CN1050150C - In-line determining method for quality index of gasoline and diesel oil - Google Patents

Abstract

The present invention provides a method for determining the dry point of gasoline on the tower top of a petroleum fractionating tower and 95% of points (or pour points and freezing points) of diesel oil utilized by middle side products. The method is characterized in that the influence of oil product components is considered besides the extension pressure of temperatures and oil gas, the distribution rate of the flow quantity of material distribution, inner refluxing flow quantity and the oil product components in a fractionating tower is calculated on line in time by using measurable process variables, the fractionating tower and the dynamic mathematical models of relevant equipment after the test point of the fractionating tower for oil products is necessarily changed so as to determine the dry point of gasoline and 95% of points of diesel oil at any time, the distribution rate adapts to a dynamic operating process and the variation of the characteristics of raw materials (feeding materials in the fractionating tower) for instructing operation, and the distribution rate is used as data for further control according to quality indexes.

Description

Online definite method of gasoline and diesel quality index

The present invention relates to method at 95% by online definite quality of gasoline index of the relevant measuring point of petroleum fractionating tower (doing) and diesel quality index (or pour point or zero pour), belong to the petroleum fractionating tower in line computation and control field.

Prior art is all with the separation column temperature and pressure of surveying, press steady state relation estimation gasoline or diesel product quality, for example: Applied Automation INC. (A.A. company), Lanzhou oil-refining chemical head factory Institute of Automation, Refinery of Gaoqiao Petrochemical Co., Shanghai ... or the like.

The prior art weak point is not consider the variation of oil product component, thereby can not adapt to the variation of feedstock property; Only use steady state relation, can not adapt to the dynamic change situation that production process exists at any time.

The objective of the invention is: provide one under the situation that operation dynamic change and feedstock property change, utilization can getable real measured data and dynamic mathematical models determine the method for gasoline and diesel quality index in real time.As controlling quality, and then the foundation of raising productive rate.

The present invention utilizes temperature after the measuring point to oil distillation column carries out necessary change, oily vapour dividing potential drop and oil product component are divided rate, online definite gasoline and diesel quality index.

Oil vapour dividing potential drop is to obtain according to actual measurement separation column pressure and the various logistics of Ta Nei (rich gas, gasoline, diesel oil and water vapor) flow rate calculation; Be in dynamically down in operation, calculating these logistics fluxs is characteristics of the present invention.

Another characteristics of the present invention are that under operation was in dynamically, calculating separation column internal reflux flow and oil product component were divided rate (or component factor), and then the quality index of definite oil product, now These characteristics are described as follows:

Oil distillation column (K-1) flow process is seen wherein F of accompanying drawing (3) ₁, F ₂..., F ₉Be each actual measurement logistics flux, P ₁, P ₂Be observed pressure, L ₁, L ₂Be actual measurement liquid level, T ₁, T ₂... T ₅T ' ₁..., T ' ₄Be observed temperature.(K-1) being separation column, (K-2) is the diesel oil stripping tower, (V-1) is the overhead oil air water separator.One. the method for calculation of logistics flux in the separation column

1. the rich gas flow at separation column (K-1) top and the calculating of gasoline flow:

Cat head rich gas flow: $G_{a1}={\mathrm{<figure-callout\; id="1"\; label="W\; n"\; filenames="C9510118300141.png,C9510118300151.png"\; state="\{\{state\}\}">W</figure-callout>}}_n\frac{{\mathrm{<figure-callout\; id="2"\; label="dP"\; filenames="C9510118300142.png,C9510118300151.png"\; state="\{\{state\}\}">dP</figure-callout>}}_2}{\mathrm{dt}}+F_1----\left(1\right)$

Cat head gasoline flow: ${\mathrm{<figure-callout\; id="1"\; label="G\; g"\; filenames="C9510118300141.png,C9510118300151.png"\; state="\{\{state\}\}">G</figure-callout>}}_g=D_1{A}_1\frac{{\mathrm{<figure-callout\; id="1"\; label="dL"\; filenames="C9510118300141.png,C9510118300151.png"\; state="\{\{state\}\}">dL</figure-callout>}}_1}{\mathrm{dt}}+{\mathrm{<figure-callout\; id="2"\; label="F"\; filenames="C9510118300142.png,C9510118300151.png"\; state="\{\{state\}\}">F</figure-callout>}}_2+F_3----\left(2\right)$

Overhead vapor stream flow: G _A1=F ₅+ F ₆+ F ₇(3)

Wherein: W _A1: the air-capacitor amount of V-1 (unit desired gas amount of pressure rising);

A ₁: the sectional area of V-1;

D ₁: gasoline density;

F ₅, F ₆, F ₇Be respectively in the raw material, at the bottom of the tower and steam stripped steam flow;

F ₁: the rich gas flow after excess temperature, pressure correction;

F ₂: actual measurement gasoline flow;

F ₃: top cold reflux flow.2. cat head gasoline dividing potential drop: $P_g=\frac{{\mathrm{<figure-callout\; id="1"\; label="G\; g"\; filenames="C9510118300141.png,C9510118300151.png"\; state="\{\{state\}\}">G</figure-callout>}}_g/M_g}{G_{a1}/M_a+G_{a1}/M_a+{\mathrm{<figure-callout\; id="1"\; label="G\; g"\; filenames="C9510118300141.png,C9510118300151.png"\; state="\{\{state\}\}">G</figure-callout>}}_g/M_g}{P}_1----\left(4\right)$

Wherein: M _a, M _a, M _gBe respectively that water vapor, rich gas, petrol molecule amount 3. diesel oil distillate flow from separation column (K-1): $G_d=D_2{A}_2\frac{{\mathrm{<figure-callout\; id="2"\; label="dL"\; filenames="C9510118300142.png,C9510118300151.png"\; state="\{\{state\}\}">dL</figure-callout>}}_2}{\mathrm{dt}}+F_4----\left(5\right)$

Wherein:

A ₂: the K-2 sectional area;

D ₂: diesel oil density;

F ₄: actual measurement diesel oil flow.4. other logistics of the diesel oil section of distillating:

The gasoline flow: ${\mathrm{<figure-callout\; id="2"\; label="G\; g"\; filenames="C9510118300142.png,C9510118300151.png"\; state="\{\{state\}\}">G</figure-callout>}}_g={\mathrm{<figure-callout\; id="2"\; label="W\; g"\; filenames="C9510118300142.png,C9510118300151.png"\; state="\{\{state\}\}">W</figure-callout>}}_g\frac{{\mathrm{<figure-callout\; id="1"\; label="dP"\; filenames="C9510118300141.png,C9510118300151.png"\; state="\{\{state\}\}">dP</figure-callout>}}_1}{\mathrm{dt}}{+G}_{g1}----\left(6\right)$

The rich gas flow: ${\mathrm{<figure-callout\; id="2"\; label="G\; g"\; filenames="C9510118300142.png,C9510118300151.png"\; state="\{\{state\}\}">G</figure-callout>}}_g=W_{a2}\frac{{\mathrm{<figure-callout\; id="1"\; label="dP"\; filenames="C9510118300141.png,C9510118300151.png"\; state="\{\{state\}\}">dP</figure-callout>}}_1}{\mathrm{dt}}{+G}_{a1}----\left(7\right)$

Wherein: W _G2, W _A2Be respectively K-1 top gasoline, rich gas air-capacitor amount; P ₁Be actual measurement K-1 top pressure.5. diesel oil oil gas dividing potential drop: $P_d=\frac{G_d/M_d}{G_{a1}/M_a+G_{a2}/M_a+{\mathrm{<figure-callout\; id="2"\; label="G\; g"\; filenames="C9510118300142.png,C9510118300151.png"\; state="\{\{state\}\}">G</figure-callout>}}_g/M_g+G_d/M_d}{P}_1----\left(8\right)$

Wherein: M _dMolecular weight for diesel oil.Two. the calculating of internal reflux flow

This is adopted following separation column dynamicmodel to calculate tower top section (being used for determining gasoline endpoint) internal reflux flow: ${\mathrm{<figure-callout\; id="1"\; label="C\; h"\; filenames="C9510118300141.png,C9510118300151.png"\; state="\{\{state\}\}">C</figure-callout>}}_h\frac{{\mathrm{<figure-callout\; id="3"\; label="dT"\; filenames="C9510118300141.png,C9510118300142.png"\; state="\{\{state\}\}">dT</figure-callout>}}_3}{\mathrm{dt}}+{\mathrm{<figure-callout\; id="2"\; label="C\; h"\; filenames="C9510118300142.png,C9510118300151.png"\; state="\{\{state\}\}">C</figure-callout>}}_h\frac{{\mathrm{<figure-callout\; id="1"\; label="dT"\; filenames="C9510118300141.png,C9510118300151.png"\; state="\{\{state\}\}">dT</figure-callout>}}_1}{\mathrm{dt}}=G_1{H}_g\left(T_4\right)-G_{g1}{H}_g\left(T_1\right)+$

+G _a[H _a(T ₄)-H _a(T ₁)]+G _a[H _a(T ₄)-H _a(T ₁)]

-Q ₁-R ₁h ₁(T ₃)+F ₃h ₂(T ₅) (9)

Q ₁＝F ₃*[h ₁(T ₃)-h ₁(T ₂)] (10) $W_{\mathrm{<figure-callout\; id="1"\; label="g\; dR"\; filenames="C9510118300141.png,C9510118300151.png"\; state="\{\{state\}\}">g</figure-callout>}}\frac{{\mathrm{dR}}_{}}{}\frac{{}_1}{\mathrm{dt}}=G_1-G_{g1}-R_1+F_3----\left(11\right)$

Wherein:

C _H1: tower top section liquid phase thermal capacity (comprising the gas wall) (institute of unit heat requirement of temperature rising);

C _H2: tower top section gas phase thermal capacity;

H _g(T): gasoline T (℃) time the gas phase heat content;

H _a(T): water vapor T (℃) time the gas phase heat content;

H _a(T): rich gas T (℃) time the gas phase heat content;

h ₁(T): the enthalpy of top pump around circuit (liquid phase) when temperature T;

h ₂(T): the enthalpy of top cold reflux (liquid phase) when temperature T;

F ₃: top cold reflux flow;

F _s: top pump around circuit flow;

W _g: tower top section liquid phase amount of savings;

In the time of in definite diesel quality index, need to calculate midsection internal reflux flow R ₂, its method of calculation and above-mentioned various identical just change related variable and parameter into separation column stage casing (in) and respectively survey variable and parameter.Three. component divides rate and quality index to calculate

The present invention has provided the method for following two kinds of online definite gasoline and diesel quality index:

1. calculate component and divide rate, determine the oil quality index according to this:

Heavy constituent branch rate is in the cat head gasoline: $Y{\left(k\right)}_{12}=\frac{A_1{R}_1}{B_1{R}_1+B_2{G}_{g1}}----\left(12\right)$

Gasoline endpoint is pressed following formula and is determined: $X_q\left(k\right)=T_{h0}+(T_{h0}-T_{10})\frac{Y_{12}}{1-Y_{12}}+C_4----\left(13\right)$

Wherein: A ₁=C ₁T ₁+ C ₂-T _H0

B ₁＝C ₃T ₁P

B ₂＝T _h1-C ₁T ₁-C ₂+B ₁Y ₁₂(k-1)

T _H0The initial boiling point of=heavy constituent (final boiling point of light constituent);

T _H1The final boiling point of=heavy constituent; T ₁₀The initial boiling point of=light constituent;

C1, C2, C3, C4 are adjustable parameter;

K and unreceipted person be current sampling instant it; K-1 be last sampling instant it.

Heavy constituent divide definite method of rate and 95% point (pour point or zero pour) thereof identical with (12) (13) formula in the diesel oil, just with T ₁, R ₁And G _G1Be changed to T respectively ₁', R ₂And G _dAnd parameter is adjusted accordingly).2. utilize observed temperature, the oily vapour dividing potential drop and the component factor are determined the oil quality index:

X _q＝a ₀+a ₁T ₁+a ₂PT ₂+a ₃P+a ₄C[1.0+a ₅(T ₃-T ₃₀)] (14)

X _q: gasoline endpoint or diesel oil 95% point (pour point or zero pour);

T ₁: gasoline or diesel oil vapor phase temperature;

T ₃: internal reflux (liquid phase) temperature;

P: gasoline or diesel oil dividing potential drop;

T ₃₀: T ₃Specified (design) temperature;

a ₂＝a ₂₁+a ₂₂P； a ₃＝a ₃₁+a ₃₂P；

a ₀, a ₁, a ₂₁, a ₂₂, a ₃₁, a ₃₂, a ₄, a ₅: coefficient.

C: the component factor;

Calculate for gasoline endpoint, the component factor is defined as follows: $C_g=\frac{R_1}{{\mathrm{<figure-callout\; id="1"\; label="R"\; filenames="C9510118300141.png,C9510118300151.png"\; state="\{\{state\}\}">R</figure-callout>}}_1+G_{g1}}----\left(15\right)$

Wherein: R ₁It is separation column (K-1) top section internal reflux flow.For diesel oil 95% point (pour point or zero pour), the component factor is defined as follows: $C_d=\frac{R_2}{{\mathrm{<figure-callout\; id="2"\; label="R"\; filenames="C9510118300142.png,C9510118300151.png"\; state="\{\{state\}\}">R</figure-callout>}}_2+G_d}----\left(16\right)$ Wherein: R ₂It is separation column (K-1) stage casing internal reflux flow.

Four. embodiment

1. realize that with single-loop regulator (PMK or other model) the (see figure 1) gasoline endpoint is in line computation.

Because the PMK input terminal is less, only is applicable to following situation:

(I)F ₃＝0；

(II) steam rates G _aLess, can ignore.

With 1. (PMK single-loop regulator), realize that by (1), (2), (3), (4) formula the oil gas dividing potential drop calculates,

Provide cat head gasoline flow G simultaneously _g, rich gas flow G _a

With 2. (PMK single-loop regulator), calculate R by (9), (10), (11), (15) formula ₁(internal reflux flow)

And component factor C.

With 3. (PMK single-loop regulator), (P C) calculates gasoline endpoint by (14) formula and aforementioned calculation result.

The used input variable of each PMK and setting parameter such as following table:

The PMK signal	Input variable	Setting parameter	Calculation result
				①	F 1 F 2 P 2，P 1 L 1	W a1 A 1，D 1 M g，M a L 1Range	G u1 G a G g1 P g
②	T 1 T 4 T 2 T 3	C h1，W g C h2 H g(T)，h 1(T) H 1(T) H a(T)	R 1 C g
				③	P g C g T 3 T 1	a 0，a 1 a 2 a 3 a 4 a 5 T 30	X 9

Wherein: F ₁, F ₂..., F ₉Be measured discharge, T ₁..., T ₄Be observed temperature.

P ₁, P ₂Be observed pressure, L ₁Be the actual measurement liquid level.

Utilize the functional block of PMK during enforcement, carry out configuration by above-mentioned each relational expression and get final product.Be noted that: 1. will be actual measurement process variable (F ₁, F ₂, P ₁, P ₂, L ₁, F ₃) carry out filtering to reduce the measurement The noise.2. the method with PMK functional block calculating dL/dt (dT/dt) is as follows:

MVAR (30S): running mean module (30 seconds running means)

MVAR (60S): running mean module (60 seconds running means)

X2: four arithmetic operations module Lr=2 (Z1-Z2)

L (T): 2. (Distributed Computer Control System DCS) goes up the realization (see figure 2) in distributing system for actual measurement liquid level (L) or temperature (T)

By control station or monitoring station 4., operator terminal 1., online computing system is formed with slip-stick artist's terminal in the common data area 2. 3..

The main effect 4. of control station or monitoring station is to gather required actual measurement process variable, and it is carried out filtering process, also can utilize its configuration function to carry out necessary calculating.

Above-mentioned various calculating mainly is to carry out on operator terminal (station) or slip-stick artist's terminal (station), needs to determine by the characteristics of each DCS system and the High-Level Language that provides.DL/dt (or dT/dt) can be calculated as follows:

DL/dt=[L (k)-L (k-1)]/Ts (Ts is the sampling period, can select Ts=30 second)

Gasoline and diesel quality index are calculated with (13) formula.

On 1., show calculation result; Adjust to calculating used parameter 2. going up by the slip-stick artist; Monitor calculation result and record relevant data simultaneously.Parameter after the slip-stick artist adjusts deposit in the common data area 3. in so that when line computation, call at any time.Calculation result and required actual measurement process variable so that 1. and 2. call, monitor online calculation result in also depositing in 3..

Table 1 laboratory values and calculated value (unit: ℃) relatively

Preface	Laboratory values	Calculated value	Deviation	Preface	Laboratory values	Calculated value	Deviation
								00 01 02 03 04 05 06 07 08 09	204.60 205.00 205.20 205.60 205.40 205.80 204.50 202.50 200.60 206.70	204.39 205.00 204.86 205.23 205.43 205.78 204.38 203.60 201.00 206.45	-0.21 0.00 -0.34 -0.37 0.03 -0.02 -0.12 1.10 0.40 -0.25	39 40 41 42 43 44 45 46 47 48	202.20 203.20 203.60 204.80 203.40 203.60 203.20 204.00 204.80 203.00	202.31 203.34 204.28 204.64 203.20 203.78 203.27 204.44 204.54 202.37	0.11 0.14 0.68 -0.16 -0.20 0.18 0.07 0.44 -0.26 -0.63
10 11 12 13 14 15 16 17 18 19	204.50 203.40 202.60 203.10 206.00 202.80 206 00 204.90 204.80 204.50	204.50 203.51 202.56 202.68 205.76 202.81 205.60 205.32 205.19 205.07	0.00 0.11 -0.04 -0.42 -0.24 0.01 -0.40 0.42 0.39 0.57	49 50 51 52 53 54 55 56 57 58	202.80 204.20 203.20 205.30 202.70 200.80 204.20 204.90 202.40 204.30	201.34 204.22 203.34 204.10 202.10 199.96 204.40 205.05 203.35 204.27	-0.98 -0.08 0.11 -1.29 -0.69 -0.84 -0.16 0.15 0.95 0.07
								20 21 22 23 24 25 26 27 28 29	204.90 207.40 205.60 205.00 205.30 204.10 202.90 203.00 202.80 202.70	205.46 206.45 204.44 204.75 205.38 204.11 203.14 203.42 203.12 203.06	0.56 -0.95 -1.16 -0.25 0.08 0.01 0.24 0.42 0.32 0.36	59 60 61 62 63 64 65 66 67 68	204.00 205.82 206.00 202.90 202.00 202.40 202.30 203.90 203.00 203.00	204.18 204.90 204.94 203.10 202.28 202.16 202.52 204.56 203.78 202.16	0.18 -0.90 -1.90 0.11 0.28 -0 24 0.22 0.36 -0.12 -0.84
30 31 32 33 34 35 36 37 38	200.00 198.90 200.60 202.40 204.40 203.40 202.70 201.50 199.20	200.30 199.03 201.31 202.57 204.42 203.77 203.47 201.04 200.41	0.30 0.13 0.71 0.17 0.02 0.37 0.77 -0.46 1.21	69 70 71 72 73 74 75 76 77	202.60 202.50 201.80 201.30 203.90 204.10 203.40 205.20 205.00	202.35 202.85 202.58 200.98 202.59 204.31 203.46 206.62 204.94	-0.25 0.35 0.78 -0.34 -1.31 0.12 0.06 1.42 -0.06

Standard deviation=0.56 ℃

Claims (2)

1. online definite method of gasoline and diesel quality index comprises the steps:

I. measure various processing parameters, as actual measurement logistics flux (F ₁, F ₂, F ₃, F ₄, F ₅, F ₆, F ₇, F ₈, F ₉), observed pressure (P ₁, P ₂), actual measurement liquid level (L ₁, L ₂), observed temperature (T ₁, T ₂, T ₃, T ₄, T ₅T ＇ ₁, T ＇ ₂, T ＇ ₃, T ＇ ₄);

II. calculate logistics flux in the separation column:

I. the rich gas flow at separation column (K-1) top and the calculating of gasoline flow:

Cat head rich gas flow: $G_{a1}=W_{a1}\frac{{\mathrm{dP}}_2}{\mathrm{dt}}+F_1----\left(1\right)$

Cat head gasoline flow: $G_{g1}=D_1{A}_1\frac{{\mathrm{dL}}_1}{\mathrm{dt}}{+F}_2+F_3----\left(2\right)$

Overhead vapor stream flow: G _S1=F ₅+ F ₆+ F ₇(3)

Wherein:

W _A1: the air-capacitor amount of V-1 (unit desired gas amount of pressure rising);

A ₁: the sectional area of V-1;

D ₁: gasoline density;

F ₅, F ₆, F ₇Be respectively in the raw material, at the bottom of the tower and steam stripped steam flow;

F ₁: the rich gas flow after excess temperature, pressure correction;

F ₂: actual measurement gasoline flow;

F ₃: top cold reflux flow;

Ii. cat head gasoline dividing potential drop: $P_g=\frac{G_{g1}/M_g}{G_{s1}/M_s+G_{a1}/M_a+G_{g1}/M_g}{P}_1----\left(4\right)$

Wherein: M _s, M _a, M _gBe respectively water vapor, rich gas, petrol molecule amount;

Iii. diesel oil distillates flow from separation column (K-1): $G_d=D_2{A}_2\frac{{\mathrm{dL}}_2}{\mathrm{dt}}{+F}_4----\left(5\right)$

Wherein: A ₂: the K-2 sectional area;

D ₂: diesel oil density;

F ₄: actual measurement diesel oil flow;

Iv. other logistics of the diesel oil section of distillating:

The gasoline flow: $G_{g2}=W_{g2}\frac{{\mathrm{dP}}_1}{\mathrm{dt}}+G_{g1}----\left(6\right)$

The rich gas flow: $G_{a2}=W_{a2}\frac{{\mathrm{dP}}_1}{\mathrm{dt}}+G_{a1}----\left(7\right)$

Wherein: W _G2, W _A2Be respectively K-1 top gasoline, rich gas air-capacitor amount;

P ₁Be actual measurement K-1 top pressure;

V. diesel oil oil gas dividing potential drop: $P_d=\frac{G_d/M_d}{G_{s1}/M_s+G_{a2}/M_a+G_{g2}/M_g+G_d/M_d}{P}_1----\left(8\right)$

Wherein: M _dMolecular weight for diesel oil;

III. calculate the internal reflux flow:

When determining gasoline endpoint, adopt following separation column dynamicmodel to calculate tower top section internal reflux flow R ₁: $C_{h1}\frac{{\mathrm{dT}}_3}{\mathrm{dt}}+C_{h2}\frac{{\mathrm{dT}}_1}{\mathrm{dt}}=G_1{H}_g\left(T_4\right)-G_{g1}{H}_g\left(T_1\right)+$

G _s[H _s(T ₄)-H _s(T ₁)]+G _a[Ha(T ₄)-H _a(T ₁)] (9)

-Q ₁-R ₁h ₁(T ₃)+F ₃h ₂(T ₅)

Q ₁＝F ₈ ^*[h ₁(T ₃)-h ₁(T ₂)] (10) $W_g\frac{{\mathrm{dR}}_1}{\mathrm{dt}}=G_1-G_{g1}-R_1+F_3----\left(11\right)$

Wherein:

C _H1: tower top section liquid phase thermal capacity (comprising the gas wall) (institute of unit of temperature rising

Heat requirement);

C _H2: tower top section gas phase thermal capacity;

H _g(T): gasoline T (℃) time the gas phase heat content;

H _s(T): water vapor T (℃) time the gas phase heat content;

H _a(T): rich gas T (℃) time the gas phase heat content;

h ₁(T): top pump around circuit (liquid phase) temperature T (℃) time enthalpy;

h ₂(T): top cold reflux (liquid phase) temperature T (℃) time enthalpy;

F ₃: top cold reflux flow;

F ₈: top pump around circuit flow;

W _g: tower top section liquid phase amount of savings;

When definite diesel quality index, need to calculate midsection internal reflux flow R ₂, its method of calculation and above-mentioned various identical just change related variable and parameter into separation column stage casing (in) and respectively survey variable and parameter;

IV. calculate component branch rate, determine the oil quality index:

I. heavy constituent branch rate is in the cat head gasoline: $Y{\left(k\right)}_{12}=\frac{A_1{R}_1}{B_1{R}_1+B_2{G}_{g1}}----\left(12\right)$

Gasoline endpoint is pressed following formula and is determined: $X_q\left(k\right)=T_{h0}+(T_{h0}-T_{10})\frac{Y_{12}}{1-Y_{12}}+C_4----\left(13\right)$

Wherein:

A ₁＝C ₁T ₁+C ₂-T _h0

B ₁＝C ₃T ₁P _g

B ₂＝T _h1-C ₁T ₁-C ₂+B ₁Y ₁₂(k-1)

T _H0The initial boiling point of=heavy constituent (final boiling point of light constituent);

T _H1The final boiling point of=heavy constituent;

T ₁₀The initial boiling point of=light constituent;

C ₁, C ₂, C ₃, C ₄Be adjustable parameter;

K and unreceipted person are current sampling instant value;

K-1 is last sampling instant value; Ii. heavy constituent branch rate is in the diesel oil: $Y{\left(k\right)}_{12}=\frac{A_1{R}_2}{B_1{R}_2+B_2{G}_d}----{\left(12\right)}^{\&prime;}$

Diesel oil 95% point (pour point or zero pour) is calculated as follows: $X_q\left(k\right)=T_{h0}+(T_{h0}-T_{10})\frac{Y_{12}}{1-Y_{12}}+C_4----{\left(13\right)}^{\&prime;}$

Wherein:

A ₁＝C ₁T＇ ₁ +C ₂-T _ho

B ₁＝C ₃T＇ ₁P _d

B ₂＝T _h1-C ₁T＇ ₁-C ₂+B ₁Y ₁₂(k-1)

T _H0The initial boiling point of=heavy constituent (final boiling point of light constituent);

T _H1The final boiling point of=heavy constituent;

T ₁₀The initial boiling point of=light constituent;

C ₁, C ₂, C ₃, C ₄Be adjustable parameter;

K and unreceipted person are current sampling instant value;

K-1 is last sampling instant value;

2. online definite method of gasoline and diesel quality index comprises the steps:

I. measure various processing parameters, as actual measurement logistics flux (F ₁, F ₂, F ₃, F ₄, F ₅, F ₆, F ₇, F ₈, F ₉), observed pressure (P ₁, P ₂), actual measurement liquid level (L ₁, L ₂), observed temperature (T ₁, T ₂, T ₃, T ₄, T ₅T ' ₁, T ' ₂, T ' ₃, T ' ₄);

II. calculate logistics flux in the separation column:

I. the rich gas flow at separation column (K-1) top and the calculating of gasoline flow:

Cat head rich gas flow: $G_{a1}=W_{a1}\frac{{\mathrm{dP}}_2}{\mathrm{dt}}+F_1----\left(1\right)$

Cat head gasoline flow: $G_{g1}=D_1{A}_1\frac{{\mathrm{dL}}_1}{\mathrm{dt}}+F_2+F_3----\left(2\right)$

Overhead vapor stream flow: G _S1=F ₅+ F ₆+ F ₇(3)

Wherein:

W _A1: the air-capacitor amount of V-1 (unit desired gas amount of pressure rising);

A ₁: the sectional area of V-1;

D ₁: gasoline density;

F ₅, F ₆, F ₇Be respectively in the raw material, at the bottom of the tower and steam stripped steam flow;

F ₁: the rich gas flow after excess temperature, pressure correction;

F ₂: actual measurement gasoline flow;

F ₃: top cold reflux flow; Ii. cat head gasoline dividing potential drop: $P_g=\frac{G_{g1}/M_g}{G_{s1}/M_s+G_{a1}/M_a+G_{g1}/M_g}{P}_1----\left(4\right)$

Wherein: M _s, M _a, M _gBe respectively water vapor, rich gas, petrol molecule amount; Iii. diesel oil distillates flow from separation column (K-1): $G_d=D_2{A}_2\frac{{\mathrm{dL}}_2}{\mathrm{dt}}+F_4----\left(5\right)$

Wherein: A ₂: the K-2 sectional area;

D ₂: diesel oil density;

F ₄: actual measurement diesel oil flow; Iv. other logistics of the diesel oil section of distillating:

The gasoline flow: $G_{g2}=W_{g2}\frac{{\mathrm{dP}}_1}{\mathrm{dt}}+G_{g1}----\left(6\right)$

The rich gas flow: $G_{a2}=W_{a2}\frac{{\mathrm{dP}}_1}{\mathrm{dt}}+G_{a1}----\left(7\right)$

Wherein: W _G2, W _A2Be respectively K-1 top gasoline, rich gas air-capacitor amount;

P ₁Be actual measurement K-1 top pressure; V. diesel oil oil gas dividing potential drop: $P_d=\frac{G_d/M_d}{G_{s1}/M_s+G_{a2}/M_a+G_{g2}/M_g+G_d/M_d}{P}_1----\left(8\right)$

Wherein: M _dMolecular weight for diesel oil;

III. calculate the internal reflux flow:

When determining gasoline endpoint, adopt following separation column dynamicmodel to calculate tower top section internal reflux flow: $C_{h1}\frac{{\mathrm{dT}}_3}{\mathrm{dt}}+C_{h2}\frac{{\mathrm{dT}}_1}{\mathrm{dt}}=G_1{H}_g\left(T_4\right)-G_{g1}{H}_g\left(T_1\right)+$

G _s[H _s(T ₄)-H _s(T ₁)]+G _a[Ha(T ₄)-H _a(T ₁)] (9)

-Q ₁-R ₁h ₁(T ₃)+F ₃h ₂(T ₅)

Q ₁＝F ₈ ^*[h ₁(T ₃)-h ₁(T ₂)] (10) $W_g\frac{{\mathrm{dR}}_1}{\mathrm{dt}}=G_1-G_{g1}-R_1+F_3----\left(11\right)$

Wherein:

C _H1: tower top section liquid phase thermal capacity (comprising the gas wall) (institute of unit of temperature rising

Heat requirement);

C _H2: tower top section gas phase thermal capacity;

H _g(T): gasoline T (℃) time the gas phase heat content;

H _s(T): water vapor T (℃) time the gas phase heat content;

H _a(T): rich gas T (℃) time the gas phase heat content;

h ₁(T): top pump around circuit (liquid phase) temperature T (℃) time enthalpy;

h ₂(T): top cold reflux (liquid phase) temperature T (℃) time enthalpy;

F ₃: top cold reflux flow;

F ₈: top pump around circuit flow;

W _g: tower top section liquid phase amount of savings;

When definite diesel quality index, need to calculate midsection internal reflux flow R ₂, its method of calculation and above-mentioned various identical just change related variable and parameter into separation column stage casing (in) and respectively survey variable and parameter;

IV. utilize observed temperature,, determine the quality index of gasoline and diesel oil according to the oil gas dividing potential drop and the component factor:

X _q＝a ₀+a ₁T ₁+a ₂PT ₂+a ₃P+a ₄C[1.0+a ₅(T ₃-T ₃₀)]

X _q: gasoline endpoint or diesel oil 95% point (pour point or zero pour);

T ₁: gasoline or diesel oil vapor phase temperature;

T ₃: internal reflux (liquid phase) temperature;

P: gasoline or diesel oil dividing potential drop;

T ₃₀: T ₃Specified (design) temperature;

a ₂＝a ₂₁+a ₂₂P； a ₃＝a ₃₁+a ₃₂P；

a ₀, a ₁, a ₂₁, a ₂₂, a ₃₁, a ₃₂, a ₄, a ₅: coefficient;

C: the component factor;

Calculate for gasoline endpoint, the component factor is defined as follows: $C_g=\frac{R_1}{R_1+G_{g1}}----\left(15\right)$

Wherein: R ₁It is separation column (K-1) top section internal reflux flow;

For diesel oil 95% point (pour point or zero pour), the component factor is defined as follows: $C_d=\frac{R_2}{R_2+G_d}----\left(16\right)$

Wherein: R ₂It is separation column (K-1) stage casing internal reflux flow.

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