CN102643662B - Crude oil blending optimization method - Google Patents

Abstract

The invention discloses a crude oil blending optimization method, which supports minimum deviation of property and content of blended crude oil to target oil for crude oil manufacturers, namely under certain constraint conditions, percentages of various blended crude oils are obtained by minimization using a deviation function for related properties and contents of the blended crude oils and the set target. For safety and economy, the method further supports three optimization ways for property and content of the crude oil, namely in-range characterization, lower limit oriented optimization and upper limit oriented optimization. The method further supports economic optimization of targets, namely the minimum deviation between property and content of the blended crude oil and the targets is considered, and minimization of production cost is achieved. By the method, blending percentages of the crude oils are automatically generated and downloaded to a control system for execution, the crude oils meeting processing requirements are provided for CDUs (central distillation units), damage of the CDUs and subsequent processing devices due to property change of the crude oils is avoided, production efficiency and economic benefit are improved, and the method is especially applicable to crude oil processing in oil refinery.

Description

A kind of crude oil concoction optimization method

Technical field

The present invention relates to oil refining enterprise's crude oil manufacture field, especially the optimization method of crude oil blending.

Background technology

At present, in petroleum and petrochemical sector, the widespread use of processed oil (as gasoline, diesel oil) concoction optimization technology, is used concoction optimization technology but have no in crude oil processing.Atmospheric and vacuum distillation unit (CDU) is the first link of crude oil processing, CDU has strict demand to former oil properties content (as sulphur content and acid content) aborning, crude oil processing enterprise extensively adopts artificial blending method at present, respectively mix refining crude oil accounting by hand computation, it is optimum that proportional quantity often can not reach, and causes the problems such as the large and bad economic results of fluctuation.

Summary of the invention

In the present invention seeks to produce for the crude oil blending of crude oil processing enterprise, extensively adopt at present the artificial crude oil accounting of calculating, have the problems such as fluctuation is large, bad economic results, proposed a kind of crude oil concoction optimization method.Meeting under the prerequisite of apparatus and process constraint condition, minimum or take into account economic optimum and be optimized blending as target taking oil property content target deviation, and adopt scope default value, optimize three kinds of optimal way to lower limit optimization with to the upper limit, obtain optimum blending formula, downloading to Controlling System carries out, the infringement of avoiding oil property content to bring to CDU and following process device, and enhance productivity and economic benefit.

Technical scheme of the present invention is:

A kind of crude oil concoction optimization method, the method comprises the following steps:

First, carry out this blending parameter initialization, it is lower limit and the upper limit of each component oil accounting that setting crude oil is respectively mixed refining line; Secondly, select optimization aim, comprise the rear oil property content of blending and target deviation minimum and two kinds of optimization aim of economic optimum; Again, select the rear crude oil of blending to participate in character and scope, optimal way and the weight optimized, optimal way adopts scope default value, optimizes three kinds of modes to lower limit optimization with to the upper limit;

Finally, obtain crude oil respectively mix refining line be the current character data of component oil, meet set constraint condition under, concoct according to the mode that optimization aim is corresponding, obtain respectively mix refining line be the accounting of component oil, issue Controlling System carry out.

In the present invention, the method adopts the mode of the rear oil property content of blending and target deviation minimum as optimization aim, solve the true correlation matter content of the rear crude oil of blending and the departure function of the rear crude oil relevant nature content target setting of blending by minimizing, employing formula (1) calculates the accounting of each component oil:

$\mathrm{\Φ}\left(X\right)=\underset{j=1}{\overset{m}{\mathrm{\Σ}}}{\mathrm{\λ}}_j|\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{a}_{\mathrm{ji}}{x}_i-p_j|$

$s.t.\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{x}_i=1$

wX≤tB (1)

tX≤V

X _min≤X≤X _max

In formula (1), Φ (X) is objective function; I represents that it is component oil number that mixing of participation blending crude oil refined line number, and j represents the number of component oil or the rear crude oil relevant nature of blending; X is the accounting of each component oil, X=[x ₁, x ₂x _n] ^t, X>=0; λ _jfor crude oil j, j=1,2 ... the weight of m kind character, λ _j>=0; a _jifor i article of crude oil is mixed the i.e. j kind character content of i kind component oil of refining line; p _jfor the blending target of crude oil j kind character content, p _j>=0; W is current batch of blending total amount, w>=0; T is current batch of blending expected time, t>=0; B is that crude oil is respectively mixed refining line Peak Flow Rate, B=[b ₁, b ₂b _n] ^t, B>=0; V is to be that each component oil can be for concocting total amount, V=[v with respectively mixing each tempering tank of being connected of refining line ₁, v ₂v _n] ^t, V>=0; X _minand X _maxbe respectively lower limit and the upper limit of predefined each component oil accounting, X _min=[x _1min, x _2minx _nmin] ^t, X _min>=0, X _max=[x _1max, x _2maxx _nmax] ^t, X _max>=0.

In the present invention, adopt scope default value, optimize three kinds of modes to lower limit optimization with to the upper limit for former oil properties content after blending:

The blending target p of the j character content of crude oil after blending _jmeet formula (2),

p _jmin≤p _j≤p _jmax (2)

In formula (2), p _jminfor concocting rear crude oil j kind character content lower limit, p _jmaxfor concocting rear crude oil j kind character upper content limit.

So, in the time that optimizing, gets lower limit p _j=p _jmin; In the time that optimizing, the upper limit gets p _j=p _jmax; P when scope default value is optimized _jno longer adjust.

In the present invention, consider for security and economy, in the time solving objective function, for the productive capacity of sulphur content, in above-mentioned setting range, to upper limit optimization, get p _j=p _jmax.And for the productive capacity of acid content, in above-mentioned setting range, to lower limit optimization, get p _j=p _jmin.For the productive capacity of refinery's naphtha yield and residual oil yield, p _jdo not remake upwards the adjustment of limit or lower limit direction, take scope default value optimal way.

In the present invention, the method adopts the mode of economic optimum as optimization aim, when considering the rear oil property content of blending and target deviation minimum, realizes production cost and minimizes, meeting under the constraint condition of setting, employing formula (3) calculates the accounting of each component oil:

$\mathrm{\Ψ}\left(X\right)=\underset{j=1}{\overset{m}{\mathrm{\Σ}}}{\mathrm{\λ}}_j|\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{a}_{\mathrm{ji}}{x}_i-p_j|+\mathrm{\γ}\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{c}_i{x}_i$

$s.t.\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{x}_i=1$

wX ≤tB (3)

tX≤V

X _min≤X≤X _max

In formula (3), Ψ (X) is for having considered the objective function after economic optimum; I represents that it is component oil number that mixing of crude oil refined line number, and j represents crude oil, component oil properties number; X is the accounting of each component oil, X=[x ₁, x ₂x _n] ^t, X>=0; λ _jfor crude oil, component oil j, j=1,2 ... the weight of m kind character, λ _j>=0; a _jifor i article of crude oil is mixed the i.e. j kind character content of i kind component oil of refining line; p _jfor the blending target of crude oil j kind character content, p _j>=0; W is current batch of blending total amount, w>=0; T is current batch of blending expected time, t>=0; B is that crude oil is respectively mixed refining line Peak Flow Rate, B=[b ₁, b ₂b _n] ^t, B>=0; V is to be that each component oil can be for concocting total amount, V=[v with respectively mixing each tempering tank of being connected of refining line ₁, v ₂v _n] ^t, V>=0; X _minand X _maxbe respectively lower limit and the upper limit of predefined each component oil accounting, X _min=[x _1min, x _2minx _nmin] ^t, X _min>=0, X _max=[x _1max, x _2maxx _nmax] ^t, X _max>=0; c _ibe the procurement price of i kind component oil, c _i>=0; γ is price weight, γ>=0.

Beneficial effect of the present invention:

The present invention realizes a kind of crude oil concoction optimization method, for CDU provides the crude oil accounting that meets character processing request, after crude oil blending Controlling System is carried out, can avoid oil property to change the infringement bringing to CDU and following process device, ensure the security of producing, and improved production efficiency and economic benefit.

Brief description of the drawings

Fig. 1 is crude oil blending system the general frame.

Fig. 2 is crude oil concoction optimization subsystem work schema.

Embodiment

Below in conjunction with drawings and Examples, the present invention is further illustrated.

Below with the present invention in the actual performance of certain Petrochemical Enterprises and in conjunction with a concrete example, provide detailed computation process and concrete operating process.There are 3 oil component tanks in this enterprise, mixes refining line for 3, mixes refining line for every and uses a blending component tank.Blending is by batch carrying out, and every batch of total amount that blending is certain, carries out next batch blending again after this batch of blending completes.The present embodiment is implemented under taking technical solution of the present invention as prerequisite, but protection scope of the present invention is not limited to following embodiment.

As shown in Figure 1, this crude oil blending system comprises following part: crude oil concoction optimization subsystem 1, laboratory test data management system 2, crude oil blending control subsystem 3 and on-the-spot equipment and instrument.Equipment and instrument specifically comprise blending component tank 4, blending pump 5, under meter 6, variable valve 7, static mixer 8 and atmospheric and vacuum distillation unit 9.Crude oil blending control subsystem 3 is accepted the oil flow accounting instruction from crude oil concoction optimization subsystem 1, controls on-the-spot equipment and instrument and complete detection and the control of flow.

As shown in Figure 2, the workflow of crude oil concoction optimization subsystem 1 mainly comprises the following steps:

Step 1: this batch of blending parameter initialization.

In conjunction with a concrete example, suppose this batch of blending total amount w=10000t, expected time t=16h.

Mix the setting of refining pipeline maximum flow rate.Suppose that 1# mixes refining line Peak Flow Rate b ₁=300t/h; 2# mixes refining line Peak Flow Rate b ₂=900t/h; 3# mixes refining line Peak Flow Rate b ₃=300t/h, B=[300 900 300] ^t.

By gathering the data of blending component tank 4, obtain the blending amount that storage tank can participate in.Suppose 1# storage tank controlled variable v ₁=4000t; 2# storage tank controlled variable v ₂=8000t; 3# storage tank controlled variable v ₃=5000t, V=[4000 8,000 5000] ^t.

This optimization system allows manually rule of thumb to preset flow proportional lower limit and the upper limit.Suppose that 1# mixes refining linear flow rate accounting x _1min=0%, x _1max=30%; 2# mixes refining linear flow rate accounting x _2min=12.5%, x _2max=70%; 3# mixes refining linear flow rate accounting x _3min=0%, x _3max=35%.Thereby, X _min=[0% 12.5% 0%] ^t, X _max=[30% 70% 35%] ^t.

Step 2: select optimization aim.

Suppose that optimization aim elects target deviation minimum as, i.e. formula (1) situation.

Step 3: oil property and scope, optimal way and the weight of selecting to participate in optimization.

Suppose to select three kinds of oil properties to participate in optimizing, i.e. sulphur content, acid content and naphtha yield.Wherein,

Sulphur content lower limit p _1min=0%, upper limit p _1max=2.50%, optimal way is to optimize p to the upper limit ₁=2.50%, weight is λ ₁=5;

Acid content lower limit p _2min=0mgKOH/g, upper limit p _2max=0.50mgKOH/g, optimal way is to optimize p to the upper limit ₂=0.50mgKOH/g, weight is λ ₂=5;

Naphtha yield lower limit p _3min=18%, upper limit p _3max=22%, optimal way is scope default value p ₃=20%, weight is λ ₃=8.

Step 4: obtain and mix the current character data of refining crude oil.

The present embodiment by with laboratory test data management system 2 interface communications, obtain the current refining oil property data of mixing.Suppose that the concrete data that gather are as follows:

1# storage tank: sulphur content 0.13%, acid content 0.75mgKOH/g, naphtha yield 30.49%;

2# storage tank: sulphur content 2.54%, acid content 0.26mgKOH/g, naphtha yield 17.7%;

3# storage tank: sulphur content 2.83%, acid content 0.24mgKOH/g, naphtha yield 14.97%.

$\left[a_{\mathrm{ji}}\right]=\left[\begin{array}{ccc}{a}_{11}& a_{12}& a_{13}\\ a_{21}& a_{22}& a_{23}\\ a_{31}& a_{32}& a_{33}\end{array}\right]=\left[\begin{array}{ccc}0.13& 2.54& 2.83\\ 0.75& 0.26& 0.24\\ 30.49& 17.7& 14.97\end{array}\right].$

Step 5: calculate and mix refining crude oil blending accounting.

Utilize formula (1) automatically to calculate three and mix refining crude oil blending accounting X.Formula (1) to solve method of calculation a lot, in the present embodiment, by simple Calling MATLAB Optimization Solution function f goalattain, obtain concocting accounting: x ₁=21.2%; x ₂=63.92%; x ₃=14.88%, i.e. X=[21.2% 63.92% 14.88%] ^t.

Step 6: accounting is issued to Controlling System and carries out.

Mix refining crude oil accounting and be issued to the execution of blending Controlling System through communication interface.

Step 7: judge whether this blending completes.

If this batch of blending completes, finish.If do not completed, return to step 4.

If select economic optimum optimization aim, only need to increase in the above-described embodiments the setting of the correlation parameter such as crude oil procurement price and price weight, method for solving is identical with said process.

The present invention do not relate to method all the prior art that maybe can adopt same as the prior art realized.

Claims (2)

1. a crude oil concoction optimization method, is characterized in that the method comprises the following steps:

First, carry out this blending parameter initialization, it is lower limit and the upper limit of each component oil accounting that setting crude oil is respectively mixed refining line;

Secondly, select optimization aim, comprise the rear oil property content of blending and target deviation minimum and two kinds of optimization aim of economic optimum; Again, select the rear crude oil of blending to participate in character and scope, optimal way and the weight optimized, optimal way adopts scope default value, optimizes three kinds of modes to lower limit optimization with to the upper limit;

Finally, obtain crude oil respectively mix refining line be the current character data of component oil, meet set constraint condition under, concoct according to the mode that optimization aim is corresponding, obtain respectively mix refining line be the accounting of component oil, issue Controlling System carry out;

When wherein after the method employing blending, the mode of oil property content and target deviation minimum is as optimization aim, solve the true correlation matter content of the rear crude oil of blending and the departure function of the rear crude oil relevant nature content target setting of blending by minimizing, employing formula (1) calculates the accounting of each component oil:

$\mathrm{\Φ}\left(X\right)=\underset{j=1}{\overset{m}{\mathrm{\Σ}}}{\mathrm{\λ}}_j|\underset{j=1}{\overset{n}{\mathrm{\Σ}}}{a}_{\mathrm{ji}}{x}_i-p_j|$

$\begin{array}{cc}s.t.& \underset{i=1}{\overset{n}{\mathrm{\Σ}}}{x}_i=1\\ & \mathrm{wX}\≤\mathrm{tB}\\ & \mathrm{tX}\≤V\\ & X_{\min }\≤X\≤X_{\max }\end{array}---\left(1\right)$

In formula (1), Φ (X) is objective function; I represents that it is component oil number that mixing of participation blending crude oil refined line number, and j represents the number of component oil or the rear crude oil relevant nature of blending; X is the accounting of each component oil, X=[x ₁, x ₂x _n] ^t, X>=0; λ _jfor crude oil j, j=1,2 ... the weight of m kind character, λ _j>=0; a _jifor i article of crude oil is mixed the i.e. j kind character content of i kind component oil of refining line; p _jfor the blending target of crude oil j kind character content, p _j>=0; W is current batch of blending total amount, w>=0; T is current batch of blending expected time, t>=0; B is that crude oil is respectively mixed refining line Peak Flow Rate, B=[b ₁, b ₂b _n] ^t, B>=0; V is to be that each component oil can be for concocting total amount, V=[v with respectively mixing each tempering tank of being connected of refining line ₁, v ₂v _n] ^t, V>=0; X _minand X _maxbe respectively lower limit and the upper limit of predefined each component oil accounting, X _min=[x _1min, x _2minx _nmin] ^t, X _min>=0, X _max=[x _1max, x _2maxx _nmax] ^t, X _max>=0;

Adopt scope default value, optimize three kinds of modes to lower limit optimization with to the upper limit for former oil properties content after blending:

The blending target p of the j character content of crude oil after blending _jmeet formula (2),

p _jmin≤p _j≤p _jmax (2)

In formula (2), p _jminfor concocting rear crude oil j kind character content lower limit, p _jmaxfor concocting rear crude oil j kind character upper content limit;

So, in the time that optimizing, gets lower limit p _j=p _jmin; In the time that optimizing, the upper limit gets p _j=p _jmax; P when scope default value is optimized _jno longer adjust;

When the method adopts the mode of economic optimum as optimization aim, when considering the rear oil property content of blending and target deviation minimum, realize production cost and minimize, meeting under the constraint condition of setting, employing formula (3) calculates the accounting of each component oil:

$\mathrm{\Ψ}\left(X\right)=\underset{i=1}{\overset{m}{\mathrm{\Σ}}}{\mathrm{\λ}}_j|\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{a}_{\mathrm{ji}}{x}_i-p_j|+\mathrm{\γ}\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{c}_i{x}_i$

$\begin{array}{cc}s.t.& \underset{i=1}{\overset{n}{\mathrm{\Σ}}}{x}_i=1\\ & \mathrm{wX}\≤\mathrm{tB}\\ & \mathrm{tX}\≤V\\ & X_{\min }\≤X\≤X_{\max }\end{array}---\left(3\right)$

In formula (3), Ψ (X) is for having considered the objective function after economic optimum; I represents that it is component oil number that mixing of crude oil refined line number, and j represents crude oil, component oil properties number; X is the accounting of each component oil, X=[x ₁, x ₂x _n] ^t, X>=0; λ _jfor crude oil, component oil j, j=1,2 ... the weight of m kind character, λ _j>=0; a _jifor i article of crude oil is mixed the i.e. j kind character content of i kind component oil of refining line; p _jfor the blending target of crude oil j kind character content, p _j>=0; W is current batch of blending total amount, w>=0; T is current batch of blending expected time, t>=0; B is that crude oil is respectively mixed refining line Peak Flow Rate, B=[b ₁, b ₂b _n] ^t, B>=0; V is to be that each component oil can be for concocting total amount, V=[v with respectively mixing each tempering tank of being connected of refining line ₁, v ₂v _n] ^t, V>=0; X _minand X _maxbe respectively lower limit and the upper limit of predefined each component oil accounting, X _min=[x _1min, x _2minx _nmin] ^t, X _min>=0, X _max=[x _1max, x _2maxx _nmax] ^t, X _max>=0;

C _ibe the procurement price of i kind component oil, c _i>=0; γ is price weight, γ>=0.

2. crude oil concoction optimization method according to claim 1, is characterized in that considering for security and economy, in the time solving objective function, for the productive capacity of sulphur content, in above-mentioned setting range, to upper limit optimization, gets p _j=p _jmax, and for the productive capacity of acid content, in above-mentioned setting range, to lower limit optimization, get p _j=p _jmin, for the productive capacity of refinery's naphtha yield and residual oil yield, p _jdo not remake upwards the adjustment of limit or lower limit direction, take scope default value optimal way.