modelMulticomponentDistillationFUG
Extends from DistillationBase.
Information
It is a non standard implementation of the Fenske-Underwood-Gilliland shortcut method for multicomponent distillation.
The following simplifications are made:
- The distribution of components between the distillate and bottom, obtained by the Fenske equation for total reflux, is considered valid for the actual and minimum reflux.
- It is considered just one pinch point, close to the feed composition. As the distillate composition is taken from the Fenske's equation, only one Underwood set of equations is needed in order to calculate the minimum reflux. This may give poor calculation if there is an important distribution of any component between distillate and bottom.
The feed must be specified as flow, in kmol/h or kg/h. The top light, and the bottom heavy, can be specified as flow or concentration. Flow is recommended for best convergence.
The model is lacking one equation. You can configure the needed equation by selecting the required parameter. It is done at the graphical menu under the "Operating conditions" tab. You can select one of the options as true: fix the reflux to a constant value, or as a multiplier of the minimum reflux. Or fix the heat exchange at the condenser or the reboiler. Or you can add the extra equation (for example the value of the vpor flow at the stripping section) by hand.
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Modelica.Units.SI.MolarMass | mwL (from DistillationBalance) | 0 | light component molecular weight |
| Modelica.Units.SI.MolarMass | mwH (from DistillationBalance) | 0 | heavy component molecular weight |
| Boolean | molarBasis (from DistillationBalance) | true | if true, use molar fraction and kmol/h, otherwise mass fraction and kg/h |
| Modelica.Units.SI.MolarMass[nNonKey] | mwI | fill(0, nNonKey) | nonkey components molecular weight |
| Feed data | |||
| Boolean | isBinaryDistillation (from DistillationBalance) | true | if true only two components are considered |
| Real | ffl (from DistillationBalance) | fixed feed flow rate of light component in kmol/h or kg/h | |
| Real | ffh (from DistillationBalance) | fixed feed flow rate of heavy component in kmol/h or kg/h | |
| Modelica.Units.SI.TemperatureDifference | fSuperHeating (from DistillationBalance) | 0 | feed superheating, subcooling if negative |
| Fraction | fGfSat (from DistillationBalance) | 0 | gas fraction of the feed, if in saturated conditions |
| Modelica.Units.SI.MolarEnthalpy | hvF (from DistillationBalance) | 41000 | feed molar vaporization enthalpy |
| Modelica.Units.SI.MolarHeatCapacity | cpFl (from DistillationBalance) | 0 | feed liquid heat capacity, if subcooled |
| Modelica.Units.SI.MolarHeatCapacity | cpFv (from DistillationBalance) | 0 | feed vapor heat capacity, if superheated |
| String | fLight | "" | key light component name |
| String | fHeavy | "" | key heavy component name |
| String | fNonKeys | "" | feed nonkey components |
| Integer | nNonKey | 1 | number of nonkey components |
| Real[nNonKey] | ffi | fill(0, nNonKey) | fixed feed flow of nonkey components in kmol/h or kg/h |
| Top data | |||
| FreeFluids.Types.PerformanceSpecification | topFixed (from DistillationBalance) | FreeFluids.Types.PerformanceSpecification.FixedComposition | composition, flow, recovery or none are fixed |
| Fraction | dyl (from DistillationBalance) | 0.0 | fixed distillate light fraction |
| Real | dfl (from DistillationBalance) | 0.0 | fixed distillate light flow. kmol/h or kg/h |
| Fraction | dlr (from DistillationBalance) | 0.95 | fixed light recovery in distillate |
| Modelica.Units.SI.TemperatureDifference | dSubCooling (from DistillationBalance) | 0 | distillate subcooling, if total condenser used |
| Modelica.Units.SI.MolarEnthalpy | hvD (from DistillationBalance) | 41000 | distillate molar vaporization enthalpy |
| Modelica.Units.SI.MolarHeatCapacity | cpDl (from DistillationBalance) | 0 | distillate liquid heat capacity |
| Bottom data | |||
| FreeFluids.Types.PerformanceSpecification | bottomFixed (from DistillationBalance) | FreeFluids.Types.PerformanceSpecification.FixedComposition | composition, flow, recovery or none are fixed |
| Fraction | bxh (from DistillationBalance) | 0.0 | fixed bottom heavy fraction |
| Real | bfh (from DistillationBalance) | 0.0 | fixed bottom heavy flow. kmol/h or kg/h |
| Fraction | brh (from DistillationBalance) | 0.95 | fixed heavy recovery in bottom |
| Modelica.Units.SI.MolarEnthalpy | hvB (from DistillationBalance) | 41000 | bottom molar vaporization enthalpy |
| Operating conditions | |||
| Boolean | fixRatioToMinReflux (from DistillationBalance) | false | if true, the ratio reflux/minimum reflux is fixed |
| Real | minRratio (from DistillationBalance) | 1.3 | ratio used, if previous is true |
| Boolean | fixRefluxRatio (from DistillationBalance) | false | if true, the ratio reflux/distillate is fixed |
| Real | rr (from DistillationBalance) | 0 | fixed internal reflux/distillate ratio |
| Boolean | fixCondenserPower (from DistillationBalance) | false | |
| Modelica.Units.SI.Power | wc (from DistillationBalance) | 0 | fixed power removed at condenser |
| Boolean | fixReboilerPower (from DistillationBalance) | false | |
| Modelica.Units.SI.Power | wb (from DistillationBalance) | 0 | fixed power added at reboiler |
| Boolean | isPartialCondenser (from DistillationBalance) | false | if true the distillate leaves as gas |
| FreeFluids.Types.ReboilerType | reboilerType (from DistillationBase) | FreeFluids.Types.ReboilerType.Kettle | |
| Equilibrium data | |||
| Types.EquilibriumDataType | dataType (from DistillationBase) | Types.EquilibriumDataType.EquilibriumConstant | |
| Real | fkl (from DistillationBase) | 0 | Feed equilibrium constant of light component |
| Real | fkh (from DistillationBase) | 0 | Feed equilibrium constant of heavy component |
| Real | dkl (from DistillationBase) | 0 | Distillate equilibrium constant of light component |
| Real | dkh (from DistillationBase) | 0 | Distillate equilibrium constant of heavy component |
| Real | bkl (from DistillationBase) | 0 | Bottom equilibrium constant of light component |
| Real | bkh (from DistillationBase) | 0 | Bottom equilibrium constant of heavy component |
| Real | frv (from DistillationBase) | 0 | Feed relative volatility light/heavy |
| Real | drv (from DistillationBase) | 0 | Distillate relative volatility light/heavy |
| Real | brv (from DistillationBase) | 0 | Bottom relative volatility light/heavy |
| Real[nNonKey] | fki | fill(0, nNonKey) | Feed equilibrium constant of nonkey components |
| Real[nNonKey] | dki | fill(0, nNonKey) | Distillate equilibrium constant of nonkey components |
| Real[nNonKey] | bki | fill(0, nNonKey) | Bottom equilibrium constant of nonkey components |
| Real[nNonKey] | frvi_h | fill(0, nNonKey) | feed relative volatility of nonkey components |
| Real[nNonKey] | drvi_h | fill(0, nNonKey) | distillate relative volatility of nonkey components |
| Real[nNonKey] | brvi_h | fill(0, nNonKey) | bottom relative volatility of nonkey components |
Components
| Type | Name | Default | Description |
|---|---|---|---|
| Modelica.Units.SI.MolarFlowRate | F (from DistillationBalance) | feed molar flow rate | |
| Modelica.Units.SI.MolarFlowRate | D (from DistillationBalance) | distillate molar flow rate | |
| Modelica.Units.SI.MolarFlowRate | B (from DistillationBalance) | bottom purge molar flow rate | |
| Modelica.Units.SI.MolarMass | Fmw (from DistillationBalance) | feed molar mass | |
| Modelica.Units.SI.MassFlowRate | Fmass (from DistillationBalance) | feed mass flow rate | |
| Modelica.Units.SI.MassFlowRate | FflMass (from DistillationBalance) | feed light mass flow rate | |
| Modelica.Units.SI.MassFlowRate | FfhMass (from DistillationBalance) | feed heavy mass flow rate | |
| Modelica.Units.SI.MolarMass | Dmw (from DistillationBalance) | distillate molar mass | |
| Modelica.Units.SI.MassFlowRate | Dmass (from DistillationBalance) | distillate mass flow rate | |
| Modelica.Units.SI.MassFlowRate | DflMass (from DistillationBalance) | distillate light mass flow rate | |
| Modelica.Units.SI.MassFlowRate | DfhMass (from DistillationBalance) | distillate heavy mass flow rate | |
| Modelica.Units.SI.MolarMass | Bmw (from DistillationBalance) | bottom molar mass | |
| Modelica.Units.SI.MassFlowRate | Bmass (from DistillationBalance) | bottom mass flow rate | |
| Modelica.Units.SI.MassFlowRate | BfhMass (from DistillationBalance) | bottom heavy mass flow rate | |
| Modelica.Units.SI.MassFlowRate | BflMass (from DistillationBalance) | bottom light mass flow rate | |
| Fraction | FZl (from DistillationBalance) | feed molar fraction of light component | |
| Fraction | FZlMass (from DistillationBalance) | feed mass fraction of light component | |
| Fraction | FZh (from DistillationBalance) | feed molar fraction of heavy component | |
| Fraction | FZhMass (from DistillationBalance) | feed mass fraction of heavy component | |
| Modelica.Units.SI.MolarFlowRate | Ffl (from DistillationBalance) | feed molar flow rate of light component | |
| Modelica.Units.SI.MolarFlowRate | Ffh (from DistillationBalance) | feed molar flow rate of heavy component | |
| Fraction | DYl (from DistillationBalance) | distillate molar fraction of light comp. | |
| Fraction | DYlMass (from DistillationBalance) | distillate mass fraction of light comp. | |
| Fraction | DYh (from DistillationBalance) | distillate molar fraction of heavy comp. | |
| Fraction | DYhMass (from DistillationBalance) | distillate mass fraction of heavy comp. | |
| Modelica.Units.SI.MolarFlowRate | Dfl (from DistillationBalance) | distillate molar flow rate of light component | |
| Modelica.Units.SI.MolarFlowRate | Dfh (from DistillationBalance) | distillate molar flow rate of heavy component | |
| Fraction | BXl (from DistillationBalance) | bottom molar fraction of light comp. | |
| Fraction | BXlMass (from DistillationBalance) | bottom mass fraction of light comp. | |
| Fraction | BXh (from DistillationBalance) | bottom molar fraction of heavy comp. | |
| Fraction | BXhMass (from DistillationBalance) | bottom mass fraction of heavy comp. | |
| Modelica.Units.SI.MolarFlowRate | Bfl (from DistillationBalance) | bottom molar flow rate of light component | |
| Modelica.Units.SI.MolarFlowRate | Bfh (from DistillationBalance) | bottom molar flow rate of heavy component | |
| Fraction | Fgf (from DistillationBalance) | feed gas fraction | |
| Real | Q (from DistillationBalance) | feed enthalpy parameter | |
| Real | RR (from DistillationBalance) | internal reflux ratio, after heating of subcooled reflux | |
| Real | RRext (from DistillationBalance) | external reflux ratio, as observed at condenser | |
| Real | BR (from DistillationBalance) | boil ratio | |
| Modelica.Units.SI.Power | Wc (from DistillationBalance) | heat removed at condenser | |
| Modelica.Units.SI.Power | Wb (from DistillationBalance) | heat added at the reboiler | |
| Modelica.Units.SI.MolarFlowRate | Le (from DistillationBalance) | liquid molar flow rate in the enrichment section | |
| Modelica.Units.SI.MolarFlowRate | Ve (from DistillationBalance) | gas molar flow rate in the enrichment section | |
| Modelica.Units.SI.MolarFlowRate | Ls (from DistillationBalance) | liquid molar flow rate in the stripping section | |
| Modelica.Units.SI.MolarFlowRate | Vs (from DistillationBalance) | gas molar flow rate in the stripping section | |
| Real | Rmin (from DistillationBase) | minimum reflux ratio | |
| Fraction | RYl (from DistillationBase) | operation lines intersection Y value | |
| Fraction | RXl (from DistillationBase) | operation lines intersection X value | |
| Real | Frv (from DistillationBase) | relative volatility of light/heavy at feed conditions | |
| Real | Drv (from DistillationBase) | top of column relative volatility l/h | |
| Real | Brv (from DistillationBase) | bottom of column relative volatility l/h | |
| Real | RVavg (from DistillationBase) | average relative volatility l/h | |
| Real | NstagesMin (from DistillationBase) | number of states at total reflux | |
| Real | Nstages (from DistillationBase) | number of stages at working reflux | |
| Real | Nplates (from DistillationBase) | number of plates needed at working reflux | |
| Real | Fstage (from DistillationBase) | optimum stage for fee, from top | |
| Fraction[nNonKey] | FZi | molar fraction of nonkey components in feed | |
| Modelica.Units.SI.MolarFlowRate[nNonKey] | Ffi | molar fraction of nonkey components in feed | |
| Fraction[nNonKey] | DYi | molar fraction of nonkey components in distillate | |
| Modelica.Units.SI.MolarFlowRate[nNonKey] | Dfi | molar fraction of nonkey components in distillate | |
| Fraction[nNonKey] | BXi | molar fraction of nonkey components in bottom | |
| Modelica.Units.SI.MolarFlowRate[nNonKey] | Bfi | molar fraction of nonkey components in distillate | |
| Real[nNonKey] | Frvi_h | top of column relative volatility nonkey/heavy | |
| Real[nNonKey] | Drvi_h | top of column relative volatility nonkey/heavy | |
| Real[nNonKey] | Brvi_h | bottom of column relative volatility nonkey/heavy | |
| Real[nNonKey] | RVavgi_h | average relative volatility nonkey/heavy | |
| Real | Sigma1 | ||
| Real[nNonKey] | Sigma1i | ||
| Real | Sigma2 | ||
| Real[nNonKey] | Sigma2i | ||
| Real | Theta | Underwood parameter | |
| Real | Rmin1 | minimum reflux for type 1 pinch point |