modelTestFlow1D2phDB
Extends from Modelica.Icons.Example (Icon for runnable examples).
Information
The model is designed to test the component Flow1D2phDB (fluid side of a heat exchanger, finite volumes, two-phase flow, computation of the heat transfer coefficient).
This model represent the fluid side of a once-through boiler with an applied external linear temperature profile. The operating fluid is water.
The simulation proceeds through the following steps:
- t=0 s. The initial state of the water is subcooled liquid. After 40 seconds all the thermal transients have settled.
- t=100 s. Ramp increase of the external temperature profile. The water starts boiling at t=118 s. At the end of the transient (t=300) the outlet fluid is superheated vapour.
- t=500 s. Ramp decrease of the external temperature profile. After the transient has settled, the fluid in the boiler is again subcooled water.
During the transient it is possible to observe the change in the heat transfer coefficients when boiling takes place; note that the h.t.c.'s do not change abruptly due to the smoothing algorithm inside the Flow1D2phDB model.
Simulation Interval = [0...1000] sec
Integration Algorithm = DASSL
Algorithm Tolerance = 1e-8
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Real | pi | Modelica.Constants.pi | |
| Integer | Nnodes | 8 | |
| SI.Length | Lhex | 20 | |
| SI.Diameter | Dhex | 0.01 | |
| SI.Thickness | thhex | 0.002 | |
| SI.Radius | rhex | Dhex/2 | |
| SI.Length | omegahex | pi*Dhex | |
| SI.Area | Ahex | pi*rhex^2 | |
| SI.PerUnit | Cfhex | 0.005 |
Components
| Type | Name | Default | Description |
|---|---|---|---|
| Water.Flow1D2phDB | hex | ||
| ThermoPower.Water.ValveLin | valve | ||
| ThermoPower.Water.SinkPressure | Sink | ||
| Modelica.Blocks.Sources.Step | hIn | ||
| Modelica.Blocks.Sources.Ramp | extTemp1 | ||
| ThermoPower.Water.SourceMassFlow | Source | ||
| Modelica.Blocks.Sources.Ramp | extTemp2 | ||
| Modelica.Blocks.Math.Add | Add1 | ||
| Modelica.Blocks.Sources.Ramp | xValve | ||
| Thermal.MetalTube | Tube | ||
| Thermal.ConvHT_htc | htFluid | ||
| Thermal.ConvHT | htExt | ||
| Thermal.TempSource1Dlin | tempSource | ||
| Modelica.Blocks.Math.Add | Add2 | ||
| Modelica.Blocks.Sources.Constant | DT | ||
| System | system |
Contents
| Name | Description |
|---|---|
 Medium |
Revisions
- 4 Feb 2004 by Francesco Casella:
First release.