Aspen Plus石油煉制過程的模擬解析課件

Aspen

Plus高級班2023/10/12石油煉制過程的模擬高級精餾在化工領(lǐng)域的應(yīng)用2023/10/12RADFRAC單元操作模型的應(yīng)用、收斂方法和參數(shù)的選??；三相蒸餾、萃取蒸餾、共沸蒸餾和反應(yīng)蒸餾等特殊蒸餾過程的模擬；電解質(zhì)過程的模擬等。石油煉制過程的模擬方法2023/10/12以一套典型的常減壓裝置為主線，講授下列5部分內(nèi)容：油品餾程分析數(shù)據(jù)的處理；初餾塔的模擬計算；常壓塔的模擬計算；減壓塔的模擬計算；計算原油中所含雜質(zhì)硫在各種產(chǎn)品中的分布。掌握如下新的內(nèi)容：2023/10/221)石油煉制過程蒸餾單元的模擬步驟；2)流程模擬軟件中石油餾份的特殊處理方法；3)

掌握PETROFRAC單元操作模型的使用；4)產(chǎn)品中雜質(zhì)分布的計算。復(fù)習(xí)：建立流程模擬模型的基本步驟2023/10/22確定模擬范圍，繪制模擬流程圖；將已知條件輸入相應(yīng)表格：SETUPCOMPONENTSPROPERTIESSTREAMSBLOKS。運行模擬計算檢查結(jié)果油品分析和虛擬組分目標:學(xué)習(xí)輸入石油分析數(shù)據(jù),創(chuàng)建調(diào)和組分(油品混合),以及表征石油餾分Aspen

Plus

參考資料:User

Guide,

Chapter

6,

Specifying

ComponentsUser

Guide,

Chapter

32,

Petroleum

AssaysandPseudocomponents本章概況表征石油流體的挑戰(zhàn)油品餾程數(shù)據(jù)和性質(zhì)數(shù)據(jù)的輸入蒸餾曲線的轉(zhuǎn)換生成虛擬組分油品調(diào)和用戶自定義的虛擬組分2023/10/22石油的表征2023/10/22石油是烴類化合物和雜質(zhì)組成的寬沸程的混合物.石油或石油餾分的性質(zhì)取決于它們的組成，但是其組成難以定量分析石油用虛擬組分(pseudocomponents)來表征,虛擬組分是蒸餾曲線上較小的片斷.每一個虛擬組分的基本性質(zhì)由下列關(guān)聯(lián)式來計算:分子量(MW)正常沸點(TBP)重度或者Watson

UOP

KAssays

和Blends

組分Assay

Data(TBP,D86)PseudocomponentsAssay-1Assay-2BlendPseudocomponents2023/10/22輸入輸出輸入油品餾程分析數(shù)據(jù)在Data

Browser下面,選擇Components,

然后選Assay-Blend.在Assay-Blend

目標管理器下,創(chuàng)建一個assay

并且提供一個名稱(ID).

在BasicData\DistCurve表中，輸入蒸餾曲線數(shù)據(jù).在BasicData\DistCurve表中，輸入油品重度，或者在BasicData\Gravity/UOPK表中，輸入重度曲線或UOPK曲線數(shù)據(jù).虛擬組分將在模擬計算之初自動生成.2023/10/22ASSAY組分的表征2023/10/22輸入蒸餾曲線蒸餾曲線分割為很多個片段(TBP

Cutpoints)每一個片段生成一個虛擬組分每一個虛擬組分的性質(zhì)以下列參數(shù)的平均值為基礎(chǔ)進行估算：分子量(MW)正常沸點(NBP)密度或比重(API

or

SG)虛擬組分的流率在流股結(jié)果表中報告.Assay組分BasicData\DistCurve

表2023/10/22重度的規(guī)定2023/10/22油品整體重度比重API

重度重度曲線比重API

重度API=141.5/SG-131.5Watson

UOPK

曲線

NBP=(UOPK*SG)3Assay組分BasicData\Gravity/UOPK

表2023/10/22蒸餾曲線2023/10/22蒸餾曲線類型:–

ASTM

D86,

D1160,

D2887實沸點蒸餾曲線(TBP)(重量或體積基準)真空蒸餾曲線(重量或體積基準)每一個蒸餾曲線至少需要輸入4個點.報告中的蒸餾曲線為:ASTM

D86ASTM

D1160Vacuum

(liquid

volume)油品分析數(shù)據(jù)計算程序Version

9

或更新的版本Version

8

或更老的版本蒸餾曲線轉(zhuǎn)換方法ASTM

D86

至實沸點(True

boiling

point)EdmisterEdmister-OkamotaPMLD2887

至True

boiling

pointAPI87API94TBPWT2023/10/22蒸餾曲線計算方法曲線處理選項初餾點(Initial

boiling

point)0.5%(缺省)終餾點(Final

boiling

point)99%

(default)外延方法Probability(缺省)Quadratic鋸齒段擬合方法Harwell(缺省)Hermite?曲線處理選項在Components\PetroCharacterization\AnalysisOptions\AssayProcedure表上.2023/10/22蒸餾曲線計算方法(續(xù))虛擬組分從油品分析數(shù)據(jù)生成.

你可以規(guī)定切割溫度或切割片段(窄餾份)的寬度.Components\PetroCharacterization\Generation\Cuts表上，規(guī)定切割溫度等.缺省值是40個切割點:2023/10/22TBP

Range(F)No.

of

CutsIncrements(F)100

-

8002825800

-

12008501200

-

16004100切割溫度蒸餾曲線的切割2023/10/22虛擬組分性質(zhì)用Watson/UOP

“K”和API關(guān)聯(lián)式估算：典型地10

<

UOPK

<

13此處

10.0

表示芳烴含量很高13.0

表示烷烴含量很高2023/10/22所生成虛擬組分的命名2023/10/22Components\PetroCharacterization\Generation

規(guī)定命名選項自動生成的名稱可以是:實際計算出來的NBP(如:PC864F)沸程下限溫度(如:PC800F)沸程上限溫度(如:PC900F)用戶選擇的順序號(如:PC1,PC2…)用戶定義的名稱附加的ASSAY組分數(shù)據(jù)2023/10/22可選的性質(zhì)曲線:輕端組分分析(light-ends

matching)比重或者API重度曲線Watson

UOPK

曲線分子量曲線性質(zhì)曲線(多于30種性質(zhì))絕對&動力粘度曲線如果輸入油品整體性質(zhì)，單獨的曲線數(shù)值被歸一到整體性質(zhì).可以應(yīng)用用戶性質(zhì)曲線Assays組分的用戶性質(zhì)曲線在表格Properties\Advanced\UserProperties

上，建立用戶性質(zhì)曲線.在表格中激活A(yù)ssay

Curve

properties

選項在表格Component\Assay/Blend\PropertyCurve上，輸入用戶性質(zhì)曲線的數(shù)據(jù)。對于高度非線性調(diào)和現(xiàn)象，如馬達法辛烷值，建議使用用戶調(diào)和子程序。2023/10/22性質(zhì)曲線的流股計算2023/10/22性質(zhì)曲線被切割為與虛擬組分同樣多的片段。為每一個片段計算出平均的性質(zhì)數(shù)值流股的性質(zhì)數(shù)值由虛擬組分以及它們在流股中的濃度做調(diào)和計算得出計算虛擬組分混合物的性質(zhì)，有各種調(diào)和計算選項。石油性質(zhì)的調(diào)和2023/10/22石油性質(zhì)調(diào)和方法:標準體積(StdVol)摩爾(Mole)質(zhì)量(Mass)用戶(User)用于性質(zhì)計算的用戶調(diào)和子程序：用戶子程序名稱為BLDPPU.“調(diào)和選項”可以規(guī)定.性質(zhì)可以外延與否.在Components\PetroCharacterization\Analysis

Options\BlendOptions\上，調(diào)和規(guī)則可以修改。Assay(石油)數(shù)據(jù)庫2023/10/22軟件內(nèi)置的Assay

數(shù)據(jù)庫，包含194

種石油的分析數(shù)據(jù),其中有:-來自Phillips石油數(shù)據(jù)庫的10

種石油-來自文獻的184種石油在ComponentSpecifications\Petroleum表，查找Assay

庫文件。和Phillips

Petroleum

石油分析數(shù)據(jù)庫的接口，其中收集了超過250種石油的數(shù)據(jù)**

需要與Phillips

Petroleum簽訂License協(xié)議。Assay(石油)數(shù)據(jù)庫2023/10/22每一種石油至少提供如下信息:餾程分析重度和/或重度曲線某些石油有附加的性質(zhì)曲線:苯胺點閃點凝固點硫含量金屬含量硫醇研究法/馬達法辛烷值烷烴環(huán)烷烴芳烴雷諾蒸汽壓訪問Assay數(shù)據(jù)庫2023/10/22創(chuàng)建Blends組分2023/10/22通過規(guī)定blend

中每個assay

的百分數(shù)，由assay創(chuàng)建blend.調(diào)和可以是Mole,Mass,

或StdVol基準.要創(chuàng)建一個blend，至少規(guī)定2個assay組分.一個blend中的assay的數(shù)量沒有上限.報告中的蒸餾曲線為:ASTM

D86ASTM

D1160Vacuum

(liquid

volume)輸入Blend組分在數(shù)據(jù)瀏覽器Data

Browser,選擇組分Components,

然后選擇Assay-Blend.In

the

Assay-Blend

目標管理器,創(chuàng)建一個blend

并且提供名稱(ID).在Mixture\Specifications表上，輸入各

assay

組分的調(diào)和分數(shù).虛擬組分將在模擬計算之初自動生成.2023/10/22Blend組分之Mixture\Specifications表2023/10/22Assay/Blend

結(jié)果Assay/blend

的計算結(jié)果可以在表格Components\Assay-Blend

Results查看.每一個assay

或blend

組分有自己單獨的結(jié)果表格(results

form).2023/10/22Generation\Cuts

表格2023/10/22虛擬組分的生成2023/10/22缺省情況,一套完整的虛擬組分由輸入的所有assay組分生成.在表格Components\Petro

Characterization\Generation\Specifications上，用戶可以規(guī)定生成虛擬組分時，包括/不包括特別的assay.只有在表格Generation\Specifications上選出的

assays和blends

，才用于生成虛擬組分。在表格

Generation\Specifications上未選用的Assays

or

blends，將不被使用，

它們的IDs

不在流股輸入表格上顯示.虛擬組分命名2023/10/22虛擬組分的命名約定計算出的沸點(例如：PC125,PC136,…)規(guī)定起始編號切割溫度上限(例如：將225-250F

窄餾份命名為PC250)切割溫度下限(例如：將225-250F

窄餾份命名為PC225)用戶定義的名稱列表在表格Components\PetroCharacterization\Generation\Naming

Options上，規(guī)定命名約定.如果你要將Aspen

Plus

生成的虛擬組分與反應(yīng)器或者分離模塊關(guān)聯(lián)，應(yīng)使用用戶定義的名稱列表。Generation\NamingOptions表格2023/10/221.在表格Components\Specifications\Selection上，2023/10/22輸入組分IDs

并且選擇Pseudocomponent類型。在表格

Components\Pseudocomponents\Specifications

上,至少提供下列參數(shù)中的兩個：正常沸點NBP,重度Gravity(Specific

gravity,

API

gravity,

or

Liquiddensity),分子量Molecular

weight?Aspen

Plus可以估算第3性質(zhì).可選地,輸入與溫度相關(guān)的性質(zhì)數(shù)據(jù):液相粘度Liquid

viscosity水溶解度Water

solubility飽和蒸汽壓Vapor

pressure定義用戶虛擬組分虛擬組分規(guī)定表格2023/10/22虛擬組分物性方法2023/10/22方法名稱描述ASPEN

(default)API-METHCOAL-LIQLKAPI-TWUAPI

procedure

with

Aspen

modificationsAPI

procedureCorrelations

for

coal-liquid

fractionsLee

Kesler

correlationsAPI

procedure

with

Twu

correlationsfor

critical

properties注意:

不要將虛擬組分物性方法與流程模擬物性方法混淆，前者只是用于虛擬組分石油性質(zhì)參數(shù)的計算。虛擬組分計算結(jié)果生成的虛擬組分在表格Components\

PetroCharacterization\Results上瀏覽檢查。2023/10/22表格Analysis

Options\Assay

Procedure2023/10/22石油性質(zhì)模型2023/10/22基本的虛擬組分性質(zhì)模型分子量Molecular

Weight臨界溫度Critical

Temperature臨界壓力Critical

Pressure臨界體積Critical

Volume偏心因子Accentric

Factor飽和蒸汽壓Vapor

Pressure液相摩爾體積Liquid

Molar

Volume水溶解度Water

Solubility粘度Viscosity基本的虛擬組分性質(zhì)模型可以在表格

Components\Petro

Characterization\PropertiesMethods\Basic

上修改。石油性質(zhì)模型(續(xù))2023/10/22虛擬組分熱力學(xué)性質(zhì)模型理想氣體熱容Ideal

Gas

Heat

Capacity汽化焓Enthalpy

of

Vaporization標準生成焓Standard

Enthalpy

of

Formation標準生成自由能Standard

Free

Energy

of

Formation?基本的虛擬組分性質(zhì)模型可以在表格Components\Petro

Characterization\PropertiesMethods\Thermodynamic上修改.石油性質(zhì)模型(續(xù))2023/10/22虛擬組分狀態(tài)方程(EOS)性質(zhì)模型RKS

Interaction

ParametersBWR

Orientation

ParameterBWR

Critical

TemperatureBWR

Critical

Volume基本的虛擬組分性質(zhì)模型可以在表格

Components\Petro

Characterization\Properties

Methods\EOS上修改.石油交互作用參數(shù)2023/10/22虛擬組分與下列常規(guī)組分的交互作用參數(shù)Kijs:H2SN2CO2COH2CH4物性方法的修改用戶可以建立自己的虛擬組分石油性質(zhì)方法.各種性質(zhì)的計算模型可以改變.大多數(shù)虛擬組分性質(zhì)可以應(yīng)用子程序.在線幫助中有每一種性質(zhì)方法的簡要說明2023/10/22流程模擬計算2023/10/22在流程模擬計算期間,不區(qū)分虛擬組分和真實組分.產(chǎn)品流股中的虛擬組分調(diào)和在一起，并且生成蒸餾曲線產(chǎn)品終餾點(即D86

95%point)

或者初餾點

(D86

5%point)

可以規(guī)定為單元操作的性能指標：塔內(nèi)部的設(shè)計規(guī)定用于其它單元操作的外部設(shè)計規(guī)定檢查蒸餾塔各產(chǎn)品之間的分離效果(重疊度)2023/10/22Petroleum

Properties

and

Property

SetsObjective:Become

familiar

with

petroleum

properties

andlearn

the

use

of

stream

analysisAspen

Plus

References:User

Guide,

Chapter

32,

Petroleum

AssaysandPseudocomponentsPetroleum

Properties2023/10/22Reid

vapor

pressureAPI

and

specific

gravityWatson

UOP

K

factorAniline

pointPour

pointFlash

pointCetane

numberCarbon

to

hydrogen

ratioGross

heating

valuePetroleum

Properties

(Continued)2023/10/22Mean

and

volume

average

boiling

pointHydrate

formation

pressure

and

temperatureRefractive

indexLiquid

viscosity

indexD86

temperatures

at

(0,

5,

10,

…95%)D1160

temperatures

at

(0,

5,

10,

…95%)D2887

temperatures

at

(0,

5,

10,

…95%)TBP

temperaturesVacuum

temperaturesPetroleum

Properties

(Continued)Properties

(curves)

from

Assay

AnalysisPointsAniline,

cloud,

flash,

freeze,

smokeContentsAromatic,

olefin,

paraffin,

naphthalene,

mercaptanC,

H,

O,

NImpurities: S,

V,

Fe,

NiIndices:Antiknock,

vapor

knock,

refractive,

warm-upNumbers:Motor

and

research

octaneLuminometerViscosity?

Generally

input

curves

for

assays

to

generatethese

curves

for

p2r02o3/d10u/22ct

streams

is

needed.Distillation

Curves2023/10/22Volume

and

weight

basisASTM

D86ASTM

D1160ASTM

D2887

(weight

percent

only)VacuumTBPAPI

GravityGravityMWProperty

Sets2023/10/22A

property

set

(Prop-Set)

is

a

way

of

accessing

acollection,

or

set,

of

properties

as

an

object

with

auser-givenname. Only

the

name

of

the

property

setis

referenced

when

using

the

properties

inanapplication.Use

property

sets

to

report

thermodynamic,

transport,and

other

property

values.Current

property

set

applications

include:Design

specifications,

Fortran

blocks,

sensitivityStreamreportsPhysical

property

tables

(Property

Analysis)Tray

properties

(RadFrac,

PetroFrac,

etc.)Heating/cooling

curves

(Flash2,

MHeatX,

etc.)Properties

included

inProp-Sets2023/10/22Properties

commonly

included

in

property

sets

include:API -

APIgravitySGSTD -

Standard

specific

gravity

(60

F,

1

atm)REIDVP

-

Reid

vapor

pressureD86TMUMXD86

temperatureViscosityAvailable

properties

include:Thermodynamic

properties

of

components

in

a

mixturePure

component

thermodynamic

propertiesTransport

propertiesElectrolyte

propertiesPetroleum-related

propertiesReference:

Aspen

Plus

Physical

Property

Data

Reference

Manual,

Chapter4,Property

Sets

has

a

complete

list

of

properties

that

can

be

included

in

aproperty

set.Defining

Property

Sets2023/10/22Specifications

for a

property

set

include:Property

name

and

unitsTemperature

and

pressure

at

whichtocalculateInclude

or

exclude

waterphase

qualifier

(V,

L,

L1,

L2,

T,

S)Specifying

Property

SetsUse

the

Properties

Prop-Sets

form

tospecifyproperties

in

a

property

set.used

to

search

for

a?

The

Search

button

canproperty.beAll

specified

qualifiers

apply

to

each

propertyspecified,

where

applicable.Users

can

define

new

properties

on

the

PropertiesAdvanced

User-Propertiesform

by

providing

a

Fortransubroutine.2023/10/22Predefined

PropertySetsSome

simulation

Templates

contain

predefinedproperty

sets.The

following

table

lists

predefined

propertysets

and

the

types

of

properties

they

contain

forthe

General

Template:2023/10/22Predefined

PetroleumProp-Sets

(Continued)2023/10/22Predefined

Prop-Sets

with

the

PetroleumApplication

template:PREDEFINEDPROPERTY

SETTYPES

OF

PROPERTIESCUTS

-

EVolumetric

flow

rate

of

petroleum

cuts

at

100F

intervalsD86

-

5ASTM

D86

temperature

at

5%

liquid

volume

distilledD86

-

95ASTM

D86

temperature

at

95%

liquid

volume

distilledGAS

-PROPSCompressibility,

volumetric

flow

rate,

heat

capacity

ratioKINVISCLiquid

kinematic

viscosity

at

100F

and

212FLIGHTPetroleum

characteristics

for

light

distillatesMIDDLEPetroleum

characteristics

for

middle

distillatesPETROVolumetric

flowrate,

gravity,

Watson

K,

distillation

curvesTBP-5True

boiling

point

temp.

at

5%

liquid

volume

distilledTBP-95True

boiling

point

temp.

at

95%

liquid

volume

distilledPetroleum

Prop-SetsMost

petroleum

properties

are

calculatedfrom

input

property

curves.Some

petroleum

properties

are

calculatedfrom

correlations(FLSH-API,

POUR-API)Properties

are

accessed

and

usedinexactly

the

same

way

as

otherprop-setproperties2023/10/22Stream

Results

OptionsOn

the

Setup

Report

Options

Stream

sheet,use:Flow

Basis

and

Fraction

Basis

check-boxes

to

specify

howstream

composition

is

reportedProperty

Sets

button

to

specify

names

of

propertysetscontaining

additional

properties

to

be

reported

for

eachstream2023/10/22Prop-sets

DiscussionGive

two

reasons

that

a

property

set

isneeded.How

do

you

define

a

property

set?A

user

defined

aprop-set

for

viscosityand

then

ran

thesimulation. Afterthesimulation

was

complete,

he

opened

thestream

results. To

his

surprise,

he

did

notsee

viscosity. What

happened?2023/10/22PetroFracObjective:Introduce

the

features

of

the

PetroFracmodel

and

its

use

in

simulating

a

crudetowerAspen

Plus

References:Unit

Operation

Models

Reference

Manual,

ChapterCharacteristics

of

Refining

ProcessWide

boiling

range

fluidsLarge

temperature

gradients

along

columnMost

fluid

compositions

are

unknownbuttheir

distillation

analysis

is

knownThree

phase

with

free

waterSide

strippers

and

pumparoundsPetroleum

specific

physical

propertiesHigh

degree

of

heat

integrationMetal

and

sulfur

contents2023/10/22Petroleum

Refining

Applications2023/10/22PetroFrac

is

a

distillation

model

specificallydesigned

for

petroleum

refining

applications:preflash

towercrude

unitvacuum

unitvacuum

lube

fractionatorFCC

main

fractionatordelayed

coker

main

fractionatorquench

tower/primary

fractionatorPetroFrac

Features2023/10/22Integration

of

furnace,

column,

side

stripper

andpumparoundADA/PCS

for

assay

input,

crude

blend

andbreakdownConversion

between

different

ASTM

curvesUser

specification

of

cutsPetroleum

oriented

specificationsTray

and

packing

sizing

and

ratingOther

featuresInitialization

and

convergenceExample

Crude

TowerGASDECANTWATERNAPHTHAJET

FUELKEROSENEDIESELGASOILRESID

CRUDE

FEEDSTEAM2023/10/22PetroFrac

-

ConnectivityVapor

DistillateBottomsFeedsFeeds

OverflashPumparoundPumparoundLiq

ReturnStripper

BottomsSide

ProductsLiquid

DistillateWater

Distillate2023/10/22

Overhead

FeedHeatBottom

StageorReboiler

Heat

DutyTop

Stage

orCond.

HeatDutyHeat

orReboilerHeatDutySteam

FeedPetroFrac

-

Flowsheet

ConnectivityAny

number

of

pumparounds

and

sidestrippersSteam

or

reboiler

strippersStripper

hot

liquid

returnMultiple

feeds

to

strippersTotal

pumparound

and

product

drawoffsInterstage

water

decantersHeat

streams

for

pumparound

coolersPseudostreams2023/10/22PetroFrac

-

ModelSpecifications2023/10/22Setup

form

(required) Number

of

stages Condenser

and

ReboilerDistillate

rate,

Bottoms

rate,

Condenser

duty,Reboiler

duty,

or

Reflux

RatioFeed/Product

(required)Feed

convention:

furnace,

on-stage,

above-stagePres-Profile

(required)PumparoundsStrippersPetroFrac

-

Pumparound

Specifications2023/10/22Draw

and

return

stage

locations

(required)For

total

drawoffs,

specify

one

of

thefollowing:return

temperaturetemperature

change

(negative

if

cooled)duty

(negative

if

cooled)For

partial

drawoffs,

specify

liquid

flowrateand

one

of

theabove.PetroFrac

-

Side

Stripper

Specifications2023/10/22Stage

NumberFor

each

stripper,

the

trays

are

numberedfromtop

to

bottom

starting

with

stage

1.SteamStripperSpecifying

a

steam-to-product

ratio

willoverride

the

steam

flow

rate.Reboiler

StripperSpecify

a

reboiler

duty.PetroFrac

-

Side

Stripper2023/10/22ConventionsLiquid

draw

always

goes

to

the

stripper

topstage.Vapor

always

returns

to

the

main

columnOther

SpecificationsA

fraction

of

the

stripper

bottoms

can

bereturned

to

the

main

columnMultiple

drawoffs

from

different

stages

as

feedsto

the

same

stripper

are

allowedPetroFrac

-

Other

Specifications2023/10/22Steam

to

product

flow

ratio

(mass)Feed

overflashFurnace

outlet

temperatureLiquid

runback

from

a

stageASTM

temps

and

gapsPetroleum

properties

(RVP,

flash

point,

pour

point,etc…)Murphree

efficiencyMultiple

property

option

specificationsFree

water

calcs

in

the

condenser

or

on

all

trays–

Blocks

PetroFrac

Properties

form

to

specify

internal

stageschecked

for

free

water

-

condenser

is

checked

automaticallyTray/packingPetroFrac

-

Design

Specifications2023/10/22Meet

product

property

by

varying:stripping

steam

flow

rate/reboiler

dutyproduct

flow

ratepumparound

flow

rate

or

return

temperaturefurnace

temperatureMeet

a

particular

stage

temperaturebyvarying:furnace

outlet

temperaturepumparound

flow

rate

or

return

temperatureMeet

product

flow

rate

by

varying:furnace

outlet

temperaturePetroFrac

-

Definitions2023/10/22RunbackLiquid

flow

rate

from

a

stage

to

a

lower

stage,equivalent

to

stage

liquid

flow

rate

lesssidedrawsThe

Runback

form

is

used

to

specify

therunback

from

a

stage. The

manipulatedvariable

is

the

pumparound

duty

or

flowrateLiquid

FlowIn

PetroFrac,

stage

liquid

flow

reported

inthetray

profile

is

the

sum

of

runback,

side

draw,and

pumparound.In

RadFrac,

stage

liquid

flow

excludes

any

sideproduct

draw

and

pumparound.Outside

LoopPhysical

Properties

(ai,

KB,

HV,

HL)Inside

Loopcmi

=cmi

outyi

=Ki

xi

xi

=

1.0,

yi

=

1.0

Hi

in

=

Hi

outl,

v,

x,

y,L

=

li,

V

=

viTInside

loop

solved

byNewton

method

withor

withoutlog-leg2023/10/22PetroFrac

-

ConvergenceSum-Rates

variant

of

the

inside-outalgorithmPetroFrac

-

Convergence2023/10/22Algorithm:

sum-rates

variant

of

the

inside-outInitialization:

designed

for

refiningapplicationTo

enhance

convergence:provide

column/stripper

temperature

estimatesvary

convergence

damping

factors

to

enhancestabilitychange

design

specificationsPetroFrac

-

Summary2023/10/22PetroFrac

combines

Furnace,

Column,

Pumparound,

andSidestripper

into

one

model

which

makes

the

simulation

easy

tosetup

and

converge.Feed

characteristics

can

be

user

input

or

from

the

assay

library.Multiple

feeds

can

be

blended

to

create

a

feed

mixture.Additional

properties

of

a

particular

product

can

be

reportedbyadding

property

sets.Runback

from

a

stage

is

the

liquid

flow

rate

leaving

the

stageand

entering

the

stage

below. Runback

and

liquid

flow

can

bedifferent.Most

crude

towers

do

not

have

a

reboiler

at

the

bottom.

Eitherthe

bottom

steam

rate

or

the

furnace

duty

is

varied

to

meet

theenergy

requirement

(energybalance).PetroFrac

-

Discussion2023/10/22RadFrac

and

MultiFrac

can

also

be

used

to

simulate

the

crudetower. Why

choosePetroFrac?

If

you

have

the

characteristics

of

all

the

products,

but

not

thecrude,

how

do

you

ru