JP2022142540A - Water heater - Google Patents

Abstract

To prevent hot water from being suddenly supplied without user's recognition in recovering from power failure.SOLUTION: A water heater 1 has: a burner unit 4; a heat exchanger 5; a water supply pipe 18 connected to the heat exchanger 5; a hot water supply pipe 19 connected to the heat exchanger 5; a water amount sensor 23 detecting water conduction in an appliance; and a controller 35 controlling the burner unit 4. When the power source is turned on, the controller 35 prohibits combustion of the burner unit 4 until a water stop condition in the appliance is confirmed by the water amount sensor 23.SELECTED DRAWING: Figure 1

Description

TECHNICAL FIELD The present disclosure relates to a water heater that heats water passing through a heat exchanger with combustion exhaust of a burner and supplies hot water.

In the water heater, when the controller detects water passing through the appliance, the burner is combusted, and water passing through the heat exchanger is heated by combustion exhaust gas of the burner to be discharged. An external remote control is connected to the controller, and various operations such as ON/OFF of operation and setting of outlet hot water temperature are possible with an operation unit provided on the remote control (see Patent Document 1, for example). In some cases, these various operations can also be performed by an operation unit provided on the controller.
On the other hand, as a water heater, there is known one that has an instant hot water function by connecting a return pipe equipped with a circulation pump to a water supply pipe connected to a heat exchanger (see Patent Document 2, for example). In this water heater with instant hot water function, by connecting the hot water supply pipe and the return pipe with an external pipe, the hot water supply pipe, the external pipe, the return pipe, and the water supply pipe form a circulation path, and the water circulates through this circulation path. A hot water supply system capable of keeping warm is constructed by heating with a heat exchanger while circulating hot water with a pump. Therefore, hot water can be supplied immediately when the hot water tap provided in the external pipe is opened.

Japanese Patent Application Laid-Open No. 2020-204440 JP-A-2004-286397

In such a water heater, if a power failure occurs while hot water is being supplied (while the burner is burning) and water supply continues when the power failure is restored, combustion control of the burner will be performed as it is. In this case, if the user does not recognize the recovery from the power outage, the user will be surprised when hot water suddenly comes out while the water is being used.
On the other hand, in a water heater whose operation switch can be turned ON/OFF by an operation unit such as a remote controller, if a power failure occurs while the operation switch is ON, it is set to turn OFF the operation switch when recovering from the power failure. may be In this case, the user who recognizes the recovery from the power failure has to close the hot water tap to temporarily stop the supply of water, and also need to turn on the operation switch again, which is troublesome.

Accordingly, an object of the present disclosure is to provide a water heater that does not suddenly supply hot water without the user's recognition when recovering from a power failure.

In order to achieve the above object, the present disclosure includes a burner, a heat exchanger, a water supply pipe connected to the heat exchanger, a hot water discharge pipe connected to the heat exchanger, and water flow in the fixture. A water heater having water flow detection means for detecting and control means for controlling the burner,
The control means, when the power is turned on, prohibits the combustion of the burner until the water detection means confirms that the water inside the appliance is stopped.
Another aspect of the present disclosure, in the above configuration, further has an operation means capable of switching ON/OFF of the operating state of the appliance,
The control means cancels the prohibition of combustion of the burner when it is confirmed that the operating state has been switched to ON by the operation means before the water flow detection means confirms the water stop state in the appliance. characterized by
Another aspect of the present disclosure is characterized in that, in the above configuration, there is provided an informing means for informing that combustion of the burner is prohibited.

According to the present disclosure, when the power is turned on, the control means prohibits the combustion of the burner until the water detection means confirms that the water inside the fixture is stopped. Even if the water supply is continued when the water is restored, hot water does not suddenly come out during the use of water. Therefore, the user can recognize the recovery from the power failure, and can restart the use of hot water after stopping the supply of water.
According to another aspect of the present disclosure, in addition to the above effects, the control means has the operation state switched to ON by the operation means until the water flow detection means confirms the water stop state in the appliance. is confirmed, the prohibition of burner combustion is released. Therefore, the prohibition of burner combustion can be released only by turning ON the operation switch without stopping the water once. Therefore, the user's trouble is reduced and usability is improved.
According to another aspect of the present disclosure, in addition to the above effects, the notification means notifies that the combustion of the burner is prohibited, so that the user can quickly recognize that the combustion is prohibited when the power is restored. can be used to stop water.

1 is a schematic diagram of a hot water supply system; FIG. 4 is a flowchart of hot water supply control after power is turned on; 9 is a flowchart of a modified example of hot water supply control after power is turned on;

Embodiments of the present disclosure will be described below with reference to the drawings.
FIG. 1 is a schematic diagram showing an example of a water heater. This water heater 1 has an immediate hot water supply function with a return pipe 26 having a circulation pump 27, and constructs a hot water supply system S capable of immediate hot water supply by connecting an external piping 30 for circulation.
First, in the water heater 1 , a combustion chamber 3 is installed inside the housing 2 . The combustion chamber 3 is provided with three burner units 4, 4, . . . , a heat exchanger 5, and an exhaust hood 6 from below. The bottom surface of the housing 2 is provided with a gas connection port 7 to which an external gas pipe is connected, a water supply connection port 8 to which an external water supply pipe is connected, a hot water supply connection port 9 to which an external hot water supply pipe is connected, and a return port. A connection port 10 is provided.
The burner units 4, 4, . . . consist of a plurality of burners of different numbers. A gas pipe 11 having a main solenoid valve 12 and a proportional control valve 13 is connected to the gas connection port 7 . The gas pipe 11 branches into three branch pipes 14, 14 . . . A fan 16 for supplying combustion air to the burner unit 4 is provided in the lower portion of the combustion chamber 3 .

The heat exchanger 5 is of a fin-tube type having a heat transfer tube passing through a plurality of fins arranged in parallel at predetermined intervals in the thickness direction in a meandering manner. A water supply pipe 18 connected to the water supply connection port 8 is connected to the inlet end of the heat transfer tube. A hot water outlet pipe 19 connected to the hot water supply connection port 9 is connected to the outlet end of the heat transfer pipe. A bypass pipe 20 that bypasses the heat exchanger 5 is connected between the water supply pipe 18 and the hot water discharge pipe 19 .
Further, on the upstream side of the connecting portion of the bypass pipe 20 in the water supply pipe 18, a water side on-off valve 21, an incoming water temperature sensor 22 such as a thermistor for detecting the incoming water temperature, and a water quantity sensor 23 for detecting the quantity of water are provided. ing. Furthermore, an outlet temperature sensor 24 such as a thermistor for detecting the outlet temperature from the heat exchanger 5 is provided upstream from the connecting portion of the hot water pipe 19 with the bypass pipe 20, and downstream from the connecting portion is provided. An outlet hot water temperature sensor 25 such as a thermistor for detecting temperature is provided.

A return pipe 26 having a circulation pump 27 and a check valve 28 positioned on the discharge side is connected between the return connection port 10 and the water supply pipe 18 on the upstream side of the water quantity sensor 23 . there is
The external pipe 30 is connected between the hot water supply connection port 9 and the return connection port 10, and has a plurality of hot water taps 31, 31, . One of the hot water taps 31 is for supplying hot water to the bathtub 32 (hereinafter referred to as "hot water tap 31A" when distinguished from the other hot water taps 31).
As a result, hot water discharged from the hot water discharge pipe 19 returns to the return pipe 26 through the external pipe 30, reaches the heat exchanger 5 via the water supply pipe 18, and forms a circulation path in which hot water is discharged from the hot water discharge pipe 19 again. be done.
A controller 35 controls the operation of the water heater 1 and the hot water supply system S. FIG. A remote controller 36 is connected to the controller 35 . The remote controller 36 is provided with an operation section such as an operation switch, a hot water supply switch, and a set temperature change button, and an operation state display section. The operation unit and display unit may also be provided in the controller 35 in some cases.

In the hot water supply system S configured as described above, when the operation switch provided on the controller 35 or the remote control 36 is turned on, the controller 35 operates the circulation pump 27 to open the water side on-off valve 21, and Circulate water. At the same time, the main solenoid valve 12 and the on-off valve 15 are opened to supply fuel gas to the burner unit 4, and the fan 16 is driven to perform ignition control and burn the burner unit 4. Then, the controller 35 controls the opening of the proportional control valve 13 and the rotation speed of the fan 16 so that the temperature detected by the outlet hot water temperature sensor 25 becomes the set temperature set by the controller 35 or the remote controller 36, thereby performing heat retention operation. conduct. Therefore, when any one of the hot water taps 31 is opened, hot water can be immediately supplied at the set temperature.
On the other hand, when the hot water supply switch provided on the controller 35 or the remote control 36 is pressed to open the hot water supply tap 31A, the controller 35 detects the water flow in the appliance by the water quantity sensor 23, and burns the burner unit 4. Automatic hot water supply control is possible to supply hot water at a set temperature to the bathtub 32 until the amount of water detected by the water amount sensor 23 reaches the set amount of hot water.

When a power failure occurs during operation of the hot water supply system S, the heat retention operation of the hot water supply system S is stopped and the combustion of the burner unit 4 is stopped.
However, if the controller 35 is set to return to the operating state (warming operation ON) when the power failure is restored, or if the hot water supply valve 31 is open, the controller 35 that detects the water flow through the circulation path is turned on by the burner. When the unit 4 is burned, hot water suddenly comes out while water is being used, which surprises the user.
Therefore, the controller 35 prohibits the combustion of the burner unit 4 until the water quantity sensor 23 confirms that the water in the circulation path has stopped when the power failure is restored.
The hot water supply control after the power is turned on will be described below with reference to the flowchart of FIG.

First, when the power is turned on after recovering from the power failure in S1, the controller 35 prohibits the combustion of the burner unit 4 in S2. This combustion prohibition is performed by turning off the operation switch or prohibiting the combustion of the burner unit 4 by internal control regardless of whether the operation switch is on.
At the same time, the remote controller 36 notifies that combustion is prohibited. This notification is made by displaying characters or graphics on the display section of the remote controller 36 to the effect that combustion is being prohibited, or by emitting a buzzer or synthetic voice.
Next, in S3, it is determined whether or not the circulation path is in a water stop state. Here, when NO, that is, water flow due to the opening of the hot water tap 31 is detected by the water quantity sensor 23, the combustion of the burner unit 4 is not permitted and the prohibition of combustion is continued.
On the other hand, if the water flow through the circulation path is not confirmed in S3 depending on whether the water is stopped when the power is turned on or whether the user closes the hot water tap 31 in response to the notification from the remote control 36, the controller 35 proceeds to S4. Combustion of the burner unit 4 is permitted. Therefore, when the hot water supply tap 31 is opened again in S5 and the flow of water is confirmed by the water quantity sensor 23, the controller 35 burns the burner unit 4 in S6 to execute hot water supply control.

As described above, in the water heater 1 and the hot water supply system S of the above-described embodiments, the controller 35 (control means) checks the water stop state in the appliance by the water quantity sensor 23 (water flow detection means) when the power is turned on. Combustion of the burner unit 4 (burner) is prohibited until .
According to this configuration, even if a power failure occurs while hot water is being supplied and the water supply is continued when the power failure is restored, hot water will not be suddenly supplied while water is being used. Therefore, the user can recognize the recovery from the power failure, and can restart the use of hot water after stopping the supply of water.
In particular, since the remote control 36 (informing means) notifies that the combustion of the burner unit 4 is prohibited, the user can quickly recognize that the combustion is prohibited when the power is restored and stop the water supply. .

In the above embodiment, the controller 35 is set to return to the operating state ON when recovering from a power failure. In this case, the user is troublesome because it is necessary to temporarily stop the water flow and to turn on the operation switch again with the remote controller 36 . Therefore, a modified example that can reduce this trouble will be described based on the flowchart of FIG.
When the power is turned on after the power failure is restored in S11, the controller 35 prohibits the combustion of the burner unit 4 in S12, and informs that the combustion is prohibited by the remote controller 36.
Next, in S13, it is determined whether or not the circulation path is in a water stop state. If YES here, that is, if water flow through the circulation path is not confirmed, combustion of the burner unit 4 is permitted in S14. Therefore, when the hot water supply tap 31 is opened in S15 and the flow of water is confirmed by the water quantity sensor 23, the controller 35 burns the burner unit 4 in S16 to execute hot water supply control. The process up to this point is the same as in FIG.

However, when it is determined in S13 that water is flowing through the circulation path due to the opening of the hot water tap 31, the controller 35 determines in S17 whether or not the operation switch has been turned ON. If the ON operation cannot be confirmed here, the combustion of the burner unit 4 is not permitted and the prohibition of combustion is continued.
On the other hand, when the ON operation of the operation switch is confirmed in S17, the controller 35 permits the combustion of the burner unit 4 in S14. Therefore, the burner unit 4 is combusted together with the operation of the circulation pump 27 to restart the heat-retaining operation, and immediate hot water supply becomes possible.
The reason why the confirmation of the ON operation of the operation switch is set as the permission condition for combustion is that the user's ON operation of the operation switch can be regarded as an operation after recognizing the recovery from the power failure. This is because it does not surprise the user.

In this modified example as well, even if a power failure occurs while hot water is being supplied and the water supply is continued when the power failure is restored, the user will not be surprised by the sudden appearance of hot water while using water.
However, if the controller 35 confirms that the operation state has been switched to ON by the controller 35 or the remote controller 36 (operation means) before the water amount sensor 23 confirms the water stop state in the appliance, the water flow state is reached. Since the prohibition of combustion of the burner unit 4 is released even if there is water, the prohibition of combustion of the burner unit 4 can be released only by turning ON the operation switch without stopping the water once. Therefore, the user's trouble is reduced and usability is improved.

In the above embodiment, a return pipe and a circulation pump are provided in the housing and connected to the external pipe. A circulation pump and a check valve may be provided in the external piping. In this case, the circulation pump may be provided in the water pipe, or may be provided in the water supply pipe upstream of the water quantity sensor.
However, the present invention can also be applied to a water heater that does not have an external pipe and does not have an immediate hot water supply function (does not have a circulation pump). The operation state of this water heater ON means that when the control means detects the passage of water in the appliance, the hot water supply control that burns the burner is possible, and the operation part such as the remote control can be used to fill the hot water, reheat, and set. A state in which various operations such as temperature change can be accepted and executed.
In addition, the configuration of the water heater is not limited to the above configuration, and the number of burner units can be increased or decreased, and the present invention can be applied even to a latent heat recovery type equipped with a sub heat exchanger.

DESCRIPTION OF SYMBOLS 1... Water heater, 2... Housing, 3... Combustion chamber, 4... Burner unit, 5... Heat exchanger, 6... Exhaust hood, 7... Gas connection port, 8... Water supply connection port , 9 Hot water supply connection port 10 Return connection port 11 Gas pipe 16 Fan 18 Water supply pipe 19 Hot water discharge pipe 21 Water side opening/closing valve 22 In Water temperature sensor 23 Water quantity sensor 24 Outlet temperature sensor 25 Hot water temperature sensor 26 Return pipe 27 Circulation pump 30 External pipe 31 (31A) Hot water tap 32...Bathtub, 35...Controller, 36...Remote control, S...Hot water supply system.

Claims (3)

A burner, a heat exchanger, a water supply pipe connected to the heat exchanger, a hot water outlet pipe connected to the heat exchanger, a water flow detecting means for detecting water flow in the appliance, and controlling the burner. A water heater having a control means for
The water heater is characterized in that, when the power supply is turned on, the control means prohibits the combustion of the burner until the water flow detection means confirms that water has stopped in the appliance. further comprising an operation means capable of switching ON/OFF of the operating state of the appliance;
The control means cancels the prohibition of combustion of the burner when it is confirmed that the operating state has been switched to ON by the operation means before the water flow detection means confirms the water stop state in the appliance. The water heater according to claim 1, characterized by: 3. The water heater according to claim 1, further comprising an informing means for informing that combustion of said burner is prohibited.

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