JP5449683B2 - Hot water system - Google Patents

Description

  The present invention relates to a hot water supply system that can store heated hot water and supply hot water using the stored hot water. In particular, the present invention relates to a hot water supply system that mixes hot water and cold water stored in hot water and supplies the hot water to a hot water use location (such as a hot water tap or a bath tub).

  There is known a hot water supply system that stores hot water that has been heated, mixes the hot water with cold water using a mixing valve, and supplies hot water. In such a hot water supply system, generally, a mixing valve is controlled based on a temperature detected by a temperature sensor, and hot water having a temperature desired by a user is supplied to a hot water use location. Since the failure of the temperature sensor leads to the possibility of high temperature hot water, when the temperature sensor fails, it is required to detect the failure as soon as possible. For example, in the case of a fault that causes an extreme output fluctuation such as disconnection or short circuit, it is easy to detect the fault, but an intermediate fault (in this specification, the sensor performance gradually decreases and the sensor detection error gradually increases. In the case of a failure that does not cause an extreme output fluctuation, as in the case of increasing to a large value), it is difficult to detect a temperature sensor failure because it is difficult to detect a decrease in sensor performance. .

  Patent Document 1 describes a technique for detecting an intermediate failure of a mixed water temperature sensor that detects a water temperature after mixing hot water and cold water in a hot water supply system. In this technique, an abnormality monitoring sensor is provided near the downstream of the mixed water temperature sensor. The abnormality monitoring sensor outputs an abnormality detection signal when a temperature higher than the threshold temperature is detected. The threshold temperature is set higher than the set temperature of the hot water supplied to the hot water use location. The mixing ratio of hot water and cold water is adjusted so that the temperature detected by the mixed water temperature sensor becomes the set temperature. Therefore, if there is no failure in the mixed water temperature sensor, the temperature detected by the abnormality monitoring sensor reaches the threshold temperature. No abnormality detection signal is output. When the sensor performance of the mixed water temperature sensor gradually decreases and the temperature detection error of the mixed water temperature sensor increases, the actual water temperature after mixing hot water and cold water may exceed the set temperature. In this case, the temperature detected by the abnormality monitoring sensor reaches the threshold temperature, and an abnormality detection signal is output. According to this technique, an intermediate failure of the mixed water temperature sensor can be detected.

JP 2003-074971 A

  According to the technique of Patent Document 1, a failure of the mixed water temperature sensor is determined on the assumption that the sensor function of the abnormality monitoring sensor is normal. However, in practice, the mixed water temperature sensor may fail or the abnormality monitoring sensor may fail. In the technique of Patent Document 1, when an abnormality detection signal is output, it is not possible to determine which of the mixed water temperature sensor and the abnormality monitoring sensor has failed. The sensor that has failed cannot be identified.

  The present invention has been proposed to solve the above problems. That is, an object of the present invention is to provide a hot water supply system that can detect an intermediate failure of a temperature sensor and can identify a failed temperature sensor.

The present invention relates to a hot water supply system that can store heated hot water and supply hot water using the stored hot water.
The hot water supply system of the present invention includes a hot water storage tank that stores hot water, a hot water supply path that supplies hot water from the upper part of the hot water storage tank to the hot water tap , a second hot water supply path that branches from the hot water supply path and supplies hot water to the bath tub, A hot water supply valve that is provided on the second hot water supply path and opens and closes the second hot water supply path, and a water supply path that supplies cold water from the cold water supply source to the lower part of the hot water storage tank. The cold water supply source is, for example, a water pipe.
The hot water supply system of the present invention connects a hot water supply path and a water supply path upstream of a branching portion with the second hot water supply path, and mixes cold water supplied from a cold water supply source with hot water supplied from a hot water storage tank. It has a route.

  The hot water supply system of the present invention is provided on a mixing path, and includes a mixing valve that adjusts a mixing ratio between a flow rate of cold water supplied from a cold water supply source and a flow rate of hot water supplied from a hot water storage tank. The mixing valve may be provided at any position on the mixing path.

The hot water supply system of the present invention is provided on the water supply path upstream from the connection part with the mixing path, and the connection part between the water supply temperature sensor for detecting the temperature of the water supplied from the cold water supply source and the mixing path And a hot water supply temperature sensor that detects the temperature of hot water supplied from the hot water storage tank .
Hot water supply system of the present invention, the mixing has been eclipsed set on the upstream of the hot water supply path of the branch portion of the second hot-water supply path A downstream from the connection portion with the path, the temperature of the water flowing through the hot water supply path A hot water temperature sensor to be detected and a bath temperature sensor which is provided on the second hot water supply path and detects the temperature of the water flowing through the second hot water supply path are provided. According to such a configuration, when the hot water filling valve is opened and the opening of the mixing valve is fully opened on the water side and water is supplied from the cold water supply source, the water supply temperature sensor, the hot water temperature sensor, and the bath temperature sensor The temperatures of the water flowing through the path provided with the three temperature sensors are all equal. In addition, when the hot water filling valve is opened and the opening of the mixing valve is fully opened, and hot water is poured from the hot water storage tank, three temperature sensors are provided: a hot water temperature sensor, a hot water temperature sensor, and a bath temperature sensor. The temperature of the hot water flowing through the path is all equal.
The hot water supply system of the present invention is provided with a controller for controlling the hot water filling valve and the mixing valve as well as the detection signals of the hot water temperature sensor, the hot water temperature sensor, the hot water temperature sensor, and the bath temperature sensor, respectively. The controller can execute a first failure diagnosis operation and a second failure diagnosis operation described below.

The first failure diagnosis operation is a step of opening the hot water filling valve and opening the opening of the mixing valve to fully open the water side, and comparing temperatures detected by the feed water temperature sensor, the hot water temperature sensor, and the bath temperature sensor, respectively. when it is detected a temperature difference of more than a predetermined temperature between one temperature sensor and other one temperature sensor in, and a step of determining a failure of the temperature sensor in which the temperature difference is detected. The predetermined temperature as used herein refers to a temperature higher than 2 ° C. For example, when three temperature sensors including a feed water temperature sensor are provided and the predetermined temperature is 5 ° C., the temperature detected by the feed water temperature sensor is higher than the temperature detected by any other temperature sensor. If there is a temperature difference of 5 ° C. or more, it is determined that the feed water temperature sensor is malfunctioning.

In the first failure diagnosis operation, an intermediate failure of the temperature sensor is determined using at least three or more temperature sensors that detect the temperature of water flowing through the same path. Since the temperature sensor failure is determined by comparing the temperatures detected by the temperature sensors, the failure can be detected even when the sensor function of the temperature sensor gradually decreases. Further, if the temperature detected by one temperature sensor has a temperature difference of a predetermined temperature or more than the temperature detected by any other temperature sensor, it is possible to determine that one temperature sensor is a failure. An intermediate failure of the temperature sensor can be detected, and the failed temperature sensor can be specified.

The second failure diagnosis operation is a step of opening the hot water filling valve and opening the mixing valve fully opening the hot water side, and comparing temperatures detected by the hot water supply temperature sensor, the hot water temperature sensor, and the bath temperature sensor, when it is detected a temperature difference of more than a predetermined temperature between one temperature sensor and other one temperature sensor in, and a step of determining a failure of the temperature sensor in which the temperature difference is detected.

In the second failure diagnosis operation, an intermediate failure of the temperature sensor is determined using at least three or more temperature sensors that detect the temperature of hot water flowing through the same path. Since the temperature sensor failure is determined by comparing the temperatures detected by the temperature sensors, the failure can be detected even when the sensor function of the temperature sensor gradually decreases. Further, if the temperature detected by one temperature sensor has a temperature difference of a predetermined temperature or more than the temperature detected by any other temperature sensor, it is possible to determine that one temperature sensor is a failure. An intermediate failure of the temperature sensor can be detected, and the failed temperature sensor can be specified.

In the hot water supply system of the present invention, it is preferable that the controller periodically executes the first failure diagnosis operation and the second failure diagnosis operation during automatic hot water filling of the bath based on the accumulated amount of operation time of the hot water supply system. . The determination of the intermediate failure described above requires hot water supply with the mixing valve fully opened on the water side or fully open on the hot water side regardless of the set temperature of the hot water supply, and hot water is temporarily supplied at a temperature different from the set temperature. However, in the case of bath filling, even if hot water having a temperature different from the set temperature temporarily flows into the bath, if the hot water at the set temperature is finally filled in the bath, the user There is no inconvenience. According to this hot water supply system, it is possible to determine the intermediate failure of the temperature sensor without making the user feel inconvenience by performing the determination of the intermediate failure in a short time and thereafter performing the normal hot water filling operation. The temperature sensor that has failed can be identified.

The first failure diagnosis operation and the second failure diagnosis operation are detected by the temperature sensor determined to be faulty when the temperature difference between the temperature sensor determined to be faulty and all other temperature sensors is less than a specific temperature. and temperature, based on the average value of the temperature detected by other temperature sensors, further comprising the step of calculating a correction value of the temperature detected by the temperature sensor is determined that failure.

  According to the hot water supply system described above, the temperature difference between the temperature detected by the temperature sensor determined to be faulty and the average value of the temperatures detected by other temperature sensors is calculated as a correction value. By correcting the temperature detected by the temperature sensor determined to be faulty to be equal to the average value of the temperatures detected by other temperature sensors, the temperature sensor determined to be faulty can also detect the accurate temperature. . Even when the temperature sensor has an intermediate failure, it is possible to continue the hot water supply without replacing the temperature sensor.

The first failure diagnosis operation and the second failure diagnosis operation further include a step of stopping hot water supply when the temperature difference between the temperature sensor determined to be a failure and any of the other temperature sensors is equal to or higher than a specific temperature. . The specific temperature as used in this specification is 10 degreeC or more, for example. If the temperature difference between the temperature sensor determined to be faulty and another temperature sensor is large, there is a high possibility that the fault has a large output fluctuation such as disconnection or short circuit. In this case, it is preferable to replace the temperature sensor determined to be faulty with a new temperature sensor, rather than correcting the detected temperature of the temperature sensor determined to be faulty and continuing hot water supply. To stop. The safety of the hot water supply system can be ensured.

  According to the hot water supply system of the present invention, it is possible to provide a hot water supply system capable of detecting an intermediate failure of a temperature sensor and identifying a failed temperature sensor.

Preferred features of the embodiments described below are listed.
(First feature) The temperature difference of the temperatures detected by the respective temperature sensors when the temperature of the mixer is opened at the time of trial operation of the hot water supply system and water with a known temperature is supplied is stored. Thereafter, the temperature detected by each temperature sensor is output as a value corrected based on the stored temperature difference.

(First embodiment)
In FIG. 1, the schematic diagram of the hot water supply system 100 which is 1st Example of this invention is shown. The hot water supply system 100 is connected to a bath tub 66a, a hot water tap 66b, and the like, which are hot water use locations 66. The hot water supply system 100 includes a power generation unit 24, a hot water storage tank 18, a mixing unit 44, a remote controller 70, a controller 68, and the like.

  The power generation unit 24 is a power generation device using a solid polymer fuel cell. The power generation unit 24 generates power according to the power demand. When performing power generation, the power generation unit 24 drives the exhaust heat recovery pump 20. When the exhaust heat recovery pump 20 is driven, water is sucked out from the lower part of the hot water storage tank 18. The sucked water is heated by the generated heat in the exhaust heat recovery heat exchanger 22 and returned to the upper part of the hot water storage tank 18. The temperature of the hot water returned from the power generation unit 24 to the upper part of the hot water storage tank 18 is measured by the exhaust heat recovery thermistor 26 and output to the controller 68. When the temperature of the hot water returned to the upper part is low, the hot water storage tank 18 is bypassed by switching the three-way exhaust heat switching valve 28 to be returned to the power generation unit 24 and heated again.

  The hot water storage tank 18 stores hot water heated by the heat generated by the power generation unit 24. The hot water stored in the hot water storage tank 18 is used for hot water supply or bathing. A temperature stratification is formed inside the hot water storage tank 18, and hot water having a temperature higher than that of the lower part is stored in the upper part of the hot water storage tank 18. Therefore, even when the amount of heat stored in the hot water storage tank 18 is small, hot water can be used by discharging the hot water from the upper part of the hot water storage tank 18. A tank upper thermistor 32 for detecting the hot water temperature is provided at the upper part of the hot water storage tank 18, and the detected temperature is output to the controller 68.

  The lower part of the hot water storage tank 18 is connected to the water pipe (cold water supply source) 2 via the tank water supply path 16, the mixing unit 44 and the water supply path 4. A pressure reducing valve 6 is provided in the water supply path 4, and the water supply pressure from the water pipe 2 is adjusted. The upper part of the hot water storage tank 18 is connected to the hot water tap 66b via the tank hot water supply path 34, the mixing unit 44, and the first hot water supply path 48. The tank hot water supply path 34 is provided upstream of the connection part 42 with the mixing path 40, and the first hot water supply path 48 is provided downstream of the connection part 42 with the mixing path 40. When the hot water tap 66b is opened, the hot water in the hot water storage tank 18 is pushed up from the lower part to the upper part by the water supply pressure, and the hot water is discharged from the upper part of the hot water storage tank 18 to the tank hot water supply path 34. Hot water discharged from the hot water storage tank 18 is mixed with tap water by the mixing unit 44, adjusted to a desired temperature, and then supplied to the hot water tap 66b.

  The mixing unit 44 mixes tap water with hot water discharged from the upper part of the hot water storage tank 18 to adjust the temperature to a desired temperature. The mixing unit 44 branches a part of tap water flowing from the water supply path 4 to the tank water supply path 16 to the mixing path 40 and mixes it with hot water flowing from the tank hot water supply path 34 to the first hot water supply path 48. A mixer (mixing valve) 14 is provided at a connecting portion of the water supply path 4, the tank water supply path 16, and the mixing path 40. The mixer 14 has a built-in stepping motor, and when this is driven, the opening of the tank water supply path 16 and the opening of the mixing path 40 are adjusted to mix with the flow rate of tap water flowing into the tank water supply path 16. The ratio of the flow rate of tap water flowing to the path 40 is adjusted. The flow rate of tap water supplied from the mixing unit 44 to the lower part of the hot water storage tank 18 is equal to the flow rate of hot water discharged from the upper part of the hot water storage tank 18 to the mixing unit 44. Therefore, by adjusting the ratio of the flow rate of tap water branched to the tank water supply path 16 by the mixer 14 and the flow rate of tap water branched to the mixing path 40, the tap water from the mixing path 40 and the tank hot water supply path 34 are adjusted. The mixing ratio of hot water can be adjusted.

  The tank hot water supply path (hot water supply path) 34 is provided with a tank solenoid valve 36 and a hot water supply thermistor (hot water supply temperature sensor) 38. The tank solenoid valve 36 is controlled by a controller 68, and opens and closes when a built-in solenoid is driven. In the state where the tank solenoid valve 36 is closed, even if the hot-water tap 66b is opened, hot water is not discharged from the hot water storage tank 18, and tap water is supplied to the hot-water tap 66b via the water supply path 4 and the mixing path 40. . The hot water supply thermistor 38 detects the temperature of hot water flowing through the tank hot water supply path 34 and outputs it to the controller 68.

  A hot water supply thermistor 46 is provided in the first hot water supply path (hot water supply path) 48. The hot water thermistor 46 detects the temperature of the hot water flowing through the first hot water supply path 48 and outputs it to the controller 68.

  The water supply path 4 is provided with a water supply thermistor (water supply temperature sensor) 8, a hot water supply amount sensor 10, and a hot water supply amount servo 12. The water supply thermistor 8 detects the temperature of the tap water flowing through the water supply path 4 and outputs it to the controller 68. The hot water supply amount sensor 10 detects the flow rate of tap water flowing through the water supply path 4 and outputs it to the controller 68. Since the flow rate of tap water flowing from the water supply path 4 to the mixing unit 44 is equal to the flow rate of hot water flowing from the mixing unit 44 to the first hot water supply path 48, the flow rate detected by the hot water supply amount sensor 10 is supplied from the mixing unit 44. It is equal to the flow rate of hot water. The hot water supply amount servo 12 controls the flow rate of tap water flowing through the water supply path 4. Since the flow rate of tap water flowing from the water supply path 4 to the mixing unit 44 is equal to the flow rate of hot water flowing from the mixing unit 44 to the first hot water supply path 48, the mixing unit is controlled by controlling the flow rate of tap water flowing through the water supply path 4. The flow rate of the hot water flowing from 44 to the first hot water supply path 48 can be controlled.

  On the upper and lower portions of the hot water storage tank 18, a path 29 a is provided through a three-way tank switching valve 30 toward a heat source machine (not shown). In the heat source machine, hot water in the hot water storage tank 18 is heated as necessary. The heated hot water is returned to the upper part of the hot water storage tank 18 from the path 29b. The hot water heated by the heat source device may be returned directly to the hot water storage tank 18, for example, heat exchange is performed with a heat medium used as a heat source of the heating terminal, and the floor heating or bath reheating is performed. In some cases, the hot water tank 18 is returned to the hot water storage tank 18 after being used. The hot water tank 18 may be supplied with hot water heated by the heat source device, or may be supplied with hot water heated by the power generation unit 24.

  A second hot water supply path (hot water supply path) 62 is connected to the bath tub 66a. A bath pump 54, a bath water flow switch 56, and a bath thermistor 58 are provided in the second hot water supply path 62. When the bath pump 54 is driven by the controller 68, hot water is sucked from the bath tub 66a into the second hot water supply path 62. The hot water sucked out from the bath tub 66a is heated by the bath heat exchanger 60 and returned to the tub 66a. The temperature of the hot water heated by the bath heat exchanger 60 is detected by a bathing thermistor 64.

  The second hot water supply path 62 communicates with the first hot water supply path 48 via the hot water filling valve 50 and the hot water filling amount sensor 52. By opening the hot water filling valve 50, hot water filling to the bathtub 66a is performed. The hot water filling valve 50 is controlled by the controller 68. The hot water amount sensor 52 detects the amount of hot water flowing from the first hot water supply path 48 to the second hot water supply path 62. The temperature of warm water from the first hot water supply path 48 toward the second hot water supply path 62 is detected by a bath thermistor 58.

  The remote controller 70 includes a display board and operation switches. The user can operate the remote controller 70 to input ON / OFF of the operation of the hot water supply system 100, start / end of various operation modes, a hot water supply set temperature, a bath set temperature, and the like. The remote controller 70 can communicate with the controller 68 and transmits the user's operation contents to the controller 68.

  The controller 68 stores a control program. The controller 68 receives an operation signal from the remote controller 70, a detection signal from the hot water supply amount servo 12, detection signals from various thermistors, and the like. The controller 68 processes the input signal with a control program, and controls various pumps, various valves, the mixer 14 and the like. The controller 68 has a built-in timer counter.

  FIG. 2 shows a flowchart for explaining operations performed during a trial operation in hot water supply system 100. In the flowchart, TH represents a thermistor.

  In step S102, it is confirmed whether or not the automatic hot water filling operation of the bath tub 66a is started. If it has been started (YES in step S102), the process proceeds to step S104. If not started (NO in step S102), the process waits until the hot water filling operation of the bath tub 66a is started.

  In step S104, the hot water filling valve 50 is opened. The first hot water supply path 48 and the second hot water supply path 62 communicate with each other. Moreover, the opening degree of the mixer 14 is fully opened on the water side. Water flows from the water pipe 2 toward the bath tub 66a. Further, the hot water supply amount servo 12 is controlled to adjust the flow rate detected by the hot water supply amount sensor 10 (the flow rate of water flowing through the water supply path 4) to 5 liters / min.

  In step S106, the temperatures detected in each of the water supply thermistor 8, the hot water thermistor 46, and the bath thermistor 58 are compared. Since the mixer 14 is fully open on the water side, the temperature of the water flowing on the path where each thermistor is provided (the path from the water pipe 2 toward the bath tub 66a) is equal.

  In step S108, it is determined whether there is a temperature difference (temperature variation) between the temperatures compared in step S106. For example, when the detection temperature of the water supply thermistor 8 is 19 ° C., the detection temperature of the hot water thermistor 46 is 20 ° C., and the detection temperature of the bath thermistor 58 is 20 ° C., the detection temperature of the water supply thermistor 8 and the detection of the hot water thermistor 46 and the bath thermistor 58 are detected. Since there is a temperature difference of 1 ° C between the temperatures, it is determined that there is a temperature difference. If there is a temperature difference (YES in step S108), the process proceeds to step S110. If there is no temperature difference (NO in step S108), the process proceeds to step S112.

  In step S110, the detected temperature difference is stored for each thermistor. At this time, when considering safety, it is preferable to store the temperature difference based on the highest temperature. This is because it is less likely that the hot water is accidentally discharged when the correction is made according to the detected temperature on the high temperature side. When the temperature difference is stored, the process proceeds to step S112, and the automatic hot water filling operation at the time of trial operation is terminated. Thereafter, the temperature detected by each thermistor is corrected based on the stored temperature difference. It is possible to correct the temperature variation during the trial operation of each thermistor and reflect the corrected value in the detected temperature during the normal operation of the hot water supply system 100. For example, when the detected temperature of the water supply thermistor 8 is 19 ° C., the detected temperature of the hot water thermistor 46 is 20 ° C., and the detected temperature of the bath thermistor 58 is 20 ° C., the temperature of the water supply thermistor is based on 20 ° C. (the highest temperature). Store the difference as plus 1 ° C. Thereafter, a value obtained by adding a correction of plus 1 ° C. to the temperature detected by the water supply thermistor 8 is output as the temperature detected by the water supply thermistor 8.

  In step S112, the hot water filling valve 50 is closed, and the automatic hot water filling operation at the time of the trial operation is finished.

  FIG. 3 is a flowchart illustrating an operation for determining an intermediate failure when the bath tub 66a is filled in the hot water supply system 100 in the present embodiment.

  In step S152, it is confirmed whether or not the automatic hot water filling operation of the bath tub 66a is started. If started (YES in step S152), the process proceeds to step S154. If not started (NO in step S152), the process waits until the hot water filling operation of the bath 66a is started.

  In step S154, it is determined whether or not the intermediate failure check mode is set. The intermediate failure check mode is periodically started based on the accumulated amount of operation time of the hot water supply system 100. If the intermediate failure check mode is set (YES in step S154), the process proceeds to step S158. If not (NO in step S154), the process proceeds to step S156.

  In step S156, it is determined that there is no need to check the intermediate failure of each temperature sensor, and a normal hot water filling operation is performed.

  In step S158, the hot water filling valve 50 is opened. The first hot water supply path 48 and the second hot water supply path 62 communicate with each other. Moreover, the opening degree of the mixer 14 is fully opened on the water side. Water flows from the water pipe 2 toward the bath 66a. Further, the hot water supply amount servo 12 is controlled to adjust the flow rate detected by the hot water supply amount sensor 10 (the flow rate of water flowing through the water supply path 4) to 5 liters / min. By checking the intermediate failure at such a small flow rate, it is possible to minimize the influence on the subsequent hot water filling. There is no inconvenience to users.

  In step S160, the temperatures detected in each of the water supply thermistor 8, the hot water thermistor 46, and the bath thermistor 58 are compared. Since the mixer 14 is fully open on the water side, the temperature of the water flowing on the path where each thermistor is provided (the path from the water pipe 2 toward the bath tub 66a) is equal.

  In step S162, it is determined whether an intermediate failure has been detected. In the temperature comparison performed in step S160, if the temperature detected by one thermistor is 2 ° C. higher than the temperature detected by any other thermistor, the thermistor from which the temperature difference has been detected is determined to be an intermediate failure. To do. For example, when the detected temperature of the feed water thermistor 8 is 25 ° C., the detected temperature of the hot water thermistor 46 is 28 ° C., and the detected temperature of the bath thermistor 58 is 25 ° C., only the detected temperature of the hot water thermistor 46 is 3 ° C. higher than the detected temperature of other thermistors. Since it is high, it is determined that the hot water thermistor 46 is an intermediate failure. If an intermediate failure is detected (YES in step S162), the process proceeds to step S164. If no intermediate failure is detected (NO in step S162), the process returns to step S156, and a normal hot water filling operation is performed.

  In step S164, it is determined whether or not the temperature difference between the thermistor determined to be the intermediate failure and any of the other thermistors is 10 ° C. or more. If a temperature difference of 10 ° C. or more is detected (YES in step S164), the process proceeds to step S166. If not detected (NO in step S164), the process proceeds to step S168.

  In step S166, an abnormality of the thermistor is notified, the hot water filling valve 50 is closed, and hot water filling is stopped. When the temperature difference between the thermistor determined to be faulty and any of the other thermistors is 10 ° C. or more, the thermistor determined to be faulty is likely to be disconnected or short-circuited. It is desirable to stop the hot water filling and replace the thermistor determined to be faulty with a new thermistor.

  In step S168, the temperature difference between the detected temperature in the thermistor determined to be a failure and the average value of the detected temperatures in other thermistors is calculated as a correction value. Thereafter, the temperature detected by the temperature sensor determined to be faulty is corrected based on the correction value and output. For example, if the temperature difference between the detected temperature of the thermistor determined to be faulty and the average value of the detected temperatures of other thermistors is 3 ° C, the temperature detected by the thermistor determined to be faulty is 3 ° C thereafter. Corrected and output as detected temperature. When the correction value is calculated, the process returns to step S156 and a normal hot water filling operation is performed.

  In the hot water supply system 100 according to the present embodiment, when the bath tub 66a is filled, the opening of the mixer 14 is fully opened, and an intermediate failure determination of each thermistor is performed. Since an intermediate failure is determined using three thermistors (water supply thermistor 8, hot water thermistor 46, bath thermistor 58), when any one of the thermistors fails, the temperature detected by the other two thermistors By comparing the temperature differences, it is possible to identify the thermistor that has failed. An intermediate failure of the thermistor can be detected, and the thermistor that has failed can be identified. In addition, an abnormality monitoring thermistor is provided downstream of the hot water supply path 48, and the opening of the mixer 14 is fully opened when hot water is supplied from the hot water tap 66b. May be used to determine an intermediate failure.

(Second embodiment)
Since the hot water supply system of the second embodiment has the same structure as the hot water supply system 100 of the first embodiment, the description thereof is omitted. Since the operation performed during the trial operation of the hot water supply system according to the second embodiment is the same as the procedure shown in FIG. FIG. 4 shows a flowchart for explaining the operation of determining an intermediate failure by fully opening the mixer 14 at the hot water side when the bath tub 66a is filled in the hot water supply system of the second embodiment.

  In step S202, it is confirmed whether the automatic hot water filling operation of the bath tub 66a is started. If it has been started (YES in step S202), the process proceeds to step S204. If not started (NO in step S202), the process waits until the hot water filling operation of the bath 66a is started.

  In step S204, it is determined whether or not the intermediate failure check mode is set. The intermediate failure check mode is periodically started based on the accumulated amount of operation time of the hot water supply system 100. If the intermediate failure check mode is set (YES in step S204), the process proceeds to step S208. If not (NO in step S204), the process proceeds to step S206.

  In step S206, it is determined that there is no need to check the intermediate failure of each temperature sensor, and a normal hot water filling operation is performed.

  In step S208, the hot water filling valve 50 is opened. The first hot water supply path 48 and the second hot water supply path 62 communicate with each other. Moreover, the opening degree of the mixer 14 is fully opened on the hot water side. Hot water flows from the hot water storage tank 18 toward the bath 66a. Further, the hot water supply amount servo 12 is controlled to adjust the flow rate detected by the hot water supply amount sensor 10 (the flow rate of water flowing through the water supply path 4) to 5 liters / min. When the opening of the mixer 14 is fully open on the hot water side, the flow rate of water flowing through the water supply path 4 and the flow rate of hot water flowing through the tank hot water supply path 34 are equal, so the flow rate of hot water flowing through the tank hot water supply path 34 is also 5 liters / min. Adjusted. By checking the intermediate failure at such a small flow rate, it is possible to minimize the influence on the subsequent hot water filling. There is no inconvenience to users.

  In step S210, the temperature detected in each of hot water supply thermistor 38, hot water thermistor 46, and bath thermistor 58 is compared. Since the mixer 14 is fully open on the hot water side, the temperature of the hot water flowing on the path where each thermistor is provided (the path from the hot water storage tank 18 to the bath tub 66a) is equal.

  In step S212, it is determined whether an intermediate failure has been detected. In the temperature comparison performed in step S210, if the temperature detected by one thermistor is greater than 2 ° C. than the temperature detected by any other thermistor, the thermistor from which the temperature difference has been detected is determined to be an intermediate failure. To do. If an intermediate failure is detected (YES in step S212), the process proceeds to step S214. If no intermediate failure is detected (NO in step S212), the process returns to step S206, and a normal hot water filling operation is performed.

  In step S214, it is determined whether or not the temperature difference between the thermistor determined to be an intermediate failure and any of the other thermistors is 10 ° C. or more. If a temperature difference of 10 ° C. or more is detected (YES in step S214), the process proceeds to step S216. If not detected (NO in step S214), the process proceeds to step S218.

  In step S216, the thermistor abnormality is notified, the hot water filling valve 50 is closed, and hot water filling is stopped. When the temperature difference between the thermistor determined to be faulty and any of the other thermistors is 10 ° C. or more, the thermistor determined to be faulty is likely to be disconnected or short-circuited. It is desirable to stop the hot water filling and replace the thermistor determined to be faulty with a new thermistor.

  In step S218, the temperature difference between the detected temperature in the thermistor determined to be a failure and the average value of the detected temperatures in other thermistors is calculated as a correction value. Thereafter, the temperature detected by the temperature sensor determined to be faulty is corrected based on the correction value and output. When the correction value is calculated, the process returns to step S206, and a normal hot water filling operation is performed.

  In the hot water supply system of the present embodiment, when the bath tub 66a is filled with water, the opening degree of the mixer 14 is fully opened, and an intermediate failure determination of each thermistor is performed. Since an intermediate failure is determined using three thermistors (a hot water supply thermistor 38, a hot water thermistor 46, and a bath thermistor 58), when any one of the thermistors fails, the temperature detected by the other two thermistors By comparing the temperature differences, it is possible to identify the thermistor that has failed. An intermediate failure of the thermistor can be detected, and the thermistor that has failed can be identified. In addition, an abnormality monitoring thermistor is provided downstream of the hot water supply path 48, and the opening of the mixer 14 is fully opened when hot water is supplied from the hot water tap 66b. May be used to determine an intermediate failure.

As mentioned above, although the Example of this invention was described in detail, these are only illustrations and do not limit a claim. The technology described in the claims includes various modifications and changes of the specific examples illustrated above.
For example, in the hot water supply system according to the embodiment of the present invention, three thermistors are provided on the first hot water supply path 48 and the second hot water supply path 62, but four or more thermistors may be provided. In the hot water supply system according to the embodiment of the present invention, intermediate failure determination is performed using three thermistors. However, intermediate failure determination may be performed using a total of four thermistors including the bathing thermistor 64.
The technical elements described in this specification or the drawings exhibit technical usefulness alone or in various combinations, and are not limited to the combinations described in the claims at the time of filing. In addition, the technology exemplified in this specification or the drawings can achieve a plurality of objects at the same time, and has technical usefulness by achieving one of the objects.

The schematic diagram of the hot water supply system 100 which is 1st Example is shown. The flowchart explaining the operation | movement at the time of the trial run of the hot water supply system 100 is shown. The flowchart explaining the operation | movement which judges the middle failure by making the mixer into the water side full open in the hot water supply system 100 is shown. The flowchart explaining the operation | movement which judges a middle failure by making the mixer into the hot water side full open in the hot water supply system 100 is shown.

Explanation of symbols

2: Water pipe (cold water supply source)
4: Water supply path 6: Pressure reducing valve 8: Water supply thermistor (water supply temperature sensor)
10: Hot water amount sensor 12: Hot water amount servo 14: Mixer (mixing valve)
16: Tank water supply path 18: Hot water storage tank 20: Waste heat recovery pump 22: Waste heat recovery heat exchanger 24: Power generation unit 26: Waste heat recovery thermistor 28: Three-way exhaust heat switching valves 29a, 29b: Path 30: Three-way tank switching Valve 32: Tank upper thermistor 34: Tank hot water supply path 36: Tank solenoid valve 38: Hot water supply thermistor (hot water temperature sensor)
40: Mixing path 42: Connection between tank hot water supply path, mixing path and first hot water supply path 44: Mixing unit 46: Hot water thermistor 48: First hot water supply path 50: Hot water filling valve 52: Hot water filling water amount sensor 54: Bath pump 56: Bath water flow switch 58: Bath thermistor 60: Bath heat exchanger 62: Second hot water supply path 64: Bath thermistor 66: Hot water use location 66a: Bath tub 66b: Hot water tap 68: Controller 70: Remote control

Claims (2)

A hot water supply system capable of storing heated hot water and supplying hot water using the stored hot water,
A hot water storage tank for storing hot water,
A hot water supply path for supplying hot water from the upper part of the hot water storage tank to the hot water tap ,
A second hot water supply path that branches from the hot water supply path and supplies hot water to the bath tub;
A hot water filling valve that is provided on the second hot water supply path and opens and closes the second hot water supply path;
A water supply path for supplying cold water from a cold water supply source to the lower part of the hot water storage tank;
A hot water supply path and a water supply path upstream of a branching section with the second hot water supply path are connected, and a mixing path for mixing cold water supplied from a cold water supply source with hot water supplied from a hot water storage tank;
A mixing valve that is provided on the mixing path and adjusts a mixing ratio between a flow rate of cold water supplied from a cold water supply source and a flow rate of hot water supplied from a hot water storage tank;
A water supply temperature sensor that is provided on the water supply path upstream from the connection with the mixing path and detects the temperature of the water supplied from the cold water supply source;
A hot water supply temperature sensor that is provided on the hot water supply path upstream from the connection with the mixing path, and that detects the temperature of hot water supplied from the hot water storage tank;
Mixing has been eclipsed set on the upstream of the hot water supply path of the branch portion of the second hot-water supply path A downstream from the connecting portion of a path, and the hot water temperature sensor for detecting the temperature of the water flowing through the hot water supply path ,
A bath temperature sensor which is provided on the second hot water supply path and detects the temperature of water flowing through the second hot water supply path;
A detection signal of a hot water temperature sensor, a hot water temperature sensor, a hot water temperature sensor, and a bath temperature sensor is input, and a controller for controlling the hot water filling valve and the mixing valve is provided .
The controller can execute a first failure diagnosis operation and a second failure diagnosis operation,
The first fault diagnosis operation is
Opening the hot water filling valve and opening the mixing valve to the water side fully open, and comparing the temperatures detected by the feed water temperature sensor, the hot water temperature sensor and the bath temperature sensor , respectively ;
When it is detected a temperature difference of more than a predetermined temperature between one temperature sensor and other one temperature sensor in the steps of determining a failure of the temperature sensor in which the temperature difference is detected,
When the temperature difference between the temperature sensor determined to be the failure and all other temperature sensors is less than a specific temperature, the temperature detected by the temperature sensor determined to be the failure and the other temperature sensors a step of based on the average value of the temperature, to calculate a correction value of the temperature detected by the temperature sensor is determined that the failure was,
Stopping the hot water supply when the temperature difference between the temperature sensor determined to be the failure and any other temperature sensor is equal to or higher than a specific temperature ,
The second fault diagnosis operation is
Opening the hot water filling valve and opening the mixing valve fully open on the hot water side, and comparing the temperatures detected by the hot water supply temperature sensor, the hot water temperature sensor, and the bath temperature sensor;
When a temperature difference of a predetermined temperature or more is detected between one temperature sensor and any other temperature sensor, the temperature sensor from which the temperature difference is detected is determined to be a failure;
When the temperature difference between the temperature sensor determined to be the failure and all other temperature sensors is less than a specific temperature, the temperature detected by the temperature sensor determined to be the failure and the other temperature sensors Calculating a correction value of the temperature detected by the temperature sensor determined to be the failure based on the average value of the detected temperature;
Including a step of stopping hot water supply when a temperature difference between the temperature sensor determined to be the failure and any other temperature sensor is equal to or higher than a specific temperature.
Hot water system. Wherein the controller is based on the integrated amount of operating time of the hot water supply system, when the automatic water filling operation of the bath, run first failure diagnosis operation and the second failure diagnosis operation periodically, according to claim 1 hot water system.

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