JPH0517554Y2 - - Google Patents

Description

[Detailed description of the invention] [Industrial application field] This invention has an instant hot water function that circulates hot water within the hot water supply piping system and provides hot water at the desired temperature as soon as the hot water tap is opened. It concerns water heaters.

[Conventional technology]

A hot water heater with an instant hot water function has been proposed, which circulates hot water at a desired temperature in the hot water supply piping system so that hot water at the desired temperature can be obtained immediately when the hot water tap is opened. Figures 2 and 3 show examples of such a device.

In FIG. 2, reference numeral 1 indicates a water heater, and a water supply pipe 2 and a gas pipe 3 are connected to the inlet side of the water heater.
Further, inside the water heater 1, a burner 4 disposed at the end of the gas pipe 3 and a heat exchanger 5 for absorbing heat generated by combustion of the burner are disposed. A check valve 16 and a flow sensor 19 are installed in the water supply pipe 2 upstream of the heat exchanger 5, and the water supply pipe 6 downstream of the heat exchanger 5 is connected to an outflow pipe 22 via a temperature sensor 11. has been done. An arbitrary desired number of hot water taps 24 are connected to the tip of the outgoing pipe 22, and the piping returns to the appliance 1 via a return pipe 23. A branch pipe 8 branched from the water supply pipe 2 is connected to the heat exchanger 5 - hot water pipe 6 - outgoing pipe 22 - return pipe 23 - branch pipe 8.
- The water supply pipe 2 forms a loop-shaped circulation path, and the return pipe 23 is provided with a check valve 9, a pump 7, and a water flow switch 12. Also,
Reference numeral 25 denotes an electric control section which inputs signals from the flow sensor 19, temperature sensor 11, water flow switch 12, etc. and controls the electromagnetic gas valve 10, pump 7, etc. as described later.

The water heater with an instant hot water function configured as described above drives the pump 7 to circulate hot water in the circulation path when the flow sensor 19 does not detect flowing water and circulates hot water in the circulation path, and detects a drop in the temperature of the hot water using the temperature sensor. 11, the electromagnetic gas valve 10 is opened to maintain the set temperature using the burner 4, thus circulating hot water at the desired temperature within the hot water supply piping system, so that when the hot water tap 24 is opened, hot water at the desired temperature is immediately obtained. It is set as.

However, as shown in Fig. 2, when the water supply pressure is directly utilized, when performing the warming circulation operation when hot water is not being supplied as described above, the circulating water in the heat exchanger and circulation path expands due to volumetric expansion due to heating. As the pressure increases, the circulation path including the heat exchanger is considered a boiler, which violates the "supply head pressure of 10 m or less" stipulated in Article 1, Items 3 and 4 of the Industrial Safety and Health Act Enforcement Ordinance. Therefore, it is not acceptable to use it as an instant hot water device as it is.

Therefore, as shown in FIG. 3, it has been proposed to provide a water heater with an instant hot water function that supplies water from the water supply pipe 2 through the pressure reducing valve 17 into the appliance 1.
In addition, since FIG. 3 shows the water heater shown in FIG. 2 only with the addition of a pressure reducing valve 17, the same parts are given the same reference numerals and a detailed explanation will be omitted.

[The problem that the idea attempts to solve]

However, as shown in Fig. 3, if the pressure reducing valve 17 is used to reduce the water head pressure to 10 m or less, there is no problem in the heat retention circulation operation when hot water is not being supplied, but when hot water is supplied by opening the hot water faucet 24, the amount of hot water coming out is If the amount decreases, it will no longer be a satisfactory water heater.

As mentioned above, the present invention improves the problems of the conventional technology in that it is not acceptable to directly use the water supply pressure, and on the other hand, it is not possible to obtain a satisfactory amount of hot water when the pressure is reduced. During operation, the supply water pressure is reduced (head pressure 10 m or less),
The purpose of the present invention is to provide a water heater with an instant hot water function that can supply hot water at the water supply pressure in the same way as a normal water heater.

[Means to solve the problem]

In order to achieve the above-mentioned purpose, the present invention
A heat exchanger connected to a water supply pipe, an outgoing pipe leading from a hot water pipe downstream of the heat exchanger to a hot water tap, and a branch branching from the tip of the outgoing pipe and a water supply pipe upstream of the heat exchanger. A loop-shaped circulation path is formed with a return pipe that connects the water supply pipe, and a flow sensor and a check valve are provided in the water supply pipe upstream from the connection part of the branch pipe, and a flow sensor and a check valve are provided in the water supply pipe, a sensor is disposed, and at least a pump and a check valve are disposed in the return pipe;
In a water heater with an instant hot water function, the water heater includes an electric control unit that controls combustion of the burner for the heat exchanger and drive of the pump by inputting signals from each of the sensors, etc.
A pressure reducing valve is provided in the water supply pipe upstream of the flow sensor, and a bypass path is provided to bypass the pressure reducing valve, and an electromagnetic on-off valve is provided in the bypass path, and when the flow sensor does not detect flowing water. closes the electromagnetic on-off valve, drives the pump and controls combustion of the burner to keep and circulate and heat water in the circulation path; when the flow sensor detects flowing water, opens the electromagnetic on-off valve and stops the pump. The present invention is characterized in that the electric control section is used to control the combustion of the burner.

[Effect]

Since the water heater with an instant hot water function of the present invention has the above-described configuration, when hot water is not being supplied, the electromagnetic on-off valve is closed and a heat-retaining circulation operation can be performed with the pressure reduced by the pressure reducing valve. This can be done without violating pressure vessel safety regulations. In addition, when supplying hot water, the electromagnetic on-off valve can be opened and the water supply pressure can be used as is, so it is possible to supply a large amount of hot water similar to that of a regular water heater, and it is also possible to supply hot water to multiple locations at the same time without any discomfort. I can do it.

〔Example〕

An example of the implementation of the present invention will be described below with reference to FIG.

In FIG. 1, 1 is a water heater, to which a water supply pipe 2 and a gas pipe 3 are connected. Inside this water heater 1, there is a burner 4 installed at the end of the gas pipe 3.
A heat exchanger 5 is provided to absorb heat generated by combustion in the burner 4. A check valve 16 and a pressure reducing valve 17 are disposed in the water supply pipe 2 upstream of the heat exchanger 5, and a bypass pipe 15 that bypasses the pressure reducing valve 17 is provided in the water supply pipe 2. An electromagnetic on-off valve 18 is interposed therein. Also,
A hot water pipe 6 downstream of the heat exchanger 5 is connected to an outgoing pipe 22 via a temperature sensor 11. Outbound pipe 2
An arbitrary desired number of hot water taps 24 are connected to the tip of 2, and it is also connected to the appliance 1 via a return pipe 23. Further, a branch pipe 8 is branched from the water supply pipe 2 upstream of the heat exchanger 5, and the branch pipe 8 has a check valve 9,
It is connected to the return pipe 23 via a pump 7, a pressure switch 14, and an electric valve 21. Further, an overpressure relief valve 13 is connected between the electric valve 21 and the pressure switch 14.

10 is an electromagnetic gas valve disposed in the middle of the gas pipe 3 upstream of the burner 4, 20 is a check valve disposed in the water supply pipe 2 upstream of the heat exchanger 5, and the branch pipe 8 is connected to this valve. It is led out from between the check valve 20 and the heat exchanger 5. 19 is the bypass pipe 15 of the water supply pipe.
This is a flow sensor disposed between the check valve 20 and the check valve 20.

25 opens and closes the electromagnetic gas valve 10 based on a signal from the temperature sensor 11, a signal from the water flow switch 12, a signal from the flow sensor 19, etc.
The electromagnetic on-off valve 18 and the electric valve 21 are switched by the signal from the flow sensor 1.
This is an electric control section configured to drive and stop the pump 7 based on signals from the pump 9 and the pressure switch 14.

Next, the operation of the water heater of the present invention having the above configuration will be explained. Incidentally, since the electric control section 25 is well known, a detailed explanation of its structure and operation will be omitted.

First, when using the water heater, open the main valves (not shown) of the water supply pipe 2 and gas pipe 3 and turn on the power switch (not shown) of the electric control section 25. The passage of the return pipe 23 and branch pipe 8 is opened, and the pressure switch 14 detects whether the water head pressure in the pipe has become 10 m or less. In addition, if the water head pressure in the piping is 10 m or more, the pressure is released with the overpressure relief valve 13 to reduce the water head pressure to 10 m or less. At this time, the electromagnetic on-off valve 18 is closed. In this way, when the pressure switch 14 detects a water head pressure of 10 m or less, the electric control section 25 turns the pump 7 on.
is driven, and the water is depressurized by the pressure reducing valve 17 (e.g.
6.5m) and flows into the water supply pipe 2, heat exchanger 5,
It passes through the hot water supply pipe 6 and the outgoing pipe 22 and reaches the tap 24 . However, since the tap 24 is closed, the water passes through the return pipe 23, passes through the electric valve 21, the pump 7, and the check valve 9, joins with the water flowing out from the water supply pipe 2, and returns to the heat exchanger 5. It circulates through a return loop-shaped circulation path.

When the water circulates in this way, the running water switch 12 inserted in the branch pipe 8 is turned on, and the temperature sensor 11 inserted in the hot water supply pipe 6 is set to a controller (not shown). When it is detected that the temperature is below, the electric control unit 25 fully opens the electromagnetic gas valve 10 and sends the gas to the burner 4, which is ignited by an appropriate ignition means and burns the burner 4 at its maximum capacity.

The water circulating in this way is heated and the temperature of the water passing through the hot water pipe 6 rises, and when the temperature sensor 11 detects that the temperature has approached the set temperature, an electric current is applied to throttle the electromagnetic gas valve 10 accordingly. Control part 2
5 controls, and thus hot water at a desired temperature is circulated within the circulation pipe.

Next, when the hot water tap 24 is opened from the above state, the flow sensor 19 inserted into the water supply pipe 2 is turned on, and the signal is input to the electric control unit 25, which stops the pump 7 and turns on the electric valve. 21 to close the passage to the pump 7, and switch the electromagnetic on-off valve 1.
Open 8. Therefore, the water supply pressure via the bypass pipe 15 is applied to the hot water at the set temperature in the water supply pipe 6 and the outgoing pipe 22 from the heat exchanger 5, and the water supply pressure is maintained at the desired temperature from the beginning according to the water supply pressure. The desired amount of hot water is supplied, and the electromagnetic gas valve 10 is controlled by the electric control unit 25 based on the signal from the flow sensor 19 to send gas to the burner 4 at an appropriate opening, thus continuing to maintain the desired temperature and desired temperature. The required amount of hot water is supplied.

[Effect of idea]

As described above, according to the water heater with the instant hot water function of the present invention, the unreduced water supply pressure can be used as is when supplying hot water, making it possible to supply a large amount of hot water, improving comfort and Simultaneous hot water supply can be performed without any discomfort. On the other hand, during the heat retention circulation operation for instant hot water when hot water is not being supplied, the operation is performed not at the water supply pressure but at a reduced pressure, so it can be carried out without violating boiler and pressure vessel safety regulations.

[Brief explanation of drawings]

Figure 1 is a water system diagram showing an embodiment of a water heater with an instant hot water function according to the present invention, Figure 2 is a water system diagram showing a conventional example using water supply pressure, and Figure 3 is a pressure reducing valve. It is a water system diagram showing a conventional example using. 1...Water heater, 2...Water pipe, 3...Gas pipe,
4... Burner, 5... Heat exchanger, 6... Hot water pipe,
7... Pump, 8... Branch pipe, 9, 16, 20...
... Check valve, 10 ... Electromagnetic gas valve, 11 ... Temperature sensor, 12 ... Water flow switch, 13 ... Overpressure relief valve, 14 ... Pressure switch, 15 ... Bypass pipe, 17 ... Pressure reduction Valve, 18... Solenoid on/off valve, 19... Flow sensor, 21... Electric valve, 2
2... Outgoing pipe, 23... Return pipe, 24... Hot water tap,
25...Electric control section.

Claims (1)

[Scope of utility model registration request] A heat exchanger connected to a water supply pipe, an outgoing pipe leading from a hot water pipe downstream of the heat exchanger to a hot water tap, and a branch branching from the tip of the outgoing pipe and a water supply pipe upstream of the heat exchanger. A loop-shaped circulation path is formed with a return pipe that connects the water supply pipe, and a flow sensor and a check valve are provided in the water supply pipe upstream from the connection part of the branch pipe, and a flow sensor and a check valve are provided in the water supply pipe, A sensor is disposed, at least a pump and a check valve are disposed in the return pipe, and an electric control unit is provided that controls combustion of the burner for the heat exchanger and driving of the pump by inputting signals from each of the sensors and the like. In a water heater with an instant hot water function, a pressure reducing valve is provided in the water supply pipe upstream of the flow sensor, a bypass path is provided to bypass the pressure reducing valve, and an electromagnetic on-off valve is provided in the bypass path, When the flow sensor does not detect running water, the electromagnetic on-off valve is closed, and the pump is driven and combustion of the burner is controlled to keep the water in the circulation path warm and circulated. When the flow sensor detects running water, the electromagnetic on-off valve is 1. A water heater with an instant hot water function, characterized in that the electric control section is configured to open an on-off valve, stop a pump, and control combustion of a burner.