JP2001355917A - Hot water storing type electrical hot water heater - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve a durability of a hot water storing type electrical hot water heater without causing the heater always to be exposed in a high temperature hot water during a boiling-up operation. SOLUTION: Both a heater 11 and an upper hot water temperature sensor 12 are positioned at an upper part of a hot water storing tank 10. There is provided a circulation pump 13 for transferring water kept at a lower region of the hot water storing tank 10 to its upper region. Even in the case that residual high temperature hot water is present at the upper region of the hot water storing tank, the circulation pump 13 is driven at the time of starting the boiling-up operation, a surrounding hot water temperature of the heater 11 is decreased down to an intermediate boiling-up set temperature T1, a total amount within the hot water storing tank is kept at the intermediate temperature until the temperature becomes the intermediate boiling-up set temperature T1 and then the heater 11 is prevented from being always exposed to the high temperature hot water.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hot water storage type electric water heater in which a heater is provided above a hot water tank and hot water is stored from above the hot water tank.

[0002]

2. Description of the Related Art Conventionally, this type of water heater is disclosed in Japanese Patent Application Laid-Open No. 7-23.
No. 9153 has the following. FIG. 9 shows a conventional electric water heater described in the above publication.

In FIG. 9, 1 is a hot water tank, 2 is a hot water tank 1
The heater 3 disposed at the upper part of the hot water storage tank 1 has a circulation path communicating the area above the heater 2 in the hot water storage tank 1 and the lower part of the hot water storage tank 1.
Is a circulation pump, 5 is a first temperature sensor located slightly above the heater 2 on the wall of the hot water tank 1, 6 is a second temperature sensor located below the hot water tank 1, and 7 is the heater 2 and the circulation pump 4.
Is an energization control device that performs the above control. Then, when the first temperature sensor 5 detects that the water in the upper region of the hot water storage tank 1 is rapidly heated by the heater 2 to become hot water and reaches, for example, 85 ° C., the circulation pump 4 is controlled by the power supply control device 7.
The first temperature sensor 5 detects that the cold water in the lower part of the hot water tank 1 is circulated to the high temperature hot water in the upper part of the hot water tank 1 and the temperature of the hot water in the upper region of the hot water tank 1 drops, for example, to 75 ° C. Then, the power supply control device 7 stops the circulation pump. By repeatedly driving and stopping the circulation pump 4 as described above, the entire hot water in the hot water storage tank 1 is heated. Upon detecting that the second temperature sensor 6 at the lower part of the hot water storage tank has reached the set temperature, the energization control device 7 energizes the heater 2 and activates the circulation pump 4.
Stop driving.

[0004]

However, in the above-mentioned conventional configuration, even if the upper region of the hot water storage tank 1 is water, it is quickly heated to water immediately after the start of boiling, and the first temperature sensor 5 is set. When the temperature reaches 85 ° C., the circulation pump 4 is driven. When the temperature of the hot water drops to 75 ° C. is detected, the circulation pump 4 is stopped. Accordingly, the temperature of the hot water surrounding the heater 2 during the heating becomes high immediately, and then the high temperature state is continued until the heating is completed. Usually, the electric water heater uses the midnight electric power every day to boil the entire amount of the hot water tank. At the start of the heating, the hot water remaining in the upper region of the hot water tank 1 is often present. There has been a problem that the ambient temperature is constantly maintained at a high temperature.

[0005] The present invention is to solve the above problems,
Even when high-temperature remaining hot water exists in the upper region of the hot water tank, the temperature of the hot water around the heater is lowered to the intermediate boiling set temperature at the start of boiling, and the medium temperature is maintained until the entire amount in the hot water tank reaches the intermediate boiling set temperature. It is an object of the present invention to provide a hot water storage type electric water heater in which the heater is not always exposed to the high temperature of the hot water and the durability can be improved.

[0006]

SUMMARY OF THE INVENTION In order to solve the above-mentioned conventional problems, the present invention provides a hot water storage tank, a heater positioned above the hot water storage tank, and an upper hot water temperature detector positioned above the hot water storage tank. A circulating pump for transporting water or hot water in the lower area of the hot water tank to the upper area of the hot water tank, and an intermediate boiling set temperature and a final boiling set temperature higher than the intermediate boiling set temperature as the set boiling temperature. A boiling controller for performing boiling control according to the set temperature is provided, and the boiling controller determines that there is remaining hot water higher than the intermediate boiling set temperature in the upper region of the hot water tank at the start of boiling. When it is detected by the upper hot water temperature detector, the circulating pump is driven to stir and cool the remaining hot water to the intermediate boiling set temperature with the water in the lower area of the hot water tank, and then the entire hot water temperature in the hot water tank is detected based on the upper hot water temperature detector. Intermediate boiling After controlling the heater and the circulating pump so as to be at the set temperature, a full-boiling control means for controlling the heater and the circulating pump so that the temperature of the entire hot water in the hot water tank becomes the set temperature at the final boiling. It had.

According to the above invention, even when high-temperature remaining hot water is present in the upper region of the hot-water storage tank, the temperature of hot water around the heater is lowered to the intermediate boiling set temperature at the start of boiling,
The medium temperature will be maintained until the whole amount in the hot water tank reaches the intermediate boiling set temperature. Therefore, the heater is not always exposed to the high temperature of the hot water, and the durability can be improved.

[0008]

The invention as set forth in claim 1 is characterized in that a hot water tank, a heater positioned above the hot water tank, an upper hot water temperature detector positioned above the hot water tank, and the hot water tank A circulating pump for transporting water or hot water in the lower region to the upper region of the hot water storage tank, and having an intermediate boiling set temperature and a final boiling set temperature as the set boiling temperatures, and performing boiling control in accordance with the set temperatures; A boiling controller is provided, and the boiling controller drives the circulation pump when the upper hot water temperature detector detects that there is remaining hot water higher than the intermediate boiling set temperature in the upper region of the hot water tank at the start of boiling. The remaining water is agitated and cooled to the intermediate boiling set temperature with the water in the lower area of the hot water tank, and then the heater and the heater are set so that the entire hot water temperature in the hot water tank becomes the intermediate boiling set temperature based on the upper hot water temperature detector. Circulation pong After control to, and to have a total volume of boiling-up control means for the hot water temperature of the entire hot water tank to control the heater and the circulating pump to a final boiling temperature setting.

[0009] Even when high-temperature remaining hot water is present in the upper region of the hot water tank, the temperature of the hot water surrounding the heater is lowered to the intermediate boiling set temperature at the start of boiling, so that the entire amount in the hot water tank is set to the intermediate boiling temperature. Since the medium temperature is maintained until the temperature reaches the temperature, the heater is not always exposed to the high temperature of the hot water, and the durability can be improved.

The invention according to claim 2 further comprises a lower hot water temperature detector located at a lower portion of the hot water storage tank, wherein the upper hot water temperature is controlled while the heater and the circulation pump are being controlled at an intermediate boiling set temperature. When the difference between the hot water temperatures detected by the temperature detector and the lower hot water temperature detector falls below a first preset temperature, the set boiling temperature is switched to the final heated set temperature, and the heater and the circulation pump are controlled. Is provided with a boiling controller having a total amount boiling control means for performing the following.

When a large amount of high-temperature remaining hot water is present in the hot water tank, the circulation pump is driven to lower the temperature of the hot water with stirring in the lower region of the hot water tank to an intermediate boiling set temperature. Even when it is not possible, the entire hot water tank is agitated, so the agitation status is determined based on the difference between the detected hot water temperatures of the upper hot water detector and the lower hot water detector, and the boiling set temperature is set to the final boiling set temperature. Can be switched,
Boiling with high-temperature hot water can be continued from the hot water tank upper region.

According to the third aspect of the present invention, when the hot water is completely discharged from the hot water storage tank at the final boiling set temperature, the lower hot water temperature detector falls below the second preset temperature. Detecting that the temperature of the entire hot water storage tank reaches the final boiling set temperature, based on the temperature detected by the upper hot water temperature detector, and has an additional flushing control means for controlling the heater and the circulation pump. A boiling controller is provided.

[0013] Then, when the hot water is detected to have reached the mounting position of the lower hot water temperature detector and the water is heated, the water is heated at the final boiling set temperature to lower the hot water temperature in the hot water storage tank. The amount of hot water for the hot water can be boiled without causing the hot water to flow.

Further, according to the present invention, the difference between the hot water temperature detected by the upper temperature detector and the lower temperature detector or the temperature difference detected by the upper temperature detector and the middle temperature detector after the completion of the boiling of the entire amount of the hot water tank is preset. If the temperature exceeds the set fifth set temperature, an abnormality detecting means for detecting an abnormality is provided, and a boiling controller having a pump abnormality control means for repeatedly stopping and driving the circulating pump a predetermined number of times when an abnormality occurs is provided. Like that.

[0015] When a circulating pump for transporting water in the lower region of the hot water tank to the upper region of the hot water tank or a hot water temperature difference that detects an abnormality in the transport path is determined, the circulating pump is repeatedly stopped and driven a predetermined number of times. In the case of an abnormality due to a bite or the like, it may be possible to return to normal, and normal boiling can be continued.

Further, in the invention according to claim 5, the central hot water temperature detector positioned in the middle of the hot water storage tank is set in advance at the time of tapping after the entire amount of the hot water storage tank has been heated at the final boiling set temperature. When detecting that the temperature is lower than the third set temperature, the hot water temperature in the hot water storage tank is set to a first set time or a hot water temperature of the central hot water detector higher than the third set temperature. Until the temperature exceeds a fourth set temperature, draining the hot water to control the heater and the circulating pump based on the detected temperature of the upper hot water temperature detector so that the upper region of the hot water storage tank becomes the final boiling set temperature. A boiling controller having a control means is provided.

Then, when the hot water is detected to have reached the mounting position of the central hot water temperature detector and the water is heated, the water is heated at the final boiling set temperature so that the temperature of the hot water in the upper area of the hot water storage tank is reduced. It is possible to continue to secure a fixed amount of hot water without lowering.

Further, the invention described in claim 6 is an abnormality detection for detecting that the entire amount of the hot water tank has been heated during the heating by the hot water flushing control means based on the temperature detected by the upper hot water temperature detector. Means, and a boiling controller having a pump abnormality control means for repeatedly stopping and driving the circulating pump a predetermined number of times when an abnormality occurs.

If the circulation pump for transporting the water in the lower area of the hot water tank to the upper area of the hot water tank or the hot water temperature difference detecting the abnormality of the transport path is determined, the stop and the driving of the circulation pump are repeated a predetermined number of times. In the case of an abnormality due to a bite or the like, it may be possible to return to normal, and normal boiling can be continued.

According to a seventh aspect of the present invention, after the circulation pump is stopped and driven a predetermined number of times when an abnormality occurs, the circulation pump is driven again, and the circulation pump is driven again by a predetermined second set time. When the upper hot water temperature detector detects that the hot water temperature has dropped to a predetermined sixth set temperature, the upper hot water temperature detector restarts boiling, and stops the lamination pump when the second set time has elapsed. And a boiling controller.

When the state of the circulation pump or the conveyance path is restored by repeating the stop and drive of the circulation pump a predetermined number of times, the water in the lower area of the hot water tank is conveyed to the upper area of the hot water tank. The hot water detector detects the temperature drop, determines that the temperature has returned to normal, and performs boiling again, so that a necessary amount of hot water in the hot water storage tank can be secured.

Further, according to the invention described in claim 8, the pump for canceling the pump abnormality and performing the boiling when the condition for starting the boiling of the entire amount of the hot water storage tank by the midnight electric power in a state where the abnormality of the pump is determined is satisfied. A boiling controller having an abnormality canceling means is provided.

Then, under the condition that the entire hot water tank is heated using the late-night electric power, the abnormality is released and the water is heated, so that the dust abnormality control processing is performed every day by the pump abnormality control means. As a result, it may be possible to return to normal, and normal boiling can be resumed. Further, even when the heater does not return to the normal state, it is possible to keep the daily hot water in the area above the heater.

[0024]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a structural view of a hot water storage type electric water heater according to the present invention.

In FIG. 1, 10 is a hot water tank, 11 is a heater positioned above the hot water tank 10, and 12 is a hot water tank 10.
The upper hot water temperature detector, located at the top of the tank, 13 is the hot water tank 1
A circulating pump for transporting water or hot water in the lower region of 0 to the upper region of the hot water storage tank 10. The circulating pump 14 sets the intermediate boiling set temperature T1 as the boiling set temperature and the final boiling set temperature T2 higher than the intermediate boiling set temperature. A boiling controller for performing boiling control in accordance with the set temperature; 14a an intermediate temperature setting means for setting an intermediate boiling temperature T1; 14b
Is a final temperature setting means for setting the final boiling temperature T2,
15 is a lower hot water temperature detector positioned at the lower part of the hot water storage tank 10, 16 is a middle hot water temperature detector positioned at the center of the hot water storage tank 10, 17 is full boiling control means, 18 is additional follow-up control means, 19 is a control means for flushing out of hot water, 20 is an abnormality detecting means for detecting an abnormality of the circulation pump 13 or the conveyance path, 21 is a pump abnormality control means for controlling the circulation pump 13 when an abnormality is detected, and 22 is an abnormality. It is configured by pump abnormality canceling means for temporarily canceling the abnormality.

The operation and operation of the hot water storage type electric water heater configured as described above will be described below with reference to FIG.

First, at the start of boiling by the total boiling control means 17, if the upper region of the hot water storage tank 10 is water,
The heater 11 is energized under the control of the boiling controller 14, and the region above the heater 11 is rapidly heated to become hot water.
The temperature detected by the upper hot water temperature detector 12 is set to the intermediate temperature setting means 14.
When the intermediate boiling set temperature (T1) set in a is reached,
ON / OFF control of the circulation pump 13 is performed, and the hot water storage tank 10 is controlled.
The water is transported to the upper region of the hot water storage tank 10 and is heated so that the entire amount of the hot water storage tank 10 becomes the intermediate heating set temperature (T1). After the entire amount is heated, the set boiling temperature is switched to the final set temperature (T2) set by the final temperature setting means 14b, and the entire amount of the hot water storage tank 10 is set to the final set temperature (T2).
As described in 2), the circulation pump 13 is turned on again by performing ON / OFF control. When the temperature detected by the upper hot water temperature detector 12 at the start of boiling is equal to or higher than the intermediate boiling set temperature (T1), energization of the heater 11 is started by the control of the boiling controller 14 and the circulation pump 13 is started. Is driven to transport water to the upper region of the hot water storage tank 10. At this time, the circulating pump 13 is continuously driven with a circulating amount in which the cooling ability by stirring the conveyed water is higher than the heating capacity of the heater 11. And the upper hot water temperature detector 12
When ON detects the intermediate boiling set temperature (T1), ON / OFF control of the circulation pump 13 is performed so that the entire amount of the hot water storage tank 10 becomes the intermediate boiling set temperature (T1).

FIG. 3 shows a specific method of boiling when the entire amount of the hot water storage tank 10 is boiled at the intermediate boiling set temperature (T1) or the final boiling set temperature (T2). First, the set temperature at that time (TOF
When the detected temperature of the upper hot water temperature detector 12 is higher than F), the circulation pump 13 is turned on. When the water is conveyed to the upper region of the hot water storage tank 10 by driving the circulation pump 13, the temperature of the hot water decreases, and when the temperature reaches the set temperature (TOFF), the circulation pump 13 is turned off. Since the transport of water to the upper region is stopped, the temperature of the hot water rises due to the heating of the heater 12. Then, the upper hot water temperature detector 12 detects the set temperature (TOF).
F) When the pump ON temperature (TON) of a higher temperature is detected, the circulation pump 13 is turned on. The above operation is repeated, and the hot water of the set temperature (TOFF) is supplied to the heater 1.
2, the hot water is stored from the upper area of the hot water storage tank 10 toward the lower area,
You can boil the whole amount.

The switching of the set boiling temperature is controlled as follows. When the entire amount of the hot water storage tank 10 rises, the water temperature in the lower region also rises, and the temperature of the upper region decreases even if the circulation pump 13 is continuously turned on to lower the temperature to the set temperature (tOFF). Disappears. As the time elapses, the water temperature in the lower region also rises to the set temperature (tOFF), so that the temperature of the hot water in the upper region rises even if the circulation pump 13 is continuously turned on. Then, the upper hot water temperature detector 12 turns on the pump ON temperature (TON).
When a higher temperature is detected, the set boiling temperature is switched to the final set boiling temperature (T2). In addition, the condition for completing the boiling is similarly performed. The entire amount of the hot water storage tank 10 is heated at the final boiling set temperature (T2), and the hot water temperature in the lower region rises, so that the upper hot water temperature detector 12 is higher than the pump ON temperature (TON) at that time. When the temperature is detected, the boiling is completed.

Thus, at the start of boiling, hot water tank 10
When the upper hot water temperature detector 12 detects that there is remaining hot water higher than the intermediate boiling set temperature (T1) in the upper region of
The circulation pump 13 is driven to stir and cool the remaining hot water to the intermediate boiling set temperature (T1) with the water in the lower area of the hot water tank 10, and then, based on the upper hot water temperature detector 12, the temperature of the entire hot water in the hot water tank 10 is changed to the intermediate temperature. After controlling the heater 12 and the circulation pump 13 so as to reach the set boiling temperature (T1), the hot water tank 1
By controlling the temperature of the entire hot water to be equal to the final boiling set temperature (T2), the medium temperature is maintained until the entire amount in the hot water storage tank 10 reaches the intermediate boiling set temperature (T1). Is not always exposed to the high temperature of the hot water, and the durability can be improved.

As shown in FIG. 4, at the time of starting the boiling by the total boiling control means 17 when there is a lot of remaining hot water, the temperature detected by the upper hot water temperature detector 12 is set to the intermediate boiling set temperature (T1). In the above, the heater 11 is energized by the control of the boiling controller 14 and the circulation pump 13 is driven. May not fall to the intermediate boiling set temperature (T1). The boiling operation at this time is performed as follows. First, the circulation pump 1
3 is driven, and water is conveyed to the upper region of the hot water storage tank 10, so that the temperature detected by the upper hot water temperature detector 12 decreases. However, when stirring is performed to the lower region of the hot water storage tank 10 due to a large amount of remaining hot water, the temperature of the lower region increases, so that the detection temperature of the upper hot water temperature detector 12 does not decrease. At this time, the upper hot water temperature detector 12 and the lower hot water temperature detector 15
Is determined, and when the temperature falls below the first set temperature (K1), it is determined that the temperature of the hot water in the upper region does not decrease even if the circulating pump 13 is driven any further, and the set boiling temperature is set to the final boiling temperature. The temperature is switched to the set temperature (T2).

Thus, when there is a lot of high-temperature remaining hot water in the hot water storage tank 10, the circulating pump 13 is driven and the intermediate boiling set temperature (T
Even when the remaining hot water is not fully lowered even if the remaining hot water is stirred and cooled until 1), the entire amount of the hot water storage tank 10 is stirred and the stirring state is determined based on the detected hot water temperature difference between the upper hot water temperature detector 12 and the lower hot water temperature detector 15. By doing so, it is possible to switch the boiling set temperature to the final boiling set temperature (T2), and it is possible to continue boiling with hot water from the upper region of the hot water storage tank 10.

As shown in FIG. 5, after the entire amount of the hot water storage tank 10 is completely heated at the final boiling set temperature (T2), the hot water is discharged, and the lower hot water temperature detector 15 is set to the second set temperature (preset). When it is detected that the temperature has fallen below T3), the additional start-up control means 18 starts boiling. At this time, the heater 11 and the circulation pump 13 are controlled with the set boiling temperature as the final set boiling temperature (T2) to store hot water from the upper region of the hot water storage tank 10 to the lower region. Boil. The completion condition of the boiling is the same as that of the total boiling control means 17, and the upper hot water temperature detector 1
When the temperature 2 is higher than the pump ON temperature (TON) at that time, the boiling is finished.

Accordingly, when it is detected that the hot water has been discharged to the mounting position of the lower hot water temperature detector 15 and the water is heated,
By performing the heating at the final heating setting temperature (T2), the amount of hot water for the hot water can be heated without lowering the temperature of the hot water in the hot water storage tank 10.

As shown in FIG. 6, after the entire amount of the hot water tank 10 is completely heated at the final boiling set temperature (T2), the hot water is discharged and the central hot water temperature detector 16 positioned in the middle of the hot water tank 10 is used. Is a preset third set temperature (T4)
Is detected, the boiling control is started by the hot water draining control means 19. At this time, the heater 11 and the circulation pump 13 are controlled with the set boiling temperature as the final set boiling temperature (T2), and the hot water storage tank 10 is heated.
The hot water is stored from the upper area to the lower area and boiled. Completion condition of boiling is Chubu hot water detector 16
Is higher than a fourth set temperature (T5) higher than the third set temperature (T4). Alternatively, as shown in FIG. 7, the completion condition of the boiling is that a first set time (H1) set in advance elapses.

Thus, when it is detected that the hot water has been discharged to the mounting position of the central hot water temperature detector 16 and the water is heated,
By performing the boiling at the final boiling set temperature (T2), it is possible to perform the boiling that ensures a certain amount of hot water without running out of the hot water without lowering the hot water temperature in the hot water storage tank 10.

The means for detecting an abnormality upon completion of boiling will be described with reference to the flowchart of FIG.

First, it is determined which boiling means is being controlled by the control means that is currently boiling (processing 31 in FIG. 8;
Simply described as processing 31). Then, when it is determined that the control is the total heating control means 17 or the additional flush control means 18, the heating is performed to the completion condition of the heating by the upper hot water temperature detector 12 (process 32). Upon completion of the boiling, the heater 12 and the circulation pump 13 are stopped (process 3).
3). Then, the difference between the detected temperature (Ttop) of the upper hot water temperature detector 12 and the detected temperature (Tunder) of the lower temperature detector 15 or the middle temperature detector 16 at the time of completion of boiling is preset by the abnormality detecting means 20. It is compared with the set fifth temperature (K2) (process 34). If the temperature difference of the hot water at this time is equal to or lower than the fifth set temperature (K2), the process ends assuming that the boiling has been completed normally. If the hot water temperature difference is equal to or higher than the fifth set temperature (K2), it is determined that the transport amount of water to the upper region of the hot water tank 10 has decreased or stopped, and the pump abnormality control means 21 performs pump abnormality processing. First, the circulation pump 13 is turned on (process 35) and turned off (process 36). This operation is performed a predetermined number of times (step 37). After the predetermined number of times, the circulation pump 13 is turned on again.
(Step 38). When the circulation pump 13 is driven at this time, when it is detected that the detected temperature (Ttop) of the upper hot water temperature detector 12 has dropped to a predetermined sixth set temperature (T6), (step 39) The boiling is restarted (process 40). If the detected temperature (Ttop) does not decrease to the sixth set temperature (T6) and the predetermined second set time (H2) elapses (process 41), the abnormality is determined (process 42). . When it is determined that the control means which is currently boiling is the hot water draining control means 19, the following processing is performed. First, the central hot water temperature detector 16, which is a condition for completing the boiling of the hot water flushing control means 19, exceeds a fourth set temperature (T5) or a first set time (H1).
(Step 43). When the above-described boiling completion condition is satisfied, the heater 12 and the circulation pump 13 are stopped (Step 45), and the boiling is completed. Before the above-mentioned boiling completion condition is satisfied, if the upper hot water temperature detector 12 detects the boiling completion condition of the total amount boiling control means 17 or the additional chasing control means 18 (process 44), the hot water tank 10 The pump abnormality control is performed assuming that the amount of water transported to the upper region of the pump has decreased or stopped. Subsequent processing is the same as the above-described pump abnormality control of the full-boiling control means 17 or the additional follow-up control means 18.

By repeating the stop and drive of the circulating pump 13 a predetermined number of times, it may be possible to return to a normal state in the case of an abnormality such as a bite of dust or the like. The hot water in the hot water storage tank can be secured by determining that the water has returned to the normal temperature and performing boiling again.

In the state where the pump abnormality has been determined,
When the condition for starting the boiling of the entire amount of the hot water storage tank 10 by the late-night electric power is reached, a pump abnormality canceling means 22 for canceling the pump abnormality and heating the tank is provided.

Thus, under the condition that the entire amount of the hot water storage tank 10 is to be heated, the abnormality is canceled and the water is heated, so that the dust abnormality control processing by the pump abnormality control means 21 is performed every day. As a result, it may be possible to return to normal, and normal boiling can be resumed. Further, even when the heater does not return to the normal state, it is possible to keep the daily hot water in the area above the heater.

[0043]

As described above, according to the first aspect of the present invention, the medium temperature is maintained until the entire volume in the hot water tank reaches the intermediate boiling set temperature, and the heater is constantly exposed to the high temperature hot water temperature. And the durability can be improved.

According to the second aspect of the present invention, even when the remaining hot water is not fully lowered even when the remaining hot water is stirred and cooled to the intermediate boiling set temperature, the set boiling temperature is set to the final boiling set temperature. By switching, it is possible to continue boiling with hot water from the upper region of the hot water storage tank.

According to the third aspect of the present invention, the amount of hot water can be raised without lowering the temperature of the hot water in the hot water storage tank.

According to the fourth aspect of the present invention, when the circulating pump for transferring the water in the lower area of the hot water tank to the upper area of the hot water tank or the hot water temperature difference detecting the abnormality in the transport path is determined, the circulating pump is stopped. And the drive are repeated a predetermined number of times, it may be possible to return to a normal state in the case of an abnormality due to dust biting or the like, and normal boiling can be continued.

According to the fifth aspect of the present invention, when it is detected that the hot water has been discharged to the mounting position of the central hot water temperature detector and the water is heated, the water is heated at the final boiling set temperature. Thereby, it is possible to continue to secure a fixed amount of hot water without lowering the hot water temperature in the hot water storage tank upper region.

According to the sixth aspect of the present invention, if the circulation pump for transferring water in the lower area of the hot water tank to the upper area of the hot water tank or a difference in hot water temperature that detects an abnormality in the transfer path is determined, the circulation pump is stopped. And the drive are repeated a predetermined number of times, it may be possible to return to a normal state in the case of an abnormality due to dust biting or the like, and normal boiling can be continued.

According to the seventh aspect of the present invention, the upper hot water temperature detector detects the temperature drop by the abnormal control, and if it is determined that the temperature has returned to the normal state, the upper hot water detector is again heated and the water in the hot water storage tank is returned. The required amount of hot water can be secured.

According to the eighth aspect of the present invention, by performing the dust bite control processing by the pump abnormality control means every day, it may be possible to return to normal, and normal boiling can be resumed. Even in a case where the heater does not return to the normal state, it is possible to keep the daily hot water in the area above the heater.

[Brief description of the drawings]

FIG. 1 is a structural diagram of a hot-water storage type electric water heater according to one embodiment of the present invention.

FIG. 2 is an explanatory diagram of an operation of full-boiling control of the electric water heater.

FIG. 3 is an explanatory diagram of the operation of full-boiling control of the electric water heater.

FIG. 4 is an explanatory diagram of the operation of full-boiling control of the electric water heater.

FIG. 5 is an explanatory diagram of an operation of additional flushing control of the electric water heater.

FIG. 6 is an explanatory diagram of the operation of the hot water flushing control of the electric water heater.

FIG. 7 is an explanatory diagram of the operation of the hot water flushing control of the electric water heater.

FIG. 8 is a flowchart showing the operation of the electric water heater at the time of abnormal operation.

FIG. 9 is a structural diagram of a conventional hot water storage type electric water heater.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Hot water storage tank 11 Heater 12 Upper hot water temperature detector 13 Circulation pump 14 Boiling controller 14a Intermediate temperature setting means 14b Final temperature setting means 15 Lower hot water temperature detector 16 Middle hot water temperature detector 17 Full amount boiling control means 18 Addition Idle control means 19 Running out of hot water control means 20 Abnormality detection means 21 Pump abnormality control means 22 Pump abnormality release means

 ──────────────────────────────────────────────────の Continuing on the front page (72) Inventor Shinji Kushida 1006 Kadoma Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd.

Claims (8)

[Claims] 1. A hot water storage tank, a heater positioned above the hot water storage tank, an upper hot water temperature detector positioned above the hot water storage tank, and water or hot water in a lower area of the hot water storage tank, A circulating pump for transporting the mixture to a region, a boiling controller having an intermediate boiling set temperature and a final boiling set temperature as a set boiling temperature, and performing a boiling control in accordance with the set temperature. When the upper hot water temperature detector detects that there is residual hot water higher than the intermediate boiling set temperature in the upper area of the hot water tank at the start of boiling, the circulating pump is driven and the hot water in the lower area of the hot water tank is heated. The remaining hot water is agitated and cooled to the set temperature, and then the heater and the circulation pump are controlled so that the entire hot water temperature in the hot water tank is raised to the set temperature based on the upper hot water temperature detector. Hot water A hot water storage type electric water heater having a total amount boiling control means for controlling the heater and the circulation pump so that the temperature becomes a final boiling set temperature. 2. A method according to claim 1, further comprising: a lower hot water temperature detector positioned below the hot water storage tank, wherein the upper hot water temperature detector and the lower hot water temperature detector detect the temperature while controlling the heater and the circulation pump at the intermediate boiling set temperature. 2. A total amount boiling control means for switching a set boiling temperature to a final set boiling temperature and controlling the heater and the circulation pump when the temperature difference of the hot water falls below a first set temperature set in advance. The described hot water storage type electric water heater. 3. When the lower hot water temperature detector detects that the temperature of the hot water storage tank has dropped below a second preset temperature at the final hot water set temperature after the entire quantity of water has been heated in the hot water storage tank, the hot water storage tank 2. The hot water storage type electric water heater according to claim 1, further comprising an additional flushing control means for controlling the heater and the circulation pump based on the detected temperature of the upper hot water temperature detector so that the entire hot water temperature becomes the final boiling set temperature. 4. A hot water temperature difference detected by the upper temperature detector and the lower temperature detector or the upper temperature detector and the middle temperature detector after completion of the boiling of the entire amount of the hot water storage tank exceeds a fifth set temperature set in advance. 4. The apparatus according to claim 3, further comprising abnormality detection means for detecting abnormality, and pump abnormality control means for repeating stop and drive of the circulating pump a predetermined number of times when an abnormality occurs.
The described hot water storage type electric water heater. 5. A hot water tank after the entire amount of water in the hot water tank has been completely heated at the final boiling set temperature, and the central hot water temperature detector located in the middle of the hot water tank has fallen below a third set temperature set in advance. Is detected, the temperature of the hot water in the hot water storage tank is set to a predetermined first set time or until the central hot water temperature detector exceeds a fourth set temperature higher than the third set temperature. 2. A hot-water storage type according to claim 1, further comprising a hot-water drainage control means for controlling a heater and a circulation pump based on a temperature detected by an upper hot-water temperature detector so that an upper region of the hot-water storage tank has the final boiling set temperature. Electric water heater. 6. An abnormality detecting means for detecting that the entire amount of the hot water tank has been heated during the heating by the hot water flushing control means based on the temperature detected by the upper hot water temperature detector. 6. The hot water storage type electric water heater according to claim 5, further comprising a pump abnormality control means for repeating the stop and drive of the pump a predetermined number of times. 7. After the circulation pump is stopped and driven a predetermined number of times when an abnormality occurs, the circulation pump is driven again, and the upper hot water temperature detector is set to a predetermined value by a predetermined second set time. 7. The hot water storage type according to claim 4, further comprising pump abnormality control means for restarting boiling when detecting that the temperature of the hot water has dropped to the sixth set temperature, and for stopping the circulating pump when the second set time has elapsed. Electric water heater. 8. A pump abnormality canceling means for canceling a pump abnormality and performing boiling when a condition for starting boiling of the entire amount of the hot water storage tank by midnight electric power is reached in a state where the pump abnormality is determined. 6. A hot water storage type electric water heater according to 6.