A kind of coal-fired boiler combustion operation method and burning runtime
Technical field
The invention belongs to power domain, and in particular to a kind of coal-burning boiler carries out the long-term method surely fired.
Background technology
As coal resources are increasingly deficient and the market price increasingly rises, coal-fired cost accounted for the 70% of cost of electricity-generating with
On, in order to ensure fuel normal supply and reduction fuel cost, most coal-burning power plant's coal as received matter far inferior to boiler design ature of coal,
Cause boiler operatiopn to there are problems, especially in low load stage, often occur unstable combustion even boiler extinguishment problem.
At present, to meet coal-burning boiler low-load combustion-stabilizing needs, be substantially all be equipped with big oil gun, it is micro- oil or one kind in plasma or
A variety of corollary apparatus, these configurations meet boiler low load stable combustion requirement, but operation and maintenance cost is higher, and fuel system
Need to be equipped with corresponding fire-fighting system, especially oil price lattice amount of increase is larger in recent years, most power plant take many means control combustions
Oil mass, to reach the purpose of control cost.In a word, fuel system is costly and potential safety hazard is more;Later plasma ignition is in electricity
Factory tests successfully, and plasma ignition system solves the potential safety hazard of fuel system presence, and need not be equipped with corresponding fire-fighting
System, but plasma cathode head only has the service life of tens hours, as the low and each electricity power group of electricity market is to machine
The requirement of group operational flexibility, long-term underload will turn into normality, and it is clearly not to carry out long-term steady combustion using plasma oil gun
Desirable method.
The content of the invention
The invention aims to solve defect present in prior art there is provided a kind of cost it is low, can be steady for a long time
The method of combustion.
In order to achieve the above object, the invention provides a kind of coal-fired boiler combustion operation method, coal-fired boiler combustion fortune
Row method sprays into assistant coal burning in burner hearth using biomass gasified gas.
Coal-fired boiler combustion operation method specifically includes following steps:
(1)Biomass gasified gas is pre-processed:By gasification of biomass, produce gas and purified through cyclone separator ash disposal, obtain biology
Matter gasification gas;
(2)By step(1)The biomass gasified gas of middle preparation is passed through in burner hearth to be fired again, assistant coal burning:In underload
Section, by step(1)The biomass gasified gas of middle preparation is passed through the main burning area of burner hearth;In middle and high load section, by step(1)In
The biomass gasified gas of preparation is passed through the reducing zone of burner hearth.
Wherein, biomass gasified gas is being passed through before burner hearth fired again, is first cooled to 400 DEG C.
In underload section, biomass gasified gas is with coal-fired intake calorific value ratio:1:60-1:20;In middle and high load
Section, biomass gasified gas and coal-fired intake calorific value ratio are:1:10-3:20.
Present invention also offers a kind of coal-fired boiler combustion runtime of the use above method, including feeding belt, give
Material machine, gasification furnace, cyclone separator, gas-gas heat exchanger, reducing zone gas pipeline, main burning area gas pipeline;Feeding belt leads to
Batcher is crossed with gasification furnace to be connected;The gas of gasification furnace generation passes through reducing zone gas pipeline and master respectively through gas-gas heat exchanger
Combustion zone gas pipeline enters in the burner hearth of coal-burning boiler;Reducing zone gas pipeline, main burning area gas pipeline each lead into stove
Reducing zone, the main burning area of thorax;Electrically operated valve is equipped with reducing zone gas pipeline, main burning area gas pipeline.
Wherein, multiple reducing zone combustion gas spouts are provided with the reducing zone of coal-burning boiler burner hearth;Reducing zone combustion gas spout with
Reducing zone gas pipeline is connected.
Reducing zone combustion gas spout is uniformly distributed in the reducing zone of the coal-burning boiler burner hearth;Main burning area gas pipeline and stove
Main burner spout is connected in thorax.
The flue gas of the stove chamber inner combustion output of coal-burning boiler passes sequentially through pendant superheater, finishing superheater, cryogenic overheating
Device, economizer, air preheater, deduster and air-introduced machine, then after gas-gas heat exchanger, into the gasification furnace wind of gasification furnace
Room.
Gasification stream gauge is provided between cyclone separator and gas-gas heat exchanger;It is provided between air-introduced machine and gas-gas heat exchanger
Flue gas flow meter.
Reducing zone gas pipeline and main burning area gas pipeline are connected with facing stove respectively, and connecting place, which is equipped with, faces stove closing
Valve.
The present invention has advantages below compared with prior art:
1st, the present invention utilizes biomass gasification technology, produces gasification pneumatic transmission and enters in burner hearth, carries out coal-fired auxiliary combustion, be not only able to
Avoid the fouling and slagging and etching problem of burner hearth, additionally it is possible to significantly reduce SO2With NOx concentration of emission, unburned carbon in flue dust is reduced,
Realize that the high-grade of low-grade biomass energy is utilized.
2nd, in underload section, partial fuel coal is substituted by biomass gasified gas and directly sprayed into by main burner in burner hearth, can
With replacing fuel oil system and plasma system, as a kind of new low-load combustion-stabilizing mode, the steady of boiler at low load operation is improved
It is qualitative, this external enwergy increase exhaust gas volumn(The exhaust gas volumn that biomass gasified gas burning is produced is to wait calorific value coal dust firing to produce exhaust gas volumn
5-8 times), increase the caloric receptivity of convection heating surface, improve final stage vapor (steam) temperature.Biomass sulfur content itself is low simultaneously, utilizes
Biogas substitutes partial fuel coal, can effectively reduce desulphurization system entrance SO2Concentration, the expense of reduction desulphurization system operation.
3rd, in middle and high load section, biomass gasified gas is sprayed into burner hearth from reducing zone, biogas is carried out and fires again, can
With the NO for generating main burner areaxReduced, divided equivalent to burning has been carried out on the basis of air classification in reducing zone
Level, had both reduced the fire box temperature in main burner area, and had reduced thermal NOxGeneration, while reducing zone spray into secondary fuel
Biomass gasified gas, adds reducing zone reducing substances(CO、H2、CH4、CmHn)Concentration so that more NOxIt is reduced into
N2, significantly reduce furnace outlet NOxConcentration, denitrating system ammonia spraying amount is accordingly reduced, and the escaping of ammonia is also reduced therewith, to a certain degree
On reduce air preheater blocking risk.
4th, transformation of the present invention to existing coal-fired boiler combustion system is smaller, and cost is low, integral combustion runtime structure
Simple and non-secondary pollution, by biomass gas reutilization technology, not only solves that biomass energy is extensive, efficiently utilizes
Problem, and realize low-load combustion-stabilizing and middle and high load fires the low NO of heat drop againxPurpose.Simultaneously through rotation after gasification of biomass
Substantial amounts of biomass ash at wind separator separation can be sold as bio-fertilizer, can increase the economic well-being of workers and staff of power plant.
5th, the present invention can improve boiler low load stable combustion ability, make by using the mode of biogas and coal cofiring
Boiler reach do not throw oil or plasma during more underload and can stable operation, a kind of way of depth peak regulation can be realized as unit
Footpath.
Brief description of the drawings
Fig. 1 is the structural representation of coal-fired boiler combustion runtime of the present invention;
Fig. 2 is the structural representation in burner hearth in Fig. 1;
Fig. 3 is the distribution schematic diagram of gas injection mouthful in burner hearth in Fig. 2;
Fig. 4 is another distribution schematic diagram of gas injection mouthful in burner hearth in Fig. 2.
In figure, 1- burner hearths, 2- air preheaters, 3- dedusters, 4- air-introduced machines, 5- flue gas flow meters, 6- mixed gas flows
Meter, 7- gasification furnaces, 8- feeding belts, 9- batchers, 10- gasification furnace air compartments, 11- cyclone separators, 12- gasification stream gauge,
13- augers, 14- gas-gas heat exchangers, 15- reducing zones gas pipeline, 16- main burner gas pipelines, 17- reducing zones gas pipeline
Valve, 18- main burner burnt gas valves, 19- fire air nozzles, 20- reducing zones combustion gas spout, 21- main burner combustion gas spouts, 22
Pendant superheater, 23- finishing superheaters, 24- final reheaters, 25- low temperature superheaters, 26- economizers, 27- faces stove shut-off valve.
Embodiment
The present invention is described in detail below in conjunction with the accompanying drawings.
As shown in figure 1, coal-fired boiler combustion runtime of the present invention is transformed existing coal-burning boiler, including outside burner hearth
The biomass gasified gas generating means that portion is provided with, the biomass of bundling processing is delivered to batcher 9 by belt conveyor 8, then
Into gasification furnace 7, while gasifying medium enters gasification furnace 7 by gasification furnace air compartment 10, biomass gasification in gasification furnace 7 is produced
Biomass gasified gas enters under cyclone separator 11, most biomass ash under separation, uncombusted biomass ash and separation
The auger 13 that the bed particle come is set by bottom is delivered in gasification furnace 7 again, and biomass gasified gas is through gas-gas heat exchanger
400 DEG C or so are cooled to after 14, is passed through in burner hearth 1 and carries out auxiliary combustion.
Periodically in underload section(Load is less than 50%BMCR operating modes), come by the conveying of multiple main burner gas pipelines 16
About 400 DEG C of biomass gasified gas after ash disposal and cooling, according to the yield of biomass gasified gas, control main burner combustion gas
Valve 18 is fully or partially opened, and gas is injected in burner hearth 1 by main burner combustion gas spout 21, is substituted part coal dust and is fired
Burn, coal dust intake and biomass gasified gas intake heat control ratio to be 1:60~1:20.Biomass gasified gas can simultaneously
Sprayed into by the center combustion gas spout of main burner spout 21.
In middle and high load stage(50% ~ 100%BMCR operating modes), the warp come is conveyed by multiple reducing zone gas pipelines 15
About 400 DEG C of biomass gasified gas after cooling after ash disposal are crossed out, flow is controlled by respective reducing zone gas pipeline valve 17, passed through
The penetrating burner hearth 1 of reducing zone combustion gas spout 20 is arranged in be burnt.
As shown in Fig. 2 sequentially passing through pendant superheater 22, finishing superheater 23, final stage in the flue gas that hearth combustion is produced
Reheater 24, low temperature superheater 25, economizer 26 and air preheater 2, subsequently into deduster 3, most enter through air-introduced machine 4 afterwards
Desulphurization system and chimney.
After neat stress after purification is mixed through flue gas flow meter 5 with First air, by mixed airflow gauge 6, gas gas is passed through
In heat exchanger 14, through biomass gasified gas(After the dedusting of cyclone separator 11, about 600 DEG C)After heating, into the gasification of gasification furnace 7
It in stove air compartment 10, can improve into stove wind-warm syndrome to 400 DEG C~450 DEG C, improve the rate of gasification and fuel gases calorific value of gasification furnace, reduce simultaneously
Biomass gasified gas temperature makes it meet requirement of the combustion gas induced-draught fan to temperature, can also reduce combustion gas spout to 400 DEG C or so
Area.
Under the method for operation of underload section, face stove shut-off valve 27, reducing zone gas pipeline valve 17 and keep full off state.Should
Unstable combustion during boiler at low load operation can be solved in the case where not throwing oil or plasma by planting biogas Land use systems
Problem, while long-time underload stable operation can be met, had both saved oil firing or the expense for the plasma power consumption generation that comes into operation,
Also the problem of plasma can not continuously be run for a long time is solved.
In middle and high load section, main burner combustion gas spout 21 sprays into the coal dust and Secondary Air and reducing zone gas injection of burner hearth 1
Mouth 20 sprays into biomass gasified gas primary combustion in stove of burner hearths, uncombusted coke and fuel gas and fire air nozzle 19
The burnout degree of penetrating carries out mixing after-flame.Under the method for operation, face stove shut-off valve 27, main burner burnt gas valve 18 and keep fully closed
Or part is closed.The intake heat ratio for controlling biomass gasified gas and coal dust is:1:10-3:20.This kind of biogas profit
The NO that main burner area can be generated with modexReduced, carried out equivalent on the basis of air classification in reducing zone
Burning classification, had both reduced the fire box temperature in main burner area, reduces thermal NOxGeneration, while reducing zone spray into
Secondary fuel biomass gasified gas, adds reducing zone reducing substances(CHi and CO)Concentration so that more NOxReduction
Into N2, significantly reduce furnace outlet NOxConcentration, denitrating system ammonia spraying amount is accordingly reduced, and the escaping of ammonia is also reduced therewith, certain journey
The risk of air preheater blocking is reduced on degree.
The flexible arrangement of reducing zone combustion gas spout 20, unanimously can be arranged in front-back wall with main burner combustion gas spout 21(Such as Fig. 3
It is shown), both walls can also be arranged according to field condition.As shown in figure 3, when reducing zone combustion gas spout 20 is arranged in front-back wall
When, it is consistent with main burner combustion gas spout 21 with the quantity of layer reducing zone combustion gas spout 20 and level interval, it is arranged in the superiors master
Region between burner combustion gas spout 21 and fire air nozzle 19, is distributed according to the uniform amount of reducing zone combustion gas spout 20;Such as
Shown in Fig. 4, when reducing zone combustion gas spout 20 is arranged in both walls, arrangement height is consistent with front-back wall, and spacing is according to spray
Mouth uniform amount distribution.
When emergency or furnace shutting down process occurs in boiler, opening faces stove shut-off valve 27, and biogas is transported to and faces stove and enters
Row burning, the continuous operation of gasification furnace is not influenceed.