Improvements

  • Improved robustness of steady state initialization of flat tube and plate heat exchangers.
  • The number of flattubes per pass is now a non-structural parameter when using the air side model for stand-alone heat exchangers. This means that the number of flattubes can be changed between simulations without re-compiling the model.
  • Improved Modelica compliance.

Fixed issues

  • Fixed an issue that pressure drop was over-estimated for multi layered flat tube heat exchangers. The affected correlations are the ones by Kim and Bullard, Chang and Hsu and Manglik and Bergles. Deprecated variants of these correlations have been included and user models will be converted to deprecated variants for result consistency. It is recommended to use the fixed versions for models that have not yet been calibrated. Single-layered components were note affected and will give equal results with fixed and deprecated correlations.
  • Fixed an issue that not all available correlations for air side pressure drop in flat tube heat exchangers would show up in the drop-down menu.

Conversion of user libraries

The provided conversion script can perform all required conversions of user models. The script is available at modelica://HeatExchanger/Resources/Scripts/Convert_to_1.5.mos

User models using correlations affected by the bugs described above will be converted to deprecated correlation models to avoid result differences after conversion.

Requirements

Heat Exchanger Library 1.5 is based on Modelon Base Library 2.5 and Modelica Standard Library 3.2.2.