Using unshaded pyranometer for measuring solar radiation components - - PowerPoint PPT Presentation

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Jun 11, 2023 236 likes •429 views

Using unshaded pyranometer for measuring solar radiation components in the automatic mode Zuev S. V. zuev@imces.ru Institute of Monitoring of Climatic and Ecological Systems SB RAS Russia, 634055, Tomsk, 10/3, Academichesky ave. Shotwave

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Using unshaded pyranometer for measuring solar radiation components in the automatic mode

Zuev S. V. zuev@imces.ru Institute of Monitoring of Climatic and Ecological Systems SB RAS Russia, 634055, Tomsk, 10/3, Academichesky ave.

SLIDE 2

Shotwave radiation balance Bk = Qk - Rk Qk = S` + D S0=1367 W/m² 99 %

λ=0,17-4,0 µm

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Standard methods for measurement of total solar radiation Q

Qk = S`+D Qk = D Qk = (Q`-D)·Kh·Ka+D

SLIDE 4

Shortcomings of standard methods

6 measurements once a day;
requires two devices;
requires human presence or sun tracker.

SLIDE 5

Using unshaded pyranometer

The practice of using unshaded pyranometer for measurement of total solar radiation Qk in automatic mode. Pyranometer CM-11 Kipp & Zonen. Measurement error ≤ 3%. Price 2400 €

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Using unshaded pyranometer

Pyranometer М-115М. Measurement error ≤ 15-20% depending on the altitude and azimuth of the sun

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Correction of the measured total solar radiation

Using clouds like shade disk for unshaded pyranometer (Qk = D) for separation of total solar radiation Q on components S` and D

Qk = S` + D Qk = S`·Kh·Ka + D

for CM-11
for М-115М

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Estimation of direct S` and diffuse D radiations

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Estimation of direct S` and diffuse D radiations

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Estimation of direct S` and diffuse D radiations

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Estimation of direct S` and diffuse D radiations

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Estimation of direct S` and diffuse D radiations Qk = S`·Kh·Ka + D Qk = S` + D

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Duration of solar irradiation

Time when S ≥ 140 W/m2

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Estimation of solar irradiation duration using unshaded pyranometer

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Atmospheric transmission coefficient

using the Bouguér formula

30 ,

S S P

=

using the special tabs

SLIDE 16

Atmospheric turbidity coefficient

using the Linke formula
using the special tabs

=

30 ,

lg 5 , 11

S S T

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Solar radiation characteristics defined by unshaded piranometer

total solar radiation Q;
direct solar radiation S`;
diffuse solar radiation D;
duration of solar irradiation;
atmospheric transmission

coefficient P;

atmospheric turbidity coefficient T.

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