| 摘要 |
<p>PURPOSE:To reduce the quantity of heat radiated and shorten the rise time in heating up water, by a method wherein a pump is provided in a passage conducting water or low-temperature water from a hot water storing tank to a heat exchanger, and a throttle valve is provided in a passage for returning high-temperature water from the heat exchanger to the hot water storing tank. CONSTITUTION:A thermally insulated hot water storing tank 1 and the heat exchanger 4 provided with a combustion part 10 and separated from the tank 1 are provided, the pump 3 is provided in the passage conducting water or low- temperature water from the tank 1 to the heat exchanger 4, and the throttle valve 5 is provided in the passage for returning high-temperature water from the heat exchanger 4 to the tank 1. Namely, since the pressure inside the heat exchanger 4 can be raised, boiling at a heat-transmitting surface for exchanging heat can be restricted, and scaling hardly occurs on the heat-transmitting surface. After hot water temperature in the tank 1 is raised and the pump 3 and combustion are stopped, hot water in the tank 1 flows reversely through a return pipe 9, the heat exchanger 4 and a feed pipe 8 due to natural convection while releasing heat, in this case, the circulating quantity is reduced as the passage resistance is increased. Therefore, the quantity of heat radiated is reduced by providing the valve 5.</p> |
