.Buildings.Fluid.Interfaces.PrescribedOutlet

Information

This model sets the temperature or the water vapor mass fraction of the medium that leaves port_a to the value given by the input TSet or X_wSet, subject to optional limitations on the capacity for heating and cooling, or limitations on the humidification or dehumidification moisture mass flow rate. Also, optionally the model allows to take into account first order dynamics.

If the parameters 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.

This model has no pressure drop. See Buildings.Fluid.HeatExchangers.PrescribedOutlet for a model that instantiates this model and that has a pressure drop.

In case of reverse flow, the fluid that leaves port_a has the same properties as the fluid that enters port_b.

Revisions

• March 3, 2022, by Michael Wetter:
  Removed massDynamics.
  This is for issue 1542.
• April 29, 2021, by Michael Wetter:
  Removed duplicate declaration of m_flow_nominal which is already declared in the base class.
  
• March 19, 2018, by Michael Wetter:
  Added bugfix as the old model did not track TSet and X_wSet simultaneously.
  This is for #893.
• May 3, 2017, by Michael Wetter:
  Refactored model to allow X_wSet as an input.
  This is for #763.
• January 26, 2016, by Michael Wetter:
  Removed inequality comparison of real numbers in restrictCool and in restrictHeat as this is not allowed in Modelica.
• November 10, 2014, by Michael Wetter:
  First implementation.