JP2003028443A - Water heater for bath - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a water heater for a bath having a function for heating a bathroom, in which hot-water temperature in a closed circuit formed in a room-heating operation can be dropped before reheating of bathtub water in an open circuit without causing a user to feel unpleasantly. SOLUTION: In a bathroom-heating operation, three-way valves A, B are switched so as to form a closed circuit passing through a radiator 51 and bypassing a bathtub 5. After the heating operation or before starting the next operation by switching to an open state passing through the bathtub 5, water in the closed circuit is circulated to be cooled in the heat exchanger 22 under conditions of combustion of a burner 21 being stopped, and a combustion fan 23 being operated for performing air-supply and exhaust for the burner 21 and the heat exchanger 22.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a bath water heater having a function of heating a bathroom.

[0002]

2. Description of the Related Art Utility model registration gazette No. 2521199 as a bath water heater having a function of heating a bathroom is equipped with a three-way valve on each of the return pipe and the forward pipe of a bath heating path of the bath, and is replaced with a bathtub. Then, a configuration is disclosed in which the bath heating route is switched so that a closed circuit passing through a radiator in the warm air unit is formed.

In order to increase the heating capacity, the temperature of the hot water circulating in the closed circuit that does not pass through the bathtub is made higher. However, when switching from heating operation to additional heating operation, the hot inside the closed circuit is hot. Hot water should not flow into the bathtub. Therefore, in the heating system disclosed in Japanese Unexamined Patent Publication No. 2000-65370, when the bath heating route is switched from the closed circuit to the open circuit, the hot water temperature in the closed circuit is lowered and then the open circuit is entered. Has become. In this heating system, heat is dissipated from a radiator for heating to lower the hot water temperature, or hot water in a closed circuit is drained from a drain valve and replaced with room temperature water to lower the hot water temperature. .

[0004]

When the heat is dissipated from the radiator for heating, the fan for the radiator is operated in order to improve the heat dissipation efficiency. However, if the hot water temperature in the closed circuit is lowered immediately after the heating operation is stopped, the ventilation will continue for a while even after the user presses the heating stop switch. It gives the user anxiety about whether to do it. On the other hand, when lowering the hot water temperature in the closed circuit at the time of starting the additional heating operation that is switched to the open circuit, when the additional heating switch etc. is pressed, the ventilation for heating will start and the user Makes you feel uncomfortable.

The present invention has been made by paying attention to the problems of the prior art as described above, and the hot water temperature in the closed circuit formed during the heating operation can be maintained in the open circuit without giving the user a feeling of strangeness. It is an object of the present invention to provide a bath water heater that can be lowered before the reheating operation of.

[0006]

The gist of the present invention for achieving the above object resides in the inventions of the following items. [1] One end is connected to the heat receiving pipe (24) passing through the heat exchanger (22) heated by the burner (21) and the inlet side of the heat receiving pipe (24), and the other end is open to the bath (5). Return pipe (2
5) and a bath heating path (20) comprising one end connected to the outlet side of the heat receiving pipe (24) and the other end open to the bathtub (5), and the forward pipe (26) And a return pipe (25) for connecting the bypass pipe (41) and the bath heating path (20) to the bathtub (5) through the bypass pipe (41) to form a closed circuit. And a radiator (51) arranged in the middle of the closed circuit, and a path switching means (A, B) for switching between an open state via the bathtub (5) and a bath heating path (20). In the bath water heater capable of heating operation, the heating is performed by the burner (21) and the heat is dissipated by the radiator (51) in a state where the closed circuit is set and water is circulated in the closed circuit. After the end of the operation, the operation of switching the bath heating route (20) to the open state is performed. Until, bath water heater, characterized in that said heat exchanger (22) for cooling water in the closed circuit by using as a heat sink.

[2] Heat receiving pipe (24) passing through the heat exchanger (22) heated by the burner (21) and the heat receiving pipe (2)
4) one end is connected to the inlet side and the other end is open to the bath (5), one end is connected to the return side of the return pipe (25) and the heat receiving pipe (24), and the other end is open to the bath (5) The bath heating route (20) including the forward pipe (26), the bypass pipe (41) connecting the forward pipe (26) and the return pipe (25), and the bath heating route (20), Path switching means (A, B) for switching between a closed state in which a closed circuit is formed to bypass the bathtub (5) through the bypass pipe (41) and an open state through the bathtub (5); A heat radiator (51) disposed on the way, and the bath heating path (20) is set to the closed state and water is circulated in the closed circuit and heated by the burner (21); Completion of the heating operation in a bath water heater capable of heating operation that radiates heat in the radiator (51) , Before performing the operation to switch the bath additionally 焚経 path (20) in the open state, the burner (2
By circulating the water in the closed circuit with the combustion fan (23) for supplying and exhausting the burner (21) and the heat exchanger (22) being stopped while the heating by 1) is stopped. A bath water heater characterized by a cooling operation for cooling.

[3] The bath water heater according to [2], characterized in that the cooling operation is performed immediately after the heating operation is finished, also as a post-purge of the combustion chamber.

[4] The cooling operation is performed also as the pre-purge of the combustion chamber before the operation of switching the bath heating path (20) to the open state is started, and the cooling operation is performed. Bath water heater.

[5] When a heating operation stop instruction is received,
The bath water heater according to any one of [1] to [4], characterized in that the blowing of air to the radiator (51) is immediately stopped.

[6] The bath water heater according to any one of [1] to [5], characterized in that a radiator (51) is arranged in the middle of a bypass pipe (41) for forming a closed circuit. .

[7] The cooling operation is terminated when the water temperature at a predetermined location on the inlet side of the radiator (51) of the bypass pipe (41) becomes lower than a certain temperature [6]. Bath water heater described in.

The present invention operates as follows. When performing heating operation, the bath heating path (20) is set to a closed state to form a closed circuit, and heating and heating in the burner (21) are performed with water circulated in the closed circuit. Radiator (5
Heat is dissipated in 1). The cooling of the water in the closed circuit is performed after the heating operation is finished and before the operation of switching the bath heating path (20) to the open state (heating operation or pouring operation).
The heat exchanger (22) is used as a cooling radiator.
For example, to circulate the water in the closed circuit while stopping the heating by the burner (21) and operating the combustion fan (23) for supplying and exhausting the burner (21) and the heat exchanger (22). Cool with. In addition, when receiving a heating operation stop instruction from the user, the fan for the radiator (51) is immediately stopped.

As described above, after the heating operation is completed, the heat exchanger (22) is used as a cooling radiator to close the bath heating path (20) until it is switched to the open state and operated. Since the water in the circuit is cooled, the air continues to be blown even after the heating stop switch is pressed, as in the case of cooling with a blower for heating, or the air blow for heating starts when the reheating switch is pressed. Therefore, the water in the closed circuit can be cooled without giving the user a feeling of strangeness or anxiety.

Further, when the cooling operation is performed immediately after the heating operation is completed and also serves as the post-purge of the combustion chamber, the fan is cooled as compared with the case where the cooling in the radiator (51) for heating and the post-purge are performed separately. Power costs can be saved. The same applies to the case where the cooling operation is performed also as the pre-purge of the combustion chamber immediately before the operation of switching the bath heating path (20) to the open state is started.

A bypass pipe (4) for forming a closed circuit
In the case where the radiator (51) is arranged in the middle of 1), the bypass pipe (41) does not pass through the radiator (51) when the bath is heated and the radiator (51) is installed near the ceiling of the bathroom. Since the part of () should be extended, the circuit length during bath heating does not become long, and the heating efficiency is good. Further, if the cooling operation is terminated when the water temperature at a predetermined location on the inlet side of the radiator (51) of the bypass pipe (41) becomes equal to or lower than a certain temperature, the cooling operation time can be minimized. That is, since the water temperature on the downstream side of the radiator (51) has already dropped when heating is stopped, the bypass pipe (41)
If the cooling operation is performed until the water temperature at the predetermined location on the inlet side of the radiator (51) becomes a certain temperature or less, the hot water does not flow out to the bathtub (5) even after switching to the open circuit.

[0017]

BEST MODE FOR CARRYING OUT THE INVENTION An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 shows a schematic configuration of a bath water heater 10 according to an embodiment of the present invention. The bath water heater 10 includes a bath water heater body 10a, a bath warm switching unit 40, and a bath warm unit 50.

The bath water heater body 10a includes a burner 21 and
A heat exchanger 22 heated by the burner 21 and a combustion fan 23 for supplying and exhausting the burner 21 and the heat exchanger 22 are provided. The bath reheating path 20 for reheating the bath includes a heat receiving pipe 24 that passes through the heat exchanger 22 so as to bend back a plurality of times, and a return pipe 25 for returning the water in the bathtub 5 to the heat exchanger 22 side. , A forward pipe 26 for guiding the water heated in the heat exchanger 22 to the bath 5.

In the middle of the return pipe 25, a circulation pump 27 for attaching water in the bath heating path 20 to the outward pipe 26 from the return pipe 25 via the heat receiving pipe 24 is attached. A pouring pipe 28 for receiving hot water supply from a hot water supply circuit (not shown) at the time of pouring the hot water into the bathtub 5 is connected to the return pipe 25.
A pouring valve 29, which is normally closed and opened during the pouring operation, is attached in the middle of the pouring pipe 28. In addition, in the middle of the return pipe 25, a bath water flow switch, a bath thermistor, etc. (not shown) are attached. Further, a forward bath thermistor 31 for detecting the water temperature at the location is attached near the outlet side of the heat exchanger 22 in the forward pipe 26.

Return pipe 25 extended from the bath heating route 20
The forward pipe 26 communicates with the bathtub 5 via a bath warming switching unit 40 installed below the apron of the bathtub 5. Inside the bus warm switching unit 40, the return pipe 2
A three-way valve A is attached in the middle of 5, and a three-way valve B is attached in the middle of the forward pipe 26. From the portion of the three-way valve B to the bypass pipe 41
Is branched and extended, the radiator 5 in the bath warming unit 50
It returns to the bus warming switching unit 40 via 1 and is connected to the three-way valve A.

By switching between the three-way valve A and the three-way valve B, the bath heating path 20 bypasses the bathtub 5 through the bypass pipe 41 and passes through the radiator 51 to form a closed circuit (circuit shown by a thick line in the figure). The formed closed state is switched to the open state in which the bypass pipe 41 is separated via the bath 5 to form an open circuit.

The bypass pipe 41 is connected to the radiator 51 on the upstream side and the return side by a flow dividing pipe 42 so as to bypass the radiator 51 inside the bus warm switching unit 40. A relay thermistor 43 for detecting the water temperature is provided in the bypass pipe 41 on the way to the radiator 51 and between the three-way valve B and the diversion pipe 42. An air separator 44 is provided between the flow dividing pipe 42 and the three-way valve A on the return pipe side of the bypass pipe 41 from the radiator 51.
Is attached.

The bath warming unit 50 has a radiator 5 inside.
1 and a fan 52 for sending hot air to the bathroom by sending air to the radiator 51. Bath warming unit 50
Is usually installed near the ceiling of the bathroom. If the bath warming unit 50 is installed near the ceiling, the pressure loss becomes large, and even if water is circulated by the circulation pump 27 when the closed circuit is formed, it is not possible to secure a flow rate enough to turn on the bath water switch. Things can happen. For this reason, a diversion pipe 42 for bypassing the bath warming unit 50 is provided inside the bus warming switching unit 40 installed at a low place such as under the apron of the bathtub 5 so that the flow rate at the time of forming a closed circuit is earned. There is.

The control circuit 100 of the bath water heater 10 is built in the bath heating path 20 and stores a CPU (central processing unit) 101 that plays a central role in various controls and a program and various fixed data. Main components are a ROM (Read Only Memory) 102 and a RAM (Random Access Memory) 103 for storing data and the like that are temporarily necessary for executing a program. The CPU 101 includes a combustion fan 23, a blower 52, a three-way valve A, a three-way valve B, a circulation pump 27, and an outgoing bath thermistor 3 through the input / output interface circuit 105.
1, a relay thermistor 43, a pouring valve 29, a solenoid valve (not shown), a thermistor sensor, etc. are connected.

A main remote controller installed in a kitchen (not shown) and a bath remote controller installed in the bathroom are also connected. The main remote controller and the bath remote controller have an operation unit including operation switches and the like, and a display unit including a liquid crystal display and the like. The operation unit also has a switch for switching the heating on and off.

Next, the operation will be described. When performing the heating operation, the three-way valve A and the three-way valve B are switched to form a closed circuit. In this state, heating is performed by the burner 21, water in the closed circuit is circulated by the circulation pump 27, and the fan 52 is operated in the bath warming unit 50 to radiate heat from the radiator 51 to heat the bathroom. In heating operation,
In order to improve the heating efficiency, the outlet temperature of the heat exchanger 22 is approximately 8
Combustion is controlled so as to reach 0 ° C.

Next, the cooling operation for cooling the water temperature in the closed circuit, which has become high during the heating operation, will be described. The cooling operation is performed after the heating operation is completed and before the bath heating path 20 is switched to the open circuit state, for example, before the bath heating operation or the pouring operation to the bathtub 5.

First, the case where the cooling operation is performed immediately after the heating operation is completed will be described. When the heating operation switch on the bath remote control or the like is turned off, the combustion of the burner 21 is stopped and the blower 52 is stopped. Then, while the closed circuit is still formed, the circulation pump 27 circulates the water in the closed circuit while operating the combustion fan 23. As a result, the heat exchanger 22 functions as a radiator, and the heat exchanger 22
When passing through, the water in the bath heating path 20 is cooled.

Since the cooling operation is performed by operating the combustion fan 23 immediately after the combustion of the burner 21 is turned off, it also functions as a post-purge of the combustion chamber. Therefore, by using the cooling operation for part or all of the post-purge, it becomes unnecessary to operate the combustion fan 23 exclusively for the post-purge, or the operation time is shortened.

The cooling operation is terminated when the temperature detected by the relay thermistor 43 drops below a certain level. When the heating operation is stopped, high-temperature hot water exists in the water pipe in the portion from the heat exchanger 22 to the radiator 51, and the water in the water pipe on the return side from the radiator 51 to the heat exchanger 22 radiates heat. Since the heat has already been dissipated when passing through the container 51, it is low, and it is not necessary to further cool it by the cooling operation.

Therefore, in order to keep the water temperature of a portion through which water is passed when operating with the bath heating path 20 opened, the water pipe portion from the heat exchanger 22 to the three-way valve B is Just make sure that the hot water is gone.
Therefore, if the temperature detected by the relay thermistor 43 arranged at a position after the branch from the outward pipe 26 by the three-way valve B becomes equal to or lower than a certain temperature, the water pipe from the part of the heat exchanger 22 to the three-way valve B is reached. It guarantees that there is no hot water,
At this point, the cooling operation is finished.

Instead of performing the cooling operation immediately after the heating operation is finished, the cooling operation may be performed immediately before the bath heating operation in which the bath heating path 20 is switched to the open state after the heating operation is started. That is, at the end of the heating operation, the bath heating path 20 is left in the state in which the closed circuit is formed. After that, when a start instruction for a bath heating operation or the like is received, the cooling operation is performed for a predetermined time. After the cooling operation is completed, the three-way valve A and the three-way valve B are switched to bring the bath heating path 20 into an open circuit state, and the bath heating operation and the like are started. At this time, the cooling operation causes all or part of the pre-purge of the combustion chamber to be performed before the ignition of the burner 21 in the bath heating operation or the like. As a result, it becomes unnecessary to operate the combustion fan 23 only for the prepurge, or the operation time is shortened.

In the embodiment described above, the cooling operation is performed immediately after the heating operation is completed or immediately before the operation in which the operation is switched to the open circuit is started. However, it is not expected that the post-purge and the pre-purge can be used together. The cooling operation may be performed at any timing after the end of the heating operation and before the start of the operation of switching to the open circuit next. In addition,
When the cooling operation is performed immediately before the start of the operation that is switched to the open circuit, whether or not the temperature inside the water pipe has already decreased is detected by the outdoor bath thermistor 31 or the like, and if the temperature has decreased, the cooling operation May be omitted.

[0034]

According to the bath water heater of the present invention, the heat exchanger serves as a cooling radiator after the heating operation is completed and before the operation of switching the bath heating path to the open state is performed. Since the water in the closed circuit is used to cool, the air continues to be blown even after the heating stop switch is pressed, as in the case of cooling with a blower for heating, or the air blown for heating when the reheating switch is pressed. It is possible to cool the water in the closed circuit without causing the user to feel discomfort or anxiety.

Further, when the cooling operation is performed immediately after the heating operation is completed, which also serves as the post-purge of the combustion chamber, the fan power cost is reduced as compared with the case where the cooling by the radiator for heating and the post-purge are performed separately. Savings are possible. The same applies to the case where the cooling operation is performed also as the pre-purge of the combustion chamber immediately before the operation of switching the bath heating path to the open state is started.

Further, in the case where the radiator is arranged in the middle of the bypass pipe for forming the closed circuit, the circuit length does not become long and the radiator does not pass through when heating the bath, so that the reduction of the heating efficiency is prevented. To be done.

If the cooling operation is terminated when the water temperature at a predetermined location on the radiator inlet side of the bypass pipe becomes equal to or lower than a certain temperature, the cooling operation time can be minimized to the required minimum.

[Brief description of drawings]

FIG. 1 is an explanatory diagram showing a schematic configuration of a bath water heater according to an embodiment of the present invention.

[Explanation of symbols]

A ... three-way valve B ... Three-way valve 5 ... Bathtub 10 ... Bath water heater 10a ... Bath water heater body 20 ... Bath heating route 21 ... Burner 22 ... Heat exchanger 23 ... Combustion fan 24 ... Heat receiving tube 25 ... Return pipe 26 ... Outgoing 27 ... Circulation pump 28 ... Pouring pipe 29 ... Pouring valve 31… Outdoor bath thermistor 40 ... Bus warm switching unit 41 ... Bypass pipe 42 ... Dividing pipe 43 ... Relay thermistor 44 ... Air separator 50 ... Bath warming unit 51 ... Radiator 52 ... Blower

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Claims (7)

[Claims] 1. A heat receiving pipe passing through a heat exchanger heated by a burner, one end of which is connected to an inlet side of the heat receiving pipe and the other end of which is connected to an outlet side of the heat receiving pipe and one end of which is connected to an outlet side of the heat receiving pipe. A bath heating path having a forward pipe with the other end open to the bath, a bypass pipe connecting the forward pipe and the return pipe, and a bath heating route for closing the bath bypassing the bath pipe through the bypass pipe. A path switching means for switching between a closed state in which a circuit is formed and an open state through the bath, and a radiator disposed in the middle of the closed circuit, and the bath heating path is set to the closed state. In a bath water heater capable of heating operation that performs heating by the burner and heat dissipation by the radiator in a state where water is circulated in the closed circuit, after the heating operation is completed, the bath heating path is in an open state The heat exchange is performed before switching to A bath water heater characterized in that the water in the closed circuit is cooled by using the water heater as a radiator for cooling. 2. A heat receiving pipe passing through a heat exchanger heated by a burner, one end of which is connected to an inlet side of the heat receiving pipe, and the other end of which is connected to an outlet side of the heat receiving pipe and one end of which is connected to an outlet side of the heat receiving pipe. A bath heating path having a forward pipe with the other end open to the bath, a bypass pipe connecting the forward pipe and the return pipe, and a bath heating route for closing the bath bypassing the bath pipe through the bypass pipe. A path switching means for switching between a closed state in which a circuit is formed and an open state through the bath, and a radiator disposed in the middle of the closed circuit, and the bath heating path is set to the closed state. In a bath water heater capable of heating operation that performs heating by the burner and heat dissipation by the radiator in a state where water is circulated in the closed circuit, after the heating operation is completed, the bath heating path is in an open state Before switching to the A bath characterized by performing a cooling operation in which water in the closed circuit is circulated and cooled while heating is stopped and a combustion fan for supplying and exhausting the burner and the heat exchanger is operated. Water heater. 3. The bath water heater according to claim 2, wherein immediately after the heating operation is finished, the cooling operation is performed also as post-purging of the combustion chamber. 4. The bath water heater according to claim 2, wherein the cooling operation is performed also as pre-purge of the combustion chamber before the operation of switching the bath heating route to the open state is started. 5. The bath water heater according to any one of claims 1 to 4, wherein when the instruction to stop the heating operation is received, the blowing of air to the radiator is immediately stopped. 6. The bath water heater according to claim 1, wherein a radiator is arranged in the middle of a bypass pipe for forming a closed circuit. 7. The bath water heater according to claim 6, wherein the cooling operation is terminated when the water temperature at a predetermined portion of the bypass pipe on the inlet side of the radiator falls below a certain temperature.