CN106569517A - Coking waste-gas desulfurization process optimized control method - Google Patents

Coking waste-gas desulfurization process optimized control method Download PDF

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CN106569517A
CN106569517A CN201610961095.2A CN201610961095A CN106569517A CN 106569517 A CN106569517 A CN 106569517A CN 201610961095 A CN201610961095 A CN 201610961095A CN 106569517 A CN106569517 A CN 106569517A
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desulfurization
value
control method
determined
current working
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CN106569517B (en
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王学雷
李亚宁
谭杰
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Institute of Automation of Chinese Academy of Science
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Institute of Automation of Chinese Academy of Science
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    • GPHYSICS
    • G05CONTROLLING; REGULATING
    • G05DSYSTEMS FOR CONTROLLING OR REGULATING NON-ELECTRIC VARIABLES
    • G05D21/00Control of chemical or physico-chemical variables, e.g. pH value
    • G05D21/02Control of chemical or physico-chemical variables, e.g. pH value characterised by the use of electric means
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01DSEPARATION
    • B01D53/00Separation 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
    • B01D53/34Chemical or biological purification of waste gases
    • B01D53/46Removing components of defined structure
    • B01D53/48Sulfur compounds
    • B01D53/50Sulfur oxides
    • B01D53/501Sulfur oxides by treating the gases with a solution or a suspension of an alkali or earth-alkali or ammonium compound
    • GPHYSICS
    • G05CONTROLLING; REGULATING
    • G05BCONTROL OR REGULATING SYSTEMS IN GENERAL; FUNCTIONAL ELEMENTS OF SUCH SYSTEMS; MONITORING OR TESTING ARRANGEMENTS FOR SUCH SYSTEMS OR ELEMENTS
    • G05B13/00Adaptive control systems, i.e. systems automatically adjusting themselves to have a performance which is optimum according to some preassigned criterion
    • G05B13/02Adaptive control systems, i.e. systems automatically adjusting themselves to have a performance which is optimum according to some preassigned criterion electric
    • G05B13/04Adaptive control systems, i.e. systems automatically adjusting themselves to have a performance which is optimum according to some preassigned criterion electric involving the use of models or simulators
    • G05B13/042Adaptive control systems, i.e. systems automatically adjusting themselves to have a performance which is optimum according to some preassigned criterion electric involving the use of models or simulators in which a parameter or coefficient is automatically adjusted to optimise the performance
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01DSEPARATION
    • B01D2251/00Reactants
    • B01D2251/20Reductants
    • B01D2251/206Ammonium compounds
    • B01D2251/2062Ammonia
    • BPERFORMING OPERATIONS; TRANSPORTING
    • B01PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
    • B01DSEPARATION
    • B01D2258/00Sources of waste gases
    • B01D2258/02Other waste gases
    • B01D2258/0283Flue gases

Abstract

The present invention relates to a coking waste-gas desulfurization process optimized control method applied to a desulfurization and denitrification integrated process device. The method includes the following steps that: a current working condition is determined through using a fuzzy identification algorithm according to flue gas temperature, flue gas flow rate, flue gas oxygen content and sulfur dioxide concentration at the entrance of the desulfurization and denitrification integrated process device; the optimal pH value of a desulfurization absorption liquid under the current working condition is determined by using a variable step size progressive decrease method; the amount of ammonia compensation under the current working condition is determined through using a neural network model; the amount of ammonia control under the current working condition is determined through using an inner membrane control method and according to the sulfur dioxide concentration at the entrance of the desulfurization and denitrification integrated process device; and the pH value of the desulfurization absorption liquid is controlled according to the amount of ammonia compensation and the amount of ammonia control and based on the optimal pH value of the desulfurization absorption liquid. With the coking waste-gas desulfurization process optimized control method provided by the embodiments of the invention adopted, the fastness and accuracy of control are improved, and the desulfurization and denitrification integrated process device can operate under a most economical and environmentally friendly state, and the operating cost of the desulfurization and denitrification integrated process device can be reduced.

Description

Coking exhuast gas desulfurization procedure optimization control method
Technical field
The present invention relates to technical field of industrial control, more particularly to a kind of coking exhuast gas desulfurization procedure optimization control method.
Background technology
Sulfur dioxide and nitrogen oxides are main atmosphere pollutions, are the principal elements for affecting air quality.China is Maximum coking manufacturing country in the world, due to due to history, for a long time, domestic coking industry coking flue gas is all without desulfurization Denitration process and be directly discharged into air, become one of important source of atmospheric pollution.Formal enforcement from 1 day January in 2015《Refining Coking pollutant emission standard》The discharge index of sulfur dioxide and nitrogen oxides to coking industry proposes strict and clear and definite Quantization require.
Certain coke-oven plant takes the lead in using the desulfurization of wet-type ammonia forced turbulent in the country and forces oxidation carbamide denitrification integral work Process and equipment (abbreviation desulfurization and denitrification integral process device) is used as a kind of important means for processing coking industry flue gas.The technique dress Putting the equipment for including has air-introduced machine, heat recovery boiler, booster fan, desulfurizing tower, denitrating tower, ammonium sulfate circulating slot, solid-liquid point From the relevant devices such as device, carbamide dissolving tank, pipeline and donkey pump, Detection of Process Parameters device, procedure parameter adjusting means, DCS (Distributed Control System, dcs or Distributed Control System are a kind of computer controls to system System) etc. (as shown in Figure 1).
The technical process of above-mentioned process unit is as follows:
Flue gas Jing air-introduced machines in process of coking send into heat recovery boiler, and flue-gas temperature is down to 160 DEG C of left sides by 300 DEG C The right side, through booster fan, converged before into desulfurizing tower with ozone input channel, and the part NO in flue gas is quickly anti-with ozone NO should be generated2.Flue gas enters desulfurizing tower enriching section, through spray, washing, is cooled to 60 DEG C or so, then Jing gas caps enter into it is de- The absorber portion of sulfur tower, the desulfurization absorbing liquid counter current contacting with top spray;SO in flue gas2It is anti-with the ammonium sulfite in absorbent Ammonium bisulfite, SO should be generated2It is able to removing purification.The liquid of absorber portion bottom is back to the reservoir of desulfurization tower bottom.For Recover the absorbability of absorbing liquid, need to supplement ammonia.Desulfurizing tower top spray technique keeps the liquid level of reservoir in reasonable model In enclosing.Liquid storage trench bottom blasts air, by the part (NH in reservoir4)2SO3It is oxidized to (NH4)2SO4, for sulphuric acid in enriching section Spray-the evaporation-concentration of ammonium and subsequent treatment.
Flue after desulfurization is connected with ozone input channel, the ozone mixed in 60 DEG C or so of flue gas to after desulfurization, Part NO in flue gas generates NO with ozone fast reaction2, denitrating tower bottom is subsequently entered, the carbamide with denitrating tower top spray Solution counter current contacting, NO, NO2There is reduction reaction with the carbamide in solution and generate N2、CO2And H2O, completes denitration.Reach environmental protection The flue gas of discharge standard enters air at the top of denitrating tower, so as to complete whole processing procedures of flue gas.
Said process can be divided into two subprocess, i.e. sweetening process and denitrification process.For sweetening process, to obtain Higher desulfuration efficiency, the most important pH value for seeking to absorbing liquid in control tower, because it is to SO in flue gas in tower2Absorption There is most direct impact.And at this stage there is following Railway Project in the control of its sweetening process:1st, controlled variable is directly net SO in flue gas after change2Concentration, and (proportional integral differential control, P represents ratio, and I represents integration, D only with simple PID Represent differential) control, overshoot is very big with delayed, and stability and the accuracy for controlling cannot be ensured completely;2nd, process of coking has Sufficiently complex working condition, causes its multi-state characteristic, the index error such as the temperature of flue gas, flow, concentration under different operating modes It is different very big;3rd, the requirement that pH value is only defined in technological requirement is 4.5-6.5, and scope is excessive and does not account for different flue gas conditions Under difference, cause a large amount of wastes even the escaping of ammonia of raw material, be unfavorable for economy, the ring of desulfurization and denitrification integral process device Protect operation.
In view of this, it is special to propose the present invention.
The content of the invention
In order to solve the problems referred to above of the prior art, it has been and has solved how to guarantee sweetening process in most economical environmental protection Under the conditions of the technical problem that steadily carries out and a kind of coking exhuast gas desulfurization procedure optimization control method is provided.
To achieve these goals, there is provided technical scheme below:
A kind of coking exhuast gas desulfurization procedure optimization control method, the optimal control method is applied to desulfurization and denitrification integral Process unit, the control method includes:
Flue-gas temperature, flue gas flow according to the desulfurization and denitrification integral process device portal, oxygen content of smoke gas and two Sulfur oxide concentration, using fuzzy recognition algorithm, determines current working;
The method successively decreased using variable step, determines the optimum pH value of the desulfurization absorbing liquid under the current working;
The ammonia compensation dosage under the current working is determined using neural network model;
Based on the sulfur dioxide concentration that the desulfurization and denitrification integral process device is exported, determined using inner membrance control method Ammonia controlled quentity controlled variable under the current working;
Based on the optimum pH value of the desulfurization absorbing liquid, control with reference to the ammonia compensation dosage and the ammonia controlled quentity controlled variable Make the pH value of the desulfurization absorbing liquid.
Preferably, flue-gas temperature, flue gas flow, the flue gas according to the desulfurization and denitrification integral process device portal Oxygen content and sulfur dioxide concentration, using fuzzy recognition algorithm, determine current working, specifically include:
The flue-gas temperature, the flue gas flow, the oxygen content of smoke gas and the sulfur dioxide concentration are set as into shape State vector;
Clustered based on the state vector, determined sorting criterion, and state set is obtained by the sorting criterion;
By weighted fuzzy identification algorithm, the fuzzy membership relation square of the state vector and the state set is obtained Battle array;
Based on the fuzzy membership relational matrix, the current working is determined by maximum membership grade principle.
Preferably, the method that the employing variable step successively decreases, determines the optimum of the desulfurization absorbing liquid under the current working PH value, specifically includes:
The optimum pH value of the desulfurization absorbing liquid under the current working is determined according to following formula using variable step diminishing method:
In formula, the n represents iterationses, n>=2;The PHnRepresent pH value during nth iteration;The PHn-1Table Show pH value during (n-1)th iteration;The WmaxWith the WminThe maximum and minimum value of step-length is represented respectively;The knRepresent and work as Front iterationses;The kmaxRepresent maximum iteration time;T0 is represented after the desulfurization and denitrification integral process device stable operation Initial time;The P (t0) represents the desulfurization and denitrification integral process device exiting flue gas sulfur dioxide concentration value;It is described PLimitRepresent the sulfur dioxide concentration value for limiting;The T represents the sampling period;The ε represents termination threshold value.
Preferably, the neural network model is multiple radial basis function neural networks model in parallel.
Preferably, the sulfur dioxide concentration exported based on desulfurization and denitrification integral process device, using inner membrance control Method determines the ammonia controlled quentity controlled variable under current working, specifically includes:
Desulphurization denitration process transfer function model is set up using closed loop two channel relay feedback frequency domain identification method;
Using the desulphurization denitration process transfer function model, exported based on the desulfurization and denitrification integral process device Sulfur dioxide concentration, using internal model control method, determines ammonia controlled quentity controlled variable.
Preferably, the employing closed loop two channel relay feedback frequency domain identification method come set up desulphurization denitration process transmission Function model, specifically includes:
According to the ammonia addition during the desulphurization denitration and the output of limit cycles oscillations, estimated using Fourier transform Meter obtains the frequency response of the desulphurization denitration process and estimates;
Estimated according to the frequency response of the sweetening process, using identification algorithm and nonlinear optimization algorithm, estimated de- Sulfur denitrification process transfer function model.
Preferably, it is described to be estimated according to the frequency response of the sweetening process, calculated using identification algorithm and nonlinear optimization Method, estimates desulphurization denitration process transfer function model, specifically includes:
Estimated according to the frequency response of sweetening process, be defined below object function:
Wherein, the ciRepresent weights;The m represents selected phase place number;It is describedRepresent by the dual pathways after Electrical characteristics test, in ωiUnder Multiple points frequency response estimate;G (the j ω0) represent frequency characteristic to be estimated;The J tables Show the object function;
Based on object function, using identification algorithm, transmission function is obtained;
Using nonlinear optimization algorithm, the constant in the transmission function is solved, so that it is determined that the desulphurization denitration process Transfer function model.
Preferably, the transmission function adds delayed transmission function for one order inertia;
The employing nonlinear optimization algorithm, solves the constant in the transmission function, so that it is determined that the desulphurization denitration Process transfer function model, specifically includes:Using nonlinear optimization algorithm, solve the proportionality constant in the transmission function, be used to Property constant and hysteresis constant, so that it is determined that the one order inertia of the desulphurization denitration process adds delayed transfer function model.
It is excellent that the embodiment of the present invention provides a kind of coking exhuast gas desulfurization process for being applied to desulfurization and denitrification integral process device Change control method.The method includes:Flue-gas temperature, flue gas flow according to desulfurization and denitrification integral process device portal, flue gas Oxygen content and sulfur dioxide concentration, using fuzzy recognition algorithm, determine current working;The method successively decreased using variable step, it is determined that The optimum pH value of the desulfurization absorbing liquid under current working;The ammonia compensation dosage under current working is determined using neural network model; Based on the sulfur dioxide concentration that desulfurization and denitrification integral process device is exported, determined under current working using inner membrance control method Ammonia controlled quentity controlled variable;Based on the optimum pH value of desulfurization absorbing liquid, desulfurization absorption is controlled with reference to ammonia compensation dosage and ammonia controlled quentity controlled variable The pH value of liquid.The embodiment of the present invention as controlled variable, ties pH value using the internal model control with feedforward neural network compensation Structure, substantially increases the rapidity and accuracy of control, it is ensured that the SO2 contents control of flue gas is in the case where index is limited;Walked using becoming The long strategy for successively decreasing change PH setting values is optimized to sweetening process, and SO2 concentration of flue gas can be made to reach under restriction index, also Ammonia consumption can be minimized, it is to avoid the phenomenon of the escaping of ammonia occurs, and makes desulfurization and denitrification integral process plant running most In the state of economic and environment-friendly, the control and optimization of sweetening process is realized, reduce operating cost.
Description of the drawings
Fig. 1 is the schematic diagram of desulfurization and denitrification integral process device;
Fig. 2 is the schematic flow sheet of the coking exhuast gas desulfurization procedure optimization control method according to the embodiment of the present invention;
Fig. 3 is the structural representation of the closed loop two channel relay feedback according to the embodiment of the present invention;
Fig. 4 is the structural representation of the two channel relay according to the embodiment of the present invention.
Specific embodiment
With reference to the accompanying drawings describing the preferred embodiment of the present invention.It will be apparent to a skilled person that this A little embodiments are used only for explaining the know-why of the present invention, it is not intended that limit the scope of the invention.
The basic thought of the embodiment of the present invention is:Using desulfurization absorbing liquid pH value as controlled variable, ammonia spirit adds and becomes a mandarin Amount adopts the internal model control structure with feedforward compensation as control variable, meanwhile, by corresponding optimisation strategy, control is de- The pH value of sulfur absorbing liquid, finds optimum pH value under current working, so as to ensure desulfurization and denitrification integral process device most economical Steadily transport under the condition (sulfur dioxide concentration is in indication range and desulfurization absorbing liquid pH value is in neutral range for outlet) of environmental protection OK.
The embodiment of the present invention proposes a kind of coking exhuast gas desulfurization procedure optimization control method.The method is applied to desulphurization denitration Integral process device, as shown in Fig. 2 the method can include:
S100:Flue-gas temperature, flue gas flow, oxygen content of smoke gas and two according to desulfurization and denitrification integral process device portal Sulfur oxide concentration, using fuzzy recognition algorithm, determines current working.
Sweetening process is divided into different operating modes, such as operating mode S1, operating mode S2, operating mode S3 by this step.Wherein, operating mode S1 can be with It is dense including first entrance flue-gas temperature, first entrance flue gas flow, first entrance oxygen content of smoke gas and first entrance sulfur dioxide Degree.Operating mode S2 can include that second entrance flue-gas temperature, second entrance flue gas flow, second entrance oxygen content of smoke gas and second enter Mouth sulfur dioxide concentration.By that analogy, it may be determined that other operating modes.The embodiment of the present invention replaces operating mode with classification code name. The flow velocity of flue gas, grey density characteristics are different under different operating modes, and specific category number is depending on practical situation.
Above-mentioned fuzzy recognition algorithm is preferably weighted fuzzy identification algorithm.
By taking weighted fuzzy identification algorithm as an example, can include the step of determine current working:
S101:By the flue-gas temperature of desulfurization and denitrification integral process device portal, flue gas flow, oxygen content of smoke gas and dioxy Change sulphur concentration and be set as state vector.
S102:Cluster is carried out based on state vector and determines sorting criterion, state set is obtained by sorting criterion.
This step is clustered state vector as state sample collection.Clustering method can be calculated for K- averages etc. Method.
Describe cluster process in detail by taking k- means clustering algorithms as an example below.
The individual objects of K (it takes positive integer) are first randomly selected as initial cluster centre.Then, calculate each object with it is each The distance between individual seed cluster centre, distributes to each object apart from its nearest cluster centre.So constantly repeat, directly To meeting end condition.
Using cluster result as sorting criterion, namely the foundation of setting operating mode species.For example, if current historical data 4 classes are divided into by clustering algorithm, then can determine that total operating mode classification is S1, S2, S3, S4Class.This step just operating mode can be divided into S1, S2... class, obtain state set S, S={ S1, S2……Sn}.Divided by operating mode and recognition methodss, according to cigarette under different operating modes The difference of gas characteristic " divides and rule control problem ".
S103:By weighted fuzzy identification algorithm, the fuzzy membership relational matrix of state vector and state set is obtained.
As an example, fuzzy membership relational matrix can be as follows:
Wherein, in formula, rijR{ei, sj, 0≤rij≤ 1 (i, j=1,2,3 ... n) represent the state quilt in state vector It is chosen as SjThe probability of operating mode;λRRepresent the probability function of state vector and state set.Define ri=w1×r1j+w2×r2j+...+wn ×rnj, wherein w1, w2 ... wn represents weight.
S104:Based on fuzzy membership relational matrix, current working is determined by maximum membership grade principle.
Describe the process for determining operating mode in detail with a preferred embodiment below.
Setting state vector E={ e1, e2, e3, e4, in formula, e1To e4Entrance flue gas temperature, inlet flue gas stream are represented respectively Speed, entrance SO2Concentration and inlet flue gas oxygen content.
Sorting criterion is determined based on the cluster of state sample collection, state set S is obtained by sorting criterion;Operating mode is divided into S1, S2, S3, S4Class.S={ S1, S2, S3, S4}。
By weighted fuzzy identification, the fuzzy membership relational matrix R of state vector and state set is obtained, i.e.,:
In formula, rijR{ei, sj, 0≤rij≤ 1 (i, j=1,2,3,4) represents the e in state vectoriDimension index quilt It is chosen as SjThe probability of operating mode;λRRepresent the probability function of state vector and state set.Define ri=w1×r1j+w2×r2j+w3×r13 +wn×rnj(wherein w represents weight, it is preferable that can respectively take 0.15,0.1,0.7,0.05) for the state belong to SjOperating mode it is general Rate.
Based on state vector and the fuzzy membership relational matrix R of state set, can determine by maximum membership grade principle Current working.
For example, compare current state and the different degrees of membership of operating mode 1,2,3,4,5 be respectively 0.2,0.3,0.4, 0.5th, 0.6, wherein maximum membership degree is 0.6, it is determined that current state corresponds to operating mode 5, and operating mode 5 is defined as into current working.
S110:The method successively decreased using variable step, determines the optimum pH value of the desulfurization absorbing liquid under current working.
Specifically, this step can include:Determine that desulfurization is inhaled under current working according to following formula using variable step diminishing method Receive the optimum pH value of liquid:
In formula, n represents iterationses (n>=2);PHnRepresent pH value during nth iteration;PHn-1Represent (n-1)th time repeatedly For when pH value;WmaxAnd WminThe maximum and minimum value of step-length is represented respectively;knRepresent current iteration number of times;kmaxRepresent maximum Iterationses, preferably take 5.
Due to requiring in technique, PH is typically chosen PH between 4.5 to 6.51=6;
Wherein,For stopping criterion for iteration.
In formula, t0 is represented after change setting value, the initial time after desulfurization and denitrification integral process device stable operation;t0 Depending on can be according to practical situation.Wherein, the condition of stable operation is:During desulphurization denitration, through extremely after regulated variable It is few just to ensure within more than 2 hours the condition that device enters the even running phase.P (t0) represents that desulfurization and denitrification integral process device goes out Mouth flue gas SO2Concentration value;PLimitRepresent the SO for limiting2Concentration value, it is therefore preferable to for 50 (mg/m3);N=60/T+1, wherein T are to adopt Sample cycle, i.e. n are that poor number of times is sought in sampling in one hour;ε represents termination threshold value, preferably takes 10%, i.e., when the next hour of stable state Interior mean error is reached within the 10% of limiting concentration.
When stopping criterion for iteration is reached, it is believed that now pH value is optimum pH value.
After optimum pH value is obtained, disturbance factor can not be surveyed due to existing, for example:Ammonia spirit concentration, detection error with And because desulfurization and denitrification integral process device is aging, Changes in weather etc. reason produce cannot measure uncontrollable disturbance Deng the optimum pH value can occur minor variations.Thus, the embodiment of the present invention further takes indemnifying measure hereinafter described.
S120:The ammonia compensation dosage under current working is determined using neural network model.
Wherein, neural network model can adopt multiple neutral nets structure in parallel.Preferably, neutral net is for radially Basis function neural network (RBFNN).By the way that using Parallel neural networks structure, the precision to complex working condition process can be improved, The generalization ability of strength neural network (model).
By taking RBF neural as an example, in actual applications, three layers of RBF neural can be selected.Wherein it is possible to will be defeated Enter layer to be configured to comprising desulfurization absorbing liquid circulating load, flue-gas temperature, inlet flue gas flow velocity, inlet flue gas sulfur dioxide concentration, de- The data acquisition system of sulfur absorbing liquid pH value and inlet flue gas oxygen content and measurable disturbance;Can be using Gaussian function as intermediate layer; Then weights are multiplied by, you can exported, in embodiments of the present invention, are output as ammonia compensation dosage, i.e. ammonia spirit addition. The number of ammonia spirit addition directly affects pH value.
The embodiment of the present invention by obtaining ammonia compensation dosage, when have disturbance occur or operating mode be changed when, nerve net Network calculates at once ammonia compensation dosage, rather than is calculated ammonia controlled quentity controlled variable again after control system feedback.So Control can be prevented delayed, make ammonia addition play a role much sooner.
S130:It is true using inner membrance control method based on the sulfur dioxide concentration that desulfurization and denitrification integral process device is exported Determine the ammonia controlled quentity controlled variable under current working.
Specifically, this step can include:
S131:Desulphurization denitration process transmission function mould is set up using closed loop two channel relay feedback frequency domain identification method Type.
The regulation process of pH value is a typical non-linear process, such as, in the implementation process of the present invention, PH can be with For 4.5-6.5, in the range of this, according to the characteristic of pH value, PH regulations process can be approximately a linear process.Example Such as:If pH value is 7 or so, its regulation process has apparent non-linear, pH value from 7 more away from, the regulation process of pH value It is non-linear weaker.In actual industrial process, PH typically each in 4-5 or so, pH value from 7 farther out, so, the regulation of pH value Journey it is non-linear very weak.Therefore, the regulation process of pH value can be represented with transferring function by.
Again because coking flue gas desulfurization and denitrification is the process of the big inertia with strong disturbance and large time delay, Open-loop Identification Process model inevitably will be affected by strong disturbance and the exceeded situation of fume emission occurs and occur.So, the present invention Embodiment sets up desulphurization denitration process transfer function model using closed loop two channel relay feedback frequency domain identification method.
Fig. 3 schematically illustrates the structural representation of closed loop two channel relay feedback.Wherein, TR represents dual pathways relay Characteristic;R represents desulfurization absorbing liquid target pH value;Ud represents ammonia controlled quentity controlled variable;D represents that measurable disturbance is (not such as:Ammonia spirit is dense What the reasons such as degree, detection error, the aging, Changes in weather of desulfurization and denitrification integral process device were produced cannot measure uncontrollable Disturbance etc.);Yp represents actual measurement pH value.Wherein, surveying pH value can be from the pipeline for transporting absorbing liquid to tower top installed in desulfurizing tower bottom In sensor measurement, and will be obtained in transmitting measured values to DCS system by the sensor.Two channel relay TR's Structure is as shown in Figure 4.Wherein, the input of TR is e.Wherein, e=R-Yp, | e |≤ε.ε represents threshold value, such as it can be set as 0.1。
There is a stable operating point (namely steady operation point) in desulphurization denitration process, the operating point is current state, A series of value of variables of desulphurization denitration process stabilization can be made.For example:In industrial processes, each variable or parameter are inscribed when a certain Setting value, such as current time, it is 150 cubes of meter per seconds that ammonia addition is 50 cubes of meter per seconds, desulfurization absorbing liquid circulating load, The operating point can be considered steady operation point.Setting steady operation point meaning be when working conditions change, can at once by each State value required for specification of variables to operating mode after change, is conducive to the stability of desulfurization and denitrification integral process plant running. Due to introducing nonlinear element in the structure of closed loop two channel relay feedback, so, TR structures can be near present operating point There is limit cycles oscillations.Because the process of limit cycles oscillations is approximately linear process, so, it is possible to use the superposition of linear process Principle, obtains the output of limit cycles oscillations, i.e.,Wherein,Represent the output of limit cycles oscillations;YpRepresent real Survey pH value;R represents desulfurization absorbing liquid target pH value.Because limit cycles oscillations is a kind of controlled oscillation, so, frequency characteristic test During occur not measurable disturbance can be controlled.
By the gain controllable pH value for adjusting TR, so discharge flue gas concentration is within limit value is required.The gain of TR is For hp and hi in above-mentioned Fig. 4, gain difference, when being recognized, the maximum-minima of PH is just different.For example, Ke Yishe It is all 2 to put hp and hi, then the excursion of PH is 2-9, and this scope is in actual applications unacceptable.If arranging hp 0.5 is with hi, then PH excursions are 4-5, this scope can be in actual applications to receive.By the gain for adjusting TR To control pH value, so when transfer function model is recognized, pH value amplitude will not be excessive.
S1311:According to the ammonia addition during desulphurization denitration and the output of limit cycles oscillations, using Fourier transform Estimation obtains the frequency response of desulphurization denitration process and estimates.
In order to overcome installed in denitration tower top, and the measurement positioned at the flue gas online chemical analysis instrument of smoke outlet is made an uproar Sound, improves the precision estimated, the embodiment of the present invention adopts the frequency characteristic of the method calculating process of Fourier transform.Wherein, cigarette Gas online chemical analysis instrument is used for measuring outlet flue gas concentration, i.e., for measurements of sulfur dioxide concentrations law.The online composition point of flue gas The sulfur dioxide concentration of measurement is uploaded to DCS system by analyzer table.
As an example, the Fourier transform of input/output signal is determined according to following formula:
Wherein, u (t) represents input signal;Y (t) represents output signal;F represents Fourier transform;T0Represent time-domain signal It is T in the cycle to be0Periodic signal;ω0Represent fundamental frequency, n round numbers.
Fundametal compoment, i.e. n=1, ω=ω can be taken0Situation, then the frequency response that can determine that sweetening process is estimated as:
G (j ω in above formula0) represent frequency characteristic to be estimated in transmission function.
For example, in actual applications, frequency characteristic estimation can be obtainedIts In,Represent by two channel relay test, in ωiUnder frequency characteristic estimate (preferably Multiple points frequency response Estimate).
S1312:Estimated according to the frequency response of sweetening process, using identification algorithm and nonlinear optimization algorithm, estimated Desulphurization denitration process transfer function model.
It is preferably carried out in mode at some, this step specifically can include:
S13121:Estimated according to the frequency response of sweetening process, be defined below object function:
Wherein ciRepresent weights;M represents selected phase place number;That expression is tested by two channel relay, In ωiUnder Multiple points frequency response estimate;G(jω0) represent frequency characteristic to be estimated;J represents object function.
By above-mentioned object function, estimation becomes a nonlinear optimal problem.
S13122:Based on object function, using identification algorithm, transmission function is obtained.
S13123:Using nonlinear optimization algorithm, the constant in above-mentioned transmission function is solved, so that it is determined that transmission function mould Type.
Describe the process for determining transfer function model in detail with a preferred embodiment below.
Step A:Based on object function, using identification algorithm, following one order inertia plus delayed transmission function are obtained:
Wherein, GpS () represents the Laplace transform of output and the ratio of input;K represents proportionality constant;T represents that inertia is normal Number;τ represents hysteresis constant.
Wherein, identification algorithm includes but is not limited to method of least square, particle swarm optimization algorithm.
Step B:Using nonlinear optimization algorithm, proportionality constant in above-mentioned transmission function, inertia constant and delayed are solved Constant, so that it is determined that the one order inertia of desulphurization denitration process adds delayed transfer function model.
Above-mentioned nonlinear optimization algorithm includes but is not limited to particle cluster algorithm, genetic algorithm.
By using closed loop two channel relay feedback (being abbreviated as TRF) frequency domain identification method, the embodiment of the present invention can be with The controlled mode of closed loop obtains the Multiple points frequency response of sweetening process according to specified phase place, and then estimates to obtain sweetening process Transfer function model.
S132:Using desulphurization denitration process transfer function model, two exported based on desulfurization and denitrification integral process device Sulfur oxide concentration, using internal model control method, determines ammonia controlled quentity controlled variable.
Wherein, inner membrance control method may refer to《Internal model control and its application》, Electronic Industry Press, here no longer goes to live in the household of one's in-laws on getting married State.
This step is based on desulphurization denitration process transfer function model, using internal model control method, build feedback filter and Internal mode controller.The titanium dioxide that desulfurization and denitrification integral process device can be exported using feedback filter and internal mode controller Sulphur concentration is controlled in index.
Wherein, feedback filter adopts single order form:α represents constant.Feedback filtering Device is used for feedback filtering in internal model control, can improve robustness.
S140:Based on the optimum pH value of desulfurization absorbing liquid, desulfurization suction is controlled with reference to ammonia compensation dosage and ammonia controlled quentity controlled variable Receive the pH value of liquid.
Disturbance factor can not be surveyed due to existing, for example:Ammonia spirit concentration, detection error and due to desulphurization denitration one Chemical industry process and equipment is aging, Changes in weather etc. reason is produced cannot measure uncontrollable disturbance etc., and this step is being taken off On the basis of the optimum pH value of sulfur absorbing liquid, ammonia compensation dosage and ammonia controlled quentity controlled variable are added, so as to controlling desulfurization absorbing liquid PH value, and then realize the optimal control to coking exhuast gas desulfurization process.
Although each step is described according to the mode of above-mentioned precedence in above-described embodiment, this area Technical staff is appreciated that to realize the effect of the present embodiment, not necessarily in the execution of such order between different steps, It (parallel) execution simultaneously or can be performed with the order for overturning, these simple changes all protection scope of the present invention it It is interior.
So far, technical scheme is described already in connection with preferred implementation shown in the drawings, but, this area Technical staff is it is easily understood that protection scope of the present invention is expressly not limited to these specific embodiments.Without departing from this On the premise of the principle of invention, those skilled in the art can make the change or replacement of equivalent to correlation technique feature, these Technical scheme after changing or replacing it is fallen within protection scope of the present invention.

Claims (8)

1. a kind of coking exhuast gas desulfurization procedure optimization control method, the optimal control method is applied to desulfurization and denitrification integral work Process and equipment, it is characterised in that the control method includes:
Flue-gas temperature, flue gas flow, oxygen content of smoke gas and titanium dioxide according to the desulfurization and denitrification integral process device portal Sulphur concentration, using fuzzy recognition algorithm, determines current working;
The method successively decreased using variable step, determines the optimum pH value of the desulfurization absorbing liquid under the current working;
The ammonia compensation dosage under the current working is determined using neural network model;
Based on the sulfur dioxide concentration that the desulfurization and denitrification integral process device is exported, determined using inner membrance control method described Ammonia controlled quentity controlled variable under current working;
Based on the optimum pH value of the desulfurization absorbing liquid, with reference to the ammonia compensation dosage and the ammonia controlled quentity controlled variable to control State the pH value of desulfurization absorbing liquid.
2. optimal control method according to claim 1, it is characterised in that described according to the desulfurization and denitrification integral work The flue-gas temperature of process and equipment entrance, flue gas flow, oxygen content of smoke gas and sulfur dioxide concentration, using fuzzy recognition algorithm, it is determined that Current working, specifically includes:
By the flue-gas temperature, the flue gas flow, the oxygen content of smoke gas and the sulfur dioxide concentration be set as state to Amount;
Clustered based on the state vector, determined sorting criterion, and state set is obtained by the sorting criterion;
By weighted fuzzy identification algorithm, the fuzzy membership relational matrix of the state vector and the state set is obtained;
Based on the fuzzy membership relational matrix, the current working is determined by maximum membership grade principle.
3. optimal control method according to claim 1, it is characterised in that the method that the employing variable step successively decreases, really The optimum pH value of the desulfurization absorbing liquid under the fixed current working, specifically includes:
The optimum pH value of the desulfurization absorbing liquid under the current working is determined according to following formula using variable step diminishing method:
In formula, the n represents iterationses, n>=2;The PHnRepresent pH value during nth iteration;The PHn-1Expression n-th- PH value during 1 iteration;The WmaxWith the WminThe maximum and minimum value of step-length is represented respectively;The knRepresent current iteration Number of times;The kmaxRepresent maximum iteration time;T0 represents the starting after the desulfurization and denitrification integral process device stable operation Time;The P (t0) represents the desulfurization and denitrification integral process device exiting flue gas sulfur dioxide concentration value;The PLimitRepresent The sulfur dioxide concentration value of restriction;The T represents the sampling period;The ε represents termination threshold value.
4. optimal control method according to claim 1, it is characterised in that the neural network model is multiple radial direction bases Function Neural Network model in parallel.
5. optimal control method according to claim 1, it is characterised in that described to be filled based on desulfurization and denitrification integral process The sulfur dioxide concentration of outlet is put, the ammonia controlled quentity controlled variable under current working is determined using inner membrance control method, specifically included:
Desulphurization denitration process transfer function model is set up using closed loop two channel relay feedback frequency domain identification method;
Using the desulphurization denitration process transfer function model, based on the dioxy that the desulfurization and denitrification integral process device is exported Change sulphur concentration, using internal model control method, determine ammonia controlled quentity controlled variable.
6. optimal control method according to claim 5, it is characterised in that the employing closed loop two channel relay feedback frequency Domain discrimination method is specifically included setting up desulphurization denitration process transfer function model:
According to the ammonia addition during the desulphurization denitration and the output of limit cycles oscillations, estimated using Fourier transform Frequency response to the desulphurization denitration process is estimated;
Estimated according to the frequency response of the sweetening process, using identification algorithm and nonlinear optimization algorithm, estimate desulfurization and take off Nitre process transfer function model.
7. optimal control method according to claim 6, it is characterised in that described to be rung according to the frequency of the sweetening process Should estimate, using identification algorithm and nonlinear optimization algorithm, estimate desulphurization denitration process transfer function model, specifically include:
Estimated according to the frequency response of sweetening process, be defined below object function:
J = 1 2 Σ i = 1 m c i | G ^ ( jω i ) - G ( jω i ) | 2
Wherein, the ciRepresent weights;The m represents selected phase place number;It is describedRepresent special by dual pathways relay Property test, in ωiUnder Multiple points frequency response estimate;G (the j ω0) represent frequency characteristic to be estimated;The J represents institute State object function;
Based on object function, using identification algorithm, transmission function is obtained;
Using nonlinear optimization algorithm, the constant in the transmission function is solved, so that it is determined that desulphurization denitration process transmission Function model.
8. optimal control method according to claim 7, it is characterised in that the transmission function adds delayed for one order inertia Transmission function;
The employing nonlinear optimization algorithm, solves the constant in the transmission function, so that it is determined that the desulphurization denitration process Transfer function model, specifically includes:Using nonlinear optimization algorithm, the proportionality constant, inertia in the solution transmission function is normal Number and hysteresis constant, so that it is determined that the one order inertia of the desulphurization denitration process adds delayed transfer function model.
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Cited By (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108319146A (en) * 2018-03-09 2018-07-24 西安西热控制技术有限公司 A kind of method that radial base neural net is trained based on discrete particle cluster
CN109508832A (en) * 2018-11-22 2019-03-22 李东峰 Power plant SO based on variable compression BP neural network2Discharge flexible measurement method
CN109833773A (en) * 2019-03-08 2019-06-04 东方电气集团东方锅炉股份有限公司 A kind of NO_x Reduction by Effective ammonia flow accuracy control method
CN109932909A (en) * 2019-03-27 2019-06-25 江苏方天电力技术有限公司 The big system of fired power generating unit desulphurization system couples Multi-variables optimum design match control method
CN110038394A (en) * 2018-09-13 2019-07-23 苏治汇 Gas cleaning plant
CN110222711A (en) * 2019-04-30 2019-09-10 杭州意能电力技术有限公司 A kind of multistage inertia system Open-loop Identification method of industrial process based on deep learning
TWI681155B (en) * 2018-09-13 2020-01-01 蘇治滙 Gas cleanning apparatus
CN110935312A (en) * 2019-12-16 2020-03-31 广州珠江电力有限公司 Dynamic monitoring device and dynamic monitoring method for SCR flue gas denitration system
CN111538240A (en) * 2020-04-13 2020-08-14 大唐环境产业集团股份有限公司 Performance evaluation and self-tuning method for desulfurization system
CN113617216A (en) * 2021-07-22 2021-11-09 中国华电科工集团有限公司 Integrated control method and system for wet desulphurization absorption tower system
CN114504923A (en) * 2022-04-14 2022-05-17 广东众大智能科技有限公司 Continuous granulation reaction kettle tail gas treatment method, system and storage medium

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103041678A (en) * 2012-12-21 2013-04-17 浙江天蓝环保技术股份有限公司 Ammonia flue gas desulfuration and denitration combined process and device
CN103505999A (en) * 2013-10-23 2014-01-15 中冶长天国际工程有限责任公司 System and method for wet desulfurization and denitrification
CN104226095A (en) * 2014-07-30 2014-12-24 武汉悟拓科技有限公司 Synchronous denitration process based on wet ammonia process flue gas desulfurization
US20150352486A1 (en) * 2013-04-24 2015-12-10 Jiangsu New Century Jiangnan Environmental Protection Co., Ltd Flue gas-treating method and apparatus for treating acidic tail gas by using ammonia process
CN205323522U (en) * 2016-01-05 2016-06-22 中国科学院自动化研究所 Flue gas desulfurization denitration integration equipment of multivariable control

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103041678A (en) * 2012-12-21 2013-04-17 浙江天蓝环保技术股份有限公司 Ammonia flue gas desulfuration and denitration combined process and device
US20150352486A1 (en) * 2013-04-24 2015-12-10 Jiangsu New Century Jiangnan Environmental Protection Co., Ltd Flue gas-treating method and apparatus for treating acidic tail gas by using ammonia process
CN103505999A (en) * 2013-10-23 2014-01-15 中冶长天国际工程有限责任公司 System and method for wet desulfurization and denitrification
CN104226095A (en) * 2014-07-30 2014-12-24 武汉悟拓科技有限公司 Synchronous denitration process based on wet ammonia process flue gas desulfurization
CN205323522U (en) * 2016-01-05 2016-06-22 中国科学院自动化研究所 Flue gas desulfurization denitration integration equipment of multivariable control

Cited By (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN108319146B (en) * 2018-03-09 2020-08-11 西安西热控制技术有限公司 Discrete particle swarm training-based method for radial basis function neural network
CN108319146A (en) * 2018-03-09 2018-07-24 西安西热控制技术有限公司 A kind of method that radial base neural net is trained based on discrete particle cluster
CN110038394A (en) * 2018-09-13 2019-07-23 苏治汇 Gas cleaning plant
TWI681155B (en) * 2018-09-13 2020-01-01 蘇治滙 Gas cleanning apparatus
CN109508832A (en) * 2018-11-22 2019-03-22 李东峰 Power plant SO based on variable compression BP neural network2Discharge flexible measurement method
CN109833773A (en) * 2019-03-08 2019-06-04 东方电气集团东方锅炉股份有限公司 A kind of NO_x Reduction by Effective ammonia flow accuracy control method
CN109833773B (en) * 2019-03-08 2021-05-04 东方电气集团东方锅炉股份有限公司 Efficient denitration ammonia flow accurate control method
CN109932909A (en) * 2019-03-27 2019-06-25 江苏方天电力技术有限公司 The big system of fired power generating unit desulphurization system couples Multi-variables optimum design match control method
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CN110935312A (en) * 2019-12-16 2020-03-31 广州珠江电力有限公司 Dynamic monitoring device and dynamic monitoring method for SCR flue gas denitration system
CN110935312B (en) * 2019-12-16 2022-08-30 广州珠江电力有限公司 Dynamic monitoring device and dynamic monitoring method for SCR flue gas denitration system
CN111538240A (en) * 2020-04-13 2020-08-14 大唐环境产业集团股份有限公司 Performance evaluation and self-tuning method for desulfurization system
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CN114504923B (en) * 2022-04-14 2022-07-05 广东众大智能科技有限公司 Continuous granulation reaction kettle tail gas treatment method, system and storage medium

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