JPS6030942A - Control device of hot-water storage type electric hot-water heater - Google Patents

Abstract

PURPOSE:To contrive to supply every day the amount of hot-water responding the actual requirement of an user by a method wherein a memory device stores the up-to- date data of the amount of heat for the amount of hot-water as the past actual consumption results, and an electric power to be supplied for a heating body is determined based on said data. CONSTITUTION:A time switch 8 is made ON (4), the control is started simultaneously with the energizing, at first, the maximum value KGmax is called (5) from among the up-to-date data by a memory device 12, a necessary amount of heat presetting device 13 presets (6) the necessary amount of heat KS after mutiplying the KGmaz by the constant C including the margin. A heating temperature presetting device 14 measures (7) the hot-water supply temperature Ti in a hot-water storage tank 1 with a temperature sensor 9, presets (8) the heating up temperature To based on the capacity Vt of the hot-water storage tank. Therefore, the presetting heating temperature preset for each hot-water heater is inputted into a central control device, which outputs the energizing start signal to each heater for levelling of load through the entire time zone of the midnight electric power supply service time zone based on the required heating up temperature of hot- water. Thus, the energizing for the heating body 5 is started after receiving of each energizing start signal.

Description

[Detailed Description of the Invention] The present invention relates to a control device for a hot water storage type electric water heater that uses late-night electricity, and calculates the required amount of heat to be stored in a hot water storage tank based on the user's actual hot water usage. In this way, the capacity of conventionally fixed hot water storage type electric water heaters can be used according to the user's needs, and multiple hot water storage type electric water heaters can be controlled equally by a central control unit. It is intended to.

FIG. 1 is a block diagram of a general hot water storage type electric water heater, and FIG. 2 is a main electrical circuit diagram of a conventional hot water storage type electric water heater.

In these figures, 1 is a hot water storage tank, 2 is a water supply pipe, and 3 is a hot water storage tank.
is a hot water pipe, 4 is a hot water tap, 5 is a heating element, 6 is an automatic temperature controller, 7 is a power supply, and 8 is a time switch for late-night power, which is generally turned on from 11:00 p.m. to 7:00 the next morning. No. 8
It's time.

Next, the operation of the conventional example having the above configuration will be explained. When the time to start supplying late-night power comes, the contact of the time switch 8 is closed and the supply of electricity to the heating element 5 is started. When the temperature in the hot water storage tank 1 reaches 85°C, the contact of the automatic temperature regulator 6 is opened and the electricity to the heating element 5 is stopped. After that, the +1 automatic temperature controller 6 is opened and closed to bring the water temperature to 8.
The temperature is maintained at 5°, and in this way the total amount of hot water stored every morning is 8°.
5” (J) I’m excited.

In this way, in order to increase hot water storage efficiency, the hot water storage type electric water heater has a structure in which the boiling temperature is set as high as possible, and heating stops when the set temperature is reached. However, users do not use high-temperature hot water as it is, but mix it with water and use it as a mixed hot water at around 40 to 45°C. The formula for calculating the amount of mixed hot water obtained is as follows.

Now, the hot water storage tank capacity is Vt (text)'', the boiling temperature in hot water storage tank 1 is To ('c), the temperature of the mixed hot water to be obtained is Tm ('0), the temperature of the water to be mixed (water supply temperature ) is Ti ('0), the amount of mixed hot water Vm, (
) can be expressed as .

In this formula, the water supply temperature Ti varies greatly depending on the season. In Tokyo, the temperature ranges from around 5°C in winter to around 27°C in summer. Therefore, the amount of hot water that can be obtained as mixed hot water at an appropriate temperature is small in the winter and large in the summer. That is, when the boiling temperature TO is 85°C, the amount of mixed hot water Vm obtained when the water supply temperature Ti is 5°C is 1.6 times that obtained when the water supply temperature Ti is 27°C.

On the other hand, the amount of hot water used is approximately constant throughout the year, or in fact, the actual amount used generally decreases in the summer because hot water is used at a lower temperature, and the amount of hot water remaining in the summer is larger than in the winter. . Furthermore, some users use only 1/2 or 2/3 of the rated amount due to a decrease in the number of family members, leaving a large amount of hot water every day.

In this way, if the water supply temperature is high or there is residual hot water, the hot water will boil quickly and the hot water will be left unused for a long time.

In this way, if hot water at an unnecessarily high temperature is left unused for a long time in the equipment, heat loss due to natural heat radiation from the hot water storage tank 1 and heat radiation from hot water stagnant in the pipes will increase. There were drawbacks. Furthermore, when multiple units are operated in parallel, there is a problem in that the load is concentrated in the first half of the late-night power supply time.

This invention attempts to eliminate these drawbacks.
The amount of hot water used, for example, the amount of hot water used in the past 10 days, is stored in the storage device as heat amount data, and this data is stored every day.
It is updated based on the amount of hot water used on that day, that is, it has a learning function, and based on this data, the required time to energize the heating element is calculated so that the required amount of mixed hot water is always obtained, and the power of heating element-5 is updated. By controlling the supply so that it is leveled out over the entire period from the start of the late-night electricity supply to the end of the supply, the amount of remaining hot water is reduced and heat loss after boiling is eliminated as much as possible. It is. This invention manages a plurality of hot water storage type electric water heaters with a central control device, and distributes the start time of energization so that the load is evenly distributed throughout the late night power supply period. be.

Figure 3 shows the configuration of a hot water storage type electric water heater which is the object of control of this invention.
Shows the same thing as the figure. 9 is a temperature detection means (hereinafter referred to as a temperature sensor) such as a thermistor, which continuously detects the temperature of water supplied from the water supply pipe 2 into the hot water storage tank 1, and also detects the temperature of boiling water. Yes, it is located at the bottom of the hot water storage tank 1. Note that this temperature sensor 9 may be provided separately to detect the temperature of water and the temperature of hot water, respectively. Reference numeral 10 denotes a switch for controlling the supply of electricity to the heating element 5, which is opened and closed by the operation of a control section, which will be described later. Reference numeral 11 denotes the above-mentioned control unit, which includes a storage device 12. Required heat amount setting device 1
3. Boiling temperature setting device 142 energization control device 15. and the amount of heat used by the calculation device 16. 17 is a water meter,
It is attached to the water supply pipe 2 and indirectly measures the flow rate of hot water flowing out from the hot water storage tank 1. For example, an encoder is attached to a metering propeller that rotates depending on the flow rate.
A device that generates the number of pulses depending on the flow rate is used. Note that the water meter 17 may be provided on the hot water supply pipe 3 side.

The storage device 12 stores the amount of heat of the hot water used calculated by the amount of heat used calculation device 16, and the actual MKG for several days thereof as data. This data is set to a fixed number of days, such as 10 days, so that the latest data is always saved.

The required heat amount setting device 13 calls, for example, the maximum value KGmax of the data stored therein (in the above example, for 10 days) from the storage device 12, and calculates a constant C (for example, a margin) based on the margin rate. If the rate is 10%, it will be 1.1) to calculate the required amount of heat stored in the hot water tank 1, Ks (
kcal ) is calculated as Ks = KGmaxX C .

The boiling temperature setting device 14 sets the required amount of heat Ks (kcal
), hot water storage tank capacity vt (!:t,), and water supply temperature Ti ('O), boiling temperature T. (°C) from the formula below.

The energization control device 15 turns on the switch 10.

It is turned on by a command from a central control device, which will be described later, and turned off when the temperature sensor 9 detects the boiling temperature TO.

The amount of heat used calculation device 16 calculates the required amount of heat KG for the previous day, assuming that the amount of hot water used by the water meter 17 is V (text), the water supply temperature is Ti ('0), and the previous day's boiling temperature is To ('C). Calculate as = vX (To - Ti).

FIG. 4 is a block diagram of the overall configuration showing one embodiment of the present invention. In this figure, 100A, 100B,...
100N indicates the above-mentioned hot water storage type electric water heater according to the present invention, and inside the control unit 11, only the required heat amount setting device 13 and the energization control device 15 necessary for explanation are shown, and the others are omitted. 200 is a central control device that receives data on the required time from the required heat amount setting device 13 of each hot water storage type electric water heater 100A to 10ON, and adjusts the data so that the load is evenly distributed throughout the late night power supply period. Allocate the energization start time. There are various methods of leveling, but the simplest way is to turn on each hot water storage type electric water heater one after another.

Just turn it off. In short, the central control device 200 issues a control command to each energization control device 15 so that the peak is leveled and the load approaches a uniform load.

Next, the operation of the above embodiment will be explained with reference to FIG. Note that (1) to (13) in FIG. 5 represent each step.

At the start 1), at the end of the day's use of hot water, that is, before midnight power is supplied to the electric water heater, the amount of heat KG for the amount of hot water used that day is determined by the amount of heat used calculation device 16 (2) , this data is input to the storage device 12, and the data previously stored in the storage device 12 is updated (3).

Therefore, at midnight, for example at 23:00, the time switch 8 is turned on (4). When control is started at the same time as this energization, first, the largest value KGmax among the latest data is called from the storage device 12 (5), and the required heat amount setting device 13 sets a constant C based on KGmax with a margin factor.
The required amount of heat Ks is set by multiplying by (6). Further, in the boiling temperature setting device 14, the temperature sensor 9 measures the water supply temperature Ti in the hot water storage tank 1 (7), and the boiling temperature To is set from the hot water storage tank capacity iVt (8).

In this way, when the boiling temperature set for each water heater is input to the central controller 200, the central controller 200
0 sends a signal to start energizing each machine based on the boiling temperature so that the load is evenly distributed throughout the late night power supply period. In this way, upon receiving a signal to start energization, energization to the heating element 5 is started (9). Then, when the water temperature reaches the boiling temperature (10), the power to the heating element 5 is turned off (11).

Then, at the end of the midnight power supply time, for example 7 o'clock, the time switch 8 is turned off (12) and the sequence is stopped (13).

In the above embodiment, the required heat amount setting device 13 calculates the required heat amount Ks by using the maximum K in the data in the storage device 12.
Although Gmax is used, an average over a fixed number of days or other data may also be used. In addition, the control unit 11
A microcomputer equipped with a central processing unit (CPU) can be used as the computer.

Further, in the above embodiment, each hot water storage type electric water heater is controlled to be energized in sequence, but the present invention is not limited to this, and multiple units may be energized at the same time. It is sufficient if the power consumption is leveled out.

As explained in detail above, this invention stores the latest data on the amount of heat for the amount of hot water used as past results in the storage device, and determines the amount of electricity to be supplied to the heating element based on this data. Since the amount of hot water corresponding to the user's actual situation can be obtained every day, the amount of remaining hot water is reduced, and therefore, heat radiation loss after boiling is reduced, and maintenance costs are reduced. Furthermore, the central control unit allocates the start times of energizing multiple hot water storage type electric water heaters so that the load is evenly distributed throughout the late night power supply period, which is expected to improve power transmission efficiency. has advantages.

[Brief explanation of the drawing]

Figure 1 is a configuration diagram of a general hot water storage type electric water heater, Figure 2 is a main electrical circuit diagram of a conventional hot water storage type electric water heater, and Figure 3 is a diagram of the main electrical circuit diagram of a conventional hot water storage type electric water heater.
FIG. 4 is a block diagram showing the overall structure of an embodiment of the invention, and FIG. 5 is a control flowchart thereof. In the figure, 1 is a hot water storage tank, 2 is a water supply pipe, 3 is a hot water supply pipe, 4 is a hot water tap, 5 is a heating element, 7 is a power supply, 8 is a time switch,
9 is a temperature sensor, 10 is a switch, 11 is a control unit, 12
is a storage device, 13 is a required heat amount setting device, 14 is a boiling temperature setting device, 15 is an energization control device, 16 is a used heat amount calculation device, 77 is a water meter, 100A to 10ON are hot water storage type water heaters, 200 is a central control unit. Note that the same reference numerals in the figures indicate the same or corresponding parts. Agent Masuo Oiwa (2 others) Figure 4 Figure 5

Claims (1)

[Claims] A heating element that heats the water in the hot water storage tank using late-night electricity, a temperature detection means that detects the temperature of water supplied to the hot water storage dunk and the boiling temperature, and the actual amount of hot water used is stored as heat amount data. a storage device, a required heat amount setting device that sets the required amount of heat to be stored in the hot water storage tank based on the data, and a boiling temperature setting device that sets the boiling temperature from the water supply temperature, the required amount of heat, and the hot water storage tank capacity. and an energization control device that turns on the electricity to the heating element and stops the electricity to the heating element when the boiling temperature detected by the temperature detection means reaches the boiling temperature set by the boiling temperature setting device. A plurality of hot water storage type electric water heaters each having a hot water storage type electric water heater equipped with the following: A control device for a hot water storage type electric water heater, characterized in that it is provided with a central control device that distributes the start of energization so that the electric power supplied to the water heater is distributed evenly over the entire late night power supply period.