JoinVLE L3 Y
Created Freitag 20 November 2015
Adiabatic VLE-fluid junction model describing a fluid volume with separate dynamic energy and mass balance for each phase.
1. Purpose of Model
The model is used as mixing component with a constant volume for two inlets. The model includes pressure losses and a non-ideal mixing model.
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.
2.2 Physical Effects Considered
- Conservation of mass for each phase
- Conservation of energy for each phase
- Reverse flow
- Pressure losses
- Non-ideal mixing
2.3 Level of Insight
Pressure Loss
- NoFriction : friction free flow between inlet and outlet Basics:ControlVolumes:Fundamentals:PressureLoss:Generic PL:NoFriction L3
- LinearPressureLoss : Linear pressure loss based on nominal values Basics:ControlVolumes:Fundamentals:PressureLoss:Generic PL:LinearParallelZones L3
- QuadraticNominalPoint: Based on nominal values Basics:ControlVolumes:Fundamentals:PressureLoss:Generic PL:QuadraticParallelZones L3
Spacial Distribution
3. Limits of Validity
- The equations imply that the outlet states equal the states in the balance equations - Not true for large volumes and high gradients.
- Heat losses/input.
- incoming two-phase flows are separated according to its steam quality to the two zones
- when load changes imply significant changes of the phase interaction then the validity of the model is questionable
- the mixing process is not determined by geometrical properties of the component, e.g. local position of flanges
4. Interfaces
4.1 Physical Connectors
- inlet1, inlet2 and outlet connectors combined for:
- Mass flow rate in the connection ports [kg/s].
- Thermodynamic pressure in the connection ports [Pa].
- Specific thermodynamic enthalpy close to the connection port s [J/kg].
- Medium properties at the ports.
5. Nomenclature
6. System Description and General model approach
The model uses the VolumeVLE L3 TwoZonesNPort volume element to model the mixing.
7. Remarks for Usage
In many cases positioning of pressure losses at the ports is crucial for the overall simulation performance. In some cases so-called DAE-index reduction problems are caused by inappropriate pressure loss positioning.To help the user with this issue the connections featuring a pressure loss between the respective port and the next pressure state are marked blue, see figure below.
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
- 03.03.2013 - v.0.1 - initial implementation -Friedrich Gottelt, XRG Simulation
- 26.06.2018 - v1.3.1 - added visualisers for inlet and outlet friction - Friedrich Gottelt, XRG Simulation