PURPOSE: To prevent freezing by a method wherein a three-way mixing valve is provided between a heat accumulating tank and a heat collecting pump; the valve having an inlet on the heat accumulating side, an outlet on the pump side and an inlet to a return pipe; and the valves at the inlets are controlled to open in response to the result of detection of the temperature of the flowing out water.
CONSTITUTION: A heat collector 1 and the heat accumulating tank 4 are connected by a feed pipe 7 including a strainer 5, the heat collecting pump PM and a check valve 6 and the return pipe 9 including a check valve 8 to form a circulation circuit 10. The three-way mixing valve MV1 is provided in the feed pipe 7 between the heat accumulating tank 4 and heat collecting pump PM, with its first inlet A connected to the heat accumulating tank side and its outlet AB connected to the pump PM side. A controller 19 is made to receive signals from a heat collector sensor S1, heat accumulating tank sensor S2, freeze preventing thermostat T1, heat collector thermostat T2, outdoor temperature thermostat T3 and reciprocation thermostat T4. The control is carried out to adjust the valve opening at the first and second inlets so that the temperature on the outlet side of the three-way mixing valve is maintained at or higher than a predetermined value in the operation. Thus, the freezing of the heat collector, feed pipe and return pipe can be effectively prevented.
NUNOKAWA HIROYUKI
SEKIGAMI KUNIMORI
TOKYO SANYO ELECTRIC CO
| JPS4840303U | 1973-05-22 | |||
| JPS5226943A | 1977-02-28 | |||
| JPS5246542A | 1977-04-13 |