| 摘要 |
PURPOSE:To suppress an abnormal rise of temperature in heat collecting fin at the time of no-water heating, by providing a shape memorizing alloy in a part of heat collecting fin in plate form, and by facing the back side of the fin, of which solar rays absorbing rate is made small by bending the alloy in U-form when the temperature is high, to the solar rays. CONSTITUTION:A heat collector consists of a tubular heat collecting tube 3 being welded to a tabulate heat collecting fin 2 in a glass tube 1 of which inner side is vacuumized. In this case, the surface of the heat collecting fin 2 is treated so that its solar rays absorbing rate is high while its back side is low, as well as to connect a form remembering alloy 4 to a part of heat collecting fin 2. The shape memorizing alloy 4 is bent into a U-form which is previously determined, and the back side of a fin 2 is faced to the solar rays, when the temperature in the fin 2 reaches the shape memorizing temperature. With such an arrangement, the temperature in the heat collecting fin 2 in the heat collector is suppressed from abnormally rising under a no-water heating, and also the heat collector is prevented from being broken caused by boiling of a heating medium. |
