Solar collector having good heat transfer properties - coated with oxygen deficient lead dioxide or other selected semiconductor

摘要

A solar energy collector system comprises a heat transfer member having a surface coating of O-deficient PbO2 or of semiconductor material having a high solar absorptivity alpha, and low emissivity, E. A fluid is fed into heat transfer relationship with the transfer member and from the member to a utilisation zone. Max. heating effect is obtained when alpha, (measured at solar spectrum peaking at 0.5 mu) is high and E, (measured at collector temp or 220 degrees F is approx. 8 mu) is low giving alpha/E pref. =6. An alpha/E of 11 was obtd. from 0.00003 in O-deficient PbO2 coating and alpha/E of 9 for an Si coating of similar thickness.