JP2000297964A - Hot-water supplier - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a hot-water supplier, capable of detecting a faulty detection of a temperature detecting device, which could not be detected by a conventional trouble diagnosing function, and capable of detecting a fault in the case of deterioration of a sensitivity. SOLUTION: When a hot-water supplying cock is opened and a combustion requesting condition is established thereby necessitating combustion, the period of time from the previous use to this use during which a hot-water supplier is not used is confirmed. When the period of time during which the supplier has not been used is found to be less than a predetermined period of time from the result of the confirmation, a burner is ignited and the supply of hot-water is started. When the same period of time exceeds the predetermined period of time, the combustion of the burner is brought into a standby condition and a water feeding thermistor as well as a hot-water supplying thermistor are stabilized at a water inlet temperature, then, the thermistors are decided whether they are normal or abnormal by comparing a temperature Tc, detected by the water feeding thermistor, with the temperature Tm, detected by the hot-water supplying thermistor, and when the thermistors are normal, the burner is ignited and the supply of hot-water is started. When the thermistors are abnormal, process is not advanced to the burning operation of the burner and an error indication is indicated on a remote controller.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention comprises a temperature detecting device such as a water temperature detecting device for detecting a water temperature and a hot water temperature detecting device for detecting a hot water temperature, and a water detecting device for confirming water entering a water heater. Water heater.

[0002]

2. Description of the Related Art Conventionally, the operation of a water heater has been controlled by detecting the temperature of water supplied from a water supply source by a water supply thermistor, detecting the flow rate of water by a water flow sensor, and supplying water through a heat exchanger heated by a burner. A general control method is to calculate the required combustion heat of the burner by detecting the temperature with a hot water supply thermistor.

FIG. 1 is a schematic configuration diagram of a water heater. The water heater includes a water heater main body 1, a water supply pipe 2 for supplying water from the water supply source to the water heater main body 1, and water heated in the water heater main body 1 through a heat exchanger 3. And a hot water supply pipe 4 for supplying the hot water to the hot water tap 26. Furthermore, a bypass pipe 5 branched from the water supply pipe 2 in the water heater main body 1 and connected to the hot water supply pipe 4 without passing through the heat exchanger 3, and a junction of the bypass pipe 5 and the hot water supply pipe 4 are provided with a heat exchanger. Hot water heated in 3,
A mixing valve 6 is provided which controls mixing of water sent from the bypass pipe 5 by a stepping motor M driven based on a command pulse.

The water supply pipe 2 has a water supply thermistor 7 for detecting a water supply temperature Tc from a water supply source, a water quantity sensor 8 for confirming the quantity Q of water, and a heat upstream of the mixing valve 6 of the hot water supply pipe 4. A heat exchange thermistor 9 for detecting the temperature Th at the outlet of the heat exchanger 3 heated by the combustion heat of the burner 11 when passing through the exchanger 3, and the temperature of the mixed hot water mixed downstream of the mixing valve 6. A hot water supply thermistor 10 for detecting Tm is provided. The burner 11 includes a fan 12 for supplying air required for combustion, a spark plug 13 and an igniter 14 required for ignition, and a Cds 15 for confirming the presence or absence of a flame. An oil supply pipe 16 for supplying fuel to the burner 11 is provided. The fuel supplied by the oil supply pipe 16 is supplied to a return nozzle 18 by a pressurizing pump 17, a part of the fuel is ejected, and the fuel is supplied in the middle of a return path. The amount of combustion heat is varied by controlling the amount of oil regulating valve 19 provided in the nozzle to increase or decrease the amount of jet from the return nozzle 18. On the other hand, the reheating pipe 21 is connected to the end of the bathtub 2.
2, a circulation pump 23 for circulating hot water in the bathtub 22, a flow sensor 24 for detecting the circulation, and a bath temperature thermistor 25 for detecting the temperature of the hot water in the bathtub 22.

The operation switch 2 is provided on the remote controller 28.
9. Hot water supply temperature setting switch 30 for adjusting the set temperature Ts of the hot water supplied from the hot water tap 26, and bath setting temperature switch 3 for adjusting the reheating setting temperature Tfs of the hot water in the bathtub 22
3, a reheating switch 31 that is turned on when reheating is performed, and a display unit 32 that displays the hot water supply set temperature Ts and the reheating setting temperature Tfs.

[0006] The above hot water supply device further receives detection signals (Tc, Q, Th, Tm, Ts) from the water supply thermistor 7, water amount sensor 8, heat exchange thermistor 9, hot water supply thermistor 10, and hot water supply temperature setting switch 30. A control unit 27 is also provided for controlling the amount of combustion heat of the burner 11, the fan 12, the mixing valve 6, and the like. Further, the controller 27 can detect a failure of each thermistor installed in the water heater as a failure diagnosis function.

[0007]

In the conventional water heater, the failure of each thermistor can be detected by the failure diagnosis function. However, this failure detection is performed when the resistance value of the thermistor is extremely small. Only when it is large, actually when the thermistor is disconnected or short-circuited. In the case of an incomplete defect that cannot be distinguished from normal use, such as erroneous temperature detection due to impurity adhesion to a thermistor or a device contact defect different from such a defect, or sensitivity deterioration, etc., use the failure diagnosis function to detect it. May not be possible.

[0008] If the water heater is used in a state where the thermistor is halfway defective such that it is not distinguished from normal use such as erroneous temperature detection or sensitivity deterioration, etc., the user sets the hot water supply set temperature Ts set by the remote controller 28. In this case, hot or low-temperature hot water is supplied from the hot-water tap 26.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a method for detecting a temperature error or a sensitivity deterioration in which a failure of a thermistor cannot be detected by a conventional failure diagnosis function. An object of the present invention is to provide a water heater capable of performing detection.

[0010]

Means for Solving the Problems To achieve the above object, a first aspect of the present invention is a water supply temperature detection device for detecting a water supply temperature, a water supply temperature detection device for detecting a water supply temperature, and confirmation of water input to a water heater. In a water heater equipped with a water detection device, even when a request for combustion of the water heater is confirmed by checking the water input of the water detection device, the water heater does not proceed to the burner combustion operation, and enters a standby state in a water flowing state. Based on the obtained incoming water temperature, the water supply temperature detecting device and the hot water temperature detecting device are judged to be good or bad, and if there is no abnormality in the good or bad judgment, an operation of performing burner combustion is provided. And the like, the temperature detection device failure can be detected even in a halfway state that cannot be distinguished from the normal use.

According to a second aspect of the present invention, the condition for waiting for a water-flowing state without proceeding to the burner combustion operation until the temperature detector is judged to be good or bad is that a predetermined time elapses or a predetermined integration of the water input amount is performed. Since the amount is reached or either one of the conditions is satisfied, the temperature detected by the temperature detection device that performs the pass / fail determination can be reliably stabilized at the incoming water temperature.

[0012] The third aspect of the present invention is characterized in that the quality judgment of the temperature detecting device is performed only when the use of the water heater has not been confirmed for a predetermined time since the end of the previous use of the water heater.
Even when the water heater is used intermittently, it is possible to prevent a drop in the tapping performance, and the user can comfortably use the water heater.

According to a fourth aspect of the present invention, the quality determination of the temperature detecting device is performed each time the cumulative use time of the water heater exceeds a predetermined cumulative time, and the use of the water heater for a predetermined time from the end of the previous use of the water heater is determined. Is performed only when the temperature is not confirmed, and the determination of the quality of the temperature detecting device is performed each time the integrated amount of water flowing to the water heater reaches a predetermined integrated amount, and It is characterized in that it is performed only when the use of the water heater has not been confirmed for a predetermined time since the end of using the water heater. And the user can use the water heater comfortably.

[0014]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a schematic configuration diagram of a water heater according to an embodiment of the present invention, which is the same as a conventional water heater.

FIG. 2 is a flowchart of a process for judging the quality of the thermistor according to the first embodiment of the present invention.
First, when the operation switch 29 of the remote controller 28 is pressed and the hot water tap 26 is opened during the operation of the water heater main body 1 (step S1), the water quantity sensor 8 detects the flow rate, the water supply thermistor 7 detects the incoming water temperature, and the hot water temperature is detected. The required amount of heat is calculated from the hot water supply set temperature set by the setting switch 30, and it is determined whether the combustion request condition is satisfied (step S).
2). If the combustion request condition is satisfied and combustion is necessary, burner combustion is set to a standby state (step S3),
Wait for a predetermined time determined by the control unit 27 to elapse, or until the water flow reaches a predetermined integrated amount,
After the water supply thermistor 7 and the hot water supply thermistor 10 are stabilized at the incoming water temperature (step S4), the quality of the thermistor is determined by comparing Tc detected by the water supply thermistor 7 with Tm detected by the hot water supply thermistor 10 (step S5). ). The pass / fail judgment condition is that if the temperature difference ΔT between Tc and Tm is within a predetermined temperature range determined by the control unit 27, it is determined that the temperature difference is normal, and if the temperature difference ΔT is out of the range, it is determined to be normal (step S6). If so, the burner is burned and hot water supply is started (step S7).
8 is displayed on the display unit 32 (step S8).

In the present embodiment, in step S4, the process waits until a predetermined time determined by the control unit 27 elapses or until the water flow reaches a predetermined integrated amount, and the water supply thermistor 7 and the hot water supply thermistor 10 are turned off. Although the process proceeds to step S5 after stabilizing at the incoming water temperature, it is also possible to perform the pass / fail judgment of step S5 when the detected temperature change of each thermistor due to the incoming water temperature becomes longer with the passage of time and the detected temperature becomes stable. good.

FIG. 3 is a flowchart of a process for determining the quality of the thermistor according to the second embodiment of the present invention.
First, when the operation switch 29 of the remote controller 28 is pressed and the hot-water tap 26 is opened while the water heater main body 1 is in operation (step S9), the water sensor 8 detects the flow rate, the water-supply thermistor 7 detects the incoming water temperature, and the hot-water temperature is detected. The required heat amount is calculated from the hot water supply set temperature set by the setting switch 30, and it is determined whether the combustion request condition is satisfied (step S).
10). If the combustion request condition is satisfied and combustion is required, the control unit 27 checks the unused time t during which the water heater was not used from the time t1 when the water heater was used last time to the time t2 when the water heater was used this time. (Step S11). If the unused time t does not exceed the predetermined time tss determined by the control unit 27 as a result of the confirmation, the burner is burned and hot water supply is started (step S16). Predetermined time ts
If s has elapsed, the burner combustion is set to a standby state (step S12), and the water supply thermistor 7 and the hot water supply thermistor 10 are stabilized at the incoming water temperature as in the description of FIG. 2 (step S13). By comparing Tc detected by the water supply thermistor 7 and Tm detected by the hot water supply thermistor 10, the quality of the thermistor is determined (steps S14 and S15). If the thermistor is normal, the burner is burned to start hot water supply. (Step S16) If the thermistor is defective, the process does not proceed to the burner combustion operation, and an error is displayed on the display unit 32 of the remote controller 28 (Step S17).

In step S11, the control unit 27 determines whether to check the unused time t.
This is for preventing the quality check of the thermistor from being performed every time when the opening and closing of the device is frequently performed. If the quality of the thermistor is determined frequently, even if the hot water tap 26 is opened to use hot water, it takes time for hot water to be supplied from the hot water tap 26 because burner combustion is delayed. For example, as in the case of using a shower in a bathroom,
When the water heater is opened and closed and the water heater is used intermittently, once the hot water tap 26 is closed, the hot water tap 26 is opened again, and the hot water is re-discharged, the time required for the burner to burn by performing a pass / fail judgment of the thermistor. Is required, and the hot water is supplied at a temperature lower than the hot water supply temperature set by the remote controller 28, and the user may feel uncomfortable. Therefore, in order to prevent the above problem, the unused time t is set to, for example, 6 hours by the determination in the step S11.
If the interval between the last use of the water heater and the current use is within 6 hours, the quality of the thermistor is not determined. Therefore, even if the user uses the water heater intermittently in the shower or kitchen, You can prevent unpleasant thoughts.

FIG. 4 is a flowchart of a process for determining the quality of the thermistor according to the third embodiment of the present invention.
First, when the operation switch 29 of the remote controller 28 is pressed and the hot-water tap 26 is opened during the operation state of the water heater main body 1 (step S18), the water amount sensor 8 detects the flow rate, the water supply thermistor 7 detects the incoming water temperature, and the hot water temperature is detected. The required amount of heat is calculated from the hot water supply set temperature set by the setting switch 30,
It is determined whether the combustion request condition is satisfied (step S19). If the combustion request condition is satisfied and combustion is necessary, the accumulated time using the water heater is checked from the time when the quality of the thermistor was determined last time (step S20). If the predetermined integration time determined by the control unit 27 has not elapsed, the burner is burned to start hot water supply (step S26). If the predetermined accumulated time has elapsed, the unused time t in which the water heater was not used from the previous time t1 when the water heater was used to the time t2 this time is used is confirmed (step S21).
Subsequent operations are performed in the same manner as described with reference to FIG.

In step S20, the quality of the thermistor is determined every time the predetermined integration time determined by the control unit 27 is exceeded. Until the time is reached, the predetermined integration time for determining the quality of the thermistor is 200
It is possible to set the predetermined integration time every 100 hours when the usage integration time becomes 1000 hours or more.

FIG. 5 is a flowchart of a process for determining the quality of the thermistor according to the fourth embodiment of the present invention.
First, when the operation switch 29 of the remote controller 28 is pressed and the hot water tap 26 is opened during the operation of the water heater main body 1 (step S28), the water amount sensor 8 detects the flow rate, the water supply thermistor 7 detects the incoming water temperature, and the hot water temperature is detected. The required amount of heat is calculated from the hot water supply set temperature set by the setting switch 30,
It is determined whether the combustion request condition is satisfied (step S29). If the combustion request condition is satisfied and combustion is necessary, the cumulative amount of water that has passed through the water heater since the last time the quality of the thermistor was determined is checked (step S30). On the other hand, if the integrated water flow amount has not reached the predetermined integrated amount determined by the control unit 27, the burner is burned to start hot water supply (step S36). When the predetermined integrated amount has been reached, t
The unused time t during which the water heater was not used from 1 to the current use time t2 is checked (step S31), and the subsequent operation is the same as the procedure described in FIG. To do.

In the step S30, the quality of the thermistor is judged every time the accumulated amount exceeds the predetermined accumulated amount determined by the control unit 27. For example, the accumulated amount of water passage is determined according to the usage period of the water heater. Until the amount reaches 100,000 liters, the predetermined integrated amount for judging the quality of the thermistor is set to every 10,000 liters.
The predetermined integrated amount can be set every 5,000 liters.

In the embodiment of the present invention, the quality of the thermistor is determined by the water supply thermistor 7 and the hot water supply thermistor 10.
However, the present invention is not limited to such an embodiment, and can be applied to other thermistors attached to the water passage in the water heater main body 1. Thermistor 4, Boiling prevention thermistor 2
The pass / fail judgment can be similarly performed for 0, and the pass / fail judgment of all the thermistors can be performed simultaneously. Further, it is also possible to change the combination of the thermistors to be compared by the temperature detection every time the pass / fail judgment is made.

In the embodiment of the present invention, a description has been given using a thermistor as the temperature detecting device and a water amount sensor as the water entering detecting device. However, the present invention is not limited to the above embodiment. As long as the temperature can be detected, the temperature may be detected with a thermocouple, a resistance temperature detector, or the like, and even in a water detection device, a device such as a water flow switch that can determine that water has flowed can be used. Good.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram illustrating an example of a water heater according to an embodiment of the present invention.

FIG. 2 is a flowchart of a process for determining the quality of a thermistor according to the first embodiment of the present invention.

FIG. 3 is a flowchart of a process for determining the quality of a thermistor according to a second embodiment of the present invention.

FIG. 4 is a flowchart of a process for determining the quality of a thermistor according to a third embodiment of the present invention.

FIG. 5 is a flowchart of a process for determining the quality of a thermistor according to a fourth embodiment of the present invention.

[Explanation of Signs] 1 Hot water supply unit 3 Heat exchanger 7 Water supply thermistor 8 Water quantity sensor 9 Heat exchange thermistor 10 Hot water supply thermistor 11 Burner 20 Boiling prevention thermistor 25 Bath temperature thermistor 26 Hot water tap

Claims (5)

[Claims] 1. A hot water supply device comprising: a water supply temperature detection device for detecting a water supply temperature, a water supply temperature detection device for detecting a water supply temperature, and a water supply device provided with a water supply detection device for confirming water supply to a water heater. Even if the request for combustion of the water heater is confirmed, the system does not proceed to the burner combustion operation and enters a standby state in a water flowing state, and the water temperature detected by the water flowing at that time is used to detect the water temperature and the hot water temperature. A water heater characterized in that an operation of judging the quality of the apparatus and performing burner combustion if no abnormality is found by the quality judgment is provided. 2. A standby condition in which the temperature detection device does not proceed to the burner combustion operation and waits in a water-flowing state until the temperature detection device makes a pass / fail determination. The water heater according to claim 1, wherein the condition is satisfied until either one of the conditions is satisfied. 3. The method according to claim 1, wherein the determination of the quality of the temperature detecting device is performed only when the use of the water heater has not been confirmed for a predetermined time since the last use of the water heater. Water heater. 4. The quality judgment of the temperature detecting device is performed every time the cumulative use time of the water heater exceeds a predetermined cumulative time,
The water heater according to any one of claims 1 and 2, wherein the operation is performed only when the use of the water heater is not confirmed for a predetermined time from the end of use of the water heater last time. 5. The quality determination of the temperature detector is performed every time the cumulative amount of water supplied to the water heater reaches the predetermined cumulative amount, and the usage of the water heater is confirmed for a predetermined time since the last use of the water heater. 3. The water heater according to claim 1, wherein the operation is performed only when the operation is not performed.