modelMoistAirInterface
Extends from Buildings.Utilities.IO.BCVTB.BaseClasses.FluidInterface (Partial class for fluid interface that can be coupled to BCVTB).
Information
This model allows interfacing to the Building Controls Virtual Test Bed an air-conditioning system that uses a medium model with water vapor concentration.The model takes as input signals the temperature and water vapor concentration and, optionally, a bulk mass flow rate into or out of the system boundary. The state of the fluid that flows out of this model will be at this temperature and water vapor concentration. The output of this model are the sensible and latent heat exchanged across the system boundary.
When used with the BCVTB, a building simulation program such as EnergyPlus may compute the room air temperatures and room air humidity rate, which is then used as an input to this model. The sensible and latent heat flow rates may be sent to EnergyPlus to couple the air-conditioning system to the energy balance of the building model.
Note: The EnergyPlus building simulation program outputs the
absolute humidity ratio in units of [kg/kg dry air]. Since
Modelica.Media uses [kg/kg total mass of air], this quantity
needs to be converted. The conversion can be done with the model
Buildings.Utilities.Psychrometrics.ToTotalAir.
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Integer | nPorts (from FluidInterface) | 0 | Number of ports |
| Boolean | use_m_flow_in (from FluidInterface) | false | Get the mass flow rate from the input connector |
| Modelica.Units.SI.MassFlowRate | m_flow (from FluidInterface) | 0 | Fixed mass flow rate going out of the fluid port |
| Nominal condition | |||
| Modelica.Units.SI.MassFlowRate | m_flow_nominal (from FluidInterface) | Nominal mass flow rate, used for regularization near zero flow | |
| Advanced | |||
| Modelica.Units.SI.MassFlowRate | m_flow_small (from FluidInterface) | 1E-4*m_flow_nominal | For bi-directional flow, temperature is regularized in the region |m_flow| < m_flow_small (m_flow_small > 0 required) |
Connectors
| Type | Name | Default | Description |
|---|---|---|---|
| Modelica.Blocks.Interfaces.RealInput | m_flow_in (from FluidInterface) | Prescribed mass flow rate | |
| Modelica.Blocks.Interfaces.RealInput | T_in (from FluidInterface) | Prescribed boundary temperature | |
| Modelica.Fluid.Interfaces.FluidPorts_b[nPorts] | ports (from FluidInterface) | ||
| Modelica.Blocks.Interfaces.RealOutput | HSen_flow (from FluidInterface) | Sensible enthalpy flow rate, positive if flow into the component | |
| Modelica.Blocks.Interfaces.RealOutput | HLat_flow | Latent enthalpy flow rate, positive if flow into the component | |
| Modelica.Blocks.Interfaces.RealInput | phi | Medium relative humidity |
Components
| Type | Name | Default | Description |
|---|---|---|---|
| Buildings.Fluid.Sensors.EnthalpyFlowRate[nPorts] | totEntFloRat (from FluidInterface) | Total enthalpy flow rate (sensible plus latent) | |
| Modelica.Blocks.Math.Sum | sumHTot_flow (from FluidInterface) | Sum of total enthalpy flow rates | |
| Buildings.Fluid.Sources.MassFlowSource_T | bou (from FluidInterface) | ||
| Buildings.Fluid.Sensors.SensibleEnthalpyFlowRate[nPorts] | senEntFloRat | Sensible enthalpy flow rates | |
| Modelica.Blocks.Math.Sum | sumHSen_flow | Sum of sensible enthalpy flow rates | |
| Modelica.Blocks.Math.Feedback | diff | Difference between total and sensible enthalpy flow rate | |
| Buildings.Utilities.Psychrometrics.X_pTphi | masFra | Mass fraction |
Revisions
-
May 1, 2013, by Michael Wetter:
Removed the medium declaration in the instance of the modelBuildings.Utilities.Psychrometrics.X_pTphias this model no longer allows to replace the medium. -
April 5, 2011, by Michael Wetter:
Added nominal values that are needed by the sensor. -
September 10, 2009, by Michael Wetter:
First implementation.