Buildings.ThermalZones.ISO13790.BaseClasses

Package with base classes for Buildings.Fluid

Information

This package contains base classes that are used to construct the models in IBPSA.ThermalZones.ISO13790.

Extends from Modelica.Icons.BasesPackage (Icon for packages containing base classes).

Package Content

Name	Description
GainMass	Mass node heat flow
GainSurface	Surface node heat flow
GlazedElements	Solar gains through glazed elements
OpaqueElements	Solar gains through opaque elements

Buildings.ThermalZones.ISO13790.BaseClasses.GainMass

Mass node heat flow

Buildings.ThermalZones.ISO13790.BaseClasses.GainMass

Information

This model calculates the heat gains injected to the mass node. More information can be found in the documentation of Buildings.ThermalZones.ISO13790.Zone5R1C.Zone

Parameters

Type	Name	Description
Area	ATot	Total area of building's surfaces facing the thermal zone [m2]
Real	facMas	Effective mass area factor
Area	AFlo	Floor area [m2]

Connectors

Type	Name	Description
input RealInput	intSenGai	Internal sensible heat gains [W]
input RealInput	solGai	Solar gains [W]
output RealOutput	masGai	Heat gain to mass node [W]

Modelica definition

model GainMass "Mass node heat flow" Modelica.Units.SI.Area AMas "Effective mass area (see Table 12 in standard)"; parameter Modelica.Units.SI.Area ATot "Total area of building's surfaces facing the thermal zone"; parameter Real facMas "Effective mass area factor"; parameter Modelica.Units.SI.Area AFlo "Floor area"; Modelica.Blocks.Interfaces.RealInput intSenGai(final unit="W") "Internal sensible heat gains"; Modelica.Blocks.Interfaces.RealInput solGai(final unit="W") "Solar gains"; Modelica.Blocks.Interfaces.RealOutput masGai(final unit="W") "Heat gain to mass node"; equation AMas = facMas*AFlo; masGai=((AMas/ATot)*(0.5*intSenGai + solGai)); end GainMass;

Buildings.ThermalZones.ISO13790.BaseClasses.GainSurface

Surface node heat flow

Buildings.ThermalZones.ISO13790.BaseClasses.GainSurface

Information

This model calculates the heat gains injected to the surface node. More information can be found in the documentation of Buildings.ThermalZones.ISO13790.Zone5R1C.Zone

Parameters

Type	Name	Description
Area	ATot	Total area of building's surfaces facing the thermal zone [m2]
ThermalConductance	HWinGai	Thermal conductance through windows [W/K]
Real	facMas	Effective mass area factor
Area	AFlo	Floor area [m2]

Connectors

Type	Name	Description
input RealInput	intSenGai	Internal sensible heat gains [W]
input RealInput	solGai	Solar gains [W]
output RealOutput	surGai	Heat gain to surface node [W]

Modelica definition

model GainSurface "Surface node heat flow" Modelica.Units.SI.Area AMas "Effective mass area (see Table 12 in standard)"; parameter Modelica.Units.SI.Area ATot "Total area of building's surfaces facing the thermal zone"; parameter Modelica.Units.SI.ThermalConductance HWinGai "Thermal conductance through windows"; parameter Real facMas "Effective mass area factor"; parameter Modelica.Units.SI.Area AFlo "Floor area"; Modelica.Blocks.Interfaces.RealInput intSenGai(final unit="W") "Internal sensible heat gains"; Modelica.Blocks.Interfaces.RealInput solGai(final unit="W") "Solar gains"; Modelica.Blocks.Interfaces.RealOutput surGai(final unit="W") "Heat gain to surface node"; equation AMas = facMas*AFlo; surGai= (1 - AMas/ATot - HWinGai/(9.1*ATot))*(0.5*intSenGai + solGai); end GainSurface;

Buildings.ThermalZones.ISO13790.BaseClasses.GlazedElements

Solar gains through glazed elements

Buildings.ThermalZones.ISO13790.BaseClasses.GlazedElements

Information

This model calculates the heat flow by solar gains through each glazed element k. The heat flow is given by

Φ_sol,k =F_sh,kI_sol,kg_fac (1-F_frame) A_win,k

where F_sh,k is the shading reduction factor which is set to 1 by default, I_sol,k is the solar irradiance per square meter of surface area, g_fac is the total solar energy transmittance of the trasparent element, F_frame is the frame area fraction, and A_win,k is the overall area of the glazed element in square meters.

Additionally, an extra heat flow is modeled to represent the thermal radiation emitted towards the sky as

Φ_r,k =h_r ΔT_sky R_se U_k A_k

where h_r is the external radiative heat transfer coefficient which is approximated as 5 ε W/m²K (where ε is the emissivity for the thermal radiation of the external surface), and ΔT_sky is the average temperature difference between the external air temperature and the apparent sky temperature.

Parameters

Type	Name	Default	Description
Integer	n
Area	AWin[:]		Area of windows [m2]
Real	coeFac[:]		Coefficient of g-factor reduction
CoefficientOfHeatTransfer	UWin		U-value of windows [W/(m2.K)]
Angle	surTil[:]		Tilt angle of surfaces [rad]
Angle	surAzi[:]		Azimuth angle of surfaces [rad]
Real	eps	0.9	Emissivity of external surface
ThermalInsulance	surRes	0.04	External surface heat resistance [m2.K/W]
Real	gFac		Energy transmittance of glazings
Real	winFra		Frame fraction of windows
Real	shaRedFac	1	Shading reduction factor [1]

Connectors

Type	Name	Description
Bus	weaBus
output RealOutput	solRadWin	Solar radiation through windows

Modelica definition

model GlazedElements "Solar gains through glazed elements" parameter Integer n; parameter Modelica.Units.SI.Area AWin[:] "Area of windows"; parameter Real coeFac[:] "Coefficient of g-factor reduction"; parameter Modelica.Units.SI.CoefficientOfHeatTransfer UWin "U-value of windows"; parameter Modelica.Units.SI.Angle surTil[:] "Tilt angle of surfaces"; parameter Modelica.Units.SI.Angle surAzi[:] "Azimuth angle of surfaces"; parameter Real eps=0.9 "Emissivity of external surface"; parameter Modelica.Units.SI.ThermalInsulance surRes=0.04 "External surface heat resistance"; parameter Real gFac "Energy transmittance of glazings"; parameter Real winFra "Frame fraction of windows"; parameter Real shaRedFac( final min=0, final unit="1")= 1 "Shading reduction factor"; Buildings.BoundaryConditions.WeatherData.Bus weaBus; BoundaryConditions.SolarIrradiation.DirectTiltedSurface HDirTil[n]( final til=surTil, final azi=surAzi) "Direct solar irradiation on surface"; Modelica.Blocks.Math.Gain solRad[n](final k=AWin*gFac*shaRedFac*(1 - winFra)) "Solar radiation trasmitted through windows"; Modelica.Blocks.Interfaces.RealOutput solRadWin "Solar radiation through windows"; BoundaryConditions.SolarIrradiation.DiffusePerez HDifTil[n]( final til=surTil, final azi=surAzi) "Diffuse solar irradiation on surface"; Modelica.Blocks.Math.Gain theRadWin[n](each k=5*eps*11*0.5) "Extra thermal radiation through windows"; Modelica.Blocks.Math.Add addWin[n](each k2=-1) "Total solar gains through windows"; Modelica.Blocks.Math.Product HDirAng[n] "Direct solar irradiation considering incident angle of surface"; Utilities.Math.Polynomial polynomial[n](each a=coeFac) "Ratio of direct solar irradiation considering incident angle of surface"; protected Modelica.Blocks.Math.Add irr[n] "Total of direct and diffuse radiation on surface"; Modelica.Blocks.Math.MultiSum multiSum(nu=n) "Sum of all orientations"; protected Modelica.Blocks.Sources.RealExpression facWin[n](y=UWin*AWin*surRes) "factor"; equation for i in 1:n loop connect(weaBus,HDifTil[i].weaBus); end for; for i in 1:n loop connect(weaBus,HDirTil[i].weaBus); end for; connect(multiSum.y, solRadWin); connect(irr.y, solRad.u); connect(facWin.y,theRadWin. u); connect(theRadWin.y, addWin.u2); connect(addWin.y, multiSum.u); connect(solRad.y, addWin.u1); connect(HDirTil.H, HDirAng.u2); connect(HDifTil.H, irr.u2); connect(HDirAng.y, irr.u1); connect(HDirTil.inc, polynomial.u); connect(polynomial.y, HDirAng.u1); end GlazedElements;

Buildings.ThermalZones.ISO13790.BaseClasses.OpaqueElements

Solar gains through opaque elements

Buildings.ThermalZones.ISO13790.BaseClasses.OpaqueElements

Information

This model calculates the heat flow by solar gains through each opaque building element k. The heat flow is given by

Φ_sol,k =F_sh,kI_sol,k α_k R_se U_k A_k - F_f Φ_r,k

where F_sh,k is the shading reduction factor, I_sol,k is the solar irradiance per square meter of surface area, α_k is the dimensionless absportion coefficient for solar radiation of the opaque element, R_se is the external surface heat resistance of the opaque element in (m K/W), and A_k is the area of the opaque element.

The view factor between the building element and the sky F_f is set to 1 for roofs and 0.5 for external walls. The extra heat flow due to thermal radiation to the sky is given by

Φ_r,k =h_r ΔT_sky R_se U_k A_k

where h_r is the external radiative heat transfer coefficent which is approximated as 5 ε W/m²K (where ε is the emissivity for the thermal radiation of the external surface), and ΔT_sky is the average temperature difference between the external air temperature and the apparent sky temperature.

Parameters

Type	Name	Default	Description
Integer	n
Area	AWal[:]		Area of external walls [m2]
Area	ARoo		Area of roof [m2]
CoefficientOfHeatTransfer	UWal		U-value of external walls [W/(m2.K)]
CoefficientOfHeatTransfer	URoo		U-value of roof [W/(m2.K)]
Angle	surTil[:]		Tilt angle of surfaces [rad]
Angle	surAzi[:]		Azimuth angle of surfaces [rad]
Real	eps	0.9	Emissivity of external surface
Real	alp	0.6	Absorption coefficient
ThermalInsulance	surRes	0.04	External surface heat resistance [m2.K/W]

Connectors

Type	Name	Description
Bus	weaBus
output RealOutput	y	Solar radiation through windows

Modelica definition

model OpaqueElements "Solar gains through opaque elements" parameter Integer n; parameter Modelica.Units.SI.Area AWal[:] "Area of external walls"; parameter Modelica.Units.SI.Area ARoo "Area of roof"; parameter Modelica.Units.SI.CoefficientOfHeatTransfer UWal "U-value of external walls"; parameter Modelica.Units.SI.CoefficientOfHeatTransfer URoo "U-value of roof"; parameter Modelica.Units.SI.Angle surTil[:] "Tilt angle of surfaces"; parameter Modelica.Units.SI.Angle surAzi[:] "Azimuth angle of surfaces"; parameter Real eps=0.9 "Emissivity of external surface"; parameter Real alp=0.6 "Absorption coefficient"; parameter Modelica.Units.SI.ThermalInsulance surRes=0.04 "External surface heat resistance"; Buildings.BoundaryConditions.WeatherData.Bus weaBus; BoundaryConditions.SolarIrradiation.DirectTiltedSurface HDirTil[n]( final til=surTil, final azi=surAzi); Modelica.Blocks.Math.Gain solRadOpa[n](final k=AWal*alp*UWal*surRes) "Solar radiation on vertical opaque surfaces"; Modelica.Blocks.Interfaces.RealOutput y "Solar radiation through windows"; BoundaryConditions.SolarIrradiation.DiffusePerez HDifTil [n]( final til=surTil, final azi=surAzi); Modelica.Blocks.Math.Add irrOpa[n] "Total of direct and diffuse radiation on surface"; Modelica.Blocks.Math.Add addOpa[n](each k2=-1) "Total solar gains through vertical walls"; Modelica.Blocks.Math.Gain theRadOpa[n](each k=5*eps*11*0.5) "Extra thermal radiation through walls"; Modelica.Blocks.Math.Add irrRoo "Total of direct and diffuse radiation on the south facade"; Modelica.Blocks.Math.Gain solRadRoo(final k=ARoo*alp*URoo*surRes) "Solar radiation on roof"; Modelica.Blocks.Math.Gain theRadRoo(final k=5*eps*11*1) "Extra thermal radiation through roof"; Modelica.Blocks.Math.Add addRoo(k2=-1) "Total solar gains through roof"; Modelica.Blocks.Math.MultiSum multiSum(nu=n); Modelica.Blocks.Math.Add addTot "Total of direct and diffuse radiation on the south facade"; protected Modelica.Blocks.Sources.RealExpression facOpa[n](y=UWal*AWal*surRes) "factor"; BoundaryConditions.SolarIrradiation.DirectTiltedSurface HDirTilRoo(til=0, azi= 0); BoundaryConditions.SolarIrradiation.DiffusePerez HDifTilRof(til=0, azi=0); protected Modelica.Blocks.Sources.RealExpression facRoo(y=URoo*ARoo*surRes) "factor"; equation for i in 1:n loop connect(weaBus,HDifTil[i].weaBus); end for; for i in 1:n loop connect(weaBus,HDirTil[i].weaBus); end for; connect(HDirTil.H, irrOpa.u1); connect(HDifTil.H, irrOpa.u2); connect(irrOpa.y, solRadOpa.u); connect(HDirTilRoo.H, irrRoo.u1); connect(HDifTilRof.H, irrRoo.u2); connect(HDirTilRoo.weaBus, weaBus); connect(HDifTilRof.weaBus, weaBus); connect(irrRoo.y, solRadRoo.u); connect(facRoo.y, theRadRoo.u); connect(addOpa.y, multiSum.u); connect(solRadOpa.y, addOpa.u1); connect(theRadRoo.y, addRoo.u2); connect(solRadRoo.y, addRoo.u1); connect(addTot.y, y); connect(addRoo.y, addTot.u2); connect(multiSum.y, addTot.u1); connect(facOpa.y, theRadOpa.u); connect(theRadOpa.y, addOpa.u2); end OpaqueElements;