JPH03286960A - Hot water storing type hot water heater - Google Patents

Abstract

PURPOSE:To boil up hot water with an electrical power in a specified time range of low electrical charge by a method wherein an amount of remaining hot water is compared with a predetermined amount of hot water and a calculation means to take a transfer time between an electrical energization of an upper heater and an electrical energization of a lower heater is provided. CONSTITUTION:A calculation means 9 discriminates that an amount of remaining hot water is not much, but low and then an upper heater 7 is electrically energized at once. With such an arrangement, hot water 23 placed over a mixing layer 25 within a tank 3 is heated. When a boiling-up condition of the hot water is detected by an upper temperature sensor 2c, an electrical energization for the upper heater 7 is turned off. After this operation, in the event that there is a small amount of remaining hot water, it is sometimes found that a transfer time is zero, so that it is discriminated whether the transfer time is present or not. If the transfer time is zero, a lower heater 5 is electrically energized at once. In the event that there is a certain transfer time, the transfer time is read out from the third memory 15, drives a stored timer and after elapsing the transfer time, the lower heater 5 is electrically energized. A mixing layer 25 and water 24 in the tank 3 are heated.

Description

[Detailed Description of the Invention] (Field of Application of the Invention) The present invention relates to a storage-type electric water heater that boils and stores hot water using electricity during specific time periods when electricity is cheap, such as late-night electricity supply hours. It is also about improvement.

(Background of the Invention) Hot water storage type electric water heaters are generally supplied with water from a water inlet at the bottom of the tank and hot water from a hot water inlet at the top of the tank, and some are equipped with a heater that boils water only near the water inlet at the bottom of the tank. Most of these types require a long time for the water in the entire tank up to the hot water supply port at the top to reach a constant temperature.

This will take the longest time, especially when the tank is made entirely of wood.

In addition, if hot water remains when the heater is energized, the water supplied from the water inlet and the remaining hot water are heated and stirred, causing the temperature of the remaining hot water to drop temporarily. For example, if hot water is used after the start of 23:00 to 7:00 the next morning (e.g. around 1:00 in the morning), or if you want to use hot water urgently, for the above reasons, Due to this phenomenon, hot water cannot be used, causing inconvenience to users. .

To solve this problem, we installed an additional heater near the hot water supply port at the top of the tank, and as soon as the power is turned on late at night, the upper heater is energized preferentially to boil the water at the top of the tank to a high temperature. Japanese Unexamined Patent Publication No. 166443/1983 proposes a system in which the entire tank is heated to a high temperature by stopping the supply of electricity to the upper heater and starting supplying electricity to the lower heater. According to this two-hiter method,
Even when the remaining hot water is minimal, the amount of hot water needed for the time being can be secured in advance.

On the other hand, the applicant of this application divides the non-energized time within a specific time period, such as the late-night power on time, into travel time allocated before the energized time and slack time allocated after the energized time. , by delaying the start of energization by the travel time from the start of the specific time period, the power demand from the electric water heater is moved toward the center of the specific time period where the total power demand is minimum, and the energization time is delayed by the margin time. In a previous application, we proposed a hot water storage type electric water heater that was designed to be extendable.

If you try to adopt the above-mentioned 2-heater method to such a moving time type hot water storage type electric water heater, it is necessary to turn on the upper heater immediately at the start of the late-night power supply period, which will reduce the power demand by the electric water heater in the middle of the night. There is a problem that it is inconsistent with moving toward the center of the power supply time zone.

(Objective of the Invention) The object of the present invention is to solve the above-mentioned problems, to quickly secure the amount of hot water needed for the time being, and to contribute to the equalization of the total electricity demand for electric power companies at the same time. The object of the present invention is to provide a hot water storage type electric water heater that can be used in conjunction with the above.

(Features of the Invention) In order to achieve the above-mentioned object, the present invention provides that when the total energization time of the upper heater and the lower heater is expected to be shorter than the specified time period, The energization time is divided proportionally into a travel time that should be allocated before the total energization time and a margin time that should be allocated after the total energization time, and if the amount of remaining hot water is greater than a predetermined amount, the upper heater and calculation means for taking the moving time before energizing the lower heater and taking the moving time between energizing the upper heater and energizing the lower heater when the amount of remaining hot water is less than a predetermined amount. Therefore, when the amount of remaining hot water is less than a predetermined amount, the upper heater is immediately energized at the start of a specific time period, thereby placing emphasis on securing the amount of hot water, and when the amount of remaining hot water is greater than the predetermined amount, the upper heater is The system is characterized by placing emphasis on shifting power demand by delaying the start of energization by the travel time from the start of a specific time period.

(Embodiment of the Invention) FIG. 1 shows an embodiment of the present invention. A temperature sensor 1 using a thermistor, a lower temperature sensor 2a, a middle temperature sensor 2b, and an upper temperature sensor 2C are shown in FIG. It is attached from the bottom to the top of the outer wall of the tank 3 so that the The temperature sensor 1 is bonded to the outer wall surface of the tank 3 near the water supply port 4 and is used for both water temperature detection and boiling temperature detection.

The temperature sensors 2a and 2b are used to detect the amount of remaining hot water, and the temperature sensor 2c is used both to detect the amount of remaining hot water and to detect the boiling temperature. A lower heater 5 is installed near the water supply port 4, and an upper heater 7 is installed near the hot water supply port 6 at the top of the tank 3. Information from temperature sensors 1.2a to 2c is A/
The time zone detection means 10, which is converted into a digital value by the D converter 8 and sent to the calculation means 9 such as a microprocessor, is composed of a photocoupler, for example, as shown in FIG. When the late-night power supply time period begins and the late-night power time switch (not shown) is turned on and late-night power is applied to the heater power supply terminal 11, voltage is applied through the earth leakage breaker 12 and the heater starts operating. , sends late-night power input information to the y4 calculation means 9.

The first memory 13 stores various operation commands of the calculating means 9, water temperature values for several 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 14 stores hot water temperature control patterns A and B shown in FIG.
remember. The third memory 15 stores the moving time (details will be described later) for the total energization time of the upper heater 7 and the lower heater 5, which is predetermined based on the water supply temperature, hot water temperature control pattern, and amount of remaining hot water, as shown in FIG. Remember. The setting operation means 16 is for selecting one of the two hot water temperature control patterns A and B, and is composed of, for example, a push button type changeover switch 17 as shown in FIG. Output means 1
Reference numeral 8 drives a relay 19 that controls energization of the upper heater 7 and a relay 20 that controls energization of the lower heater 5, as shown in FIG.

As shown in FIG. 6, the display means 21 includes display elements 21a to 21e, such as light emitting diodes, which display the hot water temperature control patterns A and H and the amount of remaining hot water (high, medium, low) by lighting them.
, and is controlled by the display control means 22.

The moving time relative to the total energization time of the upper heater 7 and the lower heater 5 will be explained in detail. Once the water supply temperature, boiling temperature, and amount of remaining hot water are determined, the capacity of the tank 3 and the power consumption of the upper heater 7 and lower heater 5 are known.
The total energization time is determined by calculation. Assuming that the late-night power-on time period is 8 hours, if the power-on time is shorter than the midnight power-on time period, that non-power-on time will be divided into the travel time that should be allocated before the total power-on time and after the total power-on time. The travel time and the spare time are calculated by dividing the travel time and the spare time to be allocated at a predetermined ratio, for example, 3:1. Even if the actual total energization time differs slightly from the expected total energization time, there is almost no problem with this travel time if it is kept constant.
As shown in the figure, the travel time calculated in advance is the third
It is stored in the memory 15.

The travel time is determined in order to move the power demand from the electric water heater toward the center of the late-night power-on time period, and to minimize the heat loss from the tank 3 by making the power-on time as late as possible after the midnight power-on time period. established for the purpose of

The allowance time is designed to allow for an extension of the energization time and to provide hot water to the user, since if hot water is used during travel time, the water may not reach the specified boiling temperature during the initially expected energization time. This is provided to prevent the inconvenience of cuts as much as possible.

Next, the operation will be explained. The calculation means 9 measures the temperature using the temperature sensor 1 at predetermined time intervals, for example, every minute, for 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 called the latest mill). and A/D
The water temperature information converted into a digital value by the converter 8 is taken in.

Note that during times other than the late-night power supply time period when the upper heater 7 and lower heater 5 are not energized, a mixed layer 2 is formed between the hot water 23 and the water 24 in the tank 3, as shown in FIG.
5 is formed, and the hot water 23 and the water 24 do not mix. Therefore, by measuring the temperature of the water 24 with the temperature sensor 1 during a time period other than the late-night power supply time period, the water temperature can be obtained.

The calculation means 9 determines whether or not the taken-in water temperature is the lowest value among the latest mills, and if it is the lowest value, the water temperature value of the latest mill stored in the memory built in the operator stage 9 is set to that value. Updated and memorized.

When information indicating that the late-night power supply time period has started is input from the time period detection means 10, the calculation means 9 performs a water supply temperature calculation process.The subsequent operation will be described with reference to the flowchart of FIG. The calculation means 9 transfers the latest mortar water temperature value stored in the built-in memory to the first memory 13 and stores it therein. At the same time, the oldest water temperature value is also erased from the first memory 13. Then, the water temperature values for consecutive days (7 days) including the latest mill are read from the first memory 13, and the lowest value among them is determined as the water supply temperature for the current day.

Next, the calculation means 9 reads out the boiling temperature (see FIG. 4) corresponding to the water supply temperature from the hot water temperature control pattern stored in the second memory 14, and also detects the amount of remaining hot water. The /D converter 8 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 9. When the temperature detected by the lower temperature sensor 2a is higher than the set temperature, the operator stage 9 sends a signal indicating the maximum amount of remaining water to the display control means 22, and the display control means 22 displays the three display elements 21c to 21.
Light up both e. When the temperature detected by the lower temperature sensor 2a falls below the set temperature and the temperature detected by the middle temperature sensor 2b exceeds the set temperature, a signal indicating that the amount of hot water remaining is sent to the display control means 22, and the display control means 22 Both display elements 2d and 21e are turned on. When the detected temperature of the lower temperature sensor 2a and the middle temperature sensor 2b falls below the set temperature and the detected temperature of the upper temperature sensor 2C is higher than the set temperature, the control means 2 displays a signal instructing the minimum amount of remaining hot water.
2, and the display control means 22 lights up only one display element 21e. 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 22, and the display control means 22 turns off the three display elements 21c to 21e. The remaining hot water amount detection operation is the same as the water temperature detection operation not only when information on the start of the late-night power supply period is received, but also for 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 done at predetermined time intervals, and the amount of hot water remaining is displayed at all times.

When the calculating means 9 determines that the amount of remaining hot water is large, it reads out the water supply temperature, boiling temperature, and travel time corresponding to the amount of remaining hot water (see FIG. 5) from the third memory 15, and starts a built-in timer ( (not shown), and after the movement time has elapsed, sends an upper heater energization command to the output means 18 to energize the upper heater 7. As a result, the mixed layer 2 inside the tank 3
The hot water 23 above 5 is heated, and the upper temperature sensor 2C
When it is detected that the temperature has been raised to the boiling temperature, the power supply to the upper heater 7 is cut off. after that,
Immediately, a lower heater energization command is sent to the output means 18 to energize the lower heater 5. As a result, the mixed layer 25 and water 24 inside the tank 3 are heated, and when the temperature sensor 1 detects that the water has been boiled to a boiling temperature, the power supply to the lower heater 5 is cut off.

When the calculation means 9 determines that the amount of remaining hot water is not too large but is medium, it immediately energizes the upper heater 7. As a result, the hot water 23 above the mixed layer 25 inside the tank 3 is heated, and when the upper temperature sensor 2c detects that the hot water 23 has been raised to the boiling temperature, the supply of electricity to the upper heater 7 is cut off. After that, the travel time is determined by the third memory 15.
Then, a built-in timer is driven to energize the lower heater 5 after the movement time has elapsed. As a result, the mixed layer 25 and the wood 24 inside the tank 3 are heated, and when the temperature sensor 1 detects that the mixed layer 25 and the wood 24 have risen to a boiling temperature, the power supply to the lower heater 5 is cut off.

When the calculation means 9 determines that the amount of remaining hot water is not too high or medium, that is, it is small (including extremely small), it immediately turns on the upper heater 7.
energize. As a result, the hot water 23 above the mixing M25 inside the tank 3 is heated, and when the upper temperature sensor 2c detects that the water has been boiled to the boiling temperature, the power supply to the upper heater 7 is cut off. After that, if the amount of remaining hot water is small, as shown in Figure 5, the travel time may be zero, so it is determined whether there is enough travel time or not, and if the travel time is zero, it is immediately The lower heater 5 is energized. If there is a moving time, the moving time is read from the third memory 15, a built-in timer is driven, and the lower heater 5 is energized after the moving time has elapsed. When the mixed layer 25 and the water 24 inside the tank 3 are heated, and the temperature sensor 1 detects that the water has risen to a boiling temperature, the power supply to the lower heater 5 is cut off.

The distribution of travel time, energization time, and margin time is as shown in Figure WIJ7 depending on the amount of remaining hot water. In addition.

In the case of FIGS. 7 and 8, the capacity of the tank 3 is relatively small, and the upper heater 7 starts to be energized immediately at the start of the late-night energization period even when the amount of remaining hot water is low. When the capacity is relatively large, the upper heater 7 and the lower heater 5 are continuously energized after the travel time has elapsed from the start of the late-night power energization period, as in the case where the remaining hot water amount is medium or high. Good.

According to this embodiment, when the amount of remaining hot water is small, the upper heater tube is energized immediately after the late-night power supply period starts, so that the amount of hot water required for the time being can be quickly secured. If the amount of remaining hot water is large, the amount of hot water required to be brought out can be covered by the amount of remaining hot water, so energizing the upper heater 7 is delayed by the travel time, thereby shifting the electric power demand of the electric water heater to the center of the late-night power energization time. At the same time, heat radiation loss from the tank 3 can be minimized.

(Modified example) In the illustrated embodiment, the travel time is calculated in advance.

It is stored in the third memory 15, but each time,
The calculation means 9 may calculate the total energization time and determine the travel time from the total energization time.

Further, although the time zone detection means 10 detects the late-night power supply period, the calculation means 9 may have a built-in time switch function for detecting the late-night power supply period. The time zone detection means IO is not required.

When the amount of remaining hot water is large, the upper heater 7 and the lower heater 7 are energized continuously, but they may not be continuous and may be performed after some time.

(Effects of the Invention) As explained above, according to the present invention, when the total energization time of the upper heater and the lower heater is expected to be shorter than the specified time period, The energization time is divided proportionally into a travel time that should be allocated before the total energization time and a margin time that should be allocated after the total energization time, and if the amount of remaining hot water is greater than a predetermined amount, the upper heater and calculation means for taking the moving time before energizing the lower heater and taking the moving time between energizing the upper heater and energizing the lower heater when the amount of remaining hot water is less than a predetermined amount. Therefore, when the amount of remaining hot water is less than a predetermined amount, the upper heater is immediately energized at the start of a specific time period, thereby placing emphasis on securing the amount of hot water, and when the amount of remaining hot water is greater than the predetermined amount, the upper heater is By delaying the start of energization by the amount of travel time from the start of a specific time period, we focused on shifting power demand. This enabled us to quickly secure the amount of hot water needed for the time being and to reduce the total power demand for the power company. Contributing to averaging can be achieved at the same time.

[Brief explanation of the drawing]

Fig. 1 is a block diagram showing an embodiment of the present invention, Fig. 2 is a cross-sectional view schematically showing the tank, Fig. 3 is a circuit diagram showing the heater circuit, and Fig. 4 shows the hot water control pattern. Figure 5 is a diagram showing the travel time, Figure 6 is a front view showing the operation panel, Figure 7 is the travel time, energization time,
FIG. 8, which is a diagram showing an example of the allocation of spare time, is a flowchart showing an example of the operation. l...Temperature sensor, 2a, 2b, 2C...
...Temperature sensor, 3...Tank, 4...
・Water supply port, 5...Lower heater, 6...
Hot water inlet, 7...upper heater, 9...calculating means, 13...first memory, 14...
・Second memory, 15...Third memory, 18...
...Output means.

Claims (1)

[Claims] (1) A lower heater placed near the water supply port at the bottom of the tank and an upper heater placed near the water supply port at the top of the tank, and energization of the upper heater and energization of the lower heater during a specific time period. In a hot water storage type electric water heater that is given higher priority, when the total energization time of the upper heater and the lower heater is expected to be shorter than the specific time period,
The non-energized time within the specific time period is divided into a travel time that should be allocated before the total energized time and a margin time that should be allocated after the total energized time, and the amount of remaining hot water is less than a predetermined amount. If the remaining hot water amount is less than a predetermined amount, the moving time is taken before energizing the upper heater and the lower heater, and if the remaining amount is less than a predetermined amount, the moving time is taken between energizing the upper heater and the lower heater. A hot water storage type electric water heater characterized by being provided with a calculation means that takes up travel time.