JP5277753B2 - Water heater - Google Patents

Description

  The present invention relates to a hot water supply apparatus, and more particularly to a hot water supply apparatus having a function of detecting a shift failure (so-called halfway failure) of a tapping temperature sensor provided to detect a tapping temperature.

  A hot water supply device configured to be able to supply hot water to a hot water tap such as a curan is heated by a heating means such as a heat exchanger provided in the appliance after heating the non-heated water supplied through the water inlet pipe. The hot water is directly or directly mixed with unheated water or the like and discharged from the hot water discharge pipe, whereby hot water corresponding to the hot water supply set temperature is supplied from the hot water tap.

  That is, this type of hot water supply device is provided with at least a water temperature sensor for detecting the temperature of the incoming water supplied from the water inlet pipe and a hot water temperature sensor for detecting the temperature of the hot water discharged from the hot water pipe. The control means of the hot water supply apparatus is configured to control the heating means based on the detection values of these temperature sensors.

  Therefore, in this type of hot water supply device, there is a problem that hot water corresponding to the hot water supply set temperature cannot be supplied if there is a deviation between the temperature detected by the temperature sensor and the actual water temperature due to a shift failure of the temperature sensor. Therefore, in this type of hot water supply apparatus, various devices have been made in order to detect a shift failure of the temperature sensor.

  For example, in Patent Document 1, when a hot water tap is opened, a hot water heater unused time from the previous use of the hot water heater to the current use is confirmed, and this unused time has passed a predetermined time. When passing water without heating, wait until the detected temperature of the incoming water temperature sensor and the outgoing hot water temperature sensor stabilizes at the incoming water temperature, and compare the detected values of both temperature sensors to determine whether the temperature sensor is good or bad. ing.

[0015] of Japanese Patent Laid-Open No. 2000-297964

However, such a temperature sensor failure detection method has the following problems.
That is, in the hot water supply apparatus described in Patent Document 1 described above, the detection values of both the temperature sensors are compared after waiting for the detected temperatures of the incoming water temperature sensor and the outgoing water temperature sensor to stabilize at the incoming water temperature. However, since the water temperature in the piping from the incoming water temperature sensor to the outgoing water temperature sensor varies, even if the detected temperature of the outgoing hot water temperature sensor coincides with the detected temperature of the incoming water temperature sensor, it will happen by chance. Since the case where only the temperature is detected is included, there remains a problem in accuracy in terms of detecting a shift failure of the temperature sensor.

  In this regard, in the hot water supply apparatus of Patent Document 1, the water inlet temperature is stabilized by flowing a predetermined amount of water prior to the comparison between the detection temperature of the hot water temperature sensor and the incoming water temperature sensor. The construction conditions of the branch pipe that connects the water pipe of the hot water supply device and the water main that is the source of water vary from site to site, and even if a predetermined amount of water is flowed, water with a uniform temperature is not necessarily obtained. Not a translation. That is, depending on the construction site, a part of the branch pipe may be provided with a freezing prevention heater, or a part of the branch pipe may be exposed to direct sunlight or the like and heated. In this case, the water temperature of the part rises and water having a uniform temperature cannot be obtained. That is, even if it is configured to allow a predetermined amount of water to flow, the incoming water temperature is not necessarily stabilized, and there are cases where accurate failure detection cannot be performed in this respect. In addition, when it is going to set the water flow amount before a shift failure detection so that the difference of such construction conditions for every construction site can be absorbed, the water flow amount increases suddenly and the problem that wasteful waste water increases arises.

  The present invention has been made in view of such problems, and the object of the present invention is to accurately detect a shift failure of a temperature sensor without being affected by a difference in construction conditions, and to avoid waste. An object of the present invention is to provide a hot water supply device with a small amount of discarded water.

In order to achieve the above object, a hot water supply apparatus according to the present invention is a hot water supply apparatus provided with at least a incoming water temperature sensor for detecting the incoming water temperature from the incoming water pipe and a hot water temperature sensor for detecting the outgoing hot water temperature from the hot water pipe. , the control means, even heating means filled heating request generation conditions to the heating means while keeping the non-heated state, from the time when the detection value of the incoming water temperature sensor during this time is maintained within a predetermined temperature range On the condition that the amount of water passed corresponds to the amount of water held by the hot water supply device, the detection value of the hot water temperature sensor, the detection value of the incoming water temperature sensor and / or the incoming water temperature sensor and the outgoing hot water temperature sensor, It has a control structure which compares with the detection value of the 3rd temperature sensor installed on the pipe line between, and judges that it is abnormal in a temperature sensor when the difference exceeds a predetermined value.

That is, in the hot water supply apparatus of the present invention, when detecting the shift failure of the temperature sensor by comparing the temperature detected by the tapping temperature sensor and the other temperature sensors (the water temperature sensor and / or the third temperature sensor). The control means is a non-heated state without heating the incoming water by the heating means even when the hot water tap is opened and water is passed through the appliance, and the heating request generation condition for the heating means is satisfied accordingly. Keep it connected to the tapping pipe. In this state, the control means monitors the detected temperature of the incoming water temperature sensor and determines whether the detected temperature is within a predetermined temperature range (for example, within ± 1 ° C.) (is stable). . Then, the detected value of the temperature sensor is compared when the water flow from the time when the detected temperature of the incoming water temperature sensor falls within the predetermined temperature range reaches the amount corresponding to the retained water amount of the hot water supply device.

  That is, in the present invention, when a stable water temperature is obtained and when the piping of the appliance is filled with the stable water temperature, the detection value of the tapping temperature sensor is compared with the detection values of other temperature sensors. The temperature sensor shift failure is determined and the actual water temperature of the water whose temperature is to be detected in the tapping temperature sensor and other temperature sensors is almost the same, so the temperature sensor shift It is possible to accurately determine the failure.

  Moreover, since the condition of determining the failure of the temperature of the water entering the water heater is one of the conditions for determining the failure, even if there is a situation in which the water temperature varies in the branch pipe from the water main to the water heater. The shift failure of the temperature sensor can be determined without being affected at all. In addition, after the incoming water temperature is stabilized, if there is water flow equivalent to the amount of water stored in the hot water supply device, the shift failure of the temperature sensor is determined, so that wasteful waste water can be minimized.

  Further, as a preferred embodiment of the present invention, the control means does not maintain the detected value of the incoming water temperature sensor within a predetermined temperature range even if a predetermined period elapses after the heating request generation condition is satisfied. In this case, a control structure for canceling the non-heating state of the heating means without comparing the detection values of the tapping temperature sensor and other temperature sensors is provided.

  That is, when a configuration is adopted in which the temperature sensor shift correction determination is made after the incoming water temperature is stabilized as in the present invention, if the incoming water temperature is not stable, the water flow in the non-heated state is maintained during that time, and the discarded water is discharged. Therefore, in this embodiment, when the detection value of the incoming water temperature sensor is not stable even though a predetermined period has elapsed after the heating request generation condition is satisfied, a shift failure of the temperature sensor occurs. Cancel the judgment. Thereby, if the water flow to the appliance continues thereafter, the heating means is controlled to be in a heated state, so that the amount of waste water generated can be reduced.

  As another preferred embodiment of the present invention, the control means detects the amount of water flow corresponding to the amount of water held by the hot water supply device based on the detection value of a flow sensor that detects the amount of water flow to the heating means. It is characterized by performing.

  That is, in this embodiment, detection of water flow corresponding to the amount of water held by the hot water supply device is performed based on the detection value of the flow sensor that detects the amount of water flow to the heating means. Specifically, for example, the control unit measures the integrated value of the flow rate detected by the flow sensor, and when this integrated value (integrated water flow rate) reaches the preset water volume of the hot water supply device, Configured to perform temperature comparison. As another aspect, it is assumed that the flow rate at the initial stage when the hot-water tap is opened does not vary, and it is necessary to obtain water flow equivalent to the amount of water held by the hot water supply apparatus by the flow rate detected at the initial stage. Time is calculated, and the temperature sensors are compared when the required time has elapsed after the incoming water temperature has stabilized.

  As another preferred embodiment of the present invention, a bypass pipe that bypasses the heating means is disposed between the water inlet pipe and the hot water outlet pipe, and a flow rate adjusting means that adjusts the water flow rate of the bypass pipe is provided. The control means is configured to control the flow rate adjusting means so that the detected value of the hot water temperature sensor becomes the hot water supply set temperature even when the heating means is kept in a non-heated state. It is characterized by.

  That is, in this embodiment, since the flow rate adjusting means of the bypass pipe is controlled in accordance with the hot water supply set temperature even when the heating means is in the non-heated state, for example, hot hot water in a state heated by the heating means Even when it remains in the hot water, it is prevented that the hot water of the high temperature is discharged as it is when the water is passed in the determination of the shift failure of the temperature sensor. That is, when high temperature hot water remains, hot water adjusted to the hot water supply set temperature is discharged.

  In another preferred embodiment of the present invention, a plurality of the predetermined values are set stepwise, and the difference between the detection value of the tapping temperature sensor and the detection value of the other temperature sensor indicates a predetermined value of which step. The number of times of detection for determining the abnormality determination of the temperature sensor is varied depending on whether the temperature is exceeded.

  That is, in this embodiment, the threshold value used for detecting the shift failure of the temperature sensor is set in several steps (for example, two steps). This is because temperature sensors that detect shift faults have variations from one solid to another, and assuming that the variations from one solid to another are, for example, ± 3 ° C., the detected value of the temperature sensor compared at the time of failure determination is the maximum. A shift of 6 ° C. will occur. Therefore, when the difference in the detection values obtained as a comparison result is close to the range of variation of the individual difference (6 ° C. in the above example), it may be due to variation for each individual. In consideration of the difference in detection values due to variations among individual solids, if the difference in detection values obtained as a comparison result is close to the error range due to this variation, a shift failure immediately (with one detection) If the number of detection times reaches a predetermined number of times, a failure is determined. On the other hand, when the difference between the detection values obtained as a comparison result is considerably larger than the range of error due to this variation (for example, when it is 20 ° C. or more), the possibility of variation due to each solid is not possible. Since it is low, a shift failure is immediately determined (by one detection).

  That is, in this embodiment, the threshold value (predetermined value) used for detection of the shift failure is set in several stages in consideration of the variation due to the individual difference of the temperature sensor, and the number of detections for determining the failure is set according to the degree. Therefore, if it is clearly a shift failure, it is immediately determined as a failure, while if it is suspected to be due to individual variations, it can be determined that there is a high possibility of a shift failure and the failure can be determined. Sensor shift faults can be detected more accurately.

  As a preferred embodiment of the present invention, the control means includes a control configuration for performing a predetermined abnormality notification and / or a predetermined safe operation when it is determined that the temperature sensor is abnormal. Thereby, the abnormality of the temperature sensor can be promptly notified, and the occurrence of abnormal hot water can be prevented by the safe operation.

  According to the present invention, when the water temperature of the incoming water is stable and the inside of the piping of the hot water supply device is filled by the incoming water with the stable water temperature, the temperature sensor is compared with the detection value of the hot water temperature sensor and the other temperature sensors. Therefore, it is possible to accurately determine the shift failure of the temperature sensor.

  Moreover, according to the second aspect of the present invention, if the incoming water temperature is not stable even after a predetermined period of time, the determination of the shift failure of the temperature sensor is stopped, and then heating by the heating means is performed. It is possible to avoid an increase in waste water at the time of failure determination.

  According to the fourth aspect of the invention, since the flow rate adjusting means of the bypass pipe is controlled according to the hot water supply set temperature even when the heating means is in the non-heated state, the temperature is high when water is passed during the determination of the shift failure. It is possible to prevent hot water from being discharged, and it is excellent in safety.

  Furthermore, according to the invention according to claim 5, the predetermined value used for the detection of the shift failure is set in several stages in consideration of the variation due to the individual difference of the temperature sensor, and the number of detections for determining the failure is set according to the degree. By doing so, erroneous determination due to variation among individual temperature sensors can be suppressed, and the shift failure of the temperature sensor can be detected more accurately.

Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.
Embodiment 1
FIG. 1 is an explanatory diagram showing an example of a schematic configuration of a hot water supply apparatus according to the present invention. As shown in the figure, this hot water supply apparatus constitutes a water inlet pipe 1 connected to a branch pipe B branched from a water main pipe A serving as a water supply source, and a heating means for heating the water supplied from the water inlet pipe 1. The main parts are a heat exchanger 2 that heats and a hot water pipe 3 that leads hot water heated by the heat exchanger 2 to a hot water supply pipe D connected to a hot water tap C.

  In the hot water supply apparatus shown in the present embodiment, a bypass pipe 4 that bypasses the heat exchanger 2 is further disposed between the water inlet pipe 1 and the hot water outlet pipe 3. A bypass flow rate adjusting valve 5 is provided as a flow rate adjusting means for adjusting the flow rate. The bypass pipe 4 is provided so that when the hot water heated by the heat exchanger 2 is higher than the hot water supply set temperature, the hot water is mixed with water from the water inlet pipe 1 to obtain a hot water supply hot water set temperature. Therefore, the bypass flow rate adjusting valve 5 is configured so that the valve opening degree (that is, the flow rate of the bypass pipe 4) can be controlled by the control unit 10 described later. When the hot water heated by the heat exchanger 2 is equal to or lower than the hot water supply set temperature, the bypass flow rate adjusting valve 5 is controlled to be fully closed, and water flow from the water inlet pipe 1 to the hot water outlet pipe 3 is blocked.

  The inlet pipe 1 has an inlet temperature sensor 6 for detecting the inlet temperature of water supplied through the branch pipe B, and a flow rate sensor 7 for detecting the amount of water flowing into the heat exchanger 2. Is provided. As described above, the hot water supply apparatus shown in the present embodiment is provided with the bypass pipe 4 that guides a part of the incoming water supplied to the incoming water pipe 1 to the outgoing hot water pipe 3, and therefore detects the amount of water flowing into the heat exchanger 2. The flow sensor 7 is provided downstream of the branch point with the bypass pipe 4 (that is, a position close to the heat exchanger 2). That is, water flow to the heat exchanger 2 can be detected even when the bypass flow rate adjustment valve 5 is open. In addition, since the incoming water temperature is not affected by the presence or absence of the bypass pipe 4, it may be provided either upstream or downstream of the branch point with the bypass pipe 4. In the illustrated example, the case where it is provided upstream is shown. Yes.

  On the other hand, the tapping pipe 3 has a can body temperature sensor (third temperature sensor) 8 for detecting the temperature of hot water heated by the heat exchanger 2 and a tapping temperature from the tapping pipe 3. The hot water temperature sensor 9 is provided. Since the hot water supply apparatus shown in the present embodiment includes the bypass pipe 4 as described above, the hot water temperature sensor 9 is located downstream of the junction of the hot water pipe 3 and the bypass pipe 4 (that is, the hot water supply pipe D). Side). That is, the bypass flow rate adjusting valve 5 is opened so that the temperature of the tapping water from the tapping pipe 3 can be accurately detected even when there is water flow from the inlet pipe 1. In addition, since the can body temperature sensor 8 detects the temperature of the hot water heated by the heat exchanger 2, the can body temperature sensor 8 is provided upstream of the junction with the bypass pipe 4 (that is, a position close to the heat exchanger 2). It has been.

  Here, as the incoming water temperature sensor 6, the can body temperature sensor 8, and the tapping temperature sensor 9, a known temperature sensor such as a thermistor is used. As the flow rate sensor 7, a known flow rate sensor such as an impeller type water amount sensor is used. Further, the heat exchanger 2 is configured by a heat exchanger having a known structure that is configured to be heated by a combustion unit (not shown). The combustion unit is configured such that combustion control is performed by a control unit 10 to be described later, so that the incoming water supplied from the incoming water pipe 1 is heated and heated by the heat exchanger 2.

  And in the figure, 10 has shown the control part of the hot-water supply apparatus. This control unit 10 constitutes a control means for controlling the operation of each part of the hot water supply apparatus, and is provided with a microcomputer of a well-known aspect including a CPU, ROM, RAM, etc. as its control center. More specifically, the microcomputer is connected to the above-described various sensors 6 to 9 through signal lines (not shown), and is configured to receive detection signals from these various sensors 6 to 9. The combustion unit and the drive unit of the bypass flow rate adjustment valve 5 are connected by a signal line (not shown) so that combustion control, valve control of the bypass flow rate adjustment valve 5 and the like can be performed.

  The microcomputer is also connected to the remote controller 11 of the hot water supply device, and is described above based on operation information (for example, ON / OFF operation of the operation switch and setting operation of the hot water supply set temperature). Combustion control and valve control are possible.

  Reference numeral 11 denotes a remote controller for the hot water supply device. The remote controller is provided with a display unit and an operation unit (not shown) so that operation information on the operation unit can be input to the control unit 10.

  Therefore, the detection procedure of the shift failure of the temperature sensor in the water heater configured as described above will be described with reference to FIG.

  FIG. 2 is a flowchart illustrating an example of a procedure for diagnosing a shift failure of the temperature sensor. As shown in step S1 of FIG. 2, the diagnosis of the shift failure of the temperature sensor is started when a predetermined condition set in advance is satisfied. This predetermined condition is, for example, when the number of hot water supply reaches the predetermined number of times, or when a certain time has elapsed since the previous failure detection, and in addition to these conditions, the previous hot water supply operation (heating operation) is stopped. For example, a predetermined time has elapsed since then, and the shift failure is appropriately set so as to be detected at a predetermined interval. Therefore, the control unit 10 first determines whether or not this predetermined condition is satisfied (see step S1 in FIG. 2).

  In addition, when using the hot water supply frequency as said predetermined condition, the control part 10 is comprised so that it may count the frequency | count every time hot water supply is performed, and memorize | stores it in a predetermined memory | storage means (for example, RAM). Further, when a predetermined period has elapsed since the previous failure detection, the control unit 10 is configured to determine whether or not the predetermined period has elapsed using a timer based on an internal clock. The

  And if this predetermined condition is satisfy | filled, the control part 10 will next judge whether there exists water flow in a hot water supply apparatus (refer FIG. 2 step S2). That is, since the failure determination of the temperature sensor according to the present invention is performed at the initial stage of hot water discharge, the control unit 10 determines whether water has passed through the hot water supply device by opening the hot water tap C or the like. .

  And when there is water passing through the hot water supply device, the controller 10 keeps the heating means in an unheated state, while the detected value of the incoming water temperature sensor 6 is maintained within a predetermined temperature range during this time, It is determined whether or not a considerable amount of water has been detected (see steps S3 to 6 in FIG. 2).

  That is, even when the heating request generation condition for the heating unit is satisfied by passing water, the control unit 10 performs heating until the determination of normality / abnormality of the temperature sensor described later (see steps S8 and S9 in FIG. 2) ends. The means is maintained in an unheated state (see step S3 in FIG. 2).

  Here, the heating request for the heating means is a predetermined request such that the operation switch of the remote controller 11 is in the on mode, the incoming water temperature is equal to or lower than a predetermined temperature (high cut condition), and no error in the hot water supply device is detected. It means a requirement on control processing that occurs when water flow exceeding the minimum operating water flow rate (a flow rate that allows combustion in the combustion section of the heating means) exceeds the precondition in a state where the preconditions are satisfied. Therefore, when the condition for generating the heating request is satisfied in a state where the detection process of the shift failure of the temperature sensor is not executed, the control unit 10 starts combustion of the combustion unit and starts heating by the heat exchanger 2. . However, during the execution of the temperature sensor shift failure detection process, the control unit 10 does not start combustion by the combustion unit and the heat exchanger 2 is not heated even if the condition for generating the heating request is satisfied. Is configured to maintain.

  Then, while maintaining the heating means in the non-heated state, the control unit 10 next determines whether the incoming water temperature is stable, specifically, the detected value of the incoming water temperature sensor 6 is within a predetermined temperature range ( For example, it is determined whether it is within a range of ± 1 ° C. More specifically, in this determination, the control unit 10 stores the detected value of the incoming water temperature sensor 6 in the initial stage of hot water in storage means (for example, RAM) (see step S4 in FIG. 2). Then, it is determined whether the difference is within a predetermined temperature range while comparing the detection value detected by the incoming water temperature sensor 6 with the detection value stored in the storage means (see step S5 in FIG. 2). .

  In this determination, when the detected value of the incoming water temperature sensor 6 fluctuates beyond the predetermined range, the detected value after fluctuation is newly stored in the storage means, and again stored in the storage means. The detected value is compared with the detected value detected by the incoming water temperature sensor 6 thereafter, and it is determined whether the difference is within a predetermined temperature range.

  Thus, since the control part 10 was made to monitor the fluctuation | variation of incoming water temperature based on the detected value of the incoming water temperature sensor 6, for example, the antifreezing heater E is provided in the said branch pipe B, for example. As in the case, even when there is a variation (temperature unevenness) in the water temperature of the water stored in the branch pipe B, the failure determination described later can be performed by accurately capturing the time when the incoming water temperature is stabilized. Become.

  On the other hand, in parallel with the detection of the stability of the incoming water temperature, the control unit 10 has reached the amount equivalent to the retained water amount of the hot water supply device based on the detected value of the flow rate sensor 7. (See step S6 in FIG. 2). Specifically, this determination is made as to whether or not the amount of water flow from the time point when the detected value of the incoming water temperature sensor 6 is stored in the storage means (see step S4 in FIG. 2) has reached the amount corresponding to the amount of water stored in the hot water supply device. To do. Therefore, when the detection value of the incoming water temperature sensor 6 stored in the storage means is rewritten without the incoming water temperature being stabilized, the amount of water passing from the time of the rewriting is detected again, and the amount of water passing is detected by the hot water supply device. It will be judged whether the amount equivalent to the amount of retained water has been reached.

  Here, the amount of water retained in the hot water supply device means the amount of water accommodated in the hot water supply device, that is, the amount of water corresponding to the capacity of the pipe from the inlet pipe 1 through the heat exchanger 2 to the hot water outlet pipe 3. More specifically, since the hot water supply apparatus of the present embodiment includes the bypass pipe 4, the amount of water added to the pipe capacity of the bypass pipe 4 becomes the retained water quantity of the hot water supply apparatus. In addition, since the amount of water held in the hot water supply apparatus differs depending on the type of hot water supply apparatus, this value is stored in advance in a storage means (for example, ROM) of the control unit 10.

  In addition, the detection of water flow equivalent to the amount of water held by the hot water supply device is performed by, for example, measuring the integrated value of the flow rate (flow rate per unit time) detected by the flow rate sensor 7 by the control unit 10, and When the water amount) reaches the retained water amount of the hot water supply device stored in the storage means, it is determined that there has been passage of water equivalent to the retained water amount of the hot water supply device, or the flow rate detected in the initial stage of hot water supply does not fluctuate. Assuming that the required time to obtain water flow equivalent to the amount of water stored in the hot water supply device is calculated based on the flow rate detected in the initial stage of the hot water supply, and is retained when the required time has elapsed after the incoming water temperature has stabilized. It is constituted so that it may be judged that there was water equivalent to the amount of water.

  As described above, in this embodiment, water is supplied in an amount equivalent to the amount of water held by the hot water supply apparatus in a state where the incoming water temperature is stable, so that hot water remains in the heat exchanger 2 at the stage of the start of water flow. However, at the time of comparison of detection values of a temperature sensor described later, such residual hot water is discharged to the outside of the hot water supply device, and the temperature of the water in the hot water supply device is in a uniform state.

  When the temperature of the water in the hot water supply apparatus is made uniform in this way, the controller 10 then compares the detected value of the hot water temperature sensor 9 with the detected value of the incoming water temperature sensor 6 on this condition. Then, it is determined whether there is an abnormality in the temperature sensor. Specifically, it is determined whether the difference (detected temperature difference) obtained as a comparison result is less than a predetermined value (for example, 10 ° C.) set in advance (see step S7 in FIG. 2).

  As a result, if the difference between the detected values is less than the predetermined value, the compared temperature sensors 6 and 9 are determined to be normal (see step S8 in FIG. 2). Since it can be determined that at least one of the temperature sensors 6 and 9 has a shift failure, it is determined that the temperature sensors 6 and 9 are abnormal (see step S9 in FIG. 2).

  When it is determined that the temperature sensor is abnormal, the control unit 10 performs a predetermined abnormality notification (for example, an error is displayed on the display unit of the remote controller 11) according to a predetermined procedure, and a predetermined safe operation ( For example, the combustion operation of the combustion section is prohibited). In addition, although these processes can also be performed independently, it is comprised so that a safe operation | movement may be performed with abnormality notification.

  In the present embodiment, the case where the detection value of the hot water temperature sensor 9 and the detection value of the incoming water temperature sensor 6 are compared is shown. For example, the detection value of the hot water temperature sensor 9 and the detection value of the can body temperature sensor 8 are used. It is configured to compare, or alternatively, the detection value of the hot water temperature sensor 9 is compared with the detected values of the water temperature sensor 6 and the can body temperature sensor 8 so as to diagnose the shift failure. Is also possible. That is, in the present invention, the detected values of the temperature sensors are compared after the temperature of the water in the hot water supply device is made uniform, so that the incoming water temperature sensor 6 and the hot water temperature sensor are the temperature sensors in the hot water supply device. Compared with any temperature sensor installed on the pipe line between 9, a shift fault can be detected.

  And in the hot water supply apparatus of this embodiment, the control part 10 is that the detection value of the incoming water temperature sensor 6 is still in a predetermined temperature range even if the predetermined period passes after the conditions for generating the heating request described above are satisfied. When not maintained, the detection value of the tapping temperature sensor 9 and the other temperature sensors 6 and 8 are not compared, and the heating unit is configured to cancel the non-heating state.

  That is, in the above-described configuration, when determining the shift failure of the temperature sensor, the non-heated water flow is maintained until the incoming water temperature becomes stable. There is a risk that water will continue and wasteful wastewater will increase. For this reason, in this embodiment, in order to prevent such an increase in waste water, the detection value of the incoming water temperature sensor 6 must be stable even when a predetermined period has passed in determining the shift failure of the temperature sensor. For example, the determination of the shift failure of the temperature sensor is cancelled, the non-heating state of the heating means is canceled, and heating of the incoming water by the heating means, that is, hot water supply is started. That is, a normal hot water supply operation is performed from the time point when the determination is canceled.

  It should be noted that when the determination is canceled in this way, it is appropriately set when the next determination is performed. For example, it can be configured to be performed in the next hot water initial stage, or can be configured to perform determination when the predetermined condition is satisfied after skipping the canceled amount.

  Furthermore, in the hot water supply apparatus of the present embodiment, the control unit 10 controls the bypass flow rate adjustment valve 5 so that the detected value of the hot water temperature sensor 9 becomes the hot water supply set temperature even when the heating means is kept in the non-heated state. Configured to control.

  That is, as described above, when the temperature sensor shift failure is detected and water is passed in an unheated state, hot hot water remaining in the heat exchanger 2 is discharged from the hot water tap C. Since there is a possibility, in this embodiment, even if the heating means is kept in the non-heated state, the control unit 10 bypasses the bypass flow rate adjustment valve 5 so that the detected value of the hot water temperature sensor 9 becomes the hot water supply set temperature. It is comprised so that valve control of this may be performed.

  Thereby, for example, even when high-temperature hot water remains in the heat exchanger 2, when water flows, the control unit 10 opens the bypass flow rate adjustment valve 5, and hot water is supplied from the hot-water tap C. Hot water at the set temperature is discharged. Therefore, it is avoided that hot hot water exceeding the hot water supply set temperature is discharged in the failure determination, and the failure determination can be performed safely. In this case, since the heating means is kept in the non-heated state during the failure determination, the temperature of the hot water discharged from the hot water tap C decreases as the remaining hot water disappears, and the bypass flow rate accordingly. The regulating valve 5 is controlled to be fully closed.

Embodiment 2
Next, another embodiment of the present invention will be described. This embodiment is a modification of the final determination procedure of the abnormality of the temperature sensor in the above-described first embodiment, that is, the mode of failure determination at the time of comparing the detection values of the temperature sensor, and other configurations are common. Therefore, common parts are denoted by the same reference numerals and description thereof is omitted.

  Specifically, also in this embodiment, when detecting the shift failure of the temperature sensor, the temperature of the water in the hot water supply device is processed in advance, and then the detected temperature (detected value) of the temperature sensors 6 and 9 is set. The point which compares and calculates | requires the difference is the same as that of Embodiment 1 mentioned above.

  In the present embodiment, a plurality of predetermined values are set stepwise as the predetermined value to be compared with the detected value of the temperature sensor thus obtained. That is, since there is a variation for each temperature sensor for detecting a shift failure, the predetermined value for determining that there is a suspicion of shift failure (suspecting determination) is taken as the predetermined value in consideration of this variation. And a predetermined value for performing deterministic determination (determined determination) that it is clearly a shift failure.

  Specifically, the predetermined value for the suspicion determination is set based on the maximum variation (variation width) of the temperature sensor to be determined. For example, if the variation of the temperature sensor is ± 3 ° C., the maximum variation is 6 ° C. Therefore, the predetermined value for the above-mentioned doubt determination is larger than this 6 ° C. and a value close thereto (for example, 10 ° C. ° C) is preferably employed.

  In other words, if the predetermined value for suspicion determination is set to be narrower than the maximum variation width, there is a risk of suspicion determination even if the temperature sensor is normal. It is preferable to set it to be significantly larger. The reason why the value is set close to the maximum width of the variation is that if this value is too large, the initial stage of the shift failure cannot be found. The predetermined value for the suspicion determination is set only for the suspicion determination, and can be set slightly smaller than the maximum variation.

  On the other hand, a value larger than the predetermined value for the suspect determination is used as the predetermined value for the determination determination. In addition, as the predetermined value, a value that is at least larger than the maximum variation width of the temperature sensor to be determined is set (for example, when the maximum variation value is 6 ° C., it is set to 20 ° C. or 30 ° C. ).

  Thus, in the present embodiment, the predetermined value for the doubt determination and the predetermined value for the determination determination are provided in this way, and obtained by comparing the detected temperatures (detected values) of the temperature sensors 6 and 9. If the difference exceeds the predetermined value for the determination, the temperature sensor shift is immediately determined as a single determination. On the other hand, if it exceeds a predetermined value for doubt determination, it is not immediately determined as a shift failure, but the number of doubt determinations is stored in the storage means of the control unit 10, and the shift is performed when this number reaches the predetermined number. Judge as failure.

  That is, in the present embodiment, a plurality of the predetermined values are set stepwise, and in which step the difference between the detected value of the tapping temperature sensor 9 and the detected values of the other temperature sensors 6 and 8 exceeds the predetermined value. Accordingly, the number of detections for determining the abnormality determination of the temperature sensor is varied. As a result, the shift failure of the temperature sensor can be detected more accurately.

  In the present embodiment as well, the can body temperature sensor 8 can be used as a temperature sensor to be compared with the detected value of the tapping temperature sensor 9 as in the first embodiment. Also, if the incoming water temperature is not stable even after a predetermined period of time, the temperature sensor failure determination is stopped and the non-heating state of the heating means is released, and the heating means is kept in the non-heating state. The same applies to the point of controlling the bypass flow rate adjusting valve 5 and the point of performing a predetermined abnormality notification or safety operation when an abnormality is detected.

  Note that the above-described embodiments merely show preferred embodiments of the present invention, and the present invention is not limited to these, and various design changes can be made within the scope thereof.

  For example, although the case where the hot water supply apparatus includes the bypass pipe 4 has been described in the above-described embodiment, the present invention can also be applied to a hot water supply apparatus that does not include the bypass pipe.

  In the above-described embodiment, the case where the total amount of water stored in the hot water supply device is used as the retained water amount of the hot water supply device. However, for example, the arrangement of the hot water temperature sensor 9 from the position where the incoming water temperature sensor 6 is disposed. The pipe capacity up to the installation position can be used as the amount of water retained in the hot water supply apparatus. That is, according to the present invention, it is sufficient that the temperature of water corresponding to at least the piping capacity from the arrangement position of the incoming water temperature sensor 6 to the arrangement position of the hot water temperature sensor 9 is uniform. It is possible to make an estimate with as few as possible.

  In the above-described second embodiment, the case where one predetermined value for performing the suspicion determination of the shift failure of the temperature sensor has been provided. However, two or more predetermined determination values for the suspicion determination are set before the determination determination is made. Is also possible. In this case, the number of detections for determining a failure is set to decrease as the predetermined value increases. Further, in the second embodiment, a case is shown in which a predetermined value for determination determination that determines a shift failure of the temperature sensor is provided by one detection, but it is also possible to set only a predetermined value for doubt determination. That is, it is possible not to determine that a temperature sensor shift failure is detected once.

  In any of the first and second embodiments described above, the control unit 10 can be configured to display the shift failure of the temperature sensor or the suspicion thereof on the display unit of the remote controller 11.

It is explanatory drawing which shows an example of schematic structure of the hot water supply apparatus which concerns on this invention. It is a flowchart which shows an example of the diagnostic procedure of the shift failure of the temperature sensor in the hot water supply apparatus.

Explanation of symbols

1 Inlet pipe 2 Heat exchanger (heating means)
3 Hot water pipe 4 Bypass pipe 5 Bypass flow rate adjustment valve (flow rate adjustment means)
6 Incoming water temperature sensor 7 Flow rate sensor 8 Can body temperature sensor (third temperature sensor)
9 Hot water temperature sensor A Water supply main B Branch pipe B
C Hot-water tap E Freezing prevention heater

Claims (6)

At least in a hot water supply apparatus provided with an incoming water temperature sensor that detects an incoming water temperature from an incoming water pipe and an outgoing hot water temperature sensor that detects an outgoing hot water temperature from an outlet pipe,
The control means keeps the heating means in a non-heated state even if the heating request generation condition for the heating means is satisfied, while the detected value of the incoming water temperature sensor is maintained within a predetermined temperature range during this period . On condition that water has reached the amount corresponding to the amount of water held in the hot water supply device, the detection value of the hot water temperature sensor, the detection value of the incoming water temperature sensor and / or the incoming water temperature sensor and the outgoing hot water temperature sensor A hot water supply apparatus having a control configuration that compares a detection value of a third temperature sensor installed on a pipe line between the two and determines that the temperature sensor is abnormal when the difference exceeds a predetermined value.   If the detected value of the incoming water temperature sensor is not maintained within a predetermined temperature range even after a predetermined period of time has elapsed after the heating request generation condition is satisfied, the control means may detect the temperature of the hot water and other temperatures. The hot water supply apparatus according to claim 1, further comprising a control configuration for canceling a non-heated state of the heating means without comparing the detection value with the sensor.   The said control means performs the detection of the water flow equivalent to the amount of water holding | maintenance of the said hot water supply apparatus based on the detected value of the flow sensor which detects the water flow volume to the said heating means. The hot water supply device described. A bypass pipe that bypasses the heating means is disposed between the water inlet pipe and the hot water outlet pipe, and a flow rate adjusting means that adjusts the water flow rate of the bypass pipe is provided.
The control means is configured to control the flow rate adjusting means so that a detection value of the tapping temperature sensor becomes a hot water supply set temperature even when the heating means is kept in a non-heated state. The hot water supply device according to any one of claims 1 to 3.   A plurality of the predetermined values are set stepwise, and the abnormality determination of the temperature sensor is performed according to which step the predetermined value exceeds the difference between the detection value of the tapping temperature sensor and the detection value of the other temperature sensor. The hot water supply apparatus according to any one of claims 1 to 4, wherein the number of detection times to be determined is different.   The hot water supply apparatus according to any one of claims 1 to 5, wherein the control means includes a control configuration for performing a predetermined abnormality notification and / or a predetermined safe operation when it is determined that the temperature sensor is abnormal. .

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