JP3767959B2 - One can two water bath hot water heater - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a canned two-way bath water heater in which a hot water supply heat exchanger and a reheating heat exchanger are integrated, and the integrated heat exchanger is heated by a common burner.
[0002]
[Prior art]
FIG. 7 shows a system configuration example of a one-can two-water bath water heater developed by the applicants. In the figure, this single can two water bath water heater (equipment) has a combustion chamber 1, a burner 2 is disposed in the combustion chamber 1, and a hot water supply heat exchanger 3 and a follower are disposed above the burner 2. A soaking heat exchanger 4 is provided. These hot water supply heat exchangers 3 and reheating heat exchangers 4 are integrated. That is, a hot water supply side pipe is penetrated and attached to a plurality of common fin plates 5 to form a hot water supply heat exchanger 3. The burner 2 is configured to heat both the hot water supply heat exchanger 3 and the reheating heat exchanger 4.
[0003]
The combustion chamber 1 on the lower side of the burner 2 communicates with an air supply passage 6, and a combustion fan 7 is incorporated in the air supply passage 6. Then, air is sent to the burner 2 and exhaust gas generated by the combustion of the burner 2 is discharged to the outside from the exhaust passage 9 communicating with the combustion chamber 1 above the burner 2.
[0004]
A gas nozzle 19 is disposed opposite to the gas inlet of the burner 2, and a gas supply passage 8 for introducing fuel gas is connected to the gas nozzle 19, and the fuel gas introduced by the gas supply passage 8 is connected to the gas nozzle 19. Is supplied to the burner 2 via the gas nozzle 19. The gas supply passage 8 is provided with electromagnetic valves 10, 11a, 11b for opening and closing the passage, and a proportional valve 12 for controlling the gas supply amount by the valve opening amount.
[0005]
One end side of the water supply passage 13 is connected to the inlet side of the hot water supply heat exchanger 3, one end side of the hot water supply passage 14 is connected to the outlet side of the hot water supply heat exchanger 3, and the other end side of the water supply passage 13 is It is connected to a water supply source through an external pipe, and the other end of the hot water supply passage 14 is led to a desired hot water supply place such as a kitchen through the external pipe. Further, a bypass passage 15 and a bypass passage 16 are provided to short-circuit the water supply passage 13 on the inlet side and the hot water supply passage 14 on the outlet side of the hot water supply heat exchanger 3, and the bypass passage 16 is opened and closed. An electromagnetic valve 17 is interposed.
[0006]
One end of a pipe 18 is connected to the inlet side of the reheating heat exchanger 4, and the other end of the pipe 18 is connected to the discharge port of the circulation pump 20. One end side of the return pipe 21 is connected, and the other end side of the return pipe 21 is connected to the bathtub 22. In addition, one end side of a pipe line 23 is connected to the outlet side of the reheating heat exchanger 4, and the other end side of the pipe line 23 is connected to the bathtub 22. The return pipe 21, the pipe 18, the reheating heat exchanger 4, and the line 23 constitute a recirculation circulation path 24.
[0007]
The pipe 18 of the recirculation circulation passage 24 and the hot water supply passage 14 are communicated with each other by a hot water filling passage 25, and the hot water filling passage 25 has a pouring control valve 26 for controlling the opening and closing of the passage, and the water level of the bathtub 22. And a water level sensor 28 that detects water pressure by water pressure.
[0008]
In the figure, 30 is an air volume sensor that detects the air volume in the combustion chamber 1, 31 is a water volume sensor that is provided in the water supply passage 13 and detects the flow rate of the water supply, and 32 is water in the water supply passage 13. A water temperature sensor for detecting temperature, 34 is a flow rate control valve that is provided in the hot water supply passage 14 to control the flow rate of hot water supply, and 35 is provided in the hot water supply passage 14 to indicate that hot water is being supplied. A hot water supply confirmation switch to be detected, 36 is a water flow sensor for detecting the water flow in the recirculation circulation passage 24, and 37 is a recirculation circulation passage for detecting the hot water in the recirculation circulation passage 24 as a bath water temperature (bath temperature). A bath temperature sensor, which is a temperature sensor, is a hot water temperature sensor 38 that detects the temperature of hot water produced by the hot water supply heat exchanger 3.
[0009]
A control device 40 is provided in the single can two water bath hot water heater, and a remote controller 41 is connected to the control device 40. The remote controller 41 includes a hot water supply temperature setting means for setting the hot water supply temperature, a bath temperature setting means for setting the bath temperature of the bathtub 22, a bath water level setting means for setting the hot water level of the bathtub 22, and the bathtub 22. An automatic operation button for starting automatic operation of a series of baths from hot water filling to heat insulation is provided.
[0010]
The control device 40 takes in sensor output signals of various sensors and information from the remote controller 41, and controls operations in various operation modes such as hot water supply operation and automatic bath operation in accordance with a sequence program given in advance as follows. To do.
[0011]
For example, when a faucet of a hot water supply passage led to a kitchen or the like is opened, water flows into the water supply passage 13 from a water supply source, and the water amount sensor 31 detects water passing through the water supply passage 13, the appliance operates in the hot water supply mode. Start. First, the rotational drive of the combustion fan 7 is started, and both or one of the solenoid valves 11a and 11b and the solenoid valve 10 are opened to supply the fuel gas to the burner 2 through the gas supply passage 8, which is not shown. The burner 2 is ignited by ignition means to start combustion.
[0012]
Then, the amount of combustion heat of the burner 2 is controlled by controlling the valve opening amount of the proportional valve 12 (controlling the amount of gas supplied to the burner 2) so that the hot water temperature becomes the hot water set hot water temperature set in the remote controller 41. The hot water supply heat exchanger 3 is heated by the combustion flame of the burner 2 to produce hot water at a set temperature, and this hot water is supplied to the hot water supply place through the hot water supply passage 14.
[0013]
When the use of hot water is finished and the faucet is closed, water flow to the hot water supply heat exchanger 3 is stopped, and the electromagnetic valve 10 is closed when the water amount sensor 31 no longer detects water flow through the water supply passage 13. The combustion of the burner 2 is stopped. Thereafter, when a post-purge period (for example, 5 minutes) in which the exhaust gas in the combustion chamber 1 is almost finished has elapsed, the rotation drive of the combustion fan 7 is stopped and the operation in the hot water supply mode is ended, and the next hot water supply Prepare for.
[0014]
Further, when an automatic bath operation is commanded by the automatic operation button of the remote controller 41, first, the operation of the hot water filling mode is started as shown in step 101 of the flowchart of FIG. For example, when the pouring control valve 26 is opened and when the pouring control valve 26 is opened, water flows from the water supply source into the water supply passage 13 and the water amount sensor 31 detects the water flow through the water supply passage 13. The combustion of the burner 2 is started similarly to the operation.
[0015]
Hot water produced in the hot water supply heat exchanger 3 by the combustion flame of the burner 2 is sent to the recirculation circulation passage 24 through the hot water supply passage 14 and the hot water filling passage 25 in order, and the hot water flowing into the recirculation circulation passage 24 returns. It is dropped into the bathtub 22 by two paths, a path passing through the pipe 21 and a path passing through the reheating heat exchanger 4. When the water level of the bathtub 22 detected by the water level sensor 28 reaches the set water level set in the remote controller 41, the hot water control valve 26 is closed and the solenoid valve 10 is closed to stop the combustion of the burner 2 to fill the hot water. End mode operation.
[0016]
After the operation of the hot water filling mode is finished, as shown in step 102 of FIG. 8, the circulation pump 20 is driven to recirculate hot water in the bathtub 22 and circulate it through the circulation passage 24 to stir the hot water in the bathtub 22. Then, the bath temperature of the bathtub 22 is detected by the bath temperature sensor 37. In step 104, it is determined whether or not the detected bath temperature Th is lower than the set temperature Ts of the bath. The bath temperature Th is lower than the set temperature Ts. When it is determined that the value is low, the process proceeds to step 110, and the operation in the chase mode is started.
[0017]
For example, the circulation pump 20 is continuously driven to recirculate hot water in the bathtub 22 through the recirculation circulation passage 24 and start combustion of the burner 2, and the reheating heat exchanger 4 is driven by the combustion flame of the burner 2. The circulating hot water is heated and reheated. When it is determined in step 104 that the bath temperature Th detected by the bath temperature sensor 37 has reached the set temperature Ts, the combustion of the burner 2 is stopped and the operation in the reheating mode is ended.
[0018]
And as shown to step 105, while stopping the circulation pump 20, the time measurement by the timer incorporated in the control apparatus 40 is started, and operation | movement of a heat retention mode is started.
[0019]
For example, as shown in step 106, it is determined whether or not the measurement time tc of the timer has reached a predetermined set time ts (for example, 30 minutes). When it is determined that the measurement time tc has reached the set time ts, the operation from step 102 to step 105 is performed, and when the bath temperature Th is lower than the set temperature Ts, retreat is performed. Thus, the bath temperature Th can be maintained at the set temperature Ts.
[0020]
Further, during the period in which it is determined in step 106 that the timer measurement time tc has not reached the set time ts, the water retention mode operation shown in steps 107, 108, and 109 is performed.
[0021]
First, in step 107, the sensor output detected by the water level sensor 28 is detected. The water level sensor 28 detects the water pressure of the hot water in the hot water passage 25 as the water pressure of the bathtub 22 and outputs the water pressure of the bathtub water level as a sensor output. PQ data as shown by the solid line A in FIG. 9 representing the relationship between the sensor output (P) detected by the water level sensor 28 and the amount of water (Q) in the bathtub 22 is obtained and given to the control device 40 in advance. The water level of the bathtub 22 is detected by referring to the PQ data with respect to the sensor output of the water level sensor 28.
[0022]
When it is determined in step 108 whether or not the detected water level Pk of the bathtub 22 is lower than the set water level Ps, and it is determined that the water level Pk of the bathtub 22 is not lower than the set water level Ps. When the water level detection operation by the water level sensor 28 is repeated by the operation after the step 106, and when it is determined that the water level Pk of the bathtub 22 is lower than the set water level Ps due to the use of hot water by the bather, etc. In Step 109, the hot water filling operation is started, the hot water is poured into the bathtub 22, and the water level Pk of the bathtub 22 is raised to the set water level Ps.
[0023]
The operation in the water retention mode is repeatedly performed until the measurement time tc of the timer reaches the set time ts.
[0024]
The operation in the heat retention mode including the water retention operation is performed over a predetermined period (for example, for 4 hours after the bath has boiled up).
[0025]
As described above, the single can two water bath hot water heater is a system in which the integrated hot water supply heat exchanger 3 and the reheating heat exchanger 4 are heated by using the common burner 2, and thus are provided separately. Compared with the method in which the hot water supply heat exchanger and the reheating heat exchanger are each heated by combustion using separate burners, the configuration of the apparatus can be simplified, and as a result, the apparatus can be downsized and the cost can be reduced. Become.
[0026]
[Problems to be solved by the invention]
By the way, if the single-can two-water bath water heater does not perform the reheating operation and performs the hot water supply single operation only with the hot water supply, an accurate water level of the bathtub 22 cannot be obtained immediately after the hot water supply single operation for the following reasons. It was found by the applicant's experiment.
[0027]
During the hot water supply single operation, hot water remains in the reheating heat exchanger 4 and when the burner 2 is burned for the hot water operation, not only the hot water heat exchanger 3 but also the hot water heat exchanger 3 is driven by the combustion flame of the burner 2. Since the soaking heat exchanger 4 is also heated, the staying hot water in the reheating heat exchanger 4 is heated. For this reason, the temperature of the stagnant hot water in the reheating heat exchanger 4 rises to a boiling state.
[0028]
The hot water heated at a high temperature in the reheating heat exchanger 4 flows out to both sides of the inlet line 18 and the outlet line 23 of the reheating heat exchanger 4 by a convection phenomenon, and this reheating heat exchanger. The temperature of the hot water in the hot water supply passage 25 which is a communication passage communicating with the reheating circulation passage 24 and the reheating circulation passage 24 by the heat of the hot hot water flowing out from the hot water 4 is considerably high, for example, 70 to 80 ° C. To rise.
[0029]
As described above, when the hot water temperature in the hot water filling passage 25 rises to a high temperature, a predetermined guaranteed temperature range of the water level sensor 28 (a water temperature range in which accurate water level detection is guaranteed (for example, 5 to 48). ))), The water level sensor 28 cannot detect an accurate water pressure, and the sensor output of the water level sensor 28 changes the water level of the bathtub 22 as shown in FIG. In spite of this, it shifts in the direction of ascending or descending with a large temperature dependency.
[0030]
In addition, as described above, hot water heated at a high temperature in the reheating heat exchanger 4 flows out to both sides of the inlet line 18 and the outlet line 23 of the reheating heat exchanger 4, and the line 18 Then, convection in which warm hot water flows into the reheating heat exchanger 4 from both sides of the pipe line 23 is generated, and the convection of the hot water causes irregular vibrations in the reheating circulation passage 24 and the hot water passage 25. The irregular vibration of the hot water in the hot water filling passage 25 causes the sensor output of the water level sensor 28 to vibrate irregularly as shown in FIG.
[0031]
As described above, when the hot water in the reheating heat exchanger 4 is heated at a high temperature during the hot water supply single operation, the rise in the temperature of the hot water in the hot water filling passage 25 and irregular vibrations are synergistically involved, and the water level sensor 28. The sensor output fluctuates irregularly, and it is difficult to accurately detect the water level of the bathtub 22 based on the sensor output of the water level sensor 28.
[0032]
As described above, it becomes difficult to accurately detect the water level of the bathtub 22 by hot water supply single operation. For example, when a hot water supply interruption is performed and the hot water supply single operation is performed during the operation in the heat retention mode of automatic operation, the water level sensor When the output of 28 shifts upward, a water level higher than the water level of the bathtub 22 is detected, and a malfunction occurs such that the water retention operation is not performed even though the water level of the bathtub 22 is lower than the set water level. May end up. Further, when the output of the water level sensor 28 shifts downward, a water level lower than the water level of the bathtub 22 is detected, and the water retention operation is performed even though the water level of the bathtub 22 is not lower than the set water level. There is.
[0033]
The present invention has been made in order to solve the above-described problems, and its purpose is to provide a single can two water channel that can prevent the appliance from malfunctioning due to irregular fluctuations in the water level sensor output caused by hot water single operation. The purpose is to provide a bath water heater.
[0034]
[Means for Solving the Problems]
In order to achieve the above object, the present invention has the following configuration as means for solving the above problems. That is, the first invention is a hot water heat exchanger that heats water supplied from the water supply passage and sends it to the hot water supply passage, and circulating hot water that is incorporated in the recirculation circulation passage of the bathtub hot water and circulates in the recirculation circulation passage. A reheating heat exchanger that performs reheating, a recirculation circulation path temperature sensor that is disposed in the recirculation circulation passage to detect hot water temperature, and a communication passage that communicates with the recirculation circulation passage or the recirculation circulation passage. A water level sensor for detecting the water level of the hot water in the bathtub by water pressure, the hot water heat exchanger and the reheating heat exchanger are integrated, and the integrated hot water supply heat exchanger and reheating heat exchanger are heated. In a single can / two water channel type bath water heater in which a common burner is provided and the water level detection operation is performed by the water level sensor at a predetermined timing, the single can / two water bath water heater performs a chasing operation. A hot water supply single operation monitoring unit for monitoring whether or not the hot water supply single operation is performed, or a direct detection value that directly detects the water temperature at the position where the water level sensor is disposed after the hot water supply single operation is stopped. The water level is detected by the water level sensor until the estimated detection value obtained by estimating the water temperature at the position where the water level sensor is arranged reaches a predetermined threshold value or until a predetermined margin period elapses after the threshold value is reached. A means for solving the above problems is provided with a configuration in which a water level detection stop unit for stopping the operation is provided.
[0035]
The second invention is a hot water heat exchanger that heats water supplied from the water supply passage and sends it to the hot water supply passage, and recirculation of the circulating hot water that is incorporated in the recirculation circulation passage of the bathtub hot water and circulates in the recirculation circulation passage. And a water level sensor that is disposed in the recirculation passage or the communication passage communicating with the recirculation passage and detects the water level of the hot water in the bathtub by water pressure, the heat supply heat exchanger and the reheating heat exchanger. The fired heat exchanger is integrated, a common burner for heating the integrated hot water supply heat exchanger and the reheating heat exchanger, and a combustion fan for supplying and exhausting the burner are provided, and are determined in advance. In a single can / two water channel type bath water heater where the water level detection operation is performed by the above water level sensor at the same time, the single water / two water channel bath water heater performs a hot water supply independent operation without performing a reheating operation. A hot water single operation monitoring section for monitoring whether or not; a fan drive section for continuously driving the combustion fan after the hot water single operation is stopped and cooling the heat exchanger; and disposing a water level sensor after the hot water single operation is stopped. The direct detection value obtained by directly detecting the water temperature at the position or the estimated detection value obtained by estimating the water temperature at the position where the water level sensor is installed reaches a predetermined threshold value or after reaching the above threshold value. And a water level detection stop unit that stops the water level detection operation by the water level sensor until a predetermined margin period elapses.
[0036]
In the third invention, the means for directly detecting the water temperature at the position where the water level sensor is arranged constituting the first or second invention is constituted by a recirculation circulation path temperature sensor. The means for estimating and detecting the water temperature is based on the amount of heat stored in the reheating heat exchanger, which is obtained using at least the parameters of the hot water single operation time during which the hot water single operation is performed and the combustion operation information of the hot water single operation. Retained heat amount detection means for estimating and detecting the water temperature at the installation position, or a supply air temperature detection means for estimating and detecting the water temperature at the installation position of the water level sensor based on the supply air temperature of the single can two water bath hot water heater It is constituted by any one of the retained heat quantity / air temperature detection means for estimating and detecting the water temperature at the position where the water level sensor is arranged by combining the retained heat quantity of the heat exchanger and the supply air temperature. And a means to solve the problem with the formation.
[0037]
A fourth aspect of the invention relates to a hot water heat exchanger that heats water supplied from the water supply passage and sends it to the hot water supply passage, and recirculation of the circulating hot water that is incorporated in the recirculation circulation passage of the bathtub hot water and circulates in the recirculation circulation passage. And a water level sensor that is disposed in the recirculation passage or the communication passage communicating with the recirculation passage and detects the water level of the hot water in the bathtub by water pressure, the heat supply heat exchanger and the reheating heat exchanger. The fired heat exchanger is integrated, a common burner for heating the integrated hot water supply heat exchanger and the reheating heat exchanger, and a combustion fan for supplying and exhausting the burner are provided, and are determined in advance. In a single can / two water channel type bath water heater where the water level detection operation is performed by the above water level sensor at the same time, the single water / two water channel bath water heater performs a hot water supply independent operation without performing a reheating operation. A hot water supply single operation monitoring unit for monitoring whether or not; a fan drive unit for continuously driving the combustion fan until a predetermined fan drive extension time elapses after the hot water supply single operation is stopped; A water level detection stop unit that stops the water level detection operation by the water level sensor until the drive is stopped or until a predetermined margin period has elapsed after the drive is stopped is provided as a means for solving the above problems. .
[0038]
According to a fifth aspect of the present invention, in addition to the configuration of the fourth aspect of the present invention, an air temperature sensor for detecting the air temperature of the single can two water channel bath water heater is provided, and based on the air temperature detected by the air temperature sensor. Fan driving extension time data for setting a fan driving extension time is given, and the problem is solved by providing an extension time setting unit that variably sets the fan driving extension time according to the air temperature detected by the air temperature sensor. As a means.
[0039]
In addition to the configuration of the fourth aspect of the invention, a sixth aspect of the invention includes time measuring means for measuring a time during which the single can two-channel bath water heater is performing a single hot water supply operation; at least combustion heat amount information of the single hot water supply operation; The stored heat amount data for obtaining the retained heat amount of the reheating heat exchanger given to the reheating heat exchanger by the combustion heat of the burner by the hot water supply independent operation with the hot water independent operation time as a parameter is given, and the above-mentioned for obtaining the retained heat amount data With the configuration provided with an extended time setting unit that takes in parameter information at the time of hot water supply single operation and obtains the retained heat amount of the reheating heat exchanger from the retained heat amount data, and variably sets the fan drive extension time according to the retained heat amount As a means to solve the problem.
[0040]
In the invention of the above configuration, for example, the hot water supply single operation monitoring unit monitors whether or not the single can two-channel bath water heater is performing the hot water single operation, and the hot water single operation is terminated by the monitoring information of the hot water single operation monitoring unit Until the direct detection value or the estimated detection value of the water temperature at the position where the water level sensor is disposed reaches the threshold value or after the direct detection value or the estimated detection value reaches the threshold value. The water level detection stop unit detects the water level with the water level sensor until the specified margin period elapses, until the combustion fan drive stops, or until the predetermined margin period elapses after the combustion fan drive stops. Stop operation.
[0041]
When the direct detection value or the estimated detection value reaches a threshold value after the hot water supply single operation, or when a margin period elapses after the direct detection value or the estimated detection value reaches the threshold value, or hot water supply When the combustion fan stops after the stand-alone operation, or when a predetermined margin period has elapsed after the stop of the combustion fan, the hot water temperature of the reheating heat exchanger that has become high due to the hot water supply stand-alone operation is cooled. Since the hot water in the recirculation passage and the communication passage communicating with the recirculation passage is cooled and the sensor output of the water level sensor is stabilized, the sensor output of the water level sensor is stabilized as described above. Until the detection value or estimated detection value reaches the threshold value, or until the margin period elapses after the direct detection value or estimated detection value reaches the threshold value, or hot water supply alone The water level detection operation by the water level sensor is stopped until the combustion fan stops after the rotation or until the predetermined margin period elapses after the combustion fan stops. It is possible to avoid the detection of an incorrect bath water level by the sensor output of the water level sensor, and the malfunction of the appliance operation due to the incorrect detection bath water level is prevented.
[0042]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
[0043]
The single can two-way bath water heater of the first embodiment has the system configuration shown in FIG. 7, and FIG. 1 shows a block configuration showing a characteristic control configuration in this embodiment. Since the system configuration shown in FIG. 7 has been described above, a duplicate description thereof will be omitted.
[0044]
As shown in FIG. 1, the control device 40 that is characteristic in this embodiment includes a combustion operation control unit 43, a hot water supply single operation monitoring unit 44, a data storage unit 46, a fan drive unit 47, and a water level detection stop. Part 48.
[0045]
The combustion operation control unit 43 is preliminarily provided with sequence programs for various operation modes such as hot water supply and automatic operation. According to the sequence program, various sensor outputs, information from the remote controller 41, and the like are taken in and various operations are performed. Perform mode operation.
[0046]
The hot water supply independent operation monitoring unit 44 takes in information on the operation of the combustion operation control unit 43, and based on this information, the hot water control valve 26 is closed, and the water flow sensor 36 is replenished. When water flow in the water supply sensor 31 is not detected and the water amount sensor 31 detects water flow in the water supply passage 13, it is detected that the hot water supply single operation is being performed, and otherwise, the hot water supply single operation is performed. It is detected that the hot water supply is not operated, and whether or not the hot water supply single operation is being performed is monitored.
[0047]
The fan drive unit 47 captures the operation information of the combustion operation control unit 43, and when the combustion operation control unit 43 outputs a fan drive command, the fan drive unit 47 rotates the combustion fan 7, and the combustion operation control unit 43 stops the fan. When the command is output, the combustion fan 7 is stopped. In this embodiment, the post-purge period (for example, 5 minutes), which is the fan drive extension time for continuously driving the combustion fan 7 in order to exhaust the exhaust gas in the combustion chamber 1 after the combustion of the burner 2 is stopped, is data. The combustion operation control unit 43 gives a stop command for the combustion fan 7 to the fan drive unit when the post-purge period (fan drive extension time) ends after the combustion of the burner 2 is stopped. The fan drive unit 47 receives this stop command and stops the drive of the combustion fan 7. By doing so, the exhaust gas in the combustion chamber 1 can be substantially discharged outside after the combustion of the burner 2 is stopped.
[0048]
The data storage unit 46 further stores a predetermined threshold temperature Tsp (for example, 48 ° C.). This threshold temperature Tsp is set based on a guaranteed temperature predetermined for the water level sensor 28. In this embodiment, the upper limit value within the guaranteed temperature range of the water level sensor 28 is data as the threshold temperature Tsp. It is given to the storage unit 46.
[0049]
The water level detection stop unit 48 takes in the monitoring information of the hot water supply single operation monitoring unit 44 and, based on this information, detects that the single can two water bath hot water heater (appliance) has started the hot water supply single operation, the water level sensor 28. Starts output of a water level detection stop command signal for stopping the water level detection operation by. This command signal is output to the combustion operation control unit 43, and the combustion operation control unit 43 performs hot water supply interruption during operation in the operation mode involving the water level detection operation by the water level sensor 28 such as the hot water filling mode and the water retention mode. When the independent operation is performed, the water level detection operation by the water level sensor 28 is stopped in response to the water level detection stop command signal.
[0050]
Thereafter, when the hot water supply independent operation is stopped, the water level detection stop unit 48 takes in the threshold temperature Tsp from the data storage unit 46 and detects the sensor output detected and output by the bath temperature sensor 37 directly as a detected hot water. As the water temperature, the detection of the hot water temperature detected by the bath temperature sensor 37 is started, and the threshold temperature Tsp and the detected hot water temperature of the bath temperature sensor 37 are compared. If it is determined from this comparison that the detected hot water temperature of the bath temperature sensor 37 is higher than the threshold temperature Tsp, the water level detection stop unit 48 continuously outputs the water level detection stop command signal.
[0051]
This is because the place where the bath temperature sensor 37 is provided is close to the place where the water level sensor 28 is provided, and the temperature detected by the bath temperature sensor 37 is the hot water at the place where the water level sensor 28 is provided. Since it is considered that the water temperature is substantially equal to the water temperature, the detected hot water temperature of the bath temperature sensor 37 is more than the threshold temperature Tsp (in this embodiment, the threshold temperature Tsp is the upper limit value of the guaranteed temperature of the water level sensor 28 as described above). Is that the hot water temperature at the position where the water level sensor 28 is disposed exceeds the guaranteed temperature range of the water level sensor 28, and the hot water temperature in the reheating heat exchanger 4 is higher. It is determined that the convection phenomenon is not suppressed at a high temperature, and the sensor output of the water level sensor 28 is caused by a synergistic relationship between the temperature dependence of the water level sensor 28 and the occurrence of the convection phenomenon due to the hot water in the reheating heat exchanger 4. This is because it is judged that an accurate bathtub water level cannot be detected because the force fluctuates irregularly.
[0052]
After the hot water supply independent operation is stopped, the hot water temperature in the recirculation circulation passage 24 and the hot water filling passage 25 decreases with the passage of time, and thereby the hot water temperature detected by the bath temperature sensor 37 decreases and the bath temperature sensor 37 When the detected hot water temperature falls below the threshold temperature Tsp, the hot water temperature at the position where the water level sensor 28 is disposed falls to a hot water temperature within the guaranteed temperature range of the water level sensor 28, and a reheating heat exchanger. 4, it is determined that the convection phenomenon of the hot and cold water in the tank 4 has been suppressed, and the water level detection stop unit 48 is combusted assuming that the sensor output of the water level sensor 28 is stable and the water level sensor 28 can accurately detect the bathtub water level. The output of the water level detection stop signal to the operation control unit 43 is stopped.
[0053]
According to this embodiment, since the hot water supply single operation monitoring unit 44 and the water level detection stop unit 48 are provided, the detected hot water temperature of the bath temperature sensor 37 is equal to or lower than the threshold temperature Tsp during the single hot water supply operation and after the single hot water supply operation. The water level detection operation by the water level sensor 28 can be stopped until it decreases to As a result, the hot water temperature at the position where the water level sensor 28 is disposed is a high temperature exceeding the guaranteed temperature range, the sensor output of the water level sensor 28 shifts with a large temperature dependence, and the high temperature of the reheating heat exchanger 4 is increased. The water level detection operation by the water level sensor 28 is not performed during the period in which the sensor output of the water level sensor 28 is irregularly vibrated due to the occurrence of the convection phenomenon caused by the heated hot water. And an inaccurate bathtub water level is detected due to irregular fluctuations in the sensor output of the water level sensor 28 due to the synergy between the hot water in the reheating heat exchanger 4 and the occurrence of convection in the hot water. It is possible to reliably avoid the malfunction of the appliance operation due to the appliance operation being performed on the basis.
[0054]
In addition, since the combustion fan 7 is continuously driven after the hot water supply single operation, the supply air ventilation by the drive of the combustion fan 7 is generated in the combustion chamber 1 to forcibly cool the reheating heat exchanger 4 and the hot water supply alone. Compared to the case where the combustion fan 7 is not driven after the operation, the reheating heat exchanger 4 is cooled earlier, and the hot water in the reheating heat exchanger 4 can be cooled quickly, and the convection of the reheating water in the reheating heat exchanger 4 is achieved. It is possible to suppress the phenomenon and accelerate the decrease in hot water temperature at the position where the water level sensor 28 is disposed.
[0055]
Of course, in this embodiment, since the water level detection stop operation by the water level sensor 28 is terminated when the detected hot water temperature of the bath temperature sensor 37 is lowered to the threshold temperature Tsp after the hot water supply single operation, as described above, By continuously driving the combustion fan 7 after operation, the sensor output of the water level sensor 28 can be quickly stabilized after the hot water supply single operation, and before the continuous drive of the combustion fan 7 is stopped after the hot water supply single operation (the post purge period is It is possible to end the water level detection stop operation in a short time before the end).
[0056]
In FIG. 2, a block diagram showing a characteristic control configuration in the second embodiment is shown by a solid line. The second embodiment is different from the first embodiment in that the timing for terminating the water level detection stop operation after hot water single operation is determined based on the detected hot water temperature of the bath temperature sensor 37. Instead, the water level detection stop operation is terminated in synchronization with the stop of the combustion fan 7 after the hot water supply single operation, and the configuration other than the water level detection stop unit 48 is the same as that of the first embodiment. is there. In this embodiment, the same reference numerals are assigned to the same names as those in the first embodiment, and the components other than the water level detection stop unit 48 are the same as those in the first embodiment as described above. Therefore, the duplicate description is omitted.
[0057]
The water level detection stop unit 48 takes in the monitoring information of the hot water supply single operation monitoring unit 44, and outputs a water level detection stop signal to the combustion operation control unit 43 when detecting that the appliance has started the hot water supply single operation based on this information. Start. The combustion operation control unit 43 receives the water level detection stop signal and stops the water level detection operation by the water level sensor 28 in the hot water filling mode or the water retention mode.
[0058]
After the hot water supply single operation is stopped, the water level detection stop unit 48 captures information on one or both of the combustion operation control unit 43 and the fan drive unit 47, and detects the stop of the combustion fan 7 based on the captured information. In addition, the output of the water level detection stop signal to the combustion operation control unit 43 is stopped for the following reason.
[0059]
The combustion fan 7 is continuously driven during the post-purge period after the combustion of the burner 2 is stopped, whereby ventilation is generated in the combustion chamber 1 by the intake air taken in from the outside, and this ventilation allows the hot water supply heat exchanger 3 and The reheating heat exchanger 4 is forcibly cooled, and the hot water temperature in the reheating heat exchanger 4 is lowered. As the hot water in the reheating heat exchanger 4 is cooled, the hot water temperature in the recirculation circulation passage 24 and the hot water filling passage 25 also decreases, and the convection phenomenon of the hot water temperature in the reheating heat exchanger 4 occurs. Since the irregular vibrations of the hot water in the recirculation circulation passage 24 and the hot water filling passage 25 are suppressed, the hot water temperature at the position where the water level sensor 28 is disposed when the post-purge period elapses. It is considered that the hot water falls within the guaranteed temperature range of the water level sensor 28 and the irregular vibration of the hot water at the position where the water level sensor 28 is disposed is eliminated.
[0060]
Therefore, as described above, when the driving of the combustion fan 7 is stopped after the hot water supply single operation, the hot water temperature at the position where the water level sensor 28 is disposed is lowered to the guaranteed temperature of the water level sensor 28 and the water level sensor 28 is arranged. The water level detection stop unit 48 determines that the water level sensor 28 can detect the accurate bathtub water level by eliminating the irregular vibration of the hot and cold water at the installation position and stabilizing the sensor output of the water level sensor 28. The output of the water level detection stop signal to the unit 43 is stopped. By stopping the output of the water level detection stop signal, the combustion operation control unit 43 can restart the water level detection operation by the water level sensor 28.
[0061]
According to this embodiment example, the water level detection stop unit 48 is configured to stop the water level detection operation by the water level sensor 28 until the drive of the combustion fan 7 is stopped during the hot water supply single operation and after the hot water supply single operation. The water level detection operation by the water level sensor 28 can be stopped during a period when the sensor output of the water level sensor 28 is considered to fluctuate irregularly due to the hot water supply single operation. From this, an incorrect bathtub water level is detected due to irregular fluctuations in the sensor output of the water level sensor 28, and an erroneous operation of the appliance operation due to the appliance operation being performed based on this incorrect bathtub water level is avoided. can do.
[0062]
The third embodiment will be described below. What is characteristic in this embodiment is that the air supply temperature sensor 27 that detects the temperature of the supply air supplied to the burner 2 by driving the combustion fan 7 is connected to the air supply passage 6 and the gas nozzle as shown by the dotted line in FIG. 19 and the like, and in addition to the control configuration shown in the second embodiment, as shown by the dotted line in FIG. 2, the fan drive extension time after the hot water supply single operation is variably set according to the air supply temperature. The time setting unit 50 is provided. The configuration other than the combustion operation control unit 43, the data storage unit 46, and the extended time setting unit 50 is the same as that of the second embodiment, and the description of the common parts is omitted.
[0063]
By the way, when ventilation is generated in the combustion chamber 1 due to the continuous drive of the combustion fan 7 after the hot water supply independent operation is stopped, if the supply air temperature is low, the ventilation is replenished and the amount of heat taken away from the heat exchanger 4 is large. Thus, the speed at which the reheating heat exchanger 4 cools becomes faster. On the other hand, when the supply air temperature is high, the amount of heat taken by the ventilation from the reheating heat exchanger 4 decreases, and the cooling rate of the reheating heat exchanger 4 becomes slow. As described above, the cooling rate of the reheating heat exchanger 4 becomes faster as the supply air temperature decreases, and conversely, the cooling rate becomes slower as the supply air temperature becomes higher.
[0064]
For this reason, even after the post-purge period after the hot water supply single operation, the hot water in the reheating heat exchanger 4 is not cooled down due to the high temperature of the hot water, and the hot water in the reheating heat exchanger 4 is high. In some cases, the convection phenomenon is not suppressed, and the hot water temperature at the position where the water level sensor 28 is disposed is higher than the guaranteed temperature of the water level sensor 28. Therefore, in this embodiment, the fan drive extension time after the hot water supply single operation is variably set according to the air supply temperature.
[0065]
In the data storage unit 46, fan drive extension time data is obtained and stored in advance by experiments or calculations. As shown in FIGS. 3A and 3B, the fan drive extension time data is provided with a fan drive extension time corresponding to the supply air temperature. In this embodiment, the supply air temperature is When the temperature is less than the supply air temperature Ta shown in (a) or (b) of FIG. 3 obtained by experiments, calculations, etc., the fan drive extension time is constant during a predetermined post-purge period, and is greater than the supply air temperature Ta. In this case, the fan drive extension time becomes longer continuously or stepwise from the post purge period as the air supply temperature becomes higher.
[0066]
Further, in the data storage unit 46, the fan drive extended time for continuously driving the combustion fan 7 after the combustion of the burner 2 due to the hot water single operation is stopped and the combustion of the burner 2 due to the operation other than the hot water single operation are stopped. Later, a post-purge period for continuously driving the combustion fan 7 is stored separately. In this embodiment, the combustion operation control unit 43 performs the above-described fan operation after the combustion of the burner 2 in the hot water supply single operation is stopped. The combustion fan 7 is continuously driven until the drive extension time ends, and after the combustion of the burner 2 other than the hot water supply independent operation is stopped, the combustion fan 7 is continuously driven until the post-purge period ends.
[0067]
The extended time setting unit 50 takes in the monitoring information of the hot water supply individual operation monitoring unit 44 and reads out the fan drive extended time data in the data storage unit 46 when it is detected that the hot water supply single operation is in progress based on this information. The sensor output detected and output by 27 is taken in as the detected air temperature. Then, the fan drive extension time corresponding to the detected air temperature is obtained from the fan drive extension time data and set, and the set fan drive extension time is overwritten on the fan drive extension time of the data storage unit 46. To do.
[0068]
The combustion operation control unit 43 reads out the fan drive extension time of the data storage unit 46 from the data storage unit 46 after the hot water supply single operation, and when the fan drive extension time is over, the combustion fan 7 continues to drive the combustion chamber 1 in the combustion chamber 1. It is determined that the exhaust gas is almost exhausted, the hot water temperature in the reheating heat exchanger 4 is cooled to suppress the convection phenomenon of the hot water, and the hot water temperature at the position where the water level sensor 28 is disposed is the water level sensor. 28, the sensor output of the water level sensor 28 is stable, and it is determined that the bathtub water level can be accurately detected by the bathtub water level detection operation by the water level sensor 28, and the combustion fan 7 continues. A stop signal for stopping the drive is output to the fan drive unit 47, and the fan drive unit 47 stops the combustion fan 7.
[0069]
According to this embodiment, the extended time setting unit 50 is provided so that the fan drive extended time is variably set according to the supply air temperature. When the sensor output of the water level sensor 28 is not stable due to the high temperature, the fan drive extension time can be set longer than the post-purge period according to the supply air temperature, and the fan drive of the combustion fan 7 is extended beyond the post-purge period. Until the time ends, that is, the hot water temperature in the reheating heat exchanger 4 is cooled, the hot water convection phenomenon is suppressed, and the hot water temperature at the position where the water level sensor 28 is disposed becomes the guaranteed temperature of the water level sensor 28. It can be continuously driven until it decreases.
[0070]
Due to the continuous drive of the combustion fan 7, the forced cooling of the hot water in the reheating heat exchanger 4 by the supply air ventilation can be continued. Cooling of hot water can be accelerated. In addition, the hot water temperature in the reheating heat exchanger 4 is cooled to suppress the hot water convection phenomenon, and the hot water temperature at the position where the water level sensor 28 is disposed is lowered to the guaranteed temperature of the water level sensor 28, so that the combustion fan Since the water level detection operation by the water level sensor 28 is stopped by the operation of the water level detection stop unit 48 until the stop 7 is stopped, the instrument caused by irregular fluctuations in the sensor output of the water level sensor 28 as in the above embodiments. A malfunction of driving can be prevented.
[0071]
Of course, even if the supply air temperature is high, in most cases, when the post-purge period elapses after the hot water supply single operation, the convection phenomenon of hot water is substantially suppressed by the supply air ventilation by driving the combustion fan 7, and the water level The hot / cold water temperature at the position where the sensor 28 is disposed falls close to the guaranteed temperature of the water level sensor 28, so that the sensor output of the water level sensor 28 is substantially stabilized. From this, regardless of the supply air temperature, the operation of the appliance almost malfunctions even when the driving of the combustion fan 7 is stopped and the water level detection operation by the water level sensor 28 is restarted at the end of the post-purge period after the hot water supply single operation. It is possible to avoid it.
[0072]
The fourth embodiment will be described below. What is characteristic in this embodiment is that, as shown in FIG. 4, an extended time setting unit 50, a time measurement unit 51, and a retained heat amount detection unit 52 are provided and given to the reheating heat exchanger 4 by hot water supply single operation. The obtained retained heat amount is obtained, and the fan drive extension time is variably set according to the retained heat amount. Other configurations are the same as those in each of the above-described embodiments, and a duplicate description of common portions is omitted. In FIG. 4, the combustion operation control unit 43, the hot water supply single operation monitoring unit 44, the fan drive unit 47, and the water level detection stop unit 48 shown in each of the above embodiments are omitted.
[0073]
The time measuring unit 51 is configured to take in the information of the hot water supply single operation monitoring unit 44 and measure the hot water supply single operation time from the start of the hot water supply single operation to the end of the hot water supply single operation based on this information.
[0074]
In the data storage unit 46, retained heat amount data for determining the retained heat amount of the reheating heat exchanger 4 given to the reheating heat exchanger 4 by the combustion of the burner 2 is obtained and stored in advance by experiments or calculations. As shown in FIG. 5, the stored heat quantity data is provided with the retained heat quantity of the reheating heat exchanger 4 corresponding to the hot water supply single operation time for each combustion heat quantity. At the start of operation, the amount of heat retained by the reheating heat exchanger 4 increases with time, and thereafter, the amount of heat retained by the reheating heat exchanger 4 is saturated.
[0075]
The stored heat quantity detection unit 52 takes in the monitoring information of the hot water supply single operation monitoring unit 44, and when it detects that the hot water supply single operation is being performed based on this information, the combustion operation control unit 43 obtains information on the combustion heat quantity of the burner 2 alone. It is taken in as combustion heat quantity information for operation, and data corresponding to the combustion heat quantity of the burner 2 is selected from the heat quantity data held in the data storage unit 46 and read. And if it detects that the hot water supply independent operation was complete | finished by the information of the hot water supply independent operation monitoring part 44, the hot water supply independent operation time which the said time measurement part 51 measured was taken in, and this hot water supply independent operation time was read into the said stored heat amount data The retained heat amount of the reheating heat exchanger 4 by the hot water supply single operation is obtained in light of the above, and a signal corresponding to the obtained retained heat amount is output to the extension time setting unit 50.
[0076]
The data storage unit 46 further stores fan drive extension time data as shown in FIGS. 6A and 6B. The fan driving extension time data is data for variably setting the fan driving extension time after the hot water supply single operation according to the stored heat amount given to the reheating heat exchanger 4 by the hot water supply single operation, and corresponding to the stored heat amount. Fan drive extension time is given. In this embodiment, when the heat retention amount Pc shown in FIGS. 6A and 6B obtained in advance by experiment, calculation, etc. is less than the retained heat amount Pc, the fan drive extension time is constant in the post-purging period, When it is equal to or greater than the retained heat amount Pc, the fan drive extension time becomes longer continuously or stepwise from the post purge period as the retained heat amount of the reheating heat exchanger 4 increases.
[0077]
This is because when the reheating heat exchanger 4 has a large amount of heat, it takes time for the reheating heat exchanger 4 to be cooled by the ventilation by driving the combustion fan 7, and the reheating heat exchanger 4. Therefore, it is necessary to spend a long time until the hot water temperature at the position where the water level sensor 28 is disposed is lowered to the guaranteed temperature, and on the contrary, the amount of heat held in the reheating heat exchanger 4 is small. In this case, since the reheating heat exchanger 4 is cooled quickly, the convection phenomenon of hot and cold water is suppressed, and the hot water temperature at the position where the water level sensor 28 is disposed becomes the guaranteed temperature, and the sensor output of the water level sensor 28 is This is because it takes less time to stabilize.
[0078]
However, since it is considered that the combustion fan 7 needs to be continuously driven during the post-purge period after the combustion of the burner 2 is stopped in order to exhaust the exhaust gas generated by the combustion of the burner 2 from the combustion chamber 1 to the outside, this embodiment example Then, the fan drive extension time is not shorter than the post-purge period.
[0079]
The extended time setting unit 50 takes in the monitoring information of the hot water supply independent operation monitoring unit 44, reads the fan drive extended time data from the data storage unit 46 when the hot water supply independent operation is finished, and the retained heat amount detection unit 52 detects it. The fan drive extension time is obtained and set by referring to the fan drive extension time data with respect to the output heat amount of the reheating heat exchanger 4 that has been output. The set fan drive extension time is overwritten with the fan drive extension time of the data storage unit 46 (fan drive extension time stored separately from the post-purge period after the combustion of the burner 2 other than hot water supply independent operation). . The combustion operation control unit 43 continues to drive the combustion fan 7 until the fan drive extension time of the data storage unit 46 ends after the hot water supply single operation.
[0080]
Of course, also in this embodiment, the water level detection stop unit 48 stops the water level detection until the drive of the combustion fan 7 is stopped after the hot water supply single operation is started, that is, until the sensor output of the water level sensor 28 is stabilized. The water level detection operation by the water level sensor 28 is stopped by the operation.
[0081]
According to this embodiment, since the time measuring unit 51 and the retained heat amount detecting unit 52 are provided, it is possible to obtain the retained heat amount given to the reheating heat exchanger 4 by the hot water supply single operation. In this embodiment, since the fan drive extension time is variably set according to the obtained stored heat amount, if the retained heat amount of the reheating heat exchanger 4 by the hot water supply single operation is large, after the hot water supply single operation The fan drive extension time can be extended longer than the post-purge period.
[0082]
For this reason, for example, when the reheating heat exchanger 4 has a large amount of heat, the sensor output of the water level sensor 28 is stable when the sensor output of the water level sensor 28 is not stable even after the post-purge period after the hot water supply single operation. It is possible to drive the combustion fan 7 continuously until this occurs.
[0083]
Further, since the water level detection operation by the water level sensor 28 is stopped until the driving of the combustion fan 7 is stopped, the water level sensor is determined until it is determined that the sensor output of the water level sensor 28 is stable and the driving of the combustion fan 7 is stopped. The water level detection operation by the water level sensor 28 is stopped, and when the sensor output of the water level sensor 28 fluctuates irregularly, the appliance operation based on the sensor output of the water level sensor 28 is not performed, and the sensor output of the water level sensor 28 is detected. It is possible to avoid the malfunction of the appliance operation due to the irregular fluctuation of the.
[0084]
The fifth embodiment will be described below. What is characteristic in this embodiment is that the combustion operation control unit 43 has a fan drive unit so that the amount of air in the combustion chamber 1 is larger after the hot water supply single operation than the post purge period after the combustion operation other than the hot water supply single operation. The rotation control of the combustion fan 7 is performed via 47. Other configurations are the same as those in each of the above-described embodiments, and a duplicate description thereof is omitted.
[0085]
When the combustion fan 7 is continuously driven during the post-purge period after the combustion operation, the rotation control of the combustion fan 7 is performed so that the air volume is much smaller than the air volume generated in the combustion chamber 1 during the combustion operation of the burner 2. There are many cases. In this embodiment, as described above, the rotational drive of the combustion fan 7 is controlled so that the air volume in the combustion chamber 1 is larger after the hot water supply single operation than the post purge period after the combustion operation other than the hot water supply single operation. The forced cooling of the reheating heat exchanger 4 after the hot water supply single operation is further promoted.
[0086]
According to this embodiment, the same effects as those of the above embodiments can be obtained, and the air volume in the combustion chamber 1 after the hot water single operation is longer than the post-purge period after the combustion operation other than the single hot water operation. Since the rotation of the combustion fan 7 is controlled so as to increase, the amount of air in the combustion chamber 1 after the hot water supply single operation becomes larger than that during the post-purge period, and the recuperation heat is generated by the air supply ventilation after the hot water supply single operation. The exchanger 4 can be cooled more effectively.
[0087]
When the rotation control of the combustion fan 7 is performed so that the air volume in the combustion chamber 1 is larger than the post-purge period after the combustion operation other than the hot water supply single operation after the single hot water supply operation as in this embodiment. Since the exhaust gas generated by the combustion of the burner 2 is discharged earlier than during the post-purge period, the fan drive extension time can be set shorter than the post-purge period.
[0088]
The sixth embodiment will be described below. This embodiment is different from the first embodiment in that the hot water temperature at the position where the water level sensor 28 is disposed is not directly detected by the bath temperature sensor 37 after the hot water supply single operation. The hot water temperature at the position where the water level sensor 28 is disposed is estimated and detected based on the air temperature, and the water level detection stop operation is terminated when the estimated detection value reaches a predetermined threshold value. The rest of the configuration is the same as that of the first embodiment, and redundant description of common parts is omitted.
[0089]
In this embodiment, as shown by the dotted line in FIG. 1, an air temperature sensor 27 serving as an air temperature detecting means is provided. As described above, when the combustion fan 7 is continuously driven after the hot water supply single operation, the supply air ventilation is generated in the combustion chamber 1 by the driving of the combustion fan 7 after the hot water supply single operation. The heat amount of the exchanger 4 is deprived and the reheating heat exchanger 4 is cooled as time passes, and the cooling water of the reheating heat exchanger 4 lowers the hot water temperature at the position where the water level sensor 28 is disposed. As the air supply temperature is lowered, the reheating heat exchanger 4 is cooled more quickly, and the hot water temperature at the position where the water level sensor 28 is disposed is rapidly lowered. On the contrary, as the supply air temperature increases, the cooling of the reheating heat exchanger 4 is delayed, and the decrease in the hot water temperature at the position where the water level sensor 28 is disposed is delayed.
[0090]
As described above, the decreasing tendency of the hot water temperature at the position where the water level sensor 28 is disposed differs depending on the supply air temperature. Therefore, the elapsed time after the hot water single operation is stopped and the decrease in the hot water temperature at the position where the water level sensor 28 is disposed. The temperature relationship can be obtained for each supply air temperature, which makes it possible to estimate and detect the hot water temperature at the position where the water level sensor 28 is disposed based on the elapsed time since the hot water supply single operation stopped and the supply air temperature. It is.
[0091]
In view of the above, in this embodiment, the threshold time until the hot water temperature at the position where the water level sensor 28 is disposed decreases to the threshold temperature Tsp shown in the first embodiment after the single operation of hot water supply. tα is obtained in advance by experiment, calculation, or the like for each supply air temperature, and stored in the data storage unit 46 as water temperature estimation detection data. The water temperature estimation detection data is stored in the data storage unit 46 in a data format such as graph data, table data, and arithmetic expression data indicating the relationship between the supply air temperature and the threshold time tα.
[0092]
The water level detection stop unit 48 takes in the sensor output of the air temperature sensor 27 as the detected air supply temperature after the hot water supply single operation, refers to this detected air supply temperature to the water temperature estimation detection data in the data storage unit 46, and arranges the water level sensor 28. A threshold time tα until the hot water temperature at the installation position decreases to the threshold temperature Tsp is obtained.
[0093]
Further, the water level detection stop unit 48 resets and drives the timer 53 indicated by the dotted line in FIG. 1 when the hot water supply independent operation is completed, and starts measuring the elapsed time after the hot water supply independent operation is stopped. When the estimated detection value reaches the threshold time tα, it is determined that the hot water temperature at the position where the water level sensor 28 is arranged has reached the threshold temperature Tsp. Then, it is determined that the sensor output of the water level sensor 28 is stable, and the water level detection stop operation is terminated.
[0094]
According to this embodiment example, since the hot water temperature at the position where the water level sensor 28 is disposed is estimated and detected based on the elapsed time after the hot water single operation and the supply air temperature, the end timing of the water level detection stop operation is determined. As in the above embodiments, the water level detection stop unit 48 can stop the water level detection until the sensor output of the water level sensor 28 is stabilized after the hot water supply single operation, and the water level sensor 28 caused by the hot water supply single operation can be stopped. It is possible to avoid the problem that the instrument malfunctions due to unstable sensor output.
[0095]
Further, in this embodiment, the hot water temperature at the position where the water level sensor 28 is disposed is estimated and detected to determine the end timing of the water level detection stop operation. Therefore, as described above, the combustion fan 7 is continuously driven after the hot water supply single operation. When the hot water temperature at the position where the water level sensor 28 is disposed can be cooled earlier and the sensor output of the water level sensor 28 stabilizes quickly, the water level detection stop operation is performed in a short time before the end of the post-purge period. Can be terminated.
[0096]
The seventh embodiment will be described below. This embodiment is different from the first embodiment in that the hot water temperature at the position where the water level sensor 28 is disposed is estimated and detected based on the amount of heat held in the reheating heat exchanger 4 after the hot water supply single operation. In other words, the end timing of the water level detection stop operation is determined. The other configuration is the same as that of the first embodiment, and a duplicate description thereof is omitted.
[0097]
As described above, as the amount of heat retained in the reheating heat exchanger 4 increases, it takes time until the hot water temperature at the position where the water level sensor 28 is disposed decreases to the predetermined threshold temperature Tsp after the hot water supply single operation. On the contrary, as the amount of heat retained in the reheating heat exchanger 4 decreases, the time required for the hot water temperature at the position where the water level sensor 28 is disposed to decrease to the threshold temperature Tsp after the hot water supply single operation is reduced. In this way, the relationship between the elapsed time since the hot water supply single operation has stopped and the temperature at which the water level sensor 28 is lowered can be determined for each amount of heat retained by the heat exchanger 4. Thus, it is possible to estimate and detect the hot water temperature at the position where the water level sensor 28 is disposed based on the amount of heat held by the reheating heat exchanger 4 and the elapsed time after the hot water supply single operation.
[0098]
From the above, the control device 40 shown in this embodiment example has the stored heat amount detection means shown by the chain line in FIG. 1, which includes the time measuring unit 51 and the stored heat amount detection unit 52 shown in the fourth embodiment example. 54 is configured in addition to the control configuration of the solid line in FIG. The retained heat amount detecting means 54 obtains the retained heat amount of the reheating heat exchanger 4 after the hot water supply single operation as in the fourth embodiment.
[0099]
In the data storage unit 46, the time until the hot water temperature at the position where the water level sensor 28 is disposed decreases to a predetermined threshold temperature Tsp after the hot water supply single operation is tracked. The temperature is obtained in advance and stored as water temperature estimation detection data. The water level detection stop unit 48 refers to the stored heat amount obtained by the stored heat amount detection means 54 with reference to the water temperature estimation detection data in the data storage unit 46, and the hot water temperature at the position where the water level sensor 28 is disposed becomes the threshold temperature Tsp. The threshold time required to decrease is obtained.
[0100]
In addition, the water level detection stop unit 48 resets and drives the timer 53 when the hot water supply independent operation stops, starts measurement of the elapsed time after the hot water supply independent operation stops, and estimates and detects the measurement time of the timer 53 When the measured time of the timer 53 reaches the threshold time, it is determined that the hot water temperature at the position where the water level sensor 28 is disposed has dropped to the threshold temperature Tsp. It is determined that the sensor output is stable, and the water level detection stop operation is terminated.
[0101]
According to this embodiment, the hot water temperature at the position where the water level sensor 28 is disposed is estimated and detected based on the elapsed time after the hot water supply single operation and the amount of heat retained in the reheating heat exchanger 4, and the water level detection stop after the hot water supply single operation is performed. Since the operation end timing is determined, the water level detection stop unit 48 stops the water level detection operation during a period until the sensor output of the water level sensor 28 is stabilized after the hot water supply single operation, as in the above embodiments. It is possible to avoid the problem that the appliance malfunctions due to the unstable sensor output of the water level sensor 28 caused by the hot water supply single operation.
[0102]
The eighth embodiment will be described below. A characteristic of this embodiment different from the first embodiment is that the hot water temperature at the position where the water level sensor 28 is disposed is estimated and detected by combining the supply air temperature and the amount of heat retained in the reheating heat exchanger 4. It is set as the structure which determines the completion | finish timing of the water level detection stop operation after hot water supply independent operation. The rest of the configuration is the same as that of the first embodiment, and redundant description of common parts is omitted.
[0103]
In this embodiment, in addition to the control configuration shown by the solid line in FIG. 1, the retained heat amount / air temperature detection means 55 shown by the two-dot chain line in FIG. 1 is provided. The stored heat quantity / air supply temperature detecting means 55 includes the time measurement unit 51 and the stored heat quantity detection unit 52 shown in the fourth embodiment, and the stored heat quantity detection unit 52 is a time measurement unit. Based on the hot water supply single operation time and the supply air temperature measured by 51, the retained heat amount of the reheating heat exchanger 4 is obtained after the hot water supply single operation.
[0104]
The data storage unit 46 requires the water temperature estimation detection data shown in the seventh embodiment, that is, the hot water temperature at the position where the water level sensor 28 is disposed after the hot water supply single operation is lowered to the threshold temperature Tsp. The data given for each amount of heat retained in the heat exchanger 4 is stored.
[0105]
The water level detection stop unit 48 uses the stored heat amount of the reheating heat exchanger 4 detected by the stored heat amount detection unit 52 of the stored heat amount / heating temperature detection means 55 after the hot water supply single operation, as the water temperature estimation detection data of the data storage unit 46. To obtain the threshold time. Further, the water level detection stop unit 48 resets and drives the timer 53 when the hot water supply individual operation is stopped to measure the measurement time after the hot water supply single operation is stopped, and the measured time of the timer 53 is estimated as the detected value. When the measurement time of the timer 53 reaches the threshold time, it is determined that the hot water temperature at the position where the water level sensor 28 is disposed has dropped to the threshold temperature Tsp, and the sensor of the water level sensor 28 It is determined that the output is stable, and the water level detection stop operation is terminated.
[0106]
According to this embodiment example, the end timing of the water level detection stop operation after the hot water supply single operation is determined based on the amount of heat retained in the reheating heat exchanger 4 in consideration of the supply air temperature. In addition, during the period until the sensor output of the water level sensor 28 is stabilized after the hot water supply single operation, the water level detection stop unit 48 can stop the water level detection operation, and the unstable sensor output of the water level sensor 28 due to the hot water supply single operation. Therefore, it is possible to avoid the problem that the instrument malfunctions.
[0107]
The present invention is not limited to the above embodiments, and various embodiments can be adopted. For example, in the first embodiment, the threshold temperature is set to the upper limit value of the guaranteed temperature range of the water level sensor 28, but the threshold temperature is limited to the upper limit value of the guaranteed temperature range of the water level sensor 28. Is not to be done. For example, when the hot water temperature detected by the bath temperature sensor 37 after the hot water supply single operation is lower than the hot water temperature at the position where the water level sensor 28 is disposed, the threshold temperature is lower than the upper limit value of the guaranteed temperature of the water level sensor 28. Is set.
[0108]
Further, when the bath temperature sensor 37 is provided near the reheating heat exchanger 4 closer to the reheating heat exchanger 4 than the position where the water level sensor 28 is disposed, the bath temperature sensor 37 is provided during the hot water supply single operation. Since the detected hot water temperature to be detected is higher than the hot water temperature at the position where the water level sensor 28 is disposed, the hot water temperature at the position where the water level sensor 28 is disposed decreases to the upper limit value of the guaranteed temperature of the water level sensor 28 after the hot water supply single operation. The detected hot water temperature of the bath temperature sensor 37 is higher than the upper limit value of the guaranteed temperature of the water level sensor 28. In such a case, the threshold temperature may be set higher than the upper limit value of the guaranteed temperature of the water level sensor 28. Of course, the threshold temperature may be set lower than the upper limit value of the guaranteed temperature of the water level sensor 28.
[0109]
Further, in the third and fourth embodiment examples, the fan drive extension time during which the combustion fan 7 is continuously driven after the combustion of the hot water supply independent operation is stopped, and the burner for the operation other than the hot water supply independent operation. 2 is provided separately from the post-purge period in which the combustion fan 7 is continuously driven after the combustion stop of 2, but only the fan drive extension time is given to stop the combustion of the burner 2 in an operation other than the hot water supply single operation. The combustion fan 7 may be continuously driven during the fan drive extension time later.
[0110]
In the third and fourth embodiment examples, the fan drive extension time data is stored in the graph data format as shown in FIGS. 3 and 6, but the air supply temperature (fourth embodiment example) is used. Then, graph data, such as table data in which the fan drive extension time is given in correspondence with the amount of heat held in the reheating heat exchanger 4), arithmetic expression data for obtaining the fan drive extension time using the air supply temperature (holding heat amount) as a parameter The fan drive extension time data may be configured in a data format other than that and stored in the data storage unit 46.
[0111]
Furthermore, in the fourth embodiment described above, the retained heat amount data is composed of graph data as shown in FIG. 5, but is composed in a data format other than graph data such as table data and arithmetic expression data. You may store in the data storage part 46. FIG.
[0112]
Further, in the fourth embodiment, the stored heat quantity detection unit 52 takes in the information of the combustion heat amount of the burner 2 from the combustion operation control unit 43, but takes in the following information as the combustion heat amount information of the burner 2. But you can. For example, since the drive amount of the combustion fan 7 is variably controlled according to the combustion heat amount of the burner 2, the drive amount of the combustion fan 7 corresponds to the combustion heat amount of the burner 2. Accordingly, the retained heat amount detection unit 52 may capture the drive amount of the combustion fan 7 as the combustion heat amount information of the burner 2.
[0113]
Further, the combustion heat amount of the burner 2 is controlled by the supply amount of the fuel gas supplied to the burner 2, and the supply amount of the combustion gas is controlled by the valve opening amount of the proportional valve 12, so that the retained heat amount detection unit 52 may take in the proportional valve drive current that controls the valve opening amount of the proportional valve 12 as combustion heat amount information of the burner 2, or the fuel gas that flows through the gas supply passage 8 according to the valve opening amount of the proportional valve 12. Since the flow rate is variable, a flow sensor for detecting the fuel gas flow rate is provided in the gas supply passage 8, and the stored heat quantity detection unit 52 takes in the flow rate of the combustion gas detected by the flow sensor as combustion heat quantity information of the burner 2. But you can.
[0114]
Further, during the hot water supply independent operation, the incoming water temperature Tin detected by the incoming water temperature sensor 32, the hot water supply set temperature Ts set in the remote controller 41, the incoming water amount Q detected by the water amount sensor 31, and the hot water temperature sensor 38 are detected. The tapping temperature Tout is taken as the combustion heat amount information of the burner 2 and burner based on the combustion heat amount detection data (for example, P = (Ts−Tin) · Q + (Tout−Tin) · Q) given in advance. The stored heat quantity detection unit 52 may directly obtain the combustion heat quantity P of 2. Further, the retained heat amount detection unit 52 may determine the retained heat amount of the reheating heat exchanger 4 during hot water supply single operation more accurately in consideration of the supply air temperature detected by the supply air temperature sensor 27.
[0115]
Further, in each of the above embodiments, the water level detection stop unit 48 stops the water level detection operation by the water level sensor 28 over the entire period in which the hot water supply single operation is performed. The water level detection operation by the water level sensor 28 may be stopped only during a part of the period during which the water level is determined.
[0116]
For example, a stop threshold temperature Tst for determining the stop of the water level detection operation by the water level sensor 28 is determined in advance, and the water level detection stop unit 48 stops the above-described detection temperature detected by the bath temperature sensor 37 during the hot water supply single operation. When the threshold temperature Tst is compared to determine that the detected temperature of the bath temperature sensor 37 is equal to or higher than the stop threshold temperature Tst, the sensor output of the water level sensor 28 begins to fluctuate irregularly. The water level detection operation by the water level sensor 28 may be stopped by determining that there is a possibility that the instrument may malfunction due to irregular fluctuations in the sensor output.
[0117]
Further, it is considered that the single operation of hot water supply is started, the reheating heat exchanger 4 starts to be heated by the combustion of the burner 2, and the sensor output of the water level sensor 28 starts to fluctuate irregularly. For example, the time tb shown in FIG. Predetermined as the threshold time, the water level detection stopping unit 48 starts to irregularly change the sensor output of the water level sensor 28 when the threshold time has elapsed since the hot water supply single operation was started. The water level detection operation by the water level sensor 28 may be stopped by determining that there is a possibility that the instrument may malfunction due to irregular fluctuations in the sensor output of the water level sensor 28. In addition, since the time until the sensor output of the water level sensor 28 becomes unstable after the hot water supply single operation is started varies depending on the amount of heat retained in the reheating heat exchanger 4, the retained heat amount detection unit 52 described above is changed. It is also possible to variably control the threshold time tb so as to decrease as the retained heat amount of the reheating heat exchanger 4 detected by the retained heat amount detection unit 52 increases.
[0118]
Further, the water level detection stop unit 48 does not perform the water level detection stop operation during the hot water supply single operation, but stops the water level detection operation by the water level sensor 28 only during the period until the predetermined period ends after the hot water supply single operation. May be.
[0119]
Furthermore, the appliance shown in each of the above embodiments is given a post-purge period in which the combustion fan 7 is continuously driven after the burner 2 is combusted. However, the present invention has the post-purge period set. It can also be applied to non-equipment. For example, as shown in the first embodiment, the water level detection stop unit 48 is provided, and the water level sensor 28 uses the hot water detected by the bath temperature sensor 37 to decrease to a predetermined threshold temperature after hot water single operation. By stopping the water level detection operation, it is possible to avoid malfunctions in instrument operation due to irregular fluctuations in the sensor output of the water level sensor 28 as in the above embodiments.
[0120]
Further, as shown in the above embodiments, the fan drive extension time after the hot water supply single operation is determined in advance, and the combustion fan 7 is continuously driven until the fan drive extension time ends after the hot water supply single operation. Thus, the reheating heat exchanger 4 heated by the hot water supply single operation can be forcibly cooled by the ventilation by driving the combustion fan 7. In addition, the water level detection stop unit 48 performs the water level detection operation during the period until the hot water temperature detected by the bath temperature sensor 37 decreases to the threshold temperature after the hot water supply single operation, or during the period when the combustion fan 7 is driven. Since it can be stopped, the malfunction of the instrument resulting from the irregular fluctuation | variation of the water level sensor 28 can be avoided.
[0121]
Further, in each of the above embodiments, the continuous drive of the combustion fan 7 is stopped when a predetermined fan drive extension time has elapsed after the hot water supply single operation, but the hot water temperature detected by the bath temperature sensor 37 is predetermined. When the temperature falls to the threshold temperature, the continuous drive of the combustion fan 7 may be stopped.
[0122]
Furthermore, in each of the first, sixth, seventh, and eighth embodiments, the direct detection value or the estimated detection value of the hot water temperature at the position where the water level sensor 28 is disposed has reached the threshold value after the hot water supply single operation. Sometimes the water level detection stop operation was terminated, but the water level detection stop operation is terminated when a predetermined margin period elapses after the direct detection value or the estimated detection value reaches the threshold value. Also good.
[0123]
Further, in each of the second, third, fourth, and fifth embodiments, the water level detection stop operation is terminated when the continuous drive of the combustion fan 7 is stopped after the hot water supply single operation, but the combustion fan 7 The water level detection stop operation may be terminated when a predetermined margin period elapses after the continuous driving is completed.
[0124]
Further, in each of the above embodiments, the hot water supply single operation monitoring unit 44 is in a state where the pouring control valve 26 is closed, and the water flow sensor 36 does not detect water flow in the recirculation circulation passage 24, In addition, when the water amount sensor 31 detects water flow in the water supply passage 13, it has been detected that the hot water supply single operation is being performed. However, the hot water supply single operation monitoring unit 44 includes the water amount sensor 31 and the hot water supply confirmation switch. When the water flow detection value of the water supply passage 13 detected by the water amount sensor 31 and the flow rate detection value of the hot water supply passage 14 detected by the hot water supply confirmation switch 35 are substantially equal. Moreover, you may make it detect that the hot water supply independent operation is performed. Furthermore, the hot water supply independent operation monitoring unit 44 detects the water flow through the hot water supply passage 14 by the hot water supply confirmation switch 35 and the water pressure (dynamic pressure) of the hot water filling passage 25 determined in advance when the hot water control valve 26 is open. When the water level sensor 28 does not detect the water pump and the circulation pump 20 is not driven, it may be detected that the hot water supply single operation is being performed.
[0125]
Furthermore, although each said embodiment demonstrated and demonstrated the instrument shown in FIG. 7 as an example, this invention is a one-can two water channel type bath water heater, and a recirculation circulation path temperature sensor is provided in a recirculation circulation path, Further, if the water level sensor for detecting the water level of the bathtub by the water pressure is provided in the recirculation circulation passage or the communication passage communicating with the recirculation circulation passage, one can two-way bath hot water supply having a system configuration other than FIG. It can also be applied to vessels. For example, the present invention can also be applied to a single can two water bath hot water heater in which the hot water filling passage 25 shown in FIG. 7 is omitted and the water level sensor 28 is disposed in the recirculation circulation passage 24. Also in this case, the water level detection operation by the water level sensor 28 is stopped in the same manner as the above embodiments, so that the sensor of the water level sensor 28 caused by the high temperature heating of the accumulated hot water of the reheating heat exchanger 4 by the hot water supply single operation. It is possible to prevent malfunction of the instrument due to irregular fluctuations in output.
[0126]
【The invention's effect】
According to the present invention, since the hot water supply single operation monitoring unit and the water level detection stop unit are provided, the direct detection value or the estimated detection value of the water temperature at the position where the water level sensor is disposed is predetermined for a predetermined period after the single hot water supply operation. Until the threshold value is reached, or until the predetermined margin period elapses after the direct detection value or estimated detection value of the water temperature at the position where the water level sensor is arranged reaches the predetermined threshold value, or the combustion fan The water level detection operation can be stopped by the water level detection stop unit until the continuous driving of the combustion fan stops or until the period until the predetermined margin period elapses after the continuous driving of the combustion fan stops. it can.
[0127]
The period during which the water level detection operation is stopped by the water level detection stop unit is a period in which it is determined that the sensor output of the water level sensor fluctuates irregularly due to heating of the reheating heat exchanger during hot water supply single operation. Thus, as described above, by stopping the water level detection operation during that period, an incorrect bath water level is detected based on the irregularly varying water level sensor output, and the appliance operation is performed based on the incorrect bath water level. It is possible to avoid the problem that the instrument is malfunctioning.
[0128]
In the case of a fan drive unit that continuously drives the combustion fan until the fan drive extension time elapses after the hot water supply single operation, the reheating heat exchanger heated by the hot water supply single operation is supplied by the combustion fan drive. Forced cooling can be performed by ventilation. Therefore, it is possible to cool the reheating heat exchanger faster than when the combustion fan is not driven after the hot water supply single operation, and this increases the period until the sensor output of the water level sensor becomes stable after the hot water supply single operation. It can be shortened.
[0129]
In the invention provided with the extended time setting unit for variably setting the fan drive extended time, the period until the sensor output of the water level sensor that has irregularly changed due to the single operation of hot water supply becomes stable after the single operation of hot water supply The fan drive extension time can be variably set according to the supply air temperature or the amount of heat held in the reheating heat exchanger, so the fan drive extension time depends on the period until the sensor output of the water level sensor stabilizes Can be adjusted accurately.
[0130]
As a result, the following problems can be avoided. For example, because the fan drive extension time is set to a long fixed time, the time from the stabilization of the sensor output of the water level sensor to the end of the fan drive extension time after a single hot water supply operation opens, resulting in wasted equipment operation. On the other hand, because the fan drive extension time is set to a short fixed time, the fan drive extension time ends before the sensor output of the water level sensor stabilizes. However, as described above, the fan drive extension time is variably set so as to match the period until the sensor output of the water level sensor is stabilized after the hot water supply single operation as described above. It is possible to avoid waste of instrument operation and malfunction of the instrument.
[Brief description of the drawings]
FIG. 1 is a block configuration diagram showing an embodiment of a single can / two water bath hot water heater that performs a water level detection stop operation based on a directly detected value or an estimated detected value of a water temperature at a position where a water level sensor is disposed.
FIG. 2 is a block diagram showing second and third embodiment examples.
FIG. 3 is a graph showing an example of fan drive extension time data in which a fan drive extension time is given in accordance with the supply air temperature.
FIG. 4 is a block diagram showing a control component characteristic of the fourth embodiment.
FIG. 5 is a graph showing an example of the temporal change in the amount of heat retained in the reheating heat exchanger given to the reheating heat exchanger by the hot water supply single operation for each amount of combustion heat.
FIG. 6 is a graph showing an example of fan drive extension time data in which fan drive extension time is given in accordance with the amount of heat retained by the reheating heat exchanger.
FIG. 7 is an explanatory diagram showing a system configuration example of a single can / two water bath hot water heater.
FIG. 8 is a flowchart showing an example of an automatic driving operation.
FIG. 9 is a graph showing an example of PQ data indicating the relationship between the sensor output of the water level sensor and the amount of bathtub water.
FIG. 10 is an explanatory diagram showing a conventional problem.
[Explanation of symbols]
2 Burner
3 Hot water supply heat exchanger
4 Reheating heat exchanger
7 Combustion fan
13 Water supply passage
14 Hot water passage
24 Recirculation passage
25 Hot water passage
28 Water level sensor
37 Bath temperature sensor
44 Hot water supply independent operation monitoring section
46 Data storage
47 Fan drive
48 Water level detection stop
50 Extension time setting section
51 Time measurement unit

Claims (6)

A hot water heat exchanger that heats the water supplied from the water supply passage and sends it to the hot water supply passage, and a reheating heat exchange that recirculates the circulating hot water that circulates in the recirculation circulation passage built in the recirculation circulation passage of the bathtub hot water And a recirculation passage temperature sensor disposed in the recirculation circulation passage for detecting hot water temperature, and a recirculation circulation passage or a communication passage communicating with the recirculation circulation passage. A water level sensor for detecting, the hot water heat exchanger and the reheating heat exchanger are integrated, and a common burner for heating the integrated hot water heat exchanger and the reheating heat exchanger is provided in advance. In a single can two water channel type bath water heater in which the water level detection operation by the water level sensor is performed at a predetermined timing, the single can two water channel bath water heater performs only the hot water supply operation without performing the reheating operation. A hot water single operation monitoring unit for monitoring whether or not the hot water single operation is performed; a direct detection value that directly detects the water temperature at the position where the water level sensor is disposed after the hot water single operation is stopped, or the position of the water level sensor. Water level detection stop that stops the water level detection operation by the water level sensor until the estimated detection value estimated by detecting the water temperature reaches a predetermined threshold value or until a predetermined margin period elapses after the threshold value is reached. One can two water bath hot water heater characterized by having provided a part; A hot water heat exchanger that heats the water supplied from the water supply passage and sends it to the hot water supply passage, and a reheating heat exchange that recirculates the circulating hot water that circulates in the recirculation circulation passage built in the recirculation circulation passage of the bathtub hot water And a water level sensor that is disposed in the recirculation passage or the communication passage that communicates with the recirculation circulation passage and detects the water level of the hot water in the bathtub by water pressure, and the hot water heat exchanger and the reheating heat exchanger are integrated. And a common burner for heating the integrated hot water supply heat exchanger and the reheating heat exchanger, and a combustion fan for supplying and exhausting the burner, and the water level sensor at a predetermined timing. In the canned and two-fluid type bath water heater in which the water level detection operation is performed, whether or not the canned and two-channel bath water heater performs a hot water supply single operation that does not perform a reheating operation but only a hot water supply operation. A hot water supply isolated operation monitoring unit; a fan drive unit that continuously drives the combustion fan after the hot water supply individual operation is stopped to cool the reheating heat exchanger; and a water temperature at the position where the water level sensor is disposed after the hot water supply individual operation is stopped. The direct detection value detected directly or the estimated detection value estimated by detecting the water temperature at the position where the water level sensor is installed reaches a predetermined threshold value, or a predetermined margin period after reaching the above threshold value And a water level detection stop unit for stopping the water level detection operation by the water level sensor until a period of time elapses. The means for directly detecting the water temperature at the position where the water level sensor is disposed is constituted by a recirculation circulation path temperature sensor, and the means for estimating and detecting the water temperature at the position where the water level sensor is disposed is a hot water supply in which the hot water supply is operated alone. Retained heat amount detecting means for estimating and detecting the water temperature at the position where the water level sensor is disposed based on the retained heat amount of the reheating heat exchanger obtained by using at least the parameters of the isolated operation time and the combustion operation information of the hot water supply isolated operation, or Air temperature detection means for estimating and detecting the water temperature at the position of the water level sensor based on the air temperature of the can two water channel bath water heater, or the water level sensor by combining the amount of heat retained by the reheating heat exchanger and the air temperature 3. A can according to claim 1, wherein said can is constituted by any one of a stored heat quantity / supply temperature detecting means for estimating and detecting a water temperature at a position. Waterway bath water heater. A hot water heat exchanger that heats the water supplied from the water supply passage and sends it to the hot water supply passage, and a reheating heat exchange that recirculates the circulating hot water that circulates in the recirculation circulation passage built in the recirculation circulation passage of the bathtub hot water And a water level sensor that is disposed in the recirculation passage or the communication passage that communicates with the recirculation circulation passage and detects the water level of the hot water in the bathtub by water pressure, and the hot water heat exchanger and the reheating heat exchanger are integrated. And a common burner for heating the integrated hot water supply heat exchanger and the reheating heat exchanger, and a combustion fan for supplying and exhausting the burner, and the water level sensor at a predetermined timing. In the canned and two-fluid type bath water heater in which the water level detection operation is performed, whether or not the canned and two-channel bath water heater performs a hot water supply single operation that does not perform a reheating operation but only a hot water supply operation. A hot water supply isolated operation monitoring unit; a fan drive unit that continuously drives the combustion fan until a predetermined fan drive extension time elapses after the hot water supply isolated operation is stopped; and the combustion fan drive is stopped after the hot water supply isolated operation is stopped. Or a water level detection stop unit for stopping the water level detection operation by the water level sensor until a predetermined margin period elapses after being stopped. An air temperature sensor for detecting the air temperature of the single can two water bath hot water heater is provided, fan driving extension time data for setting the fan driving extension time based on the air temperature detected by the air temperature sensor is given, and 5. The single can two-way bath water heater according to claim 4, further comprising an extended time setting unit that variably sets the fan drive extended time according to the air temperature detected by the air temperature sensor. A time measuring means for measuring the time during which a single can two-way bath water heater is operating the hot water supply alone; at least the combustion heat information of the hot water supply independent operation and the hot water single operation time as parameters are followed by the combustion heat of the burner in the hot water supply independent operation Retained heat amount data for obtaining the retained heat amount of the reheating heat exchanger to be given to the fired heat exchanger is given, and the parameter information at the time of the hot water supply single operation for obtaining the retained heat amount data is taken in and reheated from the retained heat amount data. 5. The single-can two-water bath water heater according to claim 4, further comprising an extended time setting unit that obtains the amount of heat retained by the heat exchanger and variably sets the fan drive extended time according to the amount of retained heat.

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