modelTwoElements

Thermal Zone with two elements for exterior and interior walls

Extends from OneElement (Thermal Zone with one element for exterior walls).

Information

This model distinguishes between internal thermal masses and exterior walls. While exterior walls contribute to heat transfer to the ambient, adiabatic conditions apply to internal masses. Parameters for the internal wall element are the length of the RC-chain nInt, the vector of the capacities CInt[nInt] and the vector of the resistances RInt[nInt]. This approach allows considering the dynamic behaviour induced by internal heat storage.

The image below shows the RC-network of this model.

Parameters

Type	Name	Default	Description
Boolean	use_moisture_balance (from OneElement)	false	If true, input connector QLat_flow is enabled and room air computes moisture balance
Dynamics › Conservation equations
Modelica.Fluid.Types.Dynamics	energyDynamics (from LumpedVolumeDeclarations)	Modelica.Fluid.Types.Dynamics.DynamicFreeInitial	Type of energy balance: dynamic (3 initialization options) or steady state
Modelica.Fluid.Types.Dynamics	substanceDynamics (from LumpedVolumeDeclarations)	energyDynamics	Type of independent mass fraction balance: dynamic (3 initialization options) or steady state
Modelica.Fluid.Types.Dynamics	traceDynamics (from LumpedVolumeDeclarations)	energyDynamics	Type of trace substance balance: dynamic (3 initialization options) or steady state
Advanced › Dynamics
Modelica.Fluid.Types.Dynamics	massDynamics (from LumpedVolumeDeclarations)	energyDynamics	Type of mass balance: dynamic (3 initialization options) or steady state, must be steady state if energyDynamics is steady state
Initialization
Medium.AbsolutePressure	p_start (from LumpedVolumeDeclarations)	Medium.p_default	Start value of pressure
Medium.Temperature	T_start (from LumpedVolumeDeclarations)	Medium.T_default	Start value of temperature
Medium.MassFraction[Medium.nX]	X_start (from LumpedVolumeDeclarations)	Medium.X_default	Start value of mass fractions m_i/m
Medium.ExtraProperty[Medium.nC]	C_start (from LumpedVolumeDeclarations)	fill(0, Medium.nC)	Start value of trace substances
Medium.ExtraProperty[Medium.nC]	C_nominal (from LumpedVolumeDeclarations)	fill(1E-2, Medium.nC)	Nominal value of trace substances. (Set to typical order of magnitude.)
Dynamics
Real	mSenFac (from LumpedVolumeDeclarations)	1	Factor for scaling the sensible thermal mass of the volume
Thermal zone
Modelica.Units.SI.Volume	VAir (from OneElement)		Air volume of the zone
Modelica.Units.SI.CoefficientOfHeatTransfer	hRad (from OneElement)		Coefficient of heat transfer for linearized radiation exchange between walls
Integer	nOrientations (from OneElement)		Number of orientations
General › Ports
Integer	nPorts (from OneElement)	0	Number of fluid ports
Windows
Modelica.Units.SI.Area[nOrientations]	AWin (from OneElement)		Vector of areas of windows by orientations
Modelica.Units.SI.Area[nOrientations]	ATransparent (from OneElement)		Vector of areas of transparent (solar radiation transmittend) elements by orientations
Modelica.Units.SI.CoefficientOfHeatTransfer	hConWin (from OneElement)		Convective coefficient of heat transfer of windows (indoor)
Modelica.Units.SI.ThermalResistance	RWin (from OneElement)		Resistor for windows
Modelica.Units.SI.TransmissionCoefficient	gWin (from OneElement)		Total energy transmittance of windows
Real	ratioWinConRad (from OneElement)		Ratio for windows between indoor convective and radiative heat emission
Boolean	indoorPortWin (from OneElement)	false	Additional heat port at indoor surface of windows
Exterior walls
Modelica.Units.SI.Area[nOrientations]	AExt (from OneElement)		Vector of areas of exterior walls by orientations
Modelica.Units.SI.CoefficientOfHeatTransfer	hConExt (from OneElement)		Convective coefficient of heat transfer of exterior walls (indoor)
Integer	nExt (from OneElement)		Number of RC-elements of exterior walls
Modelica.Units.SI.ThermalResistance[nExt]	RExt (from OneElement)		Vector of resistances of exterior walls, from inside to outside
Modelica.Units.SI.ThermalResistance	RExtRem (from OneElement)		Resistance of remaining resistor RExtRem between capacity n and outside
Modelica.Units.SI.HeatCapacity[nExt]	CExt (from OneElement)		Vector of heat capacities of exterior walls, from inside to outside
Boolean	indoorPortExtWalls (from OneElement)	false	Additional heat port at indoor surface of exterior walls
Advanced
Boolean	use_C_flow (from OneElement)	false	Set to true to enable input connector for trace substance
Interior walls
Modelica.Units.SI.Area	AInt		Area of interior walls
Modelica.Units.SI.CoefficientOfHeatTransfer	hConInt		Convective coefficient of heat transfer of interior walls (indoor)
Integer	nInt		Number of RC-elements of interior walls
Modelica.Units.SI.ThermalResistance[nInt]	RInt		Vector of resistances of interior walls, from port to center
Modelica.Units.SI.HeatCapacity[nInt]	CInt		Vector of heat capacities of interior walls, from port to center
Boolean	indoorPortIntWalls	false	Additional heat port at indoor surface of interior walls

Connectors

Type	Name	Description
Modelica.Blocks.Interfaces.RealInput[nOrientations]	solRad (from OneElement)	Solar radiation transmitted through windows
Modelica.Blocks.Interfaces.RealInput	QLat_flow (from OneElement)	Latent heat gains for the room
Modelica.Blocks.Interfaces.RealOutput	TAir (from OneElement)	Indoor air temperature
Modelica.Blocks.Interfaces.RealOutput	TRad (from OneElement)	Mean indoor radiation temperature
Modelica.Fluid.Vessels.BaseClasses.VesselFluidPorts_b[nPorts]	ports (from OneElement)	Auxiliary fluid inlets and outlets to indoor air volume
Modelica.Thermal.HeatTransfer.Interfaces.HeatPort_a	extWall (from OneElement)	Ambient port for exterior walls
Modelica.Thermal.HeatTransfer.Interfaces.HeatPort_a	window (from OneElement)	Ambient port for windows
Modelica.Thermal.HeatTransfer.Interfaces.HeatPort_a	intGainsConv (from OneElement)	Auxiliary port for sensible internal convective gains
Modelica.Thermal.HeatTransfer.Interfaces.HeatPort_a	intGainsRad (from OneElement)	Auxiliary port for internal radiative gains
Modelica.Thermal.HeatTransfer.Interfaces.HeatPort_a	windowIndoorSurface (from OneElement)	Auxiliary port at indoor surface of windows
Modelica.Thermal.HeatTransfer.Interfaces.HeatPort_a	extWallIndoorSurface (from OneElement)	Auxiliary port at indoor surface of exterior walls
Modelica.Blocks.Interfaces.RealInput	C_flow (from OneElement)	Trace substance mass flow rate added to the thermal zone
Modelica.Thermal.HeatTransfer.Interfaces.HeatPort_a	intWallIndoorSurface	Auxiliary port at indoor surface of interior walls

Components

Type	Name	Description
Fluid.MixingVolumes.MixingVolume	volAir (from OneElement)	Indoor air volume
Fluid.MixingVolumes.MixingVolumeMoistAir	volMoiAir (from OneElement)	Indoor air volume
Modelica.Thermal.HeatTransfer.Components.ThermalResistor	resWin (from OneElement)	Resistor for windows
Modelica.Thermal.HeatTransfer.Sources.PrescribedHeatFlow	convHeatSol (from OneElement)	Solar heat considered as convection
Modelica.Thermal.HeatTransfer.Sources.PrescribedHeatFlow[nOrientations]	radHeatSol (from OneElement)	Solar heat considered as radiation
BaseClasses.ThermSplitter	thermSplitterIntGains (from OneElement)	Splits incoming internal gains into separate gains for each wall element, weighted by their area
BaseClasses.ThermSplitter	thermSplitterSolRad (from OneElement)	Splits incoming solar radiation into separate gains for each wall element, weighted by their area
BaseClasses.ExteriorWall	extWallRC (from OneElement)	RC-element for exterior walls
BaseClasses.InteriorWall	intWallRC	RC-element for interior walls

Revisions

March 7, 2022, by Michael Wetter:
Removed massDynamics.
This is for #1542.
July 11, 2019, by Katharina Brinkmann:
Renamed alphaInt to hConInt, alphaIntWall to hConIntWall
January 25, 2019, by Michael Wetter:
Added start value to avoid warning in JModelica.
April 18, 2015, by Moritz Lauster:
First implementation.