Vapor Cycle Library - Release Information

Version 1.2.2 contains the changes described below.

Improvements

  • Improved Modelica compliance
  • Improved documentation

Conversion of user libraries

There is no need for conversion of user libraries.

Requirements

Vapor Cycle 1.2.2 is based on the Modelon base library 2.3 and Modelica Standard Library 3.2.1. It can be combined with Liquid Cooling Library 1.4.1 and Heat Exchanger Library 1.4.

It has been tested with:

  • Dymola 2016 FD01
  • Dymola 2016

Improvements

  • Improved Modelica compliance.
  • Improved Tutorial.
  • Improved documentation for the heat exchangers.

Conversion of user libraries

There is no need for conversion of user libraries.

Base library

Vapor Cycle 1.2.1 is based on the Modelon base library 2.2 and Modelica Standard Library 3.2.1. It can be combined with Liquid Cooling Library 1.3.1 and Heat Exchanger Library 1.3.

This library has been tested with:

  • Dymola 2015 FD01
  • Dymola 2016

New features

  • A static reversible valve , which can be used in architectures that change operation mode.
  • A turbine model parametrized with a mass flow lookup table and a efficiency look up table.
  • A compressor model with a parametrisation suitable for dynamic compressors. It is parametrised with an isentropic efficiency table and a mass flow table.
  • An ORC example experiment has been added to the libary
  • A bend component has been added to the library.
  • A counterflow internal heat exhanger has been added to the library.
  • Visualizers for all working fluids have been added to the library.
  • The library contains a new User's Guide and two Tutorials.

Improvements

  • Turbine or the compressor face correct inlet density also for two-phase inlet now. The default characteristics however do not take into account performance deterioration because of liquid at the inlet.
  • All heat transfer correlations and pressure drop correlations for pipes have been moved in order to improve user friendliness when working with a combination of different Modelon libraries. Their description and information is updated. Running the included conversion script is necessary for this update.
  • The default two phase medium model has been changed from R134a, reference properties by Tillner-Roth to R134a, short form Helmholtz EOS by Span. Its accuracy is slightly lower but still more than sufficient more most applications. The simulation speed is increased significantly with the simpler model.
  • Both the receiver and accumulator can be initialized using a liquid level.
  • Adding specific interfaces to the heat exchanger models increased replaceability and reusability of the models in a system context.
  • The default air model is replaced with one, which is better suited for challenging steady-state initialization. Basically the same assumtions apply except that the new model neglects the liquid volume in case liquid water droplets are transported by the air stream and assumes that they do not influence the specific heat capacity. The previously used model can still be selected from a drop-down list.
  • The medium model for CO2 has an improved robustness around the critical point.

Fixed bugs

  • An error in the modified Dittus-Boelter function, which is used in heat transfer correlations for evaporation has been fixed. The change is expected to have an impact on heat exchanger results only, if the secondary side is not limiting the heat transfer.
  • A small error in the heat transfer correlation for both evaporation and condensation has been fixed. The change is expected to have an impact on heat exchanger results only if the secondary side is not limiting the heat transfer.

Conversion of user libraries

Automatic conversion of user libraries from version 1.1 is supported using the included conversion script convert_to_1.2.mos located under LibraryName\Resources\Scripts.

Base library

Vapor Cycle 1.2 is based on the Modelon base library 2.1 and Modelica Standard Library 3.2.1. It can be combined with Liquid Cooling Library 1.3. and Heat Exchanger Library 1.2.

This library has been tested with:

  • Dymola 2015 FD01
  • Dymola 2015