GB/T 31155-2014Classification of solar energy resources - Global radiation (English PDF)

3.1 Total radiation

PYRANOMETER globalsolarradiation

Receiving from the horizontal plane above the 2pi solid angle to direct and diffuse radiation sum.

3.2 Direct radiation

Direct insolation directsolarradiation; beamsolarradiation

Radiation emitted from the inner surface of the day in and around a small solid angle.

Note. In general, the direct radiation from the viewing angle of about 5 ° measured instrument. Thus, it includes part of the scattered radiation around the solar surface, which ring solar radiation, and

Japan faces its own viewing angle of only about 0.5 °.

3.3 Method to direct radiation

DN And the sun's rays on a plane perpendicular to the received direct radiation.

Note. From the terms of the values of direct radiation and the normal direct radiation is the same; the difference is that direct radiation is emitted by the sun and from the perspective of the definition of law

It is defined from the perspective of the receiving surface to the direct radiation. In the field of solar energy resources, the common law to direct radiation of the term to distinguish the horizontal plane

Direct radiation.

3.4 Horizontal direct radiation

Horizontal direct insolation directhorizontalsolarradiation

DH Horizontal plane to direct radiation received.

Note. The level of direct radiation and the normal relationship between the direct radiation is. DH = DN · sinh = DN · costhetaz

Where DH is the horizontal direct radiation, DN for the law to direct radiation, h is the solar elevation angle, thetaz for the solar zenith angle.