modelKettleReboilerEq
Extends from ThermalSeparation.Icons.Color.Reboiler.
Information
Kettle reboiler - shell side
The reboiler is modelled as an evaporator with one liquid input and one liquid and vapour output respectively. The model consideres only the shell side of a kettle reboiler. On the inside the reboiler contains a weir which determines the maximum liquid level. Once the liquid level rises above the weir height a liquid stream starts to exit the reboiler. To model this process the francis-weir-formula is used.
Mass and ernergy balances contain both liquid and vapour phases together. This means both phases are at thermodynamic equilibrum at any time.
For now no startup processes from empty and cold states are considered. This means at t=0s the reboiler is already partially filled with liquid that has a temperature near the boiling point.
So far no heat transfer resistance is considered for the heating. The amount of heat introduced into the reboiler is supplied by a real Input and directly accounted for in the energy balance. Also no pressure loss is calculated at the moment.
The model can handle inert substances in the liquid phase. In case the liquid phase contains an inert the user has to specify which substances of the component vector are inert. If any chemical reactions occur they can also be taken into account. Reaction model and correlation for vapour-liquid equilibrium can both be selected via a dropdown menu.
For initialisation the user can opt for either standalone operation or usage in larger systems because in standalone operation it is not possible to initialise the pressure since it is already given by the vapour sink.
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Boolean | init_standalone | true | changes number of initial values if used in standalone operation |
| Modelica.Units.SI.HeatFlowRate | Q_loss | 0 | heat loss to ambience |
| Integer[nS,2] | mapping | {{1, 1}, {2, 2}} | parameter to map the different medium vectors one to another |
| Integer | nS | 2 | number of omspecies which are equal in vapour and liquid phase |
| Integer | nL | nSL - nS | number of additional substances which are only in liquid phase |
| Integer | nV | nSV - nS | number of additional substances which are only in the vapour phase |
| Integer | nSL | MediumLiquid.nSubstance | |
| Integer | nSV | MediumVapour.nSubstance | |
| Boolean[nSL] | inert_Liquid | fill(false, nSL) | true for inert components in liquid phase |
| Real | R | Modelica.Constants.R | |
| Modelica.Units.SI.Area | A_HT | heat exchange area | |
| Modelica.Units.SI.Area | A | 0.5 | area of reboiler |
| Modelica.Units.SI.Height | H | 1.3 | height of reboiler |
| Modelica.Units.SI.Length | h_w | 0.13 | |
| Modelica.Units.SI.Length | h_lw | 0.35 | |
| Initialization | |||
| ThermalSeparation.Components.Reboiler.InitOptionEq | init_option | Enumerations.InitializationOption.init_x | initialization options |
| Real | eps_liq_init | initial value for eps_liq | |
| Modelica.Units.SI.Temperature | T_init | initial value fr Temperature | |
| Modelica.Units.SI.Pressure | p_init | initial value for pressure | |
| Real | fixed_mol_init | molarity of solvent | |
| Modelica.Units.SI.MoleFraction[nS] | x_total_start | mole fraction of component in vapour and liquid | |
| Advanced | |||
| Modelica.Units.SI.Temperature | T_ref | systemTS.T_ref | reference temperature |
| Initialization › Init. from constant value | |||
| Boolean | init_const_vdot | false | initialise from constant vapour volume flow rate |
| Modelica.Units.SI.VolumeFlowRate | vdot_v_const | 0.08 | volume flow rate |
| Real | omega_k | 0.05 | large value if change between constant and variable shall be steep |
| Real | omega_time | 50 | inflexion point of tanh function |
Connectors
| Type | Name | Default | Description |
|---|---|---|---|
| ThermalSeparation.Interfaces.GasPortOut | gasPortOut | ||
| ThermalSeparation.Interfaces.LiquidPortIn | liquidPortIn | ||
| ThermalSeparation.Interfaces.LiquidPortOut | liquidPortOut | ||
| Modelica.Thermal.HeatTransfer.Interfaces.HeatPort_a | heatPort |
Components
Contents
| Name | Description |
|---|---|
| MediumLiquid | |
| ThermoEquilibrium | |
| Reaction | |
| Col_Geometry | |
| InnerHT |