Buildings.BoundaryConditions.SolarIrradiation

Information

Package Content

Name	Description
DiffuseIsotropic	Diffuse solar irradiation on a tilted surface with an isotropic sky model
DiffusePerez	Hemispherical diffuse irradiation on a tilted surface using Perez's anisotropic sky model
DirectTiltedSurface	Direct solar irradiation on a tilted surface
Examples	Collection of models that illustrate model use and test models
BaseClasses

Buildings.BoundaryConditions.SolarIrradiation.DiffuseIsotropic

Information

This component computes the hemispherical diffuse irradiation on a tilted surface using an isotropic model. The irradiation is a sum composed of diffuse solar irradiation and radiation reflected by the ground. For a definition of the parameters, see the User's Guide.

References

Extends from Buildings.BoundaryConditions.SolarIrradiation.BaseClasses.PartialSolarIrradiation (Partial model that is used to compute the direct and diffuse solar irradiation).

Parameters

Type	Name	Default	Description
Angle	til		Surface tilt [rad]
Real	rho	0.2	Ground reflectance

Connectors

Type	Name	Description
output RealOutput	H	Radiation per unit area [W/m2]
Bus	weaBus	Bus with weather data

Modelica definition

block DiffuseIsotropic 
  "Diffuse solar irradiation on a tilted surface with an isotropic sky model"
  extends Buildings.BoundaryConditions.SolarIrradiation.BaseClasses.PartialSolarIrradiation;
public 
  parameter Real rho=0.2 "Ground reflectance";
protected 
  Buildings.BoundaryConditions.SolarIrradiation.BaseClasses.DiffuseIsotropic
    HDifTilIso(til=til, rho=rho);

equation 
  connect(weaBus.HGloHor, HDifTilIso.HGloHor);
  connect(weaBus.HDifHor, HDifTilIso.HDifHor);

  connect(HDifTilIso.HDifTil, H);
end DiffuseIsotropic;

Buildings.BoundaryConditions.SolarIrradiation.DiffusePerez

Information

This component computes the hemispherical diffuse irradiation on a tilted surface using an anisotropic sky model proposed by Perez. For a definition of the parameters, see the User's Guide.

References

• P. Ineichen, R. Perez and R. Seals (1987). The Importance of Correct Albedo Determination for Adequately Modeling Energy Received by Tilted Surface, Solar Energy, 39(4): 301-305.
• R. Perez, R. Seals, P. Ineichen, R. Stewart and D. Menicucci (1987). A New Simplified Version of the Perez Diffuse Irradiance Model for Tilted Surface, Solar Energy, 39(3): 221-231.
• R. Perez, P. Ineichen, R. Seals, J. Michalsky and R. Stewart (1990). Modeling Dyalight Availability and Irradiance Componets From Direct and Global Irradiance, Solar Energy, 44(5):271-289.

Extends from Buildings.BoundaryConditions.SolarIrradiation.BaseClasses.PartialSolarIrradiation (Partial model that is used to compute the direct and diffuse solar irradiation).

Parameters

Type	Name	Default	Description
Angle	til		Surface tilt [rad]
Real	rho	0.2	Ground reflectance
Angle	lat		Latitude [rad]
Angle	azi		Surface azimuth [rad]

Connectors

Type	Name	Description
output RealOutput	H	Radiation per unit area [W/m2]
Bus	weaBus	Bus with weather data

Modelica definition

block DiffusePerez 
  "Hemispherical diffuse irradiation on a tilted surface using Perez's anisotropic sky model"
  extends Buildings.BoundaryConditions.SolarIrradiation.BaseClasses.PartialSolarIrradiation;

  parameter Real rho=0.2 "Ground reflectance";
  parameter Modelica.SIunits.Angle lat "Latitude";
  parameter Modelica.SIunits.Angle azi "Surface azimuth";

protected 
  BaseClasses.DiffusePerez HDifTil(final til=til, final rho=
          rho);
  BaseClasses.SkyClearness skyCle;
  BaseClasses.BrighteningCoefficient briCoe;
  BaseClasses.RelativeAirMass relAirMas;
  BaseClasses.SkyBrightness skyBri;
  SolarGeometry.IncidenceAngle incAng(
    lat=lat,
    azi=azi,
    til=til);
  SolarGeometry.ZenithAngle zen(lat=lat);
equation 
  connect(relAirMas.relAirMas, skyBri.relAirMas);
  connect(skyBri.skyBri, briCoe.skyBri);
  connect(skyCle.skyCle, briCoe.skyCle);
  connect(incAng.y, HDifTil.incAng);
  connect(zen.y, skyCle.zen);
  connect(zen.y, relAirMas.zen);
  connect(zen.y, briCoe.zen);
  connect(HDifTil.zen, zen.y);
  connect(weaBus.HGloHor, skyCle.HGloHor);
  connect(weaBus.HDifHor, skyCle.HDifHor);
  connect(weaBus.HDifHor, skyBri.HDifHor);
  connect(weaBus.HGloHor, HDifTil.HGloHor);
  connect(weaBus.HDifHor, HDifTil.HDifHor);
  connect(briCoe.F2, HDifTil.briCof2);
  connect(briCoe.F1, HDifTil.briCof1);
  connect(HDifTil.HDifTil, H);
  connect(weaBus, incAng.weaBus);
  connect(weaBus, zen.weaBus);
end DiffusePerez;

Buildings.BoundaryConditions.SolarIrradiation.DirectTiltedSurface

Information

This component computes the direct solar irradiation on a tilted surface. For a definition of the parameters, see the User's Guide.

Extends from Buildings.BoundaryConditions.SolarIrradiation.BaseClasses.PartialSolarIrradiation (Partial model that is used to compute the direct and diffuse solar irradiation).

Parameters

Type	Name	Default	Description
Angle	til		Surface tilt [rad]
Angle	lat		Latitude [rad]
Angle	azi		Surface azimuth [rad]

Connectors

Type	Name	Description
output RealOutput	H	Radiation per unit area [W/m2]
Bus	weaBus	Bus with weather data
output RealOutput	inc	Incidence angle [rad]

Modelica definition

block DirectTiltedSurface 
  "Direct solar irradiation on a tilted surface"
  import Buildings;
  extends Buildings.BoundaryConditions.SolarIrradiation.BaseClasses.PartialSolarIrradiation;

  parameter Modelica.SIunits.Angle lat "Latitude";
  parameter Modelica.SIunits.Angle azi "Surface azimuth";

  Buildings.BoundaryConditions.WeatherData.Bus weaBus;

  Modelica.Blocks.Interfaces.RealOutput inc(
    final quantity="Angle",
    final unit="rad",
    displayUnit="deg") "Incidence angle";

protected 
  SolarGeometry.IncidenceAngle incAng(
    final azi=azi,
    final til=til,
    final lat=lat);
  Buildings.BoundaryConditions.SolarIrradiation.BaseClasses.DirectTiltedSurface
    HDirTil;

equation 
  connect(incAng.y, HDirTil.incAng);

  connect(weaBus.HDirNor, HDirTil.HDirNor);
  connect(incAng.y, inc);
  connect(HDirTil.HDirTil, H);

  connect(weaBus, incAng.weaBus);
end DirectTiltedSurface;