JPS6030939A - Control device of hot-water storage type electric hot- water heater - Google Patents

Abstract

PURPOSE:To contrive to utilize the performance of a hot-water storage type electric hot-water heater according to the actual requirement of user by a method wherein the necessary amount of heat required to be stored in a hot-water storage tank is calculated based on the actual amount of hot-water consumed by the user and the predetermined necessary amount of hot-water for the next day inputted by an inputting device. CONSTITUTION:A memory device 12 stores the data KG as the actual consumption for several days with regard to the consumed total amount of heat calculated with a consumed amount of heat calculating device 17 for each pattern in an inputting device 19. The data is calculated and stored, for instance, for ten days as the constant number of days, moreover, the stored data is kept at up-to-date. A necessary amount of heat presetting device 13 calls the maximum value KGmax among the stored data in the memory device 12 (among the data for ten days in the above example), mutiplies the constant C including the margin (for instance, mutiplies 1, 1 at the 10% allowance), calculates the necessary amount of heat KS (kcal) required for storing in a hot-water storage tank 1 by the formula KS=KGmaxXC. An inputting device 19 selects the next day hot-water serving schedule such as ''bath necessary'' or ''bath unnecessary'' among the predetermined control pattern.

Description

[Detailed Description of the Invention] The present invention relates to a control device for a hot water storage type electric water heater that utilizes late-night electricity, and is based on the actual amount of hot water used by the user and the expected amount of water used the next day inputted from an input device. The purpose is to calculate the required amount of heat that should be stored in the hot water storage tank, so that the capacity of the conventional hot water storage type electric water heater can be used in accordance with the user's needs.

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 of the hot water in the hot water storage tank 1 reaches 85° C., the contacts of the automatic temperature regulator 6 are opened and the power supply to the heating element 5 is stopped.

After that, the water temperature will be 85°C by opening and closing the automatic temperature controller 6.
In this way, the entire stored hot water is heated to 85°C every morning.

In this manner, 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 (1, the boiling temperature in hot water storage tank 1 is To ('O), the temperature of the mixed hot water to be obtained is Tm ('c), and the temperature of the water to be mixed (water supply temperature) is If Ti ('0), it can be expressed by the amount of mixed hot water.

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. For this reason, the amount of hot water that can be obtained as mixed hot water at an appropriate temperature is less in the winter and more in the summer. That is, when the boiling temperature To is 85°C, the amount of mixed hot water 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, but 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, leaving unnecessarily high-temperature hot water unused for a long time has the disadvantage of increasing heat loss due to natural heat radiation from the hot water storage tank 1 and heat radiation from hot water stagnant in the pipes. was there.

This invention attempts to eliminate these drawbacks.
The usage record of hot water amount, for example, the amount of hot water used for 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 that day, that is, it has a learning function, so that the required mixed amount of hot water can always be obtained based on this data, and at the same time, the planned amount of hot water for the next day can be entered in advance. By adding an input device and controlling the required energization time to the heating element based on these conditions, the amount of remaining hot water is reduced and the heat loss after boiling is eliminated as much as possible.

An embodiment of the present invention will be described below with reference to the overall configuration diagram in Fig. 3 and Fig. 4.
The explanation will be based on the control flowchart shown in the figure.

In FIG. 3, numerals 1 to 5, 7, and 8 indicate the same parts as in FIGS. 1 and 2. 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. 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 energization of the heating element 5, which is opened and closed by operation of a control section to be described later.

Reference numeral 11 denotes the aforementioned control section, which includes a storage device 12, a required heat amount setting device 13. Boiling temperature setting device 149, energization time calculation device 152, energization control device 16, and usage heat amount calculation device 1
Consists of 7.

18 is a water meter, and 19 is an input device.

The storage device 12 stores, as data, the actual KG for several days regarding the amount of heat for the amount of hot water used calculated by the amount of heat used calculation device 17 for each pattern of the input device 19. This data is a fixed number of days, for example 10 days,
Always save the latest data.

The required heat amount setting device 13 calls the maximum value KGmax of the data stored therein (in the above example, for 10 days) from the storage device 12, for example, and sets it to a constant C based on the margin rate (for example, margin rate 10). %, it becomes 1.1) to calculate the required amount of heat KS (kc
al ) is calculated as Ks = KGmaxXC.

The boiling temperature setting device 14 sets the boiling temperature T0 as the required amount of heat Ks (kcal) and the capacity vt of the hot water storage tank 1.
(l) and the supply water temperature Ti ('Ci).

The energization time calculation device 15 calculates the energization time Hs by calculating the rated power consumption W (Kw) of the heating element 5 and the required heat amount Ks (kcal
) to 60XW.

The energization control device 16 controls the turning on of the switch 10, and starts the energization of the late-night power so that the end of the energization time Hs determined by the energization time calculation device 15 almost coincides with the end time of the energization of the late-night power. After (8-Hs) has elapsed, the switch 10 is turned on, and when it is turned off, the temperature sensor 9 reaches the boiling temperature T.

Performed when detected.

The amount of heat used calculation device 17 calculates the required amount of heat KG for the previous day, assuming that the amount of hot water used per day by the water meter 18 is v (Jlj), the temperature of the supplied water is Ti ('C), and the boiling temperature of the previous day is To ('c). is calculated as KG = vX (T, -Ti).

The water meter 18 determines the amount of hot water used by measuring the flow rate of the supplied water, and is equipped with an encoder attached to a metering propeller that rotates according to the flow rate and generates a pulse number according to the flow rate.

Note that the water meter 18 may be provided on the hot water supply pipe 3 side.

The input device 19 may say, for example, "take a bath."

The user selects the next day's hot water usage schedule, such as ``no bathing,'' from among previously prepared control patterns.

Next, the operation of the embodiment shown in FIG. 3 will be explained with reference to FIG. 4. Note that (1) to (15) in FIG. 4 represent each step.

As a starting point 1), at the end of the day's use of hot water, that is, before midnight electricity is supplied to the electric water heater, the amount of heat KG for the amount of hot water used on that day v (41) is calculated in the amount of heat used calculation device 17. (2), this data is input to the storage device 12 for each pattern of the input device 19, and the data previously stored in the storage device 12 is updated (
3) Therefore, at midnight, for example at 11pm, the time switch 8 is turned on (4). Therefore, when control is started at the same time as the power is turned on, first, the largest KGmax among the latest data stored in the storage device 12 classified by pattern is called in accordance with the input from the input device 195). In the required heat amount setting device 13, KGmax
The required amount of heat Ks is set by multiplying by a constant C based on the margin rate (6). Further, in the energization time calculation device 15, the rated power consumption W (Kw) of the heating element 5 and the required heat amount Ks (kc
Calculate the energization time Hs from (7). Next, the water supply temperature Ti is measured (8). Further, the rising temperature To is set by the rising temperature setting device 14 (9). Next, it is determined whether the time (8-H5) has elapsed since the time switch 8 was turned on (10), and when the time has elapsed, electricity is started to be applied to the heating element 5 (11). When the temperature sensor 9 detects the boiling temperature To (12), the power to the heating element 5 is turned off (13). In this case, if there is no hot water remaining in the hot water storage tank 1, the time when the power to the heating element 5 is turned off will match the time when the time switch 8 is turned off, but in reality they do not match because of the remaining hot water.

Furthermore, at the end of the midnight power supply time, for example 7 o'clock, the time switch 8 is turned off (14) and the sequence is stopped (15).

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 1
1, a microcomputer equipped with a central processing unit (CPU) can be used.

As described in detail below, the present invention stores the latest data on the amount of heat relative to the amount of hot water used as past results in the storage device, and uses the data from the input device to calculate the amount of heat to be used for the next day. Since the amount of hot water to be energized to the heating element is determined based on the amount of water that the user uses each day, the amount of hot water corresponding to the actual situation of the user can be obtained every day. Set the start time (8-H
Since the heating time is delayed by s), the heating time is closer to the end time of late night power supply, which has the advantage of reducing heat dissipation loss after heating up and lowering maintenance costs.

[Brief explanation of drawings]

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.
The figure is an overall configuration diagram showing one embodiment of the present invention, and FIG. 4 similarly shows the control flowchart 1. 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
13 is a storage device, 13 is a required heat amount setting device, 14 is a boiling temperature setting device, 15 is an energization time calculation device, 16 is an energization control device, 17 is a usage amount of heat calculation device, 18 is a water meter, 19
is an input device. Note that the same reference numerals in the figures indicate the same or corresponding parts. Agent Masuo Oiwa (2 others) Figure 1 Figure 3

Claims (1)

[Claims] An electric water heater that uses late-night electricity to energize a heating element to heat water in a hot water storage tank, includes a temperature detection means for detecting the temperature of water supplied to the hot water storage tank and the boiling temperature, and a temperature detection means for detecting the temperature of water supplied to the hot water storage tank and the temperature at which the water is boiled, and the amount of water scheduled to be used on the next day. an input device for inputting information, a storage device for storing the actual amount of hot water used as heat amount data, a required heat amount setting device for setting the required amount of heat to be stored in the hot water storage tank based on the data, and the required amount of heat and an energization time calculation device that calculates the energization time from the rated power consumption of the heating element, and a energization time calculation device that calculates the energization time from the rated power consumption of the heating element; The apparatus is characterized by comprising: an energization control device that starts energizing the hot water; and a used heat amount calculation device that calculates the amount of heat for the amount of hot water used and inputs the value into the storage device to update the data. Control device for hot water storage type electric water heater.