JP3710620B2 - Water heater - Google Patents

Description

[0001]
[Field of the Invention]
The present invention relates to a hot water supply apparatus that supplies hot water to a kitchen or the like.
[0002]
[Prior art]
As a conventional hot water supply device, there are a heat exchanger that raises the temperature of water supplied by a gas burner and supplied from a water supply pipe, a supply water temperature detecting means that detects the temperature of water supplied to the heat exchanger, and a heat exchanger There has been known one provided with a hot water temperature detecting means for detecting the temperature of hot water discharged from the water and a water amount sensor for detecting a flow rate of water passing through a water supply pipe.
[0003]
According to this, when the curan provided in the tapping pipe is opened, water supply to the heat exchanger is started, and when the flow rate detected by the water amount sensor exceeds a predetermined ignition reference water amount, the gas burner is It is ignited to start its combustion, and the heat exchanger is heated by the gas burner. The combustion amount of the gas burner is adjusted by the hot water supply control means, and the hot water temperature detected by the hot water temperature detection means so that the temperature of the hot water detected by the hot water temperature detection means matches the hot water supply target temperature set by the user. And adjusting the gas supply amount based on the amount of water detected by the water amount sensor and the tapping temperature detected by the tapping temperature detecting means.
[0004]
In addition, there is also known one that sets the ignition reference water amount according to a water supply temperature and a hot water supply target temperature. Specifically, the ignition standard is set such that the difference between the hot water supply target temperature and the water supply temperature, that is, the temperature difference that must be increased, multiplied by the ignition reference water amount that is the minimum water amount is larger than the minimum combustion amount of the gas burner. It determines the amount of water. In this way, hot water supply at a flow rate as low as possible is made possible by determining the ignition reference water amount for starting ignition of the gas burner according to the difference between the water supply temperature and the hot water supply target temperature and the minimum combustion amount.
[0005]
By the way, the water temperature and hot water temperature detection circuit provided with the feed water temperature detection means and the hot water temperature detection means is connected to the A / D port of the microcomputer and the voltage input to the A / D port. There are many known devices that recognize the detected temperature according to the above. In these detection circuits, when the harness connecting the temperature detection means is disconnected or short-circuited, the voltage input to the A / D port is out of the normal use range. Abnormality can be determined.
[0006]
However, in a conventional hot water supply apparatus, an abnormality can be detected when a harness or the like is completely disconnected or short-circuited, but there is a possibility that it cannot be detected when a short-circuit or partial disconnection occurs. In other words, if the resistance value of the temperature detection means increases or decreases due to partial short-circuiting or disconnection, and the voltage input to the A / D port does not deviate from the normal operating range, the temperature detection means Cannot determine whether it is abnormal or normal.
[0007]
On the other hand, the heating amount of the heating means is controlled so that the temperature detected by the tapping temperature detecting means coincides with the hot water supply target temperature set by the user. For this reason, when the hot water temperature detecting means becomes abnormal as described above, since the hot water temperature to be supplied is different from the set hot water supply target temperature, the user determines that the hot water temperature detecting means is abnormal. be able to. Alternatively, the inspector can directly determine the hot water temperature with a thermistor or the like, thereby determining that the detection circuit including the hot water temperature detecting means is abnormal.
[0008]
However, when the feed water temperature detecting means fails, as described above, the ignition reference water amount is determined according to the feed water temperature and the hot water supply target temperature. When it is determined that the water is at a high temperature, the ignition reference water amount is set to a large value, so that even when listening to Karan at a normal opening, the gas burner will not be ignited, giving the user a sense of incongruity There is an inconvenience. In this case, various reasons such as failure of the water supply temperature detection means, water volume sensor failure, gas solenoid valve failure, control circuit failure, etc. are considered as the reasons why heating is not started. It is difficult to identify as abnormal.
[0009]
[Problems to be solved by the invention]
An object of the present invention is to improve a hot water supply apparatus, and more specifically, to solve the above-described inconvenience, an object of the present invention is to provide a hot water supply apparatus in which failure detection of the hot water temperature detection means or the supply water temperature detection means is easy.
[0010]
[Means for Solving the Problems]
  In order to achieve the above object, a first aspect of the hot water supply apparatus of the present invention includes a heat exchanger for heating water supplied by a water supply pipe by a heating means, and hot water heated by the heat exchanger is discharged. Tapping pipe, feed water temperature detecting means for detecting the temperature of water passing through the feed water pipe, tapping temperature detecting means for detecting the temperature of hot water discharged from the tapping pipe, and temperature detected by the tapping temperature detecting means In a hot water supply apparatus provided with hot water supply control means for adjusting the heating amount of the heating means so that the temperature matches the hot water supply target temperature,A reference water amount setting means for setting an ignition reference water amount according to a temperature detected by the feed water temperature detecting means and the hot water supply target temperature; a water amount sensor for detecting a water amount per unit time of water passing through the water supply pipe; Ignition control means for operating the heating means when the amount of water detected by a water amount sensor exceeds the ignition reference water amount,When the heating unit is stopped for a predetermined timeBecause,When the flow rate detected by the water amount sensor is greater than or equal to a predetermined water amount and less than the ignition reference water amount, the tapping temperature is detected by the tapping temperature detecting means after a second predetermined time has elapsed since the feed water temperature was detected by the feed water temperature detecting means. DetectThe temperature difference between the temperature detected by the tapping temperature detection means and the temperature detected by the feed water temperature detection means is calculated, and when the temperature difference is equal to or greater than a predetermined value, an abnormality in the tapping temperature detection means or the feed water temperature detection means is detected. An abnormality detecting means for determining is provided.
[0011]
When the hot water supply device is in an operating state, the hot water heated by the heating means is discharged from the hot water discharge pipe, but when the heating means is stopped for a predetermined time, the hot water is heated for the predetermined time. By setting the time so that the hot water in the hot water discharge pipe is at room temperature, the water in the vicinity of the hot water temperature detecting means and the water in the vicinity of the feed water temperature detecting means have substantially the same temperature. Accordingly, when the temperature of the water having the same temperature is detected by the feed water temperature detecting means and the tapping temperature detecting means, if these temperature detecting means are normal, the detected values are substantially the same. On the other hand, if there is a difference between the detection values of these temperature detection means that is greater than or equal to a predetermined value, it can be determined that one of the temperature detection means has failed.
[0012]
If it is determined that one of the temperature detecting means has failed as described above, the inspector may check the hot water temperature detecting means by directly detecting the hot water temperature and comparing it with the target hot water temperature. . Here, if it is determined that the tapping temperature detecting means is defective, the tapping temperature detecting means may be repaired. If it is determined that the hot water temperature detection means is normal, it can be determined that the feed water temperature detection means is defective.
[0013]
  Moreover, in the 1st aspect of the hot water supply apparatus of this invention, the reference | standard water amount setting means which sets an ignition reference water amount according to the temperature detected by the said feed water temperature detection means and the said hot water supply target temperature, and the water which passes the said water supply pipe | tube A water amount sensor for detecting the amount of water per unit time, and an ignition control means for operating the heating means when the amount of water detected by the water amount sensor exceeds the ignition reference water amount, the abnormality detecting means, When the flow rate detected by the water amount sensor is not less than a predetermined water amount and less than the ignition reference water amount, it is determined whether or not there is an abnormality in the tapping temperature detecting means or the feed water temperature detecting means.Do.
[0014]
According to this, the temperature detection means is inspected when the heating means is stopped while water is flowing through the water supply pipe. At this time, the temperature of the water not heated by the heating means is detected by the tapping temperature detecting means. Therefore, if the tapping temperature detecting means and the feed water temperature detecting means are normal, the detected temperatures are almost the same. If the temperature difference between the two is equal to or greater than a predetermined value, one of them is out of order. Can be determined.
[0015]
  In particular, when other devices such as the feed water temperature detecting means and the water amount sensor are out of order, the heating means does not ignite even though the water is discharged even when the curan is heard at the normal opening degree. There is. In such a case, when it is determined that the abnormality is detected by the abnormality detection means, it can be determined that the hot water temperature detection means or the feed water temperature detection means is out of order.
  Further, by providing the second predetermined time, when the water whose temperature is detected by the feed water temperature detecting means passes through the feed water temperature detecting means via the feed water pipe and the tapping pipe, The temperature can be detected by the detection means. That is, since the temperature of the same water can be detected in both temperature detecting means, the temperature of water under substantially the same condition can be detected, and the failure of both temperature detecting means can be accurately determined.
[0016]
A second aspect of the hot water supply apparatus of the present invention includes a heat exchanger for heating water supplied by a water supply pipe by a heating means, a tapping pipe from which hot water heated by the heat exchanger is discharged, and the water supply pipe Water temperature detecting means for detecting the temperature of water passing through the hot water, hot water temperature detecting means for detecting the temperature of hot water discharged from the hot water pipe, and the temperature detected by the hot water temperature detecting means so as to coincide with the target hot water temperature. In a hot water supply apparatus comprising a hot water supply control means for adjusting the heating amount of the heating means, a reference water amount setting means for setting an ignition reference water amount according to a temperature detected by the feed water temperature detection means and the hot water supply target temperature, A water amount sensor for detecting a water amount per unit time of water passing through the water supply pipe; and an ignition control means for operating the heating means when the water amount detected by the water amount sensor exceeds the ignition reference water amount. The different When the flow rate detected by the water amount sensor is equal to or greater than a predetermined water amount and less than the ignition reference water amount, and the accumulated water amount from the time of detecting the water amount is equal to or greater than a predetermined amount, An abnormality detection means for calculating a temperature difference between a detected temperature and a temperature detected by the feed water temperature detection means, and determining that the tapping water temperature detection means or the feed water temperature detection means is abnormal when the temperature difference is a predetermined value or more. It is characterized by having.
[0017]
According to this, the heating means does not operate when the amount of water flowing through the water supply pipe is less than the ignition reference water amount. In this state, when the accumulated amount of water since the detection of the amount of water becomes a predetermined amount or more, an abnormality of the tapping water temperature detecting means or the feed water temperature detecting means is detected. By making this cumulative water amount such that the tapping pipe heated by the heating means is cooled to a normal temperature by the water flowing through the inside, the water in the vicinity of the tapping temperature detecting means and the feed water temperature detecting means The temperature of water in the vicinity can be made substantially the same. Therefore, when the temperature of the water having the same temperature is detected by the feed water temperature detecting means and the tapping temperature detecting means, if these temperature detecting means are normal, the detected values are substantially the same. On the other hand, if there is a difference between the detection values of these temperature detection means that is greater than or equal to a predetermined value, it can be determined that one of the temperature detection means has failed.
[0018]
Further, the abnormality detection means detects the hot water temperature by the hot water temperature detection means after a second predetermined time from the time when the water temperature is detected by the water temperature detection means, and compares the hot water temperature with the hot water temperature. Then, it is preferable to determine whether or not there is an abnormality in the hot water temperature detection means or the feed water temperature detection means. According to this, by providing the second predetermined time, when the water whose temperature is detected by the feed water temperature detecting means passes through the feed water pipe and the tapping water temperature detecting means via the tapping pipe. The temperature can be detected by the tapping temperature detecting means. That is, since the temperature of the same water can be detected in both temperature detecting means, the temperature of water under substantially the same condition can be detected, and the failure of both temperature detecting means can be accurately determined.
[0019]
Moreover, it is preferable to provide a notifying means for notifying that when the abnormality detecting means determines that the hot water temperature detecting means or the feed water temperature detecting means is abnormal. According to this, the user or the inspector can easily recognize the abnormality of the hot water temperature detection means or the feed water temperature detection means by the notification means.
[0020]
DETAILED DESCRIPTION OF THE INVENTION
Next, an example of the embodiment of the hot water supply apparatus of the present invention will be described with reference to FIGS. 1 is an overall configuration diagram showing an example of an embodiment of a hot water supply apparatus of the present invention, FIG. 2 is an external view of a remote control provided in the hot water supply apparatus of FIG. 1, and FIG. 3 is a failure detection of the hot water supply apparatus of the first embodiment. 4 is a block diagram showing the configuration of the circuit, FIG. 4 is a flowchart showing the operation of the hot water supply apparatus of FIG. 3, and FIG. 5 is a block diagram showing the configuration of the failure detection circuit of the hot water supply apparatus of another embodiment in the first embodiment. 6 is a flowchart showing the operation of the hot water supply apparatus of FIG. 5, FIG. 7 is a block diagram showing the configuration of the failure detection circuit of the hot water supply apparatus of the second embodiment, and FIG. 8 is a flowchart showing the operation of the hot water supply apparatus of FIG. .
[0021]
First, with reference to FIG. 1 thru | or FIG. 4, 1st Embodiment of the hot-water supply apparatus of this invention is described. As shown in FIG. 1, the hot water supply device 1 according to the first embodiment includes a hot water supply unit 2 and a reheating unit 3, and the controller 4 controls the hot water supply unit 2 and the reheating unit 3. Yes.
[0022]
The hot water supply unit 2 is connected to a hot water supply heat exchanger 6 (heat exchanger) heated by a hot water supply burner 5 (heating means) that operates according to a control signal from the controller 4 and a water pipe (not shown). A water supply pipe 7 for supplying water, a water amount servo 8 for adjusting the opening of the water supply pipe 7 by a control signal from the controller 4, a water supply temperature thermistor 9 for detecting the temperature of the supplied water and outputting it to the controller 4 (water supply temperature detecting means) ), A water amount sensor 10 for detecting the amount of water per unit time passing through the hot water supply heat exchanger 6, a hot water outlet pipe 11 from which hot water heated by the hot water supply heat exchanger 6 is discharged, and water supplied to the water supply pipe 7 A bypass pipe 12 for mixing a part of the outlet pipe 11 with the outlet pipe 11, a bypass servo 13 for adjusting the opening degree of the bypass pipe 12 by a control signal from the controller 4, and a junction point between the outlet pipe 11 and the bypass pipe 12. Leaving water temperature thermistor 14 for detecting the temperature of the hot water output to the controller 4 (hot water temperature detecting means), and Curran 15 provided at the distal end of the tapping pipe 11 is provided.
[0023]
A gas supply pipe 16 that supplies fuel gas to the hot water supply burner 5 has a source gas electromagnetic valve 17 that is opened and closed by a control signal from the controller 4, a hot water supply electromagnetic valve 18 and 19, and a control signal from the controller 4. Is provided with a hot water supply gas proportional valve 20 whose opening degree is adjusted by the above.
[0024]
A hot water supply combustion fan 21 supplies combustion air to the hot water supply burner 5, and its rotational speed is controlled by a control signal from the controller 4. Reference numeral 22 denotes a hot water spark plug which is applied with a high voltage via the igniter 23 in response to a control signal from the controller 4 and ignites the hot water burner 5, and 24 is a hot water heater which detects the combustion state of the hot water burner 5 and outputs it to the controller 4. It is a frame rod.
[0025]
As shown in FIG. 3, the controller 4 includes a hot water supply control means 25 and a chasing control means 26, and is constituted by a CPU, a ROM, a RAM, and the like, and a hot water supply section according to various operation modes instructed by the remote controller 27. 2 and the tracking unit 3 are controlled. Further, the controller 4 is provided with an abnormality detection means 28 and an abnormality detection timer 29 for detecting a failure of the feed water temperature thermistor 9 and the hot water temperature thermistor 14. The abnormality detection timer 29 starts the timer from the time when combustion of the hot water supply burner 5 stops, and counts whether a predetermined time has elapsed. In this embodiment, this predetermined time is set to 2 hours.
[0026]
As shown in FIG. 2, the remote controller 27 includes an operation switch 30 for instructing start and stop of the operation of the entire hot water supply device 1, a hot water supply temperature switch 31 for setting a hot water supply target temperature to the hot water discharge pipe 11, and hot water supply. And a display unit 32 for displaying temperature, time, and the like.
Since the bath chasing device including the chasing unit 3 and the other switches of the remote controller 27 have the same configuration as that of the conventional one, detailed description thereof is omitted.
[0027]
Next, the operation in the first embodiment of the present invention will be described with reference to FIGS. When the user operates the operation switch 30 of the remote controller 27, the entire hot water supply device 1 enters the operation standby state, and the operation lamp built in the operation switch 30 is turned on (STEP 1). In this state, when the currant 15 is closed (YES in STEP 2), that is, when the combustion burner 5 is stopped, the abnormality detection means 28 checks whether or not the abnormality detection timer 29 has timed up. Perform (STEP 3). Here, when the abnormality detection timer 29 is timed up (YES in STEP 3), that is, when the time when the user turns on the operation switch 30 has passed 2 hours from the time when the hot water supply burner 5 stopped last time. Performs the following fault detection operations.
[0028]
First, the abnormality detecting means 28 detects the feed water temperature Ti by the feed water temperature thermistor 9 and detects the tapping temperature To by the tapping temperature thermistor 14 (STEP 4). And the abnormality detection means 28 calculates TL which is the difference of this feed water temperature Ti and tapping temperature To (STEP5). When two hours or more have passed since the last hot water supply burner 5 stopped, the temperature of the hot water in the vicinity of the tapping temperature thermistor 14 raised by the combustion of the previous hot water supply burner 5 has also decreased to room temperature. The temperature of water in the vicinity of the thermistor 9 is almost the same. Therefore, if both the feed water temperature thermistor 9 and the tapping temperature thermistor 14 are normal, the detected temperatures are substantially the same. Here, when the absolute value of the difference TL between the detected temperatures of the two is equal to or higher than a predetermined temperature (5 ° C. in the present embodiment) (YES in STEP 6), either the feed water temperature thermistor 9 or the tapping temperature thermistor 14 has failed. Will be.
[0029]
In such a case, “ER” which is an error display on the display unit 32 and an error code indicating that either the feed water temperature thermistor 9 or the hot water temperature thermistor 14 is malfunctioning are blinked alternately in numbers. (STEP7). Thereby, the user can recognize that the hot water supply apparatus 1 is out of order. The inspector who has received a notification from the user can quickly recognize that either the feed water temperature thermistor 9 or the hot water temperature thermistor 14 is out of order by looking at the error display on the display unit 32. At this time, the inspector opens the currant 15 to detect the hot water temperature with an inspection thermistor or the like, and compares the temperature with the hot water supply target temperature to inspect whether the hot water temperature thermistor 14 is malfunctioning. If the hot water temperature thermistor 14 has not failed, it is determined that the feed water temperature thermistor 9 has failed. Thus, in the hot water supply apparatus 1 of this embodiment, the failure of the feed water temperature thermistor 9 or the hot water temperature thermistor 14 can be detected quickly.
[0030]
On the other hand, when abnormality detection timer 29 has not timed up (NO in STEP 3) with curan 15 being closed (NO in STEP 2), it is less than 2 hours since the previous combustion of hot water supply burner 5 stopped. The temperature of water near the hot water temperature thermistor 14 is expected to be higher than the temperature of water near the feed water temperature thermistor 9. Accordingly, in this case, the abnormality detection means 28 does not perform the failure detection operation of the feed water temperature thermistor 9 and the tapping temperature thermistor 14.
[0031]
If the currant 15 is opened with the operation switch 30 turned on (NO in STEP 2), the next ignition control is performed (STEP 8). The hot water supply control means 25 operates the hot water combustion fan 21 to open the original gas solenoid valve 17, the hot water supply gas proportional valve 20, the hot water supply gas electromagnetic valves 18 and 19, and applies a high voltage to the igniter 23 to apply a hot water supply spark plug. A spark discharge is generated in 22 and the hot water supply burner 5 is ignited.
Next, the hot water supply control means 25 performs the next hot water supply control (STEP 9). When the hot water supply control means 25 recognizes that the hot water supply burner 5 has been ignited by the output of the hot water supply frame rod 24, the amount of water detected by the water amount sensor 10 and the temperature of the water detected by the water supply temperature thermistor 9 Based on the hot water supply target temperature, the opening of the hot water supply gas proportional valve 20, the rotation speed of the hot water supply combustion fan 21, and the hot water supply gas solenoid valve 18 so that the detected temperature of the tapping hot water temperature thermistor 14 matches the target hot water supply temperature. , 19, opening of the water quantity servo 8, and hot water supply control for adjusting the opening of the bypass servo 13 are executed.
As a result, hot water having a temperature set by the user is supplied from the currant 15.
[0032]
Then, when the currant 15 is closed (YES in STEP 10), the combustion of the hot water supply burner 5 is completed, so that the abnormality detection timer 29 is started (STEP 11). For this reason, after the combustion of the hot water supply burner 5 is further started before the abnormality detection timer 29 expires, when the currant 15 is closed and the combustion of the hot water supply burner 5 is completed, the predetermined time from the time when the combustion is completed. Time is counted (STEP 11). Then, the above operation is performed until the operation switch 30 is turned off (NO in STEP 12).
[0033]
Next, another embodiment of the first embodiment of the present invention will be described with reference to FIG. 1, FIG. 2, FIG. 5 and FIG. In this embodiment, as shown in FIG. 5, the controller 4 includes a reference water amount setting means 33 for setting an ignition reference water amount from the detected temperature of the water supply temperature thermistor 9 and a hot water supply target temperature set by the user, and the water amount sensor 10. And an ignition control means 34 for operating the hot water supply burner 5 when the detected water amount exceeds the ignition reference water amount. The ignition control means 34 prevents the hot water supply burner 5 from operating when the water supply amount is equal to or less than the ignition reference water amount even though the user opens the currant 15. In the present embodiment, the abnormality detection means 28 detects a failure of the feed water temperature thermistor 9 or the tapping temperature thermistor 14 in such a situation. In addition, in this embodiment, since the structure of the hot water supply apparatus 1 other than the ignition control means 34 is the same as the said 1st Embodiment, detailed description is abbreviate | omitted.
[0034]
When the user operates the operation switch 30 of the remote controller 27, the entire hot water supply device 1 enters the operation standby state, and the operation lamp built in the operation switch 30 is lit (STEP 21). In this state, when the user opens the currant 15 connected to the tip of the hot water discharge pipe 11 (YES in STEP 22), water supply to the water supply pipe 7 is started, and the start of water supply to the water supply pipe 7 is started by the flow rate sensor 10. When detected, the feed water temperature is detected by the feed water temperature thermistor 9 (STEP 23). The controller 4 calculates the ignition reference water amount from the detected temperature of the feed water temperature thermistor 9 and the hot water supply target temperature by the reference water amount setting means 33 (STEP 24), and detects the water amount by the water amount sensor 10 (STEP 25). Next, the ignition control means 34 determines whether or not the water amount detected by the water amount sensor 10 is equal to or greater than the ignition reference water amount (STEP 26). Here, when the amount of water flowing through the water supply pipe 7 is equal to or greater than the ignition reference water amount (NO in STEP 26), the ignition control is performed (STEP 34), and the hot water supply control is performed (STEP 35).
[0035]
On the other hand, when the amount of water flowing through water supply pipe 7 is less than the ignition reference water amount (YES in STEP 26), hot water supply control means 25 does not ignite hot water supply burner 5. At this time, the abnormality detection means 28 checks whether or not the abnormality detection timer 29 has expired (STEP 27). When the time when water supply to the water supply pipe 7 is started by the user opening the currant 15 is two hours in the present embodiment from the time when the hot water supply burner 5 is stopped last time (YES in STEP 27) ) The following failure detection is performed.
[0036]
First, the abnormality detection means 28 detects and stores the feed water temperature Ti by the feed water temperature thermistor 9 (STEP 28). Then, the second predetermined time, 2 seconds, is in a standby state (NO in STEP 29), and the hot water temperature thermistor 14 detects the hot water temperature To after the second predetermined time has elapsed (STEP 30). Thus, in this embodiment, by providing a time difference in the temperature detection of both thermistors, the temperature of the water whose temperature is detected by the feed water temperature thermistor 9 is supplied to the tapping temperature thermistor 14 via the feed water pipe 7 and the tapping pipe 11. When it reaches, it is detected by the hot water temperature thermistor 14.
[0037]
Here, when the abnormality detection timer 29 has expired, since two hours or more have passed since the last hot water supply burner 5 stopped, the hot water discharge pipe 11 and the hot water supply heat exchanger 6 are also at room temperature. Even if the water supplied from the water supply pipe 7 passes through the hot water supply heat exchanger 6 and the hot water discharge pipe 11, the temperature does not change substantially. Therefore, if both the feed water temperature thermistor 9 and the tapping temperature thermistor 14 are normal, the detected temperatures are substantially the same.
[0038]
Here, a difference TL between the detected temperatures of the two is calculated (STEP 31), and when the absolute value of the temperature difference TL is equal to or higher than a predetermined temperature (5 ° C. in the present embodiment) (YES in STEP 32), the feed water temperature thermistor 9 or the hot water temperature thermistor 14 has failed. At this time, the controller 4 alternately flashes numerically an error code “ER” displayed on the display unit 32 and an error code indicating that either the feed water temperature thermistor 9 or the hot water temperature thermistor 14 is malfunctioning. (STEP 33). Thereby, the user can recognize that the hot water supply apparatus 1 is out of order.
[0039]
On the other hand, when the abnormality detection timer 29 has not expired (NO in STEP 27), the abnormality detection means 28 does not perform the failure detection operation of the feed water temperature thermistor 9 and the hot water temperature thermistor 14.
[0040]
Next, with reference to FIG.1, FIG.2, FIG.7 and FIG. 8, 2nd Embodiment of the hot water supply apparatus of this invention is described. In the present embodiment, when the hot water burner 5 does not ignite even though the user opens the currant 15, the abnormality detection means 28 detects a failure of the hot water temperature thermistor 9 or the hot water temperature thermistor 14. . In the present embodiment, as shown in FIG. 7, the controller 4 is provided with water amount calculation means 35 for calculating the accumulated water amount from a certain point of time based on a signal from the water amount sensor 10.
Other configurations are the same as those of the present embodiment except that the abnormality detection timer 29 in the other embodiments of the first embodiment is not provided, and thus detailed description thereof is omitted.
[0041]
When the user operates the operation switch 30 of the remote controller 27, the entire hot water supply device 1 enters the operation standby state, and the operation lamp built in the operation switch 30 is lit (STEP 41). In this state, when the user opens the currant 15 connected to the tip of the hot water discharge pipe 11 (YES in STEP 42), water supply to the water supply pipe 7 is started, and the start of water supply to the water supply pipe 7 is started. Is detected by the feed water temperature thermistor 9 (STEP 43). The controller 4 calculates the ignition reference water amount from the detected temperature of the feed water temperature thermistor 9 and the hot water supply target temperature by the reference water amount setting means 33 (STEP 44), and detects the water amount by the water amount sensor 10 (STEP 45). Next, the ignition control means 34 determines whether or not the water amount detected by the water amount sensor 10 is equal to or greater than the ignition reference water amount (STEP 46). Here, when the amount of water flowing through the water supply pipe 7 is equal to or greater than the ignition reference water amount (NO in STEP 46), the ignition control is performed (STEP 56), and the hot water supply control is performed (STEP 57).
[0042]
On the other hand, when the amount of water flowing through water supply pipe 7 is less than the ignition reference water amount (YES in STEP 46), hot water supply control means 25 does not ignite hot water supply burner 5. At this time, the water amount calculation means 35 calculates the accumulated water amount from the time when the water amount sensor 10 recognizes the start of water supply to the water supply pipe 7 (STEP 47). Specifically, since the amount of water per unit time is detected by the water amount sensor 10, the accumulated water amount is calculated by multiplying the detected value by the elapsed time and sequentially adding the result. When the accumulated amount of water exceeds a predetermined amount of 1 liter (YES in STEP 48), the temperature of water near the feed water temperature thermistor 9 and the temperature of water near the tapping temperature thermistor 14 become substantially the same temperature. . For example, even if it is not long after the end of the combustion of the previous hot water supply burner 5, the hot water supply burner 5 is not combusted when the amount of water flowing through the water supply tube 7 is less than the ignition reference water amount. If a predetermined amount of water flows from 7 and the tapping pipe 11, the hot water supply heat exchanger 6 and the tapping pipe 11 are also cooled by the water passing through the inside. In the second embodiment, the following failure detection operation is performed under such conditions.
[0043]
First, the abnormality detection means 28 detects and stores the feed water temperature Ti by the feed water temperature thermistor 9 (STEP 49). Then, a second predetermined time until the water whose temperature is detected by the feed water temperature thermistor 9 by the water amount calculation means 35 reaches the vicinity of the tapping temperature thermistor 14 is calculated from the water amount detected by the water amount sensor 10 (STEP 50). . When the second predetermined time calculated by the water amount calculating means 35 has elapsed from the time when the feed water temperature thermistor 9 detects the feed water temperature Ti (YES in STEP 51), the abnormality detecting means 28 is the tapping temperature thermistor 14. The hot water temperature To is detected by (STEP 52).
[0044]
Here, a difference TL between the detected temperatures of the two is calculated (STEP 53), and when the absolute value of the temperature difference TL is equal to or higher than a predetermined temperature (5 ° C. in the present embodiment) (YES in STEP 54), a feed water temperature thermistor. 9 or the hot water temperature thermistor 14 has failed. At this time, the controller 4 alternately flashes numerically an error code “ER” displayed on the display unit 32 and an error code indicating that either the feed water temperature thermistor 9 or the hot water temperature thermistor 14 is malfunctioning. (STEP 55). Thereby, the user can recognize that the hot water supply apparatus 1 is out of order.
[0045]
On the other hand, when the accumulated water amount from the time when the water amount sensor 10 recognizes the start of water supply to the water supply pipe 7 is less than the predetermined amount of 1 liter (NO in STEP 48), the abnormality detecting means 28 is connected to the water supply temperature thermistor 9 and the hot water supply. The malfunction detection operation of the temperature thermistor 14 is not performed.
[0046]
In the second embodiment, when the failure is detected in the feed water temperature thermistor 9 and the hot water temperature thermistor 14, the hot water temperature thermistor 14 is detected after a second predetermined time has elapsed since the temperature was detected by the feed water temperature thermistor 9. However, it is also possible to detect the failure by simultaneously detecting the temperatures of both thermistors 9 and 14 without providing a time difference. In this embodiment, since the water supply is continued until the accumulated water amount reaches a predetermined amount after the supply of water to the water supply pipe 7 is started, the temperature of the water in the vicinity of the tapping temperature thermistor 14 and the vicinity of the water supply temperature thermistor 9 This is because the temperature of water is substantially the same as the temperature of water supplied from a water pipe (not shown).
[Brief description of the drawings]
FIG. 1 is an overall configuration diagram showing an example of an embodiment of a hot water supply apparatus of the present invention.
2 is an external view of a remote controller provided in the hot water supply apparatus of FIG. 1;
FIG. 3 is a block diagram showing a configuration of a failure detection circuit of the hot water supply apparatus according to the first embodiment.
4 is a flowchart showing the operation of the hot water supply apparatus of FIG. 3;
FIG. 5 is a block diagram showing a configuration of a failure detection circuit of a hot water supply apparatus according to another embodiment in the first embodiment.
6 is a flowchart showing the operation of the hot water supply apparatus of FIG. 5;
FIG. 7 is a block diagram showing a configuration of a failure detection circuit of the hot water supply apparatus according to the second embodiment.
8 is a flowchart showing the operation of the hot water supply apparatus of FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 ... Hot water supply apparatus, 5 ... Hot water supply burner (heating means), 6 ... Hot water supply heat exchanger (heat exchanger), 7 ... Water supply pipe, 9 ... Water supply temperature thermistor (water supply temperature detection means), 11 ... Hot water pipe, 14 ... Hot water temperature thermistor (hot water temperature detection means), 25 ... Hot water supply control means, 28 ... Abnormality detection means.

Claims (4)

A heat exchanger for heating the water supplied by the water supply pipe by a heating means, a tapping pipe from which the hot water heated by the heat exchanger is discharged, and a feed water temperature detection for detecting the temperature of the water passing through the water supply pipe Hot water temperature detecting means for detecting the temperature of hot water discharged from the hot water pipe, and hot water control for adjusting the heating amount of the heating means so that the temperature detected by the hot water temperature detecting means matches the target hot water temperature. A hot water supply device comprising:
A reference water amount setting means for setting an ignition reference water amount according to a temperature detected by the feed water temperature detecting means and the hot water supply target temperature; a water amount sensor for detecting a water amount per unit time of water passing through the water supply pipe; Ignition control means for operating the heating means when the amount of water detected by a water amount sensor exceeds the ignition reference water amount,
A when the stop state of the heating means continues for a predetermined time period, when the flow rate detected by the water sensor is lower than the ignition reference water amount above a prescribed amount of water, detecting the feed water temperature by the supply water temperature detecting means After the elapse of a second predetermined time from the point of time, the hot water temperature detecting means detects the hot water temperature, calculates the temperature difference between the temperature detected by the hot water temperature detecting means and the temperature detected by the feed water temperature detecting means, and the temperature difference A hot water supply apparatus comprising: an abnormality detection means for determining that the hot water temperature detection means or the feed water temperature detection means is abnormal when the temperature is equal to or greater than a predetermined value. A heat exchanger for heating the water supplied by the water supply pipe by a heating means, a tapping pipe from which the hot water heated by the heat exchanger is discharged, and a feed water temperature detection for detecting the temperature of the water passing through the water supply pipe Hot water temperature detecting means for detecting the temperature of hot water discharged from the hot water pipe, and hot water control for adjusting the heating amount of the heating means so that the temperature detected by the hot water temperature detecting means matches the target hot water temperature. A hot water supply device comprising:
A reference water amount setting means for setting an ignition reference water amount according to a temperature detected by the feed water temperature detecting means and the hot water supply target temperature; a water amount sensor for detecting a water amount per unit time of water passing through the water supply pipe; Ignition control means for operating the heating means when the amount of water detected by a water amount sensor exceeds the ignition reference water amount,
When the flow rate detected by the previous SL water sensor cumulative amount of water from the time of the A and water detection time of less than the ignition reference water amount above a prescribed amount of water is equal to or greater than a predetermined amount, and temperature detected by the hot water temperature detecting means An abnormality detection unit is provided that calculates a temperature difference from the temperature detected by the feed water temperature detection unit and determines that the tapping water temperature detection unit or the feed water temperature detection unit is abnormal when the temperature difference is equal to or greater than a predetermined value. Hot water supply device characterized by The abnormality detecting means detects the hot water temperature by the hot water temperature detecting means after the elapse of a second predetermined time from the time when the water temperature is detected by the water temperature detecting means, and compares the hot water temperature with the hot water temperature. The hot water supply apparatus according to claim 2, wherein presence or absence of abnormality of the hot water temperature detection means or the water supply temperature detection means is determined. By the abnormality detecting means, when the hot water temperature detecting means or the sheet temperature detecting means is determined to be abnormal, either of the claims 1 to 3, further comprising a notification means for notifying to that effect A hot water supply apparatus according to claim 1.

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