BalanceTank L3

Created Dienstag 22 Dezember 2015

A liquid storage tank connected to the atmosphere or a gas piping system. Mass transfer between liquid and gas phase is not supported.

1. Purpose of Model

The model provides a mean to balance the water content of a steam cycle. For instance, the thermal degasification in deaerators or feed water tanks lead to a continuous loss of feed water which must be replaced from a reservoir. This reservoir can be modelled using the model presented here.

2. Level of Detail, Physical Effects Considered and Physical Insight

2.1 Level of Detail

Referring to Brunnemann et al. [1], this model refers to the level of detail L3 because the system is modelled with the use of balance equations for a fixed number of zones, namely the gas zone and the liquid zone.

2.2 Physical Effects Considered

dynamic mass conservation in the tank volume
dynamic energy conservation in the tank volume, neglecting changes in kinetic energy
energy storage in the surrounding metal walls
pressure differences due to friction and geodetic pressure (neglected for gas phase)
ideal phase separation
ideal mixing of the different inlet flows

2.3 Level of Insight

Heat Transfer

Currently, only simple models for heat transfer are supported. Future versions will support more models.

Pressure Loss

Currently, only simple models for pressure loss are available. Future versions may support more models. However, the geometric interpretation of the pressure loss is not always clear.

3. Limits of Validity

as evaporation of the liquid medium is not supported handling of incoming wet steam or water near the saturation temperature is not supported
if liquid water rises up to the venting connector the simulation will be aborted

4. Interfaces

5. Nomenclature

No specific nomenclature required.

6. Governing Equations

6.1 System Description and General Modelling Approach

This model instantiates Basics:ControlVolumes:FluidVolumes:VolumeVLEGas L3 and Basics:ControlVolumes:SolidVolumes:CylindricalThickWall L4

7. Remarks for Usage

The model is required if the steam cycle is open due to steam losses for instance in the deaerator or in any other vent valve in the system.

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

2014 - v 0.1 - Initial implementation - Friedrich Gottelt, XRG Simulation GmbH
28.04.2016 -v 1.1.1 - added optional visualisation and measurement conectors- Friedrich Gottelt, XRG Simulation GmbH

Backlinks: ClaRa:Basics:ControlVolumes:FluidVolumes:VolumeVLEGas L3