NusseltShell1ph L2

Created Thursday 13 June 2013

Heat transfer model based on Nusselt Number for single-phase shell flow around a tube bundle. Takes Geometry data, flow data and media data into account.

1. Purpose of Model

A detailed model for shell geometries with a tube bundle, e.g. heat exchangers, that takes all relevant dependencies into account. This model is numerically less robust than other models, e.g HeatTransport:Generic HT:CharLine L2 since it takes fluid states and flow regimes into account.

2. Level of Detail and Physical Effects Considered


2.1 Level of Detail

Referring to Brunnemann et al. [1], this model refers to the level of detail L2 because the system is modeled with the use of balance equations, which are spatially averaged over the component.

2.2 Physical Effects Considered

3. Limits of Validity

  1. no two-phase flow allowed

4. Interfaces

The model communicates via outer models and records. Thus its expects to have:

It has further a Basics:Interfaces:HeatPort a heat that shall be connected with the applying component model.

5. Nomenclature

6. Governing Equations




with the characteristic length calculated as follows:

The average Nusselt number for the whole tube bundle (for the 1 phase area) is calculated according to:


The one phase Nusselt number is calculated as follows:

with

and

and

and


The heat transfer area can be changed with the integer parameter . The geometry record provides two areas, the lateral and the inner heat surface. The mean temperature difference is defined as follows, based on the user's choice in the boolean parameter temperatureDifference:

Please note that for the choice temperatureDifference="Logarithmic mean" a number of means is applied to make the equation regular also for zero heat flow and reversing heat flows. If an unsupported string for temperatureDifference is provided an assert would raise.

7. Remarks for Usage

Check the results for meaningfulness, if the equals 1, as the boundary conditions or valid ranges of the FluidDissipation models are violated.

8. Validation

see FluidDissipation documentation

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 Simulationof 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



Backlinks: ClaRa:Components:HeatExchangers:HEXvle2vle L3 1ph BU ntu ClaRa:Components:HeatExchangers:HEXvle2vle L3 1ph BU simple ClaRa:Components:HeatExchangers:IdealShell L2 ClaRa:Basics:ControlVolumes:FluidVolumes:VolumeVLE L2