IdeallySeparated

Created Monday 10 June 2013

Ideal separation of the phases, level dependent states at the ports

1. Purpose of Model

The model is applied if phase separation dominates mixing effects (turbulence) due to slow velocities. Since the model implies the separability into two phases the applying model should ensure states in the two-phase region.

2. Physical Insight

This replaceable model is compatible to models of level of detail L2 according to Brunnemann et al. [1].

3. Limits of Validity

4. Interfaces


5. Nomenclature

6. Governing Equations


6.1 Determination of the port enthalpies

The specific enthalpy at the outlet port depends on the filling level in the vessel as illustrated below. A smooth transition between the two cases ensures robust and fast simulation.

6.2 Determination of the Filling Level

In order to derive a general form of filling level determination a concept based on pre-calculated geometry shapes is chosen here. The basic idea is to calculate the level from the liquid volume and an effective horizontal area. Thus, the actual, absolute filling level is defined as

For prismatic geometries like a vertically oriented cylinder or a block-shaped basin the effective horizontal area is a constant. In other cases, e.g. a horizontal oriented cylinder, this area depends on the level itself. It is then defined as

Obviously, the effective horizontal area is specific for every form of geometry. In order to keep the approach as general as possible the are pre-calculated and stored in the table shape. Thus, the effective horizontal area is calculated via

with the relative filling level

and the parameters and being a reference values for the horizontal area and the filling level, respectively.

7. Remarks for Usage

The model is compatible to control volumes of level of detail L2, e.g. ControlVolumes:FluidVolumes:VolumeVLE L2.

8. Validation


9. References

[1] Johannes Brunnemann and Friedrich Gottelt, Kai Wellner, Ala Renz, André Thüring, Volker Röder, Christoph Hasenbein, Christian Schulze, Gerhard Schmitz, Jörg Eiden: "Status of ClaRaCCS: Modelling and Simulation of Coal-Fired Power Plants with CO2 capture", 9th Modelica Conference, Munich, Germany, 2012

10. Authorship and Copyright Statement for original (initial) Contribution

Author:
DYNCAP/DYNSTART development team, Copyright 2011 - 2022.
Remarks:
This component was developed during DYNCAP/DYNSTART projects.
Acknowledgements:
ClaRa originated from the collaborative research projects DYNCAP and DYNSTART. Both research projects were supported by the German Federal Ministry for Economic Affairs and Energy (FKZ 03ET2009 and FKZ 03ET7060).
CLA:
The author(s) have agreed to ClaRa CLA, version 1.0. See https://claralib.com/pdf/CLA.pdf
By agreeing to ClaRa CLA, version 1.0 the author has granted the ClaRa development team a permanent right to use and modify his initial contribution as well as to publish it or its modified versions under the 3-clause BSD License.

11. Version History


Backlinks: ClaRa:Components:MechanicalSeparation:FeedWaterTank L2 ClaRa:Basics:ControlVolumes:FluidVolumes:VolumeVLE L2