JP2984722B2 - Electric water heater - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to a plurality of temperature sensors,
Means for detecting an abnormality of the temperature sensor.

[0002]

2. Description of the Related Art An electric water heater described in, for example, Japanese Utility Model Publication No. 4-74585 has been known.

[0003] This electric water heater has a hot water storage tank whose longitudinal direction is the vertical direction. The hot water storage tank heats and raises the temperature of normal-temperature water supplied from a water pipe connected to a lower portion by a heater arranged at the lowermost portion to generate hot water by convection. They are stored in a stratified form from the side. A hot water supply pipe provided with a hot water tap is connected to the upper part of the hot water storage tank, and the stored hot water is supplied to a bathtub or the like via the hot water supply pipe.

[0004] In addition, a first temperature sensor is mounted near the lower end of the hot water storage tank, and a second temperature sensor is mounted near the upper end. A third temperature sensor is mounted below the second temperature sensor, and a fourth temperature sensor is mounted below the third temperature sensor. ing.

[0005] These temperature sensors each comprise a thermistor or the like that changes the resistance value depending on the temperature, and are connected to a control device that controls a heater that heats and stores hot water using electric power in a predetermined time zone such as a midnight power time zone. Have been. Further, this control device detects the water temperature of each part of the hot water storage tank based on the resistance value of each temperature sensor. As the first temperature sensor, a sensor having a wide detection range and high accuracy is used. The first temperature sensor detects the temperature of hot water when the heater is turned on. The temperature of the water supplied from the water pipe is always detected. Also, the second
The fourth temperature sensor detects the remaining hot water amount by detecting the water temperature of each part of the hot water storage tank, or measures the temperature of the hot water supplied through the hot water supply pipe.

In such a configuration, in a predetermined time zone such as a midnight power time zone, the control means compares the measured water temperature with a hot water temperature adjustment pattern stored in an internal memory, etc. Determine the temperature rise. Then, the control device energizes the heater, and heats the heater until the first temperature sensor detects that the hot water has reached a predetermined boiling temperature.

When each of the temperature sensors is disconnected or short-circuited, the resistance value becomes zero or a value close to infinity. Then, in a state where the resistance value of the first temperature sensor becomes 0 or a value close to infinity, the control device detects an abnormality of the first temperature sensor and stops heating of the heater to prevent boiling or the like. In addition, the abnormality of each temperature sensor is displayed on a display.

[0008]

However, as in the above-described conventional case, if the power supply to the heater is always stopped in a state where the abnormality of the temperature sensor is detected, if the abnormality occurs in the first temperature sensor, If other temperature sensors are normal,
Heating of the heater is always stopped. Therefore, it is possible to prevent boiling to ensure safety, but by stopping the heating of the heater, the basic operation of boiling is also stopped. It has the problem of causing inconvenience.

In particular, in this type of electric water heater, the hot water is not used at the stage of using hot water stored in a predetermined time zone such as a late-night power time zone because it is used in a time zone other than the predetermined time zone. May not notice abnormally. Therefore, there is a problem that, even if the repair is immediately performed, the hot water is not heated unless the next predetermined time period is reached, thereby causing a great inconvenience to the user of the electric water heater.

[0010] The present invention has been made in view of the above points, and in an electric water heater having a plurality of temperature sensors,
An electric water heater that can not only detect abnormalities of these temperature sensors, but also suppress the occurrence of inconvenience such as shortage of hot water by substituting boiling temperature detection with another temperature sensor for abnormalities of this temperature sensor. The purpose is to provide.

[0011]

Means for Solving the Problems] electric water heater according to claim 1 is a savings hot water tank, the hot water of the entire hot water storage tank pairs
A heater for boiling while flowing, control means for controlling the heater, a plurality of temperature sensors for detecting the temperature of hot and cold water in the hot water storage tank, abnormality detecting means for detecting an abnormality of each of the temperature sensors, Display means for displaying an abnormal state of each of the temperature sensors detected by the detection means,
The temperature sensor comprises a first temperature sensor and a second temperature
A sensor, wherein, during normal, the previous SL first temperature sensor detects the Wakiagari temperature of the hot water during heating of the heater, also the remaining hot water that is stored by the second temperature sensor Detecting the abnormality of the first temperature sensor and detecting the boiling temperature of the hot water by the second temperature sensor at the time of heating the heater while the abnormality detecting means detects the abnormality of the first temperature sensor; The abnormal state of the temperature sensor is displayed.

[0012] The electric water heater according to the second aspect is the first aspect.
In the electric water heater described above, the temperature sensor is
A first temperature sensor having a higher measurement accuracy than the first temperature sensor;
A second temperature sensor with high measurement accuracy after the temperature sensor
It is provided with.

[0013] The electric water heater according to claim 3 is the same as in claim 1.
Or 2 in the electric water heater described in
It is provided with three or more temperature sensors.

[0014]

[Action] In the electric water heater according to claim 1, in the normal, the first temperature sensor detects the Wakiagari temperature of the hot water during heating of the heater, the control means in accordance with the detected temperature is a heating condition of the heater Control. Then, the temperature of the stored hot water is measured by the second temperature sensor to detect the amount of remaining hot water in the hot water storage tank. In the state where the abnormality detecting means detects the abnormality of the first temperature sensor, the heating temperature of the hot water is detected by the second temperature sensor when the heater is heated, and the control means controls the heating state of the heater according to the detected temperature. At the same time, an abnormal state of the first temperature sensor is displayed on the display means to prompt inspection and repair of the first temperature sensor.

In the electric water heater according to the second aspect, the first aspect is as follows.
In addition to the actions described, measurement to detect the boiling temperature of hot water
In case of failure of a highly accurate temperature sensor, another temperature sensor
By diverting, manufacturing costs can be reduced. Also,
After the first temperature sensor, the second temperature sensor with high measurement accuracy is used.
Control as high as possible by using sensors
Can be.

According to the third aspect of the present invention , there is provided an electric water heater.
Or, in addition to the actions described in 2 above, three or more
Equipped with a temperature sensor above, and the entire hot water storage tank
In a configuration in which water is boiled while convection
The temperature sensor for detecting the remaining hot water amount at the position
It becomes possible to substitute as a temperature sensor.

[0017]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of an electric water heater according to an embodiment of the present invention.

In FIG. 2, reference numeral 11 denotes a housing of an electric water heater having a rectangular tube shape or a cylindrical shape.
A hot water storage tank 14 wrapped in 12 is stored. The hot water storage tank 14 has a substantially cylindrical shape with the vertical direction being the longitudinal direction and the upper and lower surfaces being substantially spherical. And hot water storage tank 14
In the vicinity of the lower end of the hot water storage tank 14 is connected directly to a water supply pipe (not shown), a water supply pipe 16 for supplying tap water at room temperature into the hot water storage tank 14, and near the lower end of the hot water storage tank 14,
A drain pipe 17 equipped with a valve is connected so that hot water in the hot water storage tank 14 can be discharged as needed. A hot water supply pipe 18 having a hot water tap is connected near the upper end of the hot water storage tank 14, and supplies hot water at a predetermined temperature to a bathtub (not shown) via a mixing valve or the like.

Further, a heater 21 is arranged near the lower end of the hot water storage tank 14 so as to heat the hot water in the hot water storage tank 14, and a so-called first push-up type electric water heater using tap water pressure. Is configured.

A control room 23 is provided on one side of the housing 11, and a control device 24 serving as a control unit and an abnormality detection unit is accommodated in the control room 23. This control device
Reference numeral 24 is connected to a power line of an AC commercial power supply (not shown) via an earth leakage breaker 25 and the like, and energizes the heater 21 during a specific time period such as a late-night power time period to cause convection of hot water in the hot water storage tank 14. It is designed to be heated.

The controller 24 is connected to a remote controller 26 as display means. The remote control device 26 is provided with an operation unit for inputting instructions for various setting items, a display unit for displaying an operation state, and the like, so that the control device 24 can be remotely operated.

Further, a first temperature sensor TH1 is mounted on the side surface of the hot water storage tank 14 near the water supply pipe 16 at the lower end, and a second temperature sensor TH2 is mounted near the upper end on the side. Is attached. Further, a third temperature sensor TH3 is attached below the second temperature sensor TH2, and a fourth temperature sensor TH4 is located below the third temperature sensor TH3. TH4 is installed.

The temperature sensors TH1 to TH4
Are each configured by a thermistor or the like electrically connected to the control device 24, and change the resistance value according to the temperature of hot water in the hot water storage tank 14. Then, the controller 24 measures these resistance values so that the temperature of the hot and cold water at each height position in the hot water storage tank 14 can be detected.

The first temperature sensor TH1 is connected to the heater 21
At the time of electricity supply, while detecting the boiling temperature of hot water,
It detects the temperature of the water supplied from the water supply pipe 16 and has a wide detection range so as to be able to measure from a low temperature to a high temperature of about 90 ° C., and includes a port for connecting the control device 24. , With high measurement accuracy.

Then, the second to fourth temperature sensors TH2
The controller 24 can determine the remaining amount of hot water stored in a stratified state by detecting the hot water temperature at each height position of the hot water storage tank 14. For example, when the fourth temperature sensor TH4 detects a water temperature higher than a predetermined temperature, the remaining hot water amount is 180 liters or more, the fourth temperature sensor TH4 is lower than the predetermined temperature, and the third temperature sensor TH3 is higher than the predetermined temperature. If the temperature is higher than the temperature, the remaining hot water amount is 18
In the range of 0 to 120 liters, the third temperature sensor TH3 is below a predetermined temperature and the second temperature sensor TH2
Is equal to or higher than a predetermined temperature, the remaining hot water amount is in the range of 120 liters to 60 liters, and when the second temperature sensor TH2 is equal to or lower than the predetermined temperature, the remaining hot water amount is determined to be 60 liters or less.

The amount of remaining hot water measured by the second to fourth temperature sensors TH2 to TH4 is determined by a remote controller.
26, the second temperature sensor TH2 has a function of measuring the temperature of hot water supplied through the hot water supply pipe 18 and a function of detecting a boiling water described later. Because of this, a sensor having high measurement accuracy is used next to the first temperature sensor TH1.

Further, the control device 24 is always operated by a control power supply different from the midnight power or the like, and constitutes a so-called microcomputer controller, which determines the boiling temperature in accordance with the supply water temperature or has a large amount of residual hot water. In addition to having a CPU for performing so-called peak shift calculation for delaying the energization start time in the case, and various memories,
Time zone detecting means, output control means, and the like are connected.
In this memory, a plurality of types of control patterns of the boiling temperature according to the water supply temperature to the hot water storage tank 14 are stored. Is updated and stored as the supply water temperature. Further, the time zone detecting means starts operation when a timer switch is activated and power is turned on in a specific time zone such as a midnight power supply time zone, and sends midnight power input information to the CPU. ing. The output control means drives a power relay in accordance with an instruction from the CPU, and controls energization of the heater 21.

Next, the control operation by the controller 24 will be described with reference to FIG.
This will be described with reference to the flowchart of FIG.

First, the midnight power input information from the time zone detecting means is detected (step 1). If there is the midnight power input information, it is determined whether the first temperature sensor TH1 is normal (step 2). . Here, if the resistance value of the first temperature sensor TH1 is within a predetermined range, the first temperature sensor TH1
The connection between the first temperature sensor TH1 and the CPU is determined to be normal, and if the resistance value of the first temperature sensor TH1 is out of the predetermined range, it is determined to be abnormal.

When it is determined that the first temperature sensor TH1 is normal, the water supply temperature is called from the above-mentioned memory, or the hot water storage tank is directly detected by the first temperature sensor TH1.
The temperature of the water supply to the fuel cell 14 is detected (step 3), the hot water temperature adjustment pattern is selected and read out from the memory according to the water supply temperature, the remaining hot water amount and other information stored in the memory, and the boiling including the peak shift is performed. The raising temperature is determined (step 4). Then, the power relay is driven by the output control means to start energizing the heater 21 (step 5).

In this state, the heater 21 is heated, and the entire hot water in the hot water storage tank 14 is gradually heated and boiled while convectionally flowing. For example, if the water temperature in the hot water storage tank 14 is 10 ° C. in a case where there is no remaining hot water, the energization is performed for about 8 hours, and the control pattern set value is about 85
Boil to ℃. When the first temperature sensor TH1 detects that the hot and cold water has reached the set boiling temperature (step 6), the power supply to the heater 21 is stopped (step 7).

Next, if it is determined in step 2 that the first temperature sensor TH1 is abnormal, the fact that the first temperature sensor TH1 is abnormal is displayed on the display of the remote controller 26 (step 8). ), It is determined whether or not the second temperature sensor TH2 is normal (step 9).

The display section of the remote controller 26 has a first
The lamp corresponding to the temperature sensor TH1 is blinked, or a display such as “E: 01” is displayed on the liquid crystal display.

Here, when it is determined that the second temperature sensor TH2 is normal, the power supply to the heater 21 is started irrespective of the water supply temperature (step 10). When the second temperature sensor TH2 detects that the hot water reaches a predetermined boiling temperature (step 11) instead of the first temperature sensor TH1, the heater 21 is energized. Is stopped (step 12).

On the other hand, if it is determined in step 9 that the second temperature sensor TH2 is abnormal, the display unit of the remote control device 26 displays an indication that the second temperature sensor TH2 is abnormal, if necessary. Then, the power supply to the heater 21 is stopped (step 13).

As described above, according to the present embodiment, when the first temperature sensor TH1 is determined to be normal, when the heater 21 is heated, the first temperature sensor TH1 detects the boiling temperature of hot water. The controller 24 can control the energization of the heater 21 according to the detected temperature.

Further, the second to fourth temperature sensors TH2 to TH2.
With TH4, the temperature of the hot water stored in the hot water storage tank 14 in a stratified state can be measured to detect the amount of remaining hot water in the hot water storage tank, and the peak shift can be calculated as in the conventional case.

When the controller 24 detects an abnormality in the first temperature sensor TH1, the first temperature sensor TH1
Utilizing the second temperature sensor TH2, which has the second highest accuracy next to 1, the boiling temperature of hot water when the heater 21 is heated is detected,
The heating state of the heater 21 can be controlled according to the detected temperature. Therefore, even if the first temperature sensor TH1 has an abnormality, it is possible to prevent boiling and the like, and to secure a basic function of boiling hot water of a predetermined temperature, thereby preventing inconvenience such as shortage of hot water. be able to.

Further, when the abnormality of the first temperature sensor TH1 is detected, the function of detecting the temperature of the water supplied to the hot water storage tank 14 is stopped. The first temperature sensor TH
By displaying that 1 is abnormal, it is possible to prompt early inspection and repair of the first temperature sensor TH1.

Further, the heater 21 is provided inside the hot water storage tank 14.
To boil the water while convection
Temperature sensor TH1 with high measurement accuracy for detecting temperature
In the event of a failure, the measurement accuracy following the first temperature sensor TH1
The high temperature sensor TH2 can be diverted to boil. Soshi
To the temperature control for all other temperature sensors TH2 to TH4.
No need to secure required measurement accuracy, reducing manufacturing costs
Can be reduced. Also, after the first temperature sensor TH1, measurement accuracy
By diverting the second high temperature sensor TH2,
Control can be performed with the highest possible accuracy.

The heater 21 is provided in the entire hot water storage tank 14.
The first temperature sensor is used to boil the water while convection
The second temperature sensor, which is another temperature sensor
Temperature sensor TH2 can detect the boiling temperature of hot water.
You.

When an abnormality of the first temperature sensor TH1 is detected and the second temperature sensor TH2 having the second highest accuracy is used after the first temperature sensor TH1, the first temperature sensor TH1 is used.
If the set temperature of the second temperature sensor TH2 is set to a value several degrees lower (for example, 88 ° C.) than the maximum value of the set temperature of TH1 (for example, 90 ° C.), the safety against boiling is further ensured. You can also.

In the embodiment shown in the flowchart of FIG. 1, when the abnormality of the first temperature sensor TH1 is detected in step 2 and the abnormality of the second temperature sensor TH2 is detected in step 9, Although the power supply to the heater 21 has been stopped (step 13), the first and second
The third and fourth temperature sensors TH3 and TH3 for measuring the amount of remaining hot water even when abnormalities of the temperature sensors TH1 and TH2 are detected.
, TH4 having a predetermined accuracy, the heaters utilizing these temperature sensors TH3, TH4 are used.
The energization of 21 can also be controlled.

That is, as shown in the flowchart of FIG. 3, when the abnormality of the second temperature sensor TH2 is detected in Step 9, the second display is displayed on the remote control device 26.
In addition to displaying that the third temperature sensor TH2 is abnormal (step 14), it is determined whether the third temperature sensor TH3 is normal (step 15). Here, if the third temperature sensor TH3 is normal, the power supply to the heater 21 is started (step 16). Thereafter, similarly to step 11 and thereafter, the third temperature sensor TH3 detects the boiling temperature of hot and cold water, and when the temperature reaches a predetermined temperature, the power supply to the heater 21 is stopped.

If it is determined in step 15 that the third temperature sensor TH3 is abnormal, it is displayed that the third temperature sensor TH3 is abnormal (step 15).
17) It is determined whether the fourth temperature sensor TH4 is normal (step 18). Here, the fourth temperature sensor TH4
Is normal, the power supply to the heater 21 is started (step 19). Thereafter, similarly to step 11 and thereafter, the fourth temperature sensor TH4 detects the boiling temperature of hot and cold water, and when the temperature reaches a predetermined temperature, the power supply to the heater 21 is stopped.

Further, when the abnormality of the fourth temperature sensor TH4 is detected in step 18, the fact that the fourth temperature sensor TH4 is abnormal is displayed as necessary (step 20), Stop supplying power to 21.

Thus, the third and fourth temperature sensors
By controlling the energization of the heater 21 using TH3 and TH4, the user can control the first and second temperature sensors TH1 and TH4.
Even if you do not notice the abnormality in 2 and do not request repair, etc., as long as one of the temperature sensors is normal, boiling up, which is a basic function, will be performed automatically, and if there is a shortage of hot water due to No inconvenience is imposed on the user.

[0048]

Effects of the Invention According to the electric water heater according to claim 1, passing <br/> in constant heating of the heater by the first temperature sensor
Sometimes the boiling temperature of the hot water is detected, and the control means controls the heating state of the heater according to the detected temperature. And
The temperature of the stored hot water can be measured by the second temperature sensor to detect the amount of remaining hot water in the hot water storage tank. Then, in a state where the abnormality detecting means detects the abnormality of the first temperature sensor, the second temperature sensor normally used for detecting the remaining hot water amount is operated at the time of heating the heater,
Thereby, the boiling temperature of the hot water is detected, and the heating state of the heater is controlled by the control means according to the detected temperature. Therefore, even when the first temperature sensor has an abnormality, the hot water at the predetermined temperature can be heated, and inconveniences such as a shortage of the hot water can be prevented. Further, when an abnormality of the first temperature sensor is detected, an abnormal state of the first temperature sensor is displayed on the display means, and the first temperature sensor is inspected while the amount of hot water to be used for the time being can be secured. , Repairs, etc., so you can wait until the repairs are complete,
Can be used without running out of hot water. In addition, over boiling water
When the temperature sensor that detects the barring temperature fails, another temperature
The configuration that diverts the sensor can reduce the manufacturing cost
You.

According to the electric water heater according to the second aspect,
In addition to the effects described in Item 1, detecting the boiling temperature of hot water
When a temperature sensor with high measurement accuracy fails, another temperature sensor
The configuration in which the diversion is used can reduce the manufacturing cost. Ma
And, a second temperature higher measurement accuracy is about the first temperature sensor
By using a degree sensor, the accuracy is as high as possible
Can control.

According to the third aspect of the present invention, there is provided an electric water heater.
Item 1 or 2 plus three hot water storage tanks
Equipped with more than one temperature sensor, heater
In the configuration that boil the whole water while convection,
Boiling control of the temperature sensor for detecting the remaining hot water amount at any position
As a temperature sensor.

[Brief description of the drawings]

FIG. 1 is a flowchart illustrating the operation of an embodiment of an electric water heater according to the present invention.

FIG. 2 is a cross-sectional view of the electric water heater.

FIG. 3 is a flowchart illustrating the operation of another embodiment of the electric water heater of the present invention.

[Explanation of symbols]

14 Hot water storage tank 21 Heater 24 Control device which also serves as control means and abnormality detection means 26 Remote control device as display means First temperature sensor as TH1 temperature sensor Second temperature sensor as TH2 temperature sensor

────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Satoru Watanabe 2-7-1, Higashi-Gotanda, Shinagawa-ku, Tokyo Inside Osaki Electric Industry Co., Ltd. (56) References JP-A-4-158164 (JP, A) JP-A-4-169742 (JP, A) JP-A-4-158117 (JP, A) JP-A-4-28954 (JP, A) (58) Fields investigated (Int. Cl. ⁶ , DB name) F24H 1 / 18 301

Claims (3)

(57) [Claims] And 1. A savings hot water tank, water heating while convection hot water of the entire hot water storage tank
A heater that controls the heater; a plurality of temperature sensors that detect the temperature of hot and cold water in the hot water storage tank; an abnormality detector that detects an abnormality of each of the temperature sensors; Display means for displaying an abnormal state of each of the temperature sensors, wherein the temperature sensor comprises a first temperature sensor and a second temperature sensor.
A sensor, said control means, said heater during normal, the previous SL first temperature sensor
Detecting the Wakiagari temperature of the hot water during heating of data, also in a state where the second detects the pooled the remaining hot water by the temperature sensor, the abnormality detecting means detects an abnormality of the first temperature sensor, An electric water heater, wherein when the heater is heated, the second temperature sensor detects the boiling temperature of the hot water, and the display means displays an abnormal state of the first temperature sensor. 2. The temperature sensor measures from another temperature sensor.
Highly accurate first temperature sensor and first temperature sensor
This provided with a second temperature sensor highly followed measurement accuracy
The electric water heater according to claim 1, characterized in that: 3. A hot water storage tank having three or more temperature sensors.
Electrodeposition of claim 1, wherein the comprising the service
Water heater.