User manual

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• The parameter p_ambient, which is used in all air models, is propagated to the top
level of all heat exchangers. For numerical and efficiency reason this property is
constant and not the time-varying downstream pressure. Making this parameter
available at the component tops level makes it easier to simulate pressure levels
different to the atmospheric pressure. The default behavior of the models is not
influenced by this change.
• Stability state as advanced feature included in refrigerant channel models. The variable
twoPhaseFraction, which describes the fraction of a volume covered by two-phase
fluid, is turned into an additional state with an artificial delay. This can in some cases
avoid oscillations, which may occur for the hard-coupled dependency of the heat
transfer coefficient on the amount of evaporated or condensed refrigerant in the
volume. Note that activating this advanced feature may change the overall dynamic
behavior of the component. The default behavior of the affected components is not
influenced.
A conversion script is necessary (opens automatically) for used evaporation heat transfer
correlations, see note below.
3.6.2 DataFiles Library
A minor version 1.0.2 has been released.
3.6.3 Dymola Commands Library
A major version 1.1 has been released. For changes and improvements, see section “The
library DymolaCommands reviewed and updated, and automatically opened” starting on
page 21.
3.6.4 Electric Power Library
Version 2.2 of Electric Power library contains a number of improvements. Some examples:
TurboGroups package replaces Mechanics package
The package Mechanics has been replaced with a TurboGroups package. The reason for the
new package is that the Mechanics package was dedicated to construction of turbo groups
(turbines including a generator rotor) The Turbo groups are however used in all 3-phase
representations. This change should motivate the user to use dedicated mechanic libraries
for mechanics modeling.
The new TurboGroups package has the following structure:
• Actuators: Components used in experiments, e.g. tabular torque sources. No
equivalents are available in MSL (Modelica Standard Library).
• Gears: The gear components are of a specialized type, and cannot be replaced by the
MSL gear components.
• Shafts:
o ShaftNoMass is modelled as a spring, it now extends its MSL
equivalent Modelica.Mechanics.Rotational.Components.Spring.