JPS62261855A - Instantaneous hot-water supplier - Google Patents

Abstract

PURPOSE:To eliminate the delay of supplying hot-water and the uneconomical throw-away water of much amount by providing a circulating pump and a non-return valve which are connected to a return pipe. CONSTITUTION:One end of a return pipe 14 is connected to a connector 9 and the other end of the return pipe 14 is connected to a feed water pipe 7. A circulating pump 16 and a non-return valve 17 are connected to the return pipe 14. The circulating pump 16 moves water in the return pipe 14 toward the feed water pipe 7 from the connector 9 and the capacity of the same pump is so small that the flow rate thereof is 2-3l/min. When the circulating pump 16 is driven, hot-water circulates through the return pipe 14, therefore, the temperature reduction as well as the temperature variation of the hot-water in the feed water pipe 8 and the connector 9 may be prevented. Accordingly, in case a terminal water supply cock 11 is opened after comparatively long time has elapsed from the previous use of the same cock, hot-water with a desired temperature may be obtained in a short period of time.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application in terms of Sound Volume] The present invention relates to an instantaneous water heater 2 used in a general household, such as a stop-start water heater directly connected to a water supply.

[Conventional technology]

Conventionally, this type of instantaneous hot water heater has a terminal hot water tap 9 connected to a hot water pipe terminal, such as a water faucet, when the faucet is fully opened.

Water moves through the water supply pipe to the heat exchanger, is heated by combustion heat in the burner, and then flows out through the hot water supply pipe and from the terminal hot water tap.

[Problems to be Solved by the Invention] By the way, in conventional instantaneous hot water heaters, the water temperature in the hot water supply pipe drops after a relatively long time has passed since the last use. Cold water flows out. That is, it takes time for the hot water heated by the heat exchanger to flow through the hot water supply pipe to the terminal hot water tap. This causes problems such as the inconvenience that hot water does not come out immediately even when the terminal hot water tap is opened, and the uneconomical problem of discarding a large amount of water.

[Means for solving problems]

The instant hot water supply device according to the present invention includes a burner that burns fuel, a heat exchanger that is heated by the combustion heat of the burner,
It includes a water supply pipe connected to the inlet side of the heat exchanger and a hot water supply pipe connected to the outlet side of the heat exchanger, and controls hot water temperature by changing the combustion amount (including zero) in the burner. A connector connected to the tip of the water supply pipe, a terminal hot water tap connected to the connector, a return pipe connected between the connector and the water supply pipe, and the return pipe. It is characterized by comprising a circulation pump and a check valve connected to the pipe.

〔Example〕

Nine embodiments of the present invention will be described below with reference to the drawings.

Referring to FIG. 1, an instantaneous water heater according to an embodiment of the present invention includes a main body 1 of the water heater.

A burner 2 is installed inside the main body 1. Burner 2
The fuel supplied by the fuel pump 3 is combusted in the combustion chamber 4. An exhaust pipe 5 is provided above the combustion chamber 4.

A heat exchanger 6 is arranged in the combustion chamber 4. A water supply pipe 7 on the inlet side and a hot water supply pipe 8 on the outlet side are connected to the heat exchanger 6. The water supply pipe 7 is directly connected to a household water pipe (not shown). On the other hand, the hot water supply pipe 8 is extended to the outside of the main body 1, and a connector 9 is connected to the tip thereof. A plurality of (for example, three) terminal hot water taps 11 such as faucets are connected to the connector 9 . It is desirable that the distance from the connector 9 to the terminal hot water tap 11 be short. The connector 9 has a built-in flow control valve 12t and applies equal pressure to the plurality of terminal hot water taps 11, and is called a pressure equalizing header. 13 indicates a drain valve.

Further, a return pipe 14 is fully connected to the connector 9 at one end. The other end of the return pipe 14 is connected to the water supply pipe 7. A circulation pump 16 and a check valve 17 are connected to such a return pipe 14. The circulation pump 16 moves the water in the return pipe 14 in the direction from the connector 9 to the water supply pipe 7, and has a small capacity with a flow rate of 2 to 317 minutes. Also check valve 17
Needless to say, this serves to prevent water from flowing backward through the return pipe 14.

Furthermore, a flow sensor 18 is provided near the inlet of the heat exchanger 6 to detect the presence or absence of water flow in the water supply pipe 7. Also, near the outlet of the heat exchanger 6, there is a first temperature detector 21 such as a thermistor for detecting the temperature of hot water in the hot water supply pipe 8.
is provided.

The connector 9 is also provided with a second temperature detector 22 such as a thermistor for detecting the temperature of the water inside the connector 9.

The instantaneous water heater of this embodiment further includes a control device 26. This control device 26 includes the flow sensor 1 described above.
8. First temperature detector 21. and second temperature detector 22
Depending on the output from the fuel pump 3 and circulation pump 16, etc.
This controls the driving of the

When hot water supply is stopped, combustion in burner 2 is also stopped. When the terminal hot water tap 11 is opened, fuel supplied from the fuel pump 3 is combusted in the burner 2 based on the 9 ignition signal. After the water supplied through all the water supply pipes 7 is heated by the heat exchanger 6, it passes through the hot water supply pipe 8 and the connector 9, and flows out from the terminal hot water tap 11 as hot water. Further, the combustion gas generated in the burner 2 is transferred to the combustion chamber 4. It is discharged to the outside of the main body 1 through the surroundings of the heat exchanger 6 and the exhaust pipe 5.

By the way, when the circulation pump 16 is driven, hot water circulates through the entire return pipe 14, so by appropriately controlling the drive of the burner 2, the temperature of the hot water inside the hot water supply pipe 8 and the connector 9 can be reduced and Can prevent unevenness. Therefore, even if the terminal hot water tap 11 is opened after a relatively long time has elapsed since the previous use.

You can get the desired hot water in a short time.

As a result, it becomes possible to eliminate the inconvenience of delayed hot water supply and the uneconomical problem of discarding a large amount of water.

In addition, hot water pipe 8. Connector 9. As can be seen from the other embodiments shown in FIG. 2, nine of the return pipes 14 are provided with latent heat storage materials 27 facing each other and are surrounded by a heat insulating material 28. It is desirable to have a heat-retaining structure. Further, the same method can be applied to an instantaneous water heater of the type that shifts to a minute pilot combustion when hot water supply is temporarily stopped.

〔Effect of the invention〕

As explained above, according to the instantaneous water heater of the present invention,
Since the temperature of the hot water in the hot water supply pipe can be prevented from decreasing, hot water can always be obtained within a relatively short period of time, thereby eliminating the inconvenience of delayed hot water supply and the uneconomical effects of discarding a large amount of water.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of one embodiment of the present invention, and FIG. 2 is a schematic diagram of only the main parts of another embodiment. 1... Water heater main body, 2... Burner, 3... Fuel pump, 6... Heat exchanger, 7... Water supply pipe, 8...
Hot water pipe, 9... Connector, 11... Terminal hot water tap, 14
...Return pipe. 16... Circulation pump, 18... Flow sensor, 21
. . . first temperature detector, 22 . . . second temperature detector. Figure 1

Claims (1)

[Claims] 1) A burner that burns fuel, a heat exchanger heated by combustion heat in the burner, a water supply pipe connected to the inlet side of the heat exchanger, and a water supply pipe connected to the outlet side of the heat exchanger. Changes in the amount of combustion in the burner (including zero)
In an instantaneous hot water supply device that controls hot water temperature by 1. An instantaneous water heater comprising: a return pipe; a circulation pump and a check valve connected to the return pipe.