PlateHEXvle2vle L4
Created Sunday 16 January 2022
A discretized plate HX model with VLE medium at both sides. A block-geometry with corrugated plate is assumed.
1. Purpose of Model
This model is well suited to model transients of commonly designed condensers/evaporators in vapour cycles.
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 L4 because the system is modelled with the use of balance equations applied to discretized vulumes on both VLE sides of the HX.
2.2 Physical Effects Considered
- dynamic conservation of energy (neglecting kinetic energy terms) in VLE flow (flow_a) and VLE flow (flow_b)
- dynamic conservation of mass (neglecting kinetic energy terms) in VLE flow (flow_a) and VLE flow (flow_b)
- taking static pressure differences due to friction losses and geostatic into account in VLE flow (flow_a) and VLE flow (flow_b)
- calculation of heat transfer resistance between the two flows is calculated applying corresponding HT model and considering plat wall conduction
2.3 Level of Insight
Heat Transfer
- Basics:ControlVolumes:Fundamentals:HeatTransport:Generic HT:Constant L4 : All Geo || HTC || Constant
Pressure Loss
- Basics:ControlVolumes:Fundamentals:PressureLoss:Generic PL:LinearPressureLoss L4 : Linear pressure loss based on nominal values
Phase Separation
Basics:ControlVolumes:Fundamentals:SpatialDistributionAspects:Homogeneous L4 : ideally mixed phases
Basics:ControlVolumes:Fundamentals:SpatialDistributionAspects:SimpleAnalyticalSlip L4 : slip model according to Zivi.
Heat Exchanger Type
- Counter flow
- Paralle flow
3. Limits of Validity
4. Interfaces
4.1 Physical Connectors
ClaRa.Basics:Interfaces:FluidPortIn In_a
ClaRa.Basics:Interfaces:FluidPortOut Out_a
ClaRa.Basics:Interfaces:FluidPortIn In_b
ClaRa.Basics:Interfaces:FluidPortOut Out_b
5. Nomenclature
- no model specific nomenclature -
6. Governing Equations
6.1 System Description and General model approach
The combined model consists of the following components:
Basics:ControlVolumes:FluidVolumes:VolumeVLE L4 : plate (flow_a) with Plate geo record.
Basics:ControlVolumes:FluidVolumes:VolumeVLE L4 : plate (flow_b) with Plate geo record.
Basics:ControlVolumes:SolidVolumes:ThinWall L4 : plate wall
VLE cell arrays (in both flows, i.e. flow_a and flow_b) are used to discretise the HX in flow direction.
Summary
A summary record is available which bundles important component values.
7. Remarks for Usage
The model of HX allow parallel and counter-current flow configuration.
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
[2] VDI Wärmeatlas, Verein Deutscher Ingenieure VDI-Gesellschaft Verfahrenstechnik und Chemieingenieurwesen (GVC), Springer Verlag, 10. Auflage, 2006
10. Authorship and Copyright Statement for original (initial) Contribution
Author:
ClaRa development team, Copyright 2017 - 2022.
Remarks:
This component was developed for ClaRa library.
Acknowledgements:
CLA:
11. Version History
Date - Version - Description of changes - author/revisor
17.01.2022 - v0.1 - initial implementation of the model - Ales Vojacek, XRG Simulation
Backlinks: ClaRa:A User Guide:Revisions:v1.8.0