modelGHI_Splitter

Diagram of GHI_Splitter

Extends from TransiEnt.Basics.Icons.Model (Icon for models).

Information

1. Purpose of model

This model calculates the diffuse fraction of measured GHI d, to estimate the diffuse and direct fraction of GHI onto a horizontal surface. The user can choose between serveral empiric models to calculate the diffuse fraction (Skartveit and Olseth [1], Erbs, Orgill and Hollands or Reindl et al. [2]). The calculation of direct and

diffuse irradation from GHI is highly inaccurate.

2. Level of detail, physical effects considered, and physical insight

(Description)

3. Limits of validity

(Description)

4. Interfaces

irradiance_diffuse_horizontal: output for irradiance in W/m2

GHI_input: input for irradiance in W/m2

irradiance_direct_horizontal: output for irradiance in W/m2

5. Nomenclature

(no elements)

6. Governing Equations

(no equations)

7. Remarks for Usage

(none)

8. Validation

(no validation or testing necessary)

9. References

[1] Skartveit, Arvid; Olseth, Jan Asle, "A model for the diffuse fraction of hourly global radiation". In: Solar Energy 38 (4), S. 271–274. DOI: 10.1016/0038-092X(87)90049-1, 1987.

[2] PVPerformance Modeling Collaborative, "Piecewise Decomposition Models", URL: https://pvpmc.sandia.gov/modeling-steps/1-weather-design-inputs/irradiance-and-insolation-2/direct-normal-irradiance/piecewise_decomp-models, 2018.

10. Version History

Model created by Oliver Schülting (oliver.schuelting@tuhh.de), May 2018

Parameters

TypeNameDefaultDescription
StringDiffuseModel"Skartveit and Olseth"Choose the diffuse fraction correlation

Connectors

TypeNameDefaultDescription
TransiEnt.Basics.Interfaces.Ambient.IrradianceInGHI_input
TransiEnt.Basics.Interfaces.Ambient.IrradianceOutirradiance_direct_horizontalMeasured direct irradiance
TransiEnt.Basics.Interfaces.Ambient.IrradianceOutirradiance_diffuse_horizontalMeasured diffuse irradiance

Components

TypeNameDefaultDescription
Realktclearness Index
Realddiffuse fraction of GHI
Reala1
Realkc
Realdc
Reala2
RealK
Realk0
IrradianceOnATiltedSurfaceirradiance
TransiEnt.SimCentersimCenter