JP2966251B2 - Hot water storage type 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 a hot water storage type electric water heater capable of continuing the boiling operation of hot water as much as possible even if an abnormality occurs in a temperature sensor.

[0002]

2. Description of the Related Art A hot water storage type electric water heater described in Japanese Utility Model Publication No. 5-17556 discloses a temperature sensor for detecting a boiling temperature of hot water, and a temperature sensor for detecting a feed water temperature for detecting a feed water temperature. And if an abnormality occurs in the temperature sensor for detecting the boiling temperature (including related parts such as connection lines) among the plurality of temperature sensors for detecting the remaining hot water amount for detecting the remaining hot water amount, the boiling of the hot water is performed. A control means is provided for executing the boiling operation of hot water when the operation is stopped and another temperature sensor becomes abnormal. By providing such a control means, it is possible to prevent shortage of hot water when an abnormality occurs in a temperature sensor other than the temperature sensor for detecting a boiling temperature.

[0003]

In the conventional hot water storage type electric water heater, the operation of boiling the hot water is stopped when the temperature sensor for detecting the boiling temperature is abnormal. It is based on common sense that there is no temperature sensor other than a temperature sensor that can prevent hot water from boiling to an abnormally high temperature. However, even if a plurality of remaining hot water amount detection temperature sensors are normal, the operation of boiling the hot water is stopped when an abnormality occurs in the boiling temperature detection temperature sensor. It is not possible.

[0004] It is an object of the present invention to provide a hot water storage type electric water heater that can continue boiling of hot water and prevent occurrence of shortage of hot water even when an abnormality occurs in a temperature sensor for detecting a boiling temperature. is there.

[0005]

SUMMARY OF THE INVENTION A hot water storage type electric water heater to which the present invention is directed is a temperature sensor for detecting a boiling temperature of hot water and a temperature sensor for detecting a feed water temperature for detecting a feed water temperature. A plurality of remaining hot water amount detecting temperature sensors for detecting the remaining hot water amount, a sensor abnormality detecting means, a heater energizing control means, a display means for displaying operation contents and the like in accordance with a display command, and an operation control means And And multiple
Temperature sensors for detecting the amount of residual hot water are temperature sensors for detecting the boiling temperature.
The sensor is provided above the sensor at a predetermined interval. The heater power supply control means controls power supply to the heater in accordance with an operation control command output from the operation control means.

In the present invention, the operation control means determines whether or not to perform the boiling operation of the hot water based on the output of the sensor abnormality detection means, and operates the heater energization control means based on the outputs of the plurality of temperature sensors. A hot water storage type electric water heater that outputs a control command and outputs a display command to a display means, and outputs a power supply stop command to stop power supply to the heater to a heater power supply control means when the temperature of the hot water reaches a preset temperature. Target for improvement.

In the present invention, when the sensor abnormality detecting means detects that the temperature sensor for detecting the boiling temperature is normal, it outputs a power supply stop command based on the output of the temperature sensor for detecting the boiling temperature. When the sensor abnormality detecting means detects that the boiling temperature detecting temperature sensor is abnormal, the sensor is located at the lowest position among the plurality of remaining hot water amount detecting temperature sensors which are determined to be normal by the sensor abnormality detecting means.
The operation control means is configured to output an energization stop command based on the output of the remaining hot water amount detection temperature sensor . In addition, when the temperature sensor for boiling temperature detection also serves as the temperature sensor for feedwater temperature detection, the temperature sensor for feedwater temperature detection is not included in "other temperature sensors".

[0008] The sensor abnormality detecting means detects abnormality of the temperature sensor by detecting whether or not each of the detected temperatures of the plurality of temperature sensors is out of a preset normal temperature detection range. Here, the “normal temperature detection range”
The "temperature sensor abnormality" means not only an abnormality in the temperature sensor itself but also an abnormality in a related portion such as a connection line or a connection terminal (disconnection, poor connection, etc.). ).

The operating mode used for the normal boiling operation is arbitrary. An operation mode for using the remaining normal temperature sensor when a sensor abnormality is detected uses an operation mode for preventing the temperature of hot water from being raised to an abnormally high temperature using the normal temperature sensor.

If the boiling operation is continued when all of the other temperature sensors become abnormal, the temperature of the hot water becomes abnormally high, and it is necessary to prevent such a situation from occurring. For example, the boiling operation can be stopped when all other temperature sensors become abnormal.

In the present invention, a plurality of temperature sensors for detecting the amount of remaining hot water are provided.
The power supply stop instruction is output by using the output of the temperature sensor having the higher priority order . In this case, when the temperature sensor in the high priority becomes abnormal, you output an energization stop command using the output of the temperature sensor of the next rank. According to the present invention, when assigning priorities , the remaining hot water amount detection temperature located below the hot water storage tank is determined.
The priority of the degree sensor is set higher.

[0012]

Conventionally, when the temperature sensor for detecting the boiling temperature becomes abnormal, the hot water is heated to an abnormally high temperature.
At that time, he thought that the boiling operation should be stopped. This is due to the absence of the temperature sensor for detecting the boiling temperature.
Derived from the stereotype that too much boiling cannot be detected. However, in a hot water storage type electric water heater, since the water or hot water located above the heater convects inside the hot water storage tank during boiling, the boiling temperature must be detected by a temperature sensor other than the temperature sensor for detecting the boiling temperature. You can do it. The basic idea of the present invention is to provide a temperature sensor for detecting a boiling temperature when the temperature sensor for detecting a boiling temperature becomes abnormal.
At least one of the plurality of remaining hot water amount detecting temperature sensors provided above is used as a boiling temperature detecting temperature sensor.

Particularly, in the present invention, when the sensor abnormality detecting means detects that the temperature sensor for detecting the boiling temperature is abnormal, the sensor abnormality detecting means determines that the sensor is normal.
It is located at the bottom of the temperature sensors for detecting the amount of remaining hot water.
The operation control means outputs an energization stop command based on the output of the remaining hot water amount detecting temperature sensor . That is, when the temperature sensor for detecting the boiling temperature becomes abnormal, a plurality of temperatures for detecting the amount of remaining hot water provided above the temperature sensor for detecting the boiling temperature.
Detection of remaining hot water at the bottom of normal sensors
An intellectual temperature sensor is used as a temperature sensor for detecting a boiling temperature. Normal temperature sensor for detecting remaining hot water volume
The temperature sensor for detecting the amount of remaining hot water at the top
When used as a temperature sensor for temperature detection (above the hot water storage tank
The priority of the temperature sensor for remaining hot water detection
Prioritize the temperature sensors for detecting remaining hot water
), The following problems occur. Ie hot water storage
Due to the high rate of hot water remaining in the upper area of the tank,
The daily boiling temperature is the temperature of the remaining hot water in the upper area of the hot water storage tank.
If it is set lower than
Of the temperature sensor for detecting the amount of remaining hot water at the top
The remaining hot water temperature is detected higher than the boiling temperature.
No electricity is supplied to the heater and the amount of hot water on the next day is insufficient.
Things are more likely to happen.

[0014]

Embodiments of the present invention will be described below in detail with reference to the drawings. FIG. 1 is a block diagram illustrating a configuration of a control unit according to an embodiment of the present invention, and FIG. 2 is a diagram illustrating an installation state of each temperature sensor. In these figures, reference numeral 1 denotes a temperature sensor for detecting a boiling temperature, and the temperature sensor 1 detects a boiling temperature of hot water and a temperature of feed water by using a hot water storage tank 13.
Is installed above the heater 11 in the lower region of the heater.
This temperature sensor is also used as a temperature sensor for detecting feedwater temperature. Reference numerals 2a to 2c denote remaining hot water amount detecting temperature sensors provided at predetermined intervals above the temperature sensor 1 in order to detect the remaining hot water amount.

The outputs of these temperature sensors 1-2c are A
The signal is input to the / D converter 3 and converted into a digital value, which is sent to the sensor abnormality detection means 5 and the operation control means 6. The output from the timer means 4 is also input to the operation control means 6. When the power is turned on in a specific power time zone such as a midnight power time zone, the timer means 4 sends information on the power supply of the midnight power to the operation control means 6 and starts counting the time limit.
When the power is stopped, the device enters a reset state.

The sensor abnormality detecting means 5 is provided for each of the temperature sensors 1
It is detected whether or not each of the detected temperatures of .about.2c has deviated from a preset normal temperature detection range, thereby detecting an abnormality of each temperature sensor. Therefore, the sensor abnormality detecting means 5 stores data of the normal temperature detection range for each of the temperature sensors 1 to 2c in advance. Note that this data may be stored in a storage unit 7 that stores an operation program and data used for operations and the like in the operation control unit 6. Here, the normal temperature detection range when a thermistor is used as the temperature sensor can be set to −25 to + 110 ° C. as described in detail in Japanese Utility Model Publication No. 5-17556. When using another temperature sensor, the normal temperature detection range is determined according to the characteristics of the temperature sensor used.

When the operation control means 6 receives the power input information from the timer means 4, the operation control means 6 calculates the water temperature measured by the temperature sensor 1, the set temperature set by the temperature setting means (not shown), and the outputs of the temperature sensors 2a to 2c. Using the obtained remaining hot water amount, the capacity of the hot water storage tank 13, the heater capacity, and the like, an energization start time (energization shift time) to the heater 11 is calculated according to a predetermined arithmetic expression. The data and the operation program necessary for the calculation are stored in the storage means 7. Generally, the energization shift time is determined such that the hot water is heated to the set temperature at the end time of the midnight power time zone. The arithmetic expression used for calculating the energization shift time is arbitrary. As is well known, the operation mode of the hot water storage type electric water heater includes not only the operation mode in which the energization start time is shifted as in the present embodiment, but also the operation mode in which energization of the heater is started simultaneously with the start of the power supply at midnight. There are various operation modes such as an operation mode in which reheating is performed when a large amount of hot water is used.

When the sensor abnormality detecting means 5 detects an abnormality of the temperature sensor, the operation mode used for executing the boiling operation is the operation mode shown in FIGS.
Used. That is, when the temperature sensor 1 for detecting the boiling temperature becomes abnormal, the operation mode in which the lowest temperature sensor among the normal temperature sensors among the other temperature sensors 2a to 2c is used as the temperature sensor for detecting the boiling temperature. Is adopted. For example, when the boiling temperature detecting temperature sensor 1 becomes abnormal, the remaining hot water amount detecting temperature sensors 2a to 2c
If There all normal shifts the energization start time in consideration of the remaining hot water, out of the remaining hot water detecting temperature sensor 2a~2c
One temperature sensor is most located below have use the operating mode to be used as a temperature sensor for boiling up temperature detection. If a part of the remaining hot water detection temperature sensors 2a to 2c becomes abnormal, the remaining hot water cannot be detected. Therefore, the energization start time is shifted without considering the remaining hot water, and the normal remaining hot water detection is performed. An operation mode is used in which the lowest temperature sensor among the temperature sensors is used as a temperature sensor for detecting a boiling temperature. Further, when an abnormality of any of the temperature sensors is detected, an operation mode in which boiling of hot water is immediately started without shifting the energization start time may be used.

In the operation mode in which the energization start time is shifted, the water temperature is required for calculation. However, when the temperature sensor 1 for detecting the boiling temperature also serves as the temperature sensor for detecting the feed water temperature as in this embodiment. Can not know the water temperature.
In such a case, the previous water temperature may be stored in the storage means 7 and the stored water temperature may be used as in the technique disclosed in Japanese Utility Model Laid-Open No. 3-77152.
In such a case, a predetermined constant water temperature (for example, 10 ° C.) may be used.

The operation control means 6 comprises a sensor abnormality detecting means 5
When the sensor detects a sensor abnormality, it outputs a display command to the display control means 8 to display that an abnormality has occurred in the temperature sensor and the sensor in which the abnormality has occurred.

The sensor abnormality detecting means 5 and the operation control means 6 are constituted by using a microcomputer.

[0022] Figure 3 shows an example of an algorithm of a program used when implementing an example of Ru using the configuration of Figure 1. In this example, the remaining hot water amount detecting temperature sensors 2a to 2c
Have detected the set temperature, the operation control means 6 outputs an energization stop command, and the remaining hot water amount detecting temperature sensors 2a to 2c
When the sensor abnormality detecting means 5 detects that there is at least one abnormality, the boiling operation of hot water is stopped. In step ST1, it is determined whether the temperature sensor 1 for detecting a boiling temperature is normal. If the temperature sensor 1 is normal, a boiling operation is performed in the normal operation mode in step ST2. Details of step ST2 are as shown in FIG. First, at step ST21, the water temperature is detected, and at step ST22, it is determined whether or not it is in the midnight power time. If it is in the midnight power time zone, the energization shift time is calculated in step ST23. In the calculation at this time, the remaining hot water amount detected by the temperature sensors 2a to 2c is also taken into consideration. After determining the energization shift time, it is determined in step ST24 whether the energization shift time has elapsed,
If the energization shift time has elapsed, step ST25
Measure the temperature of the hot water with. If the temperature of the hot water is equal to or lower than the set temperature, the operation control means 6 outputs a power supply start command to the power supply control means 9 to start power supply. After starting the energization of the heater and detecting in step ST25 that the temperature of the hot water detected by the temperature sensor 1 has reached the set temperature, the operation control unit 6 causes the heater energization control unit 9 to stop energizing the heater. Outputs the power stop command. Thus, the normal boiling is completed.

Returning to FIG. 3, when it is determined in step ST1 that the temperature sensor 1 for detecting the boiling temperature is abnormal,
Proceeding to step ST3, the operation control means 6 outputs a display command to the display control means 8 to display that the temperature sensor 1 is abnormal. Thereafter, in step ST4, it is determined whether or not all of the remaining hot water amount detecting temperature sensors 2a to 2c are normal. If all of the temperature sensors 2a to 2c are normal, hot water is heated using the temperature sensors 2a to 2c in step ST5. Temperature sensor 2a for detecting remaining hot water
If there is an abnormality in any of the steps 2 to 2c, the process proceeds to step ST6, and the operation control unit 6 displays the temperature sensor 2a on the display unit 10.
A display command for displaying that there is an abnormal temperature sensor among the control signals is output to the display control means 8. Then, in step ST7, the boiling operation is stopped. Since it is extremely rare that an abnormality occurs in the temperature sensor 1 for detecting the boiling temperature and further an abnormality occurs in the temperature sensors 2a to 2c, shortage of hot water hardly occurs even in this case.

FIG. 5 shows an example of the operation mode in step ST5. In this operation mode, steps ST51 to ST54 are basically the same as steps ST21 to ST24 in FIG. However, since the temperature sensor 1 is abnormal and the water temperature cannot be detected, in the energization shift time calculation in step ST53, the calculation is performed using the assumed water temperature as described above. By the steps ST55 to ST57, the temperature sensors 23a to 23
The heater 11 is energized until c reaches the set temperature. When all of the temperature sensors 23a to 23c reach the set temperature, the process proceeds to step ST58, in which an operation stop command is output from the operation control unit 6 to the heater current control unit 9, and the heater 11 is turned off. Therefore, in this embodiment, 3
The three temperature sensors 23a to 23c are used as boiling temperature detecting temperature sensors.

FIG. 6 shows an algorithm of a program used in carrying out the embodiment of the present invention . In this embodiment, when the boiling upstream temperature detection temperature sensor 1 becomes abnormal, even more if the abnormality in the remaining hot water detecting temperature sensor 2a~2c occurs, one also normal temperature sensor If there is, boil the water. To make this possible,
Steps ST7 to ST9 are provided. FIG.
Shows the algorithm of the program that actually implements step ST9. Here particularly importantly, by providing a step ST94～ST101, even if there is an abnormality in one of the temperature sensor 2 a to 2 c, the hot water storage
Priority of residual temperature detection temperature sensor located below the tank
The point is that the order is raised so that another normal temperature sensor can be used as a temperature sensor for detecting a boiling temperature. With this configuration, the temperature sensor for detecting the boiling temperature is used.
If sensor 1 becomes abnormal, priority is given to the lowest temperature.
Temperature sensor is used as a temperature sensor for detecting the boiling temperature
You. If the temperature sensor 2a is abnormal,
2b is used as a temperature sensor for detecting the boiling temperature.
When the temperature sensor 2b is abnormal, the temperature sensor 2c
Used as a temperature sensor for temperature detection. And normal
When the temperature sensor detects the set temperature, the operation control means 6 outputs a power supply stop command to the heater power supply control means 9, so that the hot water can be heated without boiling the water to an abnormally high temperature. When all the temperature sensors 2a to 2c become abnormal, the process proceeds to step ST7 according to the determination in step ST8 in FIG. 6, and the boiling operation is stopped.

[0026]

According to the present invention , when the sensor abnormality detecting means detects that the temperature sensor for detecting the boiling temperature is abnormal, a plurality of residuals which are determined to be normal by the sensor abnormality detecting means are provided. The lowest position of the temperature sensor for detecting the amount of hot water
The operation control means outputs an energization stop command based on the output of the remaining hot water amount detecting temperature sensor . Therefore, when the boiling temperature detecting temperature sensor becomes abnormal, a temperature sensor other than the boiling temperature detecting temperature sensor is used. Can be used as a temperature sensor for detecting a boiling temperature , and the occurrence of shortage of hot water can be prevented.

[Brief description of the drawings]

FIG. 1 is a block diagram illustrating a configuration of a control unit according to an embodiment of the present invention.

FIG. 2 is a diagram showing a state where each temperature sensor is installed in a hot water storage tank.

FIG. 3 is a flowchart illustrating an algorithm of an example of a program used in an example that can be realized using the configuration of FIG. 1;

FIG. 4 is a flowchart showing details of step ST2 in FIG. 3;

FIG. 5 is a flowchart illustrating an example of an operation mode in step ST5 of FIG. 3;

6 is a flowchart showing an example of an algorithm of a program used when realizing the real施例of the present invention using the configuration of Figure 1.

FIG. 7 is a flowchart showing an example of an operation mode in step ST9 of FIG.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Temperature sensor for boiling temperature detection 2a-2c Temperature sensor for residual hot water amount detection 3 A / D converter 4 Timer means 5 Sensor abnormality detection means 6 Operation control means 7 Storage means 8 Display control means 9 Heater energization control means 10 Display means 11 heater 13 hot water storage tank

Claims (1)

(57) [Claims] 1. A temperature sensor for detecting a boiling temperature of hot water, a temperature sensor for detecting a supply water temperature for detecting a supply water temperature, and a plurality of temperature sensors for detecting a remaining hot water amount for detecting a remaining hot water amount. Sensor abnormality detecting means for detecting whether or not the detected temperature of each of the plurality of temperature sensors has deviated from a preset normal temperature detection range to detect abnormality of the temperature sensor; Heater energization control means for controlling energization of the heater in accordance with the condition, display means for displaying the operation contents and the like in response to a display command, and performing a boiling operation of hot water based on an output of the sensor abnormality detection means. The operation control means for determining whether or not the operation has been performed and outputting the operation control command to the heater energization control means and outputting the display command to the display means based on the outputs of the plurality of temperature sensors. Comprising the door, the plurality of remaining hot water detecting temperature sensor is the boiling uplink temperature test
The operation control unit is provided at a predetermined interval above the intellectual temperature sensor and outputs an energization stop command to stop the energization to the heater to the heater energization control unit when the temperature of the hot water reaches a preset temperature. A storage-type electric water heater, wherein the operation control means outputs the output of the boiling temperature detecting temperature sensor when the sensor abnormality detecting means detects that the boiling temperature detecting temperature sensor is normal. outputting the energization stop command based on said plurality said that the sensor abnormality detecting means when the boiling upstream temperature detecting temperature sensor is detected by the sensor abnormality detecting means that abnormal is judged to be normal Temperature sensor for detecting remaining hot water
Of the temperature sensor for detecting the amount of remaining hot water located at the bottom
And a hot-water storage type electric water heater configured to output the power-supply stop command based on the above.