modelPartialFixedbedReactorIdealGas_L4
Extends from TransiEnt.Basics.Icons.FixedBedReactor_L4.
Information
1. Purpose of model
This partial model represents a discretized fixed bed reactor with reaction kinetics with constant effectiveness factors.
2. Level of detail, physical effects considered, and physical insight
The reactor is discretized and in each volume mass, impulse and energy balances are solved. These equations are taken from Nandasana et al. [1] except that the pressure loss is assumed to be constant and the effective reaction rates are calculated using constant effectiveness factors. Also the mass balances are stationary
so changes in density are neglected.
3. Limits of validity
The model is valid if the changes of the effectiveness factors and the pressure loss are negligible.
4. Interfaces
gasPortIn: ideal gas inlet
gasPortOut: ideal gas outlet
heat: heat port
5. Nomenclature
T[N_cv] "Gas and catalyst temperature in the control volumes"
p[N_cv] "Pressure in the control volumes"
xi[N_cv,N_comp-1] "Mass fraction in the control volumes"
6. Governing Equations
The used equations are described in [1] except for the changes described in 2. The pressure calculation for each volume can be done either using the pressure in the middle or at the end of the volume.
7. Remarks for Usage
(no remarks)
8. Validation
(no remarks)
9. References
[1] Nandasana, Anjana D.; Ray, Ajay K.; Gupta, Santosh K. (2003): Dynamic Model of an Industrial Steam Reformer and Its Use for Multiobjective Optimization. In: Ind. Eng. Chem. Res. 42 (17), S. 4028–4042. DOI: 10.1021/ie0209576.
10. Version History
Model created by Carsten Bode (c.bode@tuhh.de) on Tue Apr 05 2016
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Integer | N_comp | medium.nc | number of components |
| SI.CrossSection | A_c | N_tube*pi/4*dia_tube_i^2 | total crosssectional area of all reactor tubes |
| SI.Length | Delta_x | l/N_cv | Length of one control volume |
| Fundamental Definitions | |||
| TILMedia.GasTypes.BaseGas | medium | simCenter.gasModel2 | Medium model |
| Boolean | useHomotopy | simCenter.useHomotopy | true if homotopy should be used |
| Integer | N_cv | 1 | Number of control volumes |
| Integer | N_reac | Number of reactions | |
| Integer[N_reac,N_comp - 1] | nu | Matrix with stochiometric coefficients of all components-1 in all reactions | |
| SI.MolarEnergy[N_reac] | E_i | Activation energies | |
| SI.MolarEnthalpy[N_reac] | dH_R_i | Reaction enthalpies | |
| SI.Efficiency[N_cv,N_reac] | eff | Effectiveness factors for the reactions | |
| SI.PressureDifference | Delta_p | Total pressure loss over the reactor | |
| Integer | pressureCalculation | 1 | Method of pressure calculation |
| Geometry | |||
| Real | N_tube | Number of tubes | |
| SI.Diameter | dia_tube_i | Inner tube diameter | |
| SI.Length | l | Length of reactor | |
| Catalyst | |||
| SI.Diameter | dia_part | Equivalent pellet diameter | |
| SI.VolumeFraction | eps_bed | Bed porosity | |
| SI.VolumeFraction | eps_cat | Catalyst porosity | |
| SI.Density | d_cat | Density of catalyst particle | |
| SI.Density | d_bed | d_cat*(1 - eps_bed) | Density of fixed-bed |
| SI.SpecificHeatCapacity | cp_cat | Specific heat capacity of catalyst | |
| Nominal Values | |||
| SI.Temperature[N_cv] | T_nom | Nominal gas and catalyst temperature in the control volumes | |
| SI.Pressure[N_cv] | p_nom | Nominal pressure in the control volumes | |
| SI.MassFraction[N_cv,N_comp - 1] | xi_nom | Nominal values for mass fractions | |
Connectors
| Type | Name | Default | Description |
|---|---|---|---|
| TransiEnt.Basics.Interfaces.Gas.IdealGasEnthPortIn | gasPortIn | ||
| TransiEnt.Basics.Interfaces.Gas.IdealGasEnthPortOut | gasPortOut | ||
| Modelica.Thermal.HeatTransfer.Interfaces.HeatPort_a[N_cv] | heat |
Components
| Type | Name | Default | Description |
|---|---|---|---|
| TransiEnt.SimCenter | simCenter | ||
| SI.Temperature[N_cv] | T | Gas and catalyst temperature in the control volumes | |
| SI.Pressure[N_cv] | p | Pressure in the control volumes | |
| SI.MassFraction[N_cv,N_comp - 1] | xi | Mass fraction in the control volumes |