Manual T*SOL basic 5.0 - Valentin Software

7 System Definition User Manual T*SOL
Incident angle modifiers describe the additional reflection losses when the sun is not positioned
vertically above the collector surface area.
A constant diffuse incident angle modifier is stated for diffuse irradiation. For the direct fraction of
radiation, this is defined using the incident angle. In the process, flat-plate and evacuated tube
collectors are treated differently.
For flat-plate collectors, the loss factors for all incident angles are calculated from the incident angle
modifier for the incident angle at 50% deviation from the vertical.
For evacuated tube collectors, the reflection losses differ depending on whether the irradiation is
reflected lengthwise or crosswise to the tube. Due to the multitude of different designs, these
dependencies cannot be specified by one input value. The incident angle modifiers must be given
lengthwise and crosswise to the tube at 5° intervals for all incident angles between 0 and 90°. When
crosswise, these modifiers can have a value higher than 100% due to concentration on curved glass or as
a result of mirror constructions.
7.3.2 Shading
System Definition > Collector Array > Parameters > Shading
Shading is entered in the program in three steps. Define the general parameters, a horizon, and objects
in the medium distance.
On the Parameters page, enter a new reference for every new shade.
7.3.2.1 Shading: Horizon
System Definition > Shading > Horizon
The resulting shade reduces the irradiation to the collector surface area.
Image: Definition of shading via horizon and
individual objects
In order to edit the horizon or objects which are relevant for the shading of your collectors, you must have
made a note of the prominent points of the horizon line from your solar system. This can be done with a
compass and protractor, with a sun path indicator, or with a digital camera and editing software.
A horizon point consists of the azimuth, i.e. the angle has measured from the horizontal and the
respective height angle, also measured in angle degrees.
-> For definition of the azimuth refer to: 7.3.3 Installation
page 55 / 104 Dr. Valentin EnergieSoftware GmbH