CN106621738A - Control device for reducing escaped ammonia in denitration process - Google Patents
Control device for reducing escaped ammonia in denitration process Download PDFInfo
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- CN106621738A CN106621738A CN201611128547.5A CN201611128547A CN106621738A CN 106621738 A CN106621738 A CN 106621738A CN 201611128547 A CN201611128547 A CN 201611128547A CN 106621738 A CN106621738 A CN 106621738A
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- ammonia
- denitration
- nox
- control
- nitrogen oxides
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- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 title claims abstract description 298
- 229910021529 ammonia Inorganic materials 0.000 title claims abstract description 147
- 238000000034 method Methods 0.000 title claims abstract description 15
- 238000005507 spraying Methods 0.000 claims abstract description 12
- MWUXSHHQAYIFBG-UHFFFAOYSA-N nitrogen oxide Inorganic materials O=[N] MWUXSHHQAYIFBG-UHFFFAOYSA-N 0.000 claims description 133
- 239000007921 spray Substances 0.000 claims description 26
- 238000005259 measurement Methods 0.000 claims description 15
- 238000005457 optimization Methods 0.000 claims description 12
- 238000002485 combustion reaction Methods 0.000 claims description 11
- 238000006243 chemical reaction Methods 0.000 claims description 10
- 238000004891 communication Methods 0.000 claims description 8
- GQPLMRYTRLFLPF-UHFFFAOYSA-N Nitrous Oxide Chemical class [O-][N+]#N GQPLMRYTRLFLPF-UHFFFAOYSA-N 0.000 claims description 7
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 claims description 6
- 230000007613 environmental effect Effects 0.000 claims description 6
- 239000003546 flue gas Substances 0.000 claims description 6
- 238000004458 analytical method Methods 0.000 claims description 5
- 230000005520 electrodynamics Effects 0.000 claims description 5
- 230000008859 change Effects 0.000 claims description 3
- 238000012937 correction Methods 0.000 claims description 3
- 238000010219 correlation analysis Methods 0.000 claims description 3
- 238000004088 simulation Methods 0.000 claims description 3
- 239000000779 smoke Substances 0.000 claims description 3
- 230000003044 adaptive effect Effects 0.000 claims description 2
- 239000000203 mixture Substances 0.000 claims description 2
- 230000003534 oscillatory effect Effects 0.000 claims description 2
- 230000004044 response Effects 0.000 claims description 2
- 238000005070 sampling Methods 0.000 claims description 2
- 238000010977 unit operation Methods 0.000 claims description 2
- 229910000069 nitrogen hydride Inorganic materials 0.000 claims 2
- 230000009286 beneficial effect Effects 0.000 abstract 1
- 239000003054 catalyst Substances 0.000 description 15
- 239000000463 material Substances 0.000 description 7
- 238000012544 monitoring process Methods 0.000 description 7
- 239000007789 gas Substances 0.000 description 6
- 239000003245 coal Substances 0.000 description 4
- 230000001276 controlling effect Effects 0.000 description 4
- 238000007254 oxidation reaction Methods 0.000 description 4
- 230000007423 decrease Effects 0.000 description 3
- 238000001514 detection method Methods 0.000 description 3
- 238000005516 engineering process Methods 0.000 description 3
- 230000003647 oxidation Effects 0.000 description 3
- 230000009467 reduction Effects 0.000 description 3
- BIGPRXCJEDHCLP-UHFFFAOYSA-N ammonium bisulfate Chemical compound [NH4+].OS([O-])(=O)=O BIGPRXCJEDHCLP-UHFFFAOYSA-N 0.000 description 2
- 230000033228 biological regulation Effects 0.000 description 2
- 230000000903 blocking effect Effects 0.000 description 2
- 238000000738 capillary electrophoresis-mass spectrometry Methods 0.000 description 2
- 238000006555 catalytic reaction Methods 0.000 description 2
- 230000009849 deactivation Effects 0.000 description 2
- 230000003247 decreasing effect Effects 0.000 description 2
- 238000009792 diffusion process Methods 0.000 description 2
- 238000012423 maintenance Methods 0.000 description 2
- 239000002574 poison Substances 0.000 description 2
- 231100000614 poison Toxicity 0.000 description 2
- 206010019233 Headaches Diseases 0.000 description 1
- 235000006508 Nelumbo nucifera Nutrition 0.000 description 1
- 240000002853 Nelumbo nucifera Species 0.000 description 1
- 235000006510 Nelumbo pentapetala Nutrition 0.000 description 1
- CBENFWSGALASAD-UHFFFAOYSA-N Ozone Chemical compound [O-][O+]=O CBENFWSGALASAD-UHFFFAOYSA-N 0.000 description 1
- 238000010521 absorption reaction Methods 0.000 description 1
- 238000003916 acid precipitation Methods 0.000 description 1
- 230000003197 catalytic effect Effects 0.000 description 1
- 239000007809 chemical reaction catalyst Substances 0.000 description 1
- 239000003638 chemical reducing agent Substances 0.000 description 1
- 239000003795 chemical substances by application Substances 0.000 description 1
- 235000019504 cigarettes Nutrition 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 238000013461 design Methods 0.000 description 1
- 239000000446 fuel Substances 0.000 description 1
- 231100000869 headache Toxicity 0.000 description 1
- 230000036541 health Effects 0.000 description 1
- 206010022000 influenza Diseases 0.000 description 1
- 230000007774 longterm Effects 0.000 description 1
- DOTMOQHOJINYBL-UHFFFAOYSA-N molecular nitrogen;molecular oxygen Chemical compound N#N.O=O DOTMOQHOJINYBL-UHFFFAOYSA-N 0.000 description 1
- 230000001590 oxidative effect Effects 0.000 description 1
- 231100000572 poisoning Toxicity 0.000 description 1
- 230000000607 poisoning effect Effects 0.000 description 1
- 238000000746 purification Methods 0.000 description 1
- 239000012495 reaction gas Substances 0.000 description 1
- 230000001105 regulatory effect Effects 0.000 description 1
- 230000000630 rising effect Effects 0.000 description 1
- 238000005096 rolling process Methods 0.000 description 1
- 238000007086 side reaction Methods 0.000 description 1
- 230000005619 thermoelectricity Effects 0.000 description 1
- -1 when it declines Chemical compound 0.000 description 1
Classifications
-
- 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
- B01D53/86—Catalytic processes
- B01D53/8621—Removing nitrogen compounds
- B01D53/8625—Nitrogen oxides
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D53/00—Separation of gases or vapours; Recovering vapours of volatile solvents from gases; Chemical or biological purification of waste gases, e.g. engine exhaust gases, smoke, fumes, flue gases, aerosols
- B01D53/34—Chemical or biological purification of waste gases
- B01D53/74—General processes for purification of waste gases; Apparatus or devices specially adapted therefor
- B01D53/86—Catalytic processes
- B01D53/90—Injecting reactants
-
- 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
- G05D11/139—Controlling ratio of two or more flows of fluid or fluent material characterised by the use of electric means by measuring a value related to the quantity of the individual components and sensing at least one property of the mixture
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2251/00—Reactants
- B01D2251/20—Reductants
- B01D2251/206—Ammonium compounds
- B01D2251/2062—Ammonia
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2258/00—Sources of waste gases
- B01D2258/02—Other waste gases
- B01D2258/0283—Flue gases
Abstract
The invention discloses a control device for reducing escaped ammonia in a denitration process. The control device comprises an instant inlet ammonia spraying and distribution control device, wherein the instant inlet ammonia spraying and distribution control device is composed of a main pipe, a plurality of branch pipes, ammonia spraying electric valves, flue pipes, a plurality of ammonia spraying valves, and NH and NOX detectors, wherein one end of each branch pipe is communicated onto the main pipe; the ammonia spraying electric valves are arranged on the plurality of branch pipes respectively; the flue pipes are communicated with the other ends of the plurality of branch pipes; the ammonia spraying valves are arranged on side surfaces of the flue pipes and two opposite end faces of the flue pipes; the NH and NOX detectors are arranged on the plurality of ammonia spraying valves. The control device disclosed by the invention has the beneficial effects of simple structure and high practicability.
Description
Technical field
The present invention relates to a kind of reduce the escaping of ammonia method, it is particularly a kind of to reduce denitration escape ammonia control method.
Background technology
The main source of NO_x in Air Environment is fuel, wherein nearly 70% comes from the direct burning of coal.China be with
Coal is the country of main energy sources, and coal-fired power plant amount accounts for more than half of coal in China total quantity consumed again.According to statistics, 2000
The total emission volumn of year China N0x is about 18,800,000 tons, wherein, thermal power plant nitrogen oxide emission is 4,960,000 tons.According to mesh
Front emission level measuring and calculating, it is contemplated that to the year two thousand twenty, the nitrogen oxides of China's thermoelectricity discharge are up to more than 10,000,000 tons.NOx is dense
The rising of degree, increases will oxidizing capacity, causes a series of city such as acid rain, depletion of the ozone layer, photochemical fog and area
Domain environmental problem, to health and ecological environment huge threat is constituted.Therefore, coal fired power plant denitrating flue gas are China's control
The most important thing of NOx emission.
SCR (SCR) technology is a kind of denitration technology being industrially most widely used at present, and principle is
With NH3 as reducing agent, the N0x in selective catalysis reduction flue gas is reduced to harmless N2 and H20, to remove NOx, meets increasingly tight
The environmental requirement of lattice.
At present SCR flue gas denitrification systems both domestic and external substantially (extract cigarette using laser method, FTRI methods and indirect method
Gas, measurement by catalyst with by the NO contents in catalyst sample gas) monitoring the amount of ammonia slip of denitrating system, mesh on-line
The online the escaping of ammonia monitoring situation of the SCR denitration system that front domestic each department have been put into operation is undesirable, it is at present domestic there is not yet
To ripe reliable detection method.The escaping of ammonia detection is immature, and the escaping of ammonia control is also undesirable, and most power plants are due to denitration system
System the escaping of ammonia control is bad to cause economic loss quite big, and so to say that the escaping of ammonia is the thing of current each power plant most headache.
The content of the invention
The invention aims to solve the above problems, a kind of reduction denitration escape ammonia control method is devised.
Realize that above-mentioned purpose the technical scheme is that, one kind reduces denitration escape ammonia control method, including：
Immediately entrance spray ammonia distribution control device, the instant entrance spray ammonia distribution control device is connected in mother by main pipe, one end
Arm on pipe described in several, spray ammonia electrodynamic valve, the connection being separately positioned on the arm described in several are in several institutes
The flue of the arm other end stated, located at flue side surface and flue opposite end surface several described in spray ammonia valve and set
NH, NOX detector put on the spray ammonia valve described in several is constituted.
Denitration Optimal Control System, the denitration Optimal Control System by DCS operator station, mobile TOCS work teachers station,
Denitrating system, DCS system and TOCS controllers composition, the TOCS controllers and DCS system are led to by netting twine connecting communication
Cross with DCS system data communication realize TOCS controllers data acquisition and instruction output, the mobile TOCS engineer stations with
TOCS controllers netting twine connects, and the DCS operator station is connected with DCS system netting twine, the denitrating system and DCS system netting twine
Connection.
The TOCS controllers carry out data exchange, the TOCS controllers with DCS system from MODBUS communication protocols
Data unit operation is obtained from DCS system, Jing computings provide optimum control and instruct and control corresponding execution machine by DCS system
Structure.
The discreet value of NOX changes can be calculated by denitration Optimal Control System, following sometime NOX values are drawn, gram
NOX measuring instrumentss sampling and measuring delay of response problems are taken, while and carrying out long-term modified quasi to hard measurement with the result of NOX measurements
Close so that hard measurement result is confirmed and corrected with hard measurement result, recurrence goes out relatively accurate and timely following hard measurement is tied
Really：
Denitration Optimal Control System calculates appropriate denitration efficiency setting value, after line range of going forward side by side is limited, obtains system and most closes
The denitration efficiency final optimization pass setting value of reason, the efficiency value of such operations staff's setting is actually the lower limit of a safety,
No longer at any time according to boiler operatiopn operating mode change denitration efficiency setting value in operation；
According to NOX discreet values and efficiency optimization setting value, instant computing goes out system optimization spray ammonia flow to denitration Optimal Control System
Value, optimization ammonia flow is sprayed in flue gas carries out denitration reaction, obtains more stable denitration and exports NOX indexs；
NOX indexs and the escaping of ammonia situation are exported according to denitration, in time amendment denitration efficiency setting value.Due to denitration optimal control system
System is based on opened loop control, supplemented by longer term parameters Closed-cycle correction, it is possible to obtain quick governing speed and will not
Produce oscillatory occurences.
Offline and on-line analyses of the denitration Optimal Control System to controlled system runnability：System performance it is offline
Analysis：Calculated with various performance parameters by the statistics of operation history data, obtain system system operation under various operating modes
Energy parameter, determines NOX span of control.
Automatically the Optimal Control target of denitrating system operation is calculated：Oneself study of controlled system and adaptive model are set up,
Trained by the real-time online to system model so as to approaching to reality control system.Environmental protection and economic indicator according to denitrating system,
Calculated in real time by model and found under actual motion state, the optimized control targe that controlled system can reach is excellent
Changing control targe includes, denitration rate, outlet nitrous oxides concentration, reactor ammonia consumption and outlet ammonia escape amount etc., and with this
For the optimal control that definite value realizes system.
Implement precise and stable denitrating system ammonia flow control, in denitration Optimal Control System, employ boiler and
The mode that reactor model is estimated, according to denitrating system optimal control target, directly calculates ammonia straying quatity.Model predictive control
Compared with traditional control method ammonia straying quatity more accurately and timely, following performance is included in its model：
Inlet nitrogen oxides concentration is estimated, and the amount of nitrogen oxides that boiler combustion is produced is related to the various parameters of boiler combustion,
Boiler air quantity（Load）When larger, the amount of nitrogen oxides of generation is larger.According to boiler combustion status and outlet amount of nitrogen oxides
Correlation analysiss, set up boiler combustion and amount of nitrogen oxides yield model, so as to estimate outlet amount of nitrogen oxides variation tendency,
Reduce the impact to control system that amount of nitrogen oxides measurement postpones.
In ammonia Controlling model, reactor inlet nitrogen oxides total amount is not only considered（Air quantity × nitrous oxides concentration）Simultaneously
Calculate reactor ammonia consumption rate（Reactor ammonia consumption rate=k (inlet NOx concentration-exit NOx concentration) × boiler smoke/ammonia flow）,
Wherein k value is (NH3)/n (NOx) ratios, and reactor ammonia consumption represents the consumption of chemical reaction amount and ammonia of reactor ammonia
The ratio of the total straying quatity of gas, when it declines, ammonia declines with the reactive ratio of nitrogen oxides, and the ammonia amount for exporting residual increases
Greatly.Ensure the precise control to exporting nitrogen oxides, automatically analyzed and proportioning left and right sides ammonia by spraying ammonia valve gate simulation
Straying quatity, it is ensured that denitrating system left and right sides ammonia consumption rate is balanced, reduces the escaping of ammonia rate.
The reduction denitration escape ammonia control method made using technical scheme, the system can be distributed at any time
Each sprays ammonia entrance ammonia to SCR reactors, ensures that denitrating catalyst needs the matching uniformity coefficient of ammonia, reduces the escaping of ammonia, drop
Low air preheater plugging rate, saves ammonia usage, improves catalyst life.
Description of the drawings
Fig. 1 be instant denitration entrance ammonia module of the present invention uniformly with the structural representation of matching control apparatus；
Fig. 2 is the amount ratio curve of (NH3)/n (NOx) material of the present invention；
Fig. 3 is denitration rate of the present invention and ammonia consumption rate dependence scattergram；
Fig. 4 is outlet nitrogen oxides of the present invention and ammonia consumption rate dependence scattergram；
Fig. 5 is environmentally friendly nitrous oxides concentration of the present invention and ammonia consumption rate dependence scattergram；
Fig. 6 is inlet nitrogen oxides of the present invention and boiler air quantity dependency scattergram；
Fig. 7 is the system construction drawing of denitration Optimal Control System of the present invention；
In figure, 1, main pipe；2nd, arm；3rd, ammonia electrodynamic valve is sprayed；4th, flue；5th, ammonia valve is sprayed；6th, NH3, NOX detector；7th, DCS operations
Member station；8th, mobile TOCS work teacher station；9th, denitrating system；10th, DCS system；11st, TOCS controllers；12nd, effusion meter；13rd, valve
Door.
Specific embodiment
The present invention is specifically described below in conjunction with the accompanying drawings, as shown in figs. 1-7, one kind reduces denitration escape ammonia controlling party
Method, the removal efficiency key point of NOx is analyzing：（a）Impact of the amount of material than n (NH3)/n (NOx)：Material compares n
(NH3) such as at 300 DEG C, denitration rate is with the amount of material than n (NH3)/n for the impacts of/n (NOx) to denitration efficiency
(NOx) increase and increase, when amount n (the NH3)/n (NOx) of material is less than 0. 8, its impact becomes apparent from, Ji Hucheng
Linear proportional relation is shown in Fig. 2（What denitration producer provided）.The result explanation:If NH3 input amounts are low, denitration rate is restricted;
If the reaction rate that NH3 input amounts exceed the side reactions such as requirement, NH3 oxidations will increase, such as SO2 oxidations generate SO3,
SO3 generates NH4HSO4 with excess of ammonia reaction under cryogenic conditions.NH4HSO4 can be attached to catalyst or cold section of air preheater is changed
On thermal element surface, denitration efficiency is caused to reduce or air preheater blocking.The excess of ammonia and escape compare n depending on the amount of material
(NH3)/n (NOx), working condition and catalyst active amount (engineering design the escaping of ammonia is not more than 0. 0003%,
The conversion ratio of SO2 oxidation generation SO3≤1%).The escapement ratio of ammonia increases, and while denitration rate is reduced, also increases purification
The concentration of emission of unconverted NH3, in turn results in secondary pollution in flue gas.TOCS denitration the escaping of ammonia control system reaches to export nitrogen
Oxide parameter, denitration rate and ammonia consumption rate are complex optimum index, and rolling optimization, the control of TOCS denitrations the escaping of ammonia are calculated in real time
System guarantees to be controlled 80% ~ 85% in denitration rate, it is to avoid denitration efficiency is reduced or air preheater blocking.（b）Time of contact is to denitration
The impact of rate 300 DEG C of temperature and material amount than n (NH3)/n (NOx) be 1 under conditions of, denitration rate is with reaction
Gas and catalyst time of contact t increase and increase sharply;When t increases to 200ms or so, denitration rate reaches maximum, subsequently
Denitration rate declines.This increases mainly due to the time of contact of reacting gas and catalyst, is conducive to reacting gas in catalyst
Diffusion, absorption, reaction and the desorbing of product gas, diffusion in micropore, so that denitration rate is improved;But if time of contact is long,
NH3 oxidation reactions start generation, decline denitration rate, and TOCS denitration the escaping of ammonia control system can be suitable in right times spray
Ammonia.
As shown in Figure 3 certain power plant is in May 8 to the denitration rate of May 20, reactor outlet nitrogen oxides control content curve
Figure, Environmental Protection Agency monitoring point amount of nitrogen oxides consumes rate dependence with reactor ammonia in Fig. 4 flues, and Fig. 5 is dense for environmentally friendly nitrogen oxides
Degree and ammonia consume rate dependence scattergram, and Fig. 6 is boiler total blast volume and boiler nitrogen oxides yield (reactor inlet nitrogen oxides
Concentration) dependency scattergram, per mean value coordinates position for representing a hour in figure.Put down within one hour using operation parameters
Average, because the operation in interior system per hour is different, generates larger data discrete, but still can reflect the phase of each parameter
Close characteristic；As can be seen from Figure 4 when denitration rate is less than 40%, environment monitoring more than 85%, reactor outlet amount of nitrogen oxides
When point amount of nitrogen oxides is less than 80%, ammonia consumption rate will fall rapidly upon, i.e., the consumption of ammonia declines rapidly in reactor, ammonia
Escape amount is quickly improved；As can be seen from Figure 3 denitration rate from 85% bring up to 90% when, ammonia consumption rate decline 15%；Reactor outlet nitrogen oxygen
Compound content from 40% drop to 25% when, ammonia consumption rate decline 15%；Environment monitoring point amount of nitrogen oxides drops to 60% from 80%
When, ammonia consumption rate declines 15%；Therefore it is to improve reactor ammonia consumption rate in real system control, reduces the use of denitrating system ammonia
Amount, reduces the escape amount of ammonia, should by the control of denitration rate 80% ~ 85%, the control of reactor outlet amount of nitrogen oxides 40 ~
More than 50mg/m3, the mg/m3 of environment monitoring point nitrogen oxides 70 ~ 90, ammonia consumption can be reduced, and ammonia is greatly reduced
Escape amount.
The characteristics of the present embodiment is that the system can at any time distribute SCR reactors each spray ammonia entrance ammonia, ensure de-
Denox catalyst needs the matching uniformity coefficient of ammonia, reduces the escaping of ammonia, reduces air preheater plugging rate, saves ammonia usage, improves
Catalyst life.
In the present embodiment, first, it is former by netting twine TOCS controllers and primary Power Plant DCS System connecting communication
The confession ammonia of power plant denitration DCS control systems automatically adjusts model and typically first presets a denitration efficiency, is then surveyed by CEMS
Amount SCR reactor inlet NOx concentrations, are computed drawing required ammonia flow, dense with CEMS measurement SCR reactor outlet NOx
Degree is compared, then supplies ammonia regulating valve by a PI adjusting meanss control, by realizing TOCS systems with DCS system data communication
The data acquisition of system and instruction output, are automatically controlled switching of the mode in original mode and TOCS modes；Main pipe is connected
By each spray ammonia valve position N0x, NH3 being added to measure sample point per side denitration exhaust pass, by each valve opening feedback and
More each and every one measuring point NH3, NOX data pass to TOCS controllers, and TOCS controllers collection denitration data set up denitration Controlling model.
The debugging of spray ammonia entrance matching optimization unit 100% at full capacity under, denitration environmental protection export value control is fixed in 30mg/m3 ± 10 and sprayed
The total valve opening of ammonia, then according to the aperture analysis flue outlet NOX data variations and flue outlet NH3 escape numbers of spray ammonia electrodynamic valve
According to relation, such as increase flue spray ammonia electrically operated valve aperture, flue outlet NOX reduces, and illustrates that the region ammonia spraying amount is less than summit,
Increase spray ammonia aperture is not changing until NOX, when flue outlet NH3 starts to increase, while reducing valve opening flue outlet
NOX increases, and flue outlet NH3 is reduced, and the flow of Flue valve aperture has arrived flex point, and ammonia flow distribution in 1# regions meets denitration
Need.Constant if there is switch flue spray ammonia electrically operated valve flue outlet NOX, only flue outlet NH3 is increased or decreased, and is said
The bright region catalyst module complete poison deactivation, then the spray ammonia electrodynamic valve can be only in closed mode, treat unit maintenance
When check change this region catalyst module.In the same manner other region spray ammonia valve doors also so adjust valve opening, and fixed institute is a little
Valve opening, uniformly optimization is completed the matching of spray ammonia entrance, and spray ammonia is adjusted gives total regulation valve regulation.After adjustment is finished, drop is negative
Lotus verifies uniformity to 65%.Such as occur that reactor both sides N0x concentration monitor data are inconsistent, deviation is larger.Or N0x concentration
Monitoring Data chimney entrance numerical value is inconsistent with reactor outlet data, and deviation is larger；This explanation denitration regions module catalysis
Agent catalytic capability is reduced, and to carry out at any time spraying the correction of ammonia each point inlet valve aperture, is found out and the region denitrification catalyst module
The valve opening of matching, if switch occurs in certain region, spray ammonia valve door NOX is constant, and only NH3 is increased or decreased, and illustrates the region
Catalyst module complete poison deactivation, is sprayed the closing of ammonia inlet valve, and such as catalyst poisoning region point needs to shut down more than 3
Maintenance.
During by above structure detection：
First, the amount of nitrogen oxides that boiler combustion is produced is related to the various parameters of boiler combustion, in boiler air quantity（Load）Compared with
When big, the amount of nitrogen oxides of generation is larger.According to boiler combustion status and the correlation analysiss of outlet amount of nitrogen oxides, pot is set up
Stove burns and amount of nitrogen oxides yield model, so as to estimate outlet amount of nitrogen oxides variation tendency, reduces amount of nitrogen oxides
The impact to control system that measurement postpones.
Then, in ammonia Controlling model, reactor inlet nitrogen oxides total amount is not only considered（Air quantity × nitrogen oxides are dense
Degree）Reactor ammonia consumption rate is calculated simultaneously（Reactor ammonia consumption rate=k (inlet NOx concentration-exit NOx concentration) × boiler smoke/ammonia
Throughput）, wherein k value is that (NH3)/n (NOx) compares, and reactor ammonia consumption, the chemical reaction for representing reactor ammonia disappears
The ratio of consumption and the total straying quatity of ammonia, when it declines, ammonia declines with the reactive ratio of nitrogen oxides, exports the ammonia of residual
Tolerance increases.Ensure the precise control to exporting nitrogen oxides.
Finally, automatically analyzed and proportioning left and right sides ammonia straying quatity by spraying ammonia valve gate simulation, it is ensured that denitrating system
Left and right sides ammonia consumption rate is balanced, reduces the escaping of ammonia rate.
Above-mentioned technical proposal only embodies the optimal technical scheme of technical solution of the present invention, those skilled in the art
Some of which part is made some variation embody the present invention principle, belong to protection scope of the present invention it
It is interior.
Claims (3)
1. a kind of instant denitration entrance ammonia module is uniformly and matching control apparatus, it is characterised in that include：
Immediately entrance spray ammonia distribution control device, the instant entrance spray ammonia distributes control device by main pipe（1）, one end connection exist
Main pipe（1）Go up the arm described in several（2）, be separately positioned on arm described in several（2）On spray ammonia electrodynamic valve（3）、
Arm of the connection described in several（2）The flue of the other end（4）, located at flue（4）Side surface and flue（4）Opposite end surface
Several described in spray ammonia valve（5）And the spray ammonia valve being arranged on described in several（5）On NH3, NOX detector（6）Structure
Into；
Denitration Optimal Control System, the denitration Optimal Control System is by DCS operator station（7）, mobile TOCS work teacher station
（8）, denitrating system（9）, DCS system（10）And TOCS controllers（11）Composition, the TOCS controllers（11）And DCS system
（10）By netting twine connecting communication, by with DCS system（10）TOCS controllers are realized in data communication（11）Data acquisition and
Instruction output, the mobile TOCS engineer stations（8）With TOCS controllers（11）Netting twine connects, the DCS operator station（7）With
DCS system（10）Netting twine connects, the denitrating system（9）With DCS system（10）Netting twine connects.
2. uniformly and matching control apparatus, its feature exists a kind of instant denitration entrance ammonia module according to claim 1
In the TOCS controllers（11）Data exchange, the TOCS controllers are carried out with DCS system from MODBUS communication protocols
（11）From DCS system（10）Data unit operation is obtained, Jing computings provide optimum control and instruct and by DCS system（10）Control
Corresponding actuator.
3. the one kind according to claim 1-2 reduces denitration escape ammonia control method, it is characterised in that optimized by denitration
Control system can calculate the discreet value of NOX changes, draw following sometime NOX values, overcome NOX measuring instrumentss sampling and measurings
Delay of response problem, while and amendment fitting for a long time is carried out to hard measurement with the result of NOX measurements so that hard measurement result is with firmly
Measurement result is confirmed and is corrected, and recurrence goes out relatively accurately and timely following hard measurement result：
（a）Denitration Optimal Control System calculates appropriate denitration efficiency setting value, after line range of going forward side by side is limited, obtains system most
Rational denitration efficiency final optimization pass setting value, the efficiency value of such operations staff's setting is actually the lower limit of a safety
Value, no longer at any time according to boiler operatiopn operating mode change denitration efficiency setting value in operation；
（b）According to NOX discreet values and efficiency optimization setting value, instant computing goes out system optimization spray ammonia stream to denitration Optimal Control System
Value, optimization ammonia flow is sprayed in flue gas carries out denitration reaction, obtains more stable denitration and exports NOX indexs；
（c）NOX indexs and the escaping of ammonia situation are exported according to denitration, in time amendment denitration efficiency setting value；
Because denitration Optimal Control System is based on opened loop control, supplemented by longer term parameters Closed-cycle correction, it is possible to obtain
Quickly governing speed and oscillatory occurences will not be produced；
（d）Offline and on-line analyses of the denitration Optimal Control System to controlled system runnability：System performance it is offline
Analysis：Calculated with various performance parameters by the statistics of operation history data, obtain system system operation under various operating modes
Energy parameter, determines NOX span of control；
（e）Automatically the Optimal Control target of denitrating system operation is calculated：Oneself study of controlled system and adaptive model are set up, is led to
Cross the real-time online to system model to train so as to approaching to reality control system；
Environmental protection and economic indicator according to denitrating system, is calculated in real time and is found under actual motion state by model, controlled
The optimized control targe that system can reach, optimal control target includes, denitration rate, outlet nitrous oxides concentration, reaction
Device ammonia consumption and outlet ammonia escape amount etc., and realize the optimal control of system as definite value；
（f）Implement precise and stable denitrating system ammonia flow control：
In denitration Optimal Control System, the mode that boiler and reactor model are estimated is employed, controlled according to denitrating system optimization
Target processed, directly calculates ammonia straying quatity；
Model predictive control compared with traditional control method ammonia straying quatity more accurately and timely, in its model following performance is included：
Inlet nitrogen oxides concentration is estimated：The amount of nitrogen oxides that boiler combustion is produced is related to the various parameters of boiler combustion,
Boiler air quantity（Load）When larger, the amount of nitrogen oxides of generation is larger；
According to boiler combustion status and the correlation analysiss of outlet amount of nitrogen oxides, set up boiler combustion and produce with amount of nitrogen oxides
Amount model, so as to estimate outlet amount of nitrogen oxides variation tendency, reduce that amount of nitrogen oxides measurement postpones to control system
Affect；
In ammonia Controlling model, reactor inlet nitrogen oxides total amount is not only considered（Air quantity × nitrous oxides concentration）Calculate simultaneously
Reactor ammonia consumption rate（Reactor ammonia consumption rate=k (inlet NOx concentration-exit NOx concentration) × boiler smoke/ammonia flow）, wherein
K value is (NH3)/n (NOx) ratios, and reactor ammonia consumption, the consumption of chemical reaction amount for representing reactor ammonia is total with ammonia
The ratio of straying quatity, when it declines, ammonia declines with the reactive ratio of nitrogen oxides, exports the ammonia amount increase of residual；
Ensure the precise control to exporting nitrogen oxides, automatically analyzed and proportioning left and right sides ammonia by spraying ammonia valve gate simulation
Straying quatity, it is ensured that denitrating system left and right sides ammonia consumption rate is balanced, reduces the escaping of ammonia rate.
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| CN107544288A (en) * | 2017-09-26 | 2018-01-05 | 天津拓科思科技有限公司 | A kind of denitration optimal control method and system |
| CN107551774A (en) * | 2017-10-18 | 2018-01-09 | 华润电力湖北有限公司 | A kind of denitration control method and system for thermal power plant |
| CN108159881A (en) * | 2018-01-10 | 2018-06-15 | 中国大唐集团科学技术研究院有限公司华东分公司 | A kind of SCR denitration following control system and method based on optimization operation |
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| CN112717689A (en) * | 2019-10-28 | 2021-04-30 | 国家电投集团远达环保工程有限公司重庆科技分公司 | Selective catalytic reduction denitration device and method |
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| CN108159881B (en) * | 2018-01-10 | 2020-03-06 | 中国大唐集团科学技术研究院有限公司华东分公司 | SCR denitration follow-up control system and method based on optimized operation |
| CN108645964A (en) * | 2018-04-23 | 2018-10-12 | 华北电力科学研究院有限责任公司 | The equal values determination method of SCR denitration device the escaping of ammonia based on carbamide reducing agent and system |
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| CN112717689A (en) * | 2019-10-28 | 2021-04-30 | 国家电投集团远达环保工程有限公司重庆科技分公司 | Selective catalytic reduction denitration device and method |
| WO2021082828A1 (en) * | 2019-10-28 | 2021-05-06 | 国家电投集团远达环保工程有限公司重庆科技分公司 | Selective catalytic reduction denitrification device and method |
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