CN107057749B

CN107057749B - The online soft sensor system and measurement method of gasoline stabilizer separation accuracy

Info

Publication number: CN107057749B
Application number: CN201610633279.6A
Authority: CN
Inventors: 匡华清; 关新虎; 冯新国
Original assignee: PETRIFACTION CENTURY INFORMATION TECHNOLOGY Corp
Current assignee: PETRIFACTION CENTURY INFORMATION TECHNOLOGY Corp
Priority date: 2016-08-04
Filing date: 2016-08-04
Publication date: 2018-12-07
Anticipated expiration: 2036-08-04
Also published as: CN107057749A

Abstract

The present invention relates to a kind of online soft sensor system of gasoline stabilizer separation accuracy and measurement methods, belong to oil-refining chemical process automatic control technology field, comprising: liquefied gas C5+ content measuring method and stable gasoline Lei Shi vapour pressure measurement method.The existing conventional instrument measurement process parameters such as tower top temperature, tower top pressure, column bottom temperature, tower reactor pressure of the present invention according to gasoline stabilizer, determine the online computation model of hard measurement, the separation accuracy of on-line real-time measuremen gasoline stabilizer, that is two liquefied gas C5+ content, stable gasoline Lei Shi vapour pressure quality indicator values, wherein soft-sensing model coefficient, the step of providing by the method for the present invention and rule determine, the quality index numerical value calculated in real time according to the present invention both can be used as the reference that operation adjusts in real time；The controlled variable that can also be used as Dynamic matrix control device realizes direct closed loop quality control；To propose the stationarity and accuracy of high quality control, device economical operation benefit is improved.

Description

The online soft sensor system and measurement method of gasoline stabilizer separation accuracy

Technical field

The present invention relates to oil-refining chemical process automatic control technology fields, in particular to a kind of gasoline stabilizer The online soft sensor method of separation accuracy, it may be assumed that liquefied gas C5+ content, two quality index of stable gasoline Lei Shi vapour pressure Line flexible measurement method.

Background technique

In oil-refining chemical enterprise, the heavy oil conversions such as residual oil, wax oil are light petroleum gas, are the main economic effects for refining oil part Beneficial source.It the cracking units such as executes the catalytic cracking of conversion reaction task, delayed coking, be hydrocracked, being the pass for refining oil part Key core apparatus.

Cracked reaction product mainly has gasoline component, liquefied gas component, dry gas component etc..Cracking unit reactor outlet oil Gas, by main fractionating tower, reaction product after unreacted diesel oil, slurry oil (or wax oil) component are separated, then pass through suction Stabilization process is received, the products such as stable gasoline, liquefied gas, dry gas are separated under 1MPa or so operating pressure.Vapor recovery unit process It is widely used important production process in Petrochemical Enterprises.

The major process unit of Vapor recovery unit process is absorption tower, desorber, stabilizer；The Vapor recovery unit mistake of most devices Journey is also equipped with dry gas reabsorber after absorption tower；Also the absorption tower and desorber for having partial devices are combined into one, i.e. top For absorption process, lower part is desorption process.Desorber, by thermal distillation, by condensed oil, (reaction oil gas pressurizes condensation after cooling Oil and absorbing tower base oil mixture) in C2 (ethane, ethylene) component, methane and other low-boiling point gas substances desorb into Tower top returns to absorption tower charging, and tower reactor liquid phase (commonly referred to as deethanization gasoline) is further separated into stabilizer.Most refinery enterprises The desorber of industry Vapor recovery unit process, is intended to strong desorption operations, and methane is free of in the liquefied gas for isolating subsequent stabilizer With other low-boiling point gas substances.

Stabilizer, by the distillation process of tower bottom thermal distillation and tower top cold reflux, by gasoline component and liquefied gas component point From.The yield of gasoline of cracking unit is usually more much larger than yield of liquefied gas, and the main productive target of stabilizer is further to remove Liquefied gas component in " deethanization gasoline ", is processed into stable gasoline, therefore, stabilizer, also commonly referred to as gasoline stabilizer.

Because liquefied gas is exactly C3 and C4 component, the stabilizer of some cracking units is also referred to as the de- C4 tower of gasoline or gasoline is de- Butane tower.

The separation accuracy of gasoline stabilizer, theoretically can be used: " C5 and more heavy constituent contains in the liquefied gas of tower top extraction Amount (usually write a Chinese character in simplified form are as follows: liquefied gas C5+ content) ", " content of C4 and more light component in the stable gasoline of tower bottom extraction " characterize, For stable gasoline, an important quality index is " volatility ", practical in the examination and test of products in production, generallys use " thunder Family name's vapour pressure " index, and the gasoline Lei Shi vapour pressure of petrochemical industry standard, the pass with " content of C4 and more light component in gasoline " System, is height linear approximate relationship.

In conclusion in oil-refining chemical enterprise, the separation accuracy of gasoline stabilizer generallys use that " liquefied gas C5+ contains Amount ", " stable gasoline Lei Shi vapour pressure " characterize.

It is produced in practice in Petrochemical Enterprises, liquefied gas C5+ content, stable gasoline Lei Shi vapour pressure generally use timing and adopt The analysis of sample laboratory obtains.Because manpower limits, the time interval of assay is usually long, and a few hours are primary, even one day Primary or longer, for Operating Guideline, real-time is poor.For this purpose, having many Petrochemical Enterprises configuration in-line analyzers, real-time detection The data such as liquefied gas composition.

As Advanced Control Techniques are in the popularity of refining and petrochemical processing units, with multivariable prediction coordinated control and product matter The Advanced Control Techniques that direct closed-loop control is notable feature are measured, the detection to product quality proposes online real-time continuous survey The requirement of amount.Timing sampling assay is unable to reach the requirement of online real-time continuous measurement；On-line chromatograph analyzer, but Have the defects that certain time lag, periodic calibration pulse-type disturbance, and because the analyzers such as on-line chromatograph must configure specimen preprocessing Reason system, compared with general measure instrument, failure rate is relatively high, and maintenance workload is bigger.

Liquefied gas C5+ content based on general measure instrument, stable gasoline Lei Shi vapour pressure online soft sensor model are established, On-line real-time measuremen goes out its numerical value, can greatly save hardware investment, reduce maintenance workload, and time lag can be overcome to control The influence of system, to improve control of product quality precision.

It is corresponding online even if gasoline stabilizer is configured with the in-line analyzer of liquefied gas component, stable gasoline vapour pressure Hard measurement can also play in analyzer failure and calibration and filter out impulse disturbances, prevent from causing substantially closed loop quality control Shock vibration, and in-line analyzer can be substituted during failure and continue on-line checking quality index, it is to prevent closed loop quality control The necessary complement measure of abnormal disturbances.

Since Advanced Control Techniques promote and apply, the flexible measurement method being widely used is " data-driven regression modeling " side Method, it may be assumed that according to production process experience, choose related process variable (general measure meter parameter) work that may influence tested index For input, by a large amount of sample data, soft-sensing model is established in recurrence, realizes online soft sensor.This data-driven returns Modeling, input variable it is more and with the relationship of tested index be it is uncertain, model quality influenced by sample quality it is too big, Hard measurement reliability and adaptability are usually undesirable.

Summary of the invention

In view of the deficiency of the prior art, the present invention provides a kind of easy reliable gasoline stabilizer separation accuracy Online soft sensor method.

The technical solution used in the present invention is:

A kind of online soft sensor system of gasoline stabilizer separation accuracy, including stabilizer, stabilizer include tower top dome, The space that the dome and top first layer column plate of tower surround, the interface of liquid and vault indoor gas on first layer column plate are The last one separation of ascending vapor logistics composition variation in tower, after top gaseous phase logistics is cooling, condensation enters liquid gas storage tank, Composition no longer changes, and therefore, liquefied gas C5+ content depends on the indoor vapor liquid equilibrium of tower top vault；

The sensor of thermometric instrument and the sensor of pressure gauge are arranged in tower top dome；

Thermometric instrument measures tower top dome liquidus temperature, and pressure gauge measures tower top pressure；

Liquid gas storage tank extracts logistics out, and a part goes out device as liquefied gas product, measures its flow by flow instrument；It is another Part is used as tower top cold reflux, is squeezed at the top of stabilizer after flow instrument measures；

Stabilizer includes tower reactor, the space that tower lower part the last layer column plate and tower bottom surround, bottom liquid and gas reactor Point interface, be flow downward in tower liquid phase stream composition variation the last one separation, the vapour pressure of stable gasoline, Depending on the vapor liquid equilibrium in tower reactor；

The sensor of thermometric instrument and the sensor of pressure gauge are arranged in tower reactor；

Thermometric instrument measures tower bottom liquidus temperature, and pressure gauge measures tower reactor pressure

A kind of online soft sensor method of gasoline stabilizer separation accuracy, comprising: liquefied gas C5+ content soft measuring method and Stable gasoline Lei Shi vapour pressure flexible measurement method.

The step of liquefied gas C5+ content soft measuring method are as follows:

Step (1.a) determines that the normal minimum pure material of boiling point is the pass for characterizing liquefied gas C5+ content in liquefied gas C5 component Key component pure material；

Step (2.a) determines the liquidus temperature measuring instrumentss T of gas-liquid separation interface in gasoline stabilizer tower top dome_TOP With gaseous pressure measuring instrumentss P_TOP, what industrial process instrument measurement went out is celsius temperature scale (DEG C) and relative pressure (MPa)；

If gas-liquid separation interface does not have temperature measuring instrument in the dome of gasoline stabilizer top, tower top first layer tower can be used Temperature or top gaseous phase temperature replace under plate；Gaseous pressure P at tower top gas-liquid separating interface_TOP, it is commonly configured with tower top pressure Measuring instrumentss numerical value, directlys adopt；

Step (3.a), liquefied gas C5+ content key component pure material gas-liquid separation interface liquid phase temperature in tower top dome Spend T_TOPComparison temperature T_r,C5,TOPIt is calculated as follows:

T_r,C5,TOP=(T_TOP+273.15)/T_c,C5

Wherein:

T_c,C5For the critical-temperature of liquefied gas C5+ content key component pure material, unit K

273.15 being 0 DEG C of Celsius temperature of kelvin rating

Step (4.a) calculates key component pure material saturated vapor pressure under liquidus temperature at tower top dome gas-liquid separation 's；

Using distinct methods, the saturated vapor calculated is pressed with pressure value or reduced pressure force value.Vapour pressure pressure value and Reduced pressure force value can be calculated by simple linear and be converted, and convenient for the statement of following model algorithm, which does not repartition Pressure value and reduced pressure force value；

Saturated vapor of the liquefied gas C5+ content key component pure material in tower top dome gas-liquid separation interface liquidus temperature Pressure is expressed as P_VP,C5,TOP；

Step (5.a) determines liquefied gas C5+ content soft sensor model:

Wherein:

C5_LPGFor liquefied gas C5+ content, unit %

A_0,C5、A_1.C5For model coefficient

0.101325 is the difference of absolute pressure and relative pressure, units MPa

Step (6.a), off-line calculation determines model coefficient according to the following steps:

Step (6.1a), from the gasoline stabilizer Process History of acquisition certain period of time in dcs (DCS) Data；

The stabilizer procedure parameter for needing to acquire has:

1)T_TOP: tower top dome liquidus temperature, DEG C

2)P_TOP: tower top dome gaseous pressure, MPa

If 3) be configured with in-line analyzer, increase liquefied gas C5+ content AI_C5Data；

Such as without configuration in-line analyzer, then the liquefied gas C5+ of corresponding period is collected from device analysis data library again Content analysis data (also uses AI_C5Indicate) and its sampling instant data；

Data sampling interval 1,2 or 5 minute；

Data segment time span is established rules then really are as follows:

1) model coefficient is determined using analysis data, then includes continuous 10 or more liquefied gas C5+ contents in the period Analysis data sample；The amplitude of variation of liquefied gas C5+ content value >=high limit of process chart regulation 1/2；

2) it is configured with in-line analyzer, then includes the significant fluctuating change of quality index: liquefied gas in the period The fluctuating range of C5+ content >=high limit of process chart regulation 1/3.

The above process is lasted data, imported in Excel table by step (6.2a),

For each procedure parameter, the data of the seclected time period are expressed as an array, such as T_TOP,j, j=1,2 ..., N, n is equal to seclected time period data sample number here；

Step (6.4a), it is first in the Excel table that the above process lasts data and laboratory values or in-line analyzer data Smothing filtering operation first is carried out to each process parameter data:

(Z)_j+1=(1-F_L)*(Z)_j+F_L*(Z)_j+1, j=1,2 ..., n

Wherein:

(Z) T is represented_TOP、P_TOPAnd analyzer data

F_LFor smothing filtering coefficient, value is 0.70~0.85

Then in Excel table, using later process parameter data is filtered, array column are calculated:

Step (6.5a) determines soft-sensing model coefficient using one of following two methods:

Step (6.5.1a) calculates soft-sensing model coefficient A referring to the scale calculation method of instrumentation engineering_1.C5:

Sampling instant, the numerical error of analysis data are considered, for the computational accuracy for improving model coefficient, A_1.C5Using three times Calculate the method averaged；And A_0,C5It is the zero-bit of hard measurement, when off-line calculation finds out a provisional value, and hard measurement is online It can constantly be calibrated in operation；

Observation comparative approach is shown using curve, respectively:

I. maximum three sample values of liquefied gas C5+ content laboratory values (or in-line analyzer data) are selected, from big to small It is expressed as AI_C5,MAX1、AI_C5,MAX2、AI_C5,MAX3, the X of three assay samples sampling instants_C5,jIt is expressed as X_C5,MAX1、 X_C5,MAX2、X_C5,MAX3；

Ii. the smallest three sample values of liquefied gas C5+ content laboratory values (or in-line analyzer data) are selected, from big to small It is expressed as AI_C5,MIN1、AI_C5,MIN2、AI_C5,MIN3, the X of three assay samples sampling instants_C5,jIt is expressed as X_C5,MIN1、 X_C5,MIN2、X_C5,MIN3；

It calculates and determines A_1.C5And A_0.C5Value:

A_0.C5=AI_C5,MIN1-A_1.C5*X_C5,MIN1

Step (6.5.2a), with X_C5For input variable, with AI_C5To be detected variable, is returned using PLS and obtain hard measurement Model coefficient；Regression result needs to verify: A_1.C5For positive value.Otherwise data should be chosen again to return again；

Step (7.a), it is determined that after model coefficient, the online soft sensor of liquefied gas C5+ content is realized, host computer can be used Soft instrument software, host computer calculation procedure are realized or are realized using DCS Function Block Configuration；

Liquefied gas C5+ content soft instrument or calculation procedure, by OPC obtain DCS in gasoline stabilizer tower top temperature, Liquefied gas C5+ content data is sent into DCS after the completion of calculating and shown or for used in closed-loop control by tower top pressure process data.Tower Push up liquefied gas C5+ content chemical examination/analyzer data, be sent into host computer in, by correction module periodically or real time calibration liquefied gas Zero-bit of the C5+ containing numerical quantity.

The step of stable gasoline Lei Shi vapour pressure flexible measurement method are as follows:

Step (1.b) determines that the highest pure material of normal boiling point is characterization stable gasoline Lei Shi in C4 component in stable gasoline The key component pure material of vapour pressure；

Step (2.b) determines the liquidus temperature measuring instrumentss T of gas-liquid separation interface in gasoline stabilizer tower reactor_BTMIt is gentle Phase pressure measuring instrumentss P_BTM, what industrial process instrument measurement went out is celsius temperature scale (DEG C) and relative pressure (MPa).

If there is no tower reactor gaseous pressure measuring instrumentss data in DCS, it is determined that gasoline stabilizer top gaseous phase pressure is surveyed Measure instrument P_TOP, liquefied gas output flow measurement instrument F_LPGWith overhead reflux flow measurement instrument F_RE, gasoline stabilizer tower reactor pressure The calculation method of power is provided in subsequent step (6.3b)；

Step (3.b), stable gasoline Lei Shi vapour pressure key component pure material gas-liquid separation interface liquid phase in tower reactor Temperature T_BTMComparison temperature T_r,RVP,BTMIt is calculated as follows

T_r,RVP,BTM=(T_BTM+273.15)/T_c,RVP

Wherein:

T_c,RVPFor the critical-temperature of stable gasoline Lei Shi vapour pressure key component pure material,

Unit K

273.15 be 0 DEG C of Celsius temperature of kelvin rating

Step (4.b) determines stable gasoline Lei Shi vapour pressure key component pure material liquid phase temperature at tower reactor gas-liquid separation Spend lower saturated vapor pressure；

Saturated vapor pressure table of the stable gasoline Lei Shi vapour pressure key component in tower reactor gas-liquid separation interface liquidus temperature It is shown as P_VP,RVP,BTM。

Step (5.b) determines stable gasoline Lei Shi vapour pressure soft-sensing model:

Wherein:

RVP_STABFor stable gasoline Lei Shi vapour pressure, unit kPa

A_0,RVP、A_1,RVPFor model coefficient

Step (6.b), off-line calculation obtains soft-sensing model coefficient according to the following steps:

Step (6.1b) acquires the gasoline stabilizer Process History data of certain period of time from dcs；

The stabilizer procedure parameter for needing to acquire has:

1)T_BTM: tower reactor liquidus temperature, DEG C

2)P_BTM: tower reactor gaseous pressure (if there is measuring instrumentss DCS data are shown), MPa

3) such as tower reactor gaseous pressure does not have measuring instrumentss DCS data to show, then acquires top gaseous phase pressure (MPa), liquefies Gas output flow F_LPGWith overhead reflux flow F_RE, two of them data on flows, unit is consistent

4) it is such as configured with in-line analyzer, then is further added by stable gasoline vapour pressure AI_RVPData；

Such as without configuration in-line analyzer, then the stable gasoline for collecting the corresponding period from device analysis data library again steams Vapour pressure analysis data (also uses AI_RVPIndicate) and its sampling instant data；

Sampling interval 1,2 or 5 minute；

Data segment time span is established rules then really:

Model coefficient is determined using analysis data, then includes continuous 10 or more stable gasoline vapour pressures in the period Test data sample；Amplitude of variation >=6kPa of stable gasoline vapour pressure；

It is configured with in-line analyzer, then includes the significant fluctuating change of quality index: stable gasoline in the period Fluctuating range >=4kPa of vapour pressure；

The above process is lasted data, imported in Excel table by step (6.2b)；

For each procedure parameter, the data of the seclected time period are expressed as an array, such as T_BTM,j, j=1,2 ..., N, n is equal to seclected time period data sample number here；

Step (6.3b) jumps to step (6.4b) if having collected tower reactor gaseous pressure data.This step by step, Gasoline stabilizer tower reactor pressure is calculated using following algorithm:

Stabilizer pressure drop is calculated first estimates coefficient A_DP:

Wherein:

A_DPFor constant, using mean value computation as a result, not considering unit；

P_BTM,0For constant, value is equal to the tower reactor pressure mean value obtained from operating experience or site instructions pressure gauge；

Then tower reactor pressure value array is calculated

P_BTM,j=P_TOP,j+A_DP*(F_LPG,j+F_RE,j)

Step (6.4b), it is first in the Excel table that the above process lasts data and laboratory values or in-line analyzer data Smothing filtering operation first is carried out to each process parameter data:

(Z)_j+1=(1-F_L)*(Z)_j+F_L*(Z)_j+1, j=1,2 ..., n

Wherein:

(Z) T is represented_BTM、P_BTMAnd analyzer data

F_LFor smothing filtering coefficient: for observed temperature, pressure and in-line analyzer data,

F_L=0.70~0.85；

For the tower reactor pressure data being calculated, F_L=0.85~0.97；

Step (6.5b) determines soft-sensing model coefficient using one of following two methods；

Step (6.5.1b) calculates soft-sensing model coefficient referring to the scale calculation method of instrumentation engineering；

Sampling instant, the numerical error of analysis data are considered, for the computational accuracy for improving model coefficient, A_1,RVPUsing three times Calculate the method averaged；And A_0,RVPIt is the zero-bit of hard measurement, when off-line calculation finds out a provisional value, and hard measurement is online It can constantly be calibrated in operation；

Observation comparative approach is shown using curve, respectively:

I. maximum three sample values of stable gasoline vapour pressure laboratory values (or in-line analyzer data) are selected, from big to small It is expressed as AI_RVP,MAX1、AI_RVP,MAX2、AI_RVP,MAX3, the X of three assay samples sampling instants_RVP,jIt is expressed as X_RVP,MAX1、 X_RVP,MAX2、X_RVP,MAX3；

Ii. the smallest three sample values of stable gasoline vapour pressure laboratory values (or in-line analyzer data) are selected, from greatly to It is small to be expressed as AI_RVP,MIN1、AI_RVP,MIN2、AI_RVP,MIN3, the X of three assay samples sampling instants_RVP,jIt is expressed as X_RVP,MIN1、X_RVP,MIN2、X_RVP,MIN3。

It calculates and determines A_1,RVPAnd A_0,RVPValue:

A_0.RVP=AI_RVP,MIN1-A_1.RVP*X_RVP,MIN1

Step (6.5.2b), with X_RVPFor input variable, with AI_RVPTo be detected variable, is returned using PLS and obtain hard measurement Model coefficient；Regression result needs to verify: A_1.RVPFor positive value.Otherwise data should be chosen again to return again；

When DCS does not have tower reactor pressure measured data, stable gasoline Lei Shi vapour pressure hard measurement mould that step (5.b) provides Type, pattern also can be changed are as follows:

At this point, not executing step (6.3b) and step (6.4b), the mistake that step (6.2b) imports Excel table is directlyed adopt Journey lasts data and laboratory values or in-line analyzer data, seeks model coefficient using the PLS Return Law:

Smothing filtering operation is carried out to each process parameter data first:

(Z)_j+1=(1-F_L)*(Z)_j+F_L*(Z)_j+1, j=1,2 ..., n

Wherein:

(Z) T is represented_BTM、P_TOP、And analyzer data

F_LFor smothing filtering coefficient:

For temperature, pressure and in-line analyzer data, F_L=0.70~0.85；

For data on flows: F_L=0.85~0.97；

Then in Excel table, using later process parameter data is filtered, two array column are calculated:

Finally with X1_RVP、X2_RVPFor input variable, with AI_RVPTo be detected variable, using PLS, that is, Partial Least Squares Regression Method obtains soft-sensing model coefficient；

Regression result should meet:

(1)A_1,RVP、A_2,RVPIt is positive value；

(2)Value agreement be equal to stabilizer voltage drop value.F herein_LPGAnd F_RE, above-mentioned It filters and chooses its mean value in later process parameter data.

Otherwise, data should be chosen again to return again；

Step (7b), it is determined that after model coefficient, the canbe used on line of stable gasoline Lei Shi vapour pressure hard measurement be can be used Position machine soft instrument software, host computer calculation procedure use DCS Function Block Configuration；

Stable gasoline Lei Shi vapour pressure soft instrument or calculation procedure obtain the tower bottom temperature of gasoline stabilizer in DCS by OPC Degree, tower reactor pressure (/ tower top pressure, flow of lpg and overhead reflux flow) process data, by stable gasoline after the completion of calculating Lei Shi Vapor pressure data is sent into DCS and is shown or for used in closed-loop control；Stable gasoline Lei Shi vapour pressure chemical examination/analyzer data, Be sent into host computer in, by correction module periodically or real time calibration stable gasoline Lei Shi vapour pressure numerical value zero-bit.

Step (4.a) and step (4.b) described in the online soft sensor method of gasoline stabilizer separation accuracy of the present invention: pure The saturated vapor pressure calculation method of substance, can refer to related chemistry engineering manual, and following two method usually can be used:

1) pure material hold-up vapour pressure is calculated using Riedel method:

Wherein:

For the reduced pressure force value of pure material vapour pressure, no unit；

T_rTemperature, no unit are compared for pure material；

A, B, C, D are Riedel method vapour pressure algorithm coefficient；

2) pure material hold-up vapour pressure is calculated using Lee-Kesler method:

Wherein:

T_rTemperature, no unit are compared for pure material；

ω is the eccentric factor of pure material, no unit.

Step (6.1a) and (6.1b) described in the online soft sensor method of gasoline stabilizer separation accuracy of the present invention: to make Quality index has significant change between data Harvest time, can carry out operation adjustment appropriate to stabilizer.

Step (7.a) described in the online soft sensor method of gasoline stabilizer separation accuracy of the present invention and step (7.b) institute Be related to: hard measurement zero adjustment, correction module are the basic skills or software module of hard measurement engineering technology, this patent side Method is not described further.

The present invention compared with the prior art the utility model has the advantages that

The online soft sensor method of gasoline stabilizer separation accuracy of the present invention, from distillation process vapor liquid equilibrium mechanism and correlation Physical chemistry engineering principles set out, and by the approximation under actual production conditions and simplify processing, establish deterministic simple line The soft-sensing model of sexual intercourse realizes that two the liquefied gas C5+ content of gasoline stabilizer, stable gasoline Lei Shi vapour pressure quality refer to Target online soft sensor substantially increases its reliability and adaptability.

The online soft sensor method of gasoline stabilizer separation accuracy of the present invention is surveyed using the ordinary temperature of stabilizer, pressure Meter information is measured, is calculated by soft-sensing model, on-line real-time measuremen liquefied gas C5+ content, stable gasoline Lei Shi vapour pressure, Middle soft instrument model algorithm is based on distillation process vapor liquid equilibrium mechanism and relevant physicochemical engineering principles.The hard measurement side Method is easy to be reliable, and lag time is not present, and compared with configuring in-line analyzer detection method, has with low investment, maintenance workload Advantage small, without lag time；Compared with using data-driven regression modeling method, have relationship model simple clear, reliable The advantage that property is high, adaptable, modeling data sample requirement amount is small.Hard measurement is established using the method for the present invention, resettles closed loop Quality control system can be further improved the control of product quality stationarity and accuracy of gasoline stabilizer.

Detailed description of the invention

Fig. 1 is that the liquefied gas C5+ content of the online soft sensor embodiment of the method for gasoline stabilizer separation accuracy of the present invention is soft The flow chart of measurement method；

Fig. 2 is the stable gasoline Lei Shi steam of the online soft sensor embodiment of the method for gasoline stabilizer separation accuracy of the present invention Press the flow chart of flexible measurement method；

Fig. 3 is the liquefied gas C5+ content hard measurement of the online soft sensor method of gasoline stabilizer separation accuracy of the present invention Canbe used on line schematic diagram；

Fig. 4 is the soft survey of stable gasoline Lei Shi vapour pressure of the online soft sensor method of gasoline stabilizer separation accuracy of the present invention The canbe used on line schematic diagram of amount；

Fig. 5 is gasoline stabilizer process flow and the instrument of the online soft sensor method of gasoline stabilizer separation accuracy of the present invention Table distribution schematic diagram (has tower reactor pressure DCS data)；

Fig. 6 is gasoline stabilizer process flow and the instrument of the online soft sensor method of gasoline stabilizer separation accuracy of the present invention Table distribution schematic diagram (does not have tower reactor pressure DCS data)；

Fig. 7 is the catalytic cracking dress of certain Petrochemical Enterprises of the online soft sensor method of gasoline stabilizer separation accuracy of the present invention Set the online soft sensor of the liquefied gas C5+ content of stabilizer and the comparison figure of in-line analyzer operation data；

Fig. 8 is certain Petrochemical Enterprises delayed coking unit of the online soft sensor method of gasoline stabilizer separation accuracy of the present invention The online soft sensor of the liquefied gas C5+ content of stabilizer and the comparison figure of in-line analyzer operation data；

Fig. 9 is Petrochemical Enterprises (one) the catalytic cracking dress of the online soft sensor method of gasoline stabilizer separation accuracy of the present invention Set the stable gasoline Lei Shi vapour pressure online soft sensor of stabilizer and the comparison figure of in-line analyzer operation data；

Figure 10 is Petrochemical Enterprises (two) catalytic cracking of the online soft sensor method of gasoline stabilizer separation accuracy of the present invention The stable gasoline Lei Shi vapour pressure online soft sensor of device stabilizer and the comparison figure of in-line analyzer operation data.

Specific embodiment

Referring to the drawings and embodiment the present invention will be described in detail:

The online soft sensor method of gasoline stabilizer separation accuracy of the present invention, the totality according to attached drawing 1, attached drawing 2 is real respectively Process is applied, realizes the on-line real-time measuremen of liquefied gas C5+ content, stable gasoline Lei Shi vapour pressure.

For the online soft sensor method of present invention be described in more detail gasoline stabilizer separation accuracy, first in conjunction with attached drawing 5, attached drawing 6 illustrates the process flow and instrument measurement situation of gasoline stabilizer.

Referring to attached drawing 5 or attached drawing 6.Deethanization gasoline from the extraction of desorber bottom enters from gasoline stabilizer middle and upper part, Stablize bottom reboiler and heat source is provided, the gaseous stream gone out from liquid evaporation on tower reactor, each layer column plate, across the sky of each column plate Gap flows up；Overhead reflux provides condensation power, and the high component of each layer gaseous stream mid-boiling point is just condensed into the liquid on column plate Body, to underflow stream；When device operates normally, tower top dome, each layer column plate, tower reactor are in respective vapor liquid equilibrium state.

The space that tower top dome, the i.e. dome of tower and top first layer column plate 1 surround, liquid on first layer column plate and The interface 2 of vault indoor gas, is the last one separation of ascending vapor logistics composition variation in tower, and top gaseous phase logistics is cold But, after condensation enters liquid gas storage tank, composition no longer changes, and therefore, liquefied gas C5+ content depends on the indoor gas-liquid of tower top vault Balance.Thermometric instrument 3 measures tower top dome liquidus temperature, and pressure gauge 4 measures tower top pressure.Liquid gas storage tank extraction logistics, one Part goes out device as liquefied gas product, measures its flow by flow instrument 5；Another part is as tower top cold reflux, through overcurrent Amount instrument 6 is squeezed at the top of stabilizer after measuring.

The boundary that the space that tower reactor, i.e. tower lower part the last layer column plate 7 and tower bottom surround, bottom liquid and gas reactor divide Face 8 is the last one separation of the liquid phase stream composition variation to flow downward in tower, and the vapour pressure of stable gasoline is (with C4 group Divide content height linear approximate relationship), depending on the vapor liquid equilibrium in tower reactor.Thermometric instrument 9 measures tower bottom liquidus temperature, pressure Power instrument 10 measures tower reactor pressure.

Above-mentioned temperature, pressure, flow measurement instrument are that the standard of gasoline stabilizer instrument is matched in addition to pressure gauge 10 It sets.

Cracking unit newly-built in recent years or that key technological transformation was carried out into several years, gasoline stabilizer tower reactor usually configure Pressure gauge 10 (DCS data are shown), referring to attached drawing 5.

The old device of past construction, typically no configuration tower reactor pressure gauge (DCS data are shown), referring to attached drawing 6.This When, tower reactor pressure can be estimated by tower top pressure and Ta Nei ascending vapor logistics flux by simple operation.

The online soft sensor method of gasoline stabilizer separation accuracy of the present invention, comprising:

Liquefied gas C5+ content soft measuring method and stable gasoline Lei Shi vapour pressure flexible measurement method；

The step of liquefied gas C5+ content soft measuring method:

It is checked in from the cracking unit analysis data library of place, the normal minimum pure material of boiling point is isoamyl in liquefied gas C5 component Alkane；

Step (2.a) determines the liquidus temperature T of gas-liquid separation interface in the dome of gasoline stabilizer top_TOPAnd P_TOP；

Liquid phase is replaced sometimes without temperature measuring instrument with top gaseous phase temperature at this.The instrument measurement goes out Celsius temperature, Unit DEG C；

Gas-liquid separation interface gaseous pressure P_TOP, i.e. tower top pressure measuring instrumentss directly adopt.The instrument measurement goes out phase To pressure, units MPa；

Step (3.a) is checked in from common chemical engineering/databook: the critical-temperature of isopentane is 462.926K, different Pentane gas-liquid separation interface liquidus temperature T in tower top dome_TOPComparison temperature T_r,C5,TOPAre as follows:

T_r,C5,TOP=(T_TOP+273.15)/462.926

Wherein:

273.15 be 0 DEG C of Celsius temperature of kelvin rating

Step (4.a) determines key component pure material saturated vapor pressure under liquidus temperature at tower top dome gas-liquid separation.

Using distinct methods, the saturated vapor calculated is pressed with pressure value or reduced pressure force value.Vapour pressure pressure value and Reduced pressure force value can be converted by simple computation；It is convenient to state for following model algorithm, which does not repartition pressure Value and reduced pressure force value；

Liquefied gas C5+ content key component is indicated in the saturated vapor pressure of tower top dome gas-liquid separation interface liquidus temperature For P_VP,C5,TOP；

The saturated vapor pressure of temperature is (right at gas-liquid separation in tower top dome using Riedel method calculating isopentane for embodiment Than pressure value):

Step (5.a) determines liquefied gas C5+ content soft sensor model:

Wherein:

C5_LPGFor liquefied gas C5+ content, unit %；

A_0,C5、A_1.C5；For model coefficient；

0.101325 is the difference of absolute pressure and relative pressure；

Step (6.a), model coefficient determines according to the following steps:

Step (6.1a), the gasoline stabilizer Process History data that certain period of time is acquired from DCS determine；

The stabilizer procedure parameter for needing to acquire has:

1)T_TOP: tower top dome liquidus temperature, DEG C

2)P_TOP: tower top dome gaseous pressure, MPa

3) embodiment is configured with in-line analyzer, increases liquefied gas C5+ content AI_C5Data；

Data sampling interval 5 minutes；

Data segment time span is established rules then really are as follows:

The above process is lasted data, imported in Excel table by step (6.2a)；

For each procedure parameter, the data of the seclected time period are expressed as an array, such asJ=1,2 ..., N, n is equal to seclected time period data sample number here；

(Z)_j+1=(1-F_L)*(Z)_j+F_L*(Z)_j+1, j=1,2 ..., n

Wherein:

(Z) T is represented_TOP、P_TOPAnd analyzer data AI_C5

F_LFor smothing filtering coefficient, value is 0.70~0.85

Step (6.5a) determines soft-sensing model coefficient using one of following two methods；

Step (6.5.1a) calculates soft-sensing model coefficient referring to the scale calculation method of instrumentation engineering；

For the computational accuracy for improving model coefficient, A_1.C5Using calculating the method averaged three times；And A_0,C5It is hard measurement Zero-bit, when off-line calculation, find out a provisional value, and online soft sensor has zero adjustment；

Observation comparative approach is shown using curve, respectively:

It calculates and determines A_1.C5And A_0,C5Value:

A_0.C5=AI_C5,MIN1-A_1.C5*X_C5,MIN1

Step (7.a), it is determined that after model coefficient, host computer soft instrument is can be used in the canbe used on line of liquefied gas C5+ content Software, host computer calculation procedure use DCS Function Block Configuration；

Using host computer realize liquefied gas C5+ content online soft sensor, referring to attached drawing 3: host computer soft instrument software or Calculation procedure obtains gasoline stabilizer top temperature, tower top pressure process data in DCS by OPC, based on process shown in block diagram After the completion of calculation, liquefied gas C5+ content data feeding DCS is shown or for used in closed-loop control；

Gasoline stabilizer top liquefied gas C5+ content chemical examination/analyzer data is sent into host computer, fixed by correction module The zero-bit of phase or real time calibration liquefied gas C5+ containing numerical quantity.

It is realized using DCS Function Block Configuration, also can refer to the implementation of 3 configuration of attached drawing.

The step of stable gasoline Lei Shi vapour pressure flexible measurement method:

It is checked in from the cracking unit analysis data library of place, the highest pure material of normal boiling point is in C4 component in stable gasoline 1,3- butadiene；

Step (2.b) determines the liquidus temperature T of gas-liquid separation interface in gasoline stabilizer tower reactor_BTMAnd gaseous pressure P_BTM；

If there is no tower reactor gaseous pressure measuring instrumentss data in DCS, it is determined that gasoline stabilizer top gaseous phase pressure is surveyed Measure instrument P_TOP, liquefied gas output flow measurement instrument F_LPGWith overhead reflux flow measurement instrument F_RE；Gasoline stabilizer tower reactor pressure Power is calculated using the method that subsequent step (6.3b) provides；

Step (3.b), checks in from common chemical engineering/databook: the critical-temperature of 1,3-butadiene is 446.223K then 1,3-butadiene gas-liquid separation interface liquidus temperature T in tower reactor_BTMComparison temperature T_r,RVP,BTMAre as follows:

T_r,RVP,BTM=(T_BTM+273.15)/446.223

Wherein:

273.15 be the kelvin rating of Celsius temperature DEG C

Step (4.b) determines 1,3-butadiene saturated vapor pressure under liquidus temperature at the gas-liquid separation of tower reactor；

Using distinct methods, the saturated vapor calculated is pressed with pressure value or reduced pressure force value.Vapour pressure pressure value and Reduced pressure force value can be converted by simple computation；It is convenient to state for following model algorithm, which does not repartition pressure Value and reduced pressure force value:

Embodiment calculates 1,3- butadiene using Riedel method and steams in the saturation of tower reactor gas-liquid separation interface liquidus temperature Vapour pressure (reduced pressure force value):

Wherein:

RVP_STABFor stable gasoline Lei Shi vapour pressure, unit kPa

A_0,RVP、A_1,RVPFor model coefficient；

The stabilizer procedure parameter for needing to acquire has:

1)T_BTM: tower reactor liquidus temperature, DEG C

3) such as old device does not have tower reactor gaseous pressure measuring instrumentss DCS data to show, then acquires top gaseous phase pressure (MPa), liquefied gas output flow F_LPGWith overhead reflux flow F_RE, two datas on flows, unit is consistent

4) embodiment is configured with in-line analyzer, is further added by stable gasoline vapour pressure AI_RVPData；

Sampling interval 2 minutes；

Data segment time span is established rules then really:

1) model coefficient is determined using analysis data, then includes continuous 10 or more stable gasoline vapour pressures in the period Analysis data sample；Amplitude of variation >=6kPa of stable gasoline vapour pressure；

2) it is configured with in-line analyzer, includes the significant fluctuating change of quality index: stable gasoline in the period Fluctuating range >=4kPa of vapour pressure；

The above process is lasted data, imported in Excel table by step (6.2b)；

Stabilizer pressure drop is calculated first estimates coefficient A_DP:

Wherein:

Then tower reactor pressure value array is calculated

P_BTM,j=P_TOP,j+A_DP*(F_LPG,j+F_RE,j)

(Z)_j+1=(1-F_L)*(Z)_j+F_L*(Z)_j+1, j=1,2 ..., n

Wherein:

(Z) T is represented_BTM、P_BTMAnd analyzer data

F_L=0.70~0.85；

For the tower reactor pressure data being calculated, F_L=0.85~0.97；

For the computational accuracy for improving model coefficient, A_1,RVPUsing calculating the method averaged three times；And A_0,RVPIt is hard measurement Zero-bit, when off-line calculation find out a provisional value can positive online soft sensor have zero adjustment:

Observation comparative approach is shown using curve, respectively:

It calculates and determines A_1,RVPAnd A_0.RVPValue:

A_0.RVP=AI_RVP,MIN1-A_1.RVP*X_RVP,MIN1

When DCS does not have tower reactor pressure measured data, stable gasoline Lei Shi vapour pressure hard measurement mould that step (5.b) provides Type, pattern change are as follows:

Wherein:

RVP_STABFor stable gasoline Lei Shi vapour pressure, unit kPa

A_0,RVP、A_1,RVP、A_2,RVPFor model coefficient；

At this point, not executing step (6.3b) and step (6.4b), the mistake that step (6.2b) imports Excel table is directlyed adopt Journey lasts data and laboratory values or in-line analyzer data, seeks model coefficient using PLS Return Law method:

(Z)_j+1=(1-F_L)*(Z)_j+F_L*(Z)_j+1, j=1,2 ..., n

Wherein:

(Z) T is represented_BTM、P_TOP、And analyzer data

F_LFor smothing filtering coefficient:

For temperature, pressure and in-line analyzer data, F_L=0.70~0.85；

For data on flows: F_L=0.85~0.97；

Regression result should meet:

(1)A_1,RVP、A_2,RVPIt is positive value；

Otherwise, data should be chosen again to return again；

Step (7.b), it is determined that after model coefficient, the canbe used on line of stable gasoline Lei Shi vapour pressure hard measurement be can be used Host computer soft instrument software, host computer calculation procedure use DCS Function Block Configuration；

The online soft sensor of stable gasoline Lei Shi vapour pressure is realized using host computer, referring to attached drawing 4: host computer soft instrument is soft Part or calculation procedure obtain column bottom temperature, tower reactor the pressure (/ tower top pressure, liquid gas flow of gasoline stabilizer in DCS by OPC Amount and overhead reflux flow) process data, after the completion of workflow management shown in block diagram, by stable gasoline Lei Shi Vapor pressure data DCS is sent into show or for used in closed-loop control；

Stable gasoline Lei Shi vapour pressure chemical examination/analyzer data is sent into host computer, periodically or real-time by correction module Calibrate the zero-bit of stable gasoline Lei Shi vapour pressure numerical value.

It is realized using DCS Function Block Configuration, also can refer to the implementation of 4 configuration of attached drawing.

Case verification illustrates

Attached drawing 7-10 is the liquefied gas C5+ content of gasoline stabilizer separation accuracy online soft sensor method, stable gasoline thunder Family name's vapour pressure hard measurement case verification diagram.

The data of in-line analyzer are relatively accurate, strong real-time.For verify online soft sensor operation result, following four The example that application example, selection are furnished with corresponding in-line analyzer.

In diagram, hard measurement operation data curve and in-line analyzer operation data curve are placed among the same coordinate system It is compared.

Example illustrates:

Attached drawing 7, be certain Petrochemical Enterprises Stabilizer In Fccu liquefied gas C5+ content online soft sensor and The comparison of line analysis instrument operation data, abscissa: the time, the sampling interval 1 minute；Ordinate: liquefied gas C5+ content, unit % (volume).

Attached drawing 8 is the online soft sensor and in-line analyzer of the delayed coking unit liquefied gas C5+ content of certain Petrochemical Enterprises The comparison of operation data, abscissa: the time, the sampling interval 1 minute；Ordinate: liquefied gas C5+ content, unit % (volume).

The online soft sensor operation data it can be seen that stabilizer liquefied gas C5+ content is illustrated from attached drawing 7 and 8 liang of attached drawing, With its in-line analyzer operation data, variation tendency is consistent.

Attached drawing 9 is the online soft survey of the Stabilizer In Fccu stable gasoline Lei Shi vapour pressure of Petrochemical Enterprises (one) The comparison of amount and in-line analyzer operation data, abscissa: the time, the sampling interval 1 minute；Ordinate: stable gasoline vapour pressure, Unit kPa.

The Stabilizer In Fccu tower reactor is configured with pressure measuring instruments.

Attached drawing 10 is online soft sensor and the in-line analyzer operation of the stable gasoline Lei Shi vapour pressure of Petrochemical Enterprises (two) The comparison of data, abscissa: the time, the sampling interval 1 minute；Ordinate: stable gasoline vapour pressure, unit kPa.

The Stabilizer In Fccu tower reactor does not configure pressure measuring instruments.Tower reactor pressure uses tower top pressure, liquid Change throughput, overhead reflux flow rate calculation.

From attached drawing 9 and 10 liang of attached drawing diagrams it can be seen that the online soft sensor of stabilizer stable gasoline Lei Shi vapour pressure is transported Row data, with its in-line analyzer operation data, variation tendency is consistent.

The method of the present invention passes through soft survey using based on the existing ordinary temperature of gasoline stabilizer, pressure measuring instruments signal Online liquefied gas C5+ content, stable gasoline Lei Shi vapour pressure index value in real time is calculated in amount.With the online quality analysis of configuration Instrument is compared, have it is with low investment, without the small advantage of lag time, maintenance workload.It is promoted and applied with Advanced Control Techniques at this stage In " data-driven regression analysis " modeling flexible measurement method for being widely used compare, have that input variable is few, relationship model is simple Clearly, the characteristics of model coefficient is easily obtained；For the gasoline stabilizer that temperature, pressure measuring instruments are assorted, separation accuracy Soft measuring instrument, as long as determining gain coefficient and zero-bit.The soft-sensing model of Kernel-based methods Analysis on Mechanism, adaptability for working condition It is greatly improved with reliability.

The method of the present invention with catalytic cracking, delayed coking, be hydrocracked etc. cracking units Vapor recovery unit process gasoline Stabilizer is research object, for the de- fourth of liquefied gas-gasoline separation tower similar in other oil refining apparatus, such as reformer The stabilizer of alkane tower, atmospheric and vacuum distillation unit lighter hydrocarbons recovery process, also can refer to application.

The method of the present invention is studied from Advanced Control Techniques application work and is obtained, since its modeling method is based on chemical industry machine Reason, thus in the engineering technology such as the flowsheeting of cracking unit gasoline stabilizer process, technology Calculation, these can also be applied Calculation method and computation model.

Embodiment described above only carries out the present invention in the preferred embodiment of cracking unit gasoline stabilizer Description, is not intended to limit the scope of the present invention, without departing from the spirit of the design of the present invention, ordinary skill The various changes and improvements that personnel make technical solution of the present invention, or applied to similar other liquefied gas-gasoline separation Tower should all be placed in the protection scope that claims of the present invention determines.

Claims

1. a kind of online soft sensor system of gasoline stabilizer separation accuracy, which is characterized in that including stabilizer, stabilizer includes Tower top dome, the space that the dome and top first layer column plate of tower surround, liquid and vault indoor gas on first layer column plate Interface is the last one separation of ascending vapor logistics composition variation in tower, and top gaseous phase logistics is cooling, condensation enters liquid After LPG cylinder, composition no longer changes, and therefore, liquefied gas C5+ content depends on the indoor vapor liquid equilibrium of tower top vault；

Liquid gas storage tank extracts logistics out, and a part goes out device as liquefied gas product, measures its flow by flow instrument；Another part As tower top cold reflux, squeezed into after flow instrument measures at the top of stabilizer；

Stabilizer includes tower reactor, the space that tower lower part the last layer column plate and tower bottom surround, bottom liquid and gas reactor point Interface, is the last one separation of the liquid phase stream composition variation to flow downward in tower, and the vapour pressure of stable gasoline depends on In the vapor liquid equilibrium in tower reactor；

Thermometric instrument measures tower bottom liquidus temperature, and pressure gauge measures tower reactor pressure；

Including liquefied gas C5+ content soft measuring method and stable gasoline Lei Shi vapour pressure flexible measurement method；

The step of liquefied gas C5+ content soft measuring method are as follows:

Step (1.a) determines that the normal minimum pure material of boiling point is crucial group for characterizing liquefied gas C5+ content in liquefied gas C5 component Divide pure material；

Step (2.a) determines the liquidus temperature T of gas-liquid separation interface in the dome of gasoline stabilizer top_TOPWith gaseous pressure P_TOP, What industrial process instrument measurement went out is celsius temperature scale (DEG C) and relative pressure (MPa)；

Step (3.a), liquefied gas C5+ content key component pure material gas-liquid separation interface liquidus temperature in tower top dome T_TOPComparison temperature T_r,C5,TOPIt is calculated as follows:

T_r,C5,TOP=(T_TOP+273.15)/T_c,C5

Wherein:

T_c,C5For the critical-temperature of liquefied gas C5+ content key component pure material,

273.15 be 0 DEG C of Celsius temperature of kelvin rating；

Step (4.a) determines key component pure material saturated vapor pressure under liquidus temperature at tower top dome gas-liquid separation；

Using distinct methods, the saturated vapor calculated is pressed with pressure value or reduced pressure force value；Vapour pressure pressure value and comparison Pressure value can be calculated by simple linear and be converted；It is convenient to state for following model algorithm, which does not repartition pressure Value and its reduced pressure force value；

Liquefied gas C5+ content key component is expressed as in the saturated vapor pressure of tower top dome gas-liquid separation interface liquidus temperature P_VP,C5,TOP；

Step (5.a) determines liquefied gas C5+ content soft sensor model:

Wherein:

C5_LPGFor liquefied gas C5+ content, unit %；

A_0,C5、A_1.C5For model coefficient；

0.101325 is the difference of absolute pressure and relative pressure；

Step (6.a), off-line calculation obtains model coefficient according to the following steps:

The stabilizer procedure parameter for needing to acquire has:

1)T_TOP: tower top dome liquidus temperature, DEG C；

2)P_TOP: tower top dome gaseous pressure, MPa；

If 3) be configured with in-line analyzer, it is further added by liquefied gas C5+ content AI_C5Data；

Such as without configuration in-line analyzer, then from device analysis data library, then the liquefied gas C5+ content of corresponding period is collected Analysis data and its sampling instant data；

The above process is lasted data, imported in Excel table by step (6.2a)；

For each procedure parameter, the data of the seclected time period are expressed as an array, T_TOP,j, j=1,2 ..., n, n etc. here In seclected time period data sample number；

Step (6.4a) is right first in the Excel table that the above process lasts data and laboratory values or in-line analyzer data Each process parameter data carries out smothing filtering operation:

(Z)_j+1=(1-F_L)*(Z)_j+F_L*(Z)_j+1, j=1,2 ..., n

Wherein:

(Z) T is represented_TOP、P_TOPAnd analyzer data AI_C5

F_LFor smothing filtering coefficient, value is 0.70~0.85

Sampling instant, the numerical error of analysis data are considered, for the computational accuracy for improving model coefficient, A_1.C5Using calculating three times The method averaged；And A_0,C5It is the zero-bit of hard measurement, when off-line calculation finds out a provisional value；

Observation comparative approach is shown using curve, respectively:

I. maximum three sample values of liquefied gas C5+ content laboratory values are selected, are expressed as AI from big to small_C5,MAX1、AI_C5,MAX2、 AI_C5,MAX3, the X of three assay samples sampling instants_C5,jIt is expressed as X_C5,MAX1、X_C5,MAX2、X_C5,MAX3；

Ii. the smallest three sample values of liquefied gas C5+ content laboratory values are selected, are expressed as AI from big to small_C5,MIN1、AI_C5,MIN2、 AI_C5,MIN3, the X of three assay samples sampling instants_C5,jIt is expressed as X_C5,MIN1、X_C5,MIN2、X_C5,MIN3；

It calculates and determines A_1.C5And A_0,C5Value:

A_0.C5=AI_{C5,MIN 1}-A_1.C5*X_{C5,MIN 1}

Step (6.5.2a), with X_C5For input variable, with AI_C5To be detected variable, is returned using PLS and obtain soft-sensing model system Number A_1.C5And A_0,C5；Regression result needs to verify: A_1.C5For positive value, it otherwise should choose again data and return again；

Step (7.a), it is determined that after model coefficient, it is soft that host computer soft instrument can be used in the canbe used on line of liquefied gas C5+ content Part, host computer calculation procedure use DCS Function Block Configuration；

Liquefied gas C5+ content soft instrument or calculation procedure pass through gasoline stabilizer tower top temperature, tower top pressure in OPC acquisition DCS Liquefied gas C5+ content data is sent into DCS after the completion of calculating and shown or for used in closed-loop control by process data；Tower top liquefied gas C5+ content chemical examination/analyzer data, be sent into host computer in, by correction module periodically or real time calibration liquefied gas C5+ content number The zero-bit of value；

Step (1.b) determines that the highest pure material of normal boiling point is characterization stable gasoline Lei Shi steam in C4 component in stable gasoline The key component pure material of pressure；

Step (2.b) determines the liquidus temperature T of gas-liquid separation interface in gasoline stabilizer tower reactor_BTMGaseous pressure P_BTM, industry What process instrument was measured is celsius temperature scale (DEG C) and relative pressure (MPa)；

If there is no tower reactor gaseous pressure measuring instrumentss data in DCS, it is determined that gasoline stabilizer top gaseous phase pressure-measuring device Table P_TOP, liquefied gas output flow measurement instrument F_LPGWith overhead reflux flow measurement instrument F_RE, subsequent step (6.3b) provides vapour The calculation method of oily stabilizer tower reactor pressure；

Step (3.b), stable gasoline Lei Shi vapour pressure key component pure material gas-liquid separation interface liquidus temperature in tower reactor T_BTMComparison temperature T_r,RVP,BTMIt is calculated as follows:

T_r,RVP,BTM=(T_BTM+273.15)/T_c,RVP

Wherein:

Unit K

273.15 be 0 DEG C of Celsius temperature of kelvin rating

Step (4.b) determines stable gasoline Lei Shi vapour pressure key component pure material under liquidus temperature at tower reactor gas-liquid separation Saturated vapor pressure；

Using distinct methods, the saturated vapor calculated is pressed with pressure value or reduced pressure force value；Vapour pressure pressure value and comparison Pressure value can be calculated by simple linear and be converted, and convenient for the statement of following model algorithm, which does not repartition pressure Value and reduced pressure force value；

Stable gasoline Lei Shi vapour pressure key component is expressed as in the saturated vapor pressure of tower reactor gas-liquid separation interface liquidus temperature P_VP,RVP,BTM；

Wherein:

RVP_STABFor stable gasoline Lei Shi vapour pressure, unit kPa

A_0,RVP、A_1,RVPFor model coefficient

The stabilizer procedure parameter for needing to acquire has:

1)T_BTM: tower reactor liquidus temperature, DEG C；

2)P_BTM: tower reactor gaseous pressure, MPa；

3) such as tower reactor gaseous pressure does not have measuring instrumentss DCS data to show, then acquires top gaseous phase pressure (MPa), and liquefied gas produces Outflow F_LPGWith overhead reflux flow F_RE, two of them data on flows is constant when unit is consistent and hard measurement on-line implement It can；

Such as without configuration in-line analyzer, then from device analysis data library, then the stable gasoline steam of corresponding period is collected Press analysis data and its sampling instant data；

The above process is lasted data, imported in Excel table by step (6.2b)；

For each procedure parameter, the data of the seclected time period are expressed as an array, T_BTM,j, j=1,2 ..., n, n etc. here In seclected time period data sample number；

Step (6.3b) jumps to step (6.4b) if having collected tower reactor gaseous pressure data；This is used step by step Following algorithm calculates gasoline stabilizer tower reactor pressure:

Stabilizer pressure drop is calculated first estimates coefficient A_DP:

Wherein:

Then tower reactor pressure value array is calculated

P_BTM,j=P_TOP,j+A_DP*(F_LPG,j+F_RE,j)

Step (6.4b) is right first in the Excel table that the above process lasts data and laboratory values or in-line analyzer data Each process parameter data carries out smothing filtering operation:

(Z)_j+1=(1-F_L)*(Z)_j+F_L*(Z)_j+1, j=1,2 ..., n

Wherein:

(Z) T is represented_BTM、P_BTMAnd analyzer data

F_L=0.70~0.85；

For the tower reactor pressure data being calculated, F_L=0.85~0.97；

Sampling instant, the numerical error of analysis data are considered, for the computational accuracy for improving model coefficient, A_1,RVPUsing calculating three times The method averaged；And A_0,RVPIt is the zero-bit of hard measurement, when off-line calculation finds out a provisional value；

Observation comparative approach is shown using curve, respectively:

I. maximum three sample values of stable gasoline vapour pressure laboratory values are selected, are expressed as AI from big to small_RVP,MAX1、AI_RVP,MAX2、 AI_RVP,MAX3, the X of three assay samples sampling instants_RVP,jIt is expressed as X_RVP,MAX1、X_RVP,MAX2、X_RVP,MAX3；

Ii. the smallest three sample values of stable gasoline vapour pressure laboratory values are selected, are expressed as AI from big to small_RVP,MIN1、 AI_RVP,MIN2、AI_RVP,MIN3, the X of three assay samples sampling instants_RVP,jIt is expressed as X_RVP,MIN1、X_RVP,MIN2、X_RVP,MIN3；

It calculates and determines A_1,RVPAnd A_0,RVPValue:

A_0.RVP=AI_{RVP,MIN 1}-A_1.RVP*X_{RVP,MIN 1}

Step (6.5.2b), with X_RVPFor input variable, with AI_RVPTo be detected variable, is returned using PLS and obtain soft-sensing model Coefficient；Regression result needs to verify: A_1.RVPFor positive value；Otherwise data should be chosen again to return again；

When DCS does not have tower reactor pressure measured data, the soft survey of stable gasoline Lei Shi vapour pressure that step (5.b) is provided also can be changed The pattern of model is measured, and model coefficient is sought using the PLS Return Law；

Step (7.b), it is determined that after model coefficient, the canbe used on line of stable gasoline Lei Shi vapour pressure hard measurement be can be used upper Machine soft instrument software, host computer calculation procedure use DCS Function Block Configuration；

Stable gasoline Lei Shi vapour pressure soft instrument or calculation procedure obtain column bottom temperature, the tower of gasoline stabilizer in DCS by OPC Stable gasoline Lei Shi Vapor pressure data is sent into DCS after the completion of calculating and shown or for used in closed-loop control by kettle press process data； Stable gasoline Lei Shi vapour pressure chemical examination/analyzer data is sent into host computer, by the way that correction module is regular or real time calibration is stablized The zero-bit of gasoline Lei Shi vapour pressure numerical value.

2. the online soft sensor system of gasoline stabilizer separation accuracy according to claim 1, it is characterised in that: step (2.a) can use tower top first layer column plate if gas-liquid separation interface does not have temperature measuring instrument in the dome of gasoline stabilizer top Lower temperature or top gaseous phase temperature replace；Gas-liquid separation interface gaseous pressure P_TOP, it is configured with tower top pressure measuring instrumentss number Value, directlys adopt.

3. the online soft sensor system of gasoline stabilizer separation accuracy according to claim 2, it is characterised in that: step (4.a) and step (4.b) determines that key component pure material is satisfied under liquidus temperature at gas-liquid separation in tower top dome or tower reactor With vapour pressure calculation method are as follows:

1) pure material hold-up vapour pressure is calculated using Riedel method:

Wherein:

For pure material vapour pressure reduced pressure, no unit；

T_rTemperature, no unit are compared for pure material；

A, B, C, D are Riedel method vapour pressure algorithm coefficient；

2) pure material hold-up vapour pressure is calculated using Lee-Kesler method:

Wherein:

For pure material vapour pressure reduced pressure, no unit；

T_rTemperature, no unit are compared for pure material；

ω is pure material eccentric factor, no unit.

4. the online soft sensor system of gasoline stabilizer separation accuracy according to claim 3, it is characterised in that: step (6.1a), from dcs acquire certain period of time gasoline stabilizer Process History data, the sampling interval 1,2 or 5 minutes；

Time segment length is established rules then really:

1) model coefficient is determined using analysis data, then includes continuous 10 or more liquefied gas C5+ content chemical examinations in the period Data sample；The amplitude of variation of liquefied gas C5+ content value >=high limit of process chart regulation 1/2；

2) it is configured with in-line analyzer, then include the significant fluctuating change of quality index in the period: liquefied gas C5+ contains The fluctuating range of amount >=high limit of process chart regulation 1/3；

To make quality index during acquiring data have significant change, operation adjustment appropriate can be carried out to stabilizer.

5. the online soft sensor system of gasoline stabilizer separation accuracy according to claim 4, it is characterised in that: step (6.1b), from dcs acquire certain period of time gasoline stabilizer Process History data, the sampling interval 1,2 or 5 minutes；

Time segment length is established rules then really:

1) model coefficient is determined using analysis data, then includes continuous 10 or more stable gasoline vapour pressure chemical examinations in the period Data sample；Amplitude of variation >=6kPa of stable gasoline vapour pressure；

2) it is configured with in-line analyzer, then include the significant fluctuating change of quality index in the period: stable gasoline steams Fluctuating range >=4kPa of vapour pressure；

6. the online soft sensor system of gasoline stabilizer separation accuracy according to claim 5, it is characterised in that: step (6.5.2b), when DCS does not have tower reactor pressure measured data, stable gasoline Lei Shi vapour pressure hard measurement that step (5.b) provides Model, pattern are changeable are as follows:

Wherein:

RVP_STABFor stable gasoline Lei Shi vapour pressure, unit kPa

A_0,RVP、A_1,RVP、A_2,RVPFor model coefficient

P_TOPFor gasoline stabilizer tower top pressure, relative pressure, MPa

F_LPG、F_REFor gasoline stabilizer flow of lpg and overhead reflux flow, when unit is consistent and hard measurement on-line implement not Change

P_VP,RVP,BTMFor stable gasoline Lei Shi vapour pressure key component tower reactor gas-liquid separation interface liquidus temperature saturated vapor Pressure

At this point, not executing step (6.3b) and step (6.4b), the process for directlying adopt step (6.2b) importing Excel table is gone through When data and laboratory values or in-line analyzer data, model coefficient is sought using the PLS Return Law:

(Z)_j+1=(1-F_L)*(Z)_j+F_L*(Z)_j+1, j=1,2 ..., n

Wherein:

(Z) T is represented_BTM、P_TOP、And analyzer data

F_LFor smothing filtering coefficient:

For temperature, pressure and in-line analyzer data, F_L=0.70~0.85；

For data on flows: F_L=0.85~0.97；

Finally with X1_RVP、X2_RVPFor input variable, with AI_RVPTo be detected variable, obtained using PLS, that is, partial least-squares regression method Obtain soft-sensing model coefficient；

Regression result should meet:

(1)A_1,RVP、A_2,RVPIt is positive value；

(2)Value agreement be equal to stabilizer voltage drop value；F herein_LPGAnd F_RE, in above-mentioned filtering Its mean value is chosen in later process parameter data；

Otherwise, data should be chosen again to return again.