CN107355802B - W type flame boiler staged-combustion method - Google Patents

Abstract

The present invention relates to a kind of W type flame boiler staged-combustion methods, are reacted using inflammable briquette with oxygen, become first-stage burning, and wherein inflammable briquette is the mixing of bituminous coal or bituminous coal and meager coal；The high-temperature flue gas atmosphere that first stage is formed, under the sweeping along of high-temperature flue gas, ignite anthracite, form second level burning, determine that bituminous coal and anthracitic proportion or bituminous coal, meager coal, the method that anthracitic proportion is proportion optimizing include: based on the coal elements and Industrial Analysis as a result, the combustion strategies of predetermined boiler, when to using different combustion strategies, boiler working condition is compared analysis, obtains coal blend ratio, the coal pulverizer coal powder injection mode of optimal boiler fractional combustion.The present invention determines burning coal and anthracitic proportion during boiler fractional combustion, effectively promotes the burn-off rate of second level fuel, achieve the purpose that secondary reduction flying dust, slag phosphorus content.

Description

W type flame boiler staged-combustion method

Technical field

The present invention relates to a kind of W type flame boiler staged-combustion methods.

Background technique

The problem of W type flame boiler is primarily present:

(1) air distribution is improper causes flame kernel to move up, or even forms double-U-shaped flame, and part boiler flame stroke shortens, no Conducive to anthracitic burning, unburned carbon in flue dust and slag phosphorus content are significantly increased, and furnace effect reduces.

(2) be easy to cause to float on flame when aerodynamic field tissue is unreasonable and be directly entered secondary furnace, cause superheater and The problems such as reheater overtemperature, exhaust gas temperature raising and throat site slagging.

(3) since the temperature in burner hearth is higher than 1500 DEG C (thermal NO x generate temperature), cause the production quantity of NOx compared with Greatly, higher than the mean level of tangentially-fired boiler, deviate from original design intention.

(4) each power plant's NOx discharge is generally higher, up to 1300mg/Nm3.

(5) in order to improve ignition zone temperature, enhancing kindling, it is necessary to the wall with refractory lining, refracto of laying causes burner hearth local temperature excessively high, Easily cause side wall slagging, part power plant prevents boiler coke by the arrangement of transformation side wall Secondary Air.

(6) aerodynamic field is complex, encircles lower momentum and be easy to cause greatly very much under flame and penetrate dry bottom hopper and cause slagging, on arch Momentum is too small will to be caused to lick aditus laryngis on flame.

(7) boiler structure is more complicated, and the design of chimney arch is difficult to install, burner wind powder pipe road difficult arrangement, steel consumption Greatly, cost is high, needs operating experience abundant and higher operation level, operational and administrative expenses.

In view of the above shortcomings, the designer is actively subject to research and innovation, to found a kind of raising flame boiler effect The method of rate makes it with more the utility value in industry.

In view of the above shortcomings, the designer is actively subject to research and innovation, to found a kind of W type flame boiler classification Combustion method makes it with more the utility value in industry.

Summary of the invention

In order to solve the above technical problems, the object of the present invention is to provide a kind of burn-off rate for effectively promoting second level fuel, Achieve the purpose that the W type flame boiler staged-combustion method of secondary reduction flying dust, slag phosphorus content.

W type flame boiler staged-combustion method of the present invention, comprising: reacted using inflammable briquette with oxygen, become first order combustion It burns, wherein inflammable briquette is the mixing of bituminous coal or bituminous coal and meager coal；The high-temperature flue gas atmosphere that first stage is formed, in high-temperature flue gas It sweeps along down, ignite anthracite, forms second level burning, wherein inflammable briquette is the Mixture Density Networks of bituminous coal or bituminous coal and meager coal, and bituminous coal It is proportion optimizing with anthracitic proportion or bituminous coal, meager coal, anthracitic proportion, as-fired coal dry ash free basis volatile matter content is protected It holds in 15% < Vdaf < 20%, as-fired coal low heat valve is maintained at 20MJ/kg < Qnet, ar < 22.5MJ/kg, bituminous coal, When meager coal, anthracite fractional combustion, Vdaf > 10% is needed；

Wherein it is determined that bituminous coal and anthracitic proportion or bituminous coal, meager coal, the method packet that anthracitic proportion is proportion optimizing It includes:

Several coals are chosen, coal elements and Industrial Analysis are carried out to the coal of selection based on thermogravimetric and infrared analysis；

Based on the coal elements and Industrial Analysis as a result, the combustion strategies of predetermined boiler, the combustion strategies are specific Include: (1) can be formed in boiler fractional combustion coal allocation ratio and corresponding coal pulverizer coal-grinding mode；(2) no Can be formed in boiler classification coal allocation ratio and corresponding coal pulverizer coal-grinding mode；

It is carried out according to scheduled combustion strategies, boiler oil combustion simulation obtains the operating condition of boiler, and the boiler working condition is extremely Few includes heat temperature, hot temperature, spray water flux, exhaust gas temperature, unburned carbon in flue dust, boiler slag carbon content, low heat valve, row again again Cigarette loss, empty pre- entrance oxygen amount, Mechanical adsorption, back balance furnace effect, back balance power supply mark coal, SCR inlet NOx Content；

When to using different combustion strategies, boiler working condition is compared analysis, obtains the coal of optimal boiler fractional combustion Kind proportion, coal pulverizer coal powder injection mode.

Further, aileron longitudinally opens 4 ventilation gaps and inwardly blows Secondary Air, water screen tube outer diameter at aileron 120.65mm, center are 25.4mm, aileron upper and lower part tube outer diameter away from the pipe gap for 146.4mm, water screen tube 69.85mm, water screen tube and aileron upper and lower part pipe are connected by reducer pipe, the water-cooling wall at four ventilation strips of ventilation The outer diameter of pipe is less than 120.65mm, and the pipe gap of the water screen tube at four ventilation strips of ventilation is 76.55mm, ventilation strip Height is set as the total length of aileron pipe, or is arranged in aileron top half；Combustion is defended in removal each 1 root canal in ventilation slot two sides Band.

Further, the combustion strategies of the predetermined boiler, specifically include:

The W type flame boiler configures four coal pulverizers, the first coal pulverizer A, the second coal pulverizer B, third coal pulverizer C, 4th coal pulverizer D；

One: the first coal pulverizer A of strategy, the second coal pulverizer B, third coal pulverizer C, the 4th coal pulverizer D grind pure burning anthracite；

Two: the first coal pulverizer A of strategy, the second coal pulverizer B, third coal pulverizer C, the 4th coal pulverizer D grind bituminous coal, smokeless The Mixture Density Networks of coal, grind bituminous coal: anthracite is mixed according to 1:3 ratio matches；

Three: the four coal pulverizer D of strategy grind pure bituminous coal, and single coal volatile matter is limited within 20%~30%, the first mill Coal machine A, the second coal pulverizer B, third coal pulverizer C grind anthracite, and single coal volatile matter is limited in 15% or less；

Four: the first coal pulverizer A of strategy, the second coal pulverizer B, third coal pulverizer C, the 4th coal pulverizer D grind bituminous coal, smokeless The Mixture Density Networks of coal, grind bituminous coal: anthracite is mixed according to 1:1 ratio matches, stokehold premix；

Strategy five: bituminous coal and anthracite ratio are 1:1, bituminous coal on the first coal pulverizer, third coal pulverizer, and single coal is volatilized Divide and be limited within 20%~30%, the second coal pulverizer, the 4th coal pulverizer grind upper anthracite, i.e., forward and backward wall respectively has a coal-grinding Pure bituminous coal on machine, bituminous coal and anthracite ratio are 1:1；

Strategy six: the first coal pulverizer A, third coal pulverizer C grind bituminous coal, anthracitic Mixture Density Networks, grind bituminous coal: anthracite according to 7 ︰, 3 ratio mix matching, the second coal pulverizer B, the 4th coal pulverizer D grind bituminous coal, anthracitic Mixture Density Networks, bituminous coal: anthracite according to 3 ︰, 7 ratio mix matching；

Seven: the first coal pulverizer A of strategy, the second coal pulverizer B, third coal pulverizer C, on the 4th coal pulverizer D bituminous coal grind bituminous coal, Anthracite Mixture Density Networks, bituminous coal: anthracite is mixed according to 3 ︰, 1 ratio matches；

Tactful eight: the four coal pulverizer D anthracites, single coal volatile matter are limited in 15% hereinafter, the first coal pulverizer A, the Two coal pulverizer B, third coal pulverizer C grind bituminous coal, and single coal volatile matter is limited within 20%~30%, and bituminous coal: anthracite is pressed It mixes and matches according to 3 ︰, 1 ratio；

Nine: the first coal pulverizer A of strategy, the second coal pulverizer B, third coal pulverizer C, the 4th coal pulverizer D grind mill bituminous coal, poor The Mixture Density Networks of coal, Yan Mei ︰ meager coal is mixed according to 7 ︰, 3 ratio matches；

Ten: the first coal pulverizer A of strategy, the second coal pulverizer B, third coal pulverizer C, the 4th coal pulverizer D grind mill bituminous coal, poor The Mixture Density Networks of coal, Yan Mei ︰ meager coal is mixed according to 3 ︰, 7 ratio matches；

The 11: the first coal pulverizer A of strategy, the second coal pulverizer B, third coal pulverizer C, bituminous coal grinds mill on the 4th coal pulverizer D Coal anthracite, meager coal, bituminous coal Mixture Density Networks, coal-grinding mixes and matches Wu Yan Mei ︰ Pin Mei ︰ bituminous coal=2 ︰, 4 ︰, 4 ratio；

Wherein, strategy two to six, strategy eight, strategy 11 are the coal allocation ratio that fractional combustion can be formed in boiler And corresponding coal pulverizer coal-grinding mode；

Strategy one, strategy one, seven, nine, ten are that the coal allocation ratio of classification and corresponding cannot be formed in boiler Coal pulverizer coal-grinding mode.

Further, further include the steps that determining F wind tilt angled down F wind tilt angled down and D, E wind aperture, specifically include:

Boiler in following (1), (2), (3) 3 kinds of loads and F wind tilt angled down, is fired respectively using fuel staging Burning mode is burnt, and the operation conditions in different F layer Secondary Air tilt angled downs is obtained, wherein the operation conditions is at least It include: NOx, CO, O2 of economizer exit flue gas；NOx, CO, O2 of air preheater exiting flue gas；Boiler thermal efficiency；As-fired coal work Industry, elemental analysis；Flying dust, clinker sampling analysis；Economizer exit flue-gas temperature；Air preheater exit gas temperature；Raw coal sampling； Environment temperature, humidity and atmospheric pressure；

Wherein, (1) under 325MW load, boiler operating state under 0 ゜ of F wind tilt angled down, 10 ゜, 15 ゜, 20 ゜, 30 ゜；(2) Under 300MW load, boiler operating state under 5 ゜ of F wind tilt angled down, 10 ゜, 20 ゜, 30 ゜；(3) under 260MW load, under F wind Boiler operating state under 5 ゜ of degree of tilt, 10 ゜, 20 ゜, 30 ゜；

The operation conditions of the boiler of acquisition is analyzed, determines F wind tilt angled down and D, E wind aperture are as follows:

F wind tilt angled down and D, E wind aperture are as follows:

Wall afterwards: burner D1, burner A1, burner D2, burner combustion device A2, burner are respectively corresponded from left to right The F wind angle of declination of D3, burner A3, burner D4, burner A4, burner D5, burner A5, burner D6, burner A6 Degree: 25,25,5,5,30,30,30,30,5,5,25,25；E wind aperture: 25,25,5,20,20,20,20,20,5,5,10,10；D Wind aperture: 5,5,5,5,5,5,5,5,5,5,5,5；

Front wall: burner C1, burner B1, burner C2, burner B2, burner C3, combustion are respectively corresponded from left to right The F wind tilt angled down of burner B3, burner C4, burner B4, burner C5, burner B5, burner C6, burner B6: 25, 25,5,5,30,30,30,30,5,5,25,25；E wind aperture: 25,25,5,20,20,20,20,20,5,5,10,10；D wind is opened Degree: 5,5,5,5,5,5,5,5,5,5,5,5.

Further, NOx, CO, O2 measurement of economizer exit flue gas use gridding method, and every side flue takes five measuring points, Each flue is mixed into a flue gas sample and is analyzed, and every side air preheater exiting flue gas ingredient takes the arithmetic mean of instantaneous value of flue, pot Fire grate cigarette smoke components take the arithmetic mean of instantaneous value of 2 flues；

NOx, CO, O2 measurement of air preheater exiting flue gas equally use gridding method, and every side flue takes five measuring points, Mei Geyan Road is mixed into a flue gas sample and is analyzed, and every side air preheater exiting flue gas ingredient takes the arithmetic mean of instantaneous value of flue, boiler exhaust gas Smoke components take the arithmetic mean of instantaneous value of 2 flues；

Economizer exit flue-gas temperature uses grid survey, and the arithmetic average per each measurement point side-draw is average as outlet Flue-gas temperature；

The measurement of air preheater exit gas temperature uses gridding method, totally 2 flues, and every side air preheater exports average flue-gas temperature Take the arithmetic mean of instantaneous value of measurement point.

Further, boiler thermal efficiency calculation formula is as follows:

In formula:

η_g--- boiler thermal efficiency, %；

H_f--- fuel applications base low heat valve, kJ/kg；

B --- corresponding every kilogram enters the total input physical thermal of furnace fuel, kJ/kg；

Every kilogram of L --- boiler enters the total heat loss of furnace fuel, is calculated as follows according to this boiler situation:

L=L_UC+L'_G+L_mf+L_H+L_MA+L_co+L_β+L_UN

L_UCUncompleted burned carbon heat loss, kJ/kg in-lime-ash；

L'_G- dry gas loss, kJ/kg；

L_mf- enter heat loss caused by moisture, kJ/kg in furnace fuel；

L_H- hydrogen burning generates heat loss caused by moisture, kJ/kg；

L_MAHeat loss caused by-moisture in air, kJ/kg；

L_CO- as generate carbon monoxide and caused by heat loss, kJ/kg；

L_βThe heat loss of-surface emissivity and convection current, kJ/kg；

L_UN- immeasurability heat loss (takes constant by boiler factory's design value), kJ/kg.

Further, the volatile matter content of inflammable coal is higher than anthracite, and volatile matter > 25%, bituminous coal, anthracitic Proportion is 3:1.

Further, under 335MW load, air output is controlled in 241m³/ s runs 1.83% or more oxygen amount；In 300MW Under load, air output is controlled in 222m³/ s runs 2.58% or more oxygen amount.

Further, in strategy five, when boiler combustion, the first coal pulverizer A, third coal pulverizer C disintegrating outlet temperature be 118 DEG C, the disintegrating outlet temperature of third coal pulverizer is 109 DEG C.

Further, preferential to start the first coal pulverizer, the second coal pulverizer, third coal pulverizer when boiler combustion in strategy eight Three coal pulverizers, opening mill sequence is ipsilateral, pre-cooling primary air fan, it is desirable that volatile matter 30%, calorific value 20000kJ/kg with On.

According to the above aspect of the present invention, the present invention has at least the following advantages:

(1) of the invention guarantees to stablize qualified steam parameter；(2) stable ignition improves coal dust after-flame degree；(3) it reduces dirty Contaminate the generation of object.Realize the purpose of optimization burning, it is necessary to keep reasonable wind coal cooperation, Secondary Air cooperation, send air inducing Cooperation and the burner method of operation.Reasonable wind coal cooperation is just to maintain best excess air coefficient；A reasonable Secondary Air Cooperation is exactly suitable primary air ratio and Secondary Air air distribution mode, guarantees rapid and completely burned of catching fire；Reasonably air inducing is sent to match Conjunction is just to maintain suitable combustion chamber draft, stablizes burning；The reasonable burner method of operation is exactly negative between reasonable burner Lotus distribution and shutting mode.When operating condition changes, the adjusting of these mixing ratios is appropriate, so that it may guarantee boiler The operation of stability and high efficiency.

The present invention makes full use of two-stage combustion technology, it is ensured that first order fuel and second level full combustion of fuel effectively prolong Long flame travel and the whole flame combustion distance of raising, are effectively reduced boiler flyash carbon content, improve boiler efficiency, promote boiler The ability of underrun improves boiler milling system power output.

Using grading combustion technology, primary fuel full combustion can be fully ensured that, reduce the flying dust of first-stage burning With slag combustible content；The high-temperature area that first-stage burning is formed is conducive to the anthracite formation secondary firing that ignites, and effectively mentions The burn-off rate for rising second level fuel, achievees the purpose that secondary reduction flying dust, slag phosphorus content.

The above description is only an overview of the technical scheme of the present invention, in order to better understand the technical means of the present invention, And can be implemented in accordance with the contents of the specification, the following is a detailed description of the preferred embodiments of the present invention and the accompanying drawings.

Detailed description of the invention

The position schematic diagram for the wall with refractory lining, refracto laying that Fig. 1 is；

Fig. 2 is that the present invention increases the anti-scorch wind prioritization scheme schematic diagram of aileron；

Fig. 3 is W flame boiler combustion mechanism figure；

Fig. 4 is W type flame boiler schematic diagram；

Burner arrangement schematic diagram on Fig. 5 chimney arch of the present invention；

Fig. 6 Secondary Air of the present invention has a down dip device overall structure main view sectional view；

Fig. 7 present invention encircles lower Secondary Air inclination angle pendulous device structural schematic diagram；

The A-A cross-sectional view of the independent air compartment of Fig. 8 present invention；

Fig. 9 present invention adjusts the scheme of installation of blade, regulating arm and rotation axis；

The connection schematic diagram of Figure 10 pull rod of the present invention, cursor, regulating arm and connecting rod；

Figure 11 is to encircle lower overfire air port arrangement schematic diagram；

Figure 12 is that figure is compared in the different influences mixed with strategy to furnace effect；

Figure 13 is that figure is compared in the different influences mixed with strategy to NOx emission；

Figure 14 be difference mix with strategy on net coal consumption rate influence compare figure；

Burner 1, partition 2 first adjust blade 3, lower secondary air chamber 4, connecting rod 5, pull rod 6, uniform flow orifice 7, regulating arm 8, Cursor 9, post-tensioning water screen tube 10, vertical water screen tube 11, burner hearth 12, the first midfeather 13, lateral partitions 14, the second mediastinum Plate 15, second adjusts blade 16, third midfeather 17, the 4th midfeather 18, rotation axis 19, layback water screen tube 20, wide seam wind Room 21, narrow slit air compartment 22, pin hole 24, sliding groove 25.

Specific embodiment

With reference to the accompanying drawings and examples, specific embodiments of the present invention will be described in further detail.Implement below Example is not intended to limit the scope of the invention for illustrating the present invention.

Embodiment 1

As shown in Fig. 2, the present embodiment W type flame boiler staged-combustion method, aileron are longitudinally opened 4 ventilation gaps and are inwardly blown Secondary Air, water screen tube outer diameter is larger (120.65mm) at aileron, and center is away from for 146.4mm, and pipe gap is 25.4mm, and the wing Wall upper and lower part tube outer diameter is smaller (69.85mm), and original design is connected both ends by reducer pipe, and only needs need to be divulged information Extra heavy pipe at four ventilation strips is changed to tubule (moving down top concentric reducer position), and pipe gap can broaden as 76.55mm, Ventilation effect is good, can prevent aileron water screen tube large-area coking, and it is as shown in Figure 2 to increase the anti-scorch wind prioritization scheme of aileron.It is logical The height of wind band may be configured as the total length of aileron pipe, can also be provided only on aileron top half, the longer effect of ventilation strip is more Obviously.

Aileron wall with refractory lining, refracto is not necessary to large area removal in this way, need to only remove defending in each 1 root canal in ventilation slot two sides Combustion band is smaller to combustion effects.In this scheme, after top concentric reducer position moves down, analyzed according to water circulation calculation, it can be straight The light pipe with same specification is connect, water circulation calculation is safe.

Reduce refractory belt area

According to similarity theory, aileron wall with refractory lining, refracto handling suggestion is suggested as follows: aileron pipe water circulation is safe；If Aileron wall with refractory lining, refracto is removed, the fin end temperature of portion's fin can be made close to 600 DEG C, fin is easily caused to cross cause thermal damage.So from boiler Long-term safety set out and generally do not remove wall with refractory lining, refracto at this.

Wall with refractory lining, refracto modification scheme one

According to actual motion boiler design, the operating experience of domestic more boilers, if running coal quality from now in conjunction with this engineering The case where (Vdaf >=15%), wall with refractory lining, refracto modification scheme one implement (area of wall with refractory lining, refracto with it is minimum not throw the oily load that surely fires related, The two is inversely).It is expected that minimum do not throw oily steady combustion load≤45%BMCR.

Wall with refractory lining, refracto modification scheme two

If this engineering will be run the case where coal quality (Vdaf≤12%) from now on, wall with refractory lining, refracto transformation can refer to two (wall with refractory lining, refracto of scheme Area do not throw that oily steady combustion load is related, and the two is inversely with minimum).It is expected that minimum do not throw oily steady combustion load≤40% BMCR

Wall with refractory lining, refracto modification scheme three

If this engineering will run the case where coal quality (Vdaf≤12%) from now on, in conjunction with the practical lateral thinking of owner, wall with refractory lining, refracto Transformation can refer to scheme three (area of wall with refractory lining, refracto oily surely fires that load is related, and the two is inversely with minimum do not throw), it is contemplated that most It is low not throw oily steady combustion load≤40%BMCR.

To guarantee boiler combustion stability, a large amount of wall with refractory lining, refracto are laid in burner hearth, to improve fire box temperature, guarantee to stablize combustion It burns, but fire box temperature can be higher than ash fusion point.The region of wall with refractory lining, refracto laying will be varied according to the difference of coal quality, and burning coal is got over The wall with refractory lining, refracto area that need to be laid when poor is more.Former FW wall with refractory lining, refracto laying theory (in the case of combustion anthracite, arch, front and back vertical wall, The case where aileron (cutting), 1st~4 area of side wall are both needed to lay, and 5th~6 area regard coal quality in the middle part of dry bottom hopper top, dry bottom hopper is applied as preparation If region, the position schematic diagram of wall with refractory lining, refracto laying is as shown in Figure 1.

The present invention chooses pure bituminous coal on three coal pulverizers, preferentially starts this three coal pulverizers.In hot starting, hot start, preferentially Start the coal pulverizer mixed with large scale bituminous coal, realizes the target of unit bituminous coal hot starting, hot start.Open mill sequence be changed to by opposite side it is ipsilateral. Cancel limitation of the original main steam flow less than 40%.Improve warm mill mode.Pre-cooling primary air fan, it is lower in furnace temperature Stage, in advance pre-warm heat primary air pipeline and coal pulverizer.After pulverized coal preparation system starts and throws powder, initial stage coal dust can be obviously improved Kindling, it is the time that it is combustion-supporting, which to reduce oil gun,.

Sufficient starting bituminous coal is had in coal yard, it is desirable that volatile matter is 30%, calorific value 20000kJ/kg or more.

Compared with four coal pulverizers grind the scheme that pure burning anthracite burns, the scheme NOx that the present embodiment uses is arranged It is obvious to put down drop, by 1730mg/Nm3, is reduced to 629mg/Nm3, decline about 64%.With the raising of bituminous coal ratio in furnace, furnace The remitted its fury of flame, the decline of flame of centre temperature are conducive to mitigate thermal NO x generation.

The present invention grinds bituminous coal using separate unit coal pulverizer, bituminous coal fire area Relatively centralized in furnace, and it is high to form bituminous coal kindling Temperature area is more advantageous to the temperature levels promoted in furnace, promotes anthracitic burning；Compared with stokehold premixes mode, smoke evacuation temperature Degree reduces by 7.28 DEG C, unburned carbon in flue dust reduction by 0.09%, and slag phosphorus content reduces by 0.18%, furnace effect and improves 0.40%；Power supply coal Consumption reduces 1.45g/kWh.

In the various embodiments described above, as-fired coal dry ash free basis volatile matter content is maintained at 15% < Vdaf < 20%, enters furnace Coal low heat valve is maintained at 20MJ/kg < Qnet, ar < 22.5MJ/kg.

It is relatively low to run oxygen amount.Under 335MW load, oxygen content at economizer outlet is only 1.06%, and uses anthracitic boiler For design and operation oxygen amount usually 3.35% or more, oxygen amount, which can not be replenished in time, will lead to being significantly increased for unburned carbon in flue dust.In When 262MW load, operation oxygen amount is improved to 1.60% or more, unburned carbon in flue dust namely is declined therewith.In the various embodiments described above, In Under 335MW load, air output is controlled in 241m³/ s runs 1.83% or more oxygen amount；Under 300MW load, air output control exists 222m³/ s runs 2.58% or more oxygen amount.

In the various embodiments described above, racemization pull rod is placed in extreme lower position.The position of racemization pull rod also has one to boiler energy consumption Fixing is rung.By racemization pull rod all in extreme lower position, boiler efficiency is relatively high, and desuperheating water of superheater amount can reduce about 10t/h More than, unburned carbon in flue dust is also declined, and is the more economical method of operation.

Using grading combustion technology, primary fuel full combustion can be fully ensured that, reduce the flying dust of first-stage burning With slag combustible content；The high-temperature area that first-stage burning is formed is conducive to the anthracite formation secondary firing that ignites, and effectively mentions The burn-off rate for rising second level fuel, achievees the purpose that secondary reduction flying dust, slag phosphorus content.Fractional combustion can be divided into stokehold premix Burning two ways is mixed with a point mill.The advantages of stokehold premixed mainly includes that each coal of burning is uniformly mixed in furnace, not will form The phenomenon that a large amount of cokings in part, pulverized coal preparation system safety height etc..Disadvantage mainly includes that slow, pollutant row is adjusted to bituminous coal ratio Rapid adjustment cannot be made when putting exceeded；After unit unplanned outage, being again started up oil consumption score mill, to mix burning big etc..Mill is divided to mix The advantages of burning mode, mainly mixture proportion adjusting range was big, adjusted when exceeded to NOx emission rapidly etc..Disadvantage is mainly ground The pulverized coal preparation system safety of bituminous coal is poor.

It is fully able to guarantee to reduce flying dust and slag combustible content by reasonable air distribution, improves furnace effect.Using stokehold Premix point mill mixes the fractional combustion mode matched, and there are certain deviations for combustion conditions in furnace, but this deviation is smaller, such as schemes 12, shown in 13,14.

In terms of considering stable W type boiler, efficient, low emission and mark coal, fractional combustion mode is mainly with control The parameters such as the dry ash free basis volatile matter of as-fired coal processed, net calorific value as received basis are coal blending foundation, and concrete scheme is as follows:

As-fired coal dry ash free basis volatile matter content is maintained at 15% < Vdaf < 20%.

As-fired coal low heat valve is maintained at 20MJ/kg < Qnet, ar < 22.5MJ/kg.

When bituminous coal, meager coal, anthracite fractional combustion, when Vdaf > 10%, just can guarantee the coal quality classification of high volatile in furnace The purpose of fractional combustion can just be played.

Embodiment 2

The present embodiment W type flame boiler staged-combustion method, comprising:

Several coals are chosen, coal elements and Industrial Analysis are carried out to the coal of selection based on thermogravimetric and infrared analysis；

Based on the coal elements and Industrial Analysis as a result, the combustion strategies of predetermined boiler, the combustion strategies are specific Include: (1) can be formed in boiler fractional combustion coal allocation ratio and corresponding coal pulverizer coal-grinding mode；(2) no Can be formed in boiler classification coal allocation ratio and corresponding coal pulverizer coal-grinding mode；Wherein, point of the boiler Grade burning specifically: reacted using inflammable briquette with oxygen, become first-stage burning, wherein inflammable briquette is bituminous coal or bituminous coal and meager coal Mixing；The high-temperature flue gas atmosphere that first stage is formed, under the sweeping along of high-temperature flue gas, ignite anthracite, forms second level combustion It burns；

It is carried out according to scheduled combustion strategies, boiler oil combustion simulation obtains the operating condition of boiler, and the boiler working condition is extremely Few includes heat temperature, hot temperature, spray water flux, exhaust gas temperature, unburned carbon in flue dust, boiler slag carbon content, low heat valve, row again again Cigarette loss, empty pre- entrance oxygen amount, Mechanical adsorption, back balance furnace effect, back balance power supply mark coal, SCR inlet NOx Content；

When to using different combustion strategies, boiler working condition is compared analysis, obtains the coal of optimal boiler fractional combustion Kind proportion, coal pulverizer coal powder injection mode.

In the present embodiment, the combustion strategies of the predetermined boiler are specifically included:

The W type flame boiler configures four coal pulverizers, the first coal pulverizer A, the second coal pulverizer B, third coal pulverizer C, 4th coal pulverizer D；

One: the first coal pulverizer A of strategy, the second coal pulverizer B, third coal pulverizer C, the 4th coal pulverizer D grind pure burning anthracite；

Two: the first coal pulverizer A of strategy, the second coal pulverizer B, third coal pulverizer C, the 4th coal pulverizer D grind bituminous coal, smokeless The Mixture Density Networks of coal, grind bituminous coal: anthracite is mixed according to 1:3 ratio matches；

Three: the four coal pulverizer D of strategy grind pure bituminous coal, and single coal volatile matter is limited within 20%~30%, the first mill Coal machine A, the second coal pulverizer B, third coal pulverizer C grind anthracite, and single coal volatile matter is limited in 15% or less；

Four: the first coal pulverizer A of strategy, the second coal pulverizer B, third coal pulverizer C, the 4th coal pulverizer D grind bituminous coal, smokeless The Mixture Density Networks of coal, grind bituminous coal: anthracite is mixed according to 1:1 ratio matches, stokehold premix；

Strategy five: bituminous coal and anthracite ratio are 1:1, bituminous coal on the first coal pulverizer, third coal pulverizer, and single coal is volatilized Divide and be limited within 20%~30%, the second coal pulverizer, the 4th coal pulverizer grind upper anthracite, i.e., forward and backward wall respectively has a coal-grinding Pure bituminous coal on machine, bituminous coal and anthracite ratio are 1:1；

Strategy six: the first coal pulverizer A, third coal pulverizer C grind bituminous coal, anthracitic Mixture Density Networks, grind bituminous coal: anthracite according to 7 ︰, 3 ratio mix matching, the second coal pulverizer B, the 4th coal pulverizer D grind bituminous coal, anthracitic Mixture Density Networks, bituminous coal: anthracite according to 3 ︰, 7 ratio mix matching；

Seven: the first coal pulverizer A of strategy, the second coal pulverizer B, third coal pulverizer C, on the 4th coal pulverizer D bituminous coal grind bituminous coal, Anthracite Mixture Density Networks, bituminous coal: anthracite is mixed according to 3 ︰, 1 ratio matches；

Tactful eight: the four coal pulverizer D anthracites, single coal volatile matter are limited in 15% hereinafter, the first coal pulverizer A, the Two coal pulverizer B, third coal pulverizer C grind bituminous coal, and single coal volatile matter is limited within 20%~30%, and bituminous coal: anthracite is pressed It mixes and matches according to 3 ︰, 1 ratio；

Nine: the first coal pulverizer A of strategy, the second coal pulverizer B, third coal pulverizer C, the 4th coal pulverizer D grind mill bituminous coal, poor The Mixture Density Networks of coal, Yan Mei ︰ meager coal is mixed according to 7 ︰, 3 ratio matches；

Ten: the first coal pulverizer A of strategy, the second coal pulverizer B, third coal pulverizer C, the 4th coal pulverizer D grind mill bituminous coal, poor The Mixture Density Networks of coal, Yan Mei ︰ meager coal is mixed according to 3 ︰, 7 ratio matches；

The 11: the first coal pulverizer A of strategy, the second coal pulverizer B, third coal pulverizer C, bituminous coal grinds mill on the 4th coal pulverizer D Coal anthracite, meager coal, bituminous coal Mixture Density Networks, coal-grinding mixes and matches Wu Yan Mei ︰ Pin Mei ︰ bituminous coal=2 ︰, 4 ︰, 4 ratio；

Wherein, strategy two to six, strategy eight, strategy 11 are the coal allocation ratio that fractional combustion can be formed in boiler And corresponding coal pulverizer coal-grinding mode；

Strategy one, strategy one, seven, nine, ten are that the coal allocation ratio of classification and corresponding cannot be formed in boiler Coal pulverizer coal-grinding mode.

Bituminous coal: anthracite (1:3) fractional combustion comparative test

Bituminous coal and anthracite ratio are carried out first as the comparative test of 1:3, i.e. the comparison of strategy one, two, three is specific to survey Test result see the table below.As can be seen from the table:

After mixing the bituminous coal with about 25%, exhaust gas temperature reduces about 10 DEG C；Unburned carbon in flue dust reduces about 2.5%, and machinery is endless Full combustion heat loss reduces about 1%；Furnace effect promotes about 1.6%；Net coal consumption rate reduces about 6g/kWh.

It mixes under the Blended Coal Combustion mode with certain proportion bituminous coal, bituminous coal ignition first, forms first stage kindling, be Anthracitic kindling creates advantageous condition, helps to improve anthracitic kindling and after-flame in furnace, superheated steam temperature reduction water Amount reduces about 2kg/s, and combustion flame has the tendency that obviously moving down.

Strategy two and strategy three compare, it can be seen that grind bituminous coal using separate unit coal pulverizer, bituminous coal fire area phase in furnace To concentration, bituminous coal kindling high-temperature area is formed, the temperature levels promoted in furnace is more advantageous to, promotes anthracitic burning；With furnace Preceding premix mode is compared, 7.28 DEG C of exhaust gas temperature reduction, unburned carbon in flue dust reduction by 0.09%, slag phosphorus content reduction by 0.18%, Furnace effect improves 0.40%；Net coal consumption rate reduces 1.45g/kWh.

Table 5-4 bituminous coal: anthracite (1:3) fractional combustion comparative test result

Bituminous coal: anthracite (1:1) fractional combustion comparative test

Bituminous coal and anthracite ratio are carried out as the comparative test of 1:1, i.e. the comparison of strategy four, five, six, specific test is tied Fruit see the table below.As can be seen from the table:

Strategy five is compared with strategy four, and unburned carbon in flue dust is down to 7.72% by 7.91%, and boiler slag carbon content is dropped by 7.54% To 7.13%, corresponding unburned carbon loss reduces by 0.09%, illustrates that front-back wall point mill mixes burning and preferably resolves cigarette The influence of coal " tacking " improves anthracitic burn-off rate in furnace.

For strategy five compared with strategy four, spray water flux variation less, illustrates that furnace flame center does not change significantly.

Fineness of pulverized coal is measured, for strategy five compared to strategy four, 4 mill average fineness R75 reduce 1.25%, The middle coal pulverizer fineness for burning bituminous coal reduces, and burns anthracitic coal pulverizer fineness of pulverized coal and increases.

Strategy four, strategy five increase the proportion of bituminous coal, and especially five, A/C of strategy grinds and grinds bituminous coal completely, need pair Pulverizer outlet temperature is reduced to 90 DEG C of operations, guarantees pulverized coal preparation system safety and stability.

Comprehensive strategic five, the loss of tactful four boiler items, boiler back balance furnace effect are improved by 90.60% to 90.82%, Back balance coal consumption of power supply reduces 0.78g/kWh.

Strategy six is compared with strategy four, and unburned carbon in flue dust is down to 7.57% by 7.91%, and boiler slag carbon content is by 7.54% drop To 7.26%, corresponding unburned carbon loss reduces by 0.13%, illustrates unequal proportion, and local high volatile is concentrated Atmosphere is more advantageous to anthracitic burning in entire furnace, creates advantage for the kindling and after-flame of coal dust in furnace.

For strategy six compared with strategy four, desuperheating water of superheater reduces 2.3kg/s, also further illustrates the high volatilization of part Atmosphere in diversity is conducive to anthracite ignition in furnace and shifts to an earlier date, and furnace flame center moves down.

The characteristics of tactful six unequal proportion can be made full use of, air temperature of B/D disintegrating outlet on the one hand can be improved, Improve boiler efficiency；On the other hand, can use the characteristics of A/C grinds bituminous coal large percentage, as boiler startup means (see Boiler bituminous coal starts chapters and sections).

Comprehensive strategic six and tactful four boiler items are lost, and boiler back balance furnace effect is improved extremely by 90.60% before testing 90.79%, 0.19% is increased, back balance mark coal consumption reduces 0.67g/kWh.

Overall relatively a point mill for strategy five, which is mixed, matches, and can effectively improve boiler efficiency, reduce spray water flux, reduces power supply The advantage of coal consumption and NOx emission.

Table 5-5 bituminous coal: anthracite (1:1) fractional combustion comparative test result

Bituminous coal: anthracite (3:1) fractional combustion comparative test

Bituminous coal and anthracite ratio are carried out as the comparative test of 3:1, i.e. the comparison of strategy one, seven, eight, specific test is tied Fruit see the table below.As can be seen from the table:

(1) strategy seven and strategy eight, compared with strategy one, with the raising of bituminous coal ratio in furnace, unburned carbon in flue dust is reduced About 3%, boiler slag carbon content reduces about 2.5%, and unburned carbon loss reduces about 1.5%.Illustrate with bituminous coal ratio Raising, bituminous coal and anthracitic kindling are more stable in furnace, and burn-off rate is higher.Bituminous coal is nothing as first order fuel combustion The second level burning of bituminous coal creates favorable environment, improves anthracitic burn-off rate；And with anthracitic burning, also promote The after-flame of bituminous coal in into furnace.

(2) strategy seven and strategy eight, compared with strategy one, most apparent variation is that NOx emission decline is obvious, by 1730mg/Nm3 is reduced to 629mg/Nm3, decline about 64%.Illustrate the raising with bituminous coal ratio in furnace, furnace flame it is strong Degree weakens, the decline of flame of centre temperature, is conducive to mitigate thermal NO x generation.

(3) strategy seven and strategy eight, compared with strategy one, spray water flux is down to 19.71kg/s by 26.71kg/s, reduces 7.00kg/s illustrates the raising with bituminous coal ratio in furnace, forms secondary firing mode, significantly reduces furnace flame height Degree, the interior burning of entire furnace shift to an earlier date, and anthracitic ignition distance is elongated, is conducive to the kindling of coal dust and after-flame in furnace.

(4) strategy seven is compared with strategy eight, and combustion conditions relatively, do not change significantly in entire furnace.

Table 5-6 bituminous coal: anthracite (3:1) fractional combustion comparative test result

Meager coal, bituminous coal, anthracite fractional combustion comparative test

Anthracite, meager coal, bituminous coal fractional combustion comparative test, the i.e. ratio of strategy nine, strategy ten, strategy 11 are carried out Compared with specific test result see the table below.As can be seen from the table:

Strategy nine, strategy ten, strategy 11, compared with strategy one, as anthracite ratio declines in furnace, bituminous coal and meager coal The raising of ratio, unburned carbon in flue dust reduce about 3.8%, and boiler slag carbon content reduces about 3.1%, and unburned carbon loss reduces About 1.7%.Illustrate the raising with bituminous coal, meager coal ratio, bituminous coal, meager coal, more stable, the after-flame of anthracitic kindling in furnace Rate is higher.Bituminous coal and meager coal create favorable environment for the burning of the anthracitic second level, improve as first order fuel combustion Anthracitic burn-off rate；And with anthracitic burning, the after-flame of bituminous coal in furnace, meager coal is also promoted.

(1) strategy nine, strategy ten, strategy 11, compared with strategy one, most apparent variation is that NOx emission decline is bright It is aobvious, by 1730mg/Nm3, it is reduced to 630mg/Nm3, decline about 64%；Illustrate the raising with bituminous coal ratio in furnace, furnace endogenous fire The remitted its fury of flame, the decline of flame of centre temperature are conducive to the generation for mitigating thermal NO x.

(2) strategy nine, strategy ten, strategy 11, compared with strategy one, spray water flux is down to by 26.71kg/s 18.25kg/s reduces 8.50kg/s, illustrates the raising with bituminous coal, meager coal ratio in furnace, forms secondary firing mode, effectively Ground reduces furnace flame height, and burning shifts to an earlier date in entire furnace, and anthracitic ignition distance is elongated, be conducive to coal dust in furnace Fire and after-flame.

(3) strategy nine, strategy ten, strategy 11, combustion conditions relatively, do not change significantly in entire furnace.

(4) strategy 11, coal blending difficulty is larger, is mixed by coal yard, and accuracy there is a problem of very big.

Table 5-8 meager coal, bituminous coal, anthracite fractional combustion comparative test result

Embodiment 3

The present embodiment W type flame boiler staged-combustion method, on the basis of embodiment 1, further includes: determine that F wind has a down dip It the step of angle F wind tilt angled down and D, E wind aperture, specifically includes:

Boiler in following (1), (2), (3) 3 kinds of loads and F wind tilt angled down, is fired respectively using fuel staging Burning mode is burnt, and the operation conditions in different F layer Secondary Air tilt angled downs is obtained, wherein the operation conditions is at least It include: NOx, CO, O2 of economizer exit flue gas；NOx, CO, O2 of air preheater exiting flue gas；Boiler thermal efficiency；As-fired coal work Industry, elemental analysis；Flying dust, clinker sampling analysis；Economizer exit flue-gas temperature；Air preheater exit gas temperature；Raw coal sampling； Environment temperature, humidity and atmospheric pressure；

Wherein, (1) under 325MW load, boiler operating state under 0 ゜ of F wind tilt angled down, 10 ゜, 15 ゜, 20 ゜, 30 ゜；(2) Under 300MW load, boiler operating state under 5 ゜ of F wind tilt angled down, 10 ゜, 20 ゜, 30 ゜；(3) under 260MW load, under F wind Boiler operating state under 5 ゜ of degree of tilt, 10 ゜, 20 ゜, 30 ゜；

The operation conditions of the boiler of acquisition is analyzed, determines F wind tilt angled down and D, E wind aperture are as follows:

F wind tilt angled down and D, E wind aperture are as follows:

Wall afterwards: burner D1, burner A1, burner D2, burner combustion device A2, burner are respectively corresponded from left to right The F wind angle of declination of D3, burner A3, burner D4, burner A4, burner D5, burner A5, burner D6, burner A6 Degree: 25,25,5,5,30,30,30,30,5,5,25,25；E wind aperture: 25,25,5,20,20,20,20,20,5,5,10,10；D Wind aperture: 5,5,5,5,5,5,5,5,5,5,5,5；

Front wall: burner C1, burner B1, burner C2, burner B2, burner C3, combustion are respectively corresponded from left to right The F wind tilt angled down of burner B3, burner C4, burner B4, burner C5, burner B5, burner C6, burner B6: 25, 25,5,5,30,30,30,30,5,5,25,25；E wind aperture: 25,25,5,20,20,20,20,20,5,5,10,10；D wind is opened Degree: 5,5,5,5,5,5,5,5,5,5,5,5.

In the present embodiment, SOFA spout is equipped on arch, front-back wall each four, wherein three or three liquidate, front wall right side is with after The mode that a spout is respectively set on the left of wall is arranged.

In the present embodiment, NOx, CO, O2 measurement of economizer exit flue gas use gridding method, and every side flue takes five surveys Point, each flue are mixed into a flue gas sample and are analyzed, and every side air preheater exiting flue gas ingredient takes the arithmetic mean of instantaneous value of flue, Boiler discharging flue gas ingredient takes the arithmetic mean of instantaneous value of 2 flues；

NOx, CO, O2 measurement of air preheater exiting flue gas equally use gridding method, and every side flue takes five measuring points, Mei Geyan Road is mixed into a flue gas sample and is analyzed, and every side air preheater exiting flue gas ingredient takes the arithmetic mean of instantaneous value of flue, boiler exhaust gas Smoke components take the arithmetic mean of instantaneous value of 2 flues；

Economizer exit flue-gas temperature uses grid survey, and the arithmetic average per each measurement point side-draw is average as outlet Flue-gas temperature；

The measurement of air preheater exit gas temperature uses gridding method, totally 2 flues, and every side air preheater exports average flue-gas temperature Take the arithmetic mean of instantaneous value of measurement point.

In the various embodiments described above, boiler thermal efficiency calculation formula is as follows:

In formula:

η_g--- boiler thermal efficiency, %；

H_f--- fuel applications base low heat valve, kJ/kg；

B --- corresponding every kilogram enters the total input physical thermal of furnace fuel, kJ/kg；

Every kilogram of L --- boiler enters the total heat loss of furnace fuel, is calculated as follows according to this boiler situation:

L=L_UC+L'_G+L_mf+L_H+L_MA+L_co+L_β+L_UN

L_UCUncompleted burned carbon heat loss, kJ/kg in-lime-ash；

L'_G- dry gas loss, kJ/kg；

L_mf- enter heat loss caused by moisture, kJ/kg in furnace fuel；

L_H- hydrogen burning generates heat loss caused by moisture, kJ/kg；

L_MAHeat loss caused by-moisture in air, kJ/kg；

L_CO- as generate carbon monoxide and caused by heat loss, kJ/kg；

L_βThe heat loss of-surface emissivity and convection current, kJ/kg；

L_UN- immeasurability heat loss (takes constant by boiler factory's design value), kJ/kg.

The specific verification process of the present embodiment is as follows: this time test is divided into two stages completions.

First stage tests boiler under different coals and load, and boiler is under different F layer Secondary Air tilt angled downs Operation conditions, understand its combustion case under different operating conditions, determine optimal F layers of Secondary Air tilt angled down, it is specific to test Content is shown in Table 1；Second stage, boiler reheater there are more serious overheating problem, by F wind have a down dip baffle adjustment and Under different air distribution modes, alleviate overheating problem.

Test method

1) NOx, CO, O2 measurement of economizer exit flue gas

NOx, CO, O2 measurement of economizer exit flue gas use gridding method, and every side flue takes five measuring points, and each flue is mixed A flue gas sample is synthesized to be analyzed.Every side air preheater exiting flue gas ingredient takes the arithmetic mean of instantaneous value of flue, boiler discharging flue gas Ingredient takes the arithmetic mean of instantaneous value of 2 flues.Part load test is carried out since test needs to also use single-point method.

Measuring instrument is the Testo 350-Pro flue gas analyzer of German import, to stable conditions half an hour with top Just measure.

2) NOx, CO, O2 measurement of air preheater exiting flue gas

NOx, CO, O2 measurement of air preheater exiting flue gas equally use gridding method, and every side flue takes five measuring points, Mei Geyan Road is mixed into a flue gas sample and is analyzed.Every side air preheater exiting flue gas ingredient takes the arithmetic mean of instantaneous value of flue, boiler exhaust gas Smoke components take the arithmetic mean of instantaneous value of 2 flues.Part load test is carried out since test needs to also use single-point method.

Measuring instrument is the Testo 350-Pro flue gas analyzer of German import, to stable conditions half an hour with top Just measure.

3) economizer exit smoke temperature measurement

Economizer exit flue-gas temperature uses grid survey, and the arithmetic average per each measurement point side-draw is average as outlet Flue-gas temperature.

It is that E type power plant is even that exit gas temperature, which measures primary instrument, and secondary meter is FLUKE temperature measuring set.

4) air preheater exit gas temperature measures

The measurement of air preheater exit gas temperature uses gridding method, totally 2 flues.Every side air preheater exports average flue-gas temperature Take the arithmetic mean of instantaneous value of measurement point.

It is that E type power plant is even that exit gas temperature, which measures primary instrument, and secondary meter is FLUKE data collection system.

5) raw coal sampling

Raw coal is obtained from belt layer, is sampled during test by power plant staff.

6) Fly ash sampling

Fly ash sampling during test, by the impacting type ash dropped unit for being mounted on air preheater outlet.Before test, ash is emptied Flying dust in bucket, taken flying dust sample uniformly mixes during test, and carries out unburned combustible in fly ash analysis by DianKeYuan, finally will As a result the foundation calculated as boiler thermal efficiency.

7) clinker samples

Clinker is exported in deslagging pond and is sampled during test, and each sampling interval is 30 minutes, after the test taken slag specimen Uniformly mixing carries out unburned combustible in slag analysis by DianKeYuan, another keeps on file as test, and using result as boiler hot The foundation of efficiency calculation.

8) environment temperature, humidity and atmosphere measuring

In the place not by boiler hot radiation effect, air blower inlet temperature and environment are measured with electronics Hygrothermograph Humidity, aneroid barometer measure atmospheric pressure, and the record of measurement in every 15 minutes is primary during test, take arithmetic mean of instantaneous value.

9) operation data records

By the main operation data of operations staff's recording meter panel, record is primary within every 5 minutes, and data recording result takes each record Arithmetic mean of instantaneous value.

Test result and analysis

(1) first stage test result

Under the common load such as 325MW, 300MW and 260MW, different F wind have a down dip the main measurement boiler of first stage test Influence of the angle to flying dust.

1) test result and analysis under 325MW load

Under 325MW load, under 0 ゜ of F wind tilt angled down, 10 ゜, 15 ゜, 20 ゜, 30 ゜ flying dust and smoke components survey Amount, coal analysis.

F wind tilt angled down unburned combustible in fly ash in 20-30 ゜ is relatively low, as shown in Figure 1.

F wind 30 ゜ that have a down dip can decline flying dust 10.82%, and 20~30 ゜ are relatively good tilt angled down.

2) test result and analysis under 300MW load

Under 300MW load, under 5 ゜ of F wind tilt angled down, 10 ゜, 20 ゜, 30 ゜ flying dust and smoke components measure.

When F wind tilt angled down is in 20-30 ゜, unburned combustible in fly ash is relatively low.

F wind 20 ゜ that have a down dip can decline flying dust 3.13%, and 20~30 ゜ are relatively good tilt angled down.

3) test result and analysis under 260MW load

Under 260MW load, under 5 ゜ of F wind tilt angled down, 10 ゜, 20 ゜, 30 ゜ flying dust and smoke components measure. When F wind tilt angled down is in 20-30 ゜, unburned combustible in fly ash is relatively low.

F wind 20 ゜ that have a down dip can decline flying dust 2.72%, and 20 ゜ are relatively good tilt angled down.

Second stage test result

Since there are more serious overheating problems for boiler reheater, usually operation uses the side of stoppage in transit overtemperature region nozzles Formula solves reheater overtemperatute.

During overhaul, increase SOFA spout on arch, front-back wall each four, wherein three or three liquidate, on the right side of front wall and The mode that a spout is increased separately on the left of wall afterwards is arranged.

1) underload reheat steam turbine set overtemperature adjusts

For boiler when load is lower, reheater middle position is easy overtemperature, when investigating power plant 270MW load, stoppage in transit D3 and Two burner nozzles of C4.

Left side oxygen amount is more relatively high than right side, and the oxygen amount in middle position is relatively low, and F wind air distribution mode has been left big right at this time Small mode.

Alleviate this symptom by adjusting the mode of F wind tilt angled down and the air distribution of F wind, Secondary Air air distribution mode is shown in Table 7.

7 Secondary Air air distribution mode of table

Present invention selection: coal quality 1 --- high flat anthracite, coal quality 2 --- Lvliang City's bituminous coal, coal quality 3 --- Changzhi meager coal, coal Matter 4 ---+75% bituminous coal of 25% anthracite, coal quality 5 ---+50% bituminous coal of 50% anthracite, coal quality 6 --- 75% anthracite+ + 37.5% cigarette of 25% bituminous coal, coal quality 7 ---+25% bituminous coal of 75% meager coal, coal quality 8 ---+30% meager coal of 32.5% anthracite + 42.5% meager coal of coal, coal quality 9 ---+40% bituminous coal of+35% meager coal of 25% anthracite, coal quality 10 --- 20% anthracite+ 37.5% bituminous coal carries out different coal elements and Industrial Analysis.Flat anthracite high to southeast Shanxi Shanxi, Shanxi Jinzhong Lvliang City bituminous coal, Shanxi southeast Shanxi Changzhi meager coal and various different coal quality mixing samples have carried out the thermogravimetric analysis of different types of coal, obtain coal Thermogravimetric (TG) curve, by the available weight-loss ratio of TG curve.

Test is tested under 10~20 μ l/min ventilation flow rates, can control burning excess air coefficient on 1.2 left sides It is right.Sample quality is 20 ± 0.1mg, is dried in advance；Coal powder size is ﹤ 0.2mm；Heating rate is 40K/min；Air stream Amount is 100ml/min；Operating temperature: room temperature~1200 DEG C.1200 DEG C are warming up to 40 DEG C/min when test, constant temperature 5min is obtained To combustion pattern.Bituminous coal is introduced into burning weight loss region compared with anthracite, and also early reaching burning weight loss terminates temperature, with cigarette The raising of coal mixture proportion, entire curve move to the left, it was demonstrated that combustion case changes, from compared with difficult to burn gradually to being easier to Burning is excessive.

Figure 12 is anthracite compared with bituminous coal different proportion zero-g aircraft.Match it can be seen from the figure that being mixed in anthracite Bituminous coal, with the increase of bituminous coal ratio, burning weight loss start temperature and end temperature are decreased obviously, and illustrate the bituminous coal of high volatile It has a certain impact to anthracitic kindling.When anthracite ratio is greater than 50%, bituminous coal influences to become on the kindling of mixing coal sample It is small, it was demonstrated that if mixing the fractional combustion mode matched using bituminous coal and anthracite, it should be ensured that bituminous coal ratio is higher than 50%, Cai Nengbao Demonstrate,prove the effect of fractional combustion.

The maximum weightless temperature for mixing coal quality is as shown in figure 13.Tested by thermogravimetric analysis, consider bituminous coal, anthracite according to The ratio of > 1:1 or even 3:1, which are mixed, matches, and can change the combustion characteristics of as-fired coal matter, forms furnace internal classification combustion system, can be with Igniting temperature of pulverized-coal is reduced, the combustion position in furnace is improved, it is ensured that the after-flame of coal dust has ignition of the boiler, steady combustion obvious excellent Gesture.

The present invention carries out the high flat anthracite in southeast Shanxi Shanxi, Shanxi Jinzhong Lvliang City bituminous coal, Shanxi southeast Shanxi Changzhi meager coal Sampling, by method associated with ftir Analysis, analyzes coal sample, and emphasis monitors the gas being affected to boiler combustion Body ingredient: NO, CO, H2S.

As can be seen that bituminous coal, the discharge of meager coal NO are higher from test.With bituminous coal, the raising of meager coal ratio, NO discharge Also it gradually rises, this NO belongs to fuel type NOx, can reduce the discharge of NOx with the adjustment of air distribution mode by burning.

From test, hence it is evident that the raising of bituminous coal, meager coal ratio is also relatively also easy to produce the reducibility gas such as CO, H2S, to heated The high temperature corrosion characteristic in face enhances, and should draw attention during Actual combustion.

As shown in Fig. 1 to 11, W flame boiler technical characteristics are that Double Cyclone Burner combination goes with each other all the time just Straightening blows powder system.Double Cyclone Burner is vertically disposed on arch, it is mainly separated by coal dust input pipe, grid The components such as device, bispin air duct, thin powdered coal gas flow tube, racemization blade composition.Breeze airflow is by coal dust input pipe, via lattice Grid separator is divided evenly into two parts, into two cyclone cylinders.In each cyclone cylinder, due to the effect of inertial separation, shape At deep or light two strands of breeze airflows, enter burner hearth straight down via cyclone cylinder spout and the outlet of thin powdered coal gas flow tube respectively.It is secondary Wind, which is divided into, encircles the lower two parts of upper and arch.Secondary Air accounts for about the 30% of Secondary Air total amount on arch, and annular is formed beside deep or light air-flow Secondary Air sprays into burner hearth.Encircle lower Secondary Air and account for about the 70% of Secondary Air total amount, is sprayed by the clearance type formed between vertical water-cooling wall Mouth divides three-level to feed burner hearth.Its structure is as shown in Figure 2.

At furnace height about 1/3, front wall and rear wall are inwardly formed chimney arch, and 2 × 12 cyclone burnings are disposed on arch Device, wherein front wall is followed successively by burner C1, burner B1, burner C2, burner B2, burner C3, burner from left to right B3, burner C4, burner B4, burner C5, burner B5, burner C6, burner B6；Wall is followed successively by combustion from left to right afterwards Burner D1, burner A1, burner D2, burner combustion device A2, burner D3, burner A3, burner D4, burner A4, Burner D5, burner A5, burner D6, burner A6.

The present invention, which has, encircles the device that lower Secondary Air can be swung with inclination angle, it can solve Secondary Air under coal varitation rear arch and incline Rake angle can not be adjusted, and fail to enter burner hearth by guide vane tilt angle, it is difficult to the problem of improving coal dust burn-off rate.Including Pull rod, adjusts blade, midfeather at regulating arm.

It is provided with secondary air chamber on lower hearth front-back wall, the upper secondary air chamber of arch is divided by partition and encircles lower secondary air chamber. Independent secondary air chamber, front-back wall are separated to form with longitudinal baffle according to the position of burner and quantity in secondary air chamber under arch Each 12 independent air compartments.

In the independent air compartment of corresponding each burner, wherein front wall is followed successively by burner C1, burner B1, combustion from left to right Burner C2, burner B2, burner C3, burner B3, burner C4, burner B4, burner C5, burner B5, burner C6, burner B6；Wall is followed successively by burner D1, burner A1, burner D2, burner combustion device A2, burning from left to right afterwards Device D3, burner A3, burner D4, burner A4, burner D5, burner A5, burner D6, burner A6；

In the independent air compartment of corresponding each burner, formed between post-tensioning water screen tube and two neighboring vertical water screen tube Rectangle spout.Eight pieces of adjusting blades are set along furnace height direction in each air compartment, adjust blade installation on the rotating shaft. Every piece of adjusting middle part of blade position is connected with rotation axis 19.In sustained height, the same independent indoor rotation axis of wind Across the first, second, third, fourth midfeather, blade connection will be adjusted in each air compartment, is mounted in air compartment by rotation axis, Then there are eight rotation axis along furnace height direction in each air compartment.Affixed regulating arm 8 in every rotation axis 19, regulating arm 8 are logical It crosses hinge to be connected with connecting rod 5, eight rotation axis 19 is connected.Cursor 9, In is installed in a rotation axis 19 wherein Connecting rod 6 on cursor 9.It is connected by a hinge between pull rod 6 and cursor 9, the position hinged with pull rod 6 of cursor 9 is set It is equipped with sliding groove 25, the position that 6 end of pull rod is connect with cursor 9 is provided with pin hole 24.

When the practical burning coal of boiler deviates design value, lower Secondary Air tilt angle is encircleed according to the adjustment of different coals quality.

By the way that setting adjusts blade tilt pendulous device in secondary air chamber under W type flame furnace arch, adjusts and encircle lower Secondary Air Into the wind direction of burner hearth.When the practical burning coal of boiler deviates design value, can be determined according to different coals quality secondary under best arch Wind tilt angle can obtain high Combustion Efficiency of Coal Powder, at the same can prevent again because tilt angled down it is excessive caused by flame impingement Dry bottom hopper, to cause the Serious Slagging of burner hearth.Encircle lower Secondary Air and enter burner hearth under suitable tilt angle, fire can be extended Flame stroke, lower hearth flame degree of filling are reinforced, and the after-flame effect of coal dust can be improved.

Cyclone formula burner is by a glazing bar distributor box, two cyclone cylinders, two main burning spouts, two lack of gas gears Plate, two lack of gas spouts and corresponding pipeline composition.After First air wind powder mixture enters glazing bar distributor box by pipeline, it is divided into Two strands of equal jet streams enter in two cyclone cylinders along a tangential direction respectively, and fuel is separated under the action of the centrifugal force, coal Vent damper adjustment of the powder concentration by dress ground in blast pipe, spin intensity pass through the racemization blade tune in main burner It is whole.Water-cooling wall vertical wall wind under combustion-supporting secondary air separating from ring header is vault wind and encircles.Vault wind is divided into three strands again: One with the concentric spout of lack of gas spout by being sent into furnace (A), and another stock is by being sent into furnace with the concentric spout of main burner Interior (B), there are also one to be used to combustion-assistant ignition with oil gun (C).Encircle lower Secondary Air be divided into again in vertical direction (D), in (E), Under three strands of (F).G baffle is control aileron anti-coking wind.The flow of each stock Secondary Air can be adjusted with baffle.Upper furnace Arrange pendant superheater, furnace arch, furnace nose top and lobby are disposed with high temperature superheater, high temperature reheater, and reheat steam temperature is kept off using flue gas Plate is adjusted.Every furnace air and flue system equipped with two trisector air heaters, two Rotar Blade-Adjustable Axial Forced Draft Fans, Two adjusting rotor blade axial-flow type air-introduced machines；Secondary Air use air stage feeding mode, by burner hearth encircle on go in ring secondary air box in Different baffles (A, B, C, D, E, F) control air quantity.

The above is only a preferred embodiment of the present invention, it is not intended to restrict the invention, it is noted that for this skill For the those of ordinary skill in art field, without departing from the technical principles of the invention, can also make it is several improvement and Modification, these improvements and modifications also should be regarded as protection scope of the present invention.

Claims (8)

1. a kind of W type flame boiler staged-combustion method characterized by comprising

It is reacted using inflammable briquette with oxygen, becomes first-stage burning, wherein inflammable briquette is the mixing of bituminous coal or bituminous coal and meager coal；The The high-temperature flue gas atmosphere that one stage was formed, under the sweeping along of high-temperature flue gas, ignite anthracite, forms second level burning, wherein easily Fire coal is the Mixture Density Networks of bituminous coal or bituminous coal and meager coal, and bituminous coal is with anthracitic proportion or bituminous coal, meager coal, anthracitic proportion Proportion optimizing, as-fired coal dry ash free basis volatile matter content are maintained at 15% < Vdaf < 20%, and as-fired coal low heat valve is protected It holds in 20MJ/kg < Qnet, ar < 22.5MJ/kg, bituminous coal, meager coal, anthracite fractional combustion, needs Vdaf > 10%；

Wherein it is determined that bituminous coal includes: with anthracitic proportion or bituminous coal, meager coal, the method that anthracitic proportion is proportion optimizing

Several coals are chosen, coal elements and Industrial Analysis are carried out to the coal of selection based on thermogravimetric and infrared analysis；

Based on the coal elements and Industrial Analysis as a result, the combustion strategies of predetermined boiler, the combustion strategies specifically include: (1) can be formed in boiler fractional combustion coal allocation ratio and corresponding coal pulverizer coal-grinding mode；It (2) cannot be in pot The coal allocation ratio being classified and corresponding coal pulverizer coal-grinding mode are formed in furnace；

It is carried out according to scheduled combustion strategies, boiler oil combustion simulation obtains the operating condition of boiler, and the boiler working condition at least wraps It includes reheat temperature, spray water flux, exhaust gas temperature, unburned carbon in flue dust, boiler slag carbon content, low heat valve, flue gas loss, empty enter in advance Mouth oxygen amount, Mechanical adsorption, back balance furnace effect, back balance power supply mark coal, SCR inlet NOx content；

When to using different combustion strategies, boiler working condition is compared analysis, and the coal for obtaining optimal boiler fractional combustion is matched Than, coal pulverizer coal powder injection mode；

The W type flame boiler staged-combustion method further include:

Boiler is respectively in following (1), (2), (3) 3 kinds of loads and F wind tilt angled down, using fuel-staged combustion side Formula is burnt, and the operation conditions in different F layer Secondary Air tilt angled downs is obtained, wherein the operation conditions is at least wrapped It includes: NOx, CO, O2 of economizer exit flue gas；NOx, CO, O2 of air preheater exiting flue gas；Boiler thermal efficiency；As-fired coal industry, Elemental analysis；Flying dust, clinker sampling analysis；Economizer exit flue-gas temperature；Air preheater exit gas temperature；Raw coal sampling；Ring Border temperature, humidity and atmospheric pressure；

Wherein, (1) under 325MW load, boiler operating state under 0 ゜ of F wind tilt angled down, 10 ゜, 15 ゜, 20 ゜, 30 ゜；(2) In Under 300MW load, boiler operating state under 5 ゜ of F wind tilt angled down, 10 ゜, 20 ゜, 30 ゜；(3) under 260MW load, F wind has a down dip Boiler operating state under 5 ゜ of angle, 10 ゜, 20 ゜, 30 ゜；

The operation conditions of the boiler of acquisition is analyzed, determines F wind tilt angled down and D, E wind aperture are as follows:

F wind tilt angled down and D, E wind aperture are as follows:

Wall afterwards: respectively correspond from left to right burner D1, burner A1, burner D2, burner combustion device A2, burner D3, The F wind tilt angled down of burner A3, burner D4, burner A4, burner D5, burner A5, burner D6, burner A6: 25,25,5,5,30,30,30,30,5,5,25,25；E wind aperture: 25,25,5,20,20,20,20,20,5,5,10,10；D wind Aperture: 5,5,5,5,5,5,5,5,5,5,5,5；

Front wall: burner C1, burner B1, burner C2, burner B2, burner C3, burner are respectively corresponded from left to right 25 the F wind tilt angled down of B3, burner C4, burner B4, burner C5, burner B5, burner C6, burner B6: 25, 5,5,30,30,30,30,5,5,25,25；E wind aperture: 25,25,5,20,20,20,20,20,5,5,10,10；D wind aperture: 5, 5,5,5,5,5,5,5,5,5,5,5；

Aileron longitudinally opens 4 ventilation gaps and inwardly blows Secondary Air, water screen tube outer diameter 120.65mm at aileron, center away from for 146.4mm, the pipe gap of water screen tube are 25.4mm, aileron upper and lower part tube outer diameter 69.85mm, water screen tube and the wing Wall upper and lower part pipe is connected by reducer pipe, and the outer diameter of the water screen tube at four ventilation strips of ventilation is less than The pipe gap of 120.65mm, the water screen tube at four ventilation strips of ventilation are 76.55mm, and the height of ventilation strip is set as the wing The total length of wall coil, or be arranged in aileron top half；Remove the wall with refractory lining, refracto in each 1 root canal in ventilation slot two sides.

2. W type flame boiler staged-combustion method according to claim 1, which is characterized in that the predetermined boiler Combustion strategies specifically include:

The W type flame boiler configures four coal pulverizers, the first coal pulverizer A, the second coal pulverizer B, third coal pulverizer C, the 4th Coal pulverizer D；

One: the first coal pulverizer A of strategy, the second coal pulverizer B, third coal pulverizer C, the 4th coal pulverizer D grind pure burning anthracite；

Two: the first coal pulverizer A of strategy, the second coal pulverizer B, third coal pulverizer C, the 4th coal pulverizer D grind bituminous coal, anthracitic mixed Coal is closed, grind bituminous coal: anthracite is mixed according to 1:3 ratio matches；

Three: the four coal pulverizer D of strategy grind pure bituminous coal, and single coal volatile matter is limited within 20%~30%, the first coal pulverizer A, the second coal pulverizer B, third coal pulverizer C grind anthracite, and single coal volatile matter is limited in 15% or less；

Four: the first coal pulverizer A of strategy, the second coal pulverizer B, third coal pulverizer C, the 4th coal pulverizer D grind bituminous coal, anthracitic mixed Coal is closed, grind bituminous coal: anthracite is mixed according to 1:1 ratio matches, stokehold premix；

Strategy five: bituminous coal and anthracite ratio are 1:1, bituminous coal on the first coal pulverizer, third coal pulverizer, and single coal volatile matter limits For system within 20%~30%, the second coal pulverizer, the 4th coal pulverizer grind upper anthracite, i.e., forward and backward wall respectively has on a coal pulverizer Pure bituminous coal, bituminous coal and anthracite ratio are 1:1；

Strategy six: the first coal pulverizer A, third coal pulverizer C grind bituminous coal, anthracitic Mixture Density Networks, and grind bituminous coal: anthracite is according to 7 ︰ 3 Ratio mix matching, and the second coal pulverizer B, the 4th coal pulverizer D grind bituminous coal, anthracitic Mixture Density Networks, and bituminous coal: anthracite is according to 3 ︰ 7 Ratio mix matching；

Seven: the first coal pulverizer A of strategy, the second coal pulverizer B, third coal pulverizer C, the 4th coal pulverizer D grind bituminous coal, anthracite mixing Coal, bituminous coal: anthracite is mixed according to 3 ︰, 1 ratio matches；

Eight: the four coal pulverizer D of strategy grind anthracite, and single coal volatile matter is limited in 15% hereinafter, the first coal pulverizer A, second Coal pulverizer B, third coal pulverizer C grind bituminous coal, and single coal volatile matter is limited within 20%~30%, bituminous coal: anthracite according to 3 ︰, 1 ratio, which is mixed, matches；

Nine: the first coal pulverizer A of strategy, the second coal pulverizer B, third coal pulverizer C, the 4th coal pulverizer D grind the mixing of bituminous coal, meager coal Coal, Yan Mei ︰ meager coal is mixed according to 7 ︰, 3 ratio matches；

Ten: the first coal pulverizer A of strategy, the second coal pulverizer B, third coal pulverizer C, the 4th coal pulverizer D grind the mixing of bituminous coal, meager coal Coal, Yan Mei ︰ meager coal is mixed according to 3 ︰, 7 ratio matches；

The 11: the first coal pulverizer A of strategy, the second coal pulverizer B, third coal pulverizer C, the 4th coal pulverizer D grind anthracite, meager coal, The Mixture Density Networks of bituminous coal, coal-grinding are mixed and are matched Wu Yan Mei ︰ Pin Mei ︰ bituminous coal=2 ︰, 4 ︰, 4 ratio；

Wherein, strategy two to six, strategy eight, strategy 11 be can be formed in boiler fractional combustion coal allocation ratio and Corresponding coal pulverizer coal-grinding mode；

Strategy one, seven, nine, ten is the coal allocation ratio and corresponding coal pulverizer coal-grinding that classification cannot be formed in boiler Mode.

3. W type flame boiler staged-combustion method according to claim 1, which is characterized in that

NOx, CO, O2 measurement of economizer exit flue gas use gridding method, and every side flue takes five measuring points, and each flue is mixed into One flue gas sample is analyzed, and every side air preheater exiting flue gas ingredient takes the arithmetic mean of instantaneous value of flue, boiler discharging flue gas ingredient Take the arithmetic mean of instantaneous value of 2 flues；

NOx, CO, O2 measurement of air preheater exiting flue gas equally use gridding method, and every side flue takes five measuring points, and each flue is mixed It synthesizes a flue gas sample to be analyzed, every side air preheater exiting flue gas ingredient takes the arithmetic mean of instantaneous value of flue, boiler discharging flue gas Ingredient takes the arithmetic mean of instantaneous value of 2 flues；

Economizer exit flue-gas temperature uses grid survey, and the arithmetic average per each measurement point side-draw is as the average flue gas in outlet Temperature.

4. W type flame boiler staged-combustion method according to claim 1, which is characterized in that boiler thermal efficiency calculates public Formula is as follows:

In formula:

η g --- boiler thermal efficiency, %；

Hf --- fuel applications base low heat valve, kJ/kg；

B --- corresponding every kilogram enters the total input physical thermal of furnace fuel, kJ/kg；

Every kilogram of L --- boiler enters the total heat loss of furnace fuel, is calculated as follows according to this boiler situation:

L=LUC+L'G+Lmf+LH+LMA+Lco+L β+LUN

Uncompleted burned carbon heat loss, kJ/kg in LUC-lime-ash；

L ' G-dry gas loss, kJ/kg；

Lmf-enters heat loss caused by moisture, kJ/kg in furnace fuel；

LH-hydrogen burning generates heat loss caused by moisture, kJ/kg；

Heat loss caused by LMA-moisture in air, kJ/kg；

LCO-as generate carbon monoxide and caused by heat loss, kJ/kg；

L β-surface emissivity and convection current heat loss, kJ/kg；

LUN-immeasurability heat loss, kJ/kg.

5. W type flame boiler staged-combustion method according to claim 1, which is characterized in that the volatile matter of inflammable coal Content is higher than anthracite, and volatile matter > 25%, and bituminous coal, anthracitic proportion are 3:1.

6. W type flame boiler staged-combustion method according to claim 1, which is characterized in that under 335MW load, send Boiler pressure control is in 241m³/ s runs 1.83% or more oxygen amount；Under 300MW load, air output is controlled in 222m³/ s runs oxygen 2.58% or more amount.

7. W type flame boiler staged-combustion method according to claim 2, which is characterized in that

In strategy five, when boiler combustion, the disintegrating outlet temperature of the first coal pulverizer A is 118 DEG C, the disintegrating outlet temperature of third coal pulverizer It is 109 DEG C.

8. W type flame boiler staged-combustion method according to claim 2, which is characterized in that in strategy eight, boiler combustion When, preferential to start the first coal pulverizer, three the second coal pulverizer, third coal pulverizer coal pulverizers, opening mill sequence is ipsilateral, pre-cooling Primary air fan, it is desirable that calorific value 20000kJ/kg or more.