modelTestFlow1Dfem2ph

Test case for Flow1D2ph

Extends from Modelica.Icons.Example (Icon for runnable examples).

Information

The model is designed to test the component Flow1D2ph (fluid side of a heat exchanger, finite volumes, two-phase flow).
This model represent the fluid side of a once-through boiler with an applied external heat flow. The operating fluid is water.
During the simulation, the inlet specific enthalpy and heat flux are changed, while maintaining the inlet flowrate constant:

  • t=0 s. The initial state of the water is subcooled liquid.
  • t=10 s. Ramp increase of the applied heat flow. The water starts boiling and is blown out of the outlet, whose pressure and flowrate undergo a transient increase. At the end of the transient the outlet fluid is in superheated vapour state.
  • t=30 s. Step increase of the inlet enthalpy
  • t=50 s. The heat flow is reduced to zero in 2s. The vapour collapses, causing a suddend decrease in the outlet pressure and flowrate, until the liquid fills again the entire boiler. At that instant, the pressure and flowrate rise again rapidly to the inlet values.

Simulation Interval = [0...80] sec
Integration Algorithm = DASSL
Algorithm Tolerance = 1e-6

Parameters

TypeNameDefaultDescription
IntegerNnodes11
SI.LengthLhex10
SI.DiameterDhex0.03
SI.Thicknessthhex1e-3
SI.RadiusrhexDhex/2
SI.LengthomegahexModelica.Constants.pi*Dhex
SI.AreaAhexModelica.Constants.pi*rhex^2
SI.PerUnitCfhex0.005
SI.SpecificEnthalpyhin6e5
SI.Pressurephex1e6
SI.MassFlowRatewhex1

Components

TypeNameDefaultDescription
Water.Flow1Dfem2phhex
Water.ValveLinvalve
Water.SinkPressureSink
Modelica.Blocks.Sources.StephIn
Modelica.Blocks.Sources.RampextPower
Water.SourceMassFlowSource
Modelica.Blocks.Sources.RampextPower2
Modelica.Blocks.Math.AddAdd1
Modelica.Blocks.Sources.RampxValve
Thermal.MetalTubeMetalWall
Thermal.HeatSource1DHeatSource1D1
Systemsystem

Contents

NameDescription
Medium

Revisions