Buildings.ThermalZones.ReducedOrder.RC
Package with reduced order thermal zones based on VDI 6007 Part 1
Information
This package contains the core of Reduced Order Models (ROM) that dynamically calculate the thermal behaviour of building mass.
Extends from Modelica.Icons.VariantsPackage (Icon for package containing variants).
Package Content
| Name | Description |
|---|---|
 UsersGuide
|
User's Guide |
 FourElements
|
Thermal Zone with four elements for exterior walls, interior walls, floor plate and roof |
 OneElement
|
Thermal Zone with one element for exterior walls |
 ThreeElements
|
Thermal Zone with three elements for exterior walls, interior walls and floor plate |
 TwoElements
|
Thermal Zone with two elements for exterior and interior walls |
 BaseClasses
|
Package with base classes for ROM |
Buildings.ThermalZones.ReducedOrder.RC.FourElements
Thermal Zone with four elements for exterior walls,
interior walls, floor plate and roof
Information
This model adds another element for the roof. Roofs commonly
exhibit the same excitations as exterior walls but have different coefficients
of heat transfer due to their orientation. Adding an extra element for the roof
might lead to a finer resolution of the dynamic behaviour but increases
calculation times. The roof is parameterized via the length of the RC-chain
nRoof,
the vector of capacities CRoof[nRoof], the vector of resistances
RRoof[nRoof] and remaining resistances RRoofRem.
The image below shows the RC-network of this model.
Extends from ThreeElements (Thermal Zone with three elements for exterior walls, interior walls and floor plate).
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| replaceable package Medium | PartialMedium | Medium in the component | |
| Thermal zone | |||
| Volume | VAir | Air volume of the zone [m3] | |
| CoefficientOfHeatTransfer | alphaRad | Coefficient of heat transfer for linearized radiation exchange between walls [W/(m2.K)] | |
| Integer | nOrientations | Number of orientations | |
| Windows | |||
| Area | AWin[nOrientations] | Vector of areas of windows by orientations [m2] | |
| Area | ATransparent[nOrientations] | Vector of areas of transparent (solar radiation transmittend) elements by orientations [m2] | |
| CoefficientOfHeatTransfer | alphaWin | Convective coefficient of heat transfer of windows (indoor) [W/(m2.K)] | |
| ThermalResistance | RWin | Resistor for windows [K/W] | |
| TransmissionCoefficient | gWin | Total energy transmittance of windows [1] | |
| Real | ratioWinConRad | Ratio for windows between indoor convective and radiative heat emission | |
| Boolean | indoorPortWin | false | Additional heat port at indoor surface of windows |
| Exterior walls | |||
| Area | AExt[nOrientations] | Vector of areas of exterior walls by orientations [m2] | |
| CoefficientOfHeatTransfer | alphaExt | Convective coefficient of heat transfer of exterior walls (indoor) [W/(m2.K)] | |
| Integer | nExt | Number of RC-elements of exterior walls | |
| ThermalResistance | RExt[nExt] | Vector of resistances of exterior walls, from inside to outside [K/W] | |
| ThermalResistance | RExtRem | Resistance of remaining resistor RExtRem between capacity n and outside [K/W] | |
| HeatCapacity | CExt[nExt] | Vector of heat capacities of exterior walls, from inside to outside [J/K] | |
| Boolean | indoorPortExtWalls | false | Additional heat port at indoor surface of exterior walls |
| Interior walls | |||
| Area | AInt | Area of interior walls [m2] | |
| CoefficientOfHeatTransfer | alphaInt | Convective coefficient of heat transfer of interior walls (indoor) [W/(m2.K)] | |
| Integer | nInt | Number of RC-elements of interior walls | |
| ThermalResistance | RInt[nInt] | Vector of resistances of interior walls, from port to center [K/W] | |
| HeatCapacity | CInt[nInt] | Vector of heat capacities of interior walls, from port to center [J/K] | |
| Boolean | indoorPortIntWalls | false | Additional heat port at indoor surface of interior walls |
| Floor plate | |||
| Area | AFloor | Area of floor plate [m2] | |
| CoefficientOfHeatTransfer | alphaFloor | Convective coefficient of heat transfer of floor plate (indoor) [W/(m2.K)] | |
| Integer | nFloor | Number of RC-elements of floor plate | |
| ThermalResistance | RFloor[nExt] | Vector of resistances of floor plate, from inside to outside [K/W] | |
| ThermalResistance | RFloorRem | Resistance of remaining resistor RFloorRem between capacity n and outside [K/W] | |
| HeatCapacity | CFloor[nExt] | Vector of heat capacities of floor plate, from inside to outside [J/K] | |
| Boolean | indoorPortFloor | false | Additional heat port at indoor surface of floor plate |
| Roof | |||
| Area | ARoof | Area of roof [m2] | |
| CoefficientOfHeatTransfer | alphaRoof | Convective coefficient of heat transfer of roof (indoor) [W/(m2.K)] | |
| Integer | nRoof | Number of RC-elements of roof | |
| ThermalResistance | RRoof[nExt] | Vector of resistances of roof, from inside to outside [K/W] | |
| ThermalResistance | RRoofRem | Resistance of remaining resistor RRoofRem between capacity n and outside [K/W] | |
| HeatCapacity | CRoof[nExt] | Vector of heat capacities of roof, from inside to outside [J/K] | |
| Boolean | indoorPortRoof | false | Additional heat port at indoor surface of roof |
| Dynamics | |||
| Equations | |||
| Dynamics | energyDynamics | Modelica.Fluid.Types.Dynamic... | Type of energy balance: dynamic (3 initialization options) or steady state |
| Dynamics | massDynamics | energyDynamics | Type of mass balance: dynamic (3 initialization options) or steady state |
| Real | mSenFac | 1 | Factor for scaling the sensible thermal mass of the volume |
| Initialization | |||
| AbsolutePressure | p_start | Medium.p_default | Start value of pressure [Pa] |
| Temperature | T_start | Medium.T_default | Start value of temperature [K] |
| MassFraction | X_start[Medium.nX] | Medium.X_default | Start value of mass fractions m_i/m [kg/kg] |
| ExtraProperty | C_start[Medium.nC] | fill(0, Medium.nC) | Start value of trace substances |
| ExtraProperty | C_nominal[Medium.nC] | fill(1E-2, Medium.nC) | Nominal value of trace substances. (Set to typical order of magnitude.) |
Connectors
| Type | Name | Description |
|---|---|---|
| input RealInput | solRad[nOrientations] | Solar radiation transmitted through windows [W/m2] |
| output RealOutput | TAir | Indoor air temperature [K] |
| output RealOutput | TRad | Mean indoor radiation temperature [K] |
| VesselFluidPorts_b | ports[nPorts] | Auxiliary fluid inlets and outlets to indoor air volume |
| HeatPort_a | extWall | Ambient port for exterior walls |
| HeatPort_a | window | Ambient port for windows |
| HeatPort_a | intGainsConv | Auxiliary port for internal convective gains |
| HeatPort_a | intGainsRad | Auxiliary port for internal radiative gains |
| HeatPort_a | windowIndoorSurface | Auxiliary port at indoor surface of windows |
| HeatPort_a | extWallIndoorSurface | Auxiliary port at indoor surface of exterior walls |
| HeatPort_a | intWallIndoorSurface | Auxiliary port at indoor surface of interior walls |
| HeatPort_a | floor | Ambient port for floor plate |
| HeatPort_a | floorIndoorSurface | Auxiliary port at indoor surface of floor plate |
| HeatPort_a | roof | Ambient port for roof |
| HeatPort_a | roofIndoorSurface | Auxiliary port at indoor surface of roof |
Modelica definition
model FourElements "Thermal Zone with four elements for exterior walls,
interior walls, floor plate and roof"
extends ThreeElements(AArray={ATotExt,ATotWin,AInt,AFloor,ARoof});
parameter Modelica.SIunits.Area ARoof "Area of roof";
parameter Modelica.SIunits.CoefficientOfHeatTransfer alphaRoof
"Convective coefficient of heat transfer of roof (indoor)";
parameter Integer nRoof(min=1) "Number of RC-elements of roof";
parameter Modelica.SIunits.ThermalResistance RRoof[nExt](each min=Modelica.Constants.small)
"Vector of resistances of roof, from inside to outside";
parameter Modelica.SIunits.ThermalResistance RRoofRem(min=Modelica.Constants.small)
"Resistance of remaining resistor RRoofRem between capacity n and outside";
parameter Modelica.SIunits.HeatCapacity CRoof[nExt](each min=Modelica.Constants.small)
"Vector of heat capacities of roof, from inside to outside";
parameter Boolean indoorPortRoof=false
"Additional heat port at indoor surface of roof";
Modelica.Thermal.HeatTransfer.Interfaces.HeatPort_a roof if ARoof > 0
"Ambient port for roof";
Modelica.Thermal.HeatTransfer.Interfaces.HeatPort_a roofIndoorSurface if
indoorPortRoof "Auxiliary port at indoor surface of roof";
BaseClasses.ExteriorWall roofRC(
final RExt=RRoof,
final RExtRem=RRoofRem,
final CExt=CRoof,
final n=nRoof,
final T_start=T_start) if ARoof > 0 "RC-element for roof";
protected
Modelica.Thermal.HeatTransfer.Components.Convection convRoof if ARoof > 0
"Convective heat transfer of roof";
Modelica.Blocks.Sources.Constant alphaRoofConst(final k=ARoof*alphaRoof) if
ARoof > 0 "Coefficient of convective heat transfer for roof";
Modelica.Thermal.HeatTransfer.Components.ThermalConductor resIntRoof(final G=
min(AInt, ARoof)*alphaRad) if AInt > 0 and ARoof > 0
"Resistor between interior walls and roof";
Modelica.Thermal.HeatTransfer.Components.ThermalConductor resRoofWin(final G=
min(ARoof, ATotWin)*alphaRad) if ARoof > 0 and ATotWin > 0
"Resistor between roof and windows";
Modelica.Thermal.HeatTransfer.Components.ThermalConductor resRoofFloor(final
G=min(ARoof, AFloor)*alphaRad) if ARoof > 0 and AFloor > 0
"Resistor between floor plate and roof";
Modelica.Thermal.HeatTransfer.Components.ThermalConductor resExtWallRoof(
final G=min(ATotExt, ARoof)*alphaRad) if ATotExt > 0 and ARoof > 0
"Resistor between exterior walls and roof";
equation
connect(convRoof.solid, roofRC.port_b);
connect(roofRC.port_a, roof);
connect(resRoofWin.port_a, convWin.solid);
connect(resRoofWin.port_b, convRoof.solid);
connect(resRoofFloor.port_a, convRoof.solid);
connect(resRoofFloor.port_b, resExtWallFloor.port_b);
connect(resIntRoof.port_b, intWallRC.port_a);
connect(resIntRoof.port_a, convRoof.solid);
connect(resExtWallRoof.port_a, convExtWall.solid);
connect(resExtWallRoof.port_b, convRoof.solid);
if not ATotExt > 0 and not ATotWin > 0 and not AInt > 0 and not AFloor > 0
and ARoof > 0 then
connect(thermSplitterIntGains.portOut[1], roofRC.port_a);
connect(roofRC.port_a, thermSplitterSolRad.portOut[1]);
elseif ATotExt > 0 and not ATotWin > 0 and not AInt > 0 and not AFloor > 0
and ARoof > 0 or not ATotExt > 0 and ATotWin > 0 and not AInt > 0 and
not AFloor > 0 and ARoof > 0 or not ATotExt > 0 and not ATotWin > 0 and
AInt > 0 and not AFloor > 0 and ARoof > 0 or not ATotExt > 0 and not
ATotWin > 0 and not AInt > 0 and AFloor > 0 and ARoof > 0 then
connect(thermSplitterIntGains.portOut[2], roofRC.port_a);
connect(roofRC.port_a, thermSplitterSolRad.portOut[2]);
elseif ATotExt > 0 and ATotWin > 0 and not AInt > 0 and not AFloor > 0 and
ARoof > 0 or ATotExt > 0 and not ATotWin > 0 and AInt > 0 and not AFloor >
0 and ARoof > 0 or ATotExt > 0 and not ATotWin > 0 and not AInt > 0 and
AFloor > 0 and ARoof > 0 or not ATotExt > 0 and ATotWin > 0 and AInt > 0
and not AFloor > 0 and ARoof > 0 or not ATotExt > 0 and ATotWin > 0 and
not AInt > 0 and AFloor > 0 and ARoof > 0 or not ATotExt > 0 and not
ATotWin > 0 and AInt > 0 and AFloor > 0 and ARoof > 0 then
connect(thermSplitterIntGains.portOut[3], roofRC.port_a);
connect(roofRC.port_a, thermSplitterSolRad.portOut[3]);
elseif not ATotExt > 0 and ATotWin > 0 and AInt > 0 and AFloor > 0 and ARoof >
0 or ATotExt > 0 and not ATotWin > 0 and AInt > 0 and AFloor > 0 and
ARoof > 0 or ATotExt > 0 and ATotWin > 0 and not AInt > 0 and AFloor > 0
and ARoof > 0 or ATotExt > 0 and ATotWin > 0 and AInt > 0 and not AFloor >
0 and ARoof > 0 then
connect(thermSplitterIntGains.portOut[4], roofRC.port_a);
connect(roofRC.port_a, thermSplitterSolRad.portOut[4]);
elseif ATotExt > 0 and ATotWin > 0 and AInt > 0 and AFloor > 0 and ARoof > 0
then
connect(thermSplitterSolRad.portOut[5], roofRC.port_b);
connect(thermSplitterIntGains.portOut[5], roofRC.port_b);
end if;
connect(alphaRoofConst.y, convRoof.Gc);
connect(convRoof.fluid, senTAir.port);
connect(roofRC.port_b, roofIndoorSurface);
end FourElements;
Buildings.ThermalZones.ReducedOrder.RC.OneElement
Thermal Zone with one element for exterior walls
Information
This model merges all thermal masses into one
element, parameterized by the length of the RC-chain
nExt, the vector of the capacities CExt[nExt] that is
connected via the vector of resistances RExt[nExt] and
RExtRem to the ambient and indoor air.
By default, the model neglects all
internal thermal masses that are not directly connected to the ambient.
However, the thermal capacity of the room air can be increased by
using the parameter mSenFac.
The image below shows the RC-network of this model.
Extends from Buildings.Fluid.Interfaces.LumpedVolumeDeclarations (Declarations for lumped volumes).
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| replaceable package Medium | PartialMedium | Medium in the component | |
| Thermal zone | |||
| Volume | VAir | Air volume of the zone [m3] | |
| CoefficientOfHeatTransfer | alphaRad | Coefficient of heat transfer for linearized radiation exchange between walls [W/(m2.K)] | |
| Integer | nOrientations | Number of orientations | |
| Windows | |||
| Area | AWin[nOrientations] | Vector of areas of windows by orientations [m2] | |
| Area | ATransparent[nOrientations] | Vector of areas of transparent (solar radiation transmittend) elements by orientations [m2] | |
| CoefficientOfHeatTransfer | alphaWin | Convective coefficient of heat transfer of windows (indoor) [W/(m2.K)] | |
| ThermalResistance | RWin | Resistor for windows [K/W] | |
| TransmissionCoefficient | gWin | Total energy transmittance of windows [1] | |
| Real | ratioWinConRad | Ratio for windows between indoor convective and radiative heat emission | |
| Boolean | indoorPortWin | false | Additional heat port at indoor surface of windows |
| Exterior walls | |||
| Area | AExt[nOrientations] | Vector of areas of exterior walls by orientations [m2] | |
| CoefficientOfHeatTransfer | alphaExt | Convective coefficient of heat transfer of exterior walls (indoor) [W/(m2.K)] | |
| Integer | nExt | Number of RC-elements of exterior walls | |
| ThermalResistance | RExt[nExt] | Vector of resistances of exterior walls, from inside to outside [K/W] | |
| ThermalResistance | RExtRem | Resistance of remaining resistor RExtRem between capacity n and outside [K/W] | |
| HeatCapacity | CExt[nExt] | Vector of heat capacities of exterior walls, from inside to outside [J/K] | |
| Boolean | indoorPortExtWalls | false | Additional heat port at indoor surface of exterior walls |
| Dynamics | |||
| Equations | |||
| Dynamics | energyDynamics | Modelica.Fluid.Types.Dynamic... | Type of energy balance: dynamic (3 initialization options) or steady state |
| Dynamics | massDynamics | energyDynamics | Type of mass balance: dynamic (3 initialization options) or steady state |
| Real | mSenFac | 1 | Factor for scaling the sensible thermal mass of the volume |
| Initialization | |||
| AbsolutePressure | p_start | Medium.p_default | Start value of pressure [Pa] |
| Temperature | T_start | Medium.T_default | Start value of temperature [K] |
| MassFraction | X_start[Medium.nX] | Medium.X_default | Start value of mass fractions m_i/m [kg/kg] |
| ExtraProperty | C_start[Medium.nC] | fill(0, Medium.nC) | Start value of trace substances |
| ExtraProperty | C_nominal[Medium.nC] | fill(1E-2, Medium.nC) | Nominal value of trace substances. (Set to typical order of magnitude.) |
Connectors
| Type | Name | Description |
|---|---|---|
| input RealInput | solRad[nOrientations] | Solar radiation transmitted through windows [W/m2] |
| output RealOutput | TAir | Indoor air temperature [K] |
| output RealOutput | TRad | Mean indoor radiation temperature [K] |
| VesselFluidPorts_b | ports[nPorts] | Auxiliary fluid inlets and outlets to indoor air volume |
| HeatPort_a | extWall | Ambient port for exterior walls |
| HeatPort_a | window | Ambient port for windows |
| HeatPort_a | intGainsConv | Auxiliary port for internal convective gains |
| HeatPort_a | intGainsRad | Auxiliary port for internal radiative gains |
| HeatPort_a | windowIndoorSurface | Auxiliary port at indoor surface of windows |
| HeatPort_a | extWallIndoorSurface | Auxiliary port at indoor surface of exterior walls |
Modelica definition
model OneElement "Thermal Zone with one element for exterior walls"
extends Buildings.Fluid.Interfaces.LumpedVolumeDeclarations;
parameter Modelica.SIunits.Volume VAir "Air volume of the zone";
parameter Modelica.SIunits.CoefficientOfHeatTransfer alphaRad
"Coefficient of heat transfer for linearized radiation exchange between walls";
parameter Integer nOrientations(min=1) "Number of orientations";
parameter Integer nPorts=0 "Number of fluid ports";
parameter Modelica.SIunits.Area AWin[nOrientations]
"Vector of areas of windows by orientations";
parameter Modelica.SIunits.Area ATransparent[nOrientations] "Vector of areas of transparent (solar radiation transmittend) elements by
orientations";
parameter Modelica.SIunits.CoefficientOfHeatTransfer alphaWin
"Convective coefficient of heat transfer of windows (indoor)";
parameter Modelica.SIunits.ThermalResistance RWin "Resistor for windows";
parameter Modelica.SIunits.TransmissionCoefficient gWin
"Total energy transmittance of windows";
parameter Real ratioWinConRad
"Ratio for windows between indoor convective and radiative heat emission";
parameter Boolean indoorPortWin=false
"Additional heat port at indoor surface of windows";
parameter Modelica.SIunits.Area AExt[nOrientations]
"Vector of areas of exterior walls by orientations";
parameter Modelica.SIunits.CoefficientOfHeatTransfer alphaExt
"Convective coefficient of heat transfer of exterior walls (indoor)";
parameter Integer nExt(min=1) "Number of RC-elements of exterior walls";
parameter Modelica.SIunits.ThermalResistance RExt[nExt](each min=Modelica.Constants.small)
"Vector of resistances of exterior walls, from inside to outside";
parameter Modelica.SIunits.ThermalResistance RExtRem(min=Modelica.Constants.small)
"Resistance of remaining resistor RExtRem between capacity n and outside";
parameter Modelica.SIunits.HeatCapacity CExt[nExt](each min=Modelica.Constants.small)
"Vector of heat capacities of exterior walls, from inside to outside";
parameter Boolean indoorPortExtWalls=false
"Additional heat port at indoor surface of exterior walls";
Modelica.Blocks.Interfaces.RealInput solRad[nOrientations](each final
quantity="RadiantEnergyFluenceRate", each final unit="W/m2") if sum(
ATransparent) > 0 "Solar radiation transmitted through windows";
Modelica.Blocks.Interfaces.RealOutput TAir(
final quantity="ThermodynamicTemperature",
final unit="K",
displayUnit="degC") if ATot > 0 or VAir > 0 "Indoor air temperature";
Modelica.Blocks.Interfaces.RealOutput TRad(
final quantity="ThermodynamicTemperature",
final unit="K",
displayUnit="degC") if ATot > 0 "Mean indoor radiation temperature";
Modelica.Fluid.Vessels.BaseClasses.VesselFluidPorts_b ports[nPorts](
redeclare each final package Medium = Medium)
"Auxiliary fluid inlets and outlets to indoor air volume";
Modelica.Thermal.HeatTransfer.Interfaces.HeatPort_a extWall if ATotExt > 0
"Ambient port for exterior walls";
Modelica.Thermal.HeatTransfer.Interfaces.HeatPort_a window if ATotWin > 0
"Ambient port for windows";
Modelica.Thermal.HeatTransfer.Interfaces.HeatPort_a intGainsConv if ATot > 0
or VAir > 0 "Auxiliary port for internal convective gains";
Modelica.Thermal.HeatTransfer.Interfaces.HeatPort_a intGainsRad if ATot > 0
"Auxiliary port for internal radiative gains";
Modelica.Thermal.HeatTransfer.Interfaces.HeatPort_a windowIndoorSurface if
indoorPortWin "Auxiliary port at indoor surface of windows";
Modelica.Thermal.HeatTransfer.Interfaces.HeatPort_a extWallIndoorSurface if
indoorPortExtWalls "Auxiliary port at indoor surface of exterior walls";
Fluid.MixingVolumes.MixingVolume volAir(
redeclare final package Medium = Medium,
final nPorts=nPorts,
m_flow_nominal=VAir*6/3600*1.2,
final V=VAir,
final energyDynamics=energyDynamics,
final massDynamics=massDynamics,
final p_start=p_start,
final T_start=T_start,
final X_start=X_start,
final C_start=C_start,
final C_nominal=C_nominal,
final mSenFac=mSenFac,
final use_C_flow=false) if VAir > 0 "Indoor air volume";
Modelica.Thermal.HeatTransfer.Components.ThermalResistor resWin(final R=RWin)
if ATotWin > 0 "Resistor for windows";
Modelica.Thermal.HeatTransfer.Sources.PrescribedHeatFlow convHeatSol(final
alpha=0) if ratioWinConRad > 0 and (ATot > 0 or VAir > 0) and sum(
ATransparent) > 0 "Solar heat considered as convection";
Modelica.Thermal.HeatTransfer.Sources.PrescribedHeatFlow radHeatSol[
nOrientations](each final alpha=0) if ATot > 0 and sum(ATransparent) > 0
"Solar heat considered as radiation";
BaseClasses.ThermSplitter thermSplitterIntGains(
final splitFactor=splitFactor,
final nOut=dimension,
final nIn=1) if ATot > 0 "Splits incoming internal gains into separate gains for each wall element,
weighted by their area";
BaseClasses.ThermSplitter thermSplitterSolRad(
final splitFactor=splitFactorSolRad,
final nOut=dimension,
final nIn=nOrientations) if ATot > 0 and sum(ATransparent) > 0 "Splits incoming solar radiation into separate gains for each wall element,
weighted by their area";
BaseClasses.ExteriorWall extWallRC(
final n=nExt,
final RExt=RExt,
final CExt=CExt,
final RExtRem=RExtRem,
final T_start=T_start) if ATotExt > 0 "RC-element for exterior walls";
protected
parameter Modelica.SIunits.Area ATot=sum(AArray) "Sum of wall surface areas";
parameter Modelica.SIunits.Area ATotExt=sum(AExt)
"Sum of exterior wall surface areas";
parameter Modelica.SIunits.Area ATotWin=sum(AWin)
"Sum of window surface areas";
parameter Modelica.SIunits.Area[:] AArray={ATotExt,ATotWin}
"List of all wall surface areas";
parameter Integer dimension=sum({if A > 0 then 1 else 0 for A in AArray})
"Number of non-zero wall surface areas";
parameter Real splitFactor[dimension, 1]=BaseClasses.splitFacVal(
dimension,
1,
AArray,
fill(0, 1),
fill(0, 1)) "Share of each wall surface area that is non-zero";
parameter Real splitFactorSolRad[dimension, nOrientations]=
BaseClasses.splitFacVal(
dimension,
nOrientations,
AArray,
AExt,
AWin)
"Share of each wall surface area that is non-zero, for each orientation separately";
Modelica.Thermal.HeatTransfer.Components.Convection convExtWall if ATotExt > 0
"Convective heat transfer of exterior walls";
Modelica.Blocks.Sources.Constant alphaExtWallConst(final k=ATotExt*alphaExt)
if ATotExt > 0 "Coefficient of convective heat transfer for exterior walls";
Modelica.Thermal.HeatTransfer.Components.Convection convWin if ATotWin > 0
"Convective heat transfer of windows";
Modelica.Blocks.Sources.Constant alphaWinConst(final k=ATotWin*alphaWin) if
ATotWin > 0 "Coefficient of convective heat transfer for windows";
Modelica.Blocks.Math.Gain eRadSol[nOrientations](final k=gWin*(1 -
ratioWinConRad)*ATransparent) if sum(ATransparent) > 0
"Emission coefficient of solar radiation considered as radiation";
Modelica.Blocks.Math.Gain eConvSol[nOrientations](final k=gWin*ratioWinConRad*
ATransparent) if ratioWinConRad > 0 and sum(ATransparent) > 0
"Emission coefficient of solar radiation considered as convection";
Modelica.Thermal.HeatTransfer.Components.ThermalConductor resExtWallWin(
final G=min(ATotExt, ATotWin)*alphaRad) if ATotExt > 0 and ATotWin > 0
"Resistor between exterior walls and windows";
Modelica.Thermal.HeatTransfer.Sensors.TemperatureSensor senTAir if ATot > 0
or VAir > 0 "Indoor air temperature sensor";
Modelica.Thermal.HeatTransfer.Sensors.TemperatureSensor senTRad if ATot > 0
"Mean indoor radiation temperatur sensor";
Modelica.Blocks.Math.Sum sumSolRad(final nin=nOrientations) if ratioWinConRad >
0 and sum(ATransparent) > 0
"Sums up solar radiation from different directions";
equation
connect(volAir.ports, ports);
connect(resWin.port_a, window);
connect(resWin.port_b, convWin.solid);
connect(eRadSol.y, radHeatSol.Q_flow);
connect(thermSplitterIntGains.portIn[1], intGainsRad);
connect(radHeatSol.port, thermSplitterSolRad.portIn);
connect(extWallRC.port_b, extWall);
connect(extWallRC.port_a, convExtWall.solid);
if ATotExt > 0 and ATotWin > 0 then
connect(thermSplitterSolRad.portOut[1], convExtWall.solid);
connect(thermSplitterIntGains.portOut[1], convExtWall.solid);
connect(thermSplitterSolRad.portOut[2], convWin.solid);
connect(thermSplitterIntGains.portOut[2], convWin.solid);
elseif not ATotExt > 0 and ATotWin > 0 then
connect(thermSplitterSolRad.portOut[1], convWin.solid);
connect(thermSplitterIntGains.portOut[1], convWin.solid);
elseif ATotExt > 0 and not ATotWin > 0 then
connect(thermSplitterSolRad.portOut[1], convExtWall.solid);
connect(thermSplitterIntGains.portOut[1], convExtWall.solid);
end if;
connect(eRadSol.u, solRad);
connect(resExtWallWin.port_b, convExtWall.solid);
connect(resExtWallWin.port_a, convWin.solid);
connect(alphaWinConst.y, convWin.Gc);
connect(alphaExtWallConst.y, convExtWall.Gc);
connect(convExtWall.fluid, senTAir.port);
connect(convHeatSol.port, senTAir.port);
connect(intGainsConv, senTAir.port);
connect(convWin.fluid, senTAir.port);
connect(volAir.heatPort, senTAir.port);
connect(senTAir.T, TAir);
connect(convWin.solid, windowIndoorSurface);
connect(convExtWall.solid, extWallIndoorSurface);
connect(senTRad.port, thermSplitterIntGains.portIn[1]);
connect(senTRad.T, TRad);
connect(solRad, eConvSol.u);
connect(eConvSol.y, sumSolRad.u);
connect(sumSolRad.y, convHeatSol.Q_flow);
end OneElement;
Buildings.ThermalZones.ReducedOrder.RC.ThreeElements
Thermal Zone with three elements for exterior walls,
interior walls and floor plate
Information
This model adds one further element for
the floor plate. Long-term effects dominate the excitation of the floor plate
and thus the excitation fundamentally differs from excitation of outer walls.
Adding an extra element for the floor plate leads to a finer resolution of the
dynamic behaviour but increases calculation times. The floor plate is
parameterized via the length of the RC-chain nFloor,
the vector of the capacities
CFloor[nFloor], the vector of the resistances
RFloor[nFloor]
and the remaining resistance RFloorRem.
The image below shows the RC-network of this model.
Extends from TwoElements (Thermal Zone with two elements for exterior and interior walls).
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| replaceable package Medium | PartialMedium | Medium in the component | |
| Thermal zone | |||
| Volume | VAir | Air volume of the zone [m3] | |
| CoefficientOfHeatTransfer | alphaRad | Coefficient of heat transfer for linearized radiation exchange between walls [W/(m2.K)] | |
| Integer | nOrientations | Number of orientations | |
| Windows | |||
| Area | AWin[nOrientations] | Vector of areas of windows by orientations [m2] | |
| Area | ATransparent[nOrientations] | Vector of areas of transparent (solar radiation transmittend) elements by orientations [m2] | |
| CoefficientOfHeatTransfer | alphaWin | Convective coefficient of heat transfer of windows (indoor) [W/(m2.K)] | |
| ThermalResistance | RWin | Resistor for windows [K/W] | |
| TransmissionCoefficient | gWin | Total energy transmittance of windows [1] | |
| Real | ratioWinConRad | Ratio for windows between indoor convective and radiative heat emission | |
| Boolean | indoorPortWin | false | Additional heat port at indoor surface of windows |
| Exterior walls | |||
| Area | AExt[nOrientations] | Vector of areas of exterior walls by orientations [m2] | |
| CoefficientOfHeatTransfer | alphaExt | Convective coefficient of heat transfer of exterior walls (indoor) [W/(m2.K)] | |
| Integer | nExt | Number of RC-elements of exterior walls | |
| ThermalResistance | RExt[nExt] | Vector of resistances of exterior walls, from inside to outside [K/W] | |
| ThermalResistance | RExtRem | Resistance of remaining resistor RExtRem between capacity n and outside [K/W] | |
| HeatCapacity | CExt[nExt] | Vector of heat capacities of exterior walls, from inside to outside [J/K] | |
| Boolean | indoorPortExtWalls | false | Additional heat port at indoor surface of exterior walls |
| Interior walls | |||
| Area | AInt | Area of interior walls [m2] | |
| CoefficientOfHeatTransfer | alphaInt | Convective coefficient of heat transfer of interior walls (indoor) [W/(m2.K)] | |
| Integer | nInt | Number of RC-elements of interior walls | |
| ThermalResistance | RInt[nInt] | Vector of resistances of interior walls, from port to center [K/W] | |
| HeatCapacity | CInt[nInt] | Vector of heat capacities of interior walls, from port to center [J/K] | |
| Boolean | indoorPortIntWalls | false | Additional heat port at indoor surface of interior walls |
| Floor plate | |||
| Area | AFloor | Area of floor plate [m2] | |
| CoefficientOfHeatTransfer | alphaFloor | Convective coefficient of heat transfer of floor plate (indoor) [W/(m2.K)] | |
| Integer | nFloor | Number of RC-elements of floor plate | |
| ThermalResistance | RFloor[nExt] | Vector of resistances of floor plate, from inside to outside [K/W] | |
| ThermalResistance | RFloorRem | Resistance of remaining resistor RFloorRem between capacity n and outside [K/W] | |
| HeatCapacity | CFloor[nExt] | Vector of heat capacities of floor plate, from inside to outside [J/K] | |
| Boolean | indoorPortFloor | false | Additional heat port at indoor surface of floor plate |
| Dynamics | |||
| Equations | |||
| Dynamics | energyDynamics | Modelica.Fluid.Types.Dynamic... | Type of energy balance: dynamic (3 initialization options) or steady state |
| Dynamics | massDynamics | energyDynamics | Type of mass balance: dynamic (3 initialization options) or steady state |
| Real | mSenFac | 1 | Factor for scaling the sensible thermal mass of the volume |
| Initialization | |||
| AbsolutePressure | p_start | Medium.p_default | Start value of pressure [Pa] |
| Temperature | T_start | Medium.T_default | Start value of temperature [K] |
| MassFraction | X_start[Medium.nX] | Medium.X_default | Start value of mass fractions m_i/m [kg/kg] |
| ExtraProperty | C_start[Medium.nC] | fill(0, Medium.nC) | Start value of trace substances |
| ExtraProperty | C_nominal[Medium.nC] | fill(1E-2, Medium.nC) | Nominal value of trace substances. (Set to typical order of magnitude.) |
Connectors
| Type | Name | Description |
|---|---|---|
| input RealInput | solRad[nOrientations] | Solar radiation transmitted through windows [W/m2] |
| output RealOutput | TAir | Indoor air temperature [K] |
| output RealOutput | TRad | Mean indoor radiation temperature [K] |
| VesselFluidPorts_b | ports[nPorts] | Auxiliary fluid inlets and outlets to indoor air volume |
| HeatPort_a | extWall | Ambient port for exterior walls |
| HeatPort_a | window | Ambient port for windows |
| HeatPort_a | intGainsConv | Auxiliary port for internal convective gains |
| HeatPort_a | intGainsRad | Auxiliary port for internal radiative gains |
| HeatPort_a | windowIndoorSurface | Auxiliary port at indoor surface of windows |
| HeatPort_a | extWallIndoorSurface | Auxiliary port at indoor surface of exterior walls |
| HeatPort_a | intWallIndoorSurface | Auxiliary port at indoor surface of interior walls |
| HeatPort_a | floor | Ambient port for floor plate |
| HeatPort_a | floorIndoorSurface | Auxiliary port at indoor surface of floor plate |
Modelica definition
model ThreeElements "Thermal Zone with three elements for exterior walls,
interior walls and floor plate"
extends TwoElements(AArray={ATotExt,ATotWin,AInt,AFloor});
parameter Modelica.SIunits.Area AFloor "Area of floor plate";
parameter Modelica.SIunits.CoefficientOfHeatTransfer alphaFloor
"Convective coefficient of heat transfer of floor plate (indoor)";
parameter Integer nFloor(min=1) "Number of RC-elements of floor plate";
parameter Modelica.SIunits.ThermalResistance RFloor[nExt](each min=Modelica.Constants.small)
"Vector of resistances of floor plate, from inside to outside";
parameter Modelica.SIunits.ThermalResistance RFloorRem(min=Modelica.Constants.small)
"Resistance of remaining resistor RFloorRem between capacity n and outside";
parameter Modelica.SIunits.HeatCapacity CFloor[nExt](each min=Modelica.Constants.small)
"Vector of heat capacities of floor plate, from inside to outside";
parameter Boolean indoorPortFloor=false
"Additional heat port at indoor surface of floor plate";
Modelica.Thermal.HeatTransfer.Interfaces.HeatPort_a floor if AFloor > 0
"Ambient port for floor plate";
Modelica.Thermal.HeatTransfer.Interfaces.HeatPort_a floorIndoorSurface if
indoorPortFloor "Auxiliary port at indoor surface of floor plate";
BaseClasses.ExteriorWall floorRC(
final n=nFloor,
final RExt=RFloor,
final RExtRem=RFloorRem,
final CExt=CFloor,
final T_start=T_start) if AFloor > 0 "RC-element for floor plate";
protected
Modelica.Thermal.HeatTransfer.Components.Convection convFloor if AFloor > 0
"Convective heat transfer of floor";
Modelica.Blocks.Sources.Constant alphaFloorConst(final k=AFloor*alphaFloor)
if AFloor > 0 "Coefficient of convective heat transfer for floor";
Modelica.Thermal.HeatTransfer.Components.ThermalConductor resExtWallFloor(
final G=min(ATotExt, AFloor)*alphaRad) if ATotExt > 0 and AFloor > 0
"Resistor between exterior walls and floor";
Modelica.Thermal.HeatTransfer.Components.ThermalConductor resIntWallFloor(
final G=min(AFloor, AInt)*alphaRad) if AInt > 0 and AFloor > 0
"Resistor between interior walls and floor";
Modelica.Thermal.HeatTransfer.Components.ThermalConductor resFloorWin(final G
=min(ATotWin, AFloor)*alphaRad) if ATotWin > 0 and AFloor > 0
"Resistor between floor plate and windows";
equation
connect(floorRC.port_a, convFloor.solid);
connect(floorRC.port_a, resExtWallFloor.port_b);
connect(floorRC.port_a, resIntWallFloor.port_b);
connect(floorRC.port_b, floor);
connect(resFloorWin.port_a, convWin.solid);
if not ATotExt > 0 and not ATotWin > 0 and not AInt > 0 and AFloor > 0 then
connect(thermSplitterIntGains.portOut[1], floorRC.port_a);
connect(floorRC.port_a, thermSplitterSolRad.portOut[1]);
elseif ATotExt > 0 and not ATotWin > 0 and not AInt > 0 and AFloor > 0 or
not ATotExt > 0 and ATotWin > 0 and not AInt > 0 and AFloor > 0 or not
ATotExt > 0 and not ATotWin > 0 and AInt > 0 and AFloor > 0 then
connect(thermSplitterIntGains.portOut[2], floorRC.port_a);
connect(floorRC.port_a, thermSplitterSolRad.portOut[2]);
elseif not ATotExt > 0 and ATotWin > 0 and AInt > 0 and AFloor > 0 or ATotExt >
0 and not ATotWin > 0 and AInt > 0 and AFloor > 0 or ATotExt > 0 and
ATotWin > 0 and not AInt > 0 and AFloor > 0 then
connect(thermSplitterIntGains.portOut[3], floorRC.port_a);
connect(floorRC.port_a, thermSplitterSolRad.portOut[3]);
elseif ATotExt > 0 and ATotWin > 0 and AInt > 0 and AFloor > 0 then
connect(thermSplitterIntGains.portOut[4], floorRC.port_a);
connect(floorRC.port_a, thermSplitterSolRad.portOut[4]);
end if;
connect(intWallRC.port_a, resIntWallFloor.port_a);
connect(resFloorWin.port_b, resExtWallFloor.port_b);
connect(resExtWallFloor.port_a, convExtWall.solid);
connect(alphaFloorConst.y, convFloor.Gc);
connect(convFloor.fluid, senTAir.port);
connect(floorRC.port_a, floorIndoorSurface);
end ThreeElements;
Buildings.ThermalZones.ReducedOrder.RC.TwoElements
Thermal Zone with two elements for exterior and interior 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.
Extends from OneElement (Thermal Zone with one element for exterior walls).
Parameters
| Type | Name | Default | Description |
|---|---|---|---|
| replaceable package Medium | PartialMedium | Medium in the component | |
| Thermal zone | |||
| Volume | VAir | Air volume of the zone [m3] | |
| CoefficientOfHeatTransfer | alphaRad | Coefficient of heat transfer for linearized radiation exchange between walls [W/(m2.K)] | |
| Integer | nOrientations | Number of orientations | |
| Windows | |||
| Area | AWin[nOrientations] | Vector of areas of windows by orientations [m2] | |
| Area | ATransparent[nOrientations] | Vector of areas of transparent (solar radiation transmittend) elements by orientations [m2] | |
| CoefficientOfHeatTransfer | alphaWin | Convective coefficient of heat transfer of windows (indoor) [W/(m2.K)] | |
| ThermalResistance | RWin | Resistor for windows [K/W] | |
| TransmissionCoefficient | gWin | Total energy transmittance of windows [1] | |
| Real | ratioWinConRad | Ratio for windows between indoor convective and radiative heat emission | |
| Boolean | indoorPortWin | false | Additional heat port at indoor surface of windows |
| Exterior walls | |||
| Area | AExt[nOrientations] | Vector of areas of exterior walls by orientations [m2] | |
| CoefficientOfHeatTransfer | alphaExt | Convective coefficient of heat transfer of exterior walls (indoor) [W/(m2.K)] | |
| Integer | nExt | Number of RC-elements of exterior walls | |
| ThermalResistance | RExt[nExt] | Vector of resistances of exterior walls, from inside to outside [K/W] | |
| ThermalResistance | RExtRem | Resistance of remaining resistor RExtRem between capacity n and outside [K/W] | |
| HeatCapacity | CExt[nExt] | Vector of heat capacities of exterior walls, from inside to outside [J/K] | |
| Boolean | indoorPortExtWalls | false | Additional heat port at indoor surface of exterior walls |
| Interior walls | |||
| Area | AInt | Area of interior walls [m2] | |
| CoefficientOfHeatTransfer | alphaInt | Convective coefficient of heat transfer of interior walls (indoor) [W/(m2.K)] | |
| Integer | nInt | Number of RC-elements of interior walls | |
| ThermalResistance | RInt[nInt] | Vector of resistances of interior walls, from port to center [K/W] | |
| HeatCapacity | CInt[nInt] | Vector of heat capacities of interior walls, from port to center [J/K] | |
| Boolean | indoorPortIntWalls | false | Additional heat port at indoor surface of interior walls |
| Dynamics | |||
| Equations | |||
| Dynamics | energyDynamics | Modelica.Fluid.Types.Dynamic... | Type of energy balance: dynamic (3 initialization options) or steady state |
| Dynamics | massDynamics | energyDynamics | Type of mass balance: dynamic (3 initialization options) or steady state |
| Real | mSenFac | 1 | Factor for scaling the sensible thermal mass of the volume |
| Initialization | |||
| AbsolutePressure | p_start | Medium.p_default | Start value of pressure [Pa] |
| Temperature | T_start | Medium.T_default | Start value of temperature [K] |
| MassFraction | X_start[Medium.nX] | Medium.X_default | Start value of mass fractions m_i/m [kg/kg] |
| ExtraProperty | C_start[Medium.nC] | fill(0, Medium.nC) | Start value of trace substances |
| ExtraProperty | C_nominal[Medium.nC] | fill(1E-2, Medium.nC) | Nominal value of trace substances. (Set to typical order of magnitude.) |
Connectors
| Type | Name | Description |
|---|---|---|
| input RealInput | solRad[nOrientations] | Solar radiation transmitted through windows [W/m2] |
| output RealOutput | TAir | Indoor air temperature [K] |
| output RealOutput | TRad | Mean indoor radiation temperature [K] |
| VesselFluidPorts_b | ports[nPorts] | Auxiliary fluid inlets and outlets to indoor air volume |
| HeatPort_a | extWall | Ambient port for exterior walls |
| HeatPort_a | window | Ambient port for windows |
| HeatPort_a | intGainsConv | Auxiliary port for internal convective gains |
| HeatPort_a | intGainsRad | Auxiliary port for internal radiative gains |
| HeatPort_a | windowIndoorSurface | Auxiliary port at indoor surface of windows |
| HeatPort_a | extWallIndoorSurface | Auxiliary port at indoor surface of exterior walls |
| HeatPort_a | intWallIndoorSurface | Auxiliary port at indoor surface of interior walls |
Modelica definition
model TwoElements
"Thermal Zone with two elements for exterior and interior walls"
extends OneElement(AArray={ATotExt,ATotWin,AInt});
parameter Modelica.SIunits.Area AInt "Area of interior walls";
parameter Modelica.SIunits.CoefficientOfHeatTransfer alphaInt
"Convective coefficient of heat transfer of interior walls (indoor)";
parameter Integer nInt(min=1) "Number of RC-elements of interior walls";
parameter Modelica.SIunits.ThermalResistance RInt[nInt](each min=Modelica.Constants.small)
"Vector of resistances of interior walls, from port to center";
parameter Modelica.SIunits.HeatCapacity CInt[nInt](each min=Modelica.Constants.small)
"Vector of heat capacities of interior walls, from port to center";
parameter Boolean indoorPortIntWalls=false
"Additional heat port at indoor surface of interior walls";
Modelica.Thermal.HeatTransfer.Interfaces.HeatPort_a intWallIndoorSurface if
indoorPortIntWalls "Auxiliary port at indoor surface of interior walls";
BaseClasses.InteriorWall intWallRC(
final n=nInt,
final RInt=RInt,
final CInt=CInt,
final T_start=T_start) if AInt > 0 "RC-element for interior walls";
protected
Modelica.Thermal.HeatTransfer.Components.Convection convIntWall if AInt > 0
"Convective heat transfer of interior walls";
Modelica.Blocks.Sources.Constant alphaIntWall(k=AInt*alphaInt) if AInt > 0
"Coefficient of convective heat transfer for interior walls";
Modelica.Thermal.HeatTransfer.Components.ThermalConductor resExtWallIntWall(
final G=min(ATotExt, AInt)*alphaRad) if ATotExt > 0 and AInt > 0
"Resistor between exterior walls and interior walls";
Modelica.Thermal.HeatTransfer.Components.ThermalConductor resIntWallWin(
final G=min(ATotWin, AInt)*alphaRad) if ATotWin > 0 and AInt > 0
"Resistor between interior walls and windows";
equation
connect(resExtWallIntWall.port_a, convExtWall.solid);
connect(convIntWall.solid, intWallRC.port_a);
connect(intWallRC.port_a, resExtWallIntWall.port_b);
if not ATotExt > 0 and not ATotWin > 0 and AInt > 0 then
connect(thermSplitterIntGains.portOut[1], intWallRC.port_a);
connect(thermSplitterSolRad.portOut[1], intWallRC.port_a);
elseif ATotExt > 0 and not ATotWin > 0 and AInt > 0 or not ATotExt > 0 and
ATotWin > 0 and AInt > 0 then
connect(thermSplitterIntGains.portOut[2], intWallRC.port_a);
connect(thermSplitterSolRad.portOut[2], intWallRC.port_a);
elseif ATotExt > 0 and ATotWin > 0 and AInt > 0 then
connect(thermSplitterIntGains.portOut[3], intWallRC.port_a);
connect(thermSplitterSolRad.portOut[3], intWallRC.port_a);
end if;
connect(resIntWallWin.port_b, intWallRC.port_a);
connect(resIntWallWin.port_a, convWin.solid);
connect(alphaIntWall.y, convIntWall.Gc);
connect(intWallRC.port_a, intWallIndoorSurface);
connect(convIntWall.fluid, senTAir.port);
end TwoElements;