JPH0245782B2 - - 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.
It was decided that the electricity would be cut off. Therefore,
Demand for late-night electricity will be concentrated in the first half of the late-night power supply period, resulting in a peak in late-night electricity demand. For electric power companies, it is desirable that there is an average power demand during the late-night power supply hours.

To solve this problem, electric water heaters have traditionally been designed to 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. This method was proposed in Japanese Patent Publication No. 1987-75655. However, this is also because the power demand for electric water heaters is concentrated in the latter half of the late-night power-on time period, so it is difficult to use electric water heaters in industries that work early in the morning.
This overlaps with the time period when electricity is used by ordinary households for preparing breakfast, etc., so a peak occurs as expected.

On the other hand, if we consider the heat dissipation from the tank of an electric water heater, it is best to end the power supply to the heater just before the end of the late-night power supply period, as stated in the above publication. If you use hot water during the non-power period in the first half of the time period, that is, if you take a bath or take a shower late at night, the amount of hot water remaining will be lower than at the beginning of the late-night power period. Therefore, the energization time calculated at the start of the late-night power supply period does not reach the desired boiling temperature, and the late-night power supply period ends at a lower temperature. Therefore, when a user uses hot water for lunch, dinner preparation, bathing, etc., the hot water may run out. This causes a great deal of inconvenience to the user, and the convenience of the water heater is lost.

(Objective of the Invention) The object of the present invention is to solve the above-mentioned problems and contribute to the averaging of the total electricity demand for electric power companies, while at the same time preventing the inconvenience of users from running out of hot water as much as possible. The purpose of the present invention is to provide a hot water storage type electric water heater that is capable of

(Characteristics of the Invention) In order to achieve the above object, the present invention provides, when the energization time to the heater is expected to be shorter than a specific time period, the non-energization time within the specific time period is A moving time for moving the energization time toward the center of the specific time period where the total power demand is minimized by being allocated before the energization time, and a margin time that is allocated after the energization time. and calculating means for delaying the start of energization by the travel time from the start of the specific time slot, thereby moving the power demand from the electric water heater toward the center of the specific time slot where the total power demand is minimum. In addition, the present invention is characterized in that the energization time can be extended by the margin time.

(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 an A/D converter 5 and sent to arithmetic means 6 such as a microprocessor. For example, as shown in FIG. 3, the time zone detecting means 7 is composed of a photocoupler, and when the late-night power supply time period begins and a late-night power time switch (not shown) is turned on, the heater power supply terminal is turned on. When late-night power is turned on at 8, a voltage is applied through the earth leakage circuit breaker 9, the operation is started, and the late-night power-on information is sent to the calculation means 6. The first 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 regarding the amount of remaining hot water (for example, 45° C.), and the like. Second memory 11
stores hot water temperature control patterns A and B shown in FIG. The third memory 12 stores the moving time of the energization time, which is determined in advance based on the water supply temperature, the hot water temperature control pattern, and the 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 composed of a push button type changeover switch 14, as shown in FIG. 6, for example. The output means 15 is for driving a relay 17 that controls energization of the heater 16, as shown in FIG. Heater 16
is located 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 them. It is controlled by control means 19.

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 supply time is shorter than the midnight power supply time, the non-power supply time is distributed in a predetermined ratio, for example, 3:1, before and after the power supply time, and this time is moved. When called time and margin time, it becomes as shown in FIG. 7, for example. This travel time is stored in the third memory 12 as a pre-calculated travel time because there is almost no problem if the actual energization time deviates from the expected energization time by keeping it constant.

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. In addition, at times other than the late-night power supply time when the heater 16 is not energized, a mixed layer 22 is formed between the hot water 20 and the water 21 in the tank 3, as shown in FIG. It does not mix with water 21. Therefore, the water temperature can be obtained by measuring the temperature of the water 21 with the temperature sensor 1 during a time period 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 consecutive days (7 days) including the latest day are read out 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. Note that the remaining hot water amount detection operation is performed not only when the late-night power supply information is received, but also from the beginning of the late-night power supply period to the beginning of the next late-night power supply period.
It is carried out 24 hours a day at predetermined time intervals similar to the water temperature detection operation, and the amount of remaining hot water is constantly displayed.

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 travel time, a timer built in the calculation means 6 is driven, and after the travel time has elapsed, a signal is sent to the output means 15 to control the energization of the heater 16. The inside of the tank 3 has a uniform temperature due to the circulation of the hot water 20, so the temperature sensor 1 detects the temperature of the hot water 20, and when the hot water 20 is boiled to the boiling temperature, the heater 16 is turned off or turned off. be done.

According to this embodiment, since the power-on time is shifted toward the center of the late-night power-on time period with emphasis on the latter half, the power-on time is shifted toward the center of the late-night power-on time period, so that the power supply time is shifted toward the center of the late-night power-on time period, so that the power supply time is shifted toward the center of the late-night power on time period. It is possible to reduce the power demand of the electric water heater in the final stage, and it is possible to contribute to the averaging of the total power demand for the electric power company. Furthermore, since the time for storing boiling water is shortened, loss due to natural heat radiation can be reduced.

(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 described above, according to the present invention, when it is expected that the energization time to the heater will be shorter than a specific time period, the non-energization time within the specific time period is A moving time for moving the energization time toward the center of the specific time period where the total power demand is minimized by being allocated before the energization time, and a margin time that is allocated after the energization time. and calculating means for delaying the start of energization by the travel time from the start of the specific time slot, thereby moving the power demand from the electric water heater toward the center of the specific time slot where the total power demand is minimum. At the same time, we made it possible to extend the energization time depending on the surplus time, so we can contribute to the equalization of the total electricity demand for the electric power company, and at the same time, we prevent the inconvenience of running out of hot water to the users as much as possible. can do.

[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.

Claims (1)

[Claims] 1. In a hot water storage type electric water heater equipped with a heater that boils water using electricity during a specific time period, if it is expected that the time during which electricity is applied to the heater will be shorter than in the specific time period, A moving time for moving the energized time toward the center of the specific time period where the total power demand is minimized by allocating the non-energized time before the energized time, and a moving time that is distributed after the energized time. The hot water storage type electric water heater is characterized in that it is provided with a calculation means for delaying the start of energization by the travel time from the start of the specific time period by dividing the time in proportion to the surplus time.