JP2886800B2 - Water heater - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a burner for heating a heat exchanger for water heating, to which an inlet and an outlet are connected, respectively.
Mixing of a bypass which connects the water inlet and the outlet to bypass the heat exchanger, hot water supplied to the hot water through the heat exchanger, and water supplied through the bypass. Mixing ratio adjusting means for adjusting the ratio, mixed hot water temperature detecting means for detecting the mixed hot water temperature of the hot water and water, and the detected mixed hot water temperature detected by the mixed hot water temperature detecting means to be the target hot water supply temperature. And a control unit for controlling a combustion state of the burner. The control unit is configured to, when a start of a hot water supply operation is instructed, reduce a ratio of water from the bypass passage to a normal hot water supply. In order to execute the bypass water amount suppression operation that is smaller than the ratio in the state, the bypass water amount suppression control for controlling the mixing ratio adjusting means is executed, and the detected mixed hot water temperature detected by the mixed hot water temperature detection means is set to the previous value. After the temperature exceeds the set temperature set in association with the target hot water supply temperature, the normal control of the mixing ratio adjusting means is performed to execute the normal water amount operation in which the ratio of the water from the bypass passage becomes the ratio in the normal hot water supply state. When the start of the hot water supply operation is instructed by executing the water amount control, the detected mixed hot water temperature is reduced in a state where the ratio of the water from the bypass path is the ratio in the normal hot water supply state. The present invention relates to a hot water supply device configured to control a combustion amount of the burner so as to reach a target hot water supply temperature.

[0002]

2. Description of the Related Art As shown in Japanese Patent Application No. 6-146031 filed by the present applicant, for example, when the hot water supply operation is started, the above hot water supply device reduces the ratio of water from a bypass. While the hot water temperature (mixed hot water temperature) is raised to the target hot water temperature as quickly as possible, in a steady operation state, the amount of water in the bypass passage is increased to ensure a sufficient amount of hot water. By the way, in the hot water supply apparatus having the above configuration, if the mixing ratio adjusting means does not operate normally, the hot water supply temperature (mixed hot water temperature) cannot be controlled to the target temperature.

Therefore, when the difference between the detected value of the mixed hot water temperature detecting means and the target hot water supply temperature exceeds the abnormality determination value, it is determined that the operation of the mixing ratio adjusting means is abnormal,
Corresponding post-processing, that is, a configuration in which the combustion ratio of the burner is controlled such that the mixture ratio by the mixture ratio adjusting means is fixed in a predetermined state so that the mixture temperature becomes the target supply temperature.

[0004] The abnormality discrimination value, which is a reference for judging an abnormal state, is used to prevent disadvantages such as a frequent change in the hot water supply state due to erroneous detection.
This is set to a value larger than the deviation that is considered to occur constantly in a normal hot water supply operation. Further, as described above, the control for determining the operation abnormality based on the temperature deviation is performed by:
It is executed after reaching the steady operation state in which the fluctuation of the detection value of the mixed hot water temperature detecting means is reduced.

[0005]

In the above conventional configuration, the difference between the value detected by the mixed hot water temperature detecting means, that is, the temperature of hot water actually supplied from the hot water supply path and the target hot water supply temperature is determined by the abnormality. Since the above-described post-processing is performed when the discrimination value is exceeded, there are the following disadvantages.

[0006] For example, when a failure occurs in which the operation of setting the amount of water from the bypass path to the ratio in the normal hot water supply state (bypass path side opening operation) in the mixing ratio adjusting means has occurred, the hot water supply operation is started. Then, when the temperature of the mixed hot water rises with the combustion operation of the burner,
Since the operation of setting the amount of water from the bypass to the ratio in the normal hot water supply state cannot be executed by the mixing ratio adjusting unit regardless of the control command from the control unit, the amount of water supplied from the bypass is smaller than the set amount of water. Becomes
The mixed hot water temperature rises above the target hot water supply temperature.

After that, if a steady operation state is reached and the deviation between the detected value of the mixed hot water temperature and the target hot water supply temperature exceeds the abnormality determination value, the above-described post-processing is executed, and the desired temperature is reached. However, when the temperature rises transiently until the steady operation state is reached, the temperature of the mixed hot water is already higher than the target hot water supply temperature by the temperature corresponding to the abnormality determination value at the time when the post-processing is executed. May become hot water.
As a result, there is a possibility that hot water having a high temperature is supplied temporarily until the steady operation state is reached, and that a long time is required until the hot water converges to the target hot water supply temperature (for example,
(See the broken line in FIG. 7).

[0008] In addition, when there is a failure in which the operation of setting the amount of water from the bypass passage to a ratio smaller than the ratio in the normal hot water supply state (bypass passage side closing operation) occurs in the mixing ratio adjusting means, the operation is started. Immediately after that, since the bypass water amount becomes larger than the control target amount, the temperature rise of the mixed hot water is delayed, but the bypass water amount is larger than the control target amount (the water amount on the heat exchanger side is small).
Nevertheless, the burner combustion amount is controlled by assuming that the amount of bypass water is small (the amount of water on the heat exchanger side is large). Is executed, the temperature of the hot water from the heat exchanger rises to a temperature higher than a preset temperature, and high-temperature hot water may be discharged (for example, see a broken line in FIG. 6). After that, if the deviation between the mixed hot water temperature and the target hot water supply temperature exceeds the abnormality determination value after reaching a steady operation state in which the temperature change becomes small, the above-described post-processing is executed, and the mixed hot water is executed. The temperature converges to the target hot water supply temperature, but it takes a long time to converge.

The present invention has been made in view of such a point, and an object of the present invention is to detect a failure as early as possible when a hot water supply operation is started in a case where the mixture ratio adjusting means has a failure. Another aspect of the present invention is to provide a hot water supply device capable of supplying water.

Another object of the present invention is to keep the hot water supply temperature at the target hot water supply temperature as much as possible even when the mixture ratio adjusting means is out of order.

[0011]

The features of the first invention are as follows.
A burner for heating a heat exchanger for water heating to which the water inlet and the outlet are connected respectively; a bypass for connecting the water inlet and the water outlet in a state of bypassing the heat exchanger; Mixing ratio adjusting means for adjusting a mixing ratio of hot water supplied to the hot water path through a water heater and water supplied through the bypass path, and mixed hot water temperature detecting means for detecting a mixed hot water temperature of the hot water and water And control means for controlling the combustion state of the mixture ratio adjusting means and the burner so that the detected mixed hot water temperature detected by the mixed hot water temperature detecting means becomes the target hot water supply temperature. When the start of the hot water supply operation is commanded, the bypass for controlling the mixing ratio adjusting means to execute the bypass water amount suppression operation in which the ratio of the water from the bypass passage becomes smaller than the ratio in the normal hot water supply state. Amount of water Control, and after the detected mixed hot water temperature detected by the mixed hot water temperature detection means exceeds a set temperature set in association with the target hot water supply temperature, the ratio of water from the bypass passage is changed to the normal hot water supply. In order to execute the normal water amount operation to be the ratio in the state, the normal water amount control for controlling the mixing ratio adjusting means is executed, and further, when the start of the hot water supply operation is instructed, the ratio of the water from the bypass path becomes
In such a state that the ratio is in the normal hot water supply state, the detected mixed hot water temperature becomes the target hot water supply temperature,
In the hot water supply device configured to control the combustion amount of the burner, after the normal water amount control is performed,
If it is not determined that the detected mixed hot water temperature detected by the mixed hot water temperature detecting means has decreased, the mixing ratio adjusting means is configured to determine that the failure is such that the normal water volume operation cannot be performed. It is in.

A characteristic configuration of the second invention specifies a configuration suitable for implementing the first invention, and the control means includes:
If the mixing ratio adjusting means determines that the failure is present, the bypass water amount suppressing control state is maintained, and the bypass water amount suppressing operation is executed, regardless of the detection information by the mixed hot water temperature detecting means. In such a state, the combustion amount of the burner is controlled so that the detected mixed hot water temperature becomes the target hot water supply temperature.

A feature of the third aspect of the present invention is to specify a configuration suitable for implementing the first or second aspect of the present invention. When the control means determines that the mixture ratio adjusting means has the fault, Immediately, regardless of the information detected by the mixed hot water temperature detecting means, the detected mixed hot water temperature is maintained in a state in which the bypass water amount suppression control state is continuously executed, and the bypass water amount suppression operation is performed. , So that the combustion amount of the burner is controlled so that the target hot water supply temperature is obtained.

According to a fourth aspect of the present invention, a configuration suitable for implementing the first or second aspect of the invention is specified. When the control means determines that the mixture ratio adjusting means has the fault, The combustion of the burner is stopped until the set time elapses from the time when the failure is determined, and after the set time elapses, the bypass water amount suppression control state is maintained, The point is that the state in which the combustion amount of the burner is controlled is maintained so that the detected mixed hot water temperature becomes the target hot water supply temperature in a state where the water amount suppression operation is performed.

According to a fifth aspect of the present invention, there is provided a burner for heating a heat exchanger for water heating to which a water inlet and a water outlet are connected, respectively, and bypasses the water inlet and the water outlet by the heat exchanger. A bypass path connected in a state, hot water supplied to the hot water path through the heat exchanger, and mixing ratio adjusting means for adjusting a mixing ratio of water supplied through the bypass path;
A mixed hot water temperature detecting means for detecting a mixed hot water temperature of the hot water and the water; and a mixing ratio adjusting means and the burner such that the mixed hot water temperature detected by the mixed hot water temperature detecting means becomes a target hot water supply temperature. Control means for controlling the combustion state of the, when the start of hot water supply operation is instructed,
In order to execute a bypass water amount suppression operation in which a ratio of water from the bypass passage becomes a ratio smaller than a ratio in a normal hot water supply state, a bypass water amount suppression control for controlling the mixing ratio adjusting means is executed, and After the detected mixed hot water temperature detected by the detecting means exceeds a set temperature set in association with the target hot water supply temperature, a normal water amount operation in which a ratio of water from the bypass passage becomes a ratio in a normal hot water supply state is performed. Therefore, when the normal water amount control for controlling the mixture ratio adjusting means is executed, and further, the start of the hot water supply operation is instructed, the ratio of the water from the bypass passage is the ratio in the normal hot water supply state. In the hot water supply apparatus configured to control the combustion amount of the burner such that the detected mixed hot water temperature becomes a target hot water supply temperature in a state where the bypass water is supplied, While the suppression control is being executed, an estimated value of the mixed hot water temperature is calculated when the mixing ratio adjusting means is operating normally, and the estimated value of the mixed hot water temperature is calculated by the mixed hot water detecting means. When the temperature is higher than the detected mixed hot water temperature by a set value or more, the mixing ratio adjusting means is configured to determine that the failure cannot execute the bypass water amount suppression operation.

A feature configuration of the sixth invention specifies a configuration suitable for the implementation of the fifth invention, and the control means includes:
If the mixing ratio adjusting means determines that the malfunction has occurred, then the normal water amount control state is executed and the control state is maintained regardless of the detection information by the mixed hot water temperature detecting means. The point is that the combustion amount of the burner is controlled so that the detected mixed hot water temperature becomes the target hot water supply temperature in a state where the operation is performed.

According to a seventh aspect of the present invention, a configuration suitable for implementing the fifth or sixth aspect of the invention is specified. When the control means determines that the mixing ratio adjusting means has the fault, Immediately, irrespective of the information detected by the mixed hot water temperature detecting means, the normal water amount control is executed, the control state is maintained, and the detection and mixing is performed in a state where the normal water amount operation is performed. The point is that the combustion amount of the burner is controlled so that the hot water temperature becomes the target hot water supply temperature.

An eighth aspect of the present invention is to specify a configuration suitable for implementing the fifth or sixth aspect of the present invention, wherein the control means determines that the mixing ratio adjusting means has failed. The combustion of the burner is stopped until the set time elapses after the failure is determined, and after the set time elapses, the normal water amount control is executed and the control state is maintained. And it is configured to maintain a state of controlling the combustion amount of the burner so that the detected mixed hot water temperature becomes the target hot water supply temperature in a state where the normal water amount operation is performed. On the point.

According to a ninth aspect of the present invention, a configuration suitable for implementing the first, second, third, fourth, fifth, sixth, seventh, or eighth aspect of the invention is specified. An alarm means is provided which activates an alarm when the mixture ratio adjusting means is determined to have the failure.

The characteristic structure of the tenth invention specifies a structure suitable for carrying out the first, second, third, fourth, fifth, sixth, seventh, eighth or ninth invention. When the mixture ratio adjusting means is determined to be faulty, a storage means for storing the failure is provided, and the control means stops the hot water supply operation and restarts the hot water supply operation. It is characterized in that the mixture ratio adjusting means is configured to determine the failure based on information stored in the storage means.

The feature configuration of the eleventh invention specifies a configuration suitable for implementing the first, second, third, fourth, fifth, sixth, seventh, eighth, ninth or tenth inventions. Wherein the mixing ratio adjusting means is constituted by a plurality of on-off valves provided in parallel with the bypass path, and the control means sets the mixing ratio adjusting means when it is determined that the failure is the failure. Until the time elapses, control is performed so as to open all of the plurality of on-off valves.

[0022]

According to the characteristic structure of the first invention, when the start of the hot water supply operation is instructed, the control means executes the bypass water amount suppression control, and the ratio of the water from the bypass passage is smaller than the ratio in the normal hot water supply state. The detected mixed hot water temperature is set to the target hot water supply temperature in a state where the mixing ratio adjusting means is controlled so as to be the ratio, and the ratio of the water from the bypass path is the ratio in the normal hot water supply state. The combustion amount of the burner is controlled such that Accordingly, since the ratio of the water amount on the bypass path side is small and the hot water on the heat exchanger side is heated by the burner so that the temperature in the normal hot water supply state (higher than the target hot water supply temperature), the mixed hot water temperature is set at the target. The temperature can be raised as quickly as possible to the hot water supply temperature. When the detected mixed hot water temperature rises above the set temperature, the control means executes normal water amount control, so that the ratio of water from the bypass becomes the ratio in the normal hot water supply state.
The normal hot water supply state is maintained in a state where the mixing ratio adjusting means is controlled so that the hot water heated by the heat exchanger and the water from the bypass have a normal hot water supply ratio.

When the control means executes the normal water amount control, if the mixing ratio adjusting means is operating normally, the ratio of water from the bypass increases, so that the temperature of the mixed water drops. However, if it is not determined that the detected mixed hot water temperature has dropped, the mixing ratio adjusting means determines that the failure cannot perform the normal water volume operation.

According to the characteristic configuration of the second invention, the following operation is obtained in addition to the operation of the characteristic configuration of the first invention. If it is determined that the mixing ratio adjusting unit is not capable of performing the normal water amount operation, then the bypass water amount suppression control is maintained and the bypass water amount suppression operation is performed regardless of the detection result of the mixed hot water temperature. In this state, the combustion state of the burner is controlled so that the detected mixed hot water temperature becomes the target hot water supply temperature.

Therefore, even after a failure, the burner control is performed so that the ratio of water from the bypass passage is maintained at a smaller ratio than that in the normal hot water supply state, and the mixed hot water temperature becomes the target hot water supply temperature in this state. By being executed, thereafter, even when the mixing ratio adjusting means returns to the normal state from the failure state, the mixing ratio adjusting means maintains the bypass water amount suppression operation, so that by returning to the normal state, While suppressing the change of the hot water temperature due to the unexpected change to the normal water volume operation state, the mixed hot water temperature is minimized,
The target hot water supply temperature can be maintained.

According to the characteristic configuration of the third aspect of the invention, the following operation is obtained in addition to the operation of the characteristic configuration of the first or second aspect of the invention.
If it is determined that the mixture ratio adjusting means is a failure that cannot execute the normal water amount operation, immediately without time delay,
The above-described bypass water amount suppression control and burner control are executed.

According to the feature configuration of the fourth invention, the following action is provided in addition to the action of the feature configuration of the first or second invention.
If the mixture ratio adjusting means is determined to be a failure in which the normal water amount operation cannot be performed, the combustion of the burner is stopped for the set time, so that due to the failure, due to excessive heating by the burner, The temperature of the mixed hot water can be prevented from becoming high, and after the set time has elapsed, the above-described bypass water amount suppression control and burner control are executed.

According to the characteristic configuration of the fifth invention, when the start of the hot water supply operation is instructed, the control means executes the bypass water amount suppression control, and the ratio of water from the bypass passage is smaller than the ratio in the normal hot water supply state. Since the mixing ratio adjusting means is controlled so as to achieve the ratio, the ratio of the amount of hot water on the heat exchanger side heated by the burner increases, and the temperature of the mixed hot water can be raised to the target hot water supply temperature as quickly as possible. When the detected mixed hot water temperature rises to exceed the set temperature, the control means executes normal water amount control, and the mixing ratio adjusting means is controlled so that the ratio of water from the bypass becomes the ratio in the normal hot water supply state, The normal hot water supply state is maintained in a state where the hot water heated by the heat exchanger and the water from the bypass pass at the normal hot water supply ratio.

In each of the bypass water amount suppression control and the normal hot water supply control, the control means controls the combustion state of the burner so that the detected mixed hot water temperature becomes the target hot water supply temperature.

While the bypass water amount suppression control is being executed by the control means in response to the start command of the hot water supply operation, the control means executes the following control. In other words, the estimated value of the mixed hot water temperature in the case of normal operation is calculated, and if the estimated value of the mixed hot water temperature is higher than the actual hot water temperature detected by the mixed hot water detecting means by the set value or more, the mixing It is determined that the failure is such that the ratio adjusting means cannot execute the bypass water amount suppression control.

According to the characteristic configuration of the sixth invention, the following operation is obtained in addition to the operation of the characteristic configuration of the fifth invention. If it is determined that the failure is such that the mixing ratio adjusting means cannot execute the bypass water amount suppression control, then the normal water amount control is executed and the state is maintained, and the normal water amount operation is executed. The combustion state of the burner is controlled so that the detected mixed hot water temperature becomes the target hot water supply temperature.

Therefore, even after a failure, the ratio of water from the bypass passage is maintained at the ratio in the normal hot water supply state, and burner control is executed so that the mixed hot water temperature becomes the target hot water supply temperature in that state. Even when the mixing ratio adjusting means returns to the normal state from the failure state, the mixing ratio adjusting means is normally controlled and maintained in the water amount control.By returning to the normal state, the bypass water amount suppressing operation state is unexpectedly performed. The change in the hot water temperature due to the change in the temperature is suppressed.

According to the feature configuration of the seventh aspect, the following action is provided in addition to the action of the fifth or sixth aspect.
When it is determined that the failure is such that the mixing ratio adjusting means cannot execute the bypass water amount suppression control, the normal water amount control and the burner control described above are immediately executed without a time delay.

According to the feature of the eighth aspect, the following action is obtained in addition to the action of the fifth or sixth aspect.
If it is determined that the mixture ratio adjusting means is incapable of executing the bypass water amount suppression control, the combustion of the burner is stopped until the set time elapses from the time when the determination is made. As a result, it is possible to reliably prevent the temperature of the mixed hot water from temporarily increasing due to excessive heating of the heat exchanger.

According to the ninth aspect of the present invention, in addition to the operation of the first, second, third, fourth, fourth, fifth, sixth, seventh or eighth aspect of the present invention, There is action. If it is determined that the mixing ratio adjusting means is unable to execute the bypass water amount suppression control, an alarm is activated, so that the hot water supply user can immediately recognize that the malfunction has occurred.

According to the tenth aspect of the present invention, in addition to the operation of the first, second, third, fourth, fifth, sixth, seventh, eighth, or ninth aspect of the present invention, There is action. When it is determined that the mixture ratio adjusting means is faulty, the fact is stored in the storage means, and when the hot water supply operation is temporarily stopped and then restarted, the control means, based on the storage information of the storage means, Since the failure state of the mixture ratio adjusting means can be determined, for example, when restarting the hot water supply operation, it is possible to execute the control corresponding to the failure from the beginning of the operation.

According to the feature configuration of the eleventh invention, in addition to the action of the feature configuration of the first, second, third, fourth, fifth, sixth, seventh, eighth, ninth or tenth invention, Has the following effects. When the mixture ratio adjusting means is constituted by a plurality of on-off valves provided in parallel with the bypass path, if it is determined that the malfunction has occurred, all the on-off valves are opened for a set time. For example, even if any one of the plurality of on-off valves has a valve-closing failure, the remaining on-off valves are opened to control the heat exchanger. The possibility that high-temperature hot water is temporarily discharged due to excessive heating in the above can be reduced.

[0038]

According to the characteristic structure of the first invention, the hot water supply operation is started, and in the transitional initial operation state in which the temperature of the hot water rises due to the heating in the heat exchanger, the time delay is as small as possible. It has been possible to provide a hot water supply device that can quickly determine that the mixing ratio adjusting unit is unable to perform the normal water volume operation.

According to the characteristic configuration of the second invention, the following effect is obtained in addition to the effect of the characteristic configuration of the first invention. Even if the mixing ratio adjusting means fails to execute the normal water amount operation,
It is possible to keep the hot water temperature at the target hot water temperature as much as possible to continue the hot water supply, and the mixed water temperature changes due to the mixing ratio adjusting means returning to the normal state during the operation from the failure state. Can be avoided beforehand.

According to the feature configuration of the third invention, the following effect is obtained in addition to the effect of the feature configuration of the first or second invention.
Immediately after it is determined that the mixture ratio adjusting means cannot perform the normal water amount operation, the above-described control is executed. Therefore, after the hot water supply operation is started, the hot water supply operation is performed with little time delay. Hot water supply can be performed with the temperature maintained as much as possible at the target hot water supply temperature.

According to the feature configuration of the fourth invention, the following effect is obtained in addition to the effect of the feature configuration of the first or second invention.
After it is determined that the mixing ratio adjusting means is not capable of performing the normal water amount operation, the risk of hot water being supplied due to overheating of the burner is reliably avoided. Hot water supply can be performed while maintaining the hot water supply temperature.

According to the characteristic configuration of the fifth invention, in the transitional initial operation state in which the hot water supply operation is started and the temperature of the hot water is rising due to the heating in the heat exchanger, the time is as short as possible with little time delay. It has become possible to provide a hot water supply device that can determine that the mixing ratio adjusting means is in a failure in which the bypass water amount suppression operation cannot be performed.

According to the characteristic configuration of the sixth invention, the following effect is obtained in addition to the effect of the characteristic configuration of the fifth invention. Even if the mixing ratio adjusting means cannot perform the bypass water amount suppression operation, the hot water temperature can be maintained at the target hot water temperature as much as possible to continue the hot water supply, and the mixing ratio adjusting means can be operated from the failure state during the operation. The disadvantage that the mixed hot water temperature changes due to the return to the normal state can be avoided beforehand.

According to the feature configuration of the seventh invention, the following effects are obtained in addition to the effects of the feature configuration of the fifth or sixth invention.
Immediately after it is determined that the mixing ratio adjusting unit is not capable of performing the bypass water amount suppression operation, the above-described control is performed. Therefore, after the hot water supply operation is started,
It is possible to execute hot water supply with the hot water supply temperature kept at the target hot water supply temperature as much as possible with less time delay.

According to the feature configuration of the eighth invention, the following effect is obtained in addition to the effect of the feature configuration of the fifth or sixth invention.
After it is determined that the mixing ratio adjusting means is incapable of performing the bypass water amount suppression operation, it is possible to reliably avoid the possibility of hot water being supplied due to excessive heating of the burner. Hot water supply can be performed while maintaining the target hot water supply temperature.

According to the ninth aspect of the invention, the following effect is obtained in addition to the effects of the first, second, third, fourth, fifth, sixth, seventh or eighth aspect of the invention. . Since the hot water supply user can immediately recognize that the mixing ratio adjusting means has failed, post-processing such as repair and replacement can be quickly performed.

According to the tenth aspect of the present invention, in addition to the effects of the first, second, third, fourth, fifth, sixth, seventh, eighth, or ninth aspect of the present invention, effective. Even when the hot water supply operation is restarted after being stopped, by performing the control corresponding to the failure from the beginning of the operation at the time of restarting the hot water supply, the tapping temperature temporarily increases due to the failure. Such disadvantages can be avoided beforehand.

According to the feature configuration of the eleventh invention, in addition to the effect of the feature configuration of the first, second, third, fourth, fifth, sixth, seventh, eighth, ninth or tenth invention, The following effects are obtained. Compared to a configuration in which the mixing ratio can be adjusted in a stepless manner, the configuration is such that the mixing ratio can be changed and a failure has occurred in any one of the plurality of on-off valves. In addition, by opening the other on-off valves, it is possible to reliably prevent the tapping temperature from temporarily becoming high due to the above-described failure and continuing the high-temperature state for a long time.

[0049]

Embodiments will be described below with reference to the drawings. FIG.
1 shows a hot water supply apparatus according to the present invention. The hot water supply apparatus includes a hot water supply unit K, a control unit H as control means for controlling the hot water supply operation of the hot water supply unit K, and an operation unit R to which information is transmitted between the control unit H. The hot water supply unit K,
A heat exchanger 2 for water heating, which is heated by a burner 1, is provided. A water inlet 3 and a hot water outlet 4 are connected to the heat exchanger 2, and a water inlet 3 and a hot water outlet 4 are connected to a bypass 5.
The supply water supplied from the water inlet 3 is divided into the water inlet 3 and the bypass 5, and the hot water heated by the heat exchanger 2 and the water supplied from the bypass 5 are joined. hand,
The hot water is supplied to a hot water tap (not shown) through the hot water path 4. Further, a fan 6 is provided as ventilation means for supplying combustion air to the burner 1, and an igniter 7 for ignition and a frame rod 8 for detecting whether or not the burner 1 is ignited are provided near the burner 1. Provided.

At the upstream side of the connection point of the water inlet passage 3 with the bypass passage 5, a water amount sensor 9 serving as a water amount detecting means for detecting the amount of incoming water, and an incoming water temperature sensor 10 serving as an incoming water temperature detecting means for detecting the incoming water temperature. On the downstream side of the connection point between the hot water path 4 and the bypass path 5, there is provided a hot water temperature sensor 11 as mixed hot water temperature detecting means for detecting a mixed hot water temperature (hot water supply temperature) after the hot water is mixed. Have been. or,
The outlet of the heat exchanger 2 is provided with a hot water temperature sensor 12 as a hot water temperature detecting means for detecting the temperature of the hot water heated by the heat exchanger 2.

A bypass opening / closing valve 14 is provided as a mixing ratio adjusting means for adjusting a mixing ratio of hot water supplied to the hot water path 4 through the heat exchanger 2 and water supplied through the bypass path 5.

A fuel supply passage 15 for supplying fuel to the burner 1 is provided with an electromagnetic gas on-off valve 16 and an electromagnetic gas amount adjusting valve 17 as fuel supply amount adjusting means. The operation unit R is provided so as to be able to communicate with the control unit H by wire or wirelessly. The operation unit R includes an operation switch 18 for instructing start / stop of operation of the hot water supply device, and a hot water supply temperature for setting a target hot water supply temperature. A setting switch 19, a hot water temperature display section 20 for displaying the hot water temperature, and the like are provided.

The control unit H includes the sensors 9 to 12,
The gas on / off valve 16 and the gas amount control valve 17 are controlled based on the detection information of the frame rod 8 and the like to control the fuel supply amount to the burner 1 so that the hot water supply temperature becomes the target hot water supply temperature, and to perform the hot water supply operation. At the start of the operation, the bypass opening / closing valve 14 is controlled so that the hot water supplied through the heat exchanger 2 and the hot water path 4
It is configured to control the change of the mixing ratio of the water supplied through the filter.

When the control unit H is instructed to start the hot water supply operation, the control of the bypass water amount (the bypass water amount is zero) becomes smaller than the ratio in the normal hot water supply state (the bypass water amount is zero). In order to execute the (close operation), the bypass opening / closing valve 14 is controlled (corresponding to bypass water amount suppression control), and the temperature of the mixed hot water detected by the mixed hot water temperature sensor 11 is set to a temperature slightly higher than the target hot water supply temperature. After the temperature exceeds the set temperature, the bypass opening / closing valve 14 is controlled to perform a normal water amount operation (opening operation) in which a ratio of water from the bypass passage 5 becomes a ratio in the normal hot water supply state (corresponding to normal water amount control). ) Is configured. Further, when the start of the hot water supply operation is instructed, the control unit H controls the combustion amount of the burner 1 so that the mixed hot water temperature becomes the target hot water supply temperature in a state where the normal water amount operation is performed. It is configured as follows.

When the control unit H does not determine that the detected mixed hot water temperature detected by the mixed hot water temperature sensor 11 has decreased after the opening operation control of the bypass on-off valve 14 (normal water amount control) has been executed. Is configured to determine that the bypass opening / closing valve 14 is a valve closing failure in which the opening operation (normal water volume operation) cannot be performed, and to immediately close the bypass opening / closing valve 14 when the valve closing failure is determined. Control (corresponding to bypass water amount suppression control), while maintaining the control state, and in a state where the bypass on-off valve 14 is closed (bypass water amount suppression operation is being performed), the mixed hot water temperature detection is performed. The burner combustion amount is controlled so that the detection value of the sensor becomes the target hot water supply temperature.

Further, the controller H controls the incoming water temperature sensor 10, the outgoing water temperature sensor 11,
In addition, the estimated value T ₂₁ of the mixed hot water temperature obtained based on the set mixing ratio of hot water and water at that time (in this embodiment, the heat exchanger side ratio is “1”) Temperature, which in this embodiment is approximately the same as the hot water temperature)
And whether the bypass opening / closing valve 14 has a valve opening failure or not is determined based on the actual detection value of the hot water temperature sensor 11. Is controlled so as to open (equivalent to normal water amount control), the control state is maintained, and the bypass on-off valve 14 is opened (normal water amount suppression operation is performed). The burner combustion amount is controlled so that the detected value of the mixed hot water temperature detection sensor becomes the target hot water supply temperature.

The control section H is provided with a memory Me as a storage means for storing when a valve closing failure or a valve opening failure of the bypass on-off valve 14 is determined.

Hereinafter, the control operation of the mixture ratio control in the control section H will be described with reference to the control flowcharts shown in FIGS. When the power is turned on, the memory Me is stored in the memory Me indicating that the bypass on-off valve 14 is normal, and the bypass on-off valve 14 is closed (step 1). Then, the operation switch 18 is turned on and the water amount sensor 9 is turned on.
When the water flow amount Qx exceeds the set water amount Qs for ignition (about 2 liters / minute) (when a hot water supply operation is commanded), the ignition control of the burner 1 is executed (steps 2 and 3). , 4). That is, the gas opening / closing valve 16 and the gas amount adjusting valve 17 are opened, the ventilation of the fan 6 is started, and the combustion of the burner 1 is started.

It is determined from the information stored in the memory Me whether the bypass on-off valve 14 is normal (step 5).
If it is normal, control is performed so that the bypass on-off valve 14 is closed (step 6), and the initial combustion control is executed (step 7).

In this initial combustion control, the heat exchanger
Value T of hot water temperature_3SAnd incoming water temperature T₁Deviation from
Heat exchanger water amount (in this case, the detection value Q of the water amount sensor 9)
x) to obtain the feedforward manipulated variable FF
And the detected hot water temperature T _ThreeAnd the hot water temperature target value T
_3SFeedback by PI control based on the deviation from
Although the manipulated variable FB is to be obtained, the heating water temperature target value T_3S
Is calculated based on the following (Equation 1).

[0061]

## EQU1 ## T _3S = (T _1S -T ₁ ) / Mx ₀ + T ₁

However, in (Equation 1), T _1S is the target hot water supply temperature, and T ₁ is the incoming water temperature. Mx ₀ is the mixing ratio on the heat exchanger side during the steady operation, that is, (the flow rate of the heat exchanger side / detected value of the water sensor), which is a preset value.

The fuel supply amount is controlled by adjusting and controlling the gas amount control valve 17 based on the sum of the feedforward operation amount and the feedback operation amount. Therefore, the heating temperature of the heat exchanger 2 is the target temperature in the steady combustion state, and is set to a temperature higher than the target hot water supply temperature. Therefore, in this initial combustion control, the bypass on-off valve 14
Is open (normal water volume operation is performed), the burner combustion amount is controlled so that the detected mixed hot water temperature becomes the target hot water supply temperature.

As shown in FIG. 6, the outlet temperature of the heat exchanger 2 (the hot water temperature T ₃ ) rises with the ignition of the burner 1, but at this time, the bypass on-off valve 14 is opened, for example. In the case of failure due to sticking, the rise of temperature is delayed as shown by the one-dot chain line in FIG. Therefore, utilizing the occurrence of such a delay in rising of the temperature, a valve opening failure of the bypass on-off valve 14 is detected based on the temperature deviation.

First, the temperature of the mixed hot water in the normal case (FIG. 6)
(Shown by a solid line in FIG. 3) (step 8). In this embodiment, the temperature of the mixed hot water in the normal case is the temperature when the hot water heated by the heat exchanger 2 passes to the hot and cold water mixing section.
Estimate the correct mixed bath temperature. Mixed water temperature, to the heating water temperature T ₃ shown by a thin broken line in FIG. 6, the time delay,
The temperature drops slightly. First, as shown in FIG. 4, every predetermined short time, the heat exchanger flow rate Qx (the value detected by the water flow rate sensor)
When, gradually allowed to store the detection value T ₃ of the heating hot water temperature sensor 12 in the memory Me (step 71). And heat exchanger 2
Of the hot water path 4 from the outlet to the connection point with the bypass path 5 is determined in advance, and when the integrated value S of the heat exchanger water flow exceeds the internal capacity Qa of the passage, the integration at that time is performed. obtains the number k (step 72, 73), the detection value of k times prior to the heating hot water temperature sensor 12 is determined as an estimate T ₂₁ accurate mixing hot water (step 74).

If it is not detected that the estimated value T ₂₁ of the mixed hot water temperature is larger than the detected value of the mixed hot water sensor 11 by the set value α or more, it is determined that the operation is normal, and the routine proceeds to step 10. migrated, the estimated value T ₂₁ of the estimated mixture be greater than the set value than the detection value of the mixed hot water temperature sensor 11 is detected, the possible bypass opening and closing valve 14 is determined to what is opened failure Is stored in the memory Me (step 11). Then, immediately thereafter, control is performed so that the opening operation is performed so that the closing operation is not performed even when the operation returns, and the control state is maintained (step 12), and the display of the hot water supply temperature display unit 20 of the operation unit R blinks to give an alarm. Activate (step 13). If the set value of the target hot water supply temperature T _2S exceeds 45 degrees, the temperature is forcibly set to 45 degrees so that a temperature higher than 45 degrees cannot be set (step 14). Burner 1
Is changed to the steady combustion control state (step 15), and when the detection value Qx of the water amount sensor 9 falls below the set water amount Qs, post-purge is executed and the process returns to step 2 (steps 16 and 27). The steady-state combustion control will be described later.

By executing the control corresponding to the valve opening failure in this way, the tapping temperature can converge to the target hot water supply temperature as quickly as possible, as indicated by the one-dot chain line in FIG.

When no valve opening failure has occurred and the temperature of the mixed
As indicated by the solid line, when it is detected that the detected mixed hot water temperature T ₃ has exceeded the target hot water supply temperature T _2S by the set value β (step 10), the bypass on-off valve 14
Is performed (step 17), and the control of the fuel supply amount of the burner 1 is changed to the steady combustion state (step 18).

Next, steady-state combustion control will be described. As shown in FIG. 5, a feedforward manipulated variable FF is obtained based on the difference between the target hot water supply temperature T _2S and the incoming water temperature T ₁ and the incoming water amount Qx (step 171), and the detected hot water temperature T ₃ And the feedback operation amount FB is calculated based on the deviation from the heating water temperature target value T _3S ,
The heating water temperature target value T _3S is obtained based on the following (Equation 2).

[0070]

## EQU2 ## T _3S = (T _2S -T ₁ ) / Mx + T ₁

Here, T _2S is the target hot water supply temperature, T ₁ is the incoming water temperature, and Mx is the mixing ratio on the heat exchanger side. However, the mixing ratio Mx varies depending on individual differences between the heat exchanger 2 and the bypass on-off valve 14. Therefore, the mixing ratio Mx used here is determined based on actual detection information. Is learned to obtain an accurate target value of the hot water temperature T _3S, thereby reducing the steady temperature deviation.

That is, the preset mixing ratio Mx
₀Heat exchanger water amount Q based on the detection value Qx of the water amount sensor 9₁
Is calculated, and every predetermined short time (for example, 0.5 seconds)
The heat exchanger water volume Q₁And the detected value T of the hot water temperature sensor 12
_ThreeAre sequentially stored (steps 172 and 17).
3). Then, a connection with the bypass passage 5 is made from the outlet of the heat exchanger.
Determine the passage capacity Qa of the hot water path 4 up to the continuation point in advance.
The heat exchanger water flow Q ₁Of the passage is
If the quantity Qa is exceeded, the integrated number k at that time is obtained (step
174, 175), the heating water temperature sensor 12 detected k times before
Hot water temperature T on the heat exchanger side immediately before the hot / water mixing section with accurate output value
_2K(Step 176). And (number
According to 3), an accurate mixing ratio Mx is obtained (step S3).
177).

[0073]

Mx = (T ₂ −T ₁ ) / (T _2K −T ₁ )

Further, an accurate heating water temperature target value T _3S is obtained from the mixing ratio Mx and (Equation 2), and a deviation between the heating water temperature target value T _3S and the detection value T ₃ of the heating water temperature sensor 12 is obtained. The feedback operation amount FB is obtained by PI control based on the above (steps 178, 179). Then, the gas amount adjusting valve 17 is adjusted and controlled by the added value of the feedforward operation amount FF and the feedback operation amount FB (step 180).

Accordingly, the combustion amount of the burner 1 is controlled so that the detected mixed hot water temperature reaches the target hot water supply temperature, assuming that the bypass on-off valve 14 is open (normal water amount operation is being performed). Become.

Then, as described above, the bypass on-off valve 1
When the opening operation control of Step 4 is executed, the amount of water from the bypass passage 5 increases and the temperature of the mixed hot water decreases (see the solid line in FIG. 7). For example, as shown by a broken line in FIG. 7, if a decrease in temperature is detected based on the detection information of No. 11, it is determined that the valve is a valve closing failure in which the bypass on-off valve 14 is not opened, and Is stored in the memory Me (step 1).
9, 20, 21). Then, immediately thereafter, control is performed to close the bypass opening / closing valve 14 so that the opening / closing valve 14 does not open even when the valve is restored, and the control state is maintained (step 2).
Along with 2), the mixture ratio Mx in the steady combustion control is set to "1" (step 23). That is, the target hot water temperature T _3S is made to match the target hot water supply temperature T _2S . In addition, the display of the hot water supply temperature display section 20 of the operation section R is blinked to activate an alarm (step 24). Thereafter, the control of the fuel supply amount of the burner 1 is changed to the steady combustion control state (step 25), and when the detection value Qx of the water amount sensor 9 falls below the set water amount Qs, post-purge is executed and the process returns to step 2 (step 2).
6, 27). In the combustion control executed in step 25, since the mixture ratio Mx is set to “1”, as a result, the bypass on-off valve 14 is closed (the bypass water amount suppression operation is performed). ), The burner combustion amount is controlled such that the detection value of the mixed hot water temperature detection sensor becomes the target hot water supply temperature.

As described above, by executing the control corresponding to the valve closing failure, it is possible to suppress the temporary rise in the tapping temperature as shown by the one-dot chain line in FIG. It can be converged to the hot water supply temperature.

If it is determined in step 18 that the temperature of the mixed hot water has dropped normally, the steady combustion control is continued,
When the detected value Qx is less than the set water amount Qs, post-purge is executed, the bypass on-off valve 14 is closed, and the process returns to step 2 (steps 26 and 27).

When the hot water supply operation is restarted after the failure of the bypass on-off valve is determined, the failure state of the bypass on-off valve 14 is determined based on the information stored in the memory Me. The control is immediately shifted to appropriate control. That is, if it is determined in step 5 that the bypass opening / closing valve 14 is faulty, it is determined whether the valve is a valve closing fault or a valve opening fault (step 32). Then, the burner 1 is controlled to perform steady-state combustion by executing the opening operation control and the alarm operation of the bypass on-off valve 14. As a result, at the time of tapping after the failure, as shown by a two-dot chain line in FIG.
Overheating is further suppressed, and the possibility of hot water being discharged is reduced.

If it is determined in step 32 that a valve closing failure has occurred, the process proceeds to step 22 in which the bypass on-off valve 14
Is performed, and the burner 1 is controlled to perform steady combustion. As a result, at the time of re-watering, as shown by the two-dot chain line in FIG. 7, excessive heating in the heat exchanger 2 is further suppressed, and the possibility of hot water being discharged is reduced.

The contents stored in the memory Me are based on the OF of the power supply.
When reset by F and the power is turned on, it is stored as a normal state (step 1).

The bypass on-off valve may be a normally open type on-off valve or a normally closed type on-off valve.

[Alternative Embodiment] (1) In the above-described embodiment, when a failure in closing or opening the bypass on-off valve 14 is detected, control corresponding to the content of the failure is immediately executed to start the hot water supply operation. 8 and 9, if a failure is determined, the combustion of the burner 1 is stopped (step 12).
a), post-purge is executed until a predetermined time (for example, about 1 second) elapses (steps 13a and 14).
a), the bypass on-off valve 14 is closed (step 1).
5a), the control may be executed to return to step 2.

With this configuration, the bypass on-off valve 1
Due to the failure of 4, the overheating by the heat exchanger 2 can be reliably prevented beforehand, and the risk of hot water being discharged can be further reduced.

(2) In the above embodiment, the case where one bypass opening / closing valve is provided in the bypass passage has been exemplified.
0, as shown in FIG.
a and 5b are provided with a plurality of bypass on-off valves 14a and 14a, respectively.
b, and each of the branch bypass paths 5a and 5b may be provided with throttle portions 13a and 13b for suppressing the flow of water. Then, as shown in FIG. 11, based on the detection information of the mixed hot water temperature, after opening only one open / close valve, open both open / close valves, and so on.
May be gradually mixed.
In this configuration, the first stage valve opening operation and the second stage
If a decrease in the temperature of the mixed hot water is not detected in any of the valve opening operations at the stages, it can be determined that one of the on-off valves has a valve closing failure. In this case, in step 21 in the above embodiment, Are controlled to open once, and after a lapse of a predetermined time until the hot water in the heat exchanger is discharged, all the on-off valves 1a and 14b are opened.
4a and 14b are controlled to be closed. Further, a valve opening failure can be determined based on a deviation between the estimated mixed hot water temperature and the detected mixed hot water temperature in the control state of each of the on-off valves 14a, 14b. In this case, too, all the on-off valves 14a, 14b
Is controlled to open.

In this way, if different control patterns corresponding to the failure patterns are stored in advance for each on-off valve, the storage capacity increases. However, such disadvantages can be avoided and reasonable hot water supply temperature control can be performed. Can be realized.

The above-mentioned on-off valves may be arranged in three or more rows.

(3) In the above embodiment, the case where the on-off valve is used as the mixing ratio adjusting means has been exemplified. However, the mixing ratio in which the mixing ratio between the amount of water in the bypass passage and the amount of hot water in the heat exchanger can be adjusted steplessly. It may be configured in the form of a valve.

(4) In the above embodiment, the control is shifted from the bypass water flow suppression control to the normal water flow control to be in a steady operation state. However, as described above, the structure in which a plurality of on-off valves are provided or the mixing valve type is used. In such a case, a configuration may be adopted in which control is performed so as to return to the normal water amount after shifting from the bypass water amount suppression control to the normal water amount control, further changing the flow rate to a post-boiling prevention flow rate larger than the normal water amount. (5) In the above embodiment, when the detected mixed hot water temperature exceeds the set temperature higher than the target hot water supply temperature, the control is shifted from the bypass water flow suppression control to the normal water flow control to be in a steady operation state. May be set in association with the target hot water supply temperature, and may be set to the same temperature as the target hot water supply temperature or a temperature slightly lower than the target hot water supply temperature.

(6) In the above embodiment, when the failure of the bypass on-off valve is determined, the hot water supply temperature display of the operation section is made to blink, and an alarm is issued. May be generated, a configuration may be adopted in which an abnormality display lamp is turned on, or a configuration in which these are used in combination.

(7) In the above embodiment, the configuration is such that both the closed failure and the open failure of the bypass on-off valve are detected. However, the configuration may be such that only the closed failure is detected or only the open failure is detected. .

(8) In the above embodiment, the failure of the bypass on-off valve is stored in the storage means. However, a configuration without such storage means may be employed.

[0093] In the claims, reference numerals are provided for facilitating comparison with the drawings, but the present invention is not limited to the configuration shown in the attached drawings.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a water heater.

FIG. 2 is a flowchart of a control operation.

FIG. 3 is a flowchart of a control operation.

FIG. 4 is a flowchart of a control operation.

FIG. 5 is a flowchart of a control operation.

FIG. 6 is a diagram showing a temperature change at the time of a valve opening failure;

FIG. 7 is a diagram showing a temperature change at the time of a valve closing failure.

FIG. 8 is a flowchart of a control operation according to another embodiment.

FIG. 9 is a flowchart of a control operation according to another embodiment.

FIG. 10 is a configuration diagram of a water heater according to another embodiment.

FIG. 11 is a diagram showing a temperature change in another embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Burner 2 Heat exchanger 3 Inlet channel 4 Outlet channel 5 Bypass channel 11 Mixed hot water temperature detecting means 14 Mixing ratio adjusting means 14a, 14b Open / close valve H control means Me storage means

──────────────────────────────────────────────────続 き Continuation of the front page (72) Inventor Hideaki Fujikawa 1-1-52 Oka, Minami-shi, Minato-ku, Osaka-shi, Osaka (56) References JP-A-57-49755 (JP, A) JP-A-Hei 6-288640 (JP, A) JP-A-6-288639 (JP, A) JP-A 64-6646 (JP, A) JP-A 64-3438 (JP, A) JP-A 1-118036 (JP, A) A) JP-A-6-257854 (JP, A) JP-A-8-14659 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) F24D 17/00

Claims (11)

(57) [Claims] 1. A burner (1) for heating a heat exchanger (2) for water heating, to which a water inlet channel (3) and a hot water channel (4) are connected, respectively, and the water inlet channel (3) and a hot water channel (3). 4) that connects the heat exchanger (2) in a state of bypassing the heat exchanger (2); hot water supplied to the tapping path (4) through the heat exchanger (2); (5) a mixing ratio adjusting means (14) for adjusting a mixing ratio with water supplied through (5); a mixed hot water detecting means (11) for detecting a mixed hot water temperature of the hot water and water; The mixing ratio adjusting means (14) and control means (H) for controlling the combustion state of the burner (1) so that the detected mixed hot water temperature detected by the detecting means (11) becomes the target hot water supply temperature. When the start of the hot water supply operation is instructed, the control means (H) controls the bypass passage (5).
A bypass water amount suppression control for controlling the mixing ratio adjusting means (14) so as to execute a bypass water amount suppression operation in which a ratio of water from the tank is smaller than a ratio in a normal hot water supply state; After the detected mixed hot water temperature detected by the detecting means (11) exceeds a set temperature set in association with the target hot water supply temperature, the ratio of water from the bypass passage (5) becomes equal to the ratio in the normal hot water supply state. In order to execute the normal water amount operation, the normal water amount control for controlling the mixture ratio adjusting means (14) is executed. Further, when the start of the hot water supply operation is instructed, the normal water amount operation is executed. A hot water supply device configured to control a combustion amount of the burner (1) so that the detected mixed hot water temperature becomes a target hot water supply temperature in a state where the temperature of the mixed hot water reaches a target hot water supply temperature. After executing the water amount control, if it is not determined that the detected mixed hot water temperature detected by the mixed hot water temperature detecting means (11) has dropped, the mixing ratio adjusting means (14).
Is configured to determine that the failure cannot perform the normal water volume operation. 2. The control means (H), if the mixing ratio adjusting means (14) determines that the failure has occurred, thereafter, regardless of the information detected by the mixed hot water temperature detecting means (11), the bypass means The combustion amount of the burner (1) is controlled such that the detected mixed hot water temperature becomes the target hot water supply temperature in a state where the water flow suppression control state is maintained and the bypass water flow suppression operation is performed. The hot water supply apparatus according to claim 1, wherein the hot water supply apparatus is configured as follows. 3. The control means (H), as soon as the mixing ratio adjusting means (14) determines that the failure has occurred, regardless of the information detected by the mixed hot water temperature detecting means (11). The combustion amount of the burner (1) is set such that the detected mixed hot water temperature becomes the target hot water supply temperature in a state where the water amount suppression control state is continuously executed and the bypass water amount suppression operation is performed. The hot water supply device according to claim 1, wherein the hot water supply device is configured to control the water supply. 4. The control means (H), when the mixture ratio adjusting means (14) determines that the failure is, the control means (H) keeps the control means (H) until the set time elapses after the failure is determined. After the combustion of the burner (1) is stopped, after the set time has elapsed, the bypass water amount suppression control is executed, the state is maintained, and
In such a state that the bypass water amount suppression operation is performed, the detected mixed hot water temperature becomes the target hot water supply temperature,
The hot water supply device according to claim 1 or 2, wherein the hot water supply device is configured to control a combustion amount of the burner (1). 5. A burner (1) for heating a heat exchanger (2) for water heating to which a water inlet channel (3) and a hot water channel (4) are connected, respectively, and the water inlet channel (3) and a hot water channel (5). 4) that connects the heat exchanger (2) in a state of bypassing the heat exchanger (2); hot water supplied to the tapping path (4) through the heat exchanger (2); (5) a mixing ratio adjusting means (14) for adjusting a mixing ratio with water supplied through (5); a mixed hot water detecting means (11) for detecting a mixed hot water temperature of the hot water and water; The mixing ratio adjusting means (14) and control means (H) for controlling the combustion state of the burner (1) so that the detected mixed hot water temperature detected by the detecting means (11) becomes the target hot water supply temperature. When the start of the hot water supply operation is instructed, the control means (H) controls the bypass passage (5).
A bypass water amount suppression control for controlling the mixing ratio adjusting means (14) so as to execute a bypass water amount suppression operation in which a ratio of water from the tank is smaller than a ratio in a normal hot water supply state; After the detected mixed hot water temperature detected by the detecting means (11) exceeds a set temperature set in association with the target hot water supply temperature, the ratio of water from the bypass passage (5) becomes equal to the ratio in the normal hot water supply state. In order to execute the normal water amount operation, the normal water amount control for controlling the mixture ratio adjusting means (14) is executed. Further, when the start of the hot water supply operation is instructed, the normal water amount operation is executed. A hot water supply device configured to control a combustion amount of the burner (1) so that the detected mixed hot water temperature becomes a target hot water supply temperature in a state where the bypass water amount suppression control is performed. While the mixing ratio adjusting means (14) is operating normally, an estimated value of the mixed hot water temperature is calculated, and the estimated value of the mixed hot water temperature is calculated by the mixed hot water detecting means ( 1
A water heater configured to determine that the mixing ratio adjusting means (14) is unable to perform the bypass water amount suppression operation if the temperature is higher than a detected mixed water temperature detected by 1) by a set value or more. 6. The control means (H), when the mixing ratio adjusting means (14) determines that the failure has occurred, thereafter, regardless of the detection information by the mixed hot water temperature detecting means (11), The burner (1) performs water amount control and maintains the control state, and further burns the burner (1) so that the detected mixed hot water temperature becomes a target hot water supply temperature in a state where the normal water amount operation is performed. The hot water supply apparatus according to claim 5, wherein the hot water supply apparatus is configured to maintain a state of controlling the amount. 7. The control means (H), as soon as the mixing ratio adjusting means (14) determines that the malfunction has occurred, irrespective of information detected by the mixed hot water temperature detecting means (11). The combustion amount of the burner (1) is controlled so that the water amount control is continuously performed and the detected mixed hot water temperature becomes the target hot water supply temperature in a state where the normal water amount operation is performed. The hot water supply apparatus according to claim 5, wherein the hot water supply apparatus is configured to continuously execute the state. 8. The control means (H), when the mixture ratio adjusting means (14) determines that the malfunction has occurred, the control means (H) determines whether or not the mixture ratio adjustment means (14) has malfunctioned until a set time elapses after the malfunction is determined. A state in which the combustion of the burner (1) is stopped, and after the set time has elapsed, the normal water amount control is restarted, the control state is maintained, and the normal water amount operation is performed. 7. The hot water supply apparatus according to claim 5, wherein a state in which the combustion amount of the burner is controlled is maintained such that the detected mixed hot water temperature becomes a target hot water supply temperature. 9. An alarming means (20) which activates an alarm when said mixture ratio adjusting means (14) is determined to have said failure.
The hot water supply apparatus according to claim 1, wherein the hot water supply apparatus is provided with: 10. When the mixture ratio adjusting means (14) is determined to be in failure, a storage means (Me) for storing the failure is provided, and the control means (H) stops the hot water supply operation. After that, when the hot water supply operation is resumed,
8. The apparatus according to claim 1, wherein said mixture ratio adjusting means determines said failure based on information stored in said storage means. , 8
Or the hot water supply apparatus of 9. 11. The mixing ratio adjusting means (14) includes a plurality of on-off valves (14a) and (14b) provided in parallel with the bypass path (5). If the mixture ratio adjusting means (14) determines that the malfunction has occurred, control is performed to open all of the plurality of on-off valves (14a) and (14b) until the set time has elapsed. Claims 1, 2, 3, 4, 5,
The hot water supply apparatus according to 6, 7, 8, 9 or 10.