Encontro de Energia no Meio Rural

Resumen

RECIERI, Reinaldo Prandini, QUALLIO, Silvana, FERRUZZI, Yuri et al. Models in the estimate of the diffuse solar radiation. In Anales del 5º Encontro de Energia no Meio Rural, 2004, Campinas (SP) [online]. 2004 [citado 28 Abril 2024]. Disponible en: <http://www.proceedings.scielo.br/scielo.php?script=sci_arttext&pid=MSC0000000022004000200022&lng=es&nrm=iso> .

In this work we evaluate, by means of polynomial regression analysis, several models that relate the diffuse fraction of the global radiation (K_d) with the clearness index (K_t). The experiment was conducted in the Solar Radiometry Station of Cascavel/PR from the first of January to the 31^st of December, in the year of 2001. The solar radiation components were monitored by the following manufactured instruments: Pyranometer (KIPP&ZONEN (CM3) and pirheliometer (EPPLEY NIP) connected in a sun tracker (ST-1 model). A datalogger CR10X from the CAMPBELL SCIENTIFIC was used in the data acquisition. This datalogger was programmed in the frequency of 1 Hz storing an average of 5 minutes of collected data. Among the equations the best values of RMSE an MBE were find in the 4^th and 3^rd degrees, respectively. We also find that the 4^th degree polynomial equation ( K_d=1,172-1,001K_t+3,992K_t²-11,742K _t³+7,698K_t⁴) generalizes the utilization of equations for diffuse solar radiation estimation. This means that this equation probably can be applied for any place and climatic conditions.

Palabras llave : Radiação solar difusa; Modelo de estimativa; índice de claridade.