CN110975581B - Device for improving SNCR (selective non-catalytic reduction) denitration efficiency of circulating fluidized bed boiler - Google Patents

Device for improving SNCR (selective non-catalytic reduction) denitration efficiency of circulating fluidized bed boiler Download PDF

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CN110975581B
CN110975581B CN201911270290.0A CN201911270290A CN110975581B CN 110975581 B CN110975581 B CN 110975581B CN 201911270290 A CN201911270290 A CN 201911270290A CN 110975581 B CN110975581 B CN 110975581B
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fluidized bed
circulating fluidized
bed boiler
ammonia water
vertical shaft
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CN110975581A (en
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刘海力
张旭
洪庆超
刘浩宇
陈旺
许君
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Hunan University of Humanities Science and Technology
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Hunan University of Humanities Science and Technology
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    • 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
    • B01D53/77—Liquid phase processes
    • B01D53/79—Injecting reactants
    • 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
    • B01D53/346—Controlling the process
    • 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
    • B01D53/46—Removing components of defined structure
    • B01D53/54—Nitrogen compounds
    • B01D53/56—Nitrogen oxides
    • 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
    • B01D53/77—Liquid phase processes
    • B01D53/78—Liquid phase processes with gas-liquid contact
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23J—REMOVAL OR TREATMENT OF COMBUSTION PRODUCTS OR COMBUSTION RESIDUES; FLUES 
    • F23J15/00—Arrangements of devices for treating smoke or fumes
    • F23J15/006—Layout of treatment plant
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2251/00—Reactants
    • B01D2251/20—Reductants
    • B01D2251/206—Ammonium compounds
    • B01D2251/2062—Ammonia
    • B—PERFORMING OPERATIONS; TRANSPORTING
    • B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01D—SEPARATION
    • B01D2258/00—Sources of waste gases
    • B01D2258/02—Other waste gases
    • B01D2258/0283—Flue gases
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23J—REMOVAL OR TREATMENT OF COMBUSTION PRODUCTS OR COMBUSTION RESIDUES; FLUES 
    • F23J2215/00—Preventing emissions
    • F23J2215/10—Nitrogen; Compounds thereof
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23—COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23J—REMOVAL OR TREATMENT OF COMBUSTION PRODUCTS OR COMBUSTION RESIDUES; FLUES 
    • F23J2215/00—Preventing emissions
    • F23J2215/10—Nitrogen; Compounds thereof
    • F23J2215/101—Nitrous oxide (N2O)

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Environmental & Geological Engineering (AREA)
  • Health & Medical Sciences (AREA)
  • Biomedical Technology (AREA)
  • Analytical Chemistry (AREA)
  • General Chemical & Material Sciences (AREA)
  • Oil, Petroleum & Natural Gas (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Treating Waste Gases (AREA)

Abstract

The invention relates to the technical field of boiler denitration, in particular to a device for improving SNCR (selective non-catalytic reduction) denitration efficiency of a circulating fluidized bed boiler, which comprises a storage bin, a circulating fluidized bed boiler furnace and a vertical shaft flue, wherein the lower end part of the circulating fluidized bed boiler furnace is connected with the storage bin, the upper end of the circulating fluidized bed boiler furnace is connected with a separation material return mechanism, the upper end and the lower end of the separation material return mechanism are respectively connected with the upper end of the vertical shaft flue and the lower end of the circulating fluidized bed boiler furnace, the lower end of the circulating fluidized bed boiler furnace is connected with an oxygen supply mechanism, and the upper end of the vertical shaft flue is provided with a denitration mechanism. The device for improving the SNCR denitration efficiency of the circulating fluidized bed boiler generates a variable magnetic field through the electromagnetic generator, so that NH is generated3The charged ions or ion groups ionized after the molecules and NO molecules in the flue gas are violently collided improve the collision probability and the collision severity under the action of the variable magnetic field force generated by the alternating current, so that the reaction degree is correspondingly improved, the activation energy of the chemical reaction is reduced, and the denitration efficiency is improved.

Description

Device for improving SNCR (selective non-catalytic reduction) denitration efficiency of circulating fluidized bed boiler
Technical Field
The invention relates to the technical field of boiler denitration, in particular to a device for improving the SNCR denitration efficiency of a circulating fluidized bed boiler.
Background
The chemical reaction process in the prior selective non-catalytic reduction (SNCR) denitration mainly utilizes ammonia gas to reduce nitric oxide, and the total chemical reaction can be summarized as NH3+NO+O2 →H2O+N2. NH in prior selective non-catalytic reduction (SNCR) denitration process3The (ammonia) molecules and NO (nitrogen monoxide) molecules in the flue gas mutually collide under the action of the airflow and then enter at high temperatureThe chemical reaction is carried out, thereby realizing the aim of flue gas denitration, but the gas flow speed of the flue gas is faster NH3The probability of mutual collision between molecules and NO molecules in the smoke in the same airflow is low, and further NH is caused3The probability of mutual chemical reaction between molecules and NO molecules in the flue gas is reduced, so that the denitration efficiency is reduced. The current theoretical common knowledge can know that:
1) the chemical reaction is a complex process, and for the selective non-catalytic reduction denitration (SNCR) reaction, a detailed reaction mechanism comprises hundreds of elementary reactions, namely the reaction is not in one step, but a plurality of intermediate processes. This includes ions or clusters of ions, related atoms and gas molecules.
2) This is a paramagnetic substance for nitric oxide. The magnetic dipoles in the paramagnetic material align toward the direction of the external magnetic field, which enhances the magnetic field and generates an attractive force.
3) Chemical reactions require that the reactants have a certain energy, commonly referred to as the activation energy of the chemical reaction. After the molecules collide with each other, energy can be transferred correspondingly, so that the energy of the molecules is improved.
Based on the theory, under the action of a magnetic field, NH is influenced by magnetic force3Related ions or ion clusters, paramagnetic NO and NO related ions or ion clusters, and other ions or ion clusters in the flue gas are also influenced by a magnetic field, under the influence of the magnetic field with the direction changing rapidly, the collision probability of molecules, atoms, charged ions or ion clusters is high, energy is transferred more frequently, and therefore the degree of chemical reaction is improved, the denitration efficiency is improved, and the ammonia escape amount is reduced.
Disclosure of Invention
The invention aims to provide a device for improving the SNCR denitration efficiency of a circulating fluidized bed boiler so as to solve the problems in the background technology. In order to achieve the purpose, the invention provides the following technical scheme: a device for improving SNCR denitration efficiency of a circulating fluidized bed boiler comprises a storage bin, a circulating fluidized bed boiler furnace and a shaft flue, wherein the lower end part of the circulating fluidized bed boiler furnace is connected with the storage bin, the upper end of the circulating fluidized bed boiler furnace is connected with a separation feed back mechanism, the upper end and the lower end of the separation feed back mechanism are respectively connected with the upper end of the shaft flue and the lower end of the circulating fluidized bed boiler furnace, the lower end of the circulating fluidized bed boiler furnace is connected with an oxygen supply mechanism, the upper end of the shaft flue is provided with a denitration mechanism, the denitration mechanism comprises an electromagnetic generating device, a backflow mechanism, an ammonia water conveying mechanism and an automatic control system, the automatic control system is respectively electrically connected with the electromagnetic generating device, the backflow mechanism and the ammonia water conveying mechanism, the ammonia water conveying mechanism comprises an ammonia water storage tank, an ammonia water pipeline, an ammonia water flow control device and an ammonia water spray nozzle, a conveying pump is arranged inside the ammonia water, the ammonia water pipeline is connected with an ammonia water flow control device, the liquid outlet end of the delivery pump is connected with an ammonia water nozzle through the ammonia water pipeline, the ammonia water nozzle is fixed on the inner side of the upper port of the vertical shaft flue, the automatic control system comprises an automatic controller, a first nitrogen oxide detector and a second nitrogen oxide detector, the signal input end of the automatic controller is respectively electrically connected with the first nitrogen oxide detector and the second nitrogen oxide detector, the first nitrogen oxide detector and the second nitrogen oxide detector are both fixed on the inner side wall of the upper end part of the vertical shaft flue and are arranged in the vertical direction, the first nitrogen oxide detector and the ammonia water nozzle are positioned on two sides of the inner wall of the upper port of the vertical shaft flue in a position opposite to each other, the execution output end of the automatic controller is respectively electrically connected with the ammonia water flow control device and the, a push plate is fixed at the piston rod end of the air cylinder, the push plate is parallel to the central axis of the shaft flue, a slide rod is fixed at the lower end of the push plate and is vertical to the push plate, the left end of the slide rod penetrates through the right side wall of the shaft flue and is positioned in the shaft flue, the slide rod can slide left and right on the right side wall of the shaft flue, a plurality of ejector rods are fixed on one section of the slide rod positioned in the shaft flue, the ejector rods are arranged at equal intervals along the length direction of the slide rod and are vertically and upwards arranged, a plurality of sealing strips are fixed on the front and rear side walls in the shaft flue, the sealing strips are all vertical to the slide rod and are positioned below the nitrogen oxide detector II, the sealing strips are arranged at equal intervals, symmetrical notches are symmetrically arranged at the left side and the right side of the surface of the sealing strips, and a rotating shaft is fixed in each notch at the left side of the sealing strip, and the fixed shaft is rotatably connected with the sealing plate on the rotating shaft, the free end of the sealing plate can be matched with the notch on the right side of the sealing strip on the left side of the sealing plate and tightly attached to the notch, the sliding rod is positioned below the sealing plate, the sealing plate and the ejector rods are in one-to-one correspondence, and the top ends of the ejector rods can be abutted and buckled with the lower surface of the sealing plate.
Preferably, the electromagnetic generating devices are arranged in two and symmetrically fixed on two sides of the upper port of the shaft flue, the two electromagnetic generating devices are formed by connecting an electromagnetic coil and a current control device in series, the two electromagnetic generating devices are located between a first nitrogen oxide detector and a second nitrogen oxide detector, an ammonia water spray head is located above the electromagnetic generating devices, and the two current control devices in the electromagnetic generating devices are connected in parallel and then connected to the execution output end of the automatic controller.
Preferably, be provided with on the shaft flue inside wall and increase the journey subassembly, and increase the journey subassembly and set up and be in there being two the regional department of magnetic field that electromagnetism generating device produced, it includes a plurality of U-shaped boards to increase the journey subassembly, and is a plurality of to set into two rows according to upper and lower position U-shaped board, and the number of the one row of U-shaped board of downside compares one row of U-shaped board number of upside more one, two adjacent U-shaped boards in every row are equidistant to be arranged, and the U-shaped board opening that is located the upside is downward, and the U-shaped board opening that is located the downside makes progress, and the U-shaped board that is located the upside even lateral wall inserts the inboard of two adjacent U-shaped boards that next row corresponds respectively to the lateral wall of the U-shaped board of upside is parallel to each other with the U-shaped board lateral wall of downside, but contactless.
Preferably, the return mechanism still includes the back flow, the lower extreme of back flow and the right side wall connection of shaft flue, and the upper end of back flow and the upper end intercommunication of shaft flue, the lower extreme of back flow and the junction of the right side wall of shaft flue are located between two and the sealing strip of nitrogen oxide detector, the lower tip connection of back flow has the butterfly valve, and the valve rod of butterfly valve is located the one end in the back flow outside and is fixed with the gear, the upper end of push pedal is fixed with the rack, and the rack is parallel with the slide bar, the rack is connected with gear engagement.
Preferably, the separation feed back mechanism comprises a boiler feed back device and a cyclone separator, the gas inlet end of the cyclone separator is connected with the upper end of the circulating fluidized bed boiler furnace through a pipeline, the gas outlet end at the upper part of the cyclone separator is connected with the upper end of the vertical shaft flue through a pipeline, and the solid outlet end at the lower part of the cyclone separator is connected with the lower end of the circulating fluidized bed boiler furnace through a pipeline.
Preferably, the oxygen supply mechanism comprises an air preheater, a primary fan and a secondary fan, the air preheater is sleeved on the lower portion of the outer side wall of the vertical shaft flue, the air outlet ends of the primary fan and the secondary fan are connected with the air inlet port of the air preheater through air pipes respectively, and the air outlet end of the air preheater is connected with the lower end of the hearth of the circulating fluidized bed boiler through the air pipe.
Compared with the prior art, the invention has the beneficial effects that:
in the invention, the variable magnetic field is generated by the electromagnetic generator in the denitration mechanism arranged at the upper part of the vertical shaft channel, so that NH is generated3The charged ions or ion groups ionized after the molecules and NO molecules in the flue gas are violently collided improve the collision probability and the collision severity under the action of the variable magnetic field force generated by the alternating current, so that the reaction degree is correspondingly improved, the activation energy of the chemical reaction is reduced, and the denitration efficiency is improved.
According to the invention, the output quantity of the ammonia water and the magnitude of the magnetic field which are adaptive to the concentration of nitrogen oxides in the flue gas are achieved by adjusting the output quantity of the ammonia water and the magnitude of the current in the electromagnetic device through the automatic control system, so that the purposes of energy conservation and consumption reduction are achieved.
Drawings
FIG. 1 is a schematic view of the final assembly of the present invention;
FIG. 2 is a schematic cross-sectional view taken at A in FIG. 1;
FIG. 3 is an enlarged view of the structure at B in FIG. 2;
fig. 4 is a structural diagram of the closed state of the backflow mechanism in fig. 3.
In the figure: 1-an ammonia storage tank; 2-a storage bin; 3-circulating fluidized bed boiler furnace; 4-boiler returning charge device; 5-a cyclone separator; 6-air preheater; 7-a primary air fan; 8-a secondary air fan; 9-a vertical shaft flue; 10-an electromagnetic generating device; 11-ammonia water pipe; 12-ammonia water spray head; 13-a nitrogen oxide detector I; 14-ammonia flow control device; 15-current control means; 16-an automatic controller; 17-a nitrogen oxide detector II; 18-a return pipe; 19-a cylinder; 20-pushing the plate; 21-a slide bar; 22-a mandril; 23-a sealing strip; 24-a rotating shaft; 25-sealing plate; 26-a notch; 27-a rack; 28-gear; 29-U-shaped plate.
Detailed Description
The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be obtained by workers skilled in the art without any inventive work based on the embodiments of the present invention, are within the scope of the present invention.
Referring to fig. 1-4, the present invention provides a technical solution: a device for improving SNCR denitration efficiency of a circulating fluidized bed boiler comprises a storage bin 2, a circulating fluidized bed boiler hearth 3 and a shaft flue 9, wherein the lower end part of the circulating fluidized bed boiler hearth 3 is connected with the storage bin 2, the storage bin 2 is used for conveying fuel to the circulating fluidized bed boiler hearth 3, the upper end of the circulating fluidized bed boiler hearth 3 is connected with a separation material return mechanism, the upper end and the lower end of the separation material return mechanism are respectively connected with the upper end of the shaft flue 9 and the lower end of the circulating fluidized bed boiler hearth 3, the lower end of the circulating fluidized bed boiler hearth 3 is connected with an oxygen supply mechanism, the upper end of the shaft flue 9 is provided with a denitration mechanism, as shown in figure 2, the denitration mechanism comprises an electromagnetic generating device 10, a reflux mechanism, an ammonia water conveying mechanism and an automatic control system, the automatic control system is respectively and electrically connected with the electromagnetic generating device, An ammonia water pipeline 11, an ammonia water flow control device 14 and an ammonia water spray head 12, wherein a delivery pump is arranged inside an ammonia water storage tank 1, the ammonia water pipeline 11 is connected with the ammonia water flow control device 14, the liquid outlet end of the delivery pump is connected with the ammonia water spray head 12 through the ammonia water pipeline 11, the ammonia water spray head 12 is fixed on the inner side of the upper port of a shaft flue 9, an automatic control system comprises an automatic controller 16, a nitrogen oxide detector I13 and a nitrogen oxide detector II 17, the automatic controller 16 adopts a computer, the signal input end of the automatic controller 16 is respectively and electrically connected with the nitrogen oxide detector I13 and the nitrogen oxide detector II 17, the nitrogen oxide detector I13 is used for detecting the concentration of nitrogen oxide in flue gas entering from the upper port of the shaft flue 9, the nitrogen oxide detector II 17 is used for detecting the concentration of nitrogen oxide in flue gas denitrated by a denitration mechanism, and is convenient for detecting denitration efficiency, the nitrogen oxide detector I13 and the nitrogen oxide detector II 17 are both fixed on the inner side wall of the upper end part of the vertical shaft flue 9 and are arranged in the vertical direction, the nitrogen oxide detector I13 and the ammonia water spray head 12 are oppositely positioned at two sides of the inner wall of the upper port of the vertical shaft flue 9, the execution output end of the automatic controller 16 is respectively electrically connected with the ammonia water flow control device 14 and the delivery pump, as shown in figures 3 and 4, the backflow mechanism comprises an air cylinder 19 arranged at the outer side of the vertical shaft flue 9, the air cylinder 19 is electrically connected with the execution output end of the automatic controller 16, the piston rod end of the air cylinder 19 is fixed with a push plate 20, the push plate 20 is parallel to the central axis of the vertical shaft flue 9, the lower end of the push plate 20 is fixed with a slide rod 21, the slide rod 21 is mutually vertical to the push plate 20, the left end of the slide rod 21 passes through the right side wall of the vertical shaft flue 9 and is positioned in the vertical shaft flue 9, and the slide rod 21 can slide left and right on the right side wall of the vertical shaft flue 9, a plurality of ejector rods 22 are fixed on the upper side surface of one section of the slide rod 21 positioned in the shaft flue 9, the ejector rods 22 are arranged at equal intervals along the length direction of the slide rod 21, and is vertically and upwards arranged, a plurality of sealing strips 23 are fixed on the front and rear side walls inside the vertical shaft flue 9, and the sealing strips 23 are all vertical to the sliding rod 21, and is positioned below the nitrogen oxide detector II 17, a plurality of sealing strips 23 are arranged at equal intervals, symmetrical notches 26 are symmetrically formed in the left side and the right side of the surface of the sealing strip 23, a rotating shaft 24 is fixed in each notch 26 on the left side of the sealing strip 23, the rotating shaft 24 is connected with a sealing plate 25 in a fixed-shaft rotating manner, the free end of the sealing plate 25 can be matched and tightly attached with a notch 26 on the right side of a sealing strip 23 on the left side of the sealing plate, the sliding rod 21 is positioned below the sealing plate 25, the sealing plates 25 correspond to the push rods 22 one by one, and the top ends of the push rods 25 can be in abutting contact with the lower surfaces of the sealing plates 25.
In this embodiment, two electromagnetic generating devices 10 are symmetrically fixed on two sides of the upper port of the shaft flue 9, two electromagnetic generating devices 10 are formed by connecting electromagnetic coils and a current control device 15 in series, the winding directions of the two electromagnetic coils are opposite, the two electromagnetic generating devices 10 are located between a first nitrogen oxide detector 13 and a second nitrogen oxide detector 17, an ammonia water nozzle 12 is located above the electromagnetic generating devices 10, and the two current control devices 15 in the electromagnetic generating devices 10 are connected in parallel and then connected to the execution output end of the automatic controller 16.
In this embodiment, as shown in fig. 1, a plurality of range extending assemblies are arranged on the inner side wall of the shaft flue 9, and the range extending assemblies are arranged in a magnetic field area generated by two electromagnetic generating devices 10, and are arranged in sequence from top to bottom at the upper and lower positions, each range extending assembly includes a plurality of U-shaped plates 29, the U-shaped plates 29 are arranged in two rows at the upper and lower positions, the number of the U-shaped plates 29 at the lower side is one more than that of the U-shaped plates 29 at the upper side, two adjacent U-shaped plates 29 in each row are arranged at equal intervals, the U-shaped plates 29 at the upper side have downward openings, the U-shaped plates 29 at the lower side have upward openings, the side walls of the U-shaped plates 29 at the upper side are respectively inserted into the inner sides of two adjacent U-shaped plates 29 at the lower side, and the side walls of the U-shaped plates 29 at the upper side are parallel to the side walls of the U-shaped plates 29 at the lower side, but do not contact with each other, namely, a gap is left between the inner side surface of the side wall of the upper row of U-shaped plate 29 and the inner side surface of the side wall of the lower row of U-shaped plate 29 corresponding to the upper row of U-shaped plate, and the gap enables smoke to pass through, and the U-shaped plate 29 is made of non-magnetic materials, so that magnetic field loss is avoided.
In this embodiment, as shown in fig. 1, 3 and 4, the backflow mechanism further includes a backflow pipe 18, a lower end of the backflow pipe 18 is connected to the right side wall of the shaft flue 9, an upper end of the backflow pipe 18 is communicated with an upper end of the shaft flue 9, a connection position of the lower end of the backflow pipe 18 and the right side wall of the shaft flue 9 is located between the second nitrogen oxide detector 17 and the sealing strip 23, a butterfly valve is connected to a lower end of the backflow pipe 18, a gear 28 is fixed to one end, located on the outer side of the backflow pipe 18, of a valve rod of the butterfly valve, a rack 27 is fixed to the upper end of the push plate 20, the rack 27 is parallel to the slide rod 21, and the rack 27 is meshed with the gear 28.
In this embodiment, as shown in fig. 1, the separation material returning mechanism includes a boiler material returning device 4 and a cyclone separator 5, an air inlet end of the cyclone separator 5 is connected with an upper end of the circulating fluidized bed boiler furnace 3 through a pipeline, an upper gas output end of the cyclone separator 5 is connected with an upper end of the vertical shaft flue 9 through a pipeline, and a lower solid output end of the cyclone separator 5 is connected with a lower end of the circulating fluidized bed boiler furnace 3 through a pipeline.
In this embodiment, as shown in fig. 1, the oxygen supply mechanism includes an air preheater 6, a primary air fan 7 and a secondary air fan 8, the air preheater 6 is sleeved on the lower portion of the outer side wall of the vertical shaft flue 9, the air outlet ends of the primary air fan 7 and the secondary air fan 8 are connected with the air inlet port of the air preheater 6 through an air pipe respectively, and the air outlet end of the air preheater 6 is connected with the lower end of the circulating fluidized bed boiler furnace 3 through an air pipe.
The using method of the invention has the following principle and advantages: this kind of improve circulating fluidized bed boiler SNCR denitration efficiency device is when the operation, and the working process is as follows:
the fuel enters the circulating fluidized bed boiler hearth 3 from the stock bin 2 and is combusted, the primary fan 7 and the secondary fan 8 send air into the air preheater 6 for preheating, the heat source in the air preheater 6 is flue gas waste heat after denitration treatment in the vertical shaft flue 9, recycling of the flue gas waste heat is realized, energy consumption is reduced, the preheated air enters the circulating fluidized bed boiler hearth 3 to provide oxygen required by combustion for the fuel, and the air enters the circulating fluidized bed boiler hearth 3 after preheating, so that the temperature of the circulating fluidized bed boiler hearth 3 cannot be reduced too much, and the effect of keeping the fuel fully and stably combusted in the circulating fluidized bed boiler hearth 3 is further achieved;
after the fuel is combusted in the hearth 3 of the circulating fluidized bed boiler, the flue gas is generated and output to the upper part, is conveyed to the air inlet end of the cyclone separator 5 through a pipeline and enters the cyclone separator 5, under the action of the flue gas flow, a part of large particles and unburnt biomass fuel enter the cyclone separator 5 together with the flue gas flow, after separation treatment by the cyclone separator 5, the separated large particles and unburnt biomass fuel move downwards and are output to the boiler material returning device 4 through the solid discharging end of the cyclone separator 5, and is sent into a hearth 3 of the circulating fluidized bed boiler to be continuously combusted under the action of a boiler material returning device 4, the circulation ensures that the fuel is fully combusted, large particles and unburnt biomass fuel are prevented from entering the vertical shaft channel 9 along with airflow to cause the blockage of the vertical shaft channel 9, so that the normal operation of the whole equipment is ensured, and the denitration efficiency is improved;
the fuel produces nitrogen oxide (mainly NO) in the combustion process in the circulating fluidized bed boiler furnace 3, these pollutants are brought into the shaft flue 9 along with the flue gas flow, and enter the shaft flue 9 from the upper port of the shaft flue 9, after the pollutants enter the shaft flue 9, pass through the space between two electromagnetic generating devices 10, and the automatic controller 16 controls and starts the electromagnetic generating devices 10 to work at this moment, namely the current control device 15 is electrified, so that the electromagnetic coil is electrified, and produce the magnetic field of certain intensity, the magnetic field is the magnetic field that the alternating current produces, its magnetic field direction is fast changed, when the flue gas passes through this magnetic field area, the automatic controller 16 controls the delivery pump in the ammonia storage tank 1 to send the ammonia water into the ammonia water shower nozzle 12 through the ammonia water pipeline 11, and spray into this area through the ammonia water shower nozzle 12, wherein the ammonia water shower nozzle 12 adopts the atomizer, the particle size of the sprayed ammonia water is reduced, so that the ionized efficiency is improved, and NH is generated under the action of high temperature of the ammonia water3The (ammonia) molecules and NO (nitric oxide) molecules in the flue gas are ionized after violent collision, a certain amount of charged ions or ion clusters are formed after ionization, the charged ions or ion clusters have certain reaction capacity, but in a magnetic field environment, the collision probability and the collision violent degree of the charged ions or ion clusters are improved under the action of a variable magnetic field force generated by alternating current, the reaction degree is correspondingly improved, the chemical reaction activation energy is reduced, and the denitration efficiency is improved;
during the passage of the fumes through the magnetic field zone as described previously, the fumes first pass the previous oneGaps among the U-shaped plates 29 in the row are divided into the U-shaped plates 29 in the lower row, the gaps are divided into the U-shaped plates 29 in the upper row by the inner walls of the U-shaped plates 29 in the lower row, then the U-shaped plates 29 in the upper row are converged at the tops of the inner sides of the U-shaped plates 29 in the upper row, the smoke is discharged downwards from the gaps between the side walls of the two adjacent U-shaped plates 29 in the lower row and corresponding to the lower row under the action of airflow, and the smoke is continuously divided and converged under the action of the U-shaped plates 29, so that the collision contact probability of charged ions or ion clusters in the smoke is increased, the duration of the charged ions or ion clusters in a magnetic field is increased, and further NH (NH) is enabled to be further3The (ammonia) molecules react with the NO (nitric oxide) molecules in the flue gas more thoroughly, so that the denitration efficiency is improved, and NH caused by the rapid flow of flue gas flow is avoided3The contact time of molecules and NO molecules in the smoke is short, and the reaction is not thorough;
when the flue gas passes through the magnetic field region as described above, the nitrogen oxide (mainly NO) content of the flue gas not subjected to denitration is detected by a nitrogen oxide detector-13, where the nitrogen oxide content is represented as ω1When the nitrogen oxide detector I13 detects that the content of the nitrogen oxide in the flue gas is low, the ammonia water output quantity and the current in the electromagnetic device 10 are adjusted to achieve the ammonia water output quantity and the magnetic field size which are adaptive to the concentration of the nitrogen oxide in the flue gas through the control process, and further the purposes of saving energy and reducing consumption are achieved;
when the flue gas after the reaction of the denitration mechanism passes through the second nitrogen oxide detector 17, the content of the nitrogen oxide in the flue gas after the denitration is detected by the second nitrogen oxide detector 17, and the concentration of the nitrogen oxide is recorded as omega2Therefore, the denitration efficiency can be calculated:
Figure 74230DEST_PATH_IMAGE001
the numerical value of the denitration efficiency can be displayed on the automatic controller 16 in real time, according to the denitration efficiency, the automatic controller 16 can further adjust the flow of the ammonia water and the size of the magnetic field by controlling the ammonia water flow control device 14 and the current control device 15, and through the control, the power consumption and the ammonia water consumption can be reduced, so that the effect of reducing the energy consumption is achieved;
the minimum value theta of the content of the nitrogen oxides in the denitrated flue gas, namely a reference value, can be set in the automatic controller 16, and when the content of the nitrogen oxides is measured by the nitrogen oxide detector II 17, omega2Theta is not more than theta, which indicates that the flue gas meets the emission requirement after being subjected to denitration treatment by the denitration mechanism, as shown in fig. 4, at this time, the piston rod of the cylinder 19 is in a contraction state, the ejector rod 22 moves to the right, the sealing plate 25 is in a drooping state, the gap between the two adjacent sealing strips 23 is not blocked, the butterfly valve is in a closing state at this time, the return pipe 18 is not conducted, and the flue gas after denitration is discharged through the vertical shaft flue 9;
when the nitrogen oxide detector II 17 measures omega2>Theta, which indicates that the flue gas still contains more nitrogen oxides after being subjected to denitration treatment by the denitration mechanism and does not meet the emission requirement, as shown in fig. 3, at this time, the automatic controller 16 controls the cylinder 19 to work, and causes a piston rod of the cylinder 19 to extend out and push the push plate 20 to move leftwards, the left movement of the push plate 20 synchronously drives the slide rod 21 to act, so as to synchronously drive the ejector rod 22 to move leftwards, the left movement of the ejector rod 22 exerts force on the corresponding sealing plate 25, so that the sealing plate 25 rotates clockwise around the corresponding rotating shaft 24, and seals a gap between two adjacent sealing strips 23, so that the flue gas which does not meet the emission requirement cannot be continuously discharged from the shaft flue 9, and the environment pollution is avoided;
the rack 27 is moved to the left in synchronous moving of push pedal 20, and the rack 27 is moved to the left to drive gear 28 clockwise, thereby make the butterfly valve open, back flow pipe 18 switches on, and then make unsatisfied emission requirement flue gas through honeycomb duct 18 backward flow to the upper end of shaft flue 19, carry out denitration treatment once more, and then make the flue gas reach the emission requirement, until nitrogen oxide detector two 17 redetermination's omega reaches the emission requirement2Theta or less, at this time, the automatic controller 16 controls the gasCylinder 19 drives its piston rod shrink, thereby move to the right through push pedal 20 synchronous drive slide bar 21 and rack 27, the synchronous drive ejector pin 22 that moves to the right of slide bar 21 moves to the right, and do not exert the effect of power to closing plate 25, thereby make closing plate 25 be in flagging state, do not to the clearance shutoff between two adjacent sealing strips 23, and rack 27's the right side moves drive gear 28 anticlockwise rotation, make the butterfly valve be in the off-state, back flow pipe 18 does not switch on, and then the flue gas after the denitration can discharge through shaft flue 9, thereby realize guaranteeing unsatisfied emission requirement's flue gas backward flow retreatment, discharge again until satisfying emission requirement.
The foregoing shows and describes the general principles, essential features, and advantages of the invention. It will be understood by those skilled in the art that the present invention is not limited to the embodiments described above, and the preferred embodiments of the present invention are described in the above embodiments and the description, and are not intended to limit the present invention. The scope of the invention is defined by the appended claims and equivalents thereof.

Claims (6)

1. The utility model provides an improve circulating fluidized bed boiler SNCR denitration efficiency device, includes feed bin (2), circulating fluidized bed boiler furnace (3) and shaft flue (9), its characterized in that: the lower end of the circulating fluidized bed boiler furnace (3) is connected with the stock bin (2), the upper end of the circulating fluidized bed boiler furnace (3) is connected with the separation material return mechanism, the upper end and the lower end of the separation material return mechanism are respectively connected with the upper end of a vertical shaft flue (9) and the lower end of the circulating fluidized bed boiler furnace (3), the lower end of the circulating fluidized bed boiler furnace (3) is connected with an oxygen supply mechanism, and the upper end of the vertical shaft flue (9) is provided with a denitration mechanism;
the denitration mechanism comprises an electromagnetic generation device (10), a backflow mechanism, an ammonia water conveying mechanism and an automatic control system, and the automatic control system is electrically connected with the electromagnetic generation device (10), the backflow mechanism and the ammonia water conveying mechanism respectively;
the ammonia water conveying mechanism comprises an ammonia water storage tank (1), an ammonia water pipeline (11), an ammonia water flow control device (14) and an ammonia water spray head (12), a conveying pump is arranged inside the ammonia water storage tank (1), the ammonia water pipeline (11) is connected with the ammonia water flow control device (14), the liquid outlet end of the conveying pump is connected with the ammonia water spray head (12) through the ammonia water pipeline (11), and the ammonia water spray head (12) is fixed on the inner side of an upper port of a vertical shaft flue (9);
the automatic control system comprises an automatic controller (16), a first nitrogen oxide detector (13) and a second nitrogen oxide detector (17), wherein the signal input end of the automatic controller (16) is respectively and electrically connected with the first nitrogen oxide detector (13) and the second nitrogen oxide detector (17), the first nitrogen oxide detector (13) and the second nitrogen oxide detector (17) are both fixed on the inner side wall of the upper end part of the vertical shaft flue (9) and are arranged in the vertical direction, the positions of the first nitrogen oxide detector (13) and the ammonia water spray head (12) are opposite to each other and are positioned on two sides of the inner wall of the upper port of the vertical shaft flue (9), and the execution output end of the automatic controller (16) is respectively and electrically connected with the ammonia water flow control device (14) and the delivery pump;
the backflow mechanism comprises a cylinder (19) arranged outside the vertical shaft flue (9), and the cylinder (19) is electrically connected with the execution output end of the automatic controller (16), a push plate (20) is fixed at the piston rod end of the cylinder (19), the central axis of the push plate (20) is parallel to the central axis of the vertical shaft flue (9), the lower end of the push plate (20) is fixed with a slide bar (21), the slide rod (21) is vertical to the push plate (20), the left end of the slide rod (21) penetrates through the right side wall of the vertical shaft flue (9) and is positioned inside the vertical shaft flue (9), and the slide bar (21) can slide left and right on the right side wall of the shaft flue (9), a plurality of ejector rods (22) are fixed on the upper side surface of one section of the slide rod (21) positioned in the vertical shaft flue (9), the ejector rods (22) are arranged at equal intervals along the length direction of the sliding rod (21) and are vertically arranged upwards;
a plurality of sealing strips (23) are fixed on the front and rear side walls in the vertical shaft flue (9), the sealing strips (23) are all vertical to the sliding rod (21), and is positioned below the nitrogen oxide detector II (17), a plurality of sealing strips (23) are arranged at equal intervals, symmetrical notches (26) are symmetrically formed in the left side and the right side of the surface of the sealing strip (23), a rotating shaft (24) is fixed in each notch (26) in the left side of the sealing strip (23), the rotating shaft (24) is fixedly and rotatably connected with a sealing plate (25), the free end of the sealing plate (25) can be matched and tightly attached with a notch (26) on the right side of a sealing strip (23) on the left side of the sealing plate, the sliding rod (21) is positioned below the sealing plate (25), the sealing plates (25) correspond to the push rods (22) one by one, and the top ends of the push rods (22) can be in abutting contact with the lower surfaces of the sealing plates (25).
2. The apparatus of claim 1, wherein the apparatus for increasing SNCR denitration efficiency of the circulating fluidized bed boiler comprises: electromagnetism generating device (10) are provided with two to the outside both sides of port are fixed on shaft flue (9) to the symmetry formula, two electromagnetism generating device (10) are established ties by solenoid and current control device (15) and are constituteed, and two electromagnetism generating device (10) are located between nitrogen oxide detector (13) and nitrogen oxide detector two (17), and aqueous ammonia shower nozzle (12) are located the top of electromagnetism generating device (10), two connect in the execution output end department of automatic control ware (16) after current control device (15) in electromagnetism generating device (10) are parallelly connected.
3. The apparatus of claim 2, wherein the SNCR denitration efficiency of the circulating fluidized bed boiler is improved by: be provided with the increase journey subassembly on shaft flue (9) inside wall, and increase the journey subassembly setting and have two the magnetic field region department that electromagnetism generating device (10) produced, it includes a plurality of U-shaped board (29) to increase the journey subassembly, and is a plurality of U-shaped board (29) set into two rows according to upper and lower position, and the number of one row of U-shaped board (29) of downside compares one more than one of one row of U-shaped board (29) number of upside, and two adjacent U-shaped board (29) of every row are equidistant range, and U-shaped board (29) opening that is located the upside is down, and U-shaped board (29) opening that is located the downside is upwards, and the inboard of two adjacent U-shaped board (29) that next row corresponds is inserted respectively to the lateral wall of U-shaped board (29) of upside and U-shaped board (29) lateral wall of downside are parallel to each other, but do not contact.
4. The apparatus of claim 1, wherein the apparatus for increasing SNCR denitration efficiency of the circulating fluidized bed boiler comprises: the backflow mechanism further comprises a backflow pipe (18), the lower end of the backflow pipe (18) is connected with the right side wall of the vertical shaft flue (9), the upper end of the backflow pipe (18) is communicated with the upper end of the vertical shaft flue (9), the connection position of the lower end of the backflow pipe (18) and the right side wall of the vertical shaft flue (9) is located between the nitrogen oxide detector II (17) and the sealing strip (23), the lower end of the backflow pipe (18) is connected with a butterfly valve, and a gear (28) is fixed at one end, located on the outer side of the backflow pipe (18), of a valve rod of the butterfly valve;
the upper end of the push plate (20) is fixed with a rack (27), the rack (27) is parallel to the sliding rod (21), and the rack (27) is meshed with the gear (28).
5. The apparatus of claim 1, wherein the apparatus for increasing SNCR denitration efficiency of the circulating fluidized bed boiler comprises: the separation feed back mechanism comprises a boiler feed back device (4) and a cyclone separator (5), the air inlet end of the cyclone separator (5) is connected with the upper end of the circulating fluidized bed boiler furnace (3) through a pipeline, the upper gas output end of the cyclone separator (5) is connected with the upper end of a vertical shaft flue (9) through a pipeline, and the lower solid output end of the cyclone separator (5) is connected with the lower end of the circulating fluidized bed boiler furnace (3) through a pipeline.
6. The apparatus of claim 5, wherein the SNCR denitration efficiency of the circulating fluidized bed boiler is improved by: oxygen suppliment mechanism includes air heater (6), primary air fan (7) and secondary air fan (8), air heater (6) cup joint in the lateral wall lower part of shaft flue (9), and the end of giving vent to anger of primary air fan (7) and secondary air fan (8) is connected with the inlet port of air heater (6) respectively through the trachea, the end of giving vent to anger of air heater (6) is connected through the lower extreme of trachea with circulating fluidized bed boiler furnace (3).
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