modelNaturalConvectionWithControl

A case of natural convection with feedback loop control

Extends from Buildings.ThermalZones.Detailed.Examples.FFD.Tutorial.NaturalConvection (Tutorial for Natural Convection case).

Information

This model tests the coupled simulation of Buildings.ThermalZones.Detailed.CFD with the FFD program by simulating natural convection in an empty room with a PI controller and a heater to maintain the temperature at room center to be 2°C.

The configuration of the simulation is the same as Buildings.ThermalZones.Detailed.Examples.FFD.Tutorial.NaturalConvection, except that a heater with PI controller is added to maintain the desired room temperature.

The temperature at the central room is sent to the PI controller as measured temperature. Based on the difference of set temperature and measured temperaure PI controller sends signal to the heater to yield the heat flow. The heat flow is then injected into the room through the heat port as convective heat flow. After receving the heat flow from Modelica, the FFD uniformly distributes it into the space.

Please note that roo.yCFD[1] is the temperature at the center of the room and roo.yCFD[2] is the velocity magnitude at the center of the room.

Figure (a) shows the velocity vectors and temperature contours in degree Celsius on the X-Z plane at Y = 0.5 m as simulated by the FFD.

image

Figure (a)

Parameters

TypeNameDefaultDescription
IntegernConExtWin (from NaturalConvection)0Number of constructions with a window
IntegernConBou (from NaturalConvection)0Number of surface that are connected to constructions that are modeled inside the room
IntegernSurBou (from NaturalConvection)6Number of surface that are connected to the room air volume
IntegernConExt (from NaturalConvection)0Number of exterior constructions withour a window
IntegernConPar (from NaturalConvection)0Number of partition constructions

Components

TypeNameDefaultDescription
Modelica.Blocks.Sources.ConstantqRadGai_flow (from NaturalConvection)Radiative heat gain
Modelica.Blocks.Sources.ConstantqConGai_flow (from NaturalConvection)Convective heat gain
Modelica.Blocks.Sources.ConstantqLatGai_flow (from NaturalConvection)Latent heat gain
Modelica.Blocks.Routing.Multiplex3multiplex3_1 (from NaturalConvection)
BoundaryConditions.WeatherData.ReaderTMY3weaDat (from NaturalConvection)
Buildings.ThermalZones.Detailed.CFDroo (from NaturalConvection)
HeatTransfer.Sources.FixedTemperatureTWesWal (from NaturalConvection)Boundary condition for the west wall
HeatTransfer.Sources.FixedTemperatureTEasWal (from NaturalConvection)Temperature of east wall
HeatTransfer.Sources.PrescribedHeatFlowpreHeatFlo
Buildings.Controls.Continuous.LimPIDconPID
Modelica.Blocks.Sources.ConstantTSetTemperature set point

Revisions

  • September 16, 2021, by Michael Wetter:
    Removed assignment of parameter lat as this is now obtained from the weather data reader.
    This is for IBPSA, #1477.
  • July 7, 2015 by Michael Wetter:
    Removed model for prescribed heat flow boundary condition as the value was zero and hence the model is not needed. This is for issue 439.
  • July 25, 2014 by Wangda Zuo and Michael Wetter:
    Removed the initial equation section as the assignment of roo.air.yCFD[1] is done in the base class.
  • May 7, 2014, by Wei Tian:
    First implementation.