CN108954298A - A kind of circulating fluidized bed boiler low nitrogen burning exhaust system and its remodeling method - Google Patents

A kind of circulating fluidized bed boiler low nitrogen burning exhaust system and its remodeling method Download PDF

Info

Publication number
CN108954298A
CN108954298A CN201810948140.XA CN201810948140A CN108954298A CN 108954298 A CN108954298 A CN 108954298A CN 201810948140 A CN201810948140 A CN 201810948140A CN 108954298 A CN108954298 A CN 108954298A
Authority
CN
China
Prior art keywords
boiler
air
high temperature
sncr
cyclone separator
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.)
Pending
Application number
CN201810948140.XA
Other languages
Chinese (zh)
Inventor
宋恒
高富民
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
SHANDONG CONSTRUCTION HIGH PRESSURE CONTAINER CO Ltd
Original Assignee
SHANDONG CONSTRUCTION HIGH PRESSURE CONTAINER CO Ltd
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by SHANDONG CONSTRUCTION HIGH PRESSURE CONTAINER CO Ltd filed Critical SHANDONG CONSTRUCTION HIGH PRESSURE CONTAINER CO Ltd
Priority to CN201810948140.XA priority Critical patent/CN108954298A/en
Publication of CN108954298A publication Critical patent/CN108954298A/en
Pending legal-status Critical Current

Links

Classifications

    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23CMETHODS OR APPARATUS FOR COMBUSTION USING FLUID FUEL OR SOLID FUEL SUSPENDED IN  A CARRIER GAS OR AIR 
    • F23C10/00Fluidised bed combustion apparatus
    • F23C10/02Fluidised bed combustion apparatus with means specially adapted for achieving or promoting a circulating movement of particles within the bed or for a recirculation of particles entrained from the bed
    • F23C10/04Fluidised bed combustion apparatus with means specially adapted for achieving or promoting a circulating movement of particles within the bed or for a recirculation of particles entrained from the bed the particles being circulated to a section, e.g. a heat-exchange section or a return duct, at least partially shielded from the combustion zone, before being reintroduced into the combustion zone
    • F23C10/08Fluidised bed combustion apparatus with means specially adapted for achieving or promoting a circulating movement of particles within the bed or for a recirculation of particles entrained from the bed the particles being circulated to a section, e.g. a heat-exchange section or a return duct, at least partially shielded from the combustion zone, before being reintroduced into the combustion zone characterised by the arrangement of separation apparatus, e.g. cyclones, for separating particles from the flue gases
    • F23C10/10Fluidised bed combustion apparatus with means specially adapted for achieving or promoting a circulating movement of particles within the bed or for a recirculation of particles entrained from the bed the particles being circulated to a section, e.g. a heat-exchange section or a return duct, at least partially shielded from the combustion zone, before being reintroduced into the combustion zone characterised by the arrangement of separation apparatus, e.g. cyclones, for separating particles from the flue gases the separation apparatus being located outside the combustion chamber
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23CMETHODS OR APPARATUS FOR COMBUSTION USING FLUID FUEL OR SOLID FUEL SUSPENDED IN  A CARRIER GAS OR AIR 
    • F23C10/00Fluidised bed combustion apparatus
    • F23C10/18Details; Accessories
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23CMETHODS OR APPARATUS FOR COMBUSTION USING FLUID FUEL OR SOLID FUEL SUSPENDED IN  A CARRIER GAS OR AIR 
    • F23C10/00Fluidised bed combustion apparatus
    • F23C10/18Details; Accessories
    • F23C10/20Inlets for fluidisation air, e.g. grids; Bottoms
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23CMETHODS OR APPARATUS FOR COMBUSTION USING FLUID FUEL OR SOLID FUEL SUSPENDED IN  A CARRIER GAS OR AIR 
    • F23C10/00Fluidised bed combustion apparatus
    • F23C10/18Details; Accessories
    • F23C10/22Fuel feeders specially adapted for fluidised bed combustion apparatus
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23CMETHODS OR APPARATUS FOR COMBUSTION USING FLUID FUEL OR SOLID FUEL SUSPENDED IN  A CARRIER GAS OR AIR 
    • F23C10/00Fluidised bed combustion apparatus
    • F23C10/18Details; Accessories
    • F23C10/24Devices for removal of material from the bed
    • F23C10/26Devices for removal of material from the bed combined with devices for partial reintroduction of material into the bed, e.g. after separation of agglomerated parts
    • FMECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F23COMBUSTION APPARATUS; COMBUSTION PROCESSES
    • F23CMETHODS OR APPARATUS FOR COMBUSTION USING FLUID FUEL OR SOLID FUEL SUSPENDED IN  A CARRIER GAS OR AIR 
    • F23C2206/00Fluidised bed combustion
    • F23C2206/10Circulating fluidised bed

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)

Abstract

The present invention relates to boiler technology field, specially a kind of circulating fluidized bed boiler low nitrogen burning exhaust system and its remodeling method.The low nitrogen burning exhaust system includes flue gas recirculation system, SNCR denitration system, biomass fuel co-combustion system, pass through the transformation to feed system, cloth wind system, secondary air system, flue gas recirculation system, separation system, SNCR system, and combustion process adjustment, generate the good fuel adaptability that the combination of nitrogen and zoneofoxidation high-efficiency desulfurization, the local coal-air ratio uniform, Secondary Air jet stream stereoscopic arrangement the classification air feed and whole low oxygen combustion process that ensure burn-off rate effectively drop along the temperature equalization of material flow, reducing zone in CFB.By low nitrogen burning efficient in furnace, NOx raw emissions reach in 100mg/Nm3Hereinafter, again by SNCR system optimization, > 80% removal efficiency is realized on the basis of efficient low nitrogen burning in furnace, NOx emission is made to be reduced to 20mg/Nm3Hereinafter, meeting ultra-low emission of NOx demand.

Description

A kind of circulating fluidized bed boiler low nitrogen burning exhaust system and its remodeling method
Technical field
The present invention relates to boiler technology field, specially a kind of circulating fluidized bed boiler low nitrogen burning exhaust system and its change Make method.
Background technique
Circulating fluidized bed boiler is the highest clean coal-firing device of industrialization degree, and circulating fluidized bed boiler boiler is overall On be divided into front and the vertical shaft of tail portion two.Front vertical shaft is always to hang structure, and surrounding is made of fin panel casing, from bottom to top, according to Secondary is air compartment, emulsion zone, a dilute-phase zone, and back-end ductwork is followed successively by high temperature superheater, low temperature superheater from top to bottom and saves coal Device.Tail vertical well uses support construction, is connected between two vertical shafts by vertical cyclone separator, and separator lower part couples circulating ash Transportation system, circulating ash transportation system is mainly by feed back pipe, loop back device, a few part compositions such as overflow pipe and ash cooler.
The general fuel of circulating fluidized bed boiler in the prior art is mixed coal, and boiler load is lower, under overall operating condition at the beginning of NOx Beginning discharge value is higher, and the qualified discharge (cannot achieve ultralow) to realize NOx, but full burner hearth can only be run by full burner hearth hypoxemia Hypoxemia certainly will influence boiler combustion efficiency, and furnace effect is caused to reduce.
How efficient burning and low-nitrogen discharged realization to be effectively combined, is that circulating fluidized bed boiler in the prior art changes The emphasis made.
Technical solution
To solve above-mentioned problems of the prior art, this patent provides a kind of circulating fluidized bed boiler low nitrogen burning discharge System, specific technical solution are as follows:
A kind of circulating fluidized bed boiler low nitrogen burning exhaust system, including boiler, high temperature cyclone separator, back-end ductwork, it is described Boiler is connected by the gas approach of reversal chamber and high temperature cyclone separator, the exhaust pass and tail of the high temperature cyclone separator The exhaust pass of the connection of portion's flue, the back-end ductwork is connected by deduster, air-introduced machine and chimney, the high-temp. vortex separation The bottom of device is connect by refeed line with the return port on boiler, further includes flue gas recirculation system, SNCR denitration system, biology Matter fuel co-combustion system;The flue gas recirculation system includes the circulating fan connecting with the air outlet of air-introduced machine, the circulation Blower and pipeline is connect with primary air fan entrance and secondary air fan entrance respectively;The SNCR denitration system includes: reversal chamber In the middle part of the SNCR denitrification spray gun that is arranged in the SNCR denitrification spray gun of upper setting, high temperature cyclone separator exhaust pass, boiler setting The SNCR denitrification spray gun being arranged in the SNCR denitrification spray gun of setting, refeed line;The biomass fuel co-combustion system includes boiler The biomass fuel transportation system and coal powder conveying system of two sides setting;The exit of the high temperature cyclone separator is provided with slotting The exhaust pass for entering the central tube in the high temperature cyclone separator, connecting central tube and back-end ductwork, the central tube are eccentric Setting.
Preferably, the depth in the central tube insertion high temperature cyclone separator is 1700m-1800mm, the high temperature The entrance opening dimension of cyclone separator is 820mm*2400mm, central tube is in fourth quadrant deviation Membrane Separator Cylinder for CFB Boiler center 50- 100mm, central tube diameter are 1100mm-1300mm.
Preferably, being provided with two SNCR denitrification spray guns on the reversal chamber, on high temperature cyclone separator exhaust pass 4 SNCR denitrification spray guns are set, two SNCR denitrification spray guns are arranged in boiler setting middle part, two SNCR denitrations are arranged on refeed line Spray gun.
Preferably, the biomass fuel is waste cotton slag, the mixed-fuel burning proportion of the waste cotton slag is 10%-15%.
It is followed preferably, being provided on pipeline between the circulating fan and primary air fan entrance and secondary air fan entrance Total wind is provided on the pipeline in the distinguished and admirable meter of ring and circulated air regulating valve, the primary air fan outlet and secondary air fan exit Flowmeter and total wind regulating valve.
Preferably, being provided with air preheater in the back-end ductwork, the primary air fan, secondary air fan pass through air Preheater is connect with First air entrance and Secondary Air entrance respectively.
Preferably, being provided with shock wave soot blower in the back-end ductwork.
Preferably, being provided with two panels water-cooling screen in the boiler.
The invention also discloses a kind of circulating fluidized bed boiler low nitrogen burnings to discharge remodeling method, comprising:
(1) feed system is transformed: waste cotton slag co-combustion system is arranged in boiler two sides, waste cotton slag co-combustion system includes feed bin and spiral Batcher, the waste cotton slag in feed bin enter boiler by screw(-type) feeder, and waste cotton slag mixed-fuel burning proportion is 10%-15%;
(2) cloth wind system is transformed: reducing the area of boiler bottom air distribution plate, reduces primary air ratio 10%-15%;
(3) secondary air system is transformed: multiple secondary air channels are arranged in the opposite both direction of burner hearth in the classification of Secondary Air solid;
(4) increase flue gas recirculation system: circulating fan being connected by pipeline at the air outlet of air-introduced machine, circulating fan passes through Pipeline is connect with primary air fan entrance and secondary air fan entrance respectively, is followed according to the exhaust gas volumn of load control system flue gas recycled and again The proportion of ring flue gas and First air, Secondary Air;
(5) separation system is transformed: replacing the central tube of the high temperature cyclone separator, the central tube insertion high-temp. vortex separation Depth in device is 1700m-1800mm, the entrance opening dimension of the high temperature cyclone separator is 820mm*2400mm, central tube exists Fourth quadrant deviates Membrane Separator Cylinder for CFB Boiler center 50-100mm, central tube diameter is 1100mm-1300mm;
(6) the SNCR system reform: connection boiler and high temperature cyclone separator reversal chamber on be arranged two SNCR denitrification spray guns, Be arranged on high temperature cyclone separator exhaust pass 4 SNCR denitrification spray guns, two SNCR denitrification spray guns of setting in the middle part of boiler setting, Two SNCR denitrification spray guns are set on refeed line;
(7) shock wave soot blower is set in back-end ductwork, increases the water-cooling screen of two panels Natural Circulation in boiler.
Beneficial effect
The method that the present invention uses flue gas recirculation, flue gas recycled is led in primary wind pipe and secondary air duct, is utilized Partial fume is sprayed into boiler by hypothermia and hypoxia feature possessed by flue gas recycled again, controls the exhaust gas volumn of flue gas recycled And the proportion of flue gas recycled and First air, Secondary Air, local temperature in boiler furnace is reduced, local reduction atmosphere is formed, Inhibit the generation of nitrogen oxides, improves clinker coking phenomenon in boiler furnace, and improve boiler grate high temperature corrosion.Flue gas follows again Ring improves the flow velocity of burner hearth and heat convection area to a certain extent, is conducive to improve Cyclone efficiency, improves circulation Multiplying power extends residence time of the flying dust in furnace, is conducive to fly ash refiring;Circulating ash quantity increases simultaneously, is also beneficial to control material Layer temperature, flue gas recirculation reduce the bulk temperature of burner hearth, are also beneficial to reduce nitrogen oxides, and then effectively improve boiler Inner of the boiler chamber slag coking phenomenon, while controlling fire box temperature, and improve the high temperature corrosion of the fire grate of boiler, simultaneously as Reduce the production rate of nitrogen oxides, it is possible to reduce the ammonium hydroxide usage amount of SNCR has saved operating cost;In addition, recycling cigarette Gas is derived from the clean flue gas after air-introduced machine, it is possible to reduce equipment, primary wind pipe, secondary air duct and cycle flue dust stratification wind Danger.
For CFB boiler, its fluidization entirety uniformity is not only can be improved in the optimization of Secondary Air, can also be one Determine the source for inhibiting " tilting table " to be formed in degree, the hovering height of 4mm or less the particle on emulsion zone top is limited, and will Particle is shifted to vertical section combustion chamber wall surface, reduces the probability crossed at the top of " pants " at spike, make Secondary Air penetration into One step improves.
For the classification of Secondary Air solid, it can be achieved that in-furnace temperature is balanced, elimination localized hyperthermia's peak value realizes ideal 880~940 DEG C best low nitrogen temperature environment;Reduction-oxidation segmentation is realized in subregion burning, enhances the reverse process for having generated NOx, i.e. CO makees The reduction decomposition ability of N2+O2 under;Local oxygen amount is uniform, realizes whole low nitrogen environment reducing atmosphere in furnace;
The classification of Secondary Air solid, realizes space requirement when air stage feeding, improves the shifting of three dimensional particles required for efficient burning Dynamic heat and mass has played the fuel oxygen amount rolling action under the basic penetration capacity of Secondary Air jet stream.
By the transformation to separation system, improve efficiency separator, furnace exit temperature be increased to 900-930 DEG C it Between, SNCR reaction condition is optimized, the denitration efficiency of SNCR system is greatly improved, reduces the escaping of ammonia;By being transformed above, improve The on-load ability of boiler.
Cloth wind system is transformed, reduces primary air ratio, realizes the Researched of Air Staging Combustion Burning Pulverized Coal of depth, a small amount of First air both can be with Reach good fluidisation, to provide the foundation for Researched of Air Staging Combustion Burning Pulverized Coal.After primary air ratio reduces, under primary air fan power consumption is obvious Drop, power savings are significant.
Increase soot blower system, guarantees that back-end ductwork lacks dust stratification, guarantee the heat transfer effect of back-end ductwork, reduce exhaust gas temperature.
Increase the water-cooling screen heating surface of two panels Natural Circulation, on the one hand increase furnace internal heating surface, guarantees boiler load;It is another Furnace exit temperature can be effectively reduced in aspect, prevents separation device coking.
By scrap build and firing optimization process, generate CFB has the present invention along the temperature equalization of material flow, reducing zone Effect drop nitrogen and zoneofoxidation high-efficiency desulfurization combination, ensure burn-off rate local coal-air ratio uniformly, Secondary Air jet stream solid cloth The good fuel adaptability of the classification air feed of office and whole low oxygen combustion process.Pass through low nitrogen burning efficient in furnace, the original row of NOx It is unconventional and unrestrained to arrive in 100mg/Nm3Hereinafter, again by realizing > 80% on the basis of efficient low nitrogen burning in furnace to SNCR system optimization Removal efficiency makes NOx emission be reduced to 20mg/Nm3Hereinafter, meeting ultra-low emission of NOx demand.The transformation of high efficiency boiler low nitrogen burning Afterwards, realize that coal+cotton slag drafts the burning of stablizing of ratio, boiler efficiency improves 10%-15%, and boiler on-load ability improves 10%- 15%。
Detailed description of the invention
Fig. 1 is the structural schematic diagram of embodiment 1;
Fig. 2 is the structural schematic diagram of embodiment 1;
Fig. 3 is SNCR denitrification spray gun insertion position figure;
Fig. 4 is the cross-sectional structure schematic diagram of high temperature cyclone separator and boiler;
Fig. 5 is the structural schematic diagram of secondary air channel setting;
In figure, 1: boiler, 2: high temperature cyclone separator, 3: back-end ductwork, 4: reversal chamber, 5: deduster, 6: air-introduced machine, 7: cigarette Chimney, 8: refeed line, 9: circulating fan, 10: primary air fan, 11: secondary air fan, 12: central tube, 13: exhaust pass, 14: biology Matter fuel delivery system, 15: coal powder conveying system, 16: high temperature superheater, 17: low temperature superheater, 18: economizer, 19: air Preheater, 20:SNCR denitration spray gun, 21: recirculating air flow meter, 22: circulated air regulating valve, 23: total airflow meter, 24: total wind Regulating valve, 25: shock wave soot blower, 26: water-cooling screen, 27: air distribution plate, 28: First air entrance, 29: Secondary Air entrance, 30: burner hearth, 31: secondary air channel.
Specific embodiment
The invention will now be further described with reference to specific embodiments, the advantages and features of the present invention will be with description and It is apparent.But examples are merely exemplary, and it is not intended to limit the scope of the present invention in any way.Those skilled in the art answer It should be appreciated that without departing from the spirit and scope of the invention can details to technical solution of the present invention and form repair Change or replace, but these modifications and replacement are fallen within the protection scope of the present invention.
Embodiment 1
As shown in Figure 1, a kind of circulating fluidized bed boiler low nitrogen burning exhaust system, including boiler 1, high temperature cyclone separator 2, tail Portion's flue 3, the boiler 1 are connect by reversal chamber 4 with the gas approach of high temperature cyclone separator 2, the high-temp. vortex separation The exhaust pass of device is connect with back-end ductwork 3, and the exhaust pass of the back-end ductwork 3 passes through deduster 5, air-introduced machine 6 and chimney 7 The bottom of connection, the high temperature cyclone separator 2 is connect by refeed line 8 with the return port on boiler, further includes that flue gas follows again Loop system, SNCR denitration system, biomass fuel co-combustion system;The flue gas recirculation system includes the air outlet with air-introduced machine The circulating fan 9 of connection, the circulating fan are connect with 10 entrance of primary air fan and 11 entrance of secondary air fan respectively by pipeline.
As shown in figure 3, the SNCR denitration system includes: the SNCR denitrification spray gun being arranged on reversal chamber, high-temp. vortex point It is arranged in SNCR denitrification spray gun, refeed line from the SNCR denitrification spray gun, the setting of boiler setting middle part that are arranged on device exhaust pass SNCR denitrification spray gun.
The biomass fuel co-combustion system includes that the biomass fuel transportation system 14 that boiler two sides are arranged and coal dust are defeated Send system 15;The biomass fuel is waste cotton slag, and the mixed-fuel burning proportion of the waste cotton slag is 10%-15%.
The exit of the high temperature cyclone separator is provided with the central tube 12 being inserted into the high temperature cyclone separator, connects Connect the exhaust pass 13 of central tube and back-end ductwork, 12 eccentric setting of central tube.
The method that the present invention uses flue gas recirculation is mixed into the clean flue gas in part in First air, utilizes recycling Hypothermia and hypoxia feature possessed by flue gas, the fluidising air velocity of emulsion zone when by guaranteeing underload improve close when underrun The fluidization characteristic of phase region, strengthens the mixing of emulsion zone, and more pulverized coal particle is taken to dilute-phase zone, reduces emulsion zone and burns part Volume and temperature keep the temperature in entire burner hearth more uniform;In high load capacity, partial fume is mixed into First air, is enriched Emulsion zone temperature adjustment means reduce emulsion zone oxygen concentration, advantageously reduce the generation of NOx.Using the method for flue gas recirculation, portion Clean flue gas is divided to be mixed into Secondary Air, the hypothermia and hypoxia feature possessed by flue gas recycled is conducive to increase Secondary Air The wind speed of spout strengthens dilute-phase zone gas-solid, the mixing of gas gas, reduces local temperature in the burner hearth of boiler, be conducive to avoid the formation of office Portion high-temperature region, and local reduction atmosphere is formed, to reduce NOx generation.
Feed bin is arranged in boiler two sides, two material inlets is arranged on boiler both walls emulsion zone top, waste cotton slag is from boiler two Side enters furnace.Cotton slag mixed-fuel burning proportion 10%-15%(and coal heat ratio), under the operating condition, in line with burning is mixed less, frequently mix the original of burning Then, boiler improvement project amount is small, low cost, and boiler can safe and stable operation.Waste residue cotton enters screw(-type) feeder by feed bin (2.2kW, 7m3/ h) after, boiler is sent by screw(-type) feeder.Screw(-type) feeder revolving speed is adjusted by frequency converter, is sent with control Enter the waste cotton quantity of slag in boiler.By taking back boiler First air, waste cotton material is sent into burner hearth.Pneumatic lock gate hatch shields, Thermocouple sensor is provided with before flashboards, when temperature is excessively high, it is believed that be tempered, close lock gate hatch in time, stop It is fed motor.
Biomass fuel has following characteristic compared with coal: chlorinity and alkali metal content are high, fugitive constituent is high, oxygen content is high, Moisture content is high, fixed carbon is low, ash content is low, calorific value is low, sulfur content is low.Biomass is because potassium, chlorinity are higher, so ash after burning In contain a large amount of alkali metal salts, be good base fertilizer as fertilizer, but in combustion because of these alkali metal salt fusing points It is low, it is easy slagging, dust stratification on water-cooling wall and back-end surfaces.When using circulating fluidized bed combustion mode, these sylvite meetings The soil (containing sand) carried secretly with casting bed material or stalk, which reacts, generates potassium silicate class glass, be easy to cause bed material coking or particle long Greatly, therefore in operational process the large particle formed in combustion process should be excluded in time, supplements suitable bed material, maintain object in furnace Material granularity it is relatively uniform.In the case that pure burning or large scale mix burning, the corrosion of the dust stratification and superheater of back-end surfaces can be non- Chang Yanchong.In Retrofitting Heat Recovery Surface or the replacement in later period, high temperature superheater is arranged in furnace and (crosses heat shielding form), overheat Device high temperature section uses TP347H material.It is remaining go out trailing space, low temperature superheater and economizer transverse pitch are increased, reduce by The chance that heat area ash is put up a bridge.
Embodiment 2
The present embodiment the difference from embodiment 1 is that, the depth that the central tube 12 is inserted into high temperature cyclone separator is 1700m-1800mm, the high temperature cyclone separator entrance opening dimension be 820mm*2400mm, central tube fourth quadrant deviate Membrane Separator Cylinder for CFB Boiler center 50-100mm, central tube diameter are 1100mm-1300mm.The cross section of high temperature cyclone separator and boiler Structural schematic diagram is as shown in Figure 4.
Influence high temperature cyclone separator separative efficiency factor include:
(1) central tube diameter
Under identical entrance gas velocity, central tube diameter becomes smaller, and separator endoparticle tangential velocity can subtracting with central tube diameter Small and increase, central tube entrance short circuit flow rate reduces, and is conducive to separate, and reduce the nonaxisymmetry in flow field, eddy flow is not Stability reduces, but the overall presure drop of separator will increase.
(2) separator inlet speed
When separator inlet speed is too low, the particle in dust does not have enough momentum, and can not collide with separator reduces momentum It falls into separator, most of little particle can not separate, and cause under separative efficiency.When entrance velocity is excessively high, gas adds The diffusion of play, particle increases, and causes the spring, collision, dispersion of particle, and the aggravation of solid back-mixing phenomenon is counter to decline separative efficiency, It is unfavorable for particle separation, separative efficiency is not the raising with entrance velocity and monotone increasing;Abrasion loss and the entrance speed of separator The direct ratio upright three times of degree, the more high then separator abrasion of inlet air flow speed is bigger, and there are optimal designs for separator inlet flow velocity Value.
(3) central tube insertion depth
Since eddy flow moves between central tube and wall surface, central tube length and insertion depth have larger shadow to cyclone performance It rings.Central tube insertion is too deep, can shorten central tube at a distance from cone base, increases reentrainment chance;When central tube is inserted into It crosses shallowly, will cause normal eddy flow core bending, be at unstable state, also easily cause gas short circuit and reduce separation and imitate Rate.
SNCR denitrification spray gun insertion position is as shown in figure 3, be provided with two SNCR denitrification spray guns, high temperature on the reversal chamber 4 SNCR denitrification spray guns are set on Cyclone outlet flue, two SNCR denitrification spray guns, returning charges are arranged in boiler setting middle part Two SNCR denitrification spray guns are set on pipe.Separator inlet flue cross section is smaller, and the atomized ammonia air-flow that spray gun sprays is easy to Most of flue gas is covered, is uniformly mixed;Separator is entered after ammonium hydroxide and flue gas mixing, further in the case where flue gas stays turning effort Mixing, and enough residence times are able to maintain so that reaction is completed;Temperature window is suitable, equipment under normal circumstances, separation Device inlet flue gas temperature is about 920 DEG C, is suitable temperature window, and after entrance separator, which keeps very well, being conducive to ammonium hydroxide With reacting for NOx.
Circulated air flow is provided on pipeline between the circulating fan and primary air fan entrance and secondary air fan entrance Be provided on the pipeline in meter and circulated air regulating valve, primary air fan outlet and secondary air fan exit total airflow meter and Total wind regulating valve.
Air preheater is provided in the back-end ductwork, the primary air fan, secondary air fan pass through air preheater point It is not connect with First air entrance and Secondary Air entrance.
Shock wave soot blower is provided in the back-end ductwork.Two panels water-cooling screen is provided in the boiler.
In the case where primary air ratio being reduced, improving secondary air ratio enhances grading effect, either burn-off rate is improved, Slow down in furnace abrasion, improve coal quality adaptability, guarantee furnace effect, or to improve limestone desulfurization effect, enhancing De-NOx ability, Improve ciculation fluidized state, it is all highly beneficial.
Analysis is optimized to high-speed rotational separator by numerical simulation, obtains optimal case are as follows: central tube insertion Depth deviates Membrane Separator Cylinder for CFB Boiler center 50- in fourth quadrant in 1700m-1800mm, entrance opening dimension 820mm*2400mm, central tube When 100mm, central tube diameter in 1100mm-1300mm, the efficiency of the separator not only efficient pressure loss but also smaller.Do not changing Under the premise of air compartment boiler circuit, the efficient of burning is realized.After low nitrogen burning transformation, the combustion share of upper furnace can be improved, Flue gas temperature of hearth outlet differs very little with bed temperature, this is more conducive to temperature window and flying dust required by realizing later period SNCR After-flame.
Embodiment 3
A kind of circulating fluidized bed boiler low nitrogen burning discharge remodeling method, comprising:
(1) feed system is transformed: waste cotton slag co-combustion system is arranged in boiler two sides, waste cotton slag co-combustion system includes feed bin and spiral Batcher, the waste cotton slag in feed bin enter boiler by screw(-type) feeder, and waste cotton slag mixed-fuel burning proportion is 10%-15%;
(2) cloth wind system is transformed: reducing the area of boiler bottom air distribution plate, reduces primary air ratio 10%-15%;
(3) secondary air system is transformed: the classification of Secondary Air solid, as shown in figure 5, being arranged in the opposite both direction of burner hearth more A secondary air channel considerably increases penetration depth of the Secondary Air in boiler, keeps boiler combustion substantially stabilized;
(4) increase flue gas recirculation system: circulating fan being connected by pipeline at the air outlet of air-introduced machine, circulating fan passes through Pipeline is connect with primary air fan entrance and secondary air fan entrance respectively, is followed according to the exhaust gas volumn of load control system flue gas recycled and again The proportion of ring flue gas and First air, Secondary Air;
(5) separation system is transformed: replacing the central tube of the high temperature cyclone separator, the central tube insertion high-temp. vortex separation Depth in device is 1700m-1800mm, the entrance opening dimension of the high temperature cyclone separator is 820mm*2400mm, central tube exists Fourth quadrant deviates Membrane Separator Cylinder for CFB Boiler center 50-100mm, central tube diameter is 1100mm-1300mm;
(6) the SNCR system reform: connection boiler and high temperature cyclone separator reversal chamber on be arranged two SNCR denitrification spray guns, Be arranged on high temperature cyclone separator exhaust pass 4 SNCR denitrification spray guns, two SNCR denitrification spray guns of setting in the middle part of boiler setting, Two SNCR denitrification spray guns are set on refeed line;
(7) shock wave soot blower is set in back-end ductwork, increases the water-cooling screen of two panels Natural Circulation in boiler.
By scrap build and firing optimization process, generate CFB has the present invention along the temperature equalization of material flow, reducing zone Effect drop nitrogen and zoneofoxidation high-efficiency desulfurization combination, ensure burn-off rate local coal-air ratio uniformly, Secondary Air jet stream solid cloth The good fuel adaptability of the classification air feed of office and whole low oxygen combustion process.Pass through low nitrogen burning efficient in furnace, the original row of NOx It is unconventional and unrestrained to arrive in 100mg/Nm3Hereinafter, again by realizing > 80% on the basis of efficient low nitrogen burning in furnace to SNCR system optimization Removal efficiency makes NOx emission be reduced to 20mg/Nm3Hereinafter, meeting ultra-low emission of NOx demand.

Claims (9)

1. a kind of circulating fluidized bed boiler low nitrogen burning exhaust system, including boiler, high temperature cyclone separator, back-end ductwork, institute Boiler is stated to connect by the gas approach of reversal chamber and high temperature cyclone separator, the exhaust pass of the high temperature cyclone separator with The exhaust pass of back-end ductwork connection, the back-end ductwork is connected by deduster, air-introduced machine and chimney, the high-temp. vortex point Bottom from device is connect by refeed line with the return port on boiler, which is characterized in that further includes flue gas recirculation system, SNCR Denitrating system, biomass fuel co-combustion system;The flue gas recirculation system includes the circulation connecting with the air outlet of air-introduced machine Blower, the circulating fan are connect with primary air fan entrance and secondary air fan entrance respectively by pipeline;The SNCR denitration system System include: the SNCR denitrification spray gun being arranged on reversal chamber, the SNCR denitrification spray gun being arranged on high temperature cyclone separator exhaust pass, The SNCR denitrification spray gun being arranged in the SNCR denitrification spray gun that is arranged in the middle part of boiler setting, refeed line;The biomass fuel mixes burning System includes the biomass fuel transportation system and coal powder conveying system of boiler two sides setting;The high temperature cyclone separator goes out The exhaust pass for being provided with the central tube being inserted into the high temperature cyclone separator at mouthful, connecting central tube and back-end ductwork, institute State central tube eccentric setting.
2. the circulating fluidized bed boiler low nitrogen burning exhaust system according to claim 1, which is characterized in that the center Depth in cylinder insertion high temperature cyclone separator is 1700m-1800mm, the entrance opening dimension of the high temperature cyclone separator is 820mm*2400mm, central tube deviate Membrane Separator Cylinder for CFB Boiler center 50-100mm, central tube diameter in fourth quadrant for 1100mm- 1300mm。
3. circulating fluidized bed boiler low nitrogen burning exhaust system according to claim 1, which is characterized in that the reversal chamber On be provided with two SNCR denitrification spray guns, 4 SNCR denitrification spray guns, boiler settings be set on high temperature cyclone separator exhaust pass Two SNCR denitrification spray guns are set in two SNCR denitrification spray guns of middle part setting, refeed line.
4. the circulating fluidized bed boiler low nitrogen burning exhaust system according to claim 1, which is characterized in that the biology Matter fuel is waste cotton slag, and the mixed-fuel burning proportion of the waste cotton slag is 10%-15%.
5. the circulating fluidized bed boiler low nitrogen burning exhaust system according to claim 1, which is characterized in that the circulation Recirculating air flow meter and circulated air regulating valve are provided on pipeline between blower and primary air fan entrance and secondary air fan entrance, Total airflow meter and total wind regulating valve are provided on the pipeline in the primary air fan outlet and secondary air fan exit.
6. the circulating fluidized bed boiler low nitrogen burning exhaust system according to claim 1, which is characterized in that the tail portion Be provided with air preheater in flue, the primary air fan, secondary air fan by air preheater respectively with First air entrance and The connection of Secondary Air entrance.
7. the circulating fluidized bed boiler low nitrogen burning exhaust system according to claim 1, which is characterized in that the tail portion Shock wave soot blower is provided in flue.
8. the circulating fluidized bed boiler low nitrogen burning exhaust system according to claim 1, which is characterized in that the boiler Inside it is provided with two panels water-cooling screen.
9. a kind of circulating fluidized bed boiler low nitrogen burning discharges remodeling method characterized by comprising
(1) feed system is transformed: waste cotton slag co-combustion system is arranged in boiler two sides, waste cotton slag co-combustion system includes feed bin and spiral Batcher, the waste cotton slag in feed bin enter boiler by screw(-type) feeder, and waste cotton slag mixed-fuel burning proportion is 10%-15%;
(2) cloth wind system is transformed: reducing the area of boiler bottom air distribution plate, reduces primary air ratio 10%-15%;
(3) secondary air system is transformed: multiple secondary air channels are arranged in the opposite both direction of burner hearth in the classification of Secondary Air solid;
(4) increase flue gas recirculation system: circulating fan being connected by pipeline at the air outlet of air-introduced machine, circulating fan passes through Pipeline is connect with primary air fan entrance and secondary air fan entrance respectively, is followed according to the exhaust gas volumn of load control system flue gas recycled and again The proportion of ring flue gas and First air, Secondary Air;
(5) separation system is transformed: replacing the central tube of the high temperature cyclone separator, the central tube insertion high-temp. vortex separation Depth in device is 1700m-1800mm, the entrance opening dimension of the high temperature cyclone separator is 820mm*2400mm, central tube exists Fourth quadrant deviates Membrane Separator Cylinder for CFB Boiler center 50-100mm, central tube diameter is 1100mm-1300mm;
(6) the SNCR system reform: connection boiler and high temperature cyclone separator reversal chamber on be arranged two SNCR denitrification spray guns, Be arranged on high temperature cyclone separator exhaust pass 4 SNCR denitrification spray guns, two SNCR denitrification spray guns of setting in the middle part of boiler setting, Two SNCR denitrification spray guns are set on refeed line;
(7) shock wave soot blower is set in back-end ductwork, increases the water-cooling screen of two panels Natural Circulation in boiler.
CN201810948140.XA 2018-08-20 2018-08-20 A kind of circulating fluidized bed boiler low nitrogen burning exhaust system and its remodeling method Pending CN108954298A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN201810948140.XA CN108954298A (en) 2018-08-20 2018-08-20 A kind of circulating fluidized bed boiler low nitrogen burning exhaust system and its remodeling method

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN201810948140.XA CN108954298A (en) 2018-08-20 2018-08-20 A kind of circulating fluidized bed boiler low nitrogen burning exhaust system and its remodeling method

Publications (1)

Publication Number Publication Date
CN108954298A true CN108954298A (en) 2018-12-07

Family

ID=64470711

Family Applications (1)

Application Number Title Priority Date Filing Date
CN201810948140.XA Pending CN108954298A (en) 2018-08-20 2018-08-20 A kind of circulating fluidized bed boiler low nitrogen burning exhaust system and its remodeling method

Country Status (1)

Country Link
CN (1) CN108954298A (en)

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109603475A (en) * 2018-12-17 2019-04-12 山西晋城无烟煤矿业集团有限责任公司 A kind of tandem SNCR processing method for realizing nitrogen oxides minimum discharge
CN109827171A (en) * 2019-03-15 2019-05-31 镇江东亚碳素焦化有限公司 A kind of petroleum coke combustion desulfurization fluidized-bed combustion boiler
CN114509111A (en) * 2022-01-26 2022-05-17 华能威海发电有限责任公司 Method and system for detecting abnormal working conditions of power station boiler

Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN201149248Y (en) * 2007-12-21 2008-11-12 北京博朗环境工程技术股份有限公司 Biomass circulating fluid bed boiler
CN203836944U (en) * 2014-05-15 2014-09-17 北京洛卡环保技术有限公司 SNCR-SCR mixed denitration system of circulating fluidized bed boiler
CN106268261A (en) * 2016-10-10 2017-01-04 福建龙净环保股份有限公司 A kind of method of SNCR denitrating flue gas
CN106838892A (en) * 2017-02-15 2017-06-13 无锡华光锅炉股份有限公司 A kind of energy-efficient Circulating Fluidized Bed Boiler of low nitrogen
CN107191922A (en) * 2017-06-29 2017-09-22 平湖热电厂 Low nitrogen burning CFBB
CN108201784A (en) * 2018-03-02 2018-06-26 陕西大秦环境科技有限公司 A kind of grate-type biomass power plant boiler flue gas purification tapping equipment and its method
CN208750699U (en) * 2018-08-20 2019-04-16 山东省建设高压容器有限公司 A kind of circulating fluidized bed boiler low nitrogen burning exhaust system

Patent Citations (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN201149248Y (en) * 2007-12-21 2008-11-12 北京博朗环境工程技术股份有限公司 Biomass circulating fluid bed boiler
CN203836944U (en) * 2014-05-15 2014-09-17 北京洛卡环保技术有限公司 SNCR-SCR mixed denitration system of circulating fluidized bed boiler
CN106268261A (en) * 2016-10-10 2017-01-04 福建龙净环保股份有限公司 A kind of method of SNCR denitrating flue gas
CN106838892A (en) * 2017-02-15 2017-06-13 无锡华光锅炉股份有限公司 A kind of energy-efficient Circulating Fluidized Bed Boiler of low nitrogen
CN107191922A (en) * 2017-06-29 2017-09-22 平湖热电厂 Low nitrogen burning CFBB
CN108201784A (en) * 2018-03-02 2018-06-26 陕西大秦环境科技有限公司 A kind of grate-type biomass power plant boiler flue gas purification tapping equipment and its method
CN208750699U (en) * 2018-08-20 2019-04-16 山东省建设高压容器有限公司 A kind of circulating fluidized bed boiler low nitrogen burning exhaust system

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN109603475A (en) * 2018-12-17 2019-04-12 山西晋城无烟煤矿业集团有限责任公司 A kind of tandem SNCR processing method for realizing nitrogen oxides minimum discharge
CN109827171A (en) * 2019-03-15 2019-05-31 镇江东亚碳素焦化有限公司 A kind of petroleum coke combustion desulfurization fluidized-bed combustion boiler
CN109827171B (en) * 2019-03-15 2024-03-08 镇江东亚碳素焦化有限公司 Fluidized bed boiler for petroleum coke combustion desulfurization
CN114509111A (en) * 2022-01-26 2022-05-17 华能威海发电有限责任公司 Method and system for detecting abnormal working conditions of power station boiler

Similar Documents

Publication Publication Date Title
CN105020700B (en) A kind of grate firing boiler combination denitrification apparatus and method
CN102537975B (en) Circulating fluidized bed garbage incineration boiler and pollution control system with same
CN208799951U (en) A kind of circulating fluidized bed boiler flue gas desulfuration and denitrification system
CN107559821B (en) The multiple-pass industrial coal powder boiler of flue gas recirculation and vortex burner overhead
CN108905568A (en) A kind of circulating fluidized bed boiler flue gas desulfuration and denitrification system and its remodeling method
CN108954298A (en) A kind of circulating fluidized bed boiler low nitrogen burning exhaust system and its remodeling method
CN106838892A (en) A kind of energy-efficient Circulating Fluidized Bed Boiler of low nitrogen
CN103041686A (en) NOx removing device and method by means of exhaust gas recycle and ammonia agent spray
CN106838890A (en) A kind of fuel and the low emission CFBB of desulfurizing agent classification supply
CN106765067A (en) A kind of water-coal-slurry minimum discharge combustion system
CN108895430A (en) A kind of efficient low NO of coupled rotational flow coal dust firing and enhanced flue gas recirculationxChain furnace
CN103884013B (en) Manifold type environment-friendly type fluidized-bed combustion boiler combustion method and device
CN208750699U (en) A kind of circulating fluidized bed boiler low nitrogen burning exhaust system
CN105805730B (en) Realize the circulating fluidized bed boiler systems of low-nitrogen oxide discharging
CN205782865U (en) Realize the circulating fluidized bed boiler systems of low-nitrogen oxide discharging
CN107044633A (en) Vertical pulverized-coal fired boiler
CN103697465A (en) Boiler capable of achieving reignition of exhaust gas coal powder and reducing NOx by using high-temperature flue gas
CN106838891A (en) Recirculating fluidized bed oxygen-enriched combustion boiler system
CN107023824A (en) Vertical pulverized-coal fired boiler
CN106642091A (en) Low-nitrogen combustion method of fluidized-bed boiler
CN106979514A (en) A kind of sunken bed ballast group fluid bed and its application method for using super-low calorific value fuel
CN101569829B (en) Method for jointly controlling emission of NOx by utilizing multi-stage bias combustion and fuel reburning
CN203043834U (en) Device for removing NOx through smoke recycling and ammonia agent jetting
CN109578993B (en) Horizontal coal-fired furnace and flue gas recirculation system and operation method thereof
CN111981473A (en) Slag burnout system and method of biomass boiler

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