SOLAR HEAT-COLLECTING SYSTEM

PURPOSE:To obtain the title system whereby the advantage of an open type heat-collecting circuit is made the best use of, and the interval of maintenance can be lengthened by replenishing a decrease caused by the evaporation of a heat medium. CONSTITUTION:The title system 1 has a collector 2 for collecting solar heat, a heat storage tank 3 in which the solar heat can be accumulated, a heat- exchanger 4 provided at the inside of the heat storage tank 3, and a heat- collecting circuit 5 in which a heat medium is allowed to circulate between the collector 2 and the heat-exchanger 4. A heat medium-replenishing means 8 is provided, by which the heat medium is replenished in a heat medium storage tank 51 provided in the course of the heat-collecting circuit 5 when the heat medium within the heat medium storage tank 51 is decreased. For the heat mediums-replenishing means 8, a heat medium-replenishing tank 81 for storing the heat medium is provided and the lower part thereof is connected to the heat medium storage tank 51 through a check valve by which the heat medium can flow only toward the heat storage tank 51 out of the heat-replenishing tank 81.