 2 and the shell 1 are coaxially arranged.

[0137] Example 8

[0138] Repeat Example 7, except that the upstream end and downstream end of the coke oven gas channel 3 are respectively provided with a coke oven gas inlet and a coke oven gas outlet according to the direction of the coke oven gas. The upstream end and downstream end of the combustion-supporting air channel 4 are respectively provided with a combustion-supporting air inlet and a combustion-supporting air outlet. Wherein, the shell 1 is an equal-diameter cylindrical structure. The inner liner 2 includes an air inlet section, a decoking section, and an air outlet section which are arranged in sequence. The diameters of the air inlet section, the decoking section, and the air outlet section are the same, that is, the inner liner 2 is also an equal-diameter cylindrical structure. The porous medium layer 5 is arranged in the decoking section, and the diameter of the porous medium layer 5 is equal to the diameter of the decoking section.

[0139] Example 9

[0140] Repeat Example 7, except that the upstream end and downstream end of the coke oven gas channel 3 are respectively provided with a coke oven gas inlet and a coke oven gas outlet according to the direction of the coke oven gas. The upstream end and downstream end of the combustion-supporting air channel 4 are respectively provided with a combustion-supporting air inlet and a combustion-supporting air outlet. Among them, the shell 1 is an equal-diameter cylindrical structure. The inner liner 2 includes an air intake section, a decoking section, and an air outlet section which are arranged in sequence. The diameters of the air intake section, the decoking section, and the air outlet section are different. The porous medium layer 5 is arranged in the decoking section, and the diameter of the porous medium layer 5 is equal to the diameter of the decoking section.

[0141] Example 10

[0142] Example 9 is repeated, except that the diameter of the decoking section is smaller than the diameters of the air inlet section and the air outlet section.

[0143] Embodiment 11

[0144] Example 10 is repeated, except that a first pressure monitoring point 701 and a second pressure monitoring point 702 are further provided in the coke oven gas channel 3 , wherein the first pressure monitoring point 701 is located upstream of the porous medium layer 5 , and the second pressure monitoring point 702 is located downstream of the porous medium layer 5 .

[0145] Example 12

[0146] Example 11 was repeated, except that the pore size of the porous medium in the porous medium layer 5 was 1.5 mm.

[0147] Example 13

[0148] Example 11 was repeated, except that the pore size of the porous medium in the porous medium layer 5 was 2 mm.

[0149] Embodiment 14

[0150] Example 11 was repeated, except that the pore size of the porous medium in the porous medium layer 5 was 0.05 mm.

[0151] Embodiment 15

[0152] Example 11 was repeated, except that the pore size of the porous medium in the porous medium layer 5 was 0.1 mm.

[0153] Example 16

[0154] The method of using the tar self-cleaning coke oven gas burner described in Example 11 comprises the following steps:

[0155] 1) The coke oven gas and the combustion-supporting air are respectively delivered to the coke oven gas channel 3 and the combustion-supporting air channel 4. At the same time, the oxygen is delivered to the decoking oxygen pipeline 6.

[0156] 2) In the coke oven gas channel 3, the coke oven gas first passes through the porous medium layer 5, and the porous medium captures the tar in the coke oven gas. Then, the coke oven gas without tar is discharged from the coke oven gas channel 3 and ignites and burns with the combustion air discharged from the combustion air channel 4.

[0157] 3) Oxygen enters the porous medium layer 5 through the decoking oxygen pipeline 6. The oxygen entering the porous medium area undergoes an oxidation reaction with the tar captured by the porous medium. The heat released by the reaction is discharged together with the coke oven gas after the tar is removed.

[0158] Embodiment 17

[0159] The method of using the tar self-cleaning coke oven gas burner described in Example 11 comprises the following steps:

[0160] 1) The coke oven gas and the combustion-supporting air are respectively delivered to the coke oven gas channel 3 and the combustion-supporting air channel 4. At the same time, the oxygen is delivered to the decoking oxygen pipeline 6.

[0161] 2) In the coke oven gas channel 3, the coke oven gas first passes through the porous medium layer 5, and the porous medium captures the tar in the coke oven gas. Then, the coke oven gas without tar is discharged from the coke oven gas channel 3 and ignites and burns with the combustion air discharged from the combustion air channel 4.

[0162] The flow rate of the coke oven gas in the porous medium layer 5 is greater than the flame propagation speed of the coke oven gas. The porous medium is a foam metal material, and the pore size of the porous medium is 2 mm.

[0163] 3) Oxygen enters the porous medium layer 5 through the decoking oxygen pipeline 6. The oxygen entering the porous medium area undergoes an oxidation reaction with the tar captured by the porous medium. The heat released by the reaction is discharged together with the coke oven gas after the tar is removed.

[0164] Embodiment 18

[0165] Example 17 was repeated, except that in step 2), the porous medium was a powder metallurgy material and the pore size of the porous medium was 0.1 mm.

[0166] Embodiment 19

[0167] Example 17 was repeated, except that in step 2), the porous medium was a foam metal material and a powder metallurgy material, and the pore size of the porous medium was 1.2 mm.

[0168] Embodiment 20

[0169] Example 17 is repeated, except that in step 2), the flow rate of the coke oven gas in the porous medium layer 5 is greater than the flame propagation speed of the hydrogen.

[0170] Embodiment 21

[0171] The method of using the tar self-cleaning coke oven gas burner described in Example 11 comprises the following steps:

[0172] 1) The coke oven gas and the combustion-supporting air are respectively delivered to the coke oven gas channel 3 and the combustion-supporting air channel 4. At the same time, the oxygen is delivered to the decoking oxygen pipeline 6.

[0173] 2) In the coke oven gas channel 3, the coke oven gas first passes through the porous medium layer 5, and the porous medium captures the tar in the coke oven gas. Then, the coke oven gas without tar is discharged from the coke oven gas channel 3 and ignites and burns with the combustion air discharged from the combustion air channel 4.

[0174] The flow rate of the coke oven gas in the porous medium layer 5 is greater than the flame propagation speed of hydrogen. The porous medium is a foam metal material, and the pore size of the porous medium is 1.5 mm.

[0175] 3) Oxygen enters the porous medium layer 5 through the decoking oxygen pipeline 6. The oxygen entering the porous medium area undergoes an oxidation reaction with the tar captured by the porous medium. The heat released by the reaction is discharged together with the coke oven gas after the tar is removed.

[0176] Detect the volume flow rate of coke oven gas in coke oven gas channel 3 q1 = 440m 3 / h=0.122m 3 / s. The cross section of the porous medium layer 5 is assumed to be circular, and the diameter of the cross section is d0. Based on this, the superficial velocity v of the coke oven gas in the porous medium layer 5 is calculated. sup Specifically:

[0177]

[0178] The flow rate of coke oven gas in the porous medium layer 5 is set to v fuel , and the superficial velocity v of the coke oven gas in the porous medium layer 5 sup The flow velocity v of the coke oven gas in the porous medium layer 5 fuel Satisfies the following formula:

[0179] v sup =ε·v fuel ……(2).

[0180] Where: ε is the porosity of the porous medium, ε = 0.9.

[0181] Since the flow rate of the coke oven gas in the porous medium layer 5 is greater than the flame propagation speed of hydrogen, we have:

[0182] v fuel >S L ……(3).

[0183] Where: S L is the flame propagation speed of hydrogen, S L =0.3m / s.

[0184] Combining formulas (1)-(3), the cross-sectional diameter d0 of the porous medium layer 5 is calculated. That is,

[0185]

[0186] Determination of tar content in coke oven gas tar =0.04g / m 3 , tar oxidation reaction rate w = 0.5g / (m 3·s), combined with the volume flow rate of coke oven gas in coke oven gas channel 3, q1 = 0.122m 3 / s, the cross-sectional diameter of the porous medium layer 5 d0 = 0.6m (since d0 < 0.76m, d0 is taken as 0.6m), the length L of the porous medium layer 5 in the axial direction of the coke oven gas channel 3 is calculated. Specifically:

[0187] L>q1·m tar / (1 / 4×π·d0 2 ) / w=0.03454m=34.54mm……(5).

[0188] The length L of the porous medium layer 5 is 40 mm.

[0189] Embodiment 22

[0190] Example 21 was repeated except that in step 3), the tar content m in the coke oven gas was determined. tar =0.04g / m 3 , the volume flow rate of coke oven gas in coke oven gas channel 3 q1 = 0.122m 3 / s, calculate the decoking oxygen flow rate q2 that needs to be input into the porous medium layer 5. Specifically:

[0191] q2=k·j·q1·m tar / ρ1=8.33×10 -5 m 3 / s……(6).

[0192] Where: k is the oxygen excess coefficient, k = 1.06. j is the average molecular weight of oxygen consumed by complete oxidation of tar molecules, j = 23. ρ1 is the oxygen density, ρ1 = 1.429 kg / m 3 .

[0193] Embodiment 23

[0194] Example 22 is repeated, except that step 3) further includes a sub-step of adjusting the flow rate of decoking oxygen entering the porous medium layer 5, specifically comprising:

[0195] ① Input an initial decoking oxygen flow rate q2 into the porous medium layer 5.

[0196] ② Set a threshold value of the pressure difference between the upstream end and the downstream end of the porous medium layer 5 in the coke oven gas channel 3, denoted as Δp.

[0197]

[0198] Where: μ is the dynamic viscosity of coke oven gas, μ = 5.6 Pa·s. sup is the superficial velocity of coke oven gas in the porous medium layer, ε is the porosity of the porous medium, ε = 0.9. ρ is the density of coke oven gas, ρ = 0.6 kg / m 3 Dp is the equivalent diameter of the porous medium, and Dp is equal to the pore size of the porous medium, that is, Dp = 1.5 mm. L is the length of the porous medium layer, L = 40 mm.

[0199] ③ The first pressure monitoring point 701 monitors the pressure p1=110 kPa at the upstream end of the porous medium layer 5 in real time, and the second pressure monitoring point 702 monitors the pressure p2=1.5 kPa at the downstream end of the porous medium layer 5 in real time.

[0200] ④p1-p2=108.5kPa. Obviously, p1-p2>Z2×Δp, where Z2=1.1. It is judged that the decoking oxygen flow rate input into the porous medium layer 5 is insufficient. Adjust to increase the decoking oxygen flow rate entering the porous medium layer 5.

[0201] Embodiment 24

[0202] Example 23 was repeated except that in step 3),

[0203] ③ The first pressure monitoring point 701 monitors the pressure p1 = 88.3 kPa at the upstream end of the porous medium layer 5 in real time, and the second pressure monitoring point 702 monitors the pressure p2 = 2.0 kPa at the downstream end of the porous medium layer 5 in real time.

[0204] ④p1-p2=86.3kPa. Obviously, p1-p2≤Z1×Δp, where Z1=1.02. It is judged that the decoking oxygen flow rate input into the porous medium layer 5 is excessive at this time. The decoking oxygen flow rate entering the porous medium layer 5 is adjusted to reduce.

[0205] Embodiment 25

[0206] Example 23 was repeated except that in step 3),

[0207] ③ The first pressure monitoring point 701 monitors the pressure p1 = 93.4 kPa at the upstream end of the porous medium layer 5 in real time, and the second pressure monitoring point 702 monitors the pressure p2 = 1.6 kPa at the downstream end of the porous medium layer 5 in real time.

[0208] ④p1-p2=91.8 kPa. Obviously, Z1×Δp<p1-p2≤Z2×Δp, where Z1=1.02 and Z2=1.1. No adjustment is required at this time. Just keep the decoking oxygen flow rate entering the porous medium layer 5 unchanged.

Claims

1. A tar self-cleaning coke oven gas burner, characterized in that: The burner comprises a shell (1) and an inner shell (2); the inner shell (2) is arranged in the shell (1), and an interlayer chamber is provided between the inner shell (2) and the shell (1); wherein the internal space enclosed by the inner shell (2) is a coke oven gas channel (3); the internal space enclosed by the interlayer chamber is a combustion-supporting air channel (4); a porous medium layer (5) is provided in the coke oven gas channel (3); the burner further comprises a decoking oxygen pipeline (6); the decoking oxygen pipeline (6) extends from the outside into the shell (1), passes through the combustion-supporting air channel (4), and is connected to the porous medium layer (5).

2. The coke oven gas burner according to claim 1, characterized in that: The porous medium layer (5) is connected to m decoking oxygen pipelines (6); the value of m ranges from 1 to 10, preferably from 2 to 6; Preferably, the m decoking oxygen pipes (6) are evenly distributed around the periphery of the porous medium layer (5).

3. The coke oven gas burner according to claim 1 or 2, characterized in that: The decoking oxygen pipeline (6) is arranged perpendicular to the axial direction of the inner container (2); preferably, the inner container (2) and the shell (1) are arranged coaxially.

4. The coke oven gas burner according to any one of claims 1 to 3, characterized in that: According to the direction of the coke oven gas, the upstream end and the downstream end of the coke oven gas channel (3) are respectively provided with a coke oven gas inlet and a coke oven gas outlet; the upstream end and the downstream end of the combustion air channel (4) are respectively provided with a combustion air inlet and a combustion air outlet; wherein the shell (1) is a cylindrical structure of equal diameter; the inner tank (2) comprises an air inlet section, a decoking section, and an air outlet section which are arranged in sequence; the diameters of the air inlet section, the decoking section, and the air outlet section are the same or different; the porous medium layer (5) is arranged in the decoking section, and the diameter of the porous medium layer (5) is equal to the diameter of the decoking section; Preferably, the diameter of the decoking section is smaller than the diameters of the air inlet section and the air outlet section.

5. The coke oven gas burner according to any one of claims 1 to 4, characterized in that: A first pressure monitoring point (701) and a second pressure monitoring point (702) are also provided in the coke oven gas channel (3); wherein the first pressure monitoring point (701) is located upstream of the porous medium layer (5); and the second pressure monitoring point (702) is located downstream of the porous medium layer (5); and / or The pore size of the porous medium in the porous medium layer (5) is 0.001-5 mm, preferably 0.05-2 mm.

6. A method for using the tar self-cleaning coke oven gas burner according to any one of claims 1 to 5, the method comprising the following steps: 1) The coke oven gas and the combustion-supporting air are respectively transported to the coke oven gas channel (3) and the combustion-supporting air channel (4); at the same time, the oxygen is transported to the decoking oxygen pipeline (6); 2) In the coke oven gas channel (3), the coke oven gas first passes through the porous medium layer (5), and the porous medium captures the tar in the coke oven gas; then, the coke oven gas without tar is discharged from the coke oven gas channel (3) and ignites and burns with the combustion air discharged from the combustion air channel (4); 3) Oxygen enters the porous medium layer (5) through the decoking oxygen pipeline (6). The oxygen entering the porous medium area undergoes an oxidation reaction with the tar captured by the porous medium. The heat released by the reaction is discharged together with the coke oven gas after the tar is removed.

7. The method according to claim 6, characterized in that: In step 2), the flow rate of the coke oven gas in the porous medium layer (5) is greater than the flame propagation speed of the coke oven gas, preferably greater than the flame propagation speed of hydrogen; and / or In step 2), the porous medium is a foam metal material and / or a powder metallurgy material; preferably, the pore size of the porous medium is 0.001-5 mm, preferably 0.05-2 mm.

8. The method according to claim 6 or 7, characterized in that: The volume flow rate q1 of the coke oven gas in the coke oven gas channel (3) is detected; the cross section of the porous medium layer (5) is set to be circular, and the diameter of the cross section is d0; and the superficial velocity v of the coke oven gas in the porous medium layer (5) is calculated based on this. sup ; Specifically: The flow rate of coke oven gas in the porous medium layer (5) is set to v fuel , and the superficial velocity v of coke oven gas in the porous medium layer (5) sup The flow velocity v of the coke oven gas in the porous medium layer (5) fuel Satisfies the following formula: v sup =ε·v fuel ……(2); Where: ε is the porosity of the porous medium; Since the flow velocity of the coke oven gas in the porous medium layer (5) is greater than the flame propagation velocity of hydrogen, we have: v fuel >S L ……(3); Where: S L is the flame propagation speed of hydrogen; Combining formulas (1)-(3), the cross-sectional diameter d0 of the porous medium layer (5) is calculated; namely:

9. The method according to claim 8, characterized in that: Determination of tar content in coke oven gas tar , tar oxidation reaction rate w, combined with the volume flow rate q1 of the coke oven gas in the coke oven gas channel (3) and the cross-sectional diameter d0 of the porous medium layer (5), the length L of the porous medium layer (5) in the axial direction of the coke oven gas channel (3) is calculated; specifically: L>q1·m tar / (1 / 4×π·d0 2 ) / w……(5)。 10. The method according to claim 8 or 9, characterized in that: In step 3), the tar content m in the coke oven gas is measured. tar , the volume flow rate q1 of the coke oven gas in the coke oven gas channel (3), and the decoking oxygen flow rate q2 that needs to be input into the porous medium layer (5); specifically: q2=k·j·q1·m tar / ρ1……(6); Where: k is the oxygen excess coefficient, and the value range of k is 1.02-1.1; j is the average molecular weight of tar molecules that consume oxygen when completely oxidized, and the value range of j is 15-30; ρ1 is the oxygen density; Preferably, step 3) further comprises a sub-step of adjusting the flow rate of oxygen entering the porous medium layer (5) for decoking, specifically comprising: ① Inputting an initial decoking oxygen flow rate q2 into the porous medium layer (5); ② setting a threshold value of the pressure difference between the upstream end and the downstream end of the porous medium layer (5) in the coke oven gas channel (3), denoted as Δp; Where: μ is the dynamic viscosity of coke oven gas, and the value range of μ is 5.4-5.8 Pa·s; v sup is the superficial velocity of coke oven gas in the porous medium layer; ε is the porosity of the porous medium; ρ is the density of coke oven gas; Dp is the equivalent diameter of the porous medium; L is the length of the porous medium layer; ③ The first pressure monitoring point (701) monitors the pressure p1 at the upstream end of the porous medium layer (5) in real time, and the second pressure monitoring point (702) monitors the pressure p2 at the downstream end of the porous medium layer (5) in real time; ④ When Z1×Δp<p1-p2≤Z2×Δp, the decoking oxygen flow rate entering the porous medium layer (5) is kept unchanged; When p1-p2>Z2×Δp, it is determined that the decoking oxygen flow rate input into the porous medium layer (5) is insufficient, and the decoking oxygen flow rate input into the porous medium layer (5) is adjusted to increase; When p1-p2≤Z1×Δp, it is judged that the decoking oxygen flow rate input into the porous medium layer (5) is excessive, and the decoking oxygen flow rate entering the porous medium layer (5) is adjusted to reduce; Among them, Z1 and Z2 are adjustment coefficients, the value range of Z1 is 1-1.05, and the value range of Z2 is 1.08-1.15.

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