Drum L3

Created Mittwoch 21 Juni 2017

A drum model with non-ideal phase separation depending on the filling level. Ports for feedwater inlet, steam outlet, riser and downcomer are supported.

1. Purpose of Model

There are three different types of drums [1]. They differ in the internal installations which enhance the phase separation. Drums for pressures below 150 bar are equipped with demisters. Above these pressures internal cyclones are used. All types can be modelled with this component model. The characteristics of the heat and mass transfer between the liquid and vapour phase are defined in the three cases by varying the parameters in the parameter dialogue's tab "Phase Separation".

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

2.1 Level of Detail

Referring to Brunnemann et al. [2], this model refers to the level of detail L3 because the system is modelled with the use of balance equations applied to two distinct zones, i.e. the vapour volume and the liquid volume.

2.2 Physical Effects Considered

dynamic mass conservation in the vapour and liquid volume
dynamic energy conservation in the vapour and liquid volume, neglecting changes in kinetic energy
pressure differences due to friction and geostatic pressure
non-ideal, level-dependent phase separation
energy storage in the tank walls
optional insulation and heat losses to the environment

2.3 Level of Insight

Heat Transfer

Pressure Loss

PhaseSeparation

RealSeparated: non-ideal phase separation, state at ports depend on filling level and state of the distinct zones.

3. Limits of Validity

the phase separation model assumes constant values for the inter-phase heat transfer and the time constants for mass transfer between the phases.

4. Interfaces

5. Nomenclature

6. Governing Equations

6.1 System Description and General model approach

The model applies balances for mass and energy for the tank volume. There is separate balancing of steam and liquid phase. The model instantiates a Basics:ControlVolumes:FluidVolumes:VolumeVLE L3 TwoZonesNPort

6.2 General Model Equations

The heat losses to the ambient are calculated as follows

Summary

A summary is available including the following:

an outline record:

and three records of type Basics:Records:FlangeVLE named riser, down, sat and feedwater
please note that there is further summary data available from the instantiated class Basics:ControlVolumes:FluidVolumes:VolumeVLE L3 TwoZones

7. Remarks for Usage

it is strongly recommended to initialise this model with a fixed level.
see phase separation model for usage of Phase Separation parameters

8. Validation

9. References

[1] Karl Strauß: "Power Plant Technology for Exploitation of Fossil, Nuclear and Regenerative Energy" (in German), Springer, 6th edition, 2009.

[2] 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

2012 -v 0.1 - initial implementation - Friedrich Gottelt, XRG Simulation
21.06.2017 -v 1.2.2

- propagated m_flow_nom as top level parameter
- propagated mass struc, added cylinder's top and bottom wall mass
- added optional heat losses and insulation - Timm Hoppe, XRG Simulation

26.03.2019 -v 1.4.0 - parameters equalPressures and alpha_ph propagated - Timm Hoppe, XRG Simulation