Buildings.Fluid.HeatExchangers.ThermalWheels.Latent.Examples

Collection of models that illustrate model use and test models

Information

This package contains validation models for the classes in Buildings.Fluid.HeatExchangers.ThermalWheels.Latent.

Extends from Modelica.Icons.ExamplesPackage (Icon for packages containing runnable examples).

Package Content

Name	Description
SpaceCooling	Space cooling system

Buildings.Fluid.HeatExchangers.ThermalWheels.Latent.Examples.SpaceCooling

Space cooling system

Buildings.Fluid.HeatExchangers.ThermalWheels.Latent.Examples.SpaceCooling

Information

This block is identical to Buildings.Examples.Tutorial.SpaceCooling.System3, except that the heat recovery device is modelled with Buildings.Fluid.HeatExchangers.ThermalWheels.Latent.BypassDampers.

The major input signals for the heat recovery device are configured as follows:

The operating signal uRot changes from false to true at 6:00 (15552000+6*3600 seconds) and from true to false at 18:00 (15552000+18*3600 seconds).
The supply air flow rate mAir_flow changes from 0 to 0.646 at around 5:00 and from 0.646 to 0 at around 17:00.
The bypass damper positions are controlled to maintain the temperature of the air leaving the thermal wheel, senTemHXOut.T, at 298.15 K.

The expected output is:

senTemHXOut.T is less or equal to 298.15 K.

Extends from Modelica.Icons.Example (Icon for runnable examples).

Parameters

Type	Name	Default	Description
replaceable package MediumA		Buildings.Media.Air	Medium for air
replaceable package MediumW		Buildings.Media.Water	Medium for water
Volume	V	6103	Room volume [m3]
Generic	per	per(mSup_flow_nominal=mA_flo...	Performance record for the enthalpy wheel
Temperature	TASup_nominal	291.15	Nominal air temperature supplied to room [K]
DimensionlessRatio	wASup_nominal	0.012	Nominal air humidity ratio supplied to room [kg/kg] assuming 90% relative humidity [1]
Temperature	TRooSet	297.15	Nominal room air temperature [K]
Temperature	TMixSet	298.15	Nominal mixed air temperature [K]
Temperature	TOut_nominal	303.15	Design outlet air temperature [K]
Temperature	THeaRecLvg	TOut_nominal - per.epsSen_no...	Air temperature leaving the heat recovery [K]
DimensionlessRatio	wHeaRecLvg	0.0135	Air humidity ratio leaving the heat recovery [kg/kg] [1]
HeatFlowRate	QRooInt_flow	1000	Internal heat gains of the room [W]
HeatFlowRate	QRooC_flow_nominal	-QRooInt_flow - 10E3/30*(TOu...	Nominal cooling load of the room [W]
MassFlowRate	mA_flow_nominal	1.3*QRooC_flow_nominal/1006/...	Nominal air mass flow rate, increased by factor 1.3 to allow for recovery after temperature setback [kg/s]
TemperatureDifference	dTFan	2	Estimated temperature raise across fan that needs to be made up by the cooling coil [K]
HeatFlowRate	QCoiC_flow_nominal	mA_flow_nominal*(TASup_nomin...	Cooling load of coil, taking into account outside air sensible and latent heat removal [W]
Temperature	TWSup_nominal	285.15	Water supply temperature [K]
Temperature	TWRet_nominal	289.15	Water return temperature [K]
MassFlowRate	mW_flow_nominal	-QCoiC_flow_nominal/(TWRet_n...	Nominal water mass flow rate [kg/s]

Connectors

Type	Name	Description
replaceable package MediumA		Medium for air
replaceable package MediumW		Medium for water
Bus	weaBus	Weather data bus

Modelica definition

model SpaceCooling "Space cooling system" extends Modelica.Icons.Example; replaceable package MediumA = Buildings.Media.Air "Medium for air"; replaceable package MediumW = Buildings.Media.Water "Medium for water"; parameter Modelica.Units.SI.Volume V=6*10*3 "Room volume"; // Heat recovery effectiveness parameter Buildings.Fluid.HeatExchangers.ThermalWheels.Data.Generic per( mSup_flow_nominal=mA_flow_nominal, mExh_flow_nominal=mA_flow_nominal, dpSup_nominal=200, have_varSpe=false) "Performance record for the enthalpy wheel"; ///////////////////////////////////////////////////////// // Design air conditions parameter Modelica.Units.SI.Temperature TASup_nominal=291.15 "Nominal air temperature supplied to room"; parameter Modelica.Units.SI.DimensionlessRatio wASup_nominal=0.012 "Nominal air humidity ratio supplied to room [kg/kg] assuming 90% relative humidity"; parameter Modelica.Units.SI.Temperature TRooSet=297.15 "Nominal room air temperature"; parameter Modelica.Units.SI.Temperature TMixSet=298.15 "Nominal mixed air temperature"; parameter Modelica.Units.SI.Temperature TOut_nominal=303.15 "Design outlet air temperature"; parameter Modelica.Units.SI.Temperature THeaRecLvg= TOut_nominal - per.epsSen_nominal*(TOut_nominal - TRooSet) "Air temperature leaving the heat recovery"; parameter Modelica.Units.SI.DimensionlessRatio wHeaRecLvg=0.0135 "Air humidity ratio leaving the heat recovery [kg/kg]"; ///////////////////////////////////////////////////////// // Cooling loads and air mass flow rates parameter Modelica.Units.SI.HeatFlowRate QRooInt_flow=1000 "Internal heat gains of the room"; parameter Modelica.Units.SI.HeatFlowRate QRooC_flow_nominal= -QRooInt_flow -10E3/30*(TOut_nominal - TRooSet) "Nominal cooling load of the room"; parameter Modelica.Units.SI.MassFlowRate mA_flow_nominal= 1.3*QRooC_flow_nominal/1006/(TASup_nominal - TRooSet) "Nominal air mass flow rate, increased by factor 1.3 to allow for recovery after temperature setback"; parameter Modelica.Units.SI.TemperatureDifference dTFan=2 "Estimated temperature raise across fan that needs to be made up by the cooling coil"; parameter Modelica.Units.SI.HeatFlowRate QCoiC_flow_nominal=mA_flow_nominal*( TASup_nominal - THeaRecLvg - dTFan)*1006 + mA_flow_nominal*(wASup_nominal - wHeaRecLvg)*2458.3e3 "Cooling load of coil, taking into account outside air sensible and latent heat removal"; ///////////////////////////////////////////////////////// // Water temperatures and mass flow rates parameter Modelica.Units.SI.Temperature TWSup_nominal=285.15 "Water supply temperature"; parameter Modelica.Units.SI.Temperature TWRet_nominal=289.15 "Water return temperature"; parameter Modelica.Units.SI.MassFlowRate mW_flow_nominal= -QCoiC_flow_nominal/(TWRet_nominal - TWSup_nominal)/4200 "Nominal water mass flow rate"; Buildings.Fluid.MixingVolumes.MixingVolume vol( redeclare package Medium = MediumA, m_flow_nominal=mA_flow_nominal, V=V, nPorts=2, energyDynamics=Modelica.Fluid.Types.Dynamics.FixedInitial, mSenFac=3) "Indoor room"; Modelica.Thermal.HeatTransfer.Components.ThermalConductor theCon( G=10000/30) "Thermal conductance with the ambient"; Modelica.Thermal.HeatTransfer.Sources.PrescribedTemperature TOut "Outside temperature"; Modelica.Thermal.HeatTransfer.Sources.FixedHeatFlow preHea( Q_flow=QRooInt_flow) "Prescribed heat flow"; Buildings.Fluid.Movers.FlowControlled_m_flow fan( redeclare package Medium = MediumA, per(etaHydMet=Buildings.Fluid.Movers.BaseClasses.Types.HydraulicEfficiencyMethod.NotProvided, etaMotMet=Buildings.Fluid.Movers.BaseClasses.Types.MotorEfficiencyMethod.NotProvided), nominalValuesDefineDefaultPressureCurve=true, m_flow_nominal=mA_flow_nominal, energyDynamics=Modelica.Fluid.Types.Dynamics.FixedInitial) "Supply air fan"; Buildings.Fluid.HeatExchangers.ThermalWheels.Latent.BypassDampers whe( redeclare package Medium = MediumA, per=per) "Heat recovery with bypass damper"; Buildings.Fluid.HeatExchangers.WetCoilEffectivenessNTU cooCoi( redeclare package Medium1 = MediumW, redeclare package Medium2 = MediumA, m1_flow_nominal=mW_flow_nominal, m2_flow_nominal=mA_flow_nominal, dp1_nominal=6000, dp2_nominal=200, use_Q_flow_nominal=true, Q_flow_nominal=QCoiC_flow_nominal, T_a1_nominal=TWSup_nominal, T_a2_nominal=THeaRecLvg, w_a2_nominal=wHeaRecLvg, show_T=true, energyDynamics=Modelica.Fluid.Types.Dynamics.FixedInitial) "Cooling coil"; Buildings.Fluid.Sources.Outside out( redeclare package Medium = MediumA, nPorts=2) "Outdoor"; Buildings.Fluid.Sources.MassFlowSource_T souWat( nPorts=1, redeclare package Medium = MediumW, use_m_flow_in=true, T=TWSup_nominal) "Source for water flow rate"; Buildings.Fluid.Sources.Boundary_pT sinWat( nPorts=1, redeclare package Medium = MediumW) "Sink for water circuit"; Buildings.BoundaryConditions.WeatherData.ReaderTMY3 weaDat( pAtmSou=Buildings.BoundaryConditions.Types.DataSource.Parameter, TDryBul=TOut_nominal, filNam=Modelica.Utilities.Files.loadResource("modelica://Buildings/Resources/weatherdata/USA_IL_Chicago-OHare.Intl.AP.725300_TMY3.mos"), TDryBulSou=Buildings.BoundaryConditions.Types.DataSource.File) "Weather data reader"; Buildings.BoundaryConditions.WeatherData.Bus weaBus "Weather data bus"; Buildings.Controls.OBC.CDL.Reals.Sources.Pulse mAir_flow( amplitude=-mA_flow_nominal, width=0.5, period=87600, shift=0.24*87600, offset=mA_flow_nominal) "Fan air flow rate"; Buildings.Fluid.Sensors.TemperatureTwoPort senTemHXOut( redeclare package Medium = MediumA, m_flow_nominal=mA_flow_nominal) "Temperature sensor for heat recovery outlet on supply side"; Buildings.Fluid.Sensors.TemperatureTwoPort senTemSupAir( redeclare package Medium = MediumA, m_flow_nominal=mA_flow_nominal) "Temperature sensor for supply air"; Buildings.Controls.OBC.CDL.Reals.Sources.Constant TRooSetPoi( k=TRooSet) "Room temperature set point"; Modelica.Thermal.HeatTransfer.Sensors.TemperatureSensor senTemRoo "Room temperature sensor"; Buildings.Controls.OBC.CDL.Logical.Sources.Pulse opeSig( width=0.5, period=86400, shift=0.25*86400) "Operating signal"; Buildings.Controls.Continuous.LimPID conWhe( u_s(final unit="K", displayUnit="degC"), u_m(final unit="K", displayUnit="degC"), k=0.1, Ti=60) "Heat recovery controller"; Buildings.Controls.OBC.CDL.Reals.Sources.Constant TMixSetPoi( k=TMixSet) "Mixed air temperature set point"; Buildings.Fluid.Sensors.TemperatureTwoPort senTemRetAir( redeclare package Medium = MediumA, m_flow_nominal=mA_flow_nominal) "Temperature sensor for return air"; Buildings.Controls.Continuous.LimPID conRoo( k=0.1, Ti=60, yMax=mW_flow_nominal, reverseActing=false) "Room controller"; Buildings.Fluid.Sensors.MassFractionTwoPort senMasFraHXIn( redeclare package Medium = MediumA, m_flow_nominal=mA_flow_nominal) "Humidity sensor for heat recovery inlet on supply side"; Buildings.Fluid.Sensors.MassFractionTwoPort senMasFraHXOut( redeclare package Medium = MediumA, m_flow_nominal=mA_flow_nominal) "Humidity sensor for heat recovery outlet on supply side"; equation connect(theCon.port_b, vol.heatPort); connect(preHea.port, vol.heatPort); connect(fan.port_b, vol.ports[1]); connect(souWat.ports[1], cooCoi.port_a1); connect(cooCoi.port_b1, sinWat.ports[1]); connect(weaDat.weaBus, out.weaBus); connect(weaDat.weaBus, weaBus); connect(weaBus.TDryBul, TOut.T); connect(fan.m_flow_in, mAir_flow.y); connect(senTemHXOut.port_b, cooCoi.port_a2); connect(cooCoi.port_b2, senTemSupAir.port_a); connect(senTemSupAir.port_b, fan.port_a); connect(TOut.port, theCon.port_a); connect(vol.heatPort, senTemRoo.port); connect(whe.port_b2, out.ports[1]); connect(opeSig.y, whe.uRot); connect(TMixSetPoi.y, conWhe.u_s); connect(senTemHXOut.T, conWhe.u_m); connect(conWhe.y, whe.uBypDamPos); connect(vol.ports[2], senTemRetAir.port_a); connect(conRoo.u_m, senTemRoo.T); connect(TRooSetPoi.y, conRoo.u_s); connect(conRoo.y, souWat.m_flow_in); connect(whe.port_a2, senTemRetAir.port_b); connect(senMasFraHXIn.port_a, out.ports[2]); connect(senMasFraHXIn.port_b, whe.port_a1); connect(whe.port_b1, senMasFraHXOut.port_a); connect(senMasFraHXOut.port_b, senTemHXOut.port_a); end SpaceCooling;