JPH06180147A - Storage type electrical hot water heater and control thereof - Google Patents

Abstract

PURPOSE:To provide a uniform load of electrical power by a method wherein a required electrical energization time is calculated in response to a remaining amount of hot water, a temperature of the remaining hot water and a heat calorie of hot water calculated in reference to a water feeding temperature and then an electrical energization starting time is set in reference to a result of comparison between the required electrical energization time and a reference electrical energization time. CONSTITUTION:A heat calorie K2 of remained hot water is calculated at a calculation device 4 in reference to outputs from a sensor device 1 for sensing a remaining amount of hot water, a sensor device 2 for sensing a temperature of remaining hot water and a water feeding temperature sensor 3, and then a heat calorie K1 of hot water to be stored in a tank is calculated by a calculation device 6 in reference to a boiling-up hot water temperature set by the boiling-up hot water temperature setting or calculation means 5. A required electrical energization time HA for a heater 14 is calculated by a calculation device 7 in reference to both heat calories K1 and K2 and then an electrical energization starting time for starting an electrical energization for the heater 14 is determined in accordance with an electrical energization shift mode for boiling-up the hot water within a specified electrical power time range such as a mid-night electrical power time range in consideration of the electrical energization time HA. In this case, when the required electrical energization time is less than the reference electrical energization time, the specified time set during the electrical power load reducing time is set to the electrical energization starting time.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hot water storage type electric hot water capable of leveling an electric power load.

[0002]

2. Description of the Related Art In a general hot water storage type electric water heater that heats hot water by using electric power in a specific electric power time zone such as a midnight electric power time zone, a heater for a hot water is supplied to a heater based on measured data such as supplied water temperature and remaining hot water amount. The required energization time is obtained, and the energization start time at which the heater is energized is determined in accordance with a predetermined energization shift mode so that the hot water is boiled within the specific power time period in consideration of the required energization time. One that uses the energization shift mode to set the energization start time in the first half of the specific power time zone to boil the water, or one that uses the energization shift mode to set the energization start items in the latter half of the specific power time zone to boil the hot water. Has been put to practical use.

[0003]

When such a conventional water heater is used, the electric load is concentrated in the first half and the latter half of the specific electric power time zone in the summer when the demand for electric power is late at night.
Electric power load cannot be leveled. Therefore, as in the hot water storage type electric water heater disclosed in Japanese Examined Patent Publication No. 3-18106, it has been proposed to disperse the required energizing time in a specific electric power time slot to level the electric power load. However, even if the required energizing time is distributed only for a specific type of water heater, most of the hot water storage electric water heaters that have already been sold tend to increase the power load in the first half or the second half of the specific power time period. At present, it is difficult to equalize the power load under the current operation in the energization shift mode.

An object of the present invention is to provide a method and apparatus for controlling a hot water storage type electric water heater which can effectively level the electric power load.

Another object of the present invention is to provide a hot water storage type electric water heater control method and apparatus capable of effectively leveling the electric power load in each region.

[0006]

According to the first and second aspects of the invention, the required energization time to the heater is obtained based on the measured data such as the feed water temperature and the amount of remaining hot water. For example, the energization start time to start energizing the heater is determined in accordance with the energization shift mode in which the hot water is boiled within the specified power time zone and the power load tends to increase in the first half or the second half of the specific power time zone. The control method of the hot water storage type electric water heater that starts energizing the heater from the start time to boil hot water is an object of improvement.

According to the first aspect of the present invention, when the required energization time is equal to or less than the reference energization time determined in consideration of the time width of the power load reduction time zone where the power load is small within the specific power time zone, the power load reduction is performed. The specific time set during the time period is set as the energization start time, and when the required energization time is longer than the reference energization time, the energization start time is determined according to the energization shift mode.

According to the second aspect of the invention, at least one of the specific time and the reference energizing time is made variable.

According to the third and fourth aspects of the present invention, the energization time calculating means for determining the required energization time to the heater based on the measured data such as the supply water temperature and the amount of remaining hot water, and the midnight power time zone in consideration of the required energization time, etc. The energization start time that determines the energization start time to start energizing the heater according to the energization shift mode that tends to boil hot water within the specific power time zone and increase the power load in the first half or the second half of the specific power time zone A hot water storage type electric water heater including a means and an energization control device that starts energization of a heater from an energization start time to boil hot water is an object of improvement.

According to the third aspect of the present invention, the energization start time determining means sets the required energization time equal to or less than the reference energization time determined in consideration of the time width of the power load reduction time zone in which the power load is small within the specific power time zone. In this case, the specific time set during the power load reduction time period is determined as the energization start time, and when the required energization time is longer than the reference energization time, the energization start time is determined according to the energization shift mode.

According to a fourth aspect of the present invention, means for setting at least one of the specific time and the reference energization time is further provided.

[0012]

When the required energization time is equal to or less than the reference energization time determined in consideration of the time width of the power load reduction time zone in which the power load is small within the specific power time zone, as in the first and third aspects of the invention, When the specific time set during the power load reduction time period is set as the energization start time, the electric power in the time period during which the power load is reduced is used to boil the hot water, so that the power load can be effectively leveled. Focusing on the use of power in the power load reduction time zone, when the amount of hot water used is large, such as in the winter, a situation in which the hot water cannot be boiled to the desired temperature occurs, so the present invention requires more than the standard energization time. When the energization time is long, the energization start time is determined according to the normal energization shift mode.

The reference energization time is set so that the situation where the hot water cannot be boiled during the specific power time period does not occur. In addition, the specific time is set so that the power load reduction time zone can be used as effectively as possible.

If the reference energizing time and the specific time can be made variable as in the inventions of claims 2 and 4, it is possible to easily meet different power demands in different regions, and to level the power load in each region. It is possible to deal with

[0015]

Embodiments of the present invention will now be described in detail with reference to the drawings. FIG. 1 is a schematic block diagram showing the configuration of an embodiment of a hot water storage type electric water heater for carrying out the method of the present invention. In this embodiment, the energization start time is determined according to the energization shift mode of the type which has the tendency to increase the power load in the latter half of the midnight power time zone (specific power time zone). From the residual hot water amount V detected by the residual hot water amount detection device 1, the residual hot water temperature T2 detected by the residual hot water temperature detection device 2, and the feed water temperature t detected by the feed water temperature sensor 3, the arithmetic unit 14 determines the residual hot water calorie K2. = (T2-t) * V is calculated. The feed water temperature t measured by the feed water temperature sensor 3 is the temperature of the water immediately above the heater arranged in the lower region inside the hot water storage tank. Therefore, the feed water temperature t output by the feed water temperature sensor 3 after the energization of the heater is started indicates the temperature of the boiling water. The boiling water temperature T1 determined by the boiling water temperature setting or the calculation means 5 is input to the calculation device 6, and the calculation device 6 calculates the thermal calorie K1 of the hot water to be stored in the tank from the capacity of the hot water storage tank K1 = (T1− t) × V is calculated. The boiling water temperature setting or calculation means 5 automatically sets the boiling water temperature based on the operator's setting of a desired boiling water temperature T1 using a remote controller, or based on past hot water usage records and the amount of remaining hot water. Calculate and set the temperature. Residual hot water calorie K2 [= (T2-t) x] of the calculation result calculated by the calculation device 4.
V] and a calculation result K1 [= (T1 −
t) × V is input to the arithmetic unit 7. Arithmetic device 7
Is calculated from these calculation results as follows.
0 × W). Here, W is the power consumption of the heater. According to the present embodiment, the energization time calculating means is configured by the means of reference numerals 1 to 7, but the structure of the energization time calculating means is not limited to this embodiment, and the required energization time is based on the measurement data. Any configuration may be used as long as it calculates

The required energizing time HA is the energizing time comparing means 8
Entered in. The energization time comparison means 8 compares the required energization time HA with the reference energization time H0 input from the reference energization time input means 16 including a switch and stored in the reference energization time storage means 17, and the energization time required. Is less than the reference energizing time (HA ≤ H0), the shift time HS obtained by the first shift time calculating means 9 is stored in the shift time storing means 11, and the required energizing time is longer than the reference energizing time. For (HA> H0), the second shift time calculation means 1
The shift time HS 'obtained by 0 is stored in the shift time storage means 11.

Here, the reference energization time H0 is, for example, a time zone (power load reduction time zone) in which the power load is reduced due to the change state of the power load in the midnight power time zone of the area where the water heater is installed, which is announced by the power company. And determine the length of this time period. In an area with a large number of hot water storage type electric water heaters that boil hot water in the latter half of the midnight power time zone as in the present embodiment, the peak of the power load appears in the latter half of the midnight power time zone and the midnight power time zone The power load reduction time zone appears in the first half of. The longer the power load reduction time period, the longer the reference energization time H0. Electric power demands naturally differ between summer and winter, but when viewed from late-night electric power, the electric power demand in the summer decreases, and the power load reduction time period (for example, 1 am to 5 am) also increases. Therefore, if the reference energization time H0 is determined in consideration of the electric power load in the summer, the reference energization time H0 is set to 4 hours or more. If the standard energizing time H0 is set to 4 hours or more, the required energizing time H is generally required in winter.
Since A becomes longer than 4 hours, the shift time HS obtained by the first shift time calculating means 9 is exclusively used in the summer.

The first shift time calculating means 9 is a power load decreasing time zone set by the specific time input setting means 18 including a switch from the start time of the midnight power time zone and stored in the storage means 19 of the specific time. The time until a certain time (specific time X: 2:00, for example) is calculated as the shift time HS. By the way, assuming that the start time of the midnight power time zone (8 hours) is 23:00 and the end time is 7:00, the shift time H is calculated by calculating HS = 8 hours- (7:00 to 2:00) = 3 hours.
Calculate S. Note that this calculation may be obtained by storing the calculation result in a table in advance and reading the shift time from the table according to the setting of the specific time. The setting of the specific time is appropriately determined based on the change state of the power load in the power load decreasing time zone, but is set so that the required energization time HA is included in the time width of the power load decreasing time zone as much as possible.

The second shift time calculating means 10 calculates the shift time HS 'according to a shift mode in which the energization start time is shifted so that the hot water will boil at the end time of the midnight power time zone. Therefore, in the second shift time calculating means 10, H
Calculation of S '= 8 hours-HA is performed.

The shift time storage means 11 is for selectively storing the calculation results of the first and second shift time calculation means 10, and the timer 13 is for the midnight power start time (23:00).
To the midnight power end time (7 o'clock),
The energization control means 12 executes energization (heater ON) to the heater 14 from a time delayed by the shift time HS or HS 'stored in the shift time storage means 11 from the midnight power start time (23:00). Then, the boiling determination means 15 determines that the hot water temperature (hot water temperature in the lower region of the tank) t detected by the feed water temperature sensor 3 is equal to or higher than the boiling hot water temperature setting or the boiling hot water temperature T1 set by the calculation means 5. When detected, heater 1
The power supply to 4 is stopped (heater is turned off).

In the present embodiment, energization time comparison means 8, first and second shift time calculation means 9 and 10, shift time storage means 11, timer 13 and energization control means 1
A part of 2 (a part for calculating the energization start time) constitutes an energization start time determining means. Further, the energization control unit 12 and the boiling determination unit 15 constitute an energization control device.

The embodiment of FIG. 1 represents the embodiment of the present invention using the function realizing means, but FIG. 2 is a flowchart of the algorithm of the embodiment when the present invention is realized using a computer. Is shown. Step ST3
By this, the first shift time calculation means 9 of FIG. 1 is realized,
The energization time calculation means is realized by step ST5, and the energization time comparison means 8 is realized by step ST6.
The second shift time calculation means 10 is realized by step ST8, and the boiling-up determination means is realized by step ST12.

FIG. 3 shows a hot water storage type water heater using an energization shift mode of a type having a tendency to increase the electric power load mainly in the latter half of a specific electric power time zone such as a midnight electric power time zone as in the embodiment of FIG. It is a block diagram of an example to which the present invention is applied. The same blocks as those in the embodiment of FIG. 1 are designated by the same reference numerals as those in FIG. 1 and their description is omitted. The shift time calculation means 20 for the supply water temperature calculates the shift time HS ′ based on only the supply water temperature from the supply water temperature t and the tank capacity V.
= (T × V) / (860 × W) [W is power consumption of the heater] is calculated. The boiling water temperature selection means 22 selects the boiling water temperature T from the boiling temperature selection table 21 based on the feed water temperature t detected by the feed water temperature sensor 3. In the boiling temperature selection table 21, an appropriate boiling temperature corresponding to the feed water temperature previously obtained by an experiment is stored in a stepwise manner. The energization time calculating means 23 calculates the energization time HB to the heater 14 from the boiling water temperature T and the feed water temperature t. The energization time HB is HB = [(T-t) × V] / (860 ×
W).

The reference energization time storage means 17 stores the reference energization time HO input from the reference energization time input means 16. Then, the energization time comparison means 25 compares the required energization time with the reference energization time H0, and if the required energization time is shorter than the reference energization time H0 (HB ≤ H0), the shift time calculation means 9 obtains it. When the required energization time is longer than the reference energization time H0 (HB> H0), the shift time HS is stored in the shift time storage means 11, and the shift time HS 'obtained by the shift time calculation means 20 for the supply water temperature is obtained. Is stored in the shift time storage means 11. The other points are substantially the same as the embodiment of FIG. In addition, in one example of the present embodiment, a preferable result was obtained by setting the reference energization time to 4 hours and 30 minutes or more and the specific time to 2:00.

The embodiment of FIG. 3 is a representation of the second embodiment of the present invention using the function realizing means, while FIG. 4 shows the case of realizing the second embodiment using a computer. 3 shows a flow chart of the algorithm. Step S
The first shift time calculating means 9 of FIG. 1 is realized by T3, the energization time calculating means is realized by step ST6, the comparing means 8 is realized by step ST7, and the shift time calculating means 20 for the feed water temperature is realized by step ST5.
Is realized, and boiling determination means is realized by step ST11.

In both of the above two embodiments, the present invention is mainly applied to a hot water storage type electric water heater operated in an energization shift mode of a type in which the electric power load is increased in the latter half of a specific electric power time zone. It goes without saying that the present invention is mainly applicable to a hot water storage type electric water heater operated in an energization shift mode of a type in which the electric power load is increased in the first half of a specific electric power time period.

[0027]

According to the first and third aspects of the invention, when the required energization time is equal to or less than the reference energization time, the heater is energized with the specific time set during the power load reduction time zone as the energization start time. However, there is an advantage that the hot water can be boiled by using the electric power in the time zone when the electric power load decreases, and the electric power load can be effectively leveled. Further, in the present invention, when the required energization time is longer than the reference energization time, the energization start time is determined according to the normal energization shift mode, so that there occurs a situation in which the hot water cannot be boiled in the specific power time zone. Can be prevented.

Further, according to the inventions of claims 2 and 4, the reference energizing time and the specific time can be varied, so that there is an advantage that the leveling of the electric power load in each area can be dealt with.

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of an embodiment of the present invention.

FIG. 2 is a flowchart showing an example of a software algorithm used when the embodiment of FIG. 1 is implemented by using a computer.

FIG. 3 is a block diagram showing the configuration of another embodiment of the present invention.

FIG. 4 is a flowchart showing an example of a software algorithm used when the embodiment of FIG. 3 is implemented by using a computer.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Residual hot water amount detecting device 2 Residual hot water temperature detecting device 4, 6, 7 Computing device 5 Boiling hot water temperature setting or computing means 8 Comparing means for energizing time 9, 10 Shift time calculating means 11 Shift time storing means 12 Energizing controlling means 13 Timer 14 Heater 15 Boiling determination means 16 Reference energization time input means 17 Reference energization time storage means 18 Specific time input means 19 Specific time storage means 20 Shift time calculation means for water supply temperature 21 Boiling temperature selection table 22 Boiling Hot water temperature selection means 23 Required energization time calculation means

Claims (4)

[Claims] 1. The required energization time to the heater is obtained based on the measured data such as the water supply water temperature and the amount of remaining hot water. In addition, the energization start time for starting energization of the heater is determined in accordance with the energization shift mode that tends to increase the power load in the first half or the second half of the specific power time period, and energization of the heater is started from the energization start time. A method for controlling a hot water storage type electric water heater for boiling hot water, wherein the required energization time is a reference energization determined in consideration of a time width of an electric power load reduction time zone in which the electric power load is small within the specific electric power time zone. If the time is less than or equal to the time, the specific time set during the power load reduction time period is set as the energization start time, and if the required energization time is longer than the reference energization time, the energization shift is performed. The method of storage type electric water heater, characterized by determining the energization start time in accordance with over-de. 2. The method for controlling a hot water storage electric water heater according to claim 1, wherein at least one of the specific time and the reference energization time is variable. 3. An energization time calculating means for obtaining a required energization time to a heater based on measured data such as a supply water temperature and a residual hot water amount, and a specific power time zone such as a midnight power time zone in consideration of the required energization time. In boiling water in, and further, energization start time determining means for determining the energization start time to start energizing the heater according to the energization shift mode having a tendency to increase the power load in the first half or the second half of the specific power time zone, A hot water storage electric water heater comprising an energization control device for starting energization of the heater from the energization start time to boil the hot water, wherein the energization start time determining means is the specific energization time. In the case where the power load in the zone is less than or equal to the reference energization time determined in consideration of the time width of the power load reduction time zone, the specific time set during the power load reduction time zone is set to the communication time. The hot water storage type electric water heater is configured to determine the power supply start time and determine the power supply start time according to the power supply shift mode when the required power supply time is longer than the reference power supply time. 4. The method for controlling a hot water storage electric water heater according to claim 1, further comprising means for setting at least one of the specific time and the reference energization time.