modelAirHeating
Example model with an air-based heating system that conditions a thermal zone in EnergyPlus
Extends from Modelica.Icons.Example.
Information
Example of one building with one thermal zone in which the room air temperature is controlled with a PI controller. Heating is provided through recirculated air. The control output is used to compute the set point for the supply air temperature, which is met by the heating coil. The setpoint for the room air temperature changes between day and night. The fan is either off, or operating on stage 1 or 2, depending on the output of the room temperature controller. The zone also has a constant air infiltration flow rate.
Note that for simplicity, the model has no cooling system. Therefore, in summer, the house overheats.
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| Modelica.Units.SI.Volume | VRoo | 453.138 | Room volume |
| Modelica.Units.SI.Area | AFlo | 185.834 | Floor area of the whole floor of the building |
| Modelica.Units.SI.MassFlowRate | mOut_flow_nominal | 0.3*VRoo*1.2/3600 | Outdoor air mass flow rate, assuming constant infiltration air flow rate |
| Modelica.Units.SI.MassFlowRate | mRec_flow_nominal | 8*VRoo*1.2/3600 | Nominal mass flow rate for recirculated air |
Components
| Type | Name | Default | Description |
|---|---|---|---|
| Building | building | Building model | |
| Buildings.ThermalZones.EnergyPlus_24_2_0.ThermalZone | zon | Thermal zone | |
| Buildings.Fluid.Movers.FlowControlled_m_flow | fan | Fan | |
| Buildings.Controls.OBC.CDL.Reals.Sources.Pulse | TSet | Setpoint for room air | |
| Buildings.Controls.OBC.CDL.Reals.PID | conPID | Controller for heater | |
| Buildings.Fluid.HeatExchangers.Heater_T | hea | Ideal heater | |
| Buildings.Fluid.Sources.Boundary_pT | pAtm | Boundary condition | |
| Buildings.Fluid.FixedResistances.PressureDrop | duc | Duct resistance (to decouple room and outside pressure) | |
| Buildings.Fluid.Sources.MassFlowSource_WeatherData | freshAir | Outside air supply | |
| Buildings.Controls.OBC.CDL.Reals.Hysteresis | sta1 | Hysteresis to switch on stage 1 | |
| Buildings.Controls.OBC.CDL.Conversions.BooleanToReal | mSetFan1_flow | Mass flow rate for 1st stage | |
| Buildings.Controls.OBC.CDL.Reals.Hysteresis | sta2 | Hysteresis to switch on stage 2 | |
| Buildings.Controls.OBC.CDL.Conversions.BooleanToReal | mSetFan2_flow | Mass flow rate added for 2nd stage | |
| Buildings.Controls.OBC.CDL.Reals.Add | m_fan_set | Mass flow rate for fan | |
| Buildings.Controls.OBC.CDL.Reals.Add | TAirLvgSet | Set point temperature for air leaving the heater | |
| Buildings.Controls.OBC.CDL.Reals.AddParameter | TSupMin | Minimum supply air temperature | |
| Modelica.Blocks.Sources.Constant[3] | qIntGai | Internal heat gains, set to zero because these are modeled in EnergyPlus | |
| Buildings.Controls.OBC.CDL.Reals.MultiplyByParameter | gai | Gain factor |
Contents
| Name | Description |
|---|---|
| Medium | Medium model |
Revisions
-
March 13, 2024, by Michael Wetter:
Updatedidffile to add insulation, and restricted capacity of heater.
This is for issue 3707. -
March 1, 2018, by Michael Wetter:
First implementation.