Buildings.BoundaryConditions.SolarIrradiation.BaseClasses
Package with base classes for Buildings.BoundaryConditions.SolarIrradiation
Information
This package contains base classes that are used to construct the models in Buildings.BoundaryConditions.SolarIrradiation.
Extends from Modelica.Icons.BasesPackage (Icon for packages containing base classes).
Package Content
Name | Description |
---|---|
BrighteningCoefficient | Circumsolar and horizon brightening coefficients |
DiffuseIsotropic | Diffuse solar irradiation on a tilted surface with an isotropic model |
DiffusePerez | Hemispherical diffuse irradiation on a tilted surface with Perez's anisotropic model |
DirectTiltedSurface | Direct solar irradiation on a tilted surface |
PartialSolarIrradiation | Partial model that is used to compute the direct and diffuse solar irradiation |
RelativeAirMass | Relative air mass |
SkyBrightness | Sky brightness |
SkyClearness | Sky clearness |
Examples | Collection of models that illustrate model use and test models |
Buildings.BoundaryConditions.SolarIrradiation.BaseClasses.BrighteningCoefficient
Circumsolar and horizon brightening coefficients
Information
This component computes the circumsolar and horizon brightening coefficients.
Extends from Modelica.Blocks.Icons.Block (Basic graphical layout of input/output block).
Connectors
Type | Name | Description |
---|---|---|
input RealInput | zen | Zenith angle of the sun beam [rad] |
input RealInput | skyCle | Sky clearness. skyCle=1: overcast sky; skyCle=8 clear sky |
input RealInput | skyBri | Sky brightness [0,1] |
output RealOutput | F1 | Circumsolar brightening coefficient |
output RealOutput | F2 | Horizon brightening coefficient |
Modelica definition
Buildings.BoundaryConditions.SolarIrradiation.BaseClasses.DiffuseIsotropic
Diffuse solar irradiation on a tilted surface with an isotropic model
Information
This component computes the hemispherical diffuse irradiation on a tilted surface. The irradiation is composed of the diffuse horizontal solar irradiation and the irradiation that has been reflected by the ground. Both components are adjusted to take into account the tilt of the receiving surface.
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.Extends from Modelica.Blocks.Icons.Block (Basic graphical layout of input/output block).
Parameters
Type | Name | Default | Description |
---|---|---|---|
Real | rho | 0.2 | Ground reflectance |
Angle | til | til(displayUnit="deg") | Surface tilt angle [rad] |
Connectors
Type | Name | Description |
---|---|---|
input RealInput | HDifHor | Horizontal diffuse solar radiation [W/m2] |
input RealInput | HGloHor | Horizontal global radiation [W/m2] |
output RealOutput | HGroDifTil | Diffuse solar irradiation on a tilted surface from the ground [W/m2] |
output RealOutput | HSkyDifTil | Diffuse solar irradiation on a tilted surface from the sky [W/m2] |
Modelica definition
Buildings.BoundaryConditions.SolarIrradiation.BaseClasses.DiffusePerez
Hemispherical diffuse irradiation on a tilted surface with Perez's anisotropic model
Information
This component computes the hemispherical diffuse irradiation on a tilted surface by using an anisotropic model proposed by Perez.
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 Modelica.Blocks.Icons.Block (Basic graphical layout of input/output block).
Parameters
Type | Name | Default | Description |
---|---|---|---|
Real | rho | 0.2 | Ground reflectance |
Angle | til | til(displayUnit="deg") | Surface tilt angle [rad] |
Connectors
Type | Name | Description |
---|---|---|
input RealInput | briCof1 | Brightening Coeffcient F1 |
input RealInput | briCof2 | Brightening Coeffcient F2 |
input RealInput | HDifHor | Diffuse horizontal solar radiation [W/m2] |
input RealInput | HGloHor | Global horizontal radiation [W/m2] |
input RealInput | zen | Zenith angle of the sun beam [rad] |
input RealInput | incAng | Solar incidence angle on the surface [rad] |
output RealOutput | HGroDifTil | Hemispherical diffuse solar irradiation on a tilted surface from the ground [W/m2] |
output RealOutput | HSkyDifTil | Hemispherical diffuse solar irradiation on a tilted surface from the sky [W/m2] |
Modelica definition
Buildings.BoundaryConditions.SolarIrradiation.BaseClasses.DirectTiltedSurface
Direct solar irradiation on a tilted surface
Information
This component computes the direct solar irradiation on a tilted surface.
Extends from Modelica.Blocks.Icons.Block (Basic graphical layout of input/output block).
Connectors
Type | Name | Description |
---|---|---|
input RealInput | incAng | Incidence angle of the sun beam on a tilted surface [rad] |
input RealInput | HDirNor | Direct normal radiation [W/m2] |
output RealOutput | HDirTil | Direct solar irradiation on a tilted surface [W/m2] |
Modelica definition
Buildings.BoundaryConditions.SolarIrradiation.BaseClasses.PartialSolarIrradiation
Partial model that is used to compute the direct and diffuse solar irradiation
Information
This is a partial model that is used to implement the direct and diffuse irradiation.
Extends from Modelica.Blocks.Icons.Block (Basic graphical layout of input/output block).
Parameters
Type | Name | Default | Description |
---|---|---|---|
Angle | til | til(displayUnit="deg") | Surface tilt [rad] |
Connectors
Type | Name | Description |
---|---|---|
output RealOutput | H | Radiation per unit area [W/m2] |
Bus | weaBus | Bus with weather data |
Modelica definition
Buildings.BoundaryConditions.SolarIrradiation.BaseClasses.RelativeAirMass
Relative air mass
Information
This component computes the relative air mass for sky brightness.
References
R. Perez (1999). Fortran Function irrpz.f, Emailed by R. Perez to F.C. Winkelmann on May 21, 1999.Extends from Modelica.Blocks.Icons.Block (Basic graphical layout of input/output block).
Connectors
Type | Name | Description |
---|---|---|
input RealInput | zen | Zenith angle of the sun beam [rad] |
output RealOutput | relAirMas | Relative air mass |
Modelica definition
Buildings.BoundaryConditions.SolarIrradiation.BaseClasses.SkyBrightness
Sky brightness
Information
This component computes the sky brightness.
References
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 Modelica.Blocks.Icons.Block (Basic graphical layout of input/output block).
Connectors
Type | Name | Description |
---|---|---|
input RealInput | relAirMas | Relative air mass |
input RealInput | HDifHor | Horizontal diffuse solar radiation [W/m2] |
output RealOutput | skyBri | Sky brightness |
Modelica definition
Buildings.BoundaryConditions.SolarIrradiation.BaseClasses.SkyClearness
Sky clearness
Information
This component computes the sky clearness.
Implementation
In the Buildings
library, HGloHor
is always larger than 1E-4,
minus some small undershoot due to regularization. Hence,
the implementation is not simplified for
HGloHor < Modelica.Constants.small
.
The function call
Buildings.Utilities.Math.Functions.smoothMax
is such that the regularization is usually not triggered.
Extends from Modelica.Blocks.Icons.Block (Basic graphical layout of input/output block).
Connectors
Type | Name | Description |
---|---|---|
input RealInput | zen | Zenith angle of the sun beam [rad] |
input RealInput | HDifHor | Horizontal diffuse solar radiation [W/m2] |
input RealInput | HGloHor | Horizontal global solar radiation [W/m2] |
output RealOutput | skyCle | Sky clearness. skyCle=1: overast sky; skyCle=8: clear sky |