JP2004313237A - Electric boiler - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To avoid an incorrect detection of boiling attributed to a drop in the precision of detecting the boiling. <P>SOLUTION: A boil detection work restriction means 12 which forbids or restricts the boil detection work according to the operation of supplying water by a water supply means 8 is provided to forbid the detection of the boiling during the boiling period with the supply of water kept on to counter changes in the temperature of the hot water under the supply of water. The detection of the boiling is started after the end of the water supply operation. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric water heater, which is mainly used in an ordinary household or office and is provided with a water supply tank in addition to a water heater.
[0002]
[Prior art]
2. Description of the Related Art Conventionally, there has been proposed an electric water heater including a water heater container and a water supply container for storing water so that the hot water is not easily drained even when the amount of hot water consumed is large, and configured to automatically supply water to the water heater container by a water supply pump. (For example, see Patent Document 1).
[0003]
According to such an electric water heater, there has been proposed an example in which the water in the water supply container is supplied to the water heater and the water is simultaneously supplied to the water container to perform the water heating, thereby realizing the early boiling.
[0004]
[Patent Document 1]
JP 2000-135168 A
[Problems to be solved by the invention]
According to such an electric water heater, when the water in the water supply container is heated while the water in the water supply container is being supplied to the water supply container, the water in the water supply container is mixed with the supplied water, so that the fluctuation of the water temperature becomes large and the temperature detecting means detects the temperature. However, there is a problem that the accuracy of the boiling detection is reduced because the temperature at which the heating is performed fluctuates greatly.
[0006]
SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned conventional problems, and has as its object to avoid erroneous boiling detection due to a decrease in accuracy of boiling detection when water is supplied while supplying water.
[0007]
[Means for Solving the Problems]
In order to solve the above-mentioned conventional problems, the present invention provides a water supply means having a boiling detection operation suppressing means for prohibiting a boiling detection operation during a water supply operation. The detection is prohibited, and the boiling detection is started after the water supply operation is completed. With this configuration, it is possible to avoid erroneous boiling detection due to fluctuations in hot water temperature during water supply.
[0008]
BEST MODE FOR CARRYING OUT THE INVENTION
The invention according to claim 1 accommodates a kettle container for boiling water to keep the temperature warm, a heating unit for heating the kettle container, a temperature detecting unit attached to the kettle container, and water to be supplied to the kettle container. A water supply container and water supply means for supplying water from the water supply container to the water heater container are provided, and a boiling detection operation suppressing means for inhibiting a boiling detection operation during the water supply operation of the water supply means is provided.
[0009]
With this configuration, it is possible to prevent the detection of boiling when water is being boiled while supplying water, and to start the detection of boiling after the completion of the water supply operation, thereby avoiding erroneous boiling detection due to fluctuations in the temperature of the water during water supply.
[0010]
The invention according to claim 2 is, in particular, in the invention according to claim 1, further comprising water supply abnormality detection means for detecting abnormality of the water supply means, and when the abnormality of the water supply means is detected by the water supply abnormality detection means, The driving of the water supply means is stopped, and the control by the boiling detection operation suppressing means is stopped to detect the boiling.
[0011]
Thus, it is possible to prevent the boiling detection operation suppressing means from continuing boiling with the inhibition of the boiling detection even though the water supply is stopped due to the abnormality of the water supply means.
[0012]
The invention according to claim 3 is particularly configured such that the water supply abnormality detecting means according to claim 2 is configured to detect disconnection of the water supply motor, so that the water heater can be stopped when water supply is stopped when the water supply motor is disconnected. Since the boiling detection of the hot water can be started, it is possible to prevent the boiling detection operation suppressing means from continuing the boiling while inhibiting the boiling detection.
[0013]
According to a fourth aspect of the present invention, in particular, the water supply abnormality detecting means according to the second aspect is configured to detect lock of the water supply motor, so that the water heater can be stopped when the water supply stops when the water supply motor lock fails. Since the boiling detection of the hot water can be started, it is possible to prevent the boiling detection operation suppressing means from continuing the boiling while inhibiting the boiling detection.
[0014]
The invention according to claim 5 is particularly configured such that the water supply abnormality detecting means according to claim 2 is configured to detect a no-load operation state of the water supply motor, so that even if the water supply motor is in an operation state, the water heater is heated. When there is no water supply to the container, it is determined that the water supply is abnormal, and the detection of boiling of the hot water in the water heater container can be started, preventing the boiling detection operation suppression means from continuing to boil while inhibiting the detection of boiling. it can.
[0015]
According to a sixth aspect of the invention, in particular, the water supply abnormality detecting means according to the second aspect is configured to detect a continuous operation time of the water supply motor, so that the water heater can be operated even when the water supply motor is operated for a predetermined time. If the supply of water to the tank is not completed, it is determined that the water supply is abnormal, and the detection of boiling of the hot water in the water heater can be started. Can be prevented.
[0016]
According to a seventh aspect of the present invention, in particular, in the invention according to any one of the second to sixth aspects, when an abnormality of the water supply means is detected by the water supply abnormality detection means, the fact is displayed on the display means. By doing so, the user can confirm the abnormality of the water supply, so that the convenience can be improved.
[0017]
【Example】
(Example 1)
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a block diagram of an electric water heater according to Embodiment 1 of the present invention. In FIG. 1, reference numeral 1 denotes a water heater for heating the water contained therein and keeps the water warm, 2 denotes a heating means including a 925 W main heater for heating the water heater 1 and a 75 W warming heater, and 3 denotes a water pipe of the water of the water heater 1. A tapping means, which is a pump for discharging from a tapping port 5 through a tap 4, is a water amount detecting means, and comprises an infrared light emitting element mounted opposite to the water pipe 4 and light receiving elements 6a, 6b, 6c. It is configured to detect the liquid level of the water pipe 4 at which the liquid level becomes the same as that of the water heater 1. 6a is a full water detection installed at a full water position, 6c is a water supply detection installed at a position where the heating means 2 is stopped to prevent empty heating of the water heater vessel 1, and 6b is an intermediate detection installed at an intermediate position between 6a and 6c. There is a configuration in which three levels of water amounts are detected by 6a, 6b, and 6c.
[0018]
Reference numeral 7 denotes a water supply container for storing water for supplying water to the water heater container 1, and reference numeral 8 denotes a water supply means which is a motor-driven pump for supplying the water of the water supply container 7 to the water heater container 1 through the water supply pipe 9. Reference numeral 10 denotes a temperature detecting means for detecting the temperature of the hot water in the water heater 1. Reference numeral 11 denotes control means programmed by a microcomputer, which controls the driving of the heating means 2 and the water supply means 8 and detects boiling of hot water based on the inputs of the temperature detecting means 10 and the water amount detecting means 6. The operation of the above configuration will be described. When the amount of water in the water heater 1 is smaller than the water supply detection 6c, the heating of the heating means 2 is stopped. The water supply means 8 automatically starts water supply when the amount of water in the water heater vessel 1 is smaller than the full water detection 6a, and stops water supply when the water amount becomes equal to or more than the full water detection 6a. The heating means 2 starts heating when the amount of water exceeds the water supply detection 6c, and thereafter performs heating by the main heater until boiling is detected by the temperature detecting means 10, and keeps heat by a warming heater after the detection of boiling.
[0019]
In the method of boiling detection, boiling detection is performed when the temperature rise gradient obtained from the temperature detection means 10 becomes gentler than a predetermined temperature rise gradient (15 seconds / 0.5 ° C. in this embodiment). The boiling detection operation suppressing means 12 is a control means programmed by a microcomputer, and its configuration monitors a drive signal of the water supply means 8 by the control means 11 and, if the water supply motor is being driven, the boiling of the water in the water heater container 1. The control means 11 is instructed to prohibit the detection, and if the water supply motor is stopped, the boiling detection is permitted.
[0020]
As described above, according to the boiling detection operation suppressing means 12, the hot water in the heating kettle 1 and the water from the water supply pipe 9 are mixed during the water supply, and the temperature gradient of the temperature detecting means 10 rises and falls greatly due to the stirring of the hot water. In some cases, the temperature may be temporarily kept constant even though the boiling point has not been reached, so that the detection of boiling is prohibited and erroneous detection of boiling is avoided.
[0021]
(Example 2)
Hereinafter, a second embodiment of the present invention will be described with reference to the drawings. FIG. 2 is a block diagram of an electric water heater according to Embodiment 2 of the present invention. Since the basic configuration of the present embodiment is substantially the same as that of the first embodiment, the same components are denoted by the same reference numerals and description thereof will be omitted.
[0022]
In FIG. 2, reference numeral 13 denotes a water supply abnormality detecting means for detecting an operation state of the water supply motor 8 as a component of the water supply means 8 by monitoring a current value of the motor. FIG. 3 is a circuit diagram for monitoring a current value, and FIG. 4 is a diagram for explaining a method for detecting an operation state of a motor.
[0023]
In FIG. 3, reference numeral 8a denotes a water supply motor. The power supply voltage V0 is DC10V, and when the SW is turned on by the control means 11, the water supply motor 8a is driven and a voltage V1 corresponding to the motor current is generated in the resistor R1. The voltage V1 is smoothed with a time constant of about 0.1 second by the resistor R2 and the capacitor C1 to obtain the voltage V2.
[0024]
FIG. 4A is a graph of the voltage V2 when water is normally supplied. The peak at the time of starting the motor is about 4.5 V, and the state where water is continuously supplied stably is about 2.5 V. FIG. 4B is a graph of the voltage V2 when the motor winding breaks after the motor is started, and the voltage is 0V. When the monitor voltage V2 becomes equal to or less than the threshold value 0.3V after the water supply motor 8a is started, the water supply abnormality detection means 13 determines that the motor is broken.
[0025]
FIG. 4C is a graph of the voltage V2 when the lock failure of the motor occurs after the motor is started, and the voltage is about 4.2V. The water supply abnormality detection means 13 determines that the motor lock has failed if the monitor voltage V2 becomes equal to or higher than the threshold value 3.8 V one second after the water supply motor 8a is started. Next, a graph of the voltage V2 when the supply of water from the water supply container 7 is stopped after the motor is started is shown in FIG. When the water as the motor load is exhausted, the voltage V2 drops to about 1.2V and stabilizes. The water supply abnormality detecting means 13 determines that the water has run out when the monitor voltage V2 is within the range of the threshold value from 0.3 V to 1.7 V.
[0026]
Next, a case will be described in which the full water detector 6a does not detect full water even when the water supply motor 8a operates continuously for a long time. The capacity of the water supply container 7 is 2 L, and the water supply amount of the water supply motor 8a is about 40 mL per second. If water can be normally supplied, the water in the water supply container 7 can be supplied in about 50 seconds. The water supply abnormality detecting means 13 determines whether the water supply container 7 has run out of water if the full water detection 6a does not detect the full water in the water container 1 even if the driving time of the water supply motor 8a continues for 90 seconds. Is determined to be an abnormality such as lock of the pump unit and clogging of the water supply pipe 9.
[0027]
As described above, when the water supply abnormality detecting means 13 detects the abnormality of the water supply means 8, it sends a signal to the boiling detection operation suppressing means 12. Then, the boiling detection operation suppressing means 12 instructs the control means 11 to stop driving the water supply motor 8a and to permit the boiling detection.
[0028]
When boiling water while supplying water in a state in which the detection of boiling is prohibited by the boiling detection operation suppressing means 12, if the supply of water is normal, the rise in the temperature of the hot water is suppressed, so that there is no boiling, but the water supply motor 8a If the battery breaks down due to disconnection or the like, the supply of water stops and the temperature of the hot water rises in a short time and boils. Since the heating cannot be stopped because the detection of boiling is prohibited, the boiling state continues for a long time. The water supply abnormality detecting means 13 can effectively avoid such a state.
[0029]
As described above, in the present embodiment, when the abnormality of the water supply means 8 is detected by the water supply abnormality detection means 13, the boiling detection operation suppressing means 12 cancels the prohibition of the boiling detection and the boiling detection is started. An abnormal state in which the boiling state continues for a long time can be avoided, and the heating by the normal boiling detection can be terminated.
[0030]
In this embodiment, when the water supply abnormality detecting means 13 detects an abnormality of the water supply means 8, the issuing diode which is the display means 14 is made to blink. The blinking display of the display means 14 allows the user to instantly confirm that an abnormality in water supply has occurred, to supply water to the water supply container, to clean trash clogged at the bottom of the water supply container 7, and to repair the electric water heater. Information can be obtained, and thus convenience is improved.
[0031]
【The invention's effect】
As described above, according to the present invention, boiling detection is prohibited when water is being boiled while water is being supplied, and boiling detection is started after the water supply operation is completed, so that erroneous boiling detection due to fluctuations in hot water temperature during water supply can be avoided. . In addition, when the water supply is stopped due to an abnormality in the water supply mechanism, the prohibition of the boiling detection is released, so that the state of continuous boiling for a long time can be prevented. In addition, since the abnormality of the water supply mechanism is notified by the display means, the user can easily confirm the situation and the convenience is improved.
[Brief description of the drawings]
FIG. 1 is a block diagram of an electric water heater in Embodiment 1 of the present invention. FIG. 2 is a block diagram of an electric water heater in Embodiment 2 of the present invention. FIG. 3 is a circuit diagram of water supply abnormality detecting means in Embodiment 2 of the present invention. FIG. 4 is a motor detection timing chart of a water supply abnormality detection unit according to a second embodiment of the present invention.
DESCRIPTION OF SYMBOLS 1 Hot water container 2 Heating means 7 Water supply container 8 Water supply means 10 Temperature detection means 12 Boiling detection operation suppression means 13 Water supply abnormality detection means 14 Display means

Claims (7)

A water heater for heating the water heater container, a heating means for heating the water heater container, a temperature detecting means attached to the water heater container, a water supply container for storing water to be supplied to the water heater container, and water for the water supply container Water supply means for supplying water to the water heater container, and a boiling detection operation suppressing means for inhibiting the boiling detection operation during the water supply operation of the electric water heater is provided. It is provided with water supply abnormality detection means for detecting abnormality of the water supply means, and when the abnormality of the water supply means is detected by the water supply abnormality detection means, stops the drive of the water supply means and stops the control by the boiling detection operation suppression means. The electric water heater according to claim 1, which performs boiling detection. The electric water heater according to claim 2, wherein the water supply abnormality detection means detects a disconnection of a water supply motor as the water supply means. 3. The electric water heater according to claim 2, wherein the water supply abnormality detecting means detects a lock of a water supply motor as the water supply means. The electric water heater according to claim 2, wherein the water supply abnormality detection means detects a no-load operation state of a water supply motor as the water supply means. 3. The electric water heater according to claim 2, wherein the water supply abnormality detection means detects a continuous operation time of a water supply motor as the water supply means. The electric water heater according to any one of claims 2 to 6, wherein when an abnormality of the water supply means is detected by the water supply abnormality detection means, the fact is displayed on the display means.

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