modelPipeFlow_L4_Simple_isoth
Extends from TransiEnt.Basics.Icons.PipeFlow_L4_Simple.
Information
1. Purpose of model
This model is an isothermal pipe with a given surrounding temperature.
2. Level of detail, physical effects considered, and physical insight
(no remarks)
3. Limits of validity
(no remarks)
4. Interfaces
gasportIn: inlet for real gas
gasportOut: outet for real gas
5. Nomenclature
(no remarks)
6. Governing Equations
(no remarks)
7. Remarks for Usage
Use of this model can lead to warnings like "Differentiating (if pipe_xy.iCom.m_flow_in[1] > 0.0 then junction_beforePipe.gasBulk.xi[1] else junction_beforePipe.gasBulk.xi[1]) under the assumption that it is continuous at switching.". This can be ignored as long as the composition is set to the same value in every component (even in sinks etc.).
8. Validation
(no remarks)
9. References
(no remarks)
10. Version History
Created by Carsten Bode (c.bode@tuhh.de), Sep 2019
Modified by Carsten Bode (c.bode@tuhh.de), May 2020 (added quasi-stationary equations and simplified equations for only dependent mass fractions)
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Fundamental Definitions | |||
| TILMedia.VLEFluidTypes.BaseVLEFluid | medium | simCenter.gasModel1 | Medium in the component |
| Boolean | constantComposition | simCenter.useConstCompInGasComp | true if composition of gas in the pipe is constant (xi_nom will be used) |
| Integer[:] | variableCompositionEntries | simCenter.variableCompositionEntriesGasPipes | Entries of medium vector which are supposed to be completely variable |
| Integer | massBalance | simCenter.massBalanceGasPipes | Mass balance and species balance fomulation |
| Boolean | frictionAtInlet | false | True if pressure loss between first cell and inlet shall be considered |
| Boolean | frictionAtOutlet | false | True if pressure loss between last cell and outlet shall be considered |
| SI.Temperature | T_ground | simCenter.T_ground | Temperature of the surrounding ground |
| Nominal Values | |||
| ClaRa.Basics.Units.Pressure[N_cv] | p_nom | ones(N_cv)*1e5 | Nominal pressure |
| ClaRa.Basics.Units.EnthalpyMassSpecific[N_cv] | h_nom | ones(N_cv)*1e5 | Nominal specific enthalpy for single tube |
| ClaRa.Basics.Units.MassFlowRate | m_flow_nom | 100 | Nominal mass flow w.r.t. all parallel tubes |
| ClaRa.Basics.Units.PressureDifference | Delta_p_nom | 1e4 | Nominal pressure loss w.r.t. all parallel tubes |
| ClaRa.Basics.Units.MassFraction[medium.nc - 1] | xi_nom | medium.xi_default | Nominal composition |
| Geometry | |||
| ClaRa.Basics.Units.Length | length | 10e3 | Length of the pipe (one pass) |
| ClaRa.Basics.Units.Length | diameter_i | 0.5 | Inner diameter of the pipe |
| ClaRa.Basics.Units.Length | z_in | 0.1 | Height of inlet above ground |
| ClaRa.Basics.Units.Length | z_out | 0.1 | Height of outlet above ground |
| Integer | N_tubes | 1 | Number Of parallel pipes |
| Integer | N_passes | 1 | Number of passes of the tubes |
| Discretisation | |||
| Integer | N_cv | 3 | Number of finite volumes (for N_cv=1 set frictionAtInlet=true or frictionAtOutlet=true) |
| ClaRa.Basics.Units.Length[N_cv] | Delta_x | ClaRa.Basics.Functions.GenerateGrid({0}, length*N_passes, N_cv) | Discretisation scheme |
| Initialisation | |||
| Integer | initOption | simCenter.initOptionGasPipes | Type of initialization |
| ClaRa.Basics.Units.EnthalpyMassSpecific[N_cv] | h_start | TILMedia.Internals.VLEFluidConfigurations.FullyMixtureCompatible.VLEFluidFunctions.specificEnthalpy_pTxi(medium, p_start, T_start, xi_nom) | Initial specific enthalpy for single tube |
| ClaRa.Basics.Units.Pressure[N_cv] | p_start | ones(N_cv)*(simCenter.p_eff_2 + simCenter.p_amb_const) | Initial pressure |
| ClaRa.Basics.Units.MassFraction[medium.nc - 1] | xi_start | xi_nom | Initial composition for single tube |
| ClaRa.Basics.Units.MassFlowRate[N_cv + 1] | m_flow_start | ones(N_cv + 1)*0.01 | Initial mass flow rate |
| SI.Temperature[N_cv] | T_start | ones(N_cv)*T_ground | Initial temperature for single tube (used in calculation of h_start) |
| Initialisation › Model Settings | |||
| Boolean | useHomotopy | simCenter.useHomotopy | true, if homotopy method is used during initialisation |
| Summary and Visualisation | |||
| Boolean | showExpertSummary | simCenter.showExpertSummary | True, if an extended summary shall be shown, else false |
| Boolean | showData | false | True, if a data port containing p,T,h,s,m_flow shall be shown, else false |
| Boolean | contributeToCycleSummary | simCenter.contributeToCycleSummary | True if component shall contribute to automatic efficiency calculation |
| Boolean | heatFlowIsLoss | true | True if negative heat flow is a loss (not a process product) |
Connectors
| Type | Name | Default | Description |
|---|---|---|---|
| TransiEnt.Basics.Interfaces.Gas.RealGasPortIn | gasPortIn | Inlet port | |
| TransiEnt.Basics.Interfaces.Gas.RealGasPortOut | gasPortOut | Outlet port |
Components
| Type | Name | Default | Description |
|---|---|---|---|
| TransiEnt.SimCenter | simCenter | ||
| TransiEnt.Components.Gas.VolumesValvesFittings.Pipes.PipeFlow_L4_Simple | pipe | ||
| Modelica.Blocks.Sources.RealExpression | realExpression | ||
| Storage.Gas.Base.ConstantHTOuterTemperature_L2 | ht |
Contents
| Name | Description |
|---|---|
 PressureLoss | |
 MechanicalEquilibrium | |
 CostSpecsGeneral |