Chapter 3 Calculation of radiation Errors of estimation depends on: Start values of Jo Function forms of F(x) and involved influencing factors Empirical relative errors For 0: 5% For d and s: 10o For Fo: 10-15%o 2021/2/22 Assessment of Climate/Change Impacts 16 of x
Chapter 3 2021/2/22 Assessment of Climate/Change Impacts 16 of x Calculation of Radiation Errors of estimation depends on: • Start values of Jo • Function forms of F(x) and involved influencing factors • Empirical relative errors : For Q: 5% For D and S: 10% For Fo: 10-15%
Chapter 3 Calculation of ground solar radiation Q=Qi*F(X) Qi--astronomical solar radiation(Qa) Qi--clear radiance, possible ground solar radiation in a clear sky ( Qo) Qi--ground solar radiation through ideal (dry) atmosphere(Qm) 2021/2/22 Assessment of Climate/Change Impacts 17 of x
Chapter 3 2021/2/22 Assessment of Climate/Change Impacts 17 of x Calculation of Ground Solar Radiation Q=Qi*F(x) • Qi--astronomical solar radiation (Qa) • Qi--clear radiance, possible ground solar radiation in a clear sky (Qo) • Qi--ground solar radiation through ideal (dry) atmosphere (Qm)
Chapter 3 Calculation of ground solar radiation Qa(w/m'day) (24/m)o/p2)( Qsinφ·sinS+cosφ·cosS·sino) 0。= arccos(- ttgδ) l/p2=1.00011+0.03422lcoo+0.00128sino +0.000719c0s20+0.000077sin260 8=(0.006918-0.399912c0s00+0.070257sino 0.006758c0s260+0.000907sin200-0.002697c0s390 +0.000148sin30o)(180/)( degree) 60=2π(dn-1)365(弧度) p=b/a 2021/2/22 Assessment of Climate/Change Impacts 18 of x
Chapter 3 2021/2/22 Assessment of Climate/Change Impacts 18 of x Calculation of Ground Solar Radiation Qa(W/m2 day) =(24/)(Io/ 2 )(o·sin ·sin + cos· cos·sino ) • o=arccos(-tgtg) • 1/ 2 = 1.00011+0.034221coso+0.00128sino +0.000719 cos2o+0.000077sin2o • = (0.006918-0.399912coso+0.070257sino -0.006758cos2o+0.000907sin2o-0.002697cos3o +0.000148sin3o)(180/)（degree) • o = 2(dn-1)/365 (弧度） • =b/a
Chapter 3 Calculation of ground solar radiation Qa(w/mday) 247)(Io/p2)(osinφ·sinδ+cosφ·cos6·sino) Io-solar constant, 1367 W/m2 @. -solar angels of sun raise and sunset 0 φ- latitude 8sun赤纬 °dn-— the series number of the day b/a ssessment of Climate/ Change Impact 19 of x
Chapter 3 Assessment of Climate/Change Impacts 19 of x Calculation of Ground Solar Radiation Qa(W/m2 day) =(24/)(Io/ 2 )(o·sin ·sin + cos· cos·sino ) • Io –solar constant, 1367 W/m2 • o –solar angels of sun raise and sunset • --latitude • sun 赤纬 • dn—the series number of the day • =b/a
Chapter 3 Calculation of ground solar radiation Qm(w/m) ground solar radiation through dry air Reference 王炳忠等,我国太阳能资源及其计算,太阳能 学报,1980,1(1):1-9 ssessment of Climate/ Change Impact 20 of x
Chapter 3 Assessment of Climate/Change Impacts 20 of x Calculation of Ground Solar Radiation Qm(W/m2 ) • ground solar radiation through dry air Reference: 王炳忠等，我国太阳能资源及其计算，太阳能 学报，1980，1（1）：1-9