CN106268239B - The isolated control method of the integral of thermal power plant's denitration control system - Google Patents
The isolated control method of the integral of thermal power plant's denitration control system Download PDFInfo
- Publication number
- CN106268239B CN106268239B CN201610646917.8A CN201610646917A CN106268239B CN 106268239 B CN106268239 B CN 106268239B CN 201610646917 A CN201610646917 A CN 201610646917A CN 106268239 B CN106268239 B CN 106268239B
- Authority
- CN
- China
- Prior art keywords
- module
- input
- value
- output
- control
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 238000000034 method Methods 0.000 title claims abstract description 30
- QGZKDVFQNNGYKY-UHFFFAOYSA-N Ammonia Chemical compound N QGZKDVFQNNGYKY-UHFFFAOYSA-N 0.000 claims abstract description 96
- 229910021529 ammonia Inorganic materials 0.000 claims abstract description 47
- 239000007921 spray Substances 0.000 claims abstract description 33
- 238000000926 separation method Methods 0.000 claims abstract description 6
- 238000004364 calculation method Methods 0.000 claims description 51
- 230000003321 amplification Effects 0.000 claims description 39
- 238000003199 nucleic acid amplification method Methods 0.000 claims description 39
- 230000010354 integration Effects 0.000 claims description 13
- UGFAIRIUMAVXCW-UHFFFAOYSA-N Carbon monoxide Chemical compound [O+]#[C-] UGFAIRIUMAVXCW-UHFFFAOYSA-N 0.000 claims description 12
- 239000003546 flue gas Substances 0.000 claims description 12
- 230000005540 biological transmission Effects 0.000 claims description 11
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical group [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 claims description 9
- 239000001301 oxygen Substances 0.000 claims description 9
- 229910052760 oxygen Inorganic materials 0.000 claims description 9
- 238000005259 measurement Methods 0.000 claims description 8
- 238000010926 purge Methods 0.000 claims description 8
- 239000000446 fuel Substances 0.000 claims description 7
- 230000009466 transformation Effects 0.000 claims description 2
- 239000003245 coal Substances 0.000 abstract description 10
- 229920006395 saturated elastomer Polymers 0.000 abstract description 3
- 230000008901 benefit Effects 0.000 description 6
- 230000009471 action Effects 0.000 description 5
- 238000013461 design Methods 0.000 description 5
- 238000007792 addition Methods 0.000 description 4
- 230000000694 effects Effects 0.000 description 4
- 238000005516 engineering process Methods 0.000 description 3
- 230000008569 process Effects 0.000 description 3
- 238000005507 spraying Methods 0.000 description 3
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 description 2
- 238000012423 maintenance Methods 0.000 description 2
- 239000000203 mixture Substances 0.000 description 2
- 229910000069 nitrogen hydride Inorganic materials 0.000 description 2
- 230000001105 regulatory effect Effects 0.000 description 2
- 230000004044 response Effects 0.000 description 2
- 239000000523 sample Substances 0.000 description 2
- 239000000779 smoke Substances 0.000 description 2
- 230000032258 transport Effects 0.000 description 2
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 1
- 241001347978 Major minor Species 0.000 description 1
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 1
- 239000005864 Sulphur Substances 0.000 description 1
- 229910052799 carbon Inorganic materials 0.000 description 1
- 239000003054 catalyst Substances 0.000 description 1
- 238000006555 catalytic reaction Methods 0.000 description 1
- 230000008859 change Effects 0.000 description 1
- 238000006243 chemical reaction Methods 0.000 description 1
- 238000002485 combustion reaction Methods 0.000 description 1
- 230000001276 controlling effect Effects 0.000 description 1
- 230000001934 delay Effects 0.000 description 1
- 239000001257 hydrogen Substances 0.000 description 1
- 229910052739 hydrogen Inorganic materials 0.000 description 1
- 150000002431 hydrogen Chemical class 0.000 description 1
- 238000012886 linear function Methods 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 229910052757 nitrogen Inorganic materials 0.000 description 1
- 238000005192 partition Methods 0.000 description 1
- 230000009467 reduction Effects 0.000 description 1
- 238000005303 weighing Methods 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
- B01D53/76—Gas phase processes, e.g. by using aerosols
-
- 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
-
- G—PHYSICS
- G05—CONTROLLING; REGULATING
- G05B—CONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS
- G05B11/00—Automatic controllers
- G05B11/01—Automatic controllers electric
- G05B11/36—Automatic controllers electric with provision for obtaining particular characteristics, e.g. proportional, integral, differential
- G05B11/42—Automatic controllers electric with provision for obtaining particular characteristics, e.g. proportional, integral, differential for obtaining a characteristic which is both proportional and time-dependent, e.g. P. I., P. I. D.
-
- 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
Landscapes
- Engineering & Computer Science (AREA)
- Chemical & Material Sciences (AREA)
- Environmental & Geological Engineering (AREA)
- General Chemical & Material Sciences (AREA)
- Biomedical Technology (AREA)
- Analytical Chemistry (AREA)
- Health & Medical Sciences (AREA)
- Oil, Petroleum & Natural Gas (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Dispersion Chemistry (AREA)
- Physics & Mathematics (AREA)
- General Physics & Mathematics (AREA)
- Automation & Control Theory (AREA)
- Treating Waste Gases (AREA)
- Chimneys And Flues (AREA)
Abstract
The present invention relates to a kind of isolated control methods of the integral of thermal power plant's denitration control system.This method comprises the following steps: the control of S1. minimum denitration efficiency；S2. integral separation control；S3. ammonia flow set point correct is sprayed；S4. jet flow amount feedforward control.The present invention can effectively control the discharge of spray ammonia flow and thermal power plant NOx using isolated method is integrated, and integral can be prevented to be saturated, and reduce station service power consumption rate, improve efficiency of generating unit；The present invention uses cascade loop control simultaneously, spray ammonia flow set point correct circuit and ammonia amount feed forward control loop reduce the randomness of variation, the burning of coal in practical operation situation, etc. the influence that control is generated of many uncertain and perturbations.
Description
Technical field
The present invention relates to a kind of control method of thermal power plant's denitration, especially a kind of integral of thermal power plant's denitration control system
Isolated control method.
Background technique
Since 2006, China's coal unit gradually put into operation denitrating system, and selective catalysis reduction method (SCR) denitration is
A kind of relatively more extensive flue-gas denitrification technology of motor group application both at home and abroad at present.Ammonia is first mixed with the air of 20 times of oneself volumes
It closes, then is mixed with 320-400 DEG C of flue gas, denitration reaction is then completed by catalyst, spray ammonia stream is passed through according to denitration principle
Measure it is not exceeded to control SCR exit NOx concentration, and control ammonia escape command troops it is exceeded, therefore spray ammonia automatic control system tune
Section quality is better, and denitration effect is better, and ammonia escapement ratio is fewer.
Thus, for denitrating system, it is badly in need of a set of science, the integral partition method of practical denitration control system, for controlling
System spray ammonia flow, effectively controls the discharge of thermal power plant NOx, integral is prevented to be saturated, and reduces station service power consumption rate and improves efficiency of generating unit.
Summary of the invention
Technical problem to be solved by the invention is to provide the fire of a kind of effectively control spray ammonia flow and thermal power plant's NOx emission
The isolated control method of the integral of power plant's denitration control system.
It is as follows that the present invention solves technical solution used by above-mentioned technical problem:
The isolated control method of the integral of thermal power plant's denitration control system, includes the following steps:
S1. minimum denitration efficiency control: denitration efficiency setting value is inputed into the first deviation computing module, by the first deviation
The output of computing module and the measured value of entrance NOx input to the first multiplication computing module respectively, by the first multiplication computing module
Output input to the first inertial delay module, the output valve of the first inertial delay module is to export the setting value of maximum NOx；
S2. integral separation control: the input of the second inertial delay module is the measured value for exporting NOx, and is exported to third
Inertial delay module, third inertial delay module are exported to the 4th inertial delay module, and the 4th inertial delay module is exported to
One additional calculation module, the input of the first additional calculation module further includes the measured value for exporting NOx, and exports to the first coefficient and put
Big module, the input of the second additional calculation module are the output of the first coefficient amplification module and the measured value for exporting NOx, and second
The output valve of additional calculation module is revised outlet NOx measured value, and the input of small value selecting module is to export the setting of NOx
Value and outlet maximum NOx setting value, the input of the second deviation computing module are the small output for being worth selecting module and revised NOx
Measured value, and exported respectively to selecting module and the second coefficient amplification module, selecting module is exported to integration module, third addition
The input of computing module is the output of integration module and the output of the second coefficient amplification module, and third additional calculation module is defeated
Value is the spray ammonia corrected value of external loop out；
S3. spray ammonia flow set point correct: the input of third deviation computing module is entrance NOx measured value and outlet NOx
Measured value, the input of the 4th additional calculation module are that the output of third additional calculation module and third deviation computing module export, the
The input of square law computing module is the output of the 4th additional calculation module and the output of function performance module, function performance module
Input be total fuel quantity measured value, export as theoretical ammonia flow calculated value, the input of third coefficient amplification module is the
The output of square law module, the output of third coefficient amplification module are the spray ammonia flow setting value of inner looping；Wherein, function performance
Module is used to fuel measurement being converted to corresponding flue gas flow；
S4. jet flow amount feedforward control: the input of the 5th inertial delay module is entrance NOx measured value, and fifth adding calculates
The input of module is that the output of the 5th inertial delay module and entrance NOx measured value, fifth adding computing module are exported to the 4th
Coefficient amplification module；The input of 6th inertial delay module is oxygen content, and the input of the 6th additional calculation module is the 6th inertia
The output and oxygen content of Postponement module, and export to the 5th coefficient amplification module；The input of control module is the amplification of the 4th coefficient
The output of module, the output of the 5th coefficient amplification module, the output of third coefficient amplification module and the 7th inertial delay module
Output, the output of control module are that spray ammonia flow controls signal.
The present invention can effectively control the discharge of spray ammonia flow and thermal power plant NOx, Neng Goufang using isolated method is integrated
Only integral saturation, and reduce station service power consumption rate, improve efficiency of generating unit.
Preferably, denitration efficiency setting value is 100% in step S1.It the advantage is that, improve denitration efficiency and denitration
Effect.
Preferably, in step S2, at selecting module, when outlet instruments purging signal comes, selecting module it is defeated
Value is 0 out, and when purging signal does not occur, the output valve of selecting module is the output valve of the second deviation computing module.
Preferably, the output of third deviation computing module is the NOx that actual needs is neutralized in step S3.
Preferably, the first to the 7th inertial delay module is respectively used to make signal transformation slowly, and there is certain time
Delay, transmission function are as follows:Wherein, it is description linear system that G (s), which is transmission function,
The basic mathematical tool of dynamic characteristic, Y (s) are the laplace transform of output, and X (s) is the laplace transform of input quantity, k
For the proportionality coefficient of inertial element, T1, T2 are the time constant of property link, and S is complex frequency domain.It the advantage is that, can improve big
The dynamic characteristic of inertia control object accelerates system response time.
Preferably, the first to the 6th additional calculation module is respectively used to calculate the sum of two input values, calculation formula
For 1 gain of A=input value 1* input value+2 gain of input value 2* input value；First and second multiplication computing module is for calculating two
The product of a input value, calculation formula are A=input value 1* input value 2；The range of 2 gain of 1 gain of input value and input value is distinguished
It is 0 to 2.It the advantage is that, General System function coefficient is 1, and peer machine function coefficient can generate deviation, it is contemplated that logic
Gain is arranged in additional calculation module in consistency.
Preferably, the first to the 5th coefficient amplification module is respectively used to zoom in and out input value according to gain, calculate
Formula is A=input value * input value gain；The range of input value gain is 0 to 2.It the advantage is that,
Preferably, control module is for providing proportional plus integral plus derivative controller function, transmission function are as follows:Wherein, it is description linear system dynamic that G (S), which is transmission function,
The basic mathematical tool of characteristic, U (S) are the laplace transform of output quantity, and E (S) is the laplace transform of input quantity, and Kp is
Proportionality coefficient in control module, Ti are the time of integration in control module, and Td is the derivative time in control module, and S is multiple
Frequency domain.It the advantage is that, so that entire control process is more controllable, improve denitration efficiency and generating set efficiency.
Preferably, integration module is used to calculate the integral of input value；First is used to calculate to third deviation computing module
The arithmetical difference of two input values, calculation formula are A=input value 1- input value 2；Small value selecting module is used for two to input
Value carries out small selection, and when input value 1 is greater than input value 2, module output is input value 2；When input value 1 is less than input value 2,
Module output is input value 1.
The present invention compared with the existing technology has the following advantages that and effect:
1, since the invention mainly comprises four partial contents, minimum denitration efficiency controls, integral separation control, spray ammonia flow
Set point correct and ammonia spraying amount feedforward control can effectively prevent control loop integral saturation, effectively control fired power generating unit outlet
NOx emission reduces the escaping of ammonia rate, reduces station service power consumption rate, improves efficiency of generating unit.
2, it since the present invention uses cascade loop control, sprays ammonia flow set point correct circuit and ammonia amount feedforward control is returned
Road reduce the randomness of variation, the burning of coal in practical operation situation, etc. many uncertain and perturbations control is produced
Raw influence.
3, since the present invention is using integral separation control, when instrument is in maintenance process, into the deviation of integrating function block
Value switches to 0, and integral action stops, and prevents integral action from developing to saturation direction, is conducive to control loop and obtains preferably tune
Save quality
Detailed description of the invention
In order to more clearly explain the embodiment of the invention or the technical proposal in the existing technology, to embodiment or will show below
There is attached drawing needed in technical description to be briefly described, it should be apparent that, the accompanying drawings in the following description is only this
Some embodiments of invention for those of ordinary skill in the art without creative efforts, can be with
It obtains other drawings based on these drawings.
Fig. 1 is that the integral separation method of thermal power plant's denitration control system of the present invention realizes logic chart.
Label declaration:
1, minimum denitration efficiency control loop 2, integral separate control loops 3, spray ammonia flow set point correct circuit 4,
Jet flow amount feed forward control loop 102, the first deviation computing module 103, the first multiplication computing module 104, the first inertial delay
Module 105, small value selecting module 106, the second deviation computing module 107, the second additional calculation module 108, the second inertia
Postponement module 109, third inertial delay module 110, the 4th inertial delay module 111, the first additional calculation module 112,
First coefficient amplification module 113, selecting module 116, integration module 117, third additional calculation module 118, the second coefficient
Amplification module 119, third deviation computing module 120, the 4th additional calculation module 121, the 5th inertial delay module 122,
Fifth adding computing module 123, the 4th coefficient amplification module 124, the second multiplication computing module 125, function performance module
126, third coefficient amplification module 127, the 7th inertial delay module 128, the 6th inertial delay module 129, the 6th addition meter
Calculate module 130, the 5th coefficient amplification module 131, control module
Specific embodiment
The present invention will be further described in detail below with reference to the embodiments, following embodiment be explanation of the invention and
The invention is not limited to following embodiments.
Embodiment 1:
As shown in Figure 1, the control method that the integral of thermal power plant's denitration control system of the present embodiment is isolated, main following four
Part:
First part: minimum 1 part of denitration efficiency control loop.By (the i.e. denitration efficiency of denitration efficiency setting value 100%
Maximum value 100%) the first deviation computing module 102 is inputed to, by the output of the first deviation computing module 102 and entrance NOx
The first multiplication computing module 103 is given in measured value input respectively, and the output of the first multiplication computing module 103 is inputed to the first inertia
Postponement module 104, the output valve of the first inertial delay module 104 are to export the setting value of maximum NOx.
Second part: integral 2 part of separate control loops.The input of second inertial delay module 108 is to export the survey of NOx
Magnitude, and export to third inertial delay module 109, the output of third inertial delay module 109 to the 4th inertial delay module
110, the 4th inertial delay module 110 is exported to the first additional calculation module 111, and the input of the first additional calculation module 111 is also
Measured value including exporting NOx, and exporting to the first coefficient amplification module 112, the input of the second additional calculation module 107 are the
The output of one coefficient amplification module 112 and the measured value for exporting NOx, and the output valve of the second additional calculation module 107 is amendment
Outlet NOx measured value afterwards, the input of small value selecting module 105 are to export the setting value and outlet maximum NOx setting value of NOx,
The input of second deviation computing module 106 is the small output for being worth selecting module 105 and revised NOx measured value, and defeated respectively
Out to selecting module 113 and the second coefficient amplification module 118, the output of selecting module 113 to integration module 116, third addition meter
The input of module 117 is calculated as the output of integration module 116 and the output of the second coefficient amplification module 118, and third additional calculation
The output valve of module 117 is the spray ammonia corrected value of external loop.
At selecting module 113, when purging signal does not occur, the output valve of selecting module 113 is the calculating of the second deviation
The output valve of module 106；When outlet instruments purging signal comes, the output valve of selecting module 113 is 0, and integral action stops,
Prevent integral action from developing to saturation direction.
Above-mentioned revised NOx measured value is to pass through the 107, second to the 4th inertial delay mould of the second additional calculation module
What the corrective loop that block 108-110, the first additional calculation module 111 and coefficient amplification module 112 are formed obtained, using advanced stagnant
The corrective loop of post-compensation method, has the characteristics that fast response time, has modified into PID (operational loop of next link) and transports
The outlet NOx measured value of calculation, improves the dynamic characteristic of big inertia control object.
Part III: spray 3 part of ammonia flow set point correct circuit.The input of third deviation computing module 119 is entrance
NOx measured value and outlet NOx measured value, the input of the 4th additional calculation module 120 be the output of third additional calculation module 117 and
Third deviation computing module 119 exports, and the input of the second multiplication computing module 124 is the output of the 4th additional calculation module 120
With the output of function performance module 125, the input of function performance module 125 is the measured value of total fuel quantity, function performance module
125 output is theoretical ammonia flow calculated value, and the input of third coefficient amplification module 126 is the output of the second multiplier module,
The output of third coefficient amplification module 126 is the spray ammonia flow setting value of inner looping.Wherein, function performance module 125 is used to incite somebody to action
Fuel measurement is converted to corresponding flue gas flow.The output actual needs of third deviation computing module 119 is neutralized
NOx。
The effect of above-mentioned function performance module 125 is that fuel measurement is converted to corresponding flue gas flow, function
125 algorithm of functional module produces piecewise linear function.
Part IV: 4 part of jet flow amount feed forward control loop.The input of 5th inertial delay module 121 is entrance NOx survey
Magnitude, output and entrance NOx measured value of the input of fifth adding computing module 122 for the 5th inertial delay module 121, the 5th
Additional calculation module 122 is exported to the 4th coefficient amplification module 123；The input of 6th inertial delay module 128 is oxygen content, the
The input of six additional calculation modules 129 is the output and oxygen content of the 6th inertial delay module 128, and exports to the 5th coefficient and put
Big module 130；The input of control module 131 is the output of the 4th coefficient amplification module 123, the 5th coefficient amplification module 130
It exports, the output of the output of third coefficient amplification module 126 and the 7th inertial delay module 127, the output of control module 131 is
It sprays ammonia flow and controls signal.
First to the 7th inertial delay module is respectively used to make input signal after inertial delay module, converts signal
Slowly, and there are the delay of certain time, transmission function are as follows:, wherein G (s) is that transmission function is description linear system dynamic characteristic
Basic mathematical tool, Y (s) be output laplace transform, X (s) be input quantity laplace transform, k is inertia rings
The proportionality coefficient of section, T1, T2 are the time constant of property link, and S is complex frequency domain.
In above-mentioned 2 part of integral separate control loops, because being object with big inertia, an inertial delay module delays are rung
Not enough slowly it should need three inertial delay links while act on, generate the signal intensity for inputting inertial delay module certain
Delay, so as to improve the dynamic characteristic of big inertia control object.
First to the 6th additional calculation module 129 is respectively used to calculate the sum of two input values, and calculation formula is that A=is defeated
Enter 1 gain of value 1* input value+2 gain of input value 2* input value；First and second multiplication computing module 124 is defeated for calculating two
Enter the product of value, calculation formula is A=input value 1* input value 2；The range of 2 gain of 1 gain of input value and input value be respectively 0 to
2。
First to the 5th coefficient amplification module 130 is respectively used to zoom in and out input value according to gain, calculation formula A
The * input value gain of=input value；The range of input value gain is 0 to 2.
Control module 131 is for providing proportional plus integral plus derivative controller function, transmission function are as follows: wherein, G (S) is to pass
Delivery function is the basic mathematical tool for describing linear system dynamic characteristic, and U (S) is the laplace transform of output quantity, and E (S) is
The laplace transform of input quantity, Kp are the proportionality coefficient in control module 131, and Ti is the time of integration in control module 131,
Td is the derivative time in control module 131, and S is complex frequency domain.
Integration module 116 is used to calculate the integral of input value.
First is used to calculate the arithmetical difference of two input values to third deviation computing module, and calculation formula is A=input value
1- input value 2.
Small value selecting module 105 is used to carry out small selection to two values of input, when input value 1 is greater than input value 2, mould
Block output is input value 2；When input value 1 is less than input value 2, module output is input value 1.
The principle of the present invention is as follows:
Since NOx is slower process with reacting for NH3, in order to improve the regulating effect of control system, denitration machine is needed
Reason is to design control system.In flue gas, NOx mainly exists in the form of NO, and relevant spray can be obtained according to quantity such as following formula:
Wherein, QLFlow, units/kg/h are filled for theory spray ammonia.QgFor flue gas flow rate, unit Nm3/h。[NOx]inFor denitration system
System inlet flue gas NOx content, unit mg/Nm3。[NOx]outFor denitration outlet smoke NOx content, unit mg/Nm3。17/46
It is NH3The ratio between with the molecular weight of NOx.
If above flue gas flow measurement point is not installed or its corresponding measuring point error is larger, coal weighing can be passed through
It obtains, then above formula is variable are as follows:
Wherein, QcFor practical Coal-fired capacity, unit t/h.Corresponding function f (Qc) by boiler design specification or can adopt
It is calculated with following formula:
f(Qc)=1000*Vgy*Qc
Wherein, VgyFor the dry flue gas flow caused by every kg coal that burns, unit Nm3/kg.Corresponding calculation formula is as follows:
Vgy=0.01866* (Car+0.375Sar)+(0.79V°+0.008*Nar)+(α-1)V°
Wherein, Car、Sar、NarThe respectively composition quantities such as carbon, sulphur, nitrogen of As-received, it is related with the coal of burning, it is single
Position %.α is excess air coefficient, generally takes the constant between 1.1-1.4.V ° is theoretical air requirement needed for every burning 1kg coal,
Unit Nm3/kg.Corresponding calculation formula is as follows:
V °=0.0889* (Car+0.375Sar)+0.2643Har-0.0333Oar
Wherein, Har、OarThe respectively composition quantities such as hydrogen, oxygen of As-received, unit % related with the coal of burning.
If only calculating resulting ammonia spraying amount by above-mentioned theory, the ammonia spraying amount setting value of control loop can be used as, into
Enter single loop PID control, to adjust spray ammonia flow, finally controls the discharge of NOx.This control program does not consider practical transport
The randomness of variation, the burning of coal in market condition, etc. many uncertain and perturbations, necessarily cannot achieve real closed loop
Control.Therefore, the present invention proposes that outlet NOx, which is introduced another PID, carries out closed-loop corrected spray ammonia flow circuit.It need to thus adopt
With corresponding serials control circuit, control logic figure such as Fig. 1.
As shown in Figure 1, control loop is made of major-minor PID, external loop is to control outlet NOx in setting value environs
Fluctuation；Inner looping is by spray ammonia regulating valve to control spray ammonia flow；Wherein minimum denitration efficiency control loop 1 limits outlet
The maximum value of NOx setting value ensure that the efficiency of out of stock control loop.The reason calculated in spray ammonia flow set point correct circuit 3
The spray ammonia flow setting value for generating inner looping is superimposed with the spray ammonia corrected value of external loop by spray ammonia flow.And theoretical ammonia flow
Calculating is to be obtained by burning coal amount via function performance module 125.
Since the instrument of measurement smoke components often enters maintenance, purging working condition, and need to be blown every 2 hours probes
It sweeps once, each duration is 7-10 minutes.During actual engineering design control system, it is necessary to consider under this situation
Bring integrates saturated phenomenon.
As shown in Figure 1, the numerical value of NOx is constant to lead to occur PID entrance for a long time in order to prevent in meter probe purge
Deviation exists, and uses in control loop and integrates isolated method.It is realized in integral separate control loops 2 shown in Fig. 1,
This design scheme is conducive to control loop and obtains better regulation quality, reduces amount of ammonia slip to a certain extent.In addition, In
In jet flow amount feed forward control loop 4, lead-lag compensation tache is used with paralleling model and introduces system, it is big mainly for improving
The dynamic characteristic of inertia control object.Furthermore, it is contemplated that the production quantity of NOx is related with the oxygen content in flue gas, in control loop
In the conduct of oxygen amount feedforward is also introduced to control system, to eliminate the portion disturbances bring NOx in combustion process in advance
Variation.
In addition, it should be noted that, the specific embodiments described in this specification, the shape of parts and components are named
Title etc. can be different.The equivalent or simple change that all structure, feature and principles described according to the invention patent design are done, is wrapped
It includes in the scope of protection of the patent of the present invention.Those skilled in the art can be to described specific implementation
Example is done various modifications or additions or is substituted in a similar manner, and without departing from structure of the invention or surmounts this
Range as defined in the claims, is within the scope of protection of the invention.
Claims (8)
1. the isolated control method of the integral of a kind of thermal power plant's denitration control system, it is characterized in that: including the following steps:
S1. minimum denitration efficiency control: denitration efficiency setting value is inputed into the first deviation computing module, the first deviation is calculated
The output of module and the measured value of entrance NOx input to the first multiplication computing module respectively, by the defeated of the first multiplication computing module
The first inertial delay module is inputed to out, and the output valve of the first inertial delay module is to export the setting value of maximum NOx；
S2. integral separation control: the input of the second inertial delay module is the measured value for exporting NOx, and is exported to third inertia
Postponement module, third inertial delay module are exported to the 4th inertial delay module, and the 4th inertial delay module, which is exported to first, to be added
Method computing module, the input of the first additional calculation module further includes the measured value for exporting NOx, and exports to the first coefficient and amplify mould
Block, the input of the second additional calculation module are the output of the first coefficient amplification module and the measured value for exporting NOx, and the second addition
The output valve of computing module be revised outlet NOx measured value, it is small value selecting module input be outlet NOx setting value with
Maximum NOx setting value is exported, the input of the second deviation computing module is the output and revised NOx measurement of small value selecting module
Value, and exported respectively to selecting module and the second coefficient amplification module, selecting module is exported to integration module, third additional calculation
The input of module is the output of integration module and the output of the second coefficient amplification module, and the output valve of third additional calculation module
For the spray ammonia corrected value of external loop；
S3. spray ammonia flow set point correct: the input of third deviation computing module is entrance NOx measured value and outlet NOx measurement
Value, the input of the 4th additional calculation module are the output of third additional calculation module and the output of third deviation computing module, and second multiplies
The input of method computing module be the 4th additional calculation module output and function performance module output, function performance module it is defeated
Enter for the measured value of total fuel quantity, export as theoretical ammonia flow calculated value, the input of third coefficient amplification module is second to multiply
The output of method module, the output of third coefficient amplification module are the spray ammonia flow setting value of inner looping；Wherein, the function performance
Module is used to fuel measurement being converted to corresponding flue gas flow；
S4. jet flow amount feedforward control: the input of the 5th inertial delay module is entrance NOx measured value, fifth adding computing module
Input be the 5th inertial delay module output and entrance NOx measured value, fifth adding computing module export to the 4th coefficient
Amplification module；The input of 6th inertial delay module is oxygen content, and the input of the 6th additional calculation module is the 6th inertial delay
The output and oxygen content of module, and export to the 5th coefficient amplification module；The input of control module is the 4th coefficient amplification module
Output, the 5th coefficient amplification module output, the output of third coefficient amplification module and the output of the 7th inertial delay module,
The output of control module is that spray ammonia flow controls signal；
In the step S2, at selecting module, when outlet instruments purging signal comes, the output valve of selecting module is 0,
When purging signal does not occur, the output valve of selecting module is the output valve of the second deviation computing module；
The calculating of first deviation computing module large deviations is the difference of " denitration efficiency setting value " Yu constant 1, " the 7th inertial delay
The input value of module " is exactly to spray ammonia flow.
2. the isolated control method of the integral of thermal power plant's denitration control system according to claim 1, it is characterized in that: described
Step S1 in, denitration efficiency setting value be 100%.
3. the isolated control method of the integral of thermal power plant's denitration control system according to claim 1, it is characterized in that: described
Step S3 in, the output of third deviation computing module is the NOx that is neutralized of actual needs.
4. the isolated control method of the integral of thermal power plant's denitration control system according to claim 1, it is characterized in that: described
The first to the 7th inertial delay module be respectively used to make signal transformation slowly, and have the delay of certain time, transmission function are as follows:Wherein, it is the basic number for describing linear system dynamic characteristic that G (s), which is transmission function,
Tool, Y (s) are the laplace transform of output, and X (s) is the laplace transform of input quantity, and k is the ratio of inertial element
Coefficient, T1, T2 are the time constant of property link, and S is complex frequency domain.
5. the isolated control method of the integral of thermal power plant's denitration control system according to claim 1, it is characterized in that: described
The first to the 6th additional calculation module be respectively used to calculate the sum of two input values, calculation formula is that A=input value 1* is defeated
Enter 1 gain of value+2 gain of input value 2* input value；First and second multiplication computing module is used to calculate the product of two input values, meter
Calculation formula is A=input value 1* input value 2；The range of 2 gain of 1 gain of input value and input value is respectively 0 to 2.
6. the isolated control method of the integral of thermal power plant's denitration control system according to claim 1, it is characterized in that: described
The first to the 5th coefficient amplification module be respectively used to zoom in and out input value according to gain, calculation formula be A=input value *
Input value gain；The range of input value gain is 0 to 2.
7. the isolated control method of the integral of thermal power plant's denitration control system according to claim 1, it is characterized in that: described
Control module for providing proportional plus integral plus derivative controller function, transmission function are as follows:Wherein, it is description linear system dynamic that G (S), which is transmission function,
The basic mathematical tool of characteristic, U (S) are the laplace transform of output quantity, and E (S) is the laplace transform of input quantity, and Kp is
Proportionality coefficient in control module, Ti are the time of integration in control module, and Td is the derivative time in control module, and S is multiple
Frequency domain.
8. the isolated control method of the integral of thermal power plant's denitration control system according to claim 1, it is characterized in that: described
Integration module be used to calculate the integral of input value；First is used to calculate the arithmetic of two input values to third deviation computing module
Difference, calculation formula are A=input value 1- input value 2；Small value selecting module is used to carry out small selection to two values of input, when defeated
When entering value 1 greater than input value 2, module output is input value 2；When input value 1 is less than input value 2, module output is input value
1。
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610646917.8A CN106268239B (en) | 2016-08-05 | 2016-08-05 | The isolated control method of the integral of thermal power plant's denitration control system |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610646917.8A CN106268239B (en) | 2016-08-05 | 2016-08-05 | The isolated control method of the integral of thermal power plant's denitration control system |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN106268239A CN106268239A (en) | 2017-01-04 |
| CN106268239B true CN106268239B (en) | 2019-11-26 |
Family
ID=57667041
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201610646917.8A Active CN106268239B (en) | 2016-08-05 | 2016-08-05 | The isolated control method of the integral of thermal power plant's denitration control system |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN106268239B (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107803114A (en) * | 2017-12-04 | 2018-03-16 | 烟台龙源电力技术股份有限公司 | A kind of denitration control system and its control method and control device |
| CN111794820A (en) * | 2020-06-09 | 2020-10-20 | 同济大学 | Organic Rankine cycle system |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107185367A (en) * | 2017-06-09 | 2017-09-22 | 青岛艳阳天环保有限公司 | SNCR metered dispensing units and method that concentration based on ammonia is quantitatively coupled |
| CN108126517B (en) * | 2017-12-22 | 2019-08-02 | 大唐洛阳首阳山发电有限责任公司 | A kind of hydrolysis of power plant is for ammonia denitrating system and its control method |
| CN108187492B (en) * | 2018-01-17 | 2020-06-02 | 广东电科院能源技术有限责任公司 | Ammonia spraying control method and device |
| CN109395549B (en) * | 2018-11-26 | 2020-04-21 | 广东电科院能源技术有限责任公司 | Ammonia injection control method and device and computer readable storage medium |
| CN111752143B (en) * | 2020-03-21 | 2022-10-25 | 哈尔滨工程大学 | Adjustable inertia integral control method |
| CN113406881B (en) * | 2021-04-12 | 2023-09-08 | 北京北方华创微电子装备有限公司 | Semiconductor heat treatment equipment and control method for oxygen content in loading and unloading chamber thereof |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104826493A (en) * | 2015-04-23 | 2015-08-12 | 华北电力大学（保定） | Control method for selective catalytic reduction flue gas denitrification system |
| CN105045089A (en) * | 2015-06-19 | 2015-11-11 | 大唐华银电力股份有限公司金竹山火力发电分公司 | Boiler denitration control method based on outlet NOx content control and system thereof |
| CN105786035A (en) * | 2016-03-29 | 2016-07-20 | 东南大学 | Thermal power set SCR denitration optimization control system based on heuristic prediction control technology |
| CN105797576A (en) * | 2016-04-15 | 2016-07-27 | 中国大唐集团科学技术研究院有限公司西北分公司 | Coal-fired unit denitration ammonia spraying control method |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP3544716B2 (en) * | 1994-10-26 | 2004-07-21 | バブコック日立株式会社 | Method and apparatus for controlling ammonia injection amount in denitration apparatus |
-
2016
- 2016-08-05 CN CN201610646917.8A patent/CN106268239B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104826493A (en) * | 2015-04-23 | 2015-08-12 | 华北电力大学（保定） | Control method for selective catalytic reduction flue gas denitrification system |
| CN105045089A (en) * | 2015-06-19 | 2015-11-11 | 大唐华银电力股份有限公司金竹山火力发电分公司 | Boiler denitration control method based on outlet NOx content control and system thereof |
| CN105786035A (en) * | 2016-03-29 | 2016-07-20 | 东南大学 | Thermal power set SCR denitration optimization control system based on heuristic prediction control technology |
| CN105797576A (en) * | 2016-04-15 | 2016-07-27 | 中国大唐集团科学技术研究院有限公司西北分公司 | Coal-fired unit denitration ammonia spraying control method |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN107803114A (en) * | 2017-12-04 | 2018-03-16 | 烟台龙源电力技术股份有限公司 | A kind of denitration control system and its control method and control device |
| CN107803114B (en) * | 2017-12-04 | 2020-06-16 | 烟台龙源电力技术股份有限公司 | Denitration control system and control method and control device thereof |
| CN111794820A (en) * | 2020-06-09 | 2020-10-20 | 同济大学 | Organic Rankine cycle system |
| CN111794820B (en) * | 2020-06-09 | 2021-09-03 | 同济大学 | Organic Rankine cycle system |
Also Published As
| Publication number | Publication date |
|---|---|
| CN106268239A (en) | 2017-01-04 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| CN106268239B (en) | The isolated control method of the integral of thermal power plant's denitration control system | |
| CN107561941B (en) | Full-working-condition standard-reaching emission control method for thermal power generating unit denitration system | |
| CN107526292B (en) | A method of the regulation ammonia spraying amount based on inlet NOx concentration prediction | |
| CN105892504A (en) | Thermal power plant denitration ammonia supplying automatic return circuit control method and system | |
| CN104826493B (en) | A kind of control method of selective catalytic reduction flue gas denitrification system | |
| CN107243257B (en) | It is suitble to the intelligence spray ammonia control system of full load | |
| CN107544288B (en) | Denitration optimization control method and system | |
| CN110501901B (en) | SCR ammonia injection regulation optimization method based on full-load accurate denitration requirement | |
| CN105786035B (en) | Fired power generating unit SCR denitration Optimal Control System based on heuristic Prediction and Control Technology | |
| CN105797576B (en) | Denitration ammonia injection control method for coal-fired unit | |
| US9631776B2 (en) | Model-based controls for selective catalyst reduction systems | |
| RU2486405C1 (en) | Method and device to control steam temperature for steam power plant | |
| CN101842148A (en) | Adaptive control system for reagent distribution control in scr reactors | |
| CN105404145A (en) | Denitration novel cascade control method based on index prediction and time-lag pre-estimation compensation | |
| JP6761368B2 (en) | Denitration control device and denitration control method | |
| CN114307627B (en) | Denitration adjusting method based on theoretical ammonia consumption | |
| CN103977705A (en) | Reducing agent metering for cement clinker production line SNCR flue gas denitration and control system and method thereof | |
| JP2015048975A (en) | Denitrification controller | |
| US20170167341A1 (en) | System and method for emission control in power plants | |
| CN106474887B (en) | A kind of W flame Denitration in Boiler system | |
| CN111111430B (en) | SCR denitration regulation control method for urea pyrolysis furnace | |
| CN109046021A (en) | A kind of SCR system of strong adaptive ability accurately sprays ammonia control method | |
| US20140309798A1 (en) | Method and device for controlling a temperature of steam for a steam power plant | |
| CN107158935A (en) | SCR denitration is controlled to be pyrolyzed the method and device of furnace temperature | |
| CN109433003A (en) | The control method and device of denitration control system ammonia spraying amount |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| C06 | Publication | ||
| PB01 | Publication | ||
| C10 | Entry into substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |