JPS6311546Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to a freezing prevention device for a stop-start type water heater.

For water heaters used in cold regions, when hot water supply is stopped, the temperature of the atmosphere changes from the water pressure reactor, heat collector,
When the water stagnant inside the vessel consisting of piping, etc. falls to a freezing temperature, the atmospheric temperature or water temperature is detected and an antifreeze device is activated to prevent damage to the vessel due to freezing of the stagnant water. However, this antifreeze device has conventionally detected the atmospheric temperature or water temperature and opened the antifreeze valve (drain valve) to automatically drain a predetermined amount of tap water into the container to lower the temperature inside the container. In addition to water-flow type antifreeze devices that prevent water from freezing, there are other types of antifreeze devices that detect atmospheric or water temperature, open a drain valve, and drain only the water that remains inside the container. The problem is that it is considered wasteful. In addition, there are heating-type antifreeze devices that detect atmospheric temperature or water temperature and turn on a heater to heat the accumulated water and keep the accumulated water above a predetermined temperature to prevent freezing. In this case, the structure is such that the heat collector etc. are protected from freezing only by the transfer of temperature by the heater, which requires a heater with a considerably large capacity, which is extremely uneconomical.

This invention improves these drawbacks and makes it possible to prevent freezing properly, reliably, and economically.

One embodiment will be described below with reference to the drawings.

Figures 1 and 2 illustrate the case where it is applied to a first stop type instantaneous gas water heater.
A water pressure-responsive gas flasher 2 is installed in the water supply waterway, and a gas burner (not shown) can be appropriately turned on and off according to fluctuations in water supply pressure to properly heat the heat collector A. It's becoming like that. Reference numeral 3 denotes a hot water supply path from the heat collector A, which is equipped with a hot water tap (not shown) at its tip, and is of a first-stop type in which hot water can be supplied by opening and closing the hot water tap. Reference numeral 4 denotes a bypass path in which the water supply channel 1 and the hot water supply channel 3 are communicated with each other at a position below the heat collector A, and the bypass channel 4 has an air temperature or a water temperature of freezing temperature (for example, about 1 to 2 degrees Celsius) when the water is stopped. ), a heater 5 is provided which detects this and heats the retained water to cause circulating convection, and a check valve V which prevents a flow contrary to the circulating convection. The heater 5 has a structure in which the heat source is turned on and off by sensing the atmospheric temperature or the accumulated water temperature using a temperature sensing element. In addition, the check valve V is structured so that it closes due to the differential pressure between the water supply side and the hot water supply side when water is being supplied, that is, when hot water is being supplied, but it is automatically opened when water is stopped, that is, when hot water supply is stopped. There is. Its specific structure is as illustrated in FIG.
The valve stem 11 is slidably inserted into the retaining ring 12.
A spring 13 is interposed between the mounting support portion 10 and the valve 8 so that the valve 8 is kept open at all times to prevent it from coming off. The structure of this check valve V may be any suitable structure in addition to the above-mentioned embodiments, but is free to implement.

With the above configuration, when hot water is supplied, the valve 8 of the check valve V is activated by the differential pressure between the water supply side and the hot water supply side.
The water supply channel 1 is closed because it comes in close contact with the valve seat 7 against the
The water supply from the heat collector A to the hot water supply route 3 and the hot water supply from the hot water supply path 3 are properly performed by opening the hot water supply tap, and when the hot water supply tap is closed to stop hot water supply, the differential pressure between the water supply side and the hot water supply side disappears. Therefore, valve 8 of check valve V is spring 13
The resilient force causes the water supply channel 1 and the hot water supply channel 3 to communicate with each other via the bypass channel 4. Therefore, when the temperature of the atmosphere drops and the atmospheric temperature or water temperature reaches near the freezing temperature, the heater 5 is turned on to heat the accumulated water. At this time, the bypass passage 4 is provided at a position below the heat collector A, and since the accumulated water in this part is heated by the heater 5, there is a difference in water head from the heat collector A, and the lower part of the accumulated water is heated. As a result, a difference in the density of the cold water and the heated hot water occurs, and the stagnant water flows through the bypass path 4 → water supply path 1 → collector A → hot water supply path 3 → bypass path 4, as shown by arrow a in Figure 1. Circulation convection occurs slowly following the path.

Figures 3 and 4 show an example of application to a stop-start mixing type gas water heater, in which a mixing bypass passage 4 can be used, and a heater 5 and a check valve are connected to the bypass passage 4. It is sufficient to provide V. The check valve V is open during hot water supply and heating circulation convection when the hot water supply is stopped, but it is designed to automatically close against backflow from the hot water supply path 3 to prevent backflow to the water supply side. If there is no danger, the check valve V is not necessarily necessary. The heater 5 has the same structure as in the previous embodiment. In this case, when the atmospheric temperature or the water temperature drops to near the freezing temperature when hot water supply is stopped, this is detected and the heater 5 is turned on to heat the accumulated water, thereby performing its circulating convection.
Circulating convection in the case where the check valve V is provided is performed according to the same principle as in the previous embodiment, but the flow direction uses the mixing bypass path of the mixing type gas water heater as it is. Although the direction is reversed from 1 to 3 (see arrow a in Figure 3), the antifreeze effect is the same. In addition, in a mixing type, the mixing bypass path is closed when hot water is tapped at the highest temperature, so if you leave the hot water for a long time after hot water is tapped in extremely cold weather, it is necessary to return the hot water temperature adjustment shaft to a low temperature and leave the bypass path open. .

As explained above, this device has a bypass passage connecting the water supply passage and the hot water supply passage, located below the solar collector, and a heater and a check valve are provided in this bypass passage.When the air temperature or water temperature drops close to the freezing point, the heater is turned on to heat the stagnant water, and the difference in density between the cold water and the heated hot water causes it to circulate by convection, so that a small-capacity heater can be used to properly and reliably prevent freezing even in severe cold.

[Brief explanation of drawings]

FIG. 1 is a schematic configuration diagram showing an embodiment of this invention, and FIG. 2 is a sectional view showing a specific example of the check valve.
FIG. 3 is a schematic configuration diagram of a different embodiment, and FIG. 4 is a sectional view showing a specific example of the check valve. A... Heat collector, 1... Water supply channel, 2... Water pressure responsive gas blinker, 3... Hot water supply path, 4... Bypass path, 5... Heater, V... Check valve.

Claims (1)

[Scope of utility model registration request] The water supply channel to the heat collector and the hot water supply channel from the heat collector are connected by a bypass path at a position below the heat collector, and the bypass path has a heater that heats and circulates convection of the accumulated water when the water is cut off, and a heater that reverses the circulation convection. A freezing prevention device for a stop-start water heater, characterized in that it is provided with a check valve that prevents the flow from occurring.