PURPOSE: To make possible forced pumping out of water in a head collector or a heat collecting piping circuit in case there is a fear that water may be frozen by a method wherein a jet pump to which a heat collecting circulating pump is used is inserted into a heat collecting piping circuit running from a heat accumulator to a heat collector.
CONSTITUTION: If the temperature of the heat collector 21 falls, a sensor 37 on the high temperature part detects it and when it comes under the previously designated value an electro-magnetic selector value 44 is closed through a controller 36, an electric selector valve 40 is opened and the bypath 28 is opened. At the same time the heat collecting pump 22 starts. Since water flows in the bypath 28, the jet pump 39 operates and excludes forcibly the water in the heat collecting circuit composed of a heat collecting supply tube 24 through a suction tube 41, the heat collector 21 and a heat collecting return tube 25.
OZAKI YUKINORI
MATSUMOTO YOSHIHISA
INOUE TADASHI
MIYOSHI AYATERU
