JPS6335904B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to control of energization of devices that utilize late-night power, particularly electric water heaters. An object of the present invention is to reduce the peak load of late-night power immediately after the supply of late-night power starts.

Late-night power will be supplied for eight hours, from 10 p.m. to 6 a.m. tomorrow morning. Devices that use late-night power operate and store heat during this late-night power period.

The case of an electric water heater that uses electricity late at night will be explained. The heater of the water heater is energized when electricity starts to be supplied late at night, and when the water reaches a predetermined temperature, the thermostat stops the energization of the heater. As shown in Figure 1, the power changes during the late night power hours are 100% or 0% of the heater capacity, and 100% until boiling.
It becomes a load. Additionally, the amount of hot water used in ordinary homes is generally about half. Therefore, as shown in FIG. 1, the load becomes 0 in about half of the late night power hours. For this reason, as the number of installed heaters increases, immediately after the late-night power supply starts, the capacity of each heater becomes the sum total, resulting in a peak load, as shown in FIG. 2. Therefore, the transmission system for late-night power needs to have a capacity that can accommodate this peak.

Therefore, the heater is divided into two parts and installed to detect the amount of hot water remaining in the hot water storage tank.When the amount of remaining hot water is small, power is applied to the two heaters, and when the amount of remaining hot water is large, only one heater is energized. There are some that can be heated using a small amount of electricity. However, in this case, although the peak is reduced compared to the above, the effect is not large.

The present invention was invented in view of the above, and an object of the present invention is to prevent the occurrence of peak loads during late-night power supply hours. In order to achieve the above object, the present invention divides the late-night power supply time period into small time periods, sets priorities for these divided time periods, and sets the required power supply time to the small time periods according to the priority order. It allocates so that the cumulative total of small time periods is equal to or greater than the required energization time, and energizes according to this allocation.

The present invention will be explained below with reference to an embodiment shown in FIGS. 3 to 6. In FIG. 3, a heater 2 is provided at the bottom of a hot water storage tank 1, a water supply port 3 is provided at the bottom, and a hot water supply port 4 is provided at the top. 5 is a temperature detector for boiling detection, 6 is an over-rise temperature detector, 7a, 7b, 7
c and 7d are temperature sensors that detect the amount of remaining hot water;
Multiple units are installed in the vertical direction of the hot water storage tank. 9 is a cabinet.

In FIG. 4, 10 is a late-night power source, 11 is an earth leakage switch, 12 is an operation switch, 13 is a low voltage power supply circuit, 14 is an arithmetic circuit, 15 is an A/D conversion circuit, 16 is a coil 16a, This is a relay consisting of contacts 16b.

In such a configuration, the operation switch 12 is turned on, and when the midnight power period comes, the arithmetic circuit 14 operates, and the arithmetic circuit 14 receives the input from each temperature sensor 7 via the A/D conversion circuit 15.
Calculate the amount of remaining hot water based on the temperature signals of a, 7b, 7c, and 7d, then calculate the required energization time, and allocate this to each time period of the late-night power period that is time-divided into multiple times, and use the built-in timer. The heater 2 is energized by the relay 16 during each time slot assigned by the heater 2 . FIG. 5 shows a flowchart of the arithmetic circuit. When the temperature reaches boiling point, the temperature detector 5 operates to stop the power supply to the heater 2.

As an example, a control example will be described below in the case where the 8 hours of late-night power supply time are divided into 32 time periods every 15 minutes.

The required energization time calculated from the amount of remaining hot water is 2 hours and 52 minutes. This time is for each temperature sensor 7a, 7b, 7
It is calculated and determined based on each temperature outputted by c and 7d and the position of each temperature sensor.

Since the required energization time is 2 hours and 52 minutes, (2 hours and 52 minutes ÷ 15 minutes) = 11.46, and the number of times of energization in the time period is 12. In other words, the heater is energized for 12 of the 32 time periods, and the heater is not energized for the remaining 20 time periods.Next, the method of allocating these time periods is to This is done based on the remainder created when dividing by the length of the time period, 15 minutes. That is, the upper digits are used as the basis for the number of energizations, and the lower precision values are used as random numbers for assignment.

In this example, the remainder resulting from division is "0.46", so this "4" is used as the basis for allocation. That is, 32
The fourth time period from the beginning is the energization time period for heater 2, and the fourth time period from there is the energization time period,
Repeat this, and if it overlaps with a time slot that has already been assigned, shift the assignment to a time slot that has not been assigned, and use this as the basis for the next time slot. Repeat this until the number of energizations reaches 12, and then change the control pattern. create.

FIG. 6 shows the control pattern in this case. A is the fourth time slot and is the first time slot allocated. In the ninth allocation, B overlaps with A, which was allocated first, so it is allocated with a shift of one position.

Relay 16 is controlled based on a control pattern.

In this way, since the power-on time period is distributed over the eight-hour late-night power time period, the total power supply is equalized when a large number of power supply devices are installed.

Figure 7 shows an example of calculation when a large number of electric water heaters of this type are installed. Changes in the total power supply are extremely smooth, and no peak load is observed.

In the above embodiment, the allocation criterion is based on the remainder generated when the above division is performed. This is because even if the number of energizations is the same, 12, the remainder is considered to be different for each electric water heater.
The end of the required energization time varies depending on the temperature sensor 7 and the mounting error on the tank, and is not accurate. Therefore, the remainder resulting from division becomes a low value with low precision, and if this is used as a reference, the possibility that the control patterns will be the same is reduced.

In the above embodiment, only the remaining first digit is used, but by combining it with the second and subsequent digits, it may be possible to allocate the first assignment to all 32 categories.

In the above embodiment, "extra" is used for the second and subsequent times, but it is also possible to use the upper digit "11" of the number of times of energization or "12" of the number of times of energization.

Alternatively, the division may be determined by a pattern predetermined using a random number table. This would be appropriate when roughly calculating the required energization time.

In the above embodiment, all the late-night power supply hours can be allocated. However, a portion (for example, 30 minutes) at the end of the late-night power supply time period may not be set as an allocatable time, but may be set as an automatically allocated time period. The automatically allocated time period is controlled by the temperature sensor 5. This will be advantageous in case of power outages during late night power supply hours.

Further, although there is only one heater in the above embodiment, it can also be used, for example, in an electric water heater in which heaters are provided in the lower part and in the middle part, respectively.

In the above embodiment, power is supplied to the arithmetic circuit from late-night power, but the power may be input from the normal power source.

In the above embodiment, each water heater is provided with an arithmetic circuit, but the water heater may not be provided with an arithmetic circuit, and each water heater may be controlled by a central control device. In the above embodiment, the total load is leveled, but it is also possible to control the total load so that it falls within a preset allowable total load, and to provide some peaks. For example, a central control device determines the priority of energizing each water heater based on the amount of remaining hot water and setting conditions.
This is a conscious effort to increase the total load for part of the late night power hours in relation to the power company.

That is, it is possible to give a high priority to a part of the late-night power time period and allocate the power supply time according to this priority.

As described above, the present invention distributes and allocates the necessary energization time to the late-night power supply time period, and supplies the late-night power according to this allocation, thereby making it possible to prevent the occurrence of peak loads.

[Brief explanation of the drawing]

Fig. 1 is a diagram showing an example of energization to the electric heater of a conventional electric water heater, and Fig. 2 is a diagram illustrating changes in total power supply when a large number of conventional electric water heaters are installed.
FIG. 3 is a vertical sectional view of an electric water heater having an embodiment of the present invention, FIG. 4 is an electric circuit diagram of an embodiment of the present invention, and FIG. 5 is a flowchart of an arithmetic circuit of the present invention. , FIG. 6 is a diagram showing one control pattern of the present invention, and FIG. 7 is a diagram showing a calculation result showing a change in the total power supply when a large number of electric water heaters of the present invention are installed. 1... Hot water storage tank, 2... Heater, 7a, 7b, 7
c, 7d...Temperature sensor, 14...Arithmetic circuit, 15...
A/D conversion circuit, 16...relay.

Claims (1)

[Claims] 1. Divide the late-night power supply time period into small time periods, set priorities for the divided time periods, calculate the required energization time to retain the required amount of heat, and calculate the required energization time by A method for controlling late-night power utilization equipment, characterized in that the above-mentioned small time periods are allocated according to priority so that the cumulative total of the small time periods is equal to or more than the required power-on time, and late-night power is supplied in accordance with this allocation. 2. A method for controlling late-night power utilizing equipment as set forth in claim 1, wherein priorities are set in a distributed manner for small time periods. 3 Dispersion is performed by random numbers Claim 2
Method for controlling devices that use late-night power as described in Section 1. 4. The method for controlling late-night power utilization equipment according to claim 3, wherein the random number is determined from a value that is less than or equal to the guaranteed accuracy digit in calculating the required energization time.