CN105938375B - A kind of flue gas SNCR denitration restores the control method of agent flux in the process - Google Patents
A kind of flue gas SNCR denitration restores the control method of agent flux in the process Download PDFInfo
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- CN105938375B CN105938375B CN201610377549.1A CN201610377549A CN105938375B CN 105938375 B CN105938375 B CN 105938375B CN 201610377549 A CN201610377549 A CN 201610377549A CN 105938375 B CN105938375 B CN 105938375B
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- G—PHYSICS
- G05—CONTROLLING; REGULATING
- G05D—SYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES
- G05D11/00—Control of flow ratio
- G05D11/02—Controlling ratio of two or more flows of fluid or fluent material
- G05D11/13—Controlling ratio of two or more flows of fluid or fluent material characterised by the use of electric means
- G05D11/131—Controlling ratio of two or more flows of fluid or fluent material characterised by the use of electric means by measuring the values related to the quantity of the individual components
- G05D11/133—Controlling ratio of two or more flows of fluid or fluent material characterised by the use of electric means by measuring the values related to the quantity of the individual components with discontinuous action
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
- B01D53/34—Chemical or biological purification of waste gases
- B01D53/46—Removing components of defined structure
- B01D53/54—Nitrogen compounds
- B01D53/56—Nitrogen oxides
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
- B01D53/34—Chemical or biological purification of waste gases
- B01D53/74—General processes for purification of waste gases; Apparatus or devices specially adapted therefor
- B01D53/77—Liquid phase processes
- B01D53/79—Injecting reactants
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2251/00—Reactants
- B01D2251/20—Reductants
- B01D2251/206—Ammonium compounds
- B01D2251/2062—Ammonia
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Abstract
The invention discloses the control methods that agent flux is restored during a kind of flue gas SNCR denitration, reducing agent is sprayed into flue gas, SNCR denitration is carried out to flue gas, restore the nitrogen oxides in flue gas, the control method that agent flux is restored in denitration control system includes: to acquire in chimney nitrous oxides concentration [NOx] in flue gas flow Q and chimney so that reducing agent is ammonium hydroxide as an example2, reducing agent flow rate calculation value SV is calculated using formula (1):And formula, by decision condition, the initial NOx concentration of denitration control system adjust automatically [NOx] are determined according to flow rate calculation value and measured value setting1, reducing agent flow rate calculation value SV is adjusted, allows and surveys NOx concentration [NOx]2Constantly approach target NOx concentration [NOx]3, reducing agent measured discharge, which constantly levels off to, calculates flow.
Description
Technical field
The present invention relates to a kind of calculation method of denitrification reducing agent and control technologies, are especially applied to clinker production
Line, water-tube boiler, coal-burning boiler selective non-catalytic reduction (selective non-catalytic reduction,
SNCR) the metering method of the reducing agent of denitrating flue gas belongs to environmental protection and chemical engineering automation control area.
Background technique
SNCR gas denitrifying technology refers under the action of no catalyst, sprays into reducing agent in suitable temperature window,
Nitrogen oxides in flue gas is reduced to the water being safe from harm and nitrogen, is domestic and international cement furnace, water-tube boiler, coal-burning power plant
In Flue Gas Denitrification Engineering with most commonly used technology.
A kind of reducing agent of cement clinker production line SNCR denitrating flue gas is provided in patent ZL2014 2 0199444.8
Metering and control technology, the calculating basis of the technology are to utilize C1 grade preheaters of clinker line kiln tail the first CEMS of outlet, the
The 2nd CEMS of one ammonia table and kiln tail chimney, the second ammonia table major parameter as input quantity, measure ammonium hydroxide flow.Compared to routine
Only in the data of kiln tail chimney configuration the 2nd CEMS and the second ammonia table, the timeliness of metering and elegance all obtained substantially mentioning
It rises.
But current reality has three: first, is suitable for monitoring site work since C1 grades of preheaters export
Condition is severe: flue-gas temperature is up to 320-350 DEG C, and the reachable -6kPa of negative pressure, dust is up to 100g/m3(coal-burning power plant 30g/m above3
As high dirt), the first CEMS and the first ammonia table type selecting hardly possible, cost are high, and not all clinker line denitration engineering has configuration；The
Two, even if being configured with the first CEMS and the first ammonia table, due to installing point bad working environments, equipment failure rate is high, meter maintenance workers
Work amount is big, is slightly not good at, and data use value is little；Third, the enterprise of actual disposition SNCR denitration system, either cement
Clinker manufacturing enterprise, water-tube boiler, coal-burning power plant, regular situation are all only configured with CEMS and ammonia table in kiln tail chimney.
In short, SNCR flue gas denitrification system is different from SCR flue gas denitrification system, due to no initial before denitrating system
NOx concentration can only be as payment foundation, and in patent ZL2014 2 0199444.8 according to the Gas Parameters of kiln tail chimney
It calculates ammonium hydroxide flow and uses the initial concentration assumed, one is set, and does not rechange, in actual motion, due to the variation of operating condition
With the duration of runing time, it is constantly to change that the variation of operating condition and combustion raw material, which leads to initial NOx concentration in fact, although patent
ZL2014 2 0199444.8 is de- by theoretical denitrification rate and reality by K1 temperature corrected parameter, K2 the escaping of ammonia corrected parameter, K3
The ratio system automatically generated (E/F) of nitre rate is adjusted, these fine tuning parametrical faces have adjustment not to when fluctuating widely
Timely problem.
In addition, (being higher than 1000mg/m far beyond scope of design for individual initial NOx concentrations3Or it is lower than 300mg/m3)
When, since regulating valve does not operate in best open range, cause history curve to occur abnormal: such as: NOx emission is dense after denitration
Degree is still higher than practical ammonium hydroxide flow, illustrates original corrected parameter not already below set target value, the ammonium hydroxide flow of calculating
Meet extreme operating condition condition.
It is necessary to find new calculation method, to guarantee that denitrating system can cover the various works being likely to occur with gamut
Condition.
Summary of the invention
The present invention provides the control method that agent flux is restored during a kind of flue gas SNCR denitration, surveys after controlling denitration
While NOx concentration is infinitely approached to target NOx value, practical ammonium hydroxide circulation is infinitely approached to calculated value.
A kind of flue gas SNCR denitration restores the control method of agent flux in the process, and amino reductive is sprayed into flue gas, right
Flue gas carries out SNCR denitration, restores the nitrogen oxides in flue gas, and the control method that agent flux is restored in denitration control system includes:
By taking reducing agent is ammonium hydroxide as an example, acquire in chimney that nitrous oxides concentration (is before denitration in flue gas flow Q and chimney
[NOx] 1, spray ammonia after be [NOx]2), reducing agent flow rate calculation value SV is calculated using formula (1):
Wherein:
SV: ammonium hydroxide flow rate calculation value (units/kg/h)；
PV: ammonium hydroxide flow measured value (units/kg/h) can be read by the ammonium hydroxide flowmeter inside denitration control cabinet, be matched
Collaborate adjustable valve, controls practical ammonium hydroxide circulation and infinitely approached to calculated value；
Q: kiln tail chimney smoke flow (unit Nm3/h)；
[NOx]1: initial NOx concentration (unit mg/Nm3), it is manually entered, system default 800mg/m3, can also be according to reality
The border condition of production is in 400-1200mg/m3Any assignment in range.
[NOx]2: actual measurement NOx concentration (unit mg/Nm3), signal is derived from kiln tail chimney CEMS, denitrating system put into operation after take
Value is surveyed as NO, actual measurement NOx concentration [NOx]2It is NO to mark actual measurement NO conversion under dry state2In 10%O2Data under content.
[NOx]3: target NOx controlled concentration (unit mg/Nm3), it is artificial to input；According to " cement industry atmosphere pollution row
Put standard " (GB4915-2013): if environmentally friendly regulatory requirements control NOx emission concentration 320mg/Nm3Hereinafter, according to debugging situation
It is usually arranged as 220~300mg/Nm3If environmentally friendly regulatory requirements control NOx emission concentration 400mg/Nm3Hereinafter, according to debugging feelings
Condition is usually arranged as 300~380mg/Nm3；According to " emission standard of air pollutants for boilers " (GB13271-2013), setting value
It is 20-100mg/m smaller than effluent standard limit value3, it is suitable for clinker line denitration engineering and coal-burning boiler denitration engineering.
C: ammoniacal liquor mass concentration (wt%) is manually entered, concentration 15-25wt% according into factory's ammonia concn；
NSR: ammonia nitrogen molar ratio；According to target denitrification rate ηTargetSystem automatically generated:
Reducing agent flow rate calculation value SV is substituted into following judgement formula:
Wherein, PV: ammonium hydroxide flow measured value, units/kg/h；
By decision condition, the initial NOx concentration of denitration control system adjust automatically [NOx]1, to reducing agent flow rate calculation value
SV is adjusted, and is allowed and is surveyed NOx concentration [NOx]2Constantly approach target NOx concentration [NOx]3, reducing agent measured discharge constantly approaches
In calculating flow.
The parameter for needing to be manually set has: initial NOx concentration [NOx]1,[NOx]1Adjustment increment Delta, target NOx setting
It is worth [NOx]3, it is both placed in man-machine exchange operation interface.
The present invention is made by the comparison of actual measurement NOx concentration and target NOx concentration and calculating ammonium hydroxide demand and actual measurement ammonium hydroxide
The comparison of dosage is provided with four kinds of operating conditions jointly, under the conditions of nominal situation, according to calculation formula ammonia vol adjust automatically；Work as fortune
Row operating condition fluctuation or beyond design scope when (be characterized primarily by exhaust gas volumn and NOx concentration), then will appear be determined as it is different
Often, system adjusts initial NOx concentration, and can not stop iteration according to the initial NOx concentration increment of imparting, until determining that operating condition is
Normally, actual measurement NOx concentration is fluctuated with target NOx concentration, and ammonium hydroxide actual amount is persistently approached with dosage is calculated, until dynamic equilibrium.
Each hypothesis operating condition is described as follows:
Operating condition one: when actual measurement NOx concentration < target NOx concentration, system is in the state that runs at standard, and ammonium hydroxide demand (calculates
Value) it reduces, the calculating flow that system is obtained by formula (1) should be less than measured discharge, when measured discharge is leaned on to flow is calculated
When holding together, the dosage of reducing agent is reduced in actual motion, saves operating cost.If calculated value occur is greater than measured value, explanation instead
The initial NOx concentration that system was set originally is bigger than normal, and therefore, the initial NOx concentration of system adjust automatically reduces, and reducing agent is made to calculate stream
Amount decline.This determines and calculates ceaselessly iteration, until being determined as that nominal situation, initial NOx then keep dynamic stability, system
It adjusts the measured discharge of reducing agent and calculates flow infinite tendency, whole system keeps dynamic stability.
Operating condition two: when actual measurement NOx concentration < target NOx concentration, system is in and runs at standard state, and system passes through formula
(1) the calculating flow SV obtained should be less than measured discharge PV, so operating condition two is nominal situation.When measured discharge is flowed to calculating
When amount is drawn close, the dosage of reducing agent is reduced in actual motion, saves operating cost.
Operating condition three: when actual measurement NOx concentration > target NOx concentration, system is it is possible that exceeded, at this point, theoretically ammonium hydroxide
Demand (calculated value) increases, and the calculating flow SV that system is obtained by formula (1) should be greater than measured discharge PV, when actual measurement is flowed
Measure to calculate flow draw close when, increase the dosage of reducing agent, guarantee to run at standard.If occurring calculated value SV in actual motion instead
< measured value PV, the initial NOx concentration for illustrating that system was set originally is less than normal, at this point, by above-mentioned decision condition, system is adjusted automatically
Whole initial NOx concentration increases, and so that reducing agent is calculated flow and increases.Decision process and initial NOx concentration assignment procedure can be ceaselessly
Iteration, until being determined as that nominal situation, initial NOx then keep dynamic stability, the measured discharge of system call interception reducing agent and calculating
Flow infinite tendency, whole system keep dynamic stability.
Operating condition four: when actual measurement NOx concentration > target NOx concentration, system is it is possible that exceeded, at this point, theoretically ammonium hydroxide
Demand (calculated value) increases, the calculating flow SV that system is obtained by formula (1) should > measured discharge PV, when actual measurement is flowed
Measure to calculate flow draw close when, increase the dosage of reducing agent, guarantee to run at standard.If actual motion coincide, initial NOx concentration
Initial value is kept, is not changed, system keeps dynamic equilibrium.
The parameter for needing to be manually entered in method application process of the invention has: NOx initial concentration, NOx target discharge are dense
Degree and NOx initial concentration increments of change input permission and open in main operation interface to user, and system is debugged according to design parameter
Situation assigns initial value, and user can artificial adjustment on the control panel according to the actual operation.
Initial NOx concentration adjust automatically increment is defaulted as 20mg/m3, in 10-50mg/m3Adjustable in range, permission opening is given
User, when setting value is larger, adjustment amplitude is big, and response is fast, but may result in frequent adjustment, and system stability is bad, if
Set value it is smaller when, initial NOx concentration adjust automatically amplitude is small, and low-response, system sensitivity is not good enough, cement production enterprise or power station pot
Furnace enterprise can be adjusted according to the production status load fluctuation situation of oneself, it is proposed that setting value 10mg/m3、20mg/m3、
30mg/m3、40mg/m3、50mg/m3, it is not recommended that setting is excessive, and otherwise system is stablized bad.Preferably, suggesting increment setting
For 20-30mg/m3。
Initial NOx is available when denitrating system is out of service, and denitrating system can not then obtain after putting into operation, can be with
By average value during being defaulted as design value or debugging, generally no longer adjusted after setting, it is automatic after being judged by system condition
Adjustment.
Target NOx concentration due to system loading fluctuation, actual measurement NOx concentration should surrounding target NOx concentration fluctuation operation,
It being run at standard to guarantee that denitrating system is reliable and stable, the maximum value for surveying NOx concentration is necessarily less than standard limited value discharge standard, because
This, general recommendations setting target NOx concentration is smaller than standard NOx emission concentration limit, and default setting value is 30mg/ smaller than standard value
m3, generally 20-100mg/m smaller than standard value3It is adjustable in range.
The reducing agent is ammonium hydroxide or urea, is illustrated by taking ammonium hydroxide as an example in the present invention.
SNCR gas denitrifying technology is different from SCR denitration, and initial NOx emission concentration then can not after denitrating system puts into operation
Characterization, initial NOx concentration is associated with indexs such as dore furnace/furnace exit temperature, clinkers, is carried out by corrected parameter pre-
Sentence adjustment, run in steady load it is relatively stable, but when load fluctuation is larger or exceed scope of design when, due to first
The amendment amplitude of beginning NOx concentration is less than normal, usually will appear control failure.
The calculation method and control technology of SNCR denitrating flue gas reducing agent dosage provided by the invention, it is listed through the invention
Calculation formula acquires ammonium hydroxide theory demands amount SV, is compared with denitration control system actual measurement ammonium hydroxide flow PV, joint objective NOx
The comparison of concentration and actual measurement NOx concentration, determines operating condition, adjusts reduction agent flux, and adapt to operating condition substantial deviation and set
It is realized when evaluation and initial NOx concentration is constantly modified.
All Gas Parameters are all sent to denitration control system in the present invention, are automatically controlled to realize, by reduction of the invention
The calculation formula and judgement formula of agent flux calculated value SV is incorporated into original denitration control system, according to calculation formula (1) and determines
Formula is adjusted the aperture of reducing agent flow valve by denitration control system, is calculated with adjusting the measured discharge infinite tendency of reducing agent
Value.
The present invention is calculated to be mainly used in clinker line denitration engineering and coal-burning boiler denitration engineering with modification method.
When applied to clinker line denitration engineering, it is not set to can solve C1 described in technical background grades of outlet
CEMS, correction factor are not able to satisfy too low or excessively high initial NOx concentration for the amendment amplitude of initial NOx emission concentration, lead to
Setting decision condition is crossed, initial NOx emission concentration is allowed constantly to be adjusted according to operating condition, generate new initial NOx emission concentration and is made
To input parameter, for the stability for guaranteeing denitrating system, it is a kind of completely new calculating side that the amplitude and the frequency of adjustment, which are also crucial,
Method.When applied to coal-burning boiler denitration engineering, without excessive temperature parameter, it is only necessary to basic chimney CEMS data, and
Denitrating system restores the flowmeter of assignment subsystem configuration, regulating valve, and the meter that reducing agent is realized with comparing is calculated by PID
Amount and adjustment.
The present invention solve the initial NOx concentration of SNCR denitration control system cannot real-time value, load fluctuation is big or super sets
Count the technological gap that range unusual service condition adjusts failure.Compared with the prior device, the invention has the advantages that:
(1) determine that the abnormal conditions in formula illustrate the primary operating parameter of denitrating system far beyond design scope
(initial NOx concentration is excessive or too small), leads to system regulation failure, by determining and adjusting, makes denitration control system super
Effective Regulation reducing agent dosage is remained to after designing scope out；
(2) temperature, CO, clinker (or boiler load) etc. are included in calculation formula by conventionally calculation formula, as auxiliary
Parameter is controlled, but in part of cement factory or power plant, these auxiliary control parameters and the correlation of initial NOx concentration are unobvious, especially
When being reciprocation, leading regulation parameter is not easy to distinguish, above-mentioned parameter is no longer included in repairing as calculation formula by the present invention
Positive coefficient, but flow is directly calculated by true measurable NOx actual discharge concentration and NOx goal-setting concentration, reducing agent
It is compared with reducing agent actual flow, if adjusting initial NOx concentration, judgement and the process adjusted are not after discovery control failure
Disconnected iteration reduces uncertain factor until regulating and controlling to be in dynamic equilibrium；
(3) difficult point about the setting of initial NOx concentration and tracking always SNCR denitrating flue gas, the present invention is by sentencing
The setting of fixed condition solves the fixed drawback of the given value of immesurable initial NOx concentration, allows system to be in dynamic always flat
Weighing apparatus.
(4) calculation formula is no longer included in the parameters such as temperature, CO, clinker (or boiler load), and instrument arrangement can be with
The case where simplified, hardware fault rate can reduce, and control failure has also obtained effective solution.
Detailed description of the invention
Fig. 1 is cement clinker production line SNCR denitration reducing agent control system hardcore distribution of facilities figure.
Fig. 2 is coal-burning boiler SNCR denitration reducing agent control system hardcore distribution of facilities figure.
Fig. 3 is SNCR denitration reducing agent control system composition schematic diagram in Fig. 1 and Fig. 2.
Fig. 4 is the abnormal conditions figure occurred in embodiment 1 according to original calculation formula.
Appended drawing reference as shown in the figure are as follows:
1- reductant metering and control system 2- reducing agent dispensing cabinet 3-Pt100 temp probe
4- dore furnace 5-CO analyzer 6- conditioning Tower
7- waste heat boiler 8- electric precipitator 9- raw mill
10- chimney the escaping of ammonia analyzer 11- chimney CEMS analyzer 12- chimney the escaping of ammonia probe
13- chimney CEMS probe 14- kiln tail chimney 15- boiler
16- economizer 17-SCR reactor 18- air preheater
19- deduster 20- desulfurizing tower
Specific embodiment
The present invention is further illustrated with reference to the accompanying drawings and examples.
[embodiment one]
As shown in Fig. 1, specification is to produce the SNCR denitration reductant metering system of 5000t clinker production line dore furnace daily,
Using ammonium hydroxide as reducing agent.Dore furnace is provided with Pt100 temp probe, C1 grades of preheater outlets and is provided with CO analyzer, believes
It number send to denitrating system, denitration control system composition figure is as shown in Figure 3.
Before denitrification apparatus construction, for environmentally friendly regulatory requirements, it is provided with chimney CEMS, fume indication has: flue gas flow,
NOx、SO2, dust, temperature, humidity, O2.When carrying out the transformation of SNCR denitrating flue gas, the same layer platform of chimney CEMS sampling probe increases
If chimney the escaping of ammonia detector, all Gas Parameters are all sent to denitration control system.
Ammonia volume input data has: the flue gas flow (425681Nm of chimney CEMS3/ h), NOx initial concentration industry
Main root according to design parameter and debugging situation be manually entered (system give default value be 550mg/Nm3)；It is manually entered mesh after denitration
NOx controlled concentration is marked (to implement ground and execute " cement industry air pollution emission new standard (GB4915-2013) " emission limit mark
Standard, NOx emission concentration limit 400mg/m3, manual setting target NOx emission concentration is 370mg/Nm3。
According to original calculation formula, in fact it could happen that abnormal conditions shown in Fig. 4, target NOx concentration are set as 370mg/
m3, actual measurement NOx is 257.4370mg/m3, actual measurement ammonia vol SV is 197.4370L/h, and ammonium hydroxide calculation amount is 216.8L/h, according to
Logic, surveys NOx concentration < target NOx concentration, and the calculation amount SV of ammonium hydroxide should be less than measured value PV, the abnormal shape with operating condition one
Condition is coincide.Its reason essentially consists in: initial NOx concentration is not rechanged once input, after stopping denitrating system, it is found that initial NOx is dense
Degree is in 360-580mg/m3, far smaller than design initial NOx concentration 800mg/m3With NOx concentration 650mg/m initially set3, with
After surveying NOx concentration already less than target NOx concentration, the ammonium hydroxide theory demands amount SV that system-computed goes out is greater than actual measurement instead
Flow, so that system down.
After calculation method of the invention, artificially inputting initial NOx concentration increment is 25mg/m3, pass through calculation method
Attached decision condition, initial NOx concentration constantly adjust, until being reduced to 480mg/m3When, calculated value SV < measured value PV, valve
Door aperture reduces, and resumed controlling is normal, avoids adding in vain for ammonium hydroxide.
Nominal situation is relatively more, then not illustrates.
[embodiment two]
As shown in Fig. 2, the SNCR denitration reductant metering for the circulating fluidized bed boiler (CFB) that specification is 130 ton/hours
System, using ammonium hydroxide as reducing agent.Pt100 temp probe and CO analyzer are provided at burner hearth economizer, signal is sent to de-
Nitre system, denitration control system composition figure are as shown in Figure 3.
Before denitrification apparatus construction, for environmentally friendly regulatory requirements, it is provided with chimney CEMS, fume indication has: flue gas flow,
NOx、SO2, dust, temperature, humidity, O2.After carrying out the transformation of SNCR denitrating flue gas, the same layer platform of chimney CEMS sampling probe increases
If chimney the escaping of ammonia detector, all Gas Parameters are all sent to denitration control system.
Ammonia volume input data has: the flue gas flow (165681Nm of chimney CEMS3/ h), NOx initial concentration industry
Main be rule of thumb manually entered (is defaulted as 250mg/Nm3)；Target NOx controlled concentration (implements ground to execute after being manually entered denitration
" thermal power plant's air pollution emission new standard (GB13223-2011) " especially emission limit standard, NOx emission concentration limit
100mg/m3, manual setting target NOx emission concentration is 80mg/Nm3, it is possible thereby to calculating theoretical denitrification rate is 68%, control
System will automatically generate corresponding NSR=1.8, and system can effectively realize that ammonium hydroxide flow is adjusted and initial NOx concentration changes.
The foregoing is merely the specific implementation cases of the invention patent, but the technical characteristic of the invention patent is not limited to
This, within the field of the present invention, made changes or modifications all cover of the invention special any those skilled in the relevant art
Among sharp range.
Claims (9)
1. restoring the control method of agent flux during a kind of flue gas SNCR denitration, reducing agent is sprayed into flue gas, to flue gas into
Row SNCR denitration restores the nitrogen oxides in flue gas, which is characterized in that reducing agent flow rate calculation value SV are as follows:
Wherein:
SV: reducing agent flow rate calculation value, units/kg/h；
Q: flue gas flow in kiln tail chimney, unit Nm3/h；
[NOx]1: initial NOx concentration, unit mg/Nm3；
[NOx]2: NOx concentration, unit mg/Nm are surveyed in kiln tail chimney3；
[NOx]3: target NOx controlled concentration, unit mg/Nm3；
C: reducing agent mass concentration, wt%；
NSR: ammonia nitrogen molar ratio；Reducing agent flow rate calculation value SV is substituted into following judgement formula:
Wherein, PV: reduction agent flux measured value, units/kg/h；
By decision condition, initial NOx concentration [NOx] is adjusted1, reducing agent flow rate calculation value SV is adjusted, is allowed real after denitration
It surveys NOx concentration [NOx]2Constantly approach target NOx concentration [NOx]3, reduction agent flux measured value PV constantly levels off to reducing agent stream
Measure calculated value SV.
2. control method as described in claim 1, which is characterized in that the initial NOx concentration [NOx]1For 400-1200mg/m3。
3. control method according to claim 1, which is characterized in that determine [NOx] in formula1Increment Delta is set as 10mg/
m3~50mg/m3。
4. control method according to claim 1, which is characterized in that determine [NOx] in formula1Increment Delta is set as 10mg/
m3、20mg/m3、30mg/m3、40mg/m3、50mg/m3。
5. control method according to claim 1, which is characterized in that the reducing agent is ammonium hydroxide or urea, reductant concentration
15-25wt%.
6. control method according to claim 1, which is characterized in that the target NOx controlled concentration [NOx]3It is discharged than industry
Limit small 20-100mg/m3。
7. control method according to claim 1, which is characterized in that the actual measurement NOx concentration [NOx]2It is real under dry state to mark
Surveying NO conversion is NO2In 10%O2Data under content.
8. application of the control method as described in claim 1 in clinker line denitration engineering.
9. application of the control method as described in claim 1 in coal-burning boiler denitration engineering.
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| CN109806913B (en) * | 2019-03-12 | 2022-05-31 | 南京信融环保新材料有限公司 | Denitration catalyst applied to cement plant and preparation method thereof |
| CN110180347A (en) * | 2019-05-31 | 2019-08-30 | 芜湖富春染织股份有限公司 | A kind of denitration of boiler smoke method |
| CN110652856B (en) * | 2019-08-26 | 2022-07-22 | 光大环保技术研究院（南京）有限公司 | SNCR control system based on model |
| CN111135683B (en) * | 2020-02-27 | 2020-11-06 | 上海三融环保工程有限公司 | SNCR denitration automatic control method and system |
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