This component defines the interface for models with four fluid ports and two fluid streams. It is similar to Buildings.Fluid.Interfaces.PartialTwoPortInterface, but it has four ports instead of two.
The model is used by other models in this package that add heat transfer, mass transfer and pressure drop equations.
allowFlowReversal==false, removed noEvent() declaration
for sta_a and for sta_b because the variable is either
already used with inStream() in the computation of state_*_inflow,
or the result of a variable of the model that already may generate an event.allowFlowReversal==false, replaced actualStream()
with inStream() for sta_a and
removed actualStream() for sta_b.HideResult=true.min and max
attributes of port mass flow rates, as this is already
done in the base class.
import Modelica.Constants; statement.
homotopyInitialization
as it is no longer used in this model.
sta_a1,
sta_a2, sta_b1 and sta_b2,
removed the branch that uses the homotopy operator.
The rational is that these variables are conditionally enables (because
of ... if show_T). Therefore, the Modelica Language Specification
does not allow for these variables to be used in any equation. Hence,
the use of the homotopy operator is not needed here.
noEvent to the computation of the states at the port.
This is correct, because the states are only used for reporting, but not
to compute any other variable.
Use of the states to compute other variables would violate the Modelica
language, as conditionally removed variables must not be used in any equation.
V_flow and removed the parameter
show_V_flow.
The reason is that the computation of V_flow required
the use of sta_a (to compute the density),
but sta_a is also a variable that is conditionally
enabled. However, this was not correct Modelica syntax as conditional variables
can only be used in a connect
statement, not in an assignment. Dymola 2014 FD01 beta3 is checking
for this incorrect syntax. Hence, V_flow was removed as its
conditional implementation would require a rather cumbersome implementation
that uses a new connector that carries the state of the medium.
dp1 and dp2 because they cause some problem with PyFMI.
Medium.density with
Medium1.density and Medium2.density.
Changed condition to remove sta_a1 and sta_a2 to also
compute the states at the inlet port if show_V_flow=true.
The previous implementation resulted in a translation error
if show_V_flow=true, but worked correctly otherwise
because the erroneous function call is removed if show_V_flow=false.
homotopy operator.
system.p_start
to Medium.p_default since HVAC models may have water and
air, which are typically at different pressures.
C and mC_flow.