JP2530752B2 - Electric water heater - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an electric water heater, and more particularly to a boiling operation control of a multi-can electric water heater that uses daytime electric power and late-night electric power.

[Conventional technology]

This kind of electric water heater is used to save boiling energy cost by mainly using the electric power in the late night time zone (usually 23:00 to 7:00 hours) where the electric power cost is low as much as possible.

In addition, the demand for these midnight power is generally the highest around 23:00, when the time shifts to the midnight power time zone,
Since there is a tendency for the minimum around 7:00 pm when this time period ends, late-night electricity charges are also set to be cheaper in proportion to this decreasing trend, thus reducing the cost savings on the user side. In order to raise it higher, the boiling time is calculated in advance so that the boiling time is exactly completed at the end of the midnight power time zone (7:00) by controlling the normal start time. So-called "peak shift" is performed.

This type of multi-can type electric water heater has a plurality of can bodies (tanks), as shown in the schematic view of FIG.
T1 and can 2 T2 are city water (water supply etc.) side W and hot water supply side H
And the electric heaters H1 and H2 and the temperature sensors S1 and S2 are provided in the cans T1 and T2, respectively.

Further, the boiling temperature can be set to a high temperature (for example, 88 ° C.) and a low temperature (for example, 65 ° C.), and either of them can be selectively switched.

[Problems to be Solved by the Invention]

However, here, the can body 1 on the city water side W
If the temperature sensor S1 in T1 fails and it becomes impossible to detect the hot water temperature inside the can, without knowing this, the boiling temperature is set to a low temperature (65 ° C) If the raising operation is performed or the peak shift is performed in the midnight electric power time zone, there is a problem that it is impossible to prevent the influence of hot water shortage due to the inability to boil the city water side W can body 1 T1.

The present invention has been made in view of the above problems of the conventional electric water heater of this type.
It is an object of the present invention to provide a boiling operation control means that prevents hot water from running out even if the temperature sensor S1 of T1 fails.

[Means for solving the problem]

Therefore, in the present invention, it is possible to use the daytime power and the midnight power in a selectable manner, and when using the midnight power, an electric water heater that performs a boiling operation by peak cysts, and
In an electric water heater that has a plurality of cans connected in series from the city water side to the hot water supply side and is capable of switching between high temperature and low temperature boiling, the temperature sensor of the city water side can fails and When the hot water temperature cannot be detected, only the hot water supply side can body is heated to the high temperature, and the peak shift is not performed even in the midnight power time zone. By providing the control means for starting, it is intended to achieve the above object.

[Action]

With the configuration of the electric water heater of the present invention as described above, even if the temperature sensor of the city water side can body fails, hot water runout or the like will not occur.

[Examples] The present invention will be described below based on Examples. FIG. 1 shows an example of two modes of a boiling operation control time chart when the temperature sensor S1 fails in an embodiment of the multi-can electric water heater according to the present invention.

On the horizontal axis, daytime power hours D from 7:00 to 23:00 and 23:00
The time chart of the boiling operation control of the electric water heater including the start of the peak shift calculation is shown by taking the midnight power time zone N from 7:00 to 7:00.

(A) is the daytime power time zone D, in which only the hot water supply side can body 2 T2 has completed boiling at a high temperature of 88 ° C, and the midnight power time zone N
Now, let's boil without performing peak shift.

In (b), as in (a), daytime power hours D
Is heated at 88 ° C. only for the can 2 T2, and the peak shift is not continuously performed to shift to the midnight power time zone N continuously.

〔The invention's effect〕

As described above, according to the present invention, since the peak shift is performed when there is no failure, it is during the shift to daytime power.
Since the boiling is completed at 7 am, it is more economical than the conventional one in which the can body is heated immediately after the start of the midnight power hours without peak shift and the hot water is cooled by 7 am after the boiling is completed. It will be extremely high. Also, if the sensor on the city water side can fails and the hot water temperature inside the can is undetectable, only the hot water side can is heated to a high temperature without performing peak shift control. It is hard to run out of water even after use at 23:00. Further, since it is heated at a high temperature, a large amount of hot water can be secured when it is filled with water as compared with the low temperature boiling, and the hot water runs out very little.

[Brief description of drawings]

FIG. 1 is an example of two modes of a boiling operation control time chart when the temperature sensor of the city water side can body of one embodiment of the electric water heater according to the present invention is broken, and FIG. 2 is a multi-can body water heater. It is a schematic block diagram of an example. D / N …… Daytime / midnight power hours T1 / T2 …… Can 1/2 S1 / S2 …… Each temperature sensor W …… City water side H …… Hot water supply side

Claims (1)

(57) [Claims] 1. An electric water heater capable of selectively using daytime electric power and late-night electric power, and performing a boiling operation by a peak shift when using late-night electric power, which is connected in series from the city water side to the hot water supply side. In an electric water heater equipped with a plurality of cans and capable of switching between high temperature and low temperature boiling, if the temperature sensor of the city water side can fails and the temperature of the water in the can is undetectable, the hot water supply is performed. Only the side can body is heated to the high temperature, and the peak shift is not performed even in the midnight power hours,
An electric water heater characterized by being provided with a control means for starting the boiling operation immediately when shifting to the midnight power time zone.