JPH0454861B2 - - Google Patents

Description

[Detailed Description of the Invention] (Field of Application of the Invention) The present invention relates to an improvement in a hot water storage type electric water heater that boils and stores hot water using electric power during a specific time period such as a late-night power-on time period. It is.

(Background of the Invention) In conventional electric water heaters, when power is turned on late at night, power is immediately started to the heater, and when the water reaches boiling temperature, the thermostat is activated.
The idea was to turn off the electricity. As a result, late-night power demand concentrates in the first half of the late-night power supply period, resulting in a peak in late-night power demand.Although it is desirable for power companies to have an average power demand, Regardless, it will lead to bad results.

To solve this problem, electric water heaters have been proposed that start energizing in the middle of the late-night power supply period so that the end of the late-night power supply period coincides with the end of the power supply time to the heater. ing. (Refer to Japanese Unexamined Patent Application Publication No. 75655/1983) The applicant has also proposed an electric water heater in which the start time of energization is determined so that the non-energization time is distributed before and after the energization time to the heater. There is.

In these cases, in order to delay the power-on time, calculations are performed at the same time as the late-night power-on time period begins based on the detection of the amount of remaining hot water and the boiling temperature set by the user, and the delay time until power is started is calculated. Therefore, if a large amount of hot water was used between the beginning of the late-night power supply period and the start of power supply to the heater, after the calculated delay time,
If the electricity is turned on, there is a problem in that the late-night electricity supply period ends before the boiling temperature has been reached, resulting in a shortage of hot water.

(Objective of the Invention) The object of the present invention is to solve the above-mentioned problems, to contribute to the averaging of the total power demand for power companies, and at the same time to enable the heater to be energized from the beginning of a specific time period. To provide a hot water storage type electric water heater that does not cause a user the trouble of running out of hot water even when a lot of hot water is used before starting.

(Characteristics of the Invention) In order to achieve the above object, the present invention provides a method for applying electricity to the heater at the beginning of a specific time period when it is expected that the energization time to the heater will be shorter than that of the specific time period. calculation means for delaying the start of energization from the beginning of the specific time period and recalculating the start time of energization according to an instruction from the calculation instruction means described later;
recalculation instructing means for instructing the calculating means to recalculate at the time of detection by detecting a decrease in the amount of remaining hot water by a predetermined amount or more between the beginning of the specific time period and the start of energization of the heater; In this way, by delaying the energization time, power peaks are not concentrated in the first half of a specific time period, and even after the time to start energization has been determined, if the amount of remaining hot water decreases, it can be accommodated. The present invention is characterized in that the energization time is accelerated, that is, the energization time is lengthened.

(Embodiment of the invention) FIG. 1 shows an embodiment of the invention. A temperature sensor 1, a lower temperature sensor 2a, a middle temperature sensor 2b, and an upper temperature sensor 2, each of which uses a thermistor or the like.
c is attached from the bottom to the top of the outer wall surface of the tank 3, as shown in FIG. Temperature sensor 1
is glued to the outer wall of the tank 3 near the water supply port 4,
Can be used for both water temperature detection and boiling temperature detection.
The temperature sensors 2a to 2c are for detecting the amount of remaining hot water. Information from the temperature sensors 1, 2a to 2c is converted into digital values by the A/D converter 5 and sent to the calculation means 6. For example, as shown in FIG. 3, the time zone detection means 7 is composed of a photocoupler, and when the late-night power supply time period is entered, the power source is turned on when a late-night power time switch (not shown) is turned on. When late-night power is applied to the terminal 8, a voltage is applied through the leakage circuit and the disconnector 9, the operation is started, and the late-night power application information is sent to the calculation means 6. 1st
The memory 10 stores various operation commands of the calculation means 6, water temperature values for a plurality of days including the latest day, for example, the past seven days, a set temperature for the amount of remaining hot water (for example, 45° C.), and the like. The second memory 11 stores hot water temperature control patterns A and B shown in FIG. Third memory 12
stores the moving time of the energization time (time delayed from the beginning of the late-night power energization period at the start of energization), which is determined in advance based on the water supply temperature, hot water temperature control pattern, and amount of remaining hot water, as shown in FIG. . The setting operation means 13 is for selecting one of the two hot water temperature control patterns A and B, and is comprised of, for example, a push button type changeover switch 14 as shown in FIG. The output means 15 is for driving a relay 17 that controls energization of the heater 16, as shown in FIG. The heater 16 is placed at the bottom of the tank 3, as shown in FIG. As shown in FIG. 6, the display means 18 consists of display elements 18a to 18e such as light emitting diodes that display the water temperature control patterns A and B and the amount of remaining water (high, medium, low) by lighting. It is controlled by control means 19.

The recalculation instructing means 20 stores the amount of remaining hot water output from the calculating means 6 when the late-night power supply period begins, and monitors the decrease in the amount of remaining hot water until the power supply to the heater 16 is started. , when it is detected that the amount of remaining hot water has decreased by one level or more (for example, from high to medium),
The calculation means 6 is instructed to recalculate the moving time of the energization time. It should be noted that the recalculation instruction means 20 can be constituted by one microprocessor together with the calculation means 6, for example.

The moving time of the energization time will be further explained.
Once the water supply temperature, boiling temperature, and amount of remaining hot water are determined, the capacity of the tank 3 and the power used by the heater 16 are known, so the energization time can be determined by calculation. Assuming that the late-night power supply time period is 8 hours, if the power-on time is shorter than the midnight power supply time period, the non-power-on time is distributed in a predetermined ratio, for example, 3:1, before and after the power supply time, and this is shifted. When called time and margin time, it becomes as shown in FIG. 7, for example. Even if the actual energization time is slightly different from the expected energization time, this travel time is within the margin time, so there is almost no problem if it is kept constant. Therefore, the travel time calculated in advance is stored in the third memory 12.

Next, the operation will be explained. The calculation means 6 calculates the 24 hours from the beginning of the late-night power supply period to the beginning of the next late-night power supply period (this is referred to as the latest day);
At predetermined time intervals, for example, every minute, the temperature sensor 1
The water temperature information measured by the A/D converter 5 and converted into a digital value by the A/D converter 5 is taken in. Note that during the late-night power supply time period or later when the heater 16 is not energized, a mixed layer 23 is formed between the hot water 21 and the water 22 in the tank 3, as shown in FIG. It does not mix with water 22. Therefore, the temperature of the water 22 can be obtained by measuring the temperature of the water 22 with the temperature sensor 1 at times other than the late-night power supply time period.

The calculation means 6 determines whether the taken-in water temperature is the lowest value on the latest day. If it is the lowest value, the calculation means 6 sets the water temperature value of the latest day stored in the memory built in the calculation means 6 to that value. Update, remember.

When information indicating that power is turned on late at night is input from the time zone detection means 7, the calculation means 6 performs a water supply temperature calculation process. The subsequent operations will be explained with reference to the flowchart of FIG. The calculation means 6 stores the water temperature value of the latest day stored in the built-in memory in the first memory 1.
0 and memorize it. At the same time, the oldest water temperature value is erased from the first memory 10. Then, water temperature values for a plurality of consecutive days (7 days) including the latest day are read from the first memory 10, and the lowest value among them is determined as the current day's water supply temperature.

Next, the calculation means 6 detects the amount of remaining hot water. That is, the A/D converter 5 takes in the detected temperature information from the temperature sensors 2a to 2c in time series, sequentially converts the detected temperature information into digital values, and sends the digital values to the calculation means 6. When the temperature detected by the lower temperature sensor 2a is higher than the set temperature, the calculation means 6 sends a signal instructing that there is a large amount of hot water to the display control means 19, and the display control means 19 turns on all three display elements 18c to 18e. . When the temperature detected by the lower temperature sensor 2a falls below the set temperature and the temperature detected by the intermediate temperature sensor 2b exceeds the set temperature, a signal indicating that the amount of hot water remaining is sent to the display control means 19.
turns on both the two display elements 18d and 18e. Lower temperature sensor 2a and middle temperature sensor 2b
When the detected temperature of the upper temperature sensor 2c is lower than the set temperature and the detected temperature of the upper temperature sensor 2c is higher than the set temperature, a signal instructing that the amount of remaining hot water is low is sent to the display control means 19, and the display control means 19 displays one display element 18e. only lights up. When the temperature detected by the upper temperature sensor 2c falls below the set temperature, a signal indicating that the amount of remaining hot water is extremely low is sent to the display control means 19, and the display control means 19 turns off the three display elements 18c to 18e. A signal indicating the amount of remaining hot water at this time is also sent from the calculation means 6 to the recalculation instruction means 20 and stored there. Note that the remaining hot water amount detection operation is performed not only when the late-night power supply information is received, but also during the 24-hour period from the beginning of the late-night power supply period to the beginning of the next late-night power supply period, and during the same predetermined time period as the water temperature detection operation. This is done at regular intervals, and the amount of hot water remaining is displayed at all times.

The calculating means 6 reads the boiling temperature corresponding to the water supply temperature from the hot water temperature control pattern stored in the second memory 11, and stores the moving time corresponding to the water supply temperature, the boiling temperature, and the amount of remaining hot water in the third memory 11.
If the travel time is zero, a signal is immediately sent to the output means 15 to control the energization of the heater 16.

If there is a travel time, a value of the travel time is set in a timer built in the calculation means 6, and the timer is driven. After the moving time has elapsed, a signal is sent to the output means 15, and the heater 1
6. Performs energization control. The inside of the tank 3 has a uniform temperature due to the circulation of the hot water 21, so the temperature sensor 1 detects the temperature of the hot water 21, and when the hot water 21 is boiled to the boiling temperature, the power to the heater 16 is cut off. be done.

Within this travel time, the recalculation instruction means 20:
The current amount of remaining hot water outputted from the calculation means 6 is compared with the amount of remaining hot water at the beginning of the late-night power supply period, and if it is detected that the amount has decreased by one step or more, the calculation means 6 is instructed to recalculate the travel time. As a result, the calculation means 6 re-detects the amount of remaining hot water and reads out from the third memory 12 the supply water temperature, boiling temperature, and new travel time corresponding to the re-detected amount of remaining hot water. and,
A travel time subtraction process is performed to subtract the elapsed time from the beginning of the late-night power supply period to the current time from the new travel time, a timer is reset to the subtracted travel time, and this timer is driven.

According to this embodiment, if more than a certain amount of hot water is used (drawn hot water) during the elapse of the travel time, the travel time is recalculated at that point, so the start of energization is brought forward. It is possible to boil water by the end of the late-night electricity supply period.

(Modification) In the illustrated embodiment, the travel time is calculated in advance,
Although this is stored in the third memory 12, the calculation means may calculate the energization time each time, and calculate the travel time from the energization time.

(Effects of the Invention) As explained above, according to the present invention, when it is expected that the energization time to the heater will be shorter at the beginning of a specific time period than in the specific time period, the heater calculation means for delaying the start of energization of the heater from the beginning of the specific time period and recalculating the start time of the energization based on an instruction from the recalculation instruction means described later; and a recalculation instructing means for instructing the calculating means to recalculate at the time of detection by detecting a decrease in the amount of remaining hot water by a predetermined amount or more until the amount of hot water decreases by a predetermined amount or more. In addition, even after the time to start energization is determined, if the amount of remaining hot water decreases, the energization time is accelerated to correspond to the decrease, that is, the energization time is lengthened. This makes it possible to contribute to averaging the total electricity demand for the electric power company, and at the same time, when a large amount of hot water is used from the beginning of a specific time period to the start of energizing the heater, It is possible to prevent users from experiencing the inconvenience of running out of hot water. In addition, by monitoring whether the amount of remaining hot water has decreased by more than a predetermined amount from the beginning of a specific time period (by comparing and monitoring changes in the amount of remaining hot water at the beginning of a specific time period and after that), the amount of remaining hot water at the beginning of a specific time period can be adjusted. Regardless, it is possible to capture subsequent changes and perform recalculations (corrective calculations) at the time of starting energization, improving followability to prevent hot water from running out when hot water is used immediately after energization starts and afterward. This makes it possible to take practical measures.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing one embodiment of the present invention;
Figure 2 is a sectional view showing the outline of the tank, Figure 3 is a circuit diagram showing its heater circuit, Figure 4 is a diagram showing its control pattern, Figure 5 is a diagram showing its travel time, and Figure 6 is a front view showing the operation panel surface, No. 7
The figure shows an example of the movement of the energization time, and FIG. 8 is a flowchart showing the operation. 1...Temperature sensor, 2a, 2b, 2c...Temperature sensor, 3...Tank, 6...Calculating means, 7...
Time zone detection means, 10...first memory, 11...
Second memory, 12...Third memory, 15...Output means, 16...Heater, 20...Recalculation instruction means.

Claims (1)

[Claims] 1. A hot water storage type electric tank that is equipped with a tank that is supplied with water from the bottom and hot water from the top, multiple temperature sensors attached to the wall of the tank to detect the amount of remaining hot water, and a heater that boils water using electricity during a specific time period. In the water heater, at the beginning of the specific time period,
delaying the start of energizing the heater from the beginning of the specific time period when it is expected that the energization time to the heater will be shorter than the specific time period;
Calculation means for recalculating the energization start time based on instructions from the recalculation instruction means described later, and detecting a decrease in the amount of remaining hot water by a predetermined amount or more between the beginning of the specific time period and the start of energization to the heater. 2. A hot water storage type electric water heater, further comprising recalculation instructing means for instructing said calculating means to recalculate at the time of said detection.