Effective heat collection and effective solar irradiance of solar heating

Aiming at the problem of traditional solar heating design, proposes the concepts of effective heat collection and effective solar irradiance. Systematically analyses the effective heat collection and effective solar irradiance indexes in typical areas and makes a comparison with the traditional daily average heat collection calculation method. The results show that 11% to 15% of the solar irradiance in winter is invalid, which should be removed from the collector selection calculation and installation orientation optimization. The heat collection temperature has an important effect on the effective heat collection. For the Lhasa area, the effective heat collection of flat plate collectors decreases by about 8% for every 5 ℃ increase of heat collection temperature, and that of vacuum tube collectors decreases by about 4%. The traditional heat collection calculation method adopts daily average calculation methods for both the irradiance and heat collection efficiency, which leads to the uncertainty error of the calculation results. The error is related to local temperature fluctuations, solar irradiance characteristics, heat collection parameters, collector types and so on.