blockAbsorbedRadiation

Absorbed radiation by window

Extends from Buildings.HeatTransfer.Windows.BaseClasses.PartialRadiation (Partial model for variables and data used in radiation calculation).

Information

The model calculates absorbed solar radiation on the window. The calculations follow the description in Wetter (2004), Appendix A.4.3.

The absorbed radiation by exterior shades includes:

the directly absorbed exterior radiation: AWin*uSha*(HDir+HDif)*(1-tau-rho)
the indirectly absorbed exterior radiantion from reflection (angular part): AWin*uSha*HDir*tau*rho(IncAng)*(1-tau-rho)
the indirectly absorbed of exterior irradiantion from reflection (diffusive part): AWin*uSha*HDif*tau*rho(HEM)*(1-tau-rho)
the absorbed interior radiation is neglected.

The output is absRad[2, 1]

The absorbed radiation by interior shades includes:

the absorbed exterior radiation (angular part): AWin*uSha*HDir*alpha(IncAng)
the absorbed exterior radiation (diffusive part): AWin*uSha*HDif*alpha(HEM)
the absorbed interior radiation (diffusive part): AWin*uSha*HRoo*(1-tau-rho)

The output is absRad[2, N+2]

The absorbed radiation by glass includes:

the absorbed radiation by unshaded part (diffusive part): AWin*(1-uSha)*(HDif*alphaEx(HEM)+HRoo*alphaIn(HEM))
the absorbed radiation by unshaded part (angular part from exterior source): AWin*(1-uSha)*HDir*alphaEx(IncAng)
the absorbed radiaiton by shaded part (diffusive part): AWin*uSha*(HDif*alphaExSha(HEM)+HRoo*alphaInSha(HEM))
the absorbed radiation by shaded part (angular part from exterior source): AWin*uSha*HDir*alphaExSha(IncAng)

The output is absRad[1, 2:N+1] = Part1 + Part2; absRad[2, 2:N+1] = Part3 + Part4

References

Michael Wetter.
Simulation-based Building Energy Optimization.
Dissertation. University of California at Berkeley. 2004.

Parameters

Type	Name	Default	Description
Integer	NSta (from RadiationBaseData)	size(tauGlaSol, 2)	Number of window states for electrochromic windows (set to 1 for regular windows)
Boolean	haveExteriorShade (from PartialRadiation)		Set to true if window has an exterior shade
Boolean	haveInteriorShade (from PartialRadiation)		Set to true if window has an interior shade
Modelica.Units.SI.Area	AWin (from PartialRadiation)		Area of window
Boolean	haveShade (from PartialRadiation)	haveExteriorShade or haveInteriorShade	Set to true if window has a shade
Buildings.HeatTransfer.Windows.BaseClasses.RadiationData	radDat (from PartialRadiation)		Optical properties of window for different irradiation angles
Glass
Integer	N (from RadiationBaseData)		Number of glass layers
Modelica.Units.SI.Length[N]	xGla (from RadiationBaseData)		Thickness of glass
Modelica.Units.SI.TransmissionCoefficient[N,:]	tauGlaSol (from RadiationBaseData)		Solar transmissivity of glass
Modelica.Units.SI.ReflectionCoefficient[N,NSta]	rhoGlaSol_a (from RadiationBaseData)		Solar reflectivity of glass at surface a (facing outside)
Modelica.Units.SI.ReflectionCoefficient[N,NSta]	rhoGlaSol_b (from RadiationBaseData)		Solar reflectivity of glass at surface b (facing room-side)
Shade
Modelica.Units.SI.TransmissionCoefficient	tauShaSol_a (from RadiationBaseData)		Solar transmissivity of shade for irradiation from air-side
Modelica.Units.SI.TransmissionCoefficient	tauShaSol_b (from RadiationBaseData)		Solar transmissivity of shade for irradiation from glass-side
Modelica.Units.SI.ReflectionCoefficient	rhoShaSol_a (from RadiationBaseData)		Solar reflectivity of shade for irradiation from air-side
Modelica.Units.SI.ReflectionCoefficient	rhoShaSol_b (from RadiationBaseData)		Solar reflectivity of shade for irradiation from glass-side

Connectors

Type	Name	Description
Modelica.Blocks.Interfaces.RealInput	uSha (from PartialRadiation)	Control signal for shading (0: unshaded; 1: fully shaded)
Modelica.Blocks.Interfaces.RealInput	HDif (from PartialRadiation)	Diffussive solar radiation
Modelica.Blocks.Interfaces.RealInput	incAng (from PartialRadiation)	Incident angle
Modelica.Blocks.Interfaces.RealInput	HDir (from PartialRadiation)	Direct solar radiation
Modelica.Blocks.Interfaces.RealInput	HRoo	Diffussive radiation from room
Modelica.Blocks.Interfaces.RealOutput[NSta]	QAbsExtSha_flow	Absorbed interior and exterior radiation by exterior shading device
Modelica.Blocks.Interfaces.RealOutput[NSta]	QAbsIntSha_flow	Absorbed interior and exterior radiation by interior shading device
Modelica.Blocks.Interfaces.RealOutput[N,NSta]	QAbsGlaUns_flow	Absorbed interior and exterior radiation by unshaded part of glass
Modelica.Blocks.Interfaces.RealOutput[N,NSta]	QAbsGlaSha_flow	Absorbed interior and exterior radiation by shaded part of glass

Components

Type	Name	Default	Description
Modelica.Units.SI.Power[2,N + 2,NSta]	absRad		Absorbed interior and exterior radiation. (absRad[2,1,iSta]: exterior shading device, absRad[1,2 to N+1,iSta]: glass (unshaded part), absRad[2,2 to N+1,iSta]: glass (shaded part), absRad[2,N+2,iSta]: interior shading device) with iSta being the state of the (electrochromic) window

Revisions

October 22, 2016, by Michael Wetter:
Added range for loop variable for JModelica.
Made units of HRoo final.
Removed unused protected constants k, Interior and Exterior.
August 7, 2015, by Michael Wetter:
Revised model to allow modeling of electrochromic windows. This is for issue 445.
January 21, 2015, by Michael Wetter:
Changed initial algorithm to initial equation section and removed dublicate assignments. This is required for OpenModelica.
October 17, 2014, by Michael Wetter:
Added missing each keywords in parameter declarations.
March 4, 2011, by Wangda Zuo:
Removed the if-statement and integer function that can trigger events.
February 2, 2010, by Michael Wetter:
Made connector uSha a conditional connector.
December 15, 2010, by Wangda Zuo:
Separate transmittance and absorbance.
December 12, 2010, by Michael Wetter:
Replaced record Buildings.HeatTransfer.Data.GlazingSystems with the parameters used by this model. This was needed to integrate the radiation model into the room model.
December 10, 2010, by Wangda Zuo:
First implementation.