CN112691544B - Ammonia spraying device for denitration and cracking furnace system with same - Google Patents
Ammonia spraying device for denitration and cracking furnace system with same Download PDFInfo
- Publication number
- CN112691544B CN112691544B CN201911007003.7A CN201911007003A CN112691544B CN 112691544 B CN112691544 B CN 112691544B CN 201911007003 A CN201911007003 A CN 201911007003A CN 112691544 B CN112691544 B CN 112691544B
- Authority
- CN
- China
- Prior art keywords
- ammonia
- denitration
- spraying
- wall surface
- area
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
- B01D53/34—Chemical or biological purification of waste gases
- B01D53/74—General processes for purification of waste gases; Apparatus or devices specially adapted therefor
- B01D53/86—Catalytic processes
- B01D53/8621—Removing nitrogen compounds
- B01D53/8625—Nitrogen oxides
- B01D53/8631—Processes characterised by a specific device
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
- B01D53/34—Chemical or biological purification of waste gases
- B01D53/74—General processes for purification of waste gases; Apparatus or devices specially adapted therefor
- B01D53/86—Catalytic processes
- B01D53/90—Injecting reactants
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C4/00—Preparation of hydrocarbons from hydrocarbons containing a larger number of carbon atoms
- C07C4/02—Preparation of hydrocarbons from hydrocarbons containing a larger number of carbon atoms by cracking a single hydrocarbon or a mixture of individually defined hydrocarbons or a normally gaseous hydrocarbon fraction
- C07C4/04—Thermal processes
-
- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
- C10G9/00—Thermal non-catalytic cracking, in the absence of hydrogen, of hydrocarbon oils
-
- C—CHEMISTRY; METALLURGY
- C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
- C10G—CRACKING HYDROCARBON OILS; PRODUCTION OF LIQUID HYDROCARBON MIXTURES, e.g. BY DESTRUCTIVE HYDROGENATION, OLIGOMERISATION, POLYMERISATION; RECOVERY OF HYDROCARBON OILS FROM OIL-SHALE, OIL-SAND, OR GASES; REFINING MIXTURES MAINLY CONSISTING OF HYDROCARBONS; REFORMING OF NAPHTHA; MINERAL WAXES
- C10G9/00—Thermal non-catalytic cracking, in the absence of hydrogen, of hydrocarbon oils
- C10G9/14—Thermal non-catalytic cracking, in the absence of hydrogen, of hydrocarbon oils in pipes or coils with or without auxiliary means, e.g. digesters, soaking drums, expansion means
- C10G9/18—Apparatus
- C10G9/20—Tube furnaces
Abstract
The invention relates to the technical field of denitration, and discloses an ammonia injection device for denitration and a cracking furnace system with the same. Wherein, denitration is with spouting ammonia device includes: the denitration device comprises a flue gas channel section, a denitration device and a denitration device, wherein a denitration area is formed in the flue gas channel section, the denitration area comprises a first area and a second area which cover the cross sections of the denitration area together, and the flue gas channel section comprises a first wall surface and a second wall surface, wherein the first wall surface corresponds to the first area, and the second wall surface corresponds to the second area; the first ammonia spraying pipes are arranged on the first wall surface and used for spraying ammonia to the first area; the second ammonia spraying pipes are arranged on the second wall surface and used for spraying ammonia to the second area; the first pipeline structure is connected with the first ammonia spraying pipe and is suitable for conveying ammonia gas with corresponding quantity for the first ammonia spraying pipe according to the content of nitrogen oxides in the first area; and the second pipeline structure is connected with the second ammonia spraying pipe and is suitable for conveying ammonia gas with corresponding quantity for the second ammonia spraying pipe according to the content of the nitrogen oxides in the second area. The device can satisfy the denitration operation demand of more operating modes, improves the denitration effect.
Description
Technical Field
The invention relates to the technical field of denitration, in particular to an ammonia injection device for denitration and a cracking furnace system with the same.
Background
According to the generation mechanism of NOx, the current domestic and foreign ethylene cracking furnaces for NOx emission reduction mainly comprise denitrification before combustion, control during combustion and reduction after combustion, wherein a Selective Catalytic Reduction (SCR) process is widely applied due to the advantages of high denitration efficiency, low reaction temperature, no secondary pollution and the like. The main principle of the SCR denitration process is that a reducing agent (generally, a mixed gas of ammonia gas and air) enters a flue gas channel through an ammonia spraying device, and nitrogen oxides in flue gas are fully mixed with the reducing agent and react under the action of a catalyst, and finally converted into nitrogen gas and water, thereby achieving the purpose of denitration. The even degree of mixing of reductant and flue gas can produce direct influence to the operational effect of denitration reactor, when the mixed effect is not good, can appear that local spraying ammonia is excessive, the ammonia escape rate risees and denitration efficiency reduces scheduling problem, causes even that NOx content in the flue gas after the purification can not satisfy the environmental protection standard requirement.
Cracking furnaces are used as core devices in ethylene production, and the design and research of high-energy cracking furnaces are already the development direction of large-scale ethylene plants. At present, most cracking furnaces with annual ethylene production capacity exceeding 10 ten thousand tons adopt a structure that two radiation sections share one convection section. Because the cracking furnace has the characteristic of double radiation sections, one radiation section can be adopted for cracking working conditions, and the other radiation section can be adopted for burning working conditions, the operation mode is favorable for improving the annual production time of the cracking furnace, increasing the annual ethylene yield of the cracking furnace and saving the fuel consumption. Usually, the NOx content in the flue gas of the double-radiation-section cracking furnace has obvious difference under the working conditions of cracking and burning, but the ammonia injection device in the prior art hardly meets the operation requirements of the working conditions, so that the denitration effect is not ideal.
Disclosure of Invention
The invention aims to overcome the technical problem that an ammonia spraying device in the prior art is difficult to meet denitration operation requirements under various working conditions, so that the denitration effect is not ideal, and provides an ammonia spraying device for denitration and a cracking furnace system with the same.
In order to achieve the above object, the present invention provides an ammonia injection device for denitration, comprising: the denitration device comprises a flue gas channel section, a first partition plate and a second partition plate, wherein a denitration area is formed in the flue gas channel section, the denitration area comprises a first area and a second area which cover the cross sections of the denitration area together, and the flue gas channel section comprises a first wall surface and a second wall surface, the first wall surface corresponds to the first area, and the second wall surface corresponds to the second area; a plurality of first ammonia spraying pipes which are arranged on the first wall surface and used for spraying ammonia to the first area; a plurality of second ammonia spraying pipes arranged on the second wall surface and used for spraying ammonia to the second area; the first pipeline structure is connected with the first ammonia injection pipe and is suitable for conveying a corresponding amount of ammonia gas to the first ammonia injection pipe according to the content of nitrogen oxides in the first area; and the second pipeline structure is connected with the second ammonia injection pipe and is suitable for conveying a corresponding amount of ammonia gas to the second ammonia injection pipe according to the content of the nitrogen oxides in the second area.
Preferably, the first ammonia spraying pipes and the second ammonia spraying pipes are arranged in pairs, the axes of each pair of the first ammonia spraying pipes and the second ammonia spraying pipes are collinear, one end, far away from the first wall surface, of each first ammonia spraying pipe is abutted to one end, far away from the second wall surface, of each second ammonia spraying pipe, and the first ammonia spraying pipes and the second ammonia spraying pipes cover the cross section of the denitration area at uniform intervals.
Preferably, the first pipeline structure comprises a plurality of first ammonia conveying pipes which are connected with the first ammonia spraying pipes in a one-to-one correspondence manner, and the first ammonia conveying pipes are connected with one ends, located outside the flue gas channel, of the first ammonia spraying pipes through valves; the second pipeline structure comprises a plurality of second ammonia conveying pipes which are connected with the second ammonia spraying pipes in a one-to-one correspondence mode, and the second ammonia conveying pipes are connected with one ends, located outside the smoke channel, of the second ammonia spraying pipes through valves.
Preferably, a plurality of first ammonia spraying holes and a plurality of second ammonia spraying holes are respectively arranged on the first ammonia spraying pipe and the second ammonia spraying pipe in rows and at even intervals, the ammonia spraying direction of the first ammonia spraying holes is consistent with the flowing direction of the flue gas, and the ammonia spraying direction of the second ammonia spraying holes is perpendicular to the flowing direction of the flue gas.
Preferably, the second ammonia spraying holes are arranged in two rows, the two rows of ammonia spraying holes on the first ammonia spraying pipe are symmetrically arranged relative to the axis of the first ammonia spraying pipe, the two rows of ammonia spraying holes on the second ammonia spraying pipe are symmetrically arranged relative to the axis of the second ammonia spraying pipe, and the two rows of ammonia spraying holes oppositely arranged on two adjacent first ammonia spraying pipes or two adjacent second ammonia spraying pipes are staggered.
Preferably, the distance between the first ammonia injection hole on the first ammonia injection pipe close to the first wall surface and the first wall surface is half of the distance between the other two adjacent first ammonia injection holes; the distance between the second ammonia spraying hole on the first ammonia spraying pipe close to the first wall surface and the first wall surface is half of the distance between the other two adjacent second ammonia spraying holes; the distance between the first ammonia spraying hole on the second ammonia spraying pipe close to the second wall surface and the second wall surface is half of the distance between the other two adjacent first ammonia spraying holes; the distance between the second ammonia spraying hole on the second ammonia spraying pipe close to the second wall surface and the second wall surface is half of the distance between the other two adjacent second ammonia spraying holes.
Preferably, the first ammonia injection hole is a circular hole, and the second ammonia injection hole is a tapered hole with gradually increasing hole diameter.
The invention also provides a cracking furnace system which comprises a cracking furnace and the ammonia spraying device for denitration, which is arranged on the cracking furnace.
Preferably, the cracking furnace is a dual radiant section cracking furnace.
Preferably, the ammonia injection device for denitration is arranged at the preheating section part of the convection section of the cracking furnace.
Through the technical scheme, the ammonia injection device can control and adjust the ammonia injection amount in a divided manner according to different operation conditions, and is particularly suitable for a double-radiation-section cracking furnace, when the double-radiation-section cracking furnace simultaneously operates the cracking condition and the scorching condition, the NOx content in the smoke has obvious difference, when the ammonia injection device is installed, a smoke denitration area (namely a first area) corresponding to the cracking condition of the first ammonia injection pipe can be correspondingly arranged, a smoke denitration area (namely a second area) corresponding to the scorching condition of the second ammonia injection pipe is correspondingly arranged, so when the NOx content in the smoke has obvious difference, the ammonia injection amount of the first ammonia injection pipe is correspondingly controlled and adjusted according to the NOx content of the first area through the first pipeline structure, the ammonia injection amount of the second ammonia injection pipe is correspondingly controlled and adjusted according to the NOx content of the second area through the second pipeline structure, so that the two denitration areas with different NOx contents can effectively perform denitration reactions, the ammonia injection amounts of the two areas with different NOx contents are prevented from being injected, the ammonia with the same amount is prevented from being injected into the areas with different NOx contents, the ammonia injection amount is correspondingly controlled and the ammonia injection amount is not fully reacted, the ammonia injection amount, the ammonia injection device can be used for improving the operation condition that the denitration effect is not too much, and the operation condition that the operation effect is not too much more operation condition is wasted.
Drawings
FIG. 1 is a plan view of an embodiment of an ammonia sparger for denitration in accordance with the present invention;
FIG. 2 is a sectional view of the ammonia injection device for denitration shown in FIG. 1;
FIG. 3 is a sectional view of the second ammonia injection hole of the first ammonia injection pipe or the second ammonia injection pipe of the ammonia injection device for denitration shown in FIG. 2;
FIG. 4 is a schematic structural view of one embodiment of a cracking furnace system of the present invention;
description of the reference numerals
1-a second ammonia gas delivery pipe; 2-a valve; 3-a first ammonia spraying pipe; 4-a second ammonia spraying pipe; 5-a second ammonia spraying hole; 6-first ammonia injection hole; 7-a first ammonia gas duct; 8-a second wall; 9-a first wall surface; 10-convection section; 11-radiation section.
Detailed Description
The endpoints of the ranges and any values disclosed herein are not limited to the precise range or value, and such ranges or values should be understood to encompass values close to those ranges or values. For ranges of values, between the endpoints of each of the ranges and the individual points, and between the individual points may be combined with each other to give one or more new ranges of values, and these ranges of values should be considered as specifically disclosed herein.
In the present invention, unless otherwise specified, the use of directional terms such as "upper, lower, left, right" and the like are generally in accordance with the orientation as shown in the drawings.
As shown in fig. 1-2, the present invention provides an ammonia injection device for denitration, which is suitable for performing low-temperature SCR denitration on flue gas in a denitration reactor such as a cracking furnace, and is particularly suitable for a dual-radiation-section cracking furnace, and the ammonia injection device for denitration comprises: a flue gas passage section, in which a denitration region is formed, the denitration region includes a first region and a second region that cover the cross section of the flue gas passage section together, as shown in fig. 2, a left side denitration region corresponding to the first ammonia injection pipe 3 is the first region, a right side denitration region corresponding to the second ammonia injection pipe 4 is the second region (i.e. the first region and the second region are not two regions divided up and down), and the flue gas passage section includes a first wall surface 9 corresponding to the first region and a second wall surface 8 corresponding to the second region; a plurality of first ammonia injection pipes 3 arranged on the first wall surface 9 and used for injecting ammonia into the first area; a plurality of second ammonia injection pipes 4 arranged on the second wall surface 8 and used for injecting ammonia into the second area; a first pipeline structure connected with the first ammonia spraying pipe 3 and suitable for conveying a corresponding amount of ammonia gas to the first ammonia spraying pipe 3 according to the content of nitrogen oxides in the first area; and the second pipeline structure is connected with the second ammonia injection pipe 4 and is suitable for conveying a corresponding amount of ammonia gas to the second ammonia injection pipe 4 according to the content of the nitrogen oxides in the second area. By adopting the design, the ammonia gas sprayed by the first ammonia spraying pipe 3 and the ammonia gas sprayed by the second ammonia spraying pipe 4 can be the same or different; meanwhile, the first area and the second area are only used for virtually dividing the denitration area, and no solid interface exists in the denitration area actually. The first wall surface for installing the first ammonia spraying pipe and the second wall surface for installing the second ammonia spraying pipe can be arranged oppositely or vertically, can be the whole wall surface or a part of the wall surface, and the number of the first wall surface and the second wall surface can be one or two.
The ammonia injection device can control and adjust the ammonia injection amount in different regions according to different operation conditions, the ammonia injection device is particularly suitable for the double-radiation-section cracking furnace, when the double-radiation-section cracking furnace simultaneously performs cracking conditions and scorching conditions, the NOx (nitrogen oxide) content in the smoke has obvious difference, when the ammonia injection device is installed, the first ammonia injection pipe 3 can be correspondingly arranged with a smoke denitration region (namely a first region) corresponding to the cracking conditions, the second ammonia injection pipe 4 is correspondingly arranged with a smoke denitration region (namely a second region) corresponding to the scorching conditions, so when the NOx content in the smoke has obvious difference, the ammonia injection amount of the first ammonia injection pipe 3 is correspondingly controlled and adjusted according to the NOx content of the first region through the first pipeline structure, the ammonia injection amount of the second ammonia injection pipe 4 is correspondingly controlled and adjusted according to the NOx content of the second region through the second pipeline structure, thereby, the two denitration regions with different NOx contents can more effectively perform denitration reactions, the ammonia injection amount of the two regions with different NOx contents is prevented from being injected into the same regions, the ammonia injection amount is caused by the excessive ammonia injection amount, the ammonia injection operation condition that the ammonia injection effect is not enough, and the more operation condition that the ammonia injection effect is not enough is caused, and the more operation condition that the denitration effect is not enough.
In one embodiment, the end of the first ammonia injection pipe 3 away from the first pipeline structure (i.e. the right end) and the end of the second ammonia injection pipe 4 away from the second pipeline structure (i.e. the left end) are both of a blocking structure.
As an embodiment, as shown in fig. 1 and fig. 2, the first ammonia spraying pipes 3 and the second ammonia spraying pipes 4 are arranged in pairs, the axes of each pair of the first ammonia spraying pipes 3 and the second ammonia spraying pipes 4 are collinear, one end of each pair of the first ammonia spraying pipes 3, which is far away from the first wall surface 9, is abutted against one end of each pair of the second ammonia spraying pipes 4, which is far away from the second wall surface 8, and a plurality of pairs of the first ammonia spraying pipes 3 and the second ammonia spraying pipes 4 are uniformly spaced and covered on the cross section of the denitration region, as shown in fig. 2, the first wall surfaces 9 and the second wall surfaces 8 are arranged oppositely, and the first ammonia spraying pipes 3 and the second ammonia spraying pipes 4 are respectively located on two sides of the flue gas passage section, in this embodiment, the first ammonia spraying pipes 3 and the second ammonia spraying pipes 4 may be an integral structure or a split structure. According to the design, the mixing strength and uniformity of ammonia gas and flue gas can be improved while the regional control is realized, the content of nitrogen oxide at the outlet of the denitration reactor and the escape rate of ammonia gas are reduced, and the denitration efficiency of the SCR denitration reactor is improved.
In one embodiment, as shown in fig. 1, the first ammonia spraying pipe 3 and the second ammonia spraying pipe 4 have the same length, which is equal to half of the length or width of the flue gas channel. The lengths of the first ammonia spraying pipe 3 and the second ammonia spraying pipe 4 can also be set to be unequal according to practical application conditions.
As an implementation mode, the first ammonia spraying pipe 3 and the second ammonia spraying pipe 4 can also be vertically arranged, so long as the ammonia sprayed out from the first ammonia spraying pipe 3 can correspond to the first area, the ammonia sprayed out from the second ammonia spraying pipe 4 can correspond to the second area, the first ammonia spraying pipe 3 and the second ammonia spraying pipe 4 can realize regional control, the ammonia with corresponding concentration is sprayed out from each area, and the mixing intensity and uniformity of the ammonia and the smoke are ensured.
As an embodiment, the first ammonia injection pipe 3 and the second ammonia injection pipe 4 may also be arranged in parallel, that is, two ends of the first ammonia injection pipe 3 located on the left side are respectively connected with two wall surfaces of the corresponding area; two ends of the second ammonia spraying pipe 4 positioned on the right side are respectively connected with two wall surfaces of the corresponding areas.
In one embodiment, the distance between two adjacent first ammonia spraying pipes 3 and two adjacent second ammonia spraying pipes 4 is set to be 100-400mm, preferably 200-300mm.
As an embodiment, as shown in fig. 1 and fig. 2, the first pipeline structure includes a plurality of first ammonia gas conveying pipes 7 connected to the first ammonia gas spraying pipes 3 in a one-to-one correspondence manner, and the first ammonia gas conveying pipes 7 are connected to one ends of the first ammonia gas spraying pipes 3 located outside the flue gas channel through valves; the second pipeline structure comprises a plurality of second ammonia conveying pipes 1 which are connected with the second ammonia spraying pipes 4 in a one-to-one correspondence mode, and the second ammonia conveying pipes 1 are connected with one ends, located outside the smoke channel, of the second ammonia spraying pipes 4 through valves. Preferably, the valves are respectively arranged at the joint of the first ammonia spraying pipe 3 and the first ammonia gas delivery pipe 7 and the joint of the second ammonia spraying pipe 4 and the second ammonia gas delivery pipe 1. The design can respectively control the ammonia amount entering the first area and the second area through the valves, so that the ammonia spraying amount of the first area and the ammonia spraying amount of the second area can be the same or different, and the ammonia spraying amount of the two areas can be flexibly adjusted; simultaneously because every spouts ammonia pipe and corresponds and connect an ammonia conveyer pipe, can also realize the subregion control to same region.
As an embodiment, as shown in fig. 1, a plurality of first ammonia spraying holes 6 and a plurality of second ammonia spraying holes 5 are respectively arranged on the first ammonia spraying pipe 3 and the second ammonia spraying pipe 4 in rows and at uniform intervals, the ammonia spraying direction of the first ammonia spraying holes 6 is consistent with the flow direction of the flue gas (i.e. the first ammonia spraying holes 6 are respectively located above the first ammonia spraying pipe 3 and the second ammonia spraying pipe 4), and the ammonia spraying direction of the second ammonia spraying holes 5 is perpendicular to the flow direction of the flue gas (i.e. the second ammonia spraying holes 5 are respectively located on two sides of the first ammonia spraying pipe 3 and the second ammonia spraying pipe 4). In the prior art, a nozzle type structure is usually adopted, the ammonia spraying effect mainly depends on the number of nozzles in a unit area, and when the denitration efficiency requirement is high, a large number of spraying pipes or nozzles need to be configured; if the spray pipes are arranged too densely, the flow fields of the ammonia gas sprayed by the nozzles with opposite spraying directions on the adjacent spray pipes interfere with each other, so that the uniformity of ammonia gas distribution is reduced, and the denitration efficiency of the reactor is further influenced; the problems of complex structure and high manufacturing and maintenance cost of the ammonia spraying device can occur when the number of the nozzles is too large; the first ammonia spraying holes 6 and the second ammonia spraying holes 5 are relatively simple in structure and low in manufacturing and maintenance cost, flow fields of ammonia gas sprayed from the ammonia spraying holes with opposite spraying directions are not easy to interfere with each other, and the uniformity of ammonia gas distribution and the denitration efficiency can be guaranteed; simultaneously two kinds of designs of spouting the ammonia hole can also make the ammonia that spouts the ammonia pipe spun more even, and with the more abundant of the nitrogen oxide reaction in the flue gas, the denitration effect is better.
As an embodiment, as shown in fig. 1, the second ammonia injection holes 5 are arranged in two rows, two rows of the ammonia injection holes on the first ammonia injection pipe 3 are symmetrically arranged with respect to the axis of the first ammonia injection pipe 3, two rows of the ammonia injection holes on the second ammonia injection pipe 4 are symmetrically arranged with respect to the axis of the second ammonia injection pipe 4, and two rows of the second ammonia injection holes 5 oppositely arranged on two adjacent first ammonia injection pipes 3 or two adjacent second ammonia injection pipes 4 are alternately arranged (i.e., two rows of the second ammonia injection holes 5 with opposite injection directions are alternately arranged, and are not necessarily in correspondence). The design can prevent the mutual interference of the ammonia gas flow fields sprayed by the second ammonia spraying holes 5 with opposite spraying directions, and the uniformity of ammonia gas distribution and the denitration efficiency are ensured; meanwhile, the design of the two rows of second ammonia spraying holes 5 can ensure that the uniformity of ammonia sprayed by the ammonia spraying pipes in the first area or the second area is better, and the ammonia reacts with nitrogen oxides in smoke more fully.
In one embodiment, as shown in fig. 1 and 2, the distance between the first ammonia injection hole 6 on the first ammonia injection pipe 3 near the first wall surface 9 and the first wall surface 9 is half of the distance between two other adjacent first ammonia injection holes 6; the distance between the second ammonia spraying hole 5 on the first ammonia spraying pipe 3 close to the first wall surface 9 and the first wall surface 9 is half of the distance between the other two adjacent second ammonia spraying holes 5; the distance between the first ammonia spraying hole 6 on the second ammonia spraying pipe 4 close to the second wall surface 8 and the second wall surface 8 is half of the distance between the other two adjacent first ammonia spraying holes 6; the distance between the second ammonia injection hole 5 on the second ammonia injection pipe 4 close to the second wall surface 8 and the second wall surface 8 is half of the distance between the other two adjacent second ammonia injection holes 5. Namely, the distance between the ammonia injection hole (the first ammonia injection hole 6 or the second ammonia injection hole 5) close to the wall surface of the flue gas channel and the wall surface is half of the distance between the other two adjacent ammonia injection holes. The design can ensure that the spraying ranges of the ammonia spraying holes on the first ammonia spraying pipe 3 and the second ammonia spraying pipe 4 are consistent, and if the distance between the ammonia spraying hole close to the wall surface and the wall surface is far or close, the uniformity of the ammonia gas in the area can be influenced.
In one embodiment, the first ammonia injection hole 6 is a circular hole, and the second ammonia injection hole 5 is a tapered hole having a gradually increasing diameter, as shown in fig. 3. The central line of the circular hole is vertical to the axes of the first ammonia spraying pipe 3 and the second ammonia spraying pipe 4, the central line of the conical hole is vertical to the axes of the first ammonia spraying pipe 3 and the second ammonia spraying pipe 4, and the central line of the circular hole is vertical to the central line of the conical hole. The design of the conical hole is beneficial to expanding the spraying range of the ammonia gas and improving the uniformity of the ammonia gas distribution. The first ammonia spraying holes 6 positioned above the first ammonia spraying pipe 3 and the second ammonia spraying pipe 4 can diffuse to the periphery due to the action of gravity, and the uniformity is better, so that circular holes can be used, and the manufacturing is simple; the second ammonia spraying holes 5 are positioned at two sides of the first ammonia spraying pipe 3 and the second ammonia spraying pipe 4, so that the sprayed ammonia gas can be more uniformly diffused by using the conical holes; through mutually supporting of the ammonia injection hole of two kinds of different grade types, can effectively improve the mixing intensity and the homogeneity of ammonia and flue gas, reduce denitration reactor export nitrogen oxide content and ammonia escape rate, improve denitration efficiency.
In one embodiment, the throat diameter d of the second ammonia injection hole 5 can be set to be 1-20mm, preferably 5-10mm; the injection diffusion angle alpha of the second ammonia injection hole 5 can be set to be 10-60 degrees, and preferably 20-50 degrees.
As an embodiment, the diameter of the circular hole may be set to 10 to 30mm, preferably 15 to 20mm.
In one embodiment, the first ammonia injection holes 6 and the second ammonia injection holes 5 are uniformly distributed on the first ammonia injection pipe 3 and the second ammonia injection pipe 4 at intervals, and the number of the second ammonia injection holes 5 is twice that of the first ammonia injection holes 6. The number of the second ammonia spraying holes 5 can be set to 10-30, preferably 12-20.
Two kinds of ammonia-spraying holes are arranged according to the mode, so that the mixing strength and uniformity of ammonia and flue gas can be effectively improved, the content of nitrogen oxides at the outlet of the denitration reactor and the escape rate of ammonia are reduced, and the denitration efficiency of the SCR denitration reactor is improved.
As shown in fig. 4, the present invention further provides a cracking furnace system, which includes a cracking furnace and the ammonia injection device for denitration arranged on the cracking furnace, wherein the ammonia injection device is used for performing low-temperature SCR denitration on flue gas in the cracking furnace.
As an embodiment, the cracking furnace is a double-radiation-section cracking furnace, as shown in fig. 4, the radiation sections 11 are arranged on both the left side and the right side of the cracking furnace, wherein the flue gas in the first region mainly flows out from the radiation section on the left side, and the flue gas in the second region mainly flows out from the radiation section on the right side. First ammonia pipe 3, the design of ammonia pipe 4 and valve is spouted to the second can satisfy the operating requirement that the dual radiation section pyrolysis furnace carries out the schizolysis operating mode simultaneously and burns the burnt operating mode, make the NOx content looks adaptation in 3 spun ammonia tolerance of first ammonia pipe and the flue gas in the first region, make the second spout the NOx content looks adaptation in 4 spun ammonia tolerance of ammonia pipe and the flue gas in the second region, thereby realize denitration reactor's subregion control and regulation, the flexibility and the denitration effect of spouting the operation of ammonia plant have been improved.
In one embodiment, the ammonia injection device for denitration is disposed in a preheating section of the convection section 10 of the cracking furnace. In practical application, the operation temperature of the denitration catalyst matched with the ammonia injection device is 120-250 ℃, and can be matched with the temperature of the preheating section of the convection section 10 of the cracking furnace. Such a design may therefore allow for reduced manufacturing installation and post-maintenance costs.
The present invention will be described in detail below by way of examples and comparative examples.
Example 1
This example is an application example of an ammonia injection device in a double radiant section cracking furnace.
The denitration operation unit is arranged in the convection section 10, the smoke quantity from the left radiation section 11 is 13800m & lt 3 & gt/h, and the concentration of NOX in inlet smoke is 110mg/m & lt 3 & gt. The smoke amount from the right side radiation section 11 is 7000m3/h, and the concentration of NOX in the inlet smoke is 155mg/m3. The amount of ammonia gas entering the left flue gas channel (i.e. the first zone) through the first ammonia injection pipe 3 is controlled by a valve to be NH3/NOX =0.9 (molar ratio), and the amount of ammonia gas entering the right flue gas channel (i.e. the second zone) through the second ammonia injection pipe 4 is NH3/NOX =1.5 (molar ratio). The reaction temperature of the denitration catalyst is 150 ℃. The number of the first ammonia spraying pipes 3 and the second ammonia spraying pipes 4 is respectively 20. The number of the second ammonia spraying holes 5 on each of the first ammonia spraying pipe 3 and the second ammonia spraying pipe 4 is 16, the throat diameter d of each second ammonia spraying hole 5 is 10mm, and the spraying diffusion angle alpha is 30 degrees. The number of the first ammonia spraying holes 6 on each of the first ammonia spraying pipe 3 and the second ammonia spraying pipe 4 is 8, and the diameter of each first ammonia spraying hole 6 is 10mm. After the flue gas is subjected to denitration treatment by the ammonia spraying device, the NOx content at the outlet of the cracking furnace is 30mg/m & lt 3 & gt during the operation period, and ammonia escape is not detected.
Comparative example 1
The cracking furnace used in this comparative example is the same as that of example 1, except that a conventional ammonia injection device for denitration is installed in the cracking furnace, and the amount of ammonia entering the flue gas passage through the ammonia injection device is NH3/NOX =1.6 (molar ratio). After the flue gas is subjected to denitration treatment, the NOx content at the outlet of the cracking furnace is 90mg/m & lt 3 & gt during the operation of the cracking furnace, and a small amount of ammonia gas is detected in the outlet flue gas.
Example 2
This example is an application example of an ammonia injection device in a single radiant section cracking furnace.
The flue gas amount of the denitration unit is 12600m3/h, the concentration of NOX in the inlet flue gas is 120mg/m3, and the ammonia gas amount at the inlet of the ammonia spraying device is controlled to be NH3/NOX =1.0 (molar ratio). The reaction temperature of the denitration catalyst is 150 ℃. The number of the first ammonia spraying pipes 3 and the second ammonia spraying pipes 4 is respectively 20. The number of the second ammonia spraying holes 5 on each of the first ammonia spraying pipe 3 and the second ammonia spraying pipe 4 is 16, the throat diameter d of each second ammonia spraying hole 5 is 10mm, and the spraying diffusion angle alpha is 25 degrees. The number of the first ammonia spraying holes 6 on each of the first ammonia spraying pipe 3 and the second ammonia spraying pipe 4 is 8, and the diameter of each first ammonia spraying hole 6 is 10mm. After the flue gas is subjected to denitration treatment by the ammonia spraying device, the NOx content at the outlet of the cracking furnace is 40mg/m & lt 3 & gt during the operation period, and ammonia escape is not detected.
Comparative example 2
The cracking furnace used in this comparative example is the same as in example 2, except that the ammonia injection device for conventional denitration was installed in the cracking furnace. After the flue gas is subjected to denitration treatment, the NOx content at the outlet of the cracking furnace is 70mg/m < 3 > during the operation of the cracking furnace, and a small amount of ammonia gas is detected in the outlet flue gas.
The preferred embodiments of the present invention have been described above in detail, but the present invention is not limited thereto. Within the scope of the technical idea of the invention, many simple modifications can be made to the technical solution of the invention, including combinations of various technical features in any other suitable way, and these simple modifications and combinations should also be regarded as the disclosure of the invention, and all fall within the scope of the invention.
Claims (8)
1. The utility model provides a denitration is with spouting ammonia device which characterized in that includes:
the denitration device comprises a flue gas channel section, a denitration device and a denitration device, wherein a denitration area is formed in the flue gas channel section, the denitration area comprises a first area and a second area which cover the cross section of the denitration area together, and the flue gas channel section comprises a first wall surface (9) which is arranged corresponding to the first area and a second wall surface which is arranged corresponding to the second area;
a plurality of first ammonia spraying pipes (3) arranged on the first wall surface (9) and used for spraying ammonia to the first area;
a plurality of second ammonia spraying pipes (4) arranged on the second wall surface (8) and used for spraying ammonia to the second area;
the first pipeline structure is connected with the first ammonia spraying pipe (3) and is suitable for conveying a corresponding amount of ammonia gas to the first ammonia spraying pipe (3) according to the content of nitrogen oxides in the first area;
the second pipeline structure is connected with the second ammonia spraying pipe (4) and is suitable for conveying a corresponding amount of ammonia gas to the second ammonia spraying pipe (4) according to the content of nitrogen oxides in the second area;
the first ammonia spraying pipes (3) and the second ammonia spraying pipes (4) are arranged in pairs, the axes of each pair of the first ammonia spraying pipes (3) and the second ammonia spraying pipes (4) are collinear, one end, far away from the first wall surface (9), of each pair of the first ammonia spraying pipes (3) is abutted to one end, far away from the second wall surface (8), of each pair of the second ammonia spraying pipes (4), and the pairs of the first ammonia spraying pipes (3) and the second ammonia spraying pipes (4) are uniformly covered on the cross section of the denitration area at intervals;
first spout ammonia pipe (3) with it spouts ammonia hole (5) to be provided with a plurality of first ammonia holes (6) and a plurality of second in bank and even interval respectively on second spout ammonia pipe (4), the ammonia direction of spouting of first ammonia hole (6) is unanimous with flue gas flow direction, the ammonia direction of spouting of second ammonia hole (5) with flue gas flow direction is perpendicular.
2. The ammonia injection device for denitration according to claim 1, wherein said first pipeline structure comprises a plurality of first ammonia gas delivery pipes (7) connected with said first ammonia injection pipes (3) in one-to-one correspondence, said first ammonia gas delivery pipes (7) are connected with one ends of said first ammonia injection pipes (3) located outside said flue gas channel through valves (2); the second pipeline structure comprises a plurality of second ammonia conveying pipes (1) which are connected with the second ammonia spraying pipes (4) in a one-to-one correspondence mode, and the second ammonia conveying pipes (1) are located at one ends outside the smoke channel through valves (2) and the second ammonia spraying pipes (4).
3. The ammonia injection apparatus for denitration according to claim 1, wherein the second ammonia injection holes (5) are arranged in two rows, and the two rows of the ammonia injection holes located in the first ammonia injection pipe (3) are symmetrically arranged with respect to the axis of the first ammonia injection pipe (3), the two rows of the ammonia injection holes located in the second ammonia injection pipe (4) are symmetrically arranged with respect to the axis of the second ammonia injection pipe (4), and the two rows of the second ammonia injection holes (5) located in the two adjacent first ammonia injection pipes (3) or the two adjacent second ammonia injection pipes (4) and oppositely arranged are alternately arranged.
4. The ammonia injection apparatus for denitration according to claim 1, wherein the distance between said first ammonia injection hole (6) of said first ammonia injection pipe (3) adjacent to said first wall surface (9) and said first wall surface (9) is half of the distance between other adjacent two of said first ammonia injection holes (6); the distance between the second ammonia spraying hole (5) on the first ammonia spraying pipe (3) close to the first wall surface (9) and the first wall surface (9) is half of the distance between the other two adjacent second ammonia spraying holes (5); the distance between the first ammonia spraying hole (6) on the second ammonia spraying pipe (4) close to the second wall surface (8) and the second wall surface (8) is half of the distance between the other adjacent first ammonia spraying holes (6); the distance between the second ammonia spraying hole (5) on the second ammonia spraying pipe (4) close to the second wall surface (8) and the second wall surface (8) is half of the distance between the other two adjacent second ammonia spraying holes (5).
5. The ammonia injection apparatus for denitration according to claim 3, wherein said first ammonia injection hole (6) is a circular hole, and said second ammonia injection hole (5) is a tapered hole having a gradually increasing diameter.
6. A cracking furnace system comprising a cracking furnace and the ammonia injection device for denitration according to any one of claims 1 to 5 provided in the cracking furnace.
7. The cracking furnace system of claim 6, wherein the cracking furnace is a dual radiant section cracking furnace.
8. The cracking furnace system according to claim 6, wherein the ammonia injection device for denitration is disposed in a preheating section part of the convection section (10) of the cracking furnace.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911007003.7A CN112691544B (en) | 2019-10-22 | 2019-10-22 | Ammonia spraying device for denitration and cracking furnace system with same |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201911007003.7A CN112691544B (en) | 2019-10-22 | 2019-10-22 | Ammonia spraying device for denitration and cracking furnace system with same |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN112691544A CN112691544A (en) | 2021-04-23 |
| CN112691544B true CN112691544B (en) | 2022-11-18 |
Family
ID=75504614
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201911007003.7A Active CN112691544B (en) | 2019-10-22 | 2019-10-22 | Ammonia spraying device for denitration and cracking furnace system with same |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN112691544B (en) |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN201454414U (en) * | 2009-07-24 | 2010-05-12 | 华电环保系统工程有限公司 | Ammonia injection grille device for flue gas denitration adopting SCR method |
| EP2338586A1 (en) * | 2008-08-12 | 2011-06-29 | Mitsubishi Heavy Industries, Ltd. | Exhaust gas processing device and exhaust gas processing system |
| CN102527233A (en) * | 2012-01-05 | 2012-07-04 | 北京龙电宏泰环保科技有限公司 | Zoning-regulating double-layer ammonia injection grid applied to selective catalytic reduction denitrification device for industrial flue gas |
| CN108392959A (en) * | 2018-02-08 | 2018-08-14 | 上海电气电站环保工程有限公司 | A kind of spray ammonia system and its implementation for denitrating flue gas |
| CN208161387U (en) * | 2018-02-28 | 2018-11-30 | 大唐环境产业集团股份有限公司 | A kind of partition type ammonia-spraying grid of band mixing partition |
| CN109876658A (en) * | 2019-04-08 | 2019-06-14 | 国电环境保护研究院有限公司 | Subregion vortex volume inhales spray ammonia system and spray ammonia adjusting method |
-
2019
- 2019-10-22 CN CN201911007003.7A patent/CN112691544B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP2338586A1 (en) * | 2008-08-12 | 2011-06-29 | Mitsubishi Heavy Industries, Ltd. | Exhaust gas processing device and exhaust gas processing system |
| CN201454414U (en) * | 2009-07-24 | 2010-05-12 | 华电环保系统工程有限公司 | Ammonia injection grille device for flue gas denitration adopting SCR method |
| CN102527233A (en) * | 2012-01-05 | 2012-07-04 | 北京龙电宏泰环保科技有限公司 | Zoning-regulating double-layer ammonia injection grid applied to selective catalytic reduction denitrification device for industrial flue gas |
| CN108392959A (en) * | 2018-02-08 | 2018-08-14 | 上海电气电站环保工程有限公司 | A kind of spray ammonia system and its implementation for denitrating flue gas |
| CN208161387U (en) * | 2018-02-28 | 2018-11-30 | 大唐环境产业集团股份有限公司 | A kind of partition type ammonia-spraying grid of band mixing partition |
| CN109876658A (en) * | 2019-04-08 | 2019-06-14 | 国电环境保护研究院有限公司 | Subregion vortex volume inhales spray ammonia system and spray ammonia adjusting method |
Also Published As
| Publication number | Publication date |
|---|---|
| CN112691544A (en) | 2021-04-23 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US6905658B2 (en) | Channelized SCR inlet for improved ammonia injection and efficient NOx control | |
| CN101637700B (en) | SCR denitrification process and denitrification device of ammonia injection grid adopting non-unidiameter injection orifices | |
| CN205216566U (en) | SNCR (Selective non catalytic reduction) denitration device | |
| CN202849079U (en) | Urea pyrolysis reactor applied to SCR (selective catalytic reduction) denitration | |
| CN103007750B (en) | Ammonia spraying device for flue gas denitrification | |
| CN110152480B (en) | Denitration process for improving SNCR denitration efficiency of cement plant | |
| CN203044243U (en) | Smoke denitration ammonia spraying device | |
| CN107398175B (en) | Desulfurization and denitrification integrated reactor for carbon-based catalyst | |
| CN112691544B (en) | Ammonia spraying device for denitration and cracking furnace system with same | |
| CN203112520U (en) | Device for preparing ammonia through pyrolysis of urea | |
| CN204601997U (en) | A kind of boiler smoke and ammonia mixing arrangement | |
| CN209155540U (en) | Coal-burning power plant's denitration ammonia-gas spraying device flow fieldoptimization system | |
| CN103159231A (en) | Device for guiding air flow on urea pyrolysis reactor | |
| CN103172085B (en) | Air flow guiding method for urea pyrolytic reaction | |
| CN102166472A (en) | Spiral-flow type ammonia spraying device used for selective catalytic reduction (SCR) denitrification system | |
| CN206823552U (en) | A kind of ammonia-spraying grid device | |
| CN213725792U (en) | SCR deNOx systems inner structure | |
| CN103936029A (en) | Fluidized bed reactor for preparing ammonia by virtue of pyrolysis of urea | |
| CN212142070U (en) | Ammonia gas uniform distributor for SNCR denitration process | |
| CN103611486B (en) | A kind of urea pyrolysis reactor being applied to SCR denitration | |
| CN102580442A (en) | Selective non-catalytic reduction denitration system of circulating fluidized bed boiler | |
| CN206381841U (en) | A kind of flue gas subregion mixes SCR denitration system | |
| CN108905555B (en) | Combined type flue ozone distribution system | |
| CN102580528B (en) | Blast cap type ammonia injection and mixing device for selective catalytic reduction denitration | |
| CN105854568B (en) | Low-temperature denitration flue reative cell |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |