JoinVLE L2 flex
Created Thursday 13 June 2013
Adiabatic n-port VLE-fluid junction model describing a fluid volume with dynamic energy and mass balance neglecting pressure losses.
1. Purpose of Model
The model is used as mixing component with a constant volume for more than two inlets.
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 L2.
2.2 Physical Effects Considered
- Conservation of Mass
- Conservation of Energy
- Reverse flow
3. Limits of Validity
- Ideal mixing assumptions are not valid
- The equations imply that the outlet states equal the states in the balance equations - Not true for large volumes and high gradients.
- Pressure Loss
- Heat losses/input
4. Interfaces
4.1 Physical Connectors
- inlet, 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. Governing Equations
6.1 System Description and General model approach
The model describes an ideally stirred volume element with n connection ports.
6.2 Governing Model Equations
Conservation of Mass
The mass balance for the constant volume considers mass flows through the inlet and outlet connectors. The balance equation reads:
Conservation of Momentum
Pressure loss is neglected, thus
Conservation of Energy
The energy balance for the control volume considers incoming and outgoing enthalpy flow rates. Please note, there are two terms in the equations below that take the derivatives of density and pressure into account. These terms are derived from the total derivative of the inner energy of the zone and appear here due to the special choice of state variables as discussed in Basic Concepts of Modelling. The term with the density derivative can be deactivated with setting the parameter preciseTwoPhase in the expert setting dialog to false.Thus, the influence of h is removed from the right hand side of the equation.
The model's density is taken as an explicit function of the states its total derivative should be used for completeness of the model given by:
Chemistry
no chemistry is considered:
Summary
A summary is available including the following:
- an outline record:
- Basics:Records:FlangeVLE inlet, outlet
- Basics:Records:FluidVLE L2 bulk
7. Remarks for Usage
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 implemntation -Friedrich Gottelt, XRG Simulation
- 24.04.2017 - v1.2.2 - added noEvent to actualStream operator - Timm Hoppe, XRG Simulation