A stock water solar heating system

摘要

This paper reports on the progress in the development of an inexpensive but rugged solar system to heat stock water. Insulation encased in fiber reinforced concrete is the main structural component for the collector and the partition between the unheated stock tank and the heated section. A fully wetted, drain-back collector was designed to produce a high optical efficiency and to permit its water passage to be opened for cleaning. A unique double-glazed design is used in which the inner glazing is a film with a large thermal expansion coefficient. This causes a significant drop in the stagnation temperatures since a single glazed configuration is approached at high temperatures. The collector and the partially covered insulated tank prevented freezing, and held the average water temperature at 6.4°C (44 °F) during the day while the mean daily ambient temperature was -5.4 °C (22°F) over a nine day test.