CN102643662A - 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 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 (like gasoline, diesel oil) concoction optimization technology, but do not see and in crude oil processing, use the concoction optimization technology.Crude oil unit (CDU) is the first road link of crude oil processing; CDU has strict demand to the character content (like sulphur content and acid content) of crude oil 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 big and benefit of fluctuation is not good of producing.

Summary of the invention

The present invention seeks to have problems such as the production fluctuation is big, benefit is not good, proposed a kind of crude oil concoction optimization method to extensively adopting manual calculation crude oil accounting at present in the crude oil blending production of crude oil processing enterprise.Under the prerequisite that satisfies apparatus and process constraint condition; Minimum or to take into account economic optimum be that target is optimized blending with oil property content target deviation; And adopt the scope default value, optimize three kinds of optimal way, obtain optimum blending prescription, download to system and carry out to lower limit optimization with to the upper limit; The infringement of avoiding the 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, this method may further comprise the steps:

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

At last, obtaining crude oil, respectively to mix the refining line be the current character data of component oil, satisfying under the constrained conditions set, concocts according to the optimization aim corresponding mode, obtain respectively to mix the refining line be the accounting of component oil, issue system and carry out.

Among the present invention; This method adopts the mode of blending back oil property content and target deviation minimum as optimization aim; Through minimizing true correlation matter content of finding the solution blending back crude oil and the departure function of concocting back crude oil relevant nature content target setting, 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 the formula (1), Φ (X) is an objective function; I represent to participate in to concoct crude oil to mix refining line number be the component oil number, j representes the number of component oil or blending back crude oil relevant nature; X is the accounting of each component oil, X=[x ₁, x ₂X _n] ^T, X>=0; λ _jBe crude oil j, j=1,2 ... The weight of m kind character, λ _j>=0; a _JiFor crude oil i bar is mixed the i.e. j kind character content of i kind component oil of refining line; p _jBe the blending target of crude oil j kind character content, p _j>=0; W is a 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 for being that each component oil can supply to concoct total amount with respectively mixing each tempering tank of being connected of refining line, V=[v ₁, v ₂V _n] ^T, V>=0; X _MinAnd X _MaxBe respectively the 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.

Among the present invention, adopt the scope default value, optimize three kinds of modes to lower limit optimization with to the upper limit for the character content of concocting back crude oil:

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

p _jmin≤p _j≤p _jmax (2)

In the formula (2), p _JminFor concocting back crude oil j kind character content lower limit, p _JmaxFor concocting back crude oil j kind character upper content limit.

So,, gets lower limit p when optimizing _j=p _Jmin, the upper limit gets p when optimizing _j=p _JmaxP when the scope default value is optimized _jNo longer adjust.

Among the present invention, consider, when finding the solution objective function,, in above-mentioned setting range,, get p to upper limit optimization for the productive capacity of sulphur content from security and economy _j=p _JmaxAnd, in above-mentioned setting range,, get p to lower limit optimization for the productive capacity of acid content _j=p _JminFor the productive capacity of refinery's naphtha yield and residual oil yield, p _jDo not remake the adjustment of make progress limit or lower limit direction, promptly take scope default value optimal way.

Among the present invention; This method adopts the mode of economic optimum as optimization aim, when considering that blending back oil property content and target deviation are minimum, realizes that production cost minimizes; Promptly satisfying under the constrained conditions set, 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 the formula (3), Ψ (X) is for having considered the objective function behind the economic optimum; I representes that it is the component oil number that mixing of crude oil refined the line number, and j representes crude oil, component oil properties number; X is the accounting of each component oil, X=[x ₁, x ₂X _n] ^T, X>=0; λ _jBe crude oil, component oil j, j=1,2 ... The weight of m kind character, λ _j>=0; a _JiFor crude oil i bar is mixed the i.e. j kind character content of i kind component oil of refining line; p _jBe the blending target of crude oil j kind character content, p _j>=0; W is a 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 for being that each component oil can supply to concoct total amount with respectively mixing each tempering tank of being connected of refining line, V=[v ₁, v ₂V _n] ^T, V>=0; X _MinAnd X _MaxBe respectively the 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 the 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 that satisfies character processing request accounting; After crude oil blending system is carried out; Can avoid oil property to change the infringement that brings to CDU and following process device, guarantee the security of producing, and improved production efficiency and economic benefit.

Description of drawings

Fig. 1 is a crude oil blending system The general frame.

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

Embodiment

Below in conjunction with accompanying drawing and embodiment the present invention is further described.

Below with the present invention in the actual performance of certain Petrochemical Enterprises and combine a concrete example, provide detail calculation process and concrete operating process.There are 3 oil component jars in this enterprise, mixes the refining line for 3, mixes the refining line for every and uses a blending component jar.Blending is by batch carrying out, and every batch of total amount that blending is certain is carried out the next batch blending after this batch blending is accomplished again.Present embodiment is being to implement under the prerequisite with technical scheme of the present invention, but protection scope of the present invention is not limited to following embodiment.

As shown in Figure 1, this crude oil blending system comprises with the lower section: 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 jar 4, blending pump 5, under meter 6, variable valve 7, static mixer 8 and crude oil unit 9.Crude oil blending control subsystem 3 is accepted the oil flow accounting instruction from crude oil concoction optimization subsystem 1, and equipment that control is on-the-spot and instrument are accomplished the detection and the control of flow.

As shown in Figure 2, the workflow of crude oil concoction optimization subsystem 1 mainly may further comprise the steps:

Step 1: this batch blending parameter initialization.

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

Mix the setting of the refining pipeline flow velocity upper limit.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, then B=[300 900 300] ^T

Through gathering the data of blending component jar 4, obtain the blending amount that storage tank can be participated 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, then V=[4,000 8,000 5000] ^T

This optimization system allows manual work rule of thumb to preestablish the 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 the 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.

Present embodiment through with laboratory test data management system 2 interface communications, obtain the current refining oil property data of mixing.Suppose that the concrete data of gathering are following:

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%.

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

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

Utilize formula (1) to calculate three automatically and mix refining crude oil blending accounting X.Formula (1) to find the solution method of calculation a lot, optimize solved function fgoalattain through simply calling MATLAB in the present embodiment, 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 system and carries out.

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

Step 7: judge whether this blending is accomplished.

If this batch of blending is accomplished, then finish.If do not accomplish, then return step 4.

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

The present invention does not relate to all identical with the prior art prior art that maybe can adopt of method and realizes.

Claims (5)

1. crude oil concoction optimization method is characterized in that this method may further comprise the steps:

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

Secondly, select optimization aim, comprise the minimum and two kinds of optimization aim of economic optimum of blending back oil property content and target deviation;

Once more, select blending back crude oil to participate in character and scope, optimal way and the weight of optimizing, optimal way adopts the scope default value, optimizes three kinds of modes to lower limit optimization with to the upper limit;

At last, obtaining crude oil, respectively to mix the refining line be the current character data of component oil, satisfying under the constrained conditions set, concocts according to the optimization aim corresponding mode, obtain respectively to mix the refining line be the accounting of component oil, issue system and carry out.

2. crude oil concoction optimization method according to claim 1; It is characterized in that this method adopts the mode of concocting back oil property content and target deviation minimum as optimization aim; Through minimizing true correlation matter content of finding the solution blending back crude oil and the departure function of concocting back crude oil relevant nature content target setting, 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 the formula (1), Φ (X) is an objective function; I represent to participate in to concoct crude oil to mix refining line number be the component oil number, j representes the number of component oil or blending back crude oil relevant nature; X is the accounting of each component oil, X=[x ₁, x ₂X _n] ^T, X>=0; λ _jBe crude oil j, j=1,2 ... The weight of m kind character, λ _j>=0; a _JiFor crude oil i bar is mixed the i.e. j kind character content of i kind component oil of refining line; p _jBe the blending target of crude oil j kind character content, p _j>=0; W is a 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 for being that each component oil can supply to concoct total amount with respectively mixing each tempering tank of being connected of refining line, V=[v ₁, v ₂V _n] ^T, V>=0; X _MinAnd X _MaxBe respectively the 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.

3. crude oil concoction optimization method according to claim 1 is characterized in that adopting the scope default value, optimizing three kinds of modes to lower limit optimization with to the upper limit for the character content of blending back crude oil:

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

p _jmin≤p _j≤p _jmax (2)

In the formula (2), p _JminFor concocting back crude oil j kind character content lower limit, p _JmaxFor concocting back crude oil j kind character upper content limit.

So,, gets lower limit p when optimizing _j=p _Jmin, the upper limit gets p when optimizing _j=p _JmaxP when the scope default value is optimized _jNo longer adjust.

4. crude oil concoction optimization method according to claim 3 is characterized in that considering from security and economy, when finding the solution objective function, for the productive capacity of sulphur content, in above-mentioned setting range, to upper limit optimization, gets p _j=p _JmaxAnd, in above-mentioned setting range,, get p to lower limit optimization for the productive capacity of acid content _j=p _JminFor the productive capacity of refinery's naphtha yield and residual oil yield, p _jDo not remake the adjustment of make progress limit or lower limit direction, promptly take scope default value optimal way.

5. crude oil concoction optimization method according to claim 1; The mode that it is characterized in that this method employing economic optimum is as optimization aim; When considering that blending back oil property content and target deviation are minimum; The realization production cost minimizes, and is promptly satisfying under the constrained conditions set, and 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 the formula (3), Ψ (X) is for having considered the objective function behind the economic optimum; I representes that it is the component oil number that mixing of crude oil refined the line number, and j representes crude oil, component oil properties number; X is the accounting of each component oil, X=[x ₁, x ₂X _n] ^T, X>=0; λ _jBe crude oil, component oil j, j=1,2 ... The weight of m kind character, λ _j>=0; a _JiFor crude oil i bar is mixed the i.e. j kind character content of i kind component oil of refining line; p _jBe the blending target of crude oil j kind character content, p _j>=0; W is a 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 for being that each component oil can supply to concoct total amount with respectively mixing each tempering tank of being connected of refining line, V=[v ₁, v ₂V _n] ^T, V>=0; X _MinAnd X _MaxBe respectively the 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 the price weight, γ>=0.

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