JP3236980B2 - Electric 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 boiling control of an electric water heater used in ordinary households.

[0002]

2. Description of the Related Art In recent years, there has been a demand for an electric water heater not only as a household article which can easily heat and maintain water, but also in urban areas which has a function of converting it to delicious water. As a function of converting the water into delicious water, a function of detecting the boiling state of water, maintaining the boiling for a certain period of time, and removing a chlorine component or the like in the water during the period of maintaining the boiling is generally used.

[0003] Hereinafter, a conventional electric water heater will be described with reference to the drawings. FIG. 9 is a block diagram showing a configuration of a conventional electric water heater. In the figure, 1 is a container for storing water, 2 is a heating means for heating water (hereinafter simply referred to as water) in the container 1, 3 is an energization control means for controlling energization of the heating means 2, and 4 is water A temperature sensor 5 for indirectly detecting a temperature; 5 a boiling detecting means for detecting a boiling state of water based on an input signal from the temperature sensor 4 and outputting a boiling signal indicating the boiling state; The power supply state of the heating means 2 is controlled via the power supply control means 3 based on the state. The heating means 2 and the temperature sensor 4 are arranged at the bottom of the container 1.

[0004] The interrelationship and operation of the above components will be described. The energization control means 3 includes a relay or the like, and energizes the heating means 2 by turning on the relay. The energization control means 3 is turned on to energize the heating means 2,
When the heating of the water is started, the temperature sensor 4 outputs a signal corresponding to the temperature of the water to the boiling detecting means 5. Boiling detection means 5
Detects the boiling state of water by reducing the rising gradient of the temperature data based on the input signal from the temperature sensor 4 as the water becomes boiling, and outputs a boiling signal indicating the boiling state to the boiling control means 6. .

FIG. 10 is a flowchart showing the operation of the boiling control means 6. In the figure, after heating is started by energizing the heating means 2 in step 41, step 42
Then, the boiling control means 6 constantly checks that a boiling signal is input from the boiling detecting means 5, and when a boiling signal is input, the process proceeds to step 43, initializes a 2-minute measurement counter, and then proceeds to step 44. I do. In step 44, the heating means 2 is energized, and thereafter heating is continued by a loop process of step 45-step 46-step 47-step 44 until two minutes have elapsed, and the boiling state is maintained for two minutes, and two minutes have elapsed. Then, the flow shifts to step 48, where the energization of the heating means 2 is stopped, and the processing ends. During the two-minute boiling, volatile impurities such as chlorine components are removed. As a method for controlling the energization of the heating means 2, a simple method for turning on the heating means 2 continuously for a certain period of time as shown in FIG. There is a method for suppressing the amount of steam released into the atmosphere.

[0006]

In such a conventional electric water heater, while maintaining the boiling state for two minutes after the water is boiled, normal-temperature water directly collected from the water supply port is stored in the container 1. The boiling control means 6 continues the boiling maintaining operation for two minutes despite the fact that the water temperature suddenly drops and the boiling state stops, so that the heating means 2 is intermittently discharged to the atmosphere. When the amount is suppressed, the amount of heating decreases and the water in the container 1 cannot be efficiently heated, and after 2 minutes, the boiling control means 6 determines that the water in the container 1 has not boiled. Also, there is a problem that the heating means 2 is turned off and the water heating operation is terminated.

The present invention solves the above-mentioned problem. Even if a new liquid is added to the container while the boiling state is being detected and the boiling state is maintained, the liquid is immediately heated at the maximum output and added. rear
It is an object of the present invention to provide an electric water heater capable of maintaining a boiling state after boiling water and sufficiently removing impurities.

[0008]

According to a first aspect of the present invention, there is provided a container for storing a liquid, a heating unit for heating the liquid in the container, an energization control unit for controlling energization of the heating unit, Detecting a boiling state of the liquid via a temperature sensor, and a boiling detection means for outputting a boiling signal indicating the boiling state, and detecting a temperature of the liquid via the temperature sensor,
A temperature discriminating unit that outputs a temperature-unreached signal when the temperature is lower than a predetermined temperature; and a boiling control unit that controls the heating operation of the liquid by controlling the energization control unit. The energizing operation is performed such that a water heating operation for heating the heating signal until the boiling signal is input and a boiling maintaining operation for heating the heating means while suppressing the heating amount of the heating means for a predetermined time after the input of the boiling signal are performed. An electric water heater for controlling a control means and for abandoning the boiling maintenance operation when the temperature non-attainment signal is input during the boiling maintenance operation, and controlling to restart the operation from the water heating operation. The present invention according to (2) includes a container for storing a liquid, a heating unit for heating the liquid in the container, an energization control unit for controlling energization of the heating unit, and a temperature sensor. Detecting a boiling state of the liquid, and a boiling detecting means for outputting a boiling signal indicating the boiling state; detecting a temperature decrease of the liquid via the temperature sensor; Temperature drop detecting means for outputting, and boiling control means for controlling the heating operation of the liquid by controlling the energizing control means, wherein the boiling control means heats the liquid until the boiling signal is input. The power supply control means is controlled so as to continuously perform an operation and a boiling maintaining operation of suppressing the heating amount of the heating means and heating the heating means for a predetermined time after the input of the boiling signal, and the boiling maintaining operation is performed. The electric water heater controls to abandon the boiling maintaining operation when the temperature lowering signal is input during the operation and to restart the operation from the water heating operation.

[0009]

According to the first aspect of the present invention, the temperature discriminating means detects the level of the water temperature, and outputs a signal indicating that the temperature is not reached if the temperature is lower than a predetermined temperature. If the boiling control means receives a signal indicating that the temperature has not been reached during the boiling maintaining operation following the water heating operation, the boiling maintaining operation is abandoned and the operation starts from the water heating operation again. Incidentally, the boiling detection known means can of course performing boiling detected in again kettle operation again. Also,
In the present invention according to claim 2, the temperature decrease detecting means detects a decrease in the water temperature, and outputs a temperature decrease signal if the amount of decrease is equal to or more than a predetermined value. When the boiling control means inputs the temperature decrease signal during the boiling maintaining operation following the water heating operation, the boiling maintaining operation is abandoned, and the operation is restarted from the water heating operation. Incidentally, the boiling detection known means can of course performing boiling detected in again kettle operation again.

[0010]

(Embodiment 1) An embodiment of the electric kettle of the present invention according to claim 1 will be described below with reference to the drawings. FIG. 1 is a block diagram showing the configuration of this embodiment. Note that the same components as those of the conventional example shown in FIG. 9 are denoted by the same reference numerals, and detailed description is omitted. This embodiment is different from the conventional example shown in FIG. 5 in that the temperature of the water in the container 1 is compared with a predetermined temperature via a temperature sensor 4 and a temperature not reached signal indicating that the temperature is lower than the predetermined temperature is output. And the control operation of the boiling control means 6. When the boiling detection means 5 receives a signal indicating that the temperature has not been reached from the temperature determination means 7 after detecting the boiling, the boiling detection is restarted. The boiling control means 6 supplies the temperature to the heating means 2 for two minutes while the temperature determination means 7 supplies the temperature. When a non-attainment signal is input, the heating means 2 returns to a state where power is supplied until a boiling signal is input.

The operation of the above configuration will be described. FIG. 2 is a flowchart showing the operation of the temperature determining means 7. In FIG. 2, the temperature discriminating means 7 creates the temperature data of the water in the container 1 based on the input signal from the temperature sensor 4 in step 1, and this temperature data is 88 in step 2.
Check if the temperature is lower than 88 ° C.
If it is less than the predetermined value, the process proceeds to step 4 to output an "L" signal indicating a temperature unreached signal, and if the temperature data is 88 ° C. or more, the process proceeds to step 3 to output an "H" signal. When the amount of water in the container 1 is extremely small, the water boils
There is a characteristic that the temperature data detected by the temperature sensor 4 is a low value of about 90 ° C. or more even at 0 ° C., and the reference value 88 ° C. of the temperature discriminating means 7 is determined in consideration of the above characteristics. When the small amount of water is boiled normally, the value is determined so that the temperature determining means 7 outputs the "H" signal.

FIG. 3 is a flowchart showing the operation of the boiling control means 6 in this embodiment. In step 11, the heating means 2 is turned on to start heating, and in step 12, it is checked that a boiling signal is input from the boiling detecting means 5,
Unless a boiling signal is input, the process returns to step 11 to continue heating. The boiling detecting means 5 detects the boiling of the water in the container 1 based on a change in the rising gradient of the temperature data detected by the temperature sensor 4, and outputs a boiling signal indicating the boiling state.
When a boiling signal is input from the boiling detecting means 5 in step 12, the processing shifts to step 13 to initialize a 2-minute measurement counter, and shifts to step 14 to turn on the heating means 2 to start heating and to elapse 2 minutes. Then, the process goes to step 18 to turn off the heating means 2 to end the boiling maintenance.
As long as the minutes have not elapsed, heating is continued by the loop processing of step 16-step 17-step 14-step 15 , and while the energization of the heating means 2 is being continued, a temperature non-attainment signal is indicated from the temperature determination means 7. When the "L" signal is input, the input of the under temperature signal is detected in step 19 in the loop, and the process returns to step 11 to restart the boiling maintaining operation for 2 minutes from the beginning. In this case, the boiling detecting means 5 outputs “L” indicating a signal indicating that the temperature has not been reached from the temperature determining means 7.
When a signal is input, a change in the rising gradient of the temperature data is detected again, and the boiling detection is performed again. Thereafter, when the boiling is detected, a boiling signal is output to the boiling control means 6 again.

FIG. 4A is a characteristic diagram showing the temperature of water corresponding to the re-boiling process when water is added in this embodiment, and FIG. 4B is a timing chart showing the energized state of the energization control means 3. It is. Now, when 0.7 liter of normal-temperature water is poured into the container 1 and the apparatus is operated, boiling occurs in about 4 to 5 minutes, and the boiling detecting means 5 detects the boiling (boiling detection 1 in FIG. 4) and controls the boiling. The means 6 starts the boiling maintaining operation for 2 minutes. When 1.3 liters of room temperature water is newly added to the container 1 during the maintenance of the boiling (water addition in FIG. 4), the temperature data detected by the temperature sensor 4 also decreases following the rapid decrease of the water temperature, The temperature discriminating means 7 detects that the temperature data has dropped to less than 88 ° C., and the boiling control means 6 restarts the water heating operation from the beginning (boil restart in FIG. 4).
By this treatment, 2.0 liters of water after addition is about 8-9
In a minute, the boiling detection means 5 detects the boiling again (boiling detection 2 in FIG. 4), and the boiling control means 6 restarts the boiling maintaining operation for another two minutes, and then turns off the power supply control means 3 to heat the mixture. The energization of the means 2 ends.

As described above, according to the present embodiment, even if the water temperature drops below a predetermined temperature due to the addition of normal-temperature water into the container while the boiling state is maintained, the drop is determined by the temperature discrimination. Detected by means, immediately heated at the maximum output to boil the added water, and after detecting the boiling, continue heating for a predetermined time again to maintain the boiling state, thereby removing volatile impurities such as chlorine components. It can be sufficiently removed.

After the boiling, the water in the container is kept at a first predetermined temperature, and the temperature of the water in the container is kept at a second temperature during the keeping of the temperature.
If the water in the container has a function of boiling again when the temperature of the water in the container becomes lower than the second predetermined temperature by using the automatic boiling determination means for comparing the predetermined temperature, the function of the temperature determination means is changed to the automatic boiling determination. It can also serve as a means.

(Embodiment 2) An embodiment of the present invention according to claim 2 will be described below with reference to the drawings.
FIG. 5 is a block diagram showing the configuration of the present embodiment. This embodiment is different from the conventional example in that the container 1 is connected via the temperature sensor 4.
It is provided with a new temperature decrease detecting means 8 for detecting a temperature decrease in the water inside and outputting a temperature decrease signal when a temperature decrease of a predetermined value width or more occurs, and the operation of the boiling control means 6. The boiling detecting means 5 is configured to restart the boiling detection when a temperature lowering signal is inputted from the temperature lowering detecting means 8 after the boiling detection, and the boiling control means 6 controls the temperature lowering detecting means while the energizing of the heating means 2 is continued for two minutes. When the temperature lowering signal is input from 8, the heating means 2 returns to the state of energizing until the boiling signal is input.

First, the problem of the first embodiment will be described. In the first embodiment, for example, when 1.8 liters of hot water is added and 0.3 liter of room temperature water is added while boiling is maintained, the temperature data value detected by the temperature sensor is about 98 to 1
As high as 00 ° C, the decrease in temperature data by adding water is about 5
If the temperature is small, the temperature data after the addition of water will be about 93-95 ° C. and will not be less than 88 ° C., and the temperature discriminating means 7 will not output a temperature-unreached signal, so the boiling control means 6
Cannot cope with water addition. Further, when the reference value of the temperature discriminating means 7 is raised from 88 ° C. to 93 ° C., even if a small amount of water is boiled, even if the boiling detecting means 5 once detects the boiling point, the temperature data is about 90 ° C. or more, that is, less than 93 ° C. Therefore, the temperature under-detection signal is input from the temperature discriminating means 7 and the boiling detection is performed again, and it takes a long time from the boiling of the water to the detection of the boiling, and the boiling time becomes long, and the amount of generated steam is increased. Is excessively increased. The electric kettle of the present embodiment solves the above-mentioned problem.

The operation of this embodiment will be described below with reference to the drawings. First, the operation of the temperature drop detecting means 8 will be described. FIG. 6 is a flowchart showing the operation of the temperature drop detecting means 8. In the figure, when the operation is started, temperature data based on the input signal from the temperature sensor 4 is created in step 21 and the created temperature data is held in the reference data as a comparison reference value of the temperature drop in step 22. Next, in step 23, current temperature data is created, and in step 24, the current temperature data is compared with the reference data, which is the previous temperature data, and it is checked whether or not temperature data> reference data. . If the temperature data> criterion data temperature was you have not dropped branches <br/> Te to step 25, after the reference data has been updated with the temperature data at the present time, there is no temperature reduction proceeds to step 26 , An “H” signal is output, and the process returns to step 23 to shift to the next temperature drop detection. This "H" signal means that the temperature drop signal is output at the H level.
If the temperature data ≦ reference data in step 24, there is the temperature is lowered, then the process proceeds to step 27, calculates the temperature difference between the temperature data and the reference data, and Te <br/>-up The process proceeds to 28 to check whether or not the temperature difference, that is, the temperature decrease width is 2 ° C. or more. When the temperature decrease width is smaller than 2 ° C., the process proceeds to step 26 assuming that the temperature decrease is small, but when the temperature difference is 2 ° C. or more, the process proceeds to step 29 assuming that the temperature decrease is large, and the temperature decrease signal is set to “29”. The output is set to "L", the process proceeds to step 2A, waits for a predetermined time, returns to step 21, and proceeds to the next temperature drop detection process. Note that the waiting for a predetermined time in step 2A can be executed within the output time width of the “L” signal in step 29. Further, the value of the temperature decrease width of 2 ° C. is a value which does not react to the fluctuation of the temperature data by the temperature sensor 4 when the water is normally boiled, and which can reliably detect the temperature decrease when water is added. Should be set. Further, the time width of the “L” signal at the time of detecting the temperature drop is
It goes without saying that the boiling detection means 5 and the boiling control means 6 should be set to values that can recognize the "L" signal.

Next, the operation of the boiling control means 6 in this embodiment will be described. FIG. 7 is a flowchart showing the operation of the boiling control means 6 in this embodiment. The processing operation of the boiling control means shown in FIG. 7 is different from the processing operation of the boiling control means in the first embodiment shown in FIG.
The only difference is that the operation returns to the water heating operation when the temperature decrease signal is input in step 39. In the first embodiment, the operation returns to the water heating operation again when the unreached signal is input. Other processes are the same. Briefly, heating is continued by the heating means 2 until the water is boiled by the loop processing of steps 31 and 32 to perform the water heating operation. When the boiling is detected, steps 33-34 to 35-39-3 are performed.
Boiling is maintained until 2 minutes elapse in the loop process of 6-37. During this boiling maintaining process, in step 39, a temperature drop of not less than a predetermined value width is detected, and a temperature drop signal "L" is sent to the temperature drop detection means. When input is made from step 8, the process returns to step 31 to repeat the water heating operation from the beginning. At this time, the boiling detecting means 5 receives the temperature decrease signal and restarts the boiling detection from the beginning. Also, since the processing after returning to the re-doing of the water heater operation is exactly the same as the normal water heater operation,
Needless to say, boiling is maintained for 2 minutes after boiling.

FIG. 8 (a) is a characteristic diagram showing the re-boiling operation when water is added in this embodiment, that is, the change in water temperature in the re-watering operation. FIG. 8 (b) shows the open / closed state of the power supply control means 3. It is a timing chart shown.
As shown in the figure, when 1.8 liters of room temperature water is poured into the container 1 and the apparatus is operated, it boils in about 10 to 12 minutes,
Boiling detection means 5 detects boiling (boiling detection 1 in FIG. 8),
Boiling control means 6 starts a boiling maintaining operation for 2 minutes. When 0.2 liter of normal-temperature water is newly added to the container 1 (water addition in FIG. 8) while the boiling is maintained for 2 minutes, the value of the temperature data detected by the temperature sensor 4 following the temperature decrease of the water. When the temperature drop detecting means 8 detects a temperature drop of 2 ° C. or more, the boiling control means 6 restarts the water heating operation from the beginning (the boiling restart in FIG. 8). 1. Water after addition
0 liters boil again in about 2 to 3 minutes.
, The boiling is detected again (boiling detection 2 in FIG. 8), and the boiling control means 6 repeats the boiling maintaining operation for another 2 minutes.
The power supply control means 3 is turned off, and power supply to the heating means 2 is terminated.

As described above, according to this embodiment, the temperature data value detected by the temperature sensor, such as adding a small amount of normal-temperature water to a large amount of boiling water while maintaining the boiling state, is high, and the temperature due to the addition of water is high. Even when the amount of decrease is small, the temperature decrease detecting means accurately detects that water has been added, immediately heats at the maximum output to boil the added water, and maintains the boiling state for a predetermined time. As a result, volatile impurities such as chlorine components can be sufficiently removed.

In the first and second embodiments,
The heating unit is continuously energized for a certain period of time.However, the same effect can be obtained even when the heating unit is intermittently energized at a predetermined cycle in order to suppress the amount of steam released into the atmosphere while the energization is continued. be able to. Also, the conventional example and the first embodiment
In the second embodiment, it goes without saying that some or all of the boiling detection means, the boiling control means, the temperature discrimination means, and the temperature decrease detection means can be realized by program processing of the microcomputer.

[0023]

As is apparent from the above description, the present invention according to claim 1 controls a container for storing a liquid, a heating unit for heating the liquid in the container, and an energization of the heating unit. Energization control means, a boiling state of the liquid is detected via a temperature sensor, and a boiling detection means for outputting a boiling signal indicating the boiling state; and a temperature of the liquid is detected via the temperature sensor, and is lower than a predetermined temperature. comprising a temperature determining means for outputting a temperature not reached signal when der Ru, and a boiling control means for controlling the heating operation of the liquid by controlling the energization control means, said boiling control means, the said liquid A water heating operation for heating until a boiling signal is input, and a heating amount of the heating means is suppressed for a predetermined time from the time when the boiling signal is input.
Controlling the energization control means so as to continuously perform the boiling maintaining operation of heating and heating, and when the temperature not reached signal is input during the boiling maintaining operation, the boiling maintaining operation is abandoned, and the boiling maintaining operation is performed again. By controlling to start over from the water heater operation, the amount of heating can be reduced during the boiling operation.
Also it decreases temperature by adding water to the boiling sustain operation suppresses the amount of steam to be generated, when it falls below a predetermined temperature and retry until boiling sustain operation from kettle operation
Immediately heat at maximum output and boil after adding water
Since the maintenance Teng, boiling maintained made sufficiently be sufficiently removed volatile impurities, Also, the present invention relating to claim 2, a container containing a liquid, heating means for heating the liquid in the vessel An energization control unit that controls energization of the heating unit, a boiling state detection unit that detects a boiling state of the liquid via a temperature sensor, and outputs a boiling signal indicating the boiling state; A temperature drop detecting unit that detects a temperature drop of the liquid and outputs a temperature drop signal when the temperature drops by a predetermined temperature range or more; and a boiling control unit that controls the energization control unit to control a heating operation of the liquid. ,
The boiling control means includes a water heating operation for heating the liquid until the boiling signal is input, and a boiling operation for suppressing the heating amount of the heating means and heating for a predetermined time after the input of the boiling signal. While controlling the energization control means so as to continuously perform the maintaining operation, when the temperature decrease signal is input during the boiling maintaining operation, the boiling maintaining operation is abandoned, and the operation from the water heater operation is restarted. By controlling, even if the temperature is reduced by adding water during the boiling maintaining operation, if the temperature falls by a predetermined temperature range or more, the operation from the water heating operation to the boiling maintaining operation is restarted, so that the amount of added water is slightly changed by the temperature change amount. This is an electric water heater that is more accurate than that detected by the temperature value itself, can execute the boiling maintaining operation reliably, and can sufficiently remove volatile impurities.

[Brief description of the drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention according to claim 1;

FIG. 2 is a flowchart showing the operation of a temperature determining unit in the embodiment.

FIG. 3 is a flowchart showing the operation of the boiling control means in the embodiment.

FIG. 4 is a characteristic diagram showing a re-boiling operation when water is added in the embodiment.

FIG. 5 is a block diagram showing the configuration of an embodiment of the present invention according to claim 2;

FIG. 6 is a flowchart showing an operation of a temperature drop detecting unit in the embodiment.

FIG. 7 is a flowchart showing the operation of the boiling control means in the embodiment.

FIG. 8 is a characteristic diagram showing a re-boiling operation when water is added in the embodiment.

FIG. 9 is a block diagram showing a configuration of a conventional electric water heater.

FIG. 10 is a flowchart showing the operation of a boiling control means in a conventional electric water heater.

[Description of Signs] 1 container 2 heating means 3 energization control means 4 temperature sensor 5 boiling detection means 6 boiling control means 7 temperature discrimination means 8 temperature drop detection means

────────────────────────────────────────────────── ─── Continuation of the front page (56) References JP-A-6-217885 (JP, A) JP-A-63-125217 (JP, A) JP-A-1-305913 (JP, A) JP-A-4- 261618 (JP, A) JP-A-5-253061 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) A47J 27/21

Claims (2)

(57) [Claims] 1. A container for accommodating a liquid, a heating unit for heating the liquid in the container, an energization control unit for controlling energization of the heating unit, and detecting a boiling state of the liquid via a temperature sensor. Boiling detection means for outputting a boiling signal indicating a boiling state, temperature discrimination means for detecting the temperature of the liquid via the temperature sensor, and outputting a temperature unreached signal when the temperature is lower than a predetermined temperature; Boiling control means for controlling a heating operation of the liquid by controlling a control means, wherein the boiling control means heats the liquid until the boiling signal is input, and a time when the boiling signal is input. From a predetermined time, while controlling the energization control means so as to continuously perform the boiling maintaining operation of suppressing the heating amount of the heating means and heating, and input the temperature not reached signal during the boiling maintaining operation An electric water heater that controls to abandon the boiling maintaining operation when it has occurred and to start over from the water heating operation again. 2. A container for accommodating a liquid, a heating unit for heating the liquid in the container, an energization control unit for controlling the energization of the heating unit, and detecting a boiling state of the liquid via a temperature sensor. A boiling detection unit that outputs a boiling signal indicating a boiling state, a temperature decrease detection unit that detects a temperature decrease of the liquid via the temperature sensor, and outputs a temperature decrease signal when the temperature falls by a predetermined temperature width or more, Boiling control means for controlling the energization control means to control the heating operation of the liquid, wherein the boiling control means heats the liquid until the boiling signal is input, and inputs the boiling signal. a predetermined time from the time the heating amount of said heating means
While controlling the energization control means to continuously perform the boiling maintaining operation of suppressing and heating, when the temperature decrease signal is input during the boiling maintaining operation, the boiling maintaining operation is abandoned, and the water heater is again heated. An electric water heater that controls to start over.