Process Equipment

Dynamic Simulation

Suite

Process Equipment

Invensys SimSci-Esscor 5760 Fleet Street, Suite 100,

Carlsbad, CA 92008

Dynsim 4.2 : Process Equipment The software described in this guide is furnished under a written agreement and may be used only in accordance with the terms and conditions of the license agreement under which you obtained it. The technical documentation is being delivered to you AS IS and Invensys Systems, Inc. makes no warranty as to its accuracy or use. Any use of the technical documentation or the information contained therein is at the risk of the user. Documentation may include technical or other inaccuracies or typographical errors. Invensys Systems, Inc. reserves the right to make changes without prior notice.

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Trademarks Dynsim and Invensys SIMSCI-ESSCOR are trademarks of Invensys plc, its subsidiaries and affiliates. Visual Fortran is a trademark of Intel Corporation. Windows 98, Windows ME, Windows NT, Windows 2000, Windows XP, Windows 2003 Server, Excel and MS-DOS are trademarks of Microsoft Corporation. Adobe, Acrobat, Exchange, and Reader are trademarks of Adobe Systems, Inc. OLGA 2000 is a trademark of Scandpower Petroleum Technology. All other products may be trademarks of their respective companies. U.S. GOVERNMENT RESTRICTED RIGHTS LEGEND The Software and accompanying written materials are provided with restricted rights. Use, duplication, or disclosure by the Government is subject to restrictions as set forth in subparagraph (c) (1) (ii) of the Rights in Technical Data And Computer Software clause at DFARS 252.227-7013 or in subparagraphs (c) (1) and (2) of the Commercial Computer Software-Restricted Rights clause at 48 C.F.R. 52.227-19, as applicable. The Contractor/Manufacturer is: Invensys Systems, Inc. (Invensys SIMSCI-ESSCOR) 26561 Rancho Parkway South, Suite 100, Lake Forest, CA 92630, USA. Printed in the United States of America October 2006.

Contents

Base Equipment i

Table of Contents TUIntroductionUT....................................................................................1 TULegacy ColumnUT..............................................................................2

TUIntroductionUT.................................................................................................... 2 TUFundamentals UT ................................................................................................ 3 TUExample UT ........................................................................................................ 14 TUData Entry Window UsageUT .......................................................................... 18 TUThe Column ViewerUT ..................................................................................... 33 TUParameter TableUT........................................................................................... 34

TUCombustor UT ...................................................................................51 TUIntroductionUT.................................................................................................. 51 TUFundamentals UT .............................................................................................. 52 TUExamplesUT ...................................................................................................... 55 TUData Entry Window UsageUT .......................................................................... 57 TUParameter TableUT........................................................................................... 63

TUCompressor UT .................................................................................67 TUIntroductionUT.................................................................................................. 67 TUFundamentals UT .............................................................................................. 68 TUExample UT ........................................................................................................ 76 TUData Entry Window UsageUT .......................................................................... 78 TUParameter TableUT........................................................................................... 86 TUFAQUT ............................................................................................................... 92

TUFired Heater UT..................................................................................95 TUIntroductionUT.................................................................................................. 95 TUFundamentals UT .............................................................................................. 97 TUExample UT ...................................................................................................... 106 TUData Entry Window UsageUT ........................................................................ 110 TUParameter TableUT......................................................................................... 124 TUFAQUT ............................................................................................................. 133

TUMulti ExchangerUT .........................................................................134 TUIntroductionUT................................................................................................ 134 TUFundamentals UT ............................................................................................ 135 TUData Entry Window UsageUT ........................................................................ 139 TUParameter TableUT......................................................................................... 149 TUFAQUT ............................................................................................................. 155

TUPlug Flow Reactor UT .....................................................................157 TUIntroductionUT................................................................................................ 157 TUFundamentals UT ............................................................................................ 158 TUExample UT ...................................................................................................... 163 TUData Entry Window UsageUT ........................................................................ 172 TUParameter TableUT......................................................................................... 183

TUReaction DataUT.............................................................................190 TUIntroductionUT................................................................................................ 190 TUFundamentals UT ............................................................................................ 191 TUExamplesUT .................................................................................................... 195 TUData Entry Window UsageUT ........................................................................ 207 TUParameter TableUT......................................................................................... 219

Contents

Base Equipment ii

TUFAQUT ............................................................................................................. 228 TUReaction Data Set UT ......................................................................229

TUIntroductionUT................................................................................................ 229 TUData Entry Window UsageUT ........................................................................ 230 TUParameter TableUT......................................................................................... 232 TUFAQUT ............................................................................................................. 233

TUReciprocating Compressor UT.......................................................234 TUIntroductionUT................................................................................................ 234 TUFundamentals UT ............................................................................................ 235 TUExample UT ...................................................................................................... 237 TUData Entry Window UsageUT ........................................................................ 239 TUParameter TableUT......................................................................................... 244 TUFAQUT ............................................................................................................. 247

TURelief ValveUT ................................................................................248 TUIntroductionUT................................................................................................ 248 TUFundamentals UT ............................................................................................ 249 TUMalfunctions UT............................................................................................... 252 TUExamplesUT .................................................................................................... 253 TUData Entry Window UsageUT ........................................................................ 256 TUParameter TableUT......................................................................................... 261 TUFAQUT ............................................................................................................. 264

TUSeparator UT....................................................................................265 TUIntroductionUT................................................................................................ 265 TUFundamentals UT ............................................................................................ 266 TUExample UT ...................................................................................................... 277 TUData Entry Window UsageUT ........................................................................ 281 TUParameter TableUT......................................................................................... 297 TUFAQUT ............................................................................................................. 311

TUShaft UT ...........................................................................................312 TUIntroductionUT................................................................................................ 312 TUFundamentals UT ............................................................................................ 313 TUExample UT ...................................................................................................... 314 TUData Entry Window UsageUT ........................................................................ 316 TUParameter TableUT......................................................................................... 319

TUSlate ChangeUT..............................................................................322 TUIntroductionUT................................................................................................ 322 TUFundamentals UT ............................................................................................ 323 TUExamplesUT .................................................................................................... 327 TUData Entry Window UsageUT ........................................................................ 332 TUParameter TableUT......................................................................................... 339

TUTankUT ............................................................................................343 TUIntroductionUT................................................................................................ 343 TUFundamentals UT ............................................................................................ 344 TUExample UT ...................................................................................................... 347 TUData Entry Window UsageUT ........................................................................ 349 TUParameter TableUT......................................................................................... 364 TUFAQUT ............................................................................................................. 372

Contents

Base Equipment iii

TUTowerUT ..........................................................................................373 TUIntroductionUT................................................................................................ 373 TUFundamentals UT ............................................................................................ 374 TUExample UT ...................................................................................................... 383 TUData Entry Window UsageUT ........................................................................ 387 TUThe Tower ViewerUT ...................................................................................... 401 TUParameter TableUT......................................................................................... 402 TUFAQUT ............................................................................................................. 415

Introduction

Process Equipment Version 4.2, October 2006 1

Introduction The Process Equipment library is an extension of the Base Equipment library. Process Equipment library is intended for modeling of processes found in the upstream, refining, petrochemical, and chemical industries. The process equipment models and base equipment models may be used within the same flowsheet(s) with streams connecting the models together. Please refer to the Base Equipment Fundamental section for information common to both Base and Process Equipment libraries.

Column


Legacy Column Introduction Column is a pressure node that can be used to model distillation columns and fractionators. A Column unit consists of a vapor holdup on the top for Column pressure calculation and multiple tray submodels beneath. A tray is a submodel that represents an equilibrium stage within a Column. A minimum of one tray must be present in Column although a realistic Column will normally have a much higher number of trays. The trays are linked with the vapor from the next lower tray and liquid from the next higher tray. The trays are numbered starting at the top tray as number one and increasing as you go down the Column. Each tray includes a liquid holdup to model the liquid inventory of the tray. Column uses a theoretical tray approach with an adjustment for liquid holdup based on the ratio of actual trays to modeled trays that adjusts the liquid holdup on each tray. Trays may also represent packed stages. For a packed stage, each tray represents a single equilibrium stage. The height of the tray or stage should represent the height of a theoretical packed transfer unit. Reactions can also be connected. Though reactions typically occur with packed sections of a column, reactions can be added to plate stages as well. Multiple feeds and products can be connected to any tray, both plate and packed. Products from trays are optional although the top tray should have a vapor product and the bottom tray should have a liquid product. The tray submodel contains only one liquid holdup. Vapor from the tray will directly go to the next higher tray or Column top vapor holdup if it is a top tray. Column includes the cylindrical section of a distillation column only. All peripheral equipment such as condensers, reboilers, accumulators, sidestrippers must be modeled with separate equipment models. Column base can be modeled as the bottom tray. Alternatively, a Drum or Separator model can be used to model the Columns base. If the base has a partition for a thermo siphon reboiler, use a vertical Separator with a weir orientation. Column accounts for heat transfer from fluid to the metal and metal to surroundings. Column permits heat transfer from external sources directly to the metal or fluid through heat streams that can be connected to any trays liquid holdup.

Column


Fundamentals Holdup Calculations Column Vapor Holdup Column vapor holdup calculation determines the top tray pressure. The vapor volume is calculated based on the column configuration data unless user provides the data to overwrite. The Column vapor holdup is modeled using compressible dynamic equations. The differential equations for mass and energy balance are

T

T

T

Components

T

oduct

Streams

Feed

StreamsrrffTrayTrayT

oduct

Streams

Feed

StreamsrrffTrayTray

MU

U

VolVapM

R

MM

HFHFHvFvUdtd

ZFZFYFvMdtd

=

=

=

=

=

Pr

11

Pr

11

where: F Bf B - Forward flow (kg-mol/sec) F Br B - Reverse flow (kg-mol/sec) Fv BTray1 B - Vapor flow from Tray1 (kg-mol/sec) HBf B - Forward flow enthalpy (kJ/kg-mol) HBr B - Reverse flow enthalpy (kJ/kg-mol) Hv BTray1 B - Vapor enthalpy from Tray1 (kJ/kg-mol) M BTB - Total moles (kg-mol) R - Holdup density in (kg-mol/mP3 P) U - Mole internal energy (kJ/kg-mol) UBTB - Total holdup internal energy (kJ) VolVap - Vapor holdup volume (mP3P) Z Bf B - Forward flow mole fraction component vector (fraction) Z Br B - Reverse flow mole fraction component vector (fraction) YBTray1 B - Tray 1 vapor mole fraction component vector (fraction)

Column


Vapor volume (VolVap) is calculated using the following equation, provided that the user does not set this parameter.

= NTraytray

DiaWeirHeightSpacingVolVap 2)(4

where: Dia - Tray internal diameter (m) NTray - Number of trays Spacing - The distance between two trays (m) WeirHeight - Tray weir height (m) Tray Liquid Holdup The tray liquid holdup is modeled by using the following dynamic equations for mass and energy balance.

( ) ( )

( ) ( )

T

T

Components

T

fhfimpTrayTrayTrayBelowTrayBelowTrayTray

TrayAboveTrayAbove

oduct

Streamsrrff

Feed

StreamsrrffT

TrayTrayTrayBelowTrayBelowTrayTray

oduct

StreamsTrayAboveTrayAboverrff

Feed

Streamsrrff

MH

H

MM

QQQHvFvHvFvHlFl

HlFlHFHFHFHFHdtd

YFvyFvxFl

XFlZFZFZFZFMdtd

=

=

++++

+=

+

+=

Pr

Pr

where: F Bf B- Forward flow (kg-mol/sec) Fl BTray B- Liquid flow from the tray (kg-mol/sec) Fl BTrayAbove B- Liquid flow from tray above (kg-mol/sec) F Br B- Reverse flow (kg-mol/sec) Fv BTrayBelow B- Vapor flow from tray below (kg-mol/sec) H - Mole enthalpy (kJ/kg-mol) HBf B - Forward flow liquid enthalpy (kJ/kg-mol) Hl BTray B- Enthalpy of liquid from tray (kJ/kg-mol) Hl BTrayAboveB - Enthalpy of liquid from tray above (kJ/kg-mol) HBr B - Reverse flow liquid enthalpy (kJ/kg-mol)

Column


HBTB - Total holdup enthalpy (kJ/kg-mol) Hv BTray B- Enthalpy of vapor from tray (kJ/kg-mol) Hv BTrayBelow B- Enthalpy of vapor from tray below (kJ/kg-mol) M BTB - Total moles (kg-mol) QBf B - Heat loss to metal from tray (kJ/sec) QBfh B - Heat from fluid heat stream (kJ/sec) QBimp B - Imposed heat to the tray (kJ/sec) XBTray B- Liquid mole fraction component vector from tray (fraction) XBTrayAboveB - Liquid mole fraction component vector from tray above (fraction) YBTrayBelow B- Vapor mole fraction component vector from tray below (fraction) Z Bf B - Forward flow mole fraction component vector (fraction) Z Br B - Reverse flow mole fraction component vector (fraction) A Pressure-Enthalpy flash is then performed to determine the tray liquid holdup temperature. Geometry The internal tray diameter (Dia) is used in the calculation of the plate total area

4

2DiaAreaTotalPlate = where: Dia - Internal tray diameter (m) The downcomer area fraction is used to calculate the plate active area, which is in turn used in the liquid level calculations.

)1( reaFracDownComerAAreaTotalPlateAreaActivePlate = where: DowncomerAreaFrac - Downcomer area (fraction) Downcomer Area Fraction is fixed depending on the number of passes. It takes the value of 0.1, 0.2 and 0.3 for One, Two and Four passes, respectively. The user can set this value by selecting the passes as Other. The parameter TrayFactor allows Dynsim to use the correct number of theoretical trays while calculating the correct liquid holdup in the Column by adjusting the liquid level accordingly. The tray liquid level is calculated from the area and the liquid holdup based on the ratio of modeled trays to actual trays.

ctorAerationFaeAreaPlateActivRMTrayFactor

L T=

where: L -Tray liquid level (m) M BTB -Liquid holdup total moles (kg-mol) R -Liquid holdup mole density (kg-mol/mP3P) TrayFactor -Ratio of modeled trays to actual trays (dimensionless) AerationFactorB B- B BAeration factor to account for frothing (fraction)

Column


For packed stages, the following equation is used such that L is a convenient measure of liquid holdup.

BetaHeightPackL = where: Beta - Liquid Holdup (fraction) PackHeight - Packing height (m) Hole Area Fraction is the fraction of active plate area and is used to calculate the pressure drop due to vapor flow.

actionHoleAreaFrAreaActivePlateAreaHoleEffective = Flow Calculation Tray Vapor Flow There is no vapor accumulation in the tray since the tray submodel does not have a vapor holdup. The net vapor flow (Fv) defined as the vapor phase flow resulting from the tray feed flash minus the tray vapor side draws goes directly to the upper tray or to the Column vapor holdup if it is the top tray. Tray Liquid Flow For traditional plate trays, the Francis Weir formula is used for liquid flow over the weir calculation:

llfractionlengthweirweir MWRDiaLWeirHeightLF = 5.1)(845.1 where: DiaB B-Tray diameter (m) F Bweir B- B BLiquid flow over the weir (kg-mol/sec) L B B-Liquid level (m) WeirHeightB B-Weir height (m) L Bweir length fraction B-Weir length fraction of tray diameter (fraction) MW BlB -Liquid molecular weight (kg/kg-mol) RBl B-Liquid density (kg-mol/mP3P) Weir length fraction is the fraction of the tray diameter and is used in the liquid flow calculations through the weir. This value is fixed depending on the number of passes. It takes the value of 0.6, 1.0 and 1.6 for One, Two and Four passes respectively. The user can set this value by selecting the passes as Other. The liquid weep flow occurs when the vapor flow from the tray below is less than a fixed value known as "Weep Vapor Flow. The following equation is applied for the weep flow calculation:

LDrainFracKJFF

Fweep

vapdrain = ))1,0,(LIM01.1(

Column


where: DrainFracB - BFraction of hole area available for liquid draining (fraction) F Bweep - BWeep vapor flow (kg-mol/sec) F Bvap - BVapor flow through the tray (kg-mol/sec) L B - BLiquid level (m) KJB - BFlow conductance factor (fraction) LIM01 B - BLimit function to constrain the value between zero and one F Bdrain - BWeep liquid flow (kg-mol/sec) For packed stages, the StichlmairP1 P correlation is used for calculating flow through packings:

LLL

LL

L

L

RAreaVelF

gMWRPackHeightP

KBetaBeta

PackAreaVoidgVel

AreaPackHeightRM

Beta

=

+

=

=

23

2

65.4

...201

.42.2

where: F BL B-Liquid flow rate to the tray below (kg-mol/sec) P Vel BL B- Superficial liquid velocity (m/sec) P Area - Total cross sectional area of the tower at this tray (mP2P) Void - Void fraction of the packed bed (fraction)P RBL B- Density of the liquid (kg-mol/mP3 P) MW BL B- Molecular weight of Liquid (dimensionless)B g - Gravitational constant (m/secP2 P) Beta - Liquid holdup (fraction)B P - Pressure drop across the packed stage (kPa) PackHeight - Height of the packed stage (m) PackArea - Specific surface area of packing (1/m) 1. Stichlmair, J., Bravo, J.L. and Fair, J.R. , General model for prediction of pressure drop and capacity of countercurrent gas/liquid packed columns, Gas Separation & Purification, Vol. 3 (March, 1989), pp. 19-28

Column


Pressure Calculations The Column top pressure is determined by the Explicit compressible pressure calculations of Column vapor holdup. The pressure of the remaining trays is calculated by adding the pressure drop across each tray. The pressure drop is the combination of the pressure drops from the liquid head and vapor flow. The equation for liquid static head includes a factor for aeration (frothing) on the tray.

llliq MWRctorAerationFaLgP = where: Aeration FactorB B- B BAeration factor to account for frothing (fraction) P BliqB - Delta pressure from liquid static head (kPa) g B B- B BAcceleration due to gravity (m/secP2 P) L B B- B BLiquid level (m) MW BlB - Liquid molecular weight in (kg/kg-mol) RBl B- B BLiquid density (kg-mol/mP3P) The equation for vapor pressure drop is calculated using an orifice coefficient of 0.6.

v

v

holeactivevap MW

RAAKJ

FvP =2)

506.0(

where: ABactive B- B BActive tray area (mP2 P) ABhole B- Fraction of hole area (fraction) P BvapB - Delta pressure from vapor flow (kPa) Fv B B- B BVapor flow (kg-mol/sec) MW BvB - Vapor molecular weight (kg/kg-mol) KJB B- B BFlow conductance factor (fraction) RBv B- Vapor density (kg-mol/mP3P)

KJ has a default value of one. It can be changed to tune the pressure drop across each tray. Pressure drop through a packed bed is calculated using Stichlmair correlation. Coefficients for Stichlmair correlation are required. If appropriate parameters are not available, use the default values of C1, C2, and C3 and tune pressure drop with the conductance factor KJ.

Column


Pressure drop based on Stichlmair correlation: ( )

65.4

32

2

65.402

0

5.021

35.021

0

1.1

11.

143

.10001

Re.2Re

ReRe

....1000Re

.

16

+

=

=

=

++=

=

=

=

VoidBeta

VoidVoidBetaVoid

PP

UDia

PackHeightRVoid

VoidfKJ

P

f

CC

c

CCCf

ViscVMWRUDia

ARFU

PackAreaVoidDia

c

d

Vp

gd

VV

VV

vVvpv

v

vv

p

where: diaBp B- Equivalent particle diameter (m) Void - Bed void fraction (porosity) (fraction) PackArea - Specific surface area of packing (1/m) UBV B- Superficial gas velocity through the packed bed F Bv B- Vapor Flow Rate (kg-mol/sec) RBv B- Density of vapor (kg-mol/mP3 P) A - Cross sectional area of the tower (mP2 P) ReBv B- Reynolds number for the gas ViscV - Viscosity of vapor (cp) f B0 B- Friction factor for flow past a single particle C1, C2, C3 - Coefficients for Stichlmair correlation P Bd B- Pressure drop through an unirrigated (dry) bed (kPa) RBV B- Density of gas (kg/mP3 P) PackHeight - Height of the packed bed (m) P - Pressure drop through an irrigated bed (kPa) Beta - Liquid hold-up in a packed bed (fraction) c - Exponent in the equation above The little c is an exponent in the equation. I have put the equation for calculation of c above. KJ - Conductance Factor to adjust pressure drop (dimensionless) Stichlmair Coefficients (C1, C2, C3), Specific Surface Area and Void Fraction for commonly used packings are available in the following table:

Column


Packing Type/size a

(mP2 P mP-3 P) ( - )

CB1 B CB2 B CB3 B

Structured Packing: Montz B1 300 300 0.97 2 3 0.9 B1 200 200 0.98 2 4 1.0 B1 100 100 0.99 3 7 1.0 Gempack 2A 394 0.92 3 2.4 0.31 3A 262 0.93 3 2.3 0.28 Sulzer Mellapak 250Y

(plastic) 250 0.85 1 1 0.32

Mellapak 250Y (metal)

250 0.96 5 3 0.45

BX-packing 450 0.86 15 2 0.35 Dumped ceramic packings: Raschig Rings 10 472 0.665 48 8 2.0 10 327 0.657 10 8 1.8 15 314 0.676 48 10 2.3 15 264 0.698 48 8 2.0 30 137 0.775 48 8 2.0 35 126 0.773 48 8 2.15 Pall Rings 25 192 0.742 10 3 1.2 25 219 0.74 1 4 1.0 35 139 0.773 33 7 1.4 35 165 0.76 1 6 1.1 Reflux Rings 50 120 0.78 75 15 1.6 Hiflow Rings 20 291 0.75 10 5 1.1 Berl Saddles 15 300 0.561 32 6 0.9 35 133 0.75 33 14 1.0 Intalox Saddles 20 300 0.672 30 6 1.4 25 183 0.732 32 7 1.0 35 135 0.76 30 6 1.2 Torus Saddles 25 255 0.73 19 1 0.85 50 120 0.75 10 8 0.75 Dumped metal packings: Raschig Rings 12 416 0.94 60 1 7.5 15 317 0.924 40 1 6 Pall Rings 25 215 0.94 0.05 1 3 35 130 0.95 0.1 0.1 2.1 Bialecki Rings 25 225 0.94 50 7 2.5 Nutter Rings 50 96.5 0.978 1 1 2.65 Cascade Mini Rings 25 230 0.96 -2 -2 2 Supersaddles 25 165 0.978 1 1.6 2.1 Dumped ceramic packings: Pall Rings 90 71 0.95 -5 -4 2.3 NSW-Rings 25 180 0.927 1 1 1.35 Leva 1 190 0.92 1 1 2.0 2 143 0.94 1 1 2.3

Column


Flash Calculations Tray submodel contains two flashes, feed flash and liquid flash. In a feed flash, all the feeds to the tray and recycle flow from the tray liquid holdup are mixed and a pressure-enthalpy flash is performed for separation of phases. The liquid phase enters the tray liquid holdup and the vapor phase enters the tray above. In the liquid flash, the liquid from the feed flash and the tray liquid holdup are mixed and a pressure-enthalpy flash is performed to determine the liquid holdup temperature. Phase Separation and Level Calculations Each tray of the Column makes use of the InternalPhases and ExternalPhases to determine the type of separation it performs. The InternalPhase of the Column will be used to set the InternalPhase of the Tray feed flash. InternalPhases of the Tray feed flash object can be VLE, Free Water, VLLE, or Decant. ExternalPhases can be Two or Three. For example, VLE and Two can be chosen for a typical two-phase separation while VLLE and Three can be chosen for a three-phase separation. InternalPhases of the Tray liquid flash object can only be Liquid. External phase can only be Mixed. This means that no Liquid/Liquid separation will occur in the tray liquid flash. The liquid level calculations are independent for each tray. The bottom of each tray corresponds to the reference zero level. The liquid and liquid2 levels are calculated based on this reference level. The maximum liquid level in any tray is limited to the tray spacing. If there are two parameters, L and L2, for level indication in a tray corresponding to liquid (hydrocarbon) and liquid2 (aqueous) phases, L2 will always be 0 indicating that the second liquid phase is mixed well with the first liquid phase. Liquid Holdup Recycle The liquid entering the tray from the tray above, the vapor entering from the tray below and the feed (if there is one) will be in partial equilibrium with the tray liquid holdup. The extent of equilibrium can be controlled by recycle of liquid holdup to the feed flash using the parameter KLRecycle. The reciprocal of this parameter corresponds to the simulation time required for complete recycle of the holdup. The default value of 0.003333 corresponds to 300 sec (5min) for complete holdup recycle. Since the simulation period is 0.25 sec, a value of 4 corresponds to complete recycle of liquid holdup at every time step. The user is advised to use the default values to start with and may tune these parameters to achieve the desired equilibrium. Holdup Initialization Holdup initialization for Column is available for both the vapor holdup and each trays liquid holdup. Please refer to Base Equipment Fundamentals section on Holdup Initialization.

Column


Base Vessel Initialization The Column sump can be modeled using a vertical Drum or Separator with one head. The product stream from the Base Liquid Product port of the Column can be fed directly to the base vessel and the vapors from the base vessel can be fed to Column through the Base Vapor Feed port. The base vessel pressure will be generally higher than the bottom most tray pressure. In order that the liquid flows down to the sump, the base vessel should be made a part of the Column. This is done by specifying the instance name of the base vessel against the OBase parameter of the Column. If this parameter is not initialized, the base vessel will not be a part of the Column pressure and flow solution and the liquid flow across bottom tray and the base vessel will take place only when connected via a flow device. Port Location and Diameter The general feed and product ports are used to configure feed and product streams for the tray. The port location is always with reference to the base of the tray. The maximum height of the port location is limited to tray spacing. The streams from these ports can be connected only to flow devices. There are two ports at the bottom of the Column, the base liquid product port to Column base and the base vapor feed port for vapor product from Column base. The base liquid product port is the zero reference point to the Column as a whole. The base liquid product port should be connected to a Drum or Separator that acts as a sump. The vapor stream from the sump is connected to the vapor feed port. Apart from the regular feed and product ports, Column has a set of special ports to handle vapor products from top tray, liquid products from bottom tray as well. The ports for liquid products from the bottom tray are also at the zero reference point to the Column. The ports for vapor products from the top tray are at the top of the top tray (tray number 1). Please refer to the Base Equipment Fundamentals section on Port Location and Diameter. Heat Transfer Each tray has heat transfer from the liquid holdup to the tray metal and from the tray metal to the surroundings. Please refer to the Base Equipment Fundamentals section for more details on heat transfer calculations. Heat Streams Heat transfer from an external source to the fluid or metal can be configured through heat streams. The fluid and metal heat streams are configured on a tray-to-tray basis. These heat streams should originate from any source that performs heat transfer calculations and sets Q in the heat stream, such as Utility Exchanger. Any number of heat streams can be connected. Column supports external heat input directly to the tray fluid through the parameter QBimp.B The external heat input is set on a tray-by-tray basis.

Column


Boundary Specifications Boundary specifications for the Column can be used to set the boundary vapor holdup pressure. The intermediate tray pressures will be calculated based on the liquid and vapor heads. When the boundary pressure is set, the mass and energy balance will not be satisfied. The boundary condition should be used only for simulation tuning and debugging.

Column


Example The following example shows the configuration of sour water stripper with level and pressure PID controller. Ammonia and hydrogen sulfide are stripped from sour water using steam in a stripper with 7 trays. It is desired to maintain a column pressure at 143.4kPa and sump level at 0.25m. The desired pressure drop across the column is 5 kPa at steady state. There is only two-phase separation in the Column, so the InternalPhases is set to VLE and the ExternalPhases to Two. We assume that all trays are identical, so the data can be provided on a global basis. Strippers generally have single pass trays, so the number of passes is set to One. The tray geometry parameters can be obtained from the equipment datasheet. Weeping will occur in trays when the vapor flow is less than 0.0025kg-mol/sec, so the weep vapor flow is set to this value. The sour water feed to the stripper is to the top tray and the port location is above the weir. Therefore the sour water feed tray is 1 and the port height is 0.1 m. Steam is fed to the stripper to the bottom tray and the port location is at the base of the tray. Therefore the steam feed tray is 7 and the port height is 0. The stripped sour water is drawn from the bottom tray and the port location is at the base of the tray. Therefore, the sour water product tray is 7 and the port height is 0. Steam with HB2BS and ammonia are leaving the stripper from the top. The steam product stream can be connected to the normal port at maximum height. Therefore, the steam product tray is 1 and the height is 0.67, which corresponds to the tray spacing. A level PID controller (LC1) controls the bottom tray level, so C1.Tray7.L is set as PV to the PID controller. The column top pressure is controlled using a pressure PID controller (PC1), so C1.P is set as PV to the PID controller. The desired pressure drop across the column is 5 kPa, so the flow conductance factor is tuned to a value of 0.85. The vapor holdup will have conditions similar to the stripping steam, so the vapor holdup is initialized to the Source Steam. The tray liquid holdup will have conditions similar to the sour water, so the tray liquid holdup is initialized to the Source SourWater.

Column


SOURCE: SourWater Parameter Assignment UOM Description

OProdStream[0] S1 Source product stream to the Valve XV1 Z[N2] 0.000048 fraction Boundary composition Z[METHANE] 0.000125 fraction Boundary composition Z[H2S] 0.015699 fraction Boundary composition Z[NH3] 0.031898 fraction Boundary composition Z[CO2] 0.000076 fraction Boundary composition Z[HEXANE] 0.000005 fraction Boundary composition Z[NONANE] 0.000002 fraction Boundary composition Z[H2O] 0.952146 fraction Boundary composition Spec PT Boundary condition specification. Pb 172.37 kPa Boundary pressure Tb 338.71 K Boundary temperature VALVE: XV1 Parameter Assignment UOM Description

OFeedStream S1 Valve feed stream from Source SourWater OProdStream S2 Valve product stream to Column C1 Cv 263.36 Cv Valve Cv

Op FC1.OUT fraction Flow PID controller output attached to the Valve open command. PID: FC1 Parameter Assignment UOM Description

PV S1.F kg-mol/sec Valve inlet stream flow set as PV to the PID controller SP 0.188 kg-mol/sec Set point of the flow PID controller KP 0.5 PID controller proportional gain KI 0.5 PID controller integral gain SOURCE: Steam Parameter Assignment UOM Description

OProdStream[0] S3 Source product stream to the Valve XV2 Z[N2] 0 fraction Boundary composition Z[METHANE] 0 fraction Boundary composition Z[H2S] 0 fraction Boundary composition Z[NH3] 0 fraction Boundary composition Z[CO2] 0 fraction Boundary composition Z[HEXANE] 0 fraction Boundary composition Z[NONANE] 0 fraction Boundary composition Z[H2O] 1 fraction Boundary composition Spec PT Boundary condition specification. Pb 344.74 kPa Boundary pressure Tb 411.66 K Boundary temperature E 10 m Elevation of the Source

Column


VALVE: XV2 Parameter Assignment UOM Description

OFeedStream S3 Valve feed stream from Source Steam OProdStream S4 Valve product stream to Column C1 Cv 100 Cv Valve Cv

Op FC2.OUT fraction Flow PID controller output attached to the Valve open command. PID: FC2 Parameter Assignment UOM Description

PV S3.F kg-mol/sec Valve inlet stream flow set as PV to the PID controller SP 0.038 kg-mol/sec Set point of the flow PID controller KP 0.5 PID controller proportional gain KI 0.5 PID controller integral gain COLUMN: C1 Parameter Assignment UOM Description TrayNum 7 Number of trays

TrayData ALL Tray data configuration type. Set to global basis

Dia 0.75 m Tray diameter Passes ONE Number of passes

KJ 0.85 Conductance factor for tuning vapor

pressure drop Weep Vapor Flow 0.0025 kg-mol/sec Threshold value of vapor flow

below which the liquid starts to drain from the tray

FeedTray[0] 1 Sour water feed tray number FeedTray[1] 7 Steam feed tray number OFeedStream[0] S2 Feed stream from Valve XV1 OFeedStream[1] S4 Feed stream from Valve XV2 Li[0] 0.1 m Sour water feed stream port height Li[1] 0.0 m Steam feed stream port height ProdTray[0] 1 Stripped sour water product tray

number ProdTray[1] 7 Steam product tray number OProdStream[0] S5 Product stream to Valve XV3 OProdStream[1] S7 Product stream to Valve XV4 Lx[0] 0.67 m Steam product stream port height

Lx[1] 0.0 m Sour water product stream port

height. OInitVaporSource Steam Source to which Column vapor

holdup is initialized OInitSource SourWater Source to which tray liquid holdup

is initialized. InternalPhases VLE InternalPhases ExternalPhases TWO ExternalPhases

Column


VALVE: XV3 Parameter Assignment UOM Description OFeedStream S5 Valve feed stream from Column C1 OProdStream S6 Valve product stream to Sink SNK1 Cv 329.19 Cv Valve Cv

Op PC1.OUT fraction Pressure PID controller output attached to the Valve open command.

PID: PC1 Parameter Assignment UOM Description

PV C1.P kPa Column top pressure set as PV to the PID controller

SP 143.4 kPa Set point of the pressure PID controller KP 0.1 PID controller proportional gain KI 0.05 PID controller integral gain SINK: SNK1 Parameter Assignment UOM Description OFeedStream[0] S6 Sink feed stream from Valve XV3 Pb 100 kPa Boundary pressure VALVE: XV4 Parameter Assignment UOM Description OFeedStream S7 Valve feed stream from Column C1 OProdStream S8 Valve product stream to Sink SNK2 Cv 263.36 Cv Valve Cv

Op LC1.OUT fraction Level PID controller output attached to the Valve open command. PID: LC1 Parameter Assignment UOM Description

PV C1.TRAY7.L m Column tray 7 level set as PV to the PID controller SP 0.25 m Set point of the level PID controller KP 1 PID controller proportional gain KI 0.1 PID controller integral gain SINK: SNK2 Parameter Assignment UOM Description OFeedStream[0] S8 Sink feed stream from Valve XV4 Pb 100 kPa Boundary pressure

Column


Data Entry Window Usage Configuration Dialog

Number of trays corresponds to the TrayNum parameter. Please enter the number of theoretical trays.

Column


Basic Tab

Column Elevation Elevation of the Column bottom corresponds to the E parameter. It is the elevation of the Column with respect to the reference ground level. This value is used in the static head correction of the feed and product stream pressures. The elevation of the tray above is calculated by summing tray elevation and spacing.

Column


Tray Parameters Tray configuration on global or tray-by-tray basis corresponds to the TrayData parameter. Select the option Global basis to configure the same parameters for all the trays in the Column. Select Tray by tray to set the parameters on a tray-by-tray basis. Tray Type corresponds to TrayType parameter. Select Plate if the Tray happens to be of Plate type. Select Pack if the tray happens to be a packed bed. Tray diameter corresponds to the Dia parameter. This value can be obtained from the equipment datasheet. Tray spacing corresponds to the Spacing parameter. This value can be obtained from the equipment datasheet. It is used in the vapor volume calculations, if the parameter VolVap is not initialized. Default value is 0.67m, which is typical if no data is available. Conductance factor corresponds to the KJ parameter. It is used in the pressure drop calculations due to vapor flow. The default value is 1. This value can be used to tune the pressure drop due to vapor flow across the tray. Tray factor corresponds to the TrayFactor parameter. It is defined as the ratio of number of modeled trays to number of actual trays. This parameter is used to maintain proper holdup calculations for the entire column when the column is modeled with number of theoretical trays rather than number of actual trays. Tray factor is used to scale up the holdups and other data to match the dynamic response to the actual column. By using this theoretical trays approach, the computation load can be significantly reduced while still maintaining the separation accuracy. This parameter should not be confused with the tray efficiency. Plate Parameters Weir height corresponds to the WeirHeight parameter. This value can be obtained from the equipment datasheet. Default value is 0.056m, which is typical if no data is available. Number of passes corresponds to the Passes parameter. One, Two or Four passes can be set. When the option Other is chosen the user will have to set the Weir length fraction and Downcomer area fraction. Default option is One pass. Hole area fraction corresponds to the HoleAreaFrac parameter. It is used in the pressure drop due to vapor flow calculations. The default value is 0.12, which can be used in most cases. Hole area available for liquid draining corresponds to the DrainFrac parameter. It should always be less than or equal to the hole area fraction. Use a default value of 1.0 for sieve trays. The default value of 0.1 is for valve trays with some leakage. Aeration fraction corresponds to the Aeration parameter. It is used in the pressure drop due to liquid head calculations. The default value is 0.7. This value can be used to tune pressure drop due to liquid head across the tray. Weep vapor flow corresponds to the WeepVaporFlow parameter which represents threshold value of the vapor flow below which liquid starts to drain from the tray. If the default value is left in place no draining will occur. The user may have to set this value for desired results.

Column


Heat Transfer Tab

Metal Heat Loss to Ambient Metal to ambient heat transfer coefficient corresponds to Ul parameter. It is used in the heat transfer calculation from metal to the ambient. The default value can be used in most cases. Fluid Heat Loss to Metal Natural convection heat transfer coefficient corresponds to Un parameter. It is used in heat transfer calculation from fluid to the metal. The default value can be used in most cases. Metal Mass Total Column metal mass corresponds to the Mm parameter. It is used in the metal temperature dynamic calculations. Small values can result in instability in the Column.

Column


Feeds Tab

Feed Streams Feed stream port height corresponds to the Li parameter. The feed port height is used in calculation of static head correction of feed stream pressure. The port height of the stream is specified with respect to the bottom of tray and maximum port height is limited to the tray spacing. The feed port is generally located above the tray weir. Default value of the port height is 0. User may have to set this value for desired results. Feed stream port diameter corresponds to the Di parameter. The feed port diameter is used to determine the stream properties for reverse flow case when there is a fluid interface at the port. The default value is 0, which can be used for most cases.

Column


Products Tab

Product Streams Product stream port height corresponds to the Lx parameter. The product port height is used in calculation of static head correction of product stream pressure. The port height of the stream is specified with respect to the bottom of the tray and maximum port height is limited to the tray spacing. Default value of the port height is 0 that can be used in most of the cases. Product stream port diameter corresponds to the Dx parameter. The product port diameter is used to determine the stream properties for forward flow when there is a fluid interface at the port. The default value is 0.

Column


Base Model A Drum or Separator unit used to model bottom tray corresponds to the OBase parameter. The instance of the Drum or Separator used as Column sump must be specified here. If not specified, the Drum/Separator will not be a part of the Column and the fluid will not flow to it from the Column bottom unless connected via a flow device.

Column


Heat Streams Tab

Feed Fluid Heat Stream Feed fluid heat stream corresponds to the OFeedFluidHeatStream parameter. The list of all the fluid heat streams connected to the Column will be displayed in the Stream array. The user should select the tray to which each of the heat streams is configured by selecting the tray number from the Tray array. Feed Metal Heat Stream Feed metal heat stream corresponds to the OFeedMetalHeatStream parameter. The list of all the metal heat streams connected to the Column will be displayed in the Stream array. The user should select the tray to which each of the heat streams is configured by selecting the tray number from the Tray array.

Column


Boundary Conditions Tab

Boundary Condition The Boundary Conditions Tab is used for setting boundary conditions in Column. They should be used only for simulation tuning and debugging, and should not be left in place. Boundary condition corresponds to BoundarySpec parameter. Column top vapor holdup boundary pressure can be set through this parameter. The default value of None should be used after model tuning. Pressure corresponds to the Pb parameter. This value must be set when the Pressure boundary specification is selected.

Column


Initialization Tab

Initialize Holdup Contents The Initialization Tab is used for initializing the holdup based on the Source to which it is attached. The temperature, pressure, and composition of the holdup will be initialized from the Source when a load full is performed. Source initialization object for vapor holdup corresponds to the OInitVaporSource parameter. The instance of the Source object from which the Column vapor holdup is initialized should be specified here. Reinitialize vapor holdup during Load Full corresponds to the ReInitVaporFlag parameter. Check this flag to perform vapor holdup initialization during Load Full. If no Source object is specified and ReInitFlag is checked, vapor holdup will be initialized to equimolar composition, standard temperature, and pressure.

Column


Source initialization object for the tray liquid holdup corresponds to the OInitSource parameter. The instance of the Source object from which the tray liquid holdup is initialized should be specified here. Reinitialize tray holdup during Load Full corresponds to the ReInitFlag parameter. Check this flag to perform holdup initialization during Load Full. If no Source object is specified and re-initialization flag is checked, tray holdup will be initialized to equimolar composition, standard temperature, and pressure.

Column


External Inputs Tab

The External Inputs Tab is used to set dynamic parameters. Only the initial value of these parameters can be set through the Data Entry Window. Parameter references and equations can be attached to these parameters. The numerical value of these parameters cannot be changed in the running engine through Data Entry Window and will have no affect on the running model. Ambient Temperature Ambient temperature corresponds to the Tamb parameter. It is normally associated with a global standalone point TAMBIENT. Imposed Heat to Fluid Imposed heat to fluid corresponds to the Qimp parameter. External heat input can be imposed on a tray-by-tray basis. The default value can be left in place when there is no external heat input to the trays.

Column


Thermo Tab

Thermo Options Component slate corresponds to the CompSlate parameter, Method Slate to the MethodSlate parameter, Local thermo options to LocalThermoOption parameter, and Local flash option to the LocalFlashOption. To avoid having to set these parameters for each new equipment on the flowsheet, specify the defaults in the SIM4ME thermo GUI. Phase Options InternalPhases corresponds to the InternalPhases parameter. Use this to specify the kind of flash performed by SIM4ME Thermo such as VLE, VLLE, Free Water and Decant. ExternalPhases corresponds to the ExternalPhases parameter.

Column


Others Expansion isentropic efficiency corresponds to the Flash.Eff parameter. This is an isentropic efficiency used for depressuring processes. This value can be adjusted to get the required temperature during gas depressuring. This is not commonly used for Column.

Column


Notes Tab

Column


The Column Viewer Column Viewer displays the values of the some of the base parameters as shown in the following snapshot. To invoke the Column Viewer feature, right click on the Column object on the flowsheet and select View Column. Alternatively select the Column object node from the instances tree and right click to select View Column.

Column


Parameter Table Basic Parameter Name Description

DftCls

Dft Val

Eq Ok

Arr Siz UOM

TrayType

Type of Tray The type of tray could be either Plate or Packing. 0 = PLATE 1 = PACK The option selected will create plate specific or packing specific parameters.

KI PLATE No

AreaPack

Specific surface area of packing Specific surface area is the surface area per unit of packing volume. This is also the reactive surface area if reactions are present on the tray.

KD 100 Yes 1/m

Void Void fraction of the packed bed Void fraction is the empty volume per unit volume of the packed bed.

KD 0.9 Yes fraction

C1

Coefficient for Stichlmair Correlation The default value is for Raschig Rings of size 10. User must supply correct value based on the type of packing. Please refer to user document, which provides values for these coefficients for most commonly used packings.

KD 48.0 Yes

C2

Coefficient for Stichlmair Correlation The default value is for Raschig Rings of size 10. User must supply correct value based on the type of packing. Please refer to user document which provides values for these coefficients for most commonly used packings.

KD 8.0 Yes

C3

Coefficient for Stichlmair Correlation The default value is for Raschig Rings of size 10. User must supply correct value based on the type of packing. Please refer to user document which provides values for these coefficients for most commonly used packings.

KD 2.0 Yes

PackHeight Height of the packed bed Height of the packed bed associated with this tray.

KD 1 Yes m

KBeta Holdup adjustment factor This parameter can be used to adjust the holdup.

KD 1 Yes

Column


Parameter Name Description

DftCls

Dft Val

Eq Ok

Arr Siz UOM

Aeration Factor

Aeration fraction Aeration factor controls the amount of vapor in liquid phase. At a value of 0.5, the liquid volume doubles (1/0.5) due to the presence of vapor. If the tray data option is ALL, this value will be used to set the same aeration fraction for each tray else it should be set on tray-by-tray basis

KD 0.7 Yes fraction

Dia

Tray diameter Inside diameter of the tray. If the tray data option is ALL, this value will be used to set the same diameter for each tray else it should be set on tray-by-tray basis

KD 2 Yes m

E Relative elevation KD 0 No m

DrainFrac

Fraction of hole area available for liquid drainingFraction of hole area available for liquid draining. Use 1.0 for sieve trays, use 0 for valve trays, and use 0.2 for very leaky valves. If the tray data option is ALL, this value will be used to set the same hole area fraction for liquid draining for each tray else it should be set on tray-by-tray basis

KD 0.1 Yes fraction

WeepVapFlow

Weep vapor flow It is the threshold value of vapor flow below which the liquid starts draining through the holes. If the tray data option is ALL, this value will be used to set the same dump flow for each tray, else it should be set on tray-by-tray basis. Typical value is 40% of the normal vapor flow

KD 0.01 Yes kg-mol/sec

HoleAreaFrac

Hole area fraction on the tray This is the total effective hole area given as a fraction of the active area. If the tray data option is ALL, this value will be used to set the same hole area fraction for each tray else it should be set on tray-by-tray basis

KD 0.12 Yes fraction

KJ

Flow conductance factor This factor represents a tuning factor on the tray vapor forward flow conductance. If the tray data option is ALL, this value will be used to set the same forward flow conductance for each tray else it should be set on tray-by-tray basis

KD 1 Yes fraction

Column



DftCls

Dft Val

Eq Ok

Arr Siz UOM

Passes

Number of passes The number of flow paths (passes) on each tray. If the tray data option is ALL, this value will be used to set the same number of passes for each tray, else it should be set on tray-by-tray basis. Allowable options are: 0 = ONE 1 = TWO 2 = FOUR 3 = OTHER

KI ONE No

Spacing

Tray spacing Distance between two trays. If the tray data option is ALL, this value will be used to set the same tray spacing for each tray else it should be set on tray-by-tray basis

KD 0.67 Yes m

Tray.Cpm Metal specific heat Metal specific heat. The default value is typical of carbon steel.

KD 0.5 Yes kJ/kg K

TrayEff

Tray efficiency Tray efficiency defines the fraction of vapor through the tray from the tray below. The rest of vapor will bypass the tray and feed to the tray above. If the tray data option is ALL, this value will be used to set the same tray efficiency for each tray else it should be set on tray-by-tray basis

KD 1. Yes fraction

TrayData

Tray data option Allowable options are: 0 = ALL 1 = TRAY When the option ALL is selected, all the trays in the Column will use the same parameters on a global basis. When the option TRAY is selected, the parameters can be set on tray-by-tray basis.

KI ALL

TrayName

Tray name It is set based on the tray number to identify the trays. The top most tray has tray name of Tray1 and the bottom most tray has tray name of Tray.

Tray1 No NTRAY

TrayNum

Tray number Trays are numbered from top to bottom. It is 1 for the top most tray and NTRAY (number of trays) for the bottom most tray.

DI 1 No NTRAY

Column



DftCls

Dft Val

Eq Ok

Arr Siz UOM

VolVap

Column vapor holdup volume Column vapor holdup volume used for vapor holdup and pressure calculation. If not specified, Dynsim will calculate the volume based on the Column data

KD Yes mP3 P

WeirHeight

Weir height Weir height for each tray. If the tray data option is ALL, this value will be used to set the same weir height for each tray else it should be set on tray-by-tray basis

KD 0.056 Yes m

Heat Transfer Parameter Name Description

DftCls

Dft Val

Eq Ok

Arr Siz UOM

Mm Column total metal mass Used in the metal temperature calculations KD5000 Yes kg

Ul Ambient loss heat transfer coefficient Heat transfer coefficient between metal and ambient KD0.01 Yes kW/mP2 P-K

Un

Natural convection heat transfer coefficient Natural convection heat transfer (film) coefficient from fluid to metal. There is no forced convection modeled in the Column

KD0.10 Yes kW/mP2

P-K

Solution Options


DftCls

Dft Val

Eq Ok

Arr Siz

UOM

HoldupOptions

Holdup option Only LIQUID option is available. For LIQUID option, there is only liquid holdup on the tray, no vapor holdup. It supports liquid backup between trays, but not reverse vapor flow between trays. Allowable options are: 0 - LIQUID

KI LIQUID No

Solution Option

Solution Options Allowable options are: 0 = ITERATED 1 = EXPLICIT 2 = LOCAL_ITERATED 3 = SIMULTANEOUS

KI SIMULTANEOUS

TrayEffOption Tray efficiency option Only BYPASSVAP is available. KI BYPASSVAP No

TrayFactor Tray factor Ratio of modeled trays to actual trays. It is used to maintain proper calculations for the

KD 1 Yes fraction

Column



DftCls

Dft Val

Eq Ok

Arr Siz

UOM

entire Column while simulating the Column with number of theoretical trays rather than actual trays. If the tray data option is ALL, this value will be used to set the same tray factor for each tray else it should be set on tray-by-tray basis

The values below can be entered on tray-by-tray basis

TrayEffOption Tray efficiency option Only BYPASSVAP is available. KI BYPASSVAP No

TrayFactor

Tray factor Ratio of modeled trays to actual trays. It is used to maintain proper calculations for the entire Column while simulating the Column with number of theoretical trays rather than actual trays. If the tray data option is ALL, this value will be used to set the same tray factor for each tray else it should be set on tray-by-tray basis

KD 1 Yes fraction

Reactions Parameter Name Description

Dft Cls

Dft Val

Eq Ok

Arr Siz UOM

Rxn.RxnFlag

Reaction flag This flag turns on or off the all of the reactions in the reactor. The default value is no reactions (0). If the reaction data option is ALL, this value will be used to set the same reaction flag for each tray else it should be set on tray-by-tray basis

KB false No N/A N/A

Rxn.RxnData

Tray reaction data option Allowable options are: 0 = ALL 1 = TRAY When the option ALL is selected, all the trays in the Column will use the same reaction parameters on a global basis. When the option TRAY is selected, the reaction parameters can be set on tray-by-tray basis

KI ALL No N/A N/A

Rxn.RxnFactor

Reaction factor This parameter can be used to scale all the reaction rates in the reactor to simulate the reactor efficiency. The default value is 1. If the reaction data

KD 1 Yes

Column



Dft Cls

Dft Val

Eq Ok

Arr Siz UOM

option is ALL, this value will be used to set the same reaction factor for each tray else it should be set on tray-by-tray basis

Rxn.ORxnDataSet

Reaction data set object(s) This defines the Reaction Data Set objects in the reactor. If the reaction data option is ALL, this value will be used to set the Reaction Data Set objects for each tray else it should be set on tray-by-tray basis

RXNDATASET

0 No

Rxn.RxnDataSetStatus

Reaction data set status Allowable options are: 0 = PASSIVE 1 = ACTIVE This turns on or off the Reaction Data Set in the reactor. This value, if initialized, will be used instead of the corresponding Reaction Data Set's Status parameter. If the reaction data option is ALL, this value will be used to set the Reaction data set status for each tray else it should be set on tray-by-tray basis

KI No

Rxn.DEBUGFLAGS

Reaction Data debug flags This parameter is a collection of binary flags. Each equipment model interprets the flags its own way. If the reaction data option is ALL, this value will be used to set the same debug flags for reaction data for each tray else it should be set on tray-by-tray basis

KI 0 No

Rxn.RefStateOpts

Reference state options This Parameter specifies the reference state. Allowable options are: 0 = REFPHASE 1 = REFPRES 2 = EXITPRES The Reference temperature from the Reaction Data and the option from the RefStateOpts can be used to define the reference state. If the reaction data option is ALL, this value will be used to set the same reference state option for reaction data for each tray else it should be set on tray-by-tray basis

KI REFPHASE No

Rxn.RefTemp Reference temperature This display only parameter shows the DD 298.15 No K

Column



Dft Cls

Dft Val

Eq Ok

Arr Siz UOM

reference temperature that is used for the reference state calculation. The reference temperature is defined by the Reaction Data. If the reaction data option is ALL, this value will be used to set the same reference temperature for reaction data for each tray else it should be set on tray-by-tray basis

Rxn.RefPres

Reference pressure This parameter can be used to display the reference pressure (RefStateOpts = REFPHASE) or defined the reference pressure (RefStateOpts = REFPRES). If the reaction data option is ALL, this value will be used to set the same reference for each tray else it should be set on tray-by-tray basis

DD 101.325 No kPa

Rxn.RefPhase

Reference phase This parameter can be used to define the reference phase for the reference state calculation if the RefPhase option is selected from the RefStateOpts. Allowable options are: 0 = VAPOR 1 = LIQUID 2 = UNDEFINED If Undefined is selected the reference phase is determined by the reaction data. If the reaction data option is ALL, this value will be used to set the same reference phase for reaction data for each tray else it should be set on tray-by-tray basis

KI UNDEFINEDNo

Boundary Conditions Parameter Name Description

DftCls

Dft Val

Eq Ok

ArrSiz UOM

BoundarySpec

Boundary specification option Allowable options are: 0 = NONE 1 = P Boundary specifications for tuning a simulation. Allowable options are NONE and P, H, T, PT, PH. Pressure boundaries lead to loss of mass conservation.

KI NONE No

Pb Boundary pressure For simulation tuning. The equipment will not maintain material balance if a boundary pressure is set.

KD Yes kPa

Column


Initialization Parameter Name Description

Dft Cls

Dft Val

Eq Ok

ArrSiz UOM

OInitSource

Source Initialization object If OInitSource is specified, the tray, mass and energy of the liquid holdup will be initialized from the specified, Source model. The Source should have the same Internal, and ExternalPhases specification as the Column

OBJECT

OInitVapor Source

Source initialization object for vapor holdup If OInitVaporSource is specified, the mass and energy of the Column vapor holdup will be initialized from the specified Source model.

OBJECT

ReInitFlag

Reinitialize liquid holdup flag The vessel will reinitialize from a Source model if specified. If not, the vessel will use an arbitrary, composition based on an equimolar composition, Midpoint levels will be used if an initial L or L2 is not provided

KB 0 No

ReInitVapor Flag

Reinitialize vapor holdup flag The Column vapor holdup will initialize from a Source model If specified. If not, the Column vapor holdup will use an equimolar vapor composition.

KB 0 No

External Inputs Parameter Name Description

DftCls

Dft Val

Eq Ok

Arr Siz UOM

Tamb Ambient temperature Ambient temperature. Normally associated with global standalone point TAMBIENT

DDTAMBIENTYes K

The values below can be entered on tray-by-tray basis.

Ul Ambient loss heat transfer coefficient Heat transfer coefficient between metal and ambient KD0.01 Yes kW/mP2 P-K

Un

Natural convection heat transfer coefficient Natural convection heat transfer (film) coefficient from fluid to metal. There is no forced convection modeled in the Column

KD0.10 Yes kW/ mP2

P-K

Qimp

Imposed heat to fluid External heat imposed on the fluid. It is set on tray-by-tray basis

DD0 Yes kJ/sec

Tamb Ambient temperature Ambient temperature. Normally associated with global standalone point TAMBIENT

DDTAMBIENTYes K

Column


Nozzles Parameter Name Description

DftCls

Dft Val

Eq Ok

Arr Siz UOM

Di

Diameter of inlet port This is an array of nozzle diameters that corresponds to the array of feed ports. This diameter is used to ramp transition from one phase to another as phase boundary pass. It is only used for reverse flow

KD0.05 No OFeedStreamm

DiBaseV

Diameter of base VAPOR feed port This nozzle diameter corresponds to base VAPOR feed from OBASE object port. This diameter is used to ramp transition from one phase to another as phase boundary pass. It is only used for reverse flow.

KD0.05 No m

Dx

Diameter of outlet port This is an array of nozzle diameters that corresponds to the array of product ports. This diameter is used to ramp transition from one phase to another as phase boundary pass

KD0.05 No OProdStreamm

DxBaseL

Diameter of base LIQUID product port This nozzle diameter corresponds to base LIQUID product to OBASE object port. This diameter is used toramp transition from one phase to another as phase boundary pass.

KD0.05 No m

DxL

Diameter of LIQUID outlet port This is an array of nozzle diameter that corresponds to the array of LIQUID product ports from bottom tray .This diameter is used to ramp transition from one phase to another as phase boundary pass.

KD0.05 No OProdLiquid m

DxV

Diameter of VAPOR outlet port This is an array of nozzle diameter that corresponds to the array of VAPOR product ports from top tray. This diameter is used to ramp transition from one phase to another as phase boundary pass.

KD0.05 No OProdVapor m

Li

Height of inlet port This is an array of nozzle heights that corresponds to the array of feed streams. The height is relative to the individual feed tray.

KD0 No OFeedStreamm

Lx

Height of outlet port This is an array of nozzle heights that corresponds to the array of product streams. The height is relative to the individual product tray.

KD0 No OProdStreamm

Column


Advanced Parameter Name Description

Dft Cls

DftVal

Eq Ok

Arr Siz UOM

DebugFlags

Column debug flags This parameter is a collection of binary flags. Each equipment model interprets the flags its own way.

KI 0 No

DPLiqFactor

Liquid head scale factor This parameter can be used to scale the tray liquid head. Use 1.0 for a normal tray type, and use 0.0 for a chimmy tray. If the tray data option is ALL, this value will be used to set the same level at coil bottom draining for each tray, else it should be set on tray-by-tray basis.

KD 1 Yes fraction

ViscV

Viscosity of vapor This is used in the pressure drop calculation in a packed bed. The default value supplied is that of air at 20 degC and 1 atm. User must set the correct value of the fluid involved to get accurate results.

KD 0.02Yes cp

FluidHeatTray

Fluid heat stream tray This is an array of tray location that corresponds to the array of feed fluid heat streams OFeedFluidHeatStream.

KI 0 No

OFeed Fluid Heat Stream

KJBase

Conductance scale from Base to bottom tray A value of 1.0 provides a consistent pressure drop through the bottom plate with the other tray plates in the column. Default value of 0.02 makes pressure stable for Explicit base models.

KD 0.02Yes

KLag

Dynamic response lag Used to dampen dynamic response. Can result in the loss or creation of mass and energy. Should not be used for engineering studies

KD 1 Yes fraction

LCb

Level at coil bottom The height to the bottom of an internal coil or tube bundle within the tray. It is used to calculate the heat stream AreaFrac if the Column is connected to an Utility Exchanger. If the tray data option is ALL, this value will be used to set the same level at coil bottom draining for each tray else it should

KD 0 No m

Column



Dft Cls

DftVal

Eq Ok

Arr Siz UOM

be set on tray-by-tray basis

LCt

Level at coil top The height to the top of an internal coil or tube bundle within the tray. It is used to calculate the heat stream AreaFrac if the Column is connected to an Utility Exchanger. If the tray data option is ALL, this value will be used to set the same level at coil top for each tray else it should be set on tray-by-tray basis

KD 0 No m

MetalHeatTray

Metal heat stream tray This is an array of tray location that corresponds to the array of feed metal heat streams OFeedMetalHeatStream.

KI 0 No

OFeed Metal Heat Stream

OFeedFluid HeatStream

Feed fluid feed heat stream Array of feed heat streams connected to the fluid of the Column.

HEAT STREAM No

User Specified

OFeedMetal HeatStream

Feed metal heat stream Array of feed heat streams connected to the metal wall of the Column.

HEAT STREAM No

User Specified

KLRecycle Liquid recycle tuning constant KD 0.1 Yes 1/sec

The values below can be entered tray-by-tray basis

Tray.DPLiqFactor

Liquid head scale factor This parameter can be used to scale the tray liquid head. Use 1.0 for a normal tray type, and use 0.0 for a chimmy tray. If the tray data option is ALL, this value will be used to set the same level at coil bottom draining for each tray, else it should be set on tray-by-tray basis.

KD 1 Yes fraction

Tray.KLRecycle Liquid recycle tuning constant KD 0.1 Yes 1/sec

Tray.LCb

Level at coil bottom The height to the bottom of an internal coil or tube bundle within the tray. It is used to calculate the heat stream AreaFrac if the Column is connected to an Utility Exchanger. If the tray data option is ALL, this value will be used to set the same level at coil bottom draining for each tray else it should be set on tray-by-tray basis

KD 0 No m

Column



Dft Cls

DftVal

Eq Ok

Arr Siz UOM

Tray.LCt

Level at coil top The height to the top of an internal coil or tube bundle within the tray. It is used to calculate the heat stream AreaFrac if the Column is connected to an Utility Exchanger. If the tray data option is ALL, this value will be used to set the same level at coil top for each tray else it should be set on tray-by-tray basis

KD 0 No m

Column


Calculated Values Parameter Name Description

DftCls

Dft Val

Eq Ok

Arr Siz UOM

FVSideDraw Vapor side draw from vapor holdup This value indicates total amount of vapor side draw from the vapor holdup excluded top tray.

DD0.0 No kg-mol/sec

MT Total moles Total column top vapor holdup moles in the Column for all components and phases.

DD0 No kg-mol

The values below are calculated on tray-by-tray basis

Tray.Fl Liquid product mole flow rate Liquid product mole flow rate to the tray below. DD0 No kg-mol/sec

Tray.Fv Vapor product mole flow rate Vapor product mole flow rate to the tray above. DD0 No kg-mol/sec

Tray.Hl Liquid product enthalpy Liquid product mole enthalpy to the tray below. DD1 No kJ/kg-mol

Tray.Hv Vapor product enthalpy Vapor product mole enthalpy to the tray above. DD1 No kJ/kg-mol

Tray.MWl Liquid product molecular weight Liquid product molecular weight to the tray below. DD1 No

Tray.MWv Vapor product molecular weight Vapor product molecular weight to the tray above. DD1 No

Tray.Pl Liquid product pressure Liquid product pressure to the tray below. DD101.325No kPa

Tray.Pv Vapor product pressure Vapor product pressure to the tray above. DD101.325No kPa

Tray.Rl Liquid product mole density Liquid product mole density to the tray below DD1 No kg-mol/ mP3 P

Tray.Rv Vapor product mole density Vapor product mole density to the tray above DD1 No kg-mol/ mP3 P

Tray.Tl Liquid product temperature Liquid product temperature to the tray below. DD298.15 No K

Tray.Tv Vapor product temperature Vapor product temperature to the tray above. DD298.15 No K

Tray.VFl Liquid product vapor mole fraction Liquid product vapor mole fraction to the tray below.

DD0 No fraction

Tray.VFv Vapor product vapor mole fraction Vapor product vapor mole fraction to the tray above.

DD1 No fraction

Tray.Zl Liquid product composition Liquid product mole composition to the tray below. DD0 No fraction

Tray.Zv Vapor product composition Vapor product mole composition to the tray above. DD0 No fraction

Tray.Ql Heat loss from metal to ambient Heat loss from metal to ambient. A negative value indicates that the metal is losing heat to the

DD0 No kJ/sec

Column



DftCls

Dft Val

Eq Ok

Arr Siz UOM

surroundings.

Tray.Qn Heat loss from fluid to metal Heat loss from fluid to metal. A negative value indicates that the fluid is losing heat to the metal.

DD0 No kJ/sec

Tray.L Level of liquid phase Absolute level of the first liquid phase from bottom of tray.

DD0 No m

Tray.L2 Level of liquid2 phase Absolute level of the second liquid phase from bottom of tray. It is always 0.

DD0 No m

Tray.VelV Superficial vapor velocity Used for packed stages. DD No m/sec

Tray.VelL Superficial liquid velocity Used for packed stages. DD No m/sec

Tray.Beta

Packed liquid holdup Liquid holdup fraction of the packed stage. Holdup is the liquid volume divided by the packed stage void volume.

DD No fraction

Derivatives Parameter Name Description

DftCls

Dft Val

Eq Ok

Arr Siz UOM

dHv

Specific enthalpy derivative Specific enthalpy derivative used for INCOMPRESSIBLE dynamic behavior. Will be zero for COMPRESSIBLE dynamics where dUT is used instead. Only COMPRESSIBLE option is available in Column.

DD0 No kJ/kg-mol/sec

dMv Total composition derivative Derivatives of total moles for each component in the vapor holdup.

DD0 No Comp Slate kg-mol/sec

dUTv

Total internal energy derivative Derivative of vapor holdup internal energy calculated from the enthalpy of all streams connected to the vapor holdup, fluid heat stream duty, and heat loss to metal. Only used for COMPRESSIBLE dynamics. Will be zero for INCOMPRESSIBLE where dH is used instead.

DD0 No kJ/sec

The values below are calculated on a tray-by-tray basis.

TrayM.dM

Total composition derivative Derivatives of total moles for each component. For LIQUID option, it is derivatives of component moles on liquid holdup.

DD0 No Comp Slate kg-mol/sec

TrayM.dTm Derivative of metal temperature Derivative of tray metal temperature. A positive value indicates that the metal is getting hotter.

DD0 No K/sec

Column



DftCls

Dft Val

Eq Ok

Arr Siz UOM

TrayM.dUT

Total internal energy derivative Derivative of tray internal energy calculated from the flowing enthalpy of all streams connected to the tray, fluid heat stream duty, and heat loss to metal. For LIQUID option, it considers only liquid holdup.

DD0 No kJ/kg-mol/sec

States Parameter Name

Description Dft Cls Dft Val

Eq Ok

Arr Siz UOM

Hv Specific enthalpy state Energy state used for INCOMPRESSIBLE solution.

SD 0 No kJ/kg-mol

P Pressure Column pressure SD 101.325 No kPa

UTv Total internal energy state Total internal energy state for COMPRESSIBLE dynamics.

SD 0 No kJ

Zv Specific composition state Mole fraction state for each component in the vapor holdup.

SD 0 No Comp Slate fraction

The values below are calculated on a tray-by-tray basis

Tray.M Total composition state Array that includes the total holdup moles of each component.

SD 1 No Comp Slate kg-mol

Tray.P Pressure Tray pressure SD 101.325 No kPa

Tray.Tm Metal temperature Tray metal temperature SD 298.15 No K

Tray.UT Total internal energy state SD 0 No kJ

Tray.Z Specific composition state Tray mole fraction for each component

SD 1 No Comp Slate fraction

States For the Vapor Holdup Parameter Name Description

Dft Cls

Dft Val

Dft Val

Arr Siz UOM

Mv Total composition state Top tray vapor holdup moles of each component.

SD 0 No Comp Slate kg-mol

Column


Topology Parameter Name Description

Dft Cls

Dft Val

Eq Ok

Arr Siz UOM

BaseProdLiquid

Liquid product stream to the base model This stream defines the liquid product to the bottom base model from Column bottom tray. OBASE needs to be defined.

STREAM

BaseFeedVapor

Vapor feed stream from the base model This stream defines the feed vapor from the bottom base model to the Column bottom tray. OBASE needs to be defined.

STREAM

FeedTray Feed tray location This is an array of tray location that corresponds to the array of feed streams OFeedStream.

KI 1 No OFeedStream

NTray Number of trays Total number of trays in the Column KI 0 No

OBase

Base model name The Base model can be used to simulate the Column sump. The model can be a vertical Drum or Separator with number of heads set to one. The model is connected to Column bottom through BaseFeedVapor and BaseProdLiquid streams.

OBJECT

OFeedStream

Feed Stream Column feed stream. Can be connected only from flow devices. Identifies the feed, or inlet, stream and its associated fluid properties. This entry must be unique to all other feed streams in the flowsheet. However, this entry can be the same as a product stream identifier from another unit. OFeedStream and OProdStream cannot be the same. Any number feed stream can be connected to the Column.

STREAM

OProdLiquid

Liquid-port product stream Array of Column liquid product streams from the bottom of the bottom tray. Can be connected to only flow devices. Identifies the product, or outlet, stream and its associated fluid properties. This entry must be unique to all other product streams in the flowsheet. However, this entry can be the same as a feed stream identifier to another flow device. Any number of liquid product streams can be connected from Column

STREAM

OProdStream

Product Stream Column product stream. Can be connected to only flow devices. Identifies the product, or outlet, stream and its associated fluid properties. This entry must be unique to all other product streams in the flowsheet. However, this entry can be the same as a feed stream identifier to another flow device. OFeedStream and OProdStream cannot be the

STREAM

Column



Dft Cls

Dft Val

Eq Ok

Arr Siz UOM

same. Any number of product stream can be connected from Column

OProdVapor

Vapor-port product stream Array of Column vapor product streams from the top of the top tray. Can be connected to only flow devices. Identifies the product, or outlet stream and its associated fluid properties. This entry must be unique to all other product streams in the flowsheet. However, this entry can be the same as a feed stream identifier to another flow device.Any nu

Date post:	12-Oct-2015
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