JPH0711362B2 - Failure monitoring device for electric water heater - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric water heater capable of accurately detecting a defective boiling failure due to a disconnection of a heating heater or a leak of a hot water supply piping system in an electric water heater. TECHNICAL FIELD The present invention relates to a failure monitoring device.

2. Description of the Related Art Electric water heaters that use late-night electric power to boil hot water and use the boiled hot water during the daytime have become widespread.

This one uses an electric heater to boil the hot water in the hot water storage tank, and when using this hot water, the hot water is automatically replenished in the hot water storage tank, so the hot water storage tank is always used with full water. It is like this. Also, since the amount of hot water that can be used during the daytime depends mainly on the boiling temperature, data such as the amount of hot water used in the past does not cause a situation where the amount of hot water is insufficient. In order to minimize power consumption, a technique for optimally determining the boiling temperature has been developed and is known as a so-called microcomputer type electric water heater.

DISCLOSURE OF THE INVENTION Problems to be Solved by the Invention In the case of such a conventional technique, for example, when the heater partially fails, boiling failure of hot water occurs. However, since no other display was made, there was a problem that it was extremely difficult to use as a whole.

That is, considering the case where a part of the heater is disconnected during energization of the heater during the energizing time of the late-night power, at this time, the power consumption of the heater is insufficient, so the boiling temperature is lower than the predetermined value. Become. However, the effect is revealed to the user when all the hot water is used and water comes out from the faucet, so that there is a large time delay before the failure is detected.

Also, in the electric water heater, when hot water leaks from the hot water supply pipe system, the phenomenon is similarly found as an insufficient amount of hot water, but in this case as well, there is no method for early detection of a failure. It was.

Therefore, in view of the actual situation of the prior art, an object of the present invention is to directly check the operation performance of the heater to accurately and early generate a failure such as a partial disconnection accident of the heater or a leak of the hot water supply pipe system. An object is to provide a failure monitor device for an electric water heater capable of displaying an alarm.

Means for Solving the Problems The constitution of the present invention for achieving the above-mentioned object is to provide an average temperature determining means for obtaining an average temperature in a hot water storage tank by a plurality of temperature sensors installed in the hot water storage tank, and a power supply time zone of midnight power. A check period setting means for setting a check period therein, a timer means for measuring the energization time of the heater within the check period set by the check period setting means, and a hot water storage tank before and after the energization time of the heater measured by the timer means. The gist of the present invention is to include a comparison means for comparing the average temperature difference with a set value, and a display means for displaying an alarm of a failure of the electric water heater by the output of the comparison means when the average temperature difference is smaller than the set value.

The check period setting means can set the check period in a time period in which hot water is used least in the midnight power supply time period.

Further, the comparison means may be operated only when the energization time of the heater measured by the timer means is a predetermined value or more.

Action With the configuration of the invention, the comparison means can check the operation performance of the heater by comparing the average temperature difference of the hot water storage tank before and after the energization time of the heater with the set value. That is, the comparison means reduces the power consumption of the heater when a part of the heater is broken,
Since the average temperature difference in the hot water storage tank becomes small, it is possible to detect this and display an alarm to the outside through the display means.

On the other hand, when there is a leak in the hot water supply pipe system, the same amount of water as the amount of water leakage is replenished in the hot water storage tank, and the average temperature difference in the hot water storage tank becomes smaller than the predetermined value. This can be detected as a failure and an alarm can be displayed.

If hot water is used during the check period, the average temperature difference will be smaller and it will be difficult to distinguish it from the failure. By setting the check period at 1, the risk of malfunction due to such a cause can be minimized.

Further, the comparison means can ensure the average temperature difference in the normal state to be a certain value or more by operating the heater only when the energization time of the heater is equal to or more than a predetermined value, so that reliability of failure detection can be further enhanced. it can.

Example Hereinafter, an example will be described with reference to the drawings.

The electric water heater failure monitoring device 20 is a boiling control device CTR.
Of the average temperature determining means 16,
Timer means 24, check period setting means 25, comparing means 22,
The display means 26 is provided.

The electric water heater 10 has a heater 12 in a hot water storage tank 11 including a water supply pipe 11a and a hot water supply pipe 11b. Heater 12
It is connected to a power supply AC via a switching element 14 and a timer 13 that defines a power supply time zone of late-night power. In addition, the hot water storage tank 11 has a plurality of temperature sensors 15, 15 in the vertical direction.
... is attached.

The outputs of the temperature sensors 15, 15 ... Are collectively guided to the boiling control device CTR as a temperature signal 15a, and the average temperature determining means 1
Entered in 6. The average temperature determining means 16 determines the average temperature TA in the hot water storage tank 11 by the temperature sensors 15, 15. The average temperature TA from the average temperature determination means 16 is input to the boiling control means 17 together with the boiling target temperature Ts,
The output of the boiling control means 17 is as an opening / closing control signal 17a,
It is input to the switching element 14.

The output of the average temperature determination means 16 is the comparison means 22 and the memory means.
It is also branched to 23. The memory means 23 stores the average temperature TA = TAo in the hot water storage tank 11 at the time of outputting the boiling start signal 24a from the timer means 24, and the average temperature TAo from the memory means 23 is input to the comparison means 22. Has been done. Further, the set value k is also input to the comparison means 22.

The output of the boiling control means 17 is also branched and input to the timer means 24, and the output of the timer means 24 is used as the energization time tH of the heater 12 and the boiling start signal 24a, respectively, and comparing means 2
2, input to the memory means 23. Also, the timer means 2
4, check period setting means 25, check period tck
While the start period to and the end period t1 are input, the output signal 22a from the comparison unit 22 is input to the display unit 26.

Now, the timer 13 defines the energizing time zone of the midnight power to the heater 12, the boiling control means 17, the average temperature TA in the hot water storage tank 11 from the average temperature determination means 16 and the boiling target temperature Ts. By comparison, by outputting the opening / closing control signal 17a to the switching element 14, the water in the hot water storage tank 11 can be boiled up to a predetermined boiling target temperature Ts by using the midnight power.

On the other hand, the check period setting means 25 selects an appropriate time within the energizing time zone of the late-night power, and starts the check period tck to
And the final term tl (Fig. 2). Here, the check period tck means a time period for checking whether or not the boiling performance of the heater 12 is normal,
In order that the power consumption due to the power supply of 12 may be reflected as it is in the rise of the average temperature TA in the hot water storage tank 11, the time when the hot water in the hot water storage tank 11 is used as little as possible, for example, the midpoint of the power supply time zone of midnight power. After that, it is preferable to set the length to about 1 hour.

Further, the timer means 24 measures the energization time tH of the heater 12 within the check period tck and outputs it. That is, when the boiling control means 17 starts energizing the heater 12, the timer means 24 starts measuring the energization time tH and at the same time outputs a boiling start signal 24a to the memory means 23.

On the other hand, the comparison means 22 calculates the difference between the average temperatures TAo and TA in the hot water storage tank 11 before and after the energization time tH of the heater 12,
The average temperature difference ΔT = TA−TAo is compared with the set value k. As described above, the average temperature TAo is the average temperature in the hot water storage tank 11 stored in the memory means 23 in response to the boiling start signal 24a. Therefore, the average temperature difference ΔT = TA-TAo is the energization time. t
This means that the average temperature rise in the hot water storage tank 11 at H is shown. That is, the comparison means 22 can determine whether or not the heater 12 is normal depending on whether or not the average temperature difference ΔT is larger than the set value k, and the result can be displayed on the display means 26. . When there is a leak from the hot water supply pipe 11b system, the same amount of water as the amount of water leakage is replenished, so that the average temperature difference ΔT also appears small and can be detected by the comparison means 22.

The failure monitoring device 20 can also be realized by software of a microcomputer (third part).
Figure).

This program detects the arrival of the start period to of the check period tck by a clock program (not shown) and starts the operation. However, since the start period to may be defined by the passage of a predetermined time after the start of the energizing time zone of the midnight power, the program of FIG. 3 is started by a simple timer program instead of the clock program. be able to.

The program first waits for the heater 12 to be energized (step (1) in the figure, hereinafter simply referred to as (1)), and the energization time t of the heater 12 within the check period tck.
A timer is started to measure H (2). Next, the average temperature TA in the hot water storage tank 11 at that time
Is stored as the average temperature TAo (3), and the timed element of a predetermined length is executed (4).

Next, it is confirmed that the energization time tH of the heater 12 is a predetermined value tHL or more (5), the average temperature TA at that time is read (6), and the average temperature difference ΔT = TA-TAo is calculated (7). . Subsequently, the average temperature difference ΔT is compared with a predetermined value k (8), and when ΔT <k, an alarm output indicating that the heater 12 is defective or leakage in the hot water supply pipe 11b system is assumed is output. (9).

Here, the time element of step (4) is the check period tc.
It may be considered that it gives the end tl of k, and the predetermined value tHL in step (5) may not clearly show the average temperature difference ΔT unless the energization time tH of the heater 12 is a certain value or more. In consideration of the above, the minimum length of the energization time tH is specified. It should be noted that the set value k can be determined from the average temperature difference ΔT expected when the heater 12 is in a normal state and the energization of the predetermined value tHL or more.

Now, comparing FIG. 1 and FIG. 3, the comparing means 22 in the former is the steps (5) to (8) in the latter.
The memory means 23 corresponds to step (3), the timer means 24 corresponds to steps (1) and (2), and the check period setting means 25 corresponds to a clock program (not shown) and step (4). Corresponding.

EFFECTS OF THE INVENTION As described above, according to the present invention, by providing the average temperature determining means, the check period setting means, the timer means, the comparing means, and the display means, the timer means can energize the heater. The time can be measured, and the comparison means can compare the average temperature difference before and after that with the set value and display the result on the display means. An alarm can be reliably displayed as a shortage of the difference, and the detection timing at this time is much faster than when the user discovers a failure due to a lack of boiling water amount, and therefore the failure state is left unattended, It is possible to effectively eliminate the risk of repeated hot water shortages and waste of large amounts of energy. This has the excellent effect that the risk of malfunction can be minimized by setting the check period.

BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1 to 3 show an embodiment, FIG. 1 is an overall configuration block system diagram, FIG. 2 is an operation explanatory diagram, and FIG. 3 is a program flow chart. tH ... Energization time tHL ... Predetermined value TA ... Average temperature ΔT ... Average temperature difference k ... Set value tck ... Check period 11 ... Hot water tank 12 ... Heater 15 ... Temperature sensor 16 ... Average temperature determination means 22 ... Comparison means 24 ... Timer means 25 ... Check period setting means 26 ... Display means

Claims (3)

[Claims] 1. An average temperature determining means for obtaining an average temperature in a hot water storage tank by a plurality of temperature sensors installed in the hot water storage tank, a check period setting means for setting a check period within a power supply period of midnight power, and the check. Timer means for measuring the energization time of the heater within the check period set by the period setting means, and comparing means for comparing the average temperature difference of the hot water storage tank before and after the energization time of the heater measured by the timer means with a set value, A failure monitoring device for an electric water heater, comprising: a display means for displaying an alarm of a failure of the electric water heater when the average temperature difference is smaller than a set value. 2. The electricity according to claim 1, wherein the check period setting means sets the check period in a time period in which hot water is least used, among the power supply time periods of the midnight power. Failure monitoring device for water heaters. 3. The electric hot water according to claim 1, wherein the comparison means operates only when the energization time of the heater measured by the timer means is a predetermined value or more. Failure monitoring device.