Model that allows specifying the temperature and mass fraction of the fluid
that leaves the model from port_b
.
This model forces the outlet temperature at port_b
to be equal to the temperature
of the input signal TSet
, subject to optional limits on the
heating or cooling capacity QMax_flow ≥ 0
and QMin_flow ≤ 0
.
Similarly than for the temperature,
this model also forces the outlet water mass fraction at port_b
to be
no lower than the
input signal X_wSet
, subject to optional limits on the
maximum water vapor mass flow rate that is added, as
described by the parameter mWatMax_flow
.
By default, the model has unlimited capacity, but control of temperature
and humidity can be subject to capacity limits, or be disabled.
The output signal Q_flow
is the heat added (for heating) or subtracted (for cooling)
to the medium if the flow rate is from port_a
to port_b
.
If the flow is reversed, then Q_flow=0
.
The outlet conditions at port_a
are not affected by this model.
If the parameter energyDynamics
is not equal to
Modelica.Fluid.Types.Dynamics.SteadyState
,
the component models the dynamic response using a first order differential equation.
The time constant of the component is equal to the parameter tau
.
This time constant is adjusted based on the mass flow rate using
τ_{eff} = τ |ṁ| ⁄ ṁ_{nom}
where τ_{eff} is the effective time constant for the given mass flow rate ṁ and τ is the time constant at the nominal mass flow rate ṁ_{nom}. This type of dynamics is equal to the dynamics that a completely mixed control volume would have.
Optionally, this model can have a flow resistance.
If no flow resistance is requested, set dp_nominal=0
.
For a model that uses a control signal u ∈ [0, 1] and multiplies this with the nominal heating or cooling power, use Buildings.Fluid.HeatExchangers.HeaterCooler_u
This model only adds or removes heat or water vapor for the flow from
port_a
to port_b
.
The enthalpy of the reverse flow is not affected by this model.
If this model is used to cool air below the dew point temperature, the water mass fraction will not change.
Note that for use_TSet = false
, the enthalpy of the leaving fluid
will not be changed, even if moisture is added. The enthalpy added (or removed)
by the change in humidity is neglected. To properly account for change in enthalpy
due to humidification, use instead
Buildings.Fluid.Humidifiers.SprayAirWasher_X.
The model has been validated against the analytical solution in the examples Buildings.Fluid.HeatExchangers.Validation.PrescribedOutlet and Buildings.Fluid.HeatExchangers.Validation.PrescribedOutlet_dynamic.
massDynamics
.use_dh
is no longer a parameter in the pressure drop model.