JP3242053B2 - Water heater - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hot water supply apparatus for supplying hot water to a bathtub or a kitchen.

[0002]

2. Description of the Related Art For example, in an instant gas hot water supply apparatus, a hot water supply heat exchanger that is heated by a hot water supply burner and raises the temperature of water supplied from a water supply pipe, and a flow rate of fuel gas supplied to the hot water supply burner is adjusted. A hot water supply combustion fan that supplies combustion air to the hot water supply burner, a hot water supply temperature sensor that detects the temperature of hot water supplied from the hot water supply heat exchanger through a hot water supply pipe, and a heat exchanger. And a flowing water sensor for detecting the presence or absence of flowing water passing through the water.

[0003] In such a gas hot water supply apparatus, when the user opens the currant and the flowing water sensor detects flowing water passing through the heat exchanger, the combustion of the hot water supply burner is started. Therefore, the hot water that passes through the heat exchanger and is heated from the heat exchanger is actually supplied from the heat exchanger in addition to the water remaining in the hot water supply pipe from the heat exchanger to the heat exchanger, and also stays in the heat exchanger. It is after the water that was being supplied from Kallang. For this reason, there is a time delay between the time when the user opens the curan and the time when the hot water actually reaches the curan, resulting in a disadvantage that the usability is poor.

Therefore, in order to reduce such a time delay from the opening of the curan to the start of hot water supply, a heat exchange temperature sensor for detecting the temperature of hot water near the outlet from the heat exchanger to the hot water supply pipe is provided. Even when the hot water supply is stopped (when running water is not detected by the running water sensor), a heat retention control for intermittently operating the hot water supply burner is performed so that the temperature detected by the heat exchange temperature sensor is maintained in a predetermined range. A gas hot water supply device is known (JP-A-9-243169, etc.).

[0005] By this heat retention control, the amount of water supplied from the time the user opens the curan to the time the hot water is supplied to the curan is reduced by the amount of water remaining in the hot water supply pipe from the heat exchanger to the curan. Therefore, the delay time until hot water is supplied to the curan can be reduced as compared with the case where the heat retention control is not performed.

[0006] If water leaks from the faucet through the curan to such an extent that the running water sensor does not operate, a small amount of water continuously flows into the heat exchanger from the water supply pipe during the heat retention control, so that heat exchange is performed. The rate of decrease in the temperature of the hot water in the vessel increases,
The time from the stop of the operation of the hot water supply burner to the start of the next operation is shortened. In this case, there is an inconvenience that the consumption of fuel gas in the heat retention control increases, so it is desirable to stop the heat retention control and perform processing such as notifying the user of the occurrence of water leakage.

[0007] As a method for detecting water leakage, when water leakage occurs and the rate of decrease in the temperature of the hot water in the heat exchanger increases, in the heat retention control, the operation of the hot water supply burner is stopped.
Paying attention to the fact that the time required for the temperature detected by the heat exchange temperature sensor to be equal to or lower than the heat retention start temperature (hereinafter, referred to as heat retention temperature decrease time) is shortened, the heat retention temperature decrease time is equal to or less than a predetermined reference time. Sometimes, a method of determining that water leakage has occurred can be considered.

[0008] However, the inventors of the present invention, in addition to hot water supply, perform additional heating of hot water in a bathtub, hot water supply to a hot water floor heater, and the like. In a water heater having a combined configuration in which the combustion exhaust gas of the hot water supply means and the combustion exhaust gas of the heating means are discharged from a common exhaust pipe provided in the housing, water leakage is performed by the method described above. It was found that the following inconveniences occur when the detection of is performed.

In other words, when such a composite structure is employed, even if only the hot water supply burner or only the heating burner of the heating means is burned alone, the hot water supply burner is required to prevent the backflow of the combustion exhaust gas. It is necessary to operate both a hot water supply combustion fan that supplies combustion air and a heating combustion fan that supplies combustion air to a heating burner.

When the heating control and the heat keeping control are performed in parallel under the condition that the heating combustion fan and the hot water supply combustion fan are operated together, the detection of water leakage by the above-described method is performed. It was found that there was a problem that it was not possible to accurately detect water leakage.

[0011]

SUMMARY OF THE INVENTION An object of the present invention is to provide a hot water supply apparatus which can solve the above-mentioned inconvenience and can accurately detect water leakage during heat retention control.

[0012]

In order to achieve the above object, the present invention provides a hot water supply heat exchanger for heating water supplied from a water supply pipe by a hot water supply burner, and adjusting a fuel supply amount to the hot water supply burner. Fuel supply adjusting means, a hot water supply combustion fan for supplying combustion air to the hot water supply burner, a hot water supply pipe from which hot water heated by the hot water supply heat exchanger is discharged, and a temperature of hot water supplied from the hot water supply pipe. Hot water supply means having a hot water supply temperature sensor for detecting, a heat exchange temperature sensor for detecting the temperature of hot water near the outlet of the hot water supply heat exchanger, and a flowing water sensor for detecting the presence or absence of flowing water passing through the hot water supply heat exchanger; A heating means having a heating burner for heating an object to be heated other than water supplied from the water supply pipe, a heating combustion fan for supplying combustion air to the heating burner, the hot water supply means and the heating means And the storage A combustion exhaust gas of a burner, a housing having a collective exhaust port for collecting and discharging the combustion exhaust gas of the heating burner, and operating the heating burner under predetermined conditions, and during the operation of the heating burner, the heating combustion fan. Heating control means for performing heating control for operating both the hot water supply combustion fan and, when running water is detected by the flowing water sensor, so that the detected temperature of the hot water supply temperature sensor matches a predetermined hot water supply target temperature, When the hot water supply control for adjusting the combustion amount of the hot water supply burner by the fuel supply adjusting means and when no flowing water is detected by the flowing water sensor, the temperature detected by the heat exchange temperature sensor has become lower than a predetermined temperature keeping start temperature. Hot water supply control means for performing heat retention control for operating the hot water supply burner for a heating time determined according to a predetermined heat retention target temperature. It is an improvement of the.

The heating control means operates both the heating combustion fan and the hot water supply combustion fan during execution of the heating control. Therefore, when the heat retention control is executed during the execution of the heating control, the hot water in the hot water heat exchanger is rapidly cooled by the air blown from the hot water supply combustion fan while the hot water supply burner is stopped.

That is, when the heat retention control is executed while the heating control is being executed, the temperature of the hot water supply burner is higher than when the heat retention control is executed when the heating control is not executed. The rate of decrease in the temperature of the hot water in the hot water supply heat exchanger during stoppage increases.

Therefore, the time from when the operation of the hot water supply burner is stopped in the heat keeping control until the temperature detected by the heat exchange temperature sensor becomes equal to or lower than the heat keeping start temperature (hereinafter referred to as a heat keeping temperature decreasing time) is the heating time. When the heat retention control is executed while the control is executed,
When the heating control is not executed, the time is shorter than when the heat retention control is executed.

Therefore, when the occurrence of water leakage is detected based on whether or not the heat retention temperature drop time is equal to or shorter than a predetermined reference time, the reference time is set to the heat retention temperature drop time when the heating control is not executed. When the heat retention control is performed during the execution of the heating control, the heat retention temperature drop time is equal to or shorter than the reference time, and it is erroneously determined that water is leaking even though water is not actually leaking. May be done.

On the other hand, if the reference time is set based on the heat-retention temperature drop time when the heating control is being executed, water leakage occurs when the heat-retention control is performed while the heating control is not being performed. Even if it is, the temperature lowering time of the heat retention temperature becomes equal to or longer than the reference time, and it may be erroneously determined that there is no water leakage despite the fact that water is actually leaking.

Therefore, the hot water supply control means of the present invention, when executing the heat retention control while the heating control is not being executed, when the heat retention temperature decrease time becomes equal to or less than the first reference time, water leakage occurs. When the heat retention control is executed while the heating control is being executed, it is determined that water leakage has occurred. When the heat retention temperature decrease time falls below a second reference time shorter than the first reference time, water leakage occurs. Judge that it has occurred.

As described above, the erroneous determination described above is made by changing the setting of the reference time to be compared with the heat retention temperature decrease time in accordance with the change in the heat retention temperature decrease time depending on whether or not the heating control is performed. , And accurate water leakage detection can be performed.

[0020]

FIG. 1 shows an example of an embodiment of the present invention.
This will be described with reference to FIGS. 1 is an overall configuration diagram of the hot water supply apparatus of the present invention, FIG. 2 is an external view of a remote controller provided in the hot water supply apparatus shown in FIG. 1, and FIGS. 3 to 6 are operation flowcharts of the hot water supply apparatus shown in FIG. .

Referring to FIG. 1, hot water supply apparatus 1 includes hot water supply means 2 and additional heating means 3 (corresponding to the heating means of the present invention), and is provided by controller 4 with hot water supply means 2 and additional heating means 3.
Is controlled.

The hot water supply means 2 includes a hot water supply heat exchanger 6 heated by a hot water supply burner 5 operated by a control signal from the controller 4, a water supply pipe 7 connected to a water pipe (not shown) and supplying water to the hot water supply heat exchanger 6. A water quantity servo 8 for adjusting the opening of the water supply pipe 7 according to a control signal from the controller 4, a water supply temperature sensor 9 for detecting the temperature of the supplied water and outputting it to the controller 4, and a running water passing through the hot water heat exchanger 6. Running water sensor 1 that detects presence and outputs to controller 4
0, a hot water supply pipe 11 from which hot water heated by the hot water supply heat exchanger 6 is supplied, a bypass pipe 12 for mixing a part of water supplied to the water supply pipe 7 into the hot water supply pipe 11, and a bypass by a control signal from the controller 4 A bypass servo 13 for adjusting the opening of the pipe 12; a controller 4 for detecting the temperature of hot water in a hot water supply pipe 25 downstream of a junction of the hot water supply pipe 11 and the bypass pipe 12;
, A heat exchange temperature sensor 15 that detects the temperature of the hot water near the outlet of the hot water supply heat exchanger 6 and outputs it to the controller 4, and a gas supply pipe 16. Original gas solenoid valve 17 to be opened and closed, hot water supply gas solenoid valves 18 and 19, and controller 4
A hot water supply gas proportional valve 20 (corresponding to the fuel supply adjusting means of the present invention) whose opening is adjusted by a control signal from the controller.

The rotation speed of the hot water supply means 2 is varied by a control signal from the controller 4, and a hot water supply fan 21 for supplying combustion air to the hot water burner 5, and a control signal from the controller 4 via an igniter 23. And a hot water supply ignition plug 22 for applying a high voltage to the hot water supply burner 5 and a hot water supply frame rod 24 for detecting a combustion state of the hot water supply burner 5 and outputting the combustion state to the controller 4.

On the other hand, the reheating unit 3 comprises a bath heat exchanger 4 which is heated by a bath burner 40 (corresponding to a heating burner of the present invention) which is operated by a control signal from the controller 4.
1. A circulating pump 44 for circulating hot water in a bathtub 42 through a circulation path 43 and a bath heat exchanger 41 according to a control signal from the controller 4, and a bath for detecting the temperature of the hot water in the bathtub 42 and outputting it to the controller 4. Temperature sensor 45, circulation path 43
A water flow switch 46 for detecting the presence or absence of a water flow inside and outputting to the controller 4, a bath gas solenoid valve 47 provided in the gas supply pipe 16 and opened and closed by a control signal from the controller 4, and a constant supply amount of fuel gas. A gas governor 48 for keeping the

The reheating unit 3 has a rotation speed variable according to a control signal from the controller 4, and supplies a bath combustion fan 49 (corresponding to a heating combustion fan of the present invention) for supplying combustion air to the bath burner 40. A high voltage is applied from the igniter 23 according to a control signal from the controller 4, and a bath ignition plug 50 for igniting the bath burner 40 and a combustion state of the bath burner 40 are detected.
And a bath frame rod 51 for outputting to the bathroom.

The circulation path 43 includes a pouring solenoid valve 52 which is opened and closed by a control signal from the controller 4, and a bath hot water supply pipe 5.
It is connected to the hot water supply pipe 25 via a three-way valve 54. Thereby, hot water is supplied from hot water supply means 2 to bathtub 42 by opening pouring electromagnetic valve 52. 56 is bathtub 4
A flow rate sensor 57 detects the flow rate of hot water supplied to the bath 2 and outputs it to the controller 4. Reference numeral 57 denotes a water level sensor that detects the water level of the hot water in the bathtub 42 by hydrostatic pressure and outputs the same to the controller 4.
Reference numeral 27 denotes a pressurized safety valve and a water drainage tap used to release the pressure when the pressure in the hot water supply heat exchanger 6 rises and to drain the water in the hot water supply heat exchanger 6 and the hot water supply pipe 11.

The controller 4 includes a hot water supply control means 31 and a reheating control means 32 (corresponding to the heating control means of the present invention), and is constituted by a CPU, a ROM, a RAM, and the like. The hot water supply means 2 and the additional heating means 3 are controlled according to the mode.

The hot water supply means 2 and the additional heating means 3 are arranged in an integral housing 80, and the exhaust gas of the hot water supply means 2 and the additional exhaust gas of the additional heating means 3 are provided in the housing 80. It is configured to discharge from the exhaust port 81.

When burning the bath burner 40, the additional heating control means 32 operates the hot water supply combustion fan 21 together with the bath combustion fan 49. As a result, as shown in FIG. 1, when only the bath burner 40 is burned, an air flow (white arrow) from the hot water supply combustion fan 21 toward the exhaust port 83 of the hot water supply means 2 is generated, and the additional heating means 3 is heated. Exhaust gas (black arrow) discharged from the exhaust port 82 of the hot water supply means 2
To prevent short circuit to the bath combustion fan 49.

Next, with reference to FIG.
An operation switch 60 for instructing an operation start and an operation stop of the entire hot water supply apparatus 1, and a predetermined amount of hot water supplied to the bathtub 42;
An automatic switch 61 for instructing the start of automatic operation for performing additional heating up to a predetermined boiling temperature after the hot water supply, and a hot water supply pipe 25;
Hot water supply temperature switch 62 for setting a hot water supply target temperature to
A clock setting switch 63 for specifying a clock time setting mode for setting the time of the internal clock; a reservation setting switch 64 for specifying a reservation time setting mode for setting the reservation time for the automatic operation; a clock time setting mode and a reservation time setting In the mode, an hour setting switch 65, a minute setting switch 66 for setting each time, a reservation operation switch 67 for setting the reservation for the automatic operation, and a heat retaining function for keeping the temperature of hot water in the hot water supply heat exchanger 6 within a predetermined range. It has a heat retention switch 68 for instructing execution of operation, and a display unit 69 for displaying hot water supply temperature, time, and the like.

The user operates the operation switch 6 of the remote controller 30.
When 0 is operated, the entire hot water supply device 1 enters a standby state, and the operation lamp 70 incorporated in the operation switch 60 is turned on. In this state, when the user opens the callan 26 connected to the tip of the hot water supply pipe 25, water supply to the water supply pipe 7 is started, and the flowing water sensor 10 detects flowing water. When the controller 4 recognizes the start of the water supply to the water supply pipe 7 based on the output from the flowing water sensor 10, it operates the hot water supply combustion fan 21, and operates the original gas solenoid valve 17, the hot water supply gas proportional valve 20, and the hot water supply gas solenoid valve 18. , 19 are opened, and a high voltage is applied to the igniter 23 to cause a spark discharge in the hot water supply spark plug 22 to perform the ignition processing of the hot water supply burner 5.

When the hot water supply control means 31 provided in the controller 4 recognizes from the output of the hot water supply frame rod 24 that the hot water supply burner 5 has been ignited, the detected temperature of the hot water supply temperature sensor 14 and the remote control 30 are used. The hot water gas proportional valve 20 is adjusted so that the set hot water supply target temperature matches.
Hot water supply control is performed to adjust the opening degree of the hot water supply combustion fan 21, the opening and closing of the hot water supply gas solenoid valves 18 and 19, the opening degree of the water volume servo 8, and the opening degree of the bypass servo 13. Thereby, hot water is supplied from curan 26 at the hot water supply target temperature set by remote controller 30.

In the hot water supply control, the target combustion amount of the hot water supply burner 5 is determined such that the outlet temperature of the heat from the heat exchanger 6 becomes higher than the target hot water supply temperature. The opening degree of the hot water supply gas proportional valve 20, the rotation speed of the hot water supply combustion fan 21, and the opening and closing of the hot water supply gas solenoid valves 18 and 19 are controlled in accordance with the amount. And the bypass pipe 1
The hot water at the target hot water supply temperature can be supplied from the hot water supply pipe 25 by mixing with the water from the second water.

When the user operates the automatic switch 61 of the remote controller 30, the controller 4 starts the above-mentioned automatic operation, and opens the pouring solenoid valve 52 first. By opening the pouring solenoid valve 52, water supply to the water supply pipe 7 is started,
The hot water supply burner 5 is ignited in the same manner as when the user opens the curran 26 described above, and the hot water supply pipe 11 is supplied with the hot water supply electromagnetic valve 52, the bath hot water supply pipe 53, the three-way valve 54, and the circulation path 4.
The hot water supply at the hot water supply target temperature is started via 3.

The controller 4 accumulates the amount of hot water supplied to the bathtub 42 based on the output from the flow rate sensor 56, and closes the pouring solenoid valve 52 when the accumulated value reaches the filling level.
The supply of a predetermined amount of hot water (hot water) to the bathtub 42 ends.

After completion of filling the bathtub 42, the controller 4 detects the temperature of the hot water in the bathtub 42 based on the output of the bath temperature sensor 45, and when the detected temperature is lower than the above-mentioned boiling temperature, the temperature of the boiling water is determined. Until the hot water in the bathtub 42 is heated.

In order to raise the temperature, the additional heating control means 32 provided in the controller 4 activates the bath pump 44 to circulate the hot water in the bathtub 42 through the circulation path 43, The hot gas supply fan 21 and the hot water supply combustion fan 21 are operated to open the original gas solenoid valve 17 and the bath gas solenoid valve 47, and apply a high voltage to the bath ignition plug 50 via the igniter 23 to generate spark discharge. Forty ignition processes are performed.

When the additional heating control means 32 recognizes from the output of the bath frame rod 51 that the bath burner 40 has been ignited, the temperature detected by the bath temperature sensor 45 reaches the boiling temperature. Until the above, the combustion of the bath burner 40 is continued. As a result, the temperature of the hot water in the bathtub 42 is raised to the boiling temperature (additional heating).

Note that the additional heating control means 32 keeps the temperature of the hot water in the bathtub 42 substantially at the boiling temperature for 4 hours after the hot water in the bathtub 42 reaches the boiling temperature. Thus, the bath heat keeping operation of intermittently burning the bath burner 40 is performed. Then, during the bath heat keeping operation, the heat keeping mark 72 is displayed on the display section 69 of the remote controller 30.

When the user operates the automatic switch 61 of the remote controller 30 and recognizes from the water level sensor 57 that the bathtub 42 has already been filled with water, the controller 4 returns to the bathtub. 42 is not filled, but only additional heating up to the above-mentioned boiling temperature is performed.

When the user operates the reservation operation switch 67, the reservation operation is set, and the reservation mark 71 is displayed on the display section 71 of the remote controller 30. The reservation setting switch 64, the hour switch 65, and the minute switch 6
The automatic operation described above is executed when the preset reservation time is reached in 6.

Next, when the user operates the heat retention switch 68, the hot water supply control means 31 sets the temperature of the hot water in the hot water supply heat exchanger 6 within a predetermined temperature range for a predetermined time (for example, one hour). Execute the heat retention control. This heat retention control is a process for reducing the time (delay time) from when the user opens the curan 26 to when the hot water is actually supplied to the curan 26.

As described above, the hot water supply burner 5 is normally ignited when the flowing water sensor 10 recognizes that the supply of water to the heat exchanger 6 has started. At this time, water stays in the hot water supply pipe 25, the hot water supply pipe 11, and the hot water supply heat exchanger 6. Therefore, the hot water is supplied from the curan 26 after the water staying in the hot water supply pipe 25, the hot water supply pipe 11, and the hot water supply heat exchanger 6 is supplied. The length of the pipe in the hot water supply heat exchanger 6 is, for example, 2.5 m.

Therefore, by keeping the temperature of the hot water in the hot water supply heat exchanger 6 in advance, the amount of water to be supplied before the hot water supply is started can be reduced to only the amount of water retained in the hot water supply pipe 25 and the hot water supply pipe 11. The delay time from when the user opens the curran 26 to when the hot water supply is actually started can be reduced.

Hereinafter, the processing content of the heat retention control by the hot water supply control means 31 will be described in detail with reference to the flowcharts of FIGS.

Referring to FIG. 3, when the user operates the heat retention switch 68 in STEP1, the reception lamp 73 built in the heat retention switch 68 is turned on in STEP2. Then, hot water supply control means 31 executes subroutine A in STEP3. Although details of the execution contents of the subroutine A will be described later, referring to FIG. 6, when the subroutine A of STEP48 to STEP58 is executed, in STEP48, the additional heating of the hot water in the bathtub 42 is performed by the additional heating control means 32. When the reheating is not performed, the reference time TM is set to 2 minutes (corresponding to the second reference time of the present invention), and when the reheating is not performed, the reference time TM is set to 4 minutes (the first reference time of the present invention). Equivalent).

Next, in STEP 4, one time after the previous combustion was stopped.
Wait for minutes to elapse. During the one minute waiting time, the temperature of the hot water staying in the upper portion of the hot water supply heat exchanger 6 heated from the lower portion by the combustion of the hot water supply burner 5 gradually increases due to the convection of the hot water in the hot water supply heat exchanger 6. This is the time when the temperature detected by the heat exchange temperature sensor 15 is expected to surely reach the predetermined temperature range.

Then, hot water supply control means 31 determines in STEP 5
Is determined based on the hot water temperature detected by the hot water temperature sensor 9 and the hot water target temperature set by the hot water temperature switch 62 of the remote controller 30. . In hot water supply apparatus 1 of the present embodiment, hot water supplied from hot water supply heat exchanger 6 via hot water supply pipe 11 and water supplied from water supply pipe 8 via bypass pipe 12 have hot water supply target temperatures. And supplied to the hot water supply pipe 25. Therefore, it is necessary to determine the warming start temperature of the hot water in the hot water supply heat exchanger 6 according to both the hot water supply temperature and the hot water supply target temperature.

Next, in STEP 6, the heat exchange temperature sensor 15
If the detected temperature exceeds the heat retention start temperature,
The program branches to the TEP 31 and displays an OK mark 74 indicating that the hot water in the hot water supply heat exchanger 6 has exceeded the heat retention start temperature on the display unit 69 of the remote control 30. Depending on the detection value of the feed water temperature by the temperature sensor 53 and the detection value of the temperature of the hot water in the hot water supply heat exchanger 6 by the heat exchange temperature sensor 15, the hot water supply from the hot water supply heat exchanger 6 and the water supply from the bypass pipe 12 are determined. The temperature at the time of mixing is adjusted to match the hot water supply target temperature.

On the other hand, in STEP 6, the heat exchange temperature sensor 15
If the detected temperature is equal to or lower than the heat retention start temperature, the process proceeds to STEP 7 in FIG. STEP7 and STE
STEP34 to STEP39 branched from P7 are processing for detecting water leakage from a faucet or the like.

When water leakage occurs, water is supplied from the water supply pipe 7 to the hot water supply heat exchanger 6 in response to the water leakage, so that the temperature of the hot water in the hot water supply heat exchanger 6 is reduced. Therefore, the rate of decrease in the temperature of the hot water in the hot water supply heat exchanger 6 during the stoppage of the combustion of the hot water supply burner 5 becomes greater than when no water leakage occurs, and the heat exchange temperature after the combustion of the hot water supply burner 5 stops. Sensor 15
The time during which the detected temperature of (1) decreases to the heat retention start temperature (hereinafter referred to as the heat retention temperature decrease time) is shortened.

Therefore, in the present embodiment, the hot water supply control means 31 monitors the heat retention temperature decrease time in STEP 7 and, after stopping the combustion of the hot water supply burner 5 and before the reference time TM elapses, changes the heat exchange temperature. When the temperature detected by the sensor 15 becomes equal to or lower than the heat retention start temperature, it is determined that water leakage has occurred.

As described above, when the additional heating of the hot water in the bathtub 42 is performed and the bath combustion fan 49 is operated and the bath burner 40 is burning, the hot water supply burner 5
Is not burning, the hot water supply combustion fan 21 is operated.
In this case, since the outside air sucked from the intake port 84 by the hot water supply combustion fan 21 hits the hot water supply heat exchanger 6, especially when the outside air is at a low temperature, the temperature of the hot water retained in the hot water supply heat exchanger 6 rapidly decreases. I do.

Therefore, the heat retention temperature lowering time differs greatly between when the additional heating is performed and when the additional heating is not performed. Therefore, hot water supply control means 31
As described above, in the subroutine A, the reference time T
M is switched between a first reference time (4 minutes) and a second reference time (2 minutes) depending on whether or not reheating is performed. This prevents erroneous detection of water leakage due to fluctuations in the heat retention temperature lowering time.

In order to further increase the reliability of water leak detection, in the present embodiment, STEP 34 to STE
At P36, when it is determined that water leakage has occurred three times consecutively when the heat retention temperature drop time is less than or equal to the reference time TM, the process proceeds from STEP36 to STEP37, prohibits the heat retention control, and the display of the remote controller 30 is displayed at STEP38. The OK mark 74 displayed on the section 69 is turned off.

As described above, by inhibiting the heat retention control when water leakage occurs, it is possible to prevent the hot water supply burner 5 from burning frequently and consuming a large amount of fuel gas in a state where the heat retention temperature drop time is short. Preventing.

Subsequently, it is determined in STEP 9 whether or not 5 minutes have elapsed since the combustion of the hot water supply burner 5 was stopped. During the set time of 5 minutes, the temperature of the hot water in the hot water supply heat exchanger 6 becomes more uniform after the combustion of the hot water supply burner 5 stops, and the temperature of the hot water in the hot water supply heat exchanger 6 and the heat exchange temperature sensor 15 Is the time assumed to be required to match.

In STEP 10, it is detected whether or not water exists in the hot water supply heat exchanger 6. In the present embodiment, the presence / absence of water is detected by using a thermistor for the heat exchange temperature sensor 15 and applying a high voltage to the thermistor to cause self-heating by applying a high voltage to the thermistor. The temperature decrease rate of the thermistor after the application of water is stopped depends on whether the thermistor is in water (there is water in the hot water supply heat exchanger 6) or in the air (there is no water in the hot water supply heat exchanger 6). This is done using different things.

If it is determined in STEP 11 that there is water in the hot water supply heat exchanger 6, STEP 11 to STEP 1
Proceeding to 2, the heat retention target temperature, which is the temperature at which the combustion of the hot water supply burner 5 is stopped, is determined to be a temperature higher than the heat retention start temperature by a predetermined temperature.

Then, in STEP 13, the combustion time T of the hot water supply burner 5 required to raise the temperature of the hot water in the hot water supply heat exchanger 6 from the heat retention start temperature to the heat retention target temperature is calculated. The calculation of the combustion time T is based on the hot water supply gas solenoid valve 1.
The opening of the hot water supply gas proportional valve 20 is performed based on the heating amount of the hot water supply burner 5 when the opening degree of the hot water supply gas proportional valve 20 is set to the minimum opening degree at which the hot water supply burner 5 can burn.

Next, in STEP 14, the hot water supply gas solenoid valve 1
8 and 19 are both opened, and the combustion of the hot water supply burner 5 is started in a state where the opening degree of the hot water supply gas proportional valve 20 is set to the minimum opening degree at which the combustion of the hot water supply burner 5 is possible. In this way, by burning the entire hot water supply burner 5 with the combustion amount being minimized, the temperature of the hot water in the hot water supply heat exchanger 6 is prevented from rising rapidly,
The variation in the temperature of the hot water in the hot water supply heat exchanger 6 is reduced, and the hot water supply burner 5 is prevented from frequently repeating combustion and stop of combustion.

Then, in STEP15, the timer T with the combustion time T calculated in STEP13 as a set time is started, and in STEP16, after the timer T expires, the combustion of the hot water supply burner 5 is stopped in STEP17. S
If the OK mark 74 is not displayed on the display unit 69 in STEP18, the OK mark 74 is displayed in STEP19, and the process returns to STEP4.

Thereafter, the processing of STEP4 to STEP19 is repeated, and when the temperature detected by the heat exchange temperature sensor 15 becomes lower than the heat retention start temperature in STEP6, STEP14 to STEPS
The hot water supply burner 5 is operated in TEP17. This allows
The temperature of the hot water in the hot water supply heat exchanger 6 is maintained within the range from the heat retention start temperature to the heat retention target temperature.

Next, the processing contents of the subroutine A will be described with reference to FIG. STEP48, STEP4
9 and STEP 70 are the reference time TM as described above.
Is a setting process.

In STEP 50, the heat switch 68 is turned off.
This is an operation detection unit.
When the F operation is performed, the process branches to STEP60, and when the hot water supply burner 5 is burning, in STEP64, the combustion of the hot water supply burner 5 is stopped. Then, in step 61, the display of the OK mark on the display unit 69 is turned off.
Then, the reception lamp 73 built in 8 is turned off, and the heat retention control ends.

STEP 51 is an opening / closing detection section for the curan 26. When the user opens the curan 26 and detects water supply to the water supply pipe by the output of the water flow sensor 10, the hot water supply control means 31 returns to a standby state described later in STEP 65. The flag F is reset (F = 0), a one-hour timer described later is reset in STEP 66, and the hot water supply control described above is performed in STEP 67 until the stop of water supply is detected from the output of the water flow sensor 10 in STEP 68.

STEP 52 is a determination section for determining whether or not a standby flag F indicating that a one-hour timer described later has timed out is set (F = 1). If the standby flag F is set (F = 1) If it is, S
The process branches to TEP50 to execute a wait loop of STEP50 to STEP52.

STEP 53 is a one-hour timer activation judging section. This one-hour timer manages one hour, which is the execution time of the heat retention control. If the one-hour timer is not operating in STEP53, the one-hour timer is started in STEP54. That is, when the subroutine A is first executed after the heat switch 68 is operated, and when ST
Water supply is detected in EP51 and STEP65 to STEP6
When the subroutine A is first executed after the hot water supply operation of No. 7 is completed, the one-hour timer is started.

In the flowcharts of FIGS. 3 to 6, the subroutine A is sequentially executed in each waiting loop.
When the one-hour timer times out in step 5, ST
In EP56, the presence or absence of combustion of the hot water supply burner 5 is determined, and when the hot water supply burner 5 is burning, the combustion of the hot water supply burner 5 is stopped in STEP57. Subsequently, in step 57, the standby flag F is set (F = 1), and in step 58, the display of the OK mark 74 on the display unit 69 is turned off to notify the user that the one-hour heat retention control has been completed.
Returning to step 50, a wait loop of STEP50 to STEP52 is executed.

In addition, according to the subroutine A shown in FIG.
Proceeding to TEP49, the reference time TM is set to 2
The time is switched from minutes (second reference time) to four minutes (first reference time). However, it is highly likely that the temperature of the hot water staying in the hot water supply heat exchanger 6 rapidly decreases during the bath reheating, so the reference time T is used only for the first time after the completion of the bath reheating operation.
It is preferable that the water leak determination be performed with 2 minutes (second reference temperature) without switching M to 4 minutes (first reference time).

Further, in this embodiment, a hot water supply device using a gas burner as hot water supply burner 5 and bath burner 40 has been described, but a hot water supply using a burner such as a kerosene burner to which combustion air is supplied by a combustion fan. The present invention can be applied to a device.

Although the example in which the hot water supply means 2 and the additional heating means 3 are arranged in the same casing 80 has been described, in addition to the additional heating means 3, a heating means for circulating the hot water through the floor heating device, and the like. The present invention is also applicable to a hot water supply apparatus in which other types of heating means and hot water supply means 2 are arranged in the same housing.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram of a hot water supply device of the present invention.

FIG. 2 is an external view of a remote controller provided in the water heater shown in FIG.

FIG. 3 is an operation flowchart of the water heater shown in FIG. 1;

FIG. 4 is an operation flowchart of the water heater shown in FIG. 1;

FIG. 5 is an operation flowchart of the water heater shown in FIG. 1;

FIG. 6 is an operation flowchart of the water heater shown in FIG. 1;

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Hot water supply apparatus, 2 ... Hot water supply means, 3 ... Additional heating means, 4 ... Controller, 5 ... Hot water supply burner, 6 ... Hot water supply heat exchanger, 7 ...
Water supply pipe, 8: water quantity servo, 9: water supply temperature sensor, 10 ...
Running water sensor, 11: hot water supply pipe, 12: bypass pipe, 13 ...
Bypass servo, 14 hot water supply temperature sensor, 15 heat exchange temperature sensor, 16 gas supply pipe, 17 original gas solenoid valve, 1
8, 19: hot water supply gas solenoid valve, 20: hot water supply gas proportional valve, 2
DESCRIPTION OF SYMBOLS 1 ... Hot-water supply combustion fan, 22 ... Hot-water supply ignition plug, 23 ... Igniter, 24 ... Hot-water supply frame rod, 25 ... Hot-water supply piping, 26 ... Karan, 27 ... Overpressure safety valve and drain valve, 30 ...
Remote controller, 31: Hot water supply control means, 32: Additional heating control means, 40: Bath burner, 41: Bath heat exchanger, 42: Bathtub, 43: Circulation path, 44: Circulation pump, 45: Bath temperature sensor, 46: Water flow Switch, 47 ... bath gas solenoid valve,
48: bath gas governor, 49: bath combustion fan, 50 ...
Bath ignition plug, 51: bath frame rod, 52: pouring solenoid valve, 53: bath water pipe, 54: three-way valve, 56: flow rate sensor, 57: water level sensor, 80: housing, 81: collective exhaust port, 84 … Inlet

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁷ , DB name) F24H 1/10 303

Claims (1)

(57) [Claims] 1. A hot water supply heat exchanger for heating water supplied from a water supply pipe by a hot water supply burner, a fuel supply adjusting means for adjusting a fuel supply amount to the hot water supply burner, and supplying combustion air to the hot water supply burner. A hot water supply combustion fan, a hot water supply pipe from which hot water heated by the hot water supply heat exchanger is discharged, a hot water supply temperature sensor for detecting a temperature of hot water supplied from the hot water supply pipe, and a vicinity of an outlet of the hot water supply heat exchanger. Hot water supply means having a heat exchange temperature sensor for detecting the temperature of hot water, and a flowing water sensor for detecting the presence or absence of flowing water passing through the hot water supply heat exchanger; and other heated objects other than water supplied from the water supply pipe. A heating unit having a heating burner for heating an object, a heating combustion fan for supplying combustion air to the heating burner, the hot water supply unit and the heating unit are housed, and the combustion exhaust gas of the hot water supply burner; Burner combustion exhaust gas And a housing having a collective exhaust port that collects and discharges, and heating control for operating the heating burner under predetermined conditions and operating both the heating combustion fan and the hot water supply combustion fan during operation of the heating burner. Heating control means for performing, and the amount of combustion of the hot water supply burner by the fuel supply adjusting means so that the detected temperature of the hot water supply temperature sensor matches a predetermined hot water supply target temperature when flowing water is detected by the flowing water sensor. And when the flowing water sensor is not detecting flowing water and the detected temperature of the heat exchange temperature sensor is lower than a predetermined temperature keeping start temperature, the hot water supply burner is kept at a predetermined temperature. A hot water supply control means for performing heat retention control for operating for a heating time determined in accordance with the target temperature, wherein the hot water supply control means When the heat retention control is executed when control is not being performed, the time from when the hot water supply burner stops operating until the temperature detected by the heat exchange temperature sensor becomes equal to or lower than the heat insulation start temperature is equal to or less than a first reference time. When it is determined that water leakage has occurred, and when the heating control is being executed while the heating control is being executed, the temperature detected by the heat exchange temperature sensor is changed from the stop of the operation of the hot water supply burner to the insulation. A water heater that determines that water leakage has occurred when the time until the temperature becomes equal to or less than the start temperature is equal to or less than a second reference time shorter than the first reference time.