A kind of real-time optimization device of continuous flow procedure
Technical field
The present invention relates to a kind of real-time optimization device that makes production run operate in the continuous flow procedure under the optimization state at any time.
Background technology
Many to continuous flow procedure; The size of its optimized operation situation and optimization target values (following all be up to optimum condition with desired value) all receives to survey the influence of variable and often changes; Optimization target values also can not be surveyed under many situation; How making production run operate in optimum condition at any time, is the problem that real-time optimization will solve.
For solving the real-time optimization problem; To many continuous flow procedures; Mostly adopt method: common chemical reaction process in the petrochemical production process for example based on the production process mathematics model of stable state; When operation; Raw material is formed (can not survey) and is often changed, and operating condition and running environment (wherein some variable can not be surveyed) also often change; Optimization aim, like the conversion ratio and the productive rate of reaction, or selectivity and reactant composition, also usually can not survey.For reactor is operated under the optimum condition (the peak optimization reaction degree of depth); Method commonly used is to form and catalyst activity according to the raw material that assay obtains; Actual measurement process variable when production run is in stable state is calculated the optimum operating conditions of target of sening as an envoy to mathematics model of stable state, and course of reaction is adjusted; The excellent variable of modal accent is a temperature of reaction, promptly adjusts temperature of reaction to reach optimum.Each transfer to wait for that production process operates steadily after excellent after, transfer excellently once more based on the actual measurement variable of production process and model, twice excellent interval of accent (transferring the excellent cycle) is generally more than two hours.Above method weak point is: the one, and real-time is poor, can not when production run changes, adjust to rapidly under the optimization situation and move.The 2nd, can not adapt to the dynamic change of production run actual motion; The actual measurement process variable of institute's foundation is always devious, adds that the precision of model is limited, makes to calculate gained optimal conditions and actual can not coincideing; Therefore, also seldom see effective instance of this method of foundation.
Another kind of optimization method is without model, only how to transfer next time excellently according to the variation decision of variation of transferring excellent variable and optimization aim, and it transfers excellent logic to be: when desired value increases when identical with the excellent increment change direction of accent, continue to increase the excellent variable of accent.(cycle) accent is once excellent at regular intervals, makes production run progressively approach the optimized operation situation, abbreviates as from seeking best practice. and the advantage of this method is simple, has avoided the inaccurate influence of model; Owing to, do not require the measured value absolutely accurate according to target and the relative variation of transferring excellent variable yet; Its main weak point is: the one, desired value and the change direction of transferring excellent variable are judged, if incompatibility production run dynamic perfromance possibly cause erroneous judgement.The 2nd, near the optimized operation situation, possibly transfer excellent direction all changing at every turn, form the vibration of transferring excellent variable, make the production run can not even running.The 3rd, when desired value or the variable relevant with desired value do not have real measured data,, compare with above-mentioned method with Model Calculation like the conversion ratio and the selectivity of above-mentioned chemical reactor, just can't implement to optimize.
When reality is implemented production process optimization, also need the excellent means of good accent, can adjust excellent variable rapidly accurately, can under various interference, keep the optimized operation situation again.The fault detect of production run and processing, the detection of various constraints also is necessary with handling.
Summary of the invention
The objective of the invention is to provide one and adapt to production run operation dynamic perfromance and actual conditions, effective real-time optimization device.
The real-time optimization device of continuous flow procedure of the present invention, its principal character is:
The real-time calculating of optimization aim: when optimization aim can not be surveyed, according to measurable process variable and dynamic mathematical models, online in real time calculated.
" time-out " of optimizing and " self-starting ": after optimizing makes production process optimization, or the production run situation promptly suspends optimizing when not allowing, and avoids near the vibration optimized point, prevents the abnormal running situation, remains on even running under the optimization situation.
Need to transfer when excellent when production run and environment thereof change, start optimizing automatically, make production run be in the optimization situation at any time.
" dynamic compensation ": according to the dynamic perfromance of producing with searching process, optimization target values in the optimizing cycle is implemented dynamic compensation, can optimizing when the production run dynamic change, avoid the erroneous judgement of optimizing, shorten the optimizing cycle, acceleration optimizing process.
Constraint is forecast and handled: based on dynamic mathematical models variable is tied and forecasts, when forecast was tied (reaching bound), the direction that only allows court to break away from constraint was transferred excellent, and optimizing is moved under safe and reliable condition.
Data processing and fault diagnosis: to the process variable that contains noise with optimization target values is handled and fault diagnosis, optimizing is being carried out reliably on the basis.
Intelligence optimizing: on the whether identical basic optimizing logical foundations of the change direction of judge transferring excellent variable and optimization aim, increase judge intelligent, in time " time-out " or " self-starting ", the shortening searching process is guaranteed optimizing safety.
Based on the model pre-estimating coordinating control system of dynamic model as transferring excellent means: provide rapid response, can steadily keep the excellent means of accent of optimization situation again.
The real-time optimization device of continuous flow procedure of the present invention is by production run monitor 1, the real-time counter 2 of optimization aim, and intelligent optimizing controller 3 is transferred excellent controller 4, and operation is kept watch on setting apparatus 5 five parts and is formed.The real-time optimization device is obtained the service data of production run 7 in real time through existing data input/output interface 6, and will transfer excellent effect to give production run 7 and transfer excellently, forms the real-time optimization system.
1. production run monitor: mainly contain following function:
1-1. data processing and fault diagnosis: most of prior art capable of using.A characteristic of this patent is based on the poor of dynamic mathematical models result of calculation and actual measurement variable, and whether real-time judge operating condition and real measured data be normal.
1-2. constraint forecast: according to dynamic model following variation of variable estimated, realized whether the be tied forecast of (reaching bound) of variable, forecast stop when transfiniting the transfiniting accent of direction is excellent." simplification " and " complete " dual mode is arranged having estimated of variable is following:
Simplified way: Y (t+p/t)=Y (t)+A [Y (t)-Y (t-1)] (1)
The t=current time, p=estimates time domain, the prediction coefficient that A=can be provided with
Y (t+p/t)=current time is to following t+p variable discreet value constantly
Y (t), the measured value of Y (t-1)=current time and previous moment variable
Complete mode: based on the discrete time state-space model,
Model: X (k+1)=F [X (k-τ
X), U (k-τ
U)] (2A)
Y(k)=G[X(k),U(k)] (2B)
Y=need estimate following variable X=state variable U=input variable
K=t/T
d=discrete time periodicity t=time T
d=discrete time the cycle
τ
XBetween=the state variable interactive retardation time corresponding discrete time periodicity
τ
U=input variable is to the discrete time periodicity of the retardation time of state variable influence
Forecast through the online in real time correction:
Y
C(k+p/k)=Y(k+p/k)+[Y(k)-Y(k/k-p)] (3)
Y
C(k+p/k)=revised [at following (k+p) T
dPredicted value constantly]
P is the corresponding discrete time periodicity of forecast time institute of setting
Y (k+p/k)=by (k+p) T in future of Model Calculation
dDiscreet value constantly
Y (k/k-p)=by the current time (kT of Model Calculation
d) discreet value
The measured value of Y (k)=current time k,
Y (k)-Y (k/k-p)=online in real time (to model pre-estimating) modified value.
With revised predicted value Y
C(k+p/k) whether judgment variable transfinites.
1-3. working conditions change detects: normal in the production run operation, no variable is tied, under the trouble-free situation; Owing to can not survey the variation of variable; When making production run operation depart from the optimization situation, this patent detects this working conditions change in real time, for the self-starting of optimizing provides information.
Working conditions change provided by the invention detects content and comprises: whether the size and the direction of each variable measured value have significant change when each variable that 1. relatively calculates based on state-space model [formula (2A) (2B)] and actual motion.2. the technological parameter that calculates based on the dynamic mathematical models online in real time has significant change, like the heat and mass transport coefficient, and concentration of component, etc.3. optimization target values has significant change.4. operating condition has significant change, like self-actuated controller or artificial performance variable significant change is arranged, and production decision changes, and raw material is formed and fluctuations in discharge, the variable bound changed condition, and production equipment changes, or the like.
2. the real-time counter of optimization aim: for the optimization aim that can not survey; The present invention is according to production run mechanism; The actual measurement variable; Dynamic model [formula (2A) (2B)] and the time lag that exists, online in real time is calculated and is provided the optimization aim that can not survey, when for example the conversion ratio of chemical reactor or the product in the reaction product are distributed as optimization aim; The measured discharge of each product that can be separated by its downstream product separation equipment and the dynamic mathematical models of separation equipment are calculated the flow of separation equipment inlet (being reactor outlet) each product, thereby calculate corresponding optimization aim.During calculating, all to carry out appropriate Filtering Processing, to suppress noise to actual measurement variable and result of calculation.
Another characteristics of the real-time counter of optimization aim are: when any the actual measurement variable that is used to calculate has fault or when improper, all provides failure message, optimizing is suspended.
3. intelligent optimizing device: realizing the time-out and the self-starting of optimizing, the variable quantity of the excellent back of each accent desired value is carried out dynamic compensation, stop to transfer excellent when certain condition or operating mode do not allow satisfying, is the major function of intelligent optimizing device.
Characteristics of intelligence optimizing device are " self-starting " optimizing: after not having constraint and possessing the optimizing data of enough time spans, the operator provides and transfers excellent order, or the operating mode judgement needs to transfer excellent; Or constraint release; Or (transferred last time excellent after) excellent time out of accent of setting arrives, and the optimizing device will start optimizing automatically, promptly according to the change direction of transferring excellent variable and optimization aim; Confirm to transfer the adjustment direction and the size of excellent variable, transfer excellent.Transfer for the first time when excellent,, can confirm the excellent direction of accent based on condition of setting and current working if transfer excellent variable or optimization aim no change.Each transfer excellent after, through the accent set after excellent cycle time, beginning for the second time and after each time accent excellent.
Second characteristic of intelligence optimizing device are to transfer the variation of optimization target values in the excellent cycle to have dynamic compensation to each; This is because following phenomenon can appear in the dynamic perfromance of production run and data processing: transfer at every turn excellent before, descend as if optimization aim, even transfer excellent effect to make on the target; Transferring what show after excellent possibly be that desired value is also descending; The speed that just descends is slack-off, and when an optimizing end cycle, optimization target values possibly not rise; If think that optimization aim does not rise, and will cause the accent of anisotropy excellent.The effect of dynamic compensation is exactly to prevent that wrong accent is excellent, thereby shortens the excellent process of transferring.Dynamic compensation utilizes dynamic model [method that can select for use (1) formula or (3) formula to provide], calculates when transferring excellent amount constant, transfers in the excellent cycle the 1st, 2 at one, up to the variation of N calculation time optimization aim, is called zero of optimization aim and responds.Use the optimization target values and zero respond poor of transferring excellent back practical manifestation to come out, as judging the foundation of transferring excellent direction.
The 3rd characteristics of intelligence optimizing device be in time stop to transfer excellent: multiple time-out standard can be set, make and transfer excellent process to stop, as: transfer excellent number of times to reach setting value continuously towards a direction; Twice accent is excellent in the opposite direction, transfers excellent back optimization aim not have significant change, transfers excellent suffering restraints; Used real measured data or online in real time are calculated has fault, and abnormal condition appears in production run, and excellent data are transferred in the judgement that does not possess sufficient length; Or the like
4. transfer excellent controller: the excellent effect of the accent that intelligent optimizer provides is implemented to transfer excellent through transferring excellent controller to production run.Employing based on the model pre-estimating coordinating controller of dynamic mathematical models as transferring excellent controller.The controller of recommending employing Chinese patent 99105546.2 and 200710118864.3 to provide based on model; Optimization for chemical reactor; What recommendation employing Chinese patent 200410048083.8 provided is the automatic control system of controlled variable with macroreaction heat, as transferring excellent controller.
5. operation is kept watch on and setting apparatus: the operation of real-time optimization device is had only a run switch.Can keep watch on and transfer excellent operation conditions, the function and the operational factor of real-time optimization device are carried out online adjustment.
Description of drawings
Fig. 1 is the composition frame chart of the real-time optimization device that provides of the present invention.
Embodiment
Embodiment 1: the real-time optimization of drilling process
Optimization aim is that drill speed is the highest.In general, the pressure of the drill is high more, and ROP is high more, but the rate of wear of drill bit is also high, therefore, has the pressure of the drill of an optimum.ROP can be measured in real time, but possible ROP depends on the character of the rock stratum of boring, the degree of wear of drill bit; The flow velocity of drilling fluid and character, or the like, these factors that influence drill speed all do not have real-time metrical information; And can change at any time, need carry out real-time optimizing.
Transferring excellent variable is the set-point of the pressure of the drill in the pressure of the drill automatic control system.
Need to consider various constraints, fault and improper operating mode in the evolutionary process.Main constraint has the bound of the pressure of the drill, rig moment of torsion bound, the constraint of the pressure of the drill control system etc.Except that the fault of instrument and equipment, detect when occurring bouncing of drilling tool in the drilling process with other improper operating mode, in time stop to transfer excellent.Optimizing also can suspend by the optimizing logic of setting voluntarily.
Self-running judgement of optimizing and condition are: under the situation of the normal operation of the pressure of the drill automatic control system, if ROP, the rig moment of torsion; Mud flow rate and character have significant change, and fault or improper operating mode are removed, and have the data of following two the optimizing Cycle Lengths of normal operation conditions; Or the time-out optimizing of setting time is up; Or after the automatic control of the pressure of the drill automatic control system input, obtain in optimizing under the condition of production management slip-stick artist permission, optimizing is with self-starting.
Embodiment 2: the real-time optimization of catalytic cracking reaction process
Catalytic cracking reaction is that heavier cracking of oil is generated petroleum gas, liquid hydrocarbon, gasoline, the production run of low-density oil cuts such as diesel oil.Its optimization aim is the weighted sum of intermingled dregs ratio in above each reaction product productive rate and the raw material.
Because each yield of product can not measure in real time in the reaction product, the size of each productive rate changes because of the raw material oil composition is different, and the raw material oil composition also can not measure in real time.For this reason, adopt the real-time calculator of optimization aim provided by the invention, the measured value of each product flow that distillates based on the fractionating column that product is separated into each product and other actual measurement variablees; Based on dynamic mathematical models, consider that material and the heat amount of savings in fractionating column and container changes account temperature; The interior backflow; The oil gas dividing potential drop, the influence that (except that temperature, all can not survey, also need be calculated in real time by dynamic model) such as oil gas linear speeds separates product; Consider that reactor outlet to the time lag that distillates between the product measured discharge, finally calculates the productive rate of each product of reactor outlet under the standard separate condition.Simultaneously,, calculate the amount of burnt of regenerator, take into account time lag, provide the burnt rate of product of reactor based on the dynamic mathematical models and the actual measurement variable of regenerator.
What employing Chinese patent 200410048083.8 provided is the automatic control system of controlled variable with macroreaction heat, as transferring excellent controller.The controller based on model that adopts Chinese patent 99105546.2 or 200710118864.3 to provide is implemented the float area of macroreaction heat and temperature of reaction and is coordinated control, and maintenance reaction heat is optimal value, also keeps temperature of reaction in given bound.
The main constraint of evolutionary process has: the float area of macroreaction heat and temperature of reaction is coordinated the constraint of related variable in the control, the constraint of regenerator and main air blower, and the constraint of rich gas compressor, the constraint of fractionator, or the like.
The operating mode of self-starting optimizing detects and mainly contains: under this constant situation of macroreaction hot radical; The reaction product productive rate has significant change; Transfer excellent controller output that significant change is arranged; Fractionator and regenerator operation conditions have significant change, and the optimizing data of sufficient length are arranged after constraint or fault (fault that comprises the real-time counter of optimization aim) are removed.
Embodiment 3: the real-time optimization of catalytic reforming reaction process
Here be that master's catalytic reforming reaction is an example to produce aromatic hydrocarbons, its optimization aim is that aromatics yield is the highest.But aromatics yield can not measure in real time, and the optimization aim computing device among the present invention according to the mechanism and the characteristics of reforming reaction, utilizes dynamic mathematical models and actual measurement variable to provide solution to this problem, and following three approach is arranged:
(1) calculates with reaction heat and dynamic mathematical models: mainly contain the thermonegative reaction that generates aromatic hydrocarbons in the reforming reactor and be cracked into pentane or the more themopositive reaction of light constituent.The pentane that can separate by the reactor downstream depentanizer and the measured discharge of light constituent more; Utilize the dynamic mathematical models of fractionator and associated vessel to calculate the pentane of reactor outlet and the flow of light constituent more, and then obtain the cracking reaction liberated heat.Can calculate the grand tube reaction heat (showing as thermonegative reaction) of course of reaction by the dynamic mathematical models of reactor and actual measurement variable.Can calculate aromatics yield by macroreaction heat with the hot sum of cracking reaction.
(2) the hydrogen productive rate and the dynamic mathematical models that produce with reaction are calculated: the reaction that raw material generates aromatic hydrocarbons is the reaction that attaches hydrogen producing, and cracking reaction is the reaction of consuming hydrogen.Utilize downstream depentanizer dynamic mathematical models to calculate pentane productive rate and corresponding hydrogen-consuming volume, can calculate the amounts of hydrogen that the aromatic hydrocarbons reaction produces,, calculate aromatics yield according to stoichiometric coefficient by actual measurement hydrogen yield (adding dynamic correction).
(3) by the downstream extraction tower with aromatic hydrocarbons with after non-aromatic hydrocarbons separates, utilize dynabook to learn model and carry out dynamic compensation, calculate aromatics yield.
More than three kinds of methods all consider time lag based on actual conditions.
More than three kinds of result of calculations may not be very accurately, but as long as reacting phase is to changing the requirement that just can satisfy optimizing.The basis for estimation that available three's weighted sum changes as optimization aim.If wherein certain algorithm has fault or limits and can not calculate because of physical condition, can the weighting coefficient of this algorithm be made as zero.
What employing Chinese patent 200410048083.8 provided is the automatic control system of controlled variable with macroreaction heat, as transferring excellent controller.The controller based on model that adopts Chinese patent 99105546.2 or 200710118864.3 to provide is implemented the float area of macroreaction heat and temperature of reaction and is coordinated control, and maintenance reaction heat is optimal value, also keeps temperature of reaction in given bound.
Usually catalytic reforming reaction is made up of four tandem reactors, and the cracking reaction proportion is the highest in the 4th reactor.When calculating productive rate and optimization aim, calculate the macroreaction heat and the total reaction heat of each reactor by dynamic mathematical models.When the enforcement accent was excellent, intelligent optimizing device served as to transfer excellent variable with the hot set-point of first three reactor macroreaction.
Embodiment 4: the real-time optimization of pyrolysis furnace
Pyrolysis furnace is to be raw material with light or heavy petroleum fractions, is the process units of major product with ethene and propylene.Because the complicacy of petroleum fraction in the process of Pintsch process, also can generate hydrogen and other hydrocarbon products.Along with increasing of the cracking reaction degree of depth (mainly depending on and the cracking temperature and the residence time), the productive rate of ethene and propylene will descend after reaching mxm., and the productive rate of hydrogen and methane then constantly increases.The coke that cracking produces, make in the boiler tube with the quencher coking to the coke cleaning that to a certain degree need stop production, also be the key factor that influences benefit.The size of each product yield and relevant with feedstock property and operating conditions with the situation of change of cracking severity needs a real-time optimization device at any time pyrolysis furnace to be remained under the optimization situation and moves.
Below the optional usefulness of pyrolysis furnace optimization aim one of two kinds:
(1) optimization aim 1=C
2+ w
2C
3-w
sS
M
C
2=ethylene yield C
3=productivity of propylene w
3>0, be weighting coefficient
is a kind of expression formula of cracking severity
M>=1 is setup parameter w
S>0, be weighting coefficient ,-w
sS is the penalty function (2) to coking
Number of components in the N=pyrolysis product can be selected number of components as required
C
iThe productive rate w of i component in the=pyrolysis product
iThe weighting coefficient of=the i component
Pyrolysis gas on-line chromatograph analyser can provide methane, ethene and productivity of propylene data, and the productive rate in the above-mentioned optimization aim is according to chromatographic data, the pyrolysis furnace that calculates through dynamic mathematical models exports out each product productive rate.If comprise gasoline and other heavy product, pyrolysis furnace capable of using downstream production run measured data and dynamic mathematical models online in real time are calculated in the optimization aim 2.
The controller based on model that adopts Chinese patent 99105546.2 or 200710118864.3 to provide is the controlled variable of controller with cracking severity or pyrolysis furnace outlet temperature, forms to transfer excellent controller.With the set-point of cracking severity or pyrolysis furnace outlet temperature as transferring excellent variable.