CN1399176A - In-situ catalytic cracking control system based on correlation integration - Google Patents

Abstract

The present invention relates to optimized control method of catalytic cracking course and belongs to advanced process control technology. The optimized control system reads temperature, pressure, liquid level, flow rate and other measurement information from the basic DCS controller of the catalytic cracking apparatus and calculates via correlation integration process the correlation integration among reaction temperature, pre-lifting steam flow rate, material oil heat exchange temperature, dreg mixing ratio, and other regulated variable once each minute. The system calculates the optimal values of the variables and feeds the values to controller for excution. The system has strong adaptive performance and antijamming capacity and stable control performance.

Description

Situ catalytic cracking control system based on correlation integration

The present invention relates to the optimal control method of catalytic cracking process, belong to the advanced control technology of process field.

Correlation integral method is adopted in optimal control to catalytic cracking unit, on this basis, has realized the closed-loop optimization control to product yield and device whole economic efficiency.

Catalytic cracking is the important device of crude oil secondary processing, and the optimal control of its process is the important means that further improves operant level.Catalytic cracking process is a raw material with the heavy constituent in the crude oil----wax oil, long residuum, vacuum residuum etc.Under the effect of catalyzer, by cracking reaction heavy constituent are split into light constituent, be converted into products such as dry gas, liquefied gas, gasoline, diesel oil and coke, unconverted part sends back to reactor once more and participates in reaction (being called recycle stock).Usually the catalytic cracking reaction process comprises steps such as reaction, sedimentation, regeneration, fractionation and absorption be stable.Charging has nozzle to enter reaction tube, mixes back vaporization rapidly with the high temperature catalyst of coming from regenerator.Gas entrainment after the vaporization catalyzer and is risen along reactor, enters settler, finishes the cracking reaction of heat absorption when rising, and the coke that produces in the reaction makes it lose Mars attached to catalyst surface.Reacted oil gas is in settler and catalyst separation, and oil gas enters knockout tower, and catalyzer then enters regenerator and burns.Regenerator is a fluidized-bed reactor, and main air is advanced in the bottom, makes catalyst fluidization burn reaction, recovers activity of such catalysts (being called regeneration).Catalyzer after the regeneration enters reactor cycles along pipeline through the regeneration guiding valve and uses, and the heat that burns generation is also brought reactor into by catalyzer and used for cracking reaction.Reacted oil gas separates at fractionator, and gas and gasoline are gone out by cat head, enters the raw gasoline jar through cooling, is separated into gas (rich gas) and liquid (raw gasoline) again.Rich gas and raw gasoline through pipeline to the stable absorption part.Then directly by extracting out in the tower, unconverted part (recycle stock) part enters the freshening oil tank to the isolated light diesel fuel of fractionator in the oil gas, and heavier part then drops on (slurry oil at the bottom of the tower) at the bottom of the tower.Raw gasoline and rich gas finally form products such as dry gas, liquefied gas and stabilized gasoline after the stable absorption of absorbing-stabilizing system.

The production run operation optimization, can be under the situation of not revising technology, not increasing manufacturing facilities, only just can obtain tangible economic benefit by changing operating conditions, a kind of good method of the small investment of can yet be regarded as, instant effect, thereby important research and using value are arranged.

Existing Hydrocarbon Content by Catalytic Cracking Operation control method has: regeneration guiding valve → temperature of reaction (riser outlet temperature) is controlled method automatically; Guiding valve to be generated (operation valve on the catalyst line from the settler to the regenerator) → settler material level is controlled method automatically; Slurry oil extraction amount is adjusted regenerator temperature method etc. at the bottom of the tower.And some off-line tuning systems and online micro computer monitoring or optimal control system are arranged, for example multivariable prediction control system etc.Qin Ruiqi is at " China's THE DEVELOPMENT OF COMPUTERS PROCESS CONTROL OF FCC IN " (petroleum refining and chemical industry, 1994,25 (5): summarized the characteristics of these systems 1-12), its core is that existing these catalytic cracking controls and tuning scheme are based on the control temperature of reaction.But in fact, because catalytic cracking is a chemical reaction process, be reaction depth to what install operation and product distribution influence maximum, and temperature of reaction is subjected to multiple factor affecting, can not represent reaction depth fully, therefore unsatisfactory with temperature of reaction tuning actual effect.In order to address this problem.The Yuan Pu of University of Petroleum has proposed a kind of reaction heat controlling schemes in the patent of invention (application number 90108193.0) in " observation of catalytic cracking reaction depth and control method ", but because reaction heat itself is related with feedstock property, therefore this scheme is not suitable for the frequent device of feedstock property variation, can not survey because of reaction heat simultaneously, also more abstract, so the scheme implementation difficulty is bigger.

The object of the present invention is to provide a kind of with the temperature of reaction of device, to promote steam flow, feedstock oil heat exchange temperature, intermingled dregs ratio, recycle stock ratio, slurry oil recycle ratio, raw catelyst addition in advance be the closed-loop optimization control system of regulating and control variable.

The ultimate principle of correlation integral method on-line optimization control system is: in the on-line optimization control system of flow process type process units, use correlation-integral method with the variate-value calculation optimization variable of real-time measurement and the cross-correlation integral of target variable, and obtain the gradient of objective function, and then calculate the new set-point of tuning variable, implement to regulate by the basic controller of device, thereby make objective function be issued to maximum satisfying constraint condition, realize real-time optimization control process units.

The gordian technique of correlation integral method on-line optimization control system is the correlation integral theory.Correlation integral is a kind of relevant computing with stochastic process, and in the correlation integral law theory, objective function, interference, optimization variable are regarded as stochastic process, and optimization variable is that average is controlled, usually can be expressed as: $\tilde{J}\left(t\right)=f(\tilde{u}\left(t\right),\tilde{p}\left(t\right),t)$

Wherein

Be the controlled tuning variable of m dimension average, For disturbing, f is a unknown mappings.The optimal objective function definition is: ${\tilde{J}}^{*}\left(t\right)=\underset{E\left\{\tilde{u}\left(t\right)\right\}}{\max }E\left\{f\right[E\left\{\tilde{u}\left(t\right)\right\},\tilde{p}\left(t\right),t\left]\right\}$

Here, Be the average of tuning variable, it can be the setting value of basic unit's controller or valve position etc.For univariate optimization problem, can prove that the objective function average is to the gradient of tuning variable average under certain condition $\frac{\mathrm{dEf}}{\mathrm{dE}\left\{\tilde{u}\left(t\right)\right\}}$ Satisfy following formula: $K_{\mathrm{uJ}}=K_{\mathrm{uu}}\frac{\mathrm{dEf}}{\mathrm{dE}\left\{\tilde{u}\left(t\right)\right\}}+\mathrm{\ϵ}\left(t\right)$ In the formula, ε (t) is that average is zero noise item, and K _UJBe the cross-correlation integral between tuning variable and objective function, K _UuBe tuning variable autocorrelation integral, as follows: $K_{\mathrm{uJ}}(T,M)={\∫}_{-M}^M\frac{1}{2T}{\∫}_{-T}^{T}u(t-\mathrm{\τ})J\left(t\right)\mathrm{dtd\τ}$ $K_{\mathrm{uu}}(T,M)={\∫}_{-M}^M\frac{1}{2T}{\∫}_{-T}^{T}u(t-\mathrm{\τ})u\left(t\right)\mathrm{dtd\τ}$

T, M＞0 is a constant

In the above-mentioned formula, u (t), J (t) is respectively the measured value of tuning variable and objective function.As seen K _UJ, K _UuCan calculate by the observed reading of tuning variable and objective function, so according to formula $K_{\mathrm{uJ}}=K_{\mathrm{uu}}\frac{\mathrm{dEf}}{\mathrm{dE}\left\{\tilde{u}\left(t\right)\right\}}+\mathrm{\ϵ}\left(t\right)$

The gradient of available least square method estimation objective function $\frac{\mathrm{dEf}}{\mathrm{dE}\left\{\tilde{u}\left(t\right)\right\}}.$

Calculate after the gradient of objective function, can be with the new settings value u of direct iterative computation tuning variable _s(l+1) $u_s(l+1)=u_s\left(l\right)+a\frac{\mathrm{dEf}}{\mathrm{dE}\left\{\tilde{u}\left(l\right)\right\}}$ In the formula, a is a constant.

Online the continuing of this iterative process carries out, and is zero until gradient.

For multivariable optimization problem, theoretical analysis also can obtain similar result.

Closed-loop optimization control system of the present invention is the secondary control mode.Optimal controller from the DCS basic controller of catalytic cracking process units, read must metrical information, adopt correlation-integral method, per minute calculates the once correlation integral between each variable, and the correlation integral between each variable and objective function.Optimal controller is according to these correlation integral value, and the set-point that variable is once regulated and control in calculating regularly is sent to the basic controller execution.So move in circles, realize online closed-loop optimization control, improved device automation of operation degree, do not need the operative employee to intervene substantially, operation and maintenance is more prone to carry out.Because optimization system itself has fault diagnosis system and a series of safety precautions, situation in addition occurs simultaneously, all can switch to conventional control, ensure safety as the malfunctioning grade of instrument so work as device.Fig. 1 is an optimal control structural drawing of the present invention.Fig. 2 is the specific embodiments of the invention structured flowchart.

The present invention will be further described below in conjunction with specific embodiment and control procedure thereof.

The technological process of a catalytic cracking of factory of shanghai refinery as shown in Figure 3.The combined feed control system

Can see that from the technological process of Fig. 3 the combined feed of a catalytic cracking riser reactor is by wax oil+one section oil, vacuum residuum, long residuum, recycle stock and reprocessed oil slurry five road constitute.In original control system, this five tunnel charging is by separately single loop flow control, and is independent mutually.Work as one of them flow like this, when for example the wax oil flow changes, important technical parameters such as intermingled dregs ratio, recycle ratio, reprocessed oil slurry can not remain unchanged automatically than waiting.

For optimization system can stably be worked under various operating modes, each important operation parameter can not influenced each other, need transform the total reactor feed control of original system.Amended control system is made up of following sub-loop:

1. the total fresh feed amount control of reactor

2. charging intermingled dregs ratio control

3. recycle stock ratio control

4. reprocessed oil slurry ratio control

More than each variable can keep separate, wherein during the given change of any one, other variable can keep constant automatically.1. total fresh feed amount of reactor and intermingled dregs ratio control

The total fresh feed amount control system of reactor structure as shown in Figure 4.Wax oil+one section oily flow is given, and the vacuum residuum flow is given to be calculated and got by total fresh feed amount control computing module.The long residuum flow is given, unit capacity and intermingled dregs ratio are by artificial given or from optimal controller, total fresh feed amount control computing module is according to the long residuum flow measurements, the unit capacity set-point, the intermingled dregs ratio set-point calculates wax oil+one section oily flow set-point and vacuum residuum flow set-point, and its computing formula is:

Vacuum residuum set-point=intermingled dregs ratio set-point * fresh feed total flow set-point-0.5 * long residuum flow measurements

(wax oil+one section oil) flow set-point=(1-intermingled dregs ratio set-point) * fresh feed total flow set-point-0.5 * long residuum flow measurements

In order on operator interface, to show total fresh feed flow measurements and intermingled dregs ratio measured value, also need these two amounts are calculated, computing formula is;

Fresh feed total flow measured value=(wax oil+one section oil) flow measurements+vacuum residuum flow measurements+long residuum flow measurements

Intermingled dregs ratio measured value=(vacuum residuum flow measurements+0.5 * long residuum flow measurements)/fresh feed total flow measured value 2. recycle stock ratio control systems

The recycle stock ratio control system is seen Fig. 5.Wherein

Fresh feed total flow measured value=(wax oil+one section oil) flow measurements+vacuum residuum flow measurements+long residuum flow measurements

Recycle stock is than measured value=recycle stock flow measurements/fresh feed total flow measured value

Recycle stock flow set-point=recycle stock is than set-point * fresh feed total flow measured value

Recycle stock flow set-point can be by artificial or given by optimal controller.3. reprocessed oil slurry ratio control system

The reprocessed oil slurry ratio control system is seen Fig. 6.Wherein

Fresh feed total flow measured value=(wax oil+one section oil) flow measurements+vacuum residuum flow measurements+long residuum flow measurements

Reprocessed oil slurry unit rate of flow measured value=reprocessed oil slurry flow measurements/fresh feed total flow measured value

Reprocessed oil slurry flow set-point=reprocessed oil slurry is than set-point * fresh feed total flow measured value

Reprocessed oil slurry flow set-point can be by artificial or given by optimal controller.The optimal control system

According to the market situation that present oil product is sold, consider the polytrope of catalyzed cracking processing scheme, the present process equipment condition of a comprehensive catalytic cracking requires whole optimization system to adapt to and different process raw material and produce different major products.This optimal control system can adapt to three kinds of processing schemes:

● with the liquid hydrocarbon is the prioritization scheme of major product

● with gasoline is the prioritization scheme of major product

● with diesel oil is prioritization scheme 1. objective functions of major product: be in the prioritization scheme of major product with the liquid hydrocarbon, with the liquid hydrocarbon productive rate as fast-opening target function (OBJS (t))

OBJS (t)=liquid hydrocarbon flow/motion device oil plant flow

Constraint condition: it is being in the prioritization scheme of major product with gasoline that diesel yield is not less than 25% (this value can manually be set), is fast-opening target function (OBJS (t)) with the yield of gasoline

OBJS (t)=gasoline flow/motion device oil plant flow

Constraint condition: it is being in the prioritization scheme of major product with diesel oil that diesel yield is not less than 25% (this value can manually be set), and diesel yield is taken as fast-opening target function (OBJS (t))

OBJS (t)=diesel oil flow/motion device oil plant flow

Constraint condition: liquid hydrocarbon yield is not less than 9% (this value can manually be set)

Wherein: motion device oil plant flow=wax oil flow+one section oily flow+subtract residual oil flow+normal residual oil flow

When actual optimization, optimization aim OBJ is 8 hours recurrence average yields of fast-opening target function OBJS (t), that is: $\mathrm{OBJ}=\frac{1}{8}{\∫}_{-8}\mathrm{OBJS}\left(s\right)\mathrm{ds}$

These three processing schemes can switch at any time according to the instruction of process schedule.2. the compensation of objective function

In the optimal control system, its fast-opening target function, promptly the instantaneous yield of major product be by the semi-invariant of major product output in a sampling period divided by new raw material with one-period in the semi-invariant of motion device calculate and get.This is out of question for liquid hydrocarbon and gasoline scheme.But in diesel oil scheme, its finished diesel fuel part also will be used as oil sealing etc., is back to (see figure 4) among the system, and the diesel oil of therefore real bleeder should deduct this part capacity of returns.

Among Fig. 7,201 and 202 is to receive oil tank, and LD501 and LD502 are their liquid levels.These two jars are alternately received oil and are drained the oil.Obviously,,, have in the sampling period data by material balance:

Production of diesel oil=finished diesel fuel amount-backflow diesel oil amount

Because finished diesel fuel amount and backflow diesel oil amount all do not have pick-up unit, can only go out liquid level change that device flow totalizer and two receive oil tanks by diesel oil and calculate and get.Computing formula is as follows:

Data in the sampling period:

Production of diesel oil=diesel oil goes out device semi-invariant+receipts oil than positive quantity

Receive oil than positive quantity=0.82 * π * 6.6 ²/ 4 * 0.06 * (Δ LD501+ Δ LD502)

In the formula: Δ LD501, Δ LD502 are respectively 501 and 502 jars of liquid levels at the variable quantity of data in the sampling period.Like this,

The instantaneous yield of diesel oil scheme major product=newly former in (diesel oil goes out the oily correcting value of device semi-invariant+receive in sampling period)/same sampling period

Material motion device semi-invariant 3. optimization variable

When selecting optimization variable, those in the main consideration reaction-regenerating section technology are important, are easy to the variable of controlling simultaneously again.In catalytic cracking unit, get following variable as the on-line optimization variable

● riser outlet temperature (TC701)

● promote steam flow (FC2104) in advance

● feedstock oil heat exchange temperature (TC350)

● intermingled dregs ratio (FB002.R003)

● the recycle stock ratio

● the slurry oil recycle ratio

● efflux 4. constraint condition 1 of slurry oil amount (FC205)) constraint of optimization variable

In the optimal control system, in order to protect the normal operation of positive safety and process, all optimization variable can only change in a certain tolerance band.This tolerance band is exactly the constraint of optimization variable.In native system, each optimization variable all is provided with the upper bound and lower bound, and is as shown in table 1.The constraint of considering these variablees may be along with the mode of operation of device, prioritization scheme and changing, and they can both manually be provided with as required by operator interface.

The constraint condition of optimization variable

The optimization variable name	Constraint condition
		Temperature of reaction	The artificial variable upper bound, artificial variable lower bound
The pre-steam flow that promotes	The artificial variable upper bound, artificial variable lower bound
		Feedstock oil heat exchange temperature	The artificial variable upper bound, artificial variable lower bound
Intermingled dregs ratio	The artificial variable upper bound, artificial variable lower bound
		The recycle stock ratio	The artificial variable upper bound, artificial variable lower bound
The slurry oil recycle ratio	The artificial variable upper bound, artificial variable lower bound, liquid level rule constrain at the bottom of the fractionator
		Efflux the slurry oil flow	The artificial variable upper bound, artificial variable lower bound, liquid level rule constrain at the bottom of the fractionator

In order to guarantee in the optimizing process that liquid level changes at the bottom of the fractionator in normal range, in the system also to the slurry oil recycle ratio with efflux these two of slurry oil flows and influence directly that the variable of liquid level has added rule constrain at the bottom of the fractionator.Rule is as following table.Can see that from this table the principle of constraint rule is that liquid level remains between 30% to 70% at the bottom of making fractionator as far as possible.Whether going beyond the scope then depends on the circumstances carries out is optimized instruction.

Table slurry oil recycle ratio and efflux the fractionator of slurry oil flow at the bottom of the liquid level constraint rule

Liquid level at the bottom of the fractionator	Optimize instruction	Executing rule
			＜30％	Increase	Do not execute instruction, keep initial value
＜30％	Reduce	Execution command
			＞70％	Increase	Execution command
＞70％	Reduce	Do not execute instruction, keep initial value

2) product distributes and retrains

In optimal control, may cause the decline of other products productive rate to the optimization of major product.For example, in the diesel oil prioritization scheme, the increase of diesel yield will cause the minimizing of liquid hydrocarbon yield.And in actual production process, such requirement is proposed sometimes: be not less than the yield that improves diesel oil under the prerequisite of certain value as far as possible at liquid hydrocarbon yield.This requirement can be considered a kind of constrained optimization.

In this optimization system, added this constraint condition that product is distributed, as shown in the table.

The constraint that the product of each prioritization scheme distributes

Prioritization scheme	Product distribution constraint condition
		Liquid hydrocarbon	Diesel yield is not less than certain artificial setting value
Gasoline	Diesel yield is not less than certain artificial setting value
		Diesel oil	Liquid hydrocarbon yield is not less than certain artificial setting value

The artificial setting value of the constraint condition in the last table can be made amendment by the slip-stick artist, perhaps constraint condition is removed.5. control structure

Overall control structure is the secondary control mode.Optimal controller from the basic controller of a catalytic cracking, obtain must metrical information, per minute calculates the once correlation integral between each variable, and the correlation integral between each variable and objective function.Optimizer calculated a set-point and is sent to the basic controller execution according to these correlation integral value in per ten minutes.So move in circles, finish the line closed loop optimal control.

In optimal controller, 7 optimization variable have adjustable separately bound, also can follow according to concrete condition a part of variable input is manual, and another part variable input is automatic.When the change-over switch among Fig. 7 was in A, the output of optimal controller was communicated with corresponding regulator, is optimized control.And when change-over switch was in M, regulator was outer given by artificial setting accordingly.6. report to the police and emergency system

A catalytic cracking optimal control is provided with the abnormality detection system of measuring-signal.Input signal of its per minute inspection as finding the undesired situation of signal, can send alerting signal on operator interface, remind the operator that corresponding instrument is checked.Simultaneously, the optimal control core is recombinated to optimal control according to the testing result of abnormality detection system, those variablees that are subjected to unusual measuring-signal influence is suspended optimize, keep unusual preceding state, and those variablees that not influenced by unusual measuring-signal are continued to optimize.Detect the unusual disappearance of measuring-signal when abnormality detection system after, the optimal control core is replied reorganization automatically, recovers normal control mode.

When device was in an emergency, the operator can start emergency system.After pressing red emergency button and confirming, emergency system cuts out optimal control with all variablees immediately, simultaneously the basic controller relevant with optimal control from long-range given be cut to local given.Give the operator control in all loops.

After device was returned to normal condition, the operator can optimize the variable input by normal step.7, operation interface design and systemic-function

Form below having designed on the operation interface of optimal control:

NAME	??MEAS	??GRD	??OPT	??OUTPUT	??HI?LIM	??LO?LIM	??A/M	??ALARM
									TC701
FC2104
									TC350
RSID?RA
									RCYC?RA
OILMD?RA
FC205

OBJ		CNT		OPTALM		FEED.SP
								LHC?YLD		GASL?YLD		DIES?YLD		FEED.M

MAXIMUM?SCHEME

?LIQUID?HYDROCARBON	????GASOLINE	????DIESEL?OIL
			?CONSTRAIN：9		????CONSTRAIN：25

????EMERGENCY

In table, the title implication of each row is as follows; The title of NAME optimization variable, wherein

● TC701 riser outlet temperature (DEGC)

● FC2104 promotes steam flow (T/H) in advance

● TC350 feedstock oil heat exchange temperature (DEGC)

● RSID RA intermingled dregs ratio (%)

● RCYC RA recycle stock is than (%)

● OILMD RA slurry oil recycle ratio (%)

● FC205 effluxes slurry oil amount (T/H) GRD and optimizes gradient, is the intermediate result of computation optimization.As for just, then this variable will raise, and will reduce for negative.OPT optimal control value OUTPUT controller output valve.This value will be sent on relevant controlling loop outer given.This variable can online manual amendment.The high limit of HI LIM optimal controller.When implementing optimal control, the higher limit of optimised variable.This variable can online manual amendment.LO LIM optimal controller lower bound.When implementing optimal control, the lower limit of optimised variable.This variable can online manual amendment.A/M is communicated with optimal controller and artificial given switch.Whether the indivedual variablees of this switch controls drop into optimization.When switch is in A condition,

The output of controller (OUTPUT value) links to each other with optimizer, send optimal control value (OPT) outside corresponding controller given on.As locate

In the M state, the then output of controller (OUTPUT value) is by manually given, manual amendment OUTPUT value, this moment as with reference to optimal control

Value (OPT) manual amendment OUTPUT can constitute the operation of open loop optimization guidance.ALARM optimization variable alarm.When this hurdle green light, variable is normal, as red light occurs, and then this variable monitors exceptional value.When the A/M state

During for A, optimization system can be downcut this variable automatically automatically, keeps current output valve (OUTPUT) constant, but the apparent A/M hurdle shape of going up

Attitude is constant, still is A.The currency of OBJ optimization aim function, each minute refreshes once.CNT optimizer counter.Under normal circumstances each minute adds 1 to this number.Big return 1 automatically to certain upper limit (about 485) back, week and

Renew.Duty in order to the monitoring optimizing device.The OPTALM optimizer is reported to the police.As being normal for green light, red alarm, expression optimizer monitor the key variables data exception (as calculating the target letter

The relevant instrumented data of number is unusual), optimizer enters emergency rating automatically, and each output valve (OUTPUT) keeps currency.When data extensive

After normal again, reporting to the police disappears the automatic normal operation input of optimizer.Eight hours integrating yields of LHC YLD liquid hydrocarbon.Each minute refreshes once.Calculate the integrating yield that pushes away eight hours liquid hydrocarbons before current.Eight hours integrating yields of GASL YLD gasoline.Calculate the integrating yield that pushes away eight hours gasoline before current.Eight hours integrating yields of DIESYLD diesel oil.Calculate the integrating yield that pushes away eight hours diesel oil before current.Under the MAXIMUM SCHEME title, three buttons are arranged, the Control and Optimization scheme.Press LIQUID HYDROCARBON button, optimization aim is a fecund

Liquid hydrocarbon.Press the GASOLINE button, target is voluminous gasoline.Pressing DIESEL OIL is high-yield diesel oil.It may be noted that this

A little buttons can only just can be pressed in slip-stick artist's environment.Below the LIQUID HYDROCARBON button, CONSTRAIN:9 is arranged, be liquid hydrocarbon yield constraint condition (9%), this project has only when adopting bavin

It is just effective that oil is optimized prioritization scheme, and purpose is to make liquid hydrocarbon yield more than or equal under 9% the preceding topic, improves the yield of diesel oil as far as possible.Should

The constraint condition value can be set under slip-stick artist's environment.When this constraint condition value less than 1% the time, constraint condition is cancelled.Below the DIESEL OIL button, CONSTRAIN:25 is arranged, be diesel yield constraint condition (25%), this project has only when adopting liquid hydrocarbon or vapour

It is just effective that oil is optimized prioritization scheme, and purpose is to make diesel yield more than or equal under 25% the preceding topic, improves the receipts of liquid hydrocarbon or gasoline as far as possible

Rate.This constraint condition value can be set under slip-stick artist's environment.When this constraint condition value less than 1% the time, constraint condition is cancelled.The EMERGENCY button only uses when emergency condition takes place.After pressing this button and affirmation, control system is the following emergency procedure of starting automatically:

1) all each optimization system is related control loop setting value R are cut to L, and are given in promptly outer given being cut to.

2) A with each optimization variable is cut to M, promptly is cut to artificial setting from optimization.

The acquisition process of each measuring-signal in the above-mentioned embodiment, optimal controller are realized by Distributed Control System (DCS) (DCS) and host computer thereof.This scheme is applied on the commercial plant, has reached automatic adjustment performance variable, optimization aim function, the purpose of raising device target product yield.To the medium-sized catalytic cracking process units of 900,000 tons/year in factory of shanghai refinery, a year economic benefit is more than more than 500 ten thousand yuan.

Claims (2)

1, situ catalytic cracking control system based on correlation integration, it is characterized in that: in the on-line optimization control system of catalytic cracking unit, whether the application correlation-integral method is under the optimum operation conditions with the variate-value calculation element of real-time measurement, and according to the temperature of reaction of result calculated regulating device, the pre-steam flow that promotes, feedstock oil heat exchange temperature, intermingled dregs ratio, the recycle stock ratio, the slurry oil recycle ratio, optimization variable such as raw catelyst addition, thereby make objective function (the liquid hydrocarbon productive rate of device, gasoline yield, the whole economic efficiency of diesel yield or device etc.) be issued to maximum satisfying constraint condition, realize the real-time optimization control of catalytic cracking unit.

2, method according to claim 1, it is characterized in that: whether the objective function (whole economic efficiency of liquid hydrocarbon productive rate, gasoline yield, diesel yield or device etc.) that is calculated device by the real-time variable value application correlation integral method that installs is in optimum condition, and then the temperature of reaction of regulating device, promote optimization variable such as steam flow, feedstock oil heat exchange temperature, intermingled dregs ratio, recycle stock ratio, slurry oil recycle ratio, raw catelyst addition in advance, thereby realized utilizing the closed-loop optimization control of these variablees.

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