modelBaseTube

Base class for spatial discretized tubes

Extends from SiemensPower.Utilities.BaseClasses.PartialTwoPortTransport (Base class for components with two fluid ports).

Information

This base class describes the geometry and most important variables for the water/steam flow in a pipe.
It will be a 1-dimensional flow model. In the derived class, the following quantities/equations have to be set:

  • pressure(s)
  • mass flow rate(s) + momentum balance(s) incl hydrostatic and friction pressure drop
  • mass densities d[1], ...d[numberOfNodes] for each cell + continuity equation(s)
  • specific enthalpies h[1], ..., h[numberOfNodes] (energy balances)

Author: Haiko Steuer SCD
Checked by:
Protection class: public

License, Copyright and Disclaimer


Licensed by Siemens AG under the Siemens Modelica License 2

Copyright 2007-2012 Siemens AG. All rights reserved.

This Modelica package is free software and the use is completely at your own risk; it can be redistributed and/or modified under the terms of the Siemens Modelica License 2. For license conditions (including the disclaimer of warranty) see Siemens Modelica License 2 .

Parameters

TypeNameDefaultDescription
RealgModelica.Constants.g_n
RealpiModelica.Constants.pi
IntegernumberOfNodes2Number of nodes for thermal variables
SI.LengthdiameterInnergeoPipe.d_out - 2*geoPipe.s
SI.LengthdzgeoPipe.L/numberOfNodes
SI.VolumeVgeoPipe.A*geoPipe.L
SI.AreaAgeoPipe.A
SI.VolumeVTotalgeoPipe.Nt*V
SI.VolumeVCellV/numberOfNodes
RealsinphigeoPipe.H/geoPipe.L
Initialization
Modelica.SIunits.MassFlowRatem_flow_start (from PartialTwoPortTransport)1Guess value for mass flow rate
Medium.AbsolutePressurepIn_start (from PartialTwoPortTransport)Medium.reference_pStart value of inlet pressure
Medium.AbsolutePressurepOut_start (from PartialTwoPortTransport)Medium.reference_pStart value of outlet pressure
BooleanuseTemperatureStartValue (from PartialTwoPortTransport)falseUse T_start if true, otherwise h_start
Medium.SpecificEnthalpyhIn_start (from PartialTwoPortTransport)if useTemperatureStartValue then Medium.specificEnthalpy_pTX(pIn_start, TIn_start, XIn_start) else Medium.h_defaultStart value of specific enthalpy
Medium.SpecificEnthalpyhOut_start (from PartialTwoPortTransport)if useTemperatureStartValue then Medium.specificEnthalpy_pTX(pOut_start, TOut_start, XOut_start) else Medium.h_defaultStart value of specific outlet enthalpy
Medium.TemperatureTIn_start (from PartialTwoPortTransport)if useTemperatureStartValue then Medium.reference_T else Medium.temperature_phX(pIn_start, hIn_start, XIn_start)Start value of temperature
Medium.TemperatureTOut_start (from PartialTwoPortTransport)if useTemperatureStartValue then Medium.reference_T else Medium.temperature_phX(pOut_start, hOut_start, XOut_start)Start value of outlet temperature
Medium.MassFraction[Medium.nX]XIn_start (from PartialTwoPortTransport)Medium.reference_XStart value of mass fractions m_i/m
Medium.MassFraction[Medium.nX]XOut_start (from PartialTwoPortTransport)Medium.reference_XStart value of mass fractions m_i/m
BooleaninitializeInletPressuretrueadd steady state equation for pressure
BooleaninitializeSteadyStateEnthalpiestruelets initialize der(h)=0
BooleaninitializeSteadyStateInletEnthalpytruesteady state initial condition for input enthalpy
Geometry and correlations
SiemensPower.Utilities.Structures.PipeGeogeoPipeGeometry of tube
Advanced › Initialization
Medium.SpecificEnthalpy[numberOfNodes]h_starthIn_start*ones(numberOfNodes) + (hOut_start - hIn_start)*equalCellDistributionguess values for initial enthalpy vector
SI.HeatFlowRate[numberOfNodes]Q_flow_start(hOut_start - hIn_start)*m_flow_start/(geoPipe.Nt*numberOfNodes)*ones(numberOfNodes)Detailed start values for heat flow
Advanced › Inner heat transfer
SI.AreaheatedAreageoPipe.Nt*geoPipe.L*Modelica.Constants.pi*diameterInnerTotal Area for heat transfer

Connectors

TypeNameDefaultDescription
Modelica.Fluid.Interfaces.FluidPort_aportIn (from PartialTwoPortTransport)Inlet port
Modelica.Fluid.Interfaces.FluidPort_bportOut (from PartialTwoPortTransport)Outlet port

Components

TypeNameDefaultDescription
Medium.SpecificEnthalpyhIn (from PartialTwoPortTransport)actual state at portIn
Medium.SpecificEnthalpyhOut (from PartialTwoPortTransport)actual state at portOut
SI.Pressuredp (from PartialTwoPortTransport)
Medium.BaseProperties[numberOfNodes]fluid
Medium.MassFlowRate[numberOfNodes]m_flows
Medium.Densityd_av
SI.SpecificVolumevol_av
SI.Pressuredpfric
SI.Pressuredphyd

Revisions

  • December 2006, added by Haiko Steuer