JP6597095B2 - Electric water heater - Google Patents

Description

  The present invention relates to an electric water heater suitable for performing a boiling operation during a midnight power energization time period.

2. Description of the Related Art Conventionally, an electric water heater installed in a general house includes a hot water storage tank having a water supply port at the lower portion and a hot water outlet at the upper portion, and a lower heater (electric heater) attached to the lower portion of the hot water storage tank. When the boiling operation is performed during the midnight power energization time zone (480 minutes from 11:00 pm to 7:00 am), the hot water in the hot water storage tank is heated to the boiling temperature by the lower heater.
Hereinafter, for the sake of simplicity, the heating operation of the electric water heater in the midnight power energization time zone is referred to as “night heating operation”.

The electric water heater's night boiling operation ends at 7:00 am, which is the end of the midnight power energization time. Tank capacity V (liter) of hot water storage tank, remaining hot water volume Q (liter), boiling setting Necessary for boiling by the following equation (1) using the temperature T (° C), the feed water temperature Wt (° C), the remaining hot water temperature LWt (° C) in the hot water storage tank and the heater capacity P (kW) of the lower heater Calculate the energization time HT (min)
HT = {(V−Q) × (T−Wt) + Q × (T−LWt)} / (860 × P × 0.9) (1)
By using the calculated energization time HT, the energization start delay time PT (minutes) is calculated by the following equation (2), thereby delaying the energization start time.
PT = 480-HT (2)
However, PT = 0 when PT <0.

  FIG. 4 shows a time zone of the night boiling operation when the energization time HT = 240 (minutes) calculated from the above equation (1) for the five electric water heaters 1a to 1e. In this example, since the energization start delay time PT = 480−240 = 240 (minutes) from the above equation (2), the start time of the night heating operation of each of the electric water heaters 1a to 1e is from 3 am to 7 am 4 hours until the time (= 240 minutes).

In Patent Document 1 below, the required energization time to the lower heater (heating element) is calculated from the feed water temperature, and the timer device is operated so as to spring up at the midnight power energization time end time (7 am). A control device for a hot water storage type electric water heater is disclosed.
Further, in Patent Document 2 below, from the following equation (3) (approximate equation), only the two variables of the feed water temperature and the boiling set temperature whose peak shift time is not related to the size of the model are used as parameters. An electric water heater is disclosed that is configured so as to unify the peak shift calculation formulas in all models into one formula.
Peak shift time = 480−C × (boiling set temperature−feed water temperature) (3)
Where C = constant

JP 58-124147 A JP 7-167499 A

  However, in the above-described conventional electric water heater, the night boiling operation ends at 7:00 am, which is the end time of the midnight power energization time. From 5 am to 7 am, the night boiling operation is performed, which causes a problem of inducing an overload of the transformer depending on the number of electric water heaters.

  The objective of this invention is providing the electric water heater which can prevent the overload induction of a transformer by night boiling operation.

The electric water heater of the present invention is an electric water heater (1) that performs a night boiling operation during a midnight power energization time zone, and has an energization time (HT) required for boiling when performing the night boiling operation. Energizing time calculating means for calculating, and delaying the start time of the night boiling operation by a predetermined time corresponding to an electric water heater identification code including a numerical value for identifying the electric water heater, Night heating operation start time determination means for concentrating the heat storage load in the time when the load becomes lightest throughout the summer and winter in the midnight power energization time zone, and performing the night heating operation,
It is characterized by comprising.
Here, the electric water heater is provided with a hot water storage tank (2) provided with a water supply port at a lower portion and a hot water outlet at an upper portion, and for supplying water from the water supply port of the hot water storage tank to the hot water storage tank. A hot water supply pipe (3), a hot water supply pipe (4) for supplying hot water from the hot water outlet of the hot water storage tank, a lower heater (5) provided at a lower part of the hot water storage tank, and the energization time A control unit (10) functioning as a calculating means and a night boiling operation start time determining means, a feed water temperature sensor (S _Wt ) attached in the feed water pipe, and a remaining hot water temperature sensor attached in the hot water storage tank (S _{LWt1 to} S _LWt5 ) and a flow sensor (S _F ) attached in the hot water supply pipe may be provided.
The electric water heater identification code may be an end number (EN) of a device manufacturing number of the electric water heater.
The control unit includes an energization time calculation unit (11) that functions as the energization time calculation unit, a night heating operation start time determination unit (12) that functions as the night heating operation start time determination unit, and the lower heater Lower heater on / off control unit (15) for on / off control of the water heater, tank capacity data (D _V ), heater capacity data (D _P ), and boiling set temperature data (D _T ) of the electric water heater And a memory (16) for storing tail number data (D _EN ), wherein the energization time calculation unit reads the tank capacity data, the heater capacity data, and the boiling set temperature data read from the memory; The flow rate data (D _F ) input from the flow rate sensor, the remaining hot water temperature data (D _{LWt1 to} D _LWt5 ) input from the remaining hot water temperature sensor, and the feed water temperature The energization time is calculated based on the feed water temperature data (D _Wt ) input from the sensor, and the night boiling operation start time determination unit determines the end number indicated by the end number data read from the memory. Based on the energization time calculated by the energization time calculation unit and the determined energization start delay time, the night heating operation start time is determined and determined. The lower heater on / off control unit may be instructed to turn on the lower heater at the night boiling operation start time.
The night heating operation start time determination unit may instruct the lower heater on / off control unit to turn off the lower heater when the energization time has elapsed from the determined night heating operation start time.
The night boiling operation start time determination unit may instruct the lower heater on / off control unit to turn off the lower heater when the remaining hot water temperature reaches the boiling setting temperature.
When the sum of the energization time and the energization start delay time is greater than the midnight power energization time zone, the night boiling operation start time determination unit changes the end number by a predetermined value, and changes the tail A new energization start delay time may be determined again based on the number.
The night boiling operation start time determining unit determines the night boiling operation start time as the midnight power energization time start time in the midnight power energization time zone when the changed tail number is smaller than “0”. The night boiling operation end time may be determined as the midnight power energization time end time in the midnight power energization time zone .

The electric water heater of the present invention has the following effects.
(1) Since the night heating operation is performed by concentrating the heat storage load at the time when the load is lightest throughout the summer and winter in the midnight electricity energizing time zone, the overload induction of the transformer due to the night heating operation is prevented. can do.
(2) By preventing power concentration in the early morning and preventing an increase in transformer capacity, the facility utilization rate can be improved.
(3) Since it is possible to prevent the service line fuse from being blown off due to an overload in the early morning, it is possible to make the service wire thinner.

It is a figure for demonstrating the structure of the electric water heater 1 by one Example of this invention, (a) is a figure which shows the structure of the electric water heater 1, (b) is a block which shows the structure of the control part 10 FIG. It is a flowchart for demonstrating operation | movement of the control part 10 shown in FIG.1 (b). It is a figure which shows an example of the night heating operation time slot | zone of the five electric water heaters 1a-1e of the structure similar to the electric water heater 1 shown to Fig.1 (a). It is a figure which shows the conventional night heating operation time slot | zone of five electric water heaters 1a-1e in the case of energization time HT = 240 (minutes).

  The above object has been realized by generating a multi-stage shift time by using an electric water heater identification code including a numerical value and performing a night boiling operation.

Hereinafter, embodiments of the electric water heater of the present invention will be described with reference to the drawings.
The electric water heater according to the present invention generates a five-stage shift time every 50 minutes using, for example, the last number of the electric water heater device serial number, so that the load is lightest throughout the summer and winter from 12:00 pm to am Concentrate the heat storage load at 5am and perform the night boiling operation to reduce the number of electric water heaters that are energized during peak hours of morning power consumption due to breakfast preparation from 5am to 7am Thus, it is characterized by preventing the overload induction of the transformer due to the night boiling operation.

Therefore, as shown in FIG. 1A, an electric water heater 1 according to an embodiment of the present invention includes a hot water storage tank 2 having a water supply port provided in the lower part and a hot water outlet provided in the upper part, and a hot water storage tank 2. A water supply pipe 3 for supplying water from the water supply port to the hot water storage tank 2, a hot water supply pipe 4 for supplying hot water from the outlet of the hot water storage tank 2 to the outside, and a lower heater provided in the lower part of the hot water storage tank 2 5, a control unit 10, a feed water temperature sensor S _Wt attached in the feed water pipe 3, and first to fifth remaining hot water temperature sensors S _LWt1 attached in the hot water storage tank 2 in order from the top in equal intervals. It includes a S _LWt5, a flow sensor S _F attached to the hot water supply pipe 4.

  Here, as shown in FIG. 1B, the control unit 10 includes an energization time calculation unit 11, a night heating operation start time determination unit 12, a clock 13, a timer 14, and a lower heater on / off control unit. 15 and a memory 16.

In the memory 16, tank capacity data D _V indicating the tank capacity V of the hot water storage tank 2 and heater capacity data D _P indicating the heater capacity P of the lower heater 5 are stored in advance, and the boiling setting inputted from the outside is stored. Temperature data D _T (data indicating the boiling set temperature T) and end number data D _EN (data indicating the end number EN of the manufacturing number of the electric water heater 1) are stored.

Energization time calculation unit 11, and the tank capacity data D _V, the heater capacity data D _P and boiling temperature setting data D _T read from the memory 16, and the flow rate data D _F which is input from the flow rate sensor S _F, first to a fifth remaining hot water temperature sensor S _LWt1 ~S _LWt5 first to fifth remaining hot water temperature data D _LWt1 ~D _LWt5 input from, based on the water temperature data D _Wt inputted from the feed water temperature sensor S _Wt Thus, the energization time HT required for boiling is calculated using the above equation (1).
At this time, since the same amount of water as the hot water used is supplied to the hot water storage tank 2 via the water supply pipe 3, the energizing time calculation unit 11 is based on the flow rate F indicated by the flow rate data _DF . The remaining hot water amount Q is calculated. Further, the energization time calculation unit 11 is based on the _{first to fifth} remaining hot water temperatures LWt _{1 to} LWt ₅ indicated by the first to fifth remaining hot water temperature data D _{LWt1 to} D _LWt5 (for example, the first to _fifth remaining hot water temperatures L _{Wt1 to} D _LWt5) . An average value of the _fifth remaining hot water temperatures LWt _{1 to} LWt ₅ is calculated), and the remaining hot water temperature LWt in the hot water storage tank 2 is calculated.

The night boiling operation start time determination unit 12 determines the energization start delay time PT based on the end number EN of the manufacturing number of the electric water heater 1 indicated by the end number data D _EN read from the memory 16.
The night boiling operation start time determination unit 12 starts the night heating operation of the electric water heater 1 based on the energization time HT calculated by the energization time calculation unit 11 and the determined energization start delay time PT. (Hereinafter referred to as “night boiling operation start time”) is determined, and when the determined night heating operation start time is indicated by the time data input from the clock 13, the lower heater 5 is instructed to be turned on. A lower heater ON instruction signal is output to the lower heater ON / OFF control unit 15, and a timer start signal is output to the timer 14 to start the timer 14.
Furthermore, the night heating operation start time determination unit 12 indicates that the lower heater 5 is to be turned off when the elapsed time data input from the timer 14 indicates the energization time HT calculated by the energization time calculation unit 11. A heater off instruction signal is output to the lower heater on / off control unit 15 and a timer stop signal is output to the timer 14 to stop the timer 14.

When the sum of the energization time HT calculated by the energization time calculation unit 11 and the determined energization start delay time PT is greater than 480 minutes, the night boiling operation start time determination unit 12 determines that the end number data D _EN is The end number EN of the production number of the electric water heater 1 shown is reduced by a predetermined value, and the energization start delay time PT is determined again based on the reduced end number EN.

The lower heater on / off control unit 15 receives the lower heater on / off instruction signal input from the night heating operation start time determination unit 12 and turns on or off the lower heater 5 when the lower heater on / off instruction signal is input. An OFF control signal S _{ON / OFF} is output to the lower heater 5.

Next, five electric water heaters 1a to 1e configured in the same manner as the electric water heater 1 (the end numbers EN of the production numbers are “1”, “3”, “4”, “7” and “8”) The operation of the control unit 10 of the electric water heaters 1a to 1e when performing the night boiling operation will be described with reference to the flowchart shown in FIG.
For the electric water heaters 1 with the end numbers EN “0” and “1”, the initial value of the energization start delay time PT is 0 minutes, and the electric water heaters with the end numbers EN “2” and “3” are set. The initial value of the energization start delay time PT is 50 minutes for the water heater 1, and the initial value of the energization start delay time PT is 100 minutes for the electric water heaters 1 whose tail numbers EN are “4” and “5”. For the electric water heaters 1 with the end numbers EN “6” and “7”, the initial value of the energization start delay time PT is 150 minutes, and the end numbers EN are “8” and “9”. For the electric water heater 1, it is assumed that the initial value of the energization start delay time PT is 200 minutes.
Further, it is assumed that energization start delay time initial value data indicating an initial value of the energization start delay time PT is stored in the memory 16 in advance.

First, operation | movement of the control part 10 of the electric water heater 1a is demonstrated.
The energization time calculation unit 11 of the control unit 10 of the electric water heater 1a includes tank capacity data D _V of the hot water storage tank 2 of the electric water heater 1a, heater capacity data D _P of the lower heater 5 of the electric water heater 1a, and the electric water heater 1a. the boiling temperature setting data D _T from the memory 16, read the tank volume data D _V, a heater capacity data D _P and the set temperature data D _T, flow rate inputted from the flow rate sensor S _F of the electric water heater 1a and data D _F, and the first to fifth remaining hot water temperature sensor S _LWt1 ~S of the first to fifth input from _LWt5 remaining hot water temperature data D _LWt1 ~D _LWt5 electric water heater 1a, the electric water heater 1a Based on the feed water temperature data D _Wt input from the feed water temperature sensor S _{Wt, the} energization time HT required for boiling is calculated using the above equation (1) (step S11).
In this example, it is assumed that the energization time HT = 240 (minutes) is calculated.

The night boiling operation start time determination unit 12 of the control unit 10 of the electric water heater 1a reads the tail number data _DEN and the energization start delay time initial value data of the electric water heater 1a from the memory 16, and the read tail number data the energizing start delay time PT based on end number EN = 1 indicated by D _EN determined with 0 (minute) (step S12, S13, S18).

Thereafter, the night boiling operation start time determination unit 12 adds the energization time HT = 240 (min) calculated by the energization time calculation unit 11 and the determined energization start delay time PT = 0 (min) = 240 (min ) And determines whether or not the calculated sum is 480 (minutes) or less (step S23).
In this case, since the calculated sum = 240 (minutes) is 480 (minutes) or less and the determined energization start delay time PT = 0 (minutes), the night heating operation start time determination unit 12 is The night boiling operation start time is determined to be 11:00 pm, which is the midnight power energization time start time.

  Thereafter, the night boiling operation start time determination unit 12 indicates that the lower heater 5 is to be turned on when the time data input from the clock 13 indicates 11:00 pm, which is the determined night heating operation start time. A heater on instruction signal is output to the lower heater on / off controller 15 and a timer start signal is output to the timer 14 to start the timer 14 (steps S24 and S25).

  Thereafter, when the elapsed time data input from the timer 14 indicates the energization time HT = 240 (minutes) calculated by the energization time calculation unit 11, the night boiling operation start time determination unit 12 turns off the lower heater 5. A lower heater off instruction signal for instructing the above is output to the lower heater on / off control unit 15 and a timer stop signal is output to the timer 14 (steps S26 to S27).

At this time, instead of step S26, the night boiling operation start time determination unit 12 _receives the first to fifth remaining hot water temperature data D input from the first to fifth remaining hot water temperature sensors S _{LWt1 to} S _{LWt5. The remaining hot} water temperature LWt is constantly monitored based on the _{first to} fifth remaining hot water temperatures LWt _{1 to} LWt ₅ indicated by _{LWt1 to} D _{LWt5, and} when the remaining hot water temperature LWt reaches the boiling set temperature T, the lower heater off instruction signal May be output to the lower heater on / off control unit 15 and a timer stop signal may be output to the timer 14.
In this case, the timer 14 may not be provided.

  As a result, as indicated by a bidirectional arrow in FIG. 3A, the lower heater 5 of the electric water heater 1a is turned on at 11 pm by the lower heater on / off control unit 15 and then the energization time HT = 11 pm It is turned off at 3 am after 240 minutes.

Next, operation | movement of the control part 10 of the electric water heater 1b is demonstrated.
The control unit 10 of the electric water heater 1b operates in the same manner as the control unit 10 of the electric water heater 1a described above. However, since the end number EN of the electric water heater 1b is “3”, the night boiling operation start time determination unit 12 determines the energization start delay time PT as 50 (minutes) (steps S12, S14, S19).
As a result, the night boiling operation start time determination unit 12 starts the night boiling operation at 11:50 pm after the energization start delay time PT = 50 (minutes) has elapsed from 11 pm which is the night boiling operation start time. Decide with time.
As a result, as indicated by a bidirectional arrow in FIG. 3A, the lower heater 5 of the electric water heater 1b is turned on at 11:50 pm by the lower heater on / off control unit 15 and then from 11:50 pm It is turned off at 3:50 am after the energization time HT = 240 (minutes).

However, for example, when the energization time HT calculated by the energization time calculation unit 11 is 440 (min), the energization start delay time PT = 50 (min) determined as energization time HT = 440 (min) in step S23. ) = 490 (minutes) is larger than 480 (minutes), the night boiling operation start time determination unit 12 sets the end number EN = 3 indicated by the end number data D _EN read from the memory 16 to “ By subtracting 2 ″, the energization start delay time PT is determined again with the new end number EN = 1 (steps S28 and S29).
As a result, the night boiling operation start time determination unit 12 re-determines the energization start delay time PT as 0 (minutes) (steps S13 and S18), and repeats the operations after step S23.

In this case, since the sum of the energization start delay time PT = 0 (min) determined again in step S23 as energization time HT = 440 (min) = 440 (min) is less than 480 (min), The boiling operation start time determination unit 12 determines 11:00 pm, which is the night boiling operation start time, as the night boiling operation start time.
As a result, as indicated by a bidirectional arrow in FIG. 3B, the lower heater 5 of the electric water heater 1b is turned on at 11 pm by the lower heater on / off control unit 15 and then the energization time HT = 11 pm Turned off at 6:20 am after 440 minutes.

Next, operation | movement of the control part 10 of the electric water heater 1c is demonstrated.
The control unit 10 of the electric water heater 1c operates in the same manner as the control unit 10 of the electric water heater 1a described above, but since the tail number EN of the electric water heater 1c is “4”, the night boiling operation start time determination unit 12 determines the energization start delay time PT as 100 (minutes) (steps S12, S15, S20).
As a result, the night boiling operation start time determination unit 12 starts the night boiling operation at 12:40 pm after the energization start delay time PT = 100 (minutes) has elapsed from 11 pm, which is the night boiling operation start time. Decide with time.
As a result, as indicated by a bidirectional arrow in FIG. 3A, the lower heater 5 of the electric water heater 1c is turned on at 12:40 pm by the lower heater on / off control unit 15 and then the energization time HT = 240. It will be turned off at 4:40 am after (minutes).

However, for example, when the energization time HT calculated by the energization time calculation unit 11 is 410 (min), the energization start delay time PT = 100 (min) determined as energization time HT = 410 (min) in step S23. Therefore, the night boiling-up operation start time determination unit 12 sets the end number EN = 4 indicated by the end number data D _EN read from the memory 16 to “2”. The current start delay time PT is determined again by subtracting "" as a new end number EN = 2 (steps S28 and S29).
As a result, the night boiling operation start time determination unit 12 re-determines the energization start delay time PT as 50 (minutes) (steps S14 and S19), and repeats the operations after step S23.

At this time, since the sum of the energization start delay time PT = 50 (min) determined again in step S23 as energization time HT = 410 (min) = 460 (min) is 480 (min) or less, it is heated at night The operation start time determination unit 12 sets 11:50 pm after the energization start delay time PT = 50 (minutes) re-determined from 11 pm, which is the night boiling operation start time, as the night boiling operation start time. decide.
As a result, as indicated by a bidirectional arrow in FIG. 3B, the lower heater 5 of the electric water heater 1c is turned on at 11:50 pm by the lower heater on / off control unit 15 and then from 11:50 pm It is turned off at 6:40 am after the energization time HT = 410 (minutes) has elapsed.

For example, when the energization time HT calculated by the energization time calculation unit 11 is 450 (minutes), the energization start delay time PT = 50 (determined as energization time HT = 450 (min) in step S23. Min) = 500 (minutes) is greater than 480 (minutes), so the night boiling operation start time determination unit 12 subtracts the new end number EN = 2 by “2” again to create a new end The energization start delay time PT is determined again with the number EN = 0 (steps S28 and S29).
As a result, the night boiling operation start time determination unit 12 again determines the energization start delay time PT as 0 (minutes) (steps S13 and S18), and repeats the operations after step S23.

At this time, the sum of the energization time HT = 450 (min) and the energization start delay time PT = 0 (min) re-determined in step S23 becomes 450 (min) or less, so The raising operation start time determination unit 12 determines 11:00 pm, which is the night boiling operation start time, as the night boiling operation start time.
As a result, as indicated by a broken-line bidirectional arrow in FIG. 3B, the lower heater 5 of the electric water heater 1c is turned on by the lower heater on / off control unit 15 at 11:00 pm, and then the energization time HT = 450 ( Min) Turned off at 6:30 am after elapse.

Next, the operation of the control unit 10 of the electric water heater 1d will be described.
The control unit 10 of the electric water heater 1d operates in the same manner as the control unit 10 of the electric water heater 1a described above, but since the tail number EN of the electric water heater 1d is “7”, the night boiling operation start time is determined. The unit 12 determines the energization start delay time PT as 150 (minutes) (steps S12, S16, S21).
As a result, the night boiling operation start time determination unit 12 starts the night boiling operation from 11:00 pm, which is the night boiling operation start time, at 1:30 am after the energization start delay time PT = 150 (minutes) has elapsed. Decide with time.
As a result, as indicated by a bidirectional arrow in FIG. 3A, the lower heater 5 of the electric water heater 1d is turned on at 1:30 am by the lower heater on / off control unit 15 and then the energization time HT = 240. It will be turned off at 5:30 am after (minutes).

  When the sum of the energization time HT and the energization start delay time PT = 150 (min) determined in step S23 is greater than 480 (min), the same operation as the electric water heater 1c described above is performed ( Steps S23, S28, S29).

Next, operation | movement of the control part 10 of the electric water heater 1e is demonstrated.
The control unit 10 of the electric water heater 1e operates in the same manner as the control unit 10 of the electric water heater 1a described above, but since the tail number EN of the electric water heater 1e is “8”, the night boiling operation start time is determined. The unit 12 determines the energization start delay time PT as 200 (minutes) (steps S12, S17, S22).
As a result, the night boiling operation start time determination unit 12 starts the night boiling operation at 2:20 am after the energization start delay time PT = 200 (minutes) has elapsed from 11:00 pm, which is the night boiling operation start time. Decide with time.
As a result, as indicated by a bidirectional arrow in FIG. 3A, the lower heater 5 of the electric water heater 1e is turned on at 2:20 am by the lower heater on / off control unit 15 and then the energization time HT = 240. It will be turned off at 6:20 am after (minutes).

  When the sum of the energization time HT and the energization start delay time PT = 150 (min) determined in step S23 is greater than 480 (min), the same operation as the electric water heater 1c described above is performed ( Steps S23, S28, S29).

In addition, when the new end number EN subtracted by “2” in step S28 becomes smaller than “0”, the night heating operation start time determination unit 12 of the control unit 10 of the electric water heaters 1a to 1e is The night boiling operation start time is determined to be 11:00 pm, which is the midnight power energization time start time, and the night boiling operation end time is determined to be 7:00 am, which is the midnight power energization time end time (steps S29 to S33). ).
Thus, the lower heater 5 of the electric water heaters 1a to 1e is turned on at 11 pm by the lower heater on / off control unit 15 and then turned off at 7:00 am.

In the above description, the initial value of the energization start delay time PT is determined by using the end number EN of the device manufacturing number of the electric water heater 1, but any device that can group the electric water heaters 1 is acceptable. An electric water heater identification code including a numerical value such as a number, an instrument number, or a telephone number may be used.
Further, the energization start delay time PT is changed at intervals of 50 minutes, but may be set at an arbitrary interval such as an interval of 30 minutes or an interval of 60 minutes.

1, 1a to 1e Electric water heater 2 Hot water storage tank 3 Water supply pipe 4 Hot water supply pipe 5 Lower heater 10 Control unit 11 Energizing time calculation unit 12 Night heating operation start time determination unit 13 Clock 14 Timer 15 Lower heater on / off control unit 16 Memory S _{Wt Feed} water temperature sensor S _{LWt1 to} S _LWt5 First to fifth remaining hot water temperature sensors S _F Flow rate sensor EN End number F Flow rate HT Energizing time LWt Remaining hot water temperatures LWt _{1 to} LWt ₅ First to fifth remaining hot water temperatures P Heater capacity PT Energization start delay time Q Remaining hot water amount T Boiling set temperature V Tank capacity Wt _Feed water temperature D _EN end number data D _F Flow data D _{LWt1 to} D _LWt5 First to fifth remaining hot water temperature data D _T Boiling Set temperature data D _P heater capacity data D _V tank capacity data D _Wt feed water temperature data S _{ON / OFF} lower heater on / off control signals S11 to S33 Steps

Claims (8)

An electric water heater (1) that performs a night boiling operation during a midnight power energization time period,
Energization time calculating means for calculating energization time (HT) required for boiling when performing the night boiling operation;
The start time of the night heating operation is delayed by a predetermined time corresponding to an electric water heater identification code including a numerical value for identifying the electric water heater, and the summer power supply is performed in the midnight power energizing time zone. Night heating operation start time determining means for concentrating the heat storage load in the time zone when the load is lightest and performing the night boiling operation;
An electric water heater, comprising: The electric water heater is
A hot water storage tank (2) having a water supply port at the bottom and a hot water outlet at the top;
A water supply pipe (3) for supplying water from the water supply port of the hot water storage tank to the hot water storage tank;
A hot water supply pipe (4) for supplying hot water to the outside from the outlet of the hot water storage tank;
A lower heater (5) provided at a lower portion in the hot water storage tank;
A control unit (10) functioning as the energization time calculation means and the night boiling operation start time determination means;
A feed water temperature sensor (S _Wt ) installed in the feed pipe;
A remaining hot water temperature sensor (S _{LWt1 to} S _LWt5 ) mounted in the hot water storage tank;
A flow sensor (S _F ) mounted in the hot water pipe;
The electric water heater according to claim 1, comprising:   The electric water heater according to claim 1 or 2, wherein the electric water heater identification code is an end number (EN) of an equipment manufacturing number of the electric water heater. The control unit is
An energization time calculation unit (11) functioning as the energization time calculation means;
A night boiling operation start time determination unit (12) functioning as the night boiling operation start time determining means;
A lower heater on / off controller (15) for on / off control of the lower heater;
A memory (16) for storing the tank capacity data (D _V ), heater capacity data (D _P ), boiling set temperature data (D _T ) and end number data (D _EN ) of the electric water heater; ,
The energization time calculation unit reads the tank capacity data, the heater capacity data, and the boiling set temperature data read from the memory, the flow data (D _F ) input from the flow sensor, and the remaining hot water temperature sensor. The energization time is calculated based on the remaining hot water temperature data (D _{LWt1 to} D _LWt5 ) input from the water supply temperature data (D _Wt ) input from the water supply temperature sensor,
The night heating operation start time determination unit determines an energization start delay time (PT) based on the end number indicated by the end number data read from the memory, and the energization calculated by the energization time calculation unit A night heating operation start time is determined based on the time and the determined energization start delay time, and the lower heater on / off control unit is instructed to turn on the lower heater at the determined night heating operation start time To
The electric water heater according to claim 3, wherein   The night heating operation start time determination unit instructs the lower heater on / off control unit to turn off the lower heater when the energization time has elapsed from the determined night heating operation start time. The electric water heater according to claim 4.   The night heating operation start time determination unit instructs the lower heater on / off control unit to turn off the lower heater when the remaining hot water temperature reaches the boiling setting temperature. Item 5. An electric water heater according to item 4.   When the sum of the energization time and the energization start delay time is greater than the midnight power energization time zone, the night boiling operation start time determination unit changes the end number by a predetermined value, and changes the tail The electric water heater according to any one of claims 4 to 6, wherein a new energization start delay time is re-determined based on the number. The night boiling operation start time determining unit determines the night boiling operation start time as the midnight power energization time start time in the midnight power energization time zone when the changed tail number is smaller than “0”. The electric water heater according to claim 7 , wherein a night boiling operation end time is determined as a midnight power energization time end time in the midnight power energization time zone .

Images