| 摘要 |
PURPOSE:To prevent freezing efficiently without starting and stopping a circulating pump frequently and take out liquid heat medium in the upper part of a heat accumulating tank effectively by a method wherein a circulating circuit, circulating the liquid heat medium in the lower part of the heat accumulating tank to the upper part of the same tank through a heat collector, is provided to circulate the liquid heat medium. CONSTITUTION:A pipe 5, sending the heat medium to the heat collector, is provided with the circulating pump, capable of effecting normal and reverse operations and whose flow amount upon the reverse operation is smaller than the same of the normal operation. When water temperature has become lower than the dangerous temperature of freezing upon heat non-collecting operation in winter, a pump driving device 14 effects the reverse operation of the circulating pump 8 based on the output of a detecting device 13. Hot-water in the upper part of the heat accumulating tank 1 is supplied to the circulating circuit 7 by this operation, therefore, the detecting temperature of a high-temperature side sensor 11 becomes higher than the dangerous temperature of freezing and the freezing of the liquid heat medium may be prevented surely. On the other hand, the circulating amount of heat medium is reduced by the reverse operation of the circulating pump 8 while water, cooled in the circulating circuit, is returned to the lower part of the heat accumulating tank 1, therefore, mixing of hot-water in the upper and lower parts of the same tank 1 is minimized and high- temperature hot-water may be taken out of the heat accumulating tank 1. |
